• Journal of the Computational Structural Engineering Institute of Korea
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• v.23 no.3
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• pp.325-330
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• 2010

In the fields of design within civil engineering, BIM based Utilization of 3D object model is still far from commercialization. In this paper, BIM based 3D object model is composed for PSC box girder, super structure of railway bridge. The basic unit of the model is part model. The part model is the minimum unit model. And it has hierarchy to reflect the characteristics of structures. Change orders of structural designer must be reflected quickly in the 3D object model. Repetitive change orders are occurred in actual construction process. To prepare that, we classified design variables to parameters. Change orders of structural designer can be reflected quickly in the 3D object model because those parameters are related with information of 3D object model. In this paper, we studied various benefits of BIM based design method with 3D object model in the fields of design within civil engineering, and proposed the efficient application method of 3D object model for PSC box girder.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.864-865
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• 2015

차량 운전 시 주변에 경고를 하는 수단인 Vehicle Horn은 경험에 의존하는 방식으로 설계되고 있다. 그러나 Vehicle horn의 성능 및 제작비용을 고려한 최적설계를 위해서는 정형화된 설계 process가 필요하다. 이러한 필요를 충족시키고자 본 논문에서는 Vehicle Horn의 초기 설계 process를 제안한다. 자기등가회로를 이용해 특성을 예측하여 Vehicle horn의 초기 형상을 결정한다. 그리고 초기 형상에 대한 FEA를 수행하여 자기등가회로를 검증하고 전자기 파라미터를 산정한다. 마지막으로 전자기 파라미터를 Vehicle horn의 전기-기계 시스템을 구현한 Dynamic Simulator에 적용하여 Vehicle horn의 거동을 예측한다.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.13 no.3
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• pp.246-251
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• 2008

The conceptual design evaluation of Deep-Sea Manganese Nodule Miner(DSNM) based on Axiomatic Design was preformed. Functional Requirements(FRs) in functional domain and Design Parameters(DPs) in physical domain were embodied for the given concept design of DSNM. Interactions between FRs and DPs were sequentially analyzed from the first level hierarchy to the lower level hierarchy. The interactions were expressed as design matrices which showed the dependence or independence between FRs and DPs. The results showed that the design of DSNM was not a coupled one, but a decoupled. Finally, it was conceptually verified that DSNM was a good design satisfying the independence axiom of the Axiomatic Design.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.8
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• pp.997-1004
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• 2007

High resolution synthetic aperture radar image could be sensitive to the various parameters of the payload, platform, and ground system. In this paper, a parameter based SAR simulator is presented for two-dimensional image formation and image quality analysis. Functional modules are implemented by Matalb code and GUI for the flexibility and expandability. Main function of this simulator includes the SAR input signal generation, range-doppler algorithm(RDA) based SAR image formation, and the SAR image quality analysis which is relevant to the SAR system design parameters. This simulator can effectively be used for the SAR image quality performance evaluation, which can be applicable to the airborne as well as spaceborne SAR system design and analysis.

• Journal of Navigation and Port Research
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• v.31 no.1 s.117
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• pp.55-64
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• 2007

In general mechanical servo systems, friction deteriorates the performance of controllers by its nonlinear characteristics. Especially, friction phenomenon causes steady-state tracking errors and limit cycles in position and velocity control systems, even though gains of controllers are tuned well in linear system model. Even if sensor is used higher accuracy level, it is difficult to improve tracking performance of the position to the same level with a general control method such as PID type. Therefore, many friction models were proposed and compensation methods have been researched actively. In this paper, we consider that the variation of mover's mass is various by loading and unloading. The normal force variation occurs by it and other parameters. Therefore, the proposed control system is composed of main position controller and a friction compensator. A parameter estimator for a nonlinear friction model is designed by adaptive control law and adaptive backstepping control method.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2006.11a
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• pp.279-282
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• 2006

