• Korean Journal of Plant Resources
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• v.22 no.5
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• pp.446-453
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• 2009

RAPD analyses were performed to investigate genetic relationships and useful molecular maker for 3 species and their 17 regional populations of the Pueraria lobata and related taxa. The length of amplified DNA fragments ranged from 200 to, 2,800 bp. Two hundred and eight scorable polymorphic makers and three scorable monomorphic makers were found from the PCR reactions with 15 random oligo primers, and those were analyzed by Nei's genetic distance coefficient. Based on the UPGMA phenogram from RAPD analyses, two major groups (9 populations from Korea; 3 populations from foreign countries) were recognized. And it showed distinct genetic differences from related taxa. The RAPD results was very useful to define the samples by geographical distribution and to discuss the relationships among the populations and their related taxa of the Pueraria lobata.

• Korean Journal of Plant Resources
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• v.33 no.6
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• pp.615-623
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• 2020

Brassica rapa is one of the most valuable vegetable crops worldwide. Cultivated varieties of B. rapa exhibit diverse developmental and morphological appearances, which includes important vegetables, oilseeds, and fodder crops. In this study, various phenotypes of recombinant inbred lines (RILs) of B. rapa were investigated, including their responses to five different pathogenic Botrytis cinerea isolates, responses to aphid and thrips during flowering stages, days to flowering, and plant heights. Responses of 113 RILs to five different B. cinerea isolates showed variations, suggesting that genetic factors controlling resistance or tolerance against each isolate were dependent on isolate/genotype pairs. Correlation analysis was performed to understand the nature of genetic factors and the relationship among these phenotypes. Although high levels of correlation were not detected between phenotypes assessed in this study, statistically significant correlation was detected for several combinations. Significant positive correlations were found for different B. cinerea isolates, supporting that certain levels of commonality could exist in genetic components controlling resistance against different B. cinerea isolates. Based on correlation analysis using numbers of insects counted on plants, it was speculated that genetic factors responsible for aphid tolerance or repellence might be also involved in the response against thrips. Relationship between vegetative growth and tolerance against B. cinereal or insects is rather more complicated. However, it was observed that shorter plants appeared to have a certain level of tolerance or repellence against both aphids and thrips. Data presented in this study could be used to assist further genetic studies and breeding efforts to obtain Botritis and insect resistance for B. rapa.

• Journal of Radiation Industry
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• v.4 no.4
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• pp.307-312
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• 2010

Plants have evolved physiological, biochemical and metabolic mechanisms to increase their survival under the adverse conditions. This present study has been performed to select salt-tolerant rice mutant lines through in vivo and in vitro mutagenesis with gamma-rays. For the selection of the salt-tolerant rice mutants, we conducted three times of selection procedure using 1,500 gamma ray mutant lines resulted from an embryo culture of the original rice cv. Dongan (wild-type, WT): first, selection in the a nutrient solution with 171 mM NaCl; second, selection under in vitro condition with 171 mM NaCl; and third, selection in a reclaimed saline land. Based on a growth comparison of the entries, out of the mutant lines, two putative 2 salt tolerant (ST) rice mutant lines, ST-87 and ST-301, were finally selected. The survival rate of the WT, ST-87 and ST-301 were 36.6%, 60% and 66.3% after 7 days in 171 mM NaCl treatment, respectively. The WT and two salt tolerant mutant lines were used to analyze their genetic variations. A total of 21 EcoRI and Msel primer combinations were used to analyze the genetic relationship of among the two salt-tolerant lines and the WT using the ABI3130 capillary electrophoresis system. In the AFLP analysis, a total of 1469 bands were produced by the 21 primer combinations, and 700 (47.6%) of them were identified as having polymorphism. The genetic similarity coefficients were ranged from 0.52 between the ST-87 and WT to 0.24 between the ST-301 and the WT. These rice mutant lines will be used as a control plot for physiological analysis and genetic research on salt tolerance.

