• Journal of dental hygiene science
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• v.15 no.5
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• pp.603-611
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• 2015

This research is aimed at cutting off hearing loss and other harmful factors due to noise and providing basic material for noise reduction plan. As the research method, this research assessed noise by measuring acoustic pressure level and frequency in various situation of non-treatment and treatment. As the measurement result, average noise degree of high speed handpiece of non-treatment, ultrasonic waves scaler, and low speed handpiece showed 58~66 dB(A). Average noise degree of scaling of treatment, tooth elimination, and denture adjust showed 73~81 dB(A). The result is inferior to recognized standards of noise induced hearing loss. But the result of assessing this with (noise rating) NR curve was NR-73~78, which exceeded general workplace noise standard. This level can cause hearing loss when exposed to a long time. Therefore, treatment office noise during dental treatment can cause psychological and physical damage in dental clinic employees, and it is urgently required to establish systematic and active noise reduction plan.

• Journal of the Korea Institute of Building Construction
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• v.15 no.5
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• pp.515-525
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• 2015

Currently, according to the climate change, serious damage by typhoon has been occurred in the world. In this respect, the research on the prediction model to minimize the damage from various natural disaster has been conducted in several developed countries. In the case of U.S, various models to predict building damage costs have been used widely in many organizations such as insurance companies and governments. In South Korea, although studies regarding damage prediction model according to typhoon have been conducted, the scope has been only limited to consider the property of typhoon. However, it is necessary to consider various factors such as typhoon information, geography, construction environment, and socio-economy factors to predict the damages. Therefore, to address this issue, first, correlation analysis is conducted between various variables based on the data of typhoon from 2003 to 2012. Second, the damage prediction model by using regression analysis is developed based on suggested influence factors. The findings of this study can be utilized to develop the model for predicting the damage costs of buildings by typhoon like HAZUS-MH of US.

• Parasites, Hosts and Diseases
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• v.30 no.4
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• pp.283-288
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• 1992

To observe the transmission patterns of karyotype of Pneumocystis carinii (Pc) by rat colonies, three strains of rats, Sprague-Dawlcy(SD), Wistar(W) and Fisher (F) from various animal vendors, were suppressed of their immunity by injection of methyl prednisolone. They were kept for 5 to 13 weeks in 3 different animal rooms, A, B, and C. The purified organisms were prepared in low melting point agarose gel by embedded Iysis method for pulsed field gel electrophoresis. Field inversion gel electrophoresis showed 2 patterns of the kart·otype of Pc. The rooms A and C contained SD rats from the source p, and also the room A was used for F and W rats. However, Pc from all of the SD and F rats in the room A showed same karyotypes, the pattern I. The SD rats from difFerent vendors, M and 5, were reared in the room B, and shared the same Pc karyotypes, the pattern II . The rats of W strain were from the vendor M, and immune-suppressed in the animal room A. Five weeks after the expe- riment, the Pc showed the karyotype pattern II but the pattern became mixed with the type I after 7 to 8 weeks. The Bindings revealed that the animals born and reared in the same animal quarter harbored Pc with same karyotypes. If the animals were kept under immune-suppression in the same room with heavily infected hosts, they could be infected by Pc from their neighbors. The present experimental findings suggest that Pc is transmitted among rats through the air.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.5 no.4
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• pp.335-345
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• 2000

Physical and acoustic properties of the Southeastern Yellow Sea Mud (SEYSM) of Korea were studied by using 10 piston cores. The data were also compared with mudbelt sediments in the South Sea and the East Sea (southeastern inner shelf) of Korea. The sediments were mainly composed of homogeneous silt. Sandy mud and mud were minor components. The major source of sediment in the study area is probably the Keum River. Finegrained sediments discharged from the river are transported southward by coastal current, resulting in a gradual southward increase in porosity and a decrease in wet bulk density and sound velocity. The mean grain size especially appears to be the most important variable to determine the physical properties and velocity. The variations of physical properties with burial depth are dependent more strongly on sediment texture (especially, silt content) than compaction and/or consolidation. Correlations between the physical properties and the sediment texture show slight deviations from those of the East Sea and the South Sea of Korea in spite of similar pattern within the limiting values. This is probably due to the differences in silt contents, sedimentary environments, mineral compositions, and gas contents.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.11
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• pp.949-956
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• 2016

There are a number of effects by solar radiation in many aerospace industrial fields, such as degradation of mechanical properties, sealing effect of sealants or decolorization. Because it takes long time to investigate these effects by using the light of natural state, new methods are developed for accelerating this phenomenon. In this paper, we developed an apparatus to simulate accelerated solar radiation phenomenon selecting irradiation intensity $1,120W/m^2$ as the designed environment. Epoxy polymer as the composite material was chosen and processed by ASTM-D638, a reference for tensile test of polymer and plastic. Total color shift was selected as the test category to evaluate acceleration of the test. We obtained acceleration factors and numerical model from test data and concluded it can shorten test periods by accelerated irradiation intensity of $1,120W/m^2$.

