• Child Health Nursing Research
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• v.25 no.2
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• pp.165-174
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• 2019

Purpose: This study investigated differences in the relationships of factors including emotional problems, self-perception, parental behavior, and peer attachment with smartphone dependency (SD) among middle school, high school, and college students in South Korea. Methods: This study used data from a nationwide sample of 1,882 middle school, 1,821 high school, and 1,346 college students who owned smartphones. Descriptive statistics and multiple regression analysis were conducted to investigate the predictors of SD based on school level. Results: SD scores significantly differed across school levels. Female gender, more aggressive behavior, less ego-identity, and less monitoring parental behavior were linked to higher SD at all school levels. Less self-esteem and intrusive parental behavior were linked to SD in middle school students. In high school students, additional factors related to higher levels of SD were resilience, intrusive / inconsistent parental behavior, peer trust and alienation, and depression. Additionally, resilience, over-expectant parental behavior, and peer trust were linked to higher SD in college students. Conclusion: This study provides insights into SD and predictors of SD among middle school, high school, and college students. Based on these findings, SD prevention programs should be developed according to the developmental stages of adolescents and young adults.

• Imaging Science in Dentistry
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• v.52 no.1
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• pp.83-91
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• 2022

Purpose: This study assessed the associations between chronological age, dental maturation (DM), cervical vertebrae maturation (CVM), and hand-wrist maturation (HWM) in individuals aged 9-19 years. In addition, this study aimed to derive practical methods to evaluate the skeletal age using DM, CVM, or HWM for orthodontic, medical, and forensic purposes and to compare which of these 3 developmental parameters is more accurate for estimating the age of individuals in a Turkish population. Materials and Methods: Panoramic, lateral cephalometric, and hand-wrist radiographs of 284 patients aged 9-19 years were used in this study. The DM, CVM, and HWM stages were determined. The Kolmogorov-Smirnov, kappa, Wilcoxon, Kruskal-Wallis, chi-square, and Spearman correlation tests and simple linear regression analysis were used for statistical analysis. The significance level was 0.05. Results: Statistically significant differences were found between chronological age and DM, chronological age and CVM, and chronological age and HWM in both sexes (P<0.05). DM did not show statistically significant differences according to sex (P>0.05), but CVM and HWM were statistically different between males and females (P<0.05). The DM-estimated age yielded more accurate values than the other methods. Conclusion: All correlations between skeletal and dental stages were statistically significant. Our results showed that there was no statistically significant difference between chronological age and DM-estimated age. Therefore, it can be concluded that DM stages have the potential to be used for legal purposes.

• Nuclear Engineering and Technology
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• v.54 no.5
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• pp.1835-1844
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• 2022

Single-orifice plate is wildly utilized in the piping system of the nuclear power plant to throttle and depressurize the fluid of the pipeline. The cavitation induced by the single-orifice plate may cause some serious vibration of the pipeline. This study aims to find the optimal designs of the single-orifice plates that may have weak cavitation possibilities. For this purpose, a new single-orifice plate with a convergent-flat-divergent hole was modeled, a multi-objective optimization method was proposed to optimize the shape of a single-orifice plate, while computational fluid dynamics method was adopted to obtain the fluid physical quantities. The reciprocal cavitation number and the developmental integral were treated as cavitation indexes (e.g., objectives for the optimization algorithm). Two non-dominant designs ultimately achieved illustrated obvious reduction in the cavitation indexes at a Reynolds number Re = 1 ×10⁵ defined based on fluid velocity. Besides, the sensitivity analysis and temperature effects were also performed. The results indicated that the convergent angle of the single-orifice plate dominants the cavitation behavior globally. The optimal designs of single-orifice plates result in lower downstream jet areas and lower upstream pressure. For a constant Reynolds number, the higher temperature of liquid water, the easier it is to undergo cavitation. Whereas there is a diametric phenomenon for a constant fluid velocity. Moreover, the regression models were carried out to establish the mathematical relation between temperature and cavitation indexes.

• Child Health Nursing Research
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• v.30 no.2
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• pp.97-107
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• 2024

Purpose: This study aimed to investigate the impact of family resilience on caregiver well-being across various age groups of children diagnosed with ADHD (attention-deficit/hyperactivity disorder) groups (0-5, 6-11, and 12-17 years). Methods: Utilizing secondary data from the 2022 US National Survey of Child Health, this cross-sectional study involved 2,752 children who were formally diagnosed with ADHD. Statistical analysis included descriptive analysis, Spearman's rank correlation, chi-square tests, and linear regression, conducted using SPSS version 27. Results: The study revealed a moderate positive correlation (r=.35, p<.001) between family resilience and caregiver well-being. Controlling for covariates, family resilience accounted for 25.2%, 21.1%, and 22.1% of caregiver well-being variance in age groups 0-5, 6-11, and 12-17 years, respectively. Additionally, factors like employment status, family structure, and caregiver age showed varying influences on caregiver well-being across these developmental stages. A consistent pattern emerged across these age groups: unemployment and non-traditional family structures were associated with negative impacts on caregiver well-being, whereas older caregiver age positively influenced well-being. Conclusion: This research underscores the importance of age-specific family resilience strategies to improve caregiver well-being and family interactions in ADHD contexts. Investigating these aspects through qualitative studies across various cultures could deepen our understanding of well-being and inform culturally sensitive interventions.

