• 제목/요약/키워드: Two-step search

검색결과 154건 처리시간 0.024초

고속 움직임 추정을 위한 적응형 육각 탐색 방법 (An Adaptive Hexagon Based Search for Fast Motion Estimation)

  • 전병태;김병천
    • 한국통신학회논문지
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    • 제29권7A호
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    • pp.828-835
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    • 2004
  • 본 논문에서는 일반적인 비디오 압축에 사용되는 블록 움직임 예측 방법을 위한 육각형 탐색 형태를 이용한 적응형 블록 정합 탐색 알고리즘(Adaptive hexagon based search : AHBS)을 제안한다. 제한하는 알고리즘은 다이아몬드 형태를 이용한 초기 탐색 과정과 제안한 두개의 육각 형태를 이용하여 적응적으로 탐색하는 과정으로 이루어져 있으며, 육각형 탐색 형태의 중앙값에 블록 정합을 위한 목적 함수의 최소간이 발생할 때 그 과정을 종료하는 것으로 구성되어 있다. 또한, 탐색 과정에 있어 적용할 육각형 탐색 형태의 결정은 이전 탐색 과정에서 발생한 최소 값의 위치에 따라 이루어진다. 제안한 알고리즘의 성능측정은 전역탐색 방법을 포함 기존의 다양한 고속 탐색 방법들과 전역 탐색 방법의 결과와의 비교를 통하여 이루어졌다. 기존의 고속 탐색 방법에 비하여 본 논문에서 제안한 방법의 성능이 우수하고 그 수행 속도 또한 개선된 것을 실험 결과 알 수 있다.

A New Pivot Algorithm for Star Identification

  • Nah, Jakyoung;Yi, Yu;Kim, Yong Ha
    • Journal of Astronomy and Space Sciences
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    • 제31권3호
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    • pp.205-214
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    • 2014
  • In this study, a star identification algorithm which utilizes pivot patterns instead of apparent magnitude information was developed. The new star identification algorithm consists of two steps of recognition process. In the first step, the brightest star in a sensor image is identified using the orientation of brightness between two stars as recognition information. In the second step, cell indexes are used as new recognition information to identify dimmer stars, which are derived from the brightest star already identified. If we use the cell index information, we can search over limited portion of the star catalogue database, which enables the faster identification of dimmer stars. The new pivot algorithm does not require calibrations on the apparent magnitude of a star but it shows robust characteristics on the errors of apparent magnitude compared to conventional pivot algorithms which require the apparent magnitude information.

Design method of computer-generated controller for linear time-periodic systems

  • Jo, Jang-Hyen
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1992년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 19-21 Oct. 1992
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    • pp.225-228
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    • 1992
  • The purpose of this project is the presentation of new method for selection of a scalar control of linear time-periodic system. The approach has been proposed by Radziszewski and Zaleski [4] and utilizes the quadratic form of Lyapunov function. The system under consideration is assigned either in closed-loop state or in modal variables as in Calico, Wiesel [1]. The case of scalar control is considered, the gain matrix being assumed to be at worst periodic with the system period T, each element being represented by a Fourier series. As the optimal gain matrix we consider the matrix ensuring the minimum value of the larger real part of the two Poincare exponents of the system. The method, based on two-step optimization procedure, allows to find the approximate optimal gain matrix. At present state of art determination of the gain matrix for this case has been done by systematic numerical search procedure, at each step of which the Floquet solution must be found.

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A NEW EXPLICIT EXTRAGRADIENT METHOD FOR SOLVING EQUILIBRIUM PROBLEMS WITH CONVEX CONSTRAINTS

  • Muangchoo, Kanikar
    • Nonlinear Functional Analysis and Applications
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    • 제27권1호
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    • pp.1-22
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    • 2022
  • The purpose of this research is to formulate a new proximal-type algorithm to solve the equilibrium problem in a real Hilbert space. A new algorithm is analogous to the famous two-step extragradient algorithm that was used to solve variational inequalities in the Hilbert spaces previously. The proposed iterative scheme uses a new step size rule based on local bifunction details instead of Lipschitz constants or any line search scheme. The strong convergence theorem for the proposed algorithm is well-proven by letting mild assumptions about the bifunction. Applications of these results are presented to solve the fixed point problems and the variational inequality problems. Finally, we discuss two test problems and computational performance is explicating to show the efficiency and effectiveness of the proposed algorithm.

