• Title/Summary/Keyword: Faults

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Movement History of Faults Considered from the Geometric and Kinematic Characteristics of Fracture System in Gilan-cheongsong Area, Gyeongsang Basin, Korea (경상분지 길안-청송 지역에서 단열계의 기하학적.운동학적 특성으로부터 고찰된 단층운동사)

  • Lee, Deok-Seon;Kang, Ji-Hoon
    • The Journal of the Petrological Society of Korea
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    • v.18 no.4
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    • pp.293-305
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    • 2009
  • The Gilan-Cheongsong area, which is in contact with Yeongyang and Uiseong Blocks of Gyeongsang Basin, Korea, consists of Precambrian metamorphic rocks, Triassic Cheongsong granite, Cretaceous sedimentary rocks(Iljik, Hupyeongdong, Jeomgok Formations), and Cretaceous igneous rocks(andesite, quartz porphyry, felsite). In this area are developed faults trending in (W)NW, NNW, ENE, NS, (N)NE directions which are representative in the Gyeongsang Basin. We analyzed the geometric and kinematic characteristics of fracture systems to inquire into movement history and sense of these faults in this area. This study suggests that these faults were mainly strike-slip movement. The orientations of fracture sets show ENE, NNW, (W)NW, (N)NE, NS in descending order of frequency. Their prolongation presents (W)NW, NNW, ENE, (N)NE, NS in descending order of predominance, and also agrees with that of faults in this area. The development sequence and movement sense of fracture sets are summarized as follows; (1) (W)NW: dextral shearing $\rightarrow$ (2) (W)NW and NNW: conjugate shearing(the former: dextral, the latter: sinistral) $\rightarrow$ (3) NNW: dextral shearing $\rightarrow$ (4) (W)NW: sinistral shearing $\rightarrow$ (5) ENE: dextral shearing $\rightarrow$ (6) ENE and NS: conjugate shearing(the former: sinistral, the latter: dextral) $\rightarrow$ (7) (N)NE: sinistral shearing, and this result is closely associated with the development sequence and movement sense of faults developed in this area.

Changes and Challenges in the Concept of Industrial Accident Insurance in Korea (산업재해 인정 형태 변화와 보상체계 합리화 연구)

  • Kim, Jin-Soo;Ra, Ji-Hun;Lee, Seong-Young
    • Korean Journal of Social Welfare
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    • v.59 no.3
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    • pp.59-73
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    • 2007
  • The compensation system in industrial accident insurance is systemized with "either receiving all or no benefits at all" according to "admited or denied as an industrial accident". Therefore, they are centered on the decision as "industrial accident" or "non-industrial accident", but judging between the two is very complicated, and has inherent conflicting factors. In the early stage of industrialization, industrial accident compensation was based on the indemnity liability for employer's faults. In order to be compensated any damage, the injured worker should prove that the accident was not due to his or her faults. However it was very difficult for injured worker or his or her family to prove the employer's faults, so it was almost impossible to get compensation. Thereafter industrialization progress and improvement of workers' political status lead to conversion from principle of liability with employer's faults to principle of liability without employer's faults. In addition to that, coverage of industrial accident compensation was also expanded. This improvement strengthened the benefit payment principle of "All or Nothing". Even though the "All or Nothing" principle provokes tremendous criticism, the reason why it's difficult for industrialized countries to adopt partial compensation system, is that partial compensation system worsens the administrative hardship, therefore industrialized countries overcome the restrictions of the "All or Nothing" principle with making balance in provisions for any risk to some extent. However, in Korea because the general compensation system for covering medical cost and income loss from accidents, is not equipped, it could be possible to cause acute conflicts with regard to coverage of industrial accidents. Therefore it is required to improve the industrial accident insurance with the acceptance of the significance and logic of discriminated compensation, and create the integrated compensation system in the long run.

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On Designing Domino CMOS Circuits for High Testability (고 Testability를 위한 Domino CMOS회로의 설계)

  • 이재민;강성모
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.19 no.3
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    • pp.401-417
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    • 1994
  • In this paper, a new testable design technique for domino CMOS circuits is proposed to detect stuck-at(s-at), stuck-open(s-op) and stuck-on(s-on) faults in the circuits by observing logic test reponses. The proposed technique adds one pMOS transistor per domino CMOS gate for s-op and s-on faults testing of nMOS transistors and one nMOS transistors and one nMOS transistor per domino gate or multilevel circuit to detect s-on faults in pMOS transistors of inverters in the circuit. The extra transistors enable the proposed testable circuit to operate like a pseudo static nMOS circuit while testing nMOS transistors in domino CMOS circuits. Therefore, the two=phase operation of a precharge phase and a evaluation phase is not needed to keep the domino CMOS circuit from malfunctionong due to circuit delays in the test mode, which reduces the testing time and the complexity of test generation. Most faults of th transistors in the proposed testable domino CMOS circuit can be detected by single test patterns. The use of single test patterns makes the testing of the proposed testable domino CMOS circuit free from path delays, timing skews, chage sharing and glitches. In the proposed design, the testing of the faults which, require test sequences also becomes free from test invalidation. The conventional automatic test pattern generators(ATPG) can be used for generating test patterns to detect faults in the circuits.

