• Advances in Computational Design
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• 제5권3호
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• pp.233-260
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• 2020

The main purpose to introduce model based controller in proposed control technique is to provide better and fast learning of the floating dynamics by means of fuzzy logic controller and also cancelling effect of nonlinear terms of the system. An iterative adaptive dynamic programming algorithm is proposed to deal with the optimal trajectory-tracking control problems for autonomous underwater vehicle (AUV). The optimal tracking control problem is converted into an optimal regulation problem by system transformation. Then the optimal regulation problem is solved by the policy iteration adaptive dynamic programming algorithm. Finally, simulation example is given to show the performance of the iterative adaptive dynamic programming algorithm.

• 대한전기학회논문지:시스템및제어부문D
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• 제54권3호
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• pp.148-155
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• 2005

A seam-line determination algorithm is proposed to determine image border-line in mosaicing using the transformation of gray value differences and dynamic programming. Since visually good border-line is the one along which pixel differences are as small as possible, it can be determined in association with an optimal path finding algorithm. A well-known effective optimal path finding algorithm is the Dynamic Programming (DP). Direct application of the dynamic programming to the seam-line determination causes the distance effect, in which seam-line is affected by its length as well as the gray value difference. In this paper, an adaptive cost transform algorithm with which the distance effect is suppressed is proposed in order to utilize the dynamic programming on the transformed pixel difference space. Also, a figure of merit which is the summation of fixed number of the biggest pixel difference on the seam-line (SFBPD) is suggested as an evaluation measure of seamlines. The performance of the proposed algorithm has been tested in both quantitively and visually on various kinds of images.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2004년도 ICEIC The International Conference on Electronics Informations and Communications
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• pp.438-441
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• 2004

Image binarization using a global threshold value [3] performs at high speed, but usually results in undesired binary images when the source images are of poor quality. In such cases, adaptive local thresholding algorithms [1][2][3] are used to obtain better results, and the algorithm proposed by A.E.Savekis which chooses local threshold using fore­ground and background clustering [1] is one of the best thresholding algorithms. However, this algorithm runs slowly due to its re-computing threshold value of each central pixel in a local window MxM. In this paper, we present a dynamic programming approach for the step of calculating local threshold value that reduces many redundant computations and improves the execution speed significantly. Experiments show that our proposal improvement runs more ten times faster than the original algorithm.

• 한국통신학회논문지
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• 제31권3B호
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• pp.175-182
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• 2006

본 논문에서는 Localized Aptive QoS 라우팅을 위해 POMDP(Partially Observable Markov Decision Processes)와 Exploration Bonus 기법을 사용하는 방법을 제안하였다. 또한, POMDP 문제를 해결하기 위해 Dynamic Programming을 사용하여 최적의 행동을 찾는 연산이 매우 복잡하고 어렵기 때문에 CEA(Certainty Equivalency Approximation) 기법을 통한 기댓값 사용으로 문제를 단순하였으며, Exploration Bonus 방식을 사용해 현재 경로보다 나은 경로를 탐색하고자 하였다. 이를 위해 다중 경로 탐색 알고리즘(SEMA)을 제안했다. 더욱이 탐색의 횟수와 간격을 정의하기 위해 $\phi$와 k 성능 파라미터들을 사용하여 이들을 통해 탐색의 횟수 변화를 통한 서비스 성공률과 성공 시 사용된 평균 홉 수에 대한 성능을 살펴보았다. 결과적으로 $\phi$ 값이 증가함에 따라 현재의 경로보다 더 나은 경로를 찾게 되며, k 값이 증가할수록 탐색이 증가함을 볼 수 있다.

• 센서학회지
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• 제6권2호
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• pp.123-130
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• 1997

이 논문은 다음과 같은 두가지 요소로 구성되는 독창적인 stereo vision system을 논술한다. declivity라는 새로운 개념을 도입한 자동선택 영상 분할처리 (self-adaptive image segmentation process) 와 자동선택 결정변수 (self-adaptive decision parameters) 를 응용하여 설계된 신속한 stereo matching algorithm. 현재, 실내 image의 depth map을 완성하는데 SUN-IPX 에서 3sec가 소요되나 연구중인 DSP Chip의 조합은 이 시간을 1초 이하로 단축시킬 수 있을 것이다.