• The Journal of Korean Academy of Sensory Integration
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• v.9 no.1
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• pp.21-31
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• 2011

Objective : This study investigated the relationships of handwriting legibility and perceptual-motor skills, and handwriting speed and perceptual-motor skills. And identified the predictors that most affect the handwriting of preschool children. Methods : Twenty-three typically developing preschool aged children (mean age: 68.61 months, SD=2.04) were selected through the Korean-Denver Developmental Screening Test-2(K-DDST-2). The children were tested with regard to handwriting legibility, visual perception, visual-motor integration and fine-motor coordination. Results : First, a significant relationship was not found among handwriting legibility, visual perception, visualmotor integration and fine-motor coordination. Second, a significant relationship was found among handwriting speed, visual perception and fine-motor coordination. Third, stepwise multiple regression analyses showed that general visual perception were significant predictors for handwriting speed. Conclusion : Occupational therapists should evaluate children's visual perception levels utilizing a standardized test, and focus on general visual perception in order to improve handwriting skill(speed). Also, occupational therapists are expected to play an important role in the management and treatment of children's handwriting skills.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.7
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• pp.510-516
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• 2020

This study investigated the characteristics and factors affecting inpatient infants, children, and adolescents who experienced falling, using NHDIS data from 2008 through 2017, The study analyzed data of 116 patients who were under 18 and who experienced injuries (KSCD, S00-S99) by falling (KSCD, W00-W19). Frequency analysis, cross-tabulations, and multiple regression analysis were conducted, using SPSS 23. There were more boys than girls, and most of the falls occurred at the ages of over one to under six years old. Most of the children had respiratory diseases, and most had open wounds or bruises due to falling. Also, most of the falls were related to the bed. In the factor analysis, age (β=.318), the main diagnosis (β=.231), and injury (β=.169) except gender affected falling. This suggests that it is necessary to conduct fall prevention education for children, considering the developmental stage characteristics and age group. It is necessary to screen the risk group such as children with a disease with relatively less restriction of activities or with a hyperactive disorder, and to develop a related manual. Hopefully, the results will be used as the basic data for fall prevention education and creating a fall prevention manual according to the characteristics of children's developmental stage for patients who need hospitalization, their caregivers, and the relevant medical team.

• Journal of radiological science and technology
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• v.32 no.1
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• pp.79-86
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• 2009

The study found out developmental factors of the liver diseases in 29, 531 cases of the healthy adults who were diagnosed by using ultrasound at domestic healthcare centers in 6 cities. The results are as follows. Based on the result of the study, the liver diseases diagnosed by using ultrasound was revealed to show 43.1% of prevalence, and the occurrence was significantly higher in male (23.3%) than in female (19.8%). The prevalence of hepatic diseases related to the BMI was revealed to show highest prevalence of the fatty liver in obese group (BMI $\geqq$ 25) by recording 44.3%. Smoking contributed to the high prevalence of all liver diseases. Although the fatty liver was the most frequently occurred form of liver diseases by recording the prevalence of 49.1% (22.2% in male, 26.9% in female), the significant difference was found only in female (p < 0.05), but male group did not show significant difference (p > 0.05). The prevalence of hepatic diseases related to the hypertension was revealed to show highest prevalence of the fatty liver in hypertension group by recording 67.7%. The prevalence of hepatic diseases related to the diabetes was revealed to show highest prevalence of the fatty liver in diabetes group by recording 66.2%. The high prevalence of all hepatic diseases was related to diabetes mellitus with statistical significance (p < 0.001). The multiple regression analysis for the related factors which affect the prevalence of the liver diseases showed the higher prevalence by age. Sex, obesity and diabetes mellitus were positively related to the prevalence (p < 0.05) while hypertension and smoking showed no significant relationship to the prevalence of the disease (p > 0.05).

