• Journal of the Korea Society of Computer and Information
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• v.24 no.2
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• pp.171-177
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• 2019

This paper aims to find the most effective feature selection method for the sake of opinion mining tasks. Basically, opinion mining tasks belong to sentiment analysis, which is to categorize opinions of the online texts into positive and negative from a text mining point of view. By using the five product groups dataset such as apparel, books, DVDs, electronics, and kitchen, TF-IDF and Bag-of-Words(BOW) fare calculated to form the product review feature sets. Next, we applied the feature selection methods to see which method reveals most robust results. The results show that the stacking classifier based on those features out of applying Information Gain feature selection method yields best result.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.4
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• pp.811-818
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• 2016

A continuous fine-tuning phase locked loop with an additional negative feedback loop has been proposed. When the phase locked loop is out-of-lock, the phase locked loop has a fast locking characteristic using the continuous band-selection loop. When the phase locked loop is near in-lock, the bandwidth is narrowed with the fine loop. The additional negative feedback loop consists of a voltage controlled oscillator, a frequency voltage converter and its internal loop filter. It serves a negative feedback function to the main phase locked loop, and improves the phase noise characteristics and the stability of the proposed phase locked loop. The additional negative feedback loop makes the continuous fine-tuning loop work stably without any voltage fluctuation in the loop filter. Measurement results of the fabricated phase locked loop in $0.18{\mu}m$ CMOS process show that the phase noise is -109.6dBc/Hz at 2MHz offset from 742.8MHz carrier frequency.

• Culinary science and hospitality research
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• v.23 no.4
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• pp.10-21
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• 2017

The purposes of this study were to verify the effects of HMR (Home Meal Replacement) selection attributes on satisfaction and loyalty for HMR. In addition, the moderating role of customer value was examined among selection attributes of HMR, satisfaction and loyalty for HMR. Using a convenience sampling method, the data were collected from those who have bought HMR in Seoul and Kyonggi area. After a total of 235 responses were collected, 220 were used for the analyses. The multiple regression analyses were conducted to test the hypotheses. The results are as follows. First, it was found that product practicality and cooking convenience of HMR selection attributes had an effect on satisfaction of HMR but that ingredients safety and package & circulation period did not have an effect on satisfaction of HMR. Second, satisfaction of HMR significantly impacted loyalty for HMR. Third, in low group for customer value, product practicality of HMR selection attributes had an positive effect on satisfaction of HMR, and ingredients safety of HMR selection attributes had an negative effect on satisfaction of HMR. In high group for customer value, cooking convenience of HMR selection attributes had an positive effect on satisfaction of HMR. In low group as high group for customer value, satisfaction of HMR had a greater impact on loyalty for HMR.

• BMB Reports
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• v.51 no.1
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• pp.1-2
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• 2018

Positive selection on a new beneficial mutation generates a characteristic pattern of DNA sequence polymorphism when it reaches an intermediate allele frequency. On genome sequences of African Drosophila melanogaster, we detected such signatures of selection at 37 candidate loci and identified "sweeping haplotypes (SHs)" that are increasing or have increased rapidly in frequency due to hitchhiking. Based on geographic distribution of SH frequencies, we could infer whether selective sweeps occurred starting from de novo beneficial mutants under simple constant selective pressure. Single SHs were identified at more than half of loci. However, at many other loci, we observed multiple independent SHs, implying soft selective sweeps due to a high beneficial mutation rate or parallel evolution across space. Interestingly, SH frequencies were intermediate across multiple populations at about a quarter of the loci despite relatively low migration rates inferred between African populations. This invokes a certain form of frequency-dependent selection such as heterozygote advantage. At one locus, we observed a complex pattern of multiple independent that was compatible with recurrent frequency-dependent positive selection on new variants. In conclusion, genomic patterns of positive selection are very diverse, with equal contributions of hard and soft sweeps and a surprisingly large proportion of frequency-dependent selection in D. melanogaster populations.

