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Tomorrow’s Technology and You
Digital Planet: Tomorrow’s Technology and You George Beekman • Ben Beekman Tenth Edition Copyright © 2012 Pearson Education, Inc. publishing as Prentice Hall 1
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Table of Contents Chapter 1: Exploring Our Digital Planet
Chapter 2: Hardware Basics: Inside the Box Chapter 3: Hardware Basics: Peripherals Chapter 4: Software Basics: The Ghost in the Machine Chapter 5: Productivity Applications Chapter 6: Graphics, Digital Media, and Multimedia Chapter 7: Database Applications and Privacy Implications Chapter 8: Networking and Digital Communication
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Digital Planet: Tomorrow’s Technology and You
Chapter 1 Exploring Our Digital Planet Copyright © 2012 Pearson Education, Inc. publishing as Prentice Hall 3
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Chapter 1 Objectives Describe digital technology’s critical role in our lives Discuss several key trends in the evolution of computers and digital technology Describe the major types of computers and their principal uses Explain how the growth and evolution of the Internet is changing our lives 4 4
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Objectives (cont.) Explain how our information age differs from any time that came before Discuss the social and ethical impact of information technology on our society 5 5
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Living in a Nondigital World
Computers are everywhere. Our lives are directly affected when they do not operate. Computers have infiltrated our lives so we do not know how to function without them. 6 6
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Computers in Perspective
Computers have been with us for a short time but are built on centuries of insight and effort. Early humans counted with fingers or rocks. The abacus was used by Babylonians and Chinese for thousands of years. By early 19th century, the need for more accurate calculating tools became evident. Charles Babbage and Ada Lovelace imagined the construction of the Analytical Engine. 7 7
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Computers in Perspective (cont.)
Brief history of computers 1939—Atanasoff-Berry Computer created 1943—Alan Turing developed Colossus 1944—Mark I completed to compute ballistics tables 1945—ENIAC completed 1951—UNIVAC I (the first general-purpose commercial computer) was delivered to the U.S. Census Bureau 8 8
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Computers in Perspective (cont.)
Computer hardware Early computers used vacuum tubes. Tubes were replaced by transistors. By mid-1960s, more powerful machines were based on integrated circuits—small silicon chips containing hundreds of transistors. A vacuum tube, a transistor, and an integrated circuit. 9 9
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Computers in Perspective (cont.)
Benefits of integrated circuits Reliability: Less prone to failure Size: Single chips could replace entire boards Speed: Electricity had shorter distances to travel Efficiency: Small chips used less electrical power and created less heat Cost: Mass production techniques made it easy to manufacture inexpensive chips 10 10
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Computers Today: A Brief Taxonomy
Thanks to an abundance of low-cost microprocessors, today’s world is populated with an incredible variety of computers, each particularly well-suited to specific tasks. 11 11
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Embedded Systems Embedded system: A microprocessor used as a component of a larger system More than 90% of microprocessors are hidden inside common household and electronic devices: Thermostats, traffic lights, cars Wristwatches, toys, game machines TVs, camcorders, ovens Anything powered by electricity—battery or house current—is candidate for microprocessor implant 12 12
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Personal Computers Personal computer: Designed to be used by one person at a time Tool for enhancing productivity, creativity, communication Desktop computer has several components: Tower (containing microprocessor and other components) Monitor, keyboard, mouse, speakers Some house all components in monitor casing 13 13
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Workstations Workstation: A high-end desktop computer with massive computing power. Used for computationally intensive interactive applications Large-scale scientific data analysis Line separating workstations and desktop computers becoming less distinct. 14 14
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Portable Computers Laptop computers— sometimes called notebook computers—designed for portability Netbooks are extra-small, extra-light, no-frills computers 15 15
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Handheld Devices Personal digital assistants (PDAs)
Smart phones combine the functions of a phone, camera, PDA, game machine, and music/video player. Tablet computers bridge the gap between smart phone and notebook/netbook PC. Smart phone 16 16
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Servers Server: A computer that provides other computers connected to a network with access to data, programs, and other resources Any desktop computer can be used as a server but some are specifically designed for this purpose. Servers have faster processors, more memory, or faster network connections. Often clustered together in groups to increase processing power 17 17
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Mainframes Mainframes: Room-sized computers with price tags to match
Before microcomputers, most information processing was done on mainframe computers. Today mainframe computers are used by large organizations, such as airlines and banks. Mainframe computers can communicate with several users simultaneously through timesharing. 18 18
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Supercomputers Typical supercomputer is constructed out of thousands of microprocessors. Power users with special requirements need access to fastest, most powerful computers. 19 19
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Computer Connections: The Internet Revolution
Internet: Work began on experimental network in the in late 1960s as it evolved it became known as the Internet. In 1990s, software became more usable. The Internet was transformed from text-only to include pictures, animation, sounds, and video. The World Wide Web (WWW) became accessible to millions who connect through a Web browser. 20 20
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Computer Connections: The Internet Revolution (cont.)
Growth of the Internet Widespread and Web use Few million users in 1990s—about two billion users today Internet’s population reflects population at large More than half are now female Areas with no Internet access are harder to find 21 21
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Computer Connections: The Internet Revolution (cont.)
Web 2.0 sites are built around contributions from Web users My Space Facebook Twitter YouTube Google Maps 22 22
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Into the Information Age
10,000 years ago, people learned to domesticate animals and grow their own food. Agricultural age: Lasted until about 200 years ago Industrial age: Advances in machine technology ushered in this age Information age: A convergence of computer and network technology—where most people earn their living working with words, numbers, and ideas 23 23
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Living with Digital Technology
In 1943, Thomas Watson, Sr., declared that the world would not need more than five computers. Since then, computers have evolved from massive, expensive, unreliable calculators into (mostly) dependable, versatile machines. Who could have imagined netbooks, iPhones, PlayStations, Google, Facebook, YouTube, Twitter, eBay, robot moon rovers, or laserguided “smart bombs”? 24 24
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Phases of the Information Age
Institutional computing phase, starting about 1950: large, expensive mainframes Personal computing phase, starting about 1975: millions of PCs joined mainframes Interpersonal computing phase, starting about 1995: networks connected the PCs and mainframes Collaborative computing phase, starting about 2005: smart phones, tablets, and other digital devices join PCs on the Internet; migration to Internet “cloud” 25 25
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Explanations: Clarifying Technology
Computer hardware and software details change every few years. Internet is evolving even faster. Most of the underlying concepts remain constant. It is important to understand the basics to keep up with the changes. 26 26
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Applications: Digital Technology in Action
Everyone can benefit from knowing the following: Network applications Word processing and desktop publishing Spreadsheets and databases Graphics and image processing Audio, video, and multimedia Programming and customized problem solving Artificial intelligence 27 27
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Implications: Social and Ethical Issues
Potential risks of digital technology: Threat to personal privacy Hazards of high-tech crime Difficulty of defining and protecting intellectual property Threat of automation and the dehumanization of work Abuse of information for political and economic power Dangers of dependence on complex technology Emergence of biodigital technology 28 28
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Computer Ethics Know the rules and the law.
Don’t assume that it’s okay if it’s legal. Think scenarios. When in doubt, talk it out. Make yourself proud. Remember the golden rule. Take the long view. Do your part. 29 29
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History of the Future Today’s technology raises fascinating and difficult questions. We will need to deal with even more difficult questions as technology evolves. Exponential growth in computing power makes it likely that we will see technology that was once considered far-fetched in our everyday lives. 30 30
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Chapter 1 Summary Mechanical computing devices date back hundreds of years. First real computers were developed during 1940s. Computers have evolved at an incredible pace, becoming consistently smaller, faster, more efficient, more reliable, and less expensive. Computers today come in all shapes and sizes with specific types suited for particular jobs. 31 31
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Summary (cont.) Connecting to a network enhances the value and power of a computer. Computers share resources with other computers and facilitate electronic communication with other users. The Internet is a collection of networks connecting computers and other devices around the globe. Internet users have access to billions of pages on the World Wide Web. 32 32
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Summary (cont.) Our civilization is in a transition from an industrial economy to an information economy. Emerging technologies, such as artificial intelligence, offer promise for future applications. At the same time, computers threaten our privacy, our security, and perhaps our way of life. Our future depends on computers and our ability to understand and use them in productive, positive ways. 33 33
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Tomorrow’s Technology and You
Digital Planet: Tomorrow’s Technology and You George Beekman • Ben Beekman Tenth Edition Copyright © 2012 Pearson Education, Inc. publishing as Prentice Hall 34
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Digital Planet: Tomorrow’s Technology and You
Chapter 2 Hardware Basics Inside the Box Copyright © 2012 Pearson Education, Inc. publishing as Prentice Hall 35
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Chapter 2 Objectives Explain in general terms how computers store and manipulate information Describe the basic structure and organization of a computer Discuss the computer system’s main internal components and the ways they interact Explain why a computer typically has different types of memory and storage devices 36 36
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What Computers Do Four basic operations:
Receive input: Accept information from outside world Process information: Perform arithmetic or logical operations on information Produce output: Communicate information to outside world Store information: Store and retrieve information from memory and storage devices 37 37
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What Computers Do (cont.)
Hardware components Input devices Output devices Microprocessor (CPU) Memory and storage devices Primary storage Secondary storage Peripherals 38 38
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A Bit About Bits Information: Communication that has value because it informs or Information: Anything that can be communicated, whether it has value or not 39 39
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Bit Basics Bit: From Binary digit Byte
Smallest unit of information computer can process Can have one of two values: 0 or 1 Byte Collection of 8 bits Can represent different messages (256 = 28) 40 40
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Bits as Numbers Denotes all numbers with combinations of 0s and 1s
Decimal numbers automatically converted to binary Binary number processing hidden from user Decimal Binary 0000 5 0101 1 0001 6 0110 2 0010 7 0111 3 0011 8 1000 4 0100 9 1001 41 41
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Binary Arithmetic & Conversions
Convert the binary number 1011 to decimal Add 1011 and 1011 Convert 25 to binary 42
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Bits as Codes Codes represent each letter, digit, and special character ASCII: Most widely used Each character is a unique 8-bit code 256 unique codes for 26 letters, 10 digits, special characters Unicode: Supports more than 100,000 unique characters 43 43
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The World’s Languages ASCII character set was originally designed to include only English-language characters from 0 to 127 Unicode’s international standard character set allows for more than 100,000 distinct codes to include Chinese, Korean, Japanese, and Arabic characters 44 44
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Bits, Bytes, and Buzzwords
Byte = 8 bits or one character in ASCII Kilobyte (KB, K) Megabyte (meg, MB) Gigabyte (gig, GB) Terabyte (TB) Petabyte (PB) ≈ 1,000 bytes ≈ 1,000 KB or 1 million bytes ≈ 1,000 MB or 1 billion bytes ≈ 1 million MB or 1 trillion bytes ≈ 1 quadrillion bytes 45 45
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The Computer’s Core: CPU and Memory
A digital computer is a collection of on/off switches designed to transform information from one form to another. The user provides the computer with patterns of bits—input—and the computer follows instructions to transform that input into a different pattern of bits—output—to return to the user. 46 46
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The CPU: The Real Computer
CPU often called “processor” Performs transformations of input into output Interprets and executes instructions in programs Performs arithmetic and logical data manipulations ALU – Arithmetic and Logic Unit Communicates with other parts of the computer system indirectly through memory 47 47
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The CPU: The Real Computer (cont.)
