• Journal of Environmental Health Sciences
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• v.34 no.3
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• pp.188-198
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• 2008

Since 2003, the National Institute of Environmental Research (NIER) of Korea has been conducting "The monitoring study on exposure level and biomarkers of environmental pollutants" in the Ulsan industrial complex with the goals to establish a surveillance system for residents, to evaluate the health effects associated with chronic exposure to environmental pollutants and to develop the environmental health indicators in Ulsan industrial complex. This program consists of three phases an initial or foundation phase in which the program is developed, made operational and extended to the community, followed by an evaluation and accountability assessment of the surveillance system and finally an improvement in the quality of life and the maintenance of good health for Ulsan residents. In the period 2003 to 2008, the study program developed the surveillance system which will be used for the full-length survey. All participants in this study were contacted at a presentation meeting for residents, introduced to the objectives and protocols of the survey, and asked to participate. Informed consent was obtained from each participant. The study is now underway and includes questionnaires, health examinations and the analysis/collection/banking of bio-sample such as blood and urine. To date 828 subjects have participated and already 588 subjects have been followed up. We are committed to complete health examinations and to arrange storage of biosample for all participants. During the current year, we will analyze metals (Pb in blood and Cd, inorganic As and Hg in urine) in 1,972 samples and VOCs (11 species) and PARs (18 species) in 300 samples (blood sample). Moreover, the summary of the first step and the further preparation of the second step are currently underway. In this article, we introduce the study and its protocols and the distribution and size of the study participants. In conclusion, this survey will be continuously conducted on the established cohort and will enable the identification of relationship between environmental pollutant exposures and the health status of residents in Ulsan industrial complex.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.30 no.6
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• pp.541-547
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• 2017

Climate change has become the main cause of the exacerbation in natural disasters. Social Overhead Capital(SOC) structure needs to be checked for displacement and crack periodically to prevent damage and the collapse caused by natural disaster and ensure the safety. For efficient structure maintenance, the optical image technology is applied to the Structure Health Monitoring(SHM). However, optical image is sensitive to environmental factors. So it is necessary to verify its validity. In this paper, the accuracy of estimating the vertical displacement was verified with respect to environmental condition such as natural light, measurement distance, and the number of image sheets. The result of experiments showed that the effect of natural light on accuracy of estimating vertical displacement was the greatest of all. The measurement angle which was affected by the change in measurement distance was also important to check the vertical displacement. These findings will be taken into account by applying appropriate environmental condition to minimize errors when the bridge was measured by camera. It will also enable the application of optical images to the SHM.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.11
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• pp.1145-1151
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• 2015

High pressure components of a gas turbine engine must operate for a long life under severe conditions in order to maximize the performance and minimize the maintenance cost. Enhanced cooling design, thermal barrier coating techniques, and nickel-base superalloys have been applied for overcoming them and furthermore, material modeling, finite element analysis, statistical techniques, and etc. in design stage have been utilized widely. This article aims to evaluate the effects on the low cycle fatigue life of the high pressure turbine nozzle caused by different turbine inlet temperature profiles and installation conditions and to investigate the most favorable operating condition to the turbine nozzle. To achieve it, the structural analysis, which utilized the results of conjugate heat transfer analysis as loading boundary conditions, was performed and its results were the input for the assessment of low cycle fatigue life at several critical zones.

• Journal of Service Research and Studies
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• v.9 no.3
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• pp.17-38
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• 2019

With recent dispersion of sharing economy, consumption culture of sharing, instead of ownership, gets wide spread in the age groups of 20-30. Even though the market of car sharing expands rapidly, little research has been done in the area of service quality and consumer behavior regarding car sharing services. Given that future market potential gets larger, it seems highly meaningful to conduct research on customer satisfaction and their usage behavior regarding car sharing services. This paper intends to analyze main factors affecting overall customer satisfaction on car sharing services; satisfaction on service quality, satisfaction on service product, and satisfaction on service experience. Each dimension of the three factors is also analyzed to see if there is any differences between major three brands. Further analysis has been done for checking any effects of gender and usage purpose of customers on the overall customer satisfaction. Key results of the analysis show all the three main factors have significant effect on overall customer satisfaction. Each dimension of service quality has significant effect on satisfaction on service quality. Dimensions of parking lot accessability and vehicle maintenance in service product evaluation, have greater effect on satisfaction on service product. In service experience, positive affect have greater effect than negative affect on satisfaction on service experience. Women users perceive larger overall customer satisfaction on car sharing services than men users. On the types of usage purpose, Users with purpose of tour and dating/meeing friends perceive larger overall customer satisfaction on car sharing services than user without it. Further managerial implications of car sharing services are also provided.

