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Applied Mathematics and Computation Volume 444 pp. 127819 -
published_at 2023-03-01
We investigate symmetric equilibria of mutual reinforcement learning when both players alternately learn the optimal memory-two strategies against the oppo-nent in the repeated prisoners' dilemma game. We provide a necessary condi-tion for memory-two deterministic strategies to form symmetric equilibria. We then provide three examples of memory-two deterministic strategies which form symmetric mutual reinforcement learning equilibria. We also prove that mu-tual reinforcement learning equilibria formed by memory-two strategies are also mutual reinforcement learning equilibria when both players use reinforcement learning of memory-n strategies with n > 2.
Creators : Ueda Masahiko Publishers : Elsevier Updated At : 2023-01-17 15:31:40
村上春樹とアダプテーション研究 Volume 1 pp. 67 - 76
published_at 2023-01-31
Creators : 跡上 史郎 Publishers : 村上春樹とアダプテーション研究会 Updated At : 2023-01-20 14:17:49
村上春樹とアダプテーション研究 Volume 1 pp. 88 - 88
published_at 2023-01-31
Creators : Yamane Yumie Publishers : 村上春樹とアダプテーション研究会 Updated At : 2023-01-20 15:25:30
村上春樹とアダプテーション研究 Volume 1 pp. 22 - 37
published_at 2023-01-31
Creators : 内田 康 Publishers : 村上春樹とアダプテーション研究会 Updated At : 2023-01-20 10:54:32
村上春樹とアダプテーション研究 Volume 1 pp. 3 - 3
published_at 2023-01-31
Creators : Yamane Yumie Publishers : 村上春樹とアダプテーション研究会 Updated At : 2023-01-19 16:52:05
Bulletin of the Faculty of Education, Yamaguchi University Volume 72
published_at 2023-01-31
Publishers : Faculty of Education, Yamaguchi University Updated At : 2023-01-27 13:09:18
村上春樹とアダプテーション研究 Volume 1 pp. 52 - 62
published_at 2023-01-31
Creators : Yamane Yumie Publishers : 村上春樹とアダプテーション研究会 Updated At : 2023-01-20 13:28:49
村上春樹とアダプテーション研究 Volume 1 pp. 77 - 79
published_at 2023-01-31
Creators : 内田 康 Publishers : 村上春樹とアダプテーション研究会 Updated At : 2023-01-20 14:30:19
村上春樹とアダプテーション研究 Volume 1 pp. 63 - 66
published_at 2023-01-31
Creators : 藤城 孝輔 Publishers : 村上春樹とアダプテーション研究会 Updated At : 2023-01-20 13:45:09
村上春樹とアダプテーション研究 Volume 1 pp. 80 - 83
published_at 2023-01-31
Creators : ダルミ カタリン Publishers : 村上春樹とアダプテーション研究会 Updated At : 2023-01-20 14:55:47
村上春樹とアダプテーション研究 Volume 1 pp. 4 - 21
published_at 2023-01-31
Creators : Yamane Yumie Publishers : 村上春樹とアダプテーション研究会 Updated At : 2023-01-20 10:32:25
村上春樹とアダプテーション研究 Volume 1 pp. 84 - 87
published_at 2023-01-31
Creators : 阿部 翔太 Publishers : 村上春樹とアダプテーション研究会 Updated At : 2023-01-20 15:21:10
村上春樹とアダプテーション研究 Volume 1 pp. 38 - 51
published_at 2023-01-31
Creators : 伊藤 弘了 Publishers : 村上春樹とアダプテーション研究会 Updated At : 2023-01-20 13:09:04
IEEE Access Volume 11 pp. 5062 - 5068
published_at 2023-01-10
Imitation is simple behavior which uses successful actions of others in order to deal with one’s own problems. Because success of imitation generally depends on whether profit of an imitating agent coincides with those of other agents or not, game theory is suitable for specifying situations where imitation can be successful. One of the concepts describing successfulness of imitation in repeated two-player symmetric games is unbeatability. For infinitely repeated two-player symmetric games, a necessary and sufficient condition for some imitation strategy to be unbeatable was specified. However, situations where imitation can be unbeatable in multi-player games are still not clear. In order to analyze successfulness of imitation in multi-player situations, here we introduce a class of totally symmetric games called unexploitable games, which is a natural extension of two-player symmetric games without exploitation cycles. We then prove that, for infinitely repeated unexploitable games, there exist unbeatable imitation strategies. Furthermore, we also prove that, for infinitely repeated non-trivial unexploitable games, there exist unbeatable zero-determinant strategies, which unilaterally enforce some relationships on payoffs of players. These claims are demonstrated in the public goods game, which is the simplest unexploitable game. These results show that there are situations where imitation is unbeatable even in multi-player games.
