• Asian-Australasian Journal of Animal Sciences
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• v.33 no.8
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• pp.1360-1368
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• 2020

Objective: The aim of our study was to determine the associations of heifer reproductive performance with survival up to the first calving, first-lactation milk yield, and the probability of being culled within 50 days after first calving. Methods: Data from 33 large Holstein-Friesian commercial dairy herds were gathered from the official milk recording database in Hungary. The data of heifers first inseminated between January 1, 2011 and December 31, 2014 were analyzed retrospectively, using Cox proportional hazards models, competing risks models, multivariate linear and logistic mixed-effects models. Results: Heifers (n = 35,128) with younger age at conception were more likely to remain in the herd until calving, and each additional month in age at conception increased culling risk by 5.1%. Season of birth was related to first-lactation milk yield (MY1; n = 19,931), with cows born in autumn having the highest milk production (p<0.001). The highest MY1 was achieved by heifers that first calved between 22.00 and 25.99 months of age. Heifers that calved in autumn had the highest MY1, whereas calving in summer was related to the lowest milk production (p<0.001). The risk of culling within 50 days in milk in first lactation (n = 21,225) increased along with first calving age, e.g. heifers that first calved after 30 months of age were 5.52-times more likely to be culled compared to heifers that calved before 22 months of age (p<0.001). Calving difficulty was related to higher culling risk in early lactation (p<0.001). Heifers that required caesarean section were 24.01-times more likely to leave the herd within 50 days after first calving compared to heifers that needed no assistance (p<0.001). Conclusion: Reproductive performance of replacement heifers is closely linked to longevity and milk production in dairy herds.

• Journal of Preventive Medicine and Public Health
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• v.45 no.4
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• pp.227-234
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• 2012

Objectives: The object of this study was to determine the relationship between body mass index (BMI) and early menarche in adolescent girls in Seoul. Methods: A retrospective study was conducted with 144 middle school students in Seoul who provided informed consent. We measured their body composition, and used the questionnaire survey method for data collection from November to December 2008. Past elemental body composition data were collected from elementary school health records of first year of middle school. Results: The early menarcheal group was taller and heavier than the late menarcheal group (p<0.05 from 8-12 years old). The body fat percentage (%), BMI were higher in the early menarcheal girls than the late-menarcheal girls (p<0.05, age at 13). In the result of multiple logistic regression, the BMI at the age of 8 and 9 was associated with early menarche after adjusting for birth weight, breast feeding and age at menarche of the mother (BMI at the age of 8: p for trend=0.01, BMI at the age of 9: p for trend=0.04). An increase in BMI from 7 to 8 year was associated with early menarche after adjusting for birth weight, breast feeding, age at menarche of the mother (p for trend=0.048). Conclusions: The BMI at the age of 8 and 9 was associated with the early menarche of girls and increase in BMI from 7 to 8 year was associated with the early menarche of girls. These results suggest that BMI and increase in BMI before menarche cause early menarche. Although this study does not represent all Korean adolescent girls, it is one of the few studies that have investigated the temporal relationship between BMI and early menarche.

• Imaging Science in Dentistry
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• v.49 no.1
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• pp.19-26
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• 2019

Purpose: It has been proposed that using new prediction methods, such as neural networks based on dental data, could improve age estimation. This study aimed to assess the possibility of exploiting neural networks for estimating age by means of the pulp-to-tooth ratio in canines as a non-destructive, non-expensive, and accurate method. In addition, the predictive performance of neural networks was compared with that of a linear regression model. Materials and Methods: Three hundred subjects whose age ranged from 14 to 60 years and were well distributed among various age groups were included in the study. Two statistical software programs, SPSS 21 (IBM Corp., Armonk, NY, USA) and R, were used for statistical analyses. Results: The results indicated that the neural network model generally performed better than the regression model for estimation of age with pulp-to-tooth ratio data. The prediction errors of the developed neural network model were acceptable, with a root mean square error (RMSE) of 4.40 years and a mean absolute error (MAE) of 4.12 years for the unseen dataset. The prediction errors of the regression model were higher than those of the neural network, with an RMSE of 10.26 years and a MAE of 8.17 years for the test dataset. Conclusion: The neural network method showed relatively acceptable performance, with an MAE of 4.12 years. The application of neural networks creates new opportunities to obtain more accurate estimations of age in forensic research.

