• The Korean Journal of Emergency Medical Services
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• v.12 no.1
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• pp.53-67
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• 2008

Purpose : This study is descriptive correlation research to provide basic materials for developing program which can give practical assistance in preventing and managing obesity through more comprehensive approaches of influential factors on obesity found in existing literatures. Methods : Data were collected from the 4th, 5th and 6th graders at 2 elementary schools in Gwangju Metropolitan City and 4 elementary schools in Jeollanamdo province using questionnaire and students' physical examination results from June 15 to July 27, 2006 and data obtained from 1,866 students were used for analysis. Data collected were analyzed with technical statistics and correlation analysis using SPSS/PC(version 12.0). Results : 1. Obesity level of elementary school students was examined as follows; 33.2% had low weight, 44.3% normal, 10.8% overweight and 11.7% obese. 14.8% of boys and 8.6% of girls, 13.5% of the 4th graders, 12.1% of the 5th graders and 9.2% of the 6th graders, and 13.7% of urban students and 9.6% of rural students were obese. 2. According to general characteristics and obesity of the subjects, there were significant differences by sex(${\chi}^2=29.55$, p= .000), grade(${\chi}^2=12.84$, p= .046), region(${\chi}^2=41.96$, p= .000) and pocket money(${\chi}^2=33.43$, p= .001). 3. As genetic factors, all variables including sibling's obesity r= .128(p= .000), mother's obesity r= .098(p= .000) and father's obesity r= .081(p= .001) had influence on children's obesity. 4. Concerning environmental factors, there was positive correlation between eating habits r=- .052(p= .02) and school record r=- .048(p= .04) and there was negative correlation between internet using time r= .050(p= .03) and conflict with parents r= .048(p= .04). 5. Self-respect as psychological factor had negative correlation as r=- .048(p= .04). Conclusion : Consequently, the influential factors on obesity of elementary school students were as follows. Obesity was higher in boys than in girls, in urban areas than in rural areas, in lower grade than in higher grade, in children with obese siblings, obese father and mother, irregular and wrong eating habits, frequent internet uses, parents in conflict and lower school record and self-respect. Therefore, since it was found that these variables were more exact causes to increase children's obesity, development of various obesity mediation programs considering these variables at home, school and society is urgently required.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.2
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• pp.147-153
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• 2016

The lightning protection of information and communication facilities is very important factor to improve a reliability of the action of these equipment. Especially the transient potential rise of ground electrode being injected with the lightning current is to be a basic data of the dielectric strength for both power and communication facilities so that more accurate analysis should be required. The transient potential rise can be calculated from the ground impedance and the ground impedance is strongly dependent upon the shape of the ground electrode and the frequency-dependence of soil. The Debye's equation which is able to calculate the characteristics of dielectrics is used to analyze the frequency-dependent of soil. Also, the method to calculate the transient potential rise from the ground impedance is specified in this paper. In order to analyze the transient potential rise resulting from calculations with Debye's equation, TLM(transmission line method) and case of ${\rho}$(resistivity)-constant are simulated, respectively. The length of a horizontal ground electrode is 30 m and simulations were performed at 10, 100, $1000{\Omega}{\cdot}m$ with the standard lightning current waveform. In result, the transient potential rise of horizontal ground electrode calculating with Debye's equation is lower than it of other models.

• Journal of Korea Port Economic Association
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• v.25 no.2
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• pp.277-300
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• 2009

By using data envelopment analysis(DEA) this research measures the efficiency of Korea's seven middle-sized seaports and their Malmquist productivity from 1998 to 2007. Under the assumption of CRS(constant returns to scale) and VRS(variable returns to scale), seaports' ranking of efficiency are measured. Kunsan Port is confirmed as a middle-performed port in the various measurements. Important finding facts are as follows. 1)Kunsan Port has the efficiency level from 53% to 57% of efficient ports' level under the assumption of CRS and VRS. 2)In terms of average efficiency level, the gap among these 7 seports' efficiency levels has been widened during the period from 1998 to 2007. 3)Kunsan Port has shown the characteristics of DRS more frequently in terms of returns to scale. 4) Kunsan Port's average total factor productivity has been lower at the rate of 0.7% during the period from 1998 to 2007. 5)Kunsan Port has shown technical progress at the rate of 3.1% in this period. In future research the more and better data will be expected to improve the understanding of Korean seaports' efficiency characteristics.

