• Proceedings of the Korea Concrete Institute Conference
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• 2004.11a
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• pp.285-288
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• 2004

Generally, the autogenous shrinkage of high performance concrete is important in that it can lead the early cracks in concrete structures. In the previous study, The. autogenous shrinakge of HPC was found to decrease with incresing expansive additive and shrinakge reduction agent. In case of combined use, the autogenous shrinakge was more reduction than in case separate use. The purpose of this study is to derive a realistic equation to estimate the autogenous shrinakge model of high performance concrete with exapnsive agent and shrinakge reduction agent. investigated the durability of high performance concrete using expansive additive and shrinkage reducing agent. The proposed equation showed reasonably good correlation with test data on autogenous shrinakge of high performance concrete with material for shrinkage reduction.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.1359-1363
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• 2009

The object of this research is to develop a simulation system for earthmoving operations in consideration of the impact of congestion in-between equipment and existing traffic flow around the site. The congestion in-between equipment and traffic flow affect work productivity. The conventional discrete event simulation, however, has limitations in simulating the flow of construction equipment. To consider the impact of congestion in-between equipment and existing traffic flow, in this paper, a multi-agent based simulation model that can realize characteristics of truck behavior more accurately to consider the impact of congestion was proposed. In this simulation model, multiple agents can identify environmental changes and adapt themselves to the new environment. This modeling approach is a better choice for this problem since it describes behavioral characteristics of each agent by sensing changes in dynamic surroundings. This study suggests a detailed system design of the multi-agent based simulation system.

• Journal of Information Technology Applications and Management
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• v.19 no.1
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• pp.37-46
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• 2012

The scheduling problem of large products like ships, airplanes, space shuttles, assembled constructions, and automobiles is very complex in nature. To reduce inherent computational complexity, we often design scheduling systems that the original problem is decomposed into small sub-problems, which are scheduled independently and integrated into the original one. Moreover, the steep growth of communication technology and logistics makes it possible to produce a lot of multi-nation corporation by which products are produced across more than one plant. Therefore vertical and lateral coordination among decomposed scheduling systems is necessary. In this research, we suggest an agent-based coordinating mechanism for multi-level scheduling systems in supply chain. For design of a general coordination mechanism, at first, we propose a grammar to define individual scheduling agents which are responsible to their own plants, and a meta-level coordination agent which is engaged to supervise individual scheduling agents. Second, we suggest scheduling agent communication protocols for each scheduling agent topology which is classified according to the system architecture, existence of coordinator, and direction of coordination. We also suggest a scheduling agent communication language which consists of three layers : Agent Communication Layer, Scheduling Coordination Layer, Industry-specific Layer. Finally, in order to improve the efficiency of communication among scheduling agents we suggest a rough capacity coordination model which supports to monitor participating agents and analyze the status of them. With this coordination mechanism, we can easily model coordination processes of multiple scheduling systems. In the future, we will apply this mechanism to shipbuilding domain and develop a prototype system which consists of a dock-scheduling agent, four assembly-plant-scheduling agents, and a meta-level coordination agent. A series of experiment using the real-world data will be performed to examine this mechanism.

• Journal of KIISE:Computing Practices and Letters
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• v.7 no.5
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• pp.467-474
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• 2001

When user wants to animate more than one character, some unexpected motion animation like a collision between characters may occur. Therefore, this problem must be resolved using a proper control mechanism. Therefore, this problem must be resolved using a proper control mechanism. This paper proposes an agent-based system that controls the motion animation of the character for representing animation scenario reflecting user\`s intention. This system provides a method that coordinates a type of motion and avoids collision between characters according to the moving path of a character in three-dimensional space. Agent communicates with others for motion synchronization. Agent is extended into several intelligent agents that coordinate character\`s motion. Agent system enables not only an intended motion animation, but also the scheduling of motion to an entire character animation. It designs automata model using Petri-net analysis tool for the agent\`s interaction as a method that passes the agent\`s information and infers the current state of agents. We implement this agent system to control the motion of character using agent technology and show an example of controlling the motion of human character model to prove the possiblity of motion control.

