• Title/Summary/Keyword: Multi-Agents

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Application of Multi-agent Reinforcement Learning to CELSS Material Circulation Control

  • Hirosaki, Tomofumi;Yamauchi, Nao;Yoshida, Hiroaki;Ishikawa, Yoshio;Miyajima, Hiroyuki
    • Proceedings of the Korea Inteligent Information System Society Conference
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    • 2001.01a
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    • pp.145-150
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    • 2001
  • A Controlled Ecological Life Support System(CELSS) is essential for man to live a long time in a closed space such as a lunar base or a mars base. Such a system may be an extremely complex system that has a lot of facilities and circulates multiple substances,. Therefore, it is very difficult task to control the whole CELSS. Thus by regarding facilities constituting the CELSS as agents and regarding the status and action as information, the whole CELSS can be treated as multi-agent system(MAS). If a CELSS can be regarded as MAS the CELSS can have three advantages with the MAS. First the MAS need not have a central computer. Second the expendability of the CELSS increases. Third, its fault tolerance rises. However it is difficult to describe the cooperation protocol among agents for MAS. Therefore in this study we propose to apply reinforcement learning (RL), because RL enables and agent to acquire a control rule automatically. To prove that MAS and RL are effective methods. we have created the system in Java, which easily gives a distributed environment that is the characteristics feature of an agent. In this paper, we report the simulation results for material circulation control of the CELSS by the MAS and RL.

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A Multi-Agent Platform Capable of Handling Ad Hoc Conversation Policies (Ad Hoc한 대화 정책을 지원하는 멀티 에이전트 플랫폼에 관한 연구)

  • Ahn, Hyung-Jun
    • The KIPS Transactions:PartD
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    • v.11D no.5
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    • pp.1177-1188
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    • 2004
  • Multi-agent systems have been developed for supporting intelligent collaboration of distributed and independent software entities and are be-ing widely used for various applications. For the collaboration among agents, conversation policies (or interaction protocols) mutually agreed by agents are used. In today's dynamic electronic market environment, there can be frequent changes in conversation policies induced by the changes in transaction methods in the market, and thus, the importance of ad hoc conversation policies is increasing. In existing agent platforms, they allow the use of only several standard or fixed conversation policies, which requires inevitable re implementation for ad hoc conversation policies and leads to inefficiency and intricacy. This paper designs an agent platform that supports ad hoc conversation policies and presents the prototype implementation. The suggested system includes an exchangeable and interpretable conversation policy model, a meta conversation procedure for exchanging new conversation policies, and a mechanism for performing actual transactions with exchanged conversation policies in run time in an adaptive way.

An Optimization Strategy of Task Allocation using Coordination Agent (조정 에이전트를 이용한 작업 할당 최적화 기법)

  • Park, Jae-Hyun;Um, Ky-Hyun;Cho, Kyung-Eun
    • Journal of Korea Game Society
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    • v.7 no.4
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    • pp.93-104
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    • 2007
  • In the complex real-time multi-agent system such as game environment, dynamic task allocations are repeatedly performed to achieve a goal in terms of system efficiency. In this research, we present a task allocation scheme suitable for the real-time multi-agent environment. The scheme is to optimize the task allocation by complementing existing coordination agent with $A^*$ algorithm. The coordination agent creates a status graph that consists of nodes which represent the combinations of tasks and agents, and refines the graph to remove nodes of non-execution tasks and agents. The coordination agent performs the selective utilization of the $A^*$ algorithm method and the greedy method for real-time re-allocation. Then it finds some paths of the minimum cost as optimized results by using $A^*$ algorithm. Our experiments show that the coordination agent with $A^*$ algorithm improves a task allocation efficiency about 25% highly than the coordination agent only with greedy algorithm.

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Determination of Semen Quality and Antibacterial Susceptibility Pattern of Bacteria Isolated from Semen of Iraqi Subjects

  • Faisal, Anwer Jaber;Salman, Hamzah Abdulrahman
    • Microbiology and Biotechnology Letters
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    • v.49 no.4
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    • pp.587-593
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    • 2021
  • Infertility is a key issue affecting mood and behavior in men. Microorganisms are one of the primary etiological agents that may be associated with infertility. The objective of the present study was to identify bacterial causative agents from the semen of infertile subjects and determine the effect of bacterial infection on sperm quality, as well as determine the susceptibility of these bacteria to drugs. Forty semen samples from 30 infertile patients and 10 fertile individuals were collected. The pH, volume, motility, and concentration of semen were analyzed. The samples were processed and identified by biochemical testing using API identification kits. The antibiotic susceptibility pattern was determined using the disc diffusion method. Abnormal sperm quality was observed. The mean age of the individual and their sperm morphology, concentration, progressive motility, pH level, and pus cell content were 31.9 years, 2.7%, 10.4 million/ml, 27.3%, 8.3, and 5.7, respectively. Among the tested samples, oligoasthenozoospermia was found to show the highest occurrence, at 27/30 samples, followed by teratozoospermia, at 25/30 samples, and asthenozoospermia, at 22/30 samples. Of the tested infertile patients' sperm, 19, 6, and 5 isolates were identified as Escherichia coli, Klebsiella pneumonia, and Staphylococcus epidermidis, respectively. The results also revealed multi-drug resistance in the bacteria. Compared to that shown by the other tested antibiotics, amikacin showed higher activity against all isolated bacteria. However, the bacteria exhibited maximum resistance against gentamicin, cefotaxime, levofloxacin, and ampicillin. In conclusion, leukocytospermia and bacterial infections are possibly responsible for sperm abnormalities. Multi-drug resistant bacteria were detected. Gentamicin, cefotaxime, levofloxacin and ampicillin were shown the highest resistance, while amikacin was the most effective antimicrobial agent against the isolated bacteria.

