CHAPTER 9 COMMUNICATIONS AND NETWORKS

Communications is the process of sharing data, programs, and information between two or more computers. Applications include e-mail, instant messaging, Internet telephones, and electronic commerce.

COMMUNICATION SYSTEMS = transmit data from one location to another.

• sending and receiving devices
• communication channels ( transmission medium)
• connection (communication) devices
• data transmission specifications

COMMUNICATION CHANNELS carry data from one computer to another.

PHYSICAL CONNECTIONS

• twisted pair (telephones lines and Ethernet cables)
• coaxial cable
• fiber-optic cable

WIRELESS CONNECTIONS

• infrared
• radio frequency (RF)
• microwave
• satellite

CONNECTION DEVICES

1. modem

• telephone
• DSL
• cable
• wireless

2. connection services

• dial-up
• DSL(digital subscriber line)
• ADSL
• cable
• satellite/air
• cellular services (3G cellular networks)

NETWORK TYPE

• Local area networks ( LANs )
• Home networks
• Wireless LANs (WLANs)
• Personal area networks (PANs)
• Metropolitan area networks (MANs）
• Wide area networks (WANs）

NETWORK ARCHITECTURE describes how a computer network is configured and what strategies are employed.

TOPOLOGIES

• bus
• ring
• star
• tree
• hybrid
• mesh

STRATEGIES

• terminal
• client/server
• peer-to-peer

ORGANIZATIONAL INTERNET

• intranets
• extranets

APPRECIATION

Wuhuhu,

Finally, our blog assessment 

comes to the end.

We would like to thanks for

our lecturer-- Pn. Sharin Hazlin Huspi 

for your guidance and efforts

to our blog.

We still remembered that at the beginning 

we are blur and 

do not really know

 how to make our own blog.

However, after we explored it together

and get discussion with you,

we found that it is very easy to

create an interesting blog.

We just need to do some

researches, 

get informations, 

and reads a lots 

so that we have the contents 

to post on the wall

and share the knowledge

with the other readers.

Madam, thank you

for giving us an opportunity to 

discover the formation of this blog.

We are not only learn that 

the knowledge of

INFORMATION TECHNOLOGY,

but also the 

PROCESS TO MAKE 

A CREATIVE AND EDUCATIONAL BLOG. 

Again, THANKS A LOT.

We really appreciate 

your cooperation and efforts throughout this blog.

CHAPTER 15 Your Future and Information Technology

In this chapter, we looked into technology and organizations as well as technology and people. Besides that, we also learnt how to become a winner and exposed to the different careers in IT.

1. Technology can introduce new ways for businesses to compete with each other.

2. Some of the principal changes are as follows:

• New product: Technology creates product that operates faster, are priced cheaper, are often of better quality, or are wholly new.
• New enterprises: Information technology can build entirely new businesses. Two examples are Internet service providers and Web site development companies.
• New customer and supplier relationship: Businesses that make their information systems easily available may make their customers less likely to take their businesses elsewhere.

3. People react to changing technology in one of the four ways.

• Cynicism
• Naivete
• Frustration
• Proactivity

4. Six tips for us to be a winner in this information age.

• Stay current
• Maintain our computer competency
• Develop professional contacts
• Develop specialties
• Be alert for organizational change
• Look for innovative opportunities

5. Different careers have their own responsibilities in IT.

• Computer support specialist: Provides technical support to customers and other users.
• Computer technician: Repairs and installs computer components and systems.
• Computer trainer: Instructs users on the latest software or hardware.
• Cryptographer: Designs, tests, and researches encryption procedures.
• Data entry worker: Inputs customer information, lists, and other types of data.
• Database administrator: Uses database management software to determine the most efficient ways to organize and access data.
• Desktop publisher: Creates and formats publication-ready material.
• Information systems manager: Oversees the work of programmers, computer specialists, system analysts, and other computer professionals.
• Network administrator: Creates and maintains network.
• Programmer: Creates, tests, and troubleshoots computer programs.
• Software engineer: Analyzes users' needs and creates application software.
• System analyst: Plans and designs information systems.
• Technical writer: Prepares instruction manuals, technical reports, and other scientific or technical documents.
• Webmaster: Develops and maintains Web sites and Web resources.

