• Structural Engineering and Mechanics
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• 제85권1호
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• pp.55-64
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• 2023

Energy-based seismic design and evaluation methods are promising to be involved in the next generation design codes. Accordingly, determining the distribution of earthquake input energy demand among floor levels is quite imperative in order to develop an energy-based seismic design procedure. In this paper, peak floor input energy demands are achieved from relative input energy response histories of several reinforced concrete (RC) frames. A set of 22 horizontal acceleration histories selected from recorded near-fault earthquakes and scaled in time domain to be compatible with the elastic acceleration design spectra of Turkish Seismic Design Code are used in time history analyses. The distribution of the computed input energy per mass values and the arithmetic means through the height of the considered RC frames are presented as a result. It is found that spatial distribution of input energy per mass is highly affected by the number of stories. Very practical yet consistent formulation of distributing the total input energy to story levels is achieved, as a most important contribution of the study.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.44-46
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• 2001

This paper describes the use of the PHOENICS CFD package for the simulation of the high-current period of the arcing process in a hybrid rotating arc/auto expansion by interrupter. The operating principle of this device depends on rapid arc rotation due to the magnetic field created by the fault current through a coil which is mounted on contacts and also relies on the principle of thermal expansion created by arc energy in extinguishing chamber and finally causes pressure rise in expansion volume. This paper is divided into three main sections. The first gives a brief overview of the interrupter. The second section gives a full description of the methods used in the calculation. The final section presents some sample results for the hybrid interrupter.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 C
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• pp.1903-1905
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• 2000

Power transformers have a tendency of ultra-high voltage capacity as power demand increases day after day KEPCO also will have plan to supply transmission power from 345KV to 765KV in the early of 2000. Therefore, the fault by insulation destruction gives rise to large area of power failure in huge capacity transformers. On-line predictive diagnostics is very important in power transformers because of economic loss and its spreading effect. This study presents the algorithm for transformer oil analysis used KEPCO code, IEC code, gas pattern method and Dornenburg & Roger Ratio method. We also describe the MMI display of expert system programmed by Element Expert Tool(Neuron Data Inc.).

• Journal of Electrical Engineering and information Science
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• 제1권1호
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• pp.118-128
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• 1996

In safety critical hard real-time systems, a timing fault may yield catastrophic results. In order to eliminate the timing faults from the fast responsive real-time control systems, it is necessary to schedule a code based on high precision timing analysis. Further, the schedulability enhancement by having multiple processors is of wide spread interest. However, although an instruction level parallel processing is quite effective to improve the schedulability of such a system, none of the real-time applications employ instruction level parallel scheduling techniques because most of the real-time scheduling models have not been designed for fine-grain execution. In this paper, we present a timing constraint model specifying high precision timing constraints, and a practical approach for constructing static schedules for a VLIW execution model. The new model and analysis can guarantee timing accuracy to within a single machine clock cycle.

• 한국정보처리학회논문지
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• 제4권6호
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• pp.1481-1494
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• 1997

실시간 시스템에서 시간적 제약의 불이행의 커다란 손실을 가져오며, 이를 위한 동적 스케쥴링은 유연성을 제공하는 대신 스케쥴링 오버헤드와 분석작업의 복잡성으로 인하여 스케쥴성을 예측하기 어려움이 있다. 반면, 정적 스케쥴링은 수행 중 오버헤드가 없으므로 정확한 시간을 예측할 수 있는 장점이 있다. 따라서 명령어 수준의 정적 스케쥴링과 시간 분석을 통하여 시스템의 시간적 정확도를 보장할 수 있다. 본 논문에서는 확정된 시간 분석을 위하여 befor와 after의 시간 제약을 고급 언어에 표현하고 이를 근거로 시간적 분석에 기반을 둔 컴파일러의 명령어 수준의 스케쥴링 알고리즘을 제안하였다. 이 스케쥴링의 특징은 명령어 수준의 스케쥴링을 위한 도메인이 지나치게 과대하므로 향상된 적합 유전자 알고리즘을 적용한 것이다.

• 전기학회논문지P
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• 제60권3호
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• pp.114-119
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• 2011

Large Power transformer is a complex and critical component of power plant and consists of cellulosic paper, insulation oil, core, coil etc. Insulation materials of transformer and related equipment break down to liberate dissolved gas due to corona, partial discharge, pyrolysis or thermal decomposition. The dissolved gas kinds can be related to the type of electrical faults, and the rate of gas generation can indicate the severity of the fault. The identities of gases being generated are using very useful to decide the condition of transformation status. Therefore dissolved gas analysis is one of the best condition monitoring methods for power transformer. Also, on-line multi-gas analyzer has been developed and installed to monitor the condition of critical transformers. Rogers method, IEC method, key gas method and Duval Triangle method are used to failure diagnosis typically, and those methods are using the ratio or kinds of dissolved gas to evaluate the condition of transformer. This paper analyzes the reliability of transformer diagnostic methods considering actual dissolved gas concentration. Fault diagnosis is performed based on the dissolved gas of five transformers which experienced various fault respectively in the field, and the diagnosis result is compared with the actual off-line fault analysis. In this comparison result, Diagnostic methods using dissolved gas ratio like Rogers method, IEC method are sometimes fall outside the ratio code and no diagnosis but Duval triangle method and Key gas method is correct comparatively.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 1988년도 학술세미나 강연집
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• pp.3-67
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• 1988