Creators : Ueda Masahiko Publishers : IEEE Updated At : 2023-01-25 14:24:23
The bulletin of the Yamaguchi Medical School Volume 69 Issue 3-4 pp. 45 - 56
published_at 2022-12
Abstract Purpose: The purpose of this study was to investigate the effects of two different postures (sitting and standing) and three different ambient temperatures (10℃, 20℃, and 30℃) on heart rate variability (HRV) among healthy young adults. Methods: Twelve young adult volunteers (males 6, females 6) were recruited. Following acclimatization to any the room temperature (10℃, 20℃ or 30℃), 5-min measurements of HRV were conducted in sitting and standing postures of the subjects. Results: Compared to the sitting posture, measurements obtained in the standing posture revealed a significant decrease in high-frequency power/HF, root mean square of successive differences between RR intervals, standard deviation of Poincaré plot perpendicular to the line-of-identity or SD1 and SD1/standard deviation of Poincaré plot along the line-of-identity or SD2, and a significant increase in lowfrequency power/LF and LF/HF under all experimental conditions (p<0.05 to 0.005). Majority of HRV parameters showed significant differences while the values obtained under 10℃ were compared with 20℃ and 30℃ conditions, respectively (p<0.05 to 0.001). Conclusions: Our findings suggest the predominance of sympathetic tone in the standing compared with sitting posture. Furthermore, colder conditions caused a predominance of the parasympathetic activity in both sitting and standing postures, and such effects of ambient temperature on the sympathovagal balance were stronger in the latter posture.
Creators : Wada Sunao | Mahbub MH | Nakagami Yuki | Hase Ryosuke | Yamaguchi Natsu | Takahashi Hidekazu | Saito Hiroyuki | Shimokawa Junki | Watanabe Rie | Harada Noriaki | Tanabe Tsuyoshi Publishers : Yamaguchi University School of Medicine Updated At : 2022-11-15 11:09:37
The bulletin of the Yamaguchi Medical School Volume 69 Issue 3-4 pp. 57 - 66
published_at 2022-12
Abstract Background: Expanding nursing workload is a worldwide problem. However, any nursing workload assessment (NWA) tool requires complicated analyses of the nursing job profile. To determine the imbalance in time assignments across all nursing operations and to reduce nursing workload, a nursing job survey was conducted. Methods: A total of 25 major job categories, common to all hospital wards, were identified, and an NWA tool was developed for efficient analyses to feature easy/flexible entry of the time spent for each job category and real-time visual profiling of job time allocation. The profile could be divided by job categories, wards, shifts, and years. Results: From the preliminary analyses, undesirable time allocation was revealed in several job categories, especially the time for recording and other nonessential nursing operations. Using the analytical functions of the NWA tool between 2014 and 2016, a series of corrective measures were successfully taken to many job categories, and they were found to be effective. Consequently, excessive overtime workload was reduced from 125 min/day/nurse in 2014 to 100 and 100 min/day/ nurse in 2015 and 2016, respectively. Conclusion: Notable improvements in nursing workload and time allocation for attentive patient care could be achieved employing the novel user-aimed NWA tool.
