• Title/Summary/Keyword: 통계 모형

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Determination of Appropriate Exposure Angles for the Reverse Water's View using a Head Phantom (두부 팬텀을 이용한 Reverse Water's View에 관한 적절한 촬영 각도 분석)

  • Lee, Min-Su;Lee, Keun-Ohk;Choi, Jae-Ho;Jung, Jae-Hong
    • Journal of radiological science and technology
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    • v.40 no.2
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    • pp.187-195
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    • 2017
  • Early diagnosis for upper facial trauma is difficult by using the standard Water's view (S-Water's) in general radiograph due to overlapping of anatomical structures, the uncertainty of patient positioning, and specific patients with obese, pediatric, old, or high-risk. The purpose of this study was to analyze appropriate exposure angles through a comparison of two different protocols (S-Water's vs. reverse Water's view (R-Water's)) by using a head phantom. A head phantom and general radiograph with 75 kVp, 400 mA, 45 ms 18 mAs, and SID 100 cm. Images of R-Water's were obtained by different angles in the range of $0^{\circ}$ to $50^{\circ}$, which adjusted an angle at 1 degree interval in supine position. Survey elements were developed and three observers were evaluated with four elements including the maxillary sinus, zygomatic arch, petrous ridge, and image distortion. Statistical significant analysis were used the Krippendorff's alpha and Fleiss' kappa. The intra-class correlation (ICC) coefficient for three observers were high with maxillary, 0.957 (0.903, 0.995); zygomatic arch, 0.939 (0.866, 0.987); petrous ridge, 0.972 (0.897, 1.000); and image distortion, 0.949 (0.830, 1.000). The high-quality image (HI) and perfect agreement (PA) for acquired exposure angles were high in range of the maxillary sinus ($36^{\circ}-44^{\circ}C$), zygomatic arch ($33^{\circ}-40^{\circ}$), petrous ridge ($32^{\circ}-50^{\circ}$), and image distortion ($44^{\circ}-50^{\circ}$). Consequently, an appropriate exposure angles for the R-Water's view in the supine position for patients with facial trauma are in the from $36^{\circ}$ to $40^{\circ}$ in this phantom study. The results of this study will be helpful for the rapid diagnosis of facial fractures by simple radiography.

Control of Human Clonorchiasis at Gokseong-gun and Sunchang-gun near the Sumjin River in Korea (섬진강 유역 곡성군, 순창군 지역 주민의 간흡충증 관리)

  • Kim, Suk-Il;Yun, Woo-Sang
    • Journal of agricultural medicine and community health
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    • v.29 no.1
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    • pp.163-175
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    • 2004
  • Objectives: This study was carried out to decrease the prevalence of human clonorchiasis and to evaluate the control effect in two Clonorchis sinensis-endemic area of Gokseong-gun and Sunchang-gun adjacent to the Sumjin River in Korea. Methods: The formalin-ether concentration method for stool egg examination or ELISA was applied for the diagnosis of clonorchiasis. As a primary survey, according to the non-probability sampling, a total of 1,2.13 inhabitants at Gokseong-gun were screened through the stool examination, and 1,004 inhabitants at Sunchang-gun were screened through the ELISA. The humans infected with C. sinensis were medicated with praziquantel and educated for the prevention of reinfection with the fluke. After 9 months, as a secondary survey, each prevalence of 616 inhabitants at Gokseong-gun and 2.637 inhabitants at Sunchang-gun was followed-up for the decrease of human clonorchiasis. Results: The prevalence before the mass control was 39.0% at Gokseong-gun and 30.1% at Sunchang-gun in average from 61.5% to 8.9% according to the villages (Myeon) of the survey. In the riverside villages to the Sumjin River the prevalences were higher than other villages located far from the river. The prevalence after the control was decreased to the level of 22.4% at Gokseong-gun(P<0.0001) and 16,3% at Sunchang-gun (P<0.0001). Conclusions: These results suggested that human clonorchiasis was still highly endemic in riverside area of the Sumjin River and could be decreased through the control activities such as diagnosis, medication and education. It was highly recommended that a integrated control such as those of the present study must be adopted in other localities along the Sumjin River for the eradication of human clonorchiasis.

