• Title/Summary/Keyword: Permutation Method

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Shipyard Skid Sequence Optimization Using a Hybrid Genetic Algorithm

  • Min-Jae Choi;Yung-Keun Kwon
    • Journal of the Korea Society of Computer and Information
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    • v.28 no.12
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    • pp.79-87
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    • 2023
  • In this paper, we propose a novel genetic algorithm to reduce the overall span time by optimizing the skid insertion sequence in the shipyard subassembly process. We represented a solution by a permutation of a set of skid ids and applied genetic operators suitable for such a representation. In addition, we combined the genetic algorithm and the existing heuristic algorithm called UniDev which is properly modified to improve the search performance. In particular, the slow skid search part in UniDev was changed to a greedy algorithm. Through extensive large-scaled simulations, it was observed that the span time of our method was stably minimized compared to Multi-Start search and a genetic algorithm combined with UniDev.

Finding a Needle in a Haystack: Homophily, Communication Structure, and Information Search in an Online User Community

  • Jeongmin Kim;Soyeon Lee;Yujin Han;Dong-Il Jung
    • Asia pacific journal of information systems
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    • v.34 no.2
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    • pp.635-660
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    • 2024
  • A growing body of research explores how users of online communities navigate through large-scale platforms to find the information they seek. This study builds on the theories of homophily, structural embeddedness, and social exchange to investigate how interest homophily and existing communication structures serve as mechanisms driving information searches and the subsequent formation of communication networks in these communities. Specifically, we analyze comment-on-post tie formation using network data from "Today's House," the largest online user community specializing in interior design in Korea. Employing the LR-QAP method, a permutation-based hypothesis testing algorithm for social network data, our research identifies that network tie formation is driven by both homophilous information searches based on instrumental and hedonic interests, as well as by structurally induced searches such as preferential attachment, reciprocity, and transitivity. In addition, we investigate the contingent effects of communication structure on homophilous tie formation. Our findings suggest that while network-wide structural characteristics enhance homophilous tie formation based on instrumental interests, local network processes leverage homophily based on hedonic interests. We conclude by discussing the theoretical implications of the differential influence of participation motivations on information search patterns and the practical implications for the design of online communities.

Detection of major genotypes combination by genotype matrix mapping (유전자 행렬 맵핑을 활용한 우수 유전자형 조합 선별)

  • Lee, Jea-Young;Lee, Jong-Hyeong;Lee, Yong-Won
    • Journal of the Korean Data and Information Science Society
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    • v.21 no.3
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    • pp.387-395
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    • 2010
  • It is important to identify the interaction of genes about human disease and characteristic value. Many studies as like logistic analysis, have associated being pursued, but, previous methods did not consider the sub-group of the genotypes. So, QTL interactions and the GMM (genotype matrix mapping) have been developed. In this study, we detect the superior genotype combination to have an impact on economic traits of Korean cattle based on the study over GMM method. Thus, we identified interaction effects of single nucleotide polymorphisms (SNPs) responsible for average daily gain(ADG), marbling score (MS), carcass cold weight (CWT), longissimus muscle dorsiarea (LMA) using GMM method. In addition, we examine significance of the major genotype combination selected by implementing permutation test of the F-measure which was not obtained by Sachiko et al.

Identification of Stearoyl-CoA Desaturase (SCD) Gene Interactions in Korean Native Cattle Based on the Multifactor-dimensionality Reduction Method

  • Oh, Dong-Yep;Jin, Me-Hyun;Lee, Yoon-Seok;Ha, Jae-Jung;Kim, Byung-Ki;Yeo, Jung-Sou;Lee, Jea-Young
    • Asian-Australasian Journal of Animal Sciences
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    • v.26 no.9
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    • pp.1218-1228
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    • 2013
  • Fat quality is determined by the composition of fatty acids. Genetic relationships between this composition and single nucleotide polymorphisms (SNPs) in the stearoyl-CoA desaturase1 (SCD1) gene were examined using 513 Korean native cattle. Single and epistatic effects of 7 SNP genetic variations were investigated, and the multifactor dimensionality reduction (MDR) method was used to investigate gene interactions in terms of oleic acid (C18:1), mono-unsaturated fatty acids (MUFAs) and marbling score (MS). The g.6850+77 A>G and g.14047 C>T SNP interactions were identified as the statistically optimal combination (C18:1, MUFAs and MS permutation p-values were 0.000, 0.000 and 0.001 respectively) of two-way gene interactions. The interaction effects of g.6850+77 A>G, g.10213 T>C and g.14047 C>T reflected the highest training-balanced accuracy (63.76%, 64.70% and 61.85% respectively) and was better than the individual effects for C18:1, MUFAs and MS. In addition, the superior genotype groups were AATTCC, AGTTCC, GGTCCC, AGTCCT, GGCCCT and AGCCTT. These results suggest that the selected SNP combination of the SCD1 gene and superior genotype groups can provide useful inferences for the improvement of the fatty acid composition in Korean native cattle.