• Journal of Computing Science and Engineering
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• 제6권1호
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• pp.26-38
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• 2012

Java has been increasingly used in programming for real-time systems. However, some of Java's features such as automatic memory management and dynamic compilation are harmful to time predictability. If these problems are not solved properly then it can fundamentally limit the usage of Java for real-time systems, especially for hard real-time systems that require very high time predictability. In this paper, we propose to exploit multicore computing in order to reduce the timing unpredictability that is caused by dynamic compilation and adaptive optimization. Our goal is to retain high performance comparable to that of traditional dynamic compilation, while at the same time, obtain better time predictability for Java virtual machine (JVM). We have studied pre-compilation techniques to utilize another core more efficiently, preoptimization on another core (PoAC) scheme to replace the adaptive optimization system (AOS) in Jikes JVM and the counter based optimization (CBO). Our evaluation reveals that the proposed approaches are able to attain high performance while greatly reducing the variation of the execution time for Java applications.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1999년도 추계종합학술대회 논문집
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• pp.403-407
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• 1999

In this paper we present an architecture, implementation, and performance evaluation of an adaptive communication system (ACS) for wide-area ATM clusters. Our approach capitalizes on thread-based programming model to overlap computation and communication and develop a dynamic message-passing environment with separate data and control paths. This leads to a flexible and adaptive message-passing environment that can support multiple flow control, error control, and multicasting algorithms. We show the performance of ACS applications and compare them with p4, PVM, and MPI applications.

• 한국지리정보학회지
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• 제7권2호
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• pp.16-28
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• 2004

영상 모자이크 작업에서 두 영상 간의 경계선이 보이지 않는 최적의 seam-line을 구하기 위해 화소값 차이 변환과 동적계획법 이용 알고리즘을 제안하였다. 영상 간의 경계선은 두 영상의 화소값 차이가 적은 화소를 따라 형성되는 것이 시각적 부담이 적다. 이 화소들을 연결하는 것은 최적 경로를 찾는 알고리즘을 이용할 수 있다. 최적 경로 결정에 효과적인 동적계획법을 seam-line 결정에 직접 적용하변 화소값의 차이뿐만 아니라, seam-line의 길이에 따라 영향을 받는 거리영향문제가 발생한다. 이 논문에서는 적응적 변환함수를 사용하여 비용 변환을 수행하고, 변환된 비용공간 상에서 동적계획법을 적용하여 거리영향이 억제된 최적 seam-line을 구할 수 있는 알고리즘을 개발하였다. 또한 결정된 seam-line을 평가하기 위해 일정한 개수의 상위 화소값의 차이를 누적한 값(SFBPD)을 척도로 제시하였다. 제안한 seam-line 결정방법을 다양한 종류의 영상에 대해 적용 실험하였으며, 시각적 및 SBPD 값에 의한 수치적 결과를 제시하였다.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 1993년도 Fifth International Fuzzy Systems Association World Congress 93
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• pp.1346-1349
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• 1993

In this paper, we describe the use of certain optimization techniques, principally dynamic programming and high level computational methods, to enhance the capabilities of a fuzzy adaptive neural network controller which we had developed for on-line control and adaption on complex nonlinear processes. Potential applications to an array of processes from diverse fields are discussed.

• 대한산업공학회지
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• 제37권4호
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• pp.331-341
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• 2011

This paper considers an inbound lot-sizing and outbound dispatching problem for a single product in a thirdparty logistics (3PL) distribution center. Demands are dynamic and finite over the discrete time horizon, and moreover, each demand has a delivery time window which is the time interval with the dates between the earliest and the latest delivery dates All the product amounts must be delivered to the customer in the time window. Ordered products are shipped by multiple vehicle types and the freight cost is proportional to the vehicle-types and the number of vehicles used. First, we formulate a mixed integer programming model. Since it is difficult to solve the model as the size of real problem being very large, we design a conventional genetic algorithm with a local search heuristic (HGA) and an improved genetic algorithm called adaptive genetic algorithm (AGA). AGA spontaneously adjusts crossover and mutation rate depending upon the status of current population. Finally, we conduct some computational experiments to evaluate the performance of AGA with HGA.