Modern Microprocessor Complex collection of electronic circuits CPU housed with other chips on circuit board Circuit board containing computer’s CPU is called motherboard 48 48
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The CPU: The Real Computer (cont.)
Choosing a Computer Type of CPU is important part of decision Two important factors to consider: Compatibility Performance 49 49
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Compatibility Not all software is compatible with every CPU.
Every processor has built-in set of instructions. CPUs in same family are generally backward compatible. Designed to process instructions handled by earlier models AMD processors made to be compatible with Intel. Also, software compatible with one operating systems won’t work on a different operating system Programs written for Linux can’t run on Windows. 50 50
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Performance Some processors faster than others
Performance is determined by: Speed of internal clock—measured in gigahertz (GHz) Architecture of processor Number of bits processor can process at one time Typically 32 or 64 bits—called word size Heat generated increases with clock speed 51 51
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Performance (cont.) Multicore Processors
Single chip contains multiple CPUs (cores) Run simultaneously Divide work Most new PCs have at least two cores. Quad core becoming common Manycore – hundreds of CPUs per chip. 52 52
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Performance (cont.) Special Purpose Processors Supplement basic CPU
Typical CPU contains graphics-processing unit (GPU) which handles: 3-D graphics rendering Other visual calculations Frees main CPU to work on other tasks 9 53 53
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From Multicore to Cluster
Performance enhancing techniques aren’t confined to the insides of CPU chips. Instead of adding more cores, a large system might simply add more machines to a network. Parallel processing has been used in high-end servers and workstations for some time. Threaded processing in multicore CPUs is like a microscopic version of parallel processing used in some of the world’s biggest computing networks. 54 54
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The CPU Typical CPU is divided into several functional units:
Control unit Arithmetic logic unit (ALU) includes registers Decode unit – About 100 distinct main instructions Programs often consist of millions of instructions Bus unit Prefetch unit These units work together to complete the execution of program instructions. 55 55
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The CPU (cont.) 56 56
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Green Computing When compared to other industries the computer industry is relatively easy on the environment. The manufacture and use of computer hardware and software does have a significant environmental impact. You have some control over the environmental impact of your computing activities. 57 57
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Green Computing (cont.)
Buy green equipment Use a laptop Take advantage of energy saving features Turn off your computer when you are away Save energy, not screens Avoid moving parts Print only once Use a green font E-cycle your waste products Pass it on Send bits not atoms Consider hidden environmental costs 58 58
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The Computer’s Memory Random access memory (RAM)
Most common type of primary storage Stores program instructions and data temporarily Memory locations have unique addresses Volatile—disappears when power is turned off 59 59
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The Computer’s Memory (cont.)
Read-only memory (ROM) Information is etched on chip when manufactured Stores start-up instructions and other critical information Complementary metal-oxide semiconductor (CMOS) Special low-energy type of RAM Flash memory Can be written and erased repeatedly Used for digital cameras, cell phones, handheld computers 60 60
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Memory When you turn on the computer, the CPU automatically begins executing operating system instructions stored in ROM. The executing instructions help the system start up and tell it how to load the operating system—copy it from disk into RAM. Once instructions for the operating system are loaded into RAM, the CPU is able to execute them. 61 61
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Buses Information travels between components on the motherboard through wires called internal buses or just buses. Buses: Bridges between processor and RAM Buses connect to: Storage devices in bays Expansion slots External buses and ports 62 62
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Ports Computer has variety of ports to meet diverse needs
Video port(s) to connect monitors Audio ports to connect speakers and/or headphones USB ports to connect keyboards, pointing devices, printers, cameras, disk drives, portable storage devices, and more Some ports connected directly to system board Others connected to expansion cards 63 63
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Peripherals Slots and ports make it easy to add peripherals to computer system. Some peripherals, such as keyboards and printers, serve as communication links between people and computers. Other peripherals link computer to other machines. Still others provide long-term storage media. 64 64
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How Memory Works Memory can be thought of as millions of tiny storage cells in a row with successive addresses. Each tiny cell contains 8 bits or one byte of information. The information my include program instructions, numbers (integers, reals, extended precision reals), text characters, digital code for pictures, and other data. 65
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Memory (cont) RAM chips are usually grouped on small circuit boards called dual in-line memory modules (DIMMs) These are plugged into the mother board. RAM memory is volatile and is lost when the power is turned off. 66
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ROM and Operating System
ROM contains permanent programs (called firmware) that include part of the operating system. When the computer is started, the CPU starts executing the operating system instructions in ROM These ROM instructions are used to start up the system and to copy the rest of the operating system from disk into RAM. Once the instructions from the operating system are in RAM, the CPU can start executing them. 67
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Chapter 2 Summary A computer manipulates patterns of bits represented by two symbols: 0 and 1. Bits can be grouped into coded messages that represent alphabetic characters, pictures, colors, sounds, and other kinds of information. The microprocessor follows software instructions to perform calculations and logical manipulations that transform input data into output. 68 68
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Summary (cont.) Not all CPUs are compatible with each other.
Modern CPUs employ multicore or many core processing systems that speed calculations. The CPU uses RAM (random access memory) as a temporary storage area. ROM (read-only memory) contains unchangeable information. 69 69
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Summary (cont.) The CPU and main memory are housed in silicon chips on the motherboard and other circuit boards inside the computer. Buses connect to slots and ports that enable the computer to communicate with internal devices and external peripherals. 70 70
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Tomorrow’s Technology and You
Digital Planet: Tomorrow’s Technology and You George Beekman • Ben Beekman Tenth Edition Copyright © 2012 Pearson Education, Inc. publishing as Prentice Hall 71
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Digital Planet: Tomorrow’s Technology and You
Chapter 3 Hardware Basics Peripherals Copyright © 2012 Pearson Education, Inc. publishing as Prentice Hall 72
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Chapter 3 Objectives List several examples of input devices and explain how they can make it easier to get different types of information into the computer List several examples of output devices and explain how they make computers more useful Explain why a typical computer has different types of storage devices Diagram how the components of a computer system fit together 73 73
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Input: From Person to Processor
Nuts and bolts of information processing hidden from computer user. User sees only input and output or I/O. Early computer users had to flip switches or plug wires into switchboards. Today, users have choice of hundreds of input devices that make it easy to enter data and commands. 74 74
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The Keyboard Keyboard: Most familiar input device
QWERTY keyboard dates back to manual typewriters Typical keyboard sends signals to computer through cable—usually USB Keyboards may be wireless Ergonomic keyboards: Keys are at angles; easy on arms and hands 75 75
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Pointing Devices Mouse: Designed to move pointer around screen
Wireless mice: Use Bluetooth or other wireless frequencies Touchpad: A flat panel, sensitive to light pressure Trackpoint and trackball: Used to control pointer Game controllers, graphics tablets, touch screens: Used for inputting 76 76
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Multi-Touch Input Devices
Use multi-finger or multi-hand gestures to accomplish complex tasks quickly Touch-sensitive screen, touch tablet, or trackpad can recognize position, pressure, and movement of more than one finger or hand at a time Best known example is Apple’s iPhone iPad recognizes one- and two- fingered movements 77 77
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Reading Tools Devices allow computers to read marks that represent codes: Optical mark readers Magnetic ink character readers Bar code readers Radio frequency identification (RFID) readers Scanners and pen scanners Handwriting recognition devices Magnetic ink character readers – for checks RFID readers – uses radio waves to communicate with RFID tags RFID tags as small as grain of rice --- as large as card deck Optical character recognition – OCR – printed characters only 78 78
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Digitizing Devices and Sensors
Devices for capturing and digitizing information—converting it into digital form: Scanners Flatbed scanner Film scanners Drum scanners Digital cameras and digital video cameras Film Scanners - 79 79
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Digitizing Devices and Sensors (cont.)