Citation: Computing Essentials 2011

CHAPTER 14 Programming and Languages

In this chapter, we defined the terms of program and programming. Besides that, we also discussed the generations of programming languages.

1. Program is a list of instructions for the computer to follow to accomplish the task of processing data into information.

2. Programming, also known as software development, is a six-step procedure for creating that list of instructions.

3. The six steps are as follow:

• Program specification: The program's objectives, outputs, inputs, and processing requirements are determined.
• Program design: A solution is created using programming techniques such as top-down program design, pseudocode, flowcharts, and logic structures.
• Program code: The program is written or coded using a programming language.
• Program test: The program is tested or debugged by looking for syntax and logic errors.
• Program documentation: Documentation is an ongoing process throughout the programming process. This phase focuses on formalizing the written description and processes used in the program.
• Program maintenance: Completed programs are periodically reviewed to evaluate their accuracy, efficiency, standardization, and ease to use. Changes are made to the program's code as needed.

Software development

http://www.google.com.my/imglanding?q=software+development+cycle&hl=en&tbm=isch&tbnid=x2CYazyj-M-aZM:&imgrefurl=http://computing2008.com/computing2008/dvd:programming&imgurl=http://computing2008.com/computing2008/_media/dvd:15-1a.jpg%253Fw%253D%2526h%253D%2526cache%253Dcache&w=244&h=246&ei=6zSnTfHuDoHIvQPM0Jn9CQ&zoom=1&iact=hc&oei=5DSnTeGsK8uzrAf235ndCQ&page=2&tbnh=139&tbnw=138&start=32&ved=1t:429,r:4,s:32&biw=1639&bih=748

4. Programming languages are called lower level when they are closer to the language the computer itself uses.

5. Programming languages are called higher level when they are closer to the language humans use.

6.There are five generations of programming languages: 

• Machine languages: The First Generation
• Assembly languages: The Second Generation
• Procedural languages: The Third Generation
• Task-oriented languages: The Fourth Generation
• Problem and constraint languages: The Fifth Generation

Citation: Computing Essentials 2011

CHAPTER 13 Systems Analysis and Design

In this chapter, we defined the terms of system and systems analysis and design. Besides that, we also described the systems life cycle, prototyping and rapid application development.

1. System is a collection of activities and elements organized to accomplish a goal.

2. Systems analysis and design is a six-phase problem-solving procedure for examining and improving an information system.

3. The six phases make up the systems life cycle.

4. The phases are as follows:

• Preliminary investigation: The information problems or needs are identified.
• Systems analysis: The present system is studied in depth. New requirements are specified.
• Systems design: A new or alternative information system is designed.
• Systems development: New hardware and software are acquired, developed, and tested.
• Systems implementation: The new information system is installed and adapted to the new system, and people are trained to use it.
• Systems maintenance: In this ongoing phase, the system is periodically evaluated and updated as needed.

System life cycle

http://www.google.com.my/imglanding?q=system+life+cycle&hl=en&sa=X&tbm=isch&tbnid=9e2wkzFCjuH73M:&imgrefurl=http://www.computing2008.com/dvd:analysis&imgurl=http://www.computing2008.com/computing2008/_media/dvd:14-1a.jpg%253Fw%253D%2526h%253D%2526cache%253Dcache&w=252&h=247&ei=WB-nTf70H4-avgPurq2DCg&zoom=1&iact=hc&oei=Th-nTZmbJcbIrQeujYXnCQ&page=2&tbnh=158&tbnw=162&start=31&ved=1t:429,r:16,s:31&biw=1639&bih=748

5. Prototyping means to build a model or prototype that can be modified before the actual system is installed. 

6. Rapid applications development (RAD) involves the use of powerful development software, small specialized teams, and highly trained personnel.

