Computer-Aided Design

Computers have long been used in engineering design. Computer-aided design (CAD) programs are software programs for the design of products and structures. CAD programs, which are now available for microcomputers, help architects design buildings and work spaces and engineers design cars, planes, and electronic devices. One advantage of CAD software is that the product can be drawn in three dimensions and then rotated on the screen so the designer can see all sides.

Examples of CAD programs for beginners are Autosketch, EasyCAD2 (Learn CAD Now), and TurboCAD. One CAD program, Parametric, allows engineers to do "what if" overhauls of designs, much as users of electronic spreadsheets can easily change financial data. This feature can dramatically cut design time. For instance, using Parametric, Motorola was able to design its Micro Tac personal cellular telephone in 9 months instead of the usual 18.Yet not all CAD programs are used by technical types,- a version is avail­able now, for example, that a relatively unskilled person can use to design an office. Other programs are available for designing homes. These programs include "libraries" of options such as cabinetry, furniture, fixtures, and, in the landscaping programs, trees, shrubs, and vegetables.

A variant on CAD is CADD_r for computer-aided design and drafting, soft­ware that helps people do drafting. CADD programs include symbols (points, circles, straight lines, and arcs) that help the user put together graphic ele­ments, such as the floor plan of a house. Examples are Autodesk's AutoCAD and Intergraph's Microstation.

CAD/CAM—for computer-aided design/computer-aided manufacturing —software allows products designed with CAD to be input into an automated manufacturing system that makes the products. For example, CAD, and its companion, CAM, brought a whirlwind of enhanced creativity and efficiency to the fashion industry. Some CAD systems, says one writer, "allow design­ers to electronically drape digital-generated mannequins in flowing gowns or tailored suits that don't exist, or twist imaginary threads into yarns, yarns into weaves, weaves into sweaters without once touching needle to gar­ment." The designs and specifications are then input into CAM systems that enable robot pattern-cutters to automatically cut thousands of patterns from fabric, with only minimal waste. Whereas previously the fashion indus­try worked about a year in advance of delivery, CAD/CAM has cut that time to 8 months—a competitive edge for a field that feeds on fads.

8. Set-Top Boxes—or "Information Appliances"

If you receive television programs from a cable-TV service instead of free through the air, you may have what is called a set-top 'box. A set-top box works with a keypad to allow cable-TV viewers to change channels or, in the case of interactive systems, to exercise other commands.For example, in the 1970s the Warner-Amex interactive Quebec system was Instituted in Columbus, Ohio. The system's set-top box enabled users to request special programs, participate in quiz shows, order services or prod­ucts, or respond to surveys.⁸ Although Qube was discontinued because it was unprofitable, similar experiments are continuing, such as Time Warner's Full Service Network in Orlando, Florida.

One question about the Information Superhighway is what kind of set-top box—or so-called information appliance or communications appliance or telecomputcr—and two-way services will be available. Apple, for instance, is marketing an ezTV cable-box interface. Paul Saffo, of the Institute for the Future in Menlo Park, California, believes that the microcomputer will retain basic traits such as the display screen. However, it will mutate and blend into devices both familiar [such as TVs) and exotic (such as handheld "per­sonal digital assistants" like the Apple Newton, described later). "The true value of a personal computer," Saffo says, "is increasingly determined by what it's connected to, not by the applications it processes."

We turn now from keyboard entry to various types of source data entry, in which data is converted into machine-readable form as it is entered into the computer or other device. Source data entry is important because it cuts out the keyboarding step, thereby reducing mistakes and labor costs. For example, in many places utility companies rely on human meter readers to fight through snowdrifts and brave vicious dogs to read gas and electric meters. They then type the readings into specialized portable computers—a time-consuming and potentially error-producing step. Over the next decade, however, probably 25% of the 160 million gas and electric meters in the United States will be automated. That is, a transmitter plugged into the meter in a customer's home will send data directly to the utility company's computers—a quicker and more accurate process. (Because the ranks of human meter readers will shrink, the transmitters are being installed gradu­ally, and many workers are being retrained or reassigned.)

Дата добавления: 2015-11-14