• Journal of Preventive Medicine and Public Health
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• v.31 no.3 s.62
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• pp.384-394
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• 1998

In order to investigate the effect of the urinary excretion of sodium and potassium on the change on blood pressure over 3 years, 668 adolescents aged 13 years living in Kangwha area were investigated in a longitudinal follow-up study. Two measurements were taken on each blood pressure (diastolic, systolic) and the average of the two readings was used in the analysis. Sodium and potassium intake were estimated by the determination of those electrolytes in 24hr urine. The mixed model regression analysis was used to identify the effect of urinary sodium and potassium on the change of blood pressure after controlling for BMI of each age. On simple bivariate analysis no relationship was found between urinary sodium excretion and systolic or diastolic blood pressure among both male and female, however, a significant positive association between urinary potassium excretion and systolic blood pressure among male. The results of mixed regression analysis showed that the body mass index (BMI) were more influential that urinary electrolytes among this study subjects. It suggested that risk factors observed from the adults, may not be identical with that of the growing aged population. After control of the BMI and age, significant association between sodium and diastolic BP among male, and association between potassium and systolic BP among female, were found. In summary, the results indicate that growth has been more influential than dietary factor on blood pressure for growing aged population.

• Korean Security Journal
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• no.50
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• pp.119-141
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• 2017

The purpose of this study is to analyze the longitudinal causal relationship between organizational commitment and job satisfaction, focusing on security related workers. For this purpose, the Korean Labor and Income panel data were classified into security employees. Data were analyzed using SPSS 18.0 and AMOS 20.0, and validity and reliability analysis were conducted before hypothesis testing. The results of the analysis show that organizational commitment at time t-1 has a positive effect on organizational commitment at time t, and that job satisfaction at time t-1 has a positive effect on job satisfaction at time t Respectively. The results of this study are as follows: 1) The organizational commitment has a significant effect on the job satisfaction. 2) The effect of job satisfaction on organizational commitment was also significant 3) The cross-lagged coefficients show that organizational commitment precedes job satisfaction and serves as a predictor

• Journal of the Korean Wood Science and Technology
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• v.35 no.2
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• pp.29-38
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• 2007

This study was undertaken to investigate the variation of equilibrium moisture content (EMC) in transverse direction and three different directional (longitudinal, radial, and tangential) linear movements, and diffusion coefficients within a tree disc of Korean red pine (pinus densiflora). The EMC gradually increased in heartwood from pith. Therefore, the chemical components might differ even in heartwood and the radial variation in EMC might have a close relationship with the cellulose content within a cross section. The specific gravity increases gradually from pith and the porosity has not direct influence on the variation of EMC within a tree disk. Both the radial and tangential diffusion coefficients exhibited clear trend of increase from pith. The EMC change (${\Delta}EMC$) and tangential diffusion coefficient were close to be axisymmetrical but others were deviated from axisymmetry. The diffusion coefficient decreases with decreasing an activation energy and specific gravity, The diffusion coefficient increased with increasing ${\Delta}EMC$ and hygroscopicity of wood might be inversely proportional to the activation energy, The fJEMC may depend on the chemical constituents of cellulose, hemicellulose and lignin. As the number of sorption sites and sorption capacity of wood increase, therefore, it might be assumed that the hygroscopicity of wood increases while activation energy decreases. Modeling physico-mechanical behavior of wood, the variations should be considered to improve the accuracy.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.11a
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• pp.603-606
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• 2006

We present a study on the development of a practical and quantitative technique for the assessment of the structural health condition with using piezoceramic(PZT) sensors. The electro-impedance-based technique with the PZT patches is very sensitive for evaluation of the incipient and small damage in a high frequency range, and however the commonly traditional modal analysis method is effective only for considerably larger damages in low frequency range. The paper presents the technique in detecting and characterizing real-time damage on the specimen that is an aluminum plate fastened with bolts and nuts by different torques and as well a plate with a crack. By using the special arrangement of the PZT sensors, the required longitudinal wave is generated through the specimen. A large number of experiments are conducted and the different conditions of the specimens, i.e. the location and extent of loosening bolts, and the plate with a crack are simulated. respectively. Since fixing and loosening the loosened bolt is controlled by a torque wrench, we can control exactly the experiment of the different torques. Compared with the simulated healthy condition, we can find whether or not there is a damage in the specimen with using an impedance analyzer with the PZT sensors. Several indices are discussed and used for assessing the different simulated damages. As for the location of bolt loosening, the RMSD is found to be the most appropriate index for numerical assessment and as well the RMSD shows strongly linear relationship for assessing the extent of the bolt loosening, and the frequency peak shift ${\Delta}F$ is used to assess the cracked plate. The possibility of repeatability of the pristine condition signatures is also presented and the appropriate frequency range and interval are uniquely selected through large numbers of experiments.

