• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.1-6
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• 2007

A train is subject to a series of reliability-related tasks through its entire life cycle. Among them the reliability demonstration is required for commercial trains and the test is performed during the commissioning period or the early stage of the commercial operation. On the other hands various test are carried out for prototype trains and hence their operational condition is quit different from that of the commercial trains. One should take account of these differences when reliability assessment is needed for the prototype trains. This paper presents a procedure and an analysis method to evaluate reliability of a prototype train. Reliability data have been obtained through test runs of the HSR-350x and operational conditions for the KTX and HSR-350x have been analyzed to compare the reliability targets of the prototype train.

• 한국철도학회논문집
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• 제10권1호
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• pp.84-87
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• 2007

Auxiliary power supply developed by domestic technology has very important function that not only effect on main power converter & inverter system, traction motor and train control system which are related to performance of train, but also influence on power supply for HVAC(Heat, Ventilation, Air-conditioning) and lighting device which are related to comfort of passengers. This paper shows characteristic test results of auxiliary power supply such as working condition and performance, which is associated with velocity of train, operating mode and surrounding equipment, through test running. And, it propose a modification of design parameter for stabilizing operation and improving reliability.

• 센서학회지
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• 제16권1호
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• pp.68-76
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• 2007

In general, the braking system of a high speed train has an important role for the safety of the train. To stop safely the train at its pre-decided position, it is necessary to properly combine the various brakes. The train has adopted a combined electrical and mechanical (friction) braking systems. In order to design a good brake system, it is essential for designers to predict the brake performance. In this paper, the braking performance analysis program has been developed and verified by comparing the simulation results with the brake test results of HSR-350x; both results match very well. Also, the brake performances of high speed trains can be predicted by using this program under various conditions.

• 대한한의학회지
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• 제17권1호
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• pp.132-145
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• 1996

Ethyl ether fractions of Ferula Resina(EFR) and Lithospermi Radix(ELR) and hexane fraction of Salviae miltiorrhizae Radix(HSR) exerted an inhibitory effect on cell adhesion of A549 to extracelluar matrix most effectively in vitro cell adhesion assay. Thus, with above fractions for the evaluation of antitumor activity, T／C% was monitored in ICR bearing S-180 and for antimetastatic effect, pulmonary colonization assay, weight of organs, changes of WBC and platelet were studied. In pulmonary colonization assay incidence rate to control was 73 % 42 %, 14 % in ELR, HSR and EFR-treated groups repsectively. Gain of lung weight was significantly inhibited in all groups while spleen weight was significantly reduced only in SMR group, but no changes in kidney and liver as compared with control. Number of platelet was significantly increased in all groups to normal range as compared with thrombocytopenic contol. WBC was significantly reduced only in LR group. These results suggest that ethyl ether fraction of Ferula Resina has more effective antimetastatic activity.

• 한국수자원학회논문집
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• 제55권9호
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• pp.679-686
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• 2022

기후변화로 인한 돌발홍수의 발생 빈도 증가에 따라 X밴드 레이더를 이용한 보다 빠르고 정확한 강수 관측이 중요해지고 있다. 이에 환경부는 삼척과 울진에 2기의 이중편파 X밴드 레이더를 설치했다. 본 연구에서는 차폐 효과를 최소화하기 위해 설치된 2기의 각 레이더에서 2개의 고도각 관측을 수행한 뒤 얻어진 관측자료를 합성하여 정량강우를 산정하였다. 정량강우산정을 위해서 먼저 품질관리(QC) 기법을 적용한 뒤 비차등위상차(K_DP)를 산출하고 하이브리드 고도면 강수추정(HSR) 기법을 적용하였다. 본 연구에서는 산출된 K_DP를 이용해 R-K_DP 관계로 불리는 강우강도와 비차등위상차의 관계식을 적용하여 얻어지는 정량적 강우추정(QPE)의 정확도 상승을 위해 해당 관계식의 매개변수를 추정했다. 매개변수 추정을 위해서 여러 개의 강우량계와 레이더 자료를 바탕으로 경험적 방법을 개발하였다. 새로 제안된 매개변수를 이용한 관계식(R = 27.4K^0.81_DP)은 관측된 강수량에 대해 추정된 강수의 상관계수를 선행연구대비 1% 정도 약간 상승시켰다. 마찬가지로, 제곱평균 제곱근오차는 3.88 mm/hr에서 3.68 mm/hr로 감소했고 편차는 -1.72에서 -0.92로 상관계수보다 유의미하게 감소해 정확도가 상승했음을 보였다.

