• Journal of ILASS-Korea
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• v.9 no.2
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• pp.41-49
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• 2004

Liquid breakup under the variation of AC frequency has been studied experimentally in the electrohydrodynamic atomization. The effect of parameters such as charging voltage, flow rate, nozzle tip inner diameter and power frequency have been considered. This work was performed to investigate the experimental analysis for the effect of AC frequency on breakup process, the mapping of occurrence of disintegration region, and the relationship between the applied power and the droplet radius. The experimental results show that the increase of applied voltage in a certain frequency band leads to a reduction in the droplet size within the limits from 50Hz to 400Hz. The transition phenomena from dripping mode to spindle mode were observed under the band of sudden fall of droplet radius changing ratio, and the synchronous region were produced within the range of applied voltage from 5kV to 6kV.

• Journal of the Korea Society of Computer and Information
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• v.22 no.9
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• pp.17-24
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• 2017

Core citation recognition is to identify influential ones among the prior articles that a scholarly article cite. Previous approaches have employed citing-text occurrence information, textual similarities between citing and cited article, etc. This study proposes a term-based approach to core citation recognition, which exploits the importance of individual terms appearing in in-text citation to calculate influence-strength for each cited article. Term importance is computed using various frequency information such as term frequency(tf) in in-text citation, tf in the citing article, inverse sentence frequency in the citing article, inverse document frequency in a collection of articles. Experiments using a previous test set consisting of computational linguistics articles show that the term-based approach performs comparably with the previous approaches. The proposed technique could be easily extended by employing other term units such as n-grams and phrases, or by using new term-importance formulae.

• Journal of Internet Computing and Services
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• v.22 no.6
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• pp.51-57
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• 2021

If a company's actions to save or avoid taxes are judged to be tax evasion rather than legal tax action by the tax authorities, the company will not only pay tax but also non-tax costs such as damage to corporate image and stock price decline due to a series of tax evasion-related news articles. Therefore, this study measures the frequency of occurrence of tax evasion controversial keywords in internet news portal as a factor to measure the severity of the case, and analyzes the effect of the frequency of occurrence on corporate value. In the Korean stock market, we crawl related articles from internet news portal by using keywords that are controversial for tax evasion targeting top companies based on market capitalization, and generate a time series of the frequency of occurrence of keywords about tax evasion by company and analyze the effect of frequency of appearance on book value versus market capitalization. Through panel regression and impulse response analysis, it is analyzed that the frequency of appearance has a negative effect on the market capitalization and the effect gradually decreases until 12 months. This study examines whether the tax evasion issue affects the corporate value of Korean companies and suggests that it is necessary to take these influences into account when entrepreneurs set up tax-planning schemes.

• The Plant Pathology Journal
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• v.17 no.6
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• pp.378.3-378
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• 2001

• Journal of Oral Medicine and Pain
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• v.22 no.2
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• pp.359-371
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• 1997

Stress is recognized as a major predisposing and/ or precipitating factor in long-lastig intractable chronic pain, such as temporomandibular disorders, headache, and other psychophysiological disorders. So it is necessary to detect physical and psychological changes induced by stress as soon as possible for positive treatment outcome. This study was performed to investigate the occurrence rate of stress symptoms according to anatomic region, type of symptom, and other personal and social factors. 859 subjects from general population answered the stress symptom questionnaire devised by the author and composed of 50 items. Data from the questionnaire were analyzed statistically with SPSS program and the results obtained were as follows : 1. Oral symptom which showed the highest frequency rate of 38.8% was vesicular lesion of the lip and cheek. The other symptoms with more 20% occurrence rate were ulcerative leion of lip and cheek, toothache, paresthesia of teeth, eruption of tongue, tongue coating and taste change in descending order. 2. In extraoral symptoms, ？데 disturbance was the item which showed the highest frequency rate of 62.0%, and the items for stiffness of suboccipital region and neck, headache, facial swelling, furuncle of face were answered more than 45% of the subjects whereas only 14.0% of the subjucts complained jaw pain under stress. 3. The better one who thought his or her health status was, the fewer items were answered and the difference of symptom frequency by dwelling place and by having hobby were shown in extraoral symptoms only. 4. For relief of stress symptoms, 79.2% of the subjects replied only to take a rest whereas not more than 13, 5% of the subjects visited dental clinic. Correlationship between symptom sites were very high.

