• 한국전문물리치료학회지
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• 제24권4호
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• pp.46-53
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• 2017

Background: The MLA is supported by both the abductor hallucis (ABH) and the extrinsic muscles. Insufficient muscular support may lower the MLA when the body's weight is applied to the foot. The short foot exercise (SFE) is effective in increasing the height of the MLA for people with flat feet. Most of the research related to the SFE has simply evaluated the efficiency of the exercise using enhanced ABH electromyography (EMG) activation. Since the tibialis anterior (TA), peroneus longus (PER), and ABH are all involved in supporting the MLA, a new experiment design examining the EMG of the selected muscles during SFE should be applied to clarify its effect. Objects: Therefore, this study aimed to clarify the effect of the SFE in different ankle position on the MLA angle and the activation of both the intrinsic and extrinsic muscles and to determine the optimal position. Methods: 20 healthy subjects and 12 subjects with flat feet were recruited from Yonsei University. The surface EMG and camera were used to collect muscle activation amplitude of TA, PER, and ABH and to capture the image of MLA angle during SFE. The subjects performed the SFE while sitting in three different ankle positions-neutral (N), dorsiflexion (DF) at 30 degrees, and plantar flexion (PF) at 30 degrees. Results: ABH EMG amplitudes were significantly greater in N and DF than in PF (p<.05). Muscle activation ratio of TA to ABH was the lowest in PF (p<.05). MLA angle in both groups significantly decreased in PF (p<.01). The TA and ABH was activated at the highest level in DF. However, in PF, subjects significantly activated the ABH and PER with relatively low activation of TA. Conclusion: Therefore, researchers need to discuss which SFE condition most effectively use the arch support muscle for flat foot.

• 한국도로학회논문집
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• 제11권4호
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• pp.9-15
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• 2009

본 연구는 도로안전 시설물의 풍하중에 의한 손상발생 사례를 토대로 현행 도로안전 시설물의 구조적 휨 성능을 평가하고 이에 대한 부재별 휨 성능개선을 위한 연구이다. 본 연구의 대상구조물로는 대표적인 도로안전시설물이며 풍하중에 대한 선행 피해사례가 밝혀진 방음벽 지주프레임을 대상으로 고려하였으며 이들 지주프레임의 휨 구조성능 및 형상설계에 대한 평가를 우선적으로 수행하였다. 본 연구평가 결과에서 나타난 현행 보강재의 구조적 성능을 토대로 중량 대비 구조적 강성이 우수한 유리섬유 강화플라스틱 (GFRP)을 활용하여 다양한 보강 형태에 따른 성능개선방법을 해석 및 실험적 연구를 통하여 수행하였다. 그 결과 효율적 성능개선을 위한 GFRP 적용방법의 경우 구조적, 시공적 측면에서 효율적인 것으로 평가되었고 자체적인 형상단면 최적설계를 통한 개선방법도 성능보강에 효과적인 것으로 해석적으로 평가되었다. 본 연구에서 적용된 GFRP 단면보강 및 최적형상설계 연구는 향후 노후 도로안전 시설물의 풍하중 또는 태풍으로 인한 피해예방을 위한 기초자료로서 효율적으로 활용될 수 있을 것으로 판단된다.

• Structural Engineering and Mechanics
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• 제87권6호
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• pp.529-540
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• 2023

