• Proceedings of the Korea Concrete Institute Conference
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• 2006.11a
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• pp.357-360
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• 2006

Under sustained load, the stress variation occurs due to creep and shrinkage of concrete on the sections of steel-concrete composite girders. In standard specification for highway bridge, the method of stress estimation considering time effects is based on the concept of Yassumi method. In this study, comparing the analysis results using the AEMM and Yassumii method long-term behaviors, the rationality of specified requirements is checked.

• Journal of the Korean Society of Safety
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• v.18 no.4
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• pp.44-50
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• 2003

Design method for involute bevel gears is developed. The developed gear design system can design the optimized gear that minimize the number of pinion teeth with face tooth. Method of optimization is MS(matrix search) which is developed from this study. Design variables are pressure angle 20., transmitted power, gear volume, gear ratio, allowable contact stress and allowable bending stress. etc. Gears design method developed this study can be applied to the plane, helicopter, printer, machine tools.

• Restorative Dentistry and Endodontics
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• v.21 no.1
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• pp.339-352
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• 1996

Many dentists have been taken an interest in restoration of severly damaged teeth after endodontic treatment and it is a true that there are lots of studies about it. In these days, although we have used Para-Post, pins, threaded steel post, cast gold post and core, and so on, as a method of restoration frequently, it has been in controversy with the effects of them on the teeth and surrounding periodontal tissue. In this study, we assume that the crown of the upper 1st premolar was severly damaged, and after the root canal therapy, two most common types of restoration were carried out ; 1) coronal-radicular amalgam restoration, 2) after setting up the Para-Post, restore with amalgam core and gold crown. After restoration, in order to present the concentration of stress at internal portion of the tooth and the surrounding periodontal tissue, we doveloped a 2-dimensional finite element model of labiopalatal section, then loaded forces from 2 long perpendicular to the lingual incline of buccal ridge an the middle point, parallel to the long direction axis of tooth at the fossa-were applied. The analyzed results were as follows : 1. Stress of the normal first premolar was concentrated on the most weakest anatomical structure, that is, cervical area, and no stress on the bifurcated area of the canal. 2. Crown restoration after root canal therapy causes large stress concentration on the bifurcated area of the canal. This stress concentration has larger value in case of lateral movement of mandible, and there are decrease in the stress concentration compared with natural tooth. 3. Coronal-radicular amalgam restoration method transports more stress to the tooth structure than restoration using Para-Post. 4. There are more stress concentration around Para-Post in the case of lateral movement, and we have more favo rable result when restored with Para-Post. 5. Generally, stress in the lateral movement is larger than stress in the perpendicular load.

• Journal of the Korean Society of School Health
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• v.20 no.1
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• pp.103-111
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• 2007

Purpose : The purpose of this study was to investigate the effects of stresses to female university students and their habits of dealing with stresses through drinking alcohol and smoking. Methods : Subjects, 313 students, were selected through convenience sampling method from the 2 four-year universities in Chonbuk and Chonnam province from May to June, 2005. Data were collected through the structured questionnaires that include general characteristics, Quantity Frequency methods, the number of cigarette per day, campus stress scale, and stress coping style scale, and they were analyzed by Cronbach' alpha, descriptive statistics, ANOVA and t-test by using SPSS/PC⁺ program. Results: In this study, 80% of subjects have drunk alcohol. The mean frequency of drinking alcohol per month was 4.68 times and the mean number of alcohol consumption amount per drinking 6.16 glasses. The rate of smoking was 13.7%, and the mean number smoking cigarette per day in the previous month was 12.4. The mean score of stress was 2.20. Among 8 sub-factors of stress, study related stress scored highest among the sub-factors. The mean score of coping styles was 2.50. Among 4 coping styles, hopeful thought was mostly used. Among stresses, the concern of one's future affected her drinking habits. Faculty relationship, academic problem, and value affected smoking habits. Hopeful thought comes out to affect smoking, while drinking, perceived health status, and practice time showed no relationship with coping style. Conclusion: Based on the results, developing a life stress counseling program and effective coping program for women's university students is imperative, especially for those of who show passive attitude toward stress and solve it emotionally instead of using problem-oriented methods. Also, it will be necessary to study further nursing intervention to curb university females' drinking alcohol and smoking.

