• 한국산학기술학회논문지
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• 제15권4호
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• pp.2511-2518
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• 2014

레일 매립형 궤도시스템은 연속레일지지방식으로 하중분산 효과가 크며, 궤도부재에 발생하는 응력이 매우 작다. 다양한 장점을 갖고 있는 레일 매립형 궤도는 국내에 적용사례가 드물며, 고속 운행선 적용을 위한 연구는 매우 미흡하다. 본 논문에서는 고속운행선에서의 레일 매립형 궤도시스템 적용을 위한 기초연구로써, 실내시험을 통한 수직강성을 도출하였으며, 도출된 강성과 이론해석을 통해 최적단면을 도출하였다.

• Steel and Composite Structures
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• 제34권3호
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• pp.333-345
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• 2020

In the past, many efficient profiles have been developed for cold-formed steel (CFS) members by judicious intermediate stiffening of the cross-sections, and they have shown improved structural performance over conventional CFS sections. Most of this research work was based on numerical modelling, thus lacking any experimental evidence of the efficiency of these sections. To fulfill this requirement, experimental studies were conducted in this study, on efficient intermediately stiffened CFS sections in flexure, which will result in easy and simple fabrication. Two series of built-up sections, open sections (OS) and box sections (BS), were fabricated and tested under four-point loading with same cross-sectional area. Test strengths, modes of failure, deformed shapes, load vs. mid-span displacements and geometric imperfections were measured and reported. The design strengths were quantified using North American Standards and Indian Standards for cold-formed steel structures. This study confirmed that efficient profiling of CFS sections can improve both the strength and stiffness performance by up to 90%. Closed sections showed better strength performance whereas open sections showed better stiffness performance.

• 대한수의학회지
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• 제53권4호
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• pp.211-216
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• 2013

This study was focusing on evaluating the protection of polyphosphate kinase (ppk) deleted and/or temperature-sensitive (ts) Salmonella Enteritidis (SE) as an attenuated vaccine in chickens. We constructed SEppk, SEts and SEppk::ts mutants and screened those mutants by growth capability in vitro, protection study in mice model and antibody response in chickens. Among the mutants, SEppk::ts-3 was selected because it showed higher growth capability, good protection against highly virulent SE in mice model, and good antibody response in chickens. SEppk::ts-3 also showed good protection against highly virulent SE isolate because it decreased colonization of virulent SE challenge strain in spleen, liver and cecum compared with the non-vaccinated control. The SEppk::ts-3 mutant showed cross-protection against S. Gallinarum (SG) challenge although the its cross-protection rate was a little lower than that of SG9R, a commercial vaccine against SG infection. To use for live attenuated vaccine in chickens, it should further be characterized.

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 1997년도 추계총회 및 학술발표회 논문집
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• pp.126-130
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• 1997

A series of Thermoplastic polyurethane elastomers was prepared via a two-step polymerization process. The NCO/OH feed ratio of polyurethane synthesized in this study was varied from 1 to 1.3. Studies have been made on the effects of chemical and physical cross-linkina, and the properties of thermoplastic polyurethane elastomers based on isophorone diisocyanate (IPDI)/1,4-butanediol (BD)/poly(propylene glycol) (PPG, MW:2000), isophorone diisocyanate (IPDI)/BD /poly(oxytetramethylene) glycol (PTMG, MW:2000) was compared. These materials were characterized using FTIR spectrometer, dynamic mechanical thermal analyzer, and tensile retraction tester. PTMG based polyurethane elastomers showed higher elasomeric behavior than PPG based polyurethane elastomers at the same NCO/OH ratio. This feature has been connected with the specific nature of the polyols. The permanent set(%) was decreased with increasing maximum elongation from 50% to 300%.

• 산업융합연구
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• 제22권2호
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• pp.33-43
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• 2024

본 연구의 목적은 어떻게 브랜드배태성이 교차구매의도에 영향을 미치는지를 확인하는 것이다. 이와 함께 이들 관계에 고객만족이 매개역할을 하는지를 함께 분석하고자 한다. 이를 위하여 표본은 특정 스마트폰 브랜드를 사용하는 소비자이며, 이들을 대상으로 설문조사하여 258부를 수집하였다. 실증분석은 구조방정식모형과 고객만족의 매개효과를 확인하기 위하여 비모수 붓스트레핑분석을 통한 추가분석을 실시하였다. 그 결과는 다음과 같다. 첫째, 브랜드배태성은 고객만족과 교차구매의도에 긍정적으로 영향을 미치는 것으로 확인하였다. 둘째, 고객만족은 교차구매의도에 긍정적으로 영향을 미치는 것으로 밝혀졌다. 이들 결과와 매개효과분석결과를 종합하면, 고객만족은 브랜드배태성과 교차구매의도에 유의한 매개역할을 하며, 브랜드배태성, 고객만족, 교차구매의도의 관계가 부분매개모형인 것을 보여준다. 또한 브랜드배태성의 교차구매의도에 대한 직접효과가 고객만족을 통한 간접효과보다 큰 것으로 나타났다. 이러한 실증분석 결과는 사회자본으로써 브랜드배태성이 교차구매의도의 선행요인이 될 수 있다는 학문적 가치를 보여준다. 또한 본 연구는 브랜드 실무자가 교차구매를 증대시키기 위하여 브랜드와 관련된 고객의 배태성을 높이는 것은 물론 고객만족의 매개역할을 함께 고려할 필요성을 제안한다.