• Korean Journal of Veterinary Research
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• v.16 no.1
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• pp.11-25
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• 1976

Studies on pathogenicities and developmental stages of Nosema apis (Zander, 1909) were carried out through artificial infection to Nosema free honey bees with various levels of spores isolated from local honey bee colony. The results obtained were summarized as follows: 1. The clinical symptoms were observed as dysentery, enteritis of mid-gut (enlargement and decoloration), crawling posture and shortening of the longevity of worker bees in the rearing honey bee colony inoculated with the spores. 2. Number of spores harvested from laboratory rearing honey bees were progresively increased to 4 weeks after inoculation. The regression equations and coefficients of correlations to various spore levels were as follows in each treatment colony. Colony 1. ($$1,000{\times}10^4spores/ml$$) $$y_{c1}=471{\times}10^{4}x+454{\times}10^4(r=0.65^*$$) Colony 2. ($$500{\times}10^4spores/ml$$) $$y_{c2}=340{\times}10^{4}x+207.8{\times}10^4(r=0.99^{**}$$) Colony 3. ($$100{\times}10^4spores/ml$$) $$y_{c3}=150{\times}10^{4}x+84.2{\times}10^4(r=0.99^{**}$$) Colony 4. ($$10{\times}10^4spores/ml$$) $$y_{c4}=13.8{\times}10^{4}x+13{\times}10^4(r=0.98^{**}$$) 3. Average longevity of worker bees artificially infected with Nosema apis was shortened as 21.7~43.8% compare to the control. (p<.05, p<.01) 4. The spores which were isolated from honey bee colony infected with Nosema disease were ovoid or spherical form, and measured, as a rule, from $4.7{\mu}m$ to $6.1{\mu}m$ (mean $5.3{\mu}m$) in length and from $2.4{\mu}m$ to $3.2{\mu}m$ (mean $2.9{\mu}m$) in width. 5. In the mid-gut of honey bees, the spore was progresively germinated and became trophozoite stage. The trophozoites were grown to meronts and their binary fission were begun. The divided two sporoblasts were developed to the spores which had elastic membrane. The new spores were shed in excreta of honey bees 10~15 day after inoculation at $25{\pm}2$ centigrade. 6. The ultrastructure of spore membrane consisted of three layers, such as, outer, middle and inner layer. The sporoplasm consisting lamellar structure occupied only anterior part of the spore and was often extended to posterior direction where definite vacuoles and a polar filament was able to detect.

• Korean Journal of Social Welfare
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• v.57 no.2
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• pp.375-403
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• 2005

This Study reviews theoretical argument about the effect of retirement earnings test on the labor supply of the aged which is controversial issue in OECD countries and analyze the effect on the incidence of re-employment, re-employment period of suspended officials and the possibility of re-retirement through Government Employment Pension Corporation data. It consists of 178,363 public officials who received pension benefit or disability pension in January 2005. The main result of this research shows that public officials re-employed were 8,086 which is 4.5% of total retired, and median survival time of suspended pension payments is 3.3 years. Also the median re-employment period of 100% suspended officials is about 20 month shorter than that of 1/2 suspended officials and it is shown in regression analysis that the possibility of re-retirement by 100% suspended officials is statistically significant higher than those of 50%. It specially expects greater influence if includes in case taking lump-sum or no making effect of re-employment because current system withhold pension payments even by earned income itself. Therefore, this analysis suggests suspension of pension payment properly applied according to the age and income together with "Delayed Retirement Credit" or "Partial Pension" for developmental alternatives of civil servant's suspension of pension payments. Furthermore, It is urgently needed that distinctive quality data about re-employment including earnings to perform deep-empirical research for effective policy. Lastly, it is extremely necessary to reinforce management system of Government Employment Pension Corporation.

• Korean Journal of Organic Agriculture
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• v.28 no.2
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• pp.251-261
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• 2020

The developmental ecology and temperature-dependent growth model were calculated to develop the Scotinophara lurida control technology, which is mainly affected by environmentally friendly rice cultivation. The survival rate of S. lurida after overwintering in 2019 showed that 167 of 224 survived and the survival rate was 72.8%. Overwintering adult of S. lurida occur in rice fields in mid-June, spawn in early July, and first-generation adults develop in mid-August. In order to determine the temperature-dependent growth model, the growth periods by temperature and development stage were investigated in a incubator at 18, 21, 24, 27, 30℃ and 14L: 10D. The period from egg to adult at the temperature of 18, 21, 24, 27, 30℃ was 119.8, 73.1, 53.5, 39.4, and 82.0 days, respectively. The best development temperature was at 27℃. The regression curve was obtained by analyzing the relationship between temperature and growth rate using the Excell program, and the base temperature threshold and effective cumulative temperature for each development stage were calculated. From eggs to 5 nymphs of S. lurida the base temperature threshold was 17.9℃ and the effective cumulative temperature was 380.2 DD.