ITC 594 - E-Systems Infrastructure - Developer's Blog

Workshop 6

2009-05-16T20:35:00.000-07:00

generate a controller and an action by adding a method(s) to a controller;
create a view template for each action and to link to actions from views;
use AJAX to improve the user experience;

C:\Downloads\InstantRails3\rails_apps\login\app\controllers\account_controller.rb

C:\Downloads\InstantRails3\rails_apps\login\app\models\user.rb

C:\Downloads\InstantRails3\rails_apps\login\app\views\account\login.html.erb

C:\Downloads\InstantRails3\rails_apps\login\app\views\account\registration.html.erb

php database:

A salted value to prevent hacking is added.

The view to register a user.

Neither username or password can be blank;

Error message to be displayed:

While Wrong password is entered, the error message will be seen:

Input the correct username and password:

After registered a new user, a welcome speech will be shown:

Try to login:

Password field cannot be empty:

While correct username and password are entered, a welcome speech will be shown:

Workshop 5-C

2009-05-16T20:26:00.000-07:00

The output view:

Fill the data:

The processed output:

You can enable the following line in your controller class definition to skip the authenticity_token check:protect_from_forgery :only => [:create, :update, :destroy] is added for Instant Rails 2.0 to perform/authorize the form operation.

Assign the root for the application: map.root :controller => "Vehicle"

A index.rhtm with same code of cabtype.rhtml is added in order to skip no index error.

Workshop 5-B

2009-05-16T20:25:00.000-07:00

The output view:

Workshop 5-A

2009-05-16T20:17:00.000-07:00

The output view:

Exercise 26-2 & 3

2009-05-15T20:03:00.001-07:00

Summarise your understanding and describe its relevance (250 words max) in either your study at university or in your work environment;

IT integrated systems need to be better organized and integrated to advance the use of business information in enterprises to the next stage and thereby promote innovation in business processes and customized services for individuals.

Business Process Management (BPM) to improve business processes using the following cycle:
1) Visualization of a business process,
2) analysis and evaluation of a business process,
3) design of an improved business process, and
4) execution of an improved business process.

People in all levels, including the operational level, now require raw, real-time information so they can continuously improve their business processes. Therefore, integration middleware such as ERP and CRM will be used to enable real-time use of business information by using Web-service integration technology.

The technologies of business process integration are as follows:
1) ERP works as Web services.
2)Flow technology to enable business process monitoring. This technology includes human flow monitoring technology and event tracking technology.

Service-oriented integration middleware equipped with Web-service integration technology to support the Business Process Management framework. By using Web-service integration technology, enterprise personnel from the executive level to the operational level can use real-time information. The integration middleware has been adopted in the systems of industry-leading enterprises and will be used in other systems in various industries.

In my working environment (a secondary school), the business processing management would be the related criteria. Many processes are not standardized, updated data and information are always appeared and decrease the quality of working.

References:
Masahior Nalagawa, 5 Dec 2003, Business Process Management with Web-Service Integration Technology, p1

M. Nakagawa: Business Process Management (BPM) is mandatory in the Web services age. (in Japanese), Web Services Conference 2003.http://interstage.fujitsu.com/jp/events/2003/828wsc.html

Evan D., Morrison Alex, Menzies Koliadis el at, 2009, Business Process Integration: Method and Analysis

Exercise 26-1

2009-05-15T19:58:00.000-07:00

My topic:
Business process analysis will be chosen to manage and develop integrated systems.

Exercise 25

2009-05-15T19:48:00.000-07:00

1. What is meant by a location based service?

Location Based Service (LBS) is an intersection of three technologies like the following figure. It is created from New Information and Communication Technologies (NICTS) such as the mobile telecommunication system and hand held devices, from Internet and from Geographic Information Systems (GIS) with spatial databases.

LBS give the possibility of a two way communication and interaction. Therefore the user tells the service provider his actual context like the kind of information he needs, his preferences and his position. This helps the provider of such location services to deliver information tailored to the user needs.

The basic components of an LBS: User, Communication Network, Positioning, Service Provider and Content Provider.

The two types of services which LBS provides:
Pull services sent information on user interaction (asking for the next restaurant)
Push services deliver information without user interaction (advertisement in a shopping mall, weather warning).

The example of searching a Chinese restaurant the information chain from a service request to the answer will be described in the following and is illustrated

The information the user want is a route to a Chinese restaurant near by. Therefore the user expresses his need by selecting the appropriate function on his mobile device: e.g. menu: position information => searches => restaurants => Chinese restaurant.

1. Now if the function has been activated, the actual position of mobile device is obtained from the Positioning Service. This can be done either by the device itself using GPS or a network positioning service. Afterwards the mobile client sends the information request, which contains the objective to search for and the position via the communication network to a so called gateway.

2. The gateway has the task to exchange messages among mobile communication network and the internet. Therefore he knows web addresses from several application servers and routes the request to such a specific server. The gateway will store also information about the mobile device which has asked for the information.

3. The application server reads the request and activates the appropriate service - in our case a spatial search service.

4. Now, the service analyses again the message and decides which additional information apart from the search criteria (restaurant + Chinese) and user position is needed to answer on the request. In our case the service will find that he needs information on restaurants from the yellow pages of a specific region and will therefore ask for a data provider for such data.

5. Further the service will find that information on roads and ways is needed to check if the restaurant is reachable (e.g. sometimes a restaurant on the other river side might not be reachable since no bridge is nearby).

6. Having now all the Information the service will do a spatial buffer and a routing query (like we know from GIS) to get some Chinese restaurants. After calculating a list of close by restaurants the result is sent back to the user via internet, gateway and mobile network. The restaurants will now be presented to the user either as a text list (ordered by distance) or drawn in a map. Afterwards the user could ask for more information on the restaurants (e.g. the menu and prices), which activates a different kind of services. Finally if he has chosen a specific restaurant he can ask for a route to that restaurant.

References:
Stefan Steiniger, Moritz Neun and Alistair Edwardes, Foundations of Location Based Services, retrieving on 14 May 2009 from http://www.spatial.cs.umn.edu/Courses/Fall07/8715/papers/IM7_steiniger.pdf

Shiode, N., Li, C., Batty, M., Longley, P., Maguire, D., 2004. The impact and penetration of Location Based Services. In: Karimi, H. A., Hammad, A., ed. Telegeoinformatics. CRC Press, 349-366.

Exercise 24-4

2009-05-15T19:14:00.000-07:00

Get an account username and password from the lecturer to LC_MOO at http://ispg.csu.edu.au:7680 and login to the Welcome Lobby.

Login: user: train1, password: train1;

b. Hold a 5-minute discussion with Rocky on a special topic. Commands: act rocky (start bot) hush rocky (stop bot)

train1 activates Rocky.
Rocky says, "Gee thanks for waking me up! I must have dozed off.."

I am trying to know how to communicate with Rocky.

@who command:
Name Connected Idle time Location
---- --------- --------- --------
train1 (#853) 14 minutes 0 seconds LC_MOO Welcome Lobby
Total: 1 person, who has been active recently.

look Command: getting a description of the current room or any other object
Obvious exits: [door] to LC Cruises Inc., [bridge] to The Lawn, [enter] to Secretariat, [tool] to Tool Box Place, [skip] to Kidspace, [lily] to LilyPond, [resort] to Casuarina Conference Resort (Reception)

Tool command:
Obvious exits: [out] to LC_MOO Welcome Lobby

Conversation with Rocky:

c. Rocky is an ELIZA-like bot. Report your findings.
It operates by processing users' responses to scripts and makes interaction between human and computers.
There is an effect which is called ELIZA effect; it is the tendency to unconsciously assume computer behaviors are analogous to human behaviors.

More generally, the ELIZA effect describes any situation where, based solely on a system's output, users perceive computer systems as having "intrinsic qualities and abilities which the software controlling the (output) cannot possibly achieve" or "assume that (outputs) reflect a greater causality than they actually do."

From a psychological standpoint, the ELIZA effect is the result of a subtle cognitive dissonance between the user's awareness of programming limitations and their behavior towards the output of the program.

The discovery of the ELIZA effect was an important development in artificial intelligence, demonstrating the principle of using social engineering rather than explicit programming to pass a Turing test.

References:

http://en.wikipedia.org/wiki/ELIZA

http://en.wikipedia.org/wiki/ELIZA_effect

Exercise 24-3

2009-05-15T19:13:00.000-07:00

3. Identify various activities in e-commerce where software agents are currently in use.
Commerce agents: Software agents which mediates between two companies having a business relationship.

Data management agents: Software agents carrying out tasks with corpora of data such as processing text from websites and producing summary with associated keywords.

Government agents: Software agents carrying out activities associated with government such as search government regulations, policies and statistics etc..
News agents: Software agents concerning tasks associated with web-based news services.

Shopping agents: Most popular software agents in the Internet and are used for accessing retails sites to source for a particular product with cheapest price. For example, a shopping agent can programmed to access CD sites to source the cheapest quote for a particular CD.
Software agents: Agents, which carry out tasks relating to new updates for existing system, downloading and installing the updates when received.

Stock agents: Software agents which carry out tasks relating to stock transactions including notifying you when the stock price reaching a preset price by e-mail or sms, providing updated technical analysis based on the latest market situations or maintaining the stock portfolio and giving warning signals when the portfolio is under performed.

The following activities in e-commerce where software agents are currently in use:

Shopping agent: it automatically updates the request information regarding products which customer is interested from e-commerce site.

Personal agent: it handles great amount of information, such as identifier, address, credit card number and etc. at e-commerce sites. And it also facilitates the secure management of personal information.

Exercise 24-2

2009-05-15T19:12:00.000-07:00

Describe how techniques such as artificial intelligence and statistical techniques are used in software agents.
The intelligent agent can be programmed for the users’ aim, targets and preference with artificial intelligence. For example, an intelligent agent can be programmed with artificial intelligence to assist the users to search a specific type, model and color of car in the Internet including the negotiation on the price and closing the deal as well. Alternatively, the intelligent agent can just source the cars available in the Internet meeting the users’ requirement leaving the user to make the final decision.

Mobile agents are programmed with statistical techniques to enable them to monitor the network situation and utilization of system resources.

Like intelligent agent, when it perceives the change of environment, it will take appropriate actions so as to maximize the successful rate. It is like human learning process. And some agents respond the action based on the programmed statistic figures.

Exercise 24-1

2009-05-15T19:10:00.000-07:00

1. Differentiate the various types of software agents.
The various types of software agents:

Intelligent software agents
The design of intelligent software agents is a branch of artificial intelligence research. Capabilities of intelligent agents include ability to adapt the environment and reconfiguring in response. This can be achieved through the choice of alternative problem-solving-rules or algorithms, or through the discovery of problem solving strategies. Adaptation may also include other aspects of an agent's internal construction, such as recruiting processor or storage resources.
It also has the ability to learn through trial-and-error, it implies a capability of introspection and analysis of behavior and success. Alternatively, learning may proceed by example and generalization, it implies a capacity to abstract and generalize.

Autonomous agents
Autonomous agents are software agents that claim to be autonomous, being self-contained and capable of making independent decisions, and taking actions to satisfy internal goals based upon their perceived environment. All software agents in important applications are closely supervised by people who start them up, monitor and continually modify their behavior, and shut them down when necessary.

Distributed agents
Since agents are well suited to include their required resources in their description, they can be designed to be very loosely coupled and it becomes easy to have them executed as independent threads and on distributed processors. Thus they become distributed agents and the considerations of distributed computing apply. Agent code is particularly easy to implement in a distributed fashion and should scale well.

Multi-agent systems
Several agents may form a multi-agent system. A multiple-agent system will not have all data or all methods available to achieve an objective and thus will have to collaborate with other agents. Also, there may be little or no global control and thus such systems are sometimes referred to as swarm systems. As with distributed agents, data is decentralized and execution is asynchronous.

Mobile agents
With mobile agent, the agent code moves by itself, including its execution state, on to another machine, to continue execution there. Agents can be used to gather system information, taking back-up of files by copying them in client-server paradigm, monitoring network throughput or to check resources availability and moderating the resource utilization of system by checking the services running on system.

Fuzzy agents
In computer science a fuzzy agent is a software agent that implements fuzzy logic. This software entity interacts with its environment through an adaptive rule-base and can therefore be considered as a type of intelligent agent

References:
Jeffrey M. Bradshaw , An Introduction to Software Agents retrieving on 15 may 2009 from http://agents.umbc.edu/introduction/01-Bradshaw.pdf

Wikipedia, 4 May 2009, Software agent, retrieving on 14 may 2009 from http://en.wikipedia.org/wiki/Software_agent

Exercise 23-3

2009-05-15T19:05:00.000-07:00

3. How can you get your site listed at major search sites; and how could you improve your site ranking?

Add the website to famous search sites by paying the submission fees;
Add some meta data into the website itself as the keywords for searching in search engines; it is free but lower effectiveness.

How could you improve your site ranking?
a. Some search engine sites, such as Google, would rank a page according to the number of links and quality of links leading to the pages. Therefore, if you manage to get more important websites linking to your site, the ranking of your site would improve.

b. Google would give more weight to the title of the website, those within the "title" tags. Therefore using more meaningful title for your webpage would improve their ranking.

c. Similarly Google would index those webpage with image including ALT tags. Therefore, including ALT tags to the images of the webpage would also improve their ranking.

References:
Berkeley, UC. (2008). Meta-search engines. Retrieved April25, 2008 from http://www.lib.berkeley.edu/TeachingLib/Guides/Internet/MetaSearch.html.

Heng, C. (n.d.) How to improve your search engine ranking on Google. Retrieved April 28, 2008 from http://www.thesitewizard.com/archive/google.shtml.

TechTerms. (n.d.) Spider. Retrieved April 25, 2008 from http://www.techterms.com/definition/spidertechterms.com/definition/spider.

Web search engine (n.d.) Retrieved 25 April 2008 from:
http://en.wikipedia.org/wiki/Search_engine

Intro To Search Engine Submission, retrieving on 19 May 2009 from http://searchenginewatch.com/2168011

Exercise 23-2

2009-05-15T19:03:00.000-07:00

2. What is a meta-search engine? Provide some examples.
Meta-search engine is an application which transmits your search requests or keywords to several individual search engines and their database of web pages. Results from each search engineers would be consolidated and presented to the client grouped by their sourced search engines. Such as google & yahoo.

Here are some examples of meta-search engine:
Vivisimo: http://vivisimo.com,
Ixquick: www.us.ixquick.com
Kartoo: http://kartoo.com

Reference:
Greg R. Notess (4 Apr 2006). Meta search engines. Retrieving on 19 May 2009 from
http://www.searchengineshowdown.com/multi/

Exercise 23-1

2009-05-15T19:02:00.000-07:00

1. What is a spider? What does it do?

Spider is a program that automatically fetches web pages. It is also named as Web Crawler. It is used to feed pages to search engines. It's called a spider because it crawls over the Web. Because most web pages contain links to other pages, a spider can start almost anywhere. As soon as it sees a link to another page, it goes off and fetches it. Large search engines, like Alta Vista or Google, have many spiders working in parallel.

