Minggu, 16 Oktober 2011

Chapter 7 Database Applications and Privacy Implications

Google is one of the most successful companies on WWW.
Ø  Search for Web pages, facts, quotes, etc.
Ø  200 million queries a day
Launched by a Sergey Brin and
Larry Page (Stanford Ph.D. students)
Ø  New approach in search technology
Ø  Marks a page’s relevance by the number of times other related web pages link to it, not how often a word or phrase appeared on a page
A database:
Ø  A collection of information
stored on computer disks
Database software:
Ø  Application software
(like word processing and
spreadsheet software)
Ø  Designed to maintain databases
(collections of information)
Database program: a software tool for organizing the storage and retrieval of information
Database: a collection of information stored in an organized form in a computer
Ø  Typically composed of one or more tables
ü  A collection of related information
A collection of records
The type of information a field can hold is determined by its:
Ø  Field type or
Ø  Data type 
Database programs provide you with more than one way to view data:
Ø  Form views
q  Show one record at a time
Ø  List views
q  Display several records in lists similar to the way a spreadsheet displays data
Import: receive data in the form of text files
Browse: navigate through information
Query: find records that match specific criteria
Personal information manager (PIM): an electronic organizer
Automates some or all of the following functions:
Ø  Address/phone book
Ø  Appointment calendar
Ø  To-do list
Ø  Miscellaneous notes
Handheld computers can share information with applications such as iCalendar running on PCs and Macintoshes.
From File Managers to Database Management Systems
ü  File manager: enables users to work with one file at a time
ü  Database management system (DBMS): manipulates data in a large collection of files, cross-referencing between files as needed
Database Trends
ü  Batch processing: users accumulate transactions and input them into the computer in large batches
ü  Real-Time computing: allows instant access to information
ü  Interactive processing: has replaced batch processing for most applications
Ø  Users can now interact with data through terminals, viewing and changing values online in real-time.
Ø  Batch processing is still used for jobs in which it makes sense to do a lot of transactions at once.
Databases and the Web
Ø  Information is available via a company’s Intranet and the Internet.
Ø  HTML, the language used to construct most Web pages, wasn’t designed to build database queries.
Ø  XML, a newer, more powerful data description language, is designed with industrial-strength database access in mind.
Ø  Web database strategies revolve around directories.
Ø  Directories are at the heart of many customer relationship management (CRM) systems—software systems for organizing and tracking information on customers.
Object-Oriented
Ø  Easy manipulation of various types of data
Ø  Saves time by reusing objects
Ø  Associates actions with the data

Relational
Ø  Not good with unstructured data (audio, video clips)
Ø  Will still be used in combination with object oriented databases – as hybrids


Chapter 6 Graphics, Digital Media, and Multimedia

Tim Berners-Lee Weaves the Web for Everybody
ü  Born in London in 1955
ü  Wanted to create an open-ended distributed hypertext system with no boundaries, so scientists everywhere could link their work together
ü  Invented the World Wide Web and gave it to all
ü  Now works at MIT
ü  Heads the World Wide Web Consortium (W3C)
Pixels: tiny dots of white, black, or color that make up images on the screen
Palette of tools mimics real-world painting tools
ü  Also contains other tools that are unique to computers
Bitmapped graphics (or raster graphics): pictures that show how the pixels are mapped on the screen
Color depth: the number of bits devoted to each pixel
Resolution: the density of the pixels
Computer-Aided Manufacturing (CAM) is the process by which data related to the product design are fed into a program that controls the manufacturing of parts.
Computer-Integrated Manufacturing (CIM) refers to the combination of CAD/CAM and is a major step toward a fully automated factory.
Modern media contains dynamic information, which is information that changes over time or in response to user input.
Ø  Animation
Ø  Desktop Video
Ø  Audio
Hypertext and Hypermedia
ü  Hypertext refers to information linked in non-sequential ways.
ü  Hypermedia combines text, numbers, graphics, animation, sound effects, music, and other media in hyperlinked documents.
Ø  Useful for on-line help files
Ø  Lets the user jump between documents all over the Internet
Today we can create or explore hypermedia documents—interactive documents that mix text, graphics, sounds, and moving images with onscreen navigation buttons—on disk and on the World Wide Web.
Multimedia computer systems make a new kind of software possible—software that uses text, graphics, animation, video, music, voice, and sound effects to communicate.
Regardless of the hardware, interactive multimedia software enables the user to control the presentation rather than just watch or listen passively.

