Different uses of the computer

UC Santa CruzCMPS 10 – Introduction to Computer Sciencewww.soe.ucsc.edu/classes/cmps010/Spring11ejw@cs.ucsc.edu1 April 2011

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The final exam is scheduled for Tuesday, June 7, 8am-11am This class will have a final exam. Please plan on this.

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The many uses of computers Today, computers are used in many ways

Computation Large scale scientific simulations,

spreadsheets Data processing

Classic business functions: accounting, inventory control, order processing, customer management, payroll

Device control Embedded computers in a range of devices

controlling their functions Command and control

Battlefield awareness, air traffic control Tool for individual expression

Word processors, image editors, music and movie editing

Computational media Web, computer games

Communications Cell phones, email, instant messaging,

internet telephony (Skype) Sensors

Measuring various aspects of the world

World’s smallest computer?

A prototype of an implantable eye pressure monitor for glaucoma patients. Contains an extremely low-power microprocessor, a pressure sensor, memory, a thin-film battery, a solar cell and a wireless radio with an antenna that can transmit data to an external reader. Developed at Univ. of Michigan.www.foxnews.com/scitech/2011/02/23/worlds-smallest-computer-created/

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Interpretive flexibility of the computer An unusual quality of the computer is its wide range of

uses Most technologies are single-purpose

A knife is used for cutting. A jacket keeps you warm. Some have 2-3 purposes

A flat-head screwdriver is useful for turning screws and opening paint cans

Very rarely they have multiple purposes Consider the wide range of lights used for many different lighting

needs, from household lights to stage and cinema lighting But, still these tend to be variants on the core function of the

technology Most uses of lights are for illumination

The computer is different A broad range of uses, where many uses are substantially

different from one another It is unusual to have a single technology with such a broad

range of uses Basic building materials (wood, steel, concrete) also have a wide

range of uses, but are the building blocks of other technologies

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Why is the computer so flexible?

Some thoughts The computer can represent a wide range of activities

A wide range of things in the real world can be modeled as numbers and letters, which can be stored and processed inside a computer

Analog to digital (and digital to analog) converters allow a computer to interact directly with the real (analog) world

Allows the world to be represented as pure information, which can then be manipulated inside a computer

Permits a computer to send/receive messages Permits a computer to measure the real world Permits a computer to control devices in the world

Programs can encode very complex logic, which enables a computer to behave in multiple, complex ways

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Computation and Simulation The computer is used to perform

large numbers of computations quickly

Key driver of supercomputing Areas of large-scale simulation:

Combustion (and complex fluid simulation)

Astrophysics Modeling formation of stars, black

holes, evolution of galaxies Life sciences

Modeling behavior of biochemistry Protein folding Gene sequencing

Environment Modeling world climate

Also: personal calculators An increasingly niche area of

computing

Visualization of combustion temperature inside a gas turbinewww.psc.edu/research/fetc/combustor/combustor.php

Climate modelwww.drroyspencer.com/2009/07/how-do-climate-models-work/

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Simulation and the Sciences

In most sciences, the computer has emerged as a kind of research instrument

The computer permits the construction of executable models

Scientists develop theories These theories are converted into models The models are turned into software and executed The output of the models can be compared with real world

behavior OR, models can suggest new avenues of experimentation

Very complex computer models include the experimental and theoretical results of multiple scientists The programs act to synthesize together multiple results in a

coherent way

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Data processing The foundation of large-scale modern business Scaling large organizations requires them to develop rules,

processes, and policies. These must be enacted in a consistent way, at large scale

The computer is a powerful tool for ensuring consistency of enactment of rules and processes It permits a small number of staff to manage a large flow of data But, also reduces the cost of making more complex policies and

procedures Hence, introduction of computers tends to make bureaucratic

systems more complex. It also makes it easier for groups to exercise control, and hence

supports power centralization tendencies

Examples: Document management (claim processing, records

management), accounting, payroll, inventory control, point-of-sale, tax form processing, order processing, workflow management, many others

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Device control Use of the computer to control the behavior of a

device Key advantages over use of static controllers:

