• 제목/요약/키워드: sorting algorithm

검색결과 282건 처리시간 0.031초

분할 정복 알고리즘 학습이 창의적 문제 해결에 미치는 효과 (Effect of Learning a Divide-and-conquer Algorithm on Creative Problem Solving)

  • 김윤영;김영식
    • 컴퓨터교육학회논문지
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    • 제16권2호
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    • pp.9-18
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    • 2013
  • 정보 교과는 정보과학적 사고와 원리를 통해 창의적 문제해결력 함양을 교육목표로 하며, 문제 해결 방법과 절차 단원을 통하여 알고리즘 학습을 강조한다. 알고리즘 학습이 문제해결력 향상에 효과가 있다는 선행연구들을 바탕으로 창의적 문제해결력 향상에도 효과를 입증하는 연구들이 이루어지고 있다. 그러나 이러한 연구들이 알고리즘 내용보다는 CPS와 같은 교수학습 모형이나 콘텐츠에 의존하고 있기 때문에 알고리즘 학습의 중요성이 상대적으로 약해질 수 있다. 본 연구는 일반적인 문제해결과정과 창의적 문제해결과정이 동일하다는 관점에서 알고리즘 학습이 창의적 문제해결력 향상에 효과가 있음을 검증한다. 이를 위하여 일반적인 사고 가운데 창의적인 사고로 간주되는 유추 추론(analogical reasoning)에 대하여 살펴보고, 유추 추론에 필요한 바탕 지식으로 분할 정복 알고리즘을 선택하였다. 퀵 정렬 알고리즘 학습 실험 결과, 분할 정복 알고리즘의 원리 학습한 실험집단과 알고리즘의 절차만 학습한 통제집단이 퀵 정렬 문제를 해결하는 비율에는 차이가 없었으나, 탐색 문제에서는 실험집단이 통제집단 보다 이진 탐색을 사용하는 비율이 더 높았다. 이는 분할 정복과 같은 추상적인 원리를 포함하는 알고리즘 학습이 새로운 영역의 문제를 해결하는 유추 추론에 효과가 있으며, 이는 창의적 문제해결력 향상으로 이어질 수 있음을 의미한다.

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동적 공정계획에서의 기계선정을 위한 다목적 유전자 알고리즘 (Multi-Objective Genetic Algorithm for Machine Selection in Dynamic Process Planning)

  • 최회련;김재관;이홍철;노형민
    • 한국정밀공학회지
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    • 제24권4호
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    • pp.84-92
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    • 2007
  • Dynamic process planning requires not only more flexible capabilities of a CAPP system but also higher utility of the generated process plans. In order to meet the requirements, this paper develops an algorithm that can select machines for the machining operations by calculating the machine loads. The developed algorithm is based on the multi-objective genetic algorithm that gives rise to a set of optimal solutions (in general, known as the Pareto-optimal solutions). The objective is to satisfy both the minimization number of part movements and the maximization of machine utilization. The algorithm is characterized by a new and efficient method for nondominated sorting through K-means algorithm, which can speed up the running time, as well as a method of two stages for genetic operations, which can maintain a diverse set of solutions. The performance of the algorithm is evaluated by comparing with another multiple objective genetic algorithm, called NSGA-II and branch and bound algorithm.

기계시각에 의한 풋고추 온라인 등급판정 알고리즘 개발 (Development of On-line Grading Algorithm of Green Pepper Using Machine Vision)

  • 조남홍;이수희;황헌;이영희;최승묵;박종률;조광한
    • Journal of Biosystems Engineering
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    • 제26권6호
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    • pp.571-578
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    • 2001
  • Production of green pepper has increased for ten years in Korea, as customer's preference of a pepper tuned to fiesta one. This study was conducted to develop an on-line fading algorithm of green pepper using machine vision and aimed to develop the automatic on-line grading and sorting system. The machine vision system was composed of a professive scan R7B CCD camera, a frame grabber and sets of 3-wave fluorescent lamps. The length and curvature, which were main quality factors of a green pepper were measured while removing the stem region. The first derivative of the thickness profile was used to remove the stem area of the segmented image of the pepper. A new boundary was generated after the stem was removed and a baseline of a pepper which was used for the curvature determination was also generated. The developed algorithm showed that the accuracy of the size measurement was 86.6% and the accuracy of the bent was 91.9%. Processing time spent far grading was around 0.17 sec per pepper.

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스케줄링 문제를 위한 멀티로봇 위치 기반 다목적 유전 알고리즘 (Multi-Objective Genetic Algorithm based on Multi-Robot Positions for Scheduling Problems)

  • 최종훈;김제석;정진한;김정민;박장현
    • 한국정밀공학회지
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    • 제31권8호
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    • pp.689-696
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    • 2014
  • This paper presents a scheduling problem for a high-density robotic workcell using multi-objective genetic algorithm. We propose a new algorithm based on NSGA-II(Non-dominated Sorting Algorithm-II) which is the most popular algorithm to solve multi-objective optimization problems. To solve the problem efficiently, the proposed algorithm divides the problem into two processes: clustering and scheduling. In clustering process, we focus on multi-robot positions because they are fixed in manufacturing system and have a great effect on task distribution. We test the algorithm by changing multi-robot positions and compare it to previous work. Test results shows that the proposed algorithm is effective under various conditions.

충돌해석을 위한 병렬유한요소 알고리즘 (A Parallel Finite Element Procedure for Contact-Impact Problems)

  • 하재선
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2003년도 추계학술대회
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    • pp.1286-1290
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    • 2003
  • This paper presents a newly implemented parallel finite element procedure for contact-impact problems. Three sub-algorithms are includes in the proposed parallel contact-impact procedure, such as a parallel Belytschko-Lin-Tsay (BLT) shell element generation, a parallel explicit time integration scheme, and a parallel contact search algorithm based on the master slave slide-line algorithm. The underlying focus of the algorithms is on its effectiveness and efficiency for inclusion in future finite element systems on parallel computers. Throughout this research, a prototype code, named GT-PARADYN, is developed on the IBM SP2, a distributed-memory computer. Some numerical examples are provided to demonstrate the timing results of the procedure, discussing the accuracy and efficiency of the code.

