• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.31 no.1
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• pp.41-45
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• 2020

Objective: The objective of this study was to assess serum, hair, and urinary magnesium (Mg) levels in children with attention-deficit/hyperactivity disorder (ADHD), autism spectrum disorder (ASD), and both ASD and ADHD to reveal potential interactive effects. Methods: A total of 148 boys aged 4-9 years old were enrolled in this study, including 44 children with ADHD, 40 pediatric patients with ASD, 32 patients with both ADHD and ASD, as well as 32 healthy neurotypical children. Hair, serum, and urinary Mg levels were assessed using inductively-coupled plasma mass spectrometry (ICP-MS). Laboratory quality control was performed using certified reference materials of human hair, plasma, and urine. Results: No significant group difference in serum Mg levels was observed. Mg content in hair was found to be reduced in children with ADHD and ADHD+ASD compared to that in healthy controls by 11% and 15%, respectively. Urinary Mg levels in children with ADHD+ASD exceeded the control, ADHD, and ASD values by 51, 76, and 65%, respectively. Factorial analysis revealed significant contribution of ADHD to hair and urinary Mg levels. Multiple regression analysis demonstrated that hair and urinary Mg levels were considered as significant predictors of neurodevelopmental disorder complexity. Conclusion: We propose that impaired Mg status may provide a link between ADHD and ASD.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.1
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• pp.205-214
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• 2015

This study examined the effect on calling and the role of optimism, work hope, religion and supportive parenting. Furthermore, this study tested if personal characteristic variables (optimism and work hope) and personal environmental variables (religion and supportive parenting) would affect how the path would reach. 277 male and female undergraduate students were surveyed. The data was analyzed by AMOS and SPSS. The results were as follows. First, structural equation modeling analyses indicated that supportive parenting and optimism had a direct influence on work hope, and work hope had a significant effect on calling. Religion was not influenced by calling. Second, predictors including work hope, optimism, and supportive parenting accounted for calling well. The implication for practice and future research on calling in counseling and education area are discussed.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.10 no.2
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• pp.27-39
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• 2000

Objectives : The purpose of this study is to analyze the factors associated with respirator usage on the basis of reasoned action theory. Methods : The data were collected from August 1 to September 30 1999, and study subjects consisted of 303 workers who were employed in the manufacturing industries. A self-administered questionnaire was used to measure the attitude, subjective norm and related factors. Results : In bivariate analysis, the variables related to protector usage were prevention of occupational disease, protection of toxic material, disturbance during working, troublesome of usage, proper exchange of protector. Multivariate logit analysis was used to estimate factors associated with respirator usage. Significant predictors that are related to respirator usage were attitude toward the behavior, size of industry and proper exchange of protector. Conclusions : The results suggest that it is strongly required to focus on attitude toward the behavior in order to improve workers' usage of respirator.

• Research in Community and Public Health Nursing
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• v.5 no.1
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• pp.5-29
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• 1994

In recent years, interests in health promotion have been stimulated by the epidemiological transition from infectious to chronic diseases as lead ing causes of death, the aging of the population, rapidly escalating health care costs, and epidemiologic findings linking individual risk to morbidity and mortality. It is not surprising that the workplace has been targeted as a promising setting for health promotion. In Korea, national attention to the opportunities for workplace health promotion began in the first 1990s. But there is no in depth study to identify the relating factors to the health promotion program in the workplace. The objective of this study is behavioral and physical characteristics to find that in crease the person's risk for a range of health problems and to analysis other characteristics to influence the degree of his/her intention to change health behavior. In addition, this study is purposed to present the process of planning health promotion program in the workplace. To accomplish these objectives, one workplaces was selected. And 363 employees in those workplaces were served as subjects for the study. Major findings in this study are as follows. (1) They have many risk factors such as smoking, drinking, lack of sleep, law rate of regular exercise, irregular eating, stress. (2) Some of the health risk factors such as smoking, drinking, and stress have the negative correlation to the intention to change. (3) Among cognitive and socio-environmental factors, significant predictors to the intention are attitude and social support. (4) In the cluster analysis to segment the target population in to homogeneous unit, three clusters of lifestyle are specified. (5) Smoking cessation and exercise program are planned for the risk group to change their behavior.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.38 no.5
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• pp.655-669
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• 2018

