• Title/Summary/Keyword: Branching Problem

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An Optimal Design of Paddy Irrigation Water Distribution System (논관개용 관수로시스템의 최적설계)

  • 안태진;박정응
    • Water for future
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    • v.27 no.4
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    • pp.161-171
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    • 1994
  • The water distribution system problem consists of finding a minimum cost system design subject to hydraulic and operation constraints. The design of new branching network in a paddy irrigation system is presented here. The program based on the linear programming formulation is aimed at finding the optimal economical combination of two main factors: the capital cost of pipe network and the energy cost. Two loading conditions and booster pumps for design of pipe network are considered to obtain the least cost design.

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Wavelength Assignment Optimization in SDH over WDM Rings

  • Chung, Jibok;Lee, Heesang;Han, ChiMoon
    • Management Science and Financial Engineering
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    • v.9 no.1
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    • pp.11-27
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    • 2003
  • In this study, we propose a mathematical model based on the graph theory for the wavelength assignment problem arising in the design of SDH (Synchronous Digital Hierarchy) over WDM (Wavelength Division Multiplexing) ring networks. We propose a branch- and -price algorithm to solve the suggested models effectively within reasonable time in realistic SDH over WDM ring networks. By exploiting the structure of ring networks, we developed a polynomial time algorithm for efficient column generation and a branching rule that conserves the structure of column generation. In a computer simulation study, the suggested approach can find the optimal solutions within reasonable time and show better performance than the existing heuristics.

Multipath Routing Based on Opportunistic Routing for Improving End-to-end Reliability in Large-scale Wireless Sensor Networks (대규모 무선 센서 네트워크에서 종단 간 전송 성공률 향상을 위한 기회적 라우팅 기반 다중 경로 전송 방안)

  • Kim, SangDae;Kim, KyongHoon;Kim, Ki-Il
    • IEMEK Journal of Embedded Systems and Applications
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    • v.14 no.4
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    • pp.177-186
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    • 2019
  • In wireless sensor networks, the transmission success ratio would be decreased when the scale of the WSNs increased. To defeat this problem, we propose a multipath routing based on opportunistic routing for improving end-to-end reliability in large-scale wireless sensor networks. The proposed scheme exploits the advantages of existing opportunistic routing and achieves high end-to-end success ratio by branching like a multipath routing through local decision without information of the whole network. As a result of the simulation result, the proposed scheme shows a similar or higher end-to-end transmission success ratio and less energy consumption rather than the existing scheme.

Candidate First Moves for Solving Life-and-Death Problems in the Game of Go, using Kohonen Neural Network (코호넨 신경망을 이용 바둑 사활문제를 풀기 위한 후보 첫 수들)

  • Lee, Byung-Doo;Keum, Young-Wook
    • Journal of Korea Game Society
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    • v.9 no.1
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    • pp.105-114
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    • 2009
  • In the game of Go, the life-and-death problem is a fundamental problem to be definitely overcome when implementing a computer Go program. To solve local Go problems such as life-and-death problems, an important consideration is how to tackle the game tree's huge branching factor and its depth. The basic idea of the experiment conducted in this article is that we modelled the human behavior to get the recognized first moves to kill the surrounded group. In the game of Go, similar life-and-death problems(patterns) often have similar solutions. To categorize similar patterns, we implemented Kohonen Neural Network(KNN) based clustering and found that the experimental result is promising and thus can compete with a pattern matching method, that uses supervised learning with a neural network, for solving life-and-death problems.

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An Concave Minimization Problem under the Muti-selection Knapsack Constraint (다중 선택 배낭 제약식 하에서의 오목 함수 최소화 문제)

  • Oh, Se-Ho
    • Journal of the Korea Convergence Society
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    • v.10 no.11
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    • pp.71-77
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    • 2019
  • This paper defines a multi-selection knapsack problem and presents an algorithm for seeking its optimal solution. Multi-selection means that all members of the particular group be selected or excluded. Our branch-and-bound algorithm introduces a simplex containing the feasible region of the original problem to exploit the fact that the most tightly underestimating function on the simplex is linear. In bounding operation, the subproblem defined over the candidate simplex is minimized. During the branching process the candidate simplex is splitted into two one-less dimensional subsimplices by being projected onto two hyperplanes. The approach of this paper can be applied to solving the global minimization problems under various types of the knapsack constraints.

An Index Data Structure for String Search in External Memory (외부 메모리에서 문자열을 효율적으로 탐색하기 위한 인덱스 자료 구조)

  • Na, Joong-Chae;Park, Kun-Soo
    • Journal of KIISE:Computer Systems and Theory
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    • v.32 no.11_12
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    • pp.598-607
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    • 2005
  • We propose a new external-memory index data structure, the Suffix B-tree. The Suffix B-tree is a B-tree in which the key is a string like the String B-tree. While the node in the String B-tree is implemented with a Patricia trio, the node in the Suffix B-tree is implemented with an array. So the Suffix B-tree is simpler and easier to be Implemented than the String B-tree. Nevertheless, the branching algorithm of the Suffix B-tree is as efficient as that of the String B-tree. Consequently, the Suffix B-tree takes the same worst-case disk accesses as the String B-tree to solve the string matching problem, which is fundamental and important in the area of string algorithms.

