• 한국지형학회지
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• 제27권4호
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• pp.29-39
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• 2020

This study estimated influences of the Ulsan Fault on tectonic movement and uplift characteristics in the Eastern Block of the Ulsan Fault. The averaged uplift rate in the Northern Coast of the Eastern Block was 0.202 m/ka, while the site in Seokbyeong-ri, Guryongpo-eup, Pohang-si, showed relatively high rate of 0.249 m/ka, attributable to influences of small fault movement, called the Gangsa Fault. Higher averaged rate of 0.270 m/ka than in the Northern Coast was calculated in the Southern Coast of the Eastern Block. The site in north of Haseo-ri, Yangnam-myeon, Gyeongju-si, showed the highest rate, suggesting influences of the Eupcheon Fault. The Western Block of the Ulsan Fault indicated the averaged rate of 0.208 m/ka, similar to that of the Northern Coast. The sites approximately 10 km apart from the Ulsan Fault showed 1.3 times higher rate in the Eastern Block than in the Western Block, while similar rates were calculated in the sites >20 km apart from the Ulsan Fault. These distributions of the rate suggest that the Ulsan Fault has significantly influenced development of marine terrace and tectonic movement in the study area, while local fault movements have also played a role.

• 지구물리
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• 제9권3호
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• pp.219-230
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• 2006

Since the key issue that 'the Yangsan fault is seismically an active fault" was raised in 1983, thegeological and geomorphological studies of active fault have been made by many researchers. These studies are mainly focused on the Yangsan fault system(YFS) and Ulsan fault system(UFS) due to many historical earthquakes occurred in this area. There are two different types of active faultings under the ENE-WSW horizontal stress field in the southeastern part of the Korean Peninsula. The NNE-trending YFS is the most prominent right-lateral strike-slip fault and has a continuous trace about 200 km long. Some part of this system has been active during the late Quaternary with evidences clearly recognized on both the northern (Yugyeri and Tosung-ri areas) and southern parts (Eonyang to Tongdosa area) of the YFS. in the southern part, the estimated vertical slip rate is about 0.02 - 0.07 mm/yr, and the lateral slip rate may be several times larger than the vertical rate. The most recent event occurred prior to deposition of Holocene alluvium, in the northern part, the fault trend locally changes to almost N-S, dips to the east and has reverse movement. The average vertical slip rate is estimated to be less than 0.1 mm/yr. The most recent event probably occurred after 1314 years BP (AD 536). The NNW-SSE (or N-S) trending UFS is a predominantly reverse fault that built up U-ie eastern mountain and has been active during U-ie late Quaternary. The fault trace is not straight but irregularly undulates along the foot of the mountain on the east. From the disturbed terraces along U-ie fault, the average vertical slip rate on U-iis system is estimated to be about 0.08.13mm/yr. The latest event is not well studied, but seems to have occurred after the last glacial maximum in the Malbang fault and 14,000 years BP in the Kalgok fault of the UFS. However, important issues such as fault segmentation, recurrence interval, age of Quaternary deposits need further studies.

• 전기학회논문지
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• 제57권8호
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• pp.1470-1477
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• 2008

In this paper, a new detection method of series arc-fault signals occurring at the wiring of home appliances is proposed. The discrete wavelet transform was used for the numerical analysis of the variation rate in peak, RMS, noise energy, shoulder of the arc-fault current wave. As a results, the arc distinction threshold value of these variation rates was about 0.1 in most cases. The arc-fault current of the loads with the active PFC circuit showed a high rate of variation in noise energy and shoulder, but arc-fault current of the loads without the active PFC circuit showed a high rate of variation in peak and RMS. The arc fault current in resistive loads showed a high rate of variation in shoulder.

• 전기학회논문지
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• 제58권11호
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• pp.2122-2127
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• 2009

This study presents the failure rate and repair rate of Superconducting Fault Current Limiter(SFCL) and adjacent distribution equipments. When the fault current penetrated SFCL, the supply of electric power to the customers can be partly continued. It is expected that SFCL makes to improve the reliability index of customers. Contrary to the expectations, the series connection between SFCL and distribution system could deteriorate the reliability index. To evaluate the reliability index in the distribution system including SFCL, the failure rate and repair rate of SFCL are required as well as that of distribution equipments. Also, the insertion of SFCL makes to change the failure rate and repair rate of adjacent equipments. This study proposes a method to calculate the failure rate and repair rate of a component combining SFCL and adjacent equipments.