Optimum Interleaver Design and Performance Analysis of Double-Binary Turbo Code for Wireless Metropolitan Area Networks (WMAN 시스템의 이중 이진 구조 터보부호 인터리버 최적화 설계 및 성능 분석)

  • Park, Sung-Joon
    • Journal of the Korea Society for Simulation
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    • v.17 no.1
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    • pp.17-22
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    • 2008
  • Double-binary turbo code has been adopted as an error control code of various future communication systems including wireless metropolitan area networks(WMAN) due to its powerful error correction capability. One of the components affecting the performance of turbo code is internal interleaver. In 802.16 d/e system, an almost regular permutation(ARP) interleaver has been included as a part of specification, however it seems that the interleaver is not optimized in terms of decoding performance. In this paper, we propose three optimization methods for the interleaver based on spatial distance, spread and minimum distance between original and interleaved sequence. We find optimized interleaving parameters for each optimization method and evaluate the performances of the proposed methods by computer simulation under additive white Gaussian noise(AWGN) channel. Optimized parameters can provide up to 1.0 dB power gain over the conventional method and furthermore the obtainable gain does not require any additional hardware complexity.

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Probabilistic Risk Assessment of a Cable-Stayed Bridge Based on the Prediction Method for the Combination of Failure Modes (붕괴모드 조합 예측법에 의한 PSC사장교의 위험도평가)

  • Park, Mi-Yun;Cho, Hyo-Nam;Cho, Taejun
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.26 no.4A
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    • pp.647-657
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    • 2006
  • Probabilistic Risk Assessment considering statistically random variables is performed for the preliminary design of a Cable Stayed Bridge, which is Prestressed Concrete Bridge consisted of cable and plate girders, based on the method of Working Stress Design and Strength Design. Component reliabilities of cables and girders have been evaluated using the response surface of the design variables at the selected critical sections based on the maximum shear, positive and negative moment locations. Response Surface Method (RSM) is successfully applied for reliability analyses for this relatively small probability of failure of the complex structure, which is hard to obtain through Monte-Carlo Simulations. or through First Order Second Moment Method that can not easily calculate the derivative terms of implicit limit state functions. For the analysis of system reliability, parallel resistance system consisting of cables and plate girder is changed into series connection system and the result of system reliability of total structure is presented. As a system reliability, the upper and lower probabilities of failure for the structural system have been evaluated and compared with the suggested prediction method for the combination of failure modes. The suggested prediction method for the combination of failure modes reveals the unexpected combinations of element failures in significantly reduced time and efforts compared with the previous permutation method or system reliability analysis method, which calculates upper and lower bound failure probabilities.

Risk Assessment for a Steel Arch Bridge System Based upon Response Surface Method Compared with System Reliability (체계신뢰성 평가와 비교한 응답면기법에 의한 강재아치교의 위험성평가)

  • Cho, Tae-Jun
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.20 no.3
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    • pp.273-279
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    • 2007
  • Probabilistic Risk Assessment considering statistically random variables is performed for the preliminary design of an Arch Bridge. Component reliabilities of girders have been evaluated using the response surfaces of the design variables at the selected critical sections based on the maximum shear and negative moment locations. Response Surface Method (RSM) is successfully applied for reliability analyses lot this relatively small probability of failure of the complex structure, which is hard to be calculated by Monte-Carlo Simulations or by First Order Second Moment method that can not easily calculate the derivative terms in implicit limit state functions. For the analysis of system reliability, parallel resistance system composed of girders is modeled as a parallel series connection system. The upper and lower probabilities of failure for the structural system have been evaluated and compared with the suggested prediction method for the combination of failure modes. The suggested prediction method for the combination of failure modes reveals the unexpected combinations of element failures in significantly reduced time and efforts, compared with the previous permutation method or conventional system reliability analysis method.

