• 한국측량학회:학술대회논문집
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• 한국측량학회 2004년도 춘계학술발표회논문집
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• pp.477-482
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• 2004

Due to the traffic congestion of the city and public transportation-oriented policies, public transportation is receiving more attention and being used increasingly However, relatively less research on the design and distribution of public transportation network and limitations in quantitative approaches have made implementation and operation practically difficult. Over- or under-supply of transportation routes caused unbalanced connectivity among areas and differences in time, expenses and metal burden of users. On the other hand, the Space Syntax theory, designed to calculate the connectivity of urban or architectural space, helps generate quantitative connectivity of whole space simply based on the spacial structure. This study modified the original Space Syntax algorithm to fit the public transportation problem and showed how it is appied to a network by creating an artificial network using the GIS.

• 한국재료학회지
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• 제14권1호
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• pp.1-8
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• 2004

Laser weldability of aluminized steels for deep drawing application has been investigated. Test coupons for Nd:YAG laser welding and $CO_2$ laser welding were prepared trom the commercial steels. According to the test results, total penetration and back bead width of aluminized steels were sensitive to the welding conditions. Bead width at the half thickness of the overlap joint, however, was rather constant. Laser weldability of aluminized steels was superior to that of zinc coated steel. Weld microstructure revealed that overlap zone adjacent to the fusion line was filled with coated materials, which was thought to be desirable to protect weld from crevice corrosion. The aluminum coated materials was also found in the weld metal. Practically no spattering was observed in the laser welding of aluminized steels even when the welding was performed without joint gap. In the welding of zinc coated steel, however, spattering was so severe that it was difficult to get the acceptable weld. Bead quality of aluminized steel laser weld was smooth and stable.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2000년도 추계 학술발표회 논문집 Proceedings of EESK Conference-Fall 2000
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• pp.372-380
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• 2000

Seismic forces for member design of bridges may be determined by modifying elastic member forces induced by design earthquakes using appropriate response modification factors according to national design code of bridges. Modeling of soil/foundation system is one of the critical parameter in the process of elastic seismic analysis of bridge system which greatly affects on the analysis results. In this paper, a simplified modelling procedure of soil/foundation system which gives practically reasonable results is presented and its applicability has been validated through example bridge. Based on the results, it has been shown that the procedure is acceptable in modelling soil/foundation system for practical seismic analysis of bridges.

• 농촌지도와개발
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• 제5권1호
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• pp.123-132
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• 1998

After late 1980s, new approach is needed for satisfying with people's various information needs and better quality of life on Korean extension service. The United States began modern extension service at first and has influenced many countries. Cooperative extension service has helped people practically by searching into people's problem and developing various channel to diffuse. Cooperative extension adopts changes in extension service environment and puts them to use. Based on the extension service in the United States, following recommendations were suggested; 1) carrying out extension service to meet the changing needs of people, 2) strengthening the extension function of agricultural Colleges, 3) review of cooperative agricultural research and extension, 4) developing programs and management, 5) accumulation agricultural information and utilizing them.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 하계학술대회 논문집 C
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• pp.1229-1231
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• 1995

XLPE cable, which has excellent electrical and thermal performance, has been widely used for HV transmission & distribution lines. The most important thing to produce the cable products having good performance is to set the optimal operating conditions of cable machinery. Because it is very difficult to measure the temperature of cable under curing process practically, it is necessary to evaluate the cable temperature by using the method to simulate real conditions numerically. In this work, We investigate the basic theory on transient heat transfer between curing tube and cable for making a numerical simulation program using computer. In this program, a differential equation is approximated by a infinite differential method and a few assumptions are used to simplify the model and minimize the calculation time of program.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 추계학술대회 논문집 전기물성,응용부문
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• pp.205-207
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• 2001

This study is characteristic analysis to optimize triggering of a high-power trigatron by FEM which is used to analyse electric field distribution in the trigatron. Triggering characteristics of a trigatron depends on arrangement of voltage polarity applied on electrodes and configuration of electrodes. This study is the preliminary stage for an experiment and make it possible to experiment effectively by finding optimal triggering characteristics though 3-dimensional node-based FEM which can practically model the complex structured electrode system.

• Bulletin of the Korean Chemical Society
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• 제33권5호
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• pp.1536-1540
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• 2012

Chicken primordial germ cells (cPGCs) are founder germ cells in embryonic stage of development that eventually give rise to sperms or oocytes. Currently cPGCs are only known cells enabling germline transmission in chicken and their cultivation protocols were recently established. Although genome modifications of chickens are now theoretically possible using cPGCs, there are still several hurdles to overcome to practically use cPGCs as mediators for chicken transgenesis. First, efficiency of gene delivery into cPGCs remains low with current methods. Second, there aregene silencing mechanisms against the expression of foreign genes in cPGCs. In this study, we successfully increased the efficiency of gene delivery in cPGCs by taking advantage of the TTAA-specific $piggybac$ transposon system. Moreover, a pipette-type electroporator significantly enhanced transfection efficiency up to 5-fold compared withcuvette-type methods. Taken together, the technological advances in our study will provide practical benefits for the application to fulfill genetic modifications of chicken genome.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 춘계학술대회 논문집
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• pp.435-441
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• 2011

Track geometry changes by traffic loads. The bigger the changes are, the worse the riding comfort and running stability of train. This is so-called track irregularity and is the most important quality parameters of ballasted track. To objectively assess track irregularity, track geometry should be able to be measured. Practically, railway companies in Korea use various track recording equipments to measure track irregularity. But this various equipments output different data due to their geometrical structure even measured at same location. In this report, the correlation of various track recording data used in Korea was reviewed.

• Industrial Engineering and Management Systems
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• 제13권3호
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• pp.319-329
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• 2014

Supply chain management is a subject that has an increasing importance due to the developments in the global markets and technology. In this paper, a fuzzy multi-objective linear programming model is developed for the supply chain of a company dealing with procurement, storage, filling, and distribution of liquefied petroleum gas (LPG) in Turkey. The model intends to determine the quantities of LPG to be procured, stored, filled to cylinders, and transported between the plants and demand centers for six planning periods. In this model, which aims to minimize both total costs (sum of procurement, storage, filling, and transportation costs) and total transportation distances, demand quantities of the main demand centers and decision maker's aspiration levels about objective functions are fuzzy. After comparing the results obtained from the model with those obtained by using different methods, it is concluded that the proposed method can be applied to real world problems practically and it may be used in this type of problems in order to generate an efficient solution.

• 한국시스템다이내믹스연구
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• 제15권1호
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• pp.5-27
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• 2014

The purpose of this study is to analyze the school autonomy policy based on the system thinking perspective using causal loop diagrams. School autonomy was the main educational policy concerning school domain during the last government and was the instrument for school-based management, but it was not implemented effectively in site. The school autonomy policy practically disappeared as an explicit policy agenda in the current government. This study displays causal loop diagrams about the policy's logic and contents of school autonomy, in terms of curriculum, human resource management, and a supportive system. The causal loop diagrams depicting the implementation of the school autonomy policy are suggested concerning excessive enforcement and the confirmative mechanism for policy implementation. The conclusion provides some research implications and future directions.