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Systems, Man and Cybernetics, IEEE Transactions on

Issue 6 • Date Jun 1994

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Displaying Results 1 - 11 of 11
  • Computational analysis of robot kinematics, dynamics, and control using the algebra of rotations

    Page(s): 936 - 942
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    The basic quantities required for computations in robot kinematics, dynamics, and control are defined. By modifying the rotational operator in terms of the Euler parameters and appropriately choosing the zero reference position, the method of the algebra of rotations becomes more efficient than the homogeneous transformation method for computing these basic quantities. As a result, the computational efficiency is improved by about 50|% for robot kinematics, and by about 20|% for robot dynamics and control, if the method of the algebra of rotations is used instead of the homogeneous transformation method View full abstract»

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  • Fuzzy information in knowledge representation and processing for frame-based structures

    Page(s): 918 - 925
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    This paper presents selected aspects of information processing in frames. The slots of frames are considered as taking on linguistic values represented as fuzzy sets. Matching procedures are developed and algorithms resulting within this context are proposed. The question of modeling cases involving many exemplar frames associated with a single prototype frame is posed. Subsequently the resulting model is effectively applied to fill the values missing in an exemplar frame. The optimization task involving entropy criterion enables to minimize ambiguity associated with the reconstruction problem. The resulting interval-valued fuzzy constructs are interpreted in terms of relevancy of the reconstructed information View full abstract»

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  • Visual instrument monitoring as affected by simultaneous self-paced card sorting

    Page(s): 926 - 931
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    This study investigates several possible causes for the finding that the human monitor tends to oversample low bandwidths and undersample high bandwidths in monitoring multiple processes. The results show that this finding may be related to a tendency to conditionally sample low bandwidths whereas high bandwidths tend to be periodically sampled View full abstract»

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  • A system for aiding creative concept formation

    Page(s): 882 - 894
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    This paper describes a system named AA1 (Articulation Aid 1) which aids human users in the formation of new concepts in the domain of engineering and science. From the viewpoint of concept formation, one main process of creation is divergent thinking in which broad alternatives are searched, and another process is convergent thinking in which a unique solution is sought. From the viewpoint of human activities, creation also includes the aspect of collaboration among people and the aspect of individual reflection, although they are interrelated. AA1, the system presented in this paper, supports divergent thinking during individual reflection. Engineers and scientists usually scrawl many notes on paper while exploring new possible concepts in the divergent thinking process. A system is needed to reflect the fragments of concepts that are not articulated yet and thereby stimulate the formation of new concepts. AA1 builds a two-dimensional space from the words the user provides. Looking at this space and other precedent spaces, the user can form new concepts little by little. The main feature of AA1 different, from existing hypermedia systems and CSCW systems is the strategy for building the space presented to the user. The system is as nonprescriptive as possible, but it gives stimulation for the user to form concepts that he could not by using only pencil and paper. Experimentation has shown that the space which AA1 displays can effectively help the user to build new concepts. The most prominent effect is that empty regions in the space automatically configured by the system often lead to new concepts View full abstract»

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  • Towards a hierarchical contour description via dominant point detection

    Page(s): 942 - 949
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    An algorithm for the detection of dominant points and for building a hierarchical approximation of a digital curve is proposed. The algorithm does not require any parameter tuning and is shown to perform well for a wide variety of shapes, including scaled and rotated ones. Dominant points are first located by a coarse-to-fine detector scheme. They constitute the vertices of a polygon closely approximating the curve. Then, a criterion of perceptual significance is used to repeatedly remove suitable vertices until a stable polygonal configuration, the contour sketch, is reached. A highly compressed hierarchical description of the shape also becomes available View full abstract»

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  • Hand acceleration impulse bandwidth during target acquisition: implications for teleoperator bandwidth requirements

    Page(s): 931 - 936
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    The purpose of this experiment was to provide data about bandwidth requirements for teleoperators. During teleoperation, user inputs are changes in forces applied to the master controller arising from changes in hand acceleration during execution of goal-directed trajectories, so human hand acceleration bandwidth sets an upper bound on teleoperator feedforward bandwidth requirements. Participants completed a set of computerized target acquisition tasks using a mouse, and the computer recorded the cursor trajectory. Movement time, positioning error, the number of acceleration-deceleration impulses, impulse bandwidth, impulse amplitude, and impulse period were calculated from the trajectory trace. The results obtained show that to completely capture hand trajectories, master controllers and slave arms must have acceleration bandwidth higher than 9.20 Hz. However, it may be that only the joints closest to the end-effector need to accommodate the highest bandwidths and “shoulder” joints may only need to accommodate 5.63 Hz acceleration bandwidth View full abstract»