• Korean Journal of Psychosomatic Medicine
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• v.30 no.2
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• pp.187-195
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• 2022

Objectives : We aimed to explore weekend catch-up sleep (CUS) by age and to find out the association between CUS and depression by the age group and weekday sleep duration (SD). Methods : Using data from the 2016-2018 Korean National Health and Nutrition Examination Survey, the CUS by age of 16,174 subjects was investigated, and the depression data of 11,088 subjects were analyzed. CUS was calculated as the weekend sleep duration minus weekday sleep duration (SD). The mean of CUS and weekday SD in depression group and non-depression group was compared by early, middle, and late adulthood groups, and logistic regression analysis was performed to investigate the effect of CUS on the depression by age group when weekday SD was insufficient. Results : The CUS tended to decrease continuously with age, the mean of CUS in the late adult group was the shortest. However, the average SD, adjusted for weekend CUS, was the shortest in the middle adulthood group. Overall, the sleep durations were shorter in the depression group than in the non-depression group, but the CUS difference between the two groups was significantly only in the middle adulthood. The risk of depression was significantly higher when weekend CUS was less than 1hour with a short weekday SD of less than 6hours (OR 2.44, 95% CI: 1.78-3.35), and this finding was significant in all adult groups. Conclusions : The findings of this study suggest that short weekday SD and inadequate weekend CUS are associated with depression and that CUS is an option to compensate for sleep deprivation and prevent depression.

• Journal of Korean Academy of Nursing
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• v.36 no.4
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• pp.652-661
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• 2006

Purpose. The purposes of this study were to apply data mining tool to nursing specific knowledge discovery process and to identify the utilization of data mining skill for clinical decision making. Methods. Data mining based on rough set model was conducted on a large clinical data set containing NMDS elements. Randomized 1000 patient data were selected from year 1998 database which had at least one of the five most frequently used nursing diagnoses. Patient characteristics and care service characteristics including nursing diagnoses, interventions and outcomes were analyzed to derive the meaningful decision rules. Results. Number of comorbidity, marital status, nursing diagnosis related to risk for infection and nursing intervention related to infection protection, and discharge status were the predictors that could determine the length of stay. Four variables (age, impaired skin integrity, pain, and discharge status) were identified as valuable predictors for nursing outcome, relived pain. Five variables (age, pain, potential for infection, marital status, and primary disease) were identified as important predictors for mortality. Conclusions. This study demonstrated the utilization of data mining method through a large data set with stan dardized language format to identify the contribution of nursing care to patient's health.

• Imaging Science in Dentistry
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• v.47 no.2
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• pp.87-92
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• 2017

Purpose: The aim of this study was to determine whether the panoramic mandibular index (PMI) is useful for assessing bone mineral density. We also analyzed the potential correlations between PMI parameters and patient age. Materials and Methods: Four observers measured the PMI of both sides of the mental foramen using a picture archiving and communication system and images in the Digital Imaging and Communications in Medicine format. They studied 300 panoramic radiographic images of patients belonging to the following age groups: 40-49 years, 50-59 years, 60-69 years, 70-79 years, and 80-89 years. The observers were allowed to zoom in or out and to adjust the contrast of the images. Further, they were instructed to record the reasons for any measurements that could not be made. Then, we conducted a reliability analysis of the measured PMI and assessed the correlations between different patient age groups and the 3 parameters used for determining the PMI from the available data. Results: Among the 600 data items collected, 23 items were considered unmeasurable by at least 1 observer for the following 4 reasons: postoperative state, lesion, unidentified mental foramen, and alveolar bone loss. The intraobserver reproducibility of the measurable data was 0.611-0.752. The mandibular cortical width (MCW) decreased significantly as patient age increased. Conclusion: PMI had limited usability when the margin of the mental foramen was not clear. In contrast, MCW, a parameter used for determining the PMI, had fewer drawbacks than the PMI with respect to bone mineral density measurements and exhibited a significant correlation with patient age.

• The Research Journal of the Costume Culture
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• v.24 no.2
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• pp.248-262
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• 2016

Most Korean companies in the fashion industry are SMEs, and the role of the CEO and management ownership is important for enhancing the firm's competence and developing strategies. The study aims to examine the effect of management ownership on company financial growth. In particular, the study focuses on the moderating effect of company age and size on Korean fashion SMEs' financial outcomes. Financial data based on company financial statements from 2012 to 2014 was collected by the Data Analysis, Retrieval and Transfer System of Korea's Financial Supervisory Service. A total of 295 companies' (domestic fashion businesses) data was analyzed by the bootstrap method. The median sales value in the financial year 2014 was 47,492,403,958 KRW, and the company size was divided by it. The companies were in business for an average of 20 years. According to the results, the management ownership had a negative effect on Compound Annual Growth Rate (CAGR) for the three-years, and the relationship between the two variables was moderated by company age. Additionally, the interaction effect of management ownership and company age on 3-CAGR was also moderated by company size. When the companies had spent only a few years in business, a negative effect of management ownership for small firms and a positive effect of management ownership on financial growth for medium firms were found. These results suggest that small companies starting business need to manage their company governance structure to make flexible decisions, and after retaining financial growth, the companies can expand their businesses based on strong ownership.

