• Journal of Electrical Engineering and Technology
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• 제4권4호
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• pp.457-466
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• 2009

This paper presents efficient parallel genetic algorithm (EPGA) based decomposed network for optimal power flow with various kinds of objective functions such as those including prohibited zones, multiple fuels, and multiple areas. Two coordinated sub problems are proposed: the first sub problem is an active power dispatch (APD) based parallel GA; a global database generated containing the best partitioned network: the second subproblem is an optimal setting of control variables such as generators voltages, tap position of tap changing transformers, and the dynamic reactive power of SVC Controllers installed at a critical buses. The proposed approach tested on IEEE 6-bus, IEEE 30-bus and to 15 generating units and compared with global optimization methods (GA, DE, FGA, PSO, MDE, ICA-PSO). The results show that the proposed approach can converge to the near solution and obtain a competitive solution with a reasonable time.

• 산업경영시스템학회지
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• 제21권48호
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• pp.37-52
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• 1998

In many distribution systems important cost reductions and/or service improvements may be achieved by adopting an efficient inventory policy and proper selection of facilities. These efficiency improvements and service enhancements clearly require an integrated approach towards various logistical planning functions. The areas of inventory control and transportation planning need to be closely coordinated. The purpose of this paper is to construct an integrated model that can minimize the total cost of the transportation and inventory systems between multiple origin and destination points, where in origin point i has the supply of commodities and in destination point j requires the commodities. In this case, demands of the destination points are assumed random variables which have a known probability distribution. Using the lot-size reorder-point policy and the safety stock level that minimize total cost we find optimal distribution centers which transport the commodities to the destination points and suggest an optimal inventory policy to the selected distribution center. We also show if a demand greater than one unit will occur at a particular time, we describe the approximate optional replenishment policy from computational results of this lot-size reorder-point policy. This model is formulated as a 0-1 nonlinear integer programming problem. To solve the problem, this paper proposes heuristic computational procedures and a computer program with UNIX C language. In the usefulness review, we show the meaning and validity of the proposed model and exhibit the results of a comparison between our approach and the traditional approach, respectively.

• 로봇학회논문지
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• 제2권3호
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• pp.234-241
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• 2007

Effective tools which can alleviate the complexity and computational load problem in collision-free motion planning for multi-agent system have steadily been demanded in robotics field. To reduce the complexity, the extended collision map (ECM) which adopts decoupled approach and prioritization is already proposed. In ECM, the collision regions which represent the potential collision of robots are calculated using the computational power; the complexity problem is not resolved completely. In this paper, we propose a mathematical analysis of the extended collision map; as a result, we formulate the collision region as an equation with 5-8 variables. For mathematical analysis, we introduce realistic assumptions as follows; the path of each robot can be approximated to a straight line or an arc and every robot moves with uniform velocity or constant acceleration near the intersection between paths. Our result reduces the computational complexity in comparison with the previous result without losing optimality, because we use simple but exact equations of the collision regions. This result can be widely applicable to coordinated multi-agent motion planning.

• 국제학술발표논문집
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• The 7th International Conference on Construction Engineering and Project Management Summit Forum on Sustainable Construction and Management
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• pp.52-61
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• 2017

Considering its significant impact on the cost and schedule of construction projects, formwork as one part of temporary facility categories in construction should be arranged precisely. Current practice in the formwork planning is often conducted manually and repetitively, causing low efficiency and time waste. This study proposes an automated framework to generate more accurate and detailed formwork plans by utilizing information from building information modeling (BIM) considering the adequate geometric and semantic information provided by the BIM model. The dimensions and quantities information of elements in a building can be extracted automatically. Then, a rule is prepared for calculating the required forms erected around elements based on the contact areas. Finally, an algorithm of integrating first fit decreasing (FFD) with coordinated bottom left (CBL) is applied to automatically generate the formwork plan. The BIM-based automated planning framework is demonstrated by an illustrative example. The results show that the proposed framework can generate the formwork plan accurately and automatically, and significantly improve the efficiency in the formwork plan and reuse.

