• Journal of Power Electronics
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• 제17권4호
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• pp.983-990
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• 2017

This paper proposes a model predictive control based on the discrete Lyapunov function to improve the performance of power electronic converters. The proposed control technique, based on the finite control set model predictive control (FCS-MPC), defines a cost function for the control law which is determined under the Lyapunov stability theorem with a control error compensation. The steady state and dynamic performance of the proposed control strategy has been tested under a single phase AC/DC voltage source rectifier (S-VSR). Experimental results demonstrate that the proposed control strategy not only offers global stability and good robustness but also leads to a high quality sinusoidal current with a reasonably low total harmonic distortion (THD) and a fast dynamic response under linear loads.

• Structural Monitoring and Maintenance
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• 제10권3호
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• pp.243-260
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• 2023

Indonesia has had seismic codes for earthquake-resistant structures designs since 1970 and has been updated five times to the latest in 2019. In updating the Indonesian seismic codes, seismic hazard maps for design also update, and there are changes to the Peak Ground Acceleration (PGA). Indonesian seismic design uses the concept of building performance levels consisting of Immediate occupancy (IO), Life Safety (LS), and Collapse Prevention (CP). Related to this performance level, cases still found that buildings were damaged more than their performance targets after the earthquake. Based on the above issues, this study aims to analyze the performance of base isolation design on existing target buildings and analyze the seismic fragility for a case study in Indonesia. The target building is a prototype design 8-story medium-rise residential building using the reinforced concrete moment frame structure. Seismic fragility analysis uses Incremental Dynamic Analysis (IDA) with Nonlinear Time History Analysis (NLTHA) and eleven selected ground motions based on soil classification, magnitude, fault distance, and earthquake source mechanism. The comparison result of IDA shows a trend of significant performance improvement, with the same performance level target and risk category, the base isolation structure can be used at 1.46-3.20 times higher PGA than the fixed base structure. Then the fragility analysis results show that the fixed base structure has a safety margin of 30% and a base isolation structure of 62.5% from the PGA design. This result is useful for assessing existing buildings or considering a new building's performance.

• 대한전기학회논문지
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• 제43권7호
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• pp.1075-1083
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• 1994

In this paper, a study on the improvement of the IM speed response against load torque variation is presented. A VSCS(Variable Structure Control System) is proposed which gives the desired robustness against load torque variation using a new kind of time-varing switching plane. In order to eliminate the reaching phase of the states from one switching plane to another during variation, the switching plane is varied continuously. To verify the high dynamic performance of the proposed VSCS, simulation and experimental results are presented.

• Asia Marketing Journal
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• 제10권1호
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• pp.1-23
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• 2008

고객만족경영을 통하여 기업이 이윤의 증진을 도모하는 것은 자명한 일이다. 따라서 고객만족과 기업성과와의 직접적인 관계를 밝히는 것은 학술적으로나 실무적으로 매우 중요하다. 고객만족이 기업경영성과에 미치는 영향에 관한 지금까지의 연구에서는 주로 당기의 고객만족이 당기의 기업경영성과에 미치는 현재효과를 분석하였다. 그러나 마케팅활동이 동태적 효과를 갖는다는 연구에 의하면 고객만족이 현재뿐만 아니라 미래의 기업 경영성과에 미치는 동태적 효과의 검증이 필요하다. 만약 이 효과가 존재함에도 불구하고 이를 충분히 측정하지 못한다면 고객만족의 효과는 낮게 평가될 것이다. 이에 본 연구에서는 패널자료분석을 통하여 기업의 수익성과 기업가치에 미치는 고객만족의 동태적 효과를 추정하였다. 연구결과, 고객만족은 기업의 수익성과 기업가치에 긍정적인 영향을 주며, 동태적 효과를 갖는 것으로 분석되었다. 또한 모형 추정결과, 모형의 적합도에서 이유재와 이청림(2006)보다 개선이 이루어 졌다. 한편 고객만족의 과거 항을 2기까지 추가한 비교모형은 추정결과의 해석이 어렵고, 다중공선성 문제가 있는 것으로 분석되었다.

