• 제목/요약/키워드: crossover/non-crossover

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A Set-theoretic Account of English Crossover Effects

  • Lee, Gunsoo
    • 한국영어학회지:영어학
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    • 제1권1호
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    • pp.101-117
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    • 2001
  • In English, whether or not wh-movement creates weak crossover effects depends upon the type of wh-phrases that cross over. A bare interrogative like who shows a typical weak crossover effect whereas which N type (e.g. which girl) and partitive type (e.g. which of these girls) wh-phrases would show mere weaker and weakest crossover effects, respectively. Previous approaches to English crossover phenomena that resort to a binary notion of specificity or D-linking cannot account for the three-way contrast the three different types of wh-phrases show. To overcome this problem, I argue in this paper that specificity should be a non-binary set-theoretic notion and propose the following subset principle and optimal binding relation: Between two lexical nominal expressions A and B, A is regarded as more specific than B iff the denotation of A comes from a more narrowly defined non-singleton set than B. Between two lexical nominal expressions A and B, if A locally binds B, then the non-singleton set from which the denotation of A comes should be a subset of the set from which the denotation of B comes (i.e. B cannot be more specific than A). The smaller the subset (i.e. the wider the specificity gap between binder and binder), the more optimal the local binding relation is. A locally binds B iff A is coindexed with B, and A c-commands B, and there is no such C that does not bind A but binds B. Finally, I show that partitivity functions to carve out a smaller subset and thus make partitive wh-phrases more specific than simple which N type wh-phrases.

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도로선형최적화를 위한 유전자 연산자의 적용 (Incorporating Genetic Operators into Optimizing Highway Alignments)

  • 김응철
    • 대한교통학회지
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    • 제22권2호
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    • pp.43-54
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    • 2004
  • 본 연구에서는 인공지능(Artificial Intelligence)방법 중의 하나인 유전자 알고리즘(Genetic Algorithm)을 도로선형최적화 모형개발의 탐색엔진으로 활용하기 위한 핵심도구인 유전자 연산자(Genetic Operator)의 개발과 적용과정을 통해 그 특징과 유용성을 제시하였다. 균일돌연변이 연산자, 직선돌연변이 연산자. 비균일 돌연변이 연산자, 전체 비균일 돌연변이 연산자 등 4개의 돌연변이 연산자가 탐색영역(Search space)의 가능한 모든 부분을 탐험(Exploration)하기 위해 적용되었으며, 단순교차 연산자, 두 개의 점을 이용한 교차 연산자, 산술교차 연산자, 학습교차 연산자 등 4개의 교차 연산자가 노선대안의 우수한 유전형질을 다음세대에 효과적으로 전달(Exploitation)하기 위해 시험되었다. 사례연구와 민감도 분석과정을 통해 유전자 알고리즘 및 개발 적용된 8개 유전자 연산자의 도로선형최적화과정 도입이 우수한 노선대안을 빠르고 효과적으로 탐색함을 알 수 있었으며, 돌연변이 연산자와 교차 연산자의 효과적 조합이 상호보완기능을 통해 탐색능력의 향상에 큰 영향을 끼치는 것으로 파악되었다. 또한, 개발 적용된 연산자 이외에도 새로운 연산자의 개발 가능성이 무한하며, 이는 도로선형최적화에 유전자 알고리즘의 적용이 타당함을 반증함도 주목할 만하다.

$PM_{10}$ Exposure and Non-accidental Mortality in Asian Populations: A Meta-analysis of Time-series and Case-crossover Studies

  • Park, Hye Yin;Bae, Sanghyuk;Hong, Yun-Chul
    • Journal of Preventive Medicine and Public Health
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    • 제46권1호
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    • pp.10-18
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    • 2013
  • Objectives: We investigated the association between particulate matter less than $10{\mu}m$ in aerodynamic diameter ($PM_{10}$) exposure and non-accidental mortality in Asian populations by meta-analysis, using both time-series and case-crossover analysis. Methods: Among the 819 published studies searched from PubMed and EMBASE using key words related to $PM_{10}$ exposure and non-accidental mortality in Asian countries, 8 time-series and 4 case-crossover studies were selected for meta-analysis after exclusion by selection criteria. We obtained the relative risk (RR) and 95% confidence intervals (CI) of non-accidental mortality per $10{\mu}g/m^3$ increase of daily $PM_{10}$ from each study. We used Q statistics to test the heterogeneity of the results among the different studies and evaluated for publication bias using Begg funnel plot and Egger test. Results: Testing for heterogeneity showed significance (p<0.001); thus, we applied a random-effects model. RR (95% CI) per $10{\mu}g/m^3$ increase of daily $PM_{10}$ for both the time-series and case-crossover studies combined, time-series studies relative risk only, and case-crossover studies only, were 1.0047 (1.0033 to 1.0062), 1.0057 (1.0029 to 1.0086), and 1.0027 (1.0010 to 1.0043), respectively. The non-significant Egger test suggested that this analysis was not likely to have a publication bias. Conclusions: We found a significant positive association between $PM_{10}$ exposure and non-accidental mortality among Asian populations. Continued investigations are encouraged to contribute to the health impact assessment and public health management of air pollution in Asian countries.

