• Journal of the Korean Society of Radiology
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• v.18 no.4
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• pp.345-353
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• 2024

The purpose of this study was to suggest an appropriate collimation size and central X-ray incidence point by analyzing the correlation between the collimation size used in lumbar lateral examination and factors affecting the collimation size. the lumbar lateral examination results of 148 patients suitable for the purpose of this study were analyzed. The measurement method was to set the total horizontal width shown in the image to the size of the irradiation field(collimation) used during the examination. The distance connected vertically from the end of the dorsal field to the apophyseal joint of the third lumbar vertebra(AJD), the distance from the dorsal end of the image field to the center of the body of the third lumbar vertebra(BD), and the distance from the end of the dorsal field of the image to the center of the pedicle of the third lumbar vertebra(PD). The distance was measured. For comparative analysis of the mean values of dependent variables according to gender, age, height, weight, and body mass index, the mean values were compared using the independent samples t test and one-way ANOVA. For post hoc analysis, duncan was used. The correlation between independent and dependent variables was analyzed using Pearson correlation analysis. In this study, statistical significance was set at a p value of 0.05 or lower. The average value of the collimation size during the lumbar spine lateral examination was 252.45 mm, AJD was 102.11 mm, BD was 141.17 mm, and PD was 119.73 mm. The mean values of collimation size, AJD, BD, and PD were larger in men than in women, but statistical significance for the difference in mean values by gender was found only in BD (p<0.05). There was a slight difference in the mean value of each group according to age, but there was no statistical significance (p>0.05). The collimation size and mean values of AJD, BD, and PD according to height, weight, and body mass index differed depending on the independent variables, and the differences were all statistically significant (p<0.05). As a result of the correlation analysis, field size and AJD, BD, and PD showed no correlation with gender and age, a weak positive correlation with height, and a medium positive correlation with weight and body mass index. The results of this study showed that CS was correlated with height, weight, and BMI during lumbar lateral examination. If the entrance point of the central X-ray is moved to the appophyseal joint by considering weight and BMI when adjusting the collimation size in clinical practice, it is expected that the collimation size can be reduced bu about 5%.

• Journal of Korean Dental Hygiene Science
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• v.7 no.1
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• pp.1-15
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• 2024

Background: This study aims to determine the association between the number of remaining teeth and oral health-related quality of life according to economic activity status in elderly. Methods: Data from the 9th Korean Longitudinal Study of Ageing (KLoSA) were used to analyze 6,004 older adults aged 59 years and older. The number of remaining teeth was categorized as less than 20 and more than 20, and the Geriatric Oral Health Assessment Index (GOHAI) was used to measured the oral health-related quality of life of the elderly. Independent t-tests were performed to compare demographic, economic, sociodemographic, and health characteristics, as well as GOHAI scores, between economically active and inactive individuals. In the case of ANOVA analysis, Scheffe's post hoc analysis was performed to confirm statistical significance between groups. Linear regression analysis was conducted to determine the influence of the number of remaining teeth on GOHAI according to economic activity status. Results: Among the study population, 33.9% were economically active, which is approximately half the proportion of those were not economically active. The mean GOHAI scores were 43.32 and 40.15 for economically active and economically inactive individuals with 20 or more residual teeth, respectively (p<0.001). Simple linear regression analysis revealed that having more than 20 remaining teeth was associated with a statistically significant increase in GOHAI by approximately 4.56 times and 4.92 times compared to having fewer than 20 teeth for economically active and non-economically active individuals, respectively (p<0.001). Multiple linear regression analysis, adjusted for demographic, economic, sociodemographic, and health characteristics, showed that having more than 20 remaining teeth was associated with a statistically significant increase in GOHAI by approximately 3.62 and 2.97 times compared to having fewer than 20 teeth in economically active and non-economically active individuals, respectively (p<0.001). Conclusion: This study explored economic activity status as one of several approaches to enhance the oral health-related quality of life of the elderly. By using the number of remaining teeth as an indicator of oral health status. supporting economic activity could potentially improve both oral health and overall quality of life for older individuals. Such interventions may have positive effects on policy outcomes, including reducing economic inequality by promoting economic engagement among the elderly.