• Journal of Distribution Science
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• v.20 no.3
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• pp.1-11
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• 2022

Purpose: This study aims at understanding the impacts of three omnichannel attributes (channel transparency, channel uniformity, channel convenience) and four customer perceptions (perceived innovativeness, perceived personalization, perceived risk, perceived credibility) on customer experience and channel selection decision. Research design and methodology: A quantitative online survey with 356 shoppers was executed. The partial least squares linear structural model (PLS-SEM) and Smart PLS were adopted to analyze the collected data and test the proposed hypotheses. Results: The research findings indicate four dominant results: (i) The customers' channel selection is directly determined by customer experience; perceived innovativeness; perceived personalization; perceived risk; and perceived credibility; and (ii) among these, the perceived risk shows negative impact on the customer's experience and customers' channel selection whereas others reveal the positive status; (iii) The customer experience represents the most decisive impact on the channel selection, then perceived personalization, perceived credibility, perceived innovativeness, and perceived risk. (iv) Three proposed channel attributes (transparency, uniformity, convenience) significantly influence the overall customer experience. Conclusions: This research adds to the body of knowledge in omnichannel retailing, customer experience, and customer channel selection. Furthermore, this research provides omnichannel retailers with practical implications for improving customer channel selection.

• Journal of Labour Economics
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• v.26 no.3
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• pp.149-179
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• 2003

This study is analysing the factors determining individuals' behavior of selecting self-employment not only at the micro-level but also at the macro-level to put a particular emphasis on the financial constraint and unemployment rate representing business cycle. The data used in this study are "Korean Labor and Income Panal Study" of the Korea Labor Institute and "Economically Active Population Survey" of National Statistical Office. The main findings are as follows. First, human capital such as educational attainment and job experience has positive effects on male's selection of self-employment. The effects of job experience, however, changed negative for female's selection of self-employment. Second, real estate is significantly enhancing the selection probabilities of employer selection while the income from financial assets has negative effects. Third, entrepreneurial culture and environment are also raising the self-employment selection probability. Lastly, the regional unemployment rate representing the business cycle has positive effects on the self-employment selection after the financial crisis in 1997 both at the micro and macro level. Moreover, the coefficient of regional unemployment rate has changed positive in the structural model of self-employment selection controlling for selection bias and income opportunities, which means that individual's behavior of self-employment selection is rather complex when accounting for the uncertainties of income opportunities and diverse characteristics of self-employment workforce.

• Journal of Fashion Business
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• v.8 no.2
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• pp.42-55
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• 2004

The purpose of this study was to classify the contents of department stores and large-scale discount stores of consumer on information source, shopping orientation and store image in an effort to determine which variable gave a crucial impact on cosmetics department stores and large-scale discount stores selection behavior. The subjects of this study were 557 adult women visited department store and large-scale discount store in Busan. The data were analyzed by using Factor analysis, Frequency analysis, Correlation analysis, Cronabach $\alpha$ and Regression analysis. The results were as follows; 1. There was a difference in the demographical characteristics on department stores and large-scale discount stores of consumers. 2. Shopping Orientation of consumers were categorized into 5 types, and information source of consumers did 3 types, and store image of consumers did 5 types. 3. Leisure utilization, store & brand loyalty, store information, personal information, massmedia information, product & operate on, store atmosphere & salesperson and shopping convenience had positive correlations with cosmetics department stores selection beavior. but convenient location, rationality & economy and sales promotion had negative correlations with cosmetics department stores selection beavior. 4. Rationality & economy and sales promotion had positive correlations with cosmetics large-scale discount stores selection beavior. but convenient location, leisure utilization, store & brand loyalty, massmedia information, product & operate on, store atmosphere & salesperson and shopping convenience had negative correlations with cosmetics large-scale discount stores selection beavior. 5. Age, income, business(-), convenient location(-), rationality & economy(-), leisure utilization, store & brand loyalty, store information, personal information, massmedia information, store atmosphere & salesperson, shopping convenience and sales promotion(-) had a direct effect on cosmetics department stores selection beavior. Age, income, marriage, education had an indirect effect on department stores selection beavior through information source and store image, and information source did through store image, and shopping orientation did through store image. 6. Rationality & economy, convenient location(-), leisure utilization(-), store & brand loyalty(-), buying independence(-), personal information, massmedia information(-), product & operate on(-), shopping convenience(-) and sales promotion had a direct effect on cosmetics large-scale discount stores selection beavior. Age, income, marriage, education had an indirect effect on large-scale discount stores selection beavior through information source, shopping orientation and store image, and information source did through store image, and shopping orientation did through store image.

