• Title/Summary/Keyword: stress of the principal

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An Inquiry into Exercise Behaviors of Middle-aged Women in Korea - A Q-methodological approach - (한국 중년 여성의 운동 생활문화에 관한 탐색적 연구 - Q 방법론적 접근 -)

  • Yeun, Eun-Ja;Ryu, Eun-Jung
    • Korean Journal of Adult Nursing
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    • v.15 no.1
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    • pp.94-104
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    • 2003
  • Purpose: This study was performed to identify the factors which affected exercise and the perceived exercise behaviors in women according to Q-methodology and to provide basic strategies for health promotion of middle-aged women in Korea. Method: Q-methodology provides a scientific method for identifying perception structures that exist within certain individuals or groups. Thirty subjects in Seoul, Incheon, Chung-buk classified 35 selected Q-statements in to 9 points standard. The collected data was analyzed by using a QUANL pc program. Result: Principal component analysis identified 3 types of exercise behavior of middle-aged women in Korea and named by the researcher. They are called persistent activity preference type, living-exercise preference type, exercise mania type. In persistent activity preference type, the middle-aged women thought activity was very helpful to achieving health and releasing stress or fatigue. Also, they recognized the relationship between physical health and psychological health. In living-exercise preference type, the middle-aged women preferred maintaining stability or nonactivity to intended exercise or activity for health. In exercise mania type, the middle-aged women thought there was no other way to keep her health than to exercise. Conclusion: The findings of this study will provide the health care provider including nurse with useful information. It's very important to offer appropriate exercise intervention to the middle-aged women of each type by taking into consideration the characteristics of individual types.

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A Nonlinear Constitutive Model for Progressive Fracturing of Concrete (콘크리트의 점진적(漸進的) 파괴(破壞)에 대한 비선형(非線型) 구성(構成)모델확립연구(硏究))

  • Oh, Byung Hwan
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.4 no.2
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    • pp.55-64
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    • 1984
  • Presented is a nonlinear constitutive model for progressive tensile fracturing of concrete. The model is incremental, path-dependent, and tensorialy invariant. The total strain tensor is assumed to be a sum of a purely elastic component and an inelastic component. The material is considered to contain weak planes of all directions which characterize the planes of the microcracks. A one-to-one functional dependence is assumed between the normal stress and the normal strain across each of the weak planes. The tangential stiffness of concrete is then derived form the principle of virtual work. The present theory can be applied to loading histories which are nonproportional or during which the principal directions rotate. Good agreement with the available direct tensile test data which cover strain-softening is demonstrated.

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Numerical study on the structural stability of the precast joint buttress wall (프리캐스트 조인트 방법을 사용한 부벽식 옹벽의 구조적 안정성에 대한 수치해석 연구)

  • Kim, Joonseok
    • Journal of the Society of Disaster Information
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    • v.12 no.4
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    • pp.366-372
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    • 2016
  • Recently in case of the concrete retaining wall precast technological change in the field assembled by the way. A precast wall is devied into upper and lower respectively, and the way, assembled in field is being performed. But the assembled part could have been damaged by the earth pressure in a relatively high buttress wall. And, it have been pointed out that large-scale disaster can be occurred. Thus, in this thesis, a structural stability for the buttressed retaining wall with pre-cast joint method was analyzed by a numerical analysis method. The structural stability of the three height retaining wall(7.6m, 8.5m, 10m) was conducted respectively for earth pressure. The maximum principal stress applied to the concrete retaining wall was analyzed to occur locally in the vicinity of the fixing anchor as 23.3 ~ 43.2 MPa.

