• The Journal of Engineering Geology
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• v.19 no.4
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• pp.433-439
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• 2009

The compressed packer device is designed to improve the underground contamination prevention facilities of ground water wells. As for the device, the installation is simple because of the safety lock device and the compression of the casing are simple the installation is simple. There is no leakage of ground water because the pressure resistance with $4.5\;kg/cm^2$ makes it equipped with the watertightness The single casing is installed and the reaming for grouting is possible with 300 mm excavation so that installation cost can be saved. Silicon rubber is used for the compressed packer so that the extension rate is 590%. In terms of environmental pollution, it is an environmental friendly product which does not contain harmful ingredients such as Pb, Cd, and phenol. below the standard or undetectable level Furthermore, the installation costs are 35 to 62% or lower than the conventional grouting construction method and are 87% or lower than the expansion packer construction method, the new environmental technology No.47 Also, the device is designed to meet the relevant regulations such as Rules on Preserving the Ground Water Quality, The Standard on Jeju Island Ground Water Development and Facility Installation and Management, and The Plan and Guideline on Operating and Managing the Small-Scale Tap Water Facilities of Ministry of Environment and Ministry of Food, Agriculture, Forestry and Fisheries.

• 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.

• Korean Journal of Microbiology
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• v.49 no.4
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• pp.424-428
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• 2013

To identify risk factors for Legionella contamination, water quality variables routinely measured in examination of natural and city waters were meta-analyzed for significance of correlation to Legionella incidences. For evaluation of abundance of Escherichia coli as a risk factor, which is currently used as an indicator of Legionella contamination in an official guideline in Korea, odds ratio (OR) of above-cutoff total coliform counts for Legionella presence/absence was used as the effect size in the meta-analysis. The OR was estimated as 1.05 (0.36-3.12, 95% CI), and the probability of having identical odds reached 0.92. Also, ORs from individual studies showed significant heterogeneity (P=0.008), which contributed to 63% of total variance of the ORs. In the case of heterotrophic plate count (HPC), the OR for Legionella presence/absence was 2.72 (2.04-3.63) with highly significant deviation from identical odds (P<0.0001). ORs from different studies were seemingly homogeneous ($Q_{df=8}$=12.7, P=0.12). Turbidity and concentrations of chlorine, iron ion and cupper ion were other routine variables that could be considered as risk factors. However, statistical measures from different studies were not uniform enough to develop an appropriate effect size while the number of studies reporting the variables was also small (3-5). In conclusion, HPC appeared to be appropriate as indicator of Legionella contamination, rather than fecal bacteria contamination. HPC may imply abundance of habitats (amoebas and biofilms) of Legionella in water. This result warrants further studies for standardizing protocols and cutoff values to infer Legionella risks from HPC.

• The Journal of the Korea Contents Association
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• v.20 no.11
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• pp.101-109
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• 2020

This study sought to find out the impact of conflicts in social welfare organizations on job performance and to find out the effects of controlling participatory decision-making in their relationships. To that end, a survey was conducted on workers at social welfare centers in Seoul, Gyeonggi Province and Chungcheong Province, and 360 copies were finally used for analysis and Correlation and hierarchical regression and statistical significance analysis of the adjustment effects were performed. As a result, conflicts within the organization, job performance, and participatory decision-making showed a negative correlation, and as participatory decision-making in the relationship between conflict within the organization and job performance showed a controlled effect, the impact of conflicts within the organization on job performance was reduced. These results suggest that participatory decision-making can alleviate conflicts within an organization and at the same time increase job performance. Based on this, the following suggestions were proposed: They include conflict management strategies in the guidelines for social welfare subjects, establish guidelines for conflict management, provide training for workers, engage workers in employee evaluation and compensation system development, and operate permanent organizations such as the Conflict Handling Committee after investigating conflicts within social welfare organizations.

• Journal of agricultural medicine and community health
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• v.35 no.4
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• pp.383-394
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• 2010

Objectives: This study aims to identify dietary factors related to metabolic syndrome in middle aged Korean men who were participants in the Fourth Korea National Health and Nutrition Examination Survey(KNHANES IV) in 2007. Methods: The study targeted 361 of the 709 men aged between 40 and 64 years for a final analysis; the other 348 surveys had incomplete data which did not allow for the determination of metabolic syndrome. The definition of metabolic syndrome was based on the National Cholesterol Education Program Adult Treatment Panel III(NCEP ATP III). Results: There were significant differences in the metabolic syndrome of middle-aged men according to age, smoking pack-years, and number of resturant meals per week. Dietary factors such as vitamins, riboflavin, natrium, carbohydrate, protein and lipid intakes were not significant. Conclusions: It was verified that metabolic syndrome in middle-aged men is related to age, smoking pack-years and number of resturant meals per week. Dietary factors were not significantly related. However, further detailed studies in this area are needed.

