• The Journal of Information Systems
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• v.26 no.3
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• pp.63-90
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• 2017

Purpose This study proposes a novel system trading model using case-based reasoning (CBR) based on absolute similarity threshold. The proposed model is designed to optimize the absolute similarity threshold, feature selection, and instance selection of CBR by using genetic algorithm (GA). With these mechanisms, it enables us to yield higher returns from stock market trading. Design/Methodology/Approach The proposed CBR model uses the absolute similarity threshold varying from 0 to 1, which serves as a criterion for selecting appropriate neighbors in the nearest neighbor (NN) algorithm. Since it determines the nearest neighbors on an absolute basis, it fails to select the appropriate neighbors from time to time. In system trading, it is interpreted as the signal of 'hold'. That is, the system trading model proposed in this study makes trading decisions such as 'buy' or 'sell' only if the model produces a clear signal for stock market prediction. Also, in order to improve the prediction accuracy and the rate of return, the proposed model adopts optimal feature selection and instance selection, which are known to be very effective in enhancing the performance of CBR. To validate the usefulness of the proposed model, we applied it to the index trading of KOSPI200 from 2009 to 2016. Findings Experimental results showed that the proposed model with optimal feature or instance selection could yield higher returns compared to the benchmark as well as the various comparison models (including logistic regression, multiple discriminant analysis, artificial neural network, support vector machine, and traditional CBR). In particular, the proposed model with optimal instance selection showed the best rate of return among all the models. This implies that the application of CBR with the absolute similarity threshold as well as the optimal instance selection may be effective in system trading from the perspective of returns.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.2
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• pp.97-104
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• 2005

Mass selection (MS) is an efficient selection method to directly improve highly heritable traits. In the present study, two cycles of MS for ear length were conducted on two sweet corn populations, BC2-l0 and $BC1-10{\times}Syn-II$ after introgression of exotic germplasm. The improved populations generated from these selections were evaluated in comparison with the base populations at two locations, to determine the genetic gains and performance of the improved populations. The two base populations showed varied average realized responses to MS. In BC2-l0 derived population, the realized responses were $9.1\%$ in BC2-l0 C1 and $1.2\%$ in BC2-l0 C2, whereas in$BC1-10{\times}Syn-II$ derived population, the realized responses were$ 5.6\%$ in $BC1-10{\times}Syn-II$ C1 and $2.9\%$ in $BC1-10{\times}Syn-II$ C2. All the improved populations showed longer ears than their respective base populations and the check varieties. Ear length, which was used as the selection criterion in this study, showed high broad-sense heritability in the BC2-l0 and $BC1-10{\times}Syn-II$ derived populations, while fresh ear yield revealed low heritability, indicating that selection for ear length in these populations would be more effective than direct selection for yield. Results of this study indicate that MS conducted on BC2­10 and $BC1-10{\times}Syn-II$ had significantly increased ear length and fresh ear yield in both populations. The improved populations obtained would serve as better germplasm sources and further selection in these populations could offer better responses.

• Korean Journal of Poultry Science
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• v.9 no.1
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• pp.35-42
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• 1982

Data pertaining to the first generation of a Synthetic White Leghorn flock were used to estimate the heritabilities of and genetic correlation between partial egg production(egg number or percentage) or diversely segmented part records and other traits such as age at sexual maturity, residual and annual egg production, and to compare the expected genetic gain from selection on partial egg number or partial percent production with correlated response in other traits. The estimated heritabilites for six measures of egg Production were ranged from 29 to 35, while heritability for age at sexual maturity (SM) was intermediate (48). Genetic correlations between partial egg number (P) and annual egg number. (A), and partial percent production (P') and annual percent production (A') were 51 and 72, respectively. Genetic correlation between P and SM was estimated largely negative (-.64), while correlation bettween P' and SM was positively intermediate(34). In comparing direct response from selection on partial production (P or P') with another response in correlated trait, selection on P would be 25% more efficient than selection of P' for improving A, while selection of P' would be 94% more efficient than selection P for improving A' For shortening SM selection of P would be 98% more efficient than selection on P'.

