• 한국소음진동공학회논문집
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• 제20권8호
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• pp.703-709
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• 2010

An analysis tool for predicting transmission loss in high speed trains based on combined use of the statistical energy analysis and the finite element methods has been proposed. The analysis utilizes a commercially available numerical solver VA ONE with imbedded NASTRAN module. The proposed analysis tool is first verified by comparing numerically predicted transmission loss of a light rail transport(LRT) structure with experimental results. The comparison shows that the numerically predicted transmission loss is similar to the experimental data. The analysis tool is then applied to the prediction of transmission loss in the high speed train(HST) currently under development. Various sub-structures such as the floor, side panel and ceiling have been numerically analyzed to predict their transmission losses. The results obtained here can be used as input data for predicting the interior noise level of the HST at design stage.

• 한국소음진동공학회논문집
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• 제25권9호
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• pp.620-627
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• 2015

Long continuous bridge deck can become contracted considerably as temperature drops, which can lead to a large expansion of sleeper span at the end of it. Since this huge sleeper span then can cause problems both with safety of train operation and structural stability of tracks, it is necessary to take the issue into consideration systematically in the designing process of the bridge. In this paper, an evaluation process through the analysis of train-track interaction was presented which can basically review the effects of the expansion of sleeper span at the end of long continuous bridge deck on the safety of the train and the structural stability of the track. The analyses of the interaction between the light rail train and tracks were carried out targeting the sleeper span as a main parameter. The safety of train operation and structural stability of tracks in a light rail system due to the expansion of the sleeper span were evaluated by comparing the numerical results with the related criteria.

• 한국철도학회논문집
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• 제15권5호
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• pp.442-446
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• 2012

본 논문은 SE & SW Infra를 활용한 실용적인 시스템엔지니어링관리계획서(SEMP) 템플릿 개발에 관한 연구이다. SEMP는 시스템엔지니어링 업무활동 관리를 위한 최상위 수준의 계획서로서 경량전철 사업 수행 시 국내 실정에 맞도록 개발 하였다. 경량전철사업 수행 시 생성 되는 SEMP를 효과적이고 효율적으로 관리 및 개발하기 위하여 SE & SW 연계 Infra를 구축하였다. 본 논문을 통해서 전산기반의 SE & SW Infra 도구간 통합하는 것을 사례로 제시함으로써 향후 인력, 비용, 일정을 줄일 수 있을 것이다.

• 한국안전학회지
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• 제27권3호
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• pp.117-124
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• 2012

There have been recently introduced new types of urban metro vehicles called LRT (Light Rail Transit) running on elevated guideway such as Uijeongbu VAL(which stands for V$\acute{e}$hicule Automatique L$\acute{e}$ger: Automatic Light Rail Vehicle) system, Yong-In LIM(Linear Induction Motor) system, Incheon international airport MAGLEV(Magnetic Levitated Vehicle) system and Daegu monorail system. Most of accidents by the vehicles are bound to happen on elevated guideway. Therefore, it is of vital importance to analyze hazards related to vehicles running on elevated guideway and study emergency evacuation scenarios applicable in case of accidents on elevated guideway so as to secure the safety of the new types of urban metro vehicles. In this study, FTA(Fault Tree Analysis) model was developed to identify all possible hazards, and all possible evacuation scenarios were studied. It was also confirmed that each hazard can be corresponded to one or more evacuation scenarios. This result shows that passengers can be evacuated according to one of the scenarios identified in this study in case of an accident of "Train Stranded on Elevated Guideway".

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.1183-1184
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• 2007

Light Rail Transit (LRT) is optimized vehicle system for complex urban circumstance. LRT systems have many merits such as improved accuracy and safety. There are many LRT systems such as monorail, tram, automated guideway transit, linear induction motor propulsion and so on. These systems have been operated in Japan and other advanced countries. In Korea, local government has many projects to apply the advanced LRT system. But there are no standards regulation, performance test regulation and construction regulation for monorail system, linear induction motor system and tram in Korea. We expect that standardization brings economical construction and safety. The linear induction motor system has been usually applied to subway in Japan and ART(Advanced Rapid Transit) in Canada. In Korea, the linear induction motor system has been adopted for Yong-In LRT and currently under construction. This paper presents signalling system and TCMS(train control and monitoring system) of linear induction motor system.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.915-923
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• 2011

Our country is promoting the introduction of new means of transportation due to insufficient supply according to the existing demand of road traffic. Among them, manless light railroad transit is settled down as the most definite alternative. However, new traffic systems such as manless light railroad have certain difference between characteristics of hardware and software and subway system. Therefore, there will be many differences compared to the existing contingency system when accidents occur. Railway management organization has to establish railway contingency plan and acquire permission from the minister of the Ministry of Land, Transport, and Maritime Affairs. However, as commercial transportation is available, a new traffic system also should establish contingency plan. Therefore, the establishment of systematic contingency plan is suggested in order to analyze characteristics of manless light railroad in the beginning of introduction and to make contingency response available.

