1,479 research outputs found

    Quantum Game with Restricted Matrix Strategies

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    We study a quantum game played by two players with restricted multiple strategies. It is found that in this restricted quantum game Nash equilibrium does not always exist when the initial state is entangled. At the same time, we find that when Nash equilibrium exists the pay off function is usually different from that in the classical counterpart except in some special cases. This presents an explicit example where quantum game and classical game may differ. When designing a quantum game with limited strategies, the allowed strategy should be carefully chosen according to the type of initial state.Comment: 5 pages and 3 figure

    Multiagent Bidirectionally-Coordinated Nets: Emergence of Human-level Coordination in Learning to Play StarCraft Combat Games

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    Many artificial intelligence (AI) applications often require multiple intelligent agents to work in a collaborative effort. Efficient learning for intra-agent communication and coordination is an indispensable step towards general AI. In this paper, we take StarCraft combat game as a case study, where the task is to coordinate multiple agents as a team to defeat their enemies. To maintain a scalable yet effective communication protocol, we introduce a Multiagent Bidirectionally-Coordinated Network (BiCNet ['bIknet]) with a vectorised extension of actor-critic formulation. We show that BiCNet can handle different types of combats with arbitrary numbers of AI agents for both sides. Our analysis demonstrates that without any supervisions such as human demonstrations or labelled data, BiCNet could learn various types of advanced coordination strategies that have been commonly used by experienced game players. In our experiments, we evaluate our approach against multiple baselines under different scenarios; it shows state-of-the-art performance, and possesses potential values for large-scale real-world applications.Comment: 10 pages, 10 figures. Previously as title: "Multiagent Bidirectionally-Coordinated Nets for Learning to Play StarCraft Combat Games", Mar 201

    Service Region Design for Urban Electric Vehicle Sharing Systems

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    Emerging collaborative consumption business models have shown promise in terms of both generating business opportunities and enhancing the efficient use of resources. In the transportation domain, car sharing models are being adopted on a mass scale in major metropolitan areas worldwide. This mode of servicized mobility bridges the resource efficiency of public transit and the flexibility of personal transportation. Beyond the significant potential to reduce car ownership, car sharing shows promise in supporting the adoption of fuel- efficient vehicles, such as electric vehicles (EVs), due to these vehicles special cost structure with high purchase but low operating costs. Recently, key players in the car sharing business, such as Autolib, Car2Go and DriveNow, have begun to employ EVs in an operations model that accommodates one-way trips. On the one hand (and particularly in free-floating car sharing), the one-way model results in significant improvements in coverage of travel needs and therefore in adoption potential compared with the conventional round-trip-only model (advocated by ZipCar, for example). On the other hand, this model poses tremendous planning and operational challenges. In this work, we study the planning problem faced by service providers in designing a geographical service region in which to operate the service. This decision entails trade-offs between maximizing customer catchment by covering travel needs and controlling fleet operations costs. We develop a mathematical programming model that incorporates details of both customer adoption behavior and fleet management (including EV repositioning and charging) under imbalanced travel patterns. To address inherent planning uncertainty with regard to adoption patterns, we employ a distributionally robust optimization framework that informs robust decisions to overcome possible ambiguity (or lacking) of data. Mathematically, the problem can be approximated by a mixed integer second-order cone program, which is computationally tractable with practical scale data. Applying this approach to the case of Car2Go’s service with real operations data, we address a number of planning questions and suggest that there is potential for the future development of this service

    Cooperative three- and four- player quantum games

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    A cooperative multi-player quantum game played by 3 and 4 players has been studied. Quantum superposed operator is introduced in this work which solves the non-zero sum difficulty in previous treatment. The role of quantum entanglement of the initial state is discussed in details.Comment: 7 pages with 3 figures. To appear in Physics Letters

    The Role of Deubiquitinases in DNA Double-Strand Break Repair

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    DNA double-strand break (DSB) is a type of the most critical DNA lesions, and if not repaired promptly, it can result in cell death or a wide variety of genetic alterations including genome instability, large- or small-scale deletions, chromosome loss, loss of heterozygosity, and translocations. DSBs are repaired by double-strand break repair (DSBR), including nonhomologous end-joining (NHEJ) and homologous recombination (HR) pathway, and defects in these pathways cause genome instability and promote tumorigenesis. Accumulating evidence has demonstrated that the superfamily of deubiquitinases (DUBs) can regulate the action and stability of DNA repair enzymes involving in DSBR via modifying ubiquitination levels, a reversible posttranslational modification pathway. In this review, we will discuss ubiquitination/deubiquitination modification involving in DSBR genes, the role of DUBs in DSBR and corresponding mechanisms, and the potential effects of this modification on human diseases