Fault-tree 확률계산을 위한 근사적 방법 (An approximate approach for Computing Fault-tree probabilities)

  • 이근희;이동형
    • 품질경영학회지
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    • 제18권2호
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    • pp.25-32
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    • 1990
  • This paper presents an approximate algorithm for computing Fault-tree probabilities. The method is essentially composed of three steps. In the first step, a Fault-tree is converted into a network form. In the second step, We change the network into a parallelized diagram. In the third step, the approximate fault-tree probability is calculated from the parallelized diagram. In this paper, in order to verify the method two hypothetical Fault-tree is used by examples. The results show that the method is very useful, even though it is an approximate technique, since it needs not to search the minimal cut sets and has the simple computing rontines.

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자동 초점 조절 검사 시스템 설계 및 구현 (Implementation of Measuring System for the Auto Focusing)

  • 이영교;김영포
    • 디지털산업정보학회논문지
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    • 제8권4호
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    • pp.159-165
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    • 2012
  • The accurate focusing position should be determined for accurate measurements In VMS. Camera lens focusing is an important problem in computer vision and video measuring systems (VMS) that use CCD cameras and high precision XYZ stages. Camera focusing is a very important step in high precision measurement systems that use computer vision technique. The auto focusing process consists of two steps, the focus value measurement step and the exact focusing position determination step. It is suitable for eliminating high frequency noises with lower processing time and without blurring. An automatic focusing technique is applied to measure a crater with a one-dimensional search algorithm for finding the best focus. Throughout this paper, the suggested algorithm for the Auto focusing was combined with the learning. As a result, it is expected that such a combination would be expanded into the system of recognizing voices in a noisy environment.

Investigation of Strain Measurements using Digital Image Correlation with a Finite Element Method

  • Zhao, Jian;Zhao, Dong
    • Journal of the Optical Society of Korea
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    • 제17권5호
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    • pp.399-404
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    • 2013
  • This article proposes a digital image correlation (DIC) strain measurement method based on a finite element (FE) algorithm. A two-step digital image correlation is presented. In the first step, the gradient-based subpixels technique is used to search the displacements of a region of interest of the specimen, and then the strain fields are obtained by utilizing the finite element method in the second step. Both simulation and experiment processing, including tensile strain deformation, show that the proposed method can achieve nearly the same accuracy as the cubic spline interpolation method in most cases and higher accuracy in some cases, such as the simulations of uniaxial tension with and without noise. The results show that it also has a good noise-robustness. Finally, this method is used in the uniaxial tensile testing for Dahurian Larch wood specimens with or without a hole, and the obtained strain values are close to the results which were obtained from the strain gauge and the cubic spline interpolation method.

Fast Inter Mode Decision Algorithm Based on Macroblock Tracking in H.264/AVC Video

  • Kim, Byung-Gyu;Kim, Jong-Ho;Cho, Chang-Sik
    • ETRI Journal
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    • 제29권6호
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    • pp.736-744
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    • 2007
  • We propose a fast macroblock (MB) mode prediction and decision algorithm based on temporal correlation for P-slices in the H.264/AVC video standard. There are eight block types for temporal decorrelation, including SKIP mode based on rate-distortion (RD) optimization. This scheme gives rise to exhaustive computations (search) in the coding procedure. To overcome this problem, a thresholding method for fast inter mode decision using a MB tracking scheme to find the most correlated block and RD cost of the correlated block is suggested for early stop of the inter mode determination. We propose a two-step inter mode candidate selection method using statistical analysis. In the first step, a mode is selected based on the mode information of the co-located MB from the previous frame. Then, an adaptive thresholding scheme is applied using the RD cost of the most correlated MB. Secondly, additional candidate modes are considered to determine the best mode of the initial candidate modes that does not satisfy the designed thresholding rule. Comparative analysis shows that a speed-up factor of up to 70.59% is obtained when compared with the full mode search method with a negligible bit increment and a minimal loss of image quality.

