• Journal of Korean Institute of Industrial Engineers
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• v.22 no.4
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• pp.533-549
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• 1996

This paper is concerned with a sequencing problem in mixed model assembly lines, which is important to efficient utilization of the lines. In the problem, we deal with the two objectives of minimizing the risk of stoppage and leveling part usage, and consider sequence-dependent setup time. In this paper, we present a genetic algorithm(GA) suitable for the multi-objective optimization problem. The aim of multi-objective optimization problems is to find all possible non-dominated solutions. The proposed algorithm is compared with existing multi-objective GAs such as vector evaluated GA, Pareto GA, and niched Pareto GA. The results show that our algorithm outperforms the compared algorithms in finding good solutions and diverse non-dominated solutions.

• Journal of Electrical Engineering and Technology
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• v.9 no.5
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• pp.1694-1703
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• 2014

Lightning induced voltage is a major factor that causes interruptions on distribution lines. In this paper, analytical expressions are proposed to evaluate a lightning induced voltage on power lines directly in the time domain without the need to apply any extra conversions. The proposed expressions can consider the widely used current functions and models in contrast to the earlier analytical expressions which had a number of limitations related to the simplification of the channel base current and the current along the lightning channel. The results show that the simulated values based on the proposed method are in good agreement with the previous studies and the proposed expressions can be used for optimizing the insulation and protection level of existing and new lines being designed.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.1318-1323
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• 2007

Proposed herein is a shape design of a different rail support block with existing ones for the commercialization of the urban maglev. The rail support for existing test lines adopts monoblock steel sleeper, whereas an individual support system has been proposed to achieve an additional cost savings and to provide an emergency exit. Also, to enhance the easiness of installation and the repairability, alignment adjusting methods suitable for the new design have been devised.

• Proceedings of the KOR-KST Conference
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• 1998.09a
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• pp.17-24
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• 1998

The article expounds that the speed competition is the motive force of each transportation means. It also analyzes the current condition of the speed of Chinese railways. The developing strategy for Chinese railway is to raise the speed of the existing lines as a primary step and to construct the high-speed railway in selected sections concurrently, which proved that constructing high-speed railway in Beijing-Shanghai area is the best choice.

• Proceedings of the KIEE Conference
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• 2005.05b
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• pp.67-70
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• 2005

HVAC transmission lines must be designed to satisfy environmental regulations. Therefore it is necessary to pre-evaluate environmental problems for transmission line designer using prediction program. In this study, environment design software, TLCALC 2001 for transmission lines was developed as a comprehensive window program. It has 6 modules that are audible noise, radio noise, television noise, magnetic field, electric field and conductor surface gradient. TLCALC 2001 solved a few problems in use of the existing foreign tools and took several advantages. Experienced designers can get the results of calculation within about 15 minutes. Because the use of TLCALC 2001 is easy and practical, this program will be usefully applied to the environmental friendly design and construction of HVAC transmission lines. In the future, it is expected that public complaints and social environmental cost will be reduced by the use of TLCALC 2001.

• Korean Institute of Interior Design Journal
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• no.31
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• pp.56-63
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• 2002

This study intends to prepare a system that can be used, by applying digital technique, in analyzing complexity of architectural forms that have been visualized by the correlation based on the distribution chart made in accordance with profile lines. The profile lines are derived from the edge analysis of the architectural forms, simplified based on the visual theory. For the purpose, this study was conducted in the following ways: First, problems of the existing models for the elevation analysis were examined along with formal analysis based on visual recognition to consider the profile lines derived from the forms. Secondly, in elevation analysis, profile lines were derived by digital method to measure them qualitatively. To verify the objectivity of the measured data value, a survey was conducted based on the adjective cataloging method, and the correlation of the survey result and analyzed data was analyzed to verify the validity of the derived data. Thirdly, supplementation for the problems deducted from experiments and the possibility to use it in designing were suggested. Digital method has many advantages over the conventional analyzing system in deriving precise data value by excluding subjectivity. It also allows various analytical methods in analyzing numerous data repeatedly. Diversified models and methods of analysis considering numerous factors arising in the process of designing remain assignments to research in future.