• 대한치과기공학회지
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• 제41권2호
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• pp.103-112
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• 2019

Purpose: This article tried to find the relations between periodontal diseases, body mass index and clinical level for Korean adults over the age of 19, utilizing data of the 6th national nutrition survey. Methods: In the collected data, 14,940 adults aged 19 years or older were included in the study to determine the relationship between the general health status of Korean adults and periodontal disease. Results: As the result, 28.6% of Korean adults had periodontal diseases, there were significant differences depending on gender, age, smoking, residential aria, education level, body mass index, HDL-cholesterol, leukocyte value and fasting blood sugar. When general factors were controlled for multiple logistic regression analysis, there was significance as BMI cross rate was 1.029(95% C1, 1.007-1.051). HDL-cholesterol cross rate was 0.989(95% C1, 0.980-0.999), leukocyte cross rate was 1.086(95% C1, 1.040-1.134) and fasting bloody sugar cross rate was 1.006(95% C1, 1.003-1.009), so there were significance. In conclusion, there was a significance relation between periodontal diseases, body mass index, HDL-cholesterol and fasting bloody sugar. Conclusion: Based on the results of this study, oral health education should be used to manage and maintain healthy oral cavity by improving periodontal disease management and awareness. In addition, it will be necessary to develop periodic oral examinations and age - specific oral health education programs, and it can be used as a basic data for public oral health plan.

• Journal of Biosystems Engineering
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• 제36권5호
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• pp.377-383
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• 2011

This study proposed the new method of discerning the assembled parts and presuming the position of central point in a Cowl Cross Bar (CCB) using a Charge-Couple Device (CCD) camera attached to a robot in the auto assembly line. Three control points of an ellipse were decided by three reference points, which were equally distanced. The radii of these reference points were determined by the size of the object, and the repeated presumption secured the precise determination. The comparison of the central point of ellipse presumed by Randomized Hough Transform (RHT) with the part information stored in a database was used for determining the faulty part in an assembly. The method proposed in this study was applied for the real-time inspection of elliptical parts, such as bolt, nut hole and so on, connected to a CCB using a CCD camera. The findings of this study showed that the precise decision on whether the parts are inferior or not can be made irrespective of the lighting condition of industrial site and the noises of the surface of the part. In addition, the defect decision on the individual elliptic parts assembled in a CCB showed more than 98% accuracy within a 500-millisecond period at most.

• Nutrition Research and Practice
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• 제10권6호
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• pp.590-596
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• 2016

BACKGROUND/OBJECTIVES: The purpose of this study was to examine whether plasma lipid profiles are affected differently by snack kinds with equal calorific values. SUBJECTS/METHODS: We compared a Korean traditional confectionery (dasik) with Western confectionery (cookie) in this regard. Controlled cross-over study consisted of two 3-week snack intake phases and for separating, a 2-week washout period (3-2-3) was carried out with 30 healthy women aged between 40-59 years old. Brown rice based Korean traditional confectionery and wheat flour based Western confectionery were used. The participants consumed either dasik or cookie every day for 3 weeks, providing 93 kcal a day. RESULTS: The total cholesterol (TC) in the dasik group had decreased significantly after 3 weeks (P < 0.05). Furthermore, in the dasik group, reduction in TC and low-density lipoprotein-cholesterol were greater than those in the cookie group (P < 0.05). CONCLUSIONS: Prioritizing functional snacks like dasik improves plasma lipid profiles; this may be useful information for individuals who cannot refrain from snacking.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2005년도 춘계학술대회논문집
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• pp.51-56
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• 2005

For a fire cause judgement this paper describes the short circuit characteristics of a electric wire through the cross section analysis under ac condition. The cower wires prepared for the experiment were 1.2mm, 1.6mm, and 2.0mm in diameter. Through the cross section analysis(CSA), it was confirmed that the dendrite structure grew at the angle of about $40^{\circ}\;or\;60^{\circ}$ when the fusing current was applied to the wires. The larger the fusing current is, the more decreased the growth angle of the dendrite structure is. It was confirmed that the dendrite structure was arranged like the columnar structure. In this paper, the characteristics analysis of short circuit was carried out in the range of transient duration and the correlation constant k was investigated by measuring the short circuit duration and the fusing current.

• Journal of the Korean Wood Science and Technology
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• 제45권6호
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• pp.846-856
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• 2017

The aim of this study was to develop the details of cross-laminated timber (CLT) envelops for satisfying the design standard for energy saving (DSEA) and passive standard in South Korea. When the same thickness of 180 mm concrete or CLT was used and the same materials for other layers were used for the roof, wall, and interlayer floor, the required insulation thickness for the different building envelopes in central, southern, and Jeju island was evaluated. As a result, compared to the concrete envelop, about 43 mm of insulation thickness was reduced for wall and roof with the CLT envelope. When the CLT envelopes were modified to protect the CLT from moisture based on FPInnovations (2011), the insulation thickness was further reduced by 12 mm. When the modified CLT building envelops satisfied with a passive standard are used for 10-story building, the required insulation was decreased by $40.89m^3$ for a floor ($105.27m^2{\times}2.3m$ in height) compared to concrete building. As the number of floors increases, about 3.58 m3 of insulation per floor was additionally saved.