• Journal of the Institute of Electronics and Information Engineers
• /
• v.52 no.10
• /
• pp.47-55
• /
• 2015

To verify the function of vehicle is becoming more and more difficult because many electronic control units have been embedded in vehicle with development of electronics industry. The reliability of vehicle should be considered above all important because malfunction of vehicle can cause damage of human life. In this paper, defect diagnosis platform based on CAN network is proposed to improve the reliability of vehicle. Reliability of vehicle is significantly increased by adopting the structural test via dedicated test path after manufacturing. Besides, the test cost is reduced because additional test pins are not required.

• Smart Structures and Systems
• /
• v.22 no.2
• /
• pp.167-174
• /
• 2018

Digital input and output modules are widely used to connect digital sensors and actuators to automation systems. Digital I/O modules provide flexible connectivity extension to numerous sensors and actuators and protect systems from high voltages and currents by isolation. Components in digital I/O modules are inevitably affected by operating and environmental conditions, such as high voltage, high current, high temperature, and temperature cycling. Because digital I/O modules transfer signals or isolate the systems from unexpected voltage and current transients, their failures may result in signal transmission failures and damages to sensitive circuitry leading to system malfunction and system shutdown. In this study, the lifetime of optocouplers, one of the critical components in digital I/O modules, was predicted using Bayesian tracking approaches. Accelerated degradation tests were conducted for collecting the critical performance parameter of optocouplers, current transfer ratio (CTR), during their lifetime. Bayesian tracking approaches, including extended Kalman filter and particle filter, were applied to predict the failure. The performance of each prognostic algorithm was then compared using accuracy and robustness-based performance metrics.

• International Journal of Naval Architecture and Ocean Engineering
• /
• v.8 no.3
• /
• pp.243-251
• /
• 2016

Autonomous Underwater Vehicles (AUVs) generally work in complex marine environments. Any fault in AUVs may cause significant losses. Thus, system reliability and automatic fault diagnosis are important. To address the actuator failure of AUVs, a fault diagnosis method based on the Gaussian particle filter is proposed in this study. Six free-space motion equation mathematical models are established in accordance with the actuator configuration of AUVs. The value of the control (moment) loss parameter is adopted on the basis of these models to represent underwater vehicle malfunction, and an actuator failure model is established. An improved Gaussian particle filtering algorithm is proposed and is used to estimate the AUV failure model and motion state. Bayes algorithm is employed to perform robot fault detection. The sliding window method is adopted for fault magnitude estimation. The feasibility and validity of the proposed method are verified through simulation experiments and experimental data.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.58 no.1
• /
• pp.63-68
• /
• 2009

As the complexity of the power system becomes higher, tests of the new devices, such as exciter and PCS(Power Conversion System) of the distributed generation sources, in the real operating condition are more important. However tests of the unverified devices in the real power system may cause hazardous malfunction of the system. In order to avoid this problem, power devices may be tested with the real-time simulators instead of the real power system. This paper presents an real-time multi machine power system simulator using PCs(Personal Computer) and Fast Ethernet. Developed real-time simulator performs the electro-mechanical dynamic simulation of multi-machine power system by the network distributed computing technique. Because the simulator consists of usual PCs and Fast Ethernet, it is possible to make up a simulation system very cheaper than the conventional real-time simulator which consists of dedicated expensive hardware devices. The performance of the developed simulator is tested and verified with the scaled model excitation system. The test which adjust the control parameters of the exciter is performed with the well-known New England 10 generator 39 bus sample power system.

• Proceedings of the KIEE Conference
• /
• 2008.07a
• /
• pp.127-128
• /
• 2008

전력계통 구성의 복잡함에 따라 보다 다양한 기능이 요구되는 디지털 보호 계전기는 구성 모듈이 점점 다양해지고, 상호 복합적으로 설계된다. 그러한 결과로 개발 시, 공인 인증된 디지털 보호 계전기의 외란에 대한 신뢰성은 예상치 못한 오류 등으로 인하여 신뢰를 상실하는 경우가 있고, 최악의 경우 오동작을 유발하여 전체 전력 계통의 정전을 초래할 수 있다. 특히 디지털 보호 계전기의 시스템 이상 감시에만 그치던 자기 감시 기능은 반복되는 잘못된 이상 감지 판단으로 관리자 및 실무자의 계통 보호에 대한 신뢰의 혼동을 가져올 수 있으며, 일반적인 자기 감시 주기인 $1{\sim}2$초는 그 순환 주기 시간이 너무 길어서 제대로 된 시스템 감시를 행하지 못할 수 있다. 물론 고속의 자기 감시가 필요한 부분은 특별히 존재하지 않지만, 이는 오동작 시 전체 시스템에 미치는 영향을 고려하면, 고속 감시 항목을 미리 지정하여 자기 감시의 신뢰도를 높이는 것도 매우 중요하다. 그렇지만 일반적으로 그 주기를 고속으로 매우 짧게 가져간다면 전체적인 시스템에 무리한 부담을 유발하여 기본 기능에 대한 안정성을 악화시킬 수 있다. 그러나 가장 위험한 현상은 자기 감시 실패 시 디지털 보호 계전기 뿐 아니라 전체 계통에 막대한 피해를 유발하는 것이다. 본 논문에서는 이러한 경우 오동작을 사전에 예방할 수 있는 추가 상시 감시 Tool을 제시한다.

