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Systems, Man and Cybernetics, Part A: Systems and Humans, IEEE Transactions on

Issue 4 • Date Jul 1997

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Displaying Results 1 - 13 of 13
  • A strategy to verify chassis controller software-dynamics, hardware, and automation

    Page(s): 480 - 493
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    A real-time hardware-in-the-loop tool set is presented to test automotive chassis controllers. The use of high-speed computers, specialized hardware interfaces, and instrumentation, as well as simulation models and automation software, provide a realistic and repeatable laboratory environment to supplement in-vehicle testing. In this paper, the dynamics for a variety of chassis models are presented to support the verification of integrated controller hardware and software. To implement these mathematical descriptions the computer hardware, laboratory equipment, and simulation software are discussed. The automated testing features of the simulator permit the creation of script files and test suites for regression testing and reuse on similar programs. A number of issues such as simulator requirements, hardware interfaces, and the need for metrics are explored in order to facilitate the development and justification of a simulation capability View full abstract»

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  • Modeling human eye behavior during mammographic scanning: preliminary results

    Page(s): 494 - 505
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    We investigate the use of an inexpensive and unobtrusive eye-tracking system to explore relationships between visual scanning patterns, pupillary response, and the clinical diagnoses of mammographic experts. One radiologist and three radiological technicians each examined a series of 14 mammograms for indications of abnormalities associated with breast cancer. The status of each mammogram was verified by biopsy. The eye-tracking system was used to measure and record eye position and pupil diameter as a function of time as the subjects scanned the mammograms. Three treatments were applied to the scan data to model the experts' eye behaviors. These included quantification of dwell time and pupil diameter as a function diagnostic accuracy in regions of the mammogram where abnormalities existed or were perceived; independent clustering of lookpoints without respect to abnormalities; and analysis of scan transitions between lookpoint clusters. Results of the analysis were consistent with extensive prior studies of eye-scan measures recorded during the diagnosis of abnormalities on chest radiograms. This preliminary investigation provides a proof of concept for use of the eye-tracking technology, experimental protocols, and analysis methodologies as the basis for expanded mammographic studies, with the promise of eventual adaptation as a source of diagnostic information in clinical practice View full abstract»

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  • Anisotropic human performance in six degree-of-freedom tracking: an evaluation of three-dimensional display and control interfaces

    Page(s): 518 - 528
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    Motivated by the need for human performance evaluations of advanced interface technologies, this paper presents an empirical evaluation of a 3D interface, from the point of view of both display and control, in a pursuit tracking experiment. The paper derives methods for decomposing tracking performance into six dimensions (three in translation and three in rotation). This dimensional decomposition approach has the advantage of revealing overall performance levels in the depth dimension relative to performance in the horizontal and vertical dimensions. With interposition, linear perspective, stereoscopic disparity and partial occlusion cues incorporated into a single 3D display system, subjects' tracking errors in the depth dimension were about 35% (with no practice) to 35% (with practice) larger than those in the horizontal and vertical dimensions. It was also found that subjects initially had larger tracking errors along the vertical axis than along the horizontal axis, likely due to their attention allocation strategy. Analysis of rotation errors generated a similar anisotropic pattern View full abstract»

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  • Route finding by using knowledge about the road network

    Page(s): 436 - 448
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    Traveling is a part of every person's day-to-day life. With the massive and complicated road network of a modern city or country, finding a good route to travel from one place to another is not a simple task. In network theory, this is the shortest path problem. Shortest-path algorithms are often used to solve this problem. However, these algorithms are wasteful in terms of computation when applied to the route-finding task. They may also produce routes that are not suitable for human users. In practice, knowledge about the road network can often be used to reduce the time and space required in computation, and to produce human-oriented solutions. In this project, we have integrated knowledge-based technique and algorithmic method to solve the problem. This integrated approach substantially reduces the computation time and space required for route finding. Within the approach we present three alternative designs, which may be suitable for different situations View full abstract»

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  • Bayesian estimation of a decision using information theory