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Development of Nutrition Quotient for Korean adults: item selection and validation of factor structure (한국 성인을 위한 영양지수 개발과 타당도 검증)

  • Lee, Jung-Sug;Kim, Hye-Young;Hwang, Ji-Yun;Kwon, Sehyug;Chung, Hae Rang;Kwak, Tong-Kyung;Kang, Myung-Hee;Choi, Young-Sun
    • Journal of Nutrition and Health
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    • v.51 no.4
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    • pp.340-356
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    • 2018
  • Purpose: This study was conducted to develop a nutrition quotient (NQ) to assess overall dietary quality and food behaviors of Korean adults. Methods: The NQ was developed in three steps: item generation, item reduction, and validation. Candidate items of the NQ checklist were derived from a systematic literature review, expert in-depth interviews, statistical analyses of the Korea National Health and Nutrition Examination Survey (2010 ~ 2013) data, and national nutrition policies and recommendations. A total of 368 adults (19 ~ 64 years) participated in a one-day dietary record survey and responded to 43 items in the food behavior checklist. Pearson's correlation coefficients between responses to the checklist items and nutritional intake status of the adults were calculated. Item reduction was performed, and 24 items were selected for a nationwide survey. A total of 1,053 nationwide adult subjects completed the checklist questionnaires. Exploratory and confirmatory factor analyses were performed to develop a final NQ model. Results: The 21 checklist items were used as final items for NQ. Checklist items were composed of four factors: nutrition balance (seven items), food diversity (three items), moderation for the amount of food intake (six items), and dietary behavior (five items). The four-factor structure accounted for 41.8% of the total variance. Indicator tests of the NQ model suggested an adequate model fit (GRI = 0.9693, adjusted GFI = 0.9617, RMR = 0.0054, SRMR = 0.0897, p < 0.05), and item loadings were significant for all subscales. Standardized path coefficients were used as weights of the items. The NQ and four-factor scores were calculated according to the obtained weights of the questionnaire items. Conclusion: NQ for adults would be a useful tool for assessing adult dietary quality and food behavior. Further investigations of adult NQ are needed to reflect changes in their food behavior, environment, and prevalence of chronic diseases.

Tibial Torsion in Children of the Jeju Area (제주지역 소아의 경골 염전)

  • Song, Dong Ho;Eun, Baik-Lin;Park, Sang Hee;Lee, Joon Young;Tockgo, Young Chang
    • Clinical and Experimental Pediatrics
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    • v.48 no.1
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    • pp.75-80
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    • 2005
  • Purpose : Internal tibial torsion is prevalent in East Asian countries such as Korea and Japan, where sitting on the floor is common behavior. Internal tibial torsion or excessive lateral tibial torsion may cause esthetical, functional, or psychological problems and also may induce degenerative arthritis in older age. The purpose of this study is to measure the tibial torsion in children of the Jeju area. Methods : Tibial torsion was measured in 1,042 lower extremities of 521 children from one to 12 years of age. The values of transmalleolar angles were analyzed for each age group divided by 6 months. Quadratic and linear regression models were used to fit patterns of changes in mean values of transmalleolar angles. The age at seven, which provides the highest coefficient of determination for quadratic regression analysis, was used as a cut-off point to fit different statistical models. Results : The mean transmalleolar angle was $0.10{\pm}5.79^{\circ}$ in all children,$ 0.90{\pm}5.49^{\circ}$ in males, and $-0.80{\pm}5.97^{\circ}$ in females. The value was $4.25{\pm}4.04$ in 1 year of age, gradually decreased to the lowest level of $-1.98^{\circ}$ in four years and seven months of age, increased again with age until it reached $0.67{\pm}1.10^{\circ}$ at seven years of age, and stayed at that level thereafter. Conclusion : Internal tibial torsion in infancy is known to correct spontaneously in the normal developing process. But in this study, the mean transmalleolar angle in children of Jeju area annually decreased after one year of age; to the lowest angle at four years and seven months of age; increased again gradually to the age of seven; and persisted in that level, about $10^{\circ}$ less than western children, not correcting further thereafter. These findings suggest tibial torsion might be caused by lifestyle, especially sitting on feet. To prevent abnormalities of joints and gaits, early diagnosis of tibial torsion in childhood and posture correction or early treatment when needed, seems to be necessary.

