• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2002.12a
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• pp.375-378
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• 2002

In this paper we propose parallel GA to optimize mutation rate and crossover rate using server-client model. The performance of GA depend on the good choice of crossover and mutation rates. Although many researcher has been study about the good choice, it is still unsolved problem. proposed GA optimize crossover and mutation rates trough evolving subpopulation. In virtue of the server-client model, these parameters can be evolved rapidly with relatively low-grade

• Journal of Korean Society of Transportation
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• v.22 no.2 s.73
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• pp.43-54
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• 2004

This study analyzes characteristics and applicability of genetic algorithms and genetic operators to optimize highway alignments. Genetic algorithms, one of artificial intelligence techniques, are fast and efficient search algorithms for generating, evaluation and finding optimal highway alignment alternatives. The performance of genetic algorithms as an optimal search tool highly depends on genetic operators that are designed as a problem-specific. This study adopts low mutation operators(uniform mutation operator, straight mutation operator, non-uniform mutation operator whole non-uniform mutation operator) to explore whole search spaces, and four crossover operators(simple crossover operator, two-point crossover operator, arithmetic crossover operator, heuristic crossover operator) to exploit food characteristics of the best chromosome in previous generations. A case study and a sensitivity analysis have shown that the eight problem-specific operators developed for optimizing highway alignments enhance the search performance of genetic algorithms, and find good solutions(highway alignment alternatives). It has been also found that a mixed and well-combined use of mutation and crossover operators is very important to balance between pre-matured solutions when employing more crossover operators and more computation time when adopting more mutation operators.

• Proceedings of the KSME Conference
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• 2008.11b
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• pp.2227-2230
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• 2008

Crossover of nitrogen from cathode to anode is inevitable in typical membranes used in PEM fuel cells. This crossovered nitrogen accumulates in anode recirculation system and excessive buildup of nitrogen in the recirculating anode gas lowers the hydrogen concentration and finally affects the performance of fuel cell stacks. In this study, characterization of nitrogen gas crossover was investigated in PEM fuel cell stacks. The mass spectroscopy (MS) has been applied to measure the amount of the crossovered nitrogen at the exit of anode. Results show that anode and cathode stoichiometric number ($SR_c$) have a big effect of nitrogen crossover.

• Child Studies in Asia-Pacific Contexts
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• v.6 no.1
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• pp.31-46
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• 2016

This study explored types and characteristics of South Korean crossover picturebooks that are enjoyed across generations. Participants included three publishers, six critics, six illustrators and three picturebook researchers, and focused on 92 South Korean recommended picturebooks published from 1995 to 2014 as the research material for this study. The majority of Korean crossover picturebook type was story, followed by information and art. There were few wordless books. Common themes of the story picturebooks were contemplation, traditional culture, social changes (such as immigration and redevelopment), reminiscence, social relations, loss and death, family problems, and social incidents. Classic essays and novels were revised for picturebooks as were famous poems originally written for grown-ups. Informational books were about traditions in music, architecture, furniture and special occasions like wedding and ceremonies. The style of the drawings were precise and realistic. Some drawings were done by brush and Chinese ink on hanji (traditional Korean paper) or silk. Some books featured Korean calligraphy as well, enabling adult readers to also appreciate the beauty and delicacy of the books. Art books and wordless books were quite rare and exhibited a playful tone. Adults alone were not presumed to be the primary reading audience of the picture books. Implications were made for picturebook marketing in a society such as South Korea, where the elderly population is rapidly increasing. Various forms of art books and parodies were also welcome. One conclusion of the study was that more experimental and innovative works would be encouraging for the development of South Korean crossover picturebooks.

• Journal of Preventive Medicine and Public Health
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• v.55 no.3
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• pp.289-296
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• 2022

Objectives: Integrating retail and manufacturing enables limitless potential for food businesses, but also creates challenges for navigating within complex food safety regulations. From public health inspectors' (PHIs) perspective, this study aimed (1) to describe the characteristics of crossover businesses in Louisiana, and (2) to evaluate regulation awareness and food safety education needs for business owners and PHIs who inspect crossover businesses. Methods: A self-administered questionnaire was administered to Louisiana Department of Health PHIs using Qualtrics^®. A descriptive analysis was performed, focusing on the frequency of each item. Results: In total, 1774 retailers were conducting or planned to conduct specialized processes, while 552 food manufacturers were performing or planned to perform retail functions. Reduced oxygen packaging, the use of additives such as vinegar as a method of preservation, and smoking food as a method of preservation were observed by 62%, 36%, and 35% of the PHIs, respectively. The PHIs perceived crossover businesses as "not aware" or "somewhat aware" of the food safety regulations. The current food safety training level for these businesses was reported to range from "no training" to "some training but not sufficient." When asked for a self-assessment, the majority of PHIs reported themselves as being "familiar" with the variance requirement for specialized processing. Their confidence in inspecting crossover businesses, however, leaned towards "not confident" or "somewhat confident." Conclusions: To better guard public health, food safety training is needed for crossover food business owners, as well as PHIs, on regulations and conducting or inspecting specialized processes.