Voice Input PCs contain circuitry to convert audio signals from microphones or other sound sources into digital signals. Speech recognition software can convert voice data into words that can be edited and printed. 80 80
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Output: From Pulses to People
Output devices convert computer’s internal bit patterns into a form humans can understand. Output produced through two main devices: Display screens for immediate visual output Printers for permanent paper output 81 81
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Digitizing the Real World
Digitizing involves using an input device to take millions of tiny samples. A representation of the original image can be reconstructed by assembling all samples in sequence. 82 82
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Screen Output Display: Also called a monitor
Display size measured length of diagonal line across screen Images composed of tiny dots called pixels. Resolution: Measured in dots per inch (dpi) Aspect ratio: Relationship between width and height Monitors use liquid crystal digital (LCD) technology. 83 83
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Color Display Image is made up of rows of colored pixels
Pixels are extremely small and can’t be distinguished Monitor’s image is refreshed many times per second Each pixel is made up of mixture of red, green, blue By varying the brightness of the three colors, a monitor can display millions of unique colors 84 84
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Paper Output Printers come in two basic groups:
Impact printers: Form images by physically striking paper, ribbon, and print hammer together Nonimpact printers: Replaced impact printers Laser printers: High-quality pages, quickly Inkjet printers: Spray ink directly onto paper Photo printers: Specialized inkjets print photos 85 85
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Paper Output (cont.) Multifunction Printers
All-in-one devices: Take advantage of fact that different tools can use similar technology Devices can serve as a printer, scanner, color photocopy machine, and fax machine. 86 86
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Color Printing Most printers, like monitors, form images from tiny dots. Most printers mix various amounts of cyan, magenta, yellow, and black pigments to create a color. Matching on-screen color with printed color is difficult. Monitors can display more colors than printers. 87 87
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Fax Machines and Fax Modems
Facsimile (fax) machine: Scans page, converts it to series of electronic pulses, and sends signals over phone lines to another fax machine Fax modem: Translates document into signals that can be sent over phone wires Receiving fax machine uses signals to construct and print facsimile of original pages 88 88
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Output You Can Hear Most PCs have internal speakers
Play system sounds and spoken recordings Sound output jacks for headphones, powered speakers, and other audio output devices High-fidelity music playback Headsets are particularly useful for telephone and teleconferencing applications 89 89
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Controlling Other Machines
Many machines and systems accept orders from computers: Robot arms Telephone switchboards Transportation devices Automated factory equipment Spacecraft 90 90
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Storage Devices: Input Meets Output
Some peripherals perform both input and output functions: Storage devices: Include tape and disk drives Referred to as secondary storage Record information so it can be read later 91 91
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Magnetic Tape Tape drives: Common storage devices on most mainframe computers Can store massive amounts of information on magnetic tape in a small space at a relatively low cost Tape is sequential-access medium, so retrieving information is time consuming Primarily used to back up data No longer tape cartridges – but boxes. Access is still sequential access Used primarily for backing up data and other non-sensitive operations. 92 92
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Magnetic Disks Magnetically coated surface stores encoded information
Provide random access capability Retrieve information rapidly PCs include hard disks as main storage device Older diskettes (floppy disks) and Zip disks have all but disappeared Spins very rapidly and continuously inside computer chassis or separate box Holds hundreds of gigabytes of storage Can hold several books including images, entire music collections, several movie-length clips, and years of photographssssssssssssssssssss 93 93
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Optical Discs Optical disc drives: Use laser beams to read and write data Transparent plastic disc surface protects from physical damage – while letting laser light through Access speeds are slower than for magnetic disks Often used to make backup copies Upper surface is more sensitive to scratching – which leads to deterioration & information loss 94 94
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Optical Discs (cont.) CD-ROM (compact disc—read-only memory) discs – oldest & also identical to those used to store music CD-RW drive: Read data from CD-ROMs; record data onto CD-R and CD-RW discs CD-R (compact disc-recordable)—write-once, read-many CD-RW (compact disc rewritable) erasable Rewritable DVD drives: Commonplace in PCs today Can read and write to CD and DVD media Gradually being replaced by Blu-ray drives DVDs – GB of information. Single disc can hold 4.7 Gb 95 95
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Disc Capacity CD-ROM (read-only CD) CD-RW DVD-ROM DVD) DVD/RW BD/ROM
Blu-ray) BD/RW 4.7 GB (single-layer disc) 27 GB (single-layer 700 MB 9.4 GB (dual-layer disc) 50 GB (dual-layer disc) 96 96
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Internal and External Drives
Hard disk drives and optical disk drives can be external or internal. Internal drives: Reside inside casing of computer External drives: Can be connected through USB or FireWire ports Relatively easy to transport between locations Can be shared between computers 97 97
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Disk Storage Magnetic disks CD-ROM
Coated with a magnetic oxide similar to material used to coat cassette tapes and videotapes Hard disks consists of several platters, each accessed by a read/write head on a movable armature. CD-ROM drive contains a small laser that shines on the disc surface, “reading” reflections. Information is represented optically on bottom surface of CD. CD-ROMs are read only. Magnetic disks – Each divided into sectors and concentric tracks Accessed by a read/write head on a moveable arm-armature Head glides above disk on a thin cushion of air CD-ROM – burns pits on bottom surface in reflective metal film 98 98
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Flash Memory Storage Devices
Flash memory: Type of erasable memory Flash memory cards: Used to store images in digital cameras USB flash drives: Store and transport data Still more expensive than spinning drives Flash memory is too expensive to replace disk drives now, but price is dropping Used now to store digital images (camera), sound (digital recorders), and computer data files Almost certain to become the new standard for storage. 99 99
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Ergonomics and Health Choose equipment that’s ergonomically designed.
Create a healthful workspace. Build flexibility into work environment. Protect your ears. Rest your eyes. Let technology work for you. Stretch. Listen to your body. Don’t leave healthy habits at home. Seek help when you need it. Heavy computer users – repetitive-stress injuries, carpal tunnel syndrom 100 100
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The Computer System: The Sum of Its Parts
Four basic design classes for personal computers: Tower systems: Tall narrow boxes that generally have more expansion slots and bays Flat desktop systems: Designed to sit under the monitor like a platform All-in-one systems: Combine the monitor and system unit into a single housing Laptop computers: Include all essential components in one compact box 101 101
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Ports and Slots Revisited
Legacy ports are too slow for today’s needs: Serial ports send and receive data one bit at a time Parallel ports send and receive bits in groups USB (universal serial bus) transmits data faster: USB 1.0 data transmitted at approximately 11 Mbps USB 2.0 has transfer rates of up to 480 Mbps USB 3.0 has data transfer rate of more than 3 Gbps 102 102
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Ports and Slots Revisited (cont.)
FireWire: A high-speed connection standard developed by Apple Can move data between devices at: 400 Mbps (original version) 800 Mbps (newer FireWire 800) FireWire allows multiple devices to be connected to the same port. Also can supply power to peripherals so they don’t need an external power supply 103 103
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Wireless Peripherals, Network Peripherals, and the Cloud
Wireless technology Wireless keyboards, mice, cameras, printers Computer networks Peripherals communicate with multiple PCs Internet “cloud” Common for computers to use peripherals—especially storage devices—located somewhere in the cloud 104 104
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Chapter 3 Summary Peripherals allow computer to communicate with outside world and store information for later use. Some peripherals are strictly input devices. Others are output devices Storage devices can accept and send information. Keyboard and mouse are most common peripherals. Growing number of devices can support multi-touch technology. 105 105
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Summary (cont.) Bar code readers, optical mark readers, and magnetic ink readers recognize and translate specially printed patterns and characters. Scanners and digital cameras convert photographs, drawings, and other analog images to digital files. Sound digitizers convert information from microphone and other external audio devices. Sensors detect motion, temperature, pressure, and other characteristics. 106 106
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Summary (cont.) Output devices accept strings of bits from the computer and transform them into a form useful outside the computer. Video monitors used to display information Variety of printers produce paper output. Sound output is delivered through speakers and headphones. Output devices allow computers to control other machines. 107 107
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Summary (cont.) Storage devices designed to send and receive large quantities of data Large capacity magnetic disks are most common form of storage because of high-speed random access capability. Optical discs are most common removable storage media Solid-state flash memory is replacing disks and tapes for many applications. 108 108
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Tomorrow’s Technology and You
Digital Planet: Tomorrow’s Technology and You George Beekman • Ben Beekman Tenth Edition Copyright © 2012 Pearson Education, Inc. publishing as Prentice Hall 109
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Digital Planet: Tomorrow’s Technology and You The Ghost in the Machine
Chapter 4 Software Basics The Ghost in the Machine Copyright © 2012 Pearson Education, Inc. publishing as Prentice Hall 110
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Chapter 4 Objectives Describe three fundamental categories of software and their relationships Explain the relationship of algorithms to software Compare and contrast PC applications and Web applications Describe the role of the operating system in a modern computer system 111 111
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Objectives (cont.) Explain how file systems are organized
Outline the evolution of user interfaces from machine-language programming to futuristic interfaces Describe some challenges of applying intellectual property laws to software 112 112
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Processing with Programs
Software enables people to communicate certain types of problems to the computer. Software makes it possible for computers to communicate solutions back to people. An algorithm is a set of step-by-step procedures for accomplishing a task. Programmer’s job is to turn the algorithm into a program by adding details, testing procedures, and debugging or correcting errors. 113 113
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Linus Torvards talking to Linux Fans
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LINUX Operating System
Pronounced “Linn-uks” by its creator Initially developed by Linus Torvalds, based on a scaled-down version of the UNIX operating system. Code is freely available under the GNU (General Public License) Anyone can give away, modify, or even sell Linux as long as the source code (program instructions) remain available for others to modify. Called “Open Source Software. 115
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Open Source Software Thousands of programmers around the world have contributed to Linux. Has matured into a powerful, versatile operating system. Very popular among groups who have to operate on a tight budget, including third world countries. Has motivated many other groups to release open source software. 116
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Categories of Software
Compilers and translator programs Enable programmers to create other software Software applications Serve as productivity tools to help users solve problems System software Coordinates hardware operations 117 117
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A Fast, Stupid Machine Typical computer is only capable of:
Performing basic arithmetic operations Such as and 15 – 8 Performing simple logical comparisons Is this number less than that number? Are these two values identical? Computers seem smart because they perform these operations quickly and accurately. 118 118
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Interacting with Computers
Software allow people to interact with computers. Since computers only recognizes 0’s and 1’s, software provides the bridge that allows programmers to develop software that allow others to solve their problems using computers. A key step was based on the stored-program concept. I.e.,recognizing that programs instructions could be stored in the same manner as data in the memory of a computer. 119
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Creating Programs Instead of flipping switches and patching wires together, today’s programmers write program. I.e., sets of computer instructions designed to solve problems. The large collection of programs stored on a computer to solve problems is computer software 120
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The Language of Computers
Every computer processes instructions in machine language. Numeric codes used to represent basic operations: Adding and subtracting numbers Comparing numbers Moving numbers Repeating instructions Programmers use high-level languages. C++, Java, and Visual Basic 122 122
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Executing a Program Most programs are composed of millions of simple machine-language instructions. The program counter inside the CPU keeps track of the address of the next instruction to be executed. The instruction execution cycle has a three-step rhythm: Fetch the instruction Increment the program counter Perform the specified task 123 123
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Software Applications: Tools for Users
Software applications enable users to control computers without having to think like programmers. 125 125
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Consumer Applications
Thousands of software titles are available: Publishing programs Accounting software Graphics programs Educational titles Games Personal-information managers Programs to solve a wide range of mathematical problems … and many other 126 126
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Documentation Documentation: Instructions for installing and using software—may be printed manuals or digital files Often include “Read Me” files with installation instrutions “Help Files” that provide are often replacements for traditional manuals. These help files can be accessed through local help files on the users computer or else at the company’s website. 127 127
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Updating and Upgrading Software (Added)
Software companies often provide minor free updates that provide bug fixes and improvements several times a year. Major upgrades are often provided every year or two. An upgrade to the next major version of the program usually requires an upgrade fee Most software companies use decimals after the major version number to indicate minor upgrades. 128
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Compatibility (Added)
Compatibility Requirement: Specify the computer or operating systems requirement for a software package. Requirements such as “Windows 7 required” are usually essential. Likewise, requirements such as “Requires 2 GB of RAM” are typically also essential. 129
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Disclamers and Licensing (Added)
Disclaimer—an end-user license agreement (EULA)—protects companies from errors in programs Software is essentially never error-free Licensing: Buy software license not program You will get compiled code, so you do not have to compile it before installing it. Also, prevents you from gaining access to proprietary programs or being able to change them. Distribution by direct sales or download from Web Includes public-domain software and shareware 130
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Web Applications Growing trend toward using applications that run on remote Internet servers instead of local PCs. Google Docs Photoshop.com Webmail programs: Gmail, Hotmail, Yahoo! Mail Multiplayer games Wikis: Wikipedia Retail sites: Amazon.com and online auctions, eBay Online communities: Facebook 131 131
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Web Applications (cont.)
