• Title/Summary/Keyword: Problem-finding

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Range finding algorithm of equidistance stereo catadioptric mirror (등거리 스테레오 전방위 렌즈 영상에 대한 위치 측정 알고리즘)

  • Choi, Young-Ho
    • Journal of Internet Computing and Services
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    • v.6 no.6
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    • pp.149-161
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    • 2005
  • Catadioptric mirrors are widely used in automatic surveillance system. The major drawback of catadioptric mirror is its unequal image resolution. Equidistance catadioptric mirror can be the solution to this problem. Even double panoramic structure can generate stereo images with single camera system. So two images obtained from double panoramic equidistance catadioptric mirror can be used in finding the depth and height values of object's points. But compared to the single catadioptric mirror. the image size of double panoramic system is relatively small. This leads to the severe accuracy problem in estimation. The exact axial alignment and the exact mount of mirror are the sources that can be avoided but the focal length variation is inevitable. In this paper, the effects of focal length variation on the computation of depth and height of object' point are explained and the effective focal length finding algorithm, using the assumption that the object's viewing angles are almost same in stereo images, is presented.

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High Throughput Screening for Natural Products to Find Biologically Active Compounds : Natural Products versus Combinatorial Chemistry

  • Sankawa, Ushio
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 1997.11a
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    • pp.47-50
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    • 1997
  • Drug development began with the finding of biologically active compounds which are obtained by chemical synthesis or from natural sources. The advent of Combinatorial Chemistry is recognized as a strategy which has a potential to change the methodology of research and development(R&D) of new drugs. Drug development has been carried out with diverse strategies. In the past several decades a variety of new methodology have been introduced in R&D. Random screening of accumulated synthetic samples which had been synthesized for development of other drugs led to the discovery of new drugs. The typical examples are anti-asthma drug trimethoquinol and calcium antagonist diltiazem. (herbesser). In particular the latter drug has been used as a calcium antagonist worldwide, however it was first synthesized to find new tranquilizer and this is the reason why diltiazem has benzodiazepam skeleton. The random screening contributed in the finding of new drugs were carried out with whole animal test and it is a standard methodology in R&D of new drugs. Aspirin is the first synthetic non-steroidal antiinflammatory drug(NSAID) and has been used for more than one hundred years. It is the first example of drug developed from natural product. Salicin is the main constituent of willow bark which had been used in Europe for a long time to treat arthritis and aspirin was developed from salicin. Most of NSAID used clinically were developed from the structure of aspirin, however it took 70 years to clarify why aspirin exhibits its antiinflammatory, analgesic and antipyretic activities. The target of aspirin is cyclooxygenase(COX)which is the first enzyme involved in arachidonate cascade leading to the production of prostaglandins(PG) and thromboxan(TX). Side effect of aspirin causing ulcer in stomach is rather serious problem, since aspirin is so popular drug easily obtained in drug store(OTP). This problem is now going to be solved by a new finding on COX, which have two different types, one is constitutionally expressed COX 1 in almost all organs and the other is inducible COX 2. COX 2 is the responsible enzyme in inflammation etc and now the search of COX 2 specific inhibitors is the target of R&D of next generation NSAID.

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A Study on Developing an Efficient Algorithm for the p-median Problem on a Tree Network (트리 네트워크 상에서의 p-미디안 문제에 대한 효율적인 알고리즘 개발에 관한 연구)

  • Cho, Geon
    • Journal of the Korean Operations Research and Management Science Society
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    • v.29 no.1
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    • pp.57-70
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    • 2004
  • Given a tree network on which each node has its own demand and also stands for a candidate location of a potential facility. such as plant or warehouse, the f-median problem on the network (PMPOT) is to select less than or equal to P number of facility locations so that the whole demand on a node is satisfied from only one facility and the total demand occurred on the network can be satisfied from those facilities with the minimum total cost, where the total cost Is the sum of transportation costs and the fixed costs of establishing facilities. Tamir(1996) developed an O(p n$^2$) algorithm for PMPOT which is known to be the best algorithm In terms of the time complexity, where n is the number of nodes in the network, but he didn't make any comments or explanation about implementation details for finding the optimal solution. In contrast to Tamir's work, Kariv and Hakimi(1979) developed O(p$^2$n$^2$) algorithm for PMPOT and presented O(n$^2$) algorithm for finding the optimal solution in detail. In this paper, we not only develop another O(p n$^2$) dynamic programming algorithm for PMPOT that is competitive to Tamir's algorithm in terms of the time complexity, but also present O(n) algorithm that is more efficient than kariv and Hakimi's algorithm in finding the optimal solution. finally, we implement our algorithm on a set of randomly generated problems and report the computational results.

