• Journal of the Korea Society of Computer and Information
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• v.11 no.1 s.39
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• pp.45-53
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• 2006

Finite failure NHPP models presented in the literature exhibit either constant, monotonic increasing or monotonic decreasing failure occurrence rates per fault. In this paper, Goel-Okumoto and Yamada-Ohba-Osaki model was reviewed, proposes the $x^2$ reliability model, which can capture the increasing nature of the failure occurrence rate per fault. Algorithm to estimate the parameters used to maximum likelihood estimator and bisection method, model selection based on SSE, AIC statistics and Kolmogorov distance, for the sake of efficient model, was employed. Analysis of failure using real data set, SYS2(Allen P.Nikora and Michael R.Lyu), for the sake of proposing shape parameter of the $x^2$ distribution using the degree of freedom, was employed. This analysis of failure data compared with the $x^2$ model and the existing model using arithmetic and Laplace trend tests, Kolmogorov test is presented.

• The Korean Journal of Food And Nutrition
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• v.28 no.4
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• pp.612-619
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• 2015

The present study was designed to investigate health-related life habits, food preference, body composition for proper dietary habits, health promotion of communities in Incheon area. The effects of personal characteristics and health-related life habits such as gender, age, having breakfast, smoking, drinking, and exercise were analyzed using a surveying. 961 community subjects (262 males and 699 females) were investigated using a questionnaire and Inbody. Data were analyzed by descriptive statistics, chi squared test, and one-way ANOVA (analysis of variation) with SPSS/WIN 21.0. The result of gender distribution showed there were 262 males and 699 females, and with respect to the effect of gender on health-related life habits, smoking, drinking, and exercise showed significant differences (p < 0.05), whereas having breakfast was not significantly difference (p>0.05). Therefore, the present provide evidence of a relationship between health-related life habits and gender. Regarding the effect of BMI on health-related life habits, exercise showed significant differences (p < 0.05), whereas smoking, drinking, and having breakfast were not significantly difference (p>0.05). Thus, the present study also provides evidence of a relationship between health-related life habits and BMI. Our analysis shows that food preference and body composition were significant different from health-related life habits such as smoking, drinking, exercise, and having breakfast (p < 0.05). Our analysis showed that body composition was significant differences from health related habits such as smoking, drinking, exercise, and breakfast (p < 0.05). In conclusion, the present study suggests that diet guidelines support and improve health promotion designed by communities.

• Journal of Environmental Health Sciences
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• v.43 no.5
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• pp.382-392
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• 2017

Objectives: The purpose of this study is to obtain basic data on the development of a risk communication model through an investigation of risk perception for radon and identify effective risk communication channels. Methods: A questionnaire was used to evaluate differences in perception level according to respective communication channels. A chi-squared test was used to analyze the difference in pre- and post-risk communication by communication channel. One-way ANOVA was used to analyze the difference in the radon risk perception rate for each communication channel. Results: All of the communication channels resulted in increased radon risk perception, but there was no statistical difference between them in terms of perception (p>0.05). However, based on previous findings that it is effective to use a multi-channel approach, it is considered that communication channels based on duplicate avenues is most appropriate. Conclusions: It is expected that this study will be used as basic data to better understand the formation of public opinion about radon risk and to understand the social reaction to each risk factor.

• Korean Journal of Community Nutrition
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• v.23 no.3
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• pp.216-225
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• 2018

Objectives: This study was conducted to investigate the associations between obesity and the children's Nutrition Quotient (NQ) and to further examine the relationships between NQ and mini dietary assessment (MDA) of their parents. Methods: The subjects were 355 children aged 3 to 5 years and their parents in Dongducheon. We collected parental-reported NQ questionnaires for children and MDA of parents. Anthropometric measurements, height, weight and BMI by BIA were measured in children. Overweight and obesity were determined according to age- and sex-specific BMI percentile from the 2007 Korean national growth chart. Statistical analyses consisted of the chi-squared test, ANOVA, partial correlations and logistic regression analysis adjustments for parents BMI. Results: Approximately 20.8% of preschool children were classified as overweight or obese. Underweight children showed a significantly higher score for balance than overweight children. The NQ of the children was $61.9{\pm}11.6$, and NQ scores and their parents' MDA did not exhibit any significant differences according to degree of obesity. After adjusting for parent's BMI, children's BMI was significantly correlated with balance and moderation among NQ factors. Parent's MDA showed significant correlation with their children's NQ, balance, diversity, moderation, regularity, practice and NQ grade, except for diversity of father. Additionally, NQ grade had a significantly increased (150.1%) odds ratio (OR) of being overweight (95% CI 1.008-2.234). Conclusions: These results show that NQ for children is influenced by their parents' MDA and BMI. Furthermore, our findings support the association between overweight prevention and improvement of NQ grade among preschool children.