Reference:Spider. Retrieving on 16 May 2009 from http://www.webopedia.com/TERM/s/spider.html

Exercise 22

2009-05-15T19:00:00.000-07:00

Differentiate between software systems such as Customer Relationship Management (CRM) software, Business-to-Business e-commerce programs and Supply-Chain Management (SCM) software.

Customer Relationship Management (CRM) software, Business-to-Business e-commerce program and Supply-Chain Management software are performing different functionalities in company-wide environment.

Differentiate between software systems such as Customer Relationship Management (CRM) software, Business-to-Business e-commerce program and Supply-Chain Management software (SCM). are performing different functionalities in company-wide environment.

Customer Relationship Management (CRM) is a business philosophy involving identifying, understanding and better providing for customers while building a relationship with each customer to improve customer satisfaction and maximize profits. The CRM software helps to acquire and retain customers, improve customer loyalty, gains customer insight, and implementing customer-focused strategies. It assists the company drive new growth, maintain competitive agility, and attain operational excellence. It's about understanding, anticipating and responding to customers' needs.

Business-to-Business e-commerce program is software which automates processes or commerce transactions between businesses by using electronic. With B2B, the companies involved require negotiation and integration to enable communication between the companies for the business transaction. B2B program builds and improves the relationship between companies and business partners.

Supply chain management (SCM) is the combination of art and science that goes into improving the way your company finds the raw components it needs to make a product or service and deliver it to customers. It contains five components: Plan, Source, Make, Deliver and Return.
The SCM software is an application, which helps company to improve various company business operations and to complete the operations of the above components. The goals of SCM software are to reduce the inventory, reduce costs and allow all parties in the supply chain with better resource management, planning for future needs. And benefit from having a single major source to go to for up-to-date information.

Reference

CRM Software Solutions. retrieving on 12 May 2009 from http://www.bestpricecomputers.co.uk/glossary/crm-software-solutions.htm

Customer relationship management. Retrieving on 7 May 2009 from http://en.wikipedia.org/wiki/Customer_relationship_management.

Business to business Overview. Darwin Publications. Retrieving on 7 May 2009 from http://www.netessence.com.cy/downloads/b2b.pdf.

Srikanth, A (2000). E-commerce: a B2B guide. Retrieving on 10 May 2009 from http://www.hinduonnet.com/businessline/iw/2000/05/28/stories/0728g101.htm.

Trapp. R. (2007). How customer relationship management systems can be of benefit to your business. Retrieving on 7 May 2009 from http://www.independent.co.uk/news/business/sme/how-customer-relationship-management-systems-can-be-of-benefit-to-your-business-451821.html.

Worthen, B. (2007). ABC: An introduction to supply chain management. Retrieving on 8 May 2009 from http://www.cio.com/article/print/40940.

Customer relationship management. Retrieving on 7 May 2009 from http://en.wikipedia.org/wiki/Customer_relationship_management

Srikanth, A (2000). E-commerce: a B2B guide. Retrieving on 7 May 2009 from
http://www.hinduonnet.com/businessline/iw/2000/05/28/stories/0728g101.htm

Thomas Wailgum, 20 Nov 2008, Supply Chain Management Definition and Solutions, retrieving on 14 May 2009, from http://www.cio.com/article/40940/Supply_Chain_Management_Definition_and_Solutions

Exercise 21

2009-05-15T18:57:00.000-07:00

Develop the class diagram for the following shopping cart specifications:
A shoppingCart object is associated with only one creditCard and customer and to items in itemToBuy object. Persistent customer information such as name, billing address, delivery address, e-mail address and credit rating is stored in the customer object. The credit card object is associated with a frequentShopper discount object, if the credit rating for the customer is good. The customer can make or cancel orders as well as add and delete items to the shopping cart product. The credit card object contains the secure method for checking that the charge is authentic.

Reference
Williams B. (2003) UML class diagram for shopping carts. Database Answers. Retrieving on 4 May 2009, from http://www.databaseanswers.org/data_models/uml_class_diagram_for_shopping_cart/index.htm

Exerxise 20

2009-05-15T18:52:00.000-07:00

Use Case diagrams describe what a system does from the standpoint of an external observer. The emphasis is on what a system does rather than how.

A use case is a summary of scenarios for a single task or goal. An actor is who or what initiates the events involved in that task. Actors are simply roles that people or objects play. The picture below is a Make Appointment use case for the medical clinic. The actor is a Patient. The connection between actor and use case is a communication association (or communication for short).

A Class diagram gives an overview of a system by showing its classes and the relationships among them. Class diagrams are static -- they display what interacts but not what happens when they do interact.

Interaction diagrams are dynamic model views. They describe how objects collaborate.
A sequence diagram is an interaction diagram that details how operations are carried out -- what messages are sent and when. Sequence diagrams are organized according to time. The time progresses as you go down the page. The objects involved in the operation are listed from left to right according to when they take part in the message sequence.

Collaboration diagrams are also interaction diagrams. They convey the same information as sequence diagrams, but they focus on object roles instead of the times that messages are sent. In a sequence diagram, object roles are the vertices and messages are the connecting links.
A statechart diagram shows the possible states of the object and the transitions that cause a change in state.

An activity diagram is essentially a fancy flowchart. Activity diagrams and statechart diagrams are related. While a statechart diagram focuses attention on an object undergoing a process (or on a process as an object), an activity diagram focuses on the flow of activities involved in a single process. The activity diagram shows the how those activities depend on one another.

A component is a code module. Component diagrams are physical analogs of class diagram. Deployment diagrams show the physical configurations of software and hardware.

Reference
Randy Miller, Practical UML: A Hands-On Introduction for Developers, Retrieved on 9 may 2009 from http://edn.embarcadero.com/article/31863

Exercise 19-4

2009-05-15T18:51:00.001-07:00

4. Why is a two-phase commit protocol better than a one-phase atomic commit protocol?
With one-phase atomic commit protocol, a server could make a decision by itself to abort transaction. As a result, the consistency of the transaction would be affected.

With two-phase commit protocol, the coordinator would co-ordinate and consolidates an unique decisions of all the servers and client involved before a final decision on whether to abort or commit a transaction which could ensure the consistency of the transaction.

Two-phase commit protocol provides the advantages over one-phase atomic commit protocol. Automatic recovery mechanism: transaction will be recovered as long as a system or media is failure during transaction executing. Synchronization among all participating databases: all database servers will receive the same action, either commit or rollback.

Reference:

Ince, D. (2004). Developing distributed and e-commerce applications. Pearson Addison Wesley.

Exercise 19-3

2009-05-15T18:50:00.001-07:00

3. What is difference in load balancing with traditional and transactional MOM, RPC and conversations?

Message Orientated Middleware (MOM) supports asynchronous communication in 2 models, the point to point messaging and message queue models.
The advantage of message queue is that the remote program does not require being active while message is sent by the calling program. Both the calling and remote program can process at the own pace without disruption by the middleware. In addition, the calling program can broadcast message to more than 1 remote program at the same time.

Remote Procedure Call (RPC) is a synchronous communication where the calling application must stop processing or is blocked from proceeding until receiving the response from the remote procedure. RPC is simple but its performance is a great concern. In particular, RPC requires a lot of processing power and the numerous exchanges between the client and server is a burden to the networks.

MOM’s performance is better than RPC especially in load balancing which implement prioritization and thread pooling.

However, Transaction Process Monitoring has greater performance advantage in load balancing over both RPC and MOM. TP monitoring would implement the following in load balancing:
· use queued input buffer to protect against peak in the workload;
· priority scheduling to prioritize messages;
· support server threads to save overhead of heavy weight processes; and
· make sure that none of the process would be overloaded.

Exercise 19-2

2009-05-15T18:47:00.000-07:00

1. Describe a TP monitor environment. How can a TP monitor stop an operating system being overwhelmed?

TP monitor is usually a middleware in three tiers client-server architecture. It is a control program that manages the transfer of data between multiple local and remote terminals and the application programs that serve them. It may also include programs that format the terminal screens and validate the data entered.
In a distributed client/server environment, a TP monitor provides integrity by ensuring that transactions do not get lost or damaged. It may be placed in a separate machine and used to balance the load between clients and various application servers and database servers. It is also used to create a high availability system by switching a failed transaction to another machine. A TP monitor guarantees that all databases are updated from a single transaction.
The types of jobs performed through the TP monitor are: process management, transaction management, and client/server communication management. TP monitor can stop an operation system being overwhelmed by maintaining a pool of processes and queues transactions so that the clients can take turn to use the pool.

Reference:
TP MONITOR, retrieving on 2/5, from http://encyclopedia2.thefreedictionary.com/TP+monitor

LUISA CATALAN, DENNIS A. LUDENA R., HIDENORI HUMENO, MASAYOSHI ARITSUGI, October 2008, Design of a Real Time Transaction Processing Monitor (TPM) Benchmark Testbed, world scientific and engineering academy and society, Issue 10, Volume 5

Exercise 19-1

2009-05-15T18:45:00.000-07:00

1. Give a description in your own words of the ACID properties of a transaction.

ACID properties of a transaction are:

Atomicity: Transaction must be an un-separated action as an atom. If the transaction fails, all objects have to roll back to the original status before making transaction. There are two outcomes of a transaction, completed and not execution only.
Consistency: The condition of a transaction has to be stable. While the transaction is committed, the condition would be changed to another stable condition. If it fails, all objects would be recovered to the condition before taking transaction.
Isolation: Each transaction is independence and has the ability to make sequence, not interrupted to each others.
Durability: The raw data would not be changed until the transaction is committed. After commitment, the modified data would be kept forever, whatever there is any interruption

Exercise 18

2009-05-15T18:44:00.000-07:00

Threading demonstration in Python

A simple demonstration of the threading module in Python that uses both a lock and semaphore to control concurrency is by Ted Herman at the University of Iowa. The code and sample output below are worth a look. Report your findings.

The output is similar to the output given in the study guide. Only the records of processing time are different to the given output.

Exercise 17

2009-05-15T18:42:00.001-07:00

Exercise 17: Concurrency terms
Find definitions for eight terms and concepts used in threaded programming:

Thread Synchronisation: It refers to the act of shielding against multithreading issues such as data- races, deadlocks and starvation. Synchronisation ensures that code running in different threads access the condition variable in safety and that the condition variable is in some globally consistent state.

Locks: Each thread has a working memory, in which it may keep copies of the values of variables from the main memory that is shared between all threads. To access a shared variable, a thread usually first obtains a lock and flushes its working memory. This guarantees that shared values will thereafter be loaded from the shared main memory to the threads working memory. When a thread unlocks a lock it guarantees the values it holds in its working memory will be written back to the main memory.

Deadlock: It describes a situation where two or more threads are blocked forever, waiting for each other. When Deadlock runs, it's extremely likely that both threads will block when they attempt to invoke bow back. Neither block will ever end, because each thread is waiting for the other to exit bow.

Semaphores: It provides a mechanism to regulate access to resources. Unlike locks, semaphores aren't tied to particular scalars. It doesn't limit their values to zero and one, so they can be used to control operation to some resource that there may be more than one of file handling. Increment and decrement amounts aren't fixed at one either, so threads can reserve or return multiple resources at once.

Mutex (mutual exclusion): Its algorithms are used in concurrent programming to avoid the simultaneous use of a common resource, such as a global variable, by pieces of computer code called critical sections.

Thread: A thread is a thread of execution in a program. Every thread has a priority. Threads with higher priority are executed in preference to threads with lower priority. Each thread may or may not also be marked as a daemon. When code running in some thread creates a new Thread object, the new thread has its priority initially set equal to the priority of the creating thread, and is a daemon thread if and only if the creating thread is a daemon.

Event: Event can be considered as an action, changes or transactions in concurrent programming. In some situation, it is like a user response such as pressing a button or a key. The associated script is written to response to such action or user response as event handling scripts.

Waitable timer: Waitable timers were introduced with Windows 98 and Windows NT 4.0. and they were designed to work with threads that need to block for some times. These timers are kernel objects which are signaled in the specified time, or in regular time intervals. They can specify the callback function which gets called when timer gets signaled. This callback function is usually called a completion routine.

Exercise 16-6

2009-05-15T18:40:00.000-07:00

6. The use of digital certificates and passports are just two examples of many tools for validating legitimate users and avoiding consequences such as identity theft. What others exist?

Other than the use of digital certificates and passports, there are smart cards containing both the private and public keys and the use of biometric data for validating the legitimate users to avoid identity theft.Other than digital certificates and passport, biometric technique such as retinal scan can be used for validating legitimate users and avoiding consequences as well.

Exercise 16-4

2009-05-15T18:36:00.000-07:00

4. Visit the TRUSTe web site. Describe what services and solutions are offered.

Unlike Verisign offering a comprehensive trust mark for secure e-commerce site, TRUSTe offers the following kinds of web seals for specific applications:
· Web privacy seal – concerns measures to protect customers’ privacy;
· E-mail privacy seal – concerns measures in handling e-mails sent to customers;
· EU Safe Harbor seal – concerns compliance with international privacy laws in
US and European parties;
· International services – services for certifying foreign-language privacy policies
and administer disputes resolution in international level;
· Children’s privacy seal – concerns compliance with the Children’s Online
Privacy Protection Act (COPPA); and
· Japan privacy seal – concerns compliance with privacy standards in Japan.
· Trusted downloaded program – program for certifying download sites not
exhibiting surreptitious activities, and are distributed in a responsible manner.

Different from Verisign, TRUSTe is assisting business and consumers to identify the trustworthy online organizations by auditing the website in compliance with standard or best practice they provided and ongoing monitoring sealed websites. Now the following web seals are available:
l Web Privacy Seal
l Email Privacy Seal
l EU Safe Harbor Seal
l International Services
l Children’s Privacy Seal
l Japan Privacy Seal

Reference:http://en.wikipedia.org/wiki/TRUSTe

Exercise 16-3

2009-05-15T18:28:00.001-07:00

3. Visit the Verisign web site - what solutions does it offer for e-commerce?

E-Commerce, Trust, and SSL
Gaining the trust of online customers is vital for the success of e-commerce. Make sure your Web site earns its full potential by increasing customer confidence at transaction time.

What concerns online shoppers when making an online purchase?
87% of online shoppers are concerned about credit card fraud
85% of online shoppers are concerned about identity theft
83% of online shoppers are concerned about sharing personal information
77% of online shoppers are concerned about spyware
(Source: TNS Research, August 2006)

Shoppers Abandon Carts and Buy Offline
Fraud and identity theft have created a chilling effect on e-commerce. Of online consumers, 65% shop only at sites they know and trust, and 65% of online shoppers have abandoned a shopping cart because they did not “trust” the transaction. (Forrester Research, December 2005.)

Trust Signs Restore Consumer Confidence
Web site visitors have learned to look for the closed padlock and "https" in the URL address to show that a Web page is secure. In the latest high security browsers, they also see a green address bar when a highly authenticated Extended Validation certificate is detected.

VeriSign helps build confidence with your online customers and helps you comply with security policies to inspire trust with your business partners. Give your Web site visitors the confidence to interact online with the most trusted and secure option for SSL: Secure Site Pro with EV SSL Certificates.

