• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2000년도 추계 학술발표회 논문집 Proceedings of EESK Conference-Fall 2000
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• pp.465-472
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• 2000

Seismic isolation technique has been applied mainly in low rise buildings and its seismic performance was satisfactory during Kobe Earthquake. However, in the case of medium and/or high-rise buildings, mid-story isolation could be more technically feasible than base isolation to reduce earthquake forces. In this paper, the seismic effectiveness of mid-story isolation in medium and/or high-rise shear building as well as low rise shear building was evaluated analytically. After verifying the effectiveness of mid-story isolation technique, this method also applied in residential-commercial building. It was found that mid-story isolation, that is isolation between upper residential area and lower commercial area, could reduce inter-story drift and floor shear forces comparing to the conventional fixed base.

• 센서학회지
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• 제30권2호
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• pp.119-124
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• 2021

Isolation and separation of biological nanoparticles, such as cells and extracellular vesicles, are important techniques for their characterization. Dielectrophoresis (DEP) based on microfluidic chips is an effective method to isolate and separate the nanoparticles. However, the electrodes of the DEP chips are electrolyzed by the electrical signals applied to the nanoparticles. Thus, the isolation/separation efficiency of the nanoparticles is reduced considerably. Through this study, we developed a microfluidic DEP chip for reliable isolation/ separation of nanoparticles and developed a passivation technique for the protection of the DEP chip electrodes. The electrode passivation process was designed using a hydrogel and the stability of the hydrogel passivation layer was verified. The fabricated DEP chip and the proposed passivation technique were used for the collection and dispersion of the fluorescent polystyrene nanoparticles. The proposed chip and the technique for isolation and separation of nanoparticles can be leveraged in various bioelectronic applications.

• 한국지진공학회논문집
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• 제19권6호
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• pp.293-302
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• 2015

ASCE 4 requires that a hard stop be built around the seismic isolation system in nuclear power plants. In order to maintain the function of the isolation system, this hard stop is required to have clearance-to-stop, which should be no less than the 90th-percentile displacements for 150% Design Basis Earthquake (DBE) shaking. Huang et al. calculated clearance-to-stop by using a Latin Hypercube Sampling technique, without considering the rocking behavior of the isolated structure. This paper investigates the effects on estimation of clearance-to-stop due to 1) rocking behavior of the isolated structure and 2) sampling technique for considering the uncertainties of isolation system. This paper explains the simplified analysis model to consider the rocking behavior of the isolated structure, and the input earthquakes recorded at Diablo Canyon in the western United States. In order to more accurately approximate the distribution tail of the horizontal displacement in the isolated structure, a modified Latin Hypercube Sampling technique is proposed, and then this technique was applied to consider the uncertainty of the isolation system. Through the use of this technique, it was found that rocking behavior has no significant effect on horizontal displacement (and thus clearance-to-stop) of the isolated structure, and the modified Latin Hypercube Sampling technique more accurately approximates the distribution tail of the horizontal displacement than the existing Latin Hypercube Sampling technique.

• 한국정보과학회논문지:시스템및이론
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• 제35권3호
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• pp.111-119
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• 2008

본 논문에서는 차별화 서비스를 지원하는 웹 서버의 응답시간 성능을 향상시키기 위해 기존의 동적 성능 분리 기법에 퍼지 기법을 접목한다. 특히, 클러스터 기반 웹서버 시스템의 부하량에 대한 판단 기준 흑은 사용자 요청율 및 동적요청 비율 변화시에 발생하는 애매모호한 상황을 효과적으로 반영하기 위해, 퍼지제어 기법에 기초한 로드분배 메커니즘을 제안하였다. 이를 통해, 기존의 퍼지 기법을 활용하지 않은 성능분리 기법과 퍼지기법을 활용한 경우에 대해 응답시간(95-percentile of Response Time) 성능비교 평가를 통해 퍼지기반의 성능분리 기법이 차별화 서비스 시스템의 성능을 더욱 강건하고 효율적으로 향상시킬 수 있다는 점을 검증하였다.

• 한국정보과학회논문지:시스템및이론
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• 제28권10호
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• pp.541-547
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• 2001

코이를 기초로 설계된 칩을 테스팅 하기 위해서는 각 코어로의 테스트 데이터 접근을 위해 완전히 분리 링 필요하다. 부분 분리 링은 코어를 둘러싸고 있는 분리 링의 크기를 줄이고 분리 링으로써의 역할을 모두 수행한다. 본 논문에서는 기존의 방법들보다 부분 분리 링의 크기를 더욱 작게 하고 해법을 찾는 데 걸리는 시간보다 줄일수 있는 효율적인 방법을 제시한다. 이를 위해 테스트 가능도에 기반을 둔 효율적인 순위 결정 기법을 적용하였으며 SOC 테스팅의 특성을 살린 정렬 기법을 적용하였다. 실험결과에서 기존의 방법들보다 본 논문에 제시된 방법이 실제로 유용하다는 것을 보여준다.