• Journal of the Korean Society of Safety
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• v.37 no.6
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• pp.18-24
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• 2022

Hydrogen is a clean fuel and is used in many applications in power systems such as fuel cells. It has unique properties such as wide flammability, high burning velocity, and difficulty to liquefy, which lead to critical safety issues. Fire and explosion are the most frequently occurring accidents and one of the major reasons is autoignition. In the ignition process, the chemistry of hydrogen combustion depends mainly on radical pools, and the temperature at which chain-branching and terminating rates are equal is called the crossover temperature. This study addresses the homogeneous autoignition of diluted hydrogen-air mixtures to investigate the effects of dilution on the crossover temperature to prevent explosions in the future. The new criterion for crossover temperature is introduced by only hydrogen radicals to adjust more simply. The detailed calculations indicate that the crossover temperatures are low at high dilutions of carbon dioxide and nitrogen because the concentrations of active radicals are reduced when an inert gas is added. This result is expected to contribute to hydrogen safety and realize a hydrogen society in the future.

• Korean Journal of Social Welfare
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• v.60 no.3
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• pp.253-274
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• 2008

The link between work life and family life is an essential subject matter in understanding the lives of dual-earner couples. Concepts of spillover and crossover explain the link between work and family. The present study examines both the positive and negative aspects in these processes. The data come from the Sloan Working Families Study conducted by the Alfred P. Sloan Center on Parents, Children, and Work and NORC at the University of Chicago. The Experience Sampling Method employed explores directly the daily life experiences of the participants. The data were analysed using t-test. Both spillover and crossover were found in the lives of dual-earner couples in this study. Men and women brought happy emotions at work to home, but the data provide limited support for spillover of negative emotions. Gender differences were more apparent in examining the process of crossover. Men appear responsive to the positive and negative emotional experiences their spouse brought home while women were found not to be responsive to their spouses' positive emotional experiences at work. Furthermore, the analysis revealed an interesting trend concerning the emotions of working couples in that they generally seem to recover to their average level of emotions once home. This suggests that home can be a respite from strong emotions, a comforting place. By looking closely into the emotions experienced by working parents in their daily lives, this study adds contextual understanding concerning the link between work and family life. The findings on the effects of positive experiences at work invite social work practitioners and researchers to further investigate the phenomena of spillover and crossover processed in greater detail, taking into account this contextual aspect of family life as well as the work life of dual-earner couples.

• Journal of the Korean Data and Information Science Society
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• v.17 no.1
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• pp.245-257
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• 2006

A modified Anderson and Hauck(1983) test for analyzing a two-sequence two-period crossover design in bioequivalence trials is proposed when some observations at the second period are missing. It is based on the maximum likelihood estimators of average bioequivalence model and designed for handling missing at random(MAR) situation. The performance of the proposed test is compared to other tests using Monte Carlo simulations.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.39 no.4
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• pp.81-89
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• 2016

Distributed genetic algorithm (DGA), also known as island model or coarse-grained model, is a kind of parallel genetic algorithm, in which a population is partitioned into several sub-populations and each of them evolves with its own genetic operators to maintain diversity of individuals. It is known that DGA is superior to conventional genetic algorithm with a single population in terms of solution quality and computation time. Several researches have been conducted to evaluate effects of parameters on GAs, but there is no research work yet that deals with structure of DGA. In this study, we tried to evaluate performance of various genetic algorithms (GAs) for the famous symmetric traveling salesman problems. The considered GAs include a conventional serial GA (SGA) with IGX (Improved Greedy Crossover) and several DGAs with various combinations of crossover operators such as OX (Order Crossover), DPX (Distance Preserving Crossover), GX (Greedy Crossover), and IGX. Two distinct immigration policies, conventional noncompetitive policy and newly proposed competitive policy are also considered. To compare performance of GAs clearly, a series of analysis of variance (ANOVA) is conducted for several scenarios. The experimental results and ANOVAs show that DGAs outperform SGA in terms of computation time, while the solution quality is statistically the same. The most effective crossover operators are revealed as IGX and DPX, especially IGX is outstanding to improve solution quality regardless of type of GAs. In the perspective of immigration policy, the proposed competitive policy is slightly superior to the conventional policy when the problem size is large.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.5
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• pp.2031-2037
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• 2012

Background: Analysis of gene-gene and gene-environment interactions for complex multifactorial human disease faces challenges regarding statistical methodology. One major difficulty is partly due to the limitations of parametric-statistical methods for detection of gene effects that are dependent solely or partially on interactions with other genes or environmental exposures. Based on our previous case-control study in Chongqing of China, we have found increased risk of colorectal cancer exists in individuals carrying a novel homozygous TT at locus rs1329149 and known homozygous AA at locus rs671. Methods: In this study, we proposed statistical method-crossover analysis in combination with logistic regression model, to further analyze our data and focus on assessing gene-environmental interactions for colorectal cancer. Results: The results of the crossover analysis showed that there are possible multiplicative interactions between loci rs671 and rs1329149 with alcohol consumption. Multifactorial logistic regression analysis also validated that loci rs671 and rs1329149 both exhibited a multiplicative interaction with alcohol consumption. Moreover, we also found additive interactions between any pair of two factors (among the four risk factors: gene loci rs671, rs1329149, age and alcohol consumption) through the crossover analysis, which was not evident on logistic regression. Conclusions: In conclusion, the method based on crossover analysis-logistic regression is successful in assessing additive and multiplicative gene-environment interactions, and in revealing synergistic effects of gene loci rs671 and rs1329149 with alcohol consumption in the pathogenesis and development of colorectal cancer.