cricos provider number 00103d 1 ln-3: technologies for information management dr zhaohao sun gsitms,...
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LN-3: Technologies for Information Management
Dr Zhaohao SunGSITMS, University of Ballarat
ITECH 1005/5005: Business Information Systems
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After studying this chapter, the students should be able to Explain the relationship between software, hardware
and communications components of information systems
Evaluate the suitability of different technology components for information management
Management issuesHow do we select the appropriate technology for our
organization?What is the meaning and relevance of different
technology standards associated with the Internet?
Objectives and Outcomes
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Talking to suppliers about solutions Selecting the most cost-effective solutions Troubleshooting our own ‘kit’ Reducing the total cost of ownership of hardware (See
also Chapter 11)
Why we need to understand Hardware
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Infrastructure includes the architecture of the networks, hardware and software.
Infrastructure can be considered to include the data and documents accessed through e-business applications.Chaffey 2011:98
Technology Infrastructure Components
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Figure 3.1 A five-layer model of technology infrastructure (Chaffey 2011: 99) Source: Adapted from Chaffey (2004)
Technology Infrastructure Model
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The client/server architecture consists of client computers such as PCs sharing resources such as a database stored on more powerful server computers. Processing can be shared between the clients and the servers. A client is an end-user computerA server is a computer that provides services such as
storage or applications to other client computersMiddleware is software used to facilitate
communications between business applications Client/server architecture is significant since most modern
networked information systems are based on this structure.Chaffey 2011:99-100
Client/server Architecture
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Three-tier client-server architecture
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Distributes processing potentially giving better performance
Not vitally dependent on central mainframe Enables local data storage for convenience Empowers end-users to develop their own applications Enables remote working, e.g. sales representatives
Chaffey 2011:99-101
Reasons for Client-Server
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Desktop – system unit is horizontal, vertically in a tower or mini tower configuration.
Portable or Laptop. Handheld. Windows terminal or network computer.
Figure 3.5 The first Personal Computer Source: Rune’s PC Museum (http://pc-
museum.com/rcm-001.jpg) [email protected]
Figure 3.6 A personal digital assistant (PDA)
Source: Hewlett-Packard Company, Inc., Palo Alto CA (www.hp.com)
Chaffey 2011:101-103
Different forms of Clients
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Figure 3.7 Five alternative computing architectures Chaffey 2011:106
Source: BIM
Alternative Computing Structures
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Blade servers. Clustering storage area network (SAN) – Server
clustering is used to connect and manage networked storage devices.
Grid computing Mainframes Mini-computers
Developments in Server types
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Source: Chaffey (2002)
A typical e-commerce systems architecture for an e-tailer
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Figure 3.6 The main components of a PC (Chaffey 2011:110)
Source: www.tomshardware.com
The Main components of a PC
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The processor of a computer is so-called since it processes instructions supplied by the program code within the operating system and applications software. The “Brain” of the PC
Selection criteria for Processors
1. Manufacturer.
2. Processor architecture.
3. Clock speed.
4. System bus
Chaffey 2011:111
A Processor and selection
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Name Date Transistors Microns Clock speed MIPS
8080 1974 6,000 6 2 MHz 0.64
8088 1979 29,000 3 5 MHz 0.33
80286 1982 134,000 1.5 6 MHz 1
80386 1985 275,000 1.5 16 MHz 5
80486 1989 1,200,000 1 25 MHz 20
Pentium 1993 3,100,000 0.8 60 MHz 100
Pentium II 1997 7,500,000 0.35 233 MHz 300
Pentium III 1999 9,500,000 0.25 450 MHz 510
Pentium 4 2004 125,000,000 0.09 3.6 GHz 7,000
Source: Intel
Intel Processor Development: Chaffey 2011:112
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Figure 3.7 Intel Pentium microprocessor (a) Microprocessor (b) Microprocessor circuitry Source: Intel Corporation (http://www.intel.com/pressroom/archive/photos/p4_photos.htm)
Intel Pentium Processor: Chaffey 2011:111
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Figure 3.8 ATI Radeon 9800 graphics card with 128 Mb RAM (Chaffey 2011:112)
ATI Graphics Video Card
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Figure 3.9 Moore’s Law Source: http://www.intel.com/research/silicon/mooreslaw.htm
MOOR’S Law (Gordon Moor, 1965)
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Computer memory is used to store data and programs.
