• Title/Summary/Keyword: Depth-First Search

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Variable Ordering Algorithms Using Problem Classifying (문제분류규칙을 이용한 변수 순서화 알고리즘)

  • Sohn, Surg-Won
    • Journal of the Korea Society of Computer and Information
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    • v.16 no.4
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    • pp.127-135
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    • 2011
  • Efficient ordering of decision variables is one of the methods that find solutions quickly in the depth first search using backtracking. At this time, development of variables ordering algorithms considering dynamic and static properties of the problems is very important. However, to exploit optimal variable ordering algorithms appropriate to the problems. In this paper, we propose a problem classifying rule which provides problem type based on variables' properties, and use this rule to predict optimal type of variable ordering algorithms. We choose frequency allocation problem as a DS-type whose decision variables have dynamic and static properties, and estimate optimal variable ordering algorithm. We also show the usefulness of problem classifying rule by applying base station problem as a special case whose problem type is not generated from the presented rule.

Linkage Expansion in Linked Open Data Cloud using Link Policy (연결정책을 이용한 개방형 연결 데이터 클라우드에서의 연결성 확충)

  • Kim, Kwangmin;Sohn, Yonglak
    • Journal of KIISE
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    • v.44 no.10
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    • pp.1045-1061
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    • 2017
  • This paper suggests a method to expand linkages in a Linked Open Data(LOD) cloud that is a practical consequence of a semantic web. LOD cloud, contrary to the first expectation, has not been used actively because of the lack of linkages. Current method for establishing links by applying to explicit links and attaching the links to LODs have restrictions on reflecting target LODs' changes in a timely manner and maintaining them periodically. Instead of attaching them, this paper suggests that each LOD should prepare a link policy and publish it together with the LOD. The link policy specifies target LODs, predicate pairs, and similarity degrees to decide on the establishment of links. We have implemented a system that performs in-depth searching through LODs using their link policies. We have published APIs of the system to Github. Results of the experiment on the in-depth searching system with similarity degrees of 1.0 ~ 0.8 and depth level of 4 provides searching results that include 91% ~ 98% of the trustworthy links and about 170% of triples expanded.

Analysis of changes in air consumption according to water depth in underwater search (수중수색 시 수심에 따른 공기소모량의 변화 분석)

  • Jeon, Jai-In;Kong, Ha-Sung
    • The Journal of the Convergence on Culture Technology
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    • v.6 no.1
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    • pp.433-439
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    • 2020
  • This study compared and analyzed the change of air consumption according to water depth with human characteristics and theoretical values. The experimental results are as follows. First, subjects A and B showed similar rise rates depending on the water depth. Second, subject C had a significantly higher rate of increase in air consumption at 25m underwater because the body responded sensitively to deep water pressure, which increased air consumption because breathing was faster than other participants. Third, the subjects D and E showed significantly lower overall air consumption. D and E were 37 and 35 years of age, respectively, the youngest, strongest and most experienced in deep sea diving at the time of military service. Fourth, the average air consumption per minute of the test subjects increased from 5m in water to 1.45 times, 10m in water to 1.85 times, and 20m in water to 2.8 times. This seems to be a result of different experiences, physical fitness, the degree of adaptation of the body to underwater, and different breathing techniques. Lastly, the difference between the experimental average value and the theoretical value appears to be the result of using more or less air than the theoretical value depending on the experiences and physical strength of each of the 5 rescuers, the degree of adaptation of the body underwater, and the method of underwater breathing.

I/O Efficient Cycle Region Recognizer for General Grid Graphs (일반 그리드 그래프를 위한 입출력 효율적인 영역 구분자)

  • Her Jun-Ho;Ramakrishna R.S.
    • Proceedings of the Korean Information Science Society Conference
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    • 2005.11a
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    • pp.985-987
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    • 2005
  • 자료의 크기가 방대한 응용 프로그램에서는 메인 메모리와 저장 장치간의 자료 입출력(I/O)이 전체 계산의 주요 병목 요인으로 작용한다. 본 논문은 [2004 한국정보처리학회 추계논문집 제11권 제2호 1139-1142]에서 제안된 그리드(grid) 그래프를 위한 입출력 효율적인 depth-first search (DFS) 알고리즘을 지원하기 위한 입출력 효율적인 영역 구분자를 구하는 알고리즘을 제안 한다. 그 입출력 복잡도 (I/O-Complexity)는 O(Soft(N))이다. 여기서 N=|V|+|E|이고 $sort(N)=\Theta((N/B)log_{M/B}(N/B))$이다.

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Identification of MgII Absorbers in the Quasar Lines of Sight

  • Shim, Hyunjin
    • The Bulletin of The Korean Astronomical Society
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    • v.40 no.1
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    • pp.75.3-75.3
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    • 2015
  • Large area infrared surveys are often accompanied with follow-up optical spectroscopic surveys that has a significant legacy value even for other areas of research. Using these spectral database, we have performed a search for MgII absorption lines in the optical spectrum of background quasar. Over the ~4deg2 of AKARI North Ecliptic Pole survey field and Spitzer First Look Survey field, 18 and 16 MgII absorber systems are identified respectively. The redshift range for the background quasars was 1.0<$z_{qso}$<3.4, while the redshift range for the absorber was 0.6<$z_{abs}$<1.6. Galaxies responsible for MgII absorptions are identified in the deep optical images (CFHT r-band), yet the identification still remains ambiguous for 60% of the systems due to the limited image depth and the source crowdedness. The impact parameter ranges 20-60kpc, and the rest-frame equivalent width of MgII absorption ranges $0.7-4{\AA}$. The most critical part in the identification of MgII absorber galaxies is the existence of deep optical images in addition to the high S/N quasar spectrum with R>3000.