• Clinical and Experimental Reproductive Medicine
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• v.24 no.2
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• pp.167-177
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• 1997

Oocyte donation program developed to reach the pregnancy in those patients suffering from premature ovarian failure or surgery induced menopause, particularly in their reproductive age. With technical advances and popularity of ART (assisted reproductive technology), the indication of oocyte donation program extended to low responders, and even to naturally menopaused patients that has led them quite successfully to getting in pregnancy. The purpose of this study was to evaluate which one is involved in the decline of fertility between the oocyte and uterine factor. One hundred five cycles of oocyte donation program were performed in 84 patients from Jan., 1993 to Dec., 1996. Oocytes were donated from healthy, young, fertile anonymous donors or relatives or infertile patients with supernumerary oocytes. The study population was divided into 3 groups according to the age of recipients. Group 1 was less than 35 years old, Group 2 was between 35 to 39 years old, and Group 3 was more than 39 years old. The results were as follows: The mean age of oocyte donor was $31.5{\pm}3.3$ (range; 25-36). The mean concentration of basal serum FSH and peak serum estradiol were not different among groups. The mean number of oocytes retrieved from donors, embryos transferred to recipients, and fertilization rate were not different among groups. The clinical pregnancy rate was 37.3% in Group 1, 31.6% in Group 2, and 31.6% in Group 3, respectively. The spontaneous abortion rate was 16.0% in Group 1, 16.7% in Group 2, and 16.7 in Group 3, respectively. The multiple pregnancy rate was 20.0% in Group 1, 16.7% in Group 2, 16,7% in Group 3, respectively, The implantation rate was 11.3% in Group 1, 10.3% in Group 2 and 10.0% in Group 3, respectively. All of the pregnancy outcomes were not different statistically among groups. In conclusion, endometrial receptivity does not seem to be impaired as age increases with transfer of good quality embryos and adequate endometrial preparation.

• Journal of Convergence for Information Technology
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• v.9 no.12
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• pp.30-38
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• 2019

The purpose of this study is to analyze the level of competitiveness of semiconductor design firms of Korea. The categories of competitiveness are divided into product development, accumulated technology, market-related competencies, human resources, and management system. The sample of 73 semiconductor design companies were used, and the analysis data were gathered by parallel with the questionnaire and the surveyor visited. For respondents, importance of competitiveness factor was prioritized using nominal scale and the competitiveness of each item is expressed based on 100 points. It was confirmed that there was a difference between the order of importance and the actual level of core competence. The ranking of the importance of core competencies is in the order of product development, technical capability, market-related competencies, human resources, and management system. However, in terms of actual competitiveness in each category, human resources were the best, followed by the management level. The product development and technology competencies were in order. The market-related competitiveness was found to be the most urgently raised. In order to increase the market related competitiveness, a new customer base must be developed and the information acquisition capability of the customer, and the ability to analyze their data needs to be improved.

• Composites Research
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• v.34 no.5
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• pp.290-295
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• 2021

The application of lightweight structural composites to automobiles as a solution in line with global fuel economy regulations to curb global warming is recognized as a megatrend. This study was conducted to provide a technical approach that can respond to the issue of replacing parts that require conductive properties to maximize the application of thermoplastic carbon fiber reinforced plastics (CFRPs), which are advantageous in terms of repair, disposal and recycling. By utilizing the properties of the low-viscosity polymerizable oligomer matrix, it was possible to prepare a thermoplastic CFRP exhibiting excellent impregnation properties while uniformly mixing the conductive filler. Various carbon-based conductive fillers such as carbon black, carbon nanotubes, graphene nanoplatelets, graphite, and pitch-based carbon fibers were filled up to the maximum content, and electrical and thermal conductive properties of the fabricated composites were compared and studied. It was confirmed that the maximum incorporation of filler was the most important factor to control the conductive properties of the composites rather than the type or shape of the conductive carbon filler. Experimental results were observed in which it might be advantageous to apply a one-dimensional conductive carbon filler to improve electrical conductivity, whereas it might be advantageous to apply a two-dimensional conductive carbon filler to improve thermal conductivity. The results of this study can provide potential insight into the optimization of structural design for controlling the conductive properties of thermoplastic CFRPs.