There are two types of computer storage. Temporary or volatile storage where data is only saved when a device is switched on and permanent storage where the data is saved even when a device is powered down.
Temporary storage is best known through the acronym RAM, standing for Random Access Memory. RAM is used to store the operating system, applications and current data or documentation and is linked closely to the processor to which instructions and data are supplied from RAM.
RAM is similar to our short term memory – it is used for issues we are currently thinking about.
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RAM
Figure 3.12 RAM (Source: Kingston Technology Company, Fountain Valley, California (Chaffey 2011:114)
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Each computer also contain Read Only Memory or ROM which is permanent storage which is used to store the BIOS which is activated when a computer is first switched on before the operating system is loaded from the hard-disk or other permanent media.
When you switch a PC on, the first text screen will always refer to the BIOS (Binary Input and Output System) loading.
The BIOS is effectively constant; but it can be upgraded if required. This form of ROM is a standard component on each computer and does not affect the performance of the system, so it is not specified in PC purchase.
Read Only Memory (ROM)
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Byte – made up of 8 bits used to represent a single character or digit
Kilobyte – 1,024 Bytes Megabyte – 1,024 Kilobytes Gigabyte – 1,024 Megabytes Terabyte – 1,024 Gigabytes
Chaffey 2011:114
Storage Capacities
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Storage capacity
Approximate bytes
Power of 2 Exact Bytes
Byte Exactly 1 byte - 1 (eight bits, can represent one digit or character)
Kilobyte A thousand bytes
210 1,024
Megabyte A million bytes 220 1,048,576 bytes (1,024 Kb)
Gigabyte A thousand million bytes
230 1,073,741,824 (1,024 Mb)
Terabyte A trillion bytes 240 1,099,511,627,776 bytes1,024 Gb)
Bits and Bytes
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Label for volume (size)
? Gigabyte ? ? ?
Approx numeric amount (bytes)
? 1,000,000,000 ? ? ?
Exampledata amount:
A database for a large company
A database for a small company
A high resolution photo
A low resolution photo
A character
Example storage amount:
1 ?bcapacity server
120 ?bhard disk
512 ?bMemory
Old style 720 ?bhard disk
100 ?b to store numbers in mobile phone
ActivityComplete the table below filling in the gaps shown by ?Label for volume (size): Byte, Terabyte, Kilobyte, MegabyteNumeric amount: 1, 1,000,000:1,000,000,000,000 1,000 (Chaffey 2011:115)
Understanding Storage Capacities
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Figure 3.13 The relationship between Virtual Memory and RAM (Chaffey 2011:115)
Why RAM affects system performance
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Non-volatile storage – the data is retained after the hardware is ‘powered down’. Some say permanent storage is equivalent to our long-term memory.
Storage devices:
The main media types for permanent storage are magnetic, optical, tape and solid-state. The media may be readily removable from the computer or it is a fixed part of the system.
Permanent Storage
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Figure 3.14 Hard disk drive (Chaffey 2011:117)
Hard Disk Drive, DVD Writer. Memory Stick
Figure 3.15 Optical drive – a DVD Rewriter (Chaffey 2011:120)
Figure 3.16 Memory key or stick (Chaffey 2011:120)
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Read-only – traditional CDs and DVD used for music and film.
Recordable (denoted by CDR and DVDR) – The media can be written to, but once they reach their capacity space cannot be cleared by deleting existing files.
Rewritable (denoted by CDRW and DVDRW) – the media can be written to repeatedly.
CDs can hold around 640 to 700 Mb. DVDs can hold either 4.7 or 7.95 Gb depending on
whether they are double or single-sided.Chaffey 2011:119
Types of Optical Storage
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Capacity of device or media. Speed of reading and writing media. Cost of device. Cost of removable media. This is a relatively low cost
compared to the cost of the device. Need for permanent or removable media. In some cases
where a removable device is needed such as removable hard disk then this can add to the cost of the device. Chaffey 2011:120
Selecting Storage Media
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There are two main output devices for a computer system which are used to interact with applications and data.
The first is the monitor or display which is, of course, used for interacting with the system, the second is the printer which is used for keeping hard copy.
Output devicesUsed for viewing outputs from a system
Hard copyPrinted output from a system, distinct from soft or electronic copy
Output Devices
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Form: Text (VDU)raster/graphics (vector) based
Resolution (pixels) VGA 640 by 480SVGA 800 by 600 (design for many web sites)XGA 1024 by 768
Size: 14”, 15”, 17”, 21” Colour depth: 16, 256, 15 million etc. Choose a good graphics card which enables
higher resolutions than those chosen above.