• Journal of Intelligence and Information Systems
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• v.23 no.2
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• pp.19-38
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• 2017

Collaborative filtering (CF) algorithm has been popularly used for implementing recommender systems. Until now, there have been many prior studies to improve the accuracy of CF. Among them, some recent studies adopt 'hybrid recommendation approach', which enhances the performance of conventional CF by using additional information. In this research, we propose a new hybrid recommender system which fuses CF and the results from the social network analysis on trust and distrust relationship networks among users to enhance prediction accuracy. The proposed algorithm of our study is based on memory-based CF. But, when calculating the similarity between users in CF, our proposed algorithm considers not only the correlation of the users' numeric rating patterns, but also the users' in-degree centrality values derived from trust and distrust relationship networks. In specific, it is designed to amplify the similarity between a target user and his or her neighbor when the neighbor has higher in-degree centrality in the trust relationship network. Also, it attenuates the similarity between a target user and his or her neighbor when the neighbor has higher in-degree centrality in the distrust relationship network. Our proposed algorithm considers four (4) types of user relationships - direct trust, indirect trust, direct distrust, and indirect distrust - in total. And, it uses four adjusting coefficients, which adjusts the level of amplification / attenuation for in-degree centrality values derived from direct / indirect trust and distrust relationship networks. To determine optimal adjusting coefficients, genetic algorithms (GA) has been adopted. Under this background, we named our proposed algorithm as SNACF-GA (Social Network Analysis - based CF using GA). To validate the performance of the SNACF-GA, we used a real-world data set which is called 'Extended Epinions dataset' provided by 'trustlet.org'. It is the data set contains user responses (rating scores and reviews) after purchasing specific items (e.g. car, movie, music, book) as well as trust / distrust relationship information indicating whom to trust or distrust between users. The experimental system was basically developed using Microsoft Visual Basic for Applications (VBA), but we also used UCINET 6 for calculating the in-degree centrality of trust / distrust relationship networks. In addition, we used Palisade Software's Evolver, which is a commercial software implements genetic algorithm. To examine the effectiveness of our proposed system more precisely, we adopted two comparison models. The first comparison model is conventional CF. It only uses users' explicit numeric ratings when calculating the similarities between users. That is, it does not consider trust / distrust relationship between users at all. The second comparison model is SNACF (Social Network Analysis - based CF). SNACF differs from the proposed algorithm SNACF-GA in that it considers only direct trust / distrust relationships. It also does not use GA optimization. The performances of the proposed algorithm and comparison models were evaluated by using average MAE (mean absolute error). Experimental result showed that the optimal adjusting coefficients for direct trust, indirect trust, direct distrust, indirect distrust were 0, 1.4287, 1.5, 0.4615 each. This implies that distrust relationships between users are more important than trust ones in recommender systems. From the perspective of recommendation accuracy, SNACF-GA (Avg. MAE = 0.111943), the proposed algorithm which reflects both direct and indirect trust / distrust relationships information, was found to greatly outperform a conventional CF (Avg. MAE = 0.112638). Also, the algorithm showed better recommendation accuracy than the SNACF (Avg. MAE = 0.112209). To confirm whether these differences are statistically significant or not, we applied paired samples t-test. The results from the paired samples t-test presented that the difference between SNACF-GA and conventional CF was statistical significant at the 1% significance level, and the difference between SNACF-GA and SNACF was statistical significant at the 5%. Our study found that the trust/distrust relationship can be important information for improving performance of recommendation algorithms. Especially, distrust relationship information was found to have a greater impact on the performance improvement of CF. This implies that we need to have more attention on distrust (negative) relationships rather than trust (positive) ones when tracking and managing social relationships between users.

• Journal of Korean Institute of Industrial Engineers
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• v.20 no.3
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• pp.15-34
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• 1994

This paper considers the genetic algorithms(GAs) for the mixed model assembly line sequencing(MMALS) in which the objective is to minimize the overall line length. To apply the GAs to the MMALS, the representation, selection, genetic sequencing operators, and genetic parameters are studied. Especially, the existing sequencing binary operators such as partially map crossover(PMX), cycle crossover(CX), and order crossover (OX) are modified to be suitable for the MMALS, and a new sequencing binary operator called immediate successor relationship crossover (ISR) is introduced. These binary operators mentioned above and/or unary operators such as swap, insertion, inversion, displacement, and splice are compared to find operators which work well in the MMALS. Experimental results indicate that 1) among the binary operators ISR operator is the best, followed by the modified OX, and the modified PMX, with the modified CX being the worst, 2) among the unary operators inversion operator is the best, followed by displacement, swap, and insertion, with splice being the worst, and 3) in general, the unary operators perform better than the binary operators for the MMALS.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1996.04a
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• pp.30-35
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• 1996

