• Journal of Information Technology Applications and Management
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• 제19권1호
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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.

• 한국시스템다이내믹스연구
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• 제13권1호
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• pp.81-112
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• 2012

This study investigate the impact of supply chain contracts on supply chain performance. This study employed Price adjustment contract(PAC) and Quantity adjustment contract(QAC) as two main types of a vertical coordination mechanism. We simulate different types of coordination mechanisms with various degrees of demand uncertainties and several capacity tightness scenarios. This study shows that PAC and QAC significantly enhance the supply chain profits and fill rates suggesting that supply chain performance can be improved by implementing a proper coordination mechanism depends on the level of a capacity tightness and demand uncertainty.

• 한국운동역학회지
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• 제17권4호
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• pp.73-82
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• 2007

The purpose of this study was to qualitatively analyze coordination pattern of joints and segments during Dwichagi in Taekwondo and present a point of difference as compared with the previous study on Dolryeochagi in Taekwondo. By the utilization of three-dimensional cinematography, the angles of individual joints and segments of six male Taekwondo experts during Dwichagi were calculated by using Euler's angle. The used coordination variables were angle vs. angle plots between adjacent joints and segments and angle vs. angular velocity plots of individual joints and segments, respectively. It was observed during Dwichagi that in-phase coordination and spring-like rotational control mechanism of the lower and upper trunk were transferred into straight spring-like control mechanism of lower leg passing through flexion-extension and the fixation of degree-of-freedom of lower trunk and hip joint alternatively. This comparative study that coordination variables were used seems to be more useful research direction to deeply understand basic control mechanisms of Taekwondo kicking techniques when compared with the previous studies that defined Dwichagi as a thrust movement pattern merely based on biomechanical variables of a kicking leg.

• 지능정보연구
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• 제17권4호
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• pp.213-226
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• 2011

글로벌 공급사슬 환경에서 글로벌하게 분산 조달, 생산, 유통하게 됨에 따라 전체 공급사슬의 스케줄을 최적화하기 위해서 공급사슬상의 개별 기업 혹은 공장의 스케줄링 최적화뿐만 아니라 각 개별 기업 혹은 공장의 스케줄을 긴밀하게 연계하는 것이 필요하게 되었다. 이는 경쟁과 협력을 동시에 하는 개별 기업 혹은 공장을 개별 에이전트로 보고 각 에이전트간 커뮤니케이션을 통해 개별 에이전트가 관할하는 스케줄러의 스케줄을 조정함으로써 가능해진다. 하지만 전통적인 스케줄링 연구는 개별 스케줄러의 최적화에 집중되어 있고, 에이전트 연구는 스케줄링 도메인에 적용한 예가 제한적이며 이 예도 개별 스케줄러 내의 최적화에 적용하거나 실제 현장 문제가 아닌 실험실 문제 수준에 그치고 있다. 따라서 본 연구에서는 전체 글로벌 공급사슬 스케줄의 최적화를 위해 개별 기업 혹은 공장 스케줄러의 스케줄링을 연계하는 경쟁협력 스케줄링을 위한 에이전트 기반 플랫폼을 구축하였다. 글로벌 공급사슬에서 경쟁협력 스케줄링을 위한 에이전트 기반 플랫폼을 구축하기 위해 첫째, 경쟁협력 스케줄링 분류 체계를 확립하고, 둘째, 경쟁협력 스케줄링을 위한 에이전트를 설계하고, 셋째, 경쟁협력 스케줄링을 위한 지식기반 의사결정 모델을 개발한 후, 넷째 조선산업에 적용 가능한 프로토타입 시스템을 개발했다. 이를 통해 글로벌 공급사슬상의 전체 스케줄의 품질과 에이전트간 커뮤니케이션의 노력에 대한 균형점을 찾을 수 있다. 이를 통해 공급사슬내 개별 기업 혹은 공장의 부분 최적화를 극복할 수 있는 대안을 제시할 것으로 기대한다.

• Industrial Engineering and Management Systems
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• 제8권4호
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• pp.213-220
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• 2009

A revenue sharing contract is one of the mechanisms that coordinate decision makers in a decentralized supply chain toward the consensual goal. The transfer prices between different echelons in the supply chain influence the total supply chain profits. The study aims to explore various transfer pricing heuristics on the supply chain coordination in terms of the supply chain profits and their interactions with the revenue sharing rate. A model is proposed for formulating the collaborative production and distribution planning in a decentralized supply chain with the revenue sharing mechanism. Experiment results indicate that the transfer price and the revenue sharing rate affect significantly the coordination. Among the studied pricing heuristics, the variable-cost pricing method led to the best SC profits. Raising the revenue sharing rate reduced the SC profits no matter what heuristics were employed. Furthermore, the experiments provide us clues for finding the optimal transfer price for the supply chain.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.149.3-149
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• 2001

Task allocation is a key problem in multiagent systems. The importance of automated negotiation protocols for solving the task allocation problem is increasing as a consequence of increased multi-agent applications. In this paper, we introduce the multiagent Traveling Salesman Problem(TSP) as an example of task reallocation problem, and suggest Vickery auction as an inter-agent coordination mechanism for solving this problem. In order to apply this market-based coordination mechanism into multiagent TSPs, we define the profit of each agent, the ultimate goal of negotiation, cities to be traded out through auctions, the bidding strategy, and the order of auctions. The primary advantage of such approach is that it can find an optimal task allocation ...