• 조명전기설비학회논문지
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• 제30권1호
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• pp.28-37
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• 2016

Fault locating is an important element to minimize the damage of power system. The computation error of fault locator may occur by the influence of the DC offset component during phasor extraction. In order to minimize the bad effects of DC offset component, this paper presents an improved fault location algorithm based on a DC offset removal filter for short fault in a double circuit transmission line. We have modeled a 154kV double circuit transmission line by the ATP software to demonstrate the effectiveness of the proposed fault locating algorithm. The line to line short faults were simulated and then collected simulation data was used. It can be seen that the error rate of fault locating estimation by the proposed algorithm decreases than the error rate of fault locating estimation by conventional algorithm.

• Journal of Electrical Engineering and Technology
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• 제12권6호
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• pp.2118-2126
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• 2017

The large-scale power system blackouts have indicated that conventional protection relays that based on local signals cannot fit for modern power grids with complicated setting or heavily loaded-flow transfer. In order to accurately detect various faulted lines and improve the fault-tolerance of wide-area protection, a novel multi-section weighed fault matching and detecting algorithm is proposed. The real protection vector (RPV) and expected section protection vectors (ESPVs) for five fault sections are constructed respectively. The function of multi-section weighed fault matching is established to calculate the section fault matching degrees between RPV and five ESPVs. Then the fault degree of protected line based on five section fault degrees can be obtained. Two fault detecting criterions are given to support the higher accuracy rate of detecting fault. With the enumerating method, the simulation tests illustrate the correctness and fault-tolerance of proposed algorithm. It can reach the target of 100% accuracy rate under 5 bits error of wide-area protections. The influence factors of fault-tolerance are analyzed, which include the choosing of wide-area protections, as well as the topological structures of power grid and fault threshold.

• 융합보안논문지
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• 제13권1호
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• pp.3-10
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• 2013

본 연구에서는 소프트웨어 제품 테스팅 과정에서 관측고장시간에 근거한 결함 발생률을 고려한 소프트웨어 신뢰성 모형에 대하여 연구 하였다. 신뢰성 분야에서 많이 사용되는 S-분포모형을 이용한 새로운 결함 확률을 추가한 문제를 제시하였다. 수명분포는 유한고장 비동질적인 포아송과정을 이용하였다 본 논문의 결함 발생률을 고려한 소프트웨어 고장 자료 분석에서는 고장 시간 자료를 적용하였으며 모수추정 방법은 최우추정법을 이용하여 결함 발생 확률에 대한 관계와 신뢰도를 추정 하였다.

• 대한전기학회논문지
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• 제45권1호
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• pp.14-17
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• 1996

We analyzed the characteristics of a power system with superconducting fault current limiter and showed the possibility of the application of a superconducting fault current limiter to a real power system through manufacturing of and experiment about 220Vrms/100Apeak class superconducting fault current limiter. We experimentally confirmed that the overvoltage of superconducting fault current limiter increased as the rate of current sharing to the limiting coil grew. The fault current could be limited within a few milliseconds when it was applied to a power system in series. Therefore, we could confirm that superconducting fault current limiter was effective in protection of a substation or power plant at short-circuit fault. (author). 7 refs., 7 figs., 2 tabs.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2006년도 학술발표회 논문집
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• pp.78-85
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• 2006

The Ulsan Fault System continues from north of Gyeongju to Ulsan city, trending NNW-SSE and is about 50 km. Many Quaternary faults have been reported and investigated with outcrop observation. Lineaments have been extracted with aerial photograph interpretation and classified by their ranks. Trench excavations on the lineaments along Ulsan Fault System have been carried out to clarify the neotectonic movements and fault parameters such as the latest movement age, fault displacement, slip rate and recurrence interval. We have compiled data from previous studies on criteria of segment type such as lineament rank, seismicity, slip rate, and the latest fault movement. Based on these data, we tried to devide the Ulsan Fault System into several segments. The results of segmentation with each types of segment along the Ulsan Fault System did not show singular division point but overlapped or different length and location.

• International Journal of Automotive Technology
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• 제7권2호
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• pp.201-208
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• 2006

This paper describes the control philosophy of ESP(Electronic Stability Program) which consists of the stability control the fault diagnosis and the fault tolerant control. Besides the functional performance of the stability control, robustness of control and fault diagnosis is focused to avoid the unnecessary activation of the controller. The look-up tables are mentioned to have the accurate target yaw rate of the vehicle and obtained from vehicle tests for the whole operation range of the steering wheel angle and the vehicle speed. The wheel slip control with a design goal of wheel slip invariance is implemented for the yaw compensation and the target wheel slip is determined by difference between the target yaw rate and actual yaw rate. Since the ESP has a high severity level and the robust control is required, the robustness margin for the stability control is determined according to several uncertainties and the robust fault diagnosis is performed. Both computer simulation and test results are shown in this paper.