• Journal of agricultural medicine and community health
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• v.24 no.1
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• pp.145-159
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• 1999

To find the association, between vinyl house work and the prevalence of low back pain, a questionnaire survey was made toward 215 vinyl house farmers and 228 general farmers without vinyl house who are cared by Jungjung Community health Practioners at Soobuk Myun, Damyang-gun, Chollanamdo. 1. Vinyl house farmers were significantly younger in age, higher in educational status higher survival rate of spouse, higher economic state and less cared by medical aid than general farmers. 2. Vinyl house farmers showed shorter career for agricultural work, used modern farming instrument more frequently and worked with sitting position. 3. During unbusy season in general agriculture, vinyl house farmers consumed significantly more time in agricultural work and general activity, but no significant difference of time of the above activity among busy season. 4. During the last spring season when most vinyl house work was performed, vinyl house farmers showed significantly higher prevalence of low back pain than general farmers, but no significant difference of prevalence among the two groups for the last one week. 5. By the simple analysis statistical significant related variables with low back pain was found to be sex(p<0.001), educational status(p<0.05), work posture(p<0.001) and use of modern agricultural machine(p<0.05). 6. By the multiple logistic regression the odds ratio for low back pain among vinyl house farmers were 2.08(95% confidence interval 1.31-3.00) compared to general farmers, the odds ratio among female was 2.35(95% confidence interval 1.24-4.47) to male, the odds ratio among illiterate persons were 2.60(95% confidence interval 1.24-4.47) to high school graduate, and the odds ration among primary school graduate was 2.19(95% confidence interval 1.04-4.47) to high school graduate. In conclusion because vinyl house farmers showed significantly higher rates of low back pain compared to farmers without vinyl house, continuous study to find the true cause of low back pain among vinyl-house farmers and active effort to prevent low back pain are necessary.

• Korean journal of communication and information
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• v.32
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• pp.209-245
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• 2006

This study examines primarily the effects of perceived risk and scarcity massage on consumers in CATV homeshopping. For consumers, the perceived risk is the cause of delaying purchase decision in CATV Homeshopping while scarcity message in the Ad facilitate purchasing intention in the CATV homeshopping. And another important characteristic of consumer which exerts impact on the response of consumer to the Ad and the product is the frequency of purchasing experience. Thus the purpose of this study is to test the effect of 3 factors on consumer's response to homeshopping Ad and product: one is perceived risk, another is scarcity message and the third is consumer's difference in purchasing. And these are defined as independent variables. The responses of the consumer, the dependent variables of this test are measured in three dimensions; 1) the purchasing intention of the product, 2) the attitude toward the Ad, and 3) the attitude toward product of the consumer. 110 housewives are sampled and assigned to 4 experimental groups. All the groups first watched a video-taped homeshopping Ad messages, and then filled up their responses on the administered questionnaire. The results of this study shows as follows: 1) Perceived risk has negative effect to consumer response. 2) Scarcity message has positive effect to consumers response. 3) But especially perceived risk has negative effect to high frequency purchasing experience group. 4) Scarcity message has also negative effect to high frequency purchasing experience group. 5) The interaction effect of perceived risk and scarcity message is most prominent to the consumers of high frequent purchasing experience.

• Sleep Medicine and Psychophysiology
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• v.16 no.2
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• pp.85-90
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• 2009