• Journal of Mechanical Science and Technology
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• 제19권5호
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• pp.1123-1130
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• 2005

In view of the lack of efficient coordination of interdependent task in the collaborative design system, the mechanisms for temporal and resource coordination problems are established based on Petri Nets, respectively. Both of the mechanisms are encapsulated and implemented in the coordination component so as to increase the flexibility and acceptability of the system. We model the CSCW system based on Petri Nets for simulation, analysis and optimization. A case study on the overhead traveling crane is given to demonstrate and validate our theory.

• 한국시스템다이내믹스연구
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• 제11권4호
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• pp.5-23
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• 2010

The competition between hospitals has become an issue for many hospitals because of the sudden increased number of health providers. As the marketing or customer management have become important factors as means of competition, a number of hospital have been considered or already adopted the coordination system. A system dynamics model is developed to see the effect of the hospital coordination system. This paper after briefly explaining the structure of the system dynamics model, discusses the roles of the hospital coordination system with examples. The system dynamics model quantifies through simulations the process of effects of coordination system on the number of customers, productivities of employees (nurses and doctors), and finally the financial status. As a conclusions of the simulations and their analysis, it is concluded that coordination system could be more effective than the investment to the facilities. Since the study is based on only one hospital case, it is limited. However, it explains the mechanism of the coordination system quantitatively as well as qualitatively.

• Nuclear Engineering and Technology
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• 제54권11호
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• pp.4013-4021
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• 2022

A kind of zirconium phosphate mesoporous coordination polymer Zr-EDTMPA was successfully synthesized and characterized using XRD, FTIR, TGA, EA, SEM-EDS, and N₂ sorption-desorption measurements. The prepared Zr-EDTMPA was first employed for the removal of Co(II) from an aqueous solution, and the effects of pH, contact time, temperature, initial Co(II) concentration, reusability, and sorption mechanism were systematically investigated. The results showed that the Zr-EDTMPA is a zirconium phosphate complex formed by the coordination of EDTMPA to Zr in a molar ratio of 1:1. The sorption of Co(II) by Zr-EDTMPA was a pH-dependent, spontaneous and endothermic process, which was better fitted to the pseudo-second-order kinetic model and Langmuir isotherm model. The Zr-EDTMPA was demonstrated to have excellent reusability and presented a high sorption capacity of 73.0 mg·g^-1 for Co(II) at pH 8.0. The sorption mechanism was mainly attributed to the strong coordination between cobalt and the untapped hydroxyl functional groups on Zr-EDTMPA, which was confirmed by XPS spectra. Therefore, as a candidate sorbent with high sorption capacity and excellent reusability, Zr-EDTMPA has a great potential for the removal of Co(II) from aqueous solutions.

• Industrial Engineering and Management Systems
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• 제15권2호
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• pp.156-172
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• 2016

Complex and uncertain issues in supply chain result in integrated decision making processes in supply chains. So decentralized (distributed) decision making (DDM) approach is considered as a crucial stage in supply chain planning. In this paper, an uncertain DDM through coordination mechanism is addressed for a multi-product supply chain planning problem. The main concern of this study is comparison of DDM approach with centralized decision making (CDM) approach while some parameters of decision making are assumed to be uncertain. The uncertain DDM problem is modeled through fuzzy mathematical programming in which products' demands are assumed to be uncertain and modeled using fuzzy sets. Moreover, a CDM approach is customized and developed in presence of fuzzy parameters. Both approaches are solved using three fuzzy mathematical optimization methods. Hence, the contribution of this paper can be summarized as follows: 1) proposing a DDM approach for a multi-product supply chain planning problem; 2) Introducing a coordination mechanism in the proposed DDM approach in order to utilize the benefits of a CDM approach while using DDM approach; 3) Modeling the aforementioned problem through fuzzy mathematical programming; 4) Comparing the performance of proposed DDM and a customized uncertain CDM approach on multi-product supply chain planning; 5) Applying three fuzzy mathematical optimization methods in order to address and compare the performance of both DDM and CDM approaches. The results of these fuzzy optimization methods are compared. Computational results illustrate that the proposed DDM approach closely approximates the optimal solutions generated by the CDM approach while the manufacturer's and retailers' decisions are optimized through a coordination mechanism making lasting relationship.