A Border Line-Based Pruning Scheme for Shortest Path Computations

  • Park, Jin-Kyu;Moon, Dae-Jin;Hwang, Een-Jun
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.4 no.5
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    • pp.939-955
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    • 2010
  • With the progress of IT and mobile positioning technologies, various types of location-based services (LBS) have been proposed and implemented. Finding a shortest path between two nodes is one of the most fundamental tasks in many LBS related applications. So far, there have been many research efforts on the shortest path finding problem. For instance, $A^*$ algorithm estimates neighboring nodes using a heuristic function and selects minimum cost node as the closest one to the destination. Pruning method, which is known to outperform the A* algorithm, improves its routing performance by avoiding unnecessary exploration in the search space. For pruning, shortest paths for all node pairs in a map need to be pre-computed, from which a shortest path container is generated for each edge. The container for an edge consists of all the destination nodes whose shortest path passes through the edge and possibly some unnecessary nodes. These containers are used during routing to prune unnecessary node visits. However, this method shows poor performance as the number of unnecessary nodes included in the container increases. In this paper, we focus on this problem and propose a new border line-based pruning scheme for path routing which can reduce the number of unnecessary node visits significantly. Through extensive experiments on randomly-generated, various complexity of maps, we empirically find out optimal number of border lines for clipping containers and compare its performance with other methods.

Dynamic Programming Algorithm Path-finding for Applying Game (게임 적용을 위한 Dynamic Programming 알고리즘 길찾기)

  • Lee, Se-Il
    • Journal of the Korea Society of Computer and Information
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    • v.10 no.4 s.36
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    • pp.213-219
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    • 2005
  • In order to move NPC's to target location at game maps, various algorithm including A* has been used. The most frequently used algorithm among them is A* with fast finding speed. But A* has the following problems. The first problem is that at randomly changing map, it is necessary to calculate all things again whenever there are any changes. And when calculation is wrong, it is not possible to search for target. The second problem is that it is difficult to move avoiding dangerous locations damaging NPC such as an obstruction. Although it is possible to avoid moving to locations with high weight by giving weight to dangerous factors. it is difficult to control in case NPC moves nearby dangerous factors. In order to solve such problems, in this thesis, the researcher applied Dynamic Programming to path-finding algorithm. As the result of its application, the researcher could confirm that the programming was suitable for changes at the map with random change and NPC's avoided the factors being dangerous to them far away. In addition. when compared to A*, there were good results.

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Optimization of Transportation Problem in Dynamic Logistics Network

  • Chung, Ji-Bok;Choi, Byung-Cheon
    • Journal of Distribution Science
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    • v.14 no.2
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    • pp.41-45
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    • 2016
  • Purpose - Finding an optimal path is an essential component for the design and operation of smart transportation or logistics network. Many applications in navigation system assume that travel time of each link is fixed and same. However, in practice, the travel time of each link changes over time. In this paper, we introduce a new transportation problem to find a latest departing time and delivery path between the two nodes, while not violating the appointed time at the destination node. Research design, data, and methodology - To solve the problem, we suggest a mathematical model based on network optimization theory and a backward search method to find an optimal solution. Results - First, we introduce a dynamic transportation problem which is different with traditional shortest path or minimum cost path. Second, we propose an algorithm solution based on backward search to solve the problem in a large-sized network. Conclusions - We proposed a new transportation problem which is different with traditional shortest path or minimum cost path. We analyzed the problem under the conditions that travel time is changing, and proposed an algorithm to solve them. Extending our models for visiting two or more destinations is one of the further research topics.