Citation: Computing Essentials 2011

CHAPTER 12 - DATABASES

                   SUMMARY CHAPTER 12

DATA

• Data consists of facts or observations about people, places, things, and events. 
• Not long ago, data was limited to numbers, letters, and symbols. 
• Now data includes : 

1. Audio - captured, interpreted and saved using microphones and voice recognition systems. 
2. Music - download from the Internet and captured from others sources, rearranged, and used to create customized CDs. 
3. Photographs - captured by digital cameras, edited by image-editing software, and shared with others over the Internet. 
4. Video - captured by digital video cameras and TV tuner cards, saved, and used in presentations. 

• There are two ways or perspectives to view data : 

1. Physical view - focuses on actual format and location of data, very specialized computer professionals are concerned with this view. 
2. Logical view - focuses on meaning and content of data, end users and most computer professionals are concerned with this view. 

• This chapter presents the logical view of data and how data is stored in databases. 

DATA ORGANIZATION

• is organized by the following groups :

1. Character - the most basic logical elements, consisting of individual numbers, letters, and special characters. 
2. Field - the next level consisting of a set of related characters. Example a person's last name. A data field represents an attribute (description or characteristic) of some entity (person, place, thing, or object). 
3. Record - a collection of related fields. Example, a payroll record consisting of fields of data relating to one employee. 
4. Table - a collection of related records. Example, a payroll table consisting of all the employee records. 
5. Database - an integrated collection of related tables. Example, a personnel database contains all related employee table, including the payroll and the benefits tables. 

Key Field

• also known as the primary key. 
• is the field in a record that uniquely identifies each record. 
• Tables can be related to other tables by key fields.
• Key fields in different files can be used to integrated the data in a database. 
• Common key fields are employee ID numbers and driver's license numbers. 
• Example, in the Personnel Database, both the Payroll and the Benefits tables include the fields Employee ID. 

Batch versus Real-Time Processing

• Traditionally, data is processed in one of two ways. 
• These are batch processing, or what we might call "later", and real-time processing, or what we might call "now". 
• Two methods have been used to handle common record-keeping activities such as payroll and sales orders.

1. Batch processing - data is collected over time and then processed later all at one time (batched). Example, monthly credit card bills are typically created by processing credit card purchases throughout the past month.
2. Real-time processing (online processing) - data is processed at the same time the transaction occurs, direct access storage devices make real-time processing possible. Example, a request for cash using an ATM machine initiates a verification of funds, approval or disapproval, disbursement of cash, and an update of the account balance. 

DATABASES

• is a collection of integrated data logically related files and records. 
• Example, records for the same customer may appear in different files in the sales department, billing department, and credit department, this is called data redundancy. 
• Example, a product ordered might be sent to the new address, nut the bill might be sent to the old address, this situation result from the lack of data integrity. 

Need For Databases

• Advantages of databases are : 

1. sharing data 
2. improved security
3. reduced data redundancy
4. higher data integrity 

Database Management

• A database management systems (DBMS) is the software for creating, modifying, and gaining access to the database. 
• A DBMS consists of five subsystems : 

1. DBMS Engine - provides a bridge between logical and physical data view. 
2. Data definition subsystem - defines the logical structure of a database using a data dictionary or schema. 
3. Data manipulation subsystem - provides tools for data maintenance and data analysis, tools include query-by-example and structure query language (SQL). 
4. Application generation subsystem - provides tools for creating data entry forms with specialized programming languages. 
5. Data administration subsystem - manages the database, database administrators (DBAs) are computer professionals who help define processing rights. 

DBMS STRUCTURE

• DBMS programs are designed to work with specific data structure or database models. 
• These models define rules and standards for all the data in the database.
• Five principals database models are :

1) Hierarchical Database 

• uses nodes to link and structure fields and records; entries may have one parent node with several child nodes in a one-to-many relationship. 

2) Network Database

• is like hierarchical except a child node may have more than one parent in a many-to-many relationship; additional connections are called pointers between parent nodes and child nodes. 
• Thus, a node may be reached through more than one path.
• It may be traced down through different branches. 

3) Relational Database 

• data is stored in tables (relations); related tables must have a common data item (key field). 
• A table and its data is called a relation. 
• Common data  item enabling information stored in one table to be linked with information stored in another. 