Deep Learning-Based Dynamic Scheduling with Multi-Agents Supporting Scalability in Edge Computing Environments (멀티 에이전트 에지 컴퓨팅 환경에서 확장성을 지원하는 딥러닝 기반 동적 스케줄링)

  • JongBeom Lim
    • KIPS Transactions on Software and Data Engineering
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    • v.12 no.9
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    • pp.399-406
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    • 2023
  • Cloud computing has been evolved to support edge computing architecture that combines fog management layer with edge servers. The main reason why it is received much attention is low communication latency for real-time IoT applications. At the same time, various cloud task scheduling techniques based on artificial intelligence have been proposed. Artificial intelligence-based cloud task scheduling techniques show better performance in comparison to existing methods, but it has relatively high scheduling time. In this paper, we propose a deep learning-based dynamic scheduling with multi-agents supporting scalability in edge computing environments. The proposed method shows low scheduling time than previous artificial intelligence-based scheduling techniques. To show the effectiveness of the proposed method, we compare the performance between previous and proposed methods in a scalable experimental environment. The results show that our method supports real-time IoT applications with low scheduling time, and shows better performance in terms of the number of completed cloud tasks in a scalable experimental environment.

Understanding how agent control based on social status affects user experience factors in multi-user autonomous driving environments (다중 사용자 자율 주행 운전 환경에서 사회적 지위에 따른 에이전트의 제어권이 사용자 경험 요소에 미치는 영향)

  • JiYeon Kim;JuHye Ha;ChangHoon Oh
    • The Journal of the Convergence on Culture Technology
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    • v.9 no.1
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    • pp.735-745
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    • 2023
  • The purpose of this study is to examine how the control of an agent according to a driver's social status affects user experience factors in a multi-user environment of self-driving vehicles. We conducted a user study where participants viewed four scenarios (route changing/parking x accepting/declining a fellow passenger's command) and answered a survey, followed by a post-hoc interview. Results showed that either the routing scenario or accepting a passenger's command scenario had higher usefulness (convenience, effectiveness, efficiency) than their counterparts. Regardless of the car owner's social status, participants rated AI agents more positively when they met their goals effectively. They also stressed that vehicle owners should always be in control of their agents. This study can provide guidelines for designing future autonomous driving scenarios where an agent interacts with a driver, and passengers.

A Swarm System Design Based on Coupled Nonlinear Oscillators for Cooperative Behavior

  • Kim, Dong-Hun
    • International Journal of Control, Automation, and Systems
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    • v.1 no.3
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    • pp.301-307
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    • 2003
  • A control system design based on coupled nonlinear oscillators (CNOs) for a self- organized swarm system is presented. In this scheme, agents self-organize to flock and arrange group formations through attractive and repulsive forces among themselves using CNOs. Virtual agents are also used to create richer group formation patterns. The objective of the swarm control in this paper is to follow a moving target with a final group formation in the shortest possible time despite some obstacles. The simulation results have shown that the proposed scheme can effectively construct a self-organized multi-agent swarm system capable of group formation and group immigration despite the emergence of obstacles.

A Self-Organizing Scheme for Swarm Systems

  • Kim, Dong-Hun;Kim, Hong-Pil
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.2475-2480
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    • 2003
  • A control system design based on coupled nonlinear oscillators (CNOs) for a self-organized swarm system is presented. In this scheme, agents self-organize to flock and arrange group formations through attractive and repulsive forces among themselves using CNOs. Virtual agents are also used to create richer group formation patterns. The objective of the swarm control in this paper is to follow a moving target with a final group formation in the shortest possible time despite some obstacles. The simulation results have shown that the proposed scheme can effectively construct a self-organized multi-agent swarm system capable of group formation and group immigration despite the emergence of obstacles.

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Structural Modification of Carbon Nanotubes during Ball-milling (탄소 나노튜브의 볼밀링 시 구조 변화)

  • Nam, Hye Rim;Ahn, Jung-Ho
    • Journal of Powder Materials
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    • v.20 no.4
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    • pp.258-263
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    • 2013
  • We examined various ball-milling parameters which affect the structural and morphological modification of multi-wall carbon nanotubes. In particular, the effect of milling mode and the use of different milling agents were examined. Friction milling mode induced more structural changes than impact milling mode except the use of dry ice as a milling agent. Wet milling was helpful for reducing more effectively the agglomeration of nanotubes than dry milling. The use of hard solid particles such as silica and alumina as milling agents resulted in an effective shortening of nanotubes, but often susceptible to the amorphization and the destruction of crystallinity.

User-Centric Broadcasting Environment U sing Intelligent Agents

  • Jin, Sung-Ho;Bae, Tae-Meon;Cho, Jun-Ho;Ro, Yong-Man;Kang, Kyeong-Ok
    • Journal of Korea Multimedia Society
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    • v.8 no.6
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    • pp.814-826
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    • 2005
  • The user-centric broadcasting environment includes the agent system and personalized broadcasting services for user-adaptive TV watching. In this paper, we propose broadcasting environment consisting of personalized broadcasting services and a multi-agent broadcasting system for the services. The proposed system employs the intelligent agent technology of the Foundation for Intelligent Physical Agents (FIPA) as well as metadata technology of MPEG-7 and TV-Anytime Forum (TVAF). To verify the usefulness of the proposed environment, we implemented a test-bed and demonstrated the proposed agent system with three services including intelligent user-information management service, information mobility service, and content retrieval service.

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