• Journal of dental hygiene science
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• v.9 no.4
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• pp.369-374
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• 2009

The purpose of this study was to survey Korean soldiers' oral healthcare practice and attitudes along with their stress level, and thereby to identify possible correlations among those factors. The survey was conducted from June 11 to Oct. 10, 2008 in G-gun, Chungbuk. province for soldiers. The questionnaire was consisted of the oral healthcare practice and attitude, stress level. As a result, it was found that our respondents scored 3.55 out of possible 9 point in their stress level, which indicated that they had relatively low stress on the whole. According to survey on their oral healthcare practice and attitude depending on their general characteristics, it was found that the higher academic career was associated directly with the more practices of oral healthcare, and nonsmoking group showed more practices of oral healthcare than smoking group. It was found that 'schoolwork and workplace' and 'sexual problem' were critical stress factors on our respondents' oral healthcare attitudes. And it was also found that 'outward appearance complex', 'personality complex', 'conflicts with parents' and 'sexual problem' were critical stress factors on their oral healthcare practices. Since our soldiers' maintenance of their oral healthcare is beneficial to both individual and national aspects, it is necessary for interested parties including dental surgeons to make efforts to develop a promotional program for military dental healthcare project and provide a series of reorientations for soldiers, so that they can have more positive oral healthcare practices and attitudes.

• Journal of the East Asian Society of Dietary Life
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• v.17 no.2
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• pp.205-212
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• 2007

This study was designed to investigate a natural medicinal multi-plants extract (BG515), which consisted of multi extracts of Mori folium, Rehmannia glutinosa Liboschitz, Dioscorea japonica, Lycii fructus, and Astragalus radix, on blood glucose, insulin levels, and serum malondialdehyde (MDA) concentrations in streptozotocin-induced diabetic rats. Streptozotocin (STZ) induces a type 1 diabetes mellitus in rats. Type 1 is usually characterized by the presence of islet cell autoantibodies (ICA), autoantibodies to insulin (IAA), and autoantiboides to glutamic acid decarboxylase (GAD), which identify the autoimmune process that leads to $\beta-cell$ destruction. Thirty-five male Sprague-Dawley (SD) rats weighing $150\sim170g$ each (6 weeks old) were randomly divided into one control (Group A) and 4 STZ-induced diabetic groups, and were subjected to one of the following treatment for 12 weeks. Groups A and B were fed basal diets and Group C, D, and E received the same diets as groups A and B, but with supplements of 150 mg/kg, 300 mg/kg, and 600 mg/kg of BG515 orally for 12 weeks, respectively. Diabetes was induced in Groups B, C, D, and E by intravenous injection of 45 mg/kg of STZ per body weight in sodium citrate buffer (pH 4.5) via the tail vein. In the BG515 groups, we found increases in serum insulin levels, compared to the STZ-control group, but these data were not significant. In contrast, blood glucose and serum MDA concentrations decreased in the BG515 groups compare to the STZ-control group. At the 5th week, in all the BG515 administered groups, there were decreases in serum blood glucose levels compared to the STZ- control group, and this activity was very strong in the BG515-1 group at the 12th week. These results suggest that natural bio-complex compounds (BG515) may slightly suppress STZ-induced changes in serum MDA concentration via the maintenance of serum insulin levels, due to the prevention of $\beta-cell$ and glucagon destruction by STZ.

• Journal of the Society of Naval Architects of Korea
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• v.36 no.4
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• pp.137-146
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• 1999

Inspection becomes to be important in the safety of structure and economical viewpoint, because structural damage accompanies lots of economical cost and social problems. Especially ship structure is composed of a lot of members and it is impossible to inspect all members continuously. The purpose of this paper is to get optimal inspection plan containing inspection time and method. Crack is one of major modes on the structural failure and can lead to collapse of structure. In this paper, the deteriorating process, which contains inspection to detect the crack before the propagation to large crack, is idealized as Markov chain model. Genetic algorithm is also used to accomplish the optimization of inspection plan. Especially, the probabilistic characteristics of cracks are changed, because ship is operating in corrosive environments and the scantling of structural members is reduced due to corrosion. Non-stationary Markov chain model is used to represent the process of corrosion in structural members. In this paper, the characteristics of indivisual inspection plan are compared by numerical examples for the change of corrosion rate, the cost due to scheduled system down and target failure probability. From the numerical example, it can be seen that the improvement of fatigue life for the members with short fatigue life is the most effective way in order to reduce total maintenance cost.

