• Journal of Radiation Protection and Research
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• v.38 no.3
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• pp.157-165
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• 2013

To determine the factors affecting the external radiation dose rates of patients undergoing PET-MRI examinations and to assess the trends of these differences, we measured the changes in the dose rates of $^{18}F$-FDG during a set period of time for each body region. Consistent with theoretical predictions, the dose rate decreased over time in patients undergoing PET-MRI examinations. Furthermore, immediately after the $^{18}F$-FDG injection, the dose rate in the chest region was the highest, followed by the abdominal region, the head region, and the foot region. The dose rate decreased drastically as time passed, by 2.47-fold, from $339.23{\pm}74.70mSv\;h^{-1}$ ($6.73{\pm}5.79$ min) at the time point immediately after the $^{18}F$-FDG injection to $102.71{\pm}26.17mSv\;h^{-1}$ ($136.11{\pm}25.64$ min) after the examination. In the foot region, there were no significant changes over time, from $32.05{\pm}20.23mSv\;h^{-1}$ ($6.73{\pm}5.79$ min) at the time point immediately after the $^{18}F$-FDG injection, to $23.89{\pm}9.14mSv\;h^{-1}$ ($136.11{\pm}25.64$ min) after the examination. The dose rate is dependent on the individual characteristics of the patient, and differed depending on the body region and time point. However, the dose rates were higher in patients who had a lower body weight, shorter stature, fewer urinations, lower fluid intake, and history of diabetes mellitus. To decrease radiation exposure, it is difficult or impossible to change factors inherent to the patient, such as sex, age, height, body weight, obesity, and history of diabetes mellitus. However, factors which can be changed, such as the $^{18}F$-FDG dose, fasting time, fluid intake, number of urinations, and contrast agent dose can be controlled to minimize the external radiation exposure of the patient.

• Journal of Korean Society of Forest Science
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• v.104 no.3
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• pp.466-475
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• 2015

The purpose of this study was to investigate the educational needs targeted at city dwellers with hope of migration to mountain areas. 80 city dwellers participating in the education program operated by Korea Forestry Promotion Institute were selected. Results showed that city dwellers had higher preference for the education including medium scale(20-40 persons)and the type of camp with field experience. Real experiences and knowledge and understanding of migration to rural area are the most important element of the qualifications of the program teachers. In the contents of education, city dwellers wanted the teaching programs about 'how to have forest land', 'how to produce the forest products', 'field experience' and 'forest tourism' and so on. In other words, city dwellers who wanted to move to mountain areas were interested in basic things for living. In addition, it will need to investigate people who have real experiences migrating to mountain areas and then it is necessary to discuss educational needs and supporting system helping people can settle in mountain areas.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.7
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• pp.52-59
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• 2020

Automatic tool changers (ATCs) can be divided into drum and chain types. Drum-type ATCs contain a magazine, where the tools are mounted, and a cam gearbox, which swaps the tools via roller gear and grooved plate cams. Drum-type ATCs are advantageous in that the operating time for the tool magazine is more rapid than that of chain-type ATCs and the length of the unit is shorter. Thus, drum-type ATCs can be fabricated into various shapes and forms depending on the number of tools and the magazine size in accordance with machining center requirements and consumer demand. In particular, the price competitiveness of a machining center with a drum-type ATC is higher, while drum-type ATCs are more rigid with fewer parts, possibly reducing the need for regular servicing. This study aims to verify the structural stability and design validity of the magazine base, which is the main structure of a drum-type ATC, using finite element analysis. This study kinematically verifies the specifications of the selected drive motor and reducer and assessed the design of the cam gearbox. It also conducts a structural analysis of the roller camp, which is the core component of the cam gearbox, based on the results of the kinetodynamic analysis, thus validating the structural design.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.7
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• pp.3459-3463
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• 2016

Background: Breast cancer is the second most common cancer in women in Cambodia, a low income country in South-East Asia. The Sihanouk Hospital Centre of Hope (SHCH) is a charity hospital set up by an international non-governmental organisation, HOPE Worldwide. In 2008, SHCH partnered with AmeriCares, a global health organisation to set up and deliver a breast cancer programme to provide education, diagnosis and treatment for women with breast cancer. The objective of this study is to characterise the presentation, diagnosis, treatment and outcomes of women treated under this program. Materials and Methods: A total of 215 women newly diagnosed with breast cancer from 1 March 2008 until 31 March 2011 were studied. Age at diagnosis, tumour size, histological type, tumour grade, ER, lymph node involvement, treatment modalities (surgery, radiotherapy, chemotherapy, hormone therapy) were recorded. Data on mortality at 3 years were obtained whenever possible. Results: The median age was 47 years old. Some 77.8% were diagnosed with stage 3 and 4 lesions, and 78.5% underwent mastectomy, of which 28.4% the intent was palliative. Of those whose ER status were known, only 48.3% were ER positive. Only 6 patients could afford chemotherapy while only 1 patient had radiotherapy. Hormone therapy was provided free for those who were ER positive. The overall survival rate at 3 years was 39.1%. Conclusions: Breast cancer presents at a late stage, and because treatment is suboptimal, survival is poor in Cambodia. A more aggressive approach to early detection and treatment needs to be developed to improve outcome from this potentially curable disease.