In this study, we developed a hybrid forecasting model based on a four-parameter distribution which allows a simultaneous season-ahead forecasting for both seasonal rainfall and sub-daily rainfall in Han-River and Geum-River basins. The proposed model is mainly utilized a set of time-varying predictors and the associated model parameters were estimated within a Bayesian nonstationary rainfall frequency framework. The hybrid forecasting model was validated through an cross-validatory experiment using the recent rainfall events during 2014~2017 in both basins. The seasonal precipitation results showed a good agreement with the observations, which is about 86.3% and 98.9% in Han-River basin and Geum-River basin, respectively. Similarly, for the extreme rainfalls at sub-daily scale, the results showed a good correspondence between the observed and simulated rainfalls with a range of 65.9~99.7%. Therefore, it can be concluded that the proposed model could be used to better consider climate variability at multiple time scales.

• Journal of Forest and Environmental Science
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• v.32 no.3
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• pp.280-290
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• 2016

Stem diameter variability is an essential inventory result that provides useful information in forest management decisions. Little has been done to explore the modelling potentials of standard deviation (SDD) and coefficient of variation (CVD) of diameter at breast height (dbh). This study, therefore, was aimed at developing and testing models for predicting SDD and CVD in stands of Pinus caribaea Morelet (pine) in south west Nigeria. Sixty temporary sample plots of size $20m{\times}20m$, ranging between 15 and 37 years were sampled, covering the entire range of pine in south west Nigeria. The dbh (cm), total and merchantable heights (m), number of stems and age of trees were measured within each plot. Basal area ($m^2$), site index (m), relative spacing and percentile positions of dbh at $24^{th}$, $63^{rd}$, $76^{th}$ and $93^{rd}$ (i.e. $P_{24}$, $P_{63}$, $P_{76}$ and $P_{93}$) were computed from measured variables for each plot. Linear mixed model (LMM) was used to test the effects of locations (fixed) and plots (random). Six candidate models (3 for SDD and 3 for CVD), using three categories of explanatory variables (i.e. (i) only stand size measures, (ii) distribution measures, and (iii) combination of i and ii). The best model was chosen based on smaller relative standard error (RSE), prediction residual sum of squares (PRESS), corrected Akaike Information Criterion ($AIC_c$) and larger coefficient of determination ($R^2$). The results of the LMM indicated that location and plot effects were not significant. The CVD and SDD models having only measures of percentiles (i.e. $P_{24}$ and $P_{93}$) as predictors produced better predictions than others. However, CVD model produced the overall best predictions, because of the lower RSE and stability in measuring variability across different stand developments. The results demonstrate the potentials of CVD in modelling stem diameter variability in relationship with percentiles variables.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.1
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• pp.605-614
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• 2016

Many Korean colleges funded by the Korean government have actively implemented LINC (Leaders INdustry-university Cooperation) programs to facilitate practical training since 2012. The LINC programs have two major different categories, a technologically and innovative focused program and a field-centered program. A number of studies have applied the TPB (Theory of Planned Behavior) model proposed by Fishbein and Azjen successfully to predict the behavioral intention in many areas, such as marketing, environmental purchasing, and technology, etc. On the other hand, few studies have applied the TPB within industry-university cooperation settings. The purpose of this study was to empirically test the applicability of the TPB model in predicting the employees' participation in LINC programs. To investigate the study's purpose, a closed-ended questionnaire, composed of a total of 32 questions based on previous studies, was developed, and the data from 115 out of 132 employees in the participating companies of LINC were utilized. Specific analysis of the study showed that the attitudes, subjective norm, and perceived behavioral control were significant predictors of the LINC intention. In addition, the LINC intention was a significant predictor of the participation in LINC.

