• 융합신호처리학회논문지
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• 제5권4호
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• pp.294-300
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• 2004

디지털 미디어의 증가로 비디오 클립을 효율적으로 정합하기 위한 다양한 알고리즘이 제안되었다. 기존의 비디오 검색 알고리즘에서는 주로 프레임 단위의 질의에 관한 검색 알고리즘이 연구되었으나 비디오 클립 단위의 질의에 관한 정합 알고리즘 연구는 미진하였다. 본 논문에서는 비디오 클립 질의에 관한 효율적인 비디오 색인과 검색 알고리즘을 제안한다. 시퀀스 정합의 정확도와 성능 향상을 위하여 연속되는 프레임의 히스토그램간의 유사도 함수로 커쉬함수를 사용하였으며 기존의 방법에 비해 높은 성능을 나타내었다. 비디오 샷들로부터 추출된 키프레임들은 샷묶음 뿐만 아니라 비디오 시퀀스 정합이나 브라우징에도 사용되며 여기서 키프레임은 이전 프레임들과 중요한 차이를 보이는 프레임을 나타낸다. 실험 영상을 이용한 실험결과 제안한 방법은 기존의 방법에 비해 적은 계산량으로 높은 정합 성능을 보였다.

• 대한전자공학회논문지SP
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• 제38권2호
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• pp.129-137
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• 2001

Matching Pursuit Algorithm은 저 전송 채널에서의 비디오 부호화에 뛰어난 효과를 나타내고 있지만, 주어진 입력 영상을 가장 유사하게 표현 하는데 필요한 구성 신호들을 찾아내기 위한 연산량이 많다는 현실적 문제점을 갖고 있다. 본 논문은 영상에 열화를 주지 않고 연산량을 크게 줄일 수 있는 새로운 방법을 제안한다. 이 방법은 전체적인 Matching Pursuit Algorithm중에서 가장 많은 연산을 요구하는, 영상을 구성하는 기본 신호들을 찾아내는데 필요한 내적 연산을 줄이는데 기초한다. 이를 위해 첫번째 과정으로 기존의 고속 방법인 분리성(Separable property)을 이용한 방법을 사용하여 주어진 입력영상과 수직성분의 1차원 기본 신호를 내적 하여 생성되는 결과값들을 저장한다. 두 번째 단계에서는 수평성분의 1차원 신호와의 내적 연산에 적용되는 부분들로 이루어진 1차원 신호들을 위치벡터의 개념을 도입하여 벡터길이를 측정한 후, 그 길이 값과 현재까지의 최대 내적 절대값을 서로 비교한 후 수평성분과의 내적 연산을 수행할지 하지 않을지를 판단한다. 대부분의 신호들은 다음단계의 내적 연산을 필요로 하지 않기 때문에 내적 연산랑을 크게 줄일 수 있다. 실험결과에 나타난 바와 같이, 대부분의 영상에서 화질에 전혀 열화를 수반하지 않고 기존 Neff의 고속방법보다 약 70%정도의 내적 연산량이 줄어듦을 알 수 있다.

• 제어로봇시스템학회논문지
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• 제5권3호
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• pp.363-369
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• 1999

In this paper, we design the robust $H_{\infty}$ controller for water level control of steam generator using a mixed $H_{\infty}$ optimization with model-matching method. Firstly we choose the desired model which has good disturbance rejection performance. Secondly we design a stabilizing controller to keep the model-matching error small and also provide sufficiently large stability margin against additive perturbations of the nominal plant. Simulation results show that proposed robust $H_{\infty}$ controller at specific power operation has satisfactory performances against the variations of load power, steam flow rate, primary circuit coolant temperature, and feedwater temperature. It can be also observed that the proposed robust $H_{\infty}$ controller exhibits better robust stability than conventional PI controller.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1991년도 하계학술대회 논문집
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• pp.877-880
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• 1991

In this paper, the architecture of a dataflow logic solving processor for programmable logic controller is proposed. As the proposed DFLSP(dataflow logic solving processor) is designed based on the dataflow architecture, it has inherently concurrent processing and data synchronization capabilities. And also, it has dynamic load balancing capabilites which increases the utilization of the whole system that can he hardly implemented in other multiprocessor system. The re-matching unit gets rid of unnecessary matching cycles in LSU, which increases the performance of LSU and allows the multiple input multiple output operations.

