• Coupled systems mechanics
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• v.13 no.4
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• pp.277-291
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• 2024

The objective of this work is to study the effects of the modification of material properties on the vibration of the FGM beam using an integral shear strain model. In the present theory, the rotational displacement is replaced by an integral term in the displacement fields. The use of a shear correction factor is not necessary because our model gives a parabolic description of shear stress through the thickness while satisfying the conditions of zero shear stresses on the bottom and top surfaces of the beam. The FGM beam is assumed that the beam is a mixture of metal and ceramic, and that its properties change depending on the power functions of the thickness of the beam such as: linear, quadratic, cubic and inverse quadratic. By applying Hamilton's principle, general formulas were obtained to obtain the frequencies of the FGM beam. The effects of changing compositional characteristics of materials presented by volume fraction of FGM beams with simply supported edges on free vibration and some mode shapes are investigated.

• Korean Journal of Psychosomatic Medicine
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• v.8 no.2
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• pp.201-211
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• 2000

Objectives : The purpose of this study was to determine the validity and reliablity of the Korean version of the Global Assessment of Recent Stress(GARS) Scale developed for assessing the severity of current perceived stressors, and then to use the scale in clinical practice. Methods : The questionnaire was completed by 215 healthy subjects. A comparison was made regarding the perception of stressors among 242 patients(71 with anxiety disorder, 73 with depressive disorder, 47 with somatoform disorder, and 51 with psychosomatic disorder) and 215 healthy subjects. Factor analysis was done using oblique rotation after maximum-likelihood factor analysis. Results : Factor analysis yielded 1 subscale. Reliability was computed by administering the GARS Scale to 69 healthy subjects during a 2-week interval. Test-retest reliability for 8 items and the total score was significantly high, ranging between 0.85-.95. Internal consistency was significant(Cronbach's a for 7 items : .86). Convergent validity was computed by correlating the 8 items and the total score with the total score of the stress response inventory(SRI), the perceived stress questionnaire(PSQ), and the somatization, anxiety, depression, hostility subscales and general indices of the symptom checklist-90-revised(SCL-90-R). The correlations were all at significant levels. Discriminant validity was computed by comparing the 8 item scores of the patient and control groups. Significant differences were found in area relevant to sickness or illness and the overill global area. The patients with anxiety disorder were significantly higher in area relevant to sickness or illness than the healthy group, whereas the patients with depressive disorder was significantly higher in the overall global score than healthy group. The depressive disorder group was the highest in overall global score of the GARS scale among 4 patient groups, and showed a significant higher scores in interpersonal relationship and overall global area than the psychosomatic disorder group. Conclusions : These results indicate that the Korean version of the GARS scale is highly reliable and valid, and that it can be utilized as an effective measure of perceived stressors for research in stress-related fields. It is suggested that depressive disorder patients are more likely to perceive recent stressors than psychosomatic disorder patients.

• Journal of dental hygiene science
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• v.9 no.1
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• pp.9-15
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• 2009

Aimed at office workers at their height of Temporomandibular joint disorder(TMD), organized self-filling questionnaires were distributed from January 7 to 26, 2008 to 216 workers in the fields of service, office work, and production in D metropolitan city, to get a proper recognition about prevention and treatment of TMD by observing how strongly occupational stress influence on them. The findings of the study were as follows: 1. For subjective symptoms of joint noise as TMD, occasional was 45.8% and often 12.0%, while for joint dislocation often was 12.0%. 41.2% said they feel pains while chewing, while 24.1% said they occasionally feel pains while not chewing. 2.8% said they often experience mouth-opening disorder. 2. For joint noise, answers were significantly different according to their ages, while 30's are at their height (P < 0.05). For joint dislocation, the shorter they worked the more they have it, so less than a year worker was 37.9%, while less than 3 years 31.0%, and less than 5 years 20.7%. For work type, daytime workers have more dislocation, 58.6%, than shift-workers 34.5% (P < 0.05, P < 0.01). For pains while chewing, the shorter they worked, the more they experienced, which is the same as mouth-opening disorder (P < 0.01). 3. Workers with mouth-opening disorder have much stress on occupational autonomy (P < 0.05) and workers with dislocation and pains while chewing have much stress on relation trouble (P < 0.05, P < 0.01). Workers with highly occupational insecurity has much trouble on dislocation and pains while chewing, while workers with dislocation have significantly much stress on unproper compensation (P < 0.05). 4. For who have joint dislocation, they have much stress on relation-trouble, occupational disorder, and un-proper compensation (P < 0.01, P < 0.05). Workers with pains while not chewing showed significant difference about occupational insecurity and relation troubles (P < 0.05, P < 0.01). Who have mouth-opening disorder showed significant difference about occupational autonomy (P < 0.05).