Creators : Shimizu Yumi | Satou Kazutaka | Manago Noriko | Itou Masako | Ichihara Kiyoshi | Maekawa Tsuyoshi Publishers : Yamaguchi University School of Medicine Updated At : 2022-11-15 11:36:12
Memoirs of the faculty of engineering, Yamaguchi university Volume 73 Issue 1 pp. 1 - 9
published_at 2022-12
The Japanese Bridge Management System (J-BMS) RC version consists of the following three subsystems: (1) a bridge maintenance database system (J-BMS DB), (2) a concrete bridge rating expert system (RC-BREX) and (3) a maintenance plan optimization system (MPOS). Especially, in this paper, the RC-BREX system for deteriorating concrete bridges is described based on how to construct from a hierarchical neural network in order to carry out fuzzy inference and machine learning by using the neural network with the back-propagation method. Furthermore, the comparisons between diagnostic results by bridge experts and those of the proposed system are presented so as to demonstrate the validity of the system’s learning capability by using the training set for machine learning which obtained from inspection on actual in-service bridges and questionnaire surveys by bridge experts.
Creators : Miyamoto Ayaho Publishers : 山口大学工学部 Updated At : 2023-01-10 14:02:17
The bulletin of the Yamaguchi Medical School Volume 69 Issue 3-4 pp. 27 - 35
published_at 2022-12
Abstract Objectives: This study examined the short-term outcomes of endovascular therapy (EVT) with the GORE VIABAHN VBX (VBX) which is a balloon-expandable covered stent in patients with aortoiliac occlusive disease (AIOD) and acute limb ischemia (ALI). Methods: This was a single-center retrospective review of patients with AIOD and ALI who underwent EVT with the VBX between December 2018 and January 2021. Primary, assisted, and secondary patency rates were assessed, along with 30-day mortality rates. Results: Twenty-two patients underwent EVT with the VBX; 18 patients had AIOD, whereas 4 had ALI. The incidence of TransAtlantic Intersociety Classification II D lesions was 50% (n=9). Technical success was 100%. One patient with unilateral common iliac artery stenosis developed an intraoperative dissection of the distal edge of the VBX, which required an additional self-expanding VIABAHN stent on the distal edge of the VBX. The primary patency rate at 24 months was 100%. No patients required additional target vessel treatment at a median follow-up of 10 months (range, 1-27). EVT was also successful in the four patients with ALI, who had no complications of the target vessel. Conclusion: The present study demonstrated that EVT with the VBX is effective for AIOD and ALI.
Creators : Mizoguchi Takahiro | Morikage Noriyasu | Ike Soichi | Nagase Takashi | Samura Makoto | Harada Takasuke | Kurazumi Hiroshi | Suzuki Ryo | Suehiro Kotaro | Hamano Kimikazu Publishers : Yamaguchi University School of Medicine Updated At : 2022-11-15 10:57:48
The bulletin of the Yamaguchi Medical School Volume 69 Issue 3-4 pp. 37 - 43
published_at 2022-12
Abstract Background: Recently, the importance of nutritional management in pressure ulcer control has been pointed out. In this study, we analyzed the relationship between nutritional indicators and the presence or absence of pressure ulcers in order to reveal the importance of nutritional management in pressure ulcer control. Method: We investigated 407 inpatients for blood tests, height, weight, BMI, the Ohura-Hotta (OH) scale, nutrition method, living independence, and the presence or absence of pressure ulcers. Results: In the comparison of patients with and without pressure ulcer, significant differences were found in gender, nutrition method, serum total protein, serum albumin, hemoglobin concentration, and the OH scales. Multiple logistic regression analysis showed that gender, intravenous nutrition, serum albumin levels, and the OH scale were associated with the presence or absence of pressure ulcers. The results suggest that not only the OH scale, but the nutritional support was also important in the prediction of the pressure ulcer. It was suggested that shifting from intravenous feeding to tube feeding or oral feeding is important. Conclusion: we found that pressure ulcer was related to gender, intravenous nutrition, serum albumin level and the OH scale. The importance of nutritional management for pressure ulcer prevention was confirmed.