Selecting a Monitor
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Figure 3.16 A flat-screen monitor (Chaffey 2011:122)
Flat Screen Monitor
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TypeCharacter, graphics (raster) or graphics (vector) basedLaser printer vs Inkjet
Resolution Measured in dots per inch
Colour depth Throughput
Measured in pages per minute
Monitor Selecting Criteria
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Figure 3.19 Multi-function ink-jet printer (Chaffey 2011:123)
Multi-function Inkjet Printer
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Figure 3.18 Xerox Docutech laser printer with a capacity of 500,000 sheets per month (Chaffey 2011:123)
Laser Printer
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Data is captured or input by different hardware tools or devices that rely on movement, light or sound e.g.Keyboard, mouseScannerBarcode readerVoice recognitionFinger print readers for security
Direct Digital Input(Chaffey 2011:125)Microsoft Wireless Desktop (Chaffey 2011:126)
Data Input Devices
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Mice and keyboard are commodities, so cost reduction is key. But:
Can cause repetitive strain injury in staff if poor quality (and other issues of ergonomics)
Wireless keyboards and mice can appear neater, but require batteries, so more often used at home rather than business(Chaffey 2011:125)
Selecting Input Devices
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Computer networkA communication system that links two or more
computers and peripheral devices to enable transfer of data between these computers.
The purpose of a computer network is to transfer data between different computers or hardware devices.
The client/server model introduced earlier requires a computer network to transfer data between the client and server computer. The server may also be connected to other hardware devices such as a network printer or a backup system using a network. (Chaffey 2011:127)
Computer Network
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Local-area network (LAN)A computer network that spans a limited geographic
area such as a single office or building. Wide-area network
Computer networks covering a large area which connects businesses in different parts of the country or different countries.
Computer networks are constructed on different scales. Small-scale networks known as local-area networks (LANs) can be set up in an office, a small business or even at home. Larger-scale networks which may span a city, country, the world or space are known as wide-area networks. These effectively link together different LANs. (Chaffey 2011:127)
LAN’s and WAN’s
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Advantages Disadvantages
1. Facilitates sharing of information 1. Organization becomes overdependent on networks for access to information and applications
2. Reduces duplication of information 2. Cost of initial setup, usage and maintenance
3. More rapid information transfer including real-time information access
3. Reduced security of information as information is exposed to increased risk of internal and external access, modification and deletion
4. Reduces hardware requirements through sharing of devices
4. Can facilitate information overload as e-mails and documents are more easily distributed
5. Enables software to be managed centrally and reduces need for local copies of software
6. Assists in information security by requiring log-in for access to certain data
7. Enable transformation of business through e-business applications
8. The Internet provides potential to reach new international markets or new customer groups at a relatively low cost
Network advantages/disadvantages (Chaffey 2011:128)
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Integrated services digital network (ISDN) An ISDN telephone line provides two separate ‘channels’ allowing simultaneous voice and data transmissions.
Asymmetric Digital Subscriber Line (ADSL) services makes use of existing telephone lines to provide very high data transfer rates. ADSL is known as asymmetric since download data transfer rates are different (higher) than upload rates.
Wi-Fi (Wireless fidelity): A high-speed wireless LAN enabling wireless access to the Internet for mobile, office and home users.
Leased lines or secure virtual private networks (VPNs) with higher speed access using the T1 standard are used by larger organizations. (Chaffey 2011:128-9)
Different forms of guided media
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The speed at which data can be transferred from A to B is governed
by the channel capacity, which is measured in bits per second (bps).
Transmission of a single bit in a second is equivalent to one baud, a
binary event.
Rates are usually measured in terms of thousands of bits/second
(Kb/sec), millions of bits/sec (Mb/sec) or billions of bits/sec (Gb/sec).
A general term often used for describing capacity is bandwidth,
which is a measure of capacity given by the difference between the
lowest and highest frequencies available for a given medium.