• Journal of Korean Academy of Nursing
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• v.24 no.1
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• pp.58-69
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• 1994

In order to see the development of Nursing related research activities in Korea over the last three decades, abstracts of almost all of the Master and Ph.D theses that appeared from 1961 up to August 1991 were collected. The number of theses was 2354, from which an index of key words has been constructed. Key words were defined as those terms in each thesis title that convey major objectives of the given thesis study and the important nursing concepts dealt with in the thesis. Although all the key words were picked from the thesis title only, full use was made of the abstracts in deciding the principal objectives and essential contents of the thesis studies and their important concepts as well. In total, 539 kinds of key words were identified from the 2354 titles, and the identified words were all found to be in the International Nursing Index. On an average each title has two key words. Which key words were most frequently used, how they have changed with time, what kind of concept is preferably dealt with by each graduate school, and the concepts to which a given key word is likely to be connected were examined. The results are summerized below : 1) For each decade the theses numbers were as follows : 54(2.3%) from the 60’s, 413(17.5%) from the 70’s, 1523(64.7%) from the 80’s, and 364(15.5%) from the 90’s. Master’s thesis contributed 96% (2252) of the papers and Ph. D’s theses filled the remaining 4%(102). 2) A total of 539 key words were used, averaging about 2 for each thesis. The most frequently used key words were ‘Nurse’, ‘Anxiety’, ‘Knowledge / Attitude /Practice’, ‘Stress /Stressor’, ‘Attitude’, ‘Job-Satisfaction’, ‘Mental Disorder’, ‘Operation’, ‘Elderly’, ‘Nursing Role’. 3) Each decades key words can be classified as : the 60’s : ‘Nursing Education’, ‘Pulmonary Tuberculosis’, ‘Mother-Child Health’, ‘Growth & Development’, ‘Public Facilities’, ‘Mental Disorder’ : the 70’s : ‘Nurse’, ‘Family Planning’, ‘Attitude’ / ‘Knowledge, Attitude / Practice’, ‘Curriculum in Nursing Education’, ‘Clinical Practice in Nursing’, ‘Analysis of the Work of the Nurse’, ‘Health Education of School’, : the 80’s : ‘Nurse’, ‘Anxiety’, ‘Stress /Stressor’, ‘Operation’, ‘Nursing Role’, ‘Job Satisfaction’ : the 90’s : ‘Nurse’, ‘Elderly’, ‘Family-Support’, ‘Stress /Stressor’, ‘Home Care’. Key word ‘Nurse’ appears continuously and most frequently through the years, which indicates that there has been active study of the characteristics of nurses and related fields. The concept ‘Anxiety’ has been studied steadly from the 80’s and it shows that interest in health and disease are increasing Which comes as a result of society changing to an industrial and informational community. 4) Looking into each graduate school’s study area key words ‘Anxiety’, ‘Nurse’, ‘Mental Disorder’, ‘Stress /Stressor’, ‘Operation’, ‘Attitude’, ‘Hemo-dialysis’, were studied in the regular graduate school : ‘Family Planning /Contraception’, ‘Knowledge / Attitude /Practice’, ‘Physical Health-State /Physical Health Examination’, ‘Nurse’, ‘Using Clinical Facilities’, ‘Health Education of School’, were studied in the Graduate School of Public Health’ ; ‘Nurse’, ‘Anxiety’, ‘Stress / Stressor’, ‘Job-Satisfaction’, ‘Clinical Practice Education’, ‘Nursing Education’, were studied in the Graduate School of Education : ‘Nurse’, ‘Job Satisfaction’, ‘Nursing Role’, ‘Administration - Employment /Employment Management’, ‘Leadership’, ‘Personnel Profile’, ‘Nursing Manpower / Changing Working Place’, were studied in the Graduate School of Public Administration. 5) The Connection between key words were : ‘Nurse Job Satisfaction’, ‘Stress / Stressor ⇔ Coping / Ajustment’, ‘Nurse ⇔ Nursing Role’, ‘Anxiety ⇔ Giving Information’, ‘Nurse ⇔ Stress / Stressor’, ‘Anxiety ⇔ Operation’, ‘Nurse ⇔ Burnout’, ‘Knowledge, Attitude, Practice ⇔ Family Planning’, ‘Nurse Administration ⇔ Employment’, ‘Anxiety Muscle ⇔ Relaxation Technic’, ‘Anxiety ⇔ Mental Disorder’. From the above it can be noted that many nursing concepts were handled in the thesis titles. But there were more than enough papers on the characteristics of the nurse. It is suggested that in depth research be made on ‘Nursing Accidents’, t-‘Ethics’, ‘Nurse - Patient Interactions’, ‘Spritual Care’, ‘Dying’, ‘Hospice’, ‘Resident Helper’ and that there should be in depth research relating to the physical and mental development of youth and in particular physical concepts like ‘Drug - Abuse’, ‘Child -Abuse and Teaching’.

