• Title/Summary/Keyword: Minimum cut set

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Maximum Capacity-based Minimum Cut Algorithm (최대 수용량-기반 최소절단 알고리즘)

  • Lee, Sang-Un
    • Journal of the Korea Society of Computer and Information
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    • v.16 no.5
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    • pp.153-162
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    • 2011
  • The minimum cut problem is to minimize c(S,T), that is, to determine source S and sink T such that the capacity of the S-T cut is minimal. The flow-based algorithm is mostly used to find the bottleneck arcs by calculating flow network, and does not presents the minimum cut. This paper suggests an algorithm that simply includes the maximum capacity vertex to adjacent set S or T and finds the minimum cut without obtaining flow network in advance. On applying the suggested algorithm to 13 limited graphs, it can be finds the minimum cut value $_{\min}c$(S, T) with simply and correctly.

A Study on Transmission System Expansion Planning using Fuzzy Branch and Bound Method

  • Park, Jaeseok;Sungrok Kang;Kim, Hongsik;Seungpil Moon;Lee, Soonyoung;Roy Billinton
    • KIEE International Transactions on Power Engineering
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    • v.2A no.3
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    • pp.121-128
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    • 2002
  • This study proposes a new method for transmission system expansion planning using fuzzy integer programming. It presents stepwise cost characteristics analysis which is a practical condition of an actual system. A branch and bound method which includes the network flow method and the maximum flow - minimum cut set theorem has been used in order to carry out the stepwise cost characteristics analysis. Uncertainties of the permissibility of the construction cost and the lenient reserve rate and load forecasting of expansion planning have been included and also processed using the fuzzy set theory in this study. In order to carry out the latter analysis, the solving procedure is illustrated in detail by the branch and bound method which includes the network flow method and maximum flow-minimum cut set theorem. Finally, case studies on the 21- bus test system show that the algorithm proposed is efficiently applicable to the practical expansion planning of transmission systems in the future.

A Study on the Anthropometrical Method of Minimum Residential Space Standard for the Super-Aged Society of Korea - by Anthropometrical Data Application Methods of Karl H. E. Kroemer - (한국의 초고령사회를 대비한 최소주거면적 기준의 인체측정학적 방법 연구 - Karl H. E. Kroemer의 인체측정학적 데이터 적용 방법 -)

  • Lee, Ho Sung
    • Journal of The Korea Institute of Healthcare Architecture
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    • v.23 no.1
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    • pp.15-24
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    • 2017
  • Purpose: Korea is expected to enter an aged society in 2018 and then a super-aged society in early 2025. The country's aging is progressing faster than any other country in the world. However, the foundation of the elderly friendly industry is weak, and measures at the government level are urgently needed. Especially, housing problems of the elderly are one of the most urgent measures to be taken. Korea does not have the minimum residential area standard for the elderly, and the current general minimum residential area standard is based on the survey of the housing situation without scientific evidence. Therefore, both standards need to be revised as soon as possible based on scientific evidence. Methods: The minimum residential area standard has been calculated following Karl H. E. Kroemer's Min or Max design also being called as-single cut and dual cut theory- as the maximum population value and minimum population value theory of Ernest J. McCormick. Therefore there is a need for a formula made using a few key factors, such as corresponding dimension, practical dimension, clearance, spare dimension, integrated dimension. These elements can be defined and used as formulas to calculate minimum residential area standards. Results: Assuming the results of the spatial variability in this study showed that it is possible to raise the standard of living in a terms of sustainable minimum size for the young, old and all residents. Implications: The government should set a minimum residential area standard with scientific grounds and set up a policy improving the life of people who live in an needy residential environment.