VeriSign offers security advice and services to various sectors including Customer Products and Retail, Media and Entertainment, Financial Services, Public sectors, Healthcare and Life Sciences and Telecommunications. There are also separate categories for large enterprise, online SMB merchants and developers as well.
Verisign is providing a wide range of solutions across various industries, from healthcare to financial service, and different size of companies, from SMB to big enterprise. Its solutions for e-commerce include issuing SSL Certificate and digital ID, Security Risk Management, Security Consultancy, Fraud Detection, and even mobile or wireless solution.

Reference:
http://www.verisign.com/ssl/ssl-information-center/ecommerce-trust-ssl/

Exercise 16-2

2009-05-15T18:25:00.000-07:00

2. What measures should e-commerce provide to create trust among their potential customers? What measures can be verified by the customer?

Ans.:

The following measures should be implemented to create trust among their potential customers:

Comprehensive security and privacy policies to safeguard the security and privacy of customer data;
Implement security measures to protect the systems, servers and networks. Measures including installing firewall, SSL for pages collecting customer information, virus scanning software to detect virus with scheduled online updating for virus signature etc.;
Strictly policies regarding collection, storing, modification and subsequent destroy of customer data. These policies should be strictly followed and made known to the customers;
All customers should be pre-registered with unique username and passwords. The password should be forced to be renewed at a pre-set period.

Some certifying company such as VeriSign would issue a trust mark to e-commerce websites which have implemented premium security solutions such as Secure Sockets Layer (SSL) encryption, secure payment processing, and business identity authentication, to protect sensitive customer information during online transactions. Such certification bodies would also enables consumers to verify the level of security available on an e-commerce site prior to making a purchase online. Therefore customers can verify the security of the e-commerce sites by checking whether they have obtained trust mark from reputable certification bodies.

Strictly rules and policies are enforced to be followed by buyers and sellers Comprehensive policy or measures to protect the customers’ privacy information. Implement a range of security devices, such as firewall, IPS, Antivirus and etc., to protect the websites.

Secure the web site by SSL certificate which is issued by trusted third party Certificate Authority like Verisign and Entrust. Each customer has a unique account to store its personal information. And each account is protected by security methodologies, like hidden password, encryption. Among the measures above, SSL Certificate can be verified by customer who can view the certificate details, like issuer, issue to domain name and expiry date through web browser.

Exercise 16-1

2009-05-15T18:22:00.001-07:00

1. Visit an e-commerce website and survey the mode of payment allowed. Would you trust the site with your business?

Ans.: DELL Inc. Website: http://www.dell.com.hk/
Payment methods:

online credit card payment
auto pay with bank account
pay with check by mail
Pay by phone to Dell customer service agents

I would trust this company to buy computer products. Dell Inc. is the leader of this industry. As I am the customer of Dell, I was informed in short time to confirm the order with the Dell customer agent. The data of the online order is encrypted and is protected by SSL.

http://www.dell.com/content/topics/topic.aspx/us/segments/dhs/odg/paydpa3?c=us&cs=19&l=en&s=dhs

http://www1.ap.dell.com/content/topics/topic.aspx/ap/topics/storeinfo/en/security_privacy?c=hk&l=en&s=bsd

Exercise 15-3

2009-05-15T18:05:00.000-07:00

1. Most of the antivirus software perform an active scanning of the user activity on the Internet, detecting downloads and attachments in e-mails. Hackers have readily available resources to create new viruses. How easy is it to find a virus writing kit? Search the Internet and find such a tool. For example, see what you can find at http://vx.netlux.org/dat/vct.shtml.

It seems so easy to find a virus writing kit from the Internet. I search “Virus Writing Kit” using Google and there were approximately websites matching the above search.

Among 200,000 cases, around 10% of them are real websites providing tools or guideline how to create virus. I just took 5 minutes to source 5 websites providing virus creation tools.

Exercise 15-2

2009-05-15T18:03:00.000-07:00

2. Find out if your university or workplace has a backup policy in place. Is it followed and enforced?

My workplace has a backup policy.
All applications, data in file servers and database are backuped to hard disks at mid-night from Monday to Friday. And each hard disk will be rotated and stored in the remote area. This policy is enforced to be executed.

Exercise 15-1

2009-05-15T17:49:00.000-07:00

1. What makes a firewall a good security investment? Accessing the Internet, find two or three firewall vendors. Do they provide hardware, software or both?

A firewall is a piece of software or hardware that helps screen out hackers, viruses, and worms that try to reach computer over the Internet. If a home user or small-business user, using a firewall is the most effective to help protect your computer.

A firewall helps to screen out many kinds of malicious Internet traffic before it reaches your computer. Some firewalls can also help to prevent other people from using computer to attack other computers without network knowledge.

Generally, firewalls are configured to protect against unauthenticated interactive logins from the outside world. This, more than anything, helps prevent vandals from logging into machines on your network.

Firewalls are also important since they can provide a single “choke point”' where security and audit can be imposed. Firewalls provide an important logging and auditing function; often they provide summaries to the administrator about what kinds and amount of traffic passed through it, how many attempts there were to break into it, etc.

Software: Comodo Internet Security
It is a combination of Firewall and AntiVirus for Windows.
Comodo Firewall, constantly monitors and defends computers from Internet attacks. It's easy to install and use and passes the industry's most stringent firewall "leak" tests.
Main functions:
l Viruses, worms, spyware, key loggers and other malware
l Port scans, intrusion attempts, hackers
l Modification of critical system files

Hardware Firewall: Juniper Networks NetScreen series
The NetScreen Series Security Systems are purpose-built, firewall/VPN security systems designed for large enterprise, carrier, and data center networks.

The 2-slot NetScreen-5200 and the 4-slot NetScreen-5400 integrate firewall, VPN, DoS and DDoS protection, and traffic-management functionality in a low-profile modular chassis. Built around our third-generation security ASIC and distributed system architecture, these systems offer excellent scalability and flexibility, while providing a higher level security system through the NetScreen ScreenOS custom operating system.

The NetScreen Series Security Systems offer:

The NetScreen Series offers flexibility and scalability for large enterprises and carriers.
Virtual systems allow partitioning into multiple security domains, each with a unique set of administrators, policies, VPNs, and address books.
Varying network-connectivity requirements and future growth requirements are accommodated with a flexible interface.
Map internal, private, or overlapped IP addresses to a new IP address, providing an alternate route to the final destination and concealing it from public view.
Firewall, VPN, and DoS protections are offered with minimal change to the existing network.
A graphical Web interface, CLI, or Juniper Networks Network and Security Manager provide management features. Policy-based management: provides centralized, end-to-end life-cycle management.
Increase interface density without additional hardware expenses, lower policy-creation costs, contain unauthorized users and attacks, and simplify management of firewall/VPNs.

Software: Norton 360
Protect your PC, files, and identity with the industry’s fastest, lightest, most complete security solution.† Order Norton 360 today and get industry-leading protection from the lightest, fastest, most complete all-in-one solution available*.†
PC security defends against viruses, spyware, botnets, and more. Protects your computer and all your online activities.

Identity protection safeguards you against online identity theft. Lets you shop, bank, and browse with confidence.
PC Tuneup keeps your PC running at peak performance, makes your computer run faster and helps keep it running like new.
Automated backup and restore protects your important files from loss. Safeguards your irreplaceable photos, movies, music, and more.

References:
Firewall FAQ, 2 Jul 2001 , retrieving on 29/4 from on http://www.faqs.org/faqs/firewalls-faq/

Microsoft, February 19, 2009, Firewall: FAQ, retrieving on 29/4 from http://www.microsoft.com/protect/computer/firewall/faq.mspx

Comodo,
http://personalfirewall.comodo.com/download_firewall.html

Juniper Networks
http://www.juniper.net/us/en/products-services/security/netscreen/

Norton http://www.symantec.com/norton360/about/index.jsp

Exercise 14-2

2009-05-15T17:48:00.002-07:00

2. Can the use of cookies be a security risk?

In particular, cookies do not always accurately identify users, they can be used for security attacks, and they are at odds with the Representational State Transfer software architectural style.

Cookie hijacking
Cookies may contain sensitive information (such as user name, credit card no., etc.), their values should not be accessible to other computers. Cookie theft is the act of intercepting cookies by an unauthorized party.

Cookies can be stolen via packet sniffing in an attack called session hijacking. Traffic on a network can be intercepted and read by computers on the network other than its sender and its receiver. This traffic includes cookies sent on ordinary unencrypted http sessions. Where network traffic is not encrypted, malicious users can therefore read the communications of other users on the network, including their cookies, using programs called packet sniffers.

A different way to steal cookies is cross-site scripting and making the browser sends cookies to servers that should not receive them. Modern browsers allow execution of pieces of code retrieved from the server. If cookies are accessible during execution, their value may be communicated in some form to servers that should not access them. This type of cross-site scripting is typically exploited by attackers on sites that allow users to post HTML content.

Cookie poisoning
While cookies are supposed to be stored and sent back to the server unchanged, an attacker may modify the value of cookies before sending them back to the server. For example, a cookie contains the total value a user has to pay for the items in their shopping basket, changing this value exposes the server to the risk of making the attacker pay less than the supposed price. The process of tampering with the value of cookies is called cookie poisoning, and is sometimes used after cookie theft to make an attack persistent.

Cookie expiry
Persistent cookies have been criticized by privacy experts for not being set to expire soon enough, and thereby allowing websites to track users and build up a profile of them over time. This aspect of cookies also compounds the issue of session hijacking, because a stolen persistent cookie can potentially be used to impersonate a user for a considerable period of time.

Reference:
HTTP cookie, Retrieving on 29/4 from http://en.wikipedia.org/wiki/HTTP_cookie

Exercise 14-1

2009-05-15T17:48:00.001-07:00

1. What are cookies and how are they used to improve security?
Cookies are pieces of data which are stored on the clients’ computer by the Web browser and which can be accessed by the browser throughout their interaction with a particular Web site. For example, the cookie stores the login data of a web browser user.
Cookies are used for authenticating, session tracking and maintaining specific information about users, such as site preferences or the contents of their electronic shopping carts.

The main purpose of cookie is for identification and web server may use the message’s information to customize what it will send back to user.

Cookie can be used to improve security. For example, client can store the authentication codes into 2 parts. The first part of the authentication code could be stored as cookie assessable by the server. The second part of the authentication code cannot be assessable by the server.

The transmission of the 1st part of the authentication code would be carried out at the back-end with minimum chances of being observed by other closed by the client machine. Thus, the security of accessing the site would be improved.

References:Darrel Ince, Developing Distributed and E-commerce applications, 2nd edition, p.21

Exercise 13-2

2009-05-15T17:46:00.000-07:00

2. What is SET and how does it compare to SSL as a platform for secure electronic transaction? Is SET in common use?

SET is secure electronic transaction protocol which is a open protocol for securing electronic transactions developed jointly by Visa, Master Card and IBM. SET relies on cryptography. SET employs both symmetric and asymmetric encryption mechanism. Transaction details are encrypted with 56-bit session key in form of Data Encryption Standard (DES) and the session key is transmitted by asymmetric mechanism, public -key encryption.

Compared with SSL, SET has the following advantages over SSL:-
a. Higher Privacy via cryptography making intercepted message unreadable;
b. Higher Integrity via hashing and signing assuring message sent are not modified;
c. Authentication via digital certificate assuring parties involved in the transaction from

denying their participation in the transaction;
d. Customers’ credit cards information not accessible by merchants.

However SET has the following drawbacks compared with SSL;-
a. more complex and slower transaction;
b. require client software installation;
c. high processing cost;
d. lack of standard specification causing interoperability problems between SET

applications;
e. Problems in systems integration with merchants’ front-end and back-end applications.

SET is presently still not in common use due to the problems mentioned above.

SET, Secure Electronic Transaction, is a set of open security protocols and formats to protect privacy and ensure authenticity, of electronic transactions. It aims at securing the transaction on an open network such as Internet. SET is offering following services:
l With symmetric and asymmetric cryptography, it provides a secure communications channel between different parties involved in this transaction.
l It is based on X.509v3 digital certificates.
l It provides the ensuring privacy in which information is only available to the parties during the transaction.

Compared to SSL, other than encryption, SET can accomplish with data integrity and authentication.

Nowadays, SET is still not common in use because it is slow and the high processing cost. In addition, it requires the agent while SSL is agent less.

Reference:
Ahsan, M.S. (2002). SET vs SSL. Retrieved on 1 May 2009 from
http://islab.oregonstate.edu/koc/ece478/02Report/CA.pdf.

Exercise 13-1

2009-05-15T17:15:00.000-07:00

Exercise 12-3

2009-05-15T17:14:00.001-07:00

3. What is ‘phishing’?

Phishing is the term coined by hackers who imitate legitimate companies in e-mails to entice people to share passwords or credit-card numbers. Phishing would be the most popular and most troubling, new scam on the Internet.

The term phishing comes from the fact that Internet scammers are using increasingly sophisticated entice as they "fish" for users' financial information and password data. The most common ploy is to copy the Web page code from a major site, such as AOL and use that code to set up a replica page that appears to be part of the company's site. (This is why phishing is also called brand spoofing.)
A fake e-mail is sent out with a link to this page, which solicits the user's credit card data or password. When the form is submitted, it sends the data to the scammer while leaving the user on the company's site so they don't suspect a thing.

Andrew Shain, July 25, 2003, Phishing to steal your information, Retrieving on 28 Apr 2009 from http://www.wordspy.com/words/phishing.asp

Exercise 12-2

2009-05-15T17:13:00.001-07:00

2. What can you find out about network and host-based intrusion detection systems?
Most intrusion detection systems (IDS) look for attack signatures in specific pattern which indicate malicious or suspicious intent. When the IDS look for the attack signature in network traffic, it is classified as network-based. For IDS look for the attack signature in the log files, it is classified as host-based.

Network-based IDS is usually used to detect the intrusion in the network by examining network traffic in central network devices, like hub, network switch or network gateway. On the other hand, host-based IDS is used to detect the intrusion in particular host. As usual, an agent will be installed host to identify intrusions by examining system calls, logs, file-system and host activities.

Network Based Intrusion Detection
Network-based intrusion detection systems use raw network packets as the data source. A network-based IDS typically utilizes a network adapter running in promiscuous mode to monitor and analyze all traffic in real-time as it travels across the network. Its attack recognition module uses four common techniques to recognize an attack signature:
l Pattern, expression or byte code matching,
l Frequency or threshold crossing
l Correlation of lesser events
l Statistical anomaly detection

Once an attack has been detected, the IDS’ response module provides a variety of options to notify, alert and take action in response to the attack. These responses vary by product, but usually involve administrator notification, connection termination and/or session recording for forensic analysis and evidence collection.

Host Based Intrusion Detection
Host-based intrusion detection was common practice to review audit logs for suspicious activity. Host-based intrusion detection systems are powerful tools for understanding previous attacks and determining proper methods to defeat their future application.
Host-based IDS use audit logs, but they are much more automated, having evolved sophisticated and responsive detection techniques.
Host based IDS typically monitor system, event, security logs and system log. When any of these files change, the IDS compares the new log entry with attack signatures to see if there is a match. If so, the system responds with administrator alerts and other calls to action.