Transmission Speed
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POTS – 56Kb/sec modem ISDN – 256 or 512 Kb/sec ADSL – First introduced mainly at 512 Kb/sec, but 256
Kb/s, 1 Mb/s and 2 Mb/s options now commonMonthly capacity may be capped, e.g. 1, 15 Gb
Satellite – similar to ADSL Upload and download maximum figures differ
Internet Connection Speeds
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ModemModulator-demodulator used to convert data between digital and analogue form when transmitting data over telephone lines
HubsUsed to connect groups of computers to a network
Bridges and routersDevice used to connect networks and control the flow of data between them
FirewallHardware used to increase security of part of a network through preventing unauthorized access from beyond the network
Repeaters Device used to increase efficiency of transmission over long
distances (Chaffey 2011:129)
Communication Components
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Electronic data interchange (EDI) is the computer-to-computer exchange of structured data, sent in a form that allows for automatic processing with no manual intervention. This is usually carried out over specialist EDI networks. DTI (2003) Chaffey 2011:130
EDI
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Figure 3.22 Physical and network infrastructure components of the Internet(Chaffey 2011:131)
Internet Technology
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Figure 3.23 Internet timeline (Chaffey 2011:132)
Internet Timeline
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Figure 3.24 Information exchange between a web browser and web server (Chaffey 2011:134)
Information exchange between web-browser and web-server
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Figure 3.26 The TCP/IP Protocol (Chaffey 2011:136)
TCP/IP Protocol
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The World Wide Web, or ‘web’ for short, provides a standard method for exchanging and publishing information on the Internet.
If we take the analogy of television, then the Internet is the equivalent to the broadcasting equipment such as masts and transmitters, and the World Wide Web is equivalent to the content of different TV programmes.
The medium is based on standard document formats such as HTML (Hypertext Markup Language)
Chaffey 2011:133
World Wide Web
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HTML (Hypertext Markup Language) A standard format used to define the text and layout of web
pages. HTML files usually have the extension .HTML or .HTM.
XML or eXtensible Markup Language: A standard for transferring structured data, unlike HTML which is purely presentational.
HTML code<P> This text is <B>bold </B></P><P>This text is <I>italic</P><P>This text is <U>underlined</U></P>In browser:This text is boldThis text is italicThis text is underlined
HTM and HTML
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HTML code
<A HREF="index.htm"> Go to home page </A><BR>
<A HREF="http://www.bbc.co.uk ">Go to the BBC web site</A>
Browser:
Go to home page
Go to the BBC web site
HTML Code
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URL (Universal Resource Locator): a web address used to locate a web page on a web server.
Web addresses are structured in a standard way as follows:
http://www.domain-name.extension/filename.html
What do the following extensions or global top level domains stand for? .com .co.uk, .uk.com .org or .org.uk .gov .edu, .ac.uk .int .net, .biz, .info
Chaffey 2011:133
URL’s and Domain Names
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definition of the structure and content of a collection of data or document. ‘Data about data’.
HTML has a limited capability for describing documents through HTML meta-tags. These are presented at the start of the document in the header area. Chaffey 2011:140
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<HEAD> <TITLE>An intranet document example</TITLE> <META name="author" content="Dave Chaffey"> <META name="keywords" content="phone directory, address book"> <META name="description" content="An online phone book"> <META name="date" content="2005-11-06T08:49:37+00:00"></HEAD>
Chaffey 2011:140
HTML Metadata Example
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<rdf:Description> <dc:title>E-business and E-commerce
Management</dc:title> <dc:creator>Dave Chaffey</dc:creator> <dc:format>Book</dc:format> <dc:identifier>ISBN 0273683780</dc:identifier> </rdf:Description>
XML Metadata Example
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Wireless connection to the Internet is possible in several different forms WAP internet access from mobile phones
Wireless Application Protocol (WAP)WAP is a technical standard for transferring information to wireless devices, such as mobile phones.
3GThird generation of mobile phone technology with high speed data transfer enabling video calling.
i-ModeA mobile access platform widely used in Japan that enables display of colour graphics and content subscription services.
Chaffey 2011:149
The Wireless Internet
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SMS Messaging
SMS: short message service, is the formal name for text messaging, commonly known as “texting”
SMS is a simple form of e-mail that enables messages to the transferred between mobile phones.
Over 3 trillion text messages were sent worldwide in 2009
Texting has proved useful for business in some applications Chaffey 2011:151
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Summary
Explained the relationship between software, hardware and communications components of information systems
Evaluated the suitability of different technology components for information management
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References
Chaffey and White (2011) Business Information Management © Pearson Education Limited 2005
Chaffey and Wood (2005) Business Information Management © Pearson Education Limited
Sun Z (2010) LN-3 revisited Harvey, W. LN-2, 2008, UB