Introduction: There has been an increasing interest in the relationship between sleep and suicidality. In addition, suicidal patients habitually report their sleep problems. Although sleep-related complaints and electroencephalographic changes are generally encountered in psychiatric disorders, sleep complaints such as insomnia, hypersomnia and nightmares are more common in suicidal patients. In current study, we aimed at investigating the relationship between self-reported sleep duration and suicidality in general population. Methods: One thousand general population (male:female=500:500, mean age=$39.6{\pm}11.6$ years, ranged age=20-77 years) completed Center for Epidemiologic Study-Depression (CES-D), Beck Suicide Intent scale (BSI), Spielberger State-Trait Anger Expression Inventory (STAXI), Barratt Impulsiveness Scale (BIS), Morningness-Eveningness Scale (MES) and brief questionnaire of sleep habits. Results: After controlling for age and sex, score of BSI was correlated positively with the score of CES-D, STAXI and BIS on partial correlation analysis ($r_p$=0.251; p<0.001, $r_p$=0.352; p<0.001, and $r_p$=0.175; p<0.001, respectively). In addition, score of BSI was inversely correlated with the score of MES (rp=-0.066; p=0.037). However, score of BSI showed no significant correlation with sleep duration. However, regression analysis revealed that short (<6 hrs) or long (>10 hrs) sleep duration, the family history of psychiatric illness, the score of CES-D, and the score of STAXI predicted higher score of BSI significantly in total subjects (F=17.837, adjusted $R^2$=0.166; p=0.003, p=0.003, p<0.001, and p=0.003, respectively). This model was explained better in depressed subjects with 16 or higher score of CES-D (F=9.920, adjusted $R^2$=0.298). Conclusion: Current result suggested that not only short sleep duration (<6 hrs) but also long sleep duration (>10 hrs) might be related to suicidality.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.9
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• pp.1271-1278
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• 2009

The purpose of this study was the improvement of satisfaction for school foodservice customers through analysis of the importance and performance of school foodservice quality and the understanding what factors affected customer's loyalty. The questionnaire was distributed to three hundred students at five high schools in Busan. Students evaluated the factors of importance and performance, the order of importance was sanitation> food> service and then, the order of performance was sanitation> service> food. Gap analysis resulted 4.39 for importance factors and 2.51 for performance factors; importance scores were higher than performance scores at all areas (p<0.01) and the sanitation factor gap was the biggest gap compared to all others. Each factor's analysis resulted that the gap analysis order was taste> balance of main & sub side dish> diversity of food in food area, quick react to customer complaint> reflection of customer proposal and recommendation> provide better service than competitor in service area, sanitation of food> cleanness of tableware> cleanness of container in sanitation area. The average score of customer's loyalty was 1.66 and female' score was significantly higher than male (p<0.001). Food, service and sanitation had a significant correlation to customer's loyalty than service (p<0.01), food (p<0.05), and sanitation (p<0.05) affected customer's loyalty significantly. So, intensive control is needed in the sanitation area which had the highest gap analysis result between importance and performance in food service. Especially, service factor was very important in explaining customer's loyalty, so service improvement through training is needed to improve student's satisfaction.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.15 no.1
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• pp.209-224
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• 2020

This study started from the question of whether the preference of corporate recruitment can be achieved without any difference between the start-up experiencer and the general job seekers. Therefore, the purpose of the study is to identify the factors related to start-ups that affect the preference of job seekers for companies, and to analyze the differences in the factors related to start-ups between general job seekers and job seekers with start-up experience. Third, it is to see the difference in the preference for employment between job seekers with start-up experiences and general job seekers. The independent variables of the research model were entrepreneurship, motivation for start-up (job search), and characteristics of the job seekers (founder). The dependent variables were job preference, and the moderating variables were presented as job seekers' classification (job seekers with start-up experience vs. general job seekers). The subjects of the study were personnel managers of 100 companies with more than 5 years of establishment and 100 new companies with less than 5 years of establishment. The questionnaire was distributed in two types, and 189 respondents, including 101 job seekers with start-up experiences and 88 general job seekers, were finally used for analysis. The results of the study were as follows. First, as a result of multiple regression analysis on both experienced start-up experiencers and general job seekers, only entrepreneurship had an effect on preference for recruitment. Second, the moderating effect of job seekers' classification was found only in the relationship between motivation for start-up and preference for employment. Third, the result of multiple regression analysis based on the start-up experiencers showed that the relationship between the motivation for start-up, the preference for recruitment, the characteristics of founders and the preference for recruitment was statistically significant. On the other hand, the characteristics of the founder and the preference for employment were rejected. Fourth, the results of the study based on general job seekers showed that the motivation for job search decreased the preference for employment. The study did not provide the results of differences in recognition between different industries, traditional enterprises and venture businesses due to the limitation of small examples. There is no clear definition of start-up experiencers either. However, it is meaningful to suggest the implications of what preparations should be made when the start-up experiencers close their start-ups and turn their career into employment and to help them to accurately recognize the importance of entrepreneurship. It also provides the preference of the general job seekers for the company, the preparation for successful employment, and the implications for the direction of the future start-up revitalization.