• Journal of the Korean Society for Library and Information Science
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• v.39 no.2
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• pp.123-146
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• 2005

This study aims to find consistent strategies for feature selection and feature weighting methods, which can improve the effectiveness and efficiency of kNN text classifier. Feature selection criteria and feature weighting methods are as important factor as classification algorithms to achieve good performance of text categorization systems. Most of the former studies chose conflicting strategies for feature selection criteria and weighting methods. In this study, the performance of several feature selection criteria are measured considering the storage space for inverted index records and the classification time. The classification experiments in this study are conducted to examine the performance of IDF as feature selection criteria and the performance of conventional feature selection criteria, e.g. mutual information, as feature weighting methods. The results of these experiments suggest that using those measures which prefer low-frequency features as feature selection criterion and also as feature weighting method. we can increase the classification speed up to three or five times without loosing classification accuracy.

• Journal of the East Asian Society of Dietary Life
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• v.24 no.6
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• pp.943-953
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• 2014

The purpose of this study was to examine the influence of selection attributes of restaurants specialized in Yaksun food on purchase intentions and satisfaction level of consumers as well as mediating effects of value awareness of Yaksun food on relationships among the variables. The subjects in this study were 200 female adults in Seoul and Busan. The findings of the study were as follows: First, purchase intentions for Yaksun food were positively influenced by food quality, human service, and health effect among selection attributes for restaurants specialized in Yaksun food. Second, customer satisfaction with Yaksun food was positively affected by food quality and human service among selection attributes. Third, purchase intention for Yaksun food and customer satisfaction were positively influenced awareness of functional value, emotional value and economic value of Yaksun food. Fourth, awareness of emotional and economic value of Yaksun food had mediating effects on relationships between selection attributes for restaurants specialized in Yaksun food and purchase intentions, and awareness of functional value of Yaksun food had mediating effects on relationships between the selection attributes of restaurants specialized in Yaksun food and customer satisfaction. The findings of the study illustrate that selection attributes for restaurants specialized in Yaksun food and value awareness have an impact on purchase intentions and customer satisfaction, and value awareness of Yaksun foods has mediating effects on the relationship of selection attributes with purchase intentions and customer satisfaction.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.37 no.1
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• pp.9-25
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• 2014

It is very important to select the best employees who are suitable for their jobs and duties as considering the efficiency and productivity of the firms' performance. As a result, many kinds of selection methodologies and systems have been developed. Among them is the selection system based on the core competencies which is known as the superior selection systems that can increase the predictive validity who is the right people, compared to the traditional selection system based on the job analysis. Hence, the former has been focused in the complex business situation in recent years. In this case study, we examine the selection system case based on the core competencies of OSS team in Company A, which is one of the largest telecommunication firms and we suggest the implications. According to the results of this case study, defining the core competencies of the job and selecting the right people who had the related competencies not only decreased the turnover rate of OSS team in Company A, but also increased the employees' loyalty and satisfaction for the organizations. This study will be a benchmark to other departments that don't use competency selection system of Company A as well as the firms that want to adapt the selection system based on the core competencies. Also, this case study has a contribution that shows us an alternative model how can the firms identify and select the best right employees.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.8A
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• pp.581-590
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• 2003

This paper proposes the routing path selection mechanism for source routing-based PtMP (Point-to-Multipoint) call in ATM switching system. Especially, it suggests PtMP routing path selection method that can share the maximum resource prior to the optimal path selection, guarantee the reduction of path calculation time and cycle prevention. The searching for the nearest branch point from destination node to make the maximum share of resource is the purpose of this algorithm. Therefore among neighbor nodes from destination node by back-tracking, this algorithm fixes the node crossing first the node on existing path having the same Call ID as branch node, constructs the optimal PtMP routing path. The optimal node to be selected by back-tracking is selected by the use of Dijkstra algorithm. That is to say, PtMP routing path selection performs the step of cross node selection among neighboring nodes by back-tracking and the step of optimal node selection(optimal path calculation) among neighboring nodes by back-tracking. This technique reduces the process of search of routing information table for path selection and path calculation, also solves the cycle prevention easily during path establishment.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.3
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• pp.520-526
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• 2018

