• Journal of the Korea institute for structural maintenance and inspection
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• v.27 no.6
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• pp.152-161
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• 2023

In general, large-capacity hydrogen storage vessels, typically in the form of vertical cylindrical vessels, are constructed using steel materials. These vessels are anchored to foundation slabs that are specially designed to suit the environmental conditions. This anchoring method involves pre-installed anchors on top of the concrete foundation slab. However, it's important to note that such a design can result in concentrated stresses at the anchoring points when external forces, such as seismic events, are at play. This may lead to potential structural damage due to anchor and concrete damage. For this reason, in this study, it selected an vertical hydrogen storage vessel based on site observations and created a 3D finite element model. Artificial seismic motions made following the procedures specified in ICC-ES AC 156, as well as domestic recorded earthquakes with a magnitude greater than 5.0, were applied to analyze the structural behavior and performance of the target structures. Conducting experiments on a structure built to actual scale would be ideal, but due to practical constraints, it proved challenging to execute. Therefore, it opted for an analytical approach to assess the safety of the target structure. Regarding the structural response characteristics, the acceleration induced by seismic motion was observed to amplify by approximately ten times compared to the input seismic motions. Additionally, there was a tendency for a decrease in amplification as the response acceleration was transmitted to the point where the centre of gravity is located. For the vulnerable components, specifically the sub-system (support columns and anchorages), the stress levels were found to satisfy the allowable stress criteria. However, the concrete's tensile strength exhibited only about a 5% margin of safety compared to the allowable stress. This indicates the need for mitigation strategies in addressing these concerns. Based on the research findings presented in this paper, it is anticipated that predictable load information for the design of storage vessels required for future shaking table tests will be provided.

• Korean Journal of Occupational Health Nursing
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• v.7 no.1
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• pp.5-19
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• 1998

This descriptive-correlational study was conducted to identify the major factors affecting health promoting behaviors. 344 workers who employed in four different manutacturing plants in Taegu and Kyungbuk area were selected by convenience sampling method. Data were collected from April let to April 18th, 1998 by ready structured questionaires. The purpose of this study was to offer the basic data for health promotion theory development and health promotion strategy planning. This study was based on Pender's Health Promotion Model and examined three variables health promoting behavior, self-concept and perceived importance of health. The Life Style and Health Habit Assessment scale(LHHA) developed by Pender(1982).The Self-concept scale developed by Choi(1972) and the Health Value scale developed by Wallston, Maides and Wallston(1980) were used for this study. Data was analyzed by percentage, mean. t-test. ANOVA, Pearson Correlation Coefficient, and Stepwise Multiple Regression. The major findings of this study are as follows ; 1. The average level of health promoting behavior practice was 63.2% and possible range was from 62 to 248 point. The mean score of respondent's positive self-concept was 75.8. 81.4% of respondents put a high priority on the importance of health. 2. There was a significant difference between the practice level in the category of general self care and less amount of working hours per day(P=0.000), less amount of working hours per week(P=0.000). There was a significant difference between the practice level in the category of nutrition and age(0.002), marital status(0.000), working hour per day(0.008), working hours per week(0.001), There was a significant difference between the practice level in the category of nutriton and sex(0.000), age(0.000), marital status(0.025), education level(0.000), working hours per day(0.002), working hours per week(0.006). There was a significant difference between the practice level in the category of sleep and rest and age(0.003), marital status(0.002), working hours per day(0.001), working hours per week(0.001). There was a significant difference between the practice level in the category of stress management and working hours per day(0.001), working hours per week(0.002). There was a significant difference between the practice level in the category of self-actualization and working hours per day(0.050). 3. General characteristics influencing the respodent's self-concept were level(P=0.009) and worksite(P=0.001). 4. The results of the hypothesis tests are as follows The first hypothesis, that "The respondent who have more positive self-concept will have higher scores in the practice of health promoting behavior." was supported(r=0.2973, P=0.0001). The second hypothesis that "The respondent who have higher perception level on importance of health will have higher scores in the practice health promoting behavior." was rejected(r=- 0665, P=0.2225). 5. The most important factor that affects health promoting behavior practice was working hours per week(6.0%). The combination of working hours per week, age, education level accounted for 10.0% of the variance in health promoting behavior. In conclusion, the results of this study on industrial workers supported Pender's health promotion model in partial and showed the relatedness between self concept and the practice of health promoting behavior. Further research is required to find factors influencing health promoting behaviors of industrial workers.

