• 한국철도학회:학술대회논문집
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• 한국철도학회 2001년도 추계학술대회 논문집
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• pp.488-493
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• 2001

CWR technology is generally believed to contribute to the increase of train speed and bring a variety of significant advantages, such as the decrease in track works, noise and vibration as well as the improvement of passenger comfort. In CWR technology, welding is considered to be one of the most important element technologies. Among the various welding methods, thermit welding is the most frequently used one for site welding since the operation is simple and the instruments are light as well as easy to deal with. However, it could cause interference with safety operation of trains since thermit welding points, are essentially made of castings and there are potentialities of defects according to the operation conditions, the environment of the site as well as the dexterity of the worker. This study tries to describe the characteristics of thermit welding, defect-causing factors and defect-detection methods at welding points.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2000년도 추계학술대회 논문집
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• pp.295-302
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• 2000

Slab guideway, surface treatment, heat line installation, and joint connection for Automated Guideway Transit with rubber tire are researched. While the AGT with rubber tire is constructed in city, the precast slab guideway must be considered a reduction of the construction period and the noise under construction. which related with environment. To do that, a basic design and the structural analysis for the precast slab guideway with rubber tire are studied. The surface treatment and the heat line installation of that are also compared with currently used methods. Tining method is applied to the surface treatment adopted from the concrete pavement application currently in use. The connection method between the slab of bridge and precast guideway are suggested with a bolt type and a bond type. To minimize noise and vibration of the connection while the AGT is in driving, the slop connection method can be enhanced the serviceability.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 춘계학술대회 논문집
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• pp.97-102
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• 2005

As the railroad-base is an important factor to maintenance the rolling stocks, it is essential to improve the current problems of the environment pollution, nose, vibration, welfare, work condition and to applicate the performance betterment cases to the new base construction and pre-base maintenance. When the new base construction and pre-base maintenance is proceeded, it is necessary to construct the optimized system which includes the user's opinions enough to prevent the waste of the budget ,in that some part of the budget is spent to improve convenience, work condition, and the fault of base system after the construction. Therefore, this research intends to present the problem of the pre-constructed facilities, the testing operators' opinions, the analysis and the investigation of facilities' improvement, thorough the indication of provisions and the analysis of the result of the survey of testing operators.

• 산업경영시스템학회지
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• 제23권58호
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• pp.71-79
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• 2000

In this study, through the roadside interview, drivers'feeling about fatigue has been evaluated synthetically and systematically when they drive a vehicle according to their sex, vehicle type, driving career, etc. Also, with the human sensibility evaluation technique, we grasped the human sensibility structure for the fatigue in a vehicle and as an objective evaluation index for comfort and fatigue in a vehicle, we developed a sensibility database. Through the survey and research, extracting and understanding the importance of factors which have influence on the fatigue in driving can be used as basic data that can suggest more comfort and pleasant driving environment to drivers. Also, human sensibility database regarding to the comfort and fatigue in a vehicle can be used as basic data in ergonomic vehicle design, evaluation for seat , comfort seat development, development of vibration reduction method and so on.

• 소음진동
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• 제8권4호
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• pp.683-689
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• 1998

A control algorithm for multi-stage dampers is developed based on the mode skyhook control concept, and implemented on the full vehicle system environment. The test vehicle system is equipped with the real time controller, four-stage variable dampers and sensors. The real time controller is developed using a digital signal processor(DSP), digital I/O, A/D and D/A converters. The dampers are driven by the electromagnetic actuators of less than 20 msec response time. The sensors include accelerometers, relative displacement transducers, and steering wheel rate sensors, etc. Through a series of tests in laboratory and proving ground, the performance of the semi-active suspension system is evaluated and it is shown that the vehicle dynamic characteristics is improved with the developed damping system. Futhermore, the parameter tuning methods to enhance vehicle dynamic performance are propsoed.

• 소음진동
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• 제8권4호
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• pp.706-714
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• 1998

The purpose of this study is to analyse the main factors and attributes of psychological evaluation to noise. For this purpose, a psycho-acustic experiment was conducted by using the method of rating scale. 52 subjects were participated in the experiment, 20 stimuli were presented to subjects in random order with 23 adjectives. As a result of factor analysis, it was found that the primary factors for evaluating the quality of noise subjectively are four factors of unpleasantness, intensity, irregularity, and sharpness. And, as a result of MDPREF(multi-dimensional analysis of preference data), it was found that the noise sources including the factors of unpleasantness, intensity, and irregularity are related to the sounds of hammering in construction field, car horn, road traffic, idling of car, and printing by computer printer, and the factor of sharpness are the sounds of car siren, claps of thunder, car horn, and snowstorm etc.

• 한국전자파학회:학술대회논문집
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• 한국전자파학회 2003년도 종합학술발표회 논문집 Vol.13 No.1
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• pp.96-99
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• 2003

This paper presents the development of a Ku-band Low Noise Amplifier with the Noise figure of 1.4dBmax, the gain of 35dB, and the In/Out Return toss of -22dB/-18dB in the frequency range from 14 to 14.5GHz for Satellite transponders. All RF components were assembled using a hybrid technology with 15-mil thin-film substrates. The mechanical and thermal design of the housing was performed considering a vibration and a vacuum of space environment.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2001년도 추계학술대회 논문집(Proceeding of the KOSME 2001 Autumn Annual Meeting)
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• pp.98-104
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• 2001

Recently, the researches on the prevention of marine oil pollution being strengthened. Sludge oils were unavoidably produced in ship's operations, therefore it is necessary to manage the sludge oils inside the ship itself with the view to prevent marine oil pollution from ship. The present study deals with the ultrasonic breaking systems that recycle the sludge oil from ships into usable oil to be burnt. At the first instanceexperimental studies were carried out to investigate the homogenizing effect of the marine oils and the erosion aspect of horn disc by repeated vibration of ultrasonic transducer. The erosion damages for horn disc SS41 steel with weight loss rate and the irradiation time to max. erosion rate were examined according to the variation of the transducer amplitude, the oil temperature and the immersing depth of horn disc. As the result of it, the erosion aspects of horn disk were varied with oil environments and testing time.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2007년도 추계종합학술대회
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• pp.946-949
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• 2007

무선 센서네트워크는 온도나 소리, 진동, 압력, 움직임 등의 환경 조건을 감시할 수 있는 장치가 다른 위치에 분산되어 있는 무선 네트워크이다. 환경 모니터링은 센서 네트워크의 응용분야로 과학적으로 많은 이점을 가지고 있다. 본 논문에서는 온도, 습도, 조도 센서의 모니터링에 사용되는 센서 네트워크 시스템을 설계 ${\cdot}$ 구현한다.

• 동력기계공학회지
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• 제6권2호
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• pp.33-39
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• 2002

Commercial vehicles are mostly subjected to relatively rougher ground environment than passenger vehicles. Many driver's seats of commercial vehicles have suspension system with spring and dampers. Then, impact or vibrative forces transmitted from the vehicle to the driver can be attenuated. This study deals with a ride evaluation method using sky-hook control algorithm for the suspension dampers. Vibration amplitude transmissibilities were compared between passive dampers and semi-active dampers with sky-hook control method.