In this paper, considering the superposition transmission-based wireless cooperative multicast communication system (ST-CMS) with multiple relays and destinations, we propose a relay selection scheme to improve the data rate of multicast communication. In addition, we adopt the optimal power allocation coefficient for the superposition transmission to maximize the data rate of the proposed relay selection scheme. To propose the relay selection scheme, we derive an approximate expression for the data rate of the ST-CMS, and present the relay selection scheme using only partial channel state information based on the approximate expression. Moreover, we derive an approximate average data rate of the proposed relay selection scheme. Through numerical investigation, comparing the average data rates of the proposed relay selection scheme and the optimal relay selection scheme using full channel state information, we show that the proposed scheme provides extremely similar performance to the optimal scheme in the high signal-to-noise power ratio region.

• Korean Journal of Community Nutrition
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• v.9 no.2
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• pp.183-190
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• 2004

This study was designed to identify how customers considered menu selection attributes on menu choice, and so the instrument for measuring that question was developed and menu selection behavior types were analyzed by customers' characteristics. Cronbach's alpha to assess the internal reliability of the developed scales was 0.8361, which indicated to be highly reliable. Construct validity was assessed by principal components factor analysis with a Varimax rotation to identify underlying dimensions of menu selection and then four factors explaining 55.618% of the total variance were found. These factors were labeled as 'quality of meals', 'attractiveness of meals', 'healthfulness of meals' and 'variety of meals', respectively. As a result of analysis on menu selection factors, 'quality of meals'(3.82 out of 5) was the highest consideration followed by 'variety of meals'(3.51), 'healthfulness of meals'(3.49) and 'attractiveness of meals'(3.34), so that menu marketing approaches in the perspective of quality of meals would do lead customers' selection rates, customer satisfaction and then sales highly. Frequent visitor selected menu indifferently but customers who were interested in food and menu highly, who perceived meals' quality highly, and who were satisfied with overall foodservice did with concern. On the basis of these results of study for the target of food court-style B ＆ I foodservice operation, which was introduced as an ideal model in future foodservice market by the concept of 'customer's selection right', the following study related with customers' meal patterns and perception of foodservice by menu selection attributes would be able to predict the chances for success of food court-style foodservice operations.

• Korea Journal of Hospital Management
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• v.23 no.4
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• pp.1-14
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• 2018

Purpose : Customers with loyalty are very important to hospitals for sustainable growth in their medical market. Individuals with loyalty are likely to visit same hospital repeatedly when they need medical services. This study was to identify factors associated with selection of specialty hospitals among customers with loyalty. Methods : The subjects of this study were 735 inpatients in 22 specialty hospitals in 6 designated fields(joints, spine, colorectal-anal, obstetrics and gynecology, ophthalmology, otolaryngology). Customer types classified as customers with high loyalty, neutral customers, and customers with low loyalty according to net promoter score(NPS). Factor analysis was conducted to classify 22 hospital selection factors into some similar properties. Logistic regression analysis was conducted to confirm the selection factors related to loyal customers. Findings : Most of specialty hospitals received high NPS of 8 points or higher in all the designated fields. Five factors associated with selection of specialty hospital are (1) hospital facilities and convenience, (2) trust in doctor and hospital, (3) rapidness of treatment, (4) hospital awareness, and (5) accessibility. As a result of logistic regression analysis, selection factors related to loyal customers were 'hospital facilities and convenience', 'trust in doctor and hospital' and 'rapidness of treatment'. Differences in the degree of importance of three selection factors by customer types appeared for each designated field. Practical Implications : This study confirms the high level of patient experience among inpatients of specialty hospitals. Factors associated with selection of hospital among inpatients with loyalty are 'facilities and convenience of hospitals', 'trust of doctor and hospital' and 'rapidness of treatment'. This study will be meaningful as basic data to systematically enhance the roles and functions of the health care system and to provide securing competitiveness according to designated fields in the management aspect of specialty hospitals.