• Journal of the Korean GEO-environmental Society
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• v.19 no.4
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• pp.5-16
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• 2018

In the current study, the engineering behaviour of prebored and precast steel pipe piles was examined from a series of full-scale field measurements by conducting static pile load tests, dynamic pile load tests (EOID and restrike tests) and Class-A and Class-C1 type numerical analysis. The study includes the pile load - settlement relations, allowable pile capacity and shear stress transfer mechanism. Compared to the allowable pile capacity obtained from the static pile load tests, the dynamic pile load tests and the numerical simulation showed surprisingly large variations. Overall among these the restrike tests displayed the best results, however the reliability of the predictions from the numerical analysis was lower than those estimated from the dynamic pile load tests. The allowable pile capacity obtained from the EOID tests and the restrike tests indicated 20.0%-181.0% (avg: 69.3%) and 48.2%-181.1% (avg: 92.1%) of the corresponding measured values from the static pile loading tests, respectively. Furthermore, the computed results from the Class-A type analysis showed the largest scatters (37.1%-210.5%, avg: 121.2%). In the EOID tests, a majority of the external load were carried by the end bearing pile capacity, however, similar skin friction and end bearing capacity in magnitude were mobilised in the restrike tests. The measured end bearing pile capacity from the restrike tests were smaller than was measured from the EOID tests. The present study has revealed that if the impact energy is not sufficient in a restrike test, the end bearing pile capacity most likely will be underestimated. The shear stresses computed from the numerical analysis deviated substantially from the measured pile force distributions. It can be concluded that the engineering behaviour of the pile is heavily affected if a slime layer exists near the pile tip, and that the smaller the stiffness of the slime and the thicker the slime, the greater the settlement of the pile.

• Korean Journal of Psychosomatic Medicine
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• v.26 no.2
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• pp.102-111
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• 2018

Objectives : This study aimed to investigate the relationship between personality characteristics of medical students at their admission and the level of depression, anxiety, and resilience at their third year. Methods : Self-reported questionnaires were conducted to the students at the beginning of the first year and the third year. When the students in their first year, they performed the personality assessment inventory, the Beck depression inventory, and the Beck anxiety inventory. When they were in the third year, the students answered the composite Scale of morningness and Conner-Davidson resilience scale-10 in addition to the BDI and BAI. Multiple linear regression analyses were performed to identify predictors of the level of depression, anxiety, and resilience. Results : Of the subscales of depression in the PAI, the physiological depression (${\beta}=-0.285$, p=0.049) associated with increase in the depression from the first to the third year. Among the anxiety-related disorder subscale in the PAI phobia (${\beta}=0.119$, p=0.022) and traumatic stress (${\beta}=0.375$, p=0.007) associated with the level of depression at third grade. Somatization (${\beta}=0.631$, p<0.001) in the PAI associated with the level of anxiety at third year. The anxiety (${\beta}=-0.531$, p<0.001) in the PAI was positive associated with the resilience at third grade. Conclusions : This study showed that certain personality characteristics at admission had significant relationships with the level of depression, anxiety, and resilience at the third grade medical students.