• Journal of dental hygiene science
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• v.12 no.6
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• pp.682-688
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• 2012

This study investigates the stressors of dental hygienists and student hygienists during the bedside training by the medical center type. The survey is based on some dental hygienists who are working for dental college hospitals, general hospitals, dental hospitals and dental clinics in Seoul and Gyeonggi area which the Clinical Practice of dental hygienics students is under way in. Included are the students who are studying dental hygienics at Kyungbok University and have taken the bedside training in dental college hospitals, general hospitals, dental hospitals and dental clinics. A statistical analysis shows the following results using SPSS program. By medical center type, dental hygienists described the clinical practice of students as relatively satisfying. It also found that there is a positive correlation between stress zones, and they feel most stressed in the "Role and Activity" zone. Student hygienists felt relatively satisfied with the bedside training, and there is a positive correlation between stress zones except "Practice". It found students, who have taken the bedside training in all types of medical centers except dental clinics, felt most stressed in "Environment". It also found that students who have taken the bedside training in dental clinics felt most stressed in "Role and Activity". In conclusion, most of the dental hygienists are satisfied with students' clinical practice by pattern of hospital. Positive correlation was shown between stress factors. Behavior and attitude and ideal and value are high in stress in college dental hospitals, role and activity and treatment fields are high in stress in dental hospital, and interpersonal relationships are high in stress in dental clinics.

• Journal of Life Science
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• v.29 no.2
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• pp.215-222
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• 2019

Muscle dysfunction may arise from skeletal muscle atrophy caused by aging, injury, oxidative stress, and hereditary disease. Powdered heat-killed Enterococcus faecalis (EF-2001) has anti-allergy, anti-inflammatory, and anti-tumor effects. However, its antioxidant and anti-atrophy effects are poorly characterized. In this study, we examined the effects of EF-2001 on muscle atrophy. To determine the protective effect of EF-2001 on oxidative stress, C2C12 myoblasts were treated with $H_2O_2$ to induce oxidative stress. This induced cell damage, which was reduced by treatment with EF-2001. The mechanism of EF-2001's effect was examined in response to oxidative stress. Treatment with EF-2001 reversed the expression of HSP70 and SOD1 proteins. Also, mRNA levels of Atrogin-1/MAFbx and MuRF1 increased under oxidative stress conditions but decreased following EF-2001 treatment. To evaluate muscle volume, two and three dimensional models of the muscles were analyzed using micro-CT. As expected, muscle volume decreased after sciatic denervation and recovered after oral administration of EF-2001. Therefore, EF-2001 is a candidate for the treatment of muscular atrophy, and future discovery of the additional effects of EF-2001 may yield further applications as a functional food with useful activities in various fields.