Pulsed laser welding of Zr-1%Nb alloy

  • Elkin, Maxim A.;Kiselev, Alexey S.;Slobodyan, Mikhail S.
    • Nuclear Engineering and Technology
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    • v.51 no.3
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    • pp.776-783
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    • 2019
  • Laser welding is usually a more effective method than electron-beam one since a vacuum chamber is not required. It is important for joining Zr-1%Nb (E110) alloy in a manufacturing process of nuclear fuel rods. In the present work, effect of energy parameters of pulsed laser welding on properties of butt joints of sheets with a thickness of 0.5 mm is investigated. The most efficient combination has been found (8-11 J pulse energy, 10-14 ms pulse duration, 780-810 W peak pulse power, 3 Hz pulse frequency, 1.12 mm/s welding speed). The results show that ultimate strength under static loading can not be used as a quality criterion for zirconium alloys welds. Increased shielding gas flow rate does not allow to protect weld metal totally and contributes to defect formation without using special nozzles. Several types of imperfections of the welds have been found, but the major problem is branching microcracks on the surface of the welds. It is difficult to identify the cause of their appearance without additional research on improving the welding zone protection (gas composition and flow rate as well as nozzle configuration) and studying the hydrogen content in the welds.

Image-Based Machine Learning Model for Malware Detection on LLVM IR (LLVM IR 대상 악성코드 탐지를 위한 이미지 기반 머신러닝 모델)

  • Kyung-bin Park;Yo-seob Yoon;Baasantogtokh Duulga;Kang-bin Yim
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.34 no.1
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    • pp.31-40
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    • 2024
  • Recently, static analysis-based signature and pattern detection technologies have limitations due to the advanced IT technologies. Moreover, It is a compatibility problem of multiple architectures and an inherent problem of signature and pattern detection. Malicious codes use obfuscation and packing techniques to hide their identity, and they also avoid existing static analysis-based signature and pattern detection techniques such as code rearrangement, register modification, and branching statement addition. In this paper, We propose an LLVM IR image-based automated static analysis of malicious code technology using machine learning to solve the problems mentioned above. Whether binary is obfuscated or packed, it's decompiled into LLVM IR, which is an intermediate representation dedicated to static analysis and optimization. "Therefore, the LLVM IR code is converted into an image before being fed to the CNN-based transfer learning algorithm ResNet50v2 supported by Keras". As a result, we present a model for image-based detection of malicious code.

Shape Design Sensitivity Analysis of Dynamic Crack Propagation Problems using Peridynamics and Parallel Computation (페리다이나믹스 이론과 병렬연산을 이용한 균열진전 문제의 형상 설계민감도 해석)

  • Kim, Jae-Hyun;Cho, Seonho
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.27 no.4
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    • pp.297-303
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    • 2014
  • Using the bond-based peridynamics and the parallel computation with binary decomposition, an adjoint shape design sensitivity analysis(DSA) method is developed for the dynamic crack propagation problems. The peridynamics includes the successive branching of cracks and employs the explicit scheme of time integration. The adjoint variable method is generally not suitable for path-dependent problems but employed since the path of response analysis is readily available. The accuracy of analytical design sensitivity is verified by comparing it with the finite difference one. The finite difference method is susceptible to the amount of design perturbations and could result in inaccurate design sensitivity for highly nonlinear peridynamics problems with respect to the design. It turns out that $C^1$-continuous volume fraction is necessary for the accurate evaluation of shape design sensitivity in peridynamic discretization.

Self-Consciousness Information of Branching Minds (갈라진 두 마음의 자기의식 정보)

  • Kim, Myeong-Seok
    • Journal of Korean Philosophical Society
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    • v.142
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    • pp.27-50
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    • 2017
  • When we lose our memories or when our self-identity becomes blurred, we may feel as if our mind has split into multiple minds. If someone makes another 'me' by copying my body and mind, how should two conscious 'I's change their credences? In this article, we present a new thought experiment that can be called the 'Two Adams Problem'. This thought experiment represents a piece of philosophical inquiry that speculates on the nature of self-consciousness information that 'I am awake now'. On Sunday evening, as soon as Adam falls asleep, the philosopher Roro makes another Adam by copying Adam's original body and mind. They sleep separately in another room. Within a minute, Roro throws a fair coin. If the coin lands heads up Roro wakes just one of the Adams up on Monday. If the coin lands tails up Roro wakes both Adams up. On Monday, at least one of the Adams will wake up. To what degree ought they believe that the outcome of the coin toss is heads? We will argue that the correct answer to this question is 1/2.