• Journal of Preventive Medicine and Public Health
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• v.45 no.4
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• pp.211-218
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• 2012

Objectives: The objective of this study was to identify the differences in obesity rates among people with and without disabilities, and evaluate the relationship between obesity rates and the existence of disabilities or characteristics of disabilities. Methods: Mass screening data from 2008 from the National Disability Registry and National Health Insurance (NHI) are used. For analysis, we classified physical disability into three subtypes: upper limb disability, lower limb disability, and spinal cord injury. For a control group, we extracted people without disabilities by each subtype. To adjust for the participation rate in the NHI mass screening, we calculated and adopted the weight stratified by sex, age, and grade of disability. Differences in obesity rates between people with and without disabilities were examined by a chi-squared test. In addition, the effect of the existence of disabilities and grade of disabilities on obesity was examined by multiple logistic regression analysis. Results: People with disabilities were found to have a higher obesity rate than those without disabilities. The obesity rates were 35.2% and 35.0% (people with disabilities vs. without disabilities) in the upper limb disability, 44.5% and 34.8% in the lower limb disability, 43.4% and 34.6% in the spinal cord injury. The odds for existence of physical disability and grade of disability are higher than the nondisabilities. Conclusions: These results show that people with physical disability have a higher vulnerability to obesity.

• Journal of Korean language education
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• v.29 no.4
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• pp.225-254
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• 2018

The purpose of this study is to contrast the patterns of realization and understanding of refusal speech acts between Korean and Thai learners. This study intends to answer the following questions: (1) Do Koreans and Thai learners perform refusal speech acts differently? (2) Do Koreans and Thai learners understand refusal speech acts differently? A DCT and a follow-up interview were conducted to collect data of two groups of 30 native Korean speakers and 30 native Thai speakers. For research question 1, we analyzed the refusal strategy and provided reasons given by Koreans and Thai learners depending on the context. For research question 2, we ran a chi-squared test on the elements of the follow-up interviews, such as the weight of burden of refusing, and whether the participant would actually refuse or not. The differences between the refusal strategies of the two groups could be categorized by the preceding inducing speech act. In refusing a request, the difference was prominent in the apologizing strategy, whereas in refusing a suggestion, the difference was mainly in the direct refusal strategy. When refusing an invitation, the most evident difference was the number of refusal strategies employed. When providing an explanation of refusal to people with high social status, Koreans gave more specific reasons for refusals, whereas Thai learners tended to use more vague reasons. Moreover, when refusing an invitation, Koreans primarily mentioned the relationship, and Thai learners showed the spirit of Greng Jai. When asked the weight of burden of refusing, Koreans felt pressured to refuse a request from people with high social status, and a suggestion or invitation from people with high level of intimacy while Thai learners found it highly difficult to make a refusal in all cases. In answering whether they would actually refuse or not, Koreans tried not to make a refusal to people with high level of intimacy, and such a trend was not evident among the Thai. This study can help us better understand the learner's pragmatic failure, and serve as a basis in establishing a curriculum for teaching speech acts.

• The korean journal of orthodontics
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• v.51 no.5
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• pp.329-336
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• 2021

Objective: To compare the magnitude of external apical root resorption (EARR) 6 months after starting orthodontic treatment using orthodontic aligners (OAs) and fixed appliances (FAs). Methods: This parallel randomized clinical trial included 40 patients randomized into two groups: OA group (n = 20, 160 incisors) and FA group (n = 20, 160 incisors). For evaluation of the tooth length, periapical radiographs and standardized linear measurements of the maxillary and mandibular incisors were acquired before (T0) and 6 months after treatment initiation (T1). EARR was calculated through the difference in length between the two time points (T1-T0). Statistical comparisons were performed by means of using t-tests, chi-squared test and covariance analysis (a = 5%). Results: Rounding of the root apex was observed in both groups; the resorption involved 2.88% of the root length, so 97.12% of the tooth length remained intact. Intragroup comparisons between the two time points revealed a significant difference, with (T1-T0) ranging from -0.52 to -0.88 mm in the FA group and from -0.52 to -0.85 mm in the OA group. In the intergroup comparisons, only tooth #21 presented a statistically significant difference (OA: -0.52 ± 0.57 mm, FA: -0.86 ± 0.60 mm); however, the overall differences between groups were not clinically relevant, ranging from 0.03 to 0.35 mm. Conclusions: OA and FA treatment resulted in a similar degree of EARR in the maxillary and mandibular incisors at 6 months after treatment initiation. However, the amount of resorption was small and does not impair tooth longevity.