• Korean Journal of Occupational Health Nursing
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• v.7 no.1
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• pp.47-54
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• 1998

The purpose of this study was to identify the factors affected with health promoting lifestyle of teachers to provide the data for efficient health management of teachers. The subjects of this study were 809 teachers, who were chosen in Choong-Buk province. Data were collected by written questionnaires by mail and visiting from September 1 to 30, 1997. Data was analyzed by descriptive statistics, t-test, ANOVA using SPSS/PC(v.4.01) program. The results are as follows; 1. The mean scores of Health Promoting Lifestyle was 2.53 on the average, self-actualization 2.97, nutrition 2.90, interpersonal relationship 2.52, stress management 2.33, exercise 1.91, health responsibility 1.82. Total Health Promoting Lifestyle was significantly different by sex, age, marital status, career, teaching load, monthly income education, number of children. 2. Income was the factors affect with self-actualization, age, marital status, teaching load, number of children, career, education, income were the factors significantly affect with Nutrition. Sex, marital status were the factors affect with stress management, sex, age, career were the factors affect with exercise, and sex, age, marital status, career, teaching load, income, education, number of children were the factors affect with health responsibility. 3. Marital status, sex, age, income, number of children, living with family were the factors significantly affect with Family Function. 4. Sex affected with Self Efficacy. The above findings indicate the need to develop nursing intervention to improve Self-Efficacy, Family Function to improve Health Promoting Lifestyle. Further studies are needed to confirm these findings and to determine factors which significantly influence Health Promoting Lifestyle of teachers.

• Quality Improvement in Health Care
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• v.12 no.1
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• pp.92-102
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• 2006

Background : Most hospitalized children will experience physical pain as well as psychological distress. Painful procedure can increase anxiety and fear of pediatric patients and their parents who do not have understanding logical of their disease and hospitalization. This study attempted to identify pain reduction in related to therapeutic intervention by age and environmental improvement. Methods : A total of 194 hospitalized children and their parents were investigated. Data collection period was 3 months from March to May 2004. Four instruments were used to collect the data : Faces Pain Rating Scale(FPRS), Heart rate, Oxygen saturation and Pain behavioral check list. The data were analyzed by a SPSS program and tested x2-test, t-test, ANCOVA. Results : 1. Age from 0 to 3, the Heart rate, FPRS, Oxygen saturation and Pain behavioral check list were significantly different in theraputic intervention group when compare to control group. 2. Age from 4 to 6, FPRS, Oxygen saturation and Pain behavioral check list were significantly different in theraputic intervention group when compare to control group. But the heart rate were not significantly different when compare to control group. 3. Age from 7 to 9, FPRS and Pain behavioral check list were significantly lower in therapeutic intervention group when compare to control group but Heart rate and Oxygen saturation were not significantly different when compare to control group. Conclusion : The results of this study concludes that most children experience acute pain during IV therapy and it can be reduced by age specific therapeutic intervention and by change of surrounding environment.

• Journal of Korean Neurosurgical Society
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• v.60 no.6
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• pp.710-716
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• 2017

Objective : Among pediatric injury, brain injury is a leading cause of death and disability. To improve outcomes, many developed countries built neurotrauma databank (NTDB) system but there was not established nationwide coverage NTDB until 2009 and there have been few studies on pediatric traumatic head injury (THI) patients in Korea. Therefore, we analyzed epidemiology and outcome from the big data of pediatric THI. Methods : We collected data on pediatric patients from 23 university hospitals including 9 regional trauma centers from 2010 to 2014 and analyzed their clinical factors (sex, age, initial Glasgow coma scale, cause and mechanism of head injury, presence of surgery). Results : Among all the 2617 THI patients, total number of pediatric patients was 256. The average age of the subjects was 9.07 (standard deviation${\pm}6.3$) years old. The male-to female ratio was 1.87 to 1 and male dominance increases with age. The most common cause for trauma were falls and traffic accidents. Age (p=0.007), surgery (p<0.001), mechanism of trauma (p=0.016), subdural hemorrhage (SDH) (p<0.001), diffuse axonal injury (DAI) (p<0.001) were statistically significant associated with severe brain injury. Conclusion : Falls were the most common cause of trauma, and age, surgery, mechanism of trauma, SDH, DAI increased with injury severity. There is a critical need for effective fall and traffic accidents prevention strategies for children, and we should give attention to these predicting factors for more effective care.