• The Korea Journal of Herbology
• /
• v.26 no.1
• /
• pp.81-85
• /
• 2011

Objective : This study was designed to investigate the effects of Angelicae Gigantis Radix (AGR) on Polycystic Ovary (PCO) induced by Estradiol valerate (EV) in female rats. Methods : We investigated the effects of AGR on Changes in body weights and food and water uptake for 5 weeks. In addition, we examined the effects on ovary weights. Finally, we also observed histopathological changes in PCO rats. Results : Treatment with AGR did not affect body weights, amount of food and water uptake. Administration group of AGR restored body/ovary weight ratio to normal levels, which were lowered by induction of PCO. In histopathological observation, formation of cysts was suppressed in AGR group compared with non-treated control group. Conclusion : These results suggest that AGR can be used for patients with PCO to prevent formation of cystic follicles and malfunction of ovary.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.5 no.4
• /
• pp.350-353
• /
• 2004

The integral reactor is tripped by the boron injection to the reactor when the CEA(Control element assembly) is not available due to its malfunction. In general, the borated water is made by dissolving the boron powder in the water and is stored in a tank. and then injected. But, this method is disadvantageous from the view point of construction cost, operation and maintenance because it has many components and is complicated. In this study, the boron powder direct vessel injection method is adopted to improve the system. Injecting the boron powder directly to the vessel and decreasing of number of components, the system configuration, operation and maintenance is simplified and the construction cost is reduced.

• Proceedings of the KIEE Conference
• /
• 2003.07b
• /
• pp.1166-1168
• /
• 2003

In most power electronic applications, the AC power input provided by the electronic utility needs to first converted to a DC voltage. Such conversion is accomplished by a diode rectifier due to its circuit simplicity and low cost. However, since diode rectifiers have some intrinsic problems such as low power factor and high harmonic distortion, a wide use of such rectifiers may cause noises, malfunction and heat damage in both electrical power systems and electrical machinery systems. This paper proposes soft switched three-phase single switch boost-type converter. The proposed circuit can perform Zero Voltage Switched(ZVS) without using any current and voltage sensors. For this circuit, both simulation and experiments have been performed. The results not only confirmed the ZVS but also indicated that, compared to the conventional hard switched converter, the prosed circuit can improve the efficiency as much as 1.7 to 4.7[%] while keeping the same high power factor and small harmonic distortion in their AC input.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.23 no.3
• /
• pp.271-278
• /
• 2015

This paper develops an OBD Diagnostic Program (Program) using Visual Studio (C#), which was used to diagnosis malfunction information from OBD-II system vehicles. We accomplished this using the Program, Diagnostic tests, Board (STN1110), FTDI Basic Cable, Mini USB Cable, OBD Data Cable, and both hybrid and regular vehicles. The Program tests real-time data output, DTC output, sensor value output, engine RPM, waveform data, OBD type check, PID inspection, and whole monitoring. We found vehicles used in this research had 19 PIDs, which was within OBD-II regulations. We also gathered data on control and diagnostic code regulated by OBD-II system, such as, sensor output value, engine RPM, DTC output, each PID analytic value, OBD type, fuel mode, and whole monitoring result value. Using the data collected through the Program appropriately can lead to more effective diagnostic practices and contribute to education.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.12 no.4
• /
• pp.146-154
• /
• 1998

Broadband noise with frequency components in the range from several kHz up the tens of MHz is a major obstacle factor in normal operation of the AC line to supply the power to electrical and electronic control equipments. Because this kind of noise could damage the device or could be a source of malfunction, many devices such as filter and surge suppressor are used to cut off the noise. But those devices could not disconnected from the power line, so they result in poor common-mode of NCT as well as insulation characteristics as a isolation transformer in addition faraday shielding and proposed analysis model of NCT having tow functions of surge and noise reduction. The simulated and experimental results for the surge suppression characteristics are compared and evaluated for designed protype 1[kVA] NCT.