A Study on the Transmission System Expansion Planning using Fuzzy Integer Programming (Fuzzy 정수계획법을 이용한 송전망의 확충계획에 관한 연구)

  • Kim, Hong-Sik;Moon, Seung-Pil;Lee, Young-Jin;Choi, Hyong-Lim;Choi, Jae-Seok
    • Proceedings of the KIEE Conference
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    • 2001.11b
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    • pp.350-353
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    • 2001
  • This study proposes a new method for the transmission system expansion planning using the fuzzy integer programming. It presents stepwise cost characteristics analysis which is a practical condition of an actual systems. A branch and bound method which includes the network flow method and the maximum flow-minimum cut set theorem has been used in order to proceed the stepwise cost characteristics analysis. Uncertainties of the permission of the construction cost and not strict reserve rate and load forecasting of expansion planning have been included and also processed using fuzzy set theory in this study. In order to proceed the latter analysis, the solving procedure is illustrated in detail by branch and bound method which includes the network flow method and maximum flow-minimum cut set theorem. Finally, case studies on 21-bus test system show that the algorithm proposed is efficiently applicable to the practical expansion planning of transmission systems in future.

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Analysis of Rock Slope Stability for Natural Slope and Cut Slope of Gneiss Area in Andong, Korea (편마암지역 자연사면.절취사면의 안정성 분석 사례)

  • Kim, Man-Il;Bae, Du-Won;Kim, Jong-Tae;Chae, Byung-Gon;Jeong, Gyo-Cheol
    • The Journal of Engineering Geology
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    • v.17 no.2 s.52
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    • pp.289-297
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    • 2007
  • Slope failure that is occurred by rainfall generates a lot of property damages and loss of lives. Slope stability management and reinforcement countermeasure can be attained through continuous monitoring about various slope types that adjoin in human's life for reducing slope failure from natural and artificial cut slope hazards. The study area is rock slope that is consisted of gneiss, and large scale joint set is ranging by fault activity. This rock mass is exposed during long period and has lithological weathering property of weathered rock or soft rock. In-situ investigation carried out after divide by natural slope and cut slope. As a result, the natural slope appeared to high possibility of planar failure and wedge failure in few joint points that main joint set is formed. On the other hand, slope failure conformation in cut slope was superior only wedge failure occurrence possibility in eight joint points. In result of numerical analysis using SLIDE 2D, the minimum safety factor was analyzed slope stability for cut slope relatively low than natural slope in this study.

A Bottleneck Search Algorithm for Digraph Using Maximum Adjacency Merging Method (최대 인접 병합 방법을 적용한 방향 그래프의 병목지점 탐색 알고리즘)

  • Lee, Sang-Un
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.12 no.5
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    • pp.129-139
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    • 2012
  • Given digraph network $D=(N,A),n{\in}N,a=c(u,v){\in}A$ with source s and sink t, the maximum flow from s to t is determined by cut (S, T) that splits N to $s{\in}S$ and $t{\in}T$ disjoint sets with minimum cut value. The Ford-Fulkerson (F-F) algorithm with time complexity $O(NA^2)$ has been well known to this problem. The F-F algorithm finds all possible augmenting paths from s to t with residual capacity arcs and determines bottleneck arc that has a minimum residual capacity among the paths. After completion of algorithm, you should be determine the minimum cut by combination of bottleneck arcs. This paper suggests maximum adjacency merging and compute cut value method is called by MA-merging algorithm. We start the initial value to S={s}, T={t}, Then we select the maximum capacity $_{max}c(u,v)$ in the graph and merge to adjacent set S or T. Finally, we compute cut value of S or T. This algorithm runs n-1 times. We experiment Ford-Fulkerson and MA-merging algorithm for various 8 digraph. As a results, MA-merging algorithm can be finds minimum cut during the n-1 running times with time complexity O(N).

Minimal Cut Set of Electric Power Installations using Fault Tree Analysis (FTA를 이용한 수변전설비의 최소절단집합 도출)

  • Park, Young-Ho;Kim, Doo-Hyun;Kim, Sung-Chul
    • Journal of the Korean Society of Safety
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    • v.32 no.1
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    • pp.41-46
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    • 2017
  • In this paper, from making an electrical fire which is thought to be the most damaging among potential dangers as a top event, minimal cut sets (MCS) about it were analyzed. For this, components of a power substation were classified into 15 items. Failure rates and modes were extracted based on Korea Electrical Safety Corporation, IEEE Gold Book, and RAC. To analyze the top event (an electrical fire), main events were assorted into "safety devices for overcurrent" and "ampere meter of detecter". Failure of components was divided into failure of VCB, COS, and MCCB. A fault tree was composed of 3 AND gate, 5 OR gates and 17 basic events. Overlapped events among the basic events are things which occur from relevant components. They were attached to the tree by distinguishing identifiers. In case of FT, two minimal cut sets of "IO_METER", "MF_METER", "DO_MCCB" and "IO_METER", "MF_METER", "DO_VCB" take 46% of electrical fires. Therefore, about basic events which are included in the top two minimum cut sets, strict control is necessary.