• Women's Health Nursing
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• v.7 no.2
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• pp.169-187
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• 2001

This study was performed to probe the effect of exercise program on muscle strength, endurance, flexibility, pain, disability level and life satisfaction in female teachers of elementary school who complain of low back pain. For this study, 44 female teachers aged 30-50 years with mechanical low back pain of 6 months' duration, who had the structural normalities in the lumbar spine, were recruited from April 1 to July 10 1999. Twenty three out of them were assigned to the experimental group and twenty one to the control group. The exercise program consisted of education on right postures, the etiology and diagnosis of low back pain, and exercise intervention such as muscle relaxation, elongation and strengthening. With 8 weeks program, the subjects received two sessions of education and six sessions of group exercise in the 1st week, while three sessions of group exercise and four sessions of individual exercise weekly and two sessions of education during the later 7 weeks. The muscle strength and endurance were measured by Cybex 770, the flexibility by flexibility measurement machine, the intensity of pain by Visual Analogue Scale (VAS), the level of disability by Oswestry low back pain disability scale, depression by Beck depression inventory (BDI), and life satisfaction by Life satisfaction index-Z. Study measurements were taken before and after 8 weeks exercise program. Data were analyzed using paired t-test, t-test, and ANCOVA. The results were as follows ; 1. The flexors and extensors peak torque and flexors peak torque per body weight of experimental group were significantly increased at test velocities $30^{\circ}$/sec, $60^{\circ}$/sec compared with those of control group. There was no significant difference in extensors peak torque per flexors peak torque at $30^{\circ}/sec$, $60^{\circ}/sec$ between experimental and control group. 2. The flexors and extensors total work and flexors total work per body weight of experimental group were significantly increased at $120^{\circ}/sec$, compared with those of control group. 3.The flexibility of lumbar spine in experimental group was significantly increased compared with that of control group. The pains in anterior, posterior, left lateral and right lateral bending and in rotation of experimental group were significantly increased compared with those of control group. 4. The Oswestry disability scores of experimental and control group were significantly decreased, and there was no difference in the Oswestry disability score change between experimental and control group. 5. The scores of BDI of experimental group were significantly decreased compared with those of control group. Life satisfaction index-Z scores of experimental group were not changed, but those of control group were significantly decreased. There was no difference in the score change of Life satisfaction index-Z between experimental and control group. 6. ANCOVA analysis for the data variables of inhomogeneous baseline represented that there was no significant difference in extensors peak torque and extensors total work at $120^{\circ}/sec$ and extensor total work per body weight at $120^{\circ}/sec$ change between experimental group and control group. These findings indicate that the exercise program could be effective in increasing the muscle strength, endurance, flexibility and decreasing pain, improving depression in female teachers of elementary school with chronic low back pain. It is suggested that the exercise program could be an essential factor for the effective nursing intervention to the patients suffered from chronic low back pain.

• Korean Journal of Cognitive Science
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• v.28 no.4
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• pp.315-328
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• 2017

Even though assessment using information and communication technology will most likely lead the future of educational assessment, there is little domestic research on this topic. Computerized assessment will not only cut costs but also measure students' performance in ways not possible before. In this context, this study introduces a tool which can overcome the problems of multiple choice tests, which are most widely used type of assessment in current Korean educational setting. Multiple-choice tests, in which options are presented with the questions, are efficient in that grading can be automated; however, they allow for students who don't know the answer, to find the correct answer from the options. Park(2005) has developed a modified multiple-choice testing system (CMMT) using the interactivity of computers, that presents questions first, and options later for a short time when the student requests for them. The present study was conducted to find out if penalizing wrong answers could lower the possibility of students choosing an answer among the options when they don't know the correct answer. 116 students were tested with the directions that they will be penalized for wrong answers, but not for no response. There were 4 experimental conditions: 2 conditions of high or low percentage of penalizing, each in traditional multiple-choice or CMMT format. The results were analyzed using a two-way ANOVA for the number of no response, the test score and self-report score. Analysis showed that the number of no response was significantly higher for the CMMT format and that test scores were significantly lower when the penalizing percentage was high. The possibility of applying CMMT format tests while penalizing wrong answers in actual testing settings was addressed. In addition, the need for further research in the cognitive sciences to develop computerized assessment tools, was discussed.

