236 research outputs found

    Dynamic Domains in Data Production Planning

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    This paper discusses a planner-based approach to automating data production tasks, such as producing fire forecasts from satellite imagery and weather station data. Since the set of available data products is large, dynamic and mostly unknown, planning techniques developed for closed worlds are unsuitable. We discuss a number of techniques we have developed to cope with data production domains, including a novel constraint propagation algorithm based on planning graphs and a constraint-based approach to interleaved planning, sensing and execution

    A Constraint-Based Planner for Data Production

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    This paper presents a graph-based backtracking algorithm designed to support constrain-tbased planning in data production domains. This algorithm performs backtracking at two nested levels: the outer- backtracking following the structure of the planning graph to select planner subgoals and actions to achieve them and the inner-backtracking inside a subproblem associated with a selected action to find action parameter values. We show this algorithm works well in a planner applied to automating data production in an ecological forecasting system. We also discuss how the idea of multi-level backtracking may improve efficiency of solving semi-structured constraint problems

    Preferences in Data Production Planning

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    This paper discusses the data production problem, which consists of transforming a set of (initial) input data into a set of (goal) output data. There are typically many choices among input data and processing algorithms, each leading to significantly different end products. To discriminate among these choices, the planner supports an input language that provides a number of constructs for specifying user preferences over data (and plan) properties. We discuss these preference constructs, how we handle them to guide search, and additional challenges in the area of preference management that this important application domain offers

    Intellectual Performance as a Function of Repression and Menstrual Cycle

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    Performance on complex (Space Relations and Verbal Reasoning) and simple (Digit Symbol) tests was investigated as a function of Byrne\u27s Repression-Sensitization (RS) dimension, phase of menstrual cycle and premenstrual-menstrual (PM) symptomatology in a group of females not taking oral contraceptives. Two control groups, consisting of males and females taking oral contraceptives, were included. Equivalent tests were given at two sessions two weeks apart. Analysis of the Space Relations Test as a function of menstrual phase and Repression-Sensitization indicated the predicted interaction effect of phase by RS with poorest performance for the menstruating repressor group (p \u3c .02), but the predicted deterioration by the premenstrual repressor group was not observed. Similar analysis for the Verbal Reasoning Test yielded an interaction effect of phase by RS (p \u3c .03) and a main effect for phase (p \u3c .05). As predicted, differences on the Digit Symbol test did not reach significance. Substituting PM symptomatology for RS, a significant effect was obtained only for phase on Verbal Reasoning Test (p \u3c .05). Results were interpreted as indicating a reactive nature of repression, so that during menstruation, repression may interfere particularly with performance on complex tasks. The three subject groups did not differ significantly on any of the three tests; however, trends in the present data corroborated those quoted in the literature

    An Agent-Based Interface to Terrestrial Ecological Forecasting

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    The latest generation of NASA Earth Observing System (EOS) satellites has brought a new dimension to continuous monitoring of the living part of the Earth System, the biosphere. EOS data can now provide weekly global measures of vegetation productivity and ocean chlorophyll, and many related biophysical factors such as land cover changes or snowmelt rates. However, the highest economic value would come from forecasting impending conditions of the biosphere, to allow decision makers to mitigate dangers or exploit positive trends. NASA's strategic plan for the Earth Science Enterprise i d e n a s ecological forecasting as a focus for research. Ecological forecasting predicts the effects of changes in the physical, chemical and biological environment on ecosystem activity. Possible applications of such a system include predicting shortfalls or bumper crops of agricultural production, populations of threatened or invasive species or wildfire danger in time to allow improves preparation and logistical efficiency. Petabytes of remote sensing data are now available to help measure, understand and forecast changes in the Earth system, but using these data effectively can be surprisingly hard. The volume and variety of data files and formats are daunting. Simple data management activities, such as locating and transferring files, changing file formats, gridding point data, and scaling and reprojecting gridded data, can consume far more personnel time and resources than the actual data analysis. Some scientists commit to a particular data source or resolution just because using anything different would be more effort that it's worth. Better tools can help, but most of the tools developed to date are little more than shell scripts; they lack the flexibility to meet the diverse needs of users and are difficult to extend to handle changes in available data sources

    Partners, Politics and Positive Attitudes: A Rural Community-University Partnership to Enhance School-Based Mental Health Services

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    There is a tremendous need for mental health services in rural schools and there are valuable resources available in universities for meeting these needs. This paper reports on a three-year grant designed to form a community-university partnership to enhance school-based mental health services in a rural community in Eastern North [State]. Throughout the first year of the implementation of this grant, partners experienced several roadblocks during the collaboration process. However, these partners also learned valuable lessons about how to improve and facilitate this process. Because of the strong commitments of the partners, the first year experience strengthened the partnership. The partners were able to overcome traditional barriers and boundaries that often occur between the community and the university. Progress made in the second and third years was both encouraging and rewarding to all involved and, most importantly, beneficial to the students. The purpose of this article is to share specific information about the process and outcomes in order assist others in developing similar workable and sustainable partnerships

    Foothill High School Wind Symphony and UNLV Symphonic Winds

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    Program listing performers and works performe

    Identifying and troubleshooting low-frequency artifacts mimicking atrial flutter caused by deep brain stimulator

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    Electromagnetic interference from deep brain stimulators (DBS) is known to cause high-frequency artifact on some forms of cardiac telemetry.1 Here, we (1) present a unique case in which a DBS caused a low-frequency artifact mimicking typical atrial flutter leading to referral to electrophysiology; (2) demonstrate a method to confirm this; and (3) provide recommendations of how to minimize artifact and work around this interaction in future rhythm monitoring attempts

    First Results from HaloSat – A CubeSat to Study the Hot Galactic Halo

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    HaloSat is the first CubeSat for astrophysics funded by NASA\u27s Science Mission Directorate and is designed to map soft X-ray oxygen line emission across the sky in order to constrain the mass and spatial distribution of hot gas in the Milky Way. HaloSat will help determine if hot halos with temperatures near a million degrees bound to galaxies make a significant contribution to the cosmological budget of the normal matter (baryons). HaloSat was deployed from the International Space Station in July 2018 and began routine science operations in October 2018. We describe the on-orbit performance including calibration of the X-ray detectors and initial scientific results including an observation of a halo field and an observation of solar wind charge exchange emission from the helium-focusing cone

    Ethnic entrepreneurs and online home-based businesses: an exploratory study

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    This exploratory, qualitative study considers how online home-based businesses offer opportunities for ethnic entrepreneurs to ‘break out’ of traditional highly competitive and low margin sectors. Previous studies have found a positive association between ethnic minorities’ high levels of entrepreneurship and home computer use in ethnic groups. Despite these associations, previous studies have overlooked the particular opportunities offered by home-based online businesses to ethnic entrepreneurs. The study adopts mixed embeddedness as a theoretical lens to guide interviews with 22 ethnic entrepreneurs who have started online home-based businesses in the UK. We find online home-based businesses offer ethnic entrepreneurs novel opportunities to draw on their ethnic advantages and address the constraints they face. The unique affordances of this type of business allow entrepreneurs to develop the necessary IT skills by self-learning and experimentation and to sub-contract more difficult or time consuming aspects to others. The findings also show that, consistent with the theory of mixed embeddedness, whilst the entrepreneurs are influenced by social, economic and institutional forces, online businesses allow them to exert their own agency and provide opportunities to uniquely shape these forces
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