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A Study on Detection Algorithm of Open Phase Fault in Grid-Connected Transformer for PV System (태양광전원 연계용변압기의 결상사고 검출 알고리즘에 관한 연구)

  • Kang, Kab-Seok;Tae, Dong-Hyun;Lee, Hu-Dong;Rho, Dae-Seok
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.22 no.5
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    • pp.22-33
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    • 2021
  • In the case of open phase faults caused by the disconnection of distribution feeders interconnected to a PV system, many problems can occur depending on the core type and wiring method of the grid-connected transformers. Moreover, open phase faults are difficult to detect because the open phase voltage of the existing protection relay (Open Phase Relay (47)) can be maintained, even though a disconnection fault occurred, depending on the wiring method and the iron core type of the grid-connected transformer for a PV system. Therefore, this paper proposes a novel algorithm to detect open phase faults by comparing the currents and phases between the primary and secondary sides of a grid-connected transformer. In addition, this paper presents the modeling of a distribution system and protection devices for detecting open phase faults using PSCAD/EMTDC S/W, and implements a test protection device for detecting open phase faults based on the above-mentioned modeling. The simulation and test results confirmed that the proposed algorithm is useful for detecting open phase faults according to the wiring method and iron core type of grid-connected transformer for a PV system because operation slope and unbalance rate of the primary current exceed the setting value (30[%]) of the protection device.

Fault Detection on Voltage-source Inverter by Analytical Model (분석모델에 의한 전압헝 PWM 전동기 구동시스템에서의 고장검출)

  • Rim, Seong-Jeong
    • Proceedings of the KIEE Conference
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    • 2002.07b
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    • pp.1052-1054
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    • 2002
  • This paper presents an analytical model-based approach to detect and isolate faults in a voltage-source inverter. These faults do not affect the existing system protections. A diagnosis system which uses only the input variables of the drive is presented. It is based on the analysis of the current-vector trajectory in faulty mode. The proposed method has been verified in simulation results.

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Researches on the Potential Rises on the Neutral Line in Three Phase, Four-Wire Distribution Line Systems (공통중성선 3상4선식 배전선로의 중성선 전위상승에 관한 연구)

  • Park, Young-Moon
    • 전기의세계
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    • v.18 no.6
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    • pp.23-32
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    • 1969
  • The thesis has derived the formulas and computational algorithms useful for predicting and constraining the potential rises on the neutral line in 3-phase, 4-wire distribution line systems in the case of contact faults and single-line grounding faults. In addition it has suggested economically optimal designing conditions herewith of the distribution line systems in conduction with the potential restraining cost functions.

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Fault detection on voltage source inverter by knowledge-based model (지식기반 모델에 의한 전압형 인버터에서의 고장검출)

  • Rim, Seong-Jeong
    • Proceedings of the KIEE Conference
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    • 2001.07b
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    • pp.996-998
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    • 2001
  • This paper presents an approach based on knowledge models to detect and isolate faults in a voltage source inverter. These faults do not affect the existing system protections. A diagnosis system which uses only the input variables of the drive is presented. It is based on the analysis of the current-vector trajectory and of the instantaneous frequency in faulty mode. These two methods have been verified in simulation results.

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Fault Detection by Using an Adaptive Observer

  • Inoue, A.;Deng, M.;Yoshinaga, S.
    • 제어로봇시스템학회:학술대회논문집
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    • 2005.06a
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    • pp.710-713
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    • 2005
  • In this paper, a design method to detect faults in plants with uncertainties is proposed. When a plant has faults, the plant will be corrupted by an unknown fault signal. In addition, the plant also includes uncertainties, such as disturbances and plant parameter deviations. In this case, the proposed method estimates the fault signal by using an adaptive observer. Numerical examples are given to demonstrate the validity of the proposed method.

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A Discriminating Algorithm between Magnetizing Inrush and Internal Faults of Transformers Using Difference of a differential current (차동전류의 변화율을 이용한 변압기의 여자돌입과 내부사고 구분 알고리즘)

  • Kang, Y.C.;Lee, B.E.;Yun, J.S.
    • Proceedings of the KIEE Conference
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    • 2000.11a
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    • pp.171-173
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    • 2000
  • This paper presents a discriminating algorithm between magnetizing inrush and internal faults of transformers using difference of a differential current. Incase of inrush, change of magnetizing inductance repeats. Thus, second difference of differential current periodically shows pulse while periodic pulse is not represented in case of internal winding fault. The proposed algorithm is suitable irrespective of the amount of remanent flux.

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The Standard for Installation of Automated Distribution Switch-gear in Multi-Line Faults (다중선로 고장을 고려한 배전자동화용 개폐기 설치기준)

  • Lee, Jung-Ho;Ha, Bok-Nam;Cho, Nam-Hun;Lim, Sung-Il
    • Proceedings of the KIEE Conference
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    • 1999.07c
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    • pp.1079-1081
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    • 1999
  • This paper presents the standard for dividing/tieing the distribution lines and installing optimally the automated distribution switch-gear in multi-line faults. Also this paper recommends the distribution system design in consideration of the live load transfer of the concentrated load in the last load-side. This recommendation will be useful for designing the distribution network, developing the feeder automation software and operating the distribution automation system.

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