The effect of technology capability of product development process on R&D sales performance: Focusing on the moderating effect of government support by the growth stage (제품개발공정의 기술능력이 R&D 매출 성과에 미치는 영향: 성장단계별 정부지원의 조절효과를 중심으로)

  • Kim, Sunyoung;Ba, Kuk Jin;Park, Sangmoon;Choi, Yun Jeong
    • Journal of Technology Innovation
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    • v.22 no.4
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    • pp.235-259
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    • 2014
  • New product or new technology developments are directly linked to a firm's survival and thus their performance and improvement are gaining attention in the midst of rapidly changing business environment and aggravating competition. However, despite SMEs' significance in the national economy, they are limited in terms of size and resources in possession, so the government provides a variety of supports as a policy. According to a study on the organizational life cycle, a firm's limits and difficulties differ by growth stage, so the supports need to be tailored. Based on the data from 2,575 firms that responded to the "2011 SMEs Technological Statistics," how technological capability level and deviation in the R&D process affect the R&D sales performance was studied. The result of analysis revealed that the technological capability has a positive impact on the R&D sales performance. It was also learned that the relationship between deviation in the technological capability and R&D sales performance was moderated by the government support. For the hypothesis that the government support would have a different moderating effect by growth stage for the impact the technology level has on the R&D sales performance, the empirical analysis showed a different meaningful moderating effect for each growth stage. The theoretical implications of the study are that, instead of a simple relation of dynamics that does not take the growth stages into account, it suggested a more realistic causal relationship model that reflects the complex environment the SMEs are in and that the need for measuring and using the deviation in technological capability as a research variable has been justified. The practical implications are that the government policy for supports can be tailored to a growth stage and that the guidelines have been suggested to effectively use the government funding by encouraging the SMEs in a different growth stage to adapt to the customized policy.

Analysis of Communication of Dental Hygienist in Oral Hygiene Instruction during Scaling (치과위생사의 스케일링시 구강보건교육의 의사소통분석)

  • Kang, Su-Kyung;Bae, Hyun-Sook;Lim, Soon-Ryun
    • Journal of dental hygiene science
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    • v.14 no.4
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    • pp.546-553
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    • 2014
  • The purpose of this study was to investigate the actual condition of communication of dental hygienist in oral hygiene instruction during scaling. The research was intended for 67 dental hygienists who worked dental hospitals and clinics. Oral hygiene instruction during scaling was audiotaped. Pearson correlation analysis, t-test, one-way ANOVA, and chi-squared test were conducted. The results gained by the research were as follows. An analysis of 67 dental hygienists has found that 63 dental hygienists (94%) educated the patients with dentiform and 65 of them (97%) did rolling method. Thirty-three of them (49.3%) recommended oral care products to the patients. Only 14 of all educators (21%) said simple greetings and educated importance of care of subjects' teeth, side effect of scaling, when they finished all the scaling stage. The average time of oral hygiene education was 161.3 seconds. In detail, the dental hygienists told 155.0 seconds, the patients did 6.3 seconds on average. The percentage of education time without patients' comments and dialogue each other were 35.8% and 37.3% respectively. The conversation frequency according to the education level of dental hygienist showed significant difference (p<0.05). There was a negative correlation between total education time and patients coming for scaling per day and there was a positive correlation between total number of questions and patient talking time. The result of chi-squared test showed that there was significant difference on asking regards depending on setting a limitation of scaling time (p<0.05). The research showed that the dental hygienists seem to educate the patients mechanically, uniformly rather than educate them according to their oral hygiene condition.

Development of a Failure Probability Model based on Operation Data of Thermal Piping Network in District Heating System (지역난방 열배관망 운영데이터 기반의 파손확률 모델 개발)