    Page(s): 506 - 517
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    The problem of modeling the revision of the information of a decision maker based on the information of the expert sources is considered. The basic model assumes that the information of the decision maker and expert sources is in the form of the probability mass functions. The modeling approach is Bayesian estimation, which relies on Kullback entropy and Shannon entropy for information measurement, and produces a unique solution. Modeling of the problem not only considers information about the statistical dependence of the expert sources, but also uses information to measure the quality and importance of the individual expert sources in the form of rank ordering. The outcome shows that the effects of the dependence and rank ordering of the expert sources on the final decision cannot be isolated, In a special case where this isolation is possible, the effect of rank ordering decreases with the increase in the value of the correlation coefficient from -1 to +1, and the effect of the correlation never exceeds the effect of rank ordering. Sensitivity analysis is performed to explore other properties of the model related to the influence of the decision maker and expert sources. Extensions of the basic modeling to group decision making, group consensus, and mean value information are presented View full abstract»

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  • Sensitivity analysis in discrete Bayesian networks

    Page(s): 412 - 423
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    This paper presents an efficient computational method for performing sensitivity analysis in discrete Bayesian networks. The method exploits the structure of conditional probabilities of a target node given the evidence. First, the set of parameters which is relevant to the calculation of the conditional probabilities of the target node is identified. Next, this set is reduced by removing those combinations of the parameters which either contradict the available evidence or are incompatible. Finally, using the canonical components associated with the resulting subset of parameters, the desired conditional probabilities are obtained. In this way, an important saving in the calculations is achieved. The proposed method can also be used to compute exact upper and lower bounds for the conditional probabilities, hence a sensitivity analysis can be easily performed. Examples are used to illustrate the proposed methodology View full abstract»

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  • The relationship between three-dimensional imaging and group decision making: an exploratory study

    Page(s): 402 - 411
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    This paper describes an empirical investigation of the effect of 3D imaging on group performance in a tactical planning task. The objective of the study is to examine the role that stereoscopic imaging can play in supporting face-to-face group problem solving and decision making-in particular, the alternative generation and evaluation processes in teams. It was hypothesized that with the stereoscopic display, group members would better visualize the information concerning the task environment, producing open communication and information exchanges. The experimental setting was a tactical command and control task, and the quality of the decisions and nature of the group decision process were investigated, with three treatments: 1) noncomputerized, i.e., topographic maps with depth cues; 2) 2D imaging; and 3) stereoscopic imaging. The results were mixed on group performance. However, those groups with the stereoscopic displays generated more alternatives and spent less time on evaluation. In addition, the stereoscopic decision aid did not interfere with the group problem solving and decision-making processes. The paper concludes with a discussion of potential benefits, and the need to resolve demonstrated weaknesses of the technology View full abstract»

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  • Assessing cost/benefits of research and development investments

    Page(s): 389 - 401
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    A methodology is presented for assessing the economic and noneconomic cost/benefits of investments in research and development. It is argued that the most difficult aspect of cost/benefit analysis is not calculation, but representation of stakeholders, products, benefits, and costs. A stakeholder-based methodology is described that focuses on these representation issues. Use of this methodology is illustrated with a case study of a long-term government research and development (R&D) program View full abstract»

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  • Reliability of decision making in human-organizations

    Page(s): 543 - 549
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    In a human-organization system with n officers, a decision has to be made on whether to accept or to reject an innovation-oriented proposal that can either be good or bad. Each officer will review a given set of available information regarding the proposal in question and will thereafter return his or her decision. In the common formulation of this problem, the organization will accept the proposal if at least k officers decide for the project, where k is a prespecified threshold value. Hereby, each officer is subject to different errors and therefore, the final decision may be faulty as well. The reliability of such a system is the probability for the organization to make the right decision. In this paper, by imposing weights for each officer, generalized problem formulations are introduced and formulas for the corresponding reliability are derived View full abstract»

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  • Prediction with the dynamic Bayesian gamma mixture model