• Information Systems Review
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• v.14 no.3
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• pp.25-51
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• 2012

The purpose of this study is to analyze the key factors affecting satisfaction of the visually impaired SNS users so that they may use SNS more effectively in the future. This study has used three factors such as the information factor, the relationship factor and the speed factor and the usability as independent variables. The social presence factor was used as a parameter and the SNS user satisfaction as a dependent variable. For the research, 195 visually impaired SNS users have participated in this survey. The major findings of this study are that the relationship factor has strong effects on the self-identification factor, the social presence factor and the SNS usage satisfaction among the factors affecting the visually impaired users to be satisfied with SNS. On the other hand, the information factor and usage factor have no effects on the self-identification factor and the social presence factor. However, they have effects on the SNS usage satisfaction. Additionally, the self-identification factor has no effect on the SNS usage satisfaction, but the social presence factor has effect. Based on the above study results, this paper proposed for the government to enhance the educational program on the use of SNS for the visually impaired and to increase its financial and political support on this subject. Additionally, technical supports on SNS service accessibility and usage by the government are vital for the visually impaired. Academically, this study provides a concrete groundwork for the research on the use of SNS by the visually impaired by providing a solid research direction for further study on this subject. Socially, this study helps the visually impaired use SNS more effectively by increasing the general public awareness of the importance of SNS usages by the visually impaired so that the information gap of the society may be diminished in the future.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.10 no.1
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• pp.1-7
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• 2005

Tidal flats have been regarded to carry out transformation and removal of land-derived organic matter, and this purifying capability of organic matter by tidal flats is one of very important reasons for their conservation. However, integral biogeochemical studies on production and decomposition of organic matter by benthic microbes in tidal flats have been absent in Korea, although the information is indispensable to quantification of the purifying capability. Our major goals in this multidisciplinary research were to understand major biogeochemical processes and rates mediated by diverse groups of microbes dominating material cycles in the tidal flats, and to assess the contribution of benthic microbes to removal of organic matter and nutrients in the tidal flats. Our study sites were Ganghwa and Incheon north-port tidal flats that had been regarded as naturally well reserved and organically polluted, respectively. Our research group measured over 3 years primary production, biomass and community structure of primary producers, abundance and production of bacteria, enzyme activities, distribution of protozoa and protozoan grazing rates, rates of denitrification and sulfate reduction, early sediment diagenesis, primary production and respiration based on oxygen microelectrode. We analyzed major features of each biogeochemical process and their interactions. The results are compiled in the following articles in this special issue: An (2005), Hwang and Cho (2005), Mok et at. (2005), Na and Lee (2005), Yang et at. (2005), and Yoo and Choi (2005).