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인삼선별의 자동화를 위한 컴퓨터 시각장치 - 등급 자동판정을 위한 영상처리 알고리즘 개발 - (Computer Vision System for Automatic Grading of Ginseng - Development of Image Processing Algorithms -)

  • 김철수;이중용
    • Journal of Biosystems Engineering
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    • 제22권2호
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    • pp.227-236
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    • 1997
  • Manual grading and sorting of red-ginsengs are inherently unreliable due to its subjective nature. A computerized technique based on optical and geometrical characteristics was studied for the objective quality evalution. Spectral reflectance of three categories of red-ginsengs - "Chunsam", "Chisam", "Yangsam" - were measured and analyzed. Variation of reflectance among parts of a single ginseng was more significant than variation among the quality categories of ginsengs. A PC-based image processing algorithm was developed to extract geometrical features such as length and thickness of body, length and number of roots, position of head and branch point, etc. The algorithm consisted of image segmentation, calculation of Euclidean distance, skeletonization and feature extraction. Performance of the algorithm was evaluated using sample ginseng images and found to be mostly sussessful.

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최소 자료 이동을 위한 최적 병렬 정렬 알고리즘 (An Optimal Parallel Sort Algorithm for Minimum Data Movement)

  • 홍성수;심재홍
    • 한국정보처리학회논문지
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    • 제1권3호
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    • pp.290-298
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    • 1994
  • 본 논문은 p(p= $n^{1-x}$, 0〈x〈1)개 프로세서가 존재하는 EREW-PRAM 모델 병 렬 컴퓨터에서 시간 복잡도가 0( $n^{x}$ log n)이며 비용 (최악의 실행시간*프로세서 수)은 0(nlogn)이고, 자료 이동도가 0( $n^{1-}$x+ $n^{x}$ )인 병렬 정렬 알고리즘을 제안한다. 병렬 정렬 알고리즘은 리스트를 p개 특정키를 중심으로 분리한 다음 블럭 의 크기를 거의 일정하게 할 수 있는 엔코딩 기법을 사용했다.다.

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절삭가공에서의 기계선정을 위한 기계부하 예측 (Machine load prediction for selecting machines in machining)

  • 최회련;김재관;노형민;이홍철
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2005년도 춘계학술대회 논문집
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    • pp.997-1000
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    • 2005
  • Dynamic job shop environment requires not only more flexible capabilities of a CAPP system but higher utility of the generated process plans. In order to meet the requirements, this paper develops an algorithm that can select machines for the machining operations to be performed by predicting the machine loads. The developed algorithm is based on the multiple objective genetic algorithm that gives rise to a set of optimal solutions (in general, known as Pareto-optimal solutions). The objective shows a combination of the minimization of part movement and the maximization of machine utility balance. The algorithm is characterized by a new and efficient method for nondominated sorting, which can speed up the running time, as well as a method of two stages for genetic operations, which can maintain a diverse set of solutions. The performance of the algorithm is evaluated by comparing with another multiple objective genetic algorithm, called NSGA-II.

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초기 매칭 에러를 통한 적응적 고속 움직임 예측 알고리즘 (An Adaptive and Fast Motion Estimation Algorithm using Initial Matching Errors)

  • 정태일
    • 한국멀티미디어학회논문지
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    • 제10권11호
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    • pp.1439-1445
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    • 2007
  • 본 논문에서는 기존의 PDE방법의 계산량을 줄이고 동시에 동일한 예측화질을 얻기 위해, 초기 매칭블록의 서브블록별 SAD값의 비교를 통한 고속 움직임 예측 알고리즘을 제안한다. 제안한 방법은 최초 매칭 블록의 서브블록별 매칭 에러의 복잡도의 비교를 통해 후보블록들의 매칭순서를 변경하여 불필요한 계산량을 줄이는 방법을 제안한다. 제안한 알고리즘은 예측 화질의 저하 없이 기존의 PDE(partial distortion elimination) 알고리즘을 이용한 전영역 탐색 방법에 비해 45%의 계산량을 줄였으며, MPEG-2 및 MPEG-4 AVC를 이용하는 비디오 압축 응용분야에 유용하게 사용될 수 있을 것이다.

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A New Multi-objective Evolutionary Algorithm for Inter-Cloud Service Composition

  • Liu, Li;Gu, Shuxian;Fu, Dongmei;Zhang, Miao;Buyya, Rajkumar
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제12권1호
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    • pp.1-20
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    • 2018
  • Service composition in the Inter-Cloud raises new challenges that are caused by the different Quality of Service (QoS) requirements of the users, which are served by different geo-distributed Cloud providers. This paper aims to explore how to select and compose such services while considering how to reach high efficiency on cost and response time, low network latency, and high reliability across multiple Cloud providers. A new hybrid multi-objective evolutionary algorithm to perform the above task called LS-NSGA-II-DE is proposed, in which the differential evolution (DE) algorithm uses the adaptive mutation operator and crossover operator to replace the those of the Non-dominated Sorting Genetic Algorithm-II (NSGA-II) to get the better convergence and diversity. At the same time, a Local Search (LS) method is performed for the Non-dominated solution set F{1} in each generation to improve the distribution of the F{1}. The simulation results show that our proposed algorithm performs well in terms of the solution distribution and convergence, and in addition, the optimality ability and scalability are better compared with those of the other algorithms.