The problem of concurrent execution of user and diagnostic tasks in a self-diagnosable computer system is considered. The impact of t-diagnosable requirements on the model of scheduling user/diagnostic tasks is discus...
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The problem of concurrent execution of user and diagnostic tasks in a self-diagnosable computer system is considered. The impact of t-diagnosable requirements on the model of scheduling user/diagnostic tasks is discussed. Motivated by the NP-completeness of scheduling in a nonpreemptive mode, two polynomial-time algorithms are given: one produces a nonpreemptive schedule with a makespan less than 4/3 times optimal;the second solves the problem optimally provided that the user tasks may be preempted.
Subject selection for usability testing of computer documentation is discussed. Many of the issues presented are applicable to product testing or testing of other technical documentation, but the author's experien...
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Subject selection for usability testing of computer documentation is discussed. Many of the issues presented are applicable to product testing or testing of other technical documentation, but the author's experience has been primarily with documentation of computer software and systems. She focuses on three major activities: (1) developing appropriate user profiles;(2) locating and obtaining suitable subjects;and (3) making decisions related to the experimental design (such as sample size and population groups).
Statements have been introduced as a visual formalism for specifying the behavior of complex reactive systems. They extend classical state transition diagnosis in several ways, while retaining, and even enhancing, the...
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ISBN:
(纸本)0818607939
Statements have been introduced as a visual formalism for specifying the behavior of complex reactive systems. They extend classical state transition diagnosis in several ways, while retaining, and even enhancing, their visual appeal. A formal syntax and (operational) semantics for statecharts is given. The semantics appears to be novel in a number of ways, among which are its treatment of shared variables, chain reactions and simultaneous multiple messages.
The foundational structure of a new model of user perception of computer system response time is proposed. It is suggested that the development of such a model is now of central importance to the computer system confi...
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ISBN:
(纸本)0897912136
The foundational structure of a new model of user perception of computer system response time is proposed. It is suggested that the development of such a model is now of central importance to the computer system configuration design effort. The new model is seen to explain the success of an earlier measure, designed for the noninteractive environment, in predicting user estimates of response time for interactive systems. The results of new empirical studies, designed to delineate specific components of the model, are also discussed.
Most systems for programmable-controller (PC) programming include among their features at least a minimal capability for printing cross-reference information extracted from program logic. Since, however, most systems ...
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Most systems for programmable-controller (PC) programming include among their features at least a minimal capability for printing cross-reference information extracted from program logic. Since, however, most systems do not update the cross-reference information dynamically, retrieving it can be tedious and time-consuming. The author discusses the benefits of dynamic, online cross-reference updating in PC logic programming and the design and implementation of this feature in a computer-based PC programming system.
Sorting is linear-time transformable to the convex hull problem and all convex hull algorithms are intricately linked to the problem of sorting. Among these algorithms is the Graham algorithm, which requires an explic...
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Sorting is linear-time transformable to the convex hull problem and all convex hull algorithms are intricately linked to the problem of sorting. Among these algorithms is the Graham algorithm, which requires an explicit sort step. Using a fully dedicated sorter coprocessor, the total time complexity of the Graham algorithm is reduced to O(N). A prototype sorter has been designed, implemented, and tested. The chip was built using 4- mu m nMOS technology;it consists of 33 8-bit processors in a systolic array. The architecture of the chip is fully cascadable to handle longer lists.
Syntax-directed editors were created with the intent of aiding in and improving the programming process. Despite their potential, they have not been successful, as evidenced by limited use. In general, they are percei...
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ISBN:
(纸本)0897912136
Syntax-directed editors were created with the intent of aiding in and improving the programming process. Despite their potential, they have not been successful, as evidenced by limited use. In general, they are perceived as being too difficult to use and the benefits of their use are outweighed by the difficulties. We believe that the cognitive styles and skills of the users have been ignored in the design process. In this paper we present some of our initial results which show that cognitive styles vary over a significant spectrum and that their consideration in the design of a syntax-directed editor will result in an intelligent tool that will be right for the cognitive skills and expertise of an individual user. In turn, an approach to design that takes cognitive variation into account would support the construction of syntax-directed editors which are successfully used.
The presented software is aimed to support designing, debugging, testing and productive run of the problem-oriented software of the robotic set control system. It has been used to develop an assembling set containing ...
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ISBN:
(纸本)0080334695
The presented software is aimed to support designing, debugging, testing and productive run of the problem-oriented software of the robotic set control system. It has been used to develop an assembling set containing two manipulator robots, a stacker and a commercial two-processor CNC unit used as the control system. At the stage of the problem-oriented software designing and debugging an instrumental (auxiliary) computer is used which can be connected to the control unit.
A worst-case lower bound of OMEGA (log log n) is proved for randomized algorithms merging two sorted lists of length n in parallel using n processors on L. G. Valiant's (1975) parallel computation tree model. It i...
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ISBN:
(纸本)0818608072
A worst-case lower bound of OMEGA (log log n) is proved for randomized algorithms merging two sorted lists of length n in parallel using n processors on L. G. Valiant's (1975) parallel computation tree model. It is shown how to strengthen this result to a lower bound for the expected time taken by any algorithm on the uniform distribution. Bounds are given for the average time required for the problem when the number of processors is less than and greater than n.
An experiment was conducted to evaluate user performance under four different menu item arrangements: alphabetic, probability of selection (most popular choices are positioned near the beginning of the list), random, ...
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ISBN:
(纸本)0897912136
An experiment was conducted to evaluate user performance under four different menu item arrangements: alphabetic, probability of selection (most popular choices are positioned near the beginning of the list), random, and positionally constant (consistent assignment of individual items to screen positions). During the initial stages of practice, the rule-based approaches produced faster mean search times, but after moderate amounts of practice, the positionally constant arrangement appeared to be most efficient. People seem to remember quite easily the location of items on a display, indicating that positional constancy can be an important factor in increasing the efficiency of the search of computer menus and other displays.
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