Penalty technique perhaps is the most common technique used in the genetic algorithms for constrained optimization problems. In recent years, several techniques have been proposed in the area of evolutionary computation. However, there is no general guideline on designing penalty function and constructing an efficient penalty function is quite problem-dependent. The purpose of the paper is to give a tutorial survey of recent works on penalty techniques used in genetic algorithms and to give a better classification on exisitng works, which may be helpful for revealing the intrinsic relationship among them and for providing some hints for further studies on penalty techniques.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.4
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• pp.216-222
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• 2002

Brake Moan is a laud and strong noise occurring at any vehicle speed over 2 mph as a low frequency in below 600Hz. In this study, we targeted to shift the unstable mode that causes the brake moan from the moats frequency range to sufficiently higher frequency range to avoid the moan phenomenon. We simulated the finite element model and found out the nodes in which the brake moan occurs the most and we regarded the boundary and its relationship between the brake pad and the rotor as a spring coefficient k. With the binary set of the spring coefficient k, we finally used genetic algorithm (GA) to get the optimal topology of the brake pad and its shape to avoid the brake moan. The final result remarkably shows that genetic algorithm can be used in topology optimization procedures requiring complex eigenvalue problems.

• Communications for Statistical Applications and Methods
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• v.11 no.2
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• pp.355-368
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• 2004

In order to use Kriging, one has to estimate three parameters(nugget, sill and range) of semivariogram, which shows the relationship in the given two sites. A visual fit of the semivariogram parameters to a few standard models is widely used. But, it does not give the suitable results and not provide the automated process of Kriging. The gradient based nonlinear least squares is another choices to estimate three parameters, but it has some problems such as initial value problem. In this paper, we suggest the genetic algorithm as a compatible alternative method to solve the above mentioned problem. Finally, we estimate three parameters of semivariogram of rain-fall by adapting the genetic algorithm, compute Kriging estimate and conclude its effectiveness and compatibility.

• Journal of Life Science
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• v.13 no.5
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• pp.590-595
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• 2003

The objective of this study was to assess of genetic variation within and between pumpkin species including Cucurbita maxima, C. moschata, C. pepo and C. maxima${\times}$C. moschata using RAPD markers. The 16 primers showed the amplification of 136 scorable fragments ranging from about 100 bp to 2300 bp. A total of 94 DNA fragments were polymorphic with an average 5.9 polymorphic bands per primer. A species $(C. maxima\timesC. moschata)$ has the highest number of polymorphic loci. Based on obtained data, UPGMA cluster analysis was conducted. Twenty pumpkin cultivars were classified into three large categories and identified genetic distance of cluster ranging from 0.38 and 1.00. Clustering was in accordance with the division of Curcurbitaceae into four species, C. maxima, C. moschata, C. pepo and C. $C. maxima\timesC. moschata$. Therefore, RAPD method may be essential tool for enabling discrimination of pumpkin cultivars.

• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 2002.10a
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• pp.165-165
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• 2002

Hypertension is considered to be caused by a complicated combination of genetic and environmental factors. Atrial natriuretic peptide (ANP) has been to suppress renin activity and inhibit the synthesis and release of aldosterone. Therefore, Abnormalities of this peptide caused by genetic variation may be influence the blood pressure. The aim of present study was to examine the relationship between hypertension and Sca I RFLP of ANP gene in Korean population. The genotype distribution of this RFLP was significantly different between normotensives and hypertensives (P<0.05). However, this genetic marker was not significantly associated with any anthropometric parameters or plasma lipid concentrations in our study group. Therefore, our result suggest that Sca I RFLP of ANP gene may be useful as genetic marker in the ethiology of hypertension in Korean population, independent of any cardiovascular risk. factors studied.