• Title/Summary/Keyword: projected stress

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Global Assessment of Climate Change-Associated Drought Risk

  • Kim, Heey Jin;Kim, Yeonjoo
    • Proceedings of the Korea Water Resources Association Conference
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    • 2019.05a
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    • pp.397-397
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    • 2019
  • With the consequences of climate change becoming more evident, research on climate-associated risks has become a basis for climate adaptation and mitigation. Amongst the different sectors and natural resources considered in assessing such risks, drought is one impact to our environment that experiences stress from climate change but is often overlooked and has the potential to bring severe consequences when drought occurs. For example, when temperatures are higher, water demand increases and water supply decreases; when precipitation patterns fluctuate immensely, floods and droughts occur more frequently at greater magnitudes, putting stress on ecosystems. Hence, it is important for us to evaluate drought risk to observe how different climate change and socioeconomic scenarios can affect this vital life resource. In this study, we review the context of drought risk on the basis of climate change impacts and socioeconomic indicators. As underlined in the IPCC AR5 report, the risks are identified by understanding the vulnerability, exposure, and hazards of drought. This study analyzed drought risk on a global scale with different RCP scenarios projected until the year 2099 with a focus on the variables population, precipitation, water resources, and temperature.

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Factors Affecting Dietary & Nutrients Intake During the First, Second, and Third Trimesters and Pregnancy Outcome -I. Effects of maternal stress on dietary and nutrient intake and on neonatal weight- (임신부의 식품 및 영양섭취 상태와 임신결과에 영향을 주는 요인 -I. 임신기 스트레스에 의한 식품 및 영양소 섭취 상태-)

  • Choi, Bong-Soon;Shin, Joung-Ja;Kim, Woo-Kyung;Park, Myeung-Hee;Lee, In-Sook
    • Journal of the Korean Society of Food Culture
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    • v.16 no.3
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    • pp.203-214
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    • 2001
  • Maternal stress was very common symptom that every pregnant women could have experienced during pregnant period. We found that the causative factors of stress for subjects were physical change(50.8%), family relationship(13.6%), change of body image(7.4%), concern baby(6.8%), economic difficulties(6.4%), depress(4.3%), morning sickness(3%), and miscellaneous(3.5%). According to our study, maternal stress during the first trimester negatively correlated with food and nutrients intake of pregnant women and gave low weight gain during pregnancy and low birth weight of infants. It also significantly correlated with monthly income(p<0.001) and monthly food cost(p<0.001) during pregnant period. Mean intake of Calcium and Iron were $47{\sim}60%$ of RDA and $35{\sim}48$ of RDA, respectively. With the Iron supplement the total intake of Iron exceeded 100% of RDA. We also found majority of food items, except seaweeds, fruits and vegetables, were negatively correlated with maternal stress during three trimesters. Additional support system projected by professionals in health-care field could mediate maternal stress and lead to healthy pregnancy outcome.

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Strength Characteristics of Anlsotropic Overconsalidated Clay (이방성과압밀점토의 강도특성)

  • 홍원표
    • Geotechnical Engineering
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    • v.4 no.3
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    • pp.35-42
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    • 1988
  • A series of consolidated-undrained cubical triaxial tests was performed to investigate the three- dimensional strength characteristics of anisotropic overconsolidated clay. All specimens sampled in field were loaded under conditions of principal stress directions fixed and aligned with the directions during sampling. A sufficient number of tests It was performed to deter.mine the three- dimensional failure surface in the octahedral plane. The adjusted effective friction angles obtained by the stress state projected on the same octahedral plane did not show anisotropy, while the measured effective friction angles showed considerally difference according to the axes of speccimens. Therefore, Lade failure criterion proposed fort isotropic materials could be also used practically for anisotropic overconsolidated clay. The direction of the plastic strain increment wrectors superimposed on the principal stress space was nearly perpendicular to the traces of the failure surface in the octahedral plane.