Mashups: Web applications that provide new services by combining data or functionality from two or more external sources Web site might combine crime statistics from a police Web site with maps from Google to create visual representations of where crimes are occurring Another might combine language translation with Web search to allow a user to search for terms in another language 132 132
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Vertical-Market and Custom Software
Basic office applications are used in homes, schools, government offices, and all types of businesses. Other applications are job specific: Medical billing software Library cataloging software Legal reference software Restaurant management software Tend to cost far more than mass-market applications 133 133
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System Software: The Hardware-Software Connection
System software: Class of software that includes the operating system and utility programs Handles low-level details and hundreds of other tasks behind the scenes User does not need to be concerned about details 134 134
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What the Operating System Does
Every computer depends on an operating system to: Keep hardware running efficiently Make process of communication with hardware easier Maintains file system Keeps track of the location of all programs and data files on the hard drive. Supports multitasking In concurrent execution of concurrent processes, the operating system creates dozens of tasks Since CPU can only execute one task at a time, the operating system must do task scheduling. 135 135
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What does the Operating System Do (cont)
Manages virtual memory Space on the hard drive that simulates random access memory. Virtual memory is like RAM, except slower. Processes that are currently inactive can be stored temporarily in virtual memory. Manages authentications (verifying users are who they claim to be) and authorization (ensuring users have permission to perform certain actions) Operating system runs continuously when computer is on 136
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What the Operating System Does
The User’s View 137 137
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Utility Programs Serve as tools for doing system maintenance and repairs not handled by operating system Utilities make it easier for users to: Copy files between storage devices Repair damaged data files Translate files so different programs can read them Guard against viruses and other harmful programs Compress files so they take up less space 138 138
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Device Drivers Small programs that enable input/output devices to communicate with the computer, such as: Keyboards Mice Printers Some device drivers are included in the operating systems. Many are bundled with peripherals Others are sold as separate products 139 139
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Where the Operating System Lives
Some computers store operating systems in ROM Game machines, smart phones, special purpose computes Most modern PCs hold only a small portion of the operating system in ROM Remainder of operating system is loaded during booting, when computer is turned on Handheld devices may store operating system in flash memory 140 140
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The Operating System When you turn on the computer, the CPU automatically begins executing instructions stored in ROM. The operating system (OS) loads from the disk into part of the system’s memory. 141 141
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The Operating System (cont.) The Operating System (cont.)
The OS loads the application program into memory and remains in memory, so it can provide services to the application program—display on-screen menus, communicate with the printer, and perform other common actions. 142 142
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The Operating System (cont.) The Operating System (cont.)
To avoid losing your data file when the system is turned off, save it to the disk. When you reopen the file, the OS locates it on the disk and copies it into memory. 143 143
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The User Interface: The Human–Machine Connection
User interface: Critically important component of software Early users spent tedious hours writing and debugging machine-language instructions. Later users programmed using easier languages that were still challenging. Now, most users work with preprogrammed applications. 144 144
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Desktop Operating Systems
MS-DOS: Standard on IBM-compatible computers in Used command-line interface that required users to type commands Apple Macintosh introduced windows, icons, and mouse-driven, drop-down menus in 1984. Windows and Mac OS started as single-user operating systems but today support multiple users. 145 145
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Early Operating Systems
MS-DOS (Microsoft Disk Operating Systems) became the standard operating system on IBM compatible computers Had a command-line interface and user typed commands that the computer responded to. Applications usually had a menu-driven interface that allowed users to choose commands from on-screen lists. The Apple Macintosh introduced in 1984 replaced typed commands and menu lists with windows, icons, and mouse-driven drop-down menus 146
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Early Operating Systems (cont)
The Mac was the first low-cost computer that had an operating system designed with a graphical user interface (GUI) , called “gooey” Windows and Mac OS have evolved over the years, adding new features to their GUIs that make them easier to use. While both were single user operating systems originally, they both support multiple users today. 147
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UNIX and Linux UNIX: Command-line, character-based OS
Internet is populated with computers running UNIX Enables timesharing computer to communicate with several other computers at one time OS of choice for workstations and mainframes in research and academic settings Favored by many who require an industrial-strength, multiuser OS Linux, a UNIX clone, is distributed and supported free 148 148
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UNIX and Linux (cont) UNIX is a command-line character-based operating system. The command-line interface called its shell is similar to MS-DOS, but commands are different and much more powerful. 149
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When Good Software Goes Bad
Restart the application Recover your work Reboot the system Recheck for updates Reboot in safe mode Research your problem Request help Reinstall the program Restore the operating system Repair the hardware Replace the system Recycle your old computer 150 150
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When Good Software Goes Bad
Be sure to save your work first, if possible. If system freezes, use system’s force-quit option to shut it down In windows, Ctrl + Alt + Del, and then click Task Manager. Next, select the frozen program from list and click on End Task. Some applications have an “automatic save” that saves your work every few minutes. You should save your work frequently, to avoid loss 151
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Good Software Goes Bad (cont)
Rebooting the system will solve an amazing number of problems. Cleans out bad data and resets parameters that may be messed up due to buggy software If computer is locked down, force a shutdown by holding down the power button on your computer for a few seconds. Check you application software for updates and download and install them if needed. Reboot in safe mode – to avoid problems with other programs that run in the background On windows, press F8 key on keyboard as machine is booting and then select arrow to choose “Safe Mode” 152
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Hardware and Software Platforms
Microsoft Windows 7: Introduced in 2009 is latest version Microsoft Windows Server: Runs on small servers to the mightiest hardware Windows Embedded CE: Designed for devices such as robots, voting machines, music players, etc. Windows Phone 7: New OS for mobile phones Mac OS X (10): Standard for the Mac 153 153
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Hardware and Software Platforms (cont.)
iOS: Used for iPhone, iPad, and iPod Linux, Sun Solaris, and other Unix variations Google Chrome OS: Linux based OS for low-cost PCs, netbooks, and tablet devices Google Android: Designed for smart phones Blackberry OS: Proprietary multitasking OS Palm WebOS: Proprietary smart phone OS 154 154
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Compatibility Issues Operating systems are designed to run on particular hardware platforms. Applications are designed to run on particular operating systems. Most cloud applications are designed to run on multiple platforms. 155 155
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File Management: Where’s My Stuff?
One of the challenges of working with a computer is keeping track of the masses of information that can be collected, edited, and stored on disks. Most computers use some kind of hierarchical file system involving directories or folders to organize files. 156 156
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Organizing Files and Folders
Files may be placed in folders. Folders can be placed inside folders. Every file and folder has a unique pathname. 157 157
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Windows Explorer and the Finder: File Managers
File management utility: Makes it easy to view, rename, copy, move, and delete files and folders In Windows it is called Windows Explorer In the Mac OS it is called the Finder Can display information about a file such as size, its type, and the last time it was modified 158 158
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Windows Explorer and the Finder: File Managers (cont.)
Windows Explorer allows you to see the contents and location of the folder in the storage device’s hierarchy. 159 159
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Managing Files from Applications
Most applications support four basic file-management operations: Open: Allows you to select the file you want to work on Save: Writes current application as a disk file Save As: Allows you to choose the location and name of the file Close: Allows you to stop working on a project without quitting the application 160 160
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Locating Files Organize files logically
Store documents in folder called Documents Store photos in folder called Pictures Store music in folder called Music Modern operating systems include search tools Search for filenames or for words and phrases Virtual folders contain files that match certain criteria no matter where they are located 161 161
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Disk Formatting Hard disks are formatted by manufacturer before installing operating system: Electronic marks are put on disk. Disk is divided into series of concentric tracks. Tracks are divided into sectors. Sectors are bundled into clusters or blocks. File system provides way to link multiple clusters to store large files 162 162
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Defragmentation Contents of file may become scattered over clusters.