• Safety and Health at Work
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• v.12 no.3
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• pp.396-402
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• 2021

Background: Styrene is one of the aromatic compounds used in acetonitrile-butadiene-styrene (ABS) producing petrochemicals, which has an impact on health of workers. Therefore, this study aimed to investigate the health risks of styrene emitted from the petrochemical industry in Iran. Methods: Air samples were collected based on NIOSH 1501 method. The samples were analyzed by the Varian-cp3800 gas chromatograph. Finally, risk levels of styrene's health effects on employees were assessed by the quantitative method of the U.S. Environmental Protection Agency (U.S. EPA) and the semiquantitative way by the Singapore Occupational Safety and Health Association. Results: Based on the results, the employees had the highest average exposure to styrene vapors (4.06 × 10^-1mg.(kg - day)^-1) in the polybutadiene latex (PBL) unit. Therefore, the most top predictors of cancer and non-cancer risk were 2.3×10^-4 and 7.26 × 10^-1, respectively. Given that the lowest average exposure (1.5 × 10^-2mg.(kg - day)^-1) was in the dryer unit, the prediction showed a moderate risk of cancer (0.8 × 10^-6) and non-cancer (2.3 × 10^-3) for the employees. The EPA method also predicted that there would be a definite cancer risk in 16% and a probable risk in 76% of exposures. However, according to the semiquantitative approach, the rate of risk was at the "low" level for all staff. The results showed that there was a significant difference (p < 0.05) between the units in exposure and health risk of styrene (p < 0.05). Conclusion: Given the high risk of styrene's health effects, appropriate control measures are required to reduce the exposure level.

• Safety and Health at Work
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• v.11 no.4
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• pp.491-499
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• 2020

Background: Assembly lines work is frequently associated to work-related upper limb musculoskeletal disorders. The related disability and absenteeism make it important to implement efficient health surveillance systems. The main objective of this study was to identify self-reported variables that can determine work-related upper limb musculoskeletal symptoms-discomfort/pain-during a 6-month follow-up. Methods: This was a prospective study with a 6-month follow-up period, performed in an assembly line. Upper limb musculoskeletal discomfort/pain was assessed through the presence of self-reported symptoms. Uni- and multivariate logistic regression analyses were used to evaluate which self-reported variables were associated to upper limb symptoms after 6 months at the present and to upper limbs symptoms in the past month. Results: Of the 200 workers at baseline, 145 replied to the survey after 6 months. For both outcomes, "having upper limb symptoms during the previous 6 months" and "education" were possible predictors. Conclusion: Our results suggest that having previous upper limb symptoms was related to its maintenance after 6 months, sustaining it as a specific determinant. It can be a hypothesis that this population had mainly workers with chronic symptoms, although our results give only limited support to self-reported indicators as determinants for upper limb symptoms. Nevertheless, the development of an efficient health surveillance system for high demanding jobs should implicate self-reported indicators, but also clinical and work conditions assessment should be accounted on the future.

• Journal of Information Technology Services
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• v.19 no.6
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• pp.55-82
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• 2020

This study examined the factors that influence the turnover intention, job performance of call center representatives based on the adaptive structuration theory (AST). This study intended to empirically examine how individual characteristics of representative affect the technological and task adaptation, how they affect job performance and turnover intention. On the other hand, this study also explains how rational culture and organization a reputation which are considered as dimensions of organizational characteristics affects organizational commitment, and verifies the relationship between organizational commitment and job performance and turnover intention. Finally this paper aim to provide academic and practical implications. In order to solve the above research problems, this research proposed a model based on the adaptive structuration theory. In order to identify the relationship between the proposed variables and the AST for individual, we conducted an empirical test on the call center representatives. The structural equation model was used to verify the research model and hypotheses. The results of the empirical analysis show that the personal characteristics of counselors, such as communication skills, multitasking abilities, and innovativeness have a positive effect on skill adaptation, and skill adaptation has a positive effect on task adaptation, furthermore, it influences on job performance and turnover intention Respectively. In addition, among the factors of organizational environmental dimensions of the call center, it was found that organizational reputation not only increase continuance commitment but also increase normative commitment. Contrary to our expectations, perceived rational culture didn't have a positive effect on organizational commitment. Also, continuance commitment and normative commitment are valid predictors of job performance, but they have nothing to do with turnover intention. On the contrary, emotional commitment is the only one variable among three dimensions of organizational commitment have a positive effect on turnover intention, but is not a valid predictor of job performance.