• 대한수학회지
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• 제37권5호
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• pp.779-791
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• 2000

The nonlinear stage of the evolution of free boundary between a light fluid and a heavy fluid driven by an external force is studied by a potential flow model with a source singlarity. The potential flow model is applied to a bubble and spije evolution for constantly accelerated interface (Rayleigh-Taylor instability) and impulsively accelerated interface (Richtmyer-Meshkow instability). The numerical results of the model show that, in constantly accelerated intergace, bubble grows with constant velocity and the spike falls with gravitational acceleration at later times, while the velocity of the bubble in impulsively accelerated interface decay to zero asymp flow model for the bubble and spike for constantly accelerated interface and impulsively accelerated interface.

• 한국항공우주학회지
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• 제34권5호
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• pp.88-92
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• 2006

과학기술위성 2호 사용되는 구동기인 반작용 휠(Reaction Wheel Assembly, RWA)과 위성 시스템을 연결해주는 인터페이스를 담당하는 Reaction Wheel Assembly Interface Unit(RIU)의 Proto Flight Model의 개발이 완료되고 동작시험을 마쳤다. RIU는 RWA에 공급되는 전원을 켜고 끄는 스위치와 명령을 주고 받는 위성탑재 컴퓨터(OBC)의 통신 회선을 선택하는 멀티플렉서, 그리고 RWA에 연결되는 물리적 통신라인으로 구성된다.

• 대한전기학회논문지:전력기술부문A
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• 제50권2호
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• pp.83-89
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• 2001

This paper introduces a power flow model of SSSC for voltage stability analysis of power system installed with Static Synchronous Compensators. The SSSC model is obtained from the injection model of voltage source inverter by adding the condition that SSSC injection voltage is in quadrature with current of SSSC-installed branch. This model is incorporated into modified CPF algorithm to study effects of SSSC on the security-constrained interface flow limit. Determination of interface flow limit is simply briefed. In case study a 771-bus real system is used to show that interface flow limit can be improved by appropriate control of SSSC in terms of voltage stability.

• Structural Engineering and Mechanics
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• 제5권6호
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• pp.817-837
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• 1997

In the present contribution an interface crack model is introduced which is capable of modelling crack initialisation and growth in aluminium as well as in Fibre Metal Laminates. Interface elements are inserted in a finite element mesh with a yield function which bounds all states of stress in the interface. Hardening occurs after a state of stress exceeds the yield stress of the material. The hardening branch is bounded by the ultimate stress of the material. Thereafter, the state of stress is reduced to zero while the inelastic deformations grow. The energy dissipated by the inelastic deformations in this process equals the fracture energy of the material. The model is applied to calculate the onset and growth of cracking in centre cracked plates made of aluminium and GLARE$^{(R)}$. The impact of the model parameters on the performance of the crack model is studied by comparisons of the numerical results with experimental data.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 1998년도 추계학술대회 학술발표 논문집
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• pp.31-36
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• 1998

This paper proposes a method to select essential elements in a human evaluation model using the Choquet integral based on fuzzy measures and applies the model to the evaluation of human interface. Three kinds of concepts, Increment Degree, average of Increment Degree, Necessity coefficient, are defined. The proposed method selects essential elements by the use of the Relative necessity coefficient. The proposed method is applied to the analysis of human interface. In the experiment, (1) a warning sound, (2)a color vision, (3) the size of working area, (4) a response of confirmation, are considered as human interface elements. subjects answer the questionnarie after the experiment. From the data of questionnaire, fuzzy measures are identified and are applied to the proposed model. effectiveness of the proposed model is confirmed by the comparison of human interface elements extracted from the proposed model and those from the questionnarie.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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• pp.787-790
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• 1997

This paper proposes a method which selects essential elements in a human evaluation model using the Choquet integral based on fuzzy measures, and applies the model to the evaluation of human interface. Three kinds of concepts are defined to select essential elements. Increment Degree implies the increment degree from fuzzy measures of composed elements to the fuzzy measure of a combined element. Average of Increment Degree of an element means the relative possibility of superadditivity of the fuzzy measure of each combined element. Necessity Degree means the selection degree of each combined element as a result of the human evaluation. A task experiment, which consists of a static work and two dynamic works, is performed by the use of some human interfaces. In the experiment, (1) a warning sound which gives an attention to subjects, (2) a color vision which can be distinguished easily or not, (3) the size of working area and (4) a response of confirmation that is given from an interface, are considered as human interface elements. Subjects answer the questionnaire after the experiment. From the data of the questionnaire, fuzzy measures are identified and are applied to the proposed model. Effectiveness of the proposed model is confirmed by the comparison of human interface elements extracted from the proposed model and those from the questionnaire.

