• Title/Summary/Keyword: Decentralized method

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A Verification of the Project Manager-Oriented Model for Apartment Construction in the Public Sector (공공 아파트건설의 PMr형 사업관리모델에 대한 실증적 사레검증)

  • Sohn Jeong-Rak;Kim Jae-Jun
    • Korean Journal of Construction Engineering and Management
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    • v.5 no.6 s.22
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    • pp.191-202
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    • 2004
  • In this study, the project manager-oriented organization model has been verified by analysing it with forming a clear definition of detailed unitary duty entity to develop current non-efficient CM system constituted by functional organization with the decentralized responsibility and apply the model As a result from verification that the model provides valid solutions by comparing it with the existing, the model is better than the existing in cost savings, target profit sales rate, total rate of new on sales. Moreover, various activities in cost savings and cases where improvement is feasible are executed. However, the model caused some problems in organizational operation, project management and in division of duties so this study proposed improving management method

Protecting the iTrust Information Retrieval Network against Malicious Attacks

  • Chuang, Yung-Ting;Melliar-Smith, P. Michael;Moser, Louise E.;Lombera, Isai Michel
    • Journal of Computing Science and Engineering
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    • v.6 no.3
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    • pp.179-192
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    • 2012
  • This paper presents novel statistical algorithms for protecting the iTrust information retrieval network against malicious attacks. In iTrust, metadata describing documents, and requests containing keywords, are randomly distributed to multiple participating nodes. The nodes that receive the requests try to match the keywords in the requests with the metadata they hold. If a node finds a match, the matching node returns the URL of the associated information to the requesting node. The requesting node then uses the URL to retrieve the information from the source node. The novel detection algorithm determines empirically the probabilities of the specific number of matches based on the number of responses that the requesting node receives. It also calculates the analytical probabilities of the specific numbers of matches. It compares the observed and the analytical probabilities to estimate the proportion of subverted or non-operational nodes in the iTrust network using a window-based method and the chi-squared statistic. If the detection algorithm determines that some of the nodes in the iTrust network are subverted or non-operational, then the novel defensive adaptation algorithm increases the number of nodes to which the requests are distributed to maintain the same probability of a match when some of the nodes are subverted or non-operational as compared to when all of the nodes are operational. Experimental results substantiate the effectiveness of the detection and defensive adaptation algorithms for protecting the iTrust information retrieval network against malicious attacks.

Distributed Virtual Topology Adaptation Method to Support IP Traffic in WDM Mesh Networks (WDM Mesh 네트워크에서 IP 트래픽을 수용하기 위한 분산형 가상토폴로지 적응 기법)

  • Kim, Eal-Lae;Lee, Sung-Kuen;Lee, Yong-Won;Chang, Sun-Hyok;Lee, Myung-Moon;Park, Jin-Woo
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.32 no.1B
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    • pp.1-10
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    • 2007
  • We propose a new approach to accommodate bidirectional asymmetric traffic demands as well as unexpected dynamic internet traffic variation in the WDM mesh network by using optical networking technologies. In the proposed scheme, an intermediate node determines the optical path based on the switching statistics of IP router of the node which characterizes the Internet traffic variation, which in effect provides a dynamic and distributed traffic control over the network. It is expected to reduce the efficiency deterioration of RWA(Routing and Wavelength Assignment) due to the real-time variation of Internet traffic so that expandability and flexibility of the network can be enhanced. In this paper, we describe a methodology for traffic behavior analysis at a node, and the decision policy of the establishment/release of optical path. In addition, we evaluate the performance of the proposed scheme through the computer simulations.