• The Journal of Korean Academy of Prosthodontics
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• v.58 no.3
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• pp.221-227
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• 2020

In the case of complete edentulous patients, as the mandibular alveolar bone absorption progresses, the maintenance and stability of the existing dentures, which had satisfactory functions in the past, are deteriorated. Despite of the need to fabricate new dentures, they often hesitate due to physical burdens on the duration and intensity of future treatment progress due to the effects of aging and systemic diseases. In the case of these completely edentulous patients, it is necessary to consider the treatment goals that can reduce the number of visits and the adaptation period for new dentures before starting the treatment. This case is a case of producing complete dentures of elderly patients with deteriorated physical ability. In addition to producing suction dentures through preliminary and definitive closed mouth functional impression suggested by Sato, CAD / CAM technique was used to transfer occlusal functional information of existing dentures to facilitate adaptation to new dentures.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.43 no.4
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• pp.281-287
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• 2017

Stress in skin plays a significant role in both the direct/indirect regulation of cellular processes occurring in hair, which in turn affect the hair cycle. However, experimental data regarding the effects of stress-related corticotropin releasing factor (CRF) released by stress on the apoptotic process involved in hair is limited. Therefore, we investigated the acceleration of early-stage apoptosis induced by atopy-related stress using a 2,4-dinitrochlorobenzene NC/Nga mice model. Expression of CRF, its related proteins, annexin V, and mitochondrial dysfunction were measured by immunohistochemical analyses. Atopic stress strongly stimulated stress hormones response, such as CRF and adrenocorticotropic hormone, in outer epithelial sheath of the hair. Moreover, its stress induced mitochondrial damage and early-stage apoptosis of cells in hair root. These findings suggest that hair damage due to apoptosis in atopy model is accelerated in a high CRF environment. Importantly, the effect of stress-related CRF on apoptosis processes involved in atopy dermatitis-related hair loss, suggests that the CRF-regulating development or maintenance materials may provide effective therapeutic strategies for hair health.

• Proceedings of the Korea Water Resources Association Conference
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• 2010.05a
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• pp.273-277
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• 2010

This research was performed to examine changes in the timing of the growth of crops along with changes in temperatures due tochanges and to analyze the change of water-supply-reliability by adding an analysis of the change of agricultural water supply patterns in the basin area of Miryang dam in Korea. Had-CM3 model from U.K. was the tool adopted for the GCM model, a stochastic, daily-meteorology-generation-model called LARS-WG was alsoused for downscaling and for the climate change scenario (A1B) which represents Korea's circumstances best. First of all, to calculate changes in the timing of the growth of crops during this period, the theory of GDD was applied. Except for the period of transplanting and irrigation, there was no choice but to find the proper accumulated temperature by comparing actual temperature data and the supply pattern of agricultural use due to limited temperature data. As a result, proper temperatures were found for each period. $400^{\circ}C$ for the preparation period of a nursery bed, $704^{\circ}C$ for a nursery bed's period, $1,295^{\circ}C$ for the rice-transplanting period, $1,744^{\circ}C$ for starting irrigation, and $3,972^{\circ}C$ for finishing irrigation. To analyze future agricultural supply patter changes, the A1B scenario of Had-CM3 model was adopted, and then Downscaling was conducted adopting LARS-WG. To conduct a stochastical analysis of LARS-WG, climate scenarios were generated for the periods 2011~2030, 2046~2065, 2080~2099 using the data of precipitation andMax/Min temperatures collected from the Miryang gauging station. Upon reviewing the result of the analysis of accumulated temperatures from 2011~2030, the supply of agricultural water was 10 days earlier, and in the next periods-2046~2065, 2080~2099 it also was 10 days earlier. With these results, it is assumed that the supply of agricultural water should be about 1 month ahead of the existing schedule to meet the proper growth conditions of crops. From the results of the agricultural water supply patterns should be altered, but the reliability of water supply becomes more favorable, which is caused from the high precipitation change. Furthermore, since the unique characteristics of precipitation in Korea, which has high precipitation in the summer, water-supply-reliability has a pattern that the precipitation in September could significantly affect the chances of drought the following winter and spring. It could be more risky to make changes to the constant supply pattern under these conditions due to the high uncertainty of future precipitation. Although, several researches have been conducted concerning climate changes, in the field of water-industry, those researches have been solely dependent on precipitation. Even so, with the high uncertainty of precipitation, it is difficult for it to be reflected in government policy. Therefore, research in the field of water-supply-patterns or evapotranspiration according to the temperature or other diverse effects, which has higher reliability on anticipation, could obtain more reliable results in the future and that could result in water-resource maintenance to be safer and a more advantageous environment.