• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2018년도 춘계학술대회
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• pp.558-559
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• 2018

하네스 배선은 자동차를 구동시키는데 필요한 전기적 신호를 전달하는 매개체 역할을 하며 자동차 성능에 많은 영향을 받는다. 기존 하네스 제품에서는 0과 1을 체크하는 기능으로 운영되고 있으며, 전선 조립 공정에서의 검사를 진행 시 하네스 작업자의 눈에 의한 외부 검사와 회로 검사기를 공정에서 사용하고 있다. 따라서, 검사기에서는 합격이 되어도, 완성 자동차에서는 사용 중에 불량이 발생 되고 있다. 이와 같은 불량을 개선하고자 사용되는, FPGA 기술을 적용한 ADC 정밀 하네스 검사를 통해 선과 선이 미세하게 끊어진 상태를 측정할 수 있는 설계와 시뮬레이션 결과를 제시한다.

• 한국해양공학회지
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• 제26권1호
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• pp.64-69
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• 2012

Dissimilar friction welds were produced using 15-mm diameter solid bars of chrome molybdenum steel (KS SCM440) and carbon steel (KS SM20C) to investigate their mechanical properties. The main friction welding parameters were selected to ensure good quality welds on the basis of visual examination, tensile tests, Vickers hardness surveys of the bond area and HAZ, and macro-structure investigations. The specimens were tested as-welded and post-weld heat treated (PWHT). The tensile strength of the friction welded steel bars was increased to 100% of the SM20C base metal under the condition of a heating time of more than four seconds. Optimal welding conditions were n = 2,000 (rpm), HP = 60 (MPa), UP = 100 (MPa), HT = 5 (s),and UT = 5 (s), when the total upset length was 7.8 (mm). The hardness distribution peak of the friction welded joints could be eliminated using PWHT. The two different kinds of materials were strongly mixed to show a well-combined structure of macro-particles, with no molten material, particle growth, or defects.

• 대한전기학회논문지:시스템및제어부문D
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• 제49권8호
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• pp.473-480
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• 2000

A fuzzy PID controller is proposed for the posture control of a two DOF robot vehicle inspecting the defects of the inner wall of sewage pipes. The main difficulty in controlling these kinds of vehicles lies in that the center of two mobile shafts does not coincide with the weight center of the vehicle due to its long and wide shape. In this case the previous controller, based on the assumption that the gap between these centers are small, can not guarantee satisfactory transient response characteristics. In this paper, this gap is included in the mathematical modelling of the robot kinematics, and in order to compensate the unsatisfactory transient response characteristics, the fuzzy PID controller is proposed. This controller tunes the PID control gains with respect to the current state of the errors between the reference and the current postures. A series of simulations has been performed to investigate the tracking performance of the proposed controller for the lane changing path and the robustness to the external disturbance. The simulation results show that the proposed controller has a satisfactory tracking performance in the transient state as compared with that of the backstepping control given in reference.

• 한국해양공학회지
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• 제13권2호통권32호
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• pp.74-82
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• 1999

Nowadays, the crank shaft motor vehicle has become essential as the important component. The machining precision was asked for manufacturing the shaft. They could be unstable in the quality by the conventional are welding. Both in-process quailty control and high reliability of the weld are the major concerns in applying friction wlding to the economical and qualified mass-production. No reliable nondestructive monitoring method is avaliable at present to determine the real-time evaluation of automatic production quality control for bar-to-bar friction welding of the crank shaft of O.D 24mm for motor vehicle. This paper, so that, presents the experimental examinations and statistical quantitative analysis of the correlation between the cumulative counts of acoustic emission(AE) during plastic deformation periods of the welding and the tensile strength and other properties of the bar-to-bar welded joints of O.D. 24mm shaft as well as the various welding variables, as a new approach which attempts finally to develop real-time quality monitoring system for friction welding, resulting in practical possiblility of real-time quality control more than 100% joint efficiency showing good weld with no micro structural defects.

• 한국추진공학회지
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• 제14권2호
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• pp.39-45
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• 2010

차량이나 항공기를 개발하는데 있어서 성능과 내구성에 대한 실험은 필수 과정이지만, 이를 위해서는 많은 개발 비용과 시간이 소요되므로 그 대체 방법으로 시뮬레이터를 이용한 실험이 보편화 되고 있다. 특히 노면의 경우 시뮬레이터에 사용할 변위 데이터를 정량화하기 어렵기 때문에 가속도계를 이용하여 노면 데이터를 습득하는 것이 일반적이다. 본 연구에서는 가속도계를 이용하여 습득한 가속도 신호를 변위 신호로 변환하기 위한 소프트웨어를 개발하여 시뮬레이터에 사용되는 변위신호를 생성하였고 이를 토대로 4축 시뮬레이터를 이용한 실험을 통하여 그 타당성을 검증하였다.

