• Title/Summary/Keyword: Multi-Agents

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A Navigation System for Mobile Robot

  • Zhang, Yuanliang;Chong, Kil-To
    • Proceedings of the IEEK Conference
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    • 2009.05a
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    • pp.118-120
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    • 2009
  • In this paper, we present the Q-learning method for adaptive traffic signal control on the basis of multi-agent technology. The structure is composed of sixphase agents and one intersection agent. Wireless communication network provides the possibility of the cooperation of agents. As one kind of reinforcement learning, Q-learning is adopted as the algorithm of the control mechanism, which can acquire optical control strategies from delayed reward; furthermore, we adopt dynamic learning method instead of static method, which is more practical. Simulation result indicates that it is more effective than traditional signal system.

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The Effects of Cooperativeness and Information Redundancy on Team Performance : A Simulation Study (협동성과 정보 여분의 팀 성과에 대한 효과 : 시뮬레이션 연구)

  • Kang, Min-Cheol
    • Asia pacific journal of information systems
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    • v.12 no.2
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    • pp.197-216
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    • 2002
  • Cooperativeness within an organization can be conceptualized as the degree of members' willingness to work with others. The simulation study investigates the relationships of cooperativeness with team performance at different levels of information redundancy by using a multi-agents model called Team-Soar. The model consists of a group of four individual Al agents situated in a network, which models a naval command and control team consisting of four members. The study used a $9{\times}3$ design in which agent cooperativeness was manipulated at nine levels by gradually replacing selfish team members with increasing numbers of neutral and cooperative members, while information redundancy was controlled at three different levels(i.e., low, medium, and high). Results of the Team-Soar simulation show that cooperation has positive impacts on team performance. Further, the results reveal that the impact of agent cooperativeness on team performance depends on the amount of information needed to be processed during the decision making process.

Bifidobacterium infantis OFR-525 Strain Resistant to Rifampicin and Fluoroquinolones (리팜피신과 플로로퀴놀론계 항균제에 내성인 Bifidobacterium infantis OFR-525 균주)

  • 장현아;권애란;오태권;김동현;최응칠
    • YAKHAK HOEJI
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    • v.43 no.1
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    • pp.124-127
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    • 1999
  • Bifidobacterium infantis K-525 isolated from healthy Korean was susceptible to rifampicin and fluoroquinolones and resistant to other antituberculosis agents. When the preparation of this strain is taken as a therapeutics for human intestinal disorders with rifampicin or fluoroquinolones, its therapeutic effect can not be expected. So, B, infantis RFR-525 resistant to rifampicin was obtained by treating the parent B. infantis 525 with N-methyl-N'-nitro-N-nitrosoguanidine. B. infantis OFR-525 was produced by serial passage of B. infantis RFR-525 on agar with 2-fold minimal inhibitory concentration of ofloxacin. B. infantis OFR-525 was resistant to antituberculosis agents and fluoroquinolones up to 4∼128 fold higher than that for the original strain. The resistance of B. infantis OFR-525 against rifampicin and ofloxacin was maintained in vivo and in vitro. Conclusively, B. infantis OFR-525 can be regarded as a promising strain which can be developed as the preparation for the treatment of the intestinal disorders of the tuberculosis patients under rifampicin and ofloxacin therapy.

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Mobile Agents Location Management Scheme for Spatial Replication Based Approach in Multi-Region Mobile Agents Computing Environment (다중 지역 이동 에이전트 컴퓨팅 환경에서의 공간 기반 복제 기법을 위한 이동 에이전트 위치 관리 프로토콜)

