• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.24 no.4
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• pp.547-555
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• 2014

Objective: This study was conducted to investigate the association between subjective distress symptoms and argon welding among workers in Gyeongnam Province shipyard. Method: 31 argon and 29 non-argon welding workers were selected as study subjects in order to measure concentrations of personal dust, welding fumes and other hazardous materials such as ZnO, Pb, Cr, FeO, MnO, Cu, Ni, $TiO_2$, MgO, NO, $NO_2$, $O_3$, $O_2$, $CO_2$, CO and Ar. An interviewer-administered questionnaire survey was also performed on the same subjects. The items queried were as follows: age, height, weight, working duration, welding time, welding rod amounts used, drinking, smoking, and rate of subjective distress symptoms including headache and other symptoms such as fever, vomiting and nausea, metal fume fever, dizziness, tingling sensations, difficulty in breathing, memory loss, sleep disorders, emotional disturbance, hearing loss, hand tremors, visual impairment, neural abnormality, allergic reaction, runny nose and stuffiness, rhinitis, and suffocation. Statistical analysis was performed using SPSS software, version 18. Data are expressed as the mean ${\pm}SD$. An ${\chi}^2$-test and a normality test using a Shapiro wilk test were performed for the above variables. Logistic regression analysis was also conducted to identify the factors that affect the total score for subjective distress symptoms. Result: An association was shown between welding type (argon or non-argon welding) and the total score for subjective distress symptoms. Among the rate of complaining of subjective distress symptoms, vomiting and nausea, difficulty breathing, and allergic reactions were all significantly higher in the argon welding group. Only the concentration of dust and welding fumes was shown to be distributed normally after natural log transformation. According to logistic regression analysis, the correlations of working duration and welding type (argon or non-argon) between the total score of subjective distress symptoms were found to be statistically significant (p=0.041, p=0.049, respectively). Conclusion: Our results suggest that argon welding could cause subjective distress symptoms in shipyard workers.

• Journal of Korean society of Dental Hygiene
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• v.17 no.3
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• pp.465-478
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• 2017

Objectives: The purpose of this study was to investigate the relationship between the level of subjective stress recognition and oral symptom experiences including toothache, gum diseases, and oral soft tissue diseases in the Korean adolescents. Methods: The subjects were 68,043 adolescents recruited using a web-based survey, National Korean Youth Risk Behavior in 2015 by the Korean Center for Disease Control. For statistical analysis, SPSS 21.0 for Windows was used. Descriptive analysis and a Chi-square test were conducted to determine the factors associated with general characteristics, health behaviors, oral health behaviors, and level of subjective stress recognition. Finally, to investigate the relationship between the level of subjective stress recognition and oral symptom experiences, logistic regression analysis was performed. Results: Toothache related subjective stress recognition level was significantly higher in the moderate group with the score of 1.59 (95% CI; 1.49-1.68), and was greater in the high group with 2.38 (95% CI; 2.24-2.53) compared to the low group. Gum disease related subjective stress recognition level was significantly higher in the moderate group with 1.41 (95% CI; 1.32-1.51), and was greater in the high group with 1.99 (95% CI; 1.86-2.13). Oral soft tissue disease related subjective stress recognition level was significantly higher in the moderate group with 1.59 (95% CI; 1.45-1.74), and was greater in the high group with 2.55 (95% CI; 2.33-2.79). Bad breath related subjective stress recognition level was significantly higher in the moderate group with 1.48 (95% CI; 1.39-1.57), and was greater in the high group with 2.10 (95% CI; 1.97-2.25). Conclusions: Higher subjective stress recognition level was found to affect the oral symptoms experienced. Therefore, the stress management plan should be prepared through the cause identification of the main stress in the adolescents. Practical and systematic education is needed for oral health management in the schools.