An Iterative Data-Flow Optimal Scheduling Algorithm based on Genetic Algorithm for High-Performance Multiprocessor (고성능 멀티프로세서를 위한 유전 알고리즘 기반의 반복 데이터흐름 최적화 스케줄링 알고리즘)

  • Chang, Jeong-Uk;Lin, Chi-Ho
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.15 no.6
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    • pp.115-121
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    • 2015
  • In this paper, we proposed an iterative data-flow optimal scheduling algorithm based on genetic algorithm for high-performance multiprocessor. The basic hardware model can be extended to include detailed features of the multiprocessor architecture. This is illustrated by implementing a hardware model that requires routing the data transfers over a communication network with a limited capacity. The scheduling method consists of three layers. In the top layer a genetic algorithm takes care of the optimization. It generates different permutations of operations, that are passed on to the middle layer. The global scheduling makes the main scheduling decisions based on a permutation of operations. Details of the hardware model are not considered in this layer. This is done in the bottom layer by the black-box scheduling. It completes the scheduling of an operation and ensures that the detailed hardware model is obeyed. Both scheduling method can insert cycles in the schedule to ensure that a valid schedule is always found quickly. In order to test the performance of the scheduling method, the results of benchmark of the five filters show that the scheduling method is able to find good quality schedules in reasonable time.

An Exploratory Observation of Analyzing Event-Related Potential Data on the Basis of Random-Resampling Method (무선재추출법에 기초한 사건관련전위 자료분석에 대한 탐색적 고찰)

  • Hyun, Joo-Seok
    • Science of Emotion and Sensibility
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    • v.20 no.2
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    • pp.149-160
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    • 2017
  • In hypothesis testing, the interpretation of a statistic obtained from the data analysis relies on a probabilistic distribution of the statistic constructed according to several statistical theories. For instance, the statistical significance of a mean difference between experimental conditions is determined according to a probabilistic distribution of the mean differences (e.g., Student's t) constructed under several theoretical assumptions for population characteristics. The present study explored the logic and advantages of random-resampling approach for analyzing event-related potentials (ERPs) where a hypothesis is tested according to the distribution of empirical statistics that is constructed based on randomly resampled dataset of real measures rather than a theoretical distribution of the statistics. To motivate ERP researchers' understanding of the random-resampling approach, the present study further introduced a specific example of data analyses where a random-permutation procedure was applied according to the random-resampling principle, as well as discussing several cautions ahead of its practical application to ERP data analyses.

An Effect of a Self-Efficacy Information Resources Program on Perceived Self-Efficacy and Self-Care in Patients with Coronary Artery Disease (자기효능 정보자원 프로그램이 관상동맥 질환 환자의 지각된 자기효능감과 자가간호행위에 미치는 효과)

  • Shin, Ju-Young;Khim, Soon-Yong
    • Korean Journal of Adult Nursing
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    • v.14 no.1
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    • pp.114-124
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    • 2002
  • Purpose: This study was conducted to investigate whether a self-efficacy information resources program based on the self-efficacy theory of Bandura (1986) would increase self-efficacy and self-care in patients with CAD. Method: The study was a one group, pretest-posttest pre-experimental design research. The Self-Efficacy Information Resources Program was composed of a video tape program and a telephone coaching program and based on vicarious experiences and verbal persuation. The Program was used as an experimental treatment from February 27. to May 27, 1999. Twenty patients participated from a university hospital located in Seoul. Three days later after a pretest the telephone coaching program was given. It was repeated weekly during a 3 week period. At the end of this period post-test data were collected by mail. Data were analyzed with a random permutation test using SAS program. Result: 1) Scores on self-efficacy after the Self-Efficacy Information Resources Program were significantly higher than before the program (p=0.06). 2) Scores on self-care after the Program were significantly higher (subjective self-care, p=0.0005; objective self-care, p= 0.0002) than before the program. Conclusion: The Program was found to be an effective nursing intervention for increasing self-efficacy and self-care. When nurses who care for CAD patients plan to increase their patients' self care ability, they should always consider the concept of self-efficacy.

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