• International Journal of Aeronautical and Space Sciences
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• 제7권1호
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• pp.73-83
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• 2006

In this paper, a redundancy management system for aircraft is studied, and fault detection and isolation algorithms of inertial sensor system are proposed. Contrary to the conventional aircraft systems, UAV system cannot allow triple or quadruple hardware redundancy due to the limitations on space and weight. In the UAV system with dual sensors, it is very difficult to identify the faulty sensor. Also, conventional fault detection and isolation (FDI) method cannot isolate multiple faults in a triple redundancy system. In this paper, two FDI techniques are proposed. First, hardware based FDI technique is proposed, which combines a parity equation approach with a wavelet based technique. Second, analytic FDI technique based on the Kalman filter is proposed, which is a model-based FDI method utilizing the threshold value and the confirmation time. To provide the reference value for detecting the fault, residuals are calculated using the extended Kalman filter. To verify the effectiveness of the proposed FDI methods, numerical simulations are performed.

• 한국구조물진단유지관리공학회 논문집
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• 제18권5호
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• pp.107-115
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• 2014

본 연구에서는 건물의 질량중심과 면진층의 강성중심 사이의 차이에 따른 면진효과에 대하여 살펴보았다. 면진기술은 면진층에 설치되는 면진장치의 성능에 크게 의존하는 기술이므로 면진장치 제작 후 전수검사를 통하여 면진장치의 수평강성을 검토하게 되어 있다. 하지만 면진장치 성능실험 시 각각의 면진장치의 품질기준은 건축기준에는 정해져 있지 않으며, 이로 인해 설계 시 적용된 강성과 실제 강성의 차이가 발생하여 면진층 상부 부재에 큰 문제를 야기할 수 있다. 연구결과, 최대응답변위의 차이는 크게 나타나지 않았으나 편심이 증가할수록 최대응답가속도, 층전단력 및 상부구조의 부재력은 크게 증가하여 일부 부재에서는 과도한 손상이 예상된다. 따라서 면진층은 실제 장치 제작 후 전수검사를 실시하여 반드시 설계된 의도대로 편심이 발생하지 않도록 장치를 재배치할 필요가 있으며, 가능하다면 건물의 질량중심과 강성중심의 차이는 동일하게 설계할 것을 추천한다.

• 한국소음진동공학회논문집
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• 제21권9호
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• pp.858-867
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• 2011

As applying an active control technique to a pneumatic vibration isolation system, the settling time for the payload excitation could be remarkably reduced as well as the improvement of isolation performance for the ground vibration. Some previous researches were dealt with the settling time through the simulation or experiment but, the discussion on the simulation or experimental results including moving parts, such as a XY-stage, on the isolation table rarely exists. As considering the moving part, the dynamic model could be time varying system and in such a case the force imposed on pneumatic vibration isolation table could be described by inertial forces of moving parts according to Newton's 3rd law, the action and reaction law. In this paper, the simulation procedure of the 3-DOF active pneumatic vibration isolation system including moving parts by TDC(time delay control) technique is proposed and the effectiveness through simulation results are also shown.

• 한국자동차공학회논문집
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• 제9권2호
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• pp.168-175
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• 2001

Reduction of structure-borne noise of the compartment in a car is an important task in automotive engineering. Transfer path analysis using vibroacoustic reciprocity technique or multiple path decomposition method has generally been used for structure-borne noise path analysis. These methods are useful in solving particular problem but do net quantify the effectiveness of vibration isolation of each isolator of a vehicle. To quantify the effectiveness of vibration isolation, the vibrational power flow has been used for a simple isolation system or a laboratory based isolation system. It is often difficult to apply the vibrational power flow technique to the complex isolation system like a car. In this paper, a simple equation is derived for calculation of the vibrational power flow of an isolation system with multiple isolators such as a car. It is successfully applied to not only quantifying the relative contributions of eighteen isolators but also reducing structure-borne noise of a passenger car. According to the results, the main contributor of eighteen isolators is the rear roll mount of an engine. The reduced structure-borne noise level is about 5dBA.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2000년도 추계학술대회논문집
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• pp.208-214
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• 2000

Reduction of structure-borne noise of the compartment in a car is an important task in automotive engineering. Transfer path analysis using vibroacoustic reciprocity technique or multiple path decomposition method has generally been used for structure-borne noise path analysis. These methods are useful in solving particular problem but do not quantify the effectiveness of vibration isolation of each isolator of a vehicle. To quantify the effectiveness of vibration isolation, the vibrational power flow has been used for a simple isolation system or a laboratory based isolation system. It is often difficult to apply the vibrational power flow technique to the complex isolation system like a car. In this paper, a simple equation is derived for calculation of the vibrational power flow of an isolation system with multiple isolators such as a car. It is successfully applied to not only quantifying the relative contributions of eighteen isolators but also reducing structure-borne noise of a passenger car. According to the results, the main contributor of eighteen isolators is the rear roll mount of an engine. The reduced structure-borne noise level is about 5dBA.