• Journal of Korean Home Economics Education Association
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• v.32 no.4
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• pp.67-79
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• 2020

The purpose of the study were to analyze the patterns of adolescent suicide attempts, and to explore the effects of personal psychology (subjective depression, subjective stress), health status (BMI, subjective health perception), and subjective academic performance on the types of youth suicide attempts. For this research, data of 'The 15th Korea Youth Risk Behavior Survey' were analyzed employing a hierarchical logistic regression analysis. The findings are as follows. First, out of 1,731 youth suicide attempts 156 (9%) were impulsive and 1,575 (91%) were planned. Girls(67.3%) attempted suicide more than boys (32.5%), and middle school students (62%) attempted suicide more than high school students (38%). Second, the variables that significantly affect suicide attempt types were subjective depression, subjective stress, and subjective health perception, after controlling for gender, grade level, school type, and SES. The rate of planned suicide attempts was higher among those who experienced depression than among those who did not. In the case of subjective stress, adolescents who felt stressed were likely to commit planned suicide attempts. Those who attempted impulsive suicide showed 1.32 times higher subjective health perception scores than those who attempted planned suicide, indicating adolescents who perceived they were not healthy were more likely to attempt planned suicide. BMI and subjective academic performance did not have a significant effect on the types of youth suicide attempts. These findings suggested the necessity of systematic intervention in Home Economics classes or extra-curricular programs, to prevent potential youth suicide attempts.

• Journal of Life Science
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• v.32 no.2
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• pp.142-147
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• 2022

Oxysterols are known to be involved in the physiopathology of atherosclerosis. Since 7-ketocholesterol (7-KC) is found in large amounts in oxysterols and in atherosclerotic plaque, the study on how 7-KC may affect monocyte differentiation induced by phorbol myristate acetate (PMA) in the monocytic cell line, THP-1, is essential. 7-KC induced a dose-dependent reduction in cell proliferation without inducing cytotoxicity, and the substantial staining of Nile red demonstrates the increased absorption of intracellular lipids. Although 7-KC itself did not increase cell adhesion, it markedly decreased the adhesion of cells treated with PMA. Furthermore, by observing the effect of 7-KC on phagocytosis using fluorescent-labeled latex beads, 7-KC's ability to abolish phagocytosis in PMA-stimulated macrophages was illustrated. The effect of 7-KC on the expression of selected protein markers on the process of differentiation induced by PMA in THP-1 cells was also examined. 7-KC inhibited expression of ICAM-1, CD11a, SR-A1, and SR-B2 (CD36) in PMA-stimulated THP-1 cells. Conversely, 7-KC drastically increased the expression of SR-D1 (CD68)in PMA-stimulated THP-1 cells. In conclusion, these results suggest that 7-KC modulates monocyte differentiation and activation via the intracellular accumulation of lipid droplets.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.29 no.2
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• pp.111-118
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• 2023

In this study, the feasibility of laser patterning on the surface of food packaging polymer film was confirmed, and the surface patterning process conditions of femtosecond laser were established. In addition, it was proved that the surface properties of the film can be changed and controlled through the fabrication of various patterned films on the surface of food packaging films such as HDPE, PP, and PET. Various patterned surfaces, including large-scale circular patterns induced by a single femtosecond laser pulse, roughness patterns achieved by overlapping single pulses by 30%, straight line patterns, roughness patterns obtained by overlapping straight line patterns, and grid patterns formed by intersecting straight line patterns were fabricated. The characteristics of the patterned HDPE, PP, and PET films, based on the surface pattern structure and size, were analyzed using SEM, AFM, and contact angle measurements. Compared to the surface of each control film without femtosecond laser patterning, the contact angles of the surfaces of large-area circular patterning HDPE and PP films, large-area roughness patterning HDPE and PP films by overlapping 30% of single pulses, and large-area roughness patterning PET film by overlapping rectilinear patterning were in the range of 27.1-37.5 degree. This indicated that the HDPE, PP, and PET films became more hydrophilic after patterning. On the other hand, the HDPE film patterned with a large-scale grid pattern exhibited a contact angle of 120.4 degree, indicating that the HDPE film became more hydrophobic after patterning. Therefore, films that have been changed to hydrophilic surfaces through patterning can be used in anti-fouling applications where proteins, cells, viruses, and other food materials do not adhere or are easily detached. In addition, if a superhydrophobic surface of 150 degrees or more is fabricated through more precise lattice patterning in the future, it will be possible to use it for superhydrophobic surface applications such as self-cleaning.