    Page(s): 529 - 542
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    Consider the problem of predicting in real time the next value of a random quantity x⩾0 from past observations. We present a flexible solution to this problem, a dynamic Bayesian model which represents the probability distribution of x by a mixture of gamma distributions ΣiciG(z|ai, bi). Whenever a new observation on x becomes available, the model updates its estimates of the parameters ai, bi, and ci . It also contains a monitoring mechanism that allows it to react quickly to major changes in the behavior of the input and to adjust itself when its predictions become unsatisfactory. Numerous examples are given, which illustrate the difference between static and dynamic models, and show that the mixture form is flexible enough to represent adequately a variety of inputs, even if their distributions are very different from the gamma View full abstract»

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  • Knowledge representation in MICKEY: an expert system for designing microprocessor-based systems

    Page(s): 467 - 479
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    This paper presents the knowledge representation schemes adopted in MICKEY, a knowledge based system for designing microprocessor based systems. MICKEY is essentially a hybrid expert system, using rules and procedures for achieving the different design tasks. We briefly describe the hierarchy of tasks in this problem domain, and emphasize on the refinement paradigm, constraint propagation, conflict resolution and task management strategies adopted in MICKEY. Next, we dwell upon the different knowledge sources and their functions, with respect to the particular design domain. Finally, we present an industrial design, achieved by MICKEY, to demonstrate its applicability View full abstract»

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  • Model transformations in simulation and planning: behavior preserving model simplifications

    Page(s): 424 - 435
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    Reasoning tasks such as simulation and planning involve deriving behavior of a system from a model of the system. The information needed to solve such problems can be represented as model behavior pairs (MBPs). The problem can be stated as one or more incomplete MBPs. The problem-solving method can be expressed as a sequence of MBP completions and comparisons. A language for representing and manipulating models, behaviors, and MBPs is presented. It is independent of any specific modeling domain. An important class of model transformation operators is the behavior-preserving model transformation operators. Because they preserve behavior, they can be used to simplify a model without compromising its value for problem solving. This sort of operator can speed up computations significantly. It can be used either to select an appropriate sub-model for a specific problem or to decompose a problem into a sequence of subproblems. A behavior-preserving pruning operator is presented and shown to work in three modeling domains: discrete event simulation (DES), planning, and qualitative physics (QP). The significance of this work lies in the domain independence of the language and operators. It provides a representation midway between the computer-oriented concepts of programming languages (and knowledge representation schemes) and the problem oriented concepts of the real world. The benefits that can result from such a representation are easy mapping of problem-to-solution method, easy communication between solution methods (when more than one reasoning technique is required to solve a problem) and efficient solution of problems View full abstract»

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  • A statistically based system for prioritizing information exploration under uncertainty

    Page(s): 449 - 466
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    This paper examines the problem of prioritizing actions under uncertainty. Our motivating applications come from the domain of data mining. Data mining problems present the user with a huge collection of individual items (e.g., abstracts, medical histories, and computer users' command histories) and require that these items be prioritized according to which should be pursued thoroughly. More precisely, each data item is assumed to be generated by one of two processes: A large majority of the data comes from a common, mundane process and a very small fraction comes from a rare, phenomenon process. The problem is to rank the information so as to optimally direct the user in his or her pursuit of the data items that were generated by the phenomenon process. Our previous work has developed the theoretical foundations of the information prioritization problem. The current paper summarizes these foundations, derives new theoretical results, and details initial experimental results of a prioritization system based on the theory. We focus here on feature selection techniques and the method of model surrogates, each tailored to the classes of prioritization applications of greatest current interest. Our results demonstrate the effectiveness of the techniques and motivate further research to improve the existing system View full abstract»

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Aims & Scope

The fields of systems engineering and human machine systems: systems engineering includes efforts that involve issue formulation, issue analysis and modeling, and decision making and issue interpretation at any of the lifecycle phases associated with the definition, development, and implementation of large systems.

 

This Transactions ceased production in 2012. The current retitled publication is IEEE Transactions on Systems, Man, and Cybernetics: Systems.

Full Aims & Scope

Meet Our Editors

Editor-in-Chief
Dr. Witold Pedrycz
University of Alberta