• Archives of Pharmacal Research
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• v.12 no.4
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• pp.249-253
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• 1989

High producers or blocked mutants of aminoglycoside antibiotic-producing Streptomyces spp. were selected by application of an agar plug method and by culturing individual colonies in broth. The productivities of aminoglycoside antibiotic producing organisms were increased by selection of a high producer from colonies obtained by spreading spores of wild strain, or survived from treatment of a mutagen or from the colonies regenerated from protoplast-formation and cell-wall regenerations. Some mutagen treated colonies lost the ability to produce antibiotics (5-8%). Some A-factor negative and deostreptamine or streptidine negative mutants were obtained by N-methyl-N'-nitro-N-nitrosomethylguanidine (MNNG) treatment. Many of the survivors from the MNNG treatment lost the ability to produce antibiotics. Major colonies produced less amount of antibiotics ; only few survived colonies produced more antibiotics than the parent. Resistance of Streptomyces spp. against the antibiotics produced by itself was also markedly affected by mutagen treatment.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.6
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• pp.789-793
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• 2003

An investigation was conducted on 729 Hariana cows maintained at Government Livestock Farm, Hisar, from 1973 to 1999, with an objective to compare the efficiency of various selection indices for attaining desired genetic gains in the index traits. The various traits included were age at first calving (AFC), service period (SP), calving interval (CI), days to first service (DFS), number of services per conception (NSPC), lactation milk yield (LY), peak yield (PY), dry period (DP). Except for LY, PY and AFC the heritabilities of all other traits were low. Desirable associations among reproductive traits are supportive of the fact that any one of these traits incorporated in simultaneous selection is expected to cause correlated response in other traits. Production traits (LY and PY) were positively correlated, while DP had low negative genetic correlation with LY, and high genetic correlation with PY. Thus, DP can be taken as additional criteria in selection index for better over all improvement. Almost all production traits except DP had low negative correlation with AFC, SP, DFS and CI meaning that reduction in reproduction traits up to certain level may increase production performance. While, the correlation of NSPC with LY and PY was moderate positive. Among four trait indices I23: incorporating PY, AFC, SP and NSPC and among three trait indices I1: incorporating LY, AFC and SP were the best as these required least number of generations (4.87 and 1.35, respectively) to attain desired goals. Next in order of preference were PY or LY along with DP and SP as the best indices (I20 and I16) of which, index with PY may be preferred instead of LY as it produced considerably high correlated response in LY and reduction in NSPC as well.

• Archives of Plastic Surgery
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• v.44 no.5
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• pp.428-433
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• 2017

Background Candidate characteristics for hand surgery fellowship training remains unknown, as very little data is available in the literature. This study aims to provide information on the criteria that are employed to select candidates for the hand surgery fellowship match. Methods A 38-question survey was sent in April 2015 to all Accreditation Council for Graduate Medical Education recognized hand surgery fellowship program directors (n=81) involved in the U.S. match. The survey investigated factors used for the selection of applicants, including medical school, residency training, research experience, fellowship interview, and candidate characteristics. A 5-point Likert scale was used to grade 33 factors from "not at all important" (1) to "essential in making my decision" (5); or for five controversial factors from "very negative impact" (1) to "very positive impact in making my decision" (5). Results A total of 52% (42 out of 81) of responses were received from hand surgery fellowship program directors. The most important influential factors were interactions with faculty during interview and visit ($4.6{\pm}0.6$), interpersonal skills ($4.6{\pm}0.5$), overall interview performance in the selection process ($4.6{\pm}0.6$), professionalism and ethics ($4.6{\pm}0.7$), and letters of recommendation from hand surgeons ($4.5{\pm}0.7$). Factors that have a negative impact on the selection process include visa requirement ($2.1{\pm}1.2$), graduate of non-plastic surgery residency program ($2.4{\pm}1.3$), and graduate of a foreign medical school ($2.4{\pm}1.1$). Conclusions This study provides data on hand surgery fellowship directors' perception on the criteria important for fellowship applicant selection, and showed that interview-related criteria and letters of recommendation are the important factors.