313 research outputs found

    A study of reinforcement learning with knowledge sharing for distributed autonomous system

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    Reinforcement learning is one of effective controller for autonomous robots. Because it does not need priori knowledge and behaviors to complete given tasks are obtained automatically be repeating trial and error. However a large number of trials are required to realize complex tasks. So the task that can be obtained using the real robot is restricted to simple ones. Considering these points, various methods that prove the learning cost of reinforcement learning have been proposed. In the method that uses priori knowledge, the methods lose the autonomy that is most important feature of reinforcement learning in applying it to the robots. In the Dyna-Q, that is one of simple and effective reinforcement learning architecture integrating online planning, a model of environment is learned from real experience and by utilizing the model to learn, the learning time is decreased. In this architecture, the autonomy is held, however the model depends on the task, so acquired knowledge of environment cannot be reused to other tasks. In the real world, human beings can learn various behaviors to complete complex tasks without priori knowledge of the tasks. We can try to realize the task in our image without moving our body. After the training in the image, by trying to the real environment, we save time to learn. It means that we have model of environment and we utilize the model to learn. We consider that the key ability that makes the learning process faster is construction of environment model and utilization of it. In this paper, we have proposed a method to obtain an environment model that is independent of the task. And by utilizing the model we have decreased learning time. We consider distributed autonomous agents, and we show that the environment model is constructed quickly by sharing the experience of each agent, even when each agent has own independent task. To demonstrate the effectiveness of the proposed method, we have applied the method to the Q-learning and simulations of a puddle world are carried out. As a result effective behaviors have been obtained quickly. </p

    <ORIGINAL REPORT>IMMUNOHISTOCHEMICAL STUDIES ON LACTATE DEHYDROGENASE SUBUNITS IN LUNG CANCER CELLS

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    この論文は国立情報学研究所の学術雑誌公開支援事業により電子化されました。Immunohistochemical distribution of lactate dehydrogenase (LDH) subunits in human lung cancer cells were studied using fluorescent antibody technique. Both in cytological and histological specimen, specific fluorescence of LDH-H and LDH-M were seen in the cytoplasm of cancer cells, and in most cases no remarkable difference could be demonstrated between the distribution of H and M subunit. But in some cases specific fluorescence of M-subunit was stronger than that of H-subunit. The fluorescence of M-subunit was demonstrated as fine granules diffusely in the cytoplasm. On the other hand the fluorescence of H-subunit was rather localized and demonstrated as rather coarse granules. And this observation was discussed

    Recombinant Sendai viruses with L1618V mutation in their L polymerase protein establish persistent infection, but not temperature sensitivity

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    AbstractThe Sendai virus pi strain (SeVpi) isolated from cells persistently infected with SeV shows mainly two phenotypes: (1) temperature sensitivity and (2) an ability of establishing persistent infection (steady state). Three amino acid substitutions are found in the Lpi protein and are located at aa 1088, 1618, and 1664. Recombinant SeV(Lpi) (rSeV(Lpi)) having all these substitutions is temperature sensitive and is capable of establishing persistent infection (steady state). rSeVs carrying the fragment containing L1618V show both phenotypes. rSeV(L1618V), in which leucine at aa 1618 is replaced with valine, has the ability of establishing persistent infection, but is not a temperature-sensitive mutant, indicating that the ability of a virus to establish persistent infection can be separated from temperature sensitivity. The amino acid change at 1618(L→V) coexisting with aa 1169 threonine is required for acquirement of a temperature-sensitive phenotype. Three amino acid substitutions are also found in the Ppi protein, but rSeV(Ppi) does not show these phenotypes

    A Much Faster Algorithm for Finding a Maximum Clique

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    We present improvements to a branch-and-bound maximumclique-finding algorithm MCS (WALCOM 2010, LNCS 5942, pp. 191–203) that was shown to be fast. First, we employ an efficient approximation algorithm for finding a maximum clique. Second, we make use of appropriate sorting of vertices only near the root of the search tree. Third, we employ a lightened approximate coloring mainly near the leaves of the search tree. A new algorithm obtained from MCS with the above improvements is named MCT. It is shown that MCT is much faster than MCS by extensive computational experiments. In particular, MCT is shown to be faster than MCS for gen400 p0.9 75 and gen400 p0.9 65 by over 328,000 and 77,000 times, respectively

    Prevalence and risk factors for low back pain among professional cooks working in school lunch services

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    <p>Abstract</p> <p>Background</p> <p>The prevalence of self-reported low back pain among professional cooks was estimated to examine the effects of daily life conditions, job-related factors, and psychological factors on this disorder.</p> <p>Methods</p> <p>Data was collected using a mailed self-administered questionnaire.</p> <p>Results</p> <p>Of 7100 cooks, 5835 (82%) replied to the questionnaire, including 1010 men and 4825 women. The mean age was 41.4 for men and 47.5 for women. The prevalence of low back pain during a 1-month period was 72.2% among men and 74.7% among women, with no significant differences between groups. By logistic regression analyses, factors significantly associated with the prevalence of low back pain in 1 month were female gender (prevalence ratio [PR] 1.32; 95% CI, 1.03–1.68), current smoking (PR 1.57; 95% CI, 1.24–1.98), and past smoking (PR 1.35; 95% CI, 1.01–1.79). As for job-related factors, the number of cooked lunches per person (PR 1.28; 95% CI, 1.05–1.56), breaks in the morning session (PR 1.33; 95% CI, 1.13–1.56), kitchen environment (PR 1.09; 95%, CI, 1.03–1.15), and height of cooking equipment (PR 1.13; 95% CI, 1.08–1.19) were associated with the prevalence of low back pain. As for psychological factors, job satisfaction (PR 1.22; 95% CI, 1.03–1.45), stress at work (PR 1.68; 95% CI, 1.42–1.99), financial constraints (PR 1.23; 95% CI, 1.03–1.47), health-related stress (PR 1.31; 95% CI, 1.08–1.59) and worries about the future (PR 1.24; 95% CI, 1.01–1.52) were similarly associated.</p> <p>Conclusion</p> <p>Daily life conditions, job-related factors, and psychological factors are associated with the occurrence of low back pain. It is important to take comprehensive preventive measures to address a range of work and life conditions that can be improved to decrease the incidence of low back pain for professional cooks.</p
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