효모 감수분열과정에서의 유전자 재조합 기전 특이적 DNA 중간체의 구조 변화 (Identification of Meiotic Recombination Intermediates in Saccharomyces cerevisiae)

  • 성영진;윤상욱;김근필
    • 미생물학회지
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    • 제49권1호
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    • pp.1-7
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    • 2013
  • 유전자 재조합체는 상동염색체간의 예정된 DNA 가닥 전이와 교환이 이루어지는 상동염색체 재조합 과정에 의하여 생성된다. 이 재조합 경로는 DNA 이중 가닥 절단(double-strand breaks, DSBs)에 의해서 개시되며, 전이 과정의 중간단계에서 DNA의 구조적 변이 중간체인 단일 가닥 침투(single-end invasions, SEIs)와 이중 홀리데이 접합(double-Holliday junctions, dHJs)이 형성되어 교차성(crossover, CO) 혹은 비교차성(non-crossover, NCO) 결과물이 만들어진다. 본 연구는 이중 가닥 절단, 단일 가닥 침투, 이중 홀리데이 접합과 같은 재조합 중간체와 재조합 결과물의 구조분석에 초점을 두고, 이를 출아효모에서 인위적으로 이중 가닥 절단을 발생시킬 수 있는 HIS4LEU2 "hot spot" 을 이용한 물리적 분석방법으로 감수분열 재조합 중간체를 규명하였다. 물리적 분석을 위하여 동조화 된 세포에 감수분열을 유도한 후 hot spot 자리를 인식하는 제한효소를 처리하면, 재조합 중간체를 형성하고 있는 DNA 단편들을 Southern 분석법을 통해 탐지 및 정량 할 수 있다. 본 연구는 이 시스템으로 감수분열에서 이중가닥 절단으로부터 기인하는 단일 가닥 침투, 이중 홀리데이 접합 그리고 교차성/비교차성 재조합체로 전이되는 DNA의 구조 다형을 분석할 수 있음을 제시한다.

보강된 복합재 패널의 최적설계를 위한 유전알고리듬의 연구 (Advanced Genetic Algrorithm Strategies in Optimal Design of Stiffened Composite Panels)

  • 이종수
    • 대한기계학회논문집A
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    • 제24권5호
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    • pp.1193-1202
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    • 2000
  • The paper describes the use of genetic algorithms (GA's) to the minimum weight design of stiffened composite panels for buckling constraints. The proposed design problem is characterized by mixture of continuous and discrete design variables corresponding to panel elements and stacking sequence of laminates, respectively. Design space is multimodal and non-convex, thereby introducing the need for global search strategies. Advanced strategies in GA's such as directed crossover, multistage search and separated crossover are adopted to improve search ability and to save computational resource requirements. The paper explores the effectiveness of genetic algorithms and their advanced strategies in designing stiffened composite panels under various uniaxial compressive load conditions and the linrlit on stacking sequence of laminates.

Single Crossover-Mediated Markerless Genome Engineering in Clostridium acetobutylicum

  • Lee, Sang-Hyun;Kim, Hyun Ju;Shin, Yong-An;Kim, Kyoung Heon;Lee, Sang Jun
    • Journal of Microbiology and Biotechnology
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    • 제26권4호
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    • pp.725-729
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    • 2016
  • A novel genome-engineering tool in Clostridium acetobutylicum was developed based on single-crossover homologous recombination. A small-sized non-replicable plasmid, pHKO1, was designed for efficient integration into the C. acetobutylicum genome. The integrated pHKO1 plasmid backbone, which included an antibiotic resistance gene, can be excised in vivo by Flp recombinase, leaving a single flippase recognition target sequence in the middle of the targeted gene. Since the pSHL-FLP plasmid, the carrier of the Flp recombinase gene, employed the segregationally unstable pAMβ1 replicon, the plasmid was rapidly cured from the mutant C. acetobutylicum. Consequently, our method makes it easier to engineer C. acetobutylicum.