  • Kim, Hyoung Seok;Kim, Gye Beom;Kim, Lae Hyun
    • Korean Chemical Engineering Research
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    • v.55 no.3
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    • pp.322-331
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    • 2017
  • District heating was first introduced in Korea in 1985. As the service life of the underground thermal piping network has increased for more than 30 years, the maintenance of the underground thermal pipe has become an important issue. A variety of complex technologies are required for periodic inspection and operation management for the maintenance of the aged thermal piping network. Especially, it is required to develop a model that can be used for decision making in order to derive optimal maintenance and replacement point from the economic viewpoint in the field. In this study, the analysis was carried out based on the repair history and accident data at the operation of the thermal pipe network of five districts in the Korea District Heating Corporation. A failure probability model was developed by introducing statistical techniques of qualitative analysis and binomial logistic regression analysis. As a result of qualitative analysis of maintenance history and accident data, the most important cause of pipeline damage was construction erosion, corrosion of pipe and bad material accounted for about 82%. In the statistical model analysis, by setting the separation point of the classification to 0.25, the accuracy of the thermal pipe breakage and non-breakage classification improved to 73.5%. In order to establish the failure probability model, the fitness of the model was verified through the Hosmer and Lemeshow test, the independent test of the independent variables, and the Chi-Square test of the model. According to the results of analysis of the risk of thermal pipe network damage, the highest probability of failure was analyzed as the thermal pipeline constructed by the F construction company in the reducer pipe of less than 250mm, which is more than 10 years on the Seoul area motorway in winter. The results of this study can be used to prioritize maintenance, preventive inspection, and replacement of thermal piping systems. In addition, it will be possible to reduce the frequency of thermal pipeline damage and to use it more aggressively to manage thermal piping network by establishing and coping with accident prevention plan in advance such as inspection and maintenance.

An Empirical Study of Financial Analyst's Forecasting Activities on the Firm's Operating Performances (기업실적에 대한 재무분석가의 예측활동에 관한 실증연구)

  • Kwak, Jae-Seok
    • The Korean Journal of Financial Management
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    • v.20 no.1
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    • pp.93-124
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    • 2003
  • This paper studies the financial analyst's forecasting activities on the firm's operating performance during the period from 1999 to 2003. In this study, financial analyst's forecasting activities are focused on the sales, operating income and net income and financial analyst's forecasting accuracy, forecasting revising patterns and forecasting activities to the unexpected firm's operating performance are studied. Some empirical findings in this study are as follows. First, standard estimate error on the sales, operating income and net income are all significantly negative value and so financial analyst's forecast on the firm's operating performance are upwardly biased. Second, domestic financial analyst's forecasting activities is relatively more accuracy than foreign financial analyst's forecasting activities. Third, forecasting time is more close to the end of the operating performance announcement day, forecasting activities are more accuracy. Fourth, comparing with individual financial analyst's forecast, consensus forecast is more accuracy. Fifth, in the comparative forecasting activities study according to the prior firm's operating performance, financial analyst's forecasting revision activities are found to be upward or downward. Sixth, financial analysts overreact in the sales forecast and underreact in the operating income and net income forecast. Seventh, in the empirical analysis on the Easterwood-Nutt's test model(1999) which the firm's performance change are divided into the expected performance change and the unexpected performance change, it is found that financial analyst's forecasting activities on the firm's operating performance are systematically optimistic.

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Analysis of Relationship between Sanitary Knowledge and Sanitary Management Performance of School Foodservice Employees in Gyeongnam (경남 일부지역 학교급식 조리종사자의 위생지식과 위생관리 수행도의 관계 분석)

  • An, Jeong-Mi;Kim, Hyun-Ah
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.42 no.7
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    • pp.1139-1147
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    • 2013
  • The purpose of this study was to analyze the relationship between sanitary knowledge score and sanitary management performance among school foodservice employees. For this purpose, a paper-based questionnaire was developed and distributed to 300 school foodservice employees in Jinhae-gu, Changwon from May 13 to June 10 in 2009. A total of 276 responses were received and analyzed. The results of this study were as follows. The sanitary knowledge score of school foodservice employees was 16.60 (total score: 20). Their sanitary management performance level was 4.77 (based on a 5-point Likert scale). We found that sanitary management performance level of high sanitary knowledge score group was significantly higher than that of low sanitary knowledge score group (P<0.001). There was a significant positive correlation between sanitary knowledge score and sanitary management performance of school foodservice employees (P<0.01). Regression analysis showed that sanitary knowledge score of school foodservice employees had a positive effect on sanitary management performance (P<0.001). It implies that as school foodservice employees' sanitary knowledge increased, their sanitary management performance increased. In conclusion, to improve the sanitary quality of school foodservice, school foodservice employees' sanitary management performance level should be increased by improving their sanitary knowledge. So, a systematic and consistent sanitary education program should be conducted for school foodservice employees.

A Study on the Perception of Preferences of Corporate Recruitment for Start-up Experiencer: Focusing on the Comparison between the Job Seekers with Start-up Experiences and the General Job Seekers (창업경험자에 대한 기업채용 선호도의 인식조사: 창업경험자와 일반구직자 비교를 중심으로)

  • Hue, Je-In
    • 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.