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Adaptive Analysis and Error Estimation in Meshless Method (무요소 방법에서의 적응적 해석을 위한 오차의 평가)

  • 정흥진
    • Computational Structural Engineering
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    • v.11 no.1
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    • pp.261-274
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    • 1998
  • In this paper, local and global error estimates for the element-free Galerkin (EFG) method are proposed. The essence of proposed error estimates is to use the difference between the values of the projected stress and these given directly by the EFG solution. The stress projection can be obtained simply by taking product of shape function based on a different domain of influence with the stresses at nodes. In this study, it was found that the effectivity index is optimized if the domain of influence in stress projection procedure is the smallest that retains regularity of the matrices in EFG. Numerical tests are shown for various 1D and 2D examples illustrating the good effectiveness of the proposed error estimator in the global energy norm and in the local error estimates.

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Aristolochia ringens extract ameliorates oxidative stress and dyslipidaemia associated with streptozotocin-induced hyperglycaemia in rats

  • Sulyman, Abdulhakeem Olarewaju;Akolade, Jubril Olayinka;Aladodo, Raliat Abimbola;Ibrahim, Rasheed Bolaji;Na'Allah, Asiat;Abdulazeez, Azeemat Titilola
    • CELLMED
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    • v.8 no.3
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    • pp.12.1-12.7
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    • 2018
  • The study was designed to assess antioxidant and antidyslipidaemic effects of terpenoid-rich extract from the root of Aristolochia ringens V. Hyperglycemia-induced oxidative stress and dyslipidemia were established in rats by single intraperitoneal administration of 65 mg/kg bw streptozotocin. Based on therapeutic dose determined in previous study, streptozotocin-induced rats were orally administered with 75 and 150 mg/Kg bw of A. ringens extract for 14 days. Total protein, serum lipid profiles and biomarkers of oxidative stress in liver and kidney of the experimental rats were determined. Atherogenic and cardiovascular disease risk indices were computed. Streptozotocin-induced hyperglycaemia significantly (p < 0.05) decreased activities of superoxide dismutase, catalase and glutathione transferase as well as the amount of reduced glutathione in both tissues indicating oxidative stress induced kidney and liver injury due to glucotoxicity. In comparison to non-treated hyperglycaemic rats, activities of the antioxidant enzymes and concentration of glutathione-H were significantly (p < 0.0001) increased, whereas malondialdehyde was reduced in the tissues of rats treated with both 75 and 150 mg/Kg bw of the extract. The extract also caused significant (p < 0.001) reduction in elevated levels of total cholesterol, triglycerides and low density lipoprotein-cholesterol levels, whereas concentration of the attenuated high density lipoprotein-cholesterol was increased in serum of the treated rats. Reduced atherogenic and cardiac risk indices were projected for the A. ringens extract-treated groups. Results from this study showed that extract from A. ringens root was rich in terpenoids and may reduce risks of complications associated with hyperglycemia-induced oxidative stress and dyslipidemia.

Three Dimensional Strength Characterisics of Compressible Sand (압축성 모래의 3차원 전단강도 특성)

  • Park, Byeong-Gi;Jeong, Jin-Seop;Im, Seong-Cheol
    • Geotechnical Engineering
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    • v.6 no.3
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    • pp.65-76
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    • 1990
  • A series of consolidated drained and untrained cubical triaxial tests were performed to investigate three dimensional strength characteristics of compressible sand. All specimens, which are formed by deposisting a fine sand loosely, were used. Failure strength in terms of effective stress analysis was greatly influenced by the variation of intermediate principal stress and so was failure criterion The adjusted effective frictional angles obtained by the stress state projected on the same octahedral plane showed almost same value, while the measured effective frictional angles showed considerable difference depending on the drainage conditions. Results of total stress analysis in undrained test turned out to fit Tresca's failure criterion well, but results of effective stress analysis turned out to fit Lade's failure criterion well.

