• 제목/요약/키워드: Local search

검색결과 1,004건 처리시간 0.029초

An Adaptive Motion Estimation Algorithm Using Spatial Correlation (공간 상관성을 이용한 적응적 움직임 추정 알고리즘)

  • 박상곤;정동석
    • Proceedings of the IEEK Conference
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    • 대한전자공학회 2000년도 하계종합학술대회 논문집(4)
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    • pp.43-46
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    • 2000
  • In this paper, we propose a fast adaptive diamond search algorithm(FADS) for block matching motion estimation. Fast motion estimation algorithms reduce the computational complexity by using the UESA (Unimodal Error Search Assumption) that the matching error monotonically increases as the search moves away from the global minimum error. Recently many fast BMAs(Block Matching Algorithms) make use of the fact that the global minimum points in real world video sequences are centered at the position of zero motion. But these BMAs, especially in large motion, are easily trapped into the local minima and result in poor matching accuracy. So, we propose a new motion estimation algorithm using the spatial correlation among the adjacent blocks. We change the origin of search window according to the spatially adjacent motion vectors and their MAE(Mean Absolute Error). The computer simulation shows that the proposed algorithm has almost the same computational complexity with UCBDS(Unrestricted Center-Biased Diamond Search)〔1〕, but enhance PSNR. Moreover, the proposed algorithm gives almost the same PSNR as that of FS(Full Search), even for the large motion case, with half the computational load.

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A Fast Motion Estimation Algorithm with Motion Analysis (움직임 해석을 통한 고속 움직임 예측 알고리즘)

  • Jun, Young-Hyun;Yun, Jong-Ho;Cho, Hwa-Hyun;Choi, Myung-Ryul
    • Proceedings of the IEEK Conference
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    • 대한전자공학회 2005년도 추계종합학술대회
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    • pp.339-342
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    • 2005
  • We present an efficient block-based motion estimation algorithm with motion analysis. The motion analysis determines a size of search pattern and a maximum repeated count of search pattern. In case of large movement in large image, we reduce search points and the local minimum which caused by low performance. The proposed algorithm employs with searching step of 2. The first step determines an initial search point with neighbor block vector and a size of initial search pattern. The second step determines a size of search pattern and a maximum repeated count with motion analysis. We improve motion prediction accuracy while reducing required computational complexity compared to other fast block-based motion estimation algorithms.

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Pareto fronts-driven Multi-Objective Cuckoo Search for 5G Network Optimization

  • Wang, Junyan
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제14권7호
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    • pp.2800-2814
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    • 2020
  • 5G network optimization problem is a challenging optimization problem in the practical engineering applications. In this paper, to tackle this issue, Pareto fronts-driven Multi-Objective Cuckoo Search (PMOCS) is proposed based on Cuckoo Search. Firstly, the original global search manner is upgraded to a new form, which is aimed to strengthening the convergence. Then, the original local search manner is modified to highlight the diversity. To test the overall performance of PMOCS, PMOCS is test on three test suits against several classical comparison methods. Experimental results demonstrate that PMOCS exhibits outstanding performance. Further experiments on the 5G network optimization problem indicates that PMOCS is promising compared with other methods.

Efficient Path Search Method using Ant Colony System in Traveling Salesman Problem (순회 판매원 문제에서 개미 군락 시스템을 이용한 효율적인 경로 탐색)

  • 홍석미;이영아;정태충
    • Journal of KIISE:Software and Applications
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    • 제30권9호
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    • pp.862-866
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    • 2003
  • Traveling Salesman Problem(TSP) is a combinational optimization problem, Genetic Algorithm(GA) and Lin-Kernighan(LK) Heuristic[1]that is Local Search Heuristic are one of the most commonly used methods to resolve TSP. In this paper, we introduce ACS(Ant Colony System) Algorithm as another approach to solve TSP and propose a new pheromone updating method. ACS uses pheromone information between cities in the Process where many ants make a tour, and is a method to find a optimal solution through recursive tour creation process. At the stage of Global Updating of ACS method, it updates pheromone of edges belonging to global best tour of created all edge. But we perform once more pheromone update about created all edges before global updating rule of original ACS is applied. At this process, we use the frequency of occurrence of each edges to update pheromone. We could offer stochastic value by pheromone about each edges, giving all edges' occurrence frequency as weight about Pheromone. This finds an optimal solution faster than existing ACS algorithm and prevent a local optima using more edges in next time search.

A Neighbor Selection Technique for Improving Efficiency of Local Search in Load Balancing Problems (부하평준화 문제에서 국지적 탐색의 효율향상을 위한 이웃해 선정 기법)

  • 강병호;조민숙;류광렬
    • Journal of KIISE:Software and Applications
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    • 제31권2호
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    • pp.164-172
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    • 2004
  • For a local search algorithm to find a bettor quality solution it is required to generate and evaluate a sufficiently large number of candidate solutions as neighbors at each iteration, demanding quite an amount of CPU time. This paper presents a method of selectively generating only good-looking candidate neighbors, so that the number of neighbors can be kept low to improve the efficiency of search. In our method, a newly generated candidate solution is probabilistically selected to become a neighbor based on the quality estimation determined heuristically by a very simple evaluation of the generated candidate. Experimental results on the problem of load balancing for production scheduling have shown that our candidate selection method outperforms other random or greedy selection methods in terms of solution quality given the same amount of CPU time.