• Journal of the Korea Society of Computer and Information
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• v.27 no.6
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• pp.109-116
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• 2022

Before examining stress and physiological variables (immunity, inflammation), this study conducted a pilot test to provide basic data by analyzing depression and anxiety symptoms by age group for stress coping and coping methods. As a non-face-to-face method, BDI and STAI by age group (20s to 70s) and face-to-face survey were conducted concurrently and as follow-up surveys. In 20s to 60s, according to the coping method, there was a significant decrease after stress relief, and in all age groups, anxiety decreased significantly after stress relief, and in the 50s, stress coping with exercise was the lowest after stress relief. Based on the results of this study, through basic research according to psychological variables, physiological variables according to actual stress coping methods were further verified, and subjects with high stress levels were treated with long-term exercise therapy for depression and anxiety symptoms by exercise therapy. It will be necessary to additionally verify the appropriate stress coping method for each age group and subject, such as the correlation between improvement and immunity and inflammatory response.

• Journal of Korean society of Dental Hygiene
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• v.11 no.5
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• pp.811-822
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• 2011

Objectives : The purpose of this study was to examine the relationship of the self-efficacy of dental hygiene students to their stressors and ways of stress-adaptation patterns. Methods : The subjects in this study were dental hygiene juniors in four selected colleges located in the metropolitan area. Results : 1. They got a mean of 3.22 in self-efficacy. They gave the highest mark(3.50) to an item 'I can attain it if I set a primary goal.' 2. They got a mean of 3.18 in stressors. Among the stressors, task assignments(3.74) were identified as the greatest stressor, followed by the curriculum(3.25), learning environments(3.16), prospects of employment (3.07) and test anxiety(2.95). 3. They got a mean of 2.02 in stress-adaptation method. They got 2.31 and 1.72 in long-term and short-term adaptation respectively, which showed that long-term stress adaptation method were more prevailing than short-term ones. 4. As a result of analyzing whether there would be any gaps in self-efficacy according to general characteristics, statistically significant gaps were found in that regard according to experience of preparing for college admission after leaving high school, academic standing, satisfaction with the department of dental hygiene and prospects of employment(p<.05). 5. As a result of checking the relationship of their self-efficacy to their stressors and ways of stress adaptation method, there were statistically significant differences in that aspect according to examinations and prospect of employment(p<0.05). As for ways of stress adaptation method, there were statistically significant differences in long-term adaptation method (p<0.05). Conclusions : As it's found that the level of the self-efficacy of the dental hygiene students was linked to the efficiency of their ways of stress adaptation method, the development and implementation of programs geared toward boosting the self-efficacy of dental hygiene students are required to teach them to successfully cope with various kinds of stress that they are likely to face after getting a job.

• International Journal of Naval Architecture and Ocean Engineering
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• v.13 no.1
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• pp.379-395
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• 2021

For the complicated structural details in ships and offshore structures, the traditional hotspot stress approaches are known to be sensitive to the element variables of element topologies, sizes, and integration schemes. This motivated to develop a new approach for predicting reasonable hotspot stresses, which is less sensitive to the element variables and easy to be implemented the real marine structures. The three-point bending tests were conducted for the longitudinal attachments with the round and rectangular weld toes. The tests were reproduced in the numerical simulations using the solid and shell element models, and the simulation technique was validated by comparing the experimental stresses with the simulated ones. This paper considered three hotspot stress approaches: the ESM method based on surface stress extrapolation, the Dong's method based on nodal forces along a weld toe, and the proposed method based on nodal forces perpendicular to an imaginary vertical plane at a weld toe. In order to study the element sensitivities of each method, 16 solid element models and 8 shell element models were generated under the bending and tension loads, respectively. The element sensitivity was analyzed in terms of Stress Concentration Factors (SCFs) in viewpoints of two statistical quantities of mean and bias with respect to the reference SCFs. The average SCFs predicted by the proposed method were remarkably in good agreement with the reference SCFs based on the experiments and the ship rules. Negligibly small Coefficients of Variation (CVs) of the SCFs, which is measure of statistical bias, were drawn by the proposed method.

