A semiprocedural approach to program development in which a program is presented as base program plus extensions is presented. The procedural base program supplies the raw inputs for a set of computations, and the non...
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A semiprocedural approach to program development in which a program is presented as base program plus extensions is presented. The procedural base program supplies the raw inputs for a set of computations, and the nonprocedural extensions express outputs to be derived from these raw inputs. A target program is obtained from this specification by use of program transformations. The methodology is based on a network-oriented model of computation, and suggests that computations can be viewed as networks both at the macroscopic level and at the microscopic level.
A model of the computer manual comprehension task is proposed in which four processes operate simultaneously: task-mapping of the structure of regular procedures onto the structure of computer commands, constructing a...
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ISBN:
(纸本)0444877738
A model of the computer manual comprehension task is proposed in which four processes operate simultaneously: task-mapping of the structure of regular procedures onto the structure of computer commands, constructing a mental model of the computer system, inducing the command language grammar, and learning the structure of computer procedures. Findings from a study of five novices' comprehension problems with UNIX documentation are analyzed in terms of these four processes. The model and the findings from the study yield general heuristics and specific recommendations for document developers.
Rapid prototyping is a popular new way of developing software applications in both business and scientific environments. The technique is invaluable in providing communication between customers and developers;but like...
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ISBN:
(纸本)0882830465
Rapid prototyping is a popular new way of developing software applications in both business and scientific environments. The technique is invaluable in providing communication between customers and developers;but like any other methodology, it can fail if not used properly. This paper compares and contrasts two case studies of prototyping endeavors. One appears to be a success, and the other had major problems and may result in total failure. The reaons for the phenomena are probed, concluding with an observed successful prototyping life cycle, which, if abandoned, may negate the positive aspects of the entire prototyping process. The necessary phases of rapid analysis, database development, menu development, function development, prototype iteration, detailed design, and implementation have been well documented. It is strongly suggested that three new phases - planning, modeling, and training - be added to the cycle for a better chance of successful rapid prototyping. (Author abstract. )
The answer to the question of how to get a large natural-language system into a personal computer lies in the paging architecture of the system. The key is to use the input sentence, in conjunction with the lexicon an...
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ISBN:
(纸本)0882830465
The answer to the question of how to get a large natural-language system into a personal computer lies in the paging architecture of the system. The key is to use the input sentence, in conjunction with the lexicon and grammer table, to identify the minimal segments of both object code and data that must be brought into main memory. Once such a maximally paged architecture has been effectively implemented, it has wide ranging implications for process integration, networking and knowledge base distribution, and for the software engineering environment. The Natural Access System optimizes this architecture and exploits these implications. (Author abstract. )
This paper discusses the meaning of the much used term 'user friendliness'. Present definitions and discussions of user friendliness are tentative and often naive. Although the concept the term represents is v...
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ISBN:
(纸本)0867291761
This paper discusses the meaning of the much used term 'user friendliness'. Present definitions and discussions of user friendliness are tentative and often naive. Although the concept the term represents is valid and important, a means for objectively evaluating the user friendliness of systems is lacking. There is a need for controlled study of those factors that make a system more or less user-friendly.
It is shown that the behavior of Petri nets with exponentially distributed firing times can be represented by labeled directed 'state' graphs in which labels describe the probabilities of transitions between v...
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ISBN:
(纸本)0897911504
It is shown that the behavior of Petri nets with exponentially distributed firing times can be represented by labeled directed 'state' graphs in which labels describe the probabilities of transitions between vertices of the graph. For bounded Petri nets the corresponding state graphs are finite, and are isomorphic to finite state Markov chains, stationary descriptions can thus be otained by standard techniques. An immediate application of such a model is performance analysis of concurrent systems, and in particular queueing systems with exponentially distributed arrival and service times. A simple example of an interactive computer system model is used as an illustration of performance evaluation.
A number of experiments aimed at developing effective key-press input devices for public videotex services are reported. Results generally indicated that performance differences were minimal across a variety of device...
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ISBN:
(纸本)0444877738
A number of experiments aimed at developing effective key-press input devices for public videotex services are reported. Results generally indicated that performance differences were minimal across a variety of devices for different types of users (novice and experienced). There were, however, some distinct preference differences exhibited by the two user groups. Novices strongly favoured a simple minimal-function keypad, whereas subjects trained to a high level of Telidon proficiency preferred the perceived functionality of a full-sized keyboard, even though it did not lead to improved performance.
The external sorting of very large files presents challenges which cannot be met adequately by the current combination of architectures and classical merge-based algorithms. The framework is provided for an efficient ...
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ISBN:
(纸本)0818606371
The external sorting of very large files presents challenges which cannot be met adequately by the current combination of architectures and classical merge-based algorithms. The framework is provided for an efficient solution to this problem using a distributive method that is called tag-distribution sort. Although it uses a paradigm dual to that of a conventional mergesort, it presents more opportunities for pipelining and parallelism, makes better use of processors, and requires less temporary storage.
Compiler construction can be effectively taught by demonstrating the programming techniques commonly used in writing modern compilers. In order to present an overall view of the entire process, a complete compiler is ...
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ISBN:
(纸本)0897911520
Compiler construction can be effectively taught by demonstrating the programming techniques commonly used in writing modern compilers. In order to present an overall view of the entire process, a complete compiler is used for a Pascal-like language called EEL, Early Experimental Language. The compiler consists of several modules: the lexical analyzer, the parser, and the semantic rules, any of which can be studied individually as well as in the context of the whole compiler. SLR parsing techniques are used in a postfix translation scheme with backpatching. After SLR techniques are understood, the students are shown how other methods work, including LR(1) and recursive descent of LL techniques.
The ZOG human-computer interface has been instrumented to collect data about the system's performance and the users' behavior. We explain which data are collected and how they are recorded. We then suggest tha...
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ISBN:
(纸本)0444877738
The ZOG human-computer interface has been instrumented to collect data about the system's performance and the users' behavior. We explain which data are collected and how they are recorded. We then suggest that analyzing the instrumentation data is akin to archaeology, because one must infer behavior patterns from low-level data 'artifacts'. Finally, we provide some guidelines for instrumentation design.
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