Accessing information is faster if file is assigned to contiguous clusters. A defragmentation utility eliminates fragmented files. 163 163
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Software Piracy and Intellectual Property Laws
Software piracy: Illegal duplication of copyrighted software—is rampant Few software companies use physical copy protection methods and that makes copying easy Many people unaware of laws Others simply look the other way 164 164
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The Piracy Problem Software industry loses billions of dollars every year to software pirates. Business Software Alliance (BSA) estimates that more than one-third of software in use is illegally copied. Piracy is particularly hard on small companies. Piracy rates are highest in developing countries. Industry organizations work with law enforcement agencies to crack down on piracy. 165 165
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Intellectual Property and the Law
Intellectual property: Includes the results of intellectual activities in the arts, science, and industry Copyright laws: Protects books, plays, songs, paintings, photographs, and movies Trademark law: Protects symbols, pictures, sounds, colors, and smells. Patent law: Protects mechanical inventions Contract law: Covers trade secrets Under the law, software does not fit in these categories. 166 166
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Chapter 4 Summary Software provides communication link between humans and computers. Three main categories: translator programs, applications, and system software. Applications and documentation can be delivered on physical media or downloaded from the Web. Programmers develop vertical-market and custom packages when general commercial programs won’t do the job. 167 167
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Summary (cont.) Computer’s operating system functions behind the scenes, translating software’s instructions into messages hardware can understand. Popular operating systems include: Microsoft Windows, Mac OS X, UNIX, and Linux. Operating system manages programs and data files. Utility programs handle problems that operating system can’t solve. 168 168
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Summary (cont.) Well-designed user interface shields user from bits and bytes. Computer industry has moved towards friendlier graphical user interfaces. Future interfaces are likely to depend more on voice, 3D-graphics, and animation. Computers use hierarchical file system. Software piracy has flourished in many countries. 169 169
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Tomorrow’s Technology and You
Digital Planet: Tomorrow’s Technology and You George Beekman • Ben Beekman Tenth Edition Copyright © 2012 Pearson Education, Inc. publishing as Prentice Hall 170
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Digital Planet: Tomorrow’s Technology and You
Chapter 5 Productivity Applications Copyright © 2012 Pearson Education, Inc. publishing as Prentice Hall 171
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Chapter 5 Objectives Describe how PC and Web applications have revolutionized writing and publishing Discuss the potential impact of desktop publishing and Web publishing on freedom of the press Speculate about future developments in digital publishing Explain how computers can be used to answer what-if questions 172 172
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Objectives (cont.) Describe the functions and applications of spreadsheets and other types of statistical and simulation programs Explain how computers are used as tools for simulating mechanical, biological, and social systems 173 173
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The Wordsmith’s Toolbox
In a single generation the writing process has been transformed by word processing software. A writer can focus on developing ideas and let the machine take care of laying out words on a page. 174 174
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Donald Knuth &TEX The researcher whose work made all of this possible was Dr. Donald Knuth at Stanford University. Originally a student at CWRU in Cleveland who had an insatiable thirst for knowledge in computer science and mathematics. Had close ties with a Distinguished Professor Richard Varga in mathematics at Kent State. Prior to completion of masters, he secured a contract with Addison Wesley Publishers to write a comprehensive series of reference books in computer science and overlapping areas of mathematics called “Art of Computer Programming” Now retired from Stanford, he is devoted to bringing to completion a series covering about 7 different areas. 175
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Donald Knuth (cont) Currently has hired a large team of current and former graduate students at Stanford to move this project forward. Became upset when the book type setters for Addison Wesley (who physically created each page to be printed) could not print all of this reference books in this series using the same font and style. Created TEX software that could be used to control the formatting of printed pages, selecting font type and size, footnoting, and all aspects of printing. Set up copyrights this extremely valuable knowledge moved into the public domain – allowing very rapid developments Assignment: Use search engine to locate Donald Knuth’s webpage at Stanford University and answers to wide range of questions. 176
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Word Processing Tools and Techniques
Working with a word processor involves: Entering text Editing text Formatting the document Proofreading the document Saving the document Printing the document WYSIWYG (“wizzy-wig”) for “What You See is What You Get” word processing. 177 177
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Word Processing Tools and Techniques
Text Formatting Paragraph Character Select font and font size Change color of character Use boldface, italics, and/or underline Control space between lines Set indentation and tab stops Justification Alignment of text on a line Left, right, justify, or center 178 178
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Word Processing Tools and Techniques
Document Formatting Margins Headers Styles Columns Tables Macros Templates Footnoting Hyphenation Autoformat Autocorrect Wizards 179 179
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Font Technology A bitmapped font stores characters as a collection of tiny dots or squares. A scalable font represents each character as an outline that can be scaled without distortion. Downloadable fonts (soft fonts) are stored in the computer system and downloaded to the printer only when needed. 180 180
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Outliners and Idea Processors
Outliners: Effective at performing these functions: Arranging information into hierarchies Rearranging ideas and levels so subideas are automatically moved with parent ideas Hiding and revealing levels of detail as needed 181 181
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Digital References References available on the Web include:
Dictionaries Quotation books Encyclopedias Atlases, almanacs Thesaurus tools 182 182
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Spelling Checkers Correct spelling is an important part of written communication. Word processors include built-in spelling checkers. Flag words not in dictionary Suggest corrected spelling Careful proofreading is still essential. No dictionary contains all words. Correct spelling of words depends on the context of the sentence in which they are used. “I wood never have guest that my spelling checker would super seed my editor as my mane source of feed back.” 183 183
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Grammar and Style Checkers
Check spelling Analyze each word in context Point out possible errors Suggest improvements Typical program misses many true errors Not a substitute for practice, revision, and editing 184 184
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Form-Letter Generators
Most word processors include mail merge Produce personalized form letters Generate individually addressed letters and mailing labels Used with database of names and addresses Can incorporate custom paragraphs Makes each letter look individually written 185 185
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Collaborative Writing Tools
Large writing projects involve groups of people working together Computer networks make it easy for people to share documents Groupware keeps track of document’s history Individuals make suggested changes Changes are incorporated into a single master document Allow many people to work on manuscript at the same time. Microsoft Word’s Track Changes can mark and highlight the changes of many authors. 186 186
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Emerging Word Tools Word processing software has evolved rapidly
Current trends suggest big changes are coming Processing handwriting Processing speech Intelligent word processors 187 187
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Processing Handwriting
Pen-based systems provide an alternative tool for entering text. Handwriting recognition requires sophisticated software to interpret pen movements as characters and words. Diversity in handwriting makes it difficult to translate scribbles into text. 188 188
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Processing Speech User tells computer what to type and how to type it by talking into a microphone. User’s speech enters computer as digital audio signal. Speech recognition software looks for patterns in the sound waves. Interprets sounds by locating familiar patterns Segments input sound patterns into words Separates commands from text Passes commands to word processing software Dictation software can achieve accuracy approaching 100% under ideal conditions and “trained” to speaker. 189 189
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Intelligent Word Processors
Some possibilities for future word processors: Remind you that you have used the same word several times in the last few paragraphs Analyze writing style as you type Modify your writing to conform to organizational style guidelines Perform search of literature on the Web and report back relevant facts 190 190
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The Desktop Publishing Story
Publishing was traditionally an expensive, time-consuming, error-prone process. World of publishing was radically transformed in the s. Apple introduced first LaserWriter printer. Aldus introduced PageMaker for the Macintosh. Desktop publishing became an enterprise for anyone with a computer and a little cash. 191 191
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What Is Desktop Publishing?
Process of producing a book, magazine, or other publication includes: Writing and editing text Producing drawings, photographs, and other graphics Designing a basic format Arranging text and graphics on pages Typesetting and printing pages Binding pages into a finished publication 192 192
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Why Desktop Publishing?
Offers advantages for businesses Saves money Publishing in-house costs fractions of former costs Saves time Turnaround is days instead of weeks or months Quality control is easier to maintain Makes it easy to repurpose content for use on Web Individuals have affordable publishing alternatives 193 193
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Creating Professional-Looking Documents
Plan before you publish Use appropriate fonts Don’t go style-crazy Don’t go color-crazy Look at document though reader’s eyes Learn from a master Know your limitations Remember the message 194 194
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Creating Professional-Looking Documents
Bad Good Comparison of documents 195 195
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Beyond the Printed Page
The first books were so difficult to produce, they were considered priceless. Today we can print professional-quality publications in short order using equipment that costs less than a used car. 196 196
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Paperless Publishing and the Web
Some predict that paper publishing will be replaced by electronic media. Paper still offers advantages for countless tasks. Reading printed words is easier on the eyes. Paper documents can be read without electricity. No equivalent for the aesthetics of a beautifully designed, finely crafted book. Digital media are likely to eclipse paper for many applications. 197 197
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Paperless Publishing and the Web (cont.)
Offers unprecedented mass publishing possibilities to millions of Internet users. Many programs can save documents in HTML format Microsoft Word, Adobe InDesign, Apple Pages. Other programs are specifically designed for Web publishing. Offer advanced capabilities for layout, graphics, animation, and multimedia publishing 198 198
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E-Books, E-Readers, and E-Paper
E-book: digital version of a book May be read on a computer, PDA, smart phone, and/or an e-reader E-readers: handheld devices for reading digital publications E-paper: display technology used by most e- readers to look more like ordinary paper than an LCD display Isn’t backlit so more readable in sunlight Stays on even when powered down. No universal standard for ebooks- simple file, PDF, EPUB. 199 199
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The Spreadsheet: Software for Simulation and Speculation
Spreadsheet software enables users to take control of numbers; can make short work of tasks that involve repetitive calculations: Budgeting Investment management Business projections Grade books Scientific simulations Checkbooks 200 200
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The Malleable Matrix A spreadsheet document, called a worksheet, typically appears on the screen as a grid of numbered rows and lettered columns. Cell: intersection of a row and column Each cell contains: A numeric value An alphabetic label A formula representing a relationship in other cells Rows and Columns are often labels such as “Midterm Exam, Total Points, Monthly Wages, etc. 201 201
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The Malleable Matrix (cont.)
Spreadsheet programs share these features: Managing lists Automatic replication Automatic recalculation Predefined functions Mathematical, statistical, financial, programming -IF, etc. Macros Capture sequence of steps to allow them to be used repeatedly Formatting Templates and wizards Validation Linking Database capabilities 202 202
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“What If?” Questions Spreadsheets are valuable for answering “what if?” questions. You can change numbers and instantly see the effects of those changes Some spreadsheet programs include equation solvers that: enable you to define an equation enter your target value let the computer determine the necessary data values 203 203
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Spreadsheet Graphics: From Digits to Drawings
Spreadsheet programs include charting and graphing functionality: Pie charts: show relative proportions of parts to whole Line charts: show trends over time Bar charts: similar to line charts; more appropriate when data falls into a few categories Stack charts: show how proportions of a whole change over time Scatter charts: help discover a relationship between two variables 204 204
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Avoiding Spreadsheet and Charting Errors
Plan worksheet before entering values and formulas Make assumptions as accurate as possible Double-check every formula and value Make formulas readable Check output against other systems 205 205
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Avoiding Spreadsheet and Charting Errors (cont.)
Build in cross-checks Change the input data values and study the results Take advantage of preprogrammed functions, templates, and macros Use spreadsheet as decision-making aid, not as decision maker Take advantage of built-in error checking tools 206 206
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Avoiding Spreadsheet and Charting Errors (cont.)
Choose the right chart for the job Put the data first in the charts Avoid graphic distractions Make it easy to compare data in your charts Don’t distort data Relate your chart to the rest of the document Learn from the experts 207 207
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Avoiding Spreadsheet and Charting Errors (cont.)
