• Safety and Health at Work
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• v.9 no.2
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• pp.224-231
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• 2018

Background: Organizations are pursing complex and diverse aims to generate higher profits. Many workers experience high work intensity such as workload and work pressure in this organizational environment. Especially, psychological burden is a commonly used term in workplace of Republic of Korea. This study focused on defining the psychological burden from the perspective of occupational safety and health and tried to develop a scale for psychological burden. Methods: The 48 preliminary questionnaire items for psychological burden were prepared by a focus group interview with 16 workers through the Copenhagen Psychosocial Questionnaire II and Mindful Awareness Attention Scale. The preliminary items were surveyed with 572 workers, and exploratory factor analysis, confirmatory factor analysis, and correlation analysis were conducted for a new scale. Results: As a result of the exploratory factor analysis, five factors were extracted: organizational activity, human error, safety and health workload, work attitude, and negative self-management. These factors had significant correlations and reliability, and the stability of the model for validity was confirmed using confirmatory factor analysis. Conclusion: The developed scale for psychological burden can measure workers' psychological burden in relation to safety and health. Despite some limitations, this study has applicability in the workplace, given the relatively small-sized questionnaire.

• Journal of the Korea Safety Management & Science
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• v.19 no.3
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• pp.71-79
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• 2017

The purpose of this study was to identify the observable symptoms of musculoskeletal disease from electronic components manufacturing workers who involved in many repetitive tasks and to provide the basic data for the prevention and management. The survey was conducted on 721 people from 15 April, 2013 to 17 May, 2013 by self­recording type. The results of the study are as follows. First, symptom complaints based on different body parts are in following order, waist was 12.9%, shoulder was 10.5%, neck was 7.4%, hand/wrist/finger was 7.4%, leg/foot was 4.4%, arm/elbow was 2.8%, and 21.9% of the respondents showed symptoms in more than one body part. Sex, age, marital status, work experience, work intensity, and past accident experience were statistically significant. Second, in the job stress evaluation, all male and female workers were below the median of Korean workers in all of 8 categories. the higher the scores for lack of job autonomy, the higher the symptom complaints of musculoskeletal disease. In the case of patients complain observable symptoms of musculorskeletal disease, they should receive proper outpatient treatment, various programs such as stretching by body parts, setting up a desirable working posture, switching to cyclical work, should b developed as much as possible.

• Journal of Animal Environmental Science
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• v.11 no.3
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• pp.177-188
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• 2005

In this study, the thermal environmental factors in a layer f(arm such as dry bulb temperature, relative humidity, black globe temperature and illumination intensity were measured and analyzed to serve as basis for effective design and plan of poultry houses. The correlation analysis between the different factors was also done. Heat Index as measure of the thermal stress was also calculated and analyzed. A $1,000m^2$ laying house, 4 meters high with 52,000 layers in six-stage type cages was used in the measurement of the different environmental parameters. The results were as follows; 1. The temperature of the inside air and materials was directly related to the increase in aerial temperature based on the dry-bulb, black globe temperature reading. The correlation factor of the outside to inside air based on dry bulb setting was very significant at 0.927 The dry bulb temperature for inside temperature ranged from $19.9\~28.8^{\circ}C\;with\;SD+2.2^{\circ}C$ while that of the outside air was $16.2\~33.1^{\circ}C,\;SD+3.5^{\circ}C$. In addition, the temperature of the inside air was very stable. 2. The black globe temperature of the inside air ranged from $20.1\~28.8^{\circ}C,\;SD+2.3^{\circ}C$ while that of the outside air was $16.2\~47.5^{\circ}C,\;SD+6.0^{\circ}C$. 3. The relative humidity of the outside and inside air was $72.4\~100\;and\;50.2\~85.6\%$ with an average of $89.2\;and\;71.7\%$, respectively. 4. The illumination intensity in the laying house was less than 7 lux, with an average of $1.2\~2.5lux$ relative to height indicating that the laying house was well isolated from outside radiation. 5. The heat index of the inside air of the laying house had a high variation from $20.5^{\circ}C,\;SD+2.5^{\circ}C$ while that of the outside air was $13.1\~45.5^{\circ}C$, with an average of $21.6^{\circ}C,\;SD+6.3^{\circ}C$.

