• Proceedings of the KSR Conference
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• 2009.05a
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• pp.1859-1870
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• 2009

Suin line is expected to be opened completely in 2015 by three stages. And the line between Suwon and Incheon(54.0km) is under construction to supply the users of southwestern area transportation convenience. The route of Suin line will be constructed to share partly with Ansan line and connect directly with Bundang line to the east and Kyeongin line to the west. That's why a lot of difficulty in train and rolling stock operation IS expected. This paper proposes an alternative plan of train operation when the line is opened partly and completely and makes an optimally alternative plan through the analyses of transportation demand, the change of human resources of operation sector according to train operation plan by an alternative proposal and operation cost.

• Bulletin of the Korean Space Science Society
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• 2009.10a
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• pp.35.1-35.1
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• 2009

We have established a database of galaxy spectral line strengths for the SDSS database using an improved line measuring method. Our work includes the entire SDSS DR7 galaxies within redshift of 0.2. The absorption line strengths measured by the SDSS pipeline are seriously contaminated by emission filling. Our code, GANDALF (gas and absorption line fitting code) performs more accurate measurements by effectively separating emission lines from absorption lines. A significant improvement has also been made on the velocity dispersion measurement, more notably in late-type galaxies. We have also identified a number of broad line region galaxies which were misclassified as normal galaxies by the SDSS pipeline. We developed an effective method measuring their line strengths. The database will be provided with new parameters that are indicative of the line strength measurement quality. In addition, we made galaxy templates for the Hubble sequence. The database will be useful for many fields of galaxy studies including star formation and AGN activities.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.37 no.4
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• pp.98-105
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• 2014

According to a simple survey on the current status of the assembly line design, it was found that trial and error methods on the basis of experiences have been used mainly in domestic manufacturing industries, even though there exist a lot of excellent line balancing studies. It seems that more practical researches should be carried out to develop user-oriented line balancing tools especially for small and medium-sized enterprises. This study presents a design of the line balancing tool which can support the line balancing tasks of nonspecialists. The proposed design tool is composed of three major modules: pre-process, line balancing, and post-process. In particular, pre-process and post-process are newly proposed to increase its ease of use. We applied the proposed design to a test problem and test result showed that our practical method may contribute to enhance the efficiency of production operations management.

• Proceedings of the KSR Conference
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• 1998.05a
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• pp.184-193
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• 1998

The existence of railroad line gives many influences in various kinds of aspects. To minimize negative influences is necessary to line's improvement, but appropriate methodology doesn't show until now. In this study, Fuzzy Integration Method(FIM) are employed in an effort to give ranking for railroad line's improvement in Seoul. The FIM is designed to generalize a various influences, appeared on account of existence of railroad line. Empirical analysis is performed for railroad line in distance of 83.5㎞ in Seoul. The total lines are divided in 51 sections, and there are selected a 11 evaluation index to reflect influences. Through a questionnaire survey about residents, operator and administrator, important degree of evaluation items are decided, reveal ins the interests of related groups. Then, evaluation values are calculated wi th practical survey results about each sections. The results of evaluation reveal that the higher ranking of improvement from FIM concentrates the Kyeng-Ul Line and Kyeng-Won line because these lines appear a many public discontents and negative influences such as noise and demolition of living environment.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.11 no.5
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• pp.738-747
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• 2000

In this paper it is shown that the meander line at the low frequency can be thought as the single transmission line whose characteristic impedance is approximately equal to that without coupling. But the length is contracted from that without coupling. The approximate contraction ratio is derived for weak coupling and is compared with the circuit simulation results and the EM simulation results. The formula are in good agreement with the simulation results in weak coupling.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.5 no.6
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• pp.1-6
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• 1982

The objective of this thesis to Provide a better insight into the effect of the amount of in-process storage has on the efficiency of production line with variable operation times. It is assumed that the material enters the line at the first work station and is then processed progressively through the line until it exits at the last work station, a finite amount of in-process storage is provided before all but the first work station of the line and the operation time of the work stations are statistically independent and follow exponential distribution. Under the above assumption, optimum allocation model is developed and following two approaches are used : 1) Given the available storage capacity, optimum allocation which minimizes the number of items in the line. 2) Given the available storage capacity, optimum allocation which. maximizes the utilization factor of the line. In a balanced three stage line, the production line efficiency is maximized under both categories when the second in-process storage is larger than the first.

• Proceedings of the Safety Management and Science Conference
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• 2004.11a
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• pp.197-203
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• 2004

Railway system is consisted of various resources such as rail-line, signal, and railcar. It is necessary to efficiently utilize these limited and expensive resources as much as possible up to given line capacity. So far, we treat the line capacity as the criteria for evaluating investment alternatives or for restricting train frequencies, and this criteria is calculated statical and experimental numerical formula. But, line capacity has special attribute that changes dynamically according to operational conditions, so there is a need of new line capacity estimation system. In this paper, we present an improved systematic line capacity model. The proposed model has three main components ; TPS(lain performance simulator), PES(parameter evaluation simulator), LCS(line capacity simulator). The concept of each sub-component is described, including the evaluation method of capacity parameters. And capacity parameter evaluation and estimation results using sample line section data are presented.

• Journal of the Korean Society for Railway
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• v.14 no.6
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• pp.569-574
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• 2011

An effective approach to distributing budget to railway line facility improvement is to use investment priorities of railway line segments based on their deterioration. In this paper we present an evaluation method of railway line segment deterioration which can be used to distribute limited budget. Railway line facilities include rail track, railroad switch, subgrade, bridge, tunnel. These facilities and line shape can affect line segment deterioration. Deterioration evaluation method we present is a weighted sum of each component deterioration scores. The component weight can be obtained from experts using analytic hierarchy process.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.55 no.6
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• pp.279-285
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• 2006

Power line communication channels are very complicated and models for communication channels vary with the types of electrical equipment, devices and load fluctuations. So, modeling and analysis of power line channels for implementation of power line communication systems is a very important process. Power line channel modeling and simulation are performed based on power system transient simulation models and power system CAD tools to create precise and accurate models. In this paper, a channel modeling and simulation method is proposed for power line communication systems using PSCAD/EMTDC, in which a PN 63 sequence code generator is applied for impulse response of the power line channel in the simulation model.

• Journal of Ocean Engineering and Technology
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• v.14 no.2
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• pp.121-127
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• 2000

In this paper a new technique of inverse fairing problem for ship hull is proposed. Recently Lu solved the inverse fairing problem for automobile's body that was made by one surface element. In this system however hull surface is constructed by Gregory's composite surface interpolation method. So reflection line at boundary position is used as a tool of solving inverse problem in surface fairing. But the results are not good. The new concepts of Normal vector line and Constrained reflection line are introduced as an alternative tool. Energy minimization method for Normal Vector Line curve net and the inverse method for Constrained Reflection Line by using optimization technique are examined And the final lines from this proposed surface fairing method shows good fairness.