Model studies on the response of homgeneous earth embankment dams subjected to strike-slip fault movement have been penomed via centrifuge and finite element analysis. The centrifuge model tests have shown that crack development in earth embankment experiences two major patters: shear failure deep inside the embankment and tension failure near the surface. The shear rupture zone develops from the base level and propagates upward continuously in the transverse direction but allows no open leakage chnnel. The open tensile cracks develop near the surface of the embankment, but they disappear deep in the embankment. The functional relationship has been developed based on the results of the centrifuge model tests incorporating tile variables of amount of fault movement, embankment geometry, and crack propagation extent in earth des. This set of information can be used as a guide line to evaluate a "transient" safety of the duaged embankment subjected to strike-slip fault movement. The finite element analysis has supplemented the additional expluations on crack development behavior identified from the results of the centrifuge model tests. The bounding surface time-independent plasticity soil model was employed in the numerical analysis. Due to the assumption of continuum in the current version of the 3-D FEM code, the prediction of the soil structure response beyond the failure condition was not quantitatively accurate. However, the fundamental mechanism of crack development was qualitatively evaluated based on the stress analysis for the deformed soil elements of the damaged earth embankment. The tensile failure zone is identified when the minor principal stress of the deformed soil elements less than zero. The shear failure zone is identified when the stress state of the deformed soil elements is at the point where the critical state line intersects the bounding surface.g surface.

• 한국지리정보학회지
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• 제19권4호
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• pp.106-117
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• 2016

최근 환경보호와 신재생에너지 확보 일환으로 태양광발전소가 널리 보급되고 있으며, 태양광 모듈의 효율적인 관리를 위해서는 정기적인 점검이 필요하다. 본 연구에서는 UAV 기반 열적외선 카메라와 GIS 공간분석을 통해 태양광 모듈에 대한 고장여부를 진단할 수 있는 실험을 실시하였다. 먼저 고정익 UAV와 RGB 카메라를 이용하여 영상을 촬영한 후 Pix4D SW를 통해 정사영상을 생성하였으며, 정사영상 자료를 이용하여 태양광 모듈 레이어를 구축한 후 코드를 입력하였다. 또한 태양광 모듈 고장여부를 진단하기 위해 고무덮개를 태양광 모듈에 설치하였으며, 열적외선 카메라로부터 얻어진 온도 정보와 태양광 모듈 레이어를 기반으로 Zonalmean 함수를 통해 태양광 모듈별 평균온도를 계산할 수 있었다. 마지막으로 GIS 공간분석을 통해 이상 발열이 확인된 $37^{\circ}C$ 이상의 모듈을 자동으로 추출하고 각 모듈별 고유식별 코드를 식별함으로써 고무 덮개를 설치한 모듈의 위치를 정확하게 분석할 수 있었다.

• 전자공학회논문지
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• 제51권5호
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• pp.20-28
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• 2014

본 논문에서는 분산 제어망에서 통신 오류가 발생한 노드를 실시간으로 탐지할 수 있는 기법을 제안한다. 기존의 분산 제어망은 노드 내 오류가 발생하는 지점을 탐지하기 위해, 노드 간 의존성의 영향을 고려해야 하며 이는 전체적인 분산 제어망의 성능 저하의 원인이 될 수 있다. 이를 해결하기 위하여, 본 논문에서 제안된 기법은 각 노드의 손상으로 인해 발생되는 고장노드들을 빠른 시간 내에 탐지하기 위해 단일 Bose-Chaudhuri-Hocquenghem (BCH) 비트를 Cyclic Redundancy Check (CRC) 코드에 삽입하여 기존의 CRC 코드 내 비트와 대체하는 방식을 택한다. 고장 노드 판정의 탐지 정확성을 높이기 위해 고장 가중치 계수를 통한 고장 판단 기법을 제안한다. 제안된 기법의 효용성을 증명하기 위해 MATLAB을 이용하여 모의실험 환경을 구축하고, 제안된 기법의 성능을 분석하였다. 이를 통하여, BCH 코드 내 비트 간 분배를 통해 수정되는 정도에 관계없이 CRC 코드의 성능이 우수하게 보존됨을 알 수 있었으며, 기존의 CRC 코드 기법보다 빠른 시간 내에 손상된 노드를 탐지할 수 있음을 보였다.

• Earthquakes and Structures
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• 제8권6호
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• pp.1363-1386
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• 2015

The October 23 2011 Van Earthquake is studied from an earthquake engineering point of view. Strong ground motion processing was performed to investigate features of the earthquake source, forward directivity effects during the rupture process as well as local site effects. Strong motion characteristics were investigated in terms of peak ground motion and spectral acceleration values. Directiviy effects were discussed in detail via elastic response spectra and wide band spectograms to see the high frequency energy distributions. Source parameters and slip distribution results of the earthquake which had been proposed by different researchers were summarized. Influence of the source parameters on structural response were shown by comparing elastic response spectra of Muradiye synthetic records which were performed by broadband strong motion simulations of the earthquake. It has been emphasized that characteristics of the earthquake rupture dynamics and their effects on structural design might be investigated from a multidisciplinary point of view. Seismotectonic calculations (e.g., slip pattern, rupture velocity) may be extended relating different engineering parameters (e.g., interstorey drifts, spectral accelerations) across different disciplines while using code based seismic design approaches. Current state of the art building codes still far from fully reflecting earthquake source related parameters into design rules. Some of those deficiencies and recent efforts to overcome these problems were also mentioned. Next generation ground motion prediction equations (GMPEs) may be incorporated with certain site categories for site effects. Likewise in the 2011 Van Earthquake, Reverse/Oblique earthquakes indicate that GMPEs need to be feasible to a wider range of magnitudes and distances in engineering practice. Due to the reverse faulting with large slip and dip angles, vertical displacements along with directivity and fault normal effects might significantly affect the engineering structures. Main reason of excessive damage in the town of Erciş can be attributed to these factors. Such effects should be considered in advance through the establishment of vertical design spectra and effects might be incorporated in the available GMPEs.