CLEAR CLUTTERED MISLEADING CONFUSING 208 208
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Statistical Software: Beyond Spreadsheets
Spreadsheet software is versatile, but no program is perfect for every task. Other types of number-manipulation software are available for situations in which spreadsheets don’t quite fit the job. 209 209
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Money Managers Most businesses use professionally designed accounting and financial-management software. Records transactions—checks, cash payments, charges, and other activities Automatically adjusts the balance in every account after each transaction Can export records to programs that calculate income taxes Most popular is Intuit’s Quicken (or Quickbooks for businesses.) 210 210
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Automatic Mathematics
Higher mathematics is an essential part of the work of scientists, researchers, engineers, architects, economists, financial analysts, teachers, and others. Math-processing software makes it easier for mathematicians to create, manipulate, and solve equations A math processor generally includes an interactive, question-and-answer mode, a programming language, and tools for creating interactive documents that combine text, numerical expressions, and graphics Includes Mathematica, Matlab, Reduce and others 211 211
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Statistics and Data Analysis
Statistics—science of collecting and analyzing data— has become more important in computer age Statisticians in government, business, and science depend on computers to make sense of raw data Statistical-analysis software can suggest answers to questions by testing strength of data relationships. Can suggest relationships by providing 2D and 3D graphs. 212 212
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Scientific Visualization
Scientific-visualization software uses shape, location in space, color, brightness, and motion Scientific visualization involves the graphical representation of numerical data 213 213
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Fractal Geometry and Simulation
Computers have been used to analyze and visualize scientific data collected through experiments and observation. A computer also can serve as a virtual laboratory Problem of creating an accurate simulation helped initiate the study of chaos and fractals Chaos is now a vast field of study with applications in many disciplines. 214 214
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Calculated Risks: Computer Modeling and Simulation
Computer modeling is the use of computers to create abstract models of objects, organisms, organizations, and processes. Can be created for work, education, or play, to mimic some type of system A computer simulation allows you to see how the model will operate under certain conditions. 215 215
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Computer Simulations: The Rewards
Widely used for research in physical, biological, and social sciences, and in engineering for these reasons: Safety Economy Projection Visualization Replication 216 216
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Computer Simulations: The Risks
Capturing the subtlety and complexity of the real world is a tremendous challenge Accuracy depends on how closely mathematical model corresponds to system being simulated. Some simulations are so complex they need to be simplified to get them to run on available hardware. Risks are magnified because people take computer reports seriously at expense of other sources of knowledge. 217 217
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Productivity on a Student Budget
Low-cost or free software alternatives are available. Most programs can save files in formats compatible with Microsoft Office so they can be shared with Office users. Software program Alternative for: OpenOffice Microsoft Office Zoho Writer or Google Docs Microsoft Word Zoho Sheet or Google Spreadsheet Microsoft Excel Zoho Show or OpenOffice Impress Microsoft PowerPoint Scribus Desktop Publishing 218 218
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Chapter 5 Summary Word processing software enables the writer to edit and format text on the screen before printing. Desktop publishing produces professional-quality text and graphics documents at a reasonable cost. The Web makes it possible for publishers to reach mass audiences without the problems associated with printing and distributing paper documents. 219 219
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Summary (cont.) Spreadsheet programs are used for tracking financial transactions, forecasting economic conditions, recording scientific data, and other tasks that involve repetitive numeric calculations. Specialized accounting and tax preparation software packages perform specific financial functions. Symbolic mathematics processors can handle a variety of higher mathematics functions involving numbers, symbols, equations, and graphics. 220 220
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Summary (cont.) Statistical-analysis software is used for data collection and analysis. Scientific visualization can be done with math processors, statistical packages, graphics programs, or specialized programs designed for visualization. Computer simulation can be a powerful tool for helping people understand their world and make better decisions. 221 221
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Tomorrow’s Technology and You
Digital Planet: Tomorrow’s Technology and You George Beekman • Ben Beekman Tenth Edition Copyright © 2012 Pearson Education, Inc. publishing as Prentice Hall 222
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Digital Planet: Tomorrow’s Technology and You
Chapter 6 Graphics, Digital Media, and Multimedia Copyright © 2012 Pearson Education, Inc. publishing as Prentice Hall 223
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Chapter 6 Objectives Explain the difference between painting software, image-processing software, drawing software, and 3-D modeling software Explain effective techniques for improving the quality of slides prepared with presentation-graphics software Describe how digital technology is used in video and audio production today 224 224
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Chapter 6 Objectives (cont.)
Describe how data compression works Describe several present and future applications for multimedia technology 225 225
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Tim Berners-Lee Weaves the Web for Everybody
Born in London in 1955 Wanted to create an open-ended, distributed hypertext system with no boundaries, so scientists everywhere could link their work together Invented the World Wide Web Heads the World Wide Web Consortium (W3C) 226 226
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Painting: Bitmapped Graphics
Pixels: tiny dots of white, black, or color that make up images on the screen Painting software: Paints pixels on the screen with a pointing device Pointer movements are translated into lines and patterns on the screen Palette of tools mimics real-world painting tools 227 227
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Painting: Bitmapped Graphics
Bitmapped graphics (or raster graphics): pictures show how the pixels are mapped on the screen Gray-scale graphics: uses 8 bits per pixel; allows up to shades of gray Color depth: number of bits devoted to each pixel Resolution: density of the pixels; described as DPI (dots per inch) Anti-aliasing: smoothes out less-than-ideal resolutions 228 228
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Image Processing: Photographic Editing by Computer
Image processing: users manipulate photographs with tools such as Adobe Photoshop More powerful than traditional photo-retouching techniques Can distort and combine photos Can create fabricated images that show no evidence of tampering 229 229
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Image Processing: Photographic Editing by Computer (cont.)
Digital photo management software programs simplify and automate common tasks associated with capturing, organizing, editing, and sharing digital images. Apple iPhoto Google Picasa Adobe Lightroom 230 230
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Drawing: Object-Oriented Graphics
Drawing software stores a picture as a collection of lines and shapes (called object-oriented or vector graphics). Many drawing tools—line, shape, and text tools—are similar to painting tools in bitmapped programs. 231 231
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Drawing: Object-Oriented Graphics (cont.)
PDF (portable document format): file format developed by Adobe; enables digital documents to be exchanged between programs independent of application software, hardware, or operating system Can contain text, fonts, images, and vector graphics Can be displayed by Web browsers using Adobe’s Acrobat Reader 232 232
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Drawing: Object-Oriented Graphics (cont.)
Bitmapped painting (pixels) gives you these advantages: More control over textures, shading, and fine detail Appropriate for screen displays, simulating natural paint media, and embellishing photographs Object-oriented drawing gives you advantages, such as cleaner lines and smoother shapes 233 233
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Drawing: Object-Oriented Graphics (cont.)
Some integrated programs contain both drawing and painting modules. Allows you to choose the right tool for each job Some programs merge features of both in a single application. Blurs the distinction between types New possibilities for amateur and professional illustrators 234 234
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Creating Smart Art Choose the right tool for the job
Always keep a native copy Know your graphics file formats Borrow from the best Don’t borrow without permission Understand your rights: Consider letting others build on your work: org 235 235
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3-D Modeling Software 3-D modeling software: used to create three- dimensional objects with tools similar to those in drawing software Goal for some applications: to create an animated presentation rather than a printout Flexible: can create a 3-D model, rotate it, view it from different angles Can “walk-through” a 3-D environment that exists only in the computer’s memory 236 236
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CAD/CAM: Turning Pictures into Products
(CAD) computer-aided design: allows engineers, designers, and architects create designs on screen products ranging from computer chips to public buildings Can create 3D, solid models with physical characteristics like weight, volume, center of gravity Cheaper, faster, and more accurate than traditional design-by-hand techniques Can do stress tests to evaluate the structural performance of any part of the model 237 237
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CAD/CAM: Turning Pictures into Products
CAM (computer-aided manufacturing): process by which data related to the product design are fed into a program that controls the manufacturing of parts CIM (computer-integrated manufacturing): combination of CAD/CAM 238 238
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Making Powerful Presentations
Make plan before create slides Determine slide count Outline ideas Keep each slide focused Use large letters Be smart with art Keep it simple Do test run before making presentation Don’t read slides Pause when revealing new slide or bullet 239 239
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Dynamic Media: Beyond the Printed Page
Modern media contains dynamic information: information that changes over time or in response to user input Animation Video Audio Hypertext 240 240
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Presentation Graphics: Bringing Lectures to Life
Presentation graphics: automates creation of visual aids for lectures, training sessions, sales demonstrations, and other presentations Creates slideshows directly on computer monitors or LCD projectors, including still images, animation, and video clips 241 241
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Animation: Graphics in Time
Each frame a computer-drawn picture; frames are displayed in rapid succession Tweening: instead of drawing each frame by hand, the animator can create key frames and objects and use software to help fill in the gaps Vector graphics formats Shockwave Flash Format (SWF) Scalable Vector Graphics (SVG) 242 242
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Desktop Video: Computers, Film, and TV
Analog and digital video A video digitizer can convert analog video signals from a television broadcast or videotape into digital data. Many video digitizers can import signals from televisions, videotapes, video cameras, and other sources. Digital video cameras capture footage in digital form. Digital video can be copied, edited, stored, and played back without any loss of quality. 243 243
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Video Production Goes Digital
Storyboard describes the action, dialogue, and music in each scene. Nonlinear editing of clips stored on the hard disk can be done in any sequence. Video-editing software, such as Adobe Premiere, makes it easy to eliminate extraneous footage, combine clips from multiple takes, insert visual transitions, superimpose titles, synchronize a soundtrack, and create special effects. 244 244
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Video Production Goes Digital (cont.)
After editing, videos can be made into DVDs or Blu- ray movies. Video podcasts and posting to YouTube.com are also ways of distributing your videos. Many videos are distributed for free. 245
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Data Compression Saves storage space
Allows the processor to keep up with the quickly changing frames Image-compression software: compresses graphics and video files QuickTime Windows Media Player 246 246
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The Synthetic Musician: Computers and Audio
Synthesized: digital recording of computer sounds Sound data is sometimes called waveform audio. Recorded sound can consume massive amounts of space on disk and in memory. Higher quality results from higher sampling rates. Number of sound “snapshots” the recording equipment takes each second 247 247
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Samplers, Synthesizers, and Sequencers: Digital Audio and MIDI
Synthesizer: electronic instrument synthesizes sounds using mathematical formulas MIDI (musical instrument digital interface): standard interface allows electronic instruments and computers to communicate with each other Sequencing software: used to interpret the sequence of MIDI commands 248 248
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Samplers, Synthesizers, and Sequencers: Digital Audio and MIDI (cont.)
A piano-style keyboard sends MIDI signals to the computer; computer interprets the MIDI commands using sequencing software 249 249
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Samplers, Synthesizers, and Sequencers: Digital Audio and MIDI (cont.)
Sequencing software: turns computer into musical composing, recording, and editing machine Virtual instruments: instruments that exist only in software Electronica: music designed from the ground up with digital technology 250 250
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Digital Audio Dos and Don’ts
Don’t steal Understand downloading and streaming Know your file formats Don’t overcompress Protect your ears 251 251
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Digital Audio Dos and Don’ts (cont.)
Popular digital audio formats 252
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Hypertext and Hypermedia
Hypertext: information linked in nonsequential ways Hypermedia: combines text, numbers, graphics, animation, sound effects, music, and other media in hyperlinked documents Useful for online Help files Enables the user to jump between documents all over the Internet 253 253
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Hypertext and Hypermedia (cont.)
Hypermedia documents can be disorienting and leave you wondering what you’ve missed Documents don’t always have the links wanted Authors can’t build every possible connection into documents Some readers get frustrated because they can’t easily get “there” from “here” 254 254
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Hypertext and Hypermedia (cont.)
