• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 추계학술대회 논문집
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• pp.818-823
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• 2004

In case of the Korea Railroad, when we would decide the track structure, it has been introduced the whole track structure system based on only the foreign application cases and data offered by manufacturers without the process of the objective performance verification. The value of property for track materials, derived from the calculation of track structure, was hard to perform the objective performance evaluation among track structure systems because each manufacturer adopted the different test method and standard. To solve the above-mentioned problem, it should suggest the technical and objective evaluation method about the performance of track materials and meet with the standard of High Speed railroad and international railroad through the establishment and revision of performance standard. In the objective and technical respects, it will be a major role to decide the track structure. In this paper, I would like to summarize the case which was improved the problem of test method and standard exposed from the performance verification of Rail Fastening System among the track structure systems of High speed railroad.

• Steel and Composite Structures
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• 제44권4호
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• pp.473-488
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• 2022

A high-speed railway (HSR) bridge may undergo long-term deformation due to the degradation of material stiffness, or foundation settlement during its service cycle. In this study, an analytical model is set up to evaluate the influence of this long-term vertical bridge deformation on the track geometry. By analyzing the structural characteristics of the HSR track-bridge system, the energy variational principle is applied to build the energy functionals for major components of the track-bridge system. By further taking into account the interlayer's force balancing requirements, the mapping relationship between the deformation of the track and the one of the bridge is established. In order to consider the different behaviors of the interlayers in compression and tension, an iterative method is introduced to update the mapping relationship. As for the validation of the proposed mapping model, a finite element model is created to compare the numerical results with the analytical results, which show a good agreement. Thereafter, the effects of the interlayer's different properties of tension and compression on the mapping deformations are further evaluated and discussed.

• 대한전기학회논문지
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• 제41권4호
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• pp.411-421
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• 1992

In the conventional track while scan (TWS) system, there are two major functions to be performed : detection and tracking. These two functions are normally designed and optimised independently. So TWS algorithm ignores the available decision features that can help in resolving the plot-to-track association ambiguity. Therefore conventional TWS system cna't track the targets in a densed multi-target environment. This paper presents a new TWS algorithm for multi-target track to solve the existing TWS system problem in clutter environment. The algorithm proposed in this paper is derived by modifying the part of joint probabilistic data association (JPDA) algotithm to get the one to one correspondence instead of multiple correspondence and combined with maneuvering detection logic so that it could also track the low maneuvering targets. Simulations to confirm the performance are done in crossing, parallel and maneuvering target. The proposed algorithm was successfully tracking targets above target situations.

• 한국융합학회논문지
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• 제11권12호
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• pp.177-186
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• 2020

전 세계적으로 창업 및 기업가정신 함양교육의 중요성이 강조되는 가운데 국내 대학에서 관련 교과목을 개설하는 수가 증가하고 있다. 하지만 교육 설계방법 제시 등에 부족함이 있어 본 연구에서는 국내외 창업교육 현황을 분석하고, 그 중 K대학에 적합한 창업교육 활성화 사례를 발굴하여 다양한 교육기관에서 적용 가능한 이슈를 발굴하기 위한 목적으로 본 연구를 진행하게 되었다. 이를 위해 본 연구에서는 창업교육 선행연구 및 문헌을 고찰하였고, 국내외 대학을 중심으로 창업교육 현황 및 사례를 분석하였다. 또한 환경 분석, 교수자, 현장전문가, 교육수요자들을 대상으로 서면 및 대면 인터뷰, 자문회의를 실시하여 창업교육에서의 주요 이슈를 발굴하였다. 그 결과, 기업가정신 및 창업교육에서는 실제 창업을 위한 실행 방법론, 기업가적 인재 양성, 그리고 사회적 문제를 해결하고 가치를 창출하는 등의 교육내용이 제시되어야 함을 발견하였다. 이를 토대로 본 연구에서는 창업교육(전공)에서 벤처창업, 기업가정신융합, 소셜 벤처 활성화와 같은 3대 트랙을 도출하였고, 트랙별 전공역량 및 학습 목표 등을 제시하였다.

• 대한기계학회논문집A
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• 제40권8호
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• pp.743-750
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• 2016

트랙롤러는 건설기계의 무한궤도 메카니즘에 장착되어 차량에 가해지는 하중을 지지하는 역할을 하는 핵심부품이다. 건설기계의 작업환경은 매우 가혹하며, 이러한 환경에 노출된 트랙롤러는 반복되는 주행충격으로 누유 및 파손 등의 고장을 발생하게 된다. 트랙롤러의 고장이 발생하면 건설기계 차량의 주행에 큰 영향을 미치게 되므로, 트랙롤러 생산업체에서는 자체시험을 수행하여 제품의 성능을 확인하고 있다. 하지만 현재 트랙롤러 대부분의 시험은 수직하중을 가한 상태의 시험만을 수행하고 있다. 이는 트랙롤러가 장착된 건설기계의 선회주행시 발생되고 있는 수평방향에서 가해지는 하중을 고려하지 않은 시험평가로 실제 주행조건을 재현하지 못하는 문제점이 있다. 따라서 본 논문에서는 트랙롤러에 가해지는 수직 및 수평방향 하중 크기와 이를 고려한 시험조건을 정립하였다. 또한 수평방향 하중이 트랙롤러의 고장에 미치는 영향에 대한 해석과 시험의 결과를 제시하였다.