• 한국자동차공학회논문집
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• 제16권5호
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• pp.147-156
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• 2008

As the management of fuel efficiency becomes globally reinforced in attempts to find an environment-friendly vehicle that will operate against global warming, the interest in and the demand for the type of vehicle with a high-efficiency diesel engine using light oil. However, it also emits a greater amount of PM (particulate matter) and NOx than emissions from vehicles using other types of fuels. Therefore, the DME (Dimethyl Ether), an oxygen containing fuel draws attention as an alternative fuel for light oil that can be used for diesel engines since it generates very little smoke. But to develop and compare performance of an electric controlled common-rail DME engine, engine tests requires optimized injection conditions at required engine RPM and engine torque. These injection conditions cannot be set freely and the data configuration through the experimentally repeated application requires much time as well as a significant amount of errors and effort. The object of this study is to configure the basic injection map using the results of the DME engine experiments performed so far. For this, in this study, the functionalization of the required equations were performed along with the basic review of the factors that had influence on the data map. Through this, the information on the injection pressure, injection amount, injection duration, injection timing, etc. under certain operation condition could be obtained.

• 대한방사선치료학회지
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• 제28권1호
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• pp.77-86
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• 2016

목 적 : 방사선 치료 시 Carbon Fiber Couch에 의한 감약이 일어난다. 본 연구에서는 치료계획 시스템(Treatment Planning System: TPS)을 이용해 Varian사의 Varian Standard Couch(VSC)를 모델링 하여 유용성을 평가하고자 한다. 대상 및 방법 : 선형가속기(Clinac IX, VARIAN, USA)의 CBCT(Cone Beam Computed Tomography)를 이용하여 VSC의3가지 조건Side Rail Out Grid(SROG), Side Rail InGrid(SRIG), Side Rail In OutSpine Down Bar(SRIOS)로 스캔 한 후 TPS(Pinnacle9.8, Philips, USA)로 전송하여 Side Rail, Side Bar Upper, Side Bar Lower, Spine Down Bar를 Automatic Contouring하여 모델링 하였다. 전산화 단층촬영(Light Speed RT 16, GE, USA)으로 스캔 한 Cheese Phantom(Middelton, USA) 을 TPS로 전송하여 모델링 한 VSC를 적용하였다. 측정 점은 Cheese Phantom내의 Ion Chamber(A1SL, Standard imaging, USA)이며 Isocenter에 위치시켜 Energy(4, 10MV), Gantry Angle($5^{\circ}$간격으로 측정), Field Size($3{\times}3cm^2$, $10{\times}10cm^2$)에 변화를 주어 각 100MU의 동일한 조건에서 얻은 계산 값과 측정값을 비교하였으며 Side Bar Upper에 의한 감약을 비교하기 위해 SRIG조건에서 $127^{\circ}$를 포함하였다. 결 과 : CBCT를 이용해 얻은 VSC의 Density를 TPS에서 확인한 결과 $0.9g/cm^3$였으며 Spine Down Bar의 경우 $0.7g/cm^3$로 나타났다.Side Rail, Side Bar Upper, Side Bar Lower, Spine Down Bar에서 각 17.49%, 16.49%, 8.54%, 7.59%의 감약이 일어났으며모델링의 정확성을 평가하기 위해 계산 값과 측정값을 비교한 결과 평균 1.13%의 오차가 보였으며 Spine Down Bar를 지나는 $170^{\circ}beam$에서 1.98%로 가장 많은오차를 보였다. 결 론 : TPS이용해 모델링 한 VSC의 유용성을 평가하기 위해계산 값과 측정값을 비교한 결과 최대1.98%의 오차를 보였다. 방사선 치료계획 시 VSC를 모델링 하여 적용한다면선량에 대한 예측이 가능해 더욱 정확한 치료를 하는데 도움이 될 것으로 사료된다.

• 한국자동차공학회논문집
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• 제17권2호
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• pp.104-111
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• 2009

In this paper, optimization for frontal crashworthiness is carried out for the weight reduction design of an auto-body member with the advanced high strength steels(AHSS) such as 780TRIP and 780DP. The frontal crashworthiness is evaluated in order to optimize thicknesses for the front rail member of the ULSAB-AVC, Thicknesses of the front rail member with AHSS are optimized by comparison of crushing distance, absorbed energy and the deceleration for the auto-body with the response surface methodology. The results demonstrate that the crashworhiness of the front rail member with the optimum thicknesses of the AHSS is similar to analysis results obtained from the ULSAB-AVC project. The results also show that the weight reduction design is performed by substituting the AHSS for conventional structural steels such as 440E in the auto-body members.

• 한국분무공학회지
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• 제14권2호
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• pp.71-76
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• 2009

The aim of this investigation is to study the effect of the high injection pressure on the dimethyl ether (DME) spray characteristics injected through a common-rail diesel injector under various ambient pressures. In order to investigate the effect of the injection pressure and ambient condition, the common-rail injection system with two high pressure pumps and high pressure chamber pressurized up to 40 bar were used, respectively. Spray images of DME fuel obtained from a visualization system composed of high speed camera and two metal halide lamps as the light source. From the obtained images, the spray behaviors such as a spray development process, spray tip penetration, spray width, and spray cone angle were measured for analyzing the DME spray characteristics under various experimental conditions. It was found that the spray development slowed as the ambient pressure increased and spray tip penetration at injection pressure of 90 MPa is longer than that at 50 MPa. In addition, the spray width at the end stage of injection decreased under the atmospheric conditions due to the evaporation property of DME fuel, and DME spray shows narrow spray cone angle according to the injection pressure increased.