A novel laminated-hybrid-composite-beam (LHCB) of glass-epoxy infused with flyash and graphene is constructed for this study. The conventional mixture-rule and constitutive-relationship are modified to incorporate filler and lamina orientation. Eringen's non-local-theory is used to include the filler effect. Hamilton's principle based on fifth-order-layer-wise-shear-deformation-theory is applied to formulate the equation of motion. The analogous shear-spring-models for LHCB with multiple-cracks are employed in finite-element-analysis (FEA). Modal-experimentations are conducted (B&K-analyser) and the findings are compared with theoretical and FEA results. In terms of dimensionless relative-natural-frequencies (RNF), the dynamic-response in cantilevered support is investigated for various relative-crack-severities (RCSs) and relative-crack-positions (RCPs). The increase of RCS increases local-flexibility in LHCB thus reductions in RNFs are observed. RCP is found to play an important role, cracks present near the end-support cause an abrupt drop in RNFs. Further, multiple cracks are observed to enhance the nonlinearity of LHCB strength. Introduction of the first to third crack in an intact LHCB results drop of RNFs by 8%, 10%, and 11.5% correspondingly. Also, it is demonstrated that the RNF varies because of the lamina-orientation, and filler addition. For 0° lamina-orientation the RNF is maximum. Similarly, it is studied that the addition of graphene reduces weight and increases the stiffness of LHCB in contrast to the addition of flyash. Additionally, the response of LHCB to moving mass is accessed by appropriately modifying the numerical programs, and it is noted that the successive introduction of the first to ninth crack results in an approximately 40% to 120% increase in the dynamic-amplitude-ratio.

• 생명과학회지
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• 제21권5호
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• pp.684-692
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• 2011

본 연구는 브로일러의 성장능력을 촉진하기 위한 사료 내 이눌로프리바이오틱스의 적정 첨가수준을 결정하기 위하여 수행하였다. 부화 당일 로스계통(Ross 308)의 브로일러 수컷 320수를 4개의 처리구로 완전임의배치하여 35일 동안 사육하였다. 실험처리구는 대조구(무첨가구), 항생제 첨가구(avilamycin 8 ppm), 이눌로프리바이오틱스 200 ppm 첨가구 및 이눌로프리바이오틱스 250 ppm 첨가구로 구분하였다. 브로일러의 체중과 사료섭취량은 두개의 이눌로프리바이오틱스 첨가구가 대조구, 항생제 첨가구 보다도 높았고, 항생제 첨가구는 대조구에 비해서 높았으며 통계적인 유의차가 인정되었다. 전체 실험기간 동안 사료요구율은 대조구가 이눌로프리바이오틱스 첨가구와 비교할 때 유의하게 높았으나 항생제 첨가구와 이눌로프리바이오틱스 첨가구 사이의 통계적인 유의차는 없었다. 도체중, 도체율, 가슴살, 다리살의 무게는 이눌로프리바이오틱스 첨가구가 대조구, 항생제 첨가구에 비해서 유의하게 높았고, 이눌로프리바이오틱스 200 ppm, 250 ppm 첨가구 사이의 차이는 없었으나 항생제 첨가구는 대조구에 비해서 유의하게 높았다. 복강지방은 이눌로프리바이오틱스 첨가구가 유의하게 감소(19.08~23.30%)하였으며 혈액 면역물질과 흉선, F낭의 무게는 이눌로프리바이오틱스 첨가구가 대조구와 항생제 첨가구에 비해서 유의하게 증가하였다. 장내 유익한 Bifidobacteria와 Lactobacillu는 이눌로프리바이오틱스 첨가구가 대조구와 항생제 첨가구에 비해서 유의하게 증가하였으나 유해한 E. coli와 Salmonella는 그 반대로 나타났으며 통계적인 유의차가 인정되었다. 본 연구는 브로일러의 성장능력 향상을 위한 사료 내 이눌로프리바이오틱스의 적정 첨가수준은 200 ppm에서 결정될 수 있음을 보여준다.

