Computers are permeating almost every aspect of our lives, including many areas previously untouched by technology. 【B1】 But unl

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问题    Computers are permeating almost every aspect of our lives, including many areas previously untouched by technology. 【B1】 But unlike such other pervasive technologies as electricity, television and the motor car, computers are on the whole less reliable and less predictable in their behavior. This is because they are discrete state digital electronic devices that are prone to total and catastrophic failure. Computer systems, when they are "down," are completely down, unlike electromechanical devices, which may be only partially down and are thus partially usable.
   Computers enable enormous quantities of information to be stored, retrieved, and transmitted at great speed on a scale not possible before.【B2】 This is all very well, but it has serious implications for data security and personal privacy because computers are inherently insecure. The recent activities of hackers and data thieves in the United States, Germany, and Britain have shown how all-too-easy it still is to break into even the mast-sophisticated financial and military systems. The list of scares perpetrated by the new breed of hi-tech criminals, ranging from fraud in airline-ticket reservations to the reprogramming of the chips inside mobile phones, is growing daily.
   Computer systems are often incredibly complex-so complex, in fact, that they are not always understood even by their creators(although few are willing to admit it). This often makes them completely unmanageable. Unmanageable complexity, can result in massive foul-ups or spectacular budget "runaways." For example, Jeffrey Rothfeder in Business Week reports that Bank of America in 1988 had to abandon a $ 20-million computer system after spending five years and a further $ 60 million trying to make it work. Allstate Insurance saw the cost of its new system rise from $ 8 million to a staggering $ 100 million and estimated completion was delayed from 1987 to 1903. Moreover, the problem seems to be getting worse: in 1988 the American Arbitration.  Association took on 190 computer disputes, most of which involved defective systems. The claims totaled $ 200 million——up from only $ 31 million in 1984.
   【B3】 Complexity can also result in disaster: no computer is 100 percent guaranteed because it is virtually impossible to anticipate all sorts of critical applications, such as saving lives, flying air craft, running  nuclear power stations, transferring vast sums of money, and controlling missile systems—sometimes with tragic consequences. For example, between 1982 and 1987, some twenty-two servicemen died in five separate crashes of the United States Air Force’s sophisticated Blackhawk helicopter before the problem was traced to its computer-based "fly-by-wire" system. At least two people died after receiving overdoses of radiation emitted by the computerized. There are 25 X-ray machines, and there are many other examples of fatal computer-based foul-ups.
   Popular areas for less life-threatening computer malfunctions include telephone billing and telephone switching software, bank statements and hank-teller machines, electronic funds-transfer systems, and motor-vehicle license data bases. Although computers have often taken the "blame" on these occasions, the ultimate cause of failure in most cases is, in fact, human error.
   Every new technology creates new problems——as well as new benefits--for society, and computers are no exception.【B4】 But digital computers have rendered society especially vulnerable to hardware and software malfunctions. Sometimes industrial robots go crazy, while heart pacemakers and automatic garage door openers are rendered useless by electromagnetic radiation or "electronic smog" emitted from point-of- sale terminals, personal computers, and video games. Automated teller machines (ATMs) and pumps at gas stations are closed down because of unforeseen software snafus.
   The cost of all this downtime is huge. 【B5】 For example, it has been reported that British businesses suffer around thirty major mishaps a year. revolving losses running into millions of pounds. These are caused by machine or human error and do not include human misuse in the form of fraud and sabotage. The cost of failures in domestically produced software in the United Kingdom alone is conservatively  estimated at $ 900 million per year. In 1989, a British Computer Society committee, reported that much software was now so complex that current skills in safety assessment were inadequate and that therefore the safety of people could not be guaranteed.

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