• Journal of the Korea Concrete Institute
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• v.16 no.3 s.81
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• pp.293-302
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• 2004

The transfer of prestress force in pretensioned prestressed concrete (PSC) members is of great concern because it affects directly the distribution of stress around the transfer zone. The design provision of current design code on the transfer length considers only the prestress intensity and the diameter of prestressing steels. However, other factors such as concrete compressive strength and concrete cover may affect greatly the transfer length. The purpose of the present paper is to explore the various factors that affect the transfer length in pretensioned PSC members. The bond stress-slip relation between prestressing steel and concrete was modeled first from experimental data and then this model was incorporated into the interface element. The interface element was used to perform the finite element analysis for pretensioned PSC members. The results indicate that the compressive strength and concrete cover are also very important parameters which affect the transfer length greatly. This means that the current design code, which considers only the effective prestress and diameter of prestressing steel, must be improved to take into account the other important variables of compressive strength and concrete cover. The present study allows more realistic analysis and design of pretensioned PSC members.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.5
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• pp.308-317
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• 2017

This study aims to determine the current status of experiences of suicidal attempts of Korean women and to evaluate related factors and provide basic sources for distinguishing high risk group. The primary data of the 6th period of national health and nutrition survey by KCDC, between 2013 and 2015,wereutilized in this study.Women were selected;general characteristics, psychological characteristics, and relevant information of daily activities were collected. The collected data wereanalyzed by applying the complex sample analysis method,using the SPSS 20.0 program with an application of weighted values. The resultsof this study revealed that 1% of the study population had previously attempted suicide; the suicidal attempts in subjects with prior psychological counselling within 1 year was 5.25 times higher than those without prior counselling.Subjectswith too much stress were 14.92 times more likely to attempt suicide than those without stress. Moreover, subjects with higher-intensity work in daily lives was 4.85 times more likely to attempt suicide than those with less intense work. In addition, subjects who sat for longer period of time was 3.76 times more likely to attempt suicide. All of these were statistically significant. Therefore, these subjects should be considered as high risk for suicidal attempt.In order to prevent female suicide, guidelines that considers the psychological health status and daily activities are required. In addition, it is necessary to approach this issuewith individualized prevention programs as part of social policies.

• Journal of radiological science and technology
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• v.32 no.4
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• pp.371-380
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• 2009

This study was executed to find out the intensity of turnover intention and its associated factors of radiologic technologists who worked for private clinic and university hospitals in Daejoen. Such variables as social and demographic characteristics, job-related features, job stress, job satisfaction, job performance, organizational commitment and turnover intention were investigated based on the survey of randomly sampled 400 radiologic technologists. The results are summarized as follows. 1. College graduates of private clinic workers were significantly higher than junior college graduates of them in the mean score for turnover intention. And low age groups, unmarried group, no religion group, low job career groups and low income groups of university hospital workers were significantly higher than high age groups, married group, religion group, high job career groups and high income groups of them respectively in the mean score for turnover intention. 2. Private clinic and university hospital workers' low and high groups in the variables of job demand, job control, supervisor support, job satisfaction, organizational commitment showed significant difference in the mean score for turnover intention. specially private clinic workers' low and high groups in the variables of coworker support, job performance showed significant difference in the mean score for turnover intention. 3. A hierarchial multiple regression analysis was conducted to catch the influence of related variables on turnover intention according to private clinic workers and university hospital workers. As a result of the analysis, the higher the degrees of education and job demand were and the lower the degree of job satisfaction was for private clinic workers, the higher the degree of turnover intention was. And the lower the degrees of age, job career, job satisfaction and organizational commitment were for university hospital workers, the higher the degree of turnover intention was. In conclusion, it was found that job demand and job satisfaction for private clinic workers and job satisfaction and organizational commitment for university hospital workers influenced on turnover intention.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2006.05a
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• pp.57-58
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• 2006

The effects of lowering ECAP temperature during ECAP process and Post-ECAP annealing on microstructure, texture and mechanical properties of the AZ31 alloys have been investigated in the present study. The as-extruded materials were ECAP processed to 2 passes at 553K prior to subsequent pressing up to 6 passes at 523K or 493K. When this method of lowering ECAP temperature during ECAP was used, the rods could be successfully deformed up to 6 passes without any surface cracking. Grain refinement during ECAP process at 553K might have helped the material to endure further straining at lower deformation temperatures probably by increasing the strain accommodation effect by grain boundary sliding, causing stress relaxation. Texture modification during ECAP has a great influence on the strength of Mg alloys because HCP metals have limited number of slip systems. As slip is most prone to take place on basal planes in Mg at room temperature, the rotation of high fraction of basal planes to the directions favorable for slip as in ECAP decreases the yield stress appreciably. The strength of AZ31 Mg alloys increases with decrease of grain size if the texture is constant though ECAP deformation history is different. A standard positive strength dependence on the grain size for Mg alloys with the similar texture (Fig. 1) supports that the softening of ECAPed Mg alloys (a negative slope) typically observed despite the significant grain refinement is due to the texture modification where the rotation of basal planes occurs towards the orientation for easier slip. It could be predicted that if the original fiber texture is restored after ECAP treatment yielding marked grain refinement, yield stress as high as 500 MPa will be obtained at the grain size of ${\sim}1{\mu}m$. Differential speed rolling (DSR) with a high speed ratio between the upper and lower rolls was applied to alter the microstructure and texture of the AZ31 sheets. Significant grain refinement took place during the rolling owing to introduction of large shear deformation. Grain size as small as $1.4{\mu}m$ could be obtained at 423K after DSR. There was a good correlation between the (0002) pole intensity and tensile elongation. This result indicates that tensile ductility improvement in the asymmetrically rolled AZ31 Mg alloys is closely related to the weakening of basal texture during DSR. Further basal texture weakening occurred during annealing after DSR. According to Hall-Petch relation shown in Fig. 1, the strength of the asymmetrically rolled AZ31 is lower than that of the symmetrically rolled one when compared at the same grain size. This result was attributed to weakening of fiber texture during DSR. The DSRed AZ31, however, shows higher strength than the ECAPed AZ31 where texture has been completely replaced by a new texture associated with high Schmid factors.