• Geomechanics and Engineering
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• 제5권3호
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• pp.187-194
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• 2013

The most soil anchor works have been concerned with the uplift problem on embedded in non-reinforced soils under pullout test. Symmetrical anchor plates are a foundation system that can be resisting tensile load with the support of around soil in which symmetrical anchor plate is embedded. Engineers and authors proved that the uplift response can be improved by grouping the symmetrical anchor plates, increasing the unit weight, embedment ratio and the size of symmetrical anchor plates. Innovation of geosynthetics in the field of geotechnical engineering as reinforcement materials found to be possible solution in symmetrical anchor plate responses. Unfortunately the importance of reinforcement in submergence has received very little attention by researchers. In this paper, provision of tensile reinforcement under embedded conditions has been studied through uplift experiments on symmetrical anchor plates by few researchers. From the test results it has been showed that the provision of geogrid reinforcement system enhances the uplift response substantially under uplift test although other results are such as increase the ultimate uplift response of symmetrical anchor plate embedded using geosynthetic and Grid Fixed Reinforced (GFR) and symmetrical anchor plate improvement is very dependent on geosynthetic layer length and increases significantly until the amount of beyond that further increase in the layer length does not show a significant contribution in the anchor response.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2003년도 학술.기술논문발표회
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• pp.31-34
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• 2003

Sandwich panel is composed of the facing sheets which support the external load, the cellular core with the low thermal conductivity and the adhesive agent to bond them. The cellular core was produced by binding lightweight cellular aggregates with cement and two types of acrylic base St/BA emulsion were added with a view to improving the workability ion due to high absorption of light weight aggregate and to develope more strength, respectively. This investigation is to comprehend the effect of the addition of two types of St/BA on thermal conductivity, calorific value and exhaustion content of noxious gas in addition re compressive and flexural strength. Flexural strength of the specimen made with St/BA-2 ranged 20kgf/cm2 to 25kgf/cm2 and was about 50% to 100% as high as that of the non-fiber specimen. Thermal conductivity was recorded from 2.0 to 3.0 kcal/mh$^{\circ}C$ and calorific value of St/BA modified specimen was much lower than that of commercial sandwich panel core of EPS and urethane. Careful caution has to be taken because generation of noxious gas such as CO, NO and SO2 tend to increase with addition of polymer cement ratio.

• Journal of Microbiology and Biotechnology
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• 제19권6호
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• pp.582-587
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• 2009

Immobilized cells of Arthrohacter nitroguajacolicus ZJUTB06-99 capable of producing nitrilase were used for biotransformation of acrylonitrile to acrylic acid. Six different entrapment matrixes were chosen to search for a suitable support in terms of nitrilase activity. Ca-alginate proved to be more advantageous over other counterparts in improvement of the biocatalyst activity and bead mechanical strength. The effects of sodium alginate concentration, $CaCl_2$ concentration, bead diameter, and ratio by weight of cells to alginate, on biosynthesis of acrylic acid by immobilized cells were investigated. Maximum activity was obtained under the conditions of 1.5% sodium alginate concentration, 3.0% $CaCl_2$ concentration, and 2-mm bead size. The beads coated with 0.10% polyethylenimine (PEI) and 0.75% glutaraldehyde (GA) could tolerate more phosphate and decrease leakage amounts of cells from the gel. The beads treated with PEI/GA could be reused up to 20 batches without obvious decrease in activities, which increased about 100% compared with the untreated beads with a longevity of 11 batches.

• Journal of Nutrition and Health
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• 제28권7호
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• pp.602-611
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• 1995

This study was designed to find out the effects of $\omega$-3 and $\omega$-6 polyunsaturated and saturated fatty acid from prenatal to growing period on the brain growth and behavioral development of rats. Rats(Sprague-Dawley strain) were fed experimental diets-fish oil, corn oil or beef tallow-with different contents of $\omega$-3 and $\omega$-6 fatty acids throughout the prenatal and lactational period and up to 10 weeks of age. DNA and RNA concentration of rat brain were determined at 0, 3, 6 weeks of age and choline and acetylcholine concentrations were analyzed at 10 weeks of age. When the rats were 7 weeks of age, position reversional test in a Y-shaped water maze for 4 weeks was measured. The experimental results obtained are summarized as follows. Food intakes were significantly lower in fish oil group and body weight gain was low in the group fed beef tallow and the groups fed fish oil and corn oil were somewhat good. Food efficiency ratio was not significantly different among the groups. Brain weight was not affected by the fatty acid composition of experimental diets and DNA and RNA concentration of the rat brain were consistently maintained at the same level. It was not different significantly among the dietary groups in the DNA and RNA concentrations of the rat brain during the experimental period. The acetylcholine concentration in the fish oil group was somewhat higher than the other groups. The position reversional test in a Y-shaped water maze showed a significant difference the score of test among the experimental groups. The score of the rats fed the fish oil diet was significantly higher than the other groups and the concentration of acetylcholine in brain were too. Therefore the correlatin between the Y-shaped water maze test score and the acetylcholine concentratin in the brain was found. Above finding support the content that dietary fatty acid composition does not affect to the brain cell number and cell size but the behavior development is influenced. Therefore, the improvement of behavior development is required the effective usage of finny tribe.