• Journal of Korean Ophthalmic Optics Society
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• v.18 no.1
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• pp.1-10
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• 2013

Purpose: This study is conducted to evaluate the job stressors for opticians in Ulsan city. Methods: We investigated job stress of 180 opticians working in Ulsan. The results of this study from The Korean standard job stressors assessment tool developed by Korea occupational safety and health agency (KOSHA) was compared with Korean reference value. The questionnaire on the social, demographic characteristics of opticians was also used to find the factors affecting to job stressors by using multiple linear regression analysis. Results: Among the eight fields of stressors, the interpersonal conflict (the median value; 33.4, the measurements; men; 38.8, women; 41.5) and company culture (the median; 41.7, the measurements; men; 47.4, women; 49.3) were higher than the median value of the Korean workers. By multiple linear regression analysis, the significant factors to the interpersonal conflict were the duty, working hours, unmarried, average salary. In terms of the company culture, last school, rest day of month, job career, average salary and working hours were significantly associated to the score of company culture. Conclusions: Based on the results, important factor in the formation of a positive organizational culture through to improve treatment of opticians investigation and mutual horizontal communication systems in the workplace for the manage on interpersonal conflict and company culture.

• Journal of the Korean Society for Nondestructive Testing
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• v.22 no.4
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• pp.333-346
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• 2002

The continuous indentation techniques are one of the most effective methods to nondestructively estimate mechanical properties. There are many applications in various dimensions of materials from macro-scale, through micro-scale, even to nano-scale range. The macro-range technology of kgf-load level is now focused on the evaluation of tensile properties and residual stress of bulk materials, for example, used in conventional load-bearing structures and in-use pipelines. The technology and the apparatus were successfully developed by a domestic research group. The micro-range technology of gf-load level can be applied to investigate some property-gradient materials such as weldment. Because it has better spatial resolution than the macro-range technology. The nano-range technology (called nanoindentation technique) of mgf-load level is basically used to evaluate hardness and modulus of micro- and nano-materials. Moreover, many researches are going on to measure tensile properties and residual stress. The nanoindentation technology is easy to be applied to the various fields, such as semiconductor devices, multiphase materials, and biomaterials, though other methods are too difficult to be applied due to dimensional or environmental limitations. On the basis of these accomplishments, the international and the domestic standards are being established.

• Journal of Korean Tunnelling and Underground Space Association
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• v.4 no.3
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• pp.229-234
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• 2002

Nowadays, the blast method is mainly operated in the fields of the rock excavation accompanied by construction site in Korea. Blast method has many merits such as improvement of workability, reducement of operation period, and etc. However, blast operation also create much loss and troubles with the neighbours for the environmental pollutions such as the noise, blast vibration, fly rocks and dusts. Thus, the non-vibration and shallow vibration methods have been used but they have also another problems in the view of the economy and the efficiency in operation. In this study, we had made laboratory tests for the breaking of the various Rock types by White Light Thermal Stress. The tests shows that one unit consuming 500kilowatts of electricity, would go 90 feet a day in tunneling if the tunnel was 16 feet by 16 feet. Also, if a faster rate of tunneling could be handled, other white light units could be added.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.308-308
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• 2017

The low and unstable yield of soybean has been a major problem in Japan. Excess soil moisture conditions are one of the major factors to restrict soybean productivity. More than 80 % of soybean crops are cultivated in converted paddy fields which often have poor drainage. In central and eastern regions of Japan, the early vegetative growth of soybean tends to be restricted by the flooding damage because the early growth period is overlapped with the rainy season. Field observation shows that induced excess water stress in early vegetative stage reduces dry matter production by decreasing intercepted radiation by leaf and radiation use efficiency (RUE) (Bajgain et al., 2015). Therefore, it is necessary to evaluate the responses of soybean growth for excess water conditions to assess these effects on soybean productions. In this study, we aim to modify the soybean crop model (Sinclair et al., 2003) by adding the components of the restriction of leaf area development and RUE for adaptable to excess water conditions. This model was consist of five components, phenological model, leaf area development model, dry matter production model, plant nitrogen model and soil water balance model. The model structures and parameters were estimated from the data obtained from the field experiment in Tsukuba. The excess water effects on the leaf area development were modeled with consideration of decrease of blanch emergence and individual leaf expansion as a function of temperature and ground water level from pot experiments. The nitrogen fixation and nitrogen absorption from soil were assumed to be inhibited by excess water stress and the RUE was assumed to be decreasing according to the decline of leaf nitrogen concentration. The results of the modified model were better agreement with the field observations of the induced excess water stress in paddy field. By coupling the crop model and the ground water level model, it may be possible to assess the impact of excess water conditions for soybean production quantitatively.