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A Proposal of Scenario Generation Process for Small Scale Engagement (소규모 교전을 위한 시나리오 생성 프로세스 제안)

  • Ahn, Euikoog;Ko, Minsuk;Cheon, Sang Uk;Park, Sang Chul
    • Korean Journal of Computational Design and Engineering
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    • v.18 no.2
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    • pp.104-112
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    • 2013
  • Computer-based modeling and simulation (M&S) techniques have become an essential component in the development of new weapons systems. M&S techniques provide a means to simulate military training, strategies, military doctrines, and weapons acquisition processes. This paper proposes a small scale engagement scenario generation method. This work also includes a process for scenario generation and visualization. The proposed scenario generation methodology employs the Timed-FSA (finite state automata) and DFS (depth first search) algorithms. The proposed scenario generation method is verified using a one-on-one combat engagement scenario between two submarines. In addition, we suggest a scenario generation process including whole scenario generation and scenario visualization.

A Study on the Development of Expert System for Pneumatic Vacuum Equipment Design (공압 진공장치 설계를 위한 전문가 시스템 개발에 관한 연구)

  • 신흥열;김준식;이재원
    • Journal of the Korean Society for Precision Engineering
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    • v.14 no.4
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    • pp.15-21
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    • 1997
  • Pneumatics is widly used in the industrial implementation, in the operation of air-powered actuators and the control devices needed in their operation. However, there are many empirical factors in pneumatics design, it might cause excessive design of pneumatic components. For that reason, we developed VDES(Vacuum Design Expert System) for the economic design of pneumatic vacuum equipment. VDES is achieved with CLIPS(C Language Integrated Production System) and knowledge base that contains a number of facts and rules for pneumatic vacuum design. Forward chaining and depth first search technique are used in this system. Appling VDES to the actual field, this system is verified to be a good efficiency and could be applied to the field of pneumatic vacuum equipment design.

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Construction of Diagnosis System for Electric-fire Causes using Fuzzy Possibility Measure (퍼지가능성 척도를 이용한 전기화재 원인진단 시스템의 구축)

  • 김두현;김상철
    • Journal of the Korean Society of Safety
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    • v.7 no.4
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    • pp.105-114
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    • 1992
  • This paper presents an study on the knowledge based system for diagnosing the fire causes using the Fuzzy Possibility Measure( FPM ) about the electric-fire ignition. The Ignition values needed for causes diagnosis is computed as FPM for electric-fire ignition based on the internal scale technique that assigns numerically the characteristic difference of facts to the-tin-ear scale. For the convinience of inference, ignition sources are classified into seven types : short, ground fault, leakge of electricity, overcurrent, cord junction overheating, bad Insulation and spark. The system for causes diagnosis of electric-fire is composed of Knowledge Acquisition System, Inference Engine and Man-Machine Interface, The diagnosis system is wrritten in an artificial intelligence langusge “PROLOG” which uses depth-first search and backward chaining schemes in reasoning process.

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Analysis of Admission Officer System Research Trends of Domestic Journals : Application of Network Text Analysis (입학사정관제 관련 국내 학술지 연구 경향 분석: 네트워크 텍스트 분석방법 적용)

  • Lee, Sang-Yong
    • Journal of Fisheries and Marine Sciences Education
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    • v.24 no.5
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    • pp.643-652
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    • 2012
  • The admission officer system that is discussed by research topic was introduced just six years ago. So, domestic journals for research trends analysis of admission officer system are not enough. From the time of the end of 1st government financial support project (2007~2012) for admission officer system, it is important things that to summarize the results of study and to look at the implications. The contents of this study will help that other researchers search the study directions. The implication of the research are as follows. First, we can see that range of research is widening and research is advancing. Second, the journals that related to high school will be come out more frequently. Finally, after accumulation of data, in-depth study analysis will be also come out.

A 3D Data Compression Method Using Spiral Depth-First Search (나선형 깊이 우선 탐색 방법을 사용한 3차원 데이터 압축 방법)

  • 이신준;박우찬;이현석;양성봉
    • Proceedings of the Korea Multimedia Society Conference
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    • 2000.11a
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    • pp.49-52
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    • 2000
  • 최근에 3차원 데이터는 그 크기가 상당히 커지고 있으며, 이에 따라 3D 그래픽 파이프라인에 데이터를 전송할 때 메모리 버스 대역폭의 병목 현상에 대한 문제가 크게 대두되고 있다. 이를 해결하기 위한 방법으로 모델링된 3차원 데이터의 위상 정보를 압축하여 보내는 방법이 연구되고 있다. 본 논문에서는 3차원 데이터의 위상 정보를 효율적으로 압축하는 방법과 자료구조를 제안하였다. 기존의 위상 압축 방법들의 선형적인 탐색 방법에 비해 보다 효율적인 나선형 깊이 우선 탐색 방법을 사용하였다. 제안하는 방법은 이미 탐색한 정점들의 재사용도를 높임으로써 압축과정에서 생성되는 허프만 테이블의 크기를 줄였고 전체적으로 압축되는 데이터의 크기도 보다 줄였다. 실험한 결과, 비트수/정점이 평균 1.7 정도이었고, 비트수/폴리곤이 평균 1.3 정도고 이전 방법들보다 1.5배에서 2.5배정도 나은 결과를 보였다.

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