Software permits a device to be given new behavior without changing its hardware

Software permits a device to behave in complex ways

Software typically permits a device to support more functions than the same device without software

Wide range of uses Embedded controllers in many devices Examples around the home: television, radio,

microwave, cable box, advanced thermostats, recent cars, telephones, telephone answering machine, advanced refrigerators and ovens, digital camera, digital movie camera, digital music player, wifi router, advanced dishwasher, advanced washing machine

ArduinoArduino board, a microcontroller designed for hobbyist use (US $30)www.arduino.cc

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Command and control

The computer is used to provide a visualization of a complex arena of (human) activity Battlefield, aircraft landing, chemical plant, railroad

control

Permits small staff to: Understand the state of a complex system Take action or direct actions of others within that system

Potomac TRACONen.wikipedia.org/wiki/Air_traffic_control

Union Pacific Harriman Dispatch Centeren.wikipedia.org/wiki/Union_Pacific_Harriman_Dispatch_Center

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Tool for individual expression As computers dropped in price,

in the 1970s it became possible to have computers owned by individuals instead of companies and governments Emergence of personal computing

(microcomputers) Led to widespread adoption of

tools for expressing individual thought Word processor & spreadsheet,

then later desktop publishing, music editors, movie editors, slide presentations and many others

Emergence of computer programming as a middle class hobby

Cover of Computer Lib, by Theodor Holm Nelson, 1974

The first book to really explore what it would mean to have a personal computer.en.wikipedia.org/wiki/Computer_Lib

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Computational Media Computers have given rise to more new

forms of media than any other technology Closest competition is the printing press Computer games, world-wide web,

interactive CD-ROM, email, instant messaging, multi-person virtual worlds, digitally animated movies, Twitter, Facebook, etc.

A major new form of computational media has been emerging every 3-7 years

This is an astonishing rate of new media creation

A computational media is one is which computation is a core requirement for the delivered experience. Computer games: yes, need computation

to enact a game MP3 music: mostly just a digitization of an

existing media, analog recorded music. Think of these as digital media, but not strongly computational.

Scene from Minecraftwww.geeksmack.net/apple/minecrafts-brief-appearance-in-the-app-store

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Communications

Computers forming the heart of a system of communication among people Cell phones, email, instant messaging,

Facebook, internet telephony (Skype) Also, now the underlying technology for

television and partially radio Key enabling technology: Internet

Computers began as a technology for computation Today, embedded control and

communications are the primary uses of computers

For the average person, communication is their primary use of computing

In the future, the first computer a person will buy is a cell phone

Erna Schneider HooverInventor of computer controlled telephone switching, developed the archtiecture of the Bell System ESS phone switching system.

BA Medieval History (Wellesley), PhD Philosophy and Foundations of Mathematics, Yale

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Sensors

A new area of computing is the creation of networks of computers to perform sensing activities

Known as sensor networks

Builds on low-cost of embedded microcontrollers and increasingly low cost of wireless networking

Permits low-cost measurement of wide areas of the world

A diagram of a sensor network proposed for the Andrews Forest.oregonstate.edu/feel/about

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Homework assignment #1 First part

Pick a computer in your home, one that isn’t a general purpose laptop or desktop computer.

Briefly name the device, and what you use it for (1-3 sentences)

Broadly, describe what function(s) the computer inside this device performs

Example: dishwasher: receives instructions on which wash cycle to perform, and controls the dishwasher’s wash cycle

Do your best on this: think about what needs to be controlled, what kinds of inputs and outputs are provided (Is there a keypad? A display?)

If a device has a primary function and a computer, the computer is probably in control of that primary function

Using the categories from this lecture, describe the use (or uses) it falls under, and some explanation why.

Consider what would happen if that computer either disappeared, or was replaced by an earlier version of a device without the computer. How would your life be different? That is, what has been the impact of the computer on this device?

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Homework assignment #1

Part two Consider a computing system you don’t own Name and briefly describe this computing system Describe how you are dependent on this computer. That

is, what would happen if this computer stopped working for a month?