into a computer system, and be output by it in a correspondingly useful form Information may vary in time such as a temperature indication, in two dimensions such as the users action in moving a mouse, or even in three dimensions, and output may be as simple as closing a contact or drawing a picture containing a vast Software engineering as discussed in Chapter 90 refers to the serious problem of managing the complexity of the layers of software. This problem has few parallels in other walks of life and is exacerbated by the rate of change in computing. It is dominated by the overall question "Is this computer system reliable? " which will be referred to in Chapter 98. Some parallels can be drawn with other complex human organizations, and, fortu- nately, the computer itself can be applied to the task. Graphical input and output is the topic of Chapter 91. Early promise in the mid-1960s led to the pessim observation a decade later that this was"a solution looking for a problem, "but as computer display technology improved in quality, speed, and, most importantly, cost, attention was focused on visualization algorithms, e.g., the task of producing a two-dimensional representation of a three-di ensIo with the need to provide a natural interface between the user and the computer and has led to the development of interactive graphical techniques for drawing, pointing, etc, as well as consideration of the human factors involved c As computers have extended their scope, it has become necessary for a computer to communicate with other Chapter 92 reviews the major concepts of both local and wide area computer neon s in electronic mail mputers,whether nearby, such as a file server, or across a continent or ocean, such Many engineers were skeptical as to whether early computers would operate sufficiently long before a breakdown would prevent the production of useful results. Little recognition has been given to the pioneers of component and circuit reliability that have made digital systems virtually, but still not totally, fault-free. Critical systems, whether in medicine or national defense, must operate even if components and subsystems fail. The next chapter reviews the techniques employed to make computer systems fault-tolerant. The idea of a rule-based system, referred to earlier, is covered in Chapter 94. Application software naturally flects the nature of the application, and the term knowledge engineering has been coined to include languages and techniques for particularly demanding tasks, which cannot readily be expressed in a conventional scientific business programming language Parallel systems are emerging as the power of computer systems is extended by using multiple units. The term unit may correspond to anything from a rudimentary processor, such as a"smart word"in a massively parallel"fine grain"architecture, to a full-scale computer, in a coarse-grain parallel system with a few tens of parallel units. Chapter 95 discusses the hardware and software approaches to a wide variety of parallel systems. Operating systems, which are described in the next chapter, turn a"raw"computer into an instrument capable of performing useful, low-level tasks, such as creating a file or starting a process corresponding to an algorithm, or transferring its output to a device such as a printer, which may be busy with other tasks. society has become more dependent upon the computer and computer technology, it has become increasingly concerned with protecting the privacy of individuals and maintaining the integrity of computer systems against infiltration- by individuals, groups, and even on occasion by gor verden protecting the security of a system and ensuring individual privacy are discussed in Chapter 97 Chapter 98 discusses the overall reliability of computer systems, based on the inevitable limitations of both hardware and software mentioned earlier. Given the inevitability of failure, human or component, what can be said about the probability of a whole computer system failing? This may not be an academic issue for a assenger reading this section while flying in a modern jet airliner, which may spend over 95% of a flight under he control of an automatic pilot. He or she may be reassured to know, however, that the practitioners of reliability engineering have reduced the risk of system failure to truly negligible proportions.© 2000 by CRC Press LLC into a computer system, and be output by it in a correspondingly useful form. Information may vary in time such as a temperature indication, in two dimensions such as the user’s action in moving a mouse, or even in three dimensions, and output may be as simple as closing a contact or drawing a picture containing a vast range of colors. Software engineering as discussed in Chapter 90 refers to the serious problem of managing the complexity of the layers of software. This problem has few parallels in other walks of life and is exacerbated by the rate of change in computing. It is dominated by the overall question “Is this computer system reliable?” which will be referred to in Chapter 98. Some parallels can be drawn with other complex human organizations, and, fortu￾nately, the computer itself can be applied to the task. Graphical input and output is the topic of Chapter 91. Early promise in the mid-1960s led to the pessimistic observation a decade later that this was “a solution looking for a problem,” but as computer display technology improved in quality, speed, and, most importantly, cost, attention was focused on visualization algorithms, e.g., the task of producing a two-dimensional representation of a three-dimensional object. This is coupled with the need to provide a natural interface between the user and the computer and has led to the development of interactive graphical techniques for drawing, pointing, etc., as well as consideration of the human factors involved. As computers have extended their scope, it has become necessary for a computer to communicate with other computers, whether nearby, such as a file server, or across a continent or ocean, such as in electronic mail. Chapter 92 reviews the major concepts of both local and wide area computer networks. Many engineers were skeptical as to whether early computers would operate sufficiently long before a breakdown would prevent the production of useful results. Little recognition has been given to the pioneers of component and circuit reliability that have made digital systems virtually, but still not totally, fault-free. Critical systems, whether in medicine or national defense, must operate even if components and subsystems fail. The next chapter reviews the techniques employed to make computer systems fault-tolerant. The idea of a rule-based system, referred to earlier, is covered in Chapter 94. Application software naturally reflects the nature of the application, and the term knowledge engineering has been coined to include languages and techniques for particularly demanding tasks, which cannot readily be expressed in a conventional scientific or business programming language. Parallel systems are emerging as the power of computer systems is extended by using multiple units. The term unit may correspond to anything from a rudimentary processor, such as a “smart word” in a massively parallel “fine grain” architecture, to a full-scale computer, in a coarse-grain parallel system with a few tens of parallel units. Chapter 95 discusses the hardware and software approaches to a wide variety of parallel systems. Operating systems, which are described in the next chapter, turn a “raw” computer into an instrument capable of performing useful, low-level tasks, such as creating a file or starting a process corresponding to an algorithm, or transferring its output to a device such as a printer, which may be busy with other tasks. As society has become more dependent upon the computer and computer technology, it has become increasingly concerned with protecting the privacy of individuals and maintaining the integrity of computer systems against infiltration—by individuals, groups, and even on occasion by governments. Techniques for protecting the security of a system and ensuring individual privacy are discussed in Chapter 97. Chapter 98 discusses the overall reliability of computer systems, based on the inevitable limitations of both hardware and software mentioned earlier. Given the inevitability of failure, human or component, what can be said about the probability of a whole computer system failing? This may not be an academic issue for a passenger reading this section while flying in a modern jet airliner, which may spend over 95% of a flight under the control of an automatic pilot. He or she may be reassured to know, however, that the practitioners of reliability engineering have reduced the risk of system failure to truly negligible proportions