• Earthquakes and Structures
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• v.13 no.3
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• pp.221-230
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• 2017

One of the important phases of probabilistic performance-based methodology is establishing appropriate probabilistic seismic demand models (PSDMs). These demand models relate ground motion intensity measures (IMs) to demand measures (DMs). The objective of this paper is selection of the optimal IMs in probabilistic seismic demand analysis (PSDA) of the RC high-rise buildings. In selection process features such as: efficiency, practically, proficiency and sufficiency are considered. RC high-rise buildings with core wall structural system are selected as a case study building class with the three characteristic heights: 20-storey, 30-storey and 40-storey. In order to determine the most optimal IMs, 720 nonlinear time-history analyses are conducted for 60 ground motion records with a wide range of magnitudes and distances to source, and for various soil types, thus taking into account uncertainties during ground motion selection. The non-linear 3D models of the case study buildings are constructed. A detailed regression analysis and statistical processing of results are performed and appropriate PSDMs for the RC high-rise building are derived. Analyzing a large number of results it are adopted conclusions on the optimality of individual ground motion IMs for the RC high-rise building.

• Journal of Periodontal and Implant Science
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• v.50 no.6
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• pp.368-378
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• 2020

Purpose: Vitamin D deficiency may cause bone loss and increased inflammation, which are well-known symptoms of periodontal disease. This study investigated whether serum 25-hydroxyvitamin D (25(OH)D) levels are associated with periodontal disease status and tooth loss. Methods: Cross-sectional data from 5,405 individuals aged ≥50 years (2,253 males and 3,152 females) were obtained from the 2008-2010 Dong-gu study, a prospective cohort study of risk factors for chronic diseases. Periodontal examinations were conducted to evaluate the number of remaining teeth, the periodontal probing depth (PPD), the clinical attachment level (CAL), and bleeding on probing. The percentages of sites with PPD ≥4 mm and CAL ≥4 mm were recorded for each participant. The severity of periodontitis was classified using the Centers for Disease Control and Prevention and the American Academy of Periodontology case definitions. Serum 25(OH)D levels were classified as reflecting severe deficiency, deficiency, insufficiency, or sufficiency. Multivariate linear regression analysis was performed to assess the associations of serum 25(OH)D levels with periodontal parameters and the number of remaining teeth after adjusting for confounders including age, smoking status, alcohol consumption status, month of blood collection, and physical activity. Multivariate logistic regression was used to evaluate the association between serum vitamin D levels and severe periodontitis. An overall statistical analysis and a stratified analysis by sex were performed. Results: Overall, the rates of severe deficiency, deficiency, insufficiency, and sufficiency were 6.5%, 67.9%, 22.4%, and 3.2%, respectively. After adjustment for confounders, vitamin D levels were directly associated with the number of remaining teeth, an association that was significant in males, but not in females. Sufficient serum 25(OH)D was associated with a low frequency of severe periodontitis. Conclusions: This population-based cross-sectional study indicates that low serum 25(OH) D is significantly associated with tooth loss and severe periodontitis in Koreans aged 50 years and older.

• Journal of the Korean housing association
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• v.26 no.2
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• pp.57-66
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• 2015

The purpose of the study was to find out the relationship between subjective happiness and satisfaction of social sustainability in residential environment. The data for the analysis were collected through questionnaire survey method from October 29 to November 10, 2013, and the sample consisted of 338 residents living in Seoul and Gyeonggi-Do province. The social sustianability was composed of locality, communality and organism. Locality composed of historical and cultural reflection of regional identity and of regions. Communality composed of social integration, community program and facilities. Organism composed of employment, self-sufficiency, welfare, population, safety and housing. The findings of the study were as followings: 1) The average of subjective happiness was 3.82 points, over neutral. 2) The social sustainability in residential environment was related with the subjective happiness. 3) In the social sustainability in residential environment, the residents was satisfied with locality and organism, but they was not satisfied with communality.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.431-431
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• 2012

A compact tokamak reactor concept as a 14 MeV neutron source is desirable from an economic viewpoint for a fusion-driven transmutation reactor. LAR (Low Aspect Ratio) tokamak allows a potential of high "see full txt" operation with high bootstrap current fractions and can be used for a compact fusion neutron source. For the optimal design of a reactor, a radial build of reactor components has to be determined by considering the plasma physics and engineering constraints which inter-relate various reactor components and are constrained to use ITER physics and technology. In a transmutation reactor, the blanket should produce enough tritium for tritium self-sufficiency and the neutron multiplication factor, keff should be less than 0.95 to maintain sub-criticality. The shield should provide sufficient protection for the superconducting toroidal field (TF) coil against radiation damage and heating effects of the fusion neutrons, fission neutrons, and secondary gammas. In this work, characteristics of transmutation reactor based on LAR tokamak is investigated by using the coupled system analysis.