New Population initialization and sequential transformation methods of Genetic Algorithms for solving optimal TSP problem (최적의 TSP문제 해결을 위한 유전자 알고리즘의 새로운 집단 초기화 및 순차변환 기법)

  • Kang, Rae-Goo;Lim, Hee-Kyoung;Jung, Chai-Yeoung
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.10 no.3
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    • pp.622-627
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    • 2006
  • TSP(Traveling Salesman Problem) is a problem finding out the shortest distance out of many courses where given cities of the number of N, one starts a certain city and turns back to a starting city, visiting every city only once. As the number of cities having visited increases, the calculation rate increases geometrically. This problem makes TSP classified in NP-Hard Problem and genetic algorithm is used representatively. To obtain a better result in TSP, various operators have been developed and studied. This paper suggests new method of population initialization and of sequential transformation, and then proves the improvement of capability by comparing them with existing methods.

Cumulative Risk and Problem Behavioral of Divorced Family's Children (누적적 위험요인과 이혼가정자녀의 문제행동과의 관련성 연구)

  • Ju, So-Hee
    • Journal of the Korean Society of Child Welfare
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    • no.26
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    • pp.61-86
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    • 2008
  • This Study examines the relationship between Cumulative Risk and Behavioral Problem of children's in divorced family. The cumulative risk was Summed for each children to creative an cumulative scores. Scores on the index ranged from 0 to 12. Cumulative Risk was associated with Behavioral Problem. Moreover the analyses revealed positive, linear associated between Cumulative Risk and Behavioral Problem. Cumulative Risk predicted Problem Behavioral of Divorced Family's Children. Finding indicate that the amount of risk in Divorced Family's childrens lives was useful for determining the extent to which cumulative risk exposure plays an etiological role in Behavioral Problem. On the basis of these results, this article provided some suggestions for promoting of children welfare.

Finding State Transition Functions of One-Dimensional Cellular Automata by Evolutionary Algorithms (일차원 셀룰러 오토마타 상에서 진화 알고리즘을 이용한 상태전이함수 찾기)

  • Park, Jongwoo;Wang, Sehee;Wee, Kyubum
    • KIPS Transactions on Software and Data Engineering
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    • v.8 no.5
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    • pp.187-192
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    • 2019
  • Majority problem and synchronization problem on cellular automata(CA) are hard to solve, since they are global problems while CA operate on local information. This paper proposes a way to find state transition rules of these problems. The rules of CA are represented as CMR(conditionally matching rules) and evolutionary algorithms are applied to find rules. We find many solution rules to these problems, compared the results with the previous studies, and demonstrated the effectiveness of CMR on one-dimensional cellular automata.

Exploring the Relationships between Inquiry Problems and Scientific Reasoning in the Program Emphasized Construction of Problem: Focus on Inquiry About Osmosis (문제의 구성을 강조한 프로그램에서 나타난 탐구 문제와 과학적 추론의 관련성 탐색 -삼투 현상 탐구 활동을 중심으로-)

  • Baek, Jongho
    • Journal of The Korean Association For Science Education
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    • v.40 no.1
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    • pp.77-87
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    • 2020
  • Scientific inquiry has emphasized its importance in various aspects of science learning and has been performed according to various methods and purposes. Among the various aspects of science learning, it is emphasized to develop core competencies with science, such as scientific thinking. Therefore, it is necessary to support students to be able to formulate scientific reasoning properly. This study attempts to explore problem-finding and scientific reasoning in the process of performing scientific inquiry. This study also aims to reveal what factors influence this complex process. For this purpose, this study analyzed the inquiry process and results performed by two groups of college students who conducted the inquiry related to osmosis. To analyze, research plans, presentations, and group interviews were used. As a result, it was found that participants used various scientific reasoning, such as deductive, inductive, and abductive reasoning, in the process of problem finding for their inquiry about osmosis. In the process of inquiry and reasoning complexly, anomalous data, which appear regularly, and the characteristics of experimental instruments influenced their reasoning. Various reasons were produced for the purpose of constructing the best explanation about the phenomena observed by participants themselves. Finally, based on the results of this study, several implications for the development context of programs using scientific inquiry are discussed.