• Steel and Composite Structures
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• 제43권5호
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• pp.533-552
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• 2022

The current article deals with the dynamic stability, and structural improvement of vibrating electrically curved screen on the viscoelastic substrate. By considering optimum value for radius curvature of the electrically curved screen, the structure improvement of the system occurs. For modeling the electrically system, the Maxwell's' equation is developed. Hertz contact model in employed to obtain contact forces between impactor and structure. Moreover, variational methods and nonlinear von Kármán model are used to derive boundary conditions (BCs) and nonlinear governing equations of the vibrating electrically curved screen. Galerkin and Multiple scales solution approach are coupled to solve the nonlinear set of governing equations of the vibrating electrically curved screen. Along with the analytical solution, 3D finite element simulation via ABAQUS package is provided with the aid of a FE package for simulating the current system's response. The results are categorized in 3 different sections. First, effects of geometrical and material parameters on the vibrational performance and stability of the curves panel. Second, physical properties of the impactor are taken in to account and their effect on the absorbed energy and velocity profile of the impactor are presented. Finally, effect of the radius and initial velocity on the mode shapes of the current structure is demonstrated.

• 대한기계학회논문집
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• 제10권4호
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• pp.541-557
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• 1986

본 연구에서는 캐패시턴스 성분을 고려한 브리지(bridge) 모델을 적용하여 지 금까지 설명할 수 없었던 문제를 설명함으로서 이 모델의 정당성을 확인하고자 하며, 더욱 나아가 다른 여러가지 변수에 대한 응답특성의 예측을 가능하게 하고자 한다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 추계학술대회
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• pp.799-804
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• 2004

Dynamic characteristic of CD/DVD deck for vehicle is analyzed in this paper. Generally CD/DVD deck for vehicle is used from inferior environment with the vibration of the vehicle and shock of outside and so on. Therefore it must have the structure which is stabilized from the vibration to prevent read error. For this purpose, vibration characteristic of the deck for vehicle should be identified. To analyze characteristic of the deck system, we perform the signal analysis and modal testing using the FFT analyzer. Also we change the design factor degrading the performance of the deck system and verify the efficiency improvement using the acceleration measurement occurring to the sound discontinuation.

• 대한기계학회논문집
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• 제18권11호
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• pp.2817-2824
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• 1994

A torque split type multi-pass CVT(MPC) system consiting of CVT and planetary gear train with 4 clutches was suggested to overcome the inherent inferior acceleration performance of CVT. Also, a shifting algorithm of MPC was suggested for the two driving modes : (1) power mode and (2) economy mode. By using the shifting algorithm and the MPC vehicle dynamic model, numerical simulations were performed to estimate the performance of the MPC vehicle. Simulation results showed that comparing the performance of the conventional 4-speed automatic transmission, an improvement in acceleration can be obtained by MPC for the power mode and 31% improvement in fuel economy for the economy mode.

• 한국통신학회논문지
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• 제15권11호
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• pp.937-944
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• 1990

DSBC 음성 부호화기의 성능 개선에 관한 두 방법을 제안하였다. 첫째는 계산량이 많은 종래의 비트할당을 수정함으로써 계산량을 줄일 수 있는 방법이고 둘째는 비전송 대역 재생시 백색잡음 주입으로 인한 허상 문제를 제거하기 위한 부대역 웨이팅 방법이다. 시뮬레이션 겨로가 검토된 방법은 음성 출력의 성능 향상에 응용할 수 있음을 나타내었다.

• 대한기계학회논문집A
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• 제29권7호
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• pp.1035-1041
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• 2005

Dynamic characteristics of CD/DVD deck fur vehicle are analyzed in this paper. Generally CD/DVD deck for vehicle is used from inferior environment with the vibration of the vehicle, shock of outside and so on. Therefore it must have the structure which is stabilized from the vibration to prevent read error. For this purpose, vibration characteristic of the deck for vehicle should be identified. To analyze characteristic of the deck system, we perform the signal analysis and modal testing using the EFT analyzer. Also we change the design factor degrading the performance of the deck system and verify the efficiency improvement using the acceleration measurement occurring to the sound discontinuation.