Review & Summarize Part 2 !!

Chapter 9- Communications and Networks

We experiences communication every day in everywhere with people around us. Our communication system changes with the rapid change of technology. There are many communication systems such as email, instant messaging, internet telephone and electronic commerce.

Communication systems consists 4 basic elements which are sending and receiving devices such as computer, communication channel such as coaxial cable and infrared, connection devices such as modems and data transmission specifications such as bandwidth and protocols. 

In early stage, we can only communicate when we meet face to face but now we can just communicate with computer by network system. Local area network (LANs), Wireless LANs (WLANs), Personal area network (PANs) and Wide area networks (WANs) are the network types. 

Besides that we refer to network architecture to learn how computer network is configured (Topologies) and what strategies are employed. There are six types of topologies which are bus, ring, star, tree, hybrid and mesh. Bus and ring are older and less efficient (because pass message from device to device in sequences) types topologies. For todays, star and hybrid are more commonly in uses because it less likely to break down, more efficient and better security. And mesh network is the newest and most efficient topologies. 

To share information and resources, we need strategies which terminal server, client/server network and peer to peer 3 common strategies that been used by today. 

Besides that for the organization which have bigger capacity, there using the intranets and extranets to communicate among inside such as employees and outside such as supplier. They prefer use firewall to protect their network system against external threat.

Chapter 10- Privacy and Security

Privacy and security for computer and network become important since the increasing demand in used of network. For today world there are a lot of data flow in the network systems and this do present some opportunities for business by create some business such as information resellers which collect data and sell the personal data. 

For this it also present some ethical dilemma problems such as identify theft (illegal assumption of other identity) and mistaken identity (electronic profile been switched with other). 

The snoopware which allows organization monitor employees email and the illusion of anonymity lower the level of privacy. Besides the spyware which secretly record and report individual activities such as Ad network also lower the privacy level. 

Somehow we can use antispyware to remove spyware by detects the Web bugs and monitoring software and there are some laws governing privacy matters.

Both hackers and crackers are include in computer criminals but hackers who create or improve and share programs with fellow hackers typically are not criminals but crackers who share programs designed to gain unauthorized access to computer systems typically are criminals. 

To protect the security from malware or virus, we can use antivirus to gains alert when certain viruses entre the computer systems. 

In addition the Denial of services attack (DoS) which is an attempt to shut down the computer and scams which are fraudulent acts designed to trick individuals into spending money without return are also lower the level of security. 

There are also some laws to protect against security such as Digital Millennium Copyright Act protecting the software privacy and Computer Fraud and Abuse Act help protect against data manipulation.  

In addition, we can increase our security level by encrypting, restricting access by biometric scanning devices, password and firewalls. 

Ergonomics is the study of human factors related to things people use. 

To all users computer, we need to know the correct way to sit, rest and other when using the computer to avoid injuries. This will enhance our well-being.

Besides that, we should also become a responsible user such as supporting the green pc concept and conserving energy by turn off the computer at night.

Chapter 11- Information systems

Nowadays effective manage the information flow in an organization is important to any organization. Different functions in an organization using the information to achieve different objective and goal. 

Overall there are 3 management levels which are top level, middle level and supervisor. Top level management focus on long range and overall planning, middle level management focuses on deal with strategies to successful the planning from the top level and the supervisor monitoring the activities of worker day by day. 

Different management level has different information flow. For top level management, the information flow is primarily upward from within the organization and into the organization from the outside. For middle level management, the information flow is horizontal and vertical within department and for supervisors, the information flow is vertical. 

Because the different in level of management, there is also different in information systems used in each level. For transaction processing system (TPS) which record the day to day transaction, it suitable for level supervisors. 

While for middle level management which requires does a lot of control and decision making to support the planning from the top management, they often use management information systems (MIS) which produce predetermined periodic, exception and demand reports and decision support systems (DSS) which enable managers to get answer for unanticipated questions. 

Lastly for the top level management, they prefer use executive support systems (ESS) which summarize and analyzed data in an easy way. This enable the top level management does their planning accurately without waste time. 

Besides the four information systems, there still a lot of other information systems that use to support the information worker. 

There are two types which the first is office automation systems (OAS) which used to support data workers who are involved with distribution and communication of information such as project managers and videoconferencing systems. 

The second is knowledge work systems (KWS) which used to support knowledge workers who create information such as engineers use computer aided design/ computer aided manufacturing (CAD/CAM) systems.

Chapter 12- Database

A database is a set of data that has a regular structure and that is organized in such a way that a computer can easily find the desired information.