• Fire Science and Engineering
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• v.28 no.2
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• pp.14-19
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• 2014

A current standard exist only on the surface tension in the current domestic wetting agent technology standards, so it is difficult to the performance evaluation of the wetting agent through the standard. So this study presents the optimized performance evaluation methods by scale model experimental equipment in order to present techniques for performance evaluation of wetting agents. The purpose of this study is to investigate validity of experimental results of the self-designed scale model experiment equipment by a comparative analysis of experimental results of the NFPA 18 experiment and the experiment using the self-designed scale model experiment equipment. As a result of a comparative analysis of experimental results of the NFPA 18 experiment that evaluate only the permeation performance on the contton and the experiment using the self-designed scale model experiment equipment that evaluate the permeation performance and fire extinguishing performance on wood flour, the discrimination of the permeation performance was confirmed in both the NFPA 18 experiment and the self-designed scale model experiment equipment. And a result of self-designed experiment equipment have clear discriminatory more than NFPA 18 by internal temperature measurement using the thermocouples.

• Journal of the Korean Institute of Intelligent Systems
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• v.21 no.1
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• pp.29-35
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• 2011

In this paper, an integrated simulation model for designing multi-agent system based DEMS (distributed energy management system) in stand-alone micro-grid system is proposed. In the design of the EMS(energy management system), the multi-agent based DEMS are more effective than conventional centralized EMS, but it is difficult to design the DEMS by general design tools for power system because of various states of a microgrid system during operation of stand-alone mode. Also, since performance test of the DEMS using a real system is inefficient, an integrated simulation model is required for designing an effective multi-agent system based DEMS. The proposed model consists of Matlab/SimPowerSystems based simulation model of the microgrid system and the Multi-agnet based DEMS designed by Matlab/StateFlow tool. In order to show the effect of the proposed model, the model outputs are analyzed for specified operation conditions.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.12
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• pp.2072-2077
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• 2007

The primary objective of all power systems is to maintain the reliability and to minimize outage time for fault or the others. The frequency relaying algorithm perceives a variation of system frequency and thereafter detects the unbalance between generation and load. A multi-agent system is composed of multiple interacting computing elements that are known as agents. In this paper, frequency relaying algorithm is designed by multi-agent system and is implemented by EMTP-MODELS. To verify performance of the frequency relaying algorithm based on multi-agent system, simulations by EMTP have been carried out.

• Environmental Engineering Research
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• v.19 no.4
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• pp.369-373
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• 2014

In view of the problem of the invalidity of the incentive mechanism of the ecological subsidies, which is due to the information asymmetry between the government's supervision and the enterprise endeavor to fulfill their ecological responsibilities, this paper attempts to analyze the supervision of ecological subsidies based on the Principal-agent Model. Two conclusions are drawn: firstly, the government's supervision regarding the effect of the enterprises' fulfilling the ecological responsibilities can significantly reduce the information asymmetry; secondly, the government's incentive strength and the enterprises' endeavor level of fulfilling the ecological responsibilities are both improving the surveillance dynamics. Here is the suggestion: with the increasing of the surveillance dynamics of the government and the transparency of the enterprises' fulfilling the ecological responsibilities, the government should meanwhile increase the subsidies incentive strength, therefore, to promote the effort level of the enterprises' fulfilling the ecological responsibilities to approach to the Pareto optimal value.

• Journal of the Korean Operations Research and Management Science Society
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• v.36 no.1
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• pp.69-84
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• 2011

In this study, based on the principal-agent paradigm, we investigate a joint cost reduction activity in a buyer-supplier supply chain where a buyer motivates its operations department and a supplier to reduce the supply chain's production cost. We construct a benefit-sharing model based on the target cost scheme, a basic philosophy in practice which has not been explored in previous studies. The model also incorporates various supply chain issues such as the cooperation of multiple agents, the opportunity loss, and the degree of strategic relationship between the buyer and the supplier. Based on the analysis of the principal-agent model, we investigate the benefit-sharing rule to control agents' actions, and we also provide important managerial implications into supply chain practices via extensive comparative static analyses.

• Journal of Applied Tourism Food and Beverage Management and Research
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• v.12 no.1
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• pp.57-78
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• 2001

The propose of this study is to explore Internet business models of tourism-related business and to research ]edging product agents focused on the company \"T\". The procedure for this study is as follows: 1) Study literature review about the Internet business models of tourism-related business 2) Characterize the lodging product agents 3) Analyze the Internet business model of the agent \"T\" based upon preview studies 4) Suggest the future study of this field.study of this field.