• The Journal of Korean Academy of Prosthodontics
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• v.50 no.4
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• pp.258-270
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• 2012

Purpose: Use of inappropriate statistical methods may lead to incorrect conclusions and a waste of valuable resources. The goal of this study was to assess the frequency and the types of several common statistical errors in the published articles of the Journal of the Korean Academy of Prosthodontics (JKAP) for a 5-year period. Materials and methods: Of 336 articles in the JKAP published from 2006 to 2010, 255 articles using statistics were reviewed and classified by statistical method and year. The frequency and types of the statistical methods were examined, and the statistical errors were evaluated by the appropriateness of the experimental design, assumption check, independent outcomes, proper sample size and suitable use of statistical method. Statistical guidelines were completed based on the appropriateness. Results: Of the 255 articles using statistics, 193 articles (75.9%) used inferential statistics and 153 articles used SPSS statistical software (60.0%). Of the articles using inferential statistics, the three most frequently used statistical methods were ANOVA (41.5%), t-test (20.0%), and the nonparametric method (16.9%). The average rate of statistical errors was 61.2 percent, similar to the rate reported by several studies completed for the medical journal. Conclusion: After the whole analysis of the difference among the groups, post-hoc tests for the pairwise comparisons are required. The optimal sample size calculation is an essential part of this study protocol. To minimize the occurrence of statistical errors, statistical guidelines were developed according to each statistical test procedure and will contribute to the academic improvement in the JKAP.

• Restorative Dentistry and Endodontics
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• v.33 no.4
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• pp.341-351
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• 2008

This study investigated the effect of intermittent polymerization on the rate of polymerization shrinkage and cuspal deflection in composite resins. The linear polymerization shrinkage of each composite was measured using the custom-made linometer along with the light shutter specially devised to block the light at the previously determined interval. Samples were divided into 4 groups by light curing method; Group 1) continuous light (60s with light on); Group 2) intermittent light (cycles of 3s with 2s light on & 1s with light off for 90s): Group 3) intermittent light (cycles of 2s with 1s light on & 1s with light off for 120s); Group 4) intermittent light (cycles of 3s with 1s light on & 2s with light off for 180s). The amount of linear polymerization shrinkage was measured and its maximum rate (Rmax) and peak time (PT) in the first 15 seconds were calculated. For the measurement of cuspal deflection of teeth, MOD cavities were prepared in 10 extracted maxillary premolars. Reduction in the intercuspal distance was measured by the custom-made cuspal deflection measuring machine. ANOVA analysis was used for the comparison of the light curing groups and t-test was used to determine significant difference between the composite resins. Pyramid showed the greater amount of polymerization shrinkage than Heliomolar (p < 0.05). There was no significant difference in the linear polymerization shrinkage among the groups. The Rmax was group 4 < 3, 2 < 1 in Heliomolar and group 3 < 4 < 2, 1 in Pyramid (p < 0.05). Pyramid demonstrated greater cuspal deflection than Heliomolar. The cuspal deflection in Heliomolar was group 4 < 3 < 2, 1 and group 4, 3 < 2, 1 in Pyramid (p < 0.05). It was concluded that the reduced rate of polymerization shrinkage by intermittent polymerization can help to decrease the cuspal deflection.

• Journal of Intelligence and Information Systems
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• v.19 no.2
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• pp.39-54
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• 2013

Recent explosive increase of electronic commerce provides many advantageous purchase opportunities to customers. In this situation, customers who do not have enough knowledge about their purchases, may accept product recommendations. Product recommender systems automatically reflect user's preference and provide recommendation list to the users. Thus, product recommender system in online shopping store has been known as one of the most popular tools for one-to-one marketing. However, recommender systems which do not properly reflect user's preference cause user's disappointment and waste of time. In this study, we propose a novel recommender system which uses data mining and multi-model ensemble techniques to enhance the recommendation performance through reflecting the precise user's preference. The research data is collected from the real-world online shopping store, which deals products from famous art galleries and museums in Korea. The data initially contain 5759 transaction data, but finally remain 3167 transaction data after deletion of null data. In this study, we transform the categorical variables into dummy variables and exclude outlier data. The proposed model consists of two steps. The first step predicts customers who have high likelihood to purchase products in the online shopping store. In this step, we first use logistic regression, decision trees, and artificial neural networks to predict customers who have high likelihood to purchase products in each product group. We perform above data mining techniques using SAS E-Miner software. In this study, we partition datasets into two sets as modeling and validation sets for the logistic regression and decision trees. We also partition datasets into three sets as training, test, and validation sets for the artificial neural network model. The validation dataset is equal for the all experiments. Then we composite the results of each predictor using the multi-model ensemble techniques such as bagging and bumping. Bagging is the abbreviation of "Bootstrap Aggregation" and it composite outputs from several machine learning techniques for raising the performance and stability of prediction or classification. This technique is special form of the averaging method. Bumping is the abbreviation of "Bootstrap Umbrella of Model Parameter," and it only considers the model which has the lowest error value. The results show that bumping outperforms bagging and the other predictors except for "Poster" product group. For the "Poster" product group, artificial neural network model performs better than the other models. In the second step, we use the market basket analysis to extract association rules for co-purchased products. We can extract thirty one association rules according to values of Lift, Support, and Confidence measure. We set the minimum transaction frequency to support associations as 5%, maximum number of items in an association as 4, and minimum confidence for rule generation as 10%. This study also excludes the extracted association rules below 1 of lift value. We finally get fifteen association rules by excluding duplicate rules. Among the fifteen association rules, eleven rules contain association between products in "Office Supplies" product group, one rules include the association between "Office Supplies" and "Fashion" product groups, and other three rules contain association between "Office Supplies" and "Home Decoration" product groups. Finally, the proposed product recommender systems provides list of recommendations to the proper customers. We test the usability of the proposed system by using prototype and real-world transaction and profile data. For this end, we construct the prototype system by using the ASP, Java Script and Microsoft Access. In addition, we survey about user satisfaction for the recommended product list from the proposed system and the randomly selected product lists. The participants for the survey are 173 persons who use MSN Messenger, Daum Caf$\acute{e}$, and P2P services. We evaluate the user satisfaction using five-scale Likert measure. This study also performs "Paired Sample T-test" for the results of the survey. The results show that the proposed model outperforms the random selection model with 1% statistical significance level. It means that the users satisfied the recommended product list significantly. The results also show that the proposed system may be useful in real-world online shopping store.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.8 no.4
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• pp.129-144
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• 2013

