• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 B
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• pp.996-998
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• 2001

This paper presents an approach based on knowledge models to detect and isolate faults in a voltage source inverter. These faults do not affect the existing system protections. A diagnosis system which uses only the input variables of the drive is presented. It is based on the analysis of the current-vector trajectory and of the instantaneous frequency in faulty mode. These two methods have been verified in simulation results.

• The Journal of the Acoustical Society of Korea
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• 제29권3E호
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• pp.107-110
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• 2010

In this paper, the rationale and contents of the special issue of the Journal of the Acoustical Society of Korea regarding comprehensive reviews on past, present and future of biomedical ultrasound are described. Brief descriptions of invited articles are given, and efforts by all contributing authors are gratefully acknowledged.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1989년도 한국자동제어학술회의논문집; Seoul, Korea; 27-28 Oct. 1989
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• pp.535-540
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• 1989

This paper presents an approach for designing a linear multivariable servo mechanism for the case of constant and time varying disturbances. In this paper, we use an "observer-based" approach to consider the disturbance vector as states of the system and the resulting servomechanism design involves the design of an asymptotic observer which estimates both the actual plant states and the disturbance states. The design makes use of switching dynamics instead of switching logics to obtain the sliding mode and from the switching dynamics we can remove the undesirable chattering phenomena.phenomena.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1986년도 한국자동제어학술회의논문집; 한국과학기술대학, 충남; 17-18 Oct. 1986
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• pp.321-325
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• 1986

A new control scheme for the state space model of the robot system using the theory of optimal multi-variable structure is presented in this paper. It is proposed to optimize multi-dimensional variable structure systems for obtaining the required stabilizing signal by minimizing a performance index with respect to the state vector in the sliding mode. It is concluded the proposed variable structure controller yields better system dynamic performance than that obtained by using the only linear optimal controller inthat responses for a step disturbance have a shorter setting time, no matter what overshoot values and rising time.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 춘계학술대회논문집
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• pp.784-787
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• 2004

Modified version of subspace iteration method using accelerated starting vectors is proposed to efficiently calculate free vibration modes of structures. Proposed method employs accelerated Lanczos starting vectors that can reduce the number of iterations in the subspace iteration method. Proposed method is more efficient than the conventional method when the number of required modes is relatively small. To verify the efficiency of proposed method, two numerical examples are presented.

• Journal of the Korean Statistical Society
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• 제27권3호
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• pp.279-288
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• 1998

We propose a multiprocess dynamic Poisson model for the analysis of Poisson process with the covariates. The algorithm for the recursive estimation of the parameter vector modeling time-varying effects of covariates is suggested. Also the algorithm for forecasting of numbers of events at the next time point based on the information gathered until the current time is suggested.

• International Journal of CAD/CAM
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• 제9권1호
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• pp.79-83
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• 2010

Tidal bore is a peculiar nature phenomenon which is caused by the lunar and solar gravitation. Based on the physical characters of tidal bores, in this paper we propose a novel method to model and render this phenomenon, especially the tidal waves in Qiantang estuary. According to Boltzmann equation for tidal waves, we solve it with the novel triangle mesh of Kinectic Flux Vector Splitting (KFVS) mode. Then a method combining a curve forecasting wave and particles model is proposed to render the dynamic scenes of overturning tidal waves. Finally, with some rendering technologies, various realistic tidal waves under diversified conditions is rendered in real time.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2006년도 춘계학술대회
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• pp.253-256
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• 2006

This paper shows operating characteristics of DFIG(Double Fed Induction Generator) for wind turbine. The back to back PWM voltage-fed inverter connected between the rotor and grid network operated sub and super-synchronous operating mode, and the vector-controlled DFIG enables the decoupling between active and reactive power as well as between torque and power factor. This paper is validated by simulations and experimental results.

• Steel and Composite Structures
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• 제50권2호
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• pp.123-133
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• 2024

The paper deals with the propagation of Rayleigh waves in a nonlocal thermoelastic isotropic layer which is lying over a nonlocal thermoelastic isotropic half-space under the purview of Green-Lindsay model and Eringen's nonlocal elasticity in the presence of voids. The normal mode analysis is employed to the considered equations to obtain vector matrix differential equation which is then solved by eigenvalue approach. The frequency equation of Rayleigh waves is derived and different particular cases are also deduced. The effects of voids and nonlocality on different characteristics of Rayleigh waves are presented graphically.

• 한국멀티미디어학회논문지
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• 제11권10호
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• pp.1359-1365
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• 2008

H.264에서 채택하고 있는 기술들로 인해 H.264의 헤더는 이전 표준안들에 비해 전체 비트 열에서 더 많은 비율을 차지하기 때문에, H.264의 헤더를 압축하기 위한 새로운 기술이 필요하다. H.264에서는 구문요소를 일원화하여 부호화하는데, 부호화할 요소들의 발생 분포를 고려하지 않고 기존의 Exp-Golomb방식을 이용하기 때문에 가변 길이 부호화 관점에서 매우 비효율적이다. 헤더의 대부분을 매크로 블록 타입과 움직임 벡터 차이간이 차지하고 있으며, 본 논문에서 분석한 H.264의 헤더에서의 중복은 다음과 같은 세 가지이다. 매크로 블록 타입에서 자주 발생하는 부호와 그렇지 않는 부호가 있으며, 매크로 블록 모드가 8일 때, 네 개의 서브 매크로 블록 타입들이 모두 전송된다. 그리고 마지막으로 움직임 벡터 차이 값에서 같은 값(특히 '0')들이 발생한다. 본 논문에서는 타입 코드와 쿼드트리를 사용하는 알고리즘을 제안하고 있으며 헤더에서의 반복되는 정보를 이 두 가지 구조들을 가지고 표현한다. 타입 코드는 발생하는 매크로 블록의 모양을 나타내며, 쿼드트리는 움직임 추정 나무 구조를 나타낸다. 실험의 결과에서 제안하는 알고리즘이 JM12.4에 비해 최대 32.51% 비트율 감소를 보여준다.