• 대한조선학회논문집
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• 제33권1호
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• pp.19-26
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• 1996

프로펠러에 의한 선체변동압력을 추정하기 위해 3개의 선체에 7개의 프로펠러를 장착하여 실험과 계산치를 비교하였다. 변동압력의 계측은 KRISO의 공동터널에서 평판에 대하여 수행하였으며, 수치계산은 양력면 이론과 패널법을 사용한 수치프로그램(X-ForShip)을 사용하였다. 평판에 대한 실험값을 복잡한 선미형상에 적용하기 위하여 강체경계율(SBF)이 수정계수로 결정되었다. 실선 변동압력의 예측과 실험치의 수정을 위하여 복잡한 선미형상에서의 변동 압력을 계산하였다. 계산치와 수정된 실험치와의 좋은 일치를 보였으며, 수성계수로써 약 0.65-0.7의 값이 결정되었다.

• 대한인간공학회지
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• 제16권1호
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• pp.107-117
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• 1997

It is necessary to evaluate HMI inaspects of human factors in the design stage of MMIS(man machine interface system) and feedback the result of evaluation because operators performance is mainly influenced by the HMI. Therefore, the MMIS design should be reflected the operators psychological, behavioral and physiological characteristics in the interaction with human machine interface(HMI) in order to improve the safety and availability of the MMIS of a nuclear power plant(NPP) by reduction of human error. The development of human factors experimental evaluation techniques and integrated test facility(ITF) for the human factors evaluation become an important research field to resolve hi,am factors issues on the design of an advanced control room(ACR). We developed am ITF, which is aimed to experiment with the design of the ACR and the human machine interaction as it relates to the control of NPP. This paper presents the development of an ITF that consists of three rooms such as main test room(MTR), supporting test room(STR) and experiment control room(ECR). And, the ITF has a various facilities such as a human machine simulator(HMS), experimental measurement systems and data analysis and experiment evaluation supporting system(DAEXESS). The HMS consists of full-scope simulation model of Korean standard NPP and advanced HMI based on visual display nits (VDUS) such as touch color CRT, large scale display panel(LSDP), flat panel display unit and so on.

• Wind and Structures
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• 제10권5호
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• pp.401-420
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• 2007

Field measurements of the wind-induced response of two residential reinforced concrete buildings, among the tallest in the world, have been performed during two typhoons. Natural periods and damping values have been determined and compared with other field measurements and empirical predictors. Suitable and common empirical predictors of natural period and structural damping have been obtained that describe the trend of tall, reinforced concrete buildings whose structural vibrations have been measured in the collection of studies in Hong Kong compiled by the authors. This data is especially important as the amount of information known about the dynamic parameters of buildings of these heights is limited. Effects of the variation of the natural period and damping values on the alongwind response of a tall building for serviceability-level wind conditions have been profiled using the gust response factor approach. When using this approach on these two buildings, the often overestimated natural periods and structural damping values suggested by empirical predictors tended to offset each other. Gust response factors calculated using the natural periods and structural damping values measured in the field were smaller than if calculated using design-stage values.

• 대한조선학회논문집
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• 제38권3호
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• pp.23-30
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• 2001

고속 프로펠러들의 단면 및 기하학적 형상변화에 대한 캐비테이션 및 소음특성 연구가 새로운 실험장치를 이용하여 KRISO의 캐비테이션 터널에서 실험적으로 연구되었다. 대형 고속선형 프로펠러에 대한 날개단면, 부하분포 및 전개면적비 변화에 대한 일련의 캐비테이션 소음시험이 수행되었으며, 이런 실험결과로부터 캐비테이션 형태 및 프로펠러 형상에 대한 소음성능이 분석되었다. 새로운 실험장치를 이용하여 얻은 소음결과는 실선추정 및 고부하 저소음 추진기 설계에 유용한 자료로 활용될 수 있다.

• 대한조선학회논문집
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• 제54권4호
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• pp.275-285
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• 2017

In order to predict the sailing performance of a LNGC during actual operation, it is necessary to consider not only the information about resistance, maneuverability etc. but also the information such as sea route and sailing scenario etc., comprehensively. In this paper, we propose a new approach to conduct the sailing simulation of a LNGC without full scale measurement data. Latitude, longitude, sea route, speed over ground, time in UTC obtained from AIS data are substituted for the measured data. By combining the model test results, design information, and AIS data, prediction of sailing performance is conducted from the coast of southern Taiwan to the coast of Madagascar. The simulation is verified by comparing the calculated time histories of RPM and power with those of measured RPM and power.