• Journal of the Korean Society of Radiology
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• v.17 no.4
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• pp.581-587
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• 2023

In this study, we tried to provide basic data for radiation safety management by comparing and analyzing the exposure doses of radiation workers and frequent workers at C University Hospital in Incheon. From January 2021 to December 2022, surface dose and deep dose were analyzed for 30 radiation workers and 8 frequent workers who worked at C university hospital in Incheon. Radiation workers were targeted at radiation technicians and nurses working in the radiation oncology department and nuclear medicine department, and frequent visitors were targeted at frequent workers who manage and clean facilities in the same radiation management area. In the radiation worker group, 3.1 per 10,000 radiation technologist, 1.2 per 100,000 nurses, and 4.5 per 1,000,000 frequent workers showed the possibility of developing side effects on the lungs. The probability of radiation oncology was 1.1 per 10,000 for radiation technologist and 5.2 per 1,000,000 for nurses, and the probability of radiation technologist in nuclear medicine was 2.9 per 10,000 and for nurses was 7.1 per 1,000,000. It is hoped that this study can be used as basic data in future revisions on frequent workers, and it is considered that it will be used as basic data in the field of obstacles in relation to the stochastic effect of radiation in the future.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.33 no.2
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• pp.171-187
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• 2023

Objectives: Aircraft cabin cleaning work is characterized by being performed within a limited time in a narrow and enclosed space. The objective of this study was to evaluate the exposure levels to dust, ultra fine dust(PM2.5) and black carbon(BC) among aircraft cabin cleaners. Methods: Active personal air sampling for respirable dust(n=73) and BC(n=47) was conducted during quick transit cleaning(cabin general and vacuum-specific) and seat cover replacement and total dust and PM2.5 were area-air-sampled as well. Also, size distribution of particle was identified with the cleaning workers targeted. Dusts were collected with PVC filters using gravimetric analysis. The concentration of PM2.5 and the particle size distribution were measured with real-time direct reading portable equipment using light scattering analysis. The concentration of BC was measured by aethalometer(filter-based real-time light absorption analysis instrument). Results: The geometric mean of respirable dust was the highest at vacuum cleaning as 74.4 ㎍/m³, following by replacing seat covers as 49.3 ㎍/m³ and cabin general cleaning as 47.8 ㎍/m³ . The arithmetic mean of PM2.5 was 4.83 ~ 9.89 ㎍/m³ inside the cabin, and 28.5~44.5 ㎍/m³ outside the cabin(from bus and outdoor waiting space). From size distribution, PM_2.5/PM₁₀ ratio was 0.54 at quick transit cleaning and 0.41 at replacing seat covers. The average concentration of BC was 2~7 ㎍/m³, showing a high correlation with the PM2.5 concentration. Conclusions: The hazards concentration levels of aircraft cabin cleaners were very similar to those of roadside outdoor workers. As the main source of pollution is estimated to be diesel vehicles operating at airports, and it is necessary to replace older vehicles, strengthen pollutant emission control regulations, and introduce electric vehicles. In addition, it is necessary to provide as part of airport-inftastructure a stable standby waiting space for aircraft cabin cleaners and introduce a systematic safety and health management system for all workers in the aviation industry.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.6C
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• pp.407-419
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• 2006

Situations where support is provided solely in shaft resistance of drilled shafts are where the base of the drilled hole cannot be cleaned so that it is uncertain that any end bearing support will be developed. Alternatively, where sound bed rock underlies low strength overburden material, it may be possible to achieve the required support in end bearing on the rock only, and assume that no support is developed in the overburden. However, where the drilled shaft is drilled some depth into sound rock, a combination of side wall resistance and end bearing can be assumed. Both theoretical and field studies of the performance of rock socketed drilled shafts show that the major portion of applied load is usually carried in side wall resistance. Normal stress at the rock-concrete interface is induced by two mechanisms. First, application of a compressive load on the top of the pile results in elastic dilation of the concrete, and second, shear displacement at the rough surface of the drilled hole results in mechanical dilation of the interface. If the stiffness of the material surrounding the socket with respect to normal displacement is constant, then the normal stress will increase with increasing applied load, and there will be a corresponding increase in the shear strength. In this study, the numerical analyses are carried out to investigate the behavioral characteristics of side of rock socketed drilled shafts. The cause of non-linear head load-settlement relationship and failure mechanism at side are also investigated properly and the design charts are suggested and verified for the leading to greater efficiency and reliability in the pile design.

