Network Devices

What is a switch ?? A network switch or switching hub is a computer networking device that connects network segments or network devices. In the traditional circuit-switched telephone network, one or more switches are used to set up a dedicated though temporary connection or circuit for an exchange between two or more parties. On an Ethernet local area network (LAN), a switch determines from the physical device (Media Access Control or MAC) address in each incoming message frame which output port to forward it to and out of. In a wide area packet-switched network such as the Internet, a switch determines from the IP address in each packet which output port to use for the next part of its trip to the intended destination. Switch Function : switch is a telecommunication device which receives a message from any device connected to it and then transmits the message only to that device for which the message was meant. This makes the switch a more intelligent device than a hub

Wikis ??!!

We always use the website wikipedia as our rresearch reference , but what is a wiki exactly and what features it offers ?? Wiki is an Hawaiian word meaning "fast" or "quick". It is a piece of server software that allows users to freely create and edit Web page content using any Web browser. Ward Cunningham, was the developer of the first wiki software, WikiWikiWeb, originally described it as "the simplest online database that could possibly work. Moreover,Wiki supports hyperlinks and has a simple text syntax for creating new pages and crosslinks between internal pages on the fly.

Wiki is unusual among group communication mechanisms in that it allows the organization of contributions to be edited in addition to the content itself. Like many simple concepts, "open editing" has some profound and subtle effects on Wiki usage. Allowing everyday users to create and edit any page in a Web site is exciting in that it encourages democratic use of the Web and promotes content composition by nontechnical users. What is Wikispaces Private Label? A Wikispaces Private Label site is a secure, dedicated wiki environment — like a clone of Wikispaces.com, but with your organization’s DNA mixed in. You get unlimited wikis (and everything you need to manage them), plus tools to integrate the site with your other systems and support your users. Furthermore you can Make changes to any page on your wiki from any computer or web-enabled device, you can also create rich appealing pages that contains widgets like video, calendars, and visitor counters can make your wiki more attractive, engaging, and useful.

THE DIGITAL DIVIDE

The Digital Divide, or the digital split, is a social issue referring to the differing amount of information between those who have access to the Internet and those who do not have access. The term became popular among concerned parties, such as scholars, policy makers, and advocacy groups, in the late 1990s. Dimensions of the Divide Broadly speaking, the difference is not necessarily determined by the access to the Internet, but by access to ICT and to Media that the different segments of society can use. With regards to the Internet, the access is only one aspect, other factors such as the quality of connection and related services should be considered. Today the most discussed issue is the availability of the access at an affordable cost. The digital divide is not indeed a clear single gap which divides a society into two groups. Researchers report that disadvantage can take such forms as lower-performance computers, lower-quality or high price connections (i.e. narrowband or dialup connection), difficulty of obtaining technical assistance, and lower access to subscription-based contents. Over coming the digital divide : even though individuals might be capable of accessing the Internet, many are thwarted by barriers to entry such as a lack of means to infrastructure or the inability to comprehend the information that the Internet provides. Lack of adequate infrastructure and lack of knowledge are two major obstacles that impede mass connectivity. These barriers limit individuals' capabilities in what they can do and what they can achieve in accessing technology. Some individuals have the ability to connect, but have nonfunctioning capabilities in that they do not have the knowledge to use what information ICTs and Internet technologies provide them. This leads to a focus on capabilities and skills, as well as awareness to move from mere access to effective usage of ICT[19]. The United Nations is aiming to raise awareness of the divide by way of the World Information Society Day which has taken place yearly since May 17, 2001.[ THANKS FOR READING , I HOPE YOU ENJOYED IT , IF YOU HAVE ANY QUESTIONS AM READY TO ANSWER :)

Applications of Expert System

Hello Every one..
we have recently studies in ICT class abou "Expert Systems" and after the lesson we were asked to publish a post about some of applications of an Expert system.

What is an Expert System ?

An expert system is computer software that attempts to act like a human expert on a particular subject area.
Expert systems are often used to advise non-experts in situations where a human expert in unavailable (for example it may be too expensive to employ a human expert, or it might be a difficult to reach location).