• Korean Journal of Culture and Social Issue
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• v.15 no.1
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• pp.187-205
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• 2009

Based on the Motivational States Theory(MOST), the present research expanded and complemented Kim(2007)'s proposal to add the Life Satisfaction Expectancy Scale(LSES) to Diener et al's Satisfaction With Life Scale(SWLS) to measure subjective well-being(SWB). In the present study, the Life Satisfaction Motivation Scale(LSMS) was introduced to measure the strength of motivation for life satisfaction in general. Two hundred and eighty six college students participated in this study. Factor analyses revealed a two-factor structure, with the factors corresponding to life satisfaction and life satisfaction expectancy. Measures of internal and temporal reliability show the LSMS to be a good complement for the measure of SWB(The LSMS showed high internal and test-retest reliability). It was found that the addition of the LSES provided a significant increment in predictive power over the SWLS in the prediction of various factors related with well-being prediction. Exceptionally, in the prediction of anger the LSMS had the most predictive power. There were some differences between male and female students in the correlations among life satisfaction, life satisfaction expectancy and life satisfaction motivation and well-being-related factors. The merits of including LSES in the measurement of subjective well-being and the limitations of this study are discussed.

• Journal of the Korea Concrete Institute
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• v.21 no.3
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• pp.327-335
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• 2009

In the seismic region, non-ductile structures often form soft story and exhibit brittle collapse. However, structure demolition and new structure construction strategies have serious problems, as construction waste, environmental pollution and popular complain. And these methods can be uneconomical. Therefore, to satisfy seismic performance, so many seismic retrofit methods have been investigated. There are some retrofit methods as infill walls, steel brace, continuous walls, buttress, wing walls, jacketing of column or beam. Among them, the infilled frames exhibit complex behavior as follows: flexible frames experiment large deflection and rotations at the joints, and infilled shear walls fail mainly in shear at relatively small displacements. Therefore, the combined action of the composite system differs significantly from that of the frame or wall alone. Purpose of research is evaluation on the seismic performance of infill walls, and improvement concept of this paper is use of SHCCs (strain-hardening cementitious composites) to absorb damage energy effectively. The experimental investigation consisted of cyclic loading tests on 1/3-scale models of infill walls. The experimental results, as expected, show that the multiple crack pattern, strength, and energy dissipation capacity are superior for SHCC infill wall due to bridging of fibers and stress redistribution in cement matrix.

• Journal of Physiology & Pathology in Korean Medicine
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• v.16 no.1
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• pp.172-180
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• 2002

Polychlorinated biphenyls(PCBs) are large scale industrial chemicals which are using in diverse applications. The goal of this study was to determine if exposure to 2,2',5,5'-tetrachlorobiphenyl (PCB 52) leads to an increase in the production of active oxidants, and subsequently promotes apoptosis of neuronal SK-N-MC cells. Reactive oxygen species (ROS) formation was examined in SK-N-MC cells after treatment of PCB 52 by concentrations and incubation times, respectively. It showed that the rate of ROS production in the cells was increased in a does-dependent manner to 45 min, followed by a return towards control levels after 120 min treatment. We also examined the association of PCB-induced apoptosis with the modulation of biomakers of oxidative damage to lipids (malondialdehyde [MDA]) in SK-N-MC cells. Increased MDA was observed in a dose-dependent manner in groups treated with 10, 15, and 20 figJ me of PCB 52 for 24 h. After treatment of PCB 52, the cells did not show any significant change in the rate of Cu/Zn-superoxide dismutase (Cu/Zn-SOD) activity. Whereas, the cells had a two-fold greater rate of change in catalase activity at 20 ㎍/㎖ of PCB 52 for 24 h when compared to control group. Korean Ginseng is one of the most important crude drugs which has been used as a traditional Oriental medicine. We next investigated protective effect of extracts of ginseng on cytotoxicity induced by PCB 52 in SK-N-MC cells. Pretreatment of SK-N-MC cells with 25-200 μg/ml of ginseng were reduced cell death in a dose-dependent manner in PCB 52-treated cells. To examine the sensitivity of beta-catenin to ginseng, the protective effect of a range of ginseng concentrations was examined in SK-N-MC cells treated with PCB 52. The result demonstrated that ginseng efficiently blocked PCB 52 inducible beta-catenin proteolysis in a concentration dependent manner. The ROS formation was also measured in the presences of extract of ginseng and superoxide dismutase (inhibitor of oxygen free radical production). The both SOD (400 U/ml) and ginseng (200 μg/ml) significantly inhibited RDS generation in PCB 52-treated group.