Documents sometimes contain “lost” links, especially on the Web, where even a popular page can disappear. Documents don’t encourage scribbled margin notes, highlighting, or turned page corners for marking key passages. Hardware can be hard on humans. The art of hypermedia is still in its infancy. 255 255
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Interactive Multimedia: Eye, Ear, Hand, and Mind
Multimedia: combination of text, graphics, animation, video, music, voice, and sound effects allows the user to take an active part in the experience Requirements: high-quality color monitors, fast processors, large memory, CD–ROM drives, speakers, and sound cards Many of today’s Web pipelines can’t deliver large media files quickly enough 256 256
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Multimedia Authoring: Making Mixed Media
Multimedia authoring software: used to create and edit multimedia documents Uses authoring programs such as Adobe Flash Binds source documents together to communicate with users in an aesthetically pleasing way 257 257
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Creating an Effective Interactive Experience
Be consistent Make it intuitive Strive for simplicity Keep it lively Message more important than the media Put the user in the driver’s seat Let real people test your designs 258 258
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Interactive Media: Visions of the Future
Offers hope communication may become participatory again. Some still fear interactive media will make it possible to be further removed from society. 259 259
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Inventing the Future: Shared Virtual Spaces
Virtual reality: combines virtual worlds with networking Places multiple participants in a virtual space People see representations of each other, sometimes called avatars. Most avatars today are cartoonish, but they convey a sense of presence and emotion. 260 260
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Inventing the Future: Shared Virtual Spaces
Tele-immersion: allows multiple-remote users to interact with each other and with computer- generated objects Participants move around in shared virtual spaces, while maintaining their unique points of view. AR (augmented reality): adds virtual information to your sensory perceptions 261 261
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Chapter 6 Summary Computer graphics today encompass more than quantitative charts and graphs generated by spreadsheets. Computers today aren’t limited to working with static images; they’re widely used to create and edit documents in media that change over time or in response to user interaction. The interactive nature of the personal computer makes it possible to create nonlinear documents that enable users to take individual paths through information. 262 262
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Chapter 6 Summary (cont.)
Hypermedia documents are interactive documents that mix text, graphics, sounds, and moving images with on-screen navigation. Multimedia computer systems make a new kind of software possible—software that uses text, graphics, animation, video, music, voice, and sound effects to communicate. 263 263
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Chapter 6 Summary (cont.)
Regardless of the hardware, interactive multimedia software enables the user to control the presentation rather than watch or listen passively. 264 264
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Tomorrow’s Technology and You
Digital Planet: Tomorrow’s Technology and You George Beekman • Ben Beekman Tenth Edition Copyright © 2012 Pearson Education, Inc. publishing as Prentice Hall 265
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Digital Planet: Tomorrow’s Technology and You
Chapter 7 Database Applications and Privacy Implications Copyright © 2012 Pearson Education, Inc. publishing as Prentice Hall 266
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Chapter 7 Objectives Explain what a database is and describe its basic structure Identify the kinds of problems that can be best solved with database software Describe different kinds of database software, from simple file managers to complex relational databases 267 267
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Chapter 7 Objectives (cont.)
Describe database operations for storing, sorting, updating, querying, and summarizing information Give examples of ways in which large databases make our lives safer or more convenient Explain how databases threaten our privacy 268 268
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The Google Guys Search for Tomorrow
Google is one of the great success stories of the Internet. Handles hundreds of millions of queries a day Launched by two Stanford Ph.D. students In 2004, Google offered shares to the public. 269 269
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More About Google Pg 235-7 270
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What Good Is a Database? Comparable to a computerized file cabinet
Databases make it easier to: Store large quantities of information Retrieve information quickly and flexibly Organize and reorganize information Print and distribute information in a variety of ways 271 271
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Database Anatomy Database: organized collection of information stored in a computer Database program: software tool for organizing storage and retrieval of that information 272 272
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Database Anatomy (cont.)
Table: collection of related information Record: information related to one person, product, or event Each discrete chunk of information in a record is a field Field: holds different types of data: Numeric Date Text Computed 273 273
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Database Operations Import: receive data in the form of text files
Browse: navigate through information Query: find records that match specific criteria Sort: rearrange records (alphabetically or numerically) Print: reports, labels, and form letters Export: to another program for printing 274 274
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Database Operations (cont.)
Structured Query Language (SQL): Standard language for programming complex queries Graphical user interfaces allow point-and-click queries Is available for most database-management systems Users can avoid learning a new language when working with different hardware and software systems 275 275
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Complex Queries Can be constructed to find
The names and location of all patients in a hospital database that are on the fifth and sixth floors In a database of airline flight schedules, the least expensive way to fly from Boston to San Francisco on Tuesday afternoon. In a politicians database, all voters who contributed over $1,000 to last year’s campaign and who wrote to express concern over high taxes since the election. 276
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Complex Queries (cont.)
The exact method for performing a query depends on the user interface of the database software used. Most allow user to specify the rules of the search by filling in a dialog box or a blank on-screen form A few (usually older) require the user to type their request using a specific query language. For example, you might have to type Select * From Population Where Sex = ‘M’ and Age > = 18 and Age < = 35 Many database programs include programming languages that allow queries to be included. 277
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Smart Web Searching Get to know your search engines.
Be specific when you search. Use quotes to narrow your search to exact strings Know your pluses and minuses. Plus is assumed between listed items Search by site. Site may have search box Be selective. Are sites reputable? Bad information is worse than no information. Triangulate. If at first you don’t succeed, try another approach. 278 278
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Special-Purpose Database Programs
On home or student PC, most of the storage is taken up with media files Media Libraries: music and photo libraries Media professionals use industrial-strength databases to catalog art, photographs, and other media files PIM (personal information manager): electronic organizer like Microsoft Outlook also includes . Automates address/phone book, appt calendar, to-do list, various notes. May need to share group calendars Most smart phones include these functions. Software can be used to synchronize multiple platforms Best sync software makes process simple and all-but-invisible 279 279
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Special Purpose Database Programs (cont)
GIS (geographical information systems): include geographic and demographic data in map form Most users familiar with MapQuest, Google Maps, etc. Often used in conjunction with GPS receivers to provide travel information. A GIS system is much more advanced than this. Can combine tables such as customer sales list with information from U.S. Census records to identify best location to build a new branch store. Web databases: use XML to turn static pages into a database-driven information space Transforming Web into a collection of mostly static pages to a dynamic database driven information space. 280
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The Language of Database Queries
SQL statements are understood by MS Access, MS SQL Server, DB2, Oracle, Sybase, MySQL and others. SQL is a sublanguage that: Uses high-level, easy-to-understand statements Has a relational database orientation Is portable across a wide range of systems 281 281
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Beyond the Basics: Database- Management Systems
What is a database-management system? A DBMS can manipulate data in a large database Data redundancy: wastes space and may cause inaccuracies Data consistency: all tables must contain the correct information 282 282
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Example: Student Database Management System
Student ID, grade transcripts, financial records, telephone and address information, home contact information, major and requirements to graduate, etc. Also have course enrollment information, faculty information, etc. Update to any data items (e.g., current academic address) must be available to all other sources. Until recently, different offices kept separate database record systems. Now many use Banner, which is a front end –usually for an Oracle database system 283
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Beyond the Basics: Database- Management Systems (cont.)
What makes a database relational? Tables related – possibly over tables. Changes in one table reflected in other tables Predominate model in use today Oracle produced the first relational database Almost all Fortune companies use Oracle Fig 7.14 284 284
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Database Trends Real-time computing
Allows instant access to information. Interactive processing: allows users to access data in real time The trend toward real-time computing is accelerated by the Internet. Batch processing: requires transactions to be accumulated and then fed into computers in large batches 285 285
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Database Trends Downsizing and decentralizing Distributed databases
Client/server approach: uses requests to access database Distributed databases: spread data across networks Distributed databases Spreads data across networks: Kept on several different computers rather than store it in one central site. Connectivity software called middleware links client and server machines and hide the interaction between those machines. Data warehouses: large, centralized systems housing enterprise data Used normally in large companies and government depts 286 286
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Database Trends (cont.)
Data mining: discovery of hidden predictive information Helps to predict trends and patterns in data Uses statistical and artifical intelligence methods Maintaining database integrity Real-time database access increases the probability of data errors. Accessed by everyone, not just professionals. Dirty data: records containing errors Outdated addresses, spelling errors, obsolete values 287 287
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Database Trends (cont.)
Data scrubbing: eliminating dirty data Errors can lead to inefficiency and/or bad business decision Object-oriented databases: store objects Next expected change in databases Every object is an instance of a class. The class includes the data and the operations. The class specifies the data that is stored as well as the operations that can be used. Example is a “photograph” and data includes description, photographers name, copyright status. Operations includes creating a thumbnail-sized copy of photo 288 288
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Database Trends (cont.)
Some companies are experimenting with a combination of relational and objective oriented databases. Multidimensional database technology: stores data in more than two dimensions Based on traditional relational databases Data is organized in cubes. Provide faster access by users than traditional relational databases. 289
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Database Trends (cont.)
Intelligent searches More artificial intelligence technology Natural language queries possible Contextual search tools will classify results 290 290
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Dealing with Databases
Choose the right tool for the job. Don’t use a large company using a spread- sheet list manager Think about how you’ll get the information out. Start with a plan; be prepared to change your plan. Make your data consistent. Databases are only as good as their data. Query with care. You get what you ask for, not what you intended. 291 291
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Personal Data: All about You
Identity theft: major criminal industry Can be triggered by being careless online or by errors in judgment. Victims can face massive phone bills, threats from collection agencies, and even arrests. It can take years to clear up the damage from an identity theft. 292 292
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Personal Data: All about You (cont.)
Record matching: uses a unique field to combine information from different databases Privacy is decreasing Data can be transmitted almost instantly Workplace monitoring Surveillance cameras 293 293
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No Secrets: Computers and Privacy
Code of Fair Information Practices In early 1970s, a report to Congress Agencies ensure the reliability and security of information in their databases. Privacy Act of 1974 Broadest privacy law passed by Congress USA Patriot Act Passed in response to September 11, 2001 terrorist attacks 294 294
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Your Privacy Rights Don’t give out your Social Security number.
Don’t give away information about yourself. Say no to direct mail, phone, and solicitations. Be stingy with your address. Say no to sharing your personal information. Think before you post. Pay attention to privacy preferences. Mobilize technology to protect your privacy. If you think there’s. incorrect or damaging information about you in a file, find out. 295 295
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Summary Database programs enable users to store, organize, retrieve, communicate, and manage large amounts of information. There are many specialized databases such as media libraries, GIS, and PIMs. The trend is away from large, centralized databases accessible only to data-processing staff. 296 296
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Summary (cont.) Organizations are moving toward a client/server approach that enables users to have access to data stored in servers throughout the organization’s network. The accumulation of data by government agencies and businesses is a growing threat to our right to privacy. 297 297
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Tomorrow’s Technology and You
Digital Planet: Tomorrow’s Technology and You George Beekman • Ben Beekman Tenth Edition Copyright © 2012 Pearson Education, Inc. publishing as Prentice Hall 298
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Digital Planet: Tomorrow’s Technology and You
Chapter 8 Networking and Digital Communication Copyright © 2012 Pearson Education, Inc. publishing as Prentice Hall 299
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Chapter 8 Objectives Describe the basic types of technology that make telecommunication possible Describe the nature and function of local area networks and wide area networks Discuss the uses and implications of several different forms of online communication and collaboration Explain how wireless network technology is transforming the ways people work and communicate 300 300
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Chapter 8 Objectives (cont.)