1H NMR-based metabolite profiling of diet-induced obesity in a mouse mode

  • Jung, Jee-Youn;Kim, Il-Yong;Kim, Yo-Na;Kim, Jin-Sup;Shin, Jae-Hoon;Jang, Zi-Hey;Lee, Ho-Sub;Hwang, Geum-Sook;Seong, Je-Kyung
    • BMB Reports
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    • v.45 no.7
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    • pp.419-424
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    • 2012
  • High-fat diets (HFD) and high-carbohydrate diets (HCD)-induced obesity through different pathways, but the metabolic differences between these diets are not fully understood. Therefore, we applied proton nuclear magnetic resonance ($^1H$ NMR)-based metabolomics to compare the metabolic patterns between C57BL/6 mice fed HCD and those fed HFD. Principal component analysis derived from $^1H$ NMR spectra of urine showed a clear separation between the HCD and HFD groups. Based on the changes in urinary metabolites, the slow rate of weight gain in mice fed the HCD related to activation of the tricarboxylic acid cycle (resulting in increased levels of citrate and succinate in HCD mice), while the HFD affected nicotinamide metabolism (increased levels of 1-methylnicotineamide, nicotinamide-N-oxide in HFD mice), which leads to systemic oxidative stress. In addition, perturbation of gut microflora metabolism was also related to different metabolic patterns of those two diets. These findings demonstrate that $^1H$ NMR-based metabolomics can identify diet-dependent perturbations in biological pathways.

Effect of Freeze-Drying and Hot Air-Convection Drying on the Antioxidative Activity of Butterbur (Petasites japonicus)

  • Cheong, Sun-Hee;Kim, Mi-Yeon;Son, Chan-Wok;Kim, Min-Hee;Lee, Yun-Jin;Kim, Mee-Ree
    • Food Quality and Culture
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    • v.2 no.2
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    • pp.61-66
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    • 2008
  • The principal objective of this study was to assess the anti oxidative activities of Petasites japonicus against oxidative stress in bovine brain tissue. Petasites japonicus is found with a relatively widespread distribution, and is cultivated as a culinary vegetable in Korea. Petasites japonicus samples were dried either by freeze-drying or by hot air-convection drying ($80^{\circ}C$), then evaluated for their anti oxidative activity by measuring 1-dipheny-1,2-picrylhydrazyl (DPPH) radical scavenging, and by measuring thiobarbituric acid-reactive substances (TBARS) in brain homogenates subjected to $Fe^{2+}$-mediated lipids with or without the addition of botanical extract. Hot air convection-drying resulted in a slight increase in the extraction yield as compared with freeze-drying. However, total phenol and flavonoid contents in freeze-dried Petasites japonicas were significantly higher than those of hot air convection-drying. Freeze-drying increased the free radical scavenging activity of Petasites japonicas, leaves, and stems by 52.6, 28.6, and 248.0%, as compared with hot air convection-drying. Additionally, the $IC_{50}$ values measured by TBARS in hot air convection-dried Petasites japonicas, leaves, and stems were increased by 36.0, 31.6, and 15.9%, as compared to those of freeze-drying. Although anti oxidative activity was reduced slightly by heat processing in Petasites japonicas, freeze-drying for each portion of Petasites japonicus was the most appropriate for use as a functional food and pharmaceutical material.

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Meteorological Constraints and Countermeasures in Major Summer Crop Production (하작물의 기상재해와 그 대책)

  • Shin-Han Kwon;Hong-Suk Lee;Eun-Hui Hong
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.27 no.4
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    • pp.398-410
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    • 1982
  • Summer crops grown in uplands are greatly diversified and show a large variation in difference with year and location in Korea. The principal factor for the variation is weather, in which precipitation and temperature play a leading role and such a weather factors as wind, sun lights also influence production of the summer crops. Since artificial control of weather conditions as a main stress factor for crop production is almost impossible, it must be minimized only by an improvement of cultivation techniques and crop improvement. Precipitation plays a role as one of the most important factor for production of the summer crops and it is considered in two aspects, drought and excess moisture. This country, which belongs to monsoon territory, necessarily encounter one of this stress almost every year, even though the level is different. Therefore, the facilities for both drought and excess moisture are required, but actually it is not easy to complete for them. On this account, crops tolerant to drought, excess moisture and pests should be considered for establishing summer crops. For the districts damaged habitually every season, adequate crops should be cultured and appropriate method of planting, drainage and weed control should be applied diversely. Injuries by temperature is mainly attributed to lower temperature particularly in late fall and early spring, although higher temperature often causes some damages depending upon the kind of crops. Sometimes, lower temperature in summer season playa critical role for yield reduction in the summer crops. However, certain crops are prevented to some extent from this kind of stress by improving varieties tolerant to cold, hot weather or early maturing varieties. As is often the case, control of planting time or harvesting is able to be a good management for escaping the stress. Lodging, plant diseases and pests are considered as a direct or indirect damage due to weather stress, but these are characters able to be overcome by means of crop improvement and also controlled by other suitable methods. In addition, polytical supports capable of improving constitution of agriculture into modern industry is urgently required by programming of data for the damages, establishment of damage forecasting and compensation system.