• The Journal of Economics, Marketing and Management
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• v.11 no.3
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• pp.47-66
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• 2023

Purpose: The purpose of this study is to identify research trends related to ESG by domestic and overseas researchers so far, and to present research directions and clues for the possibility of applying ESG to Korean companies in the future and ESG practice through comparison of derived topics. Research design, data and methodology: In this study, as of October 20, 2022, after searching for the keyword 'ESG' in 'scienceON', 341 domestic papers with English abstracts and 1,173 overseas papers were extracted. For analysis, word frequency analysis, word co-occurrence frequency analysis, BERTopic, LDA, and OLS regression analysis were performed to confirm trends for each topic using Python 3.7. Results: As a result of word frequency analysis, It was found that words such as management, company, performance, and value were commonly used in both domestic and overseas papers. In domestic papers, words such as activity and responsibility, and in overseas papers, words such as sustainability, impact, and development were included in the top 20 words. As a result of analyzing the co-occurrence frequency of words, it was confirmed that domestic papers were related mainly to words such as company, management, and activity, and overseas papers were related to words such as investment, sustainability, and performance. As a result of topic modeling, 3 topics such as named ESG from the corporate perspective were derived for domestic papers, and a total of 7 topics such as named sustainable investment for overseas papers were derived. As a result of the annual trend analysis, each topic did not show a relatively increasing or decreasing tendency, confirming that all topics were neutral. Conclusions: The results of this study confirmed that although it is desirable that domestic papers have recently started research on consumers, the subject diversity is lower than that of overseas papers. Therefore, it is suggested that future research needs to approach various topics such as forecasting future risks related to ESG and corporate evaluation methods.

• Korea Journal of Hospital Management
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• v.28 no.2
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• pp.32-43
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• 2023

Purposes: This research is conducted to identify main features and trends of mission, vision and core values in Korean tertiary general hospitals by using text-mining. Methodology: For the study, 45 mission, 112 vision and 190 core values are collected from 45 tertiary general hospitals' homepages in 2022 and use word frequency analysis and Leyword co-occurrence analysis. Findings: In the tertiary general hospitals' mission, there are high frequency words such as 'health', 'humanity', 'medical treatment', 'education', 'research', 'happiness', 'love', 'best', 'spirit', and mission mainly includes the content of contributing humanity's health and happiness with these words. In case of vision, high frequency words are 'hospital', 'medical treatment', 'research', 'lead', 'trust', 'centered', 'patient', 'best', 'future'. By using these words in vision, it represents the definition and characteristics of vision such as ideal organizations in the future, goals and targets. As a result of the Leyword co-occurrence analysis, vision includes the content of 'high-tech medical treatment', 'special care for patients', 'leading education and research', 'the highest trust with customer', 'creative talents training'. -astly, the high frequency word-pairs in core values are 'social distribution', 'innovation pursuit', 'cooperation and harmony', and it defines standards of behavior for organizations. Practical Implication: To correct the problems of vision, mission and core values from findings, firstly, it needs for Korean tertiary general hospitals to use the words that can explain organization's identity and differentiate others in their mission. Secondly, considering strengthening the role of hospitals in their community and the importance of members in organizations, it is necessary to establish vision with considering community and members to activate vision effectively. Thirdly, because there are no specific guidelines of establishing mission, vision and core values for healthcare organizations, this research concepts and results could be utilized when other organizations establish mission, vision and core values.

• Journal of the Korean Home Economics Association
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• v.34 no.4
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• pp.33-47
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• 1996

The purpose of this study was to survey the stressor, frequency of the stressor, level of the stress perceived by children in Korea. The subject were 417 children of 80 second graders, 117 third graders, 111 fourth graders and 109 fifth graders selected from three elementary schools in Pusan(214 male and 203 female). A questionnaire consisting of 70-item stress scale for children and demographic questions was used for mother. Statistics used for data analysis were frequency, ANOVA, and t-test. The major finding of this study were as follows: 1. Events receiving the highest ratings for magnitude of badness were mainly family related (parents separating; gradd parents getting sick/dying; parents getting sick). 2. Events receiving the highest ratings for frequency of occurrence were test, fighting with siblings, being picked on by other kids, staying home alone. 3. There appear signigcant differences for children's perception of stress due to the grade and the socioeconomic status.

• Proceedings of the KIEE Conference
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• 2003.11a
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• pp.190-192
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• 2003

When generators trip on the occurrence of disturbance, the power system frequency declines by the amount of difference between demand and supply due to the imbalance between power generation and load. Even though the power system is operated with the same grid structure, generating capacity, and load, the resulting frequency decline and its recovery slope show different aspects according to the inertia constants of generators, spinning reserves, and the speed adjusting rates at the governors. From this point of view, we analysed differences of frequency decline at the various conditions in domestic power system.

• Structural Engineering and Mechanics
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• v.8 no.2
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• pp.181-191
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• 1999

This paper presents an investigation of the mode localization and frequency loci veering phenomena in an aircraft with disordered external stores. Two theoretical analyses are carried out to study the occurring mechanism of the two phenomena: condensation technique in the subspace spanned by modes of interest and geometric mapping theory in the complex plane. Two simple criteria for predicting the occurrence of the mode localization and frequency loci veering are put forward. The prediction of the phenomena by our theoretically proposed criteria is in good agreement with that obtained through numerical calculations of characteristic solutions of the disordered system.