• Journal of the Korean Geographical Society
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• v.51 no.1
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• pp.143-166
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• 2016

This study aims to consider spiritual therapeutic landscapes thought the case of catholic sacred places in Korea. The catholic sacred places, which have been a series of persecution, are distributed in 300 all over the country and can be divided into a formational type, a selective type, and a participatory type. In the formational type, the catholic sculptures are scattered here and there; but it seems that there are limits somewhat to feel the emotional stability and the experience of caring by God. Because the formational type is deserted or is built up in unnoticeable urban areas. The religious factors, for example, museums, special pray, Station of the Cross, Rosary way, statues of the Virgin Mary, catholic sculptures, etc. in the selective type are placed in the corners of the catholic sacred places to provide the opportunity of holy experience to pilgrims. But the level and the intensity of healing depends on the matter as to how much pilgrims experience religious factors voluntarily. Lastly, the participatory type means the experience of various religious factors following scheduled programs. The experience is for the group of pilgrims, not a person; and the human relationship via the religious experience spiritualizes the network of interest towards other participants. Furthermore, the spiritualized open mind towards other people becomes the power that can arrive at the emotional stability, the relief of stress, and the in-depth and authentic healing. Ultimately, the spiritual healing through religious factors is to realize human finitude and dedicate one's own self to God; in addition, the spiritual therapeutic landscapes are the place that can carry out such a spiritual ritual without any restraint.

• Journal of Ecology and Environment
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• v.45 no.4
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• pp.277-286
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• 2021

Background: As trade increases, the influx of various alien species and their spread to new regions are prevalent and no longer a special problem. Anthropogenic activities and climate changes have made the distribution of alien species out of their native range common. As a result, alien species can be easily found anywhere, and they have nothing but only a few differences in intensity. The prevalent distribution of alien species adversely affects the ecosystem, and a strategic management plan must be established to control them effectively. To this end, hot spots and cold spots were analyzed according to the degree of distribution of invasive alien plants, and major environmental factors related to hot spots were found. We analyzed the 10,287 distribution points of 126 species of alien plants collected through the national survey of alien species by the hierarchical model of species communities (HMSC) framework. Results: The explanatory and fourfold cross-validation predictive power of the model were 0.91 and 0.75 as AUC values, respectively. The hot spots of invasive plants were found in the Seoul metropolitan area, Daegu metropolitan city, Chungcheongbuk-do Province, southwest shore, and Jeju island. Generally, the hot spots were found where the higher maximum temperature of summer, precipitation of winter, and road density are observed, but temperature seasonality, annual temperature range, precipitation of the summer, and distance to river and sea were negatively related to the hot spots. According to the model, the functional traits accounted for 55% of the variance explained by the environmental factors. The species with higher specific leaf areas were more found where temperature seasonality was low. Taller species preferred the bigger annual temperature range. The heavier seed mass was only preferred when the max temperature of summer exceeded 29 ℃. Conclusions: In this study, hot spots were places where 2.1 times more alien plants were distributed on average than non-hot spots (33.5 vs 15.7 species). The hot spots of invasive plants were expected to appear in less stressful climate conditions, such as low fluctuation of temperature and precipitation. Also, the disturbance by anthropogenic factors or water flow had positive influences on the hot spots. These results were consistent with the previous reports about the ruderal or competitive strategies of invasive plants instead of the stress-tolerant strategy. The functional traits are closely related to the ecological strategies of plants by shaping the response of species to various environmental filters, and our result confirmed this. Therefore, in order to effectively control alien plants, it is judged that the occurrence of disturbed sites in which alien plants can grow in large quantities is minimized, and the river management of waterfronts is required.

• Journal of the Korean Society of Propulsion Engineers
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• v.19 no.6
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• pp.26-32
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• 2015

In this study, it is evaluated for fracture toughness to analyze crack resistance properties of particulate reinforced composite propellant. Fracture toughness test using WST specimen is conducted by temperature conditions from $50^{\circ}C$ to $-60^{\circ}C$. Evaluation method for fracture toughness calculated using an equation suggested by ASTM E399 with linear elastic fracture mechanics. From these result, splitting loads and stress intensity factors of propellant increase according to decrease of test temperature. Also, the strain fields of specimen surface using digital image correlation increase as temperature decreased from $50^{\circ}C$ to $-40^{\circ}C$, but it sharply decreases at $-60^{\circ}C$ because of brittle behavior.