Creators : Tanabe Nobuka | Kodama Etsuko | Matsui Mayumi | Wakuda Kayoko | Fujiwara Kazuyo | Tsutsumi Masae | Yamamoto Takeshi Publishers : Yamaguchi University School of Medicine Updated At : 2022-11-15 11:07:18
published_at 2022-11
Some textbooks of formal languages and automata theory implicitly state the structural equality of the binary n-dimensional de Bruijn graph and the state diagram of minimum state deterministic finite automaton which accepts regular language (0+1)*1(0+1)^{n-1}. Although the isomorphism in binary case is relatively easy to prove, it is desirable to rigorously prove such an isomorphism in general k-ary case. To achieve this purpose, the author introduces a new computational model, called "colored finite automata (CFA)," and give a certain characterization of the general k-ary de Bruijn graphs by regular languages. The second purpose of this study is to investigate the potential of this automaton with multi-colored accepting states. By the way, when CFA is nondeterministic (NCFA), it is desirable that the colors of accepting states are unmixed (i.e., there are no inputs that are accepted with differently colored accepting states) in order to pursuit the accurate identification. Thus, the author proposes the three decision problems (Unmixedness Verification problem, Unmixedness Partitioning problem, and Unmixedness Extension problem) concerning unmixedness and show that UV, UP, and UE problems are shown to be NLOG-complete, P, and NP-complete, respectively. The author also illustrates the applications of colored finite automata, e.g. to existing regular expression engines and model checking tools for the purpose of improvement of their efficiency and conveniency. Next, the author introduces "colored pushdown automaton (CPDA)" which is an ordinary pushdown automaton with colored accepting states. It is shown that while the computational complexity of the above-mentioned UV, UP, and UE problems of CPDA are all undecidable, restriction of CPDA are all undecidable, restriction of CPDAs to unambiguous ones simplifies some problems of them to the permanently true problems. In this way, the concept of colored accepting states can be applied to a wide range of automata that have a set of accepting states and expected to be useful in a wide range of theoretical and practical field of automata applications in the future.
Creators : 高橋 芳明 Updated At : 2022-12-09 15:48:58
Operations Research Forum Volume 3 pp. 48 -
published_at 2022-09-05
Zero-determinant strategies are memory-one strategies in repeated games which unilaterally enforce linear relations between expected payoffs of players. Recently, the concept of zero-determinant strategies was extended to the class of memory-n strategies with n _ 1, which enables more compli-cated control of payoffs by one player. However, what we can do by memory-n zero-determinant strategies is still not clear. Here, we show that memory-n zero-determinant strategies in repeated games can be used to control condi-tional expectations of payoffs. Equivalently, they can be used to control ex-pected payoffs in biased ensembles, where a history of action pro_les with large value of bias function is more weighted. Controlling conditional expectations of payoffs is useful for strengthening zero-determinant strategies, because play-ers can choose conditions in such a way that only unfavorable action pro_les to one player are contained in the conditions. We provide several examples of memory-n zero-determinant strategies in the repeated prisoner's dilemma game. We also explain that a deformed version of zero-determinant strategies is easily extended to the memory-n case.
Creators : Ueda Masahiko Publishers : Springer Nature Updated At : 2022-09-29 14:05:00
published_at 2022-09
Creators : Takahashi Yushi Updated At : 2022-10-21 11:30:51
published_at 2022-09
Creators : Tatemoto Kango Updated At : 2022-11-07 14:48:22
published_at 2022-09
Creators : Kashiwaki Yasuko | Yoshida Masaki | Uehara Masafumi Updated At : 2022-10-11 15:52:40