• 한국지반공학회논문집
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• 제24권11호
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• pp.25-34
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• 2008

본 연구에서는 고속철도 궤도의 종류에 따른 허용침하량 분포 특성을 분석하기 위하여, 기존 경부 고속철도에 사용되었던 자갈도상 궤도와 시공예정인 콘크리트 궤도의 대표단면 및 지반 물성치를 바탕으로 철도 운행 시 레일상부에서 열차하중에 의해 발생되는 침하량을 3차원수치해석을 통해 분석하였다. 특히 콘크리트궤도의 경우에는 원지반의 물성 변화에 따른 침하량 결과를 토대로 말뚝지지전면기초(pile raft foundation) 보강 시 침하 감소 효과를 분석 정리하였다. 본 연구결과, 원지반이 점성토에서는 콘크리트 궤도와 자갈도상 궤도의 사용에 따라 침하량의 차이가 컸으나, 사질토 지반의 경우는 궤도별 침하량 차이가 상대적으로 작게 나타났다. 또한 콘크리트 궤도 단면의 침하량 저감을 위한 말뚝 전면기초 시공의 경우, 무보강 단면의 해석결과보다 지지력이 확보되어 침하량 감소가 나타났으며, 말뚝의 길이가 증가될수록 침하량 감소 효과가 뚜렷하게 나타났다. 하중형태의 경우는 기존 설계에 사용되었던 객차 하중에 의한 침하량보다 기관차 하중에 의한 침하량이 더 크게 발생하여 기관차 하중을 통한 궤도 설계를 할 경우 좀 더 안전측 설계가 가능함을 확인할 수 있었다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 추계학술대회 논문집
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• pp.1077-1092
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• 2007

The structural analysis model for estimate of load carrying capacity of railway bridge on service line is important to determine safety of bridges in service, we need to take response of bridge exactly, applying analysis model similar to the real railway bridge most. Track structure which is to distribute loads and decrease vibrations occurred from running train is constructed on the railway bridges. And it is important factor which should be considered to understand exact dynamic and static responses of bridge. But track structure is currently classified as a none structural members in the structural analysis model for estimating load carrying capacity of railway bridge and not considered in analysis model. That's the reason it is difficult to understand exact behavior of bridges. Therefore, the major objective of this study is to develop an analytical track-bridge model which is similar to real railway bridges considering track structure for safety assessment of railway bridge on service line to be effectively done.

• 한국방재학회:학술대회논문집
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• 한국방재학회 2008년도 정기총회 및 학술발표대회
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• pp.299-302
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• 2008

The behavior of continuous welded rail tracks is directly affected by the following various parameters: rail size; track curvature; neutral temperature; misalignment; and ballast resistance. Most of these parameters are having the nature of random variables. Therefore, uncertainties exist in the buckling safety assessments. The evaluation of the buckling safety and the maintenance strategy based on the deterministic analysis are very inefficient since the value of deterministic parameters are selected in worst track condition. In this study, the probabilistic approach method were investigated considering the probabilistic distribution of major parameters such as the neutral temperature of rail and the ballast resistance.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2005년도 춘계 학술발표회 논문집
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• pp.145-152
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• 2005

Landslides triggered by rainfall produces severe effects on the serviceability and stability of railway operation. Since small amount of soil mass slipped on the rail can cause derailment which will cause severe danger on the human and trains, slope stability problem is one of the major concerns on the operation of railway. In this study we investigate the some of characteristics of rainfall driven landslide near railroad. A total of 23 sites were visited. From the results four types of landslides based upon the morphology of the slipped slope triggered by rainfall were classified. From the analysis dimensions of slopes (height, length and slope) do not show particular correlation with the types of landslides. In addition, morphological and geological features of slope influence on the occurrence of different types of landslides.

• 동력기계공학회지
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• 제18권5호
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• pp.94-99
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• 2014

In this study, AISI M2 powder was selected primarily through various literature in order to improve the hardness and wear resistance. Among the laser metal deposition parameters, laser power was studied to improve the deposition efficiency in the laser metal deposition using a diode pumped disk laser. SKD61 hot work steel plate and AISI M2 powder were used as a substrate and powder for laser metal deposition, respectively. Fixed parameters are CTWD, focal position, travel speed, powder feed rate, etc. Experiments for the laser metal deposition were carried out by changing laser power. Through optical micrographs analysis of cross-section in LMD track, effect of the major parameters were predicted by track pitch. As the track pitch increased, so the reheated zone width, the overlap width and the minimum thickness was decreased. The hardness was decreased in the HAZ area, the hardness in the reheated HAZ area was decreased significantly and regularly in particular.