329 research outputs found

    Strategies for Improving Visual Inspection Performance

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    This paper summarizes recent results obtained in inspection studies including several studies performed by the authors. Both static and dynamic visual inspection tasks are included. Based on these results, a proposed new integrated design procedure for inspection tasks that will approach the optimal design has been formulated. The review of recent research results includes the following primary variables: the speed of the item passing the inspector, the spacing of items, the percentage of defective items, the illumination level, the contrast between the item being inspected and the background, and the effectiveness of individual versus group inspection. The authors have used their research results in combination with the results in the literature to formulate new integrated procedures for designing inspection stations and job procedures. The authors have also analyzed the effects of inspector performance on the overall quality control plans already in use in industry. The economic effects of changes in inspector performance which result from redesign of the inspection task are then demonstrated as a part of the overall design procedure.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline

    Using Variable-Rate Alerting to Counter Boredom in Human Supervisory Control

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    A low task load, long duration experiment was conducted to evaluate the impact of cyclical attention switching strategies on operator performance in supervisory domains. The impetus for such a study stems from the lack of prior work to improve human-system performance in low task load supervisory domains through the use of design interventions. In this study, a design intervention in the form of auditory alerts is introduced and the effects of the alerts are examined. The test bed consists of a video game-like simulation environment, which allows a single operator the ability to supervise multiple unmanned vehicles. Each participant in the study completed two different four hour sessions, with and without the alerts. The results suggest that the alerts can be useful for operators who are distracted for a considerable amount of time, but that the alerts may not be appropriate for operators who are able to sustain directed attention for prolonged periods.United States. Office of Naval Researc

    q-Breathers in Discrete Nonlinear Schroedinger arrays with weak disorder

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    Nonlinearity and disorder are key players in vibrational lattice dynamics, responsible for localization and delocalization phenomena. qq-Breathers -- periodic orbits in nonlinear lattices, exponentially localized in the reciprocal linear mode space -- is a fundamental class of nonlinear oscillatory modes, currently found in disorder-free systems. In this paper we generalize the concept of qq-breathers to the case of weak disorder, taking the Discrete Nonlinear Schr\"{o}dinger chain as an example. We show that qq-breathers retain exponential localization near the central mode, provided that disorder is sufficiently small. We analyze statistical properties of the instability threshold and uncover its sensitive dependence on a particular realization. Remarkably, the threshold can be intentionally increased or decreased by specifically arranged inhomogeneities. This effect allows us to formulate an approach to controlling the energy flow between the modes. The relevance to other model arrays and experiments with miniature mechanical lattices, light and matter waves propagation in optical potentials is discussed.Comment: 5 pages, 3 figure

    Dynamic variable ordering in CSPs

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    Non-Local Configuration of Component Interfaces by Constraint Satisfaction

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    © 2020 Springer-Verlag. The final publication is available at Springer via https://doi.org/10.1007/s10601-020-09309-y.Service-oriented computing is the paradigm that utilises services as fundamental elements for developing applications. Service composition, where data consistency becomes especially important, is still a key challenge for service-oriented computing. We maintain that there is one aspect of Web service communication on the data conformance side that has so far escaped the researchers attention. Aggregation of networked services gives rise to long pipelines, or quasi-pipeline structures, where there is a profitable form of inheritance called flow inheritance. In its presence, interface reconciliation ceases to be a local procedure, and hence it requires distributed constraint satisfaction of a special kind. We propose a constraint language for this, and present a solver which implements it. In addition, our approach provides a binding between the language and C++, whereby the assignment to the variables found by the solver is automatically translated into a transformation of C++ code. This makes the C++ Web service context compliant without any further communication. Besides, it uniquely permits a very high degree of flexibility of a C++ coded Web service without making public any part of its source code.Peer reviewe

    The Vigilance Decrement in Executive Function Is Attenuated When Individual Chronotypes Perform at Their Optimal Time of Day

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    Time of day modulates our cognitive functions, especially those related to executive control, such as the ability to inhibit inappropriate responses. However, the impact of individual differences in time of day preferences (i.e. morning vs. evening chronotype) had not been considered by most studies. It was also unclear whether the vigilance decrement (impaired performance with time on task) depends on both time of day and chronotype. In this study, morning-type and evening-type participants performed a task measuring vigilance and response inhibition (the Sustained Attention to Response Task, SART) in morning and evening sessions. The results showed that the vigilance decrement in inhibitory performance was accentuated at non-optimal as compared to optimal times of day. In the morning-type group, inhibition performance decreased linearly with time on task only in the evening session, whereas in the morning session it remained more accurate and stable over time. In contrast, inhibition performance in the evening-type group showed a linear vigilance decrement in the morning session, whereas in the evening session the vigilance decrement was attenuated, following a quadratic trend. Our findings imply that the negative effects of time on task in executive control can be prevented by scheduling cognitive tasks at the optimal time of day according to specific circadian profiles of individuals. Therefore, time of day and chronotype influences should be considered in research and clinical studies as well as real-word situations demanding executive control for response inhibition.This work was supported by the Spanish Ministerio de Ciencia e Innovación (Ramón y Cajal programme: RYC-2007-00296 and PLAN NACIONAL de I+D+i: PSI2010-15399) and Junta de Andalucía (SEJ-3054)
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