• Journal of the Korean Society of Earth Science Education
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• v.13 no.1
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• pp.121-133
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• 2020

This study proposes a lesson design framework to design a science and engineering integrated lesson in a meaningful and easy way based on engineering design, which is the core feature of STEM education. The science and engineering integrated lesson design framework is developed based on the analysis of domestic and foreign theoretical and practical research papers and expert discussion on science and engineering integrated education as well as the feedbacks from science teachers. The science and engineering integrated lesson design framework uses engineering design as the main pedagogical method. The framework includes the core elements of the engineering integrated lesson suggested in previous studies and the achievement level of each grade group suggested in NGSS and provides a way for teachers to easily introduce engineering design into science classes. In addition, the framework developed in this study complements the shortcomings of the complicated Korean STEAM education framework. It can also provide specific guidance to in-service teachers as well as pre-service teachers to easily understand and apply engineering design and problem solving processes to science and engineering integrated lessons.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.9
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• pp.157-166
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• 2017

This study was conducted to identify the level of diabetes self-care knowledge, confidence, behavior and quality of life in elderly people with diabetes. The participants were 205 elderly with diabetes who visited a citizen health center located in D city. Korea. The data were collected from April, 20th to August 31th, 2015, and were analyzed by the t-test and ANOVA. The results were as follows; 1) The mean scores for diabetes self-care knowledge, confidence, behavior, and quality of life were 6.99 (2.17), 71.27 (10.21), 62.78 (1.29) and 0.86, respectively. 2) There were significant differences in the self-care behavior according to the education level, duration of diabetes mellitus and subjective health, and the quality of life differeddepending on the level of subjective health(F=35.253, p=0.000). 3) Knowledge of diabetes diet was the lowest among the various aspects of diabetes self-care knowledge. Confidence for exercise was lowest, while confidence for medication and blood sugar check was highest. However, the participants exhibited good medication behavior, whereasthey did not carry out blood glucose checks in their self-care management behavior. The most uncomfortable aspect of the quality of life was found to be pain and discomfort. Based on the results of this study, it is necessary to develop guidelines and methods for dietary education reflecting the dietary habits of Koreans, and to investigatethe reasonsfor thelow performance of theblood glucose check. In addition, customized nursing interventionstaking into consideration the characteristics of elderly with diabetes need to be developed and verified.

• Journal of Energy Engineering
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• v.23 no.3
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• pp.186-190
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• 2014

Nuclear Power Plants require the control ability of chemical condition (pH) because pH control during transient accident such as LOCA makes an able the fission product removal capability to be maintained, stress corrosion cracking of stainless steel equipment to be prevented and the production of hydrogen by aluminum and zinc to be minimized. An NPP is designed to control the pH of containment spray and sump coolant using the spray additives 30% NaOH in the event of loss of coolant accident. In this paper, the pH of sump coolant of an NPP during LOCA was analyzed and the fission products removal constant and decontamination factor were calculated according to Standard Review Plan 6.5.2 related to spray chemical conditions of pH. The calculated pH value of recirculation mode using the computer code corresponds to 8.09~9.67, which meets the chemical environment regulation requirements. The fission product removal capability caused by containment spray system is performed to provide input to radiation analysis.

• Journal of the Korean Wood Science and Technology
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• v.44 no.5
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• pp.760-766
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• 2016

This study explored the effects of heating temperature and laminae thicknesses on the time required to heat the center of air-dried Paulownia tomentosa, Pinus sp., Abies sp., and Larix sp. laminae to $56^{\circ}C$, which is a minimum core temperature of wood packaging materials defined by ISPM 15 standard, and maintain for 30 minutes in dry heat treatment schedule. Heating times were different among wood species and were Pinus sp. ${\geq}$ Abies sp. > Paulownia tomentosa > Larix sp. in decreasing order. The differences in heating times of some species were significantly different statistically, but were not different enough in practical terms to warrant heating four species separately. Heating times decreased as heating temperature increased and followed approximately power-function relationship. Also, heating times increased linearly with increasing laminae thickness. These relationships make it possible to calculate intermediate heating times relative to experimentally observed heating times. The results of this study will serve as a guideline for heat sterilization of Chinese laminae species to meet heat treatment requirements for protection against invasive pests.

• Journal of the Korea Concrete Institute
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• v.16 no.4 s.82
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• pp.529-539
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• 2004

The corrosion of steel rebars has been the major cause of reinforced concrete deterioration. FRP(Fiber-reinforced polymer) rebar has emerged as one of the most promising and affordable solutions to the corrosion problems of steel reinforcement in structural concrete. However, FRP rebar is prone to deteriorate due to other degradation mechanisms than those for steel. The high alkalinity of concrete, for instance, is a possible degradation source. Therefore, the USA, Japan, Canada, UK. etc are using environmental reduction factor. Although difference design guidelines were drawn in many, including USA, Japan, Canada, UK etc, recommendations and coefficients that could take into account the long-term behavior of FRP reinforcement were not well defined. This study focuses on recommendation of environmental reduction factor of FRP rebar. Environment reduction factor were decided using durability test result. FRP rebars were subjected to twelve type of exposure conditions including alkaline solution, acid solution, salt solution and deionized water etc. The water absorption behavior was observed by means of simple gravimetric measurements and durability properties were investigated by performing tensile, compressive and short beam tests. Based on the experimental result, environmental reduction factor of hybrid FRP rebar(A), and (C) and CFRP rebar was decided as 0.85. Also, hybrid FRP rebar(B) and GFRP rebar were decided as 0.7 for the environmental reduction factor