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.20 no.3
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• pp.151-157
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• 2015

Recent laboratory studies have documented that mixotrophic dinoflagellates Dinophysis spp. and heterotrophic dinoflagellate Oxyphysis oxytoxoides share a common prey, i.e. the mixotrophic ciliate Mesodinium rubrum. Nonetheless, very little is known about the population dynamics and species interactions among these protists in natural environments. To investigate the interactions between the dinoflagellate predators and their ciliate prey in the field, we took the samples twice a day from 26 July to 28 August, 2011 at a fixed station in Masan Bay and analyzed their abundances. During this study, salinity was highly variable, ranging from 5 to 28, due to the periodic input of rainfalls to the sampling station. Water temperature was on average $26.5^{\circ}C$ until 20 August and thereafter was about $21^{\circ}C$ by the end of the sampling period. The ciliate M. rubrum occurred persistently throughout the sampling period, ranging from 13 to $492\;cells\;mL^{-1}$. Cell densities of D. acuminata and O. oxytoxoides ranged from undetectable level to $19,833\;cells\;L^{-1}$ and from undetectable level to $100,333\;cells\;L^{-1}$, respectively. The high abundance of D. acuminata mostly followed the blooming of the ciliate M. rubrum, but it often did not peak even during heavy blooms of the prey, probably due to sensitivity to large salinity fluctuation and also presumably overlapped grazing by other mixotrophic dinoflagellates. The abundance of O. oxytoxoides was detected only when water temperature was lower than $24^{\circ}C$, indicating that water temperature is an important environmental factor to control the population dynamics of the dinoflagellate species.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.20 no.3
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• pp.141-150
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• 2015

Dinoflagellates are ubiquitous and important primary producers in the oceans. They have diverse trophic modes, i.e., phototrophic, heterotrophic, and mixotrophic modes and thereby, play important ecological role in marine microbial food-web. While many studies have been focused on planktonic dinoflagellates in pelagic ecosystems, benthic, sand-dwelling dinoflagellates that inhabit in intertidal zone have been very poorly documented worldwide. We investigated biodiversity, occurrence, and molecular phylogeny of benthic, sand-dwelling dinoflagellates from the intertidal flat of Dongho, west coast of Korea during low-tide, monthly from November 2012 to February 2014. About 27 species of 13 genera in orders Gonyaulacales, Gymnodiniales, Peridiniales, Prorocentrales have been identified, of which members in the genus Amphidinium constituted a major part of the sand-dwelling dinoflagellates in this area. A total of 34 isolates from 16 species of the sand-dwelling dinoflagellates were isolated from Dongho, Mohang, Gamami, and Songho in the west coast and Hyupjae in Jeju of Korea, their 28S rDNA sequences were successfully amplified, and applied for molecular phylogenetic analyses. In the 28S rDNA phylogeny, Amphidinium species diverged across three major clusters within the order Gymnodiniales and formed polyphyletic group. Based on the unambiguously aligned partial 28S rDNA sequences including variable D2 region, the genotypes of Amphidinium mootonorum Korean strains greatly differed from that of Canadian strain with 19.2% of pairwise nucleotide difference, suggesting that further ultrastructural studies may provide additional characters to clearly separate these genotypes. Two potential toxic species, Amphidinium carterae and A. operculatum appeared occasionally during this study. Quantitative assessment and toxicity of those species should be addressed in the future.

• The Journal of Society for e-Business Studies
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• v.25 no.1
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• pp.135-176
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• 2020

This study is to investigate the factors affecting the usage intentions of 5G service between 5G service subscribers and non-subscribers based on the Integratively Extended Technology Acceptance Model in the initial B2C 5G service market. We designed the integratively extended technology acceptance model to find the more specific factors to affect the usage intentions by integrating the exogenous factors including the technical factors, the social factors, and the personal factors with the ETAM(Extended Technology Acceptance Model). Referring to the previous studies, we constructed the hypotheses of structural influence relationship from the exogenous factors to the dependent usage intentions factors through the mediating belief factors. We designed the 5G service usage intentions model based on these hypotheses and operational definitions of the factors. Using the analysis of SEM(Structural Equation Model), the proposed model and the hypotheses were empirically tested by the data collected from 245 subscribed respondents and 245 non-subscribed respondents. As a result, the perceived ease of use has an effect on the perceived usefulness and enjoyment, and the perceived usefulness/enjoyment and the personal innovativeness have positive effects on the usage intentions of both groups.