• Journal of the Ergonomics Society of Korea
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• v.30 no.2
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• pp.297-302
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• 2011

Many WMSDs(work-related-musculoskeletal disorders) have been reported in diverse industries and have also attracted much attention in recent years. Neck-related MSD is generally known as one of common WMSDs, especially it happens to workers who are working at the automobile assembly plants and/or shipyards. The awkward posture is considered as a main cause of neck-related MSDs. A neck supporter was developed to prevent neck-related MSDs, and 10 males were recruited to evaluate the newly developed neck supporter by measuring subjective discomfort ratings of whole body, shoulder, neck and neck-muscle activities. Muscle activities from four neck muscle groups(left/right sternocleidomastoid and upper/middle trapezius) were measured while simulating an automobile assembly task. Results showed that the neck supporter help to significantly improve subjective discomfort for whole-body, shoulder as well as neck body parts. The analyses of muscular activities also showed that the activities of left/right sternocleidomastoid muscles were statistically decreased with the neck supporter in this study. The muscle activities of upper/middle trapezius in case of wearing the neck supporter were not significantly different with the muscle activities in case of no-wearing the neck supporter. Overall findings verified that the neck supporter might help to prevent neck-related MSDs based on the current study.

• Journal of Korean Physical Therapy Science
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• v.10 no.1
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• pp.102-108
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• 2003

The purpose of this study was to determine the changes of skin temperature and subjective fatigue of the thoracic vertebrae by the chiropractic adjustments. Stimulation of the sympathetic nervous system will cause the changes in the skin blood flow which can be detected by measuring the skin surface temperature. This study was to see whether chiropractic adjustments could affect the activity of the sympathetic nervous system as reflected by changes in skin temperature of the thoracic. Skin temperature and subjective fatigue on 16 subjects was measured before, within 10 sec, 10min, 20min and 30 min after a thoracic adjustment with Digital Infrared Thermal Imaging(DITI) and Visual Analogue Scale(VAS). The adjustments consisted of a straight posterior-to-anterior high-speed, low-amplitude thrust to the transverse process of T3-T10 using a reinforced hypothenar contact. The average temperature and fatigue changed when the spine was considered as an entire unit. These results illustrate that the blood flow through the soft tissue can be affected by specific adjustments to the spine. This study might be served as an useful baseline data for the changes of the circulation and fatigue after the chiropractic adjustments.

• Journal of dental hygiene science
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• v.17 no.3
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• pp.257-266
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• 2017

This study investigated factors affecting the subjective experience of oral symptoms among 2,285 elementary school students in the fourth and sixth grades using the Korean survey on the Health of Youth and Children in 2010. After conducting chi-square and Mann-Whitney U tests, we performed multiple logistic regression analysis to determine the factors affecting children's experience of oral symptoms. We found that the factors most frequently associated with the subjective experience of more oral symptoms were lower tooth brushing frequency, greater intake of foods that cause dental caries, higher stress levels, and lower levels of support from friends. In conclusion, determinants of children's oral health, such as children's oral health behaviors and psychological factors must be considered in a multifaceted approach to developing programs to promote oral health among children.

• Journal of the Ergonomics Society of Korea
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• v.31 no.3
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• pp.469-474
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• 2012

The aim of this study is to develop an ergonomic design of magic saw handle considering user experiences. Background: Frequent use of hand tool can cause musculoskeletal disorders by inadequate wrist posture, excessive strength, repetitiveness, friction and pressure, vibration, etc. A hand tool that is inappropriately designed has higher risk causing musculoskeletal disorders. Complaints for the design of magic saw handle has been raised by many users according to the increasing use of magic saw. Method: Hand tool has to be designed considering worker's characteristics and task condition to prevent worker's musculoskeletal disorders. For this, user experiences for magic saw handle were measured through questionnaire survey and observation. Results: An ergonomic design of magic saw handle considering user experiences was proposed and then its design suitability was evaluated in comparison with the existing handle design using EMG and subjective evaluation. Conclusion: The proposed handle design showed higher satisfaction and lower muscular fatigue. Application: The results of this study can be effectively used to develop a new magic saw.