Data is a collection of distinct pieces of information, particularly information that has been formatted (i.e., organized) in some specific way for use in analysis or making decisions.

More information about database... Can visit http://www.filemaker.com/solutions/database-basics/database-management.html...which not only computer are using database system but also Apple product such as iPhone 4 and also Ipad 1 & ipad 2...

Chapter 13- System analysis and design

Specification of an information system is given by their

    Structure: How it is organized.

    Function: What it does.

    Behavior: How it responds to events and stimuli.

    Data: Its meaning and organization.

There are many methodologies for the development of information systems: Systems Development Life Cycle (SDLC), Data Structure-Oriented design, Object-Oriented design, Prototyping, among others. We shall, however, be concerned here primarily with SDLC

The methodology SDLC is closely linked to what has come to be known as structured systems analysis & design. It involves a series of steps to be undertaken in the development of information systems as follows:

Problem definition: On receiving a request from the user for systems development, an investigation is conducted to state the problem to be solved.

Deliverables: Problem statement.

Feasibility study: The objective here is to clearly define the scope and objectives of the systems project, and to identify alternative solutions to the problem defined earlier.

Deliverables: Feasibility report.

Systems analysis phase: The present system is investigated and its specifications documented. They should contain our understanding of HOW the present system works and WHAT it does.

Deliverables: Specifications of the present system.

Systems design phase: The specifications of the present system are studied to determine what changes will be needed to incorporate the user needs not met by the system presently. The output of this phase will consist of the specifications, which must describe both WHAT the proposed system will do and HOW it will work. of the proposed system.

Deliverables: Specifications of the proposed system.

Systems construction: Programming the system, and development of user documentation for the system as well as the programs.

Deliverables: Programs, their documentation, and user manuals.

System testing & evaluation: Testing, verification and validation of the system just built.

Deliverables: Test and evaluation results and the system ready to be delivered to the user/client.

Chapter 14- Programming Languages

A digital computer language is a group of words or numbers that people use to issue commands to computers. Like human languages, computer languages use their own vocabulary and syntax (grammar) to convey specific meanings (semantics).

A low-level language is closely related to what the computer can execute directly, and is usually created for a specific computer. Examples are machine languages (sometimes called first generation languages) and second generation assembly languages.

A machine language consists of sets of numbers, letters, or symbols that the machine recognizes as an operation to be carried out and the rules for doing so. Typically each instruction carries a symbol, called a label or tag that identifies it and a memory address (location) for the data that it will use.

A computer operates on the principle of binary (base 2) numbers, with zero and one representing the two electrical states. To make it easier for programmers to write in machine language

Because machine language can be difficult to remember, assembly language was created. It uses some abbreviations of human language as symbols, such as MPY for multiply. It also uses symbolic names for memory addresses and data.

A high-level language uses very carefully defined human words as instructions. This allows use of the language on computers with different architectures (designs). The instructions must be translated into machine language before execution.

High-level, procedure-oriented languages, such as FORTRAN, COBOL, and BASIC, are procedure-oriented, meaning that they implement procedures or algorithms.

Fourth-generation languages are non-procedural and use English-like words to specify results, rather than the steps leading to the results. They are usually written for a specific application, such as for the "friendly" user interfaces that allow non-experts to use complex databases without having to learn the database language SQL (Structured Query Language).

Chapter 15- Your future and information technology

With the changing in time, there is also rapid change in information technology. Therefore we must adapt the change of technology to enable we successful survives in this world. 

The rapid change of technology brings many benefit or advantages for us such as it brings new product, new enterprises, new customer and supplier relationships through it innovation. We can have many new product and then it create a new enterprises. 

This can show from the present of network. After the network been introduced, many new enterprises such as e-banking and information reseller also been introduced. This also led to a new customer and supplier relationships because now they don’t have to meet directly but just a few clicks to make their transaction successful. It makes our life convenient. 

Because we are difference, so we do have difference view regarding the technology. Four common reactions to new technology are cynicism, naiveté, frustration and proactivity. 

For those who are cynicism, they believe that learning and using computers take time away from his or her real job. 

For naiveté, they might underestimate or overestimated the technology information. 

For those frustrated users, there are impatient and irritated about taking time to learn new technology. 

While for the proactive person, they look technology in a positive and realistic way. 

No matter how we view about the technology, we should stay current, maintain the computer competency, develop professional contacts, develop specialties, be alert for organizational change and look for innovations opportunities if we want to be a winner!!

References from

Computing Essentials Complete 2010 by Timothy J.O'Leary and Linda I.O'Leary from McGRAW Hill.