• Structural Monitoring and Maintenance
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• 제7권4호
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• pp.319-344
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• 2020

Inverse analysis of non-linear reinforced concrete bridge pier using recursive Gaussian filtering for in-situ condition assessment is the main theme of this work. For this purpose, minimum variance unbiased estimation using unscented sigma points is adopted here. The uniqueness of this inverse analysis lies in its approach for strain based updating of engineering demand parameters, where appropriate bound and constrained conditions are introduced to ensure numerical stability and convergence. In this analysis, seismic input is also identified, which is an added advantage for the structures having no dedicated sensors for earthquake measurement. First, the proposed strategy is tested with a simulated example whose hysteretic properties are obtained from the slow-cyclic test of a frame to investigate its efficiency and accuracy. Finally, the experimental test data of a full-scale bridge pier is used to study its in-situ condition in terms of Park & Ang damage index. Overall the study shows the ability of the augmented minimum variance unbiased estimation based recursive time-marching algorithm for non-linear system identification with the aim to estimate the engineering damage parameters that are the fundamental information necessary for any future decision making for retrofitting/rehabilitation.

• Wind and Structures
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• 제38권2호
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• pp.119-128
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• 2024

The aerodynamic damping is an essential factor that can considerably affect the dynamic response of the cable-stayed bridge induced by crosswind load. However, developing an accurate and efficient aerodynamic damping model is crucial for evaluating the crosswind load-induced response on cable-stayed bridges. Therefore, this study proposes a new method for identifying aerodynamic damping of the bridge structures under crosswind load using an extended Kalman filter (EKF) and the particle filter (PF) algorithm. The EKF algorithm is introduced to capture the aerodynamic damping ratio. PF technique is used to select the optimal spectral representation of the noise. The effectiveness and accuracy of the proposed solution were investigated through full-scale vibration measurement data of the crosswind-induced on the bridge's girder. The results show that the proposed solution can generate an efficient and robust estimation. The errors between the target and extracted values are around 0.01mm and 0.003^o, respectively, for the vertical and torsional motion. The relationship between the amplitude and the aerodynamic damping ratio is linear for small reduced wind velocity and nonlinear with the increasing value of the reduced wind velocity. Finally, the results show the influence of the level of noise.

• Wind and Structures
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• 제23권4호
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• pp.313-350
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• 2016

Taipei 101 Tower, which has 101 stories with height of 508 m, is located in Taipei where typhoons and earthquakes commonly occur. It is currently the second tallest building in the world. Therefore, the dynamic performance of the super-tall building under strong wind actions requires particular attentions. In this study, Large Eddy Simulation (LES) integrated with a new inflow turbulence generator and a new sub-grid scale (SGS) model was conducted to simulate the wind loads on the super-tall building. Three-dimensional finite element model of Taipei 101 Tower was established and used to evaluate the wind-induced responses of the high-rise structure based on the simulated wind forces. The numerical results were found to be consistent with those measured from a vibration monitoring system installed in the building. Furthermore, the equivalent static wind loads on the building, which were computed by the time-domain and frequency-domain analysis, respectively, were in satisfactory agreement with available wind tunnel testing results. It has been demonstrated through the validation studies that the numerical framework presented in this paper, including the recommended SGS model, the inflow turbulence generation technique and associated numerical treatments, is a useful tool for evaluation of the wind loads and wind-induced responses of tall buildings.

• KEPCO Journal on Electric Power and Energy
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• 제6권2호
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• pp.163-171
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• 2020

전력연구원에서 설계한 5 MW급 일괄설치시스템의 예인안정성 및 내항성능 검증을 위해 수조모형시험을 실시하였다. 1/48 축소모형을 만들어 정수 및 파랑 중 시험을 수행하였다. 실선기준 4, 5, 6 knots의 대응속도로 예인하며 예인선의 장력을 계측하고, 실선의 필요 예인 동력을 추정하였다. 또한, 관성계측장치를 이용하여 모형의 6자유도 운동을 계측하였으며, 파랑 중 구속모형시험을 통해 내항성능을 확인하였다.

• 한국강구조학회 논문집
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• 제22권5호
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• pp.445-453
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• 2010

최근 추진되는 노후화된 저층형 건물의 리모델링의 대부분이 국내기준인 KBC2005의 내진성능에 미치지 못하는 실정이다. 이에 보강을 통한 신축건물과 견줄 수 있는 성능확보에 대한 연구가 많이 이루어지고 있으나, 실제건물의 진동계측을 통해 보강효과를 검증하는 연구는 상대적으로 매우 미흡한 실정이다. 또한 실물 구조물에 대하여 파괴 직전까지의 큰 손상 후에 진동계측을 통한 동적특성에 대한 연구도 매우 미약한 실정이다. 따라서 본 연구는 3층 철근콘크리트조 건물에 강판벽을 보강한 후 엑츄에이터로 하중을 주어 건물에 손상을 준 후에 손상 전 후의 진동 계측을 통하여 동적특성을 파악하였다. 진동계측을 통하여 보강효과를 확인할 수 있었다. 또한 80mm의 수평변위를 준 결과 구조물의 파괴 직전 손상 전 후에 장변과 단변의 고유진동수는 각각 20.85%, 5.77% 감소하였고, 감쇠율은 각각 53.9%, 23.15% 감소하였다.