본 논문은 시간지연을 갖는 이산 비선형 시스템에 대한 점근적 안정화 및 $H_{\infty}$ 성능을 갖는 퍼지 제어기 설계 방법을 제안한다. 시간지연을 갖는 이산 Takagi-Sugeno 퍼지 모델에 대한 점근적 안정화 및 $H_{\infty}$ 성능을 만족하는 제어기 존재조건을 선형행렬부등식으로 나타낸다. 리아프노프 함수에 조정파라미터를 도입함으로써 제어기 존재조건을 조정파라미터를 포함하는 선형행렬 부등식으로 나타낸다. 선형행렬부등식에 있는 조정 파라미터를 조정함으로써 시스템의 응답속도 및 오버슈트 등의 동적 성능을 개선시킬 수 있다.

• Journal of the Korean Society for Railway
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• v.19 no.3
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• pp.331-340
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• 2016

Wheel load, design velocity, traffic amount (MGT), stiffness and thickness of sub-layers of asphalt concrete track are selected as performance design parameters in this study. A pseudo-static wheel load computed considering the dynamic amplification factor (DAF) based on the design velocity of the KTX was applied to the top of asphalt concrete track for full three dimensional structural analysis using the ABAQUS program. Tensile strains at the bottom of the asphalt concrete layer and vertical strains at the top of the subgrade were computed from the structural FEA with different combinations of performance parameter values for one asphalt concrete track section. Utilizing the computed structural analysis results such as the tensile strains and the vertical strains, it was possible to develop design graphs to investigate proper track sections for different combination of the performance parameters including wheel load, design velocity, traffic amount(MGT), stiffness and thickness of asphalt concrete layers for any given design life. By analyzing the proposed design graphs for asphalt concrete track, it was possible to propose simple design tables that can be used by engineers for the effective and fast design of track.

• Journal of the Korea Convergence Society
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• v.8 no.8
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• pp.17-26
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• 2017

CPV system is composed with CPV cells, modules, PCS(power conditioning system), solar tracker, system installation and balance of systems(BOS). Mention about modelling method which is applied for CPV system simulation and evaluation system analysis. This paper focuses on CPV system modeling and optimal design of the electric energy production analysis through the development of proposed optimal CPV system simulation. Calculated simulation results of the generalized CPV system in regard to loss parameter calculation method can make out optimal configuration of CPV system with high reliability and stability. The loss parameter calculation method establish a mathematical modeling for the purposed of simulation and utilization various data for economical analysis of the CPV system design.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.4C
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• pp.371-379
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• 2002

In this paper, the MMIC SPST switches operating from DC to 3GHz were designed and implemented. Prior to the design of switches, the small and large-signal switch models were needed to predict switch performance accurately. The newly proposed small-signal switch model parameters were extracted from measured S-parameters using optimization technique with estimated initial values and boundary limits. In the extraction of large-signal switch model parameters, the current source was modeled by fitting empirical equations to measured DC data and the charge model was derived from extracted channel capacitances from measured S-parameters varying the drain-source voltage. To design basic series-shunt SPST switches and isolation-improved SPST switches, we applied this model to commercial microwave circuit simulator. The improved SPST switches exhibited 0.302dB insertion loss, 35.762dB isolation, 1.249 input VSWR, 1.254 output VSWR, and about 15.7dBm PldB with 0/-3V control voltages at 3GHz.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.7
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• pp.1326-1331
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• 2006

Weld root gap is a important fact of a falling-off weld quality in various kind of weld defect. The welding quality can be controlled by monitoring important parameters, such as, the Arc voltage, welding current and welding speed during the welding process. Welding systems use either a vision sensor or an Arc sensor, both of which are unable to control these parameters directly. Therefore, it is difficult to obtain necessary bead geometry without automatically controlling the welding parameters through the sensors. In this paper we propose a novel approach using neural networks for detecting and monitoring of weld root gap and bead shape. Through experiments we demonstrate that the proposed system can be used for real welding processes. The results demonstrate that the system can efficiently estimate the weld bead shape and detect the welding defects.