• Communications for Statistical Applications and Methods
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• v.29 no.6
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• pp.629-640
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• 2022

Variable selection is one of the most crucial tasks in supervised learning, such as regression and classification. The best subset selection is straightforward and optimal but not practically applicable unless the number of predictors is small. In this article, we propose directly solving the best subset selection via the genetic algorithm (GA), a popular stochastic optimization algorithm based on the principle of Darwinian evolution. To further improve the variable selection performance, we propose to run multiple GA to solve the best subset selection and then synthesize the results, which we call ensemble GA (EGA). The EGA significantly improves variable selection performance. In addition, the proposed method is essentially the best subset selection and hence applicable to a variety of models with different selection criteria. We compare the proposed EGA to existing variable selection methods under various models, including linear regression, Poisson regression, and Cox regression for survival data. Both simulation and real data analysis demonstrate the promising performance of the proposed method.

• Journal of The Korean Society of Grassland and Forage Science
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• v.20 no.4
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• pp.243-250
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• 2000

Selection of oat variety according to cultivation period is an important to increase productivity of forage crop. To investigate the growth characters and dry matter productivity of oats according to cultivation period, early-maturing oat(EM0) and medium-maturing oat(MM0) variety were sown in spring and autumn at central district of Korea. When oats were cultivated in spring, MMO variety was longer 8 cm in leaf length and wider 5 mm in leaf width than 25 cm and 12 mm of EM0 variety, rexpectively. but in autumn, those were not different between maturities of oat varieties. Plant length of MMO variety was longer 7 cm than that of EM0 Variety in spring cultivation, but in autumn, plant length of EM0 variety was longer 14 cm than that of MMO variety. Heading dates were 20th to 22th May in EM0 variety, and 30th May to 10th June in MMO variety in spring cultivation, and ear of EM0 variety emerged 30th Oct. to loth Nov. but that of MMO variety did not emerge at harvesting day in autumn cultivation. In Spring cultivation, dry matter(DM) yield of EM0 variety was 7,349 kg/ha that was less 56% than 11,466 kg/ha of MMO variety, but In Autumn, was more 15% than 6,575 kg/ha of MMO variety. In conclusion, selection of oat variety in spring and autumn cultivation can be different with cropping system of forage crop, and this trial is suggesting that oat variety could be sown MMO variety in spring and EM0 variety in autumn at central district of Korea. (Key words : Oat variety, Productivity, Cultivation season)

• The International Journal of Costume Culture
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• v.5 no.1
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• pp.26-33
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• 2002

Re purposes of this study were to determine consumers' selection criteria of fashion shopping area and to examine the effects of clothing consumption value and fashion leadership on the selection criteria of fashion shopping area. In addition, the third purpose was to clarify the relation beかeon the above variables and shopping intent. The data were collected from 198 females in their twenties using questionnaire. The results could be summarized as follows. First, the selection criteria of fashion shopping area were composed of 5 factors: scale & variety of shopping area, convenience of location, entertainment, physical service, and atmosphere. Second, the fashion leadership and clothing consumption value except functional and social values had an effect on the selection criteria fashion shopping area. Particularly, the attractiveness-sought value best explained the selection criteria. Third, the fashion leadership and selection criteria fashion shopping area had an effect on the shopping intent. The effect clothing consumption value was not significant.

• International Journal of Internet, Broadcasting and Communication
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• v.14 no.4
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• pp.181-188
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• 2022

The purpose of this study is to identify selection attributes, functional benefits, psychological benefits, and values according to crossover shopping patterns (showrooming and webrooming). To achieve objectives of this study, a survey was designed based on the means-end chain theory, using the in-depth laddering technique and APT laddering technique which understanding the linkage of A(attributes)-FB(functional benefits)-PB(psychological benefit)-V(value). These two laddering techniques were used to construct a hierarchical value map (HVM) by linking selection attributes, functional benefits, psychological benefits, and value levels. The selection attribute items that showrooming shoppers consider important are 'price conformity', 'product information', 'product variety', and 'delivery service'. Functional benefit items were 'free purchase', 'economic benefit', 'communication', 'safety', and 'accurate Information', and psychological benefit items were 'convenience', 'relaxation', 'pleasure', 'rational consumption', and 'stability'. Finally, the value items were 'self-satisfaction', 'abundant life', 'achievement', 'happiness', and 'reasonable life'. Next, the selection attribute items that webrooming shoppers consider important are 'price conformity', 'product information', 'product variety', 'AS', 'shopping atmosphere', and 'seller service'. Functional benefit items were 'free purchase', 'economic profit', 'expression opinion', 'safety', and 'accurate information', and psychological benefit items were 'convenience', 'relaxation', 'rational consumption', and 'stability'. Finally, the value items were 'self-satisfaction', 'abundant life', 'happiness', and 'reasonable life'.