Some Application of an Expert System :

1- Highly interactive or conversational applications, IVR, voice server, chatterbot

2- Fault diagnosis for example examining a car in a garage.

3- Medical diagnosis.

4- Educational software.

5- Decision support in complex systems like interactive user guide and Tutorials softwares.

6- Providing financial advice

7- Helping to identify items such as plants / animals / rocks / etc

8- Playing strategy games like chess against a computer (the knowledge base would contain strategies and moves, the player's moves would be used as the query, and the output would be the computer's 'expert' moves)

THANKS FOR READING

Analysing a System (Flow Charts and Flow Diagrams)

When analysing a system the analyst after finishing the stsge of information collection and then selecting the output and input methods he reaches to a stage of Recording information about the system.In this stage the analyst can use data flow and data diagram charts to make this stage easier.
And in this post am gonna write about about the system data flow diagram and the others...

1- Program flow charts

Program flow charts are a way of displaying how data flows in a system and how decisions are made to control events.

To illustrate this, symbols are used. They are connected together to show what happens to data and where it goes. The basic ones include:

2- System Flow charts

A system flow chart is used to show how data in a computer system is processed. It does not involve the complex detail of the porgram instructions(which are represented by the porgram flow charts) but it gives a broad view of the system operation.

Example :

Data Flow Diagrams:

Data Flow Diagram (DFD) is an important technique for modeling a system’s high-level detail by showing how input data is transformed to output results through a sequence of functional transformations. DFDs reveal relationships among and between the various components in a program or system.
DFDs consists of four major components: entities, processes, data stores and data flows.

Example :

Process flow diagram :

A process flow diagram (PFD) is a diagram commonly used in engineering to indicate the general flow of plant processes and equipment. The PFD displays the relationship between major equipment of a plant facility and does not show minor details such as piping details and designations. Another commonly-used term for a PFD is a flowsheet. Typically, process flow diagrams of a single unit process will include the following:

Process piping
Major bypass and recirculation lines
Major equipment symbols, names and identification numbers
Flow directions
Control loops that affect operation of the system
Interconnection with other systems
System ratings and operational values as minimum, normal and maximum flow, temperature and pressure
Composition of fluids

Example :

THE END....

Designing a New System

After analysing the system the analyst has to design a new software ,programs,fourms etc...
In short design a new system different than the old one.

In most cases the new system will be computer-based. The ease with which computers can communicate and process data means that are usually the best tool for the job.

In the designing stage the analyst has to design most of the system parts like:
1- Designing the System Inputs
2- Choosing the Best Data Capture and Data Input Methods for the System
3- Designing On-Screen Forms for Data Input
4- Setting Data Validation Techniques
5- Setting Data Verification Techniques
6- Designing the System Processes
7- Designing the How the Data Will be Processed
8- Designing the System Outputs
9- Designing Printed Reports

1- Designing the system inputs :

To get data into a system is a two-part process:

- Data must first be ‘captured’ (collected in a way that then makes it easy to input)

- Data must be input into the computer

The systems analyst will select a data capture method and data input method that best suit the requirements of the new system.

Data capture and input methods:
* Manuall
* Paper Forms (Form can be a simple ones with spaces for numbers and text to be written in. The data form this form would then be typed into the computer)
Forms can also be machine-readable, such as OMR forms

* Barcode Reader (Barcode readers capture the numeric code that the barcode represents.
Typically used with POS systems and also stock-control systems)

* Card Reader (Many cards contain data stored on a magnetic strip or in a small bit of memory (smart cards) which can be captured with a card reader,used in systems such as EFTPOS)

* Camera ( Capture still or moving images which can then be input to a computer for processing)

* Fingerprint reader (employees could put a finger on the reader at the start and end of work (hard to cheat) )

The system life cycle (System Analysis)

hi every one iil be talking today about system life cycle and and speceficaly system analysis....

System analysis is defined as the examining the existing system in detail like collecting information on how the system works , recording information (data flow diagrams) and finaly identifying problems associated with the system.

Methods of collecting information :

1- Examining documents.

2- Interviews.

3- Observation.

4- Questionnaires.

Examining documents : It is a method where an analysist should go through or check an system documents like invoices , letters , order forms , payslips , bills etc...