• Proceedings of the Korean Society of Computer Information Conference
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• 2015.01a
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• pp.107-110
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• 2015

본 연구에서는 자활근로사업과 자활공동체사업 참여자를 대상으로 자립의지, 자아존중감, 사회자본 정도와 자활사업 참여집단간의 차이를 분석하고자 한다. 또한 자활근로사업과 자활공동체사업 참여자의 자립의지에 영향을 미치는 개인적 특성요인과 사회자본의 영향력을 비교 분석하고자 한다. 분석결과, 자활근로사업 참여자의 자립의지에 대한 회귀분석 결과, 연령대(B=.228), 건강상태(B=.097), 자아존중감(B=.233), 사회자본(B=.184)이 유의미한 영향을 미치는 것으로 분석되었다. 그러나 자활공동체 참여자의 자립의지에는 유의미한 변수가 나타나지 않았다.

• Korean System Dynamics Review
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• v.11 no.3
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• pp.61-86
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• 2010

This research analyzed on the future energy society of Korea in 2030 using system thinking approach. Key uncertainty factors determining the future energy society were analyzed in a multi disciplinary view point such as politics, economy, society, ecology and technology. Three causal loop diagrams for the future energy system in Korea and related policy leverages were shown as well. 'Global economic trends', 'change of industrial structure' and 'energy price' were identified as key uncertainty factors determining the Korean energy future. Three causal loop diagrams named as 'rate of energy self－sufficiency and alternative energy production', 'economic activity and energy demand' and 'Excavation of new growth engines' were developed. We integrated those causal loop diagrams into one to understand the entire energy system of the future, proposed three strategic scenarios(optimistic, pessimistic and most likely) and discussed implications and limits of this research.

• Journal of Applied Reliability
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• v.17 no.2
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• pp.150-158
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• 2017

Purpose: The RAM objective is a very important factor that has a great effect on the improvement of the operation ration during the operation maintenance and the reduction of the life cycle cost. It is used as a design criterion during the system development, and its sufficiency should be evaluated during its test evaluation. Method: This study analyzed the cases related to RAM objective setting and suggested the improvement measures. Result: The base data for RAM objective is OMS/MP, which needs to be drawn up under the supervision of the requirement military, and a high-accuracy operating availability should be set through ALDT calculation which reflects the military logistics support environment. In addition, data collection necessary for RAM objective and RAM analysis should be made by supplementing the input data of DELIIS. Conclusion: This study suggests improvement of RAM objective considering for the weapon system.

• Journal of Sasang Constitutional Medicine
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• v.14 no.2
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• pp.78-89
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• 2002

1. The purpose To know the characteristics of Sasang Constitutional Medicine treatment for cronic rhinitis patients. 2. The method We analyzed statistically 104 patients who had consulted for cronic rhinitis in Iksan Wonkwang Oriental Medicine for three years from 1999 to 2001, using electronic chart developed by Kim Jong-Yeol. 3. The results 1) The efficiency rate of treatment was 73.8% and the recurrence rate was 51.1 %. the recurrence period was within 6 months in 76.0%, so we could consider the group not recurred within 6 months as successfully treated. 2) The number of Taeumin was 64.4% of total patients, which was higher than the rate of Taeumin to all patients during same period in Iksan Wonkwang Oriental Medicine. 3) The sufficiency rate of treatment was high when the treatment period was 30-60 days. 4) The prescriptions especially efficient for treatment were those treating exterior syndrom of each constitution.

• International journal of advanced smart convergence
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• v.10 no.4
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• pp.104-109
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• 2021

In the aftermath of the global pandemic that started in 2019, there have been many changes in the import/export and supply/demand process of agricultural products in each country. Amid these changes, the necessity and importance of each country's food self-sufficiency rate is increasing. There are several conditions that must accompany efficient agricultural activities, but among them, temperature is by far one of the most important conditions. For this reason, the need for high-accuracy climate data for stable agricultural activities is increasing, and various studies on climate prediction are being conducted in Korea, but data that can visually confirm climate prediction data for farmers are insufficient. Therefore, in this paper, we propose an artificial intelligence-based temperature prediction algorithm that can predict future temperature information by collecting and analyzing temperature data of farms in Gyeonggi-do in Korea for the last 10 years. If this algorithm is used, it is expected that it can be used as an auxiliary data for agricultural activities.

• International Journal of Advanced Culture Technology
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• v.6 no.4
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• pp.214-225
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• 2018

Rice straw is the principal forage for Korean cattle. Limited supply of domestic forage forces Korea to depend on imported forage. Utilizing locally available domestic feed as an alternative would lead to self-sufficiency and stability in cattle farm management. Locally available feed can be utilized as forage. The challenge of collecting local feed has been overcome by machines that have been developed to harvest feed. Local feed can be completely consumed in the production regions, thus reducing transportation costs and increasing price competitiveness. Hitherto, studies have focused on feed technologies and price competitiveness, among other factors, while the substitution of forage has not been examined. This study conducts a quantitative analysis to estimate the extent to which local feed can replace existing forage. We find that local feed is cheaper, and abundantly available, and can thus replace high-quality forage.