• Journal of the Korean Society of Tobacco Science
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• v.24 no.2
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• pp.130-132
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• 2002

The new burley tobacco variety, KB 301, was developed by the cross combination ’(Ky 17 x TI 1068)F$_4$ x TC 613’. The modified pedigree breeding method was used in the selection procedures. The agronomic traits and chemical constituents of KB 301 were very similar to those of Burley 21. But KB 301 had significantly higher content of total DVT than Burley 21. KB 301 was also resistant to black shank, TMV and PVY.

• Journal of Navigation and Port Research
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• v.33 no.4
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• pp.271-275
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• 2009

A strategic decision making on location selection for product transportation includes many tangible and untangible factors. To choose the best locations is a difficult job in the sense that objectives usually conflict with each other. In this paper, we consider a multi stage multi criteria transshipment problem with different types of items to be transported from the sources to the destination points. For the optimization of the problem, a goal programming formulation will be presented in which the location selection for each product type will be determined under the multi objective criteria. In the study, we generalize the transshipment model with a variety of product types and finite number of different intermediate nodes between origins and destinations. For the selection of the criteria we selected the costs(fixed cost and transportation cost), location numbers, and unsatisfied demand for each type of products in multi stage transportation, which are the main goals in transshipment modelling problems. The related conditions are also modelled through linear formats.

• Journal for History of Mathematics
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• v.29 no.1
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• pp.17-30
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• 2016

This study focused on the selection and application of mathematical problems to provide mathematically challenging tasks for the gifted elementary students. For the selection, a mathematical problem from <算術管見> of Joseon dynasty, '圓容三方互求', was selected, considering the participants' experiences of problem solving and the variety of approaches to the problem. For the application, teaching strategies such as individual problem solving and sharing of the solving methods were used. The problem was provided for 13 mathematically gifted elementary students. They not only solved it individually but also shared their approaches by presentations. Their solving and sharing processes were observed and their results were analyzed. Based on this, some didactical considerations were suggested.

• Proceedings of the Korea Information Processing Society Conference
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• 2009.04a
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• pp.1307-1310
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• 2009

Web services provide the possibility of dynamically integrating distributed service components scattered over the Internet to fulfill sophisticated business demands. However due to today's wide variety of services offered to perform a specific task, it's essential that users are supported in the eventual selection of appropriate services. An example of web services for which selection of appropriate services will be crucial is Auto Repair Services. Selecting proper service from a variety of Auto Part Shops would be result of delivering high-quality service and minimizing Auto Repair Service customer's waiting time. Therefore, in this research to assist selecting proper service, we present Functional-Level Mediator and illustrate its usage in matching customer's and web service's goals. Five matching cases have been analyzed and results from experiment have been shown. Also, taking advantage of implementing multithreaded web services which reflects concurrent activity in the real world more naturally, we have significantly minimized customer's waiting time at Auto Repair Service.

• Journal of Korea Multimedia Society
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• v.21 no.10
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• pp.1182-1194
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• 2018

The Dynamic Adaptive Streaming over HTTP(DASH) is envisioned to evolve to meet an increasing demand on providing seamless video streaming services in the near future. The DASH performance heavily depends on the client's adaptive quality selection algorithm that is not included in the standard. The existing conventional algorithms are basically based on a procedural algorithm that is not easy to capture and reflect all variations of dynamic network and traffic conditions in a variety of network environments. To solve this problem, this paper proposes a novel quality selection mechanism based on the Deep Q-Network(DQN) model, the DQN-based DASH Adaptive Bitrate(ABR) mechanism. The proposed mechanism adopts a new reward calculation method based on five major performance metrics to reflect the current conditions of networks and devices in real time. In addition, the size of the consecutive video segment to be downloaded is also considered as a major learning metric to reflect a variety of video encodings. Experimental results show that the proposed mechanism quickly selects a suitable video quality even in high error rate environments, significantly reducing frequency of quality changes compared to the existing algorithm and simultaneously improving average video quality during video playback.

• Journal of Plant Biotechnology
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• v.5 no.3
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• pp.173-179
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• 2003

The combination of a radiation technique with an in vitro culture system was appiled to develop submergence tolerant rice. The 3,000 $M_3$ lines with an average 80 percent of fertile grain were utilized for the selection of submergence tolerance. Salt tolerant lines were selected based on high plant height, root length and root number after submergence in plastic pots. Of the lines tested, the tolerant line (403-6) showed a dramatic difference in morphological traits under submergence compared to its original variety (Dongjinbyeo). It was suggested that genetic variations between the original variety and $M_3$-403-6 did exist. The levels of $\alpha$-amylase and alcohol dehydrogenase activities were significantly increased in the mutant line compared to its original variety. The mutant with greater tolerance showed less electrolyte leakage indicating a greater membrane integrity and better survival. Also, this line was much more resistant to a salt stress of $1.25\%$ than the original variety. The proline level of the line was significantly (p<0.01> higher than that of the original variety. The relationships between the inhibition of growth caused by stress and the physiological changes in the plant cell were discussed.