• Journal of Korean Academy of Nursing
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• v.27 no.2
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• pp.289-302
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• 1997

The main purpose of this study was to identify the effects of integrated stress management program on the stress symptoms of psychophysiological patients. especially patients with peptic ulcer. The study employed a quasi-experimental design using two different experimental groups. The samples in the integrated stress management program participated in autogenic training with biofeedback. discussions on effective coping method. cognitive. behavioral, and emotional management. They were also provided with an educational booklet on stress management and an tape on progressive muscie relaxation. Each session lasted one hour and the program consisted of seven sessions over four weeks. The other group was only given an tape on progressive muscle relaxation. The data were collected from May 20 to september 25, 1996. A total 47 patients from one university hospital located in Seoul participated, experiment group 1(integrated stress management training) had 23 subjects and experiment group 2(progressive muscle relaxation training) had 24 subjects. The effects of these programs were measured by the stress symptom scale developed by Kogan(1991) which was translated by Lee(1992) and the healing status of the ulcer evaluated by a physician. The data were analyzed using Chi-square test, t- test, ANOVA, repeated measure ANOVA. The result are as follows : 1. The integrated stress management group reported a significantly lower stress symptom score than the group given the progressive muscle relaxation only. 2. The integrated stress management group showed a significantly improved ulcer status as compared to the group given a progressive muscle relaxation only. In conclusion, it was found that the integrated stress management program was more effective in decreasing self-reported stress and physiological symptoms among patients with peptic ulcer as compared to the progressive muscle relaxation group. Based on this finding, the following suggestions can be made. 1. It is necessary to broaden the scope of nursing practice for psychophysiological patients so nurses can include stress management as part of patient care. 2. It is necessary to develop stress management program for other patients whose symptoms are known to be related to stress. 3. It is necessary to replicated this study with a larger sample in different settings.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.10 no.3
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• pp.345-353
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• 2003

Purpose: The purpose of this study was to explore the stress-coping process used by elderly people. Method: This study was based on the grounded theory methodology of Strauss & Corbin. The participants were 15 elders selected by theoretical sampling. Over a period of 3 months, in-depth interviews using audiotape recording were used to collect the data. The data were analyzed simultaneously by a constant comparative method in which new data were continuously coded in categories and properties according to Strauss and Corbin's methodology, Result: Stress in elderly people is caused by illness, family conflict, and loss of economic power. Stress occurred in connection with aging and limitation of social activity. The central incidents for stress were fear, alienation and anxiety. It was found that action/interactional strategies of stress-coping behavior were related to social support and mobility disorders. Action/interactional strategies to stress-coping in elderly people were dependent on medical treatment, mind control, participation of social activity, and renunciation of offensive behavior. Stress-coping in elderly people resulted in stability or instability in body and mind. Conclusion: It is suggested that the results of this study may contribute to the development stress-coping strategies for elderly people. There is need to develop social support systems and a positive environment to avoid negative coping strategies.

• Journal of Ocean Engineering and Technology
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• v.10 no.2
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• pp.106-119
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• 1996

The ceramic has various high mechanical properties such as heat, abrasion, corrosion resistance and high temperature strength compared with metal. It also has low speciffic weight, low thermal expansibillity, low thermal conductivity. However, it could not be used as structural material since it is brittle and difficult for the machining. Therefore, there have been many researches to attempt to join ceramic with metal which is full of ductillity in order to compensate the weakness of ceramic.The problem is that residual stress develops around the joint area while the ceramic/metal joint material is cooled from high joining temperature to room temperature due to remarkable difference of thermal expansion coefficients between ceramic and metal. Especially, the residual stress at both edges of the specimen reduces the strngth of joint to a large amount by forming a singular stress field. In this study, two dimensional finite element method is attempted for the thermal elastic analysis. The joint residual stress of ceramic/metal developed in the cooling process is investigated and the change of joint residual stress resulted from the repetitive heat cycle is also examined. In addition, it is attempted to clarify the joint stress distribution of the case of tensile load and of the case of superposition of residual stress and actual loading stress.