• Journal of Korean Neurosurgical Society
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• v.58 no.3
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• pp.236-241
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• 2015

Objective : We report on the technical feasibility and limitations of the transmanubrial approach for cervicothoracic junction (CTJ) lesions and emphasize the advantage of bisecting the upper part of the manubrium in an inverted Y-shape. Methods : Thirteen patients who underwent the fourteen transmanubrial approach for various CTJ lesions were enrolled during 2005-2014. For the evaluation of the accessibility for the CTJ lesion, we analyzed the two parallel line defined as a straight line parallel to the inferior and superior plateau of the upper and lower healthy vertebrae, the angle of the two parallel lines and the distance from the sternal notch to lines at the sternum on preoperative magnetic resonance images. Surgical limitations and perspectives, as well as postoperative clinical outcomes were evaluated retrospectively. Results : The CTJ lesions were six metastases, three primary bone tumors, two herniated discs, and one each of a traumatic dislocation with syrinx formation and tuberculous spondylitis and ossification of the posterior longitudinal ligament. If two parallel lines pass below the sternal notch, the manubriotomy should be inevitably performed. The mean preoperative Visual analogue scale score was 8 (range, 5-10), which improved to 4 (range, 0-6) postoperatively. Seven cases showed an increase in Frankel score postoperatively. Conclusion : The spatial relationship between the sternal notch and the two parallel lines to the lesion was rational to determine the feasibility of manubriotomy. The transmanubrial approach for CTJ lesions can achieve favorable clinical outcomes by providing direct decompression of lesion and effective reconstruction.

• Journal of Preventive Medicine and Public Health
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• v.50 no.4
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• pp.228-239
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• 2017

Objectives: This study aimed to examine the association between preschool education experiences and adulthood self-rated health using representative data from a national population-based survey. Methods: Data from the Korean Labor and Income Panel Study in 2006 and 2012 were used. A total of 2391 men and women 21-41 years of age were analyzed. Log-binomial regression analyses were conducted to examine the associations between preschool education experience and self-rated health in adulthood. Parental socioeconomic position (SEP) indicators were considered as confounders of the association between preschool education experience and adulthood subjective health, while current SEP indicators were analyzed as mediators. Age-adjusted prevalence ratios (PRs) and the associated 95% confidence intervals (CIs) were estimated. Results: Compared with men without any experience of preschool education, those with both kindergarten and other preschool education experiences showed a lower prevalence of self-rated poor health (PR, 0.65; 95% CI, 0.47 to 0.89). In women, however, such an association was not evident. The relationship of preschool education experiences with self-rated poor health in adulthood among men was confounded by parental SEP indicators and was also mediated by current SEP indicators. After adjustment for parental and current SEP indicators, the magnitude of the associations between preschool education experiences and adulthood subjective health was attenuated in men. Conclusions: Preschool education experience was associated with adulthood self-rated health in men. However, this association was explained by parental and current SEP indicators. Further investigations employing a larger sample size and objective health outcomes are warranted in the future.

• Anxiety and mood
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• v.2 no.1
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• pp.22-27
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• 2006

Objectives : There is a paucity of data on the long-term course of obsessive-compulsive disorder (OCD) and chronological relationship between OC symptoms and their related symptoms such as anxiety and depression. The purpose of this study was to investigate the longitudinal course of OC symptoms as well as anxiety and depression which are believed to be associated with OC symptoms. Methods : Data for 155 patients with OCD who completed general evaluation for OCD were used. Forty four were excluded to minimize the effect of the different age of onset on the clinical course. One hundred eleven patients finally participated in the analysis. Cross-sectional correlations between each symptom as well as between such symptoms and the duration of illness were analyzed. Further correlation analysis was done within two groups that were divided by 7 years of the duration of illness. Results : There were significant correlations not only between the severity of OC symptoms and anxiety but also between anxiety and depressive symptom, regardless of the duration of illness. These correlations between such symptoms were also found within patients with the duration of illness below 7 years, whereas these were not within the group with the duration of illness above 8 years. Conclusion : Patients with OCD in this study shows the moderate to severe level of OC symptoms irrespective of the duration of illness. Our finding also suggests that the OC symptoms, especially obsessions are closely related to anxiety and depressive symptoms and these relationships might be pronounced in relatively early phase of the OCD after onset.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.8
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• pp.200-209
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• 2017