• Journal of vocational education research
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• v.37 no.4
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• pp.1-22
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• 2018

The study tried to investigate the school curriculum organization and teacher's perceptions about test subjects in vocational education division of the college scholastic ability test based in the 2015 revised national curriculum. This study asked vocational teachers to fill in basic questionnaire that consists of 9 relevant and subjective items for the school curriculum organization and test subjects in vocational education division of the college scholastic ability test based in the 2015 revised national curriculum. For this, the survey was conducted 58 schools of 92 schools in technical specialized high schools, meister high schools and vocational high schools about test subjects of 2015 revised national curriculum. As a result, the 'Successful career life' subject was 53.5%, the most organized in the first grade. 'test course 1' was 55.2% and 'test course 2' was 72.4% the most organized in the first grade. The Opinions on the test courses were the highest in the two subjects in the same series as the present. The teacher's perceptions showed that the current test subjects in vocational education division of the college scholastic ability test are valid. The most important factor affecting difficulty was 'The Ministry Education's policy' in vocational education division of the college scholastic ability test.

• Journal of Climate Change Research
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• v.2 no.3
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• pp.203-219
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• 2011

Greenhouse gas(GHG) inventories were reported recently in various fields. It, however, has been rarely to mention about the accuracy and reliability of the GHG inventory results. Some reliable assessment methods were introduced to judge the accuracy of the GHG inventory results. It is, hence, critical to develop an evaluation methodology. This project was designed 1) to develop evaluation methodology for reliability of inventory results by GHG-CAPSS, 2) to check the feasibility of the developed evaluation methodology as a result of applying this methodology to two emission sources: liquid fossil fuel and landfill, and 3) to construct the technical roadmap for future role of GHG-CAPSS. Qualitative and quantitative assessment methodologies were developed to check the reliability and accuracy of the inventory results. Qualitative assessment methodology was designed to evaluate the accuracy and reliability of estimation methods of GHG emissions from emission and sink sources, activity data, emission factor, and quality management schemes of inventory results. On the other hand, quantitative assessment methodology was based on the uncertainty assessment of emission results. According to the results of applying the above evaluation methodologies to two emission sources, those seem to be working properly. However, it is necessary to develop source-specific rating systems because emission and sink sources exhibit source-specific characteristics of GHG emissions and sinks.

• Journal of the Korean GEO-environmental Society
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• v.19 no.12
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• pp.41-46
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• 2018

The wireless sensor network system has the advantage of confirming the behavior of the entire facility by improving the disadvantages of conventional monitoring system. As a result, it is widely proposed as safety diagnosis and measurement of structures, water management systems, and management systems for dam structures. However, there is a lack of research that can evaluate the condition of facilities such as safety at the same time as monitoring. In this study, it is proposed a wireless sensor network system which can evaluate the behavior characteristics of facilities and evaluate the safety status for improving the technical disadvantages on conventional monitoring system. The geotechnical risk factors for the reservoir dam facility were evaluated and the limit values for the risk factors causing the failure of the facility were set. In other words, the system was set up so that the risk factors can be measured and the limit status can be evaluated immediately for each factor. In this study, numerical analysis is carried out for seepage and slope stability analysis using the typical cross section for reservoir dams. The stress-porewater coupling finite difference numerical analysis is performed for establishing the limit displacement for reservoir dam structures. It is developed a system that can estimate the time to reach the critical value by regression analysis using the measured datas.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.38 no.6
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• pp.887-894
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• 2018

An electric vehicle is emerging as an alternative to the response of global climate change and sustainability. However, an Electric vehicle has not been popular due to the constraints such as its price or technical limitations. In order to analyze the effect of purchasing electric vehicles, this study conducted a binary logistic regression model that demonstrates the relation between purchasing and influencing variables. Variables which have high correlation were excluded from the model through the correlation analysis to prevent multicollinearity. Socio-economic variables such as the number of owned vehicles, sex, ages are not significant. On the other hand, Variables related to prices, charging and policy are found to have a significant to effect on the purchase of electric vehicles. In accordance with the model estimated result, it seems to be necessary to improve the charging incentives, or to provide electric car information and to expand opportunities for experience electric vehicles. The result is also expected to be helpful for spreading electric vehicles and formulating policies.