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  • Uniquely representing point patterns with minimal information

    Page(s): 895 - 900
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    As an alternative to coordinate locations, patterns of points can be represented using interpoint distances. In certain applications, such as dimensioning and multidimensional scaling, interpoint distances have traditionally been used. In other applications, such as radar location, interpoint distance information is readily obtained, This paper utilizes kinematics, rigidity theory, and graph algorithms to determine the theoretical minimum interpoint distance information adequate for uniquely representing point patterns. It is shown that this theoretical minimum is comparable to that amount of information required by coordinate descriptions View full abstract»

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  • Merging strategic and tactical planning in dynamic and uncertain environments

    Page(s): 841 - 862
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    This paper presents a new approach to planning in dynamic and uncertain environments. Planning is viewed as a process in which an agent's long term goals are transformed into short term tasks and objectives, given the agent's strategy and the context of planning. The developed model allows for a dynamic balance between long term strategic planning and short term tactical planning. The notion of a strategy hierarchy is introduced to explicitly represent the process of strategy formulation and refinement. A combination of rules and plan scripts is used. Rules are used for representing domain knowledge and reasoning about strategic choices. Plan scripts are used for representing specific tasks and objectives. The uncertainty calculi of RUM/PRIMO are used for supporting reasoning under uncertainty. In the proposed model, it is also possible to achieve a seamless integration of case-based reasoning into the planning process. These ideas have been implemented in a system called MARS, which plans in the financial domain of mergers and acquisitions View full abstract»

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  • Automated exercise progression in simulation-based training

    Page(s): 863 - 874
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    As simulator-based training systems become more complex, the amount of effort required to generate, monitor, and maintain training exercises multiplies greatly. This has significantly increased the burden on the instructors, potentially making the training experience less efficient as well as less effective. Research on intelligent tutoring systems (ITS) has largely addressed this issue by replacing the instructor with a computer model of the appropriate pedagogical concepts and the domain expertise. While this approach is highly desirable, the effort required to develop and maintain an ITS can be quite significant. A more modest as well as practical alternative to an ITS is the development of intelligent computer-based tools that can support the instructors in their tasks. The advantage of this approach is that various tools can be developed to address the different aspects of the instructor's duties. Moreover, without the burden of having to replace the instructor, these tools are more easily developed and fielded in existing trainers. One aspect of an instructor's task is to assess the students' performance after each training exercise and select the next exercise based on their previous performances. It would clearly be advantageous if this exercise selection process were to be automated, thus relieving the instructor of a significant burden and allowing him to concentrate on other tasks. Therefore, the focus of this paper is the development of a stand-alone system capable of determining exercise progression and remediation automatically during a training session in a simulator-based trainer, on the basis of the students's past performance. Instructional heuristics were developed to carry out the exercise progression process. A prototype was developed and applied to gunnery training on the Army M1 main battle tank View full abstract»

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  • An open system knowledge framework and its bridge evaluation application

    Page(s): 901 - 917
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    We present OPUS, a framework that provides design guidelines for the systematic building of independent, and potentially heterogeneous, knowledge base programs for the domains of large physical structures. The term open-system refers to the integration of several of these programs to solve problems beyond their individual capabilities. The OPUS framework organizes data and knowledge about the domain into three layers. The kernel layer encodes primary domain knowledge into hierarchies of objects, the scenario layer contains autonomous knowledge programs for specific applications, and the utility layer supports system interface and inference methods. OPUS provides a focus for knowledge organization and rapid prototyping, supports multiple schemes of inference and representation, copes with the maintenance and reuse of knowledge, and enables different levels of abstraction and views of knowledge. An OPUS system BFC has been developed to cover wide-ranging applications in bridge evaluation. Examples are taken from this application to illustrate data constructs and reasoning schemes based on the OPUS framework View full abstract»

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  • Analysis of delays in networked flight simulators

    Page(s): 875 - 881
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    Networking large numbers of manned flight simulators over wide geographical areas has become feasible because of the great advances in the technologies of microprocessors, and local area and long haul networks. One of the main concerns in developing networked simulators is the effect of intersimulator time delay on the performance of these networks as training devices. Previous studies on the effects of time delays in single simulators provide guidance in analyzing this problem. This paper first introduces the networked simulator problem. Next, it reviews the basic optimal control model (OCM), one of the most useful methods for the mathematical modeling of pilots. Finally, it describes how the OCM concept can be used in the analysis of some networked flight simulator experiments. A simplified formation flight task is carefully analyzed, and a number of interesting phenomena are described View full abstract»

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