• 한국미생물·생명공학회지
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• 제11권1호
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• pp.75-79
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• 1983

Bocillus subtilis를 유전공학의 숙주 세포로서 이용하기 위해서는 우선 적당한 vector의 개발이 요구된다. Oxytetracycline의 항생물질을 생산하는 방사선균인 Streptomyces rimosuf IFO 0014로 부터 oxytetracycline-resistant plasmid DNA를 pH 9.0의 phenol-buffer system으로 추출하여 B.subtilis KPM 60[St $r^{R}$-mutant of RM 125 (leu A8, arg 15, hsr $M^{-}$, hsm $M^{-}$)] 1균주에 형질전환시키면서 이 plasmid DNA가 표현되게 하였다. 이때 형질전환의 조건으로서 KPM60을 growth medium에서 3시간, competence medium에서는 30분내지 60분간 그리고 DNA와는 20분동안 접촉시킴으로서 가장 높은 빈도로 형질전환이 일어났다. (대개 $10^{-4}$ 빈도 이상) 또 recipient cell의 competence화에는 oH7.5에서 그리고 형질전환에는 2$0^{\circ}C$에서 최적상태를 보였다.

• 대한토목학회논문집
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• 제26권1D호
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• pp.125-132
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• 2006

본 연구에서는 터널 내에서 자갈도상궤도와 콘크리트 슬래브궤도 등 궤도 형식에 따른 궤도와 차량의 진동특성을 규명하기 위해 자갈도상궤도와 콘크리트 슬래브궤도가 부설된 경부고속철도 터널 내에서 궤도와 KTX 차체의 진동가속도를 측정하여 주파수 해석을 수행하였으며, 이를 통해 궤도 형식에 따른 레일, 침목, 자갈도상, 슬래브 등 궤도 구성품과 터널 라이닝 등 궤도의 진동과 차체의 진동 특성을 분석하고, 그 상관관계를 분석하였다. 측정결과에 따르면 터널 내에서는 80Hz 대역의 주파수에서 레일과 차량의 진동이 크게 증가하였고, 특히 콘크리트 슬래브궤도가 부설된 터널에서 진동이 더욱 크게 나타났다. 연구결과에 의하면 레일 지지 스프링의 동적특성의 변화에 따라 차량을 포함한 전체 시스템의 진동특성이 달라질 수 있으며, 따라서 콘크리트 슬래브궤도의 지지강성을 결정하는 데 있어서 시스템 측면에서 차량의 진동과의 상호관계를 고려해야 한다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 춘계학술대회 논문집
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• pp.140-144
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• 2011

As a result of that the domestic railway technology has been progressed as times go by, the 1st and the 2nd steps for Gyeongbu HSR at the speed of more than 300km/h, were completed and Honam HSR - its operational speed is 350km/h - is under construction. Additionally, As a part of the expressization project for general lines, the Seoul-Chuncheon route at the speed of more than 180[km/h] is under construction and the Jeolla route is under design. At present, 11 countries (e.g. France, Germany, Belgium, Italy, the Netherlands, Spain, England, Japan, China and Taiwan) including Korea have high speed railways operated at the speed of more than 300[km/h]. As shown in the above, the domestic railway has high speed trains as good as those of countries outside Korea, but the schedule speed, which is calculated by dividing distance to destination by time, is lower than that of overseas trains. For overseas railway, the ratio of schedule speed to the highest speed is above 65%, while that of domestic railways is over 50%. It shows a significant difference between them. It is expected that the schedule speed improvement will increase the number of train operation and line capacities than now, so it shall achieve smooth transportation flow and improve the passengers' satisfaction. In this paper we describe the necessity for the improvement of schedule speed, by analyzing foreign cases related to the improvement of schedule speed in order to satisfy the increasing traffic demand.

• 한국항만학회지
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• 제11권2호
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• pp.305-320
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• 1997

The objective of this paper is to analysis & forecast on the change in spatial structures of southeast region by development of the Seoul-Pusan high-speed Rail. To measure the spatial structures, it was used the method of mean center and standard distance among of centrographic measures as analytical tools. The changes of spatial structures patten over time and space in the southeast region were surveyed using population and employment data of 57 zones. And also, to forecast the spatial structures of the southeast region after opening of the Seoul-Pusan high-speed rail, it was supposed three(3) scenarios which designed using influential area with centering around of the proposed high-speed rail stations. Therefore, the results of this research indicate as follows; 1) The spatial structures of population is showed a trend of continual concentration toward Ulsan city area, and also the spatial structures of employment is showed a trend of continual dispersion over time. 2) The forecast of three93) scenarios supposed after opening of the Seoul-Pusan high-speed rail in 2006 show a change of the spatial structures with both population concentration and employment dispersion. In the meantime, the rapid increase of population and wide dispersion of employment is reform with centering around HSR stations which builted in the southeast region after opening of high-speed rail. 3) It shall furnish valuable data to establish the development strategy of urban and local region, and also forecast the change of spatial structures about population and employment in influential area which passed on high-speed rail line & stations by method of mean center and standard distance among of centrographic measures as analytical tools.

• Journal of Electrical Engineering and Technology
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• 제11권1호
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• pp.257-264
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• 2016

In this paper, new electric railway feeding system which has active transformer is modeled for evaluating the steady state analysis using PSCAD/EMTDC. Equivalent models including power supply, feeder, train and transformers are proposed for simplifying the model of the feeding system in high speed electric railway. In case study, simulation results applied to proposed model are compared with the conventional and new systems through the catenary voltage, three-phase voltage of PCC (Point of Common Coupling) and the efficiency of regenerative braking energy.