• Safety and Health at Work
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• v.4 no.1
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• pp.27-36
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• 2013

Objectives: Mental health has been shown to be linked with certain underlying physiological mechanisms. The objective of this cross sectional study was to investigate the relationship between depressive symptoms and brachial artery reactivity (BAR) in an understudied population: police officers. Methods: Participants were 351 police officers who were clinically examined in the Buffalo Cardio-Metabolic Police Stress (BCOPS) study. BAR was performed using standard B-Mode ultrasound procedures. Depressive symptoms were measured using the Center for Epidemiological Studies Depression (CES-D) scale. Mean values of the difference between the baseline and maximum diameters of the brachial artery were determined across three categories of CES-D score using the analysis of variance and the analysis of covariance. p-values for linear trends were obtained from linear regression models. Results: The mean age (${\pm}$ standard deviation) of all officers was $40.9{\pm}7.2$ years. Women had a slightly higher mean CES-D score than men ($8.9{\pm}8.9$ vs. $7.4{\pm}6.4$) and a slightly higher percentage increase of BAR than men (6.90 vs. 5.26%). Smoking status significantly modified the associations between depressive symptoms and BAR. Among current smokers, mean absolute values of BAR significantly decreased as depressive symptoms increased after adjustment for age, gender, race/ethnicity, hypertension, and diabetes; the multivariate-adjusted p-values were 0.033 (absolute) and 0.040 (%). Associations between depressive symptoms and BAR were not statistically significant among former smokers or never smokers. Conclusion: Depressive symptoms were inversely associated with BAR among police officers who were current smokers and together may be considered a risk factor for cardiovascular disease among police officers. Further prospective research is warranted.

• Journal of the Korean GEO-environmental Society
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• v.13 no.2
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• pp.95-102
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• 2012

In this study, practical verifications for an advanced C.I.P(Cast in Place Pile) construction method were carried out. The structural characteristics of the method is to attach an angular joint in the steel-casing. This joint plays an important role in boring vertically, connected pile to pile, and protects the permeation of the ground water. For verifications, experimental research and numerical analysis were performed. In the experimental research, two model-tests were set up with the real scale steel-casing. One is to examine the leakage in the joint of piles and the other is to compare earth pressures in the front and the joint, respectively. In addition, 3 point bending test and compressive loading test were carried out and numerical analysis was performed to simulate the loading test. As a result of model-tests, the leakage in the pile joints was not shown up to 300 KPa of water pressure and stress concentration in the joint is out of the question. From the results of bending and compressive test, it was found that the new advanced C.I.P method is more convenient and superior than the conventional method.

• Journal of the Korea institute for structural maintenance and inspection
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• v.9 no.4
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• pp.119-126
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• 2005

The objective of this paper is to evaluate the flexural tensile strength of unreinforced concrete masonry wall to ensure the structural safety in out-of-plane behaviors under the wind or earthquake loads. Flexural tensile strength of unreinforced concrete masonry wall has been obtained from the full scale tests of total 327 specimens and the statistical analysis are performed for each of the cases. The flexural tensile strength derived from experiments is classified as 13 groups according to masorny units, mortar ingredients, and the direction of tensile stresses and the mean tensile strength and the variable coefficient are obtained for each case. The uniform and concentrated transverse loads have been applied over the face of the wall specimens. The ultimate mean flexural tensile strengths are distributed from 1,564 kPa to 363 kPa according to masonry units, mortar ingredients, and other factors. The allowable flexural tension stress criteria will be established based on the mean flexural tensile strengths in the future.