설계유형에 따른 향기요법의 효과 (Comparing the Effects of Aromatherapy on Dysmenorrhea by Research Design)

  • 최은희;서지영
    • 성인간호학회지
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    • 제22권1호
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    • pp.31-40
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    • 2010
  • Purpose: The purpose of this study was to examine whether there is difference in the effects of aromatherapy on dysmenorrhea by research design. Methods: Findings from the two different research designs (Nonequivalent control group pretest-posttest [NCG] design vs. two-group crossover design) were compared in regard to the effect of aromatherapy on dysmenorrhea. The subjects of the NCG design and the crossover design were a total of 58 female nursing students. The treatments (aroma essential oil inhalation and carrier oil inhalation) were given using a necklace. The data were analyzed by Fisher's exact test, t-test, Mann-Whitney test, paired t-test, and Shapiro-Wilk test using the SPSS/WIN 12.0 program. The effect size for the two research designs was calculated. Results: In both research designs, the level of dysmenorrhea and menstrual pain after the aroma treatment were not significantly different from those after the placebo treatment. The effect size of the NCG design was higher than that of the crossover design. Conclusion: Aroma inhalation may not be effective in managing dysmenorrhea and menstrual pain. In order to further clarify the efficiency of research design and the effect of aromatherapy on discomfort during menstruation, replication studies are necessary. Future studies need to examine the effects of different research design on non-interval variables.

Evaluation of the different genetic algorithm parameters and operators for the finite element model updating problem

  • Erdogan, Yildirim Serhat;Bakir, Pelin Gundes
    • Computers and Concrete
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    • 제11권6호
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    • pp.541-569
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    • 2013
  • There is a wide variety of existing Genetic Algorithms (GA) operators and parameters in the literature. However, there is no unique technique that shows the best performance for different classes of optimization problems. Hence, the evaluation of these operators and parameters, which influence the effectiveness of the search process, must be carried out on a problem basis. This paper presents a comparison for the influence of GA operators and parameters on the performance of the damage identification problem using the finite element model updating method (FEMU). The damage is defined as reduction in bending rigidity of the finite elements of a reinforced concrete beam. A certain damage scenario is adopted and identified using different GA operators by minimizing the differences between experimental and analytical modal parameters. In this study, different selection, crossover and mutation operators are compared with each other based on the reliability, accuracy and efficiency criteria. The exploration and exploitation capabilities of different operators are evaluated. Also a comparison is carried out for the parallel and sequential GAs with different population sizes and the effect of the multiple use of some crossover operators is investigated. The results show that the roulettewheel selection technique together with real valued encoding gives the best results. It is also apparent that the Non-uniform Mutation as well as Parent Centric Normal Crossover can be confidently used in the damage identification problem. Nevertheless the parallel GAs increases both computation speed and the efficiency of the method.

Tree Structure Modeling and Genetic Algorithm-based Approach to Unequal-area Facility Layout Problem

  • Honiden, Terushige
    • Industrial Engineering and Management Systems
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    • 제3권2호
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    • pp.123-128
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    • 2004
  • A tree structure model has been proposed for representing the unequal-area facility layout. Each facility has a different rectangular shape specified by its area and aspect ratio. In this layout problem, based on the assumption that the shop floor has enough space for laying out the facilities, no constraint is considered for a shop floor. Objectives are minimizing total part movement between facilities and total rectangular layout area where all facilities and dead spaces are enclosed. Using the genetic code corresponding to two kinds of information, facility sequence and branching positions in the tree structure model, a genetic algorithm has been applied for finding non-dominated solutions in the two-objective layout problem. We use three kinds of crossover (PMX, OX, CX) for the former part of the chromosome and one-point crossover for the latter part. Two kinds of layout problems have been tested by the proposed method. The results demonstrate that the presented algorithm is able to find good solutions in enough short time.

상이한 납기와 도착시간을 갖는 단일기계 일정계획을 위한 유전 알고리즘 설계 (A Genetic Algorithm for Single Machine Scheduling with Unequal Release Dates and Due Dates)

  • 이동현;이경근;김재균;박창권;장길상
    • 한국경영과학회지
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    • 제24권3호
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    • pp.73-82
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    • 1999
  • In this paper, we address a single machine non-preemptive n-job scheduling problem to minimize the sum of earliness and tardiness with different release times and due dates. To solve the problem, we propose a genetic algorithm with new crossover and mutation operators to find the job sequencing. For the proposed genetic algorithm, the optimal pair of crossover and mutation rates is investigated. To illustrate the suitability of genetic algorithm, solutions of genetic algorithm are compared with solutions of exhaustive enumeration method in small size problems and tabu search method in large size problems. Computational results demonstrate that the proposed genetic algorithm provides the near-optimal job sequencing in the real world problem.

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