• 품질경영학회지
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• 제24권1호
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• pp.10-19
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• 1996

In order to build a model to predict accidents in a complicated man-machine sytem, human errors and mechanical reliability can be viewed as the most important factors. Such factors are explicitly included in a generic model. Another point to keep in mind is that the model should be constructed so that the data in a type of accident can be utilized to predict other types of accidents. Based on such a generic prediction model, we analyze the effects of system reliability. When we improve the system reliability, in other words, when there are changes in model parameters, the predicted time to next accidents should be modified influencing the effects of system reliability improvements. We apply Bayesian approach and finds the formula to explain how a change on the machine reliability or human error probability influences the time to next accident.

• 전기학회논문지P
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• 제59권2호
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• pp.232-237
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• 2010

Fault rate of RCD is increasing due to deterioration and long period usage in domestic. According to Korean standards, the RCDs are installed in panel boards. When RCDs are installed at outdoor, the RCDs must be protected from uv, water etc. by using the housing. However, many RCDs are exposed to the external environment. As a results, many RCDs have malfunctions so that cause the electrical accidents. The RCDs manufactured by four makes were used as the sample to weathering test. Futhermore, those were analyzed the ingredients of RCD'S using SEM, EDX and FT-IR/TAR before and after weathering test.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.1087-1090
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• 2007

A wireless magnetic torque sensor is utilized to measure the torque generated in the rotating shaft in magnetic field without connecting to the shaft by any wire. In this study, a new wireless magnetic torque sensor was introduced. The structure of the sensor was explained detailed as well as its operation principle. Resulting from the torque measurement experiment results, the sensor was proven to measure the generated torque effectively. Compared with traditional contact torque sensor, the wireless one has low cost and good environment adaptation ability. Moreover, the intractable wrapping wires around the shaft are removed in this design. Hence the wireless torque sensor may be expected as a possible sensing device for many applications, such as the electric assisting rotation system in automobiles, the torque sensing system in motors, the arm rotation system in robotics and so on.

• 전기학회논문지
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• 제58권3호
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• pp.516-522
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• 2009

The dimmable magnetic ballast which applies the variable inductor needs a switching process for the dimming process, and it consists of mechanical relays because of costs and reliabilities. However, it is hard to operate with correct timing in mechanical relay, so relays reduce their own life time in inductive applications. Moreover this creates a destructive problem at the switching process. The life time reduction of relays means the life time reduction of the ballast. Thus, in this paper, we described the problem at the witching process in the dimmable magnetic ballast with a variable inductor, which consists of relays and the soft AC switching method in order to solve the problems. As result, we achieved the improvement of the life time and reliability of the ballast.

• 정신신체의학
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• 제1권1호
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• pp.98-100
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• 1993

To become an effective and successful consultation-liasion psychiatrist the psychiatrist should consider two aspects of consultation before he/she meets his/her patients. First the psychiatrist should understand the internal need and psychological state of patients who visited their physician before being refered to a psychiatrist So psychiatrists should be careful in the evaluation of the patient's intention whether they are willing to accept the psychiatric treatment approach or not Second the psychiatrist should understand the situation and the physician's internal need in the consultation. Psychiatrists should recognize whether there are any factors which interfere with the mutual understanding and cooperation between physicians and psychiatrist.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2004년도 전력전자학술대회 논문집(1)
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• pp.163-166
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• 2004

The conventional fluorescent lamp dimming system using an another control line is complex and will increased the cost. Therefore, many studies have focused on the wireless communication, but it is not fit for dimming system because of the interference generated by the infra-red light of lamp or switching noises in ballast. So, we applied the power line communication on the dimming system and we proposed a new coupling circuit using the voltage controlled impedance convertor for improving the performance of the FH/SS PLC modem. The performance for the proposed modem is evaluted by the BER.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제54권3호
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• pp.139-144
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• 2005

[ $SF_6$ ] gas circuit breakers are widely used short circuit current interruption in EHV or UHV power system. For a $SF_6$ gas circuit breaker development, the $SF_6$ gas velocity measurement is necessary during $SF_6$ circuit breaker's trip operation. Small-gap flashover characteristics are used for this measurement. So, small-gap measuring system which will be used to develope GCB should be developed. This study shows the characteristic analysis and experimental results of small-gap measuring system.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 심포지엄 논문집 정보 및 제어부문
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• pp.243-245
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• 2005

Condition monitoring is desirable for increasing machinery availability, reducing consequential damage, and improving operational efficiency. In this paper, a model-based method using neural network modeling of induction noter in vibration spectra is proposed for machine fault detection and diagnosis. The short-time Fourier transform (STFT) is used to process the quasi-steady vibration signals to continuous spectra so that the neural network model can be trained with vibration spectra. And the faults are detected from changes in the expectation of vibration spectra modeling error. The effectiveness of the proposed method is demonstrated through experimental results.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2008년도 한국컴퓨터종합학술대회논문집 Vol.35 No.1 (D)
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• pp.428-431
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• 2008

Recently, people have been interested in new intelligent transport system (ITS) architecture, so that vehicular networks are becoming an attractive research area. When vehicles try to access data through a roadside unit (RSU), data scheduling of RSU needs to improve service ratio due to limited bandwidth and service time. In this paper, we propose a service scheduling algorithm based on transmission delays and service deadlines of vehicles in order to improve the service ratio. In our algorithm, we assume the promiscuous operation of wireless nodes and it can make a single transmission of RSU serve multiple requests. We evaluated the performance of our scheme via simulations, and results show that our schemes have better performance than existing algorithms.

• 한국시뮬레이션학회:학술대회논문집
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• 한국시뮬레이션학회 2001년도 The Seoul International Simulation Conference
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• pp.387-390
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• 2001

Thermopile thermometer can measure the temperature of an object without attaching the object. It measures the temperature by receiving the radiation energy from objects. The idea of this is from the law of Stefan-Boltzmann. In the past it was not used well because the size was big and the cost was too expensive. But, In these days it can be used many field because the size become smaller and advantage of cost by using micro machine technology. However, The accuracy of measuring is not better than electric type. So we want to improve the accuracy of sensor by analyzing the heat transfer of the thermopile. To analyze temperature distribution in the thermopile sensor, we use the FEM software which is named ANSYS. The conduction and radiation heat transfer is considered to simulate the temperature distribution and time response inside of the sensor.