• 한국BIM학회 논문집
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• 제5권1호
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• pp.1-7
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• 2015

Modular technology has become a major issue of the construction industries to enhance their productivity. Modular bridge construction generally requires the data exchange between the contractors, designers, fabricators and constructors. Therefore, a readily accessible information model interface module based on BIM technology is essential for their communication during a project life-cycle. In this study, BIM based information model interface module for a modular pier was developed. For the information models, the PBS(Product Breakdown Structure) and LOD(Level of Development) were defined. Next, all components of a modular pier were conducted by the parametric modeling technique, and then 3D cell library interface was developed. An nterface module was also developed using VBA(Visua basic Application) for exchanging a data from 3D model library to other softwares such as Microstation, AutoCad and Excel and was connected with MS Access database. The developed information model interface module would improve the design quality of the modular pier and reduce the time and cost for design. Updated 3D information models could be utilized for the fabrication, assembly, and construction process for modular piers.

• 한국문헌정보학회지
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• 제26권
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• pp.167-185
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• 1994

The purpose of this study is to develop the optimal user/librarian interface in information searching. In order to achive the purpose, the 150 unskilled students as subjects have participated in the study. According to the change of the subjects' psychological information states by the access points within the library system, the subjects have been classified into the five types of model: the initial information state, the accepted identification information state, the bibliographic information state, the stack information state, and the location information state. Librarian's searching support is done for 10 minutes at the each access points. To develop the optimal user/librarian interface, the expected values of the models are calculated. The resultants are as follows: 1) The expected value of the initial information states model is 18.94: 2) The expected value of the accepted identification information model is 27.06: 3) The expected value of the bibliographic information state model is 27.06: 4) The expected value of the stack information state model is 22.38: 5) The expected value of the location information state model is 22.38. Those expected values are compared with each other. The model with the lowest expected value is chosen as the optimal user/librarian interface model. In the result, the user's initial information state model of the optimal user/librarian interface in information searching is developed. In order to search the information with the most effect, user must be interfaced with the librarian at his/her own initial information state.

• 대한토목학회논문집
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• 제26권3B호
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• pp.263-269
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• 2006

해안지역의 지하수 개발 및 관리를 위하여 해안지하수 최적모델이 개발되었다. 최적모델은 해안지하수 흐름 모델과 최적화 기법으로 구성된다. 본 논문은 최적모델의 중요 구성요소인 경계면 수치모델을 검정하는 것이 목적이다. 염수체 위에 담수체가 부양하는 현상인 담수렌즈를 실험하기 위하여 실험실 수리모형이 제작되었다. 담수-염수 경계면 위치와 관정에서의 염분 농도의 실험 결과 값들이 수치모델의 결과 값들과 비교되었다. 경계면의 위치는 평균 상대오차율은 2.91%~4.39%로써 결과 값들이 잘 일치하였다. 관정에서의 염분 농도에 대한 비교 결과 또한 적절한 값을 나타내었다. 따라서 경계면 수치모델에 의한 해안지하수 흐름 거동 평가는 적절한 결과 값을 도출할 수 있을 것으로 판단된다.

• Smart Structures and Systems
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• 제20권2호
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• pp.181-195
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• 2017

In this study, the severity of damage in tendon anchorage caused by the loss of tendon forces is quantitatively identified by using the PZT interface-based impedance monitoring technique. Firstly, a 2-DOF impedance model is newly designed to represent coupled dynamic responses of PZT interface-host structure. Secondly, the 2-DOF impedance model is adopted for the tendon anchorage system. A prototype of PZT interface is designed for the impedance monitoring. Then impedance signatures are experimentally measured from a laboratory-scale tendon anchorage structure with various tendon forces. Finally, damage severities of the tendon anchorage induced by the variation of tendon forces are quantitatively identified from the phase-by-phase model updating process, from which the change in impedance signatures is correlated to the change in structural properties.