• Journal of Electrical Engineering and Technology
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• 제4권3호
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• pp.315-322
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• 2009

Penetration and installation of a new dynamic technology known as Flexible AC Transmission Systems (FACTS) in a practical and dynamic network requires and force expert engineer to develop robust and flexible strategy for planning and control. Unified Power Flow Controller (UPFC) is one of the recent and effective FACTS devices designed for multi control operation to enhance the power system security. This paper presents a dynamic strategy based on Particle Swarm Optimization (PSO) for optimal parameters setting of UPFC to enhance the system loadability. Firstly, we perform a multi power flow analysis with load incrementation to construct a global database to determine the initial efficient bounds associated to active power and reactive power target vector. Secondly a PSO technique applied to search the new parameters setting of the UPFC within the initial new active power and reactive power target bounds. The proposed approach is implemented with Matlab program and verified with IEEE 30-Bus test network. The results show that the proposed approach can converge to the near optimum solution with accuracy, and confirm that flexible multi-control of this device coordinated with efficient location enhance the system security of power system by eliminating the overloaded lines and the bus voltage violation.

• 대한전기학회논문지
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• 제36권5호
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• pp.319-327
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• 1987

This paper presents a dynamic programming sucdessive approximation algorithm for scheduling pumped storage hydro plants and shows how this method can be coordinated with the commitment of the thermal units of the system. The general object of operation of pumped hydrostorage plants is the minimization of the overall production cost and the maximization of generation reserves. The basic procedure used to obtain a combined pumped storage-unit commitment schedule is to execute the pumped storage scheduler and unit commitment scheduler iteratively. A combined DPSA algorithm has been presented to coordinate the scheduling of the pumped storage with the scheduling of the thermal units.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1989년도 한국자동제어학술회의논문집; Seoul, Korea; 27-28 Oct. 1989
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• pp.635-642
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• 1989

We formulated the multi-robot trajectory problem into a series of NLP problem, each of which is that of finding the optimal tip positions of the robots for the next time step. The NLP problem is composed of an objective function and three constraints, namely: a) Joint position limits, b) Joint velocity limits, and c) Collision-avoidance constraints. By solving a series of NLP problem, optimally coordinated trajectories can be determined without requiring any prior path information. This is a novel departure from the previous approach in which either all paths or at least one path is assumed to be given. Practical application of the developed method is for optimal synthesis of multiple robot trajectories in off-line. To test the validity and effectiveness of the method, numerical examples are illustrated.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1991년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 22-24 Oct. 1991
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• pp.595-600
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• 1991

A competitive automated manufacturing system integrates the various control processes and data used in service of products. design, manufacturing, and, sale. CIM is a way to achieve such integration through computers and computational techniques in manufacturing, planning, and design. Developing effective CIM architectures is hampered by integration problems. The key to resolving these problems lies in a better understanding of manufacturing function and how it is related to other manufacturing functions. Integration of CIM environment requires coordinated solutions to data management problems for individual application system as well as for exchange of data between these applications. This requires a common framework for data management throughout the CIM environment. This paper discusses the design paradigm as a framework for this purpose. Designing an organizational structure to meet those goals invloves 1) analyzing the functions through functional decomposition, 2) developing a data model to coordinate functions. As a result, we propose an object-oriented design methodology for manufacturing information system.

• 대한산업공학회지
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• 제17권2호
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• pp.115-129
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• 1991

An ecconomically competitive automated manufacturing system integrates the various control processes and data used in design, manufacturing, sale and service of products. CIM is a way to achieve such integration through computers and computational techniques in design, planning, and manufacturing. Developing effective CIM architectures is hampered by integration problems. The key to resolving these problems lies in a better understanding of manufacturing function and how it is related to other manufacturing functions. Integration of CIM environment requires coordinated solutions to data management problems for individual application system as well as for exchange of data between these applications. This requires a common framework for data management throughout the CIM environment. This paper discusses the design paradigm as a framework for this purpose. Designing an organizational structure to meet those goals involves 1) analyzing the functions through functional decomposition, 2) developing a data model to coordinate functions. As a result, we propose an object-oriented design methodology for manufacturing information system.

• 한국환경복원기술학회지
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• 제23권3호
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• pp.81-89
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• 2020

The grid-based analysis is useful for conservation planning, species distribution study, education, and others'. On the west coast of Korea, it was high in species richness, rarity and endangered species richness. Our results also showed that coordinated species data can be applied to develop species distribution models due to the high correlation between total species richness and coordinated species 0richness. In hot spot analysis, high species richness areas are concentrated around the west coast, while species richness is relatively low in Gangwon and Gyeongnam. Endangered species and rarity were also concentrated on the west coast and islands. Through the complementary analysis, we selected areas which are efficient to protect species; protecting more species while minimizing the conservation effort. Our result demonstrated that simply protecting Baengyueong island, Gageo island and a part of Jeju island can conserve over 50% of bird species in South Korea. However, the validity of our analysis was limited by the absence of data from national parks, and Baekdudaegan protected areas as well as inconsistent capacity among field researchers.