• Tribology and Lubricants
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• 제40권1호
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• pp.24-27
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• 2024

A monotype valve body for a dual clutch transmission has the potential to reduce costs, weight, and manufacturing time by modularizing various parts, including those of existing solenoid packs and valve bodies, into one through the application of super-precision die casting technology. However, this approach may lead to challenges such as reduced rigidity and increased interference due to modularization and compactness, impacting both product performance due to the reduced weight as well as durability and reliability. Unlike existing products, this approach requires a high-precision thin-wall block to avoid more complicated flow line formation, interference between flow lines, and leaks, as well as a strict quality requirement standard and precise inspections including detection of internal defects. To conduct precise inspections, we built an equivalent model corresponding to a driving distance of 300,000 km. Testing involved simulating actual road loads using a real vehicle and a chassis dynamometer in the FTP-75 mode (EPA Federal Test Procedure). The aim of the study was to establish a vehicle load-based part durability model for manufacturing a mono-type valve body and to develop fundamental technology for part weight reduction through preliminary design by introducing analytical weight reduction technology based on the derived results.

• 한국철도학회논문집
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• 제18권5호
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• pp.401-409
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• 2015

철도에서 차량의 가이드 역할을 하는 레일에 결함이 발생할 경우 빠르게 진전하는 특성이 있으며 차량의 탈선과 같은 대형사고로 이어질 수 있어 레일 결함 탐상 기술은 매우 중요하다. 본 연구에서는 증속에 따른 누설자속기반 철도레일 결함탐상 기술의 적용성 검토를 위해 증속이 가능한 레일 탐상 시험 장치 제작 및 결함 레일 시편에 대한 탐상 시험을 수행하였다. 이를 위해, 철도레일 형상에 맞는 센서부 및 자화부를 설계하였고 인공결함을 갖는 결함 레일 시편을 제작하였다. 제작된 시험 장치를 이용해 4km/h에서 12km/h까지 속도를 증가시키며 결함에 의해 생성되는 누설자속을 측정하였고 원 신호의 미분을 통한 가시성 향상으로 결함 판별 및 결함 위치를 성공적으로 확인하였다. 향후 리프트 오프 유지 등 고속화에 필요한 점을 보완할 경우 고속 검측차에도 적용가능 할 것으로 생각된다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2003년도 추계학술대회 논문집(III)
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• pp.322-326
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• 2003

Dae-gu subway accident raise whole points in connection with safety facilities and operating of national urban transit system like rolling stocks, facilities, management of human. Rolling stock is made every effort for improvement of performance, guarantee of comfortableness, insurance of economical efficiency. But Security like safety of fire is not thoroughgoing enough. Especially, interior material has used although it is not prove its degree of safety. it is a main cause of Dae-gu subway accident. Safety regulation of urban transit vehicle that legislate for security in March 2000 does not applied manufacturing vehicles before in 2000. It has be prescribed in the regulations that incombustibles must be used. But detailed test standard related with incombustibles is not prescribe. Thus that regulation be required reinforcement of detailed test standard. Main cause of Dae-Gu subway accident is a fire in vehicle. However, many defects are found in infrastructure and operating vehicle of urban transit, such as inexperienced disposal of driver and CCC in early stage of the fire accident, unskilled opening and closing doors, insufficient escape facilities and safety facilities of a station house and tunnel, and incomplete communication system between vehicle and CTC, extraordinary step. Thus the aims of this study are prevention of urban transit accident, improvement plan of safety driving, and proposal of quick action plan through analysis of total faculty of vehicle.

• 한국ITS학회 논문지
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• 제17권6호
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• pp.224-239
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• 2018

자율주행자동차로 인해 기존의 교통사고 원인의 대부분을 차지하는 '운전자부주의'로 인한 교통사고가 크게 감소할 수 있지만, '트롤리 딜레마', 차량 결함, 도로 함몰 등과 같은 사고를 피할 수 없는 상황이 발생할 수 있다. 이 경우 사람과 같은 윤리적 선택이 필요해진다. 본 연구는 돌발적인 싱크홀이 발생하여 자율주행차가 교통사고를 피할 수 없는 상황을 가정하고, 자율주행자동차의 윤리적 선택에 따른 교통사고비용을 시뮬레이션 분석을 통해 추정하였다. 이 때 자율주행자동차는 (1) 탑승자의 안전을 최우선으로 하는 이기주의, (2) 인명피해를 최소화하는 의무론, (3) 사고비용을 최소화하는 공리주의의 3가지 윤리적 선택 중 한 가지를 선택하도록 하였다. 분석결과, 이기주의의 교통사고비용이 가장 높게 분석되었고, 인명피해를 최우선으로 하는 의무론의 교통사고비용이 가장 낮게 분석되었다.

• 전기학회논문지
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• 제60권1호
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• pp.85-92
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• 2011

Main characteristic in railroad is the guided movement of the wheel by the track through a metal-to-metal contact, conferring to the rail vehicle a single degree of freedom. There are defects such as head check, shelling, corrugation, squats etc in surface of the rail by interface between the wheel and rail. These defects bring about reducing the life-cycle of rails and track components and increasing noises. In case of bad conditions, it is possible to happen to full-scale accident such as derailment. Recently, the track capacity has been increased for increasing speed and operation efficiency. So, maintenance and indirect cost have been increased. Currently, a coating method of rail construction is proposed by using the ceramics in Korea. Rails are used as the earth in electrical railroad systems. Currently traction return current is flowed through wheels of trains. In case of rails coated, problems are caused in the contact power between wheel and coating material of spray. In this paper, electric model is presented in the AT feeding method. In case of rails coated, electric model is presented. Also, standard resistance of the ceramic is demonstrated by contact power between wheel and coating material of spray.