The consumption of coffee has been drastically increased last two decades. Now almost all the Korean adult people enjoy the coffee and diverse cultures related coffee have been spread widely in Korea. Therefore new marketing strategies are necessary to satisfy consumers according to ages, attitudes, and other characters. It has been continuously discussed whether the coffee gives negative impacts to health. Regardless of the discussions of the effects to health, now coffee became a part of modern daily lives. In this study the motivations of coffee consumption were classified to five; wellbeing motivation, refreshment motivation, social motivation, habitual motivation, and emotional motivation. Future intention of coffee consumption were also classified to five factors: sound mental intention, addictive intention, side-effect recovery intention, economic intention, and psychological intention. The survey was conducted in Seoul City and Kyeongki Province from January 3 to February 2, 2013. Total 500 questionaries were distributed and 450 were collected and 428 samples were used for the analysis of this study. The data were analyzed by SPSS Win 18 Version. The methods used in this study were factors analysis test, reliability test, validity test, t-testy, One-Way ANOVA, and regression analysis. The hypnosis in this study were as follows. First, The motivations of coffee consumption would influence to the intention of coffee consumption. Second, there would be statistical differences to the intention of coffee consumption according to the demographic characteristics. According to the result of the study, the motivation of coffee partially affected to the intention of coffee consumption. And there were statistical differences according to age, occupations, educational levels, and monthly incomes. The implications of this study were the factors related health and emotional feeling were considered more important than tastes and characters of coffee-shop that people thought more important before.

• 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.

• Journal of Nutrition and Health
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• v.51 no.1
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• pp.60-72
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• 2018

Purpose: The purpose of this study was to determine differences in eating-out, dietary life styles, and healthy dietary competencies among middle-aged consumers according to obesity status and gender for implications of consumer education. Methods: Data were drawn from the 2016 Food Consumption Behavior Survey, and 3,022 subjects (mail 1,388; female 1,634) who were middle-aged adults were investigated. Analysis of variance with $Scheff\acute{e}$ test, t-test, $x^2$-test, and factor analysis were performed using SPSS v.24. Results: Males showed less interest in diet than females. For both males and females, higher BMI degrees were associated with higher levels of interest in diet. For frequency, monthly average consumption expenditure, one-time cost for eating out, and drinking frequency, males showed higher levels than females. Especially for the male group, higher obesity status was associated with higher levels of eating out and drinking. Dietary lifestyles of males and females turned out to be very similar. For the male group, normal weight group was more likely to show 'health and high quality pursuit dietary life-style' than the other groups. For females, the normal weight group were more likely to show 'health and high quality pursuit dietary life-style' and 'safety pursuit dietary life-style' than the other groups. The level of 'healthy dietary competence' for females was found to be higher than that for males. For the female group, there were significant differences according to obesity status, and practice was more important than knowledge in determining a healthy dietary life. Conclusion: For dietary life-related education for obese middle-aged consumers, it is important to emphasize less eating-out and drinking and less overeating while eating-out based on the results that eating-out, drinking, and overeating in the obesity group were significantly higher than in the normal group. It is important to focus on the value of dietary life and diverse foods, based on the results that the obesity group was less likely to be have healthy dietary lifestyles and consume less diverse foods than the normal group.