Chapter 5 Productivity Applications

Even though the computer was designed to work with numbers, it can be an important tool for working with words as well.
Word processing software enables you to use commands to edit text on screen, without having to retype messages.
Outlining software, spell checkers, and online references can be very helpful.
Desktop publishing produces professional-quality text-and-graphics documents.
Spreadsheets can be used for tracking, calculating, forecasting, and almost any other task that involves repetitive numeric calculations. Most spreadsheet programs have charting capabilities.
Specialized software allows you to perform accounting tasks, tax preparation, and a variety of business functions without the aid of spreadsheets.
Symbolic mathematic and statistical-analysis software can help present data in meaningful ways.  
Scientific visualization software can help us understand relationships that are invisible to the naked eye.
Computer modeling and simulation can be powerful tools for understanding the world and making better decisions.

Chapter 4 Software Basics: The Ghost

Linus Torvalds
Ø  Best known as the Linux creator
q  The Linux operating system is the best-known example of open source software.
q  Today Linux powers Web servers, film and animation workstations, scientific supercomputers, and a handful of handhelds.
Multiple User Operating Systems: UNIX and Linux
Ø  UNIX was developed at Bell Labs before personal computers were available.
Ø  Linux was created by Linus Torvalds and continues to be a work-in-progress.
UNIX allows a timesharing computer to communicate with several other computers or terminals at once.
Hardware and Software Platforms
Windows Vista
Windows Server 2003
Windows XP
Windows ME
Microsoft Windows CE

Mac OS X (10)
Mac OS 9
Linux, Sun Solaris, and other UNIX variations


Files can be scattered all over the system, which often makes data management difficult.
Ø  One solution to this problem is to organize data files logically.
Ø  Both Windows and the Mac support the notion of common system folders with self-explanatory names:
q  My Documents (Documents)
q  My Pictures (Pictures)
q  My Music (Music)
File-Management Utilities
q  View, rename, copy, move, and delete files and folders
q  Hierarchies help with organization
q  Help with locating a file
q  Get size, file type, and last modification date
Managing Files from Applications
q  Operations: Open, Save As, Save and Close
Defragmentation
Popular operating systems include Windows, Mac OS X, UNIX, and Linux.
The user interface is a critical communication component in operating systems, applications, programming languages, and utilities.
Tomorrow’s interfaces are likely to rely on three-dimensional graphics and animation to create virtual realities.
Software piracy is a major concern in the computer industry.

Chapter 3 Hardware Basics: Peripherals

Keyboard
ü  The most familiar input device
ü  Used to enter letters, numbers and special characters
Standard keyboard
Ergonomic keyboards
ü  To address possible medical problems
Wireless keyboard
Folding keyboards
ü  Used with palm-sized computers
One-handed keyboards 
Keyboards printed on membranes
Pointing Devices
ü   Mouse
ü  Touchpad
ü  Pointing stick
ü  Trackball
ü  Joystick
ü  Graphics tablet
ü  Touch screen
ü  Stylus
Video digitizer
ü  Capture input from a:
ü  Video camera
ü  Video cassette recorder or television
Convert it to a digital signal
ü  Stored in memory and displayed on computer screens
Videoconferencing
ü  People in diverse locations can see and hear each other
ü  Used to conduct long-distance meetings
Video images transmitted through networks
Screen Output
Ø  A monitor or video display terminal (VDT) displays characters, graphics, photographic  images, animation and video.
q  Video adapter—connects the monitor to  
                                    the computer
q  VRAM or video memory—a special
                                    portion of RAM to hold video images
Ø  The more video memory, the more picture detail is displayed.
Fax Machines and Fax Modems
Ø  Facsimile (fax) machine
Ø  Sending:
Ø  scans each page as an image
Ø  converts the image into a series of electronic pulses
Ø  sends those signals over phone lines to another fax
Ø  Receiving:
Ø  uses the signals to reconstruct the image
Ø  prints black-and-white facsimiles or copies of the originals
Fax modem
Ø  Connect from PC to fax machine via modem and phone line