A Study on the Directions of Effective Farmland Use Planning (효율적인 농지이용계획수립 방향에 관한 연구)

  • 임상봉
    • Journal of Korean Society of Rural Planning
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    • v.1 no.2
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    • pp.77-92
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    • 1995
  • The initiative to determine farmland use has been transferred to local side under the decentralized government system in Korea. New Land Act and Rural Development Act support it. Changes in external and internal environments of Korean agriculture require to diversify farmland use. Lpcal development plan may be implemented when specific farmland use plan is prepared. However, (armland use planning has not been prepared by the local governments yet. This study aims to identify problems encountered in current farmland use and suggest directions of effective and reasonable farmland use planning relevant to local conditions. Questionnaire method was used to prove topographical differences of community land demand, Statistical analyses show that farmers desire to utilize marginal farmland for income increase. Growing grass(42.0%) and cash crops(41.7%) was greatly demanded by them. They were generally eager for developing touristic farm (52.1 % ). By topographical characteristics, the eager was greatest in coastal areas, on the contrary, it was relatively low in mountainous areas. There were more farmers who want to expand their farmland in rice farming(48.4%) or rice-horticulture farming(46.9%) areas. Potential retirer among farmers were most in suburban areas, However, it was expected that there would be the highest retirement rate in rice farming areas because of the high rate of aged farmers. Farmland use planning should be incorporated into food production policies and community people's needs for income increase and life improvement. Agriculture promotion areas must be maintained for scale optimized farming and cash crop farming as much as possible. However, minimum portion for other uses in each village or farming community unit should be adopted. Less favored areas will have to be utilized for both agriculture and non-agriculture uses. Priority can be put into touristic resorts as a non-agriculture use. Furthermore, such areas can be used for sustainable agriculture as well as for residence, industry, animal breeding.

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Development and Comparison of Centralized and Decentralized ATIS Models with Simulation Method

  • Kim, Hoe-Kyoung
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.10 no.2
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    • pp.1-8
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    • 2011
  • Traffic congestion is a source of significant economic and social costs in urban areas. Intelligent Transportation Systems (ITS) are a promising means to help alleviate congestion by utilizing advanced sensing, computing, and communication technologies. This paper proposes and investigates a basic and advanced ITS framework Advanced Traveler Information System (ATIS) using wireless Vehicle to Roadside (Centralized ATIS model: CA model) and Vehicle to Vehicle (DeCentralized ATIS model: DCA model) communication and assuming an ideal communication environment in the typical $6{\times}6$ urban grid traffic network. Results of this study indicate that an ATIS using wireless communication can save travel time given varying combinations of system characteristics: traffic flow, communication radio range, and penetration ratio. Also, all tested metrics of the CA and DCA models indicate that the system performance of both models is almost identical regardless of varying traffic demand and penetration ratios. Therefore, DCA model can be a reasonable alternative to the fixed infrastructure based ATIS model (CA model).

A Design of a Coordination Agent Controlling Decision with Each Other Agents in RTS (RTS 게임에서 에이전트와 상호 의사를 조절하는 조정 에이전트의 설계)

  • Park, Jin-Young;Sung, Yun-Sick;Cho, Kyung-Eun;Um, Ky-Hyun
    • Journal of Korea Game Society
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    • v.9 no.5
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    • pp.117-125
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    • 2009
  • In real-time strategy simulation (RTS) game each team is composed of agents and executes strategies to win other team. Strategy needs agents' cooperation in each team. This needs multi-agent system (MAS). Centralized decision making, one of decision making in MAS, selects actions not to agents but to team by a coordinated agent. Decentralized decision making costs high because each agent communicates with each other. In this paper we propose a system which controls agents by grouping and allocates roles through negotiation by a coordinated agent. Then, when one of allocated actions is not executed or failed, a coordinated agent allocates its role to another agent. We make experiments in starcraft, famous RTS game. When a proposed method is applied, the performance of attack and defense is increased. The improved agents' team wins eight times per ten games.