Describe how wireless phone networks are converging with digital data networks and the impact of that convergence Describe several ways to maximize effectiveness and minimize risks of online communication Describe how online social networks, wikis, and other new tools for creating online communities compare to traditional forms of community building Describe current and future trends in telecommunications and networking 301 301
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Arthur C. Clarke’s Magical Prophecy
Arthur C. Clarke: predicted the use of geostationary communications satellites Considered to be the father of satellite communications Fig. 8.2 302 302
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Basic Network Anatomy A computer network is any system of two or more computers that are linked together. Three essential components of every computer system: Hardware Networks enable people to share computer hardware resources Software Networks enable people to share data and software programs. People Networks enable people to work together, communicate, and play together 303 303
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Networks Near and Far LAN (local area network): computers are physically close to each other – usually in same building Nodes: connected to hubs or switches, which allow any node on the network to communicate with any other Ethernet: popular networking architecture developed in the 1970s; now an industry standard Most networked computers today are connected to networks today by ethernet cables, plugged into ethernet plugs. Each node in a wireless network has a radio transmitter. Convenient for small networks in homes and small businesses Generally slower than wired LANs 304
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Networks Near and Far (cont.)
WAN (wide area network): extends over a long distance Each networked LAN site is a node on the WAN Mostly used to link geographically dispersed corporate or government offices Can use web of telephone lines, microwave relay towers, and satellites that span the globe Routers: hardware devices or software programs that route messages between networks Mesh networks: alternative to networks that uses centralized routers Message hops from wireless device to wireless device 305 305
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The Importance of Bandwidth
Bandwidth: refers to the amount of data that can be transmitted through a communication medium in a given amount of time Typically measured in kilobits or megabits per second 306 306
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The Importance of Bandwidth (cont.)
Bandwidth can be affected by: Physical media of the network Amount of traffic on the network Type of network connection Fast Ethernet: carries traffic at 100 megabits per second; provided all devices are fast Ethernet compatible Gigabit Ethernet: standard is capable of transferring 1 gigabit of data per second 307 307
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Bandwidth (cont) Bandwidth is on the rise between LANs, due to fiber-optic cables that are replacing copper wires in the worldwide telephone network. Fiber optic cables use light waves to carry information at lightening speeds A single fiber-optic cable can replace 10,000 copper telephone cables. Used to connect most major communication hubs around the world. Many large businesses & government institutions are connected to the global fiber-optic network Most homes and small businesses depend on copper wires for the “last mile”. 308
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Communication Software
Protocol: set of rules for the exchange of data between devices Computers must follow the same protocols to understand each other. Have code for messages like “Are you ready”., “I am about to start sending a data file, and “Did you receive that file” TCP/IP: most famous protocol for computer networking TCP/IP controls the exchange of data. Will be discussed in detail in next chapter 309 309
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Communication Software (cont.)
Communication software takes many forms: NOS (network operating system): a system handles communications among many workstations Examples: Novell’s Netware or Microsoft’s Windows Server Shields users from nuts-and-bolts level of detail Must be able to respond to requests from many computers. Client/server model: one or more computers act as dedicated servers and all the remaining computers act as clients Used by some LANs 310 310
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Used by many small networks, including most home networks
Peer-to-peer model: every computer on the network is both client and server Used by many small networks, including most home networks Also called p-to-p or P2P Most desktop operating systems include all the software needed to operate a peer-to-peer network 311
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Linking In: Internet Connection Technologies
Early Day Connections Direct connection: a hardwired connection Faster than other connections Used by many businesses and schools Dial-up connection: uses modem and standard phone lines Modem stands for modulator/demodulator. Also called narrowband connections Broadband connection: greater bandwidth than modems 312 312
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Linking In: Internet Connection Technologies (cont.)
Most common broadband alternatives: DSL (digital subscriber line): uses telephone lines that carry voice calls Cable modems: use same network of coaxial cable as television signals Satellite connections: use dishes that provide television channels Wireless connections: used by growing numbers 313 313
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Wireless Network Technology
Fig. 8.13 314 314
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Wi-Fi Technology Wireless access point (WAP): central connection point for wireless devices A Wi-Fi hot spot Wireless: Typically up to 120 feet indoors and 300 feet outdoors. Use the 2.4 GHz and 5GHz band of the radio spectrum Wide usage: Millions installed in homes, schools, businesses, coffee shops, airports, restaurants, libraries, etc. Figure 8.9 315 315
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Wi-Fi and WiMax Technology
WiMAX (or ): new long-distance radio-based wireless standard in which a single tower can provide access to a 25-square-mile area Line-of-sight connections up to 30 miles Can be used to connecting Wi-Fi networks Wi-Fi Area Security: If not secure, skilled snoopers can “sniff” network traffic with laptop and read what you are writing, collecting addresses and personal information WEP (wired equivalent privacy): encryption scheme improves the security of wireless networks VPN (virtual private network): electronic "tunnel” through the Internet that helps to prevent eavesdropping 316 316
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Bluetooth Technology Bluetooth technology: named for Danish king who overcame his country’s religious differences Overcomes differences between mobile phones, handheld computers, and PCs, allowing communication between different operating systems Range is limited to about 30 feet PAN (personal area network): links a variety of electronic devices using Bluetooth technology Mobile phone to headset Wireless keyboard and mouse to keyboard Wireless game controller to the game console 317 317
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3G and 4G Technology 3G and 4G technology: 3G networks carry multimedia data and voice communications simultaneously Used to support communications for mobile phones Lack true broadband speeds 4G networks have gigabit broadband speeds Larger mobile devices like the iPad compete with phones for bandwidth on these networks Tethering: cabling a laptop to a mobile phone so it can send and receive Internet data through the phone’s wireless Internet connection 318 318
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Specialized Networks: From GPS to Digital Money
GPS (Global Positioning System): specialized network of the U.S. Department of Defense GPS receiver uses signals broadcast by satellites to determine its position. At any point on planet, four satellites will be above the horizon. Fig 8.14c 319 319
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The Network Advantage Networks enable people to:
Share computer hardware resources Print servers accept, prioritize, and process print jobs Share data and software programs Site licenses reduce costs for multiple copies of software Work, play, and communicate together Groupware enables several users to work on the same document at the same time. E-commerce: Financial networks make credit card purchases, automatic bill paying, electronic funds transfer, etc. possible 320
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A Home Computer Network
Figure 8.16 Copyright © 2012 Pearson Education, Inc. publishing as Prentice Hall 321 321
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The Many Faces of Email Email is built on protocols.
SMTP (Simple Mail Transfer Protocol): sending mail POP (Post Office Protocol) or IMAP (Internet Message Access Protocol): receiving mail Webmail: Web-based , such as Gmail or Hotmail Attachments: formatted documents that are sent with an Many messages are in plain ASCII text – which require only limited band-width. Often software can handle HTML, which allows formatting and inclusion of pictures. HTML use normally slow down programs HTML allow to carry web bugs Can notify sender of message opening, when received, and personal information 322 322
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Issues Spam: unsolicited, junk constitute the majority of . Some spam sneaks through even the best filters Phishing: luring people into fake Web sites to capture sensitive financial information Spreading Viruses: Mainly contained in attachments and cost billions of dollars of damage Mailing lists: enable you to participate in discussion groups Moderated groups ensure quality of the discussions. 323 323
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Newsgroups, Web Forums, and Blogs
Newsgroups: public discussion on a particular subject Messages posted on virtual bulletin board to read by anyone at anytime Web forums: accessed through a Web browser Some require membership to post Newsgroups & forums may be moderated to stop unproductive message. Blogs: (weB LOG) frequently updated online journals Political Blogs are an important source of unmonitored information Fig 8.22 324 324
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Instant Messaging, Text Messaging, and Teleconferencing
Asynchronous communication: poster and reader don’t have to be logged in simultaneously IM (instant messaging): real-time communication Text messaging: uses SMS technology; more limited than IM Chat room: public or private virtual conference room 325 325
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Computer Telephony Voice mail: voice messaging system
Internet telephony: also called Voice-over IP Many smart phones can connect to the Internet. Fig 8.24 326 326
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Online Survival Tips Let your system do as much work as possible.
Store names and addresses in a computer- accessible address book. Don’t share s and passwords. Protect your privacy. Don’t open suspicious attachments. Don’t get hooked by a phishing expedition. Keep your security systems up to date. Cross-check online information sources. Beware of urban legends. Be aware and awake. Avoid information overload. Copyright © 2012 Pearson Education, Inc. publishing as Prentice Hall 327 327
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Social Networking, Role Playing, and Virtual Communities
Facebook, LinkedIn, Plaxo: social networking services Social networking sites: have privacy and safety issues MMORPGs (massively multiplayer online role- playing games): success requires cooperation among groups of players 328
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Information Sharing: Social Bookmarking, Wikis, Media Sharing, and Crowdsourcing
Wiki: Web site designed to enable anyone who accesses it to contribute to it YouTube is a cultural phenomenon for video sharing. Viral video: popular video that spreads as a virus through , blogs, or IMs Crowdsourcing: large community of people work on a task 329
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Netiquette and Messaging Etiquette
Say what you mean; say it with care. Keep it short. Proofread your messages. Don’t assume you are anonymous. Learn the “nonverbal” language of the Net. Know your abbreviations. Keep your cool. Don’t be a source of spam. Say no—and say nothing—to spam. 330 330
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Sharing Resources: Peer-to-Peer, Grid, and Cloud Computing
Peer-to-peer: file sharing allows users to share files by making their hard drives available to other users rather than posting them on a central server Grid computing: sharing processing power rather than sharing data Cloud computing: form of grid computing where the resources come from the Internet rather than a specific source 331
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Digital Communication in Perspective
New technologies emerge all the time. Social networking is relatively new, but it has greatly changed the way we communicate. Wikis and MMORPGs are at the heart of Web 2.0. 332
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Summary Networking is an important trend in computing today.
LANs are made up of computers that are in close proximity. Most networks use the Ethernet architecture. High-bandwidth connections can transmit large amounts of information quickly. Wi-Fi makes it easy to connect devices to the Internet. 333 333
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Summary (cont.) Issues of privacy, security and censorship will continue as the Internet grows. , instant messaging, and teleconferencing are the most common forms of communication on computer networks. Peer-to-peer computing was popularized by music-sharing services. 334 334
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