Structurally Enhanced Correlation Tracking

  • Parate, Mayur Rajaram;Bhurchandi, Kishor M.
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제11권10호
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    • pp.4929-4947
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    • 2017
  • In visual object tracking, Correlation Filter-based Tracking (CFT) systems have arouse recently to be the most accurate and efficient methods. The CFT's circularly shifts the larger search window to find most likely position of the target. The need of larger search window to cover both background and object make an algorithm sensitive to the background and the target occlusions. Further, the use of fixed-sized windows for training makes them incapable to handle scale variations during tracking. To address these problems, we propose two layer target representation in which both global and local appearances of the target is considered. Multiple local patches in the local layer provide robustness to the background changes and the target occlusion. The target representation is enhanced by employing additional reversed RGB channels to prevent the loss of black objects in background during tracking. The final target position is obtained by the adaptive weighted average of confidence maps from global and local layers. Furthermore, the target scale variation in tracking is handled by the statistical model, which is governed by adaptive constraints to ensure reliability and accuracy in scale estimation. The proposed structural enhancement is tested on VTBv1.0 benchmark for its accuracy and robustness.

Local Obstacle Avoidance Method of Mobile Robots Using LASER scanning sensor (레이저 스캐닝 센서를 이용한 이동 로봇의 지역 장애물 회피 방법)

  • Kim, Sung Cheol;Kang, Won Chan;Kim, Dong Ok;Seo, Dong Jin;Ko, Nak Yong
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • 제51권3호
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    • pp.155-160
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    • 2002
  • This paper focuses on the problem of local obstacle avoidance of mobile robots. To solve this problem, the safety direction section search algorithm is suggested. This concept is mainly composed with non-collision section and collision section from the detecting area of laser scanning sensor. Then, we will search for the most suitable direction in these sections. The proposed local motion planning method is simple and requires less computation than others. An environment model is developed using the vector space concept to determine robot motion direction taking the target direction, obstacle configuration, and robot trajectory into account. Since the motion command is obtained considering motion dynamics, it results in smooth and fast as well as safe movement. Using the mobile base, the proposed obstacle avoidance method is tested, especially in the environment with pillar, wall and some doors. Also, the proposed autonomous motion planning and control algorithm are tested extensively. The experimental results show the proposed method yields safe and stable robot motion through the motion speed is not so fast.

A Rule-Based System for VLSI Gate-Level Logic Optimization (VLSI 게이트 레벨 논리설계 최적화를 위한 Rule-Based 시스템)

  • Lee, Seong-Bong;Chong, Jong-Wha
    • Journal of the Korean Institute of Telematics and Electronics
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    • 제26권1호
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    • pp.98-103
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    • 1989
  • A new system for logic optimization at gate-level is proposed in this paper. Ths system is rule-based, i which the rules represent the local trnsformation replacing a portion of circuits with the simplified equivalent circuits. In this system, 'rule generalization' and 'local optimization' are proposed for effective pattern matching. Rule generalization is used to reduce the circuit-search for pattern matching, and local optimization, to exclude unnecessary circuit-search. In additionk, in order to reduce unnecessary trial of pattern matching, the matching order of circuit patern is included in the rule descriptions. The effectiveness of this system is shown by its application ot the circuits which are generated by a hardware compiler.

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Study of Latest Trend on Acupuncture for Obesity Treatment

  • Chun, Hea-Sun;Kim, Dong-Hwan;Song, Ho-Seub
    • Journal of Pharmacopuncture
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    • 제24권4호
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    • pp.173-181
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    • 2021
  • Objectives: The aim of this review was to appraise Korean studies published between 2010 and 2021 which examined the role of acupuncture in the treatment of obesity. Methods: We performed a search of the NDSL, KISS, RISS, OASIS, PubMed, EMBASE electronic databases for relevant animal researches, case reports, and clinical trials, using the following search terms: 'obesity', 'acupuncture', 'electroacupuncture', and 'pharmacopuncture'. We excluded previous reviews and meta-analyses, studies not related to obesity or acupuncture treatment, as well as studies conducted in countries other than Korea. We also excluded studies where relevant information on acupuncture treatment in obesity could not be obtained. Results: Most studies were conducted in animals, followed by case reports and clinical trials. In animal researches and case reports, pharmacopuncture was the most used intervention. In case studies, electroacupuncture, thread-embedding therapy, manual acupuncture, acupotomy, and auricular acupuncture were also used. In animal researches, pharmacopuncture treatment was associated with improvement in obesity indices. In the case of local obesity, specific acupuncture techniques such as thread-embedding therapy and pharmacopuncture were associated with significant improvements in local obesity, even when diet and exercise were not controlled for. Conclusion: Acupuncture treatment showed significant benefit in the treatment of obesity, with a local effect evident for certain approaches, such thread-embedding therapy and acupotomy.

Efficacy of dental local anesthetics: A review

  • Badr, Nelly;Aps, Johan
    • Journal of Dental Anesthesia and Pain Medicine
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    • 제18권6호
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    • pp.319-332
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    • 2018
  • The objective of this review was to investigate the efficacy of dental local anesthetics, as it is well known among clinicians that local anesthesia may be challenging in some circumstances. Therefore, the focus of this review was on the efficacy of the products used in dental local anesthesia. In a Pubmed database literature search conducted, a total of 8646 articles were found to be related to dental local anesthetics. After having applied the inclusion criteria (human research, performed in the last 10 years, written in English language, and focus on dental local anesthetics) and having assessed the quality of the papers, 30 were deemed eligible for inclusion in this review. The conclusion of this review is that none of the dental local anesthetic amides provide 100% anesthesia. The problem appears to be more pronounced when mandibular teeth are attempted to be anaesthetized and especially if there is irreversible pulpitis involved. The authors conclude that this finding suggest exploration of more efficient techniques to administer dental local anesthesia, especially in the mandible, to establish a 100% efficacy, is needed.