483 research outputs found

    Coalition structure generation in cooperative games with compact representations

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    This paper presents a new way of formalizing the coalition structure generation problem (CSG) so that we can apply constraint optimization techniques to it. Forming effective coalitions is a major research challenge in AI and multi-agent systems. CSG involves partitioning a set of agents into coalitions to maximize social surplus. Traditionally, the input of the CSG problem is a black-box function called a characteristic function, which takes a coalition as input and returns the value of the coalition. As a result, applying constraint optimization techniques to this problem has been infeasible. However, characteristic functions that appear in practice often can be represented concisely by a set of rules, rather than treating the function as a black box. Then we can solve the CSG problem more efficiently by directly applying constraint optimization techniques to this compact representation. We present new formalizations of the CSG problem by utilizing recently developed compact representation schemes for characteristic functions. We first characterize the complexity of CSG under these representation schemes. In this context, the complexity is driven more by the number of rules than by the number of agents. As an initial step toward developing efficient constraint optimization algorithms for solving the CSG problem, we also develop mixed integer programming formulations and show that an off-the-shelf optimization package can perform reasonably well

    EXPONENTIAL ATTRACTORS FOR BELOUSOV-ZHABOTINSKII REACTION MODEL

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    Supplement 200

    INFLUENCE OF BODY WEIGHT ON PULLING FORCE IN HAMMER THROW

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    In hammer throw it can be considered that the body weight affects the throwing distance because the muscle volume is directly proportional to the body weight. The pulling force of the hammer may also be affected by the body weight. The purpose of this study was to investigate the influence of the body weight on the pulling force during throwing motion in hammer throw

    Distributed Environment Control Using Wireless Sensor/Actuator Networks for Lighting Applications

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    We propose a decentralized algorithm to calculate the control signals for lights in wireless sensor/actuator networks. This algorithm uses an appropriate step size in the iterative process used for quickly computing the control signals. We demonstrate the accuracy and efficiency of this approach compared with the penalty method by using Mote-based mesh sensor networks. The estimation error of the new approach is one-eighth as large as that of the penalty method with one-fifth of its computation time. In addition, we describe our sensor/actuator node for distributed lighting control based on the decentralized algorithm and demonstrate its practical efficacy

    MOMENT OF FORCE AND MECHANICAL POWER IN GIANT SWING ON THE HORIZONTAL BAR

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    Introduction In the giant swing backwards, frictional force acts upon the grip and air resistance acts upon the whole body (Hay, 1978; and Kreighbaum and Barthels, 1981). These resistive forces affect the rotation of the body and cause a loss of mechanical energy. Therefore in order to complete the rotation, the gymnast has to offset these energy losses using muscular work (Hay, 1978). It has been reported that changes in mechanical energy occur during the backward giant swing. The total energy of the body is decreased during the second half of the downswing and almost recovered in the first half of the upswing. These results suggest that muscular work is done in the first half of the upswing to offset the loss of mechanical energy in the last half of the downswing (Okamoto, Sakurai, Ikegami and Yabe)

    Oral granuloma with chronic graft-vs-host disease

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    BACKGROUND Oral mucositis is often observed with graft-versus-host disease (GVHD); however, the occurrence of oral granuloma is rare. The rapid increase in granulomatous lesions should be distinguished from malignant tumors in patients with GVHD because malignant diseases can develop in those patients. This case is the youngest pediatric patient with granuloma associated with GVHD. CASE SUMMARY The patient was a 1-year and 5-mo-old girl who presented to our department for the management of oral nodules. At the age of 5 mo, she was diagnosed with primary immunodeficiency disease, cord blood transplant was performed at 11 mo and bone marrow transplant at 1 year of age. After transplantation, GVHD and oral mucositis developed, and tacrolimus was administered. Interestingly, nodules appeared on the lower lip and buccal mucosa, which spontaneously disappeared. Then, a new nodule appeared on the left lateral border of the tongue. Resection was performed and the histopathological diagnosis was granuloma. The origin of these nodules were considered to be the fibroblasts activated under inflammation caused by GVHD because the calcineurin inhibitor tacrolimus acted on their proliferation. CONCLUSION It is very important to distinguish oral granulomatous lesions from malignancies if GVHD is present at the base and if immunosuppressive agents and steroids are being administered

    Intravenous infusion route in maternal resuscitation:a scoping review

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    BACKGROUND: The concept that upper extremities can be used as an infusion route during cardiopulmonary resuscitation in pregnant women is a reasonable recommendation considering the characteristic circulation of pregnant women; however, this method is not based on scientific evidence. OBJECTIVE OF THE REVIEW: We conducted a scoping review to determine whether the infusion route should be established above the diaphragm during cardiopulmonary resuscitation in a pregnant woman. DISCUSSION: We included randomized controlled trials (RCTs) and non-RCTs on the infusion of fluids in pregnant women after 20 weeks of gestation requiring establishment of an infusion route due to cardiac arrest, massive bleeding, intra-abdominal bleeding, cesarean section, severe infection, or thrombosis. In total, 3150 articles from electronic database were extracted, respectively. After title and abstract review, 265 articles were extracted, and 116 articles were extracted by full-text screening, which were included in the final analysis. The 116 articles included 78 studies on infusion for pregnant women. The location of the intravenous infusion route could be confirmed in only 17 studies, all of which used the upper extremity to secure the venous route. CONCLUSION: Pregnant women undergo significant physiological changes that differ from those of normal adults, because of pressure and drainage of the inferior vena cava and pelvic veins by the enlarged uterus. Therefore, despite a lack of evidence, it seems logical to secure the infusion route above the diaphragm when resuscitating a pregnant woman. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12873-021-00546-9
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