• 한국재료학회지
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• 제13권10호
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• pp.658-662
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• 2003

In this study, we have tried to find the optimized design variables of the matching layer which is important part of thickness mode ultrasonic transducer and finally reach the conclusion that the electrical property of piezo-element must be under consideration when the optimized acoustic impedance is estimated. Proper expression of the effective impedance of front load at free resonant frequency(: $Z_{f}$ $^{(0)}$ /) has been induced by introducing the principle of binomial multilayer transformer and gradient based numerical method is utilized to find the most acceptable value of $Z_{ f}$/$^{(0)}$ . Optimized point of acoustic impedance can be calculated directly from $Z_{f}$ $^{(0)}$ using some simple formula which we propose. We also verify our result by both numerical and experimental method and get a good enhancement especially it concern to the bandwidth of ultrasonic transducer.

• 한국자동차공학회논문집
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• 제5권6호
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• pp.192-201
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• 1997

The feedback control scheme of the pressure control system of the rear wheel steering gear which has relatively large volume and sprung load was built up in order to improve th response characteristic of the system. The control algorithm chosen was a feedback compensator joined by a feedfoward compensator and the model matching method was used in the process of control system design. The structures and properties of the reference models were inspected and the parameters of the controller were decided. The improvement of the response characteristic of the pressure control valve by means of the feedback control is affirmed. Particularly, when the order of the system model is higher than the 2nd order, the effectiveness of the feedback control on the improvement of the response characteristic of the valve is distinct. And the convenience of the model matching method is the process of control system design is confirmed as well.

• 융합신호처리학회논문지
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• 제7권1호
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• pp.11-16
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• 2006

To manipulate large video databases, effective video indexing and retrieval are required. A large number of video indexing and retrieval algorithms have been presented for frame-w]so user query or video content query whereas a relatively few video sequence matching algorithms have been proposed for video sequence query. In this paper, we propose an efficient algorithm to extract key frames using color histograms and to match the video sequences using edge features. To effectively match video sequences with low computational load, we make use of the key frames extracted by the cumulative measure and the distance between key frames, and compare two sets of key frames using the modified Hausdorff distance. Experimental results with several real sequences show that the proposed video retrieval algorithm using color and edge features yields the higher accuracy and performance than conventional methods such as histogram difference, Euclidean metric, Battachaya distance, and directed divergence methods.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 하계종합학술대회 논문집(4)
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• pp.295-298
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• 2002

This paper presents a fast block-matching algorithm to improve the conventional Three-Step Search (TSS) based method. The proposed Comparison Fast Block Matching Algorithm (CFBMA) begins with DAB for adaptive search range to choose searching method, and searches a part of search window that has high possibility of motion vector like other partial search algorithms. The CFBMA also considers the opposite direction to reduce local minimum, which is ignored in almost conventional based partial search algorithms. CFBMA uses the summation half-stop technique to reduce the computational load. Experimental results show that the proposed algorithm achieves the high computational complexity compression effect and very close or better image quality compared with TSS, SES, NTSS based partial search algorithms.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 ITC-CSCC -1
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• pp.278-281
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• 2000

Matching pursuit algorithm is a signal expansion technique whose efficiency for motion compensated residual image has already been demonstrated in the MPEG-4 framework. However, one of the practical concerns related to applying matching pursuit algorithm to real-time scalable video coding is its massive computation required for finding dictionary elements. In this respective, this paper proposes a fast algorithm, which is composed of three sub-methods. The first method utilizes the property of symmetry in 1-D dictionary element and the second uses mathematical elimination of inner product calculation in advance, and the last one uses frequency property of 2-D dictionary. Experimental results show that our algorithm needs about 30% computational load compared to the conventional fast algorithm using separable property of 2-D gabor dictionary with negligible quality degradation.

• 한국군사과학기술학회지
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• 제5권1호
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• pp.75-82
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• 2002

In this paper, the robust PID(Proportional-Integral-Derivative) controller was designed for speed control of BLDC motors using the frequency region model matching method. It was designed the robust PID controller satisfying disturbance attenuation and robust tracking performance using an H$\infty$ control method. The robust PID controller gains with the performances of the designed H$\infty$ controller are determined using the model matching method at frequency domain. Consequently, simulation results show that the proposed PID speed controller satisfies load torque disturbance attenuation and robust tracking performance, and this study has usefulness and applicability for the speed control system design of BLDC motors.