350 research outputs found

    The Secretary Problem with Predictions

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    The value maximization version of the secretary problem is the problem of hiring a candidate with the largest value from a randomly ordered sequence of candidates. In this work, we consider a setting where predictions of candidate values are provided in advance. We propose an algorithm that achieves a nearly optimal value if the predictions are accurate and results in a constant-factor competitive ratio otherwise. We also show that the worst-case competitive ratio of an algorithm cannot be higher than some constant <1/e< 1/\mathrm{e}, which is the best possible competitive ratio when we ignore predictions, if the algorithm performs nearly optimally when the predictions are accurate. Additionally, for the multiple-choice secretary problem, we propose an algorithm with a similar theoretical guarantee. We empirically illustrate that if the predictions are accurate, the proposed algorithms perform well; meanwhile, if the predictions are inaccurate, performance is comparable to existing algorithms that do not use predictions

    CHANGES IN RUNNING VELOCITY AND KINETICS OF THE LOWER LIMB JOINTS IN 100 m SPRINT RUNNING

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    The purpose of this study was to investigate the changes in kinetics of the lower limb joints in 100 m sprint running. Nine male sprinters running 100 m with the maximum effort were videotaped at every 10 m from the start to 90 m mark with five high-speed cameras and five normal VTR cameras. Analyses of the relationship between changes in running velocity and the kinetics, joint torque, joint torque power, of the leg indicated that the critical joint kinetics factors in 100 m were: In the acceleration phase, the joint torque power exerted by the hip flexors in the early recovery phase and by the hip extensors in the late recovery phase; In the maintaining phase, the joint torque power exerted by the hip flexors in the early recovery phase and by the knee flexors in the late recovery phase

    Pacemaker Inhibition During Cardioplegia in Open Heart Surgery

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    A 53-year-old patient underwent mitral valve replacement after implantation of permanent pacemaker. During cardioplegia in open heart surgery, we performed the inhibition of permanent pacemaker to obtain complete myocardial preservation and quiet heart, using stimulations of an external pulse generator. This procedure is considered available, when the patient who has had a permanent pacemaker undergoes open heart surgery more safely

    Adenocarcinoma of Ascending Colon Associated with Sarcoid Reaction in Regional Lymph Nodes

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    Lymph node swelling in the setting of malignancy generally suggests metastasis of the primary tumor. A granulomatous reaction, i.e. sarcoid reaction, occurring within the lymph nodes draining carcinomas is a well-known but uncommon occurrence. The phenomenon is especially rarely seen in colon carcinoma. We herein report a rare case of a 56-year-old Japanese male with adenocarcinoma of the ascending colon associated with sarcoid reaction in the regional lymph nodes. A typical ileocecal resection and lymph node dissection were performed. Histopathological examination revealed moderately differentiated adenocarcinoma of the ascending colon, and the dissected lymph nodes included epithelioid granulomas with multinucleated giant cells. These findings suggest the existence of a sarcoid reaction associated with colon carcinoma; there was no metastasis in the dissected lymph nodes. The significance of this rare condition is discussed

    Investigation of automotive light blinking pattern conveying a driver's intention to yield

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    This paper proposes a method of conveying a driver’s intention to yield by blinking automotive lighting. Generally, headlight flashing indicates a driver’s intention to yield to another driver or pedestrians in Japan. However, this signaling method can have several meanings, including warning other drivers of road dangers such as crashed cars, or informing other drivers of the presence of a pedestrian. There is a possibility of a misunderstanding, increasing the risk of accidents. Therefore, we have investigated an effective method for facilitating communication in traffic. This study focuses on nonverbal communication in which blinking lights convey the driver’s intentions to others. In this study, visibility is not considered. Nine blinking patterns that changed the light colors, waveform, and blinking cycle were presented to fifteen healthy participants, and visual impressions were evaluated to identify the most suitable blinking patterns. These nine patterns indicate a driver’s intention to yield to pedestrians and other drivers. The results indicated that a blue-green blinking pattern in which luminance changes with a triangular wave pattern with a one-second cycle was best conveyed the intention to yield
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