Host-based IDS have grown to include other technologies. One popular method for detecting intrusions checks key system files and executables via checksums at regular intervals for unexpected changes. The timeliness of the response is in direct relation to the frequency of the polling interval.
Finally, some products listen to port activity and alert administrators when specific ports are accessed. This type of detection brings an elementary level of network-based intrusion detection into the host-based environment.

Reference:
Anonymous , 2 Oct 1998, Network- vs. Host-based Intrusion Detection, Retrieving on 5
May 2009 from http://documents.iss.net/whitepapers/nvh_ids.pdf

Exercise 12 -1

2009-05-15T16:38:00.000-07:00

1. Find out about SET and the use of RSA 128-bit encryption for e-commerce.
Secure Electronic Transaction (SET) was a standard protocol for securing credit card transactions over insecure networks, specifically, the Internet. SET allowed parties to cryptographically identify themselves to each other and exchange information securely. However, it remains to be seen whether the protocol will be widely used because of the weakness of the encryption that it uses.

RSA was first described in 1977 by Ron Rivest, Adi Shamir, and Leonard Adleman at MIT. RSA encryption is important to the e-commerce, it is the industry standard for securing application.

RSA-128 bit encryption is considered unbreakable and is adopted as standard feature by BusinessObject XI which is considered as the most flexible and scalable businesses intelligence (BI) platform.

References:
http://en.wikipedia.org/wiki/Secure_electronic_transaction

Anonymous, 8 Mar 2005, BusinessObjects XI Increases Security By Providing RSA
128-Bit Encryption as Standard Platform Security Level, Information Management
Online, Retrieving on 5 May 2009 from http://www.information-management.com/news/1022600-1.html

Workshop 3

2009-04-15T21:01:00.000-07:00

Create a database which name is “obts” by MYSQL at http://127.0.0.1/mysql/

Create the table, “Passengers” with 13 columns;

In ruby dos command mode, enter the command, rails –d mysql otbs;
Generate an application which name is otbs;

Run the otbs application by selecting in Rails Application in InstantRails.

In the web browser, enter the address: http://127.0.0.1:3000/

This means the connection of the application is successful.

Edit the database.yml in otbs application like the following:

Generate the model for the application by the command, ruby script/generate model Passenger;

Generate the controller for the application by the command, ruby script/generate controller Passenger;

Add scaffolding by edit the passenger_controller.rb like the following:

Install scaffolding with the command, ruby script/plugin install scaffolding

Amend the passenger_controller.rb as the following:

Create a rhtml as the following in the views of the otbs application

Amend the model, passenger.rb, of otbs

Output

Output list.rhtml:

Exercise 11 :11.3

2009-04-13T00:48:00.000-07:00

SMIL is an application of XML. What is the purpose of this technology? Where does it apply?

According to the w3schools.com, SMIL is an easy-to-learn HTML-like language for describing audiovisual presentations.

SMIL stands for Synchronized Multimedia Integration Language
SMIL is pronounced "smile"
SMIL is a language for describing audiovisual presentations
SMIL is easy to learn and understand
SMIL is an HTML-like language
SMIL is written in XML
SMIL presentations can be written using a text-editor
SMIL is a W3C recommendation
Define an XML-based language that allows authors to write interactive multimedia presentations. Using SMIL, an author may describe the temporal behaviour of a multimedia presentation, associate hyperlinks with media objects and describe the layout of the presentation on a screen.
Allow reusing of SMIL syntax and semantics in other XML-based languages, in particular those who need to represent timing and synchronization. For example, SMIL components are used for integrating timing into XHTML XHTML10 and into SVG.
Extend the functionalities contained in the SMIL 2.1 into new or revised SMIL 3.0 modules.
Define new SMIL 3.0 Profiles incorporating features useful within the industry.
SMIL lets you create simple to highly complex media presentations by coordinating any number of media clips. Using SMIL, you can replicate almost all of the features that you can set through the Ram file. Plus, SMIL offers some advanced capabilities for opening HTML pages at different points during a presentation. A SMIL presentation works in RealOne Player on any operating system.

http://www.w3.org/TR/2008/REC-SMIL3-20081201/smil-introduction.html
http://www.w3schools.com/smil/default.asp

Exercise 11:11.2

2009-04-13T00:42:00.000-07:00

1. What are the benefits of adopting a schema standardized for a business sector?
XML schemas allow us to solve many of the technical challenges presented by e-commerce requirements, and to leverage the best of EDI technology.

Strong data typing
Schema languages contain native data types that align with the standard data types of some programming languages: strong numeric types like signed integers, floats, doubles, etc.; enumerated lists; date, time, and date time; and, of course, strings. It becomes possible to capture code-lists as enumerations, to limit the length of string types to fit into typical database fields, and to describe numeric types very exactly.

Manageability and componentization
Further, some schema languages (SOX and XSDL, for example, and to some extent XDR) have inherent capabilities for reusing components by doing the kind of importing and referencing that are found in programming languages such as Java. It becomes possible to take another person's schemas - assuming they are publically available in the correct schema language - and to incorporate them into schemas that you are creating.

Extension
Another aspect of XML schema that helps us solve the tough problems of e-commerce is the ability to not only reuse another person's data models, but to "refine" them. At runtime, processing applications can identify what the differences are between the parent class and it's subclasses, enabling polymorphic processing and default processing
The application of this capability from a design perspective is that minimized components were used in anticipation that they will be extended to fit particular requirements.
For supporting Global interoperability, the ability to extend, reuse, rename, and refine other people's components is a major enabling technology.

Data and documents
When schema was properly employed, also makes it fairly easy to translate document structures into normalized relational structures. This is one of the places where XDR has been effectively used. The simplest way to handle graphing requirements was to use element structures. DTDs just weren't designed to support this requirement.

http://www.gca.org/papers/xmleurope2000/papers/s21-01.html#N78329
http://xml.coverpages.org/schemas.html

Exercise 11 -11.1

2009-04-13T00:41:00.000-07:00

1. Conduct research on the Internet to find out what tools can be used to parse an XML document and ensure that the document is well formed and valid.
By the google search engine, there are many XML validators in the Internet. Some of them are listed below:
l W3school.com
n http://www.w3schools.com/Dom/dom_validate.asp

l Scholarly technology group
n http://www.stg.brown.edu/service/xmlvalid/

l Validome
n http://www.validome.org/xml/

l HTML/XML Validator
n http://validator.aborla.net/index.php5?lang=en

l XML well-formedness checker and validator
n http://www.cogsci.ed.ac.uk/~richard/xml-check.html

l DecisionSoft
n http://tools.decisionsoft.com/schemaValidate/

l XML Schema Validator
n http://schneegans.de/sv/

The above validators can be used to parse an XML document and ensure that the document is well formed and valid

Exercise 10 -10.3

2009-04-13T00:40:00.003-07:00

What are the similarities between the object-oriented development using model-view-controller (MVC) in Ruby on Rails 2.0 and Action Script 2.0 (Flash animations)?

The characteristics of object-oriented programming languages are:
l Objects: it has properties and behaviors;
l Instances and class members
l Inheritance
l Interfaces
l Encapsulation
l Polymorphism

Both Ruby on Rails 2.0 and Action Script 2.0 are object-oriented programming languages and contains the above properties.
From the tutorial, it states that Ruby follows strict concepts of Object Oriented programming languages (OOPS) which has objects, methods and classes available for programming.
Ruby also supports the common features of OOPS, such as Objects, Classes and Instances, Methods, Portability, Security.
Whenever any class method is called in Ruby, it tries to track a particular method at several locations. It also follows a specific path to locate that method so as to avoid wasting search time.
Two critical concepts in Ruby on Rails: "Convention over Configuration" and "Don't Repeat Yourself"
"Convention over Configuration" means that a programmer only needs to write code for unconventional parts of the application they're building.
"Don't Repeat Yourself". Ruby on Rails makes repeating yourself unnecessary with the help of the ActiveRecord and the method of scaffolding.
With scaffolding, a compiler automatically generates basic pieces of code necessary for the "logistics" of a website -- for creating, reading, modifying or deleting data in the database. So one is left with a sort of template upon which one can build the rest of the website with more specific code.
The Ruby on Rails framework uses the Model-View-Controller design pattern which helps the programmer to separate the actual data (model) from the interface (view) of the application.
The reason why this is extremely useful is that it provides modularity and ensures efficiency of the application, making it much easier to modify when needed and eliminating redundancy of code.
The primary feature of ActionScript 2.0 is a familiar model for creating object-oriented programs. It is based on the concept of classes and instances. A class defines all of the properties that distinguish a series of objects.

ActionScript 2.0 provides the OOP model as a syntactic formalization of the prototype chaining method used in previous versions of Flash to create objects and establish inheritance. With ActionScript 2.0, custom classes and extend Flash's built-in classes can be created.

Colin identified that not all Flash applications need to be purely object-oriented. Flash supports both procedural and object-oriented programming and allows to combine both approaches in a single Flash movie.

Not all Flash content necessarily involves timeline-based motion. If a video game is being created, it becomes impossible to predict the actions of each role by using the timeline. Therefore, ActionScript has to be used instead of the timeline to position the characters in response to user actions

Colin suggested that OOP concept is used while create:
• Traditional desktop-style applications with few transitions and standardized user interfaces
• Applications that include server-side logic
• Functionality that is reused across multiple projects
• Games
• Highly customized user interfaces that include complex visual transitions

Colin also argued that ActionScript 2.0 using MVC would provide the following benefits:
• Allows multiple representations (views) of the same information (model)
• Allows user interfaces (views) to be easily added, removed, or changed, at both compile time and runtime
• Allows response to user input (controller) to be easily changed, at both compile time and runtime
• Promotes reuse (e.g., one view might be used with different models)
• Allows multiple developers to simultaneously update the interface, logic, or input of an application without affecting other source code
• Helps developers focus on a single aspect of the application at a time

References:
Ruby on Rails tutorials, retrieving on 5 April 2009, from http://www.meshplex.org/wiki/Ruby/Ruby_on_Rails_programming_tutorials#Ruby_and_Object-Oriented_Programming

Colin Moock, Essential ActionScript 2.0, O’Reilly, retrieving on 5 April 2009, from
http://oreilly.com/catalog/0596006527/chapter/ch02.pdf, pp.19-22

Flash CS4 Professional ActionScript 2.0
http://help.adobe.com/sv_SE/AS2LCR/Flash_10.0/help.html?content=00000531.html

Colin Moock, Essential ActionScript 2.0, O’Reilly, retrieving on 5 April 2009, from
http://www.adobe.com/devnet/flash/articles/mv_controller/as2ess_ch18.pdf

Exercise 10: 10.2

2009-04-13T00:40:00.001-07:00

Why is the perception getting stronger that integration will become a critical factor in coming days? What is the role of AJAX within the enterprise software architecture?

From the industrial report of Siemen, it identifies that integration have the following benefits:
l To make the facility run more efficiently;
l To reduce costs;
l To increase the productivity of the facility staff;

Integration implies that all relevant data for a particular bounded and closed set of business processes is processed in the same software application. Updates in one application module or component are reflected throughout the business process logic, with no complex external interfacing. Data are stored once, and it is instantaneously shared by all business processes that are enabled by the software application.

Integration implies “one source of truth” for those business processes that are enabled by core ERP solutions. The concept is simple: if all data are stored once and shared, then integrity issues are less likely to occur. Furthermore, complexity is significantly reduced.

Integration can be used to some form of interfacing, even though they are loosely called system integration. Modern systems invoke shared objects to share business logic and interact with resources (such as databases or queues).

Most organizations have needs for B2B connectivity, as well as other forms of integration. Internal business processes and systems require enterprise integration efforts, where external business transactions are processed through B2B eCommerce.

AJAX or Asynchronous JavaScript and XML is a new programming technique that is based on existing standards and technologies for creating faster and more interactive web applications. The core of AJAX is XML HTTP Request that gives web applications the ability to exchange data asynchronously with the web server eliminating the need for a complete page refresh. Apart from the XML HTTP Request API AJAX uses a combination of XHTML or HTML and CSS, JavaScript, DOM and XML which is common markup languages for data formatting. It is because web pages are not always coupled and they need to be formatted before they are displayed to the user and they have to be re-loaded each time a user makes a http request. Using AJAX the page re-loading can be minimized or can be eliminated.

One of the main advantages of using AJAX is the minimization of bandwidth usage. The “transfer only what you need” was impossible to implement in classic web architectures because the data needed to be marshaled into a recognized format, such as html and the page needed to be re-loaded each time a request for a new dataset is made. Implement an AJAX based solution makes possible the asynchronous exchange of data between the client browser and the web server. The data transfer is done in the background and is formatted using JavaScript on the client side. This implementation also reduces the consumption of hardware resources on the server side because the formatting is done on the client’s machine.

Reference:
Thomas Gulledge, What is integration. Industrial Management & Data Systems, 106
(1), pp: 5-20

Reference:
Payel A. and Bogdan C.M., (2008), Object-Oriented Construction of Portals Using
AJAX, Int. J. of Computers, Communications & Control, 3, pp. 442-447

Anonymous, April 2001, Building Systems Integration: Understanding The Benefits Of Integration, Siemens Building Technologies

Exercise 10: 10-1

2009-04-13T00:39:00.001-07:00

1. Go to the website of IBM, Oracle, Microsoft and Sybase. Is there any mention of e-commerce associated with their database products? What suite or partnership do they list with related e-commerce offerings? How do they compare with open source products like MySQL?