  • 윤준원;최성진;양권우;손진곤;황종선
    • Proceedings of the Korean Information Science Society Conference
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    • 2004.04a
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    • pp.859-861
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    • 2004
  • 다중 지역으로 구성된 이동 에이전트 컴퓨팅 환경에서 결함 포용을 위한 대표적인 기법인 공간 기반 복제 기법(SRBA :Spatial-Replication-Based approach)은 이동 에이전트가 수행 중 중간 연산에 대한 빠른 결과 산출이라는 장점을 가지는 대중화된 결함 포용기법이다. 그러나 공간 기반 복제 기법을 실제 이동 에이전트 기반 컴퓨팅 환경에 적용하는데 있어서 해결되어야 하는 중요한 선결 과제 중의 하나는 단계별로 복제된 이동 에이전트들에 대한 추가 위치 관리비용을 감소시키는 것이다. 본 논문에서는 공간 기반 복제 기법에서 발생하는 불필요한 위치 관리 오버헤드를 줄이기 위해 이동에이전트를 위한 새로운 일치 관리 기법인 SRLM(Spatial Replication Location Management) 프로토콜을 제안한다. 제안된 SRLM 프로토콜은 단계군 구성시 복제된 이동 에이전트를 위한 등록 비용 및 대표 작업자에게 메시지 전달을 보강하며 메시지 전달 비용을 감소시킨다. 또한, 제안된 프로토콜은 단계 군내에서의 대표 작업자의 결함 발생시 새로운 대표 작업자의의 선출로 인한 위치 관리 문제를 해결한다.

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Evolving swarm of UAVs

  • Chi, T.Z.;Cheng, Hayong;Page, J.R.;Ahmed, N.A.
    • Advances in aircraft and spacecraft science
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    • v.1 no.2
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    • pp.219-232
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    • 2014
  • This paper reports on an ongoing study investigating the feasibility of using an evolutionary method to develop the rules governing Self-Organised (SO) systems for use in swarms of unmanned aerial vehicles. In general, it is difficult to design swarm systems that follow explicit global behaviour. Unlike optimising a predefined objective function, the solution to the problem is the emergent behaviour in the SO systems which results from simultaneous interactions among agents and between agents and their environment. In this study, evolutionary algorithms are used to investigate their control and effectiveness in synthesising the weighting of different rules on SO emergent behaviour. Both homogeneous swarms and heterogeneous swarms were considered though the results provided are for a case study investigating the simplest problem a homogeneous swarm without mutation. Though simple this study does indicate the potential of the approach.

Comparative Experimental Study on Structural Behavior of Multi-component Self-Compacting Concrete (다성분계 고유동 콘크리트의 장${\cdot}$단기거동 비교 분석)

  • Noh Jea Myoung;Kwon Ki Joo;Nah Hwan Seon;Joung Won Seoup
    • Proceedings of the Korea Concrete Institute Conference
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    • 2004.11a
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    • pp.735-738
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    • 2004
  • In this study, it was founded to make the optimal mixture for producing concrete which is self-compacting, yet, and generates low heat of hydration by using fly ash, blast furnace slags and limestone powders as binders in addition to cement while using super-plasticizers and viscosity agents as admixture agents. The structural behaviors of the concrete produced with the selected mixture were compared with those of the concrete currently using for construction of nuclear power plants. The study shows that the blended high fluidity concrete including limestone is better in workability and durability than the concrete currently in use for nuclear power plants.

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Practical Experimental Study on Multi-component Self-Compacting Concrete (다성분계 고유동 콘크리트의 현장적용성 연구)

  • Noh Jea Myoung;Kwon Ki Joo;Nah Hwan Seon;Joung Won Seoup
    • Proceedings of the Korea Concrete Institute Conference
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    • 2004.11a
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    • pp.739-742
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    • 2004
  • In this study, it was founded to make the optimal mixture for producing concrete which is self-compacting, yet, and generates low heat of hydration by using flyash, blast furnace slags and limestone powders as binders in addition to cement while using super-plasticizers and viscosity agents as admixture agents. The structural behaviors of the concrete produced with the selected mixture were compared with those of the concrete currently using for construction of nuclear power plants. The study shows that the blended high fluidity concrete including limestone is better in workability and durability than the concrete currently in use for nuclear power plants.