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ADHD 아동을 대하는 초등교사의 체험분석 (An Experiential Analysis of Elementary School Teachers Beal ing ChiIdren with Symptoms ADHD)

  • 이숙경
    • 초등상담연구
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    • 제5권1호
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    • pp.93-118
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    • 2006
  • The aim of this research is to find out the common emotional factors that elementary school teachers feel when they experience in teaching children with ADHD and to know their responding process through experiential analysis. Seven elementary school teachers took part in this research as co-investigators, and I led the experiential approach. The co-investigators have analyzed their emotional experiences during 4 sessions. They learnt about the method of experience analysis and discussed their emotional experiences of children with ADHD. And they found out some factors concerning their emotional experiences and had the time to discuss in odor to search for the common factors of that process. Finally the co-investigators took part in a session to examine the factors which they have all agreed in, and then I verified this result. 1 interpreted the factors found and constructed a psychological resolution process. Two main objectives and the results of this research are as follows. First, are there any common factors among teachers who experience in treating children with ADHD? This research showed that elementary school teachers get angry and irritated with ADHD children's troubles. Second, what kind of psychological process is there in teachers' experiences children with ADHD? The psychological process of teachers dealing children with ADHD could be conceptualized in 5 steps, the step of recognizing an action of children with ADHD, the step of first cognitive consideration, the step of giving meaning and cognitive appraisal, the step of experiencing emotion, and the step of dealing with emotion. Teachers seemed to experience a little bit different psychological process. According to whether they thought about children's behavior positively or negatively in the second step, they had different emotional experiences. If they had a positive thought, they could take children's nonadaptive behaviors as personal characteristics. However, if they took them negatively, they considered them impolite and disobedient. Even when the teachers experienced negative emotions, their responses were divided into two groups whether they took it positively or negatively. This research showed that if teachers could control their negative emotional experiences, they could calm down with children with ADHD and treat them positively.

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A Novel and Effective University Course Scheduler Using Adaptive Parallel Tabu Search and Simulated Annealing

  • Xiaorui Shao;Su Yeon Lee;Chang Soo Kim
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제18권4호
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    • pp.843-859
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    • 2024
  • The university course scheduling problem (UCSP) aims at optimally arranging courses to corresponding rooms, faculties, students, and timeslots with constraints. Previously, the university staff solved this thorny problem by hand, which is very time-consuming and makes it easy to fall into chaos. Even some meta-heuristic algorithms are proposed to solve UCSP automatically, while most only utilize one single algorithm, so the scheduling results still need improvement. Besides, they lack an in-depth analysis of the inner algorithms. Therefore, this paper presents a novel and practical approach based on Tabu search and simulated annealing algorithms for solving USCP. Firstly, the initial solution of the UCSP instance is generated by one construction heuristic algorithm, the first fit algorithm. Secondly, we defined one union move selector to control the moves and provide diverse solutions from initial solutions, consisting of two changing move selectors. Thirdly, Tabu search and simulated annealing (SA) are combined to filter out unacceptable moves in a parallel mode. Then, the acceptable moves are selected by one adaptive decision algorithm, which is used as the next step to construct the final solving path. Benefits from the excellent design of the union move selector, parallel tabu search and SA, and adaptive decision algorithm, the proposed method could effectively solve UCSP since it fully uses Tabu and SA. We designed and tested the proposed algorithm in one real-world (PKNU-UCSP) and ten random UCSP instances. The experimental results confirmed its effectiveness. Besides, the in-depth analysis confirmed each component's effectiveness for solving UCSP.