• Nutrition Research and Practice
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• 제7권3호
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• pp.207-215
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• 2013

The objective of this study was to investigate the associations between the prevalence of overweight and obesity and the degree of adherence to the Korean Dietary Action Guides for Children (KDAGC). In a cross-sectional study based on a child care center-based survey in Seoul, Korea, we collected parental-reported questionnaires (n = 2,038) on children's weight and height, frequency of fruit and vegetable consumption, and the quality of dietary and activity behaviors based on the 2009 KDAGC Adherence Index (KDAGCAI) which was developed as a composite measure of adherence to the KDAGC. Overweight and obesity were determined according to age- and sex-specific BMI percentile from the 2007 Korean national growth chart. Associations were assessed with generalized linear models and polytomous logistic regression models. Approximately 17.6% of Korean preschool children were classified as overweight or obese. Obese preschoolers had lower adherence to the KDAGCAI compared to those with lean/normal weight. Preschoolers with a high quality of dietary and activity behaviors had a 51% decreased odds ratio (OR) of being obese (highest vs. lowest tertile of KDAGCAI-score, 95% CI 0.31, 0.78; P = 0.001); the associations were more pronounced among those who were older (P = 0.048) and lived in lower income households (P = 0.014). A greater frequency of vegetable consumption, but not fruit, was associated with a borderline significant reduction in the prevalence of obesity. Our findings support the association between obesity prevention and high compliance with the Korean national dietary and activity guideline among preschool children.

• Journal of Nutrition and Health
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• 제35권6호
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• pp.650-657
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• 2002

In order to provide basic data for the means to improve food situation and nutritional status of those supported by the National Basic Livelihood Security System (NBLSS), we examined household food insecurity and nutritional status of children under the support of NBLSS. This study included 209 children aged 3-12 years (99 boys and 110 girls) and their caretakers. We measured house food insecurity using Radimer/cornell Scale, children's body sizes and nutrient intake by semi-quantitative food frequency questionnaire, and caretakers' nutritional management skills. Only 9.6％ of the households were in food secured (FS) while 8.1％ were in household food insecured, but without hunger (HFI), 42.1％ were in adult food insecured with hunger (AFI), and 40.2％ were in child hungry (CH). Important predictors of food security were nutritional management skills of the caretakers as well as their education, but neither income nor food expenditure of the households. Mean energy intake of the children was 86.0％ of the Korean Recommended Dietary Allowance (RDA). Intakes of protein, phosphorous, vitamin A and B$_1$ were relatively high ranging from 112.3％ to 124.4％ of the RDAs while those of calcium, iron, niacin, vitamin C were low showing 74.8-83.3％ of the RDAs. Height, weight and weight/height ratio were close to the reference levels. Lower nutrient intakes of children were observed as the households were more food insecured. However, nutrient intakes and body sizes of children did not differ as a function of household socioeconomic status representing by income, food expenditure and caretakers' education. Results of this study suggest the importance of food security and nutritional management skills for the children's nutrient intakes. Concerning this matter, a need for nutrition education in the program for NBLSS was discussed.