• Journal of the Korean Applied Science and Technology
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• v.35 no.1
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• pp.223-234
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• 2018

The purpose of this study was to analyze the parent-related factors affecting obesity and overweight in school-aged children. The subjects of this study were 408 students of 4th~6th grade and their parents and examined the degree of obesity, obesity-related characteristics, eating habits and exercise habits of children and their parents. The data were analyzed using $x^2-test$, t-test, ANOVA and multiple logistic regression analysis. The results of this study were as follows: father's BMI OR=1.265(95% CI: 1.133-1.412, p<.001), mother's BMI OR=1.214(95% CI: 1.077-1.368, CI: 1.113-1.725, p= .001), the child's eating habit OR=0.953(95% CI: .909- .998, p= .042), the TV watching time OR=1.385(95% CI: 1.113-1.725, p= .004), the economic state OR=0.132(95% CI: .026- .676, p= .015) were factors related affecting obesity and overweight in school-aged children. Children's obesity was influenced by parent's genetic factors, eating habits and living environment factors. Therefore, it is important to motivate the children as well as the their parents and induce the active participation of the program in order to manage the child's obesity.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.23 no.1
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• pp.44-50
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• 2013

E-glass fiber is the most widely used glass fiber for reinforced composite materials of aircrafts, automobiles and leisure equipments. But recently researches are being progressed to reduce boric oxide from 8 % to 0 (zero), as is called 'Boron free E-glass', because of increasing material cost, environmental problem, and improving chemical resistance and mechanical properties of E-glass fiber. In this study, we fabricated the bulk glass and fiber glass of 'Boron free E-glass (BF) compositions', and characterized thermal properties and optical properties. 'Boron free E-glass (BF)' was obtained by the melting of mixed batch materials at $1550^{\circ}C$ for 2 hrs with different $Al_2O_3$ compositions 5~10 %. We obtained transparent clear glass with high visible light transmittance value of 81~86 %, and low thermal expansion coefficient of $4.2{\sim}4.9{\times}10^{-6}/^{\circ}C$ and softening point of $907{\sim}928^{\circ}C$. For the chemical resistance test of 'BF' fiber samples, we identified that the higher alumina contents gives the better corrosion resistance of glass fiber.

• Journal of Digital Convergence
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• v.15 no.6
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• pp.513-523
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• 2017

The purpose of this study is to examine how career decision-making self-efficacy and ego-resilience of college students after military service influence college life adjustment. For this purpose, the questionnaire was administered to 234 male college students who returned to the four-year university in Jeonbuk area. The collected data were analyzed by correlation analysis and hierarchical regression using SPSS 18.0. As a result of examining the correlation between each variables, the subscale adaptation of college life adjustment and university environment adaptation showed a positive correlation with the goal selection of career decision self-efficacy and optimistic attitude of ego-resilience. Future plan of career decision-making self-efficacy, optimistic attitude of ego-resilience and personal-emotional adaptation of college life adaptation showed a positive correlation between self-evaluation of career decision self-efficacy and self-resilience confidence. As a result of hierarchical regression analysis, it was found that ego-resilience had more influence on college life adjustment than career decision self-efficacy. The limitations of this study were discussed along with the significance of this study, which was revealed through data collection only for students who came back after military service.

• Journal of Digital Convergence
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• v.16 no.3
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• pp.451-456
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• 2018

The purpose of this study is to propose the direction of convergence design curriculum of domestic universities in order to cultivate ablility of empathy in the $4^{th}$ industrial revolution era. The research methodology was firstly reviewed through the literature review, and the theoretical background about the background and design reengineering which became important in the time of the superconducting connection was examined, and the case study of the present situation of the convergence design curriculum of the domestic and foreign universities. As a result, it suggests a curriculum for the integration of undergraduate and graduate curriculum, which is a curriculum in which the design based on empathy is the key to linking other academic fields. Based on this, I hope that it will be used as a reference material for the activation of convergence design education in Korea in the future.

• Management & Information Systems Review
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• v.28 no.3
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• pp.45-68
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• 2009

The Korean government is actively pursuing an ambitious IT strategy to establish Korea as one of the leaders in the world IT market. To implement the strategy, successful technology transfer from research institutions to market should be achieved. Comprehensive literature identifies sixteen variables affecting the process and results of technology transfer. The research results in four key factors in technology transfer: Communication, Distance, Equivocality, and Motivation. Communication refers to the degree to which a medium is able to efficiently and accurately conveys task-relevant information and media while distance involves both physical and cultural proximity. Equivocality refers to the degree of concreteness of technology to be transferred while motivation involves incentives for and the recognition of the importance of technology transfer activities. Further analysis shows that there are four distinctive clusters and they show very contrasting characteristics in terms of four key factors. The careful mapping of the four clusters on the four key factors show very informative technology transfer patterns, the Technology Transfer Grid.