737,992 research outputs found

    SimGrid: a Sustained Effort for the Versatile Simulation of Large Scale Distributed Systems

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    In this paper we present Simgrid, a toolkit for the versatile simulation of large scale distributed systems, whose development effort has been sustained for the last fifteen years. Over this time period SimGrid has evolved from a one-laboratory project in the U.S. into a scientific instrument developed by an international collaboration. The keys to making this evolution possible have been securing of funding, improving the quality of the software, and increasing the user base. In this paper we describe how we have been able to make advances on all three fronts, on which we plan to intensify our efforts over the upcoming years.Comment: 4 pages, submission to WSSSPE'1

    It is Hobbes, not Rousseau : an experiment on social insurance

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    We perform an experiment on social insurance to provide a laboratory replica of some important features of the welfare state. In the experiment, all individuals in a group decide whether to make a costly effort, which produces a random (independent) outcome for each one of them. The group members then vote on whether to redistribute the resulting and commonly known total sum of earnings equally amongst themselves. This game has two equilibria, if played once. In one of them, all players make effort and there is little redistribution. In the other one, there is no effort and nothing to redistribute. A solution to the repeated game allows for redistribution and high effort, by the threat to revert to the worst of these equilibria. Our results show that redistribution with high effort is not sustainable. The main reason for the absence of redistribution is that rich agents do not act differently depending on whether the poor have worked hard or not. There is no social contract by which redistribution may be sustained by the threat of punishing the poor if they do not exert effort. Thus, the explanation of the behavior of the subjects lies in Hobbes, not in Rousseau

    AI, Robotics, and the Future of Jobs

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    This report is the latest in a sustained effort throughout 2014 by the Pew Research Center's Internet Project to mark the 25th anniversary of the creation of the World Wide Web by Sir Tim Berners-Lee (The Web at 25).The report covers experts' views about advances in artificial intelligence (AI) and robotics, and their impact on jobs and employment

    ENTREPRENEURSHIP AND FEMALE ENTREPRENEURSHIP IN MARAMURES COUNTY

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    Initiating and developing a business involves a considerable risk and a sustained effort in order to defeat the inertia against what is new. The person initiating a business, assuming the responsibility and risk of its development and benefiting from theentrepreneurship, female entrepreneurship, profit, businesses

    Cardiac Baroreflex Variability and Resetting during Sustained Mild Effort

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    This exploratory study assessed the pattern of closed-loop baroreflex resetting using multi-logistic-curve analysis. Operating point gain and ranges of RR-interval (RRI) and systolic blood pressure (SBP) are derived to examine how these relate to sympathetic activation. Sustained low-intensity isometric handgrip exercise, with a period of post-exercise circulatory occlusion (PECO), provided a model to study baroreflex resetting because the progression toward fatigue at constant tension induces a continuous increase in volitional contribution to neuro-cardiovascular control. Continuous measurements of muscle sympathetic nerve activity (MSNA), blood pressure, and RRI were made simultaneously throughout the experimental session. Spontaneous sequence analysis was used to detect episodes of baroreflex “engagements”, but the results are examined with a view to the fundamental difference between experimental conditions that isolate the carotid sinus (open-loop) and intact physiological conditions (closed-loop). While baroreflex function under open-loop conditions can be described in terms of a single logistic curve, intact physiologic conditions require a family of logistic curves. The results suggest that the baroreflex is in a “floating” state whereby it is continuously resetting during the timeline of the experiment but with minute-by-minute average values that mimic the less complex step-wise resetting pattern reported under open-loop conditions. Furthermore, the results indicate that baroreflex function and resetting of the operating point gain is reflected not in terms of change in the values of blood pressure or RR-interval but in terms of change in the range of values of these variables prevailing under different experimental condition

    Consumption of cocoa flavanols results in acute improvements in mood and cognitive performance during sustained mental effort

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    Cocoa flavanols (CF) positively influence physiological processes in ways that suggest their consumption may improve aspects of cognitive function. This study investigated the acute cognitive and subjective effects of CF consumption during sustained mental demand. In this randomized, controlled, double-blinded, balanced, three period crossover trial 30 healthy adults consumed drinks containing 520 mg, 994 mg CF and a matched control, with a three-day washout between drinks. Assessments included the state anxiety inventory and repeated 10-min cycles of a Cognitive Demand Battery comprising of two serial subtraction tasks (Serial Threes and Serial Sevens), a Rapid Visual Information Processing (RVIP) task and a mental fatigue scale, over the course of 1 h. Consumption of both 520 mg and 994 mg CF significantly improved Serial Threes performance. The 994 mg CF beverage significantly speeded RVIP responses but also resulted in more errors during Serial Sevens. Increases in self-reported mental fatigue were significantly attenuated by the consumption of the 520 mg CF beverage only. This is the first report of acute cognitive improvements following CF consumption in healthy adults. While the mechanisms underlying the effects are unknown they may be related to known effects of CF on endothelial function and blood flow

    Why Invest in Collaborative Leadership Development? Summary Report

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    The Casey Foundation values skillful leadership in creating sustained social change. The Foundation partnered with the University of Maryland, School of Public Policy in sculpting a new approach to match leadership ability with constructive results for children, families and communities -- a collaborative leadership style for complex social issues. Readers, especially other foundations and nonprofit investors, get a look at the findings, lessons learned and recommendations from three years of collaborative leadership capacity-building effort

    Association Between Fiscal Effort Above Required Local Effort and Accreditation in Virginia Schools

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    This study expands on previous research regarding the adequacy of educational funding in order to reach a desired academic outcome. Specifically, this study examines Virginia policies of Standards of Quality and Standards of Accreditation to see if local fiscal effort above the minimum required by Virginia has an association to the desired minimum academic outcome of school accreditation. The research in this study shows that when using a linear regression analysis or an ANCOVA there is no relationship between effort above Required Local Effort (RLE) and the percentage of students attending an accredited school. However, when looking at the non-linear data in this study, there does appear to be a relationship between effort above RLE and the percentage of students attending an accredited school. The t-tests run show a significant difference between the sustained or increased effort above RLE and decreased effort above RLE. Further, localities with sustained or increased effort above RLE had the largest average percentage of students attending accredited schools. The conclusion being that the practical significance of sustained and increasing effort above RLE has a positive relationship to a higher percentage of students attending accredited schools

    Product Innovation and Stability of Collusion

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    We study the nature of market competition in relation to stability of collusion in the infinitely repeated play of a two-stage game of product innovation and market competition, and show that cooperation in giving R&D efforts is more easily sustained when firms compete in quantity than in price.R&D Effort, Product differentiation, Collusion

    The triple task technique for studying writing processes : on which task is attention focused ?

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    The triple task technique measures the time and cognitive effort devoted to specific writing processes by combining directed retrospection with secondary task reaction time (RT). Writing a text is the primary task and rapidly detecting auditory probes to index cognitive effort is the secondary task. The third task is retrospecting and categorizing the contents of working memory at the time of each probe. The present paper reviews studies on the reactivity and validity of the technique. Further, one recent criticism of the method's validity is tested here: namely, that the primary task for the experimenter is not the primary task for the writer, thus distorting the time and effort measurements. We found that time and effort allocated to planning, translating, executing, evaluating, and revising was the same when the writer was encouraged by instructions to focus either on the speed of responding or the accuracy of retrospection instead of the text itself. Because writing requires sustained thought and attention to produce a cumulative product, it is apparently difficult to make text production anything but the primary task. The triple task technique offers a useful alternative to pause analysis and verbal protocols for investigating the functional features of writing
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