• 한국노년학
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• v.31 no.3
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• pp.527-538
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• 2011

The purpose of this investigation is to analyze the effect of employment and quality of employment of senior job training. The questionnaire administered to 576 senior job trainees(over 50 years old) and 28 training institute before and after job training to survey job training characteristics, training institute characteristics and trainee characteristics. The results were as follows : First, independence test(X2) revealed that occupational category, period of training, type of institution, training history, location, and trainee's education level had significant difference on employment. Second, The probability of employment was higher in new and well-equipped public institution than private or old public institution. Third, compared with the prior wage, the wage after training decreased. This result suggested that the unemployed senior can hardly be reemployed in prior level job. The result of analysis on the cases of increased wage after training revealed that the trainees who was women, had a little dependent family, a shorter unemployed period, and a higher prior wage showed higher wage than prior wage after training.

• Korean Journal of Poultry Science
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• v.50 no.4
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• pp.267-272
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• 2023

This study was conducted to investigate the effect of integrated pest management (IPM) with 3point 5score microscopic monitoring method for laying farms infected with poultry red mites. A total of 8 laying farms infected with poultry red mites were divided into two treatments: 1) integrated pest management with 3point 5score microscopic monitoring method and 2) normal pest management with 3point 5score microscopic monitoring method. The results revealed that there is no significant difference between the groups with respect to the score of poultry red mites not only regardless of disinfection for the laying farms but also from week 4 to week 20 (P>0.05). However, the farm with IPM had a lower (P<0.05) score than those with the normal pest management method on week 24. Based on the result of the present study, controlling the presence of poultry red mites using IPM, along with consistent monitoring and supplementation using the 3point 5score microscopic monitoring method, is deemed effective in reducing the ultimately targeted infection rate of poultry red mites.

• Journal of Christian Education in Korea
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• v.78
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• pp.191-212
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• 2024

Purpose of the study: The purpose of developing this youth mission education material is to enable youth to understand the fundamental truths and values of Christianity based on the Bible, comprehend mission work, and practice it in their lives. Research Content and Method: In this study, we examined the concept and necessity of mission education for youth, and presented cases of mission education. The development process of the the materials involved prototype development and conducting FGI, first and second rounds of materials development, expert review and proofreading, and revisions and enhancements to produce the final version. Conclusions and Suggestions: This paper presents the development of mission education materials structured in 12 lessons, specifically designed for youth engagement within churches and Christian alternative schools. These materials include editions for teachers, students, and instructional resources. The contents of mission education are designed from the perspective of Bible, history, culture, and strategy, and are organized into modules so that they can be flexibly utilized in any order in the Christian education field. Additionally, each lesson includes three mission activities to enhance student engagement and motivation. This youth mission education material can serve as a foundational resource for conducting mission education suitable for the next generation in local churches and Christian alternative schools and for continuing mission work.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.10
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• pp.656-663
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• 2012

After the construction of waterworks automatic meter reading with 15 mm diameter digital water mater with magnetoresistance sensor developed in this study at 96 households of apartment complexes located in Incheon-City B-Gu S-Dong, the feasibility of field application of waterworks automatic meter reading was evaluated. The field application of waterworks automatic meter reading was performed from July to December in 2011, and average reception rate was as low as 84.6% due to the instable wibro networks, the existence of communication blackout and temporary malfunction of router. After the extraction of 10 households with one to five residents out of 96 households by using stratified random sampling method and analysis of domestic water use, it was found that domestic water use was significant at August and showed a decreasing trend at September, followed by increase in domestic water use at November and decrease in domestic water use at December. This phenomenon should be attributed to weather factors (temperature, humidity, etc.), which significantly affected domestic water use. Similar trend in domestic water use in terms of weather factors was obtained in case of Liter per capita day of water use after the extraction of 30 households out of 96 households by using stratified random sampling method. After analysis of Liter per capita day for 96 households, single residents increases resulted in reduction of domestic water usage by about 14% of Liter per capita day. These results might be due to the fact that domestic water usage such as laundry, beverages, catering, cleaning, etc. should be required for even the household with one resident, whereas domestic water usage for those common utilization can be significantly saved for the household with more than one resident.