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A Design and Implementation of Fault Tolerance Agent on Distributed Multimedia Environment (분산 멀티미디어 환경에서 결함 허용 에이전트의 설계 및 구현)

  • Go, Eung-Nam;Hwang, Dae-Jun
    • The Transactions of the Korea Information Processing Society
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    • v.6 no.10
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    • pp.2618-2629
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    • 1999
  • In this paper, we describe the design and implementation of the FDRA(Fault Detection Recovery based on Agent) running on distributed multimedia environment. DOORAE is a good example for distributed multimedia and multimedia distance education system among students and teachers during lecture. It has primitive service agents. Service functions are implemented with objected oriented concept. FDRA is a multi-agent system. It has been environment, intelligent agents interact with each other, either collaboratively or non-collaboratively, to achieve their goals. The main idea is to detect an error by using polling method. This system detects an error by polling periodically the process with relation to session. And, it is to classify the type of error s automatically by using learning rules. The merit of this system is to use the same method to recovery it as it creates a session. FDRA is a system that is able to detect an error, to classify an error type, and to recover automatically a software error based on distributed multimedia environment.

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Synthetic Approach to 99mTc-labeled SPECT Radiotracers with Multi-nitroimidazoles for Hypoxia

  • Anh Thu Nguyen;Hee-Kwon Kim
    • The Korean Journal of Nuclear Medicine Technology
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    • v.28 no.1
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    • pp.1-11
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    • 2024
  • Hypoxia, defined as the deficiency of oxygen, is a significant hallmark of cancers presenting in the majority of solid tumors. Detection of tumor hypoxia is essential in cancer diagnosis to prevent cancer progression, metastasis, and resistance to cancer therapies in clinical practices. Single-photon emission computed tomography (SPECT) is one of the methods studied and applied for hypoxia detection with the use of radiolabeled imaging agents in which 99mTc is the common radioisotope used for radiolabeling. Nitroimidazoles are the hypoxia-targeting moieties presenting in numerous 99mTc-radiolabeled imaging agents due to their bio-reducible ability in hypoxic environments. Recently, in addition to 99mTc-labeled radiopharmaceuticals containing one nitroimidazole unit, there has been considerable attention given to 99mTc-radiopharmaceuticals bearing two or more nitroimidazole units. This review summarizes the synthesis of hypoxia-targeting chelators and radiolabeling processes to produce these 99mTc-radiopharmaceuticals for SPECT imaging.

Pedestrian Multi-Agent Model in College Town Streets (대학촌 가로의 보행환경 개선을 위한 보행자 멀티에이전트(Pedestrian Multi-Agent) 모델링)

  • Moon, Tae-Heon;Han, Soo-Chel;Sung, Han-Uk;Jeong, Kyeong-Seok
    • Journal of the Korean Association of Geographic Information Studies
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    • v.9 no.2
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    • pp.194-205
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    • 2006
  • The purpose of this study is to develop a pedestrian multi-agent model and simulation system using multi-agent theory, which may be utilized as a planning support system for building a comfort and safe environment of pedestrian street. Differing from existing pedestrian models, however, every single pedestrian was regarded as an individual agent in the model. Multiple agents like multiple pedestrians in the street then maintain their own characteristics and respond to surrounding environment. In addition their moving behavior are made by their own decision rules that they have or had acquired through the interactive communications or learning between agents like real world. After verifying the model validation, as the $R^2$ between the predicted value and observed value was up to 0.781, the developed model was applied to Gazwa district within Gyeongsang university village. The simulation system was developed by Flash MX action scripts and the physical environment of the streets was configured with the digital map and ArcGis within computer virtual space. The attribute data of buildings such as type and size of commercial business were collected through the field survey and combined with physical features. Then the effect of the variation of building attractiveness and the occurrence of street events to pedestrian environment were simulated. Through the experiments this study could make suggestions to improve pedestrian environment.

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