1,236 research outputs found

    An FPGA-based controller for collaborative robotics

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    The use of robots is becoming more common in society. Industrial robots are being developed to work with people, and lower-force collaborative robots are being developed to help people in their everyday lives. These may need fast and sophisticated motion control and behavioral algorithms, but are expected to be more compact and lower cost. This paper proposes a processor plus FPGA solution for the control systems for such robots, where the FPGA performs all real-time tasks, freeing the processor to run lower-frequency high level control and interface to other devices such as camera systems. A demonstrator robot is designed, combining multi-axis motion control with 3D robot vision

    Crowdfunding as Donations to Entrepreneurial Firms

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    The bulk of today's (“preorder-,” “reward-,” “gift-,” and “donation-based”) crowdfunding raises funds for small, private entrepreneurial ventures without granting funders private claims to the projects’ income or the ability to guarantee the realization and delivery of project outcomes. We theorize and show empirically – via a mixed-method approach applied to a representative and remarkably informative case – that the payoff structure for crowdfunders, akin to a public good contribution problem, leads to the tangible value of main project outputs exerting little influence on contributions to crowdfunding. This then raises the question of which funder motivations fund seekers may have to address to crowdfund their projects. We demonstrate the especially large role of non-pecuniary motivations and pinpoint three particular motivations that profit-seeking entrepreneurs may stimulate to be financed through crowdfunding. The findings hold important implications for entrepreneurs’ crowdfunding strategies, platform design, and our understanding of how this funding institution works in general. The study also adds to emerging research on the implications of the public good nature of crowdfunding

    Update to the study protocol Face Your Fears:Virtual reality-based cognitive behavioral therapy (VR-CBT) versus standard CBT for paranoid ideations in patients with schizophrenia spectrum disorders: a randomized clinical trial

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    We unfortunately need to make an update to our published study protocol that describes a significant change in the design of the study. The Committee on Health Research Ethics of the Capital Region Denmark recently rejected the approval of changing the primary outcome in the trial, on the invariable grounds that the trial has already commenced. It is therefore necessary to retain the Green Paranoid Thought Scale (GPTS) part B, ideas of persecution, as our primary outcome, and GPTS part A, ideas of social reference, as a secondary outcome, which is described opposite in our published study protocol. The exchange of outcomes has not affected participation in our trial or the informed consent. Intervention in both groups and assessments are unchanged. The two outcomes together constitute GPTS and the unifying concept we attempt to treat, namely paranoid ideations. As this is a blinded, methodologically rigorous trial, we did not have—and still do not have—access to preliminary data, and therefore, we have no knowledge of the distribution of our two intervention groups nor the potential effect of the intervention. The power calculation remains unchanged irrespective of the selection of the primary outcome. We have been fully transparent with the changes in primary and secondary outcomes on ClinicalTrials.gov throughout the trial. Due to the considerations mentioned above, we assumed that there would not be any ethical implications of the change of primary outcome. We sincerely apologize for the irregularity caused because of this assumption. Trial registration: ClinicalTrials.gov NCT04902066. Initial release April 19th, 2021.</p

    Face Your Fears: Virtual reality-based cognitive behavioral therapy (VR-CBT) versus standard CBT for paranoid ideations in patients with schizophrenia spectrum disorders:a randomized clinical trial

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    Background: Schizophrenia spectrum disorders cause suffering for patients, relatives, and the surrounding society. Paranoid ideations, encompassing ideas of social reference and manifest persecutory delusions, are among the most frequent symptoms in this population and a cause of significant distress. Recent meta-analyses of cognitive behavioral therapy (CBT) for psychosis show small to moderate effect sizes in reducing paranoid ideations. Virtual reality-based CBT (VR-CBT) could improve therapy efficacy as exposure and behavioral experiments in VR can be optimized, individualized, and carried out in a safe environment. Few VR-CBT studies exist for paranoid ideations and there is a need for large-scale, methodologically rigorous trials. Methods: This study is a randomized, assessor-blinded parallel-groups multi-center superiority clinical trial, fulfilling the CONSORT criteria for non-pharmacological treatment. A total of 256 patients diagnosed with schizophrenia spectrum disorder, including schizotypal disorder (ICD-10 F20-29), will be allocated to either 10 sessions of symptom-specific CBT-VR plus treatment as usual-versus 10 sessions of standard symptom-specific CBT for paranoid ideations (CBT) plus treatment as usual. All participants will be assessed at baseline, treatment end (3 months post baseline), and then 9 months post baseline. A stratified block-randomization with concealed randomization sequence will be conducted. Independent assessors blinded to the treatment will evaluate the outcome. Analysis of outcome will be carried out with the intention to treat principles. The primary outcome is ideas of social reference measured with Green Paranoid Thought Scale Part A (GPTS-A) at the cessation of treatment at 3 months post baseline. Secondary outcomes are ideas of persecution (GPTS-B), Social Interaction Anxiety Scale (SIAS), Personal and Social Performance scale (PSP), Safety Behavior Questionnaire (SBQ), and CANTAB Emotion Recognition Task. Discussion: The trial will elucidate whether VR-CBT can enhance therapy efficacy for paranoid ideations. Additionally, Trial findings will provide evidence on the effectiveness and cost-effectiveness of VR-CBT for paranoid ideations that can guide the possible dissemination and implementation into clinical practice