    Obciążenie chorobami układu sercowo-naczyniowego u osób hospitalizowanych w szpitalu w Guangzhou w Chinach, w latach 2006–2015

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    Introduction. To explore the epidemiological characters of cardiovascular disease (CVD) in patients and to give a certain clues for disease prevention and clinical treatment. Material and methods. We carried out an investigation using retrospective study method by the medical records retrieval system, and extracted the data of inpatients suffered from CVD in a hospital in Guangzhou from 2006 to 2015, including age, gender, disease onset time, clinical diagnosis, hospitalization days, cost and so on. Results. The average admissions per 5 years kept increasing in the study period. Most inpatients suffered from the CVD in December (n = 9288, 9.10%), while least in February (n = 7309, 7.16%). Most of the inpatients were 66–75-years- -old (n = 24,891, 24.37%). Gender ratio (male vs. female) of CVD inpatients showed a downward trend came with age. The gender ratio was 1.9 and 0.99 among inpatients below 26-years-old and above 85-years-old, respectively. Most common CVD were ischemic heart diseases (29.46%), cerebrovascular diseases (21.59%) and hypertensive diseases (15.18%). The adjusted hospitalization cost was 4600.30 USD in 2006 and 5473.66 USD in 2006, while the average hospitalization days were 15.63 in 2006 and 9.98 in 2015. Conclusions. More attention should be paid to the middle and elderly people with CVD risk factors, especially the senile women, to reduce the disease burden. The change of gender ratio suggested there may be other significant causes leading to the gender differences besides estrogen.Wstęp. Badanie przeprowadzono w celu oceny cech epidemiologicznych chorych hospitalizowanych z powodu chorób układu sercowo-naczyniowego i sformułowanie wskazówek dotyczących zapobiegania tym chorobom oraz ich leczenia. Materiał i metody. Badanie przeprowadzono w sposób retrospektywny na podstawie analizy danych medycznych, korzystając z dokumentacji pacjentów hospitalizowanych z powodu chorób układu sercowo-naczyniowego w szpitalu w Guangzhou w latach 2006–2015. Dane włączone do analizy obejmowały między innymi wiek, płeć, czas rozpoczęcia choroby, rozpoznanie kliniczne, okres hospitalizacji (dni), koszty związane z hospitalizacją. Wyniki. Średnia liczba hospitalizacji na 5 lat zwiększała się stale w badanym okresie. Najwięcej chorych zgłaszało się do szpitala z powodu chorób układu sercowo-naczyniowego w grudniu (n = 9288; 9,10%), natomiast najmniej w lutym (n = 7309; 7,16%). Największą grupę hospitalizowanych stanowiły osoby w wieku 66–75 lat (n = 24 891; 24,37%). Wartość współczynnika płci chorych (stosunek liczby mężczyzn do liczby kobiet) wśród osób hospitalizowanych z powodu chorób układu sercowo-naczyniowego zmniejszała się z wiekiem. Współczynnik ten wynosił 1,9 i 0,99, odpowiednio, w grupach chorych w wieku poniżej 26 lat oraz powyżej 85 lat. Do najczęstszych CVD należały choroba niedokrwienna serca (29,46%), choroba naczyniowa mózgu (21,59%) i nadciśnienie tętnicze (15,18%). Skorygowane koszty hospitalizacji wynosiły 4600,30 USD w 2006 roku i 5473,66 USD w 2015 roku, natomiast średni czas hospitalizacji wynosił odpowiednio 15,63 i 9,98 dnia. Wnioski. Aby zmniejszyć obciążenie chorobami sercowo-naczyniowymi należy zwrócić większa uwagę na osoby w średnim i podeszłym wieku, u których występują czynniki ryzyka sercowo-naczyniowego; dotyczy to zwłaszcza starszych kobiet. Zmiana proporcji płci chorych sugeruje, że oprócz estrogenu mogą istnieć inne przyczyny powodujące różnicę w liczbie zachorowań na choroby sercowo-naczyniowe
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