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Intelligent Tuning Of a PID Controller Using Immune Algorithm (면역 알고리즘을 이용한 PID 제어기의 지능 튜닝)

  • Kim, Dong-Hwa
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.51 no.1
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    • pp.8-17
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    • 2002
  • This paper suggests that the immune algorithm can effectively be used in tuning of a PID controller. The artificial immune network always has a new parallel decentralized processing mechanism for various situations, since antibodies communicate to each other among different species of antibodies/B-cells through the stimulation and suppression chains among antibodies that form a large-scaled network. In addition to that, the structure of the network is not fixed, but varies continuously. That is, the artificial immune network flexibly self-organizes according to dynamic changes of external environment (meta-dynamics function). However, up to the present time, models based on the conventional crisp approach have been used to describe dynamic model relationship between antibody and antigen. Therefore, there are some problems with a less flexible result to the external behavior. On the other hand, a number of tuning technologies have been considered for the tuning of a PID controller. As a less common method, the fuzzy and neural network or its combined techniques are applied. However, in the case of the latter, yet, it is not applied in the practical field, in the former, a higher experience and technology is required during tuning procedure. In addition to that, tuning performance cannot be guaranteed with regards to a plant with non-linear characteristics or many kinds of disturbances. Along with these, this paper used immune algorithm in order that a PID controller can be more adaptable controlled against the external condition, including moise or disturbance of plant. Parameters P, I, D encoded in antibody randomly are allocated during selection processes to obtain an optimal gain required for plant. The result of study shows the artificial immune can effectively be used to tune, since it can more fit modes or parameters of the PID controller than that of the conventional tuning methods.

A dedicated line operating and maintenance system design based on UML (UML 기반 전용회선 운용관리시스템 설계)

  • 조동권
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.6 no.6
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    • pp.827-832
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    • 2002
  • The development of dedicated network management system is essential to meet the following conditions: the system must run the configuring and repair processing for the dedicated communication network, and can manage new next generation data dedicated communication network of various types. In general it is effective that the system is consisted of decentralized module to be accessible for business logic and datum to remote area. To solve these problems, a method is to use object-oriented design techniques. That is, it is to abstract reusability objects and make component module using the abstracted objects. In this paper, we propose a management system of dedicated communication network service using object-oriented design techniques which are UML(Unified Modeling Language).

The Design and Development of a Onchain Game for Scalability Verification of Blockchain Platform (블록체인 플랫폼의 성능 및 확장성 검증을 위한 온체인 게임 설계 및 개발)

  • Jang, Kwang-Soo;Lee, Ook
    • Journal of Digital Convergence
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    • v.18 no.10
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    • pp.253-263
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    • 2020
  • Since the birth of the Ethereum in 2015, various decentralized applications (DApp) based on blockchain smart contract technology have appeared. However, CryptoKitty's case showed instability in terms of performance and scalability in real-world service environments. To solve this, a blockchain platform that developed a high transaction per second (TPS) has appeared, but there have been no environments and services to test it. Therefore, this paper intends to design and develop a game that can record the contents of all games on the chain and verify the performance and scalability of the blockchain platform through oversized transactions. The developed game generated a total of 6.3 million blocks and 8.9 million transactions through by 682 and verified the improved performance and scalability of the existing platform. Additionally, the maximum TPS was measured at 1,309 during the test period. In the future, it is expected that performance and scalability can be compared in a realistic environment through the method presented in this paper.

A Study on the Applications of Blockchain Transactions and Smart Contracts in Recordkeeping (블록체인 트랜잭션과 스마트 컨트랙트를 활용한 기록관리 적용 방안 연구)

  • Wang, Hosung;Moon, Shinhye;Han, Nungwoo
    • Journal of Korean Society of Archives and Records Management
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    • v.20 no.4
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    • pp.81-105
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    • 2020
  • This study examines the possibility of applying various recordkeeping methods through a platform built in 2019 by the National Archives of Korea. In particular, it aims to develop a way to track and store transactions using blockchain and to design and present the method of records management automation using smart contracts. In this regard, a literature review, a system analysis of CAMS and MAM, interviews with the experts, designing, implementation, and the development of the system's proof of concept were performed. These efforts resulted in the proposal of an archives and records management strategy utilizing blockchain, which guarantees transparency and accountability by preserving an audit trail on recordkeeping activities.