Magnetic Disks
Ø  Random data access
Ø  Floppy disks
q  Provide inexpensive, portable storage
Ø  Hard disks
q  Non-removable, rigid disks that spin continuously
    and rapidly
q  Provide much faster access than a floppy disk
Ø  Removable media (Zip & Jaz disks)
Provides high-capacity portable storage
CD-ROM
q  Optical drives that read CD-ROMs
CD-R
q  WORM media (write-once, read many)
CD-RW
q  Can read CD-ROMs and write, erase and
rewrite data onto CD-R & CD-RW disks
DVD (Digital Versatile Disks)
q  Store and distribute all kinds of data
q  Hold between 3.8 and 17 gigabytes of information
DVD-ROM drives
q  Can play DVD movies, read DVD data disks
q  Read standard CD-ROMs, and play audio CDs
q  Read-only: can’t record data, music, or movies
DVD-RAM drives
q  Can read, erase, and write data (but not DVD video) on multi-gigabyte
                        DVD-R (but not CD-R or CD-RW) media 

Chapter 2 Hardware Basics: Inside the Box

Basic Functions of a Computer
ü  Receive input: Accept information from the outside world
ü  Process information: Perform arithmetic or logical (decision-making) operations on information
ü  Produce output: Communicate information to the outside world
ü  Store information: Move and store information in memory
Basic Components of a Computer
ü  Input devices
Ø  Keyboards and pointing devices
(mouse)
ü  Output devices
Ø  Display or video monitor
Ø  Printer
Ø  Speakers
ü  Central Processing Unit (CPU)
Memory and storage devices
Ø  Primary storage: RAM (Random Access Memory)
Ø  Secondary storage: Storage devices that serve as
long-term repositories for data:
ü  Hard disk drives
ü  Recordable CD and DVD drives
ü  Tape drives
Computer’s information is digital
Ø   Bit, or binary digit
q  The smallest unit of information
q  Can have one of two values: 1 or 0
q  Can represent numbers, codes, or
    instructions
Ø   Byte: a collection of 8 bits
Bits, Bytes, and Buzzwords
Bit-related terminology
Byte
8 bits
Kilobyte (KB)
1  Thousand Bytes
Megabytes (MB)
1 Million Bytes
Gigabytes (GB)
1 Billion Bytes
                        Terabytes (TB)
1 Trillion Bytes

CPU (microprocessor)
Ø  Communicates with all the other parts of the computer system indirectly through memory
Ø  An extraordinarily complex collection of electronic circuits
Ø  Housed along with other chips and electronic components on the motherboard
RAM (random access memory)
Ø  Used to store program instructions and data temporarily
Ø  Unique addresses and data can be stored in any location
Ø  Can quickly retrieve information
Ø  Will not remain if power goes off  (volatile)
ROM (read-only memory)
Ø  Information stored permanently on a chip
Ø  Contains startup instructions and other permanent data
CMOS (complementary metal oxide   semiconductor)
Ø  Special low-energy kind of RAM 
Flash memory
Ø  Used for phones, pagers, portable computers, handheld computers, and PDAs
Buses
ü  Typically have 32 or 64 wires
ü  Connect to storage devices in bays
ü  Connect to expansion slots
ü  Connect to external buses and ports
Slots and ports
ü  Make it easy to add external devices, called peripherals.       
The CPU uses:
Ø  RAM (random access memory) as a temporary storage area—a scratch pad—for instructions and data
Ø  ROM (read-only memory), which contains unchangeable information that serves as reference material for the CPU as it executes program instructions
The CPU and main memory are housed in silicon chips on the motherboard.