• Tuberculosis and Respiratory Diseases
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• v.82 no.3
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• pp.194-200
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• 2019

Background: Tuberculosis (TB) is a major infectious disease in South Korea causing substantial disease burden, particularly in the elderly. This study aimed to identify the case detection rate of mobile TB screening for the elderly conducted in the Jeollanam-do region and to analyze risk factors of active TB. Methods: We screened the elderly population (${\geq}65$ years old) in Jeollanam-do from August to December 2017. Chest radiography was performed for all participants. Participants with TB presumptive signs were asked to submit sputum specimen(s). Sputum smear, culture, and polymerase chain reaction analyses were performed. Cascade analysis, chi-squared tests, and Fisher exact tests were used to evaluate screening performance. Results: In total, 12,402 participants were screened, and 211 (1.7%) were suspected to have active TB; 181 of the suspected patients (85.8%) underwent sputum smear test, and 16 (8.8%) patients were confirmed to have TB. The TB prevalence among the elderly was bacteriologically confirmed to be 129 per 100,000 individuals, which was similar to national TB notification data for the same age groups. The proportion of active TB cases increased with age, and differed based on sex and past TB history. However, TB-related symptoms, comorbidity status, and TB screening history within 12 months were not predictive of active TB. Conclusion: This study identified that the prevalence rate was similar to national TB notification data from the same age groups. Periodic, community-based, systematic TB screening among the elderly population is recommended.

• The Korean Journal of Pain
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• v.32 no.3
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• pp.178-186
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• 2019

Background: Epidural steroid injections (ESIs) have been widely used in managing spinal pain. Dexamethasone has recently emerged as a useful drug in this setting, relative to particulate steroids, although the associated systemic effects have not been fully elucidated. This study aimed to investigate the incidences and types of systemic effects after fluoroscopically guided ESI with dexamethasone. Methods: This retrospective study included 888 ESIs with dexamethasone (fluoroscopically guided at the cervical and lumbosacral levels) performed on 825 patients during January to June 2017. Data regarding systemic effects were collected via telephone interviews using a standardized questionnaire at 2 weeks after the procedure. Data on patient demographic, clinical, and procedural characteristics were collected and analyzed to identify factors that were associated with systemic effects. All statistical analyses were performed using the chi-squared test. Results: Among the 825 patients, 40 patients (4.8%) experienced systemic effects during the 2-week follow-up period. The most common systemic effect was facial flushing (12 patients, 1.5%), which was followed by urticaria (7 patients, 0.8%) and insomnia (7 patients, 0.8%). A history of spine surgery was significantly associated with the occurrence of systemic effects (P = 0.036). Systemic effects were significantly more common for injections at the cervical level than at the lumbar level (P = 0.019). Conclusions: Approximately 4.8% of the patients who underwent ESI with dexamethasone experienced minor and transient systemic effects. These effects were more common in patients who had undergone a previous spine surgery or received a cervical ESI.

• Journal of Korean society of Dental Hygiene
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• v.19 no.1
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• pp.141-149
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• 2019

Objectives: To investigate the real-world re-use of disposable dental supplies (DDS) in dental offices and assess the relationship between general characteristics of dental hygienists and reuse of DDS, with respect to infection control characteristics. Methods: A questionnaire was administered to 277 dental hygienists to assess their general characteristics, awareness of infection control/DDS management, and re-use of DDS. Nine DDS were categorized into the following categories based on their purpose: Critical, Semicritical, Noncritical, and Personal protective equipment (PPE). The association between general characteristics of dental hygienists and re-use of DDS, with respect to infection control characteristics, was assessed using the chi-squared test. Results: All 9 DDS were re-used to different extents. The highest reuse rate of supplies were for masks (64.6%), prophylaxis cups (61.0%) and plastic saliva ejectors (30.0%). Overall, 89.5% of the participants re-used DDS; subgroup analysis showed the following proportions of specific DDS re-use: PPE 66.4%; Semicritical DDS 63.9%; Noncritical DDS 19.5%; and Critical DDS 1.8%. Based on the type of clinic, the rate of re-use was higher in dental clinics than dental hospitals. Thus, the re-use of DDS may be caused by inappropriate or nonexistent guidelines or habitual practice, rather than the awareness or attitude of dental hygienists. Conclusions: In order to ensure a safe environment within the dental clinic, DDS classifications must be clearly outlined in the dental infection control guidelines; moreover, additional studies are needed regarding the regulations for DDS re-use and disposal.