• Journal for History of Mathematics
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• v.26 no.1
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• pp.21-32
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• 2013

The outbreak of the First and the Second World Wars cast great shadow across the Europe including mathematical society. The IMU led by French mathematicians after the First World War ceased to exist because it was used politically. As Europe ran into the Second World War, all the international mathematical activities were ceased. Prominent mathematicians were put into camp by Nazi or moved to the United States of America. After the war, European mathematicians did not have capacity to represent the international mathematical society anymore. This led Stone and other American mathematicians to form the new IMU, which was independent of political ideology. This paper studies the birth process of the new IMU after the War and some major events that happened to ICM in 1950s.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.15 no.4
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• pp.41-49
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• 2012

The objective of this study is to investigate the characteristics of the location and prospects of the bear shelves built by Asiatic black bears in the Jirisan National Park. Previous researchers have been analyzed bear shelves in terms of places for resting and eating, but we are going to analyze based on the prospect-and-refuge theory. Characteristics of the sites of bear shelves are measured through field survey and topographic analysis by using digital elevation model (DEM). The normalized difference vegetation index (NDVI) is used to evaluate the optimum location of bear shelves in terms of crown density. Man-made objects are identified by viewshed analysis based on geographical information system (GIS). Findings of this paper can be summarized as follows. First, most bear trees are located deep inside of the mountainous national park, slopes of 30~40 degrees, altitude of 400~1,200m, and relatively low vegetation density with NDVI value of 0.4~0.6 compared to the average NDVI of the park. Second, the average height of bear shelves is 12.44m, or 74% of the average height of bear trees. They are located at suitable places to observe nearby trails and other park facilities. Third, man-made objects within the 100m radius of bear trees include lodge, bear training center, beekeeping camp, and hiking trails. Thus we may temporarily conclude that one of the main criteria of the bear tree selection in the park has been to identify optimum places for the monitoring of human activities in their habitat.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.4
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• pp.2556-2563
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• 2015

This study aims to find out the employment effectiveness of employment preparation activities that college students experience, especially focused on analyzing employment effects of college employment-related activities such as career choice and employment support program, along with individual preparation activities such as qualification, vocational training, etc. It performed binary logistic regression analysis using 2011 Graduates Occupational Mobility Survey data of 3,249 college graduates. The results showed that In college characteristics, the higher grade point average was and the more college was located in non-metropolitan area, the higher employment probability was. In the case of major field, Medicine, Education, Engineering, Social Science, Natural science in highest first order had employment probability higher than the reference group. The results showed that the number of qualification, interview skill & resume description skill program participation, and job search experience before and after graduation among employment preparation activities had an effect on employment. The rest, that is, vocational training, career employment curriculum, work experience program, career counseling program, employment camp, in-school job experience, employment goal status before graduation did not have an direct effect on employment.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.20 no.1
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• pp.1-12
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• 2012

Many pilots of the Korean Air Force(ROKAF) leave their jobs in order to move out to civilian airlines. Thanks to this considerable turnover phenomenon, the ROKAF faces a serious lack of air defense power. While the common understanding of this problem mainly talks about 'money' as the main cause of turnover, some pilots point out rather different issues. Many pilots say in a large-scale survey that they face serious job stresses not only from relative shortage of their income compared to civilian pilots, camp life, separated family conditions, overly loaded administrative works, but also from their professional flight trainings and low promotion rate to high ranks. The survey shows, however, at the same time, that the ROKAF pilots do not consider their job trainings and overall roles as the military pilots as the main factor causing the intention to turnover. A critical aspect of the pilots' job condition is many stress factors consistently affect overall job satisfaction level which stimulates the decision to turnover when they have to choose between the extension of military service as a pilot and moving-out to civilian airlines for new pilot's life. In other words, they accept the job difficulties as pilot in the military, but their long-term job satisfaction level is negatively affected by the job stresses.

• Journal of Life Science
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• v.14 no.2
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• pp.309-314
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• 2004

Cyclic AMP receptor protein (CRP) is involved in the transcriptional regulation of more than 100 genes in E. coli. CRP dimer is converted into active form via the sequential conformation change of cAMP binding pocket, hinge region and HTH DNA binding motif by binding of cAMP. The temperature gradient gel electrophoresis (TGGE) was applied to CRP protein to know whether it was an efficient technique to study the conformational transitions and the thermal stability. TGGE showed the unfolding process of wild-type and S83G CRP proteins with the temperature gradient set from 29 to 71$^{\circ}C$ on nondenaturing polyacrylamide gel. Melting temperature (Tm) was 57$\pm$1 and 55$\pm$1$^{\circ}C$ for wild-type and S83G CRP, respectively in acidic buffer[89.8 mM Glycine and 24 mM Boric acid (pH 5.8)].

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.24 no.2
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• pp.166-171
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• 2011

We use the electrical energy and it is essential energy in modern life, but we lay cable underground due to the issue for environment and safety. Safety for worker is still insufficient for the development of safety equipment and related research has been focused on the cable lifetime diagnosis at underground cable work. I have to develop live line detector around the magnetic field were investigated at underground cable. In this paper, we were investigated by variation of coil turns and load due to detection of magnetic field at lines around. And detected value of developing products compared with measured value of milli-gauss meter. As a result, the value of the number of coil turns was found to be proportional to the measured value. But turn-numbers increase showed that the weak noise. I could be confirmed that sensor showed the optimum value from 4,000 to 5,0000.