4) Multidimensional Database

• extend two-dimensional relational tables to three or more dimensions, sometimes called a data cube.
• Multidimensional Database offer more flexible structures than relational databases, providing a more intuitive means of modeling data. 
• Two of the most significant advantages are conceptualization and processing speed. 

5) Object-Oriented Database

• stores data, instructions, and unstructured data. 
• Data is organized using classes, objects, attributes, and methods.
• Classes are general definitions
• Objects are specific instances of a class that can contain both data and instructions to manipulate the data. 
• Attributes are the data fields an objects possesses. 
• Methods are instructions for retrieving or manipulating attribute values. 

TYPES OF DATABASES

• There are four types of databases : 

1) Individual 

• Individual database or microcomputer database is used by one person.
• It is a collection of integrated files primarily used by just one person. 
• Typically, the data and the DBMS are under the direct control of the user. 

2) Company

• Company databases are usually stored on a central server and accessed by multiple people.
• These databases are typically used for company operations. 

3) Distributed

• Distributed database is spread out geographically ; not all data is physical located in one place ; it is accessible by communications links. 
• Typically, database servers on a client/server network provide the link between the data. 

4) Commercial

• Commercial databases are generally enormous and cover particular subjects ; also known as information utilities and data banks. 
• Some important commercial databases are CSi , Dialog Information Services , Dow Jones Interactive Publishing , and LexisNexis. 
• Most of the commercial databases are designed for organizational as well as individual use. 

Citation : 

• COMPUTING ESSENTIALS COMPLETE 2010

CHAPTER 11 - INFORMATION SYSTEMS

                SUMMARY CHAPTER 11

ORGANIZATIONAL INFORMATION FLOW

• is an organization through functional areas and between management levels. 

Functions

• Organization have separate departments to perform 5 functions :

1. Accounting - tracks all financial activities and generates periodic financial statements.
2. Marketing - advertise, promotes, and sells the product or service. 
3. Production - makes the product or service using raw materials and people to turn out finished goods.
4. Human Resource - finds and hires people, handles such matters as sick leave, retirement benefits, evaluation, compensation, and professional development. 
5. Research - conducts product research and development, monitors and troubleshoots new products. 

Management Levels

• The three basic management levels are : 

1. Supervisors - manage and monitor the employees or workers. Thus, these managers have responsibility relating to operational matters. 
2. Middle management - Middle-level managers deal with control, planning (also called tactical planning),  decision making. and implement the long-term goals of the organization. 
3. Top management - Top-level managers are concerned with long-range planning (also called strategic planning), and to plan the future growth. 

  http://www.managementstudyguide.com/management_levels.htm

 Information Flow

• Information flows within an organization in different directions: 

1. For top-level managers, the information flow is primarily upward from within the organization and into the organization from the outside. 
2. For middle-level managers, the information flow is horizontal and vertical within departments. 
3. For supervisors, the information flow is primarily vertical.  

INFORMATION SYSTEMS

• There have four kinds of computer-based information systems:

1. Transaction Processing Systems (TPS) - also known as data processing systems, record day-to-day transactions. Example is in accounting which handles 6 activities : sales order processing, accounts receivable, inventory control systems, and purchasing, accounts payable, payroll, and general ledger. General ledger is used to produce income statements and balance sheet. 
2. Management Information Systems ( MIS) - produce predetermined periodic, exception and demand reports. Management information systems use database management systems to integrate the databases of different departments. 
3. Decision Support Systems (DSS) - enable managers to get answers for unanticipated questions. Teams formed to address large problems use group decision support systems (GDSS). DSS consists of the users, systems software, data - internal and externals, and decision models. Three types of decision models are strategic, tactical, and operational. 
4. Executive Support Systems (ESS) - assist top-level executives. An executives support system is similar to MIS or DSS but easier to use. ESSs are designed specifically for top-level decision makers. 
5. Other Information Systems

• Office automation systems (OAS) - support data workers whoa re involved with distribution and communication of information. Project managers and videoconferencing systems are OAS. 
• Knowledge work systems (KWS) - support knowledge workers, who create information. Many engineers use computer-aided design/computer-aided manufacturing (CAD/CAM) systems. 

Citation :

• COMPUTING ESSENTIALS COMPLETE 2010