    A Cognitive Model of an Epistemic Community: Mapping the Dynamics of Shallow Lake Ecosystems

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    We used fuzzy cognitive mapping (FCM) to develop a generic shallow lake ecosystem model by augmenting the individual cognitive maps drawn by 8 scientists working in the area of shallow lake ecology. We calculated graph theoretical indices of the individual cognitive maps and the collective cognitive map produced by augmentation. The graph theoretical indices revealed internal cycles showing non-linear dynamics in the shallow lake ecosystem. The ecological processes were organized democratically without a top-down hierarchical structure. The steady state condition of the generic model was a characteristic turbid shallow lake ecosystem since there were no dynamic environmental changes that could cause shifts between a turbid and a clearwater state, and the generic model indicated that only a dynamic disturbance regime could maintain the clearwater state. The model developed herein captured the empirical behavior of shallow lakes, and contained the basic model of the Alternative Stable States Theory. In addition, our model expanded the basic model by quantifying the relative effects of connections and by extending it. In our expanded model we ran 4 simulations: harvesting submerged plants, nutrient reduction, fish removal without nutrient reduction, and biomanipulation. Only biomanipulation, which included fish removal and nutrient reduction, had the potential to shift the turbid state into clearwater state. The structure and relationships in the generic model as well as the outcomes of the management simulations were supported by actual field studies in shallow lake ecosystems. Thus, fuzzy cognitive mapping methodology enabled us to understand the complex structure of shallow lake ecosystems as a whole and obtain a valid generic model based on tacit knowledge of experts in the field.Comment: 24 pages, 5 Figure

    The Secret to Successful User Communities: An Analysis of Computer Associates’ User Groups

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    This paper provides the first large scale study that examines the impact of both individual- and group-specific factors on the benefits users obtain from their user communities. By empirically analysing 924 survey responses from individuals in 161 Computer Associates' user groups, this paper aims to identify the determinants of successful user communities. To measure success, the amount of time individual members save through having access to their user networks is used. As firms can significantly profit from successful user communities, this study proposes four key implications of the empirical results for the management of user communities

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    The internal surrogate ratio method allows for the determination of an unknown cross section, such as (n,γ), relative to a better-known cross section, such as (n,f), by measuring the relative exit-channel probabilities of a surrogate reaction that proceeds through the same compound nucleus. The validity of the internal surrogate ratio method is tested by comparing the relative γ and fission exit-channel probabilities of a 236U∗ compound nucleus, formed in the 235U(d,p) reaction, to the known 235U(n,γ) and (n,f) cross sections. A model-independent method for measuring the γ-channel yield is presented and used

    Molecular Dynamics Simulation of Spinodal Decomposition in Three-Dimensional Binary Fluids

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    Using large-scale molecular dynamics simulations of a two-component Lennard-Jones model in three dimensions, we show that the late-time dynamics of spinodal decomposition in concentrated binary fluids reaches a viscous scaling regime with a growth exponent n=1n=1, in agreement with experiments and a theoretical analysis for viscous growth.Comment: 4 pages, 3 figure

    Interleukin 7 from Maternal Milk Crosses the Intestinal Barrier and Modulates T- Cell Development in Offspring

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    Background Breastfeeding protects against illnesses and death in hazardous environments, an effect partly mediated by improved immune function. One hypothesis suggests that factors within milk supplement the inadequate immune response of the offspring, but this has not been able to account for a series of observations showing that factors within maternally derived milk may supplement the development of the immune system through a direct effect on the primary lymphoid organs. In a previous human study we reported evidence suggesting a link between IL-7 in breast milk and the thymic output of infants. Here we report evidence in mice of direct action of maternally-derived IL-7 on T cell development in the offspring. Methods and Findings  We have used recombinant IL-7 labelled with a fluorescent dye to trace the movement in live mice of IL-7 from the stomach across the gut and into the lymphoid tissues. To validate the functional ability of maternally derived IL- 7 we cross fostered IL-7 knock-out mice onto normal wild type mothers. Subsets of thymocytes and populations of peripheral T cells were significantly higher than those found in knock-out mice receiving milk from IL-7 knock-out mothers. Conclusions/Significance Our study provides direct evidence that interleukin 7, a factor which is critical in the development of T lymphocytes, when maternally derived can transfer across the intestine of the offspring, increase T cell production in the thymus and support the survival of T cells in the peripheral secondary lymphoid tissue
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