IBM:
Aviva Investors wished to move to a more flexible cost base and improve efficiency; many diverse applications and data repositories had become so intertwined over the years that decoupling selected functions presented serious challenges

Aviva Investors and IBM Premier Business Partner Alphacourt developed a ‘hub and spoke’ architecture based on the IBM WebSphere Business Integration product set

The IBM WebSphere solution is allowing Aviva Investors to change profoundly how it does business; Aviva Investors’ people can gain access to more comprehensive, accurate and timely information which will sharpen the company’s competitiveness by shortening its time to market with new products

IBM products:
WebSphere Message Broker
WebSphere MQ

Oracle:
Midea Group Share Co., Ltd. Guangdong, China

Oracle Products & Services:
l Oracle Database
l Oracle Discrete Manufacturing
l Oracle Order Management
l Oracle Financials

Key Benefits:
l Increased sales by 40% and reduced product delivery cycles by streamlining workflow for each distribution channel and product line
l Improved productivity by 15% and brought production costs under control by establishing a more efficient manufacturing processes
l Reduced inventory levels by 10% after enhancing efficiency of order management

Microsoft:
WebTrends solutions deliver enterprise Web analytics and deep visitor intelligence that help organizations measure site performance and drive customer engagement to maximize return on marketing spend.
Software and Services
Feature: Analysis ServicesFeature: Reporting ServicesMicrosoft Dynamics CRM 3.0Microsoft Office Outlook 2007Microsoft SQL Server 2005

By the Microsoft solution
l Easy Integration with Existing Services
l Flexible Deployment
l Increased Workflow Automation

Sybase:

Agriculture Bank of China

KEY BENEFITS
• Provides systematic, comprehensive, standard and accurate card analysis
• Adapts to the changing statistic requirements of the management team, avoiding repetitive system development
• Promotes quick and healthy development of the bank card business

SYBASE TECHNOLOGY
• Adaptive ServerR Enterprise
• Sybase IQ
http://www.sybase.com/detail?id=1045499

References:
IBM, 28-Apr-2008, Aviva Investors works more effectively with IBM WebSphere solutions. Retrieving on 5 April 2009 from ftp://ftp.software.ibm.com/common/ssi/pm/ab/n/swc02032gben/SWC02032GBEN.PDF

Oracle, December 2006, Midea Boosts Sales by 40%, Reduces Inventory Levels by 10%, Retrieving on 5 April 2009 from
www.oracle.com/customers/snapshots/midea-ebs-case-study.pdf

Microsoft
Microsoft , 7/11/2007, Web Analytics Integrates With CRM for More Effective Marketing, Sales, and Service, Retrieving on 5 April 2009 from
http://whitepapers.techrepublic.com.com/abstract.aspx?docid=312314

Sybase
Sybase, 2008, CUSTOMER SUCCESS STORIES: Agriculture Bank of China, Retrieving on 5 April 2009 from http://www.sybase.com/files/Success_Stories/ABC-110708-ss.pdf

Exercise 9 -9.3

2009-04-13T00:38:00.001-07:00

Can you modify the script to process the form?

name=Evan+Burke&card=Visa&number=8443261344895544&order=French+perfume

1. #!c:/usr/bin/perl
2. print "Content-type: text/html \n\n";
3. $finfo = ;
4. @pairs = split(/&/,$finfo);
5. foreach $pair (@pairs)
6. {
7. ($name,$value) = split(/=/,$pair);
8. $value=~ s/\+/ /g;
9. $value =~ s/%([0-9a-fA-F][0-9a-fA-F])/ pack("C", hex($1))/eg;
10. $FORM{$name} = $value;
11. }
12. print "$FORM{'name'}
\n";
13. print "$FORM{'card'}\n";
14. print "$FORM{'cardno'}
\n";
15. print "$FORM{'order'}\n";
16. exit (0);

description:
Line 1: perl.exe is installed at c:/usr/bin;
Line 2: display the output as HTML format;
Line 3: we use $finfo to store the standard input of the form;
Line 4: @pairs is an array used to store the data; the whole data is split into 4 parts by the sign “&”;
name=Evan+Burke;
card=Visa;
number=8443261344895544;
order=French+perfume;
Line 5: It is a loop for each element in the array;
Line 7: we use two variables to store the data; like the following:
$name=name;
$value= Evan+Burke;
Line 8: convert the symbol “+” to a space “ “;
Line 9: convert the machine codes into English-like letters;
Line 10: we use a hash to store the output;
name=Evan Burke;
card=Visa;
number=8443261344895544;
order=French perfume;
Line 12-15: call and display the related data;
Line 16: exit from the code

Exercise 9 - 9.2

2009-04-13T00:35:00.000-07:00

Write the script

Script archives exist for PERL, Python and JavaScript. Search the Web for a script that processes the HTML forms data. Read the code and list the steps involved in processing the form.

Script:

From the HTML tutorial on W3C, It illustrates that
When the user submits a form by activating a submit button, the user agent processes it as follows
1. Identify the successful controls
2. Build a form data set A form data set is a sequence of control-name/current-value pairs constructed from successful controls
3. Encode the form data set . The form data set is then encoded according to the content type specified by the enctype attribute of the FORM element.
4. Submit the encoded form data set . Finally, the encoded data is sent to the processing agent designated by the action attribute using the protocol specified by the method attribute.
This specification does not specify all valid submission methods or content types
that may be used with forms.
However, HTML 4 user agents must support the established conventions in the following cases:

If the method is "get" and the action is an HTTP URI, the user agent takes the value of action, appends a `?' to it, then appends the form data set, encoded using the "application/x-www-form-urlencoded" content type. The user agent then traverses the link to this URI. In this scenario, form data are restricted to ASCII codes.

If the method is "post" and the action is an HTTP URI, the user agent conducts an HTTP "post" transaction using the value of the action attribute and a message created according to the content type specified by the enctype attribute.

For any other value of action or method, behavior is unspecified.
User agents should render the response from the HTTP "get" and "post" transactions

Refernce:
http://www.w3.org/TR/html401/interact/forms.html#h-17.13.3
http://www.comp.it.bton.ac.uk/~mas/mas/courses/html/html2.html

Exercise 9 - 9.1

2009-04-13T00:34:00.000-07:00

Web form design and processing: A basis for e-commerce interaction

1. Design the form

“Retrofit” the form data string above for buying some French perfume into the HTML form fields and submit button on the Web page form.

name=Evan+Burke&card=Visa&number=8443261344895544&order=French+perfume

Exercise 5 - 5.3

2009-04-13T00:14:00.002-07:00

Frameworks for development. Compare and contrast any TWO of:
Java
.NET
Ruby on Rails
Turbo Gears
Google Gears
AJAX frameworks

Comparison with .NET and Java:

Java platform was first released by Sun Microsystems Inc. Java advocates its simplicities and elegance of the strong-typed object-oriented, its security features, hardware and operating system, independence and the open architecture.

The Microsoft .NET Framework is a software framework available with several Microsoft Windows operating systems. It includes a large library of coded solutions to prevent common programming problems and a virtual machine that manages the execution of programs written specifically for the framework.

Components:
Java platform
It includes following main components:
l Class loader: It’s responsible for dynamically locating and loading one type of class file, maintaining type safety by adding link-time checks, consults the security policy, and defines the class object with the appropriate permissions.
l The Class File Verifier: The class file verifier is invoked by the class loader to check all aspects of a class file from its size and structure down to its runtime characteristics.
l Memory for Storage: It stores java objects, class-specific information such as methods and static fields and native code generated for class method, or loaded from native.
l JIT Complier: Translate the class code into native code on a method-by method basis as needed. It’s optional.
l Execution engine: It is the heart of the JVM. It is the virtual processor that executes byte code and performs memory management, thread management and calls to native methods.
l Security Manager: It’s responsible for enforcing runtime security restrictions.

.NET Platform
According to MSDN .NET Beta documentation, the CLR contains following main processes which are similar to Java platform counterpart:

Class loading: There is a class loader which is used to load the implementation of a loadable type into memory and prepare it for execution. The class loader uses the name of the assembly, version information, information about the application, and administrative configuration to locate the assembly and its constituent files.
The class loader is part of the CLR security enforcement mechanism. It performs a variety of consistency checks including enforcement of certain accessibility rules and self-consistency requirements.

Verification: It ensures that consistency of type signatures is maintained within verified code.

JIT compilation: There is a JIT complier to translate the intermediate language code into native code on a method-by-method basis as needed. As part of compiling intermediate language to native code, the code must pass a verification process. Verification examines intermediate language and metadata to see whether the code can be determined to be type-safe, which means that it is known to access only the memory locations it is authorized to access

Execution: Before a method can be executed, it must be compiled to processor-specific code. Each method for which intermediate language has been generated is Just in time compiled when it is called for the first time, then executed.
During execution, managed code receives services such as automatic memory management, security, interoperability with unmanaged code, cross-language debugging support, and enhanced deployment and versioning support.

Security Check: It’s responsible for enforcing runtime security restrictions on access to resources and authentication.

They are different from their main platforms, programming libraries, formats and their runtime environments.

Standardization
.NET has been standardized by ECMA International, ISO/IEC, ANSI and the executable environment for .NET is known as the Common Language Infrastructure, (CLI) and its executable format is known as Common Intermediate Language(CIL), but excluding most of the foundation classes (the Base Class Library, or BCL).

No part of Java has been standardized by Ecma International, ISO/IEC, ANSI, or any other third-party standards organization. Sun voluntarily participates in a process called the Java Community Process (JCP) that allows interested parties to propose changes to any of Sun's Java technologies from language and tools to API via forums, consultation exercises and expert groups.

License
Java
Sun owns the license of Java, any numerous free software projects exist that are compatible with Sun Java.
Sun released the complete source code of the Class library under GPL, except some limited parts that were licensed by Sun from 3rd parties who did not want their code to be released under an open-source license. Sun's goal is to replace the parts that remain closed with alternative implementations and make the class library completely open.

.NET
Microsoft's .NET CLI executable environment and some of the corresponding class library have been standardized and can be freely operated without any license. Some standards-compliant free software environments have been implemented. Microsoft distributes a shared source version of its .NET runtime environment for academic use.

2.4.1 Java platform
Policy-based, fine-grained, easy-configured code access control
Object signing, sealing and guarding for remote object security
Cryptographic services, including secure encoding and decoding of data, as
well as many other operations, such as hashing, random number generation,
message authentication, and formation of digital signatures
2.4.2 .NET platform
Policy-based, fine-grained, easy-configured code access control
Role-based access control
Remoting security support for remote object
Cryptographic services, including secure encoding and decoding of data, as well as many other operations, such as hashing, random number generation, message authentication, and formation of digital signatures

Community
Java
In its proprietorship of Java, Sun works with an open culture, allowing multiple parties, from organizations to individuals, to steer the decision making process. Sun reserves exclusive and unlimited legal rights to its Java intellectual properties, and the Java community is subject to those rights.

.Net
Microsoft has developed C# and .NET without a formal community contribution system, the language and some parts of the executable format and runtime have been standardized and freely distributed through Ecma.

Desktop applications
Java
Java has tried to occupy the market of the desktop. Its rigid adherence to the notion of write once, run anywhere makes it difficult to use to the maximum the unique features and modes of working within each individual desktop environment.

.Net
.NET has become increasingly common in open source and free software systems due to its inclusion.

Although the design goal of each platform is different, the architecture and code
access control security mechanism of both platform are very similar.
Access control security of .NET platform is slightly better than those of Java platform
from the following aspects:
l Support Role-based security∗
l Support identity permission*
l Easy security policy configuration: four level of security policy, declarative attributes by using IL metadata
l Procedure of access control decision-making is little bit simple, by using permission demand.

Some of the advantages of the .NET Framework Stem from the fact it was designed
much later, which means you get the ground-up effect as opposed to that append-iton-
later effect.
But it’s some above slightly advantages the .NET platform over Java platform that
make access control security of .NET platform too complicated. Access control
security of Java platform, however are simple, elegant and comprehensive, even if
Java platform has to consider some backward compatibility when new features were added in it.

From above analysis, I conclude that the access control securities of both platforms
are very similar. There is no significant difference of access control security between the two platforms.

Reference:
Anonymous, 3 April 2009, Comparison of the Java and .NET platforms, Retrieving on 4
April 2009 from http://en.wikipedia.org/wiki/Comparison_of_the_Java_and_.NET_platforms

Yongqiang Li, May 2001, A Comparison of Access Control Security of Java Platform
and .NET Platform

Exercise 5 - 5.2

2009-04-13T00:14:00.001-07:00

Describe the important and distinguishing properties of Peer to Peer computing and the Grid. How is this peer to peer and the Grid architecture changing work flow and service-oriented applications?

Jussis concluded (2008) that a P2P system exhibits the following characteristics:
1. Individual nodes have unsteady connectivity;
2. Unreliable, uncoordinated, unmanaged
3. No central authority, peers are completely independent
4. Increases flexibility of individual peers, but makes the overall system unreliable
5. Resilient to attacks, heterogeneous peers make viruses and worms;
6. Large number of peers in the system
7. Large collection of resources
8. Voluntary participation, global reach

Grid Computing
It identifies that grid enables sharing, selection, and aggregation of a wide variety of resources that are geographically distributed and owned by different organizations for solving large-scale computational and data intensive problems in science, engineering, and commerce. Therefore, it creates virtual organizations and enterprises as a temporary union that come together to share resources and skills, core competencies, or resources in order to better respond to business opportunities or large-scale application processing requirements, and whose cooperation is supported by computer networks. (Mark Baker et al, 2002, p.3)

Grids can be used to provide the following types of services:
• Computational services. These are concerned with providing secure services for executing application jobs on distributed computational resources individually or collectively. Resources brokers provide the services for collective use of distributed resources.

• Data services
To provide a scalable storage and access to the data sets, they may be replicated, catalogued, and even different datasets stored in different locations to create an illusion of mass storage.

• Application services.
It is the application management and providing access to remote software and libraries transparently. The emerging technologies such as Web services are expected to play a leading role in defining application services. They build on computational and data services provided by the Grid.

• Information services.
It is the extraction and presentation of data with meaning by using the services of computational, data, and/or application services. The information is represented, stored, accessed, shared, and maintained by this service.

• Knowledge services.
Knowledge is acquired, used, retrieved, published, and maintained to assist users in achieving their particular goals and objectives. Knowledge is understood as information applied to achieve a goal, solve a problem, or execute a decision.

Mark (2002 p.27) argued that grid is not only a computing infrastructure, for large applications, it is a technology that can bond and unify remote and diverse distributed resources ranging from meteorological sensors to data vaults, and from parallel supercomputers to personal digital organizers.

As such, it will provide pervasive services to all users that need them. Scientists and engineers routinely perform their work without regard to their physical location. They will be able to interact with colleagues, access instrumentation, share data and computational resources, and access information in digital libraries. All scientific and technical journals will be available on-line, allowing readers to download documents and other forms of information, and manipulate it to interactively explore the published research. This exciting vision has a direct impact on the next generation of computer applications and on the way that they will be designed and developed.

To reduce the costs of system development, it is foreseeable that no single company or organization would be able to or hire and train all the necessary expertise necessary to build an application. This will heighten the movement towards component frameworks, enabling rapid construction from third-party ready-to-use components.

Reference:
Jussi Kangasharju, 2008, Peer-to-Peer Networks, Retrieving on 22 mar 2009, from
http://www.cs.helsinki.fi/u/jakangas/Teaching/p2p-08f.html
Mark Baker, Rajkumar Buyya and Domenico Laforenza, 2002, Grids and Grid technologies for wide-area distributed computing

Exercise 5 - 5.1

2009-04-13T00:09:00.000-07:00

Investigate a simple chat client/server system. Look at some program code and describe how it works with multiple users.