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Analysis of Composite Response Based on Microstructure Details (복합재료의 미시특성에 따른 기계적 특성해석)

  • 김태우
    • Journal of the Korean Ceramic Society
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    • v.40 no.8
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    • pp.784-790
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    • 2003
  • Present investigation shows the analysis results for ceramic reinforced metal matrix composite under uniaxial transverse tensile loading. The resulting deformation, the projected damage type, and stress-strain behavior were computed depending on microstructure details such as the type of periodic reinforcement array, and the type of interface bonding. A two-dimensional finite element analysis was conducted based on the unit-cell of square, hexagonal, or diagonal periodic away For composite with strong interface bonding, the transverse stress vs. strain curve was generally increased with the increase of the ceramic volume fraction. For the composite with weakly bonded interface, however, the transverse stress vs. strain curve was reduced against the ceramic volume fraction. The decrease was caused by the interface debonding-induced stiffness reduction of the composite. For the composite of weakly bonded interface, the relative reduction rate in the final limit stress for hexagonal array was larger than that for square array. Outcome of the present study was compared favorably with the published literature data.

The Development of the Program Using Virtual Reality Environment to Treat the Stress Disorder after Car Accident (가상현실을 이용한 교통사고 후유장애 치료 프로그램 개발)

  • 김형래;이상호;노주선;김현택;김지혜;고희동
    • Science of Emotion and Sensibility
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    • v.4 no.2
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    • pp.33-38
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    • 2001
  • This analysis has been projected as a preliminary analysis to develop the therapy program for people who is suffering from stress disorder after car accident such as sense of fear or anxiety using virtual reality. The analysis verified the effect of driving scenario which is core technology of stress disorder program and of anxiety reduction training such as relaxation training through clients. The relaxation training has been tested to 8 people; 7 normal and 1 sufferer from car accident presenting them 3 different types of driving scenarios. As a result, relaxation training was effective but, it was not statistically good enough although it showed incensement of uneasiness by each different driving scenario. In spite of normal clients, it is interesting that anxiety lever after relaxation training using VR is lowered, but this result need to verify to client suffering real car accident.

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2D SUB-3D STM Approach for Design and Analysis of 3D Structural Concrete (3D 콘크리트 부재의 해석 및 설계를 위한 2D SUB-3D STM 방법)

  • 윤영묵;김승억;오진우;박정웅
    • Proceedings of the Korea Concrete Institute Conference
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    • 1998.04b
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    • pp.415-420
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    • 1998
  • In this paper, 2D SUB-3D STM approach for analysis and design of 3D structural concrete is presented. In the approach several 2D sub strut-tie models which are representations of compressive and tensile stress flows of each projected plane of 3D structural concrete are utilized in the sketch of a 3D strut-tie model, in the evaluation of effective strengths of compressive concrete struts, and in the verification of geometric compatibility and bearing capacity of critical nodal zones of 3D strut-tie model. To prove the validity and rationality of the suggested approach, the behavior and strength of a prestressed box girder diaphragm tested to failure are evaluated.

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Influence of Local Ultrasonic Forcing on a Turbulent Boundary layer (국소적 초음파 가진이 난류경계층에 미치는 영향)

  • Park, Young-Soo;Sung, Hyung-Jin
    • 한국가시화정보학회:학술대회논문집
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    • 2005.12a
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    • pp.17-22
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    • 2005
  • An experimental study was carried out to investigate the effect of local ultrasonic forcing on a turbulent boundary layer. Stereoscopic particle image velocimetry (SPIV) was used to probe the characteristics of the flow. A ultrasonic forcing system was made by adhering six ultrasonic transducers to the local flat plate. Cavitation which generates uncountable minute air-bubbles having fast wall normal velocity occurs when ultrasonic was projected into water. The SPIV results showed that the wall normal mean velocity is increased in a boundary layer dramatically and the streamwise mean velocity is reduced. The skin friction coefficient ($C_{f}$) decreases $60\%$ and gradually recovers at the downstream. The ultrasonic forcing reduces wall-region streamwise turbulent intensity, however, streamwise turbulent intensity is increased away from the wall. Wall-normal turbulent intensity is almost the same near the wall but it increases away from the wall, In tile vicinity of the wall, Reynold shear stress, sweep strength and production of turbulent kinetic energy were decreased. This suggests that the streamwise vortical structures are lifted by ultrasonic forcing and then skin friction is reduced.

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