• Journal of the Ergonomics Society of Korea
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• v.24 no.1
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• pp.19-26
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• 2005

Mobile internet access using such devices as PDAs and cellular phones becomes popular as mobile technologies grow. However, the characteristics of small screen devices such as small screen size and pen-based input cause many usability problems. In this study, a human factors experiment was conducted to identify the factors affecting the usability of information search on a PDA. Factors manipulated in the experiment included use of wheel equipment, scroll dimension, and screen orientation. Task completion time, error frequency, and subjective satisfaction level were measured. In addition, various users' behavioral patterns such as scanning routes and mainly used scrolling methods were analyzed. Scroll dimension has a significant effect on task completion time. Scroll equipment and screen orientation affect subjective satisfaction level. The results could be applied to designing information structure of web sites for mobile use by providing vertical scroll and using external scroll equipments.

• Journal of the Korea Safety Management & Science
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• v.5 no.3
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• pp.133-143
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• 2003

Even in the present situation where any general criterion on CRM dose not exist, utilization of CRM is expected to be actively continued, which will cause many problems. In this regard, evaluating CRM counts. As the result, projects are being suspended and budgets cut, plans for introducing CRM suspended or cancelled and many CRM software vendors and technical consulting firms are facing serious management crisis. Yet, this phenomenon can be regarded as an interim one. In fact, some cases that successfully introduced CRM show that CRM is migrating from small scale which is typical when introduced to larger scale through various tests. Therefore, this study tries to segment customer for the sloving the problem. And it make efficient customer management. Using this model, SN ratio of taguchi method for each of subjective factors as well as values of weights are used in this comprehensive method for customer. A example is presented to illustrate the model and to show a rank reversal when compared to a model that does not eliminate extreme values and eliminates the highest and lowest experts' values allocating the weights and the subjective factors.

• The Journal of the Convergence on Culture Technology
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• v.6 no.4
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• pp.259-266
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• 2020

This study is a descriptive research for understanding the health behaviors, job stress, and musculoskeletal subjective symptoms of university employees, and also for examining the influence factors having effects on the musculoskeletal subjective symptoms. Targeting total 158 university employees, the data was collected from July to August 2020. In the results of this study, the characteristics related to health behaviors showed the percentages like the rate of drinking(68.6%), rate of smokers(9.6%), rate of exercising three times or more a week(15.4%), and the rate of regular eating habit(64.7%). The mean score of job stress was 63.7. The musculoskeletal disease symptom group falling under the occupational musculoskeletal subjective symptom standard of NIOSH was 18.6%, and the musculoskeletal subjective symptom of shoulders showed the highest rate. Also, the 29.5% of research subjects responded that the cause for their musculoskeletal pain was work. As the factors having effects on the musculoskeletal subjective symptoms, the sex, age, career experience, and job stress had significant effects on the subjective symptom of shoulder part(p<.01) while the regular exercise had significant effects on the subjective symptom of waist(p<.05). The educational background and regular meals had significant effects on the subjective symptom of legs and knees(p<.05). Thus, in order to prevent the musculoskeletal diseases of university employees, it would be necessary to develop/apply the programs for the relief of job stress, regular exercise, and regular meals.

• Journal of the Korea Convergence Society
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• v.12 no.12
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• pp.453-465
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• 2021

This study was attempted to identify factors affecting depression by stress causes. Data from the 2018 Korea National Health and Nutrition Examination Survey were used, total subjects was 2,939. Data were analyzed by complex sample frequency, percentage, x2-test and regression by SPSS 25.0. As a result, in the economic problem group, gender, occupation, health-related quality of life, weight change, smoking, subjective health status and subjective body image were significant influencing factors for depression, and explanatory power was 28.7% (F = 8.23, p < .001). In the parent, child, and spouse problem group, age, health-related quality of life, weight change, and subjective health status were significant, explanatory power was 33.1% (F = 6.92, p <.001). In the self and family health problem group, gender, health-related quality of life, weight change, smoking, and subjective health status were significant, explanatory power was 29.6% (F = 5.74, p < .001). Through the results, the influencing factors that appear differently according to each stress cause can be used as basic data to establish an individualized intervention strategy.