The following system(program) is written in visual basic 6.0.
Sources:
http://tw.myblog.yahoo.com/lk-hsu/article?mid=1457&next=1438&l=f&fid=16
Dim MaxClient As Integer
Private Sub Form_Activate()
X = picF.WidthY = picF.Height
nnx = Me.ScaleWidth \ Xnny = Me.ScaleHeight \ Y
For i = 0 To nny
For j = 0 To nnx
Me.PaintPicture picF.Picture, j * picF.Width, i * picF.Height
Next j, i
End Sub

Private Sub Form_Load()
Winsock_Server(0).Protocol = sckTCPProtocolWinsock_Server(0).LocalPort = 3000Winsock_Server(0).Listen
MaxClient = 20
For i = 1 To MaxClient
Load Winsock_Server(i)Next
txt.Text = EmptypicF.Visible = FalseMe.AutoRedraw = TrueMe.Top = 200
'Frm_tcpClient.Show (Test two forms of client communication)
'Frm_tcpClient.Top = Me.Top + Me.Height'Frm_tcpClient.Left = Me.Left
End Sub

Private Sub Winsock_Server_Close(Index As Integer)
For i = 0 To List1.ListCount - 1 List1.ListIndex = i (Display the text row by row) strList = Split(List1.Text, "<") If strList(0) = Index Then List1.RemoveItem List1.ListIndex List1.Refresh Exit For End IfNext Winsock_Server(Index).Close ‘(close Winsock)
Unload Winsock_Server(Index) ‘(release resources)Load Winsock_Server(Index) ‘(regeneration)
End Sub

Private Sub Winsock_Server_ConnectionRequest(Index As Integer, ByVal requestID As Long)
For i = 1 To MaxClient If Winsock_Server(i).State = sckClosed Then
Winsock_Server(i).Accept requested
List1.AddItem i & " <> <>"
txt.SelText = vbCrLf & Winsock_Server(i).RemoteHostIP & " Connection successful"
Exit For End If
Next
End Sub

Private Sub Winsock_Server_DataArrival(Index As Integer, ByVal bytesTotal As Long)
On Error Resume Next
Dim inData As StringWinsock_Server(Index).GetData inData, vbString '(RECEIVE DATA)
txt.SelColor = QBColor(Index mod 7)txt.SelText = vbNewLine & inData '(DISPLAY DATA)
For i = 1 To MaxClient '(DISPLAY TO ALL CLIENTS WHO CONNECTED)
If Winsock_Server(i).State = sckConnected Then Winsock_Server(i).SendData Trim(Str(Index)) & "," & inData DoEvents End If
Next
End Sub

Private Sub Winsock_Server_Error(Index As Integer, ByVal Number As Integer, Description As String, ByVal Scode As Long, ByVal Source As String, ByVal HelpFile As String, ByVal HelpContext As Long, CancelDisplay As Boolean)s = Indexs = s & "ERROR MESSAGES：" & Number & vbNewLines = s & "MESSAGES：" & Description & vbNewLines = s & "Scode：" & Scode & vbNewLines = s & "ERROR CODE：" & Source & vbNewLineMsgBox sEnd Sub

'Client Codes
Private Sub btnClose_Click()
txt.Text = Empty '(clear the message box) txtSend.Text = Empty '(clear the sent message box)
Winsock_Client.ClosebtnClose.Enabled = FalsebtnConnect.Enabled = TruetxtSend.Enabled = False
End Sub

Private Sub btnConnect_Click()
Winsock_Client.Protocol = sckTCPProtocolWinsock_Client.RemoteHost = Combo1.TextWinsock_Client.RemotePort = 3000 '(set the port as 3000)
Winsock_Client.ConnectbtnClose.Enabled = TruebtnConnect.Enabled = FalsetxtSend.Enabled = True
End Sub

Private Sub btnEnd_Click()
Winsock_Client.CloseUnload Me
End Sub
Private Sub Form_Activate()X = picF.WidthY = picF.Height
nnx = Me.ScaleWidth \ Xnny = Me.ScaleHeight \ Y
For i = 0 To nny For j = 0 To nnx Me.PaintPicture picF.Picture, j * picF.Width, i * picF.HeightNext j, i
End Sub
Private Sub Form_Load()
Combo1.AddItem "127.1" '(Set localhost as server)Combo1.AddItem "LocalHost" ‘(Set localhost as server)Combo1.AddItem "HSU_PC" '(Set server name)
Combo1.AddItem "192.168.1.1" ' (Set IP for server)Combo1.AddItem "122.127.21.70" '(Set Public IP Address)Combo1.ListIndex = 0 'Set default selection btnClose.Enabled = FalsetxtSend.Enabled = FalsepicF.Visible = FalseMe.AutoRedraw = True
End Sub

Private Sub txtSend_Click()
txtSend = ""End Sub

Private Sub txtSend_KeyPress(KeyAscii As Integer)
On Error GoTo errnick = txtNickName.TextIf nick = "" Then nick = "anonymous"If KeyAscii = vbKeyReturn Then
Winsock_Client.SendData nick & " says：" & txtSend.Text txtSend = ""End If
Exit Suberr:Call Winsock_Client_Error(vbError, "Can’t establish connection with remote host", vbError, "txtSend", HelpFile, HelpContext, False)
End Sub

Private Sub Winsock_Client_DataArrival(ByVal bytesTotal As Long)
Dim inData As StringWinsock_Client.GetData inData, vbString 'Receiving the contentarrData = Split(inData, ",") 'split the contentcolorData = arrData(0) 'get the indexstrData = arrData(1) 'get the contenttxt.SelColor = QBColor(colorData Mod 7) 'change the colortxt.SelText = vbCrLf & strData 'Display the content
End Sub

Private Sub Winsock_Client_Error(ByVal Number As Integer, Description As String, ByVal Scode As Long, ByVal Source As String, ByVal HelpFile As String, ByVal HelpContext As Long, CancelDisplay As Boolean)
s = ""s = s & "Error code：" & Number & vbNewLines = s & "Message：" & Description & vbNewLines = s & "Scode：" & Scode & vbNewLines = s & "Error reason：" & Source & vbNewLineMsgBox stxtSend.Enabled = FalsebtnClose.Enabled = FalsebtnConnect.Enabled = TrueWinsock_Client.Close
End Sub

Exercise 4 - 4.4

2009-04-13T00:07:00.000-07:00

What role can a VPN play in business-to-business e-commerce?
The role that a VPN play in business-to-business e-commerce is to provide confidentiality and integrity for data over ‘danger’ networks like the Internet. Therefore, it is used to secure traffic from remote workers to a VPN gateway at the edge of the company network. That gateway is responsible for authenticating users and controlling which destinations can be reached. For example, a worker on a public PC may only be permitted to check e-mail, while a worker on a company laptop may be given access to sensitive servers. A laptop missing patches or infected with a Trojan may be directed a quarantine server for remediation. Besides, a VPN allows two or more offices together to allow them to work as one. Therefore, they can share files, printers and more since the Broadband connection carries data between offices is secure and fast.

http://www1.alcatel-lucent.com/bnd/bvs/VPN_Poster_May08.pdf

http://www.vpn-for-business.co.uk/

workshop 4 - Ex 4.3

2009-04-12T23:50:00.002-07:00

3. Compare the Ruby and Python versions of the dog years calculator:

Comparison:
The purpose of both programs is to calculate the ages of dogs relate to human.
Fist, if the input is less than zero, it displays “negative age”. And if the input is less than 3 or more than 110, it also doesn’t make sense. Therefore, any input which is between 3 and 110 will multiply 7 as the output, dog years.

The syntaxes in both programs are different:

Ruby
Use “puts” to display the output
Use “gets” to get the keyboard input
Define function without any argument or variable
Call the function “dogyears” directly

Python
Use “print” to display the output
Use “input” to get the keyboard input
Define function with blank bracket “()”
Define the function “main” to call the function “dogyears”

workshop 4 - Ex 4.2

2009-04-12T23:50:00.001-07:00

2. Write a Ruby program called fizzbuzz.rb that prints the numbers from 1 to 100. But for multiples of three print "Fizz" instead of the number and for the multiples of five print "Buzz". For numbers which are multiples of both three and five print "FizzBuzz".

#!/usr/bin/ruby
def fizzbuzz
1.upto(100) do i
if i % 5 == 0 and i % 3 == 0
puts "FizzBuzz"
elsif i % 5 == 0
puts "Buzz"
elsif i % 3 == 0
puts "Fizz"
else
puts i
end
end
end
fizzbuzz

workshop 4 - Ex 4.3

2009-04-12T23:21:00.000-07:00

Challenge Problems:
1. Create, test and debug a Ruby program called dognames.rb or catnames.rb to accept 3 names from the keyboard and to display each name on the screen in alphabetical order WITHOUT using a data structure such as a list.

#!/usr/bin/env ruby
i=0my
array=[]
puts "enter the name"while i<3
STDOUT.flush
name= gets.chomp
myarray.push(name)
myarray[i].capitalize!
i+=1
end
puts "\n"myarray.sort.each { i print i, "\n"}

workshop 4 - Ex 4.2

2009-04-12T23:20:00.000-07:00

1. While Ruby and Python are quite similar, can you find some similarities between Ruby and Javascript?

Ruby:
l Ruby's class-based design approach;
l There are four eval() functions in Ruby.
l Ruby is similar to Javascript 3.0 but without punctuation;
l Ruby has a “method” method that returns a reference to the specified method. This is mostly needed because of the blurred line between properties and methods.
l It provides some modules that are convenient to programmers. They are Module#method_missing, Module#included, Class#inherited and Module#const_missing

Javascript:
l Javascript is prototype-based design approach;
l It has only the basic eval() function.
l It’s widely deployed in most web browsers;
l It misses some magic method to allow dynamically, on-demand-generated runtime methods;
l They can have own properties which is not true for Ruby methods, they can be passed as arguments, and they can be bound and unbound at will.
l It doesn’t have the four modules as Ruby mentioned above.

Reference:
http://code.google.com/p/trimpath/wiki/RubyVsJavaScript
http://www.bias2build.com/thesis/ruby_v_js_MP.html

workshop 4 - Ex 4.1

2009-04-12T23:19:00.002-07:00

1. What are the syntax differences in the way that Ruby and Javascript use the if statement?

Ruby
An if statement with an else clause (the else clause is optional)

If syntax
if var == 10 print "Variable is 10″end

If Else Syntax
if var == 10 print "Variable is 10″else print "Variable is something else"end

If Else If Syntax
Here's the key difference between Ruby and most other languages. Note that "else if" is actually spelled "elsif" without the “e”.

if var == 10 print "Variable is 10″elsif var == "20″ print "Variable is 20″else print "Variable is something else"end

Java
If (booleanexpression){
Statement (s)
}
Or
If (booleanexpression){
Statement (s)
} else {
Statement (s)
}

Example 1
def add_definition(definition)
definition.word = self if definition.word != self
@definitions << definition
end

Example 2
def add_definition(definition)
if definition.word != self
definition.word = self
end
@definitions << definition
end
In the Java language, if the body of a conditional is a single line, you can drop the brackets. In Ruby, if the body of a conditional is a single line, you can write expressions like the one shown in example 1. Also note that the same conditional could also be written as definition.word = self unless definition.word == self, which uses Ruby's unless feature.
References:
http://www.ibm.com/developerworks/library/j-ruby/

workshop 2 - Ex 2.1

2009-04-12T23:19:00.001-07:00

1. What is meant by “convention over configuration” and how does it reduce coding?

"Convention over Configuration" means a developer only needs to specify unconventional aspects of the application. For example, if there is a class Sale in the model, the corresponding table in the database is called sales by default. It is only if one deviates from this convention, such as calling the table "products sold", that the developer needs to write code regarding these names. Generally, this leads to less code and less repetition.

"Don't repeat yourself" means that information is located in a single, unambiguous place. For example, using the ActiveRecord module of Rails, the developer does not need to specify database column names in class definitions.

Reference:
Ruby on Rails, Retrieving on 26 Mar 2009 from http://en.wikipedia.org/wiki/Ruby_on_Rails

workshop 1- Ex 1.6

2009-04-12T23:13:00.000-07:00

6. Describe the steps involved with the MVC design approach.
The Model-View-Controller and its application structuring paradigm for thinking about interactive application components were developed. First, we have to create the three main elements, Model, Controller and View.

Models are those components of the system application that actually do the work. They are kept quite distinct from views, which display aspects of the models. Controllers are used to send messages to the model, and provide the interface between the model with its associated views and the interactive user interface devices.
Each view may be thought of as being closely associated with a controller, each having exactly one model, but a model may have many view/controller pairs.

A change in a model is often triggered by a controller connecting a user action to a message sent to the model. This change should be reflected in all of its views, not just the view associated with the controller that initiated the change.

Dependents
To manage change notification, the notion of objects as dependents was developed. Views and controllers of a model are registered in a list as dependents of the model, to be informed whenever some aspect of the model is changed. When a model has changed, a message is broadcast to notify all of its dependents about the change. Each view or controller responds to the appropriate model changes in the appropriate manner.
The Interaction Cycle

The user takes some input action and the active controller notifies the model to change itself accordingly. The model carries out the prescribed operations, possibly changing its state, and broadcasts to its dependents that it has changed, possibly inform them the nature of the change. Views can then inquire of the model about its new state, and update their display if necessary. Controllers may change their method of interaction depending on the new state of the model. The following diagram shown the flow of the approach.

Reference:
Glenn Krasner & Stephen Pope, 1988, A Description of the Model-View-Controller User Interface Paradigm in the Smalltalk-80 System

Exercise 8-5: PHP and MySQL database access

2009-03-29T23:22:00.001-07:00

Exercise 8-4: PHP and MySQL database access

2009-03-29T23:21:00.000-07:00

Exercise 8-3: PHP and MySQL database access

2009-03-29T23:20:00.001-07:00

Exercise 8-2: PHP and MySQL database access

2009-03-29T23:19:00.001-07:00

Exercise 8-1: PHP and MySQL database access

2009-03-29T23:17:00.000-07:00

Exercise 7-2: User input for database access with PHP

2009-03-29T23:16:00.000-07:00

2. Then, create a PHP file named submit.php with the following code:

Exercise 7-1: User input for database access with PHP

2009-03-29T21:17:00.000-07:00

1.
Create an HTML page with the form:

Output:

Exercise 4-3: Virtual Private Networks

2009-03-29T20:52:00.000-07:00

3. What do you know about building e-business applications as an Intranet, Extranet, Web portal, B2B, B2C or Virtual Private Network (VPN)? Find some examples on the Web.

Infomatika is a leading e-Business consulting company specializing in providing B2B and B2C e-commerce solutions. Infomatika helps businesses implement Internet strategies from concept to launch, to help them achieve their Internet goals. (http://www.infomatika.com/)

Infomatika offers businesses a full spectrum of Internet and telecommunication services. These include e-Business consulting, application development, marketing, dial-up and dedicated access, and high-performance web hosting.

B2B: http://www.etrenchless.com/
Etrenchless.com was formed to deliver trenchless solutions by providing a global marketplace for the underground construction industry. Their solutions allow industry participants to buy and sell assets and inventory online, search for employees and purchase products from industry suppliers.

Services Rendered:

Consulting: Strategy,
Business Process
Development: Application Architecture, Application Development, Database Design, e-commerce and Auction System.

Functionality Provided:

Member Registration
Auction
Employment Search
Admin Module - Auction, Employment
Email Notifications - Auction

B2C: Online shopping(http://www.jshoppers.com/)

JSOPPERS is the online shop where Japanese fashion items and small goods can be purchased from 120 countries worldwide.People can purchase Nissen’s items from autumn 2005. People have to register and get their own account for purchasing. Electronic payment methods in this shop are PayPal, Credit card (Visa and Master cards), Alipay and PRC debit Card for Chinese. Transactions are protected by SSL. These products can be returned under its own policies.