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3-Dimensional Strut-Tie Model Analysis and Design of Structural Concrete (콘크리트 구조부재의 3차원 스트럿-타이 모델 해석 및 설계)

  • Yun, Young Mook;Park, Jung Woong
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.26 no.3A
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    • pp.411-419
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    • 2006
  • In this study, a new approach employing 3-dimensional strut-tie models for analysis and design of 3-dimensional structural concrete with disturbed regions that are not properly occupied by current design codes is proposed. In addition, a computer graphics program for the practical application of the approach is developed. The approach adopts a grid strut-tie model to exclude the subjectivity in the selection of strut-tie model and evaluates the effective strength of concrete strut by considering the 3-dimensional failure criteria of concrete and the deviation angles between the struts and compressive principal stress trajectories. To verify the appropriateness of the approach, nine pile caps tested to failure are analyzed and a bridge pier is designed. The analysis and design results are compared with those obtained by several different methods.

Evaluation of Shear Strength of Precast-prestressed Hollow Core Slabs Based on Experiments (실험을 통한 프리캐스트-프리스트레스트 중공슬래브의 전단강도)

  • Han, Sang-Whan;Moon, Ki-Hoon;Kang, Dong-Hoon;Im, Ju-Hyeuk;Kim, Young Nam
    • Journal of the Korea Concrete Institute
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    • v.26 no.5
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    • pp.635-642
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    • 2014
  • The weight of concrete could be reduced by using hollow core slabs instead of heavy solid slabs, leading to cost reduction. The long span be also achieved by introducing prestress in hollow core slabs. but the evaluation of shear strength of precast-prestressed hollow core slabs are needed because the cross section is reduced in web and arranging shear reinforcement is not possible. In this study, the shear strength of precast-prestressed hollow core slabs were evaluated based on experimental tests. For this purpose, six full scale specimens were made and tested. The shear strength of the specimens were compared with those evaluated from current design provision(EC2 ACI, EN1168 and AASHTO).

Shear Behavior Prediction of Reinforced Concrete Beams by Transformation Angle Truss Modul (변환각 트러스 모델에 의한 철근콘크리트 보의 전단거동 예측에 관한 연구)

  • 김상우;이정윤
    • Journal of the Korea Concrete Institute
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    • v.13 no.2
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    • pp.130-138
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    • 2001
  • This paper presents on the shear behavior prediction of reinforced concrete beams using Transformation Angle Truss Model (TATM). The TATM can evaluate the stress-strain relationships for cracked concrete by transforming stresses and strains for principal plane into those over the crack surfaces. This proposed analytical method simplifies the Fixed Angle Softened Truss Model (FA-STM) and removes the limitation of applicability of the FA-STM. The shear.strength and strain of reinforced concrete beams are predicted by using the TATM. For the verification of proposed method, experimental results of reinforced concrete beams were compared with theoretical results by the TATM, FA-STM and Rotating Angle Softened Truss Model (RA-STM).

An Engineering Geological Study of Moryang Fault for Tunnel Design (터널설계를 위한 모량단층의 지질공학적 연구)

  • 방기문;우상우
    • The Journal of Engineering Geology
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    • v.10 no.3
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    • pp.237-245
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    • 2000
  • This study was for characterizing the engineering geological properties of Moryang Fault, and providing the basic data for tunnel design. Land-sat image analysis, geologic surveys, resistivity prospecting and 3-dimensional analysis for results of resistivity prospecting, core boring, mineralogical identification and chemical analysis for the bedrock, and K-Ar age dating for fault clay were carried out for the study of Moryang Fault which is located at Duckhyunri Sangbukmyun Uljinkun Ulsan metropolis. As a result of the study, it was shown that strike/dip was N20-3$0^{\circ}C$E/70-9$0^{\circ}C$NW, width of fault ranged from 20 to 60m(maximum 80m), and depth was more than 50m. K-Ar age dating results of fault clay were 5,700$\pm$1.129Ma and 1,900$\pm$0.380Ma. Hydraulic fracturing test results showed the principal stress direction similar to the strike of Moryang Fault.

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