Determination of epidemiological tetracycline MIC cut-off value for Vibrio ichthyoenteri

  • Han, Hyun-Ja;Kim, Do-Hyung;Lee, Deok-Chan;Won, Kyoung-Mi;Lee, Soon-Jeong;Cho, Mi-Young;Jee, Bo-Young;Kim, Jin-Woo
    • Journal of fish pathology
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    • v.24 no.2
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    • pp.95-102
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    • 2011
  • Normalized resistance interpretation (NRI) analysis for tetracycline was applied to generate information on the epidemiological cut-off value for Vibrio ichthyoenteri isolated from diseased olive flounder (Paralichthys olivaceus) larvae. Thus, 42 strains of V. ichthyoenteri were used to determine minimum inhibitory concentration (MIC) values of tetracycline using Etest. Also, 11 tetracycline resistance related genes were investigated by PCR method. Most tetracycline-resistant strains harbored both tetB and tetM with a few exceptions. NRI-derived mean and 2 SD above the mean of theoretical normal distributions of susceptible isolates were 0.33 mg/L and 1.66 mg/L, respectively. The epidemiological cut-off value for V. ichthyoenteri from the calculations could be set to S ${\leq}$ 2 mg/L. Of the 42 strains, 15 were classified as non-wild type (NWT), and MIC values of the NWT strains vary regardless of tetB and tetM detection, suggesting that there may be other mechanisms involved in tetracycline resistance in this Vibrio species.

Fault Tree Analysis for Risk Assessment of CO2 Leakage from Geologic Storage (지중 저장 이산화탄소의 누출 위험도 평가를 위한 결함수 분석)

  • Lee, Sang Il;Lee, Sang Ki;Hwang, Jin Hwan
    • Journal of Environmental Impact Assessment
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    • v.18 no.6
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    • pp.359-366
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    • 2009
  • CCS (Carbon Capture and Storage) is considered as the most promising interim solution to deal with the greenhouse gas such as $CO_2$ responsible for global warming. Even though carefully chosen geologic formations are known to contain stored gas for a long time period, there are potential risks of leakage. Up to now, applicable risk assessment procedures for the leakage of $CO_2$ are not available. This study presents a basis for risk analysis applicable to a complex geologic storage system. It starts with the classification of potential leakage pathways. Receptors and the leakage effect on them are identified and quantified. Then, a fault tree is constructed, which yields the minimum cut set (i.e., the most vulnerable leakage pathway) and quantifies the probability of the leakage risk through the cut set. The methodology will provide a tool for risk assessment in a CCS project. The outcomes of the assessment will not only ensure the safety of the CCS system but also offer a reliable and efficient monitoring plan.

A Tabu Search Algorithm for the Network Diversion Problem (네트워크 전환문제에 대한 타부 탐색 해법)

  • 양희원;박성수
    • Journal of the military operations research society of Korea
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    • v.30 no.1
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    • pp.30-47
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    • 2004
  • This research considers a Network Diversion Problem (NDP) in the directed graph, which is to identify a minimum cost set of links to cut so that any communication paths from a designated source node to a destination node must include at least one link from a specified set of arcs which is called the diversion arcs. We identify a redundant constraint from an earlier formulation. The problem is known to be NP-hard, however a detailed proof has not been given. We provide the proof of the NP-hardness of this problem. We develop a tabu search algorithm that includes a preprocessing procedure with two steps for removing diversion arcs as well as reducing the problem size. Computational results of the algorithm on instances of general graphs and grid graphs are reported.