VPN service: http://strongvpn.com/

This company provides VPN services as the following:

Security
Virtual firewall
Anonymous surfing
Hot spot users preventing password sniffing
Companies want to lock down access via static IP
International users blocked by Government control

Exercise 4-2: Virtual Private Networks

2009-03-29T20:50:00.001-07:00

2. Describe the TCP protocol. How is it related to the IP protocol?

The TCP provides reliable transmission of data in an IP environment. TCP corresponds to the transport layer (Layer 4) of the OSI reference model. Among the services TCP provides are stream data transfer, reliability, efficient flow control, full-duplex operation, and multiplexing.

With stream data transfer, TCP delivers an unstructured stream of bytes identified by sequence numbers. This service benefits applications because they do not have to chop data into blocks before handing it off to TCP. Instead, TCP groups bytes into segments and passes them to IP for delivery.

TCP offers reliability by providing connection-oriented, end-to-end reliable packet delivery through an internetwork. It does this by sequencing bytes with a forwarding acknowledgment number that indicates to the destination the next byte the source expects to receive. Bytes not acknowledged within a specified time period are retransmitted.

The reliability mechanism of TCP allows devices to deal with lost, delayed, duplicate, or misread packets. A time-out mechanism allows devices to detect lost packets and request retransmission.

TCP offers efficient flow control, which means that, when sending acknowledgments back to the source, the receiving TCP process indicates the highest sequence number it can receive without overflowing its internal buffers.

Full-duplex operation means that TCP processes can both send and receive at the same time. Finally, TCP's multiplexing means that numerous simultaneous upper-layer conversations can be multiplexed over a single connection.

The Internet Protocol (IP) is a routable protocol that handles IP addressing, routing, and the fragmentation and reassembly of packets.

TCP provides a one-to-one, connection-oriented, reliable communications service. TCP handles the establishment of a TCP connection, the sequencing and acknowledgment of packets sent, and the recovery of packets lost during transmission.

IP is a connectionless, unreliable datagram protocol primarily responsible for addressing and routing packets between hosts. Connectionless means that a session is not established before exchanging data. Unreliable means that delivery is not guaranteed. IP always makes a “best effort” attempt to deliver a packet. An IP packet might be lost, delivered out of sequence, duplicated, or delayed. IP does not attempt to recover from these types of errors. The acknowledgment of packets delivered and the recovery of lost packets is the responsibility of a higher-layer protocol, such as TCP.

For IP version 4, each TCP/IP host is identified by a logical IP address. The IP address is a Network layer address and has no dependence on the Data-Link layer address (such as a MAC address of a network adapter). A unique IP address is required for each host and network component that communicates using TCP/IP and can be assigned manually or by using Dynamic Host Configuration Protocol (DHCP).

The IP address identifies a system’s location on the network in the same way a street address identifies a house on a city block. Just as a street address must identify a unique residence, an IP address must be globally unique to the internetwork and have a uniform format.

References:
IP protocol-Internetworking Technology Handbook, Cisco, Retrieving on 20 Mar 2009, from
http://www.cisco.com/en/US/docs/internetworking/technology/handbook/Internet-Protocols.html#wp3632
How TCP/IP Works, Microsoft (March 28, 2003), Retrieving on 20 Mar 2009, from http://technet.microsoft.com/en-us/library/cc786128.aspx

Exercise 4-2: Virtual Private Networks

2009-03-29T20:50:00.000-07:00

2. Describe the TCP protocol. How is it related to the IP protocol?

The TCP provides reliable transmission of data in an IP environment. TCP corresponds to the transport layer (Layer 4) of the OSI reference model. Among the services that TCP provides are stream data transfer, reliability, efficient flow control, full-duplex operation, and multiplexing.

With stream data transfer, TCP delivers an unstructured stream of bytes identified by sequence numbers. This service benefits applications because they do not have to chop data into blocks before handing it off to TCP. Instead, TCP groups bytes into segments and passes them to IP for delivery.

TCP offers reliability by providing connection-oriented, end-to-end reliable packet delivery through an internetwork. It does this by sequencing bytes with a forwarding acknowledgment number that indicates to the destination the next byte the source expects to receive. Bytes not acknowledged within a specified time period are retransmitted. The reliability mechanism of TCP allows devices to deal with lost, delayed, duplicate, or misread packets. A time-out mechanism allows devices to detect lost packets and request retransmission.

TCP offers efficient flow control, which means that, when sending acknowledgments back to the source, the receiving TCP process indicates the highest sequence number it can receive without overflowing its internal buffers.
Full-duplex operation means that TCP processes can both send and receive at the same time. Finally, TCP's multiplexing means that numerous simultaneous upper-layer conversations can be multiplexed over a single connection. (Table 1)

The Internet Protocol (IP) is a routable protocol that handles IP addressing, routing, and the fragmentation and reassembly of packets.

TCP provides a one-to-one, connection-oriented, reliable communications service. TCP handles the establishment of a TCP connection, the sequencing and acknowledgment of packets sent, and the recovery of packets lost during transmission.

IP is a connectionless, unreliable datagram protocol primarily responsible for addressing and routing packets between hosts. IP always makes a “best effort” attempt to deliver a packet. An IP packet might be lost, delivered out of sequence, duplicated, or delayed. IP does not attempt to recover from these types of errors. The acknowledgment of packets delivered and the recovery of lost packets is the responsibility of a higher-layer protocol, such as TCP.

For IP version 4, each TCP/IP host is identified by a logical IP address. The IP address is a Network layer address and has no dependence on the Data-Link layer address (such as a MAC address of a network adapter). A unique IP address is required for each host and network component that communicates using TCP/IP and can be assigned manually or by using Dynamic Host Configuration Protocol (DHCP).

References:
IP protocol-Internetworking Technology Handbook, Cisco, Retrieving on 20 Mar 2009, from
http://www.cisco.com/en/US/docs/internetworking/technology/handbook/Internet-Protocols.html#wp3632

How TCP/IP Works, Microsoft (March 28, 2003), Retrieving on 20 Mar 2009, from http://technet.microsoft.com/en-us/library/cc786128.aspx

Exercise 4-1: Virtual Private Networks

2009-03-29T20:48:00.000-07:00

1. Describe the IP protocol. What is DNS?

The Internet protocols consist of a suite of communication protocols, such as Transmission Control Protocol (TCP) and the Internet Protocol (IP). (Cisco, 20 Mar, 2009)

Internet protocols were first developed in the mid-1970s, when the Defense Advanced Research Projects Agency (DARPA) became interested in establishing a packet-switched network that would facilitate communication between dissimilar computer systems at research institutions.
The Internet Protocol (IP) is a network-layer (Layer 3) protocol that contains addressing information and some control information that enables packets to be routed. IP is documented in RFC 791 and is the primary network-layer protocol in the Internet protocol suite. Along with the Transmission Control Protocol (TCP), IP represents the heart of the Internet protocols. IP has two primary responsibilities: providing connectionless, best-effort delivery of datagrams through an internetwork; and providing fragmentation and reassembly of datagrams to support data links with different maximum-transmission unit (MTU) sizes. (Table 1)

The Domain Name System (DNS) is the system in the Internet that maps names of objects (usually host names) into IP numbers or other resource record values. The name space of the Internet is divided into domains, and the responsibility for managing names within each domain is delegated, typically to systems within each domain.

The primary job that DNS performs is to map between names and numbers. Most importantly, it must provide the translation from host names to IP addresses, so that applications can effect a network connection from a command such as ftp prep.ai.mit.edu. Also, DNS must map from IP addresses back to names in order to provide some level of authentication, as with the r commands.

Reverse mapping from IP addresses to host names is performed under the auspices of the IN-ADDR.ARPA pseudo-domain. Because the order of significance in the naming system is highest on the right, the notation for addresses is reversed. Therefore, the DNS entry for the IP address 128.196.120.82 is given as 82.120.196.128.IN-ADDR.ARPA.

For example, all Internet systems that belong to the University of Arizona have names within the arizona.edu domain. The Internet's root name servers delegate the responsibility for managing the arizona.edu name space to a name server system operated by University of Arizona's CCIT Telecom (a system which also happens to be called arizona.edu with the IP addresses 128.196.128.233 and 128.196.128.234).

The Telecom name server can, in turn, delegate portions of the arizona.edu name space to departmental name servers on campus. By this system, the department gains a measure of autonomy in inventing and managing the names within its sub domain. For example, some or all of the sub domains of arizona.edu can be name served by various departments (such as Computer Science, Math, or Physics).

In addition to the Internet being divided namewise into domains and sub domains, such as arizona.edu for University of Arizona and apple.com for Apple Computer, it is divided numberwise into networks and subnets, such as 128.196.0.0 or 130.43.0.0. for University of Arizona and Apple, respectively. The namewise layout of the Internet tracks administrative responsibility, while the numberwise layout tracks physical topology.

There is no necessary relationship between the name(s) of an object in the Internet and its number(s). For example, the 128.196.0.0 network physically resides at the University of Arizona. However, if a machine that belongs to Apple were to be plugged into the University of Arizona network, its name would still be something.apple.com, even though its number would be 128.196.xxx.yyy. In this case, however, Apple and the University of Arizona would share name service responsibility for this system: Apple for the name-to-number name service, and University of Arizona for the number-to-name name service.

References:
IP protocol-Internetworking Technology Handbook, Cisco, Retrieving on 20 Mar 2009, from
http://www.cisco.com/en/US/docs/internetworking/technology/handbook/Internet-Protocols.html

Understanding the Domain Name System
http://www.cisco.com/en/US/tech/tk648/tk362/technologies_tech_note09186a00800c5e03.shtml

Exercise 1-1: Analysis of the online communitites paradigm

2009-03-29T20:21:00.000-07:00

a. What is meant by an online community and how is it important for e-commerce?
There is no unique definition of ‘online community’ as it can be meant differently to different people (Preece, 2000). Some people viewed online community as a social phenomenon; others believed that it is a structure of the supporting software.
Arens (2008) believed that ‘online communities are the primary enabler of social media, providing the audience, motivation, and system for users to create and distribute content. If today there is any community which is not based on caste, creed or culture then it’s this online community. Internet is the sole reason for emergence of this community.’ Therefore, it has attracted a group of people (with similar goals or interest) who primarily interact via computer network to connect and exchange information (Owyang, 2008). Yahoo can be a good example. Yahoo is served as a channel for both (public and private) of the Internet community. It has an impact on society – there will be a closed-tie in relative relationship and also people with similar interest. Furthermore, it allows consumers to work in ways that are impossible before.
However, online community can also be technically defined as it can be described as supporting software, such as chat, bulletin board and web-based communities (Preece, 2001); Zope is an example. Zope is a large and very busy community for web application developers and electronic businesses. It can provide solutions.

Online community is important for e-commerce by:
E-commerce entrepreneurs take a very broad view of community. Any communications software that can be added to a web site is regarded as an online community.

Reference:
Yahoo, Retrieving on 15 mar 2009, from http://docs.yahoo.com/info/values/

Whittaker, S., Issacs, E., & O'Day, V. (1997). Widening the net. Workshop report on the theory and practice of physical and network communities. SIGCHI Bulletin, 29(3), 27-30.

ZOPE, retrieving on 15 mar 2009, from http://wiki.zope.org/zope2/IntroductionToZope

b.
i. Is there a common thread and a local community sense in action?
The answer is yes. Among these three auctions sites of ebay in different countries, the common thread in action is trust between sellers and bidders. Since the sellers and bidders won’t meet one another face to face before having the transactions, so they need to have trust in each other in order to have a complete transactions (Kollmann, 2001). As a result, Ebay auction system has created its own “community trust” to constraint the users to be honest and ethical in their transactions. (Rothenbuhler, 1991)

ii. What electronic payment systems are used? Are they globally acceptable?
The electronic payment systems are used included credit card, debit card networks and ACH (Automated Clearing House) network. These methods are globally acceptable. However, there are some which can only be accepted in particular areas, such as paypal which is not acceptable in Macau SAR.

iii. What are the benefits to of an online auction sale to a buyer, a seller and E-bay owners?
Buyer – It saves time and is convenient to the buyers as they do not need to go from places to places to find the products; they can browse as many categories of goods as they want at once. There are some same or similar products that are shown in the website; therefore, the buyers can easily make a comparison on the cost of the products from different sellers.

Sellers – There will not have time limitation to the sellers. They can run their business even in 24 hours a day and 7days a week. In addition, they are not restricted by the geography. It reduces costs of operations and provides flexibility. They may not need to pay taxes as they are selling products in the Internet.

E-bay owners – They earn from the sold products. They build up a community of auction business and helpfulness to this industry.

Reference:
Ebay.com, retrieving 16 mar 2009 from http://pages.ebay.com.my/help/pay/methods.html
John Boyd (2002), In Community We Trust: Online Security Communication at eBay, CERIAS Tech Report 2002-19, P.5
Kollman, T. (2001). Measuring the acceptance of electronic marketplaces: A study based on a used-car trading site. Journal of Computer-Mediated Communication, 6:2. Retrieved 15 Mar 2009, from http://jcmc.indiana.edu/vol6/issue2/kollmann.html
Rothenbuhler, E. W. (1991). The process of community involvement. Communication Monographs, 58, 63-78.

c. Find three others examples of an online business using an online community approach.
Three others examples of online businesses using online community approach:
1. http://bizica.com/bizica/
Bizica.com is an online community directly connecting you with businesses in your neighborhood. Bizica provides the functions such as: (a) find and communicate with great neighborhood businesses; (b) shop and browse products or services; (c) compare businesses and receive reviews; (d) discover sales and business news and (e) discuss the issues of your neighborhood.

2. http://www.threadless.com/
Threadless is a community-based tee shirt company with an ongoing, open call for design submissions. It is a popular online t-shirt design business and its first store opened in Chicago. The designers submitted their designs to the Threadless store. The designers will be paid after scoring by Threadless.

3. http://www.agork.com/
With Agork, you get all the amazing services available today on the internet: blogs, forums, files sharing, micro-blogging, news, articles, knowledge base, media gallery, personal pages - all ready to let your community start sharing and all integrated into one single platform. All this power continues to expand through the development of new modules and is highly usable due to the clean and simple user interface.

Reference:
Bizica.com, Retrieving on 15 mar 2009, from http://www.bizica.com/bizica/about-bizica.html

Agork.com, Retrieving on 15 mar 09, from
http://www.agork.com

Threadless.com, Retrieving on 15 mar 2009, from http://www.threadless.com/

Exercise 6-2: Some server practice with PHP

2009-03-29T20:12:00.000-07:00

Exercise 6.2
2. Create a web application called "hello_world.php" which contains in the body:

Exercise 6-1: Some server practice with PHP

2009-03-29T19:53:00.000-07:00

Exercise 6-1
1.In this exercise with can call up and examine some environment variables on the server. The code below has the UNIX environment variable for storing your remote Internet address. UNIX environment variable are recognised by the use of upper case letters. Try the same code by replacing with $REMOTE_ADDR $SERVER_NAME, or $PHP_SELF

a).

b).

c).