• Journal of the Korean Operations Research and Management Science Society
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• v.35 no.3
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• pp.25-43
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• 2010

We consider a multi-objective balancing and sequencing problem in mixed model assembly lines, which is important for an efficient use of the assembly lines. In this paper, we present a neighborhood symbiotic evolutionary algorithm to simultaneously solve the two problems of balancing and model sequencing under multiple objectives. We aim to find a set of well-distributed solutions close to the true Pareto optimal solutions for decision makers. The proposed algorithm has a two-leveled structure. At Level 1, two populations are operated : One consists of individuals each of which represents a partial solution to the balancing problem and the other consists of individuals for the sequencing problem. Level 2, which is an upper level, works one population whose individuals represent the combined entire solutions to the two problems. The process of Level 1 imitates a neighborhood symbiotic evolution and that of Level 2 simulates an endosymbiotic evolution together with an elitist strategy to promote the capability of solution search. The performance of the proposed algorithm is compared with those of the existing algorithms in convergence, diversity and computation time of nondominated solutions. The experimental results show that the proposed algorithm is superior to the compared algorithms in all the three performance measures.

• Proceedings of the KIEE Conference
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• 2002.07a
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• pp.469-471
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• 2002

HVAC transmission lines must be designed to satisfy environmental regulations. Therefore it is necessary to pre-evaluate environmental problems for transmission line designer using prediction program. In this study, environment design software, TLCALC 2001 for transmission lines was developed as a comprehensive window program. It has 6 modules that are audible noise, radio noise, television noise, magnetic field, electric field and conductor surface gradient TLCALC 2001 solved a few problems in use of the existing foreign tools and took several advantages. Experienced designers can get the results of calculation within about 15 minutes. Because the use of TLCALC 2001 is easy and practical, this program will be usefully applied to the environmental friendly design and construction of HVAC transmission lines. In the future, it is expected that public complaints and social environmental cost will be reduced by the use of TLCALC 2001.

• Journal of applied mathematics & informatics
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• v.27 no.3_4
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• pp.703-714
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• 2009

GPS is especially suitable for location systems in flat areas, but the availability of GPS is limited in highly urbanized and mountain areas, due to the nature of satellite communications. Dead reckoning is generally used to solve a location problem when a pedestrian is out of range of GPS coverage. To extend the apparent coverage of the GPS system for a hiker in mountain areas, we propose an integrated 3D location system that interpolates a 3D dead reckoning system based on information about contour lines. The speeds of hikers vary according to the inclination of the ground in sloped areas such as mountains. To reduce location measurement errors, we determine the angle of inclination based on the contour lines of the mountain, and use the speeds based on the inclination in the location system. The simulation results show that the proposed system is more accurate than the existing location system.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.55 no.4
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• pp.151-155
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• 2006

HVAC transmission lines must be designed to satisfy environmental regulations. Therefore it is necessary to pre-evaluate environmental problems for transmission line designer using prediction program. In this study, environmental design software, TLCALC(Transmission Line CALCulation) for transmission lines was developed as a comprehensive window program. It has 6 modules that are audible noise, radio noise, television noise, magnetic field, electric field and conductor surface gradient. TLCALC solved a few problems in use of the existing foreign tools and took several advantages as follows; (1) It is a common tool that solves calculating limitations of foreign formulas, (2) It has wide application ranges and enhances accuracy of prediction. (3) It can be applied to almost transmission line configurations in Korea. (4) Experienced designers can get the results of calculation within about 15 minutes. Because the use of TLCALC is easy and practical, this program will be usefully applied to the environmental friendly design and construction of transmission lines. In the future, it is expected that public complaints and social environmental cost will be reduced by the use of TLCALC.