This study examined the mediating effect of depression on the relationship between over-control parenting styles and mobile phone dependency among children. The 5th-year longitudinal data from the Korean Children & Youth Panel Survey (KCYPS) were collected from 4th grade elementary school students. The data were analyzed by the structural equation modeling and bootstrapping. The results of this study were as follows. First, there is a positive path from over-control parenting styles to depression, from depression to mobile phone dependency, and from over-control parenting styles to mobile phone dependency. Second, depression had a mediating effect on the association between over-control parenting styles and mobile phone dependency. Based on these results, more study of elementary school students' reliance on cell phones is needed.

• Journal of Korean Neurosurgical Society
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• v.38 no.2
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• pp.102-106
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• 2005

Objective : The purposes of this study are to evaluate the efficacy of en bloc open-door laminoplasty and to investigate the validity of various factors as prognotic indicators in patients with multisegmental spondylotic myelopathy and ossification of posterior longitudinal ligament[OPLL]. Methods : The authors reviewed 43 cases in whom laminoplasty were performed for cervical myelopathy between January 2000 and December 2002. Clinical symptoms and results were evaluated using the Japanese Orthopaedic Association[JOA] scale. The recovery rate was calculated and then assessed for prognostic factors such as preoperative JOA scores, ages, history of previous trauma, duration of symptoms and signal change in cord on T2-weighted magnetic resonance Image. Results : In cervical stenosis, canal widening of antero-posterior diameter and dimension after laminoplasty is 4.16mm, $87.43mm^2$ and in OPLL is 6.20mm, $117.61mm^2$. In all cases there wasn't neurologic deterioration, mild postoperative complications developed in seven cases. Four patient had a limitation of range of neck motion and the other one showed kyphotic change and another two showed C5 radiculopathy. The recovery rate of JOA score in cervical stenosis and OPLL was 62% and 68% respectively. Duration of symptoms, the severity[preoperative JOA score], and signal change in cord on T2-weighted magnetic resonance image had close relationship to the clinical outcomes. Conclusion : Unilateral en bloc laminoplasty is simultaneous expansile and decompressive method. And preoperative JOA score, symptom duration and high signal intensity on T2-weighted magnetic resonance image can be used to predict prognosis.

• Hwankyungkyoyuk
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• v.18 no.2 s.27
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• pp.31-43
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• 2005

In this study, after establishing assessment framework and reviewing the conceptual evolution and component of EL(Environmental Literacy) through literature review, through middle school students as population, the level of EL and relationship of its related variables were examined. The investigation was consisted of second and third grades of urban and rural middle schools in Choongbook. The used measurement methods were objective evaluation and Likert-type scale. The questionnaire instrument variables were consisted of 80 items on environmental literacy variables and six items on student gender, area of residence, environmental lesson, degree of environmental concern, environmental information, environmental activity as background variables. The major findings of this study were as follows: 1. Although the broad and obscure concept of EL has been evolved until 1992, it has been developed more systematic and precise after 1992. But there is not still an agreed concept. 2. The subordinate components of EL were consisted of cognitive, affective, and behavioral aspects. Both ecological knowledge(KEOC) and environmental skill(SKILL) were determined to serve as two powerful predictors of EL. 3. The level of EL of middle school student was showed statistically significant difference to some variables by student gender, residential area, environmental lesson, environmental concern, environmental information, and environmental activity variables. And the most influential variables of EL in middle school student were environmental skill(SKILL), and locus of control (LOC). Based on the findings of this study, the following suggestions are drawn: It should be established a precise concept on EL as the ultimate aim of environmental education both interdisciplinary cooperation and experts of environmental education and also performed further longitudinal study which assessed multidimensional variables which are able to exactly measure the EL of middle school student.