Exercise 4-4: Virtual Private Networks

2009-03-27T22:22:00.000-07:00

4. What role can a VPN play in business-to-business e-commerce?

Remote Working

Work smarter with VPN wouldn't it be great to be able to switch on PDAs or laptops or desktops while away from the office and to be able to read company e-mail, upload and download files, see reports and work other employees are working on, work on projects, files, spreadsheets and databases together.

It allows users to connect to database from anywhere via the Internet securely and safely, 24 hours a day, 7 days a week and the only cost is the Internet connection fee.

Office to Office VPN
With VPN is as also possible to cheaply connect two or more offices together to allow them to work as one. The Broadband connection carries your data between offices which is secure and fast. Share files, printers and more in another remote office.

Summary - The Advantages of VPNs

Link Remote offices using the public Internet
No district limitation across the world
Keep the company confidential data behind the firewall
High-Security encryption
Users can use different kinds of connection method to connect the VPN (such as ADSL, Cable Modem, ISDN or dial-up modem)
Save huge sums of money against leased lines or direct dial-up access
Support for multiple simultaneous tunnels
Remote offices can be set up quickly, or temporarily deployed

Protocol: Most VPN routers support IPSec Tunnelling, PPTP, L2TP and L2TP over IPSec.

http://www1.alcatel-lucent.com/bnd/bvs/VPN_Poster_May08.pdf

http://www.vpn-for-business.co.uk/

Exercise 3: Finding some common ground

2009-03-27T20:55:00.000-07:00

Describe the steps involved with the Rapid Evolutionary Prototyping Approach as it applies to developing a Web application.

The Evolutionary prototype model for web application

The Evolutionary prototype model generally reduces development time compared with traditional methods, but makes it more difficult to predict when the project would be completed. In the daily build approach, the entire product is built everyday. This approach addresses the schedule risks and eliminates some of the risks that can cause extreme delays like integration problems, too many defects, missing requirements and lack of progress visibility.

The merits of Evolutionary prototype model make it extremely suitable for web projects. We can expect
1. Improved customer relations
2. Reduced or better used human resources
3. Potential knowledge gathered via customer interaction with the web site
This model is a way for the project team/ developers to exchange information with customers to the benefit of everyone involved. This process is likely to replace or at least reduce the movement of email/correspondence within the project team and between the project team and the customer/client. Hardware, software , people , data and procedures all play an important role in making the process a success. Proper technology must be used to increase the speed of information transmission .Hardware must be fast enough and big enough to transmit and store the information needed to operate. Advanced software must take advantage of the hardware available.

The most common risks with the Evolutionary prototype model for web projects are as follows:
1. Unrealistic customer expectations
Improved visibility of the work in progress can lead to unrealistic customer schedule expectations. It may be easy to complete the most visible work at a faster pace, but a great deal of the work may not be obvious to the customer or end user.
2. Poor end user or customer feedback
Prototyping does not guarantee high quality feedback from the end user/ customer.
3. Poor product performance
4. Poorly structured and inefficient code developed quickly for the prototype may contribute to low performance of the product.
5. Unrealistic performance expectations
6. The initial prototypes often have much better performance than the final product. This is because the prototype does not incorporate the functionality of the final product.
7. Poor design
The factors contributing to design deterioration are patches being added to the original design and the product taking a direction totally unanticipated at the design phase.
8. Feature creep
As the customers and end users have direct access to the prototype, the list of features desired may increase indefinitely.

The Evolutionary prototype model generally decreases development time compared with traditional methods, but makes it more difficult to predict when the project would be completed.

Reference:
Madhavi K., Alice Jacob, EVOLUTIONARY PROTOTYPE MODEL FOR WEB PROJECTS, Retrieving on 21 Mar 2009, from http://www.nestsoftware.com

How is it related to agile development?
Customer plays an important role in either EP or agile development, so both are customer centric. In addition, both of them pay more attention on the working piece of code for software product rather than its documentation. Since both of them have the iterative nature of development, management can be clearly carried even though there are changes – a change could be addressed in the next iteration. Therefore, E, steps involved in EP and agile development are similar. It can be explained as in the diagram (Kamlesh & Ahmad, 2008).

A relationship between EP and agile development

Exercise 2: Technology and the evolution of business options

2009-03-27T19:30:00.000-07:00

Web quest: Find a range of five sites each offering different business options: online shopping, electronic payments, database access, WAP sites for mobile phones. Key words for your search engine: M-commerce, T-commerce and E-wallet.

The sites are:

Online shopping: JSHOPPERS.com (http://www.jshoppers.com)
JSOPPERS is the online shop which sells Japanese fashion items and accessories. All these can be purchased to 120 countries worldwide.

People can purchase Nissen’s (Nissen is the biggest mail order company in Japan) items from autumn 2005. People have to register and get their own account for purchasing.

Electronic payment methods in this shop are PayPal, Credit card (Visa and Master cards), Alipay and PRC debit Card for Chinese. Transactions are protected by SSL. These products can be returned under its own policies.

Electronic payments: Alipay.com (https://www.alipay.com/)
Alipay.com Co.,Ltd (AliPay) is one of the China’s leading online payment service by both the number of users and the total transaction volume. It enables individuals and businesses to send and receive payments online securely, easily and quickly. AliPay works like an escrow service, solving the issue of settlement risk in China.

AliPay’s products and services are built on trust. Not only does AliPay guarantee the safety of each online transaction, but also it helps Internet users to create their own trust profile which fosters a safe online payment environment.

Database access: selectory.com (http://www.selectory.com/)
D&B® is the leading provider of global business information, tools and insight, enabling our customers to Decide with Confidence for over 160 years.D&B helps you find to new customers, increase sales and manage business risk with a full array of online information solutions.

The D&B global database of company information is the foundation for products specializing in prospecting, sales intelligence, risk and credit management, and data cleanse and append. These products allow the businessmen to grow their business and protect their cash flow - all from one trusted source – The Selectory database. It is from D&B which is backed by the patented DUNSRightTM data quality process. DUNSRight consists of more than 2,000 automated checks to guarantee that all company profiles are as complete, accurate and timely as possible. Only DUNSRight gives the industry-leading mail deliverability and phone connectivity.

WAP services for mobile phones: CTM (http://mobiweb.ctm-mobile.com/)
Companhia de Telecomuniçães de Macau S.A.R.L (CTM) is a GSM mobile phone operator and monopoly Internet Service provider in Macau. By using the WAP services from CTM, customers can enjoy the following services: such as Music, News, Finance & Real Estate information, Mobile Banking, Sports, CyberCTM Member Zone, Hung San Chon (a metaphysics expert), MSN, Games, Trendy, Disney Mobile, M-Magazine, Adult Zone, General Enquires, About Macau and CTM News.

E-Wallets: Ilium Software (http://www.iliumsoft.com/)
Ilium offers mobile software for mobile devices. eWallet® helps users protect themselves by keeping their passwords safe, but easy for them to access when they need them. It even stores the security v

erification questions that companies ask the users. Besides, users can synchronize their cards or files with eWallet on their Windows PC.

Store Your Information Securely - Using government-level (FIPS) 256-bit AES encryption, eWallet protects your personal information from falling into the wrong hands.
Never Forget Another Password - eWallet remembers your passwords so you don't have to. Create strong passwords for online banking and more - stop choosing weak passwords just so you won't forget!

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Workshop 1 - Ex 1.5

2009-03-12T23:12:00.000-07:00

5. When did Model-View-Controller begin and where is it used?
MVC was conceived in 1978 as the design solution to a particular problem. The goal was to support the user's mental model of the relevant information space and to enable the user to inspect and edit this information.

Model-View-Controller (MVC) programming is the application of this three-way factoring, whereby objects of different classes take over the operations related to the application domain (the model), the display of the application's state (the view), and the user interaction with the model and the view (the controller). In earlier Smalltalk system user interfaces, the tools that were put into the interface tended to consist of arrangements of four basic viewing idioms: paragraphs of text, lists of text (menus), choice "buttons," and graphical forms (bit- or pixel-maps). These tools also tended to use three basic user interaction paradigms: browsing, inspecting and editing. A goal
of the current Smalltalk-80 system was to be able to define user interface components for handling these idioms and paradigms once, and share them among all the programming environment tools and user-written applications using the methodology of MVC programming.

Reference:
Trygve Reenskaug, 2003, The Model-View-Controller (MVC)
Its Past and Present

Glenn E. Krasner and Stephen T. Pope, 1988, A Description of the Model-View-Controller User Interface Paradigm in the Smalltalk-80 System

Workshop 1 - Ex 1.4

2009-03-12T18:45:00.000-07:00

2. What is meant by “convention over configuration” in regards to the use of Rails
in Web application development?

"Convention over Configuration" means a developer only needs to specify unconventional aspects of the application. For example, if there is a class Sale in the model, the corresponding table in the database is called sales by default. It is only if one deviates from this convention, such as calling the table "products sold", that the developer needs to write code regarding these names. Generally, this leads to less code and less repetition.

"Don't repeat yourself" means that information is located in a single, unambiguous place. For example, using the ActiveRecord module of Rails, the developer does not need to specify database column names in class definitions.

Reference:
Ruby on Rails, Retrieving on 26 Mar 2009 from http://en.wikipedia.org/wiki/Ruby_on_Rails

Workshop 1 - Ex 1.3

2009-03-12T18:42:00.000-07:00

What is Rails and how does it work with Ruby?

Rails is a web development framework written in the Ruby language. It is designed to make programming web applications easier by making several assumptions about what every developer needs to get started. It allows you to write less code while accomplishing more than many other languages and frameworks. Longtime Rails developers also report that it makes web application development more fun.

Rails is opinionated software. That is, it assumes that there is a best way to do things, and it’s designed to encourage that best way – and in some cases to discourage alternatives. If you learn “The Rails Way” you’ll probably discover a tremendous increase in productivity. If you persist in bringing old habits from other languages to your Rails development, and trying to use patterns you learned elsewhere, you may have a less happy experience.

The Rails philosophy includes several guiding principles:

Rails has the following properties:
l Convention over configuration: application uses a few simple programming conventions that allow it to figure everything out through reflection and discovery.
l Less code: It can automatically handle many lower-level details without you having to tell it to do so.
l Generators: Rails' use of runtime reflection and metaprogramming eliminates much of the template code that you would have to create
l Zero turnaround time: The typical development cycle for testing a change to a web app has steps such as configure, compile, deploy, reset, and test. This is very time consuming. The Rails development environment has none of this.
l Scaffolding: Rails can automatically create a full set of CRUD (Create, Retrieve, Update, and Delete) operations and views on any database table. This scaffolding can get you up and running quickly with manipulating your database tables.

Reference:

Rails Guides, 13 mar 2009. Retrieving from http://guides.rubyonrails.org/getting_started.html

Curt Hibbs, 10 2005, What Is Ruby on Rails, retrieving on 1 Apr 2009 on http://www.onlamp.com/pub/a/onlamp/2005/10/13/what_is_rails.html

Workshop 1 - EX 1.2

2009-03-11T20:43:00.000-07:00

2. Ruby is “an interpreted scripting language” for quick and easy object-oriented programming”. Find out about the Ruby language and discover what this means.
Ruby is an interpreted scripting language for quick and easy object-oriented programming
Interpreted scripting language:
l ability to make operating system calls directly
l powerful string operations and regular expressions
l immediate feedback during development

Quick and easy:
l variable declarations are unnecessary
l variables are not typed
l syntax is simple and consistent
l memory management is automatic

Object oriented programming:
l everything is an object
l classes, methods, inheritance, etc.
l singleton methods
l "mixin" functionality by module
l iterators and closures

Other properties:
l multiple precision integers
l convenient exception processing
l dynamic loading
l threading support

Reference:
Ruby guides, Retrieving on 20 mar 0209 from http://guides.rubyonrails.org/getting_started.html

Workshop 1 - EX 1.1

2009-03-09T20:24:00.000-07:00

1. Make a list of all programming languages and Web development tools used by you in prior experiences. Describe what you know about Web application frameworks before we begin.

In my past study, I learnt the following programming languages:

LOGO, GWBASIC, BASIC, COBOL, C++, Common LISP, Java 6.0, Pascal, Visual Basic 6.0, SQL, VBA, etc...

Web development tools:
Frontpage, ASP 3.0, ASP.NET 3.5, Dreamweaver CS3 and visual web developer 2008 Express, etc...

A web application framework is a software framework that is designed to support the development of dynamic websites, web applications and web services. The framework aims to reduce the overhead associated with common activities used in web development.

Ruby on Rails (RoR) is a free open source web development framework based on Model-View-Controller with Ruby language to develop rapidly data-driven web applications. Ruby is a highly developer friendly, reflective and object-oriented language with features inspired from PERL, Python, Small talk, Lisp.

Reference:
Ruby on Raiils, 12 Mar 2009, Retrieving from http://rubyonrails.org/

Exercise 1-2: Analysis of the online communitites paradigm

2009-03-05T19:09:00.000-08:00

2.
a. Why has it been a successful site? How does the purchase of a book work?
Amazon has been a successful site due to the following reasons:
² Amazon is an online shopping website with one of the largest product supplies online. It is one of the first companies that sells products by housing them all in numerous warehouses and distributing products from many partner companies.
² Amazon is using cash to escape from debt. Few companies’ operations are that healthy, and the ones that are will likely emerge from the recession much stronger than their competitors.
² Amazon’s hard-line adherence to its basic strategy — keep the prices low, and the experience easy — cost it a lot of debt early on and a lot of short-term profit ever since. But now the company’s debt is being paid off and the cash on hand is growing.
² The recession is far from over, and like all companies, Amazon faces its share of challenges. But there is emerging in the company’s short history an important lesson for tech companies: Find a clear vision and, not matter how fast things change or how impatient others become, stick with it. It’s a very hard road to take. But at least it’s simple.

B. Is there any secure transactions not involving money?
Yes, there is. The membership management of Amazon.com is protected by SSL which provide a certain level of security.

C. What is the range of items that you can buy? List the steps involved and comment.
You can buy several categories of products as the following:

Books
Movies, Music & Games
Digital Downloads
Kindle
Computers & Office
Electronics
Home & Garden
Grocery, Health & Beauty
Apparel, Shoes & Jewelry
Sports & Outdoors
Tools, Auto & Industrial

The steps of buying a book:
For example, to buy the book “Developing Distributed And E-commerce Applications”
(ISBN: 9780321154224), Author: Ince, Publisher: Addison Wesley

Login into the Amazon membership account

Select the category as "Book"

Search with the ISBN; type the ISBN in the textbox;

Select the desired item;

Check the information of the chosen book;

Click to buy a new one book;

Add the item to the shopping cart;

then go to the payment method page, choose the payment method, such as creidt cards or Paypal;

check the order and wait for the shippment;

Introduction

2009-03-04T16:18:00.000-08:00

HI, everyone. I am Bill. I am a teacher for a secondary school in Macao.

I am studying MIT from CSU. This blog is used for ITC594 E-systems infrastructure.