• KSCE Journal of Civil and Environmental Engineering Research
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• v.14 no.2
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• pp.269-279
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• 1994

This paper concentrates on the finite element analysis of concrete structures considering the material nonlinearity and time-dependent structural behavior. Using the rotating crack model among the smeared cracking model, the structural behavior up to ultimate load is simulated, and concrete is assumed to be an orthotropic material. Especially to include the tension stiffening effect in bending behavior, a criterion based on the fracture mechanics concept is introduced and the numerical error according to the finite element mesh size can be minimized through the application of the proposed criterion. Besides, the governing equation for steel is systematized by embeded model to cope with the difficulty in modeling of complex geometry. Finally, to trace the structural behavior with time under cracked and/or uncracked section, an algorithm for the purpose of time-dependent analysis is formulated in plane stress-strain condition by the age-adjusted effective modulus method.

• Korean Journal of Weed Science
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• v.17 no.1
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• pp.44-51
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• 1997

Glyphosate had no effect on 5-enolpyruvylshikimate-3-phosphate synthase(EPSP-synthase) biosynthesis per se. But it inhibited clealy the activity of EPSP-synthase. EPSP-synthase seemed to be synthesized as a higher molecular weight(54 kDa) presusor protein and to be transported into plastid. The apparent molecular weight of mature EPSP-synthase in plastid is 45 kDa. Thus, the molecular size of transit peptide appeared to be about 9 kDa. The etiolation for 48 h after glyphosate application did not exhibit the inhibition of translocating level of EPSP-synthase across chloroplast envelope in actively growing meristematic leaves. But even when the plants were etiolated 2 hr after glyphosate treatment, a complete inhibition did not occur at least within 12 hr, i.e. 2 hr after beginning light period, suggesting that EPSP-synthase biosynthesis appeared to be not completely light dependent and the level of EPSP-synthase translocation to chloroplast could be controlled by an unknown regulatory mechanism of light dependent herbicidal effect of glyphosate.

• Korean Journal of Pharmacognosy
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• v.42 no.2
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• pp.201-208
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• 2011

Obesity occur from the imbalance between energy intake and energy expenditure. Obesity is a complex chronic disease that is suggested to cause other metabolic disorders such as type 2 diabetes, hyperlipidemia, hypertension, and arteriosclerosis. In this study, our purpose is to investigate the anti-hyperglycemic and anti-obesitic effects of Maydis stigma water extract in 3T3-L1 adipocytes and db/db mice. Maydis stigma water extract at dose of 100 and 500 ${\mu}g/ml$ slowly inhibited cell viability as compared to that of control in mature adipocytes. Also, the additions of 50 and 250 ${\mu}g/ml$ of Maydis stigma water extract significantly inhibited the lipid accumulations and CCAAT/enhancer-binding protein(C/EBP) ${\alpha}$ and peroxisome proliferator-activated receptor(PPAR) ${\gamma}$ expressions with dose-dependent manner in 3T3-L1 adipocytes. Maydis stigma water extract at 250, 500, and 1000 ${\mu}g/ml$ only showed the increasing pattern on lipolysis activity. The oral treatment of Maydis stigma water extract (100 or 400 mg/kg body weight) in db/db mice only showed tendency to decrease body weight, food efficiency ratio (FER), HbA1c, blood glucose, total cholesterol, triglyceride, and the adipocyte size of in db/db mice. However, Maydis stigma water extract increased the insulin level in a dose dependent manner. Thus these results indicate that Maydis stigma water extracxt inhibits adipogenesis through regulation of C/EBP${\alpha}$ and PPAR${\gamma}$ expressions in 3T3-L1 adipocytes and shows anti-hyperglycemic effect through increase of insulin secretion in db/db mice.

• Journal of Convergence for Information Technology
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• v.12 no.5
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• pp.71-82
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• 2022

This study aimed to identify the effects of death education programs among Korean aged on death anxiety and attitudes toward death in the convergence era. The searched kew words were included aged, death education program, death anxiety, and attitudes to death in the research papers published in Korea. Finally, 11 studies were selected and the effect size was calculated. Death anxiety and death attitude were selected as dependent variables, and publication type, total duration of intervention, and frequency of intervention were selected as moderator variables. The total of 11 papers were selected to estimate the effect sizes of interventions. As a result, the overall effect size of the death education program for the aged was 1.07. The overall effect size showed death education program was able to lower death anxiety (Hedges' g=1.30, 95% Cl=0.80~1.80, p<.01) and improve attitudes to death (Hedges' g=0.93, 95% Cl=0.49~1.37, p<.01) compared with the no intervention group. In the moderator analysis to identify the cause of heterogeneity, significant results were found in the frequency of intervention. We propose a study that repeatedly verifies the effect of related studies in the future by providing the theoretical basis and basic data for the development of the death education program.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.2072-2077
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• 2003

Animal-like robots are serving an important role as a linkage between biology and engineering. So, in this paper, we aim to develop a biomimetic microrobot that mimics the locomotion mechanism of a gastropod. This microrobot has 3 DOF (x, y translation and rotation), and has small size, unlimited traveling range, high resolution and low cost. Its movement can be made using propagation wave that is generated by the controllable sinusoidal voltage source and piezoelectric effects. This soft motion that can be generated by propagation wave and piezoelectric mechanism would be useful for the motion on the slippery surface. So we modeled the propagation wave mechanism including piezoelectric effect and friction on the contact surface, and could know the velocity of the microrobot is dependent on the driving frequency, input voltage peak, propagation wavelength and surface friction coefficient. With these results we design the microrobot, and accomplish its fabrication and experimentation. The development of this microrobot shall be aimed to design an autonomous moving actuator like animal. Also it can be used from micromanipulation system technology to biology and medicine.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2004.04a
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• pp.25-32
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• 2004

In this proposed work new finite element model for multi-delaminated plates is proposed. In the current analysis procedures of multi-delaminated plates, plate element based on Mindlin plate theory is used in order to obtain accurate results of out-of-plane displacement of thick plate. And for delaminated region, plate element based on Kirchhoff plate theory is considered. To satisfy the displacement continuity conditions, displacement vector based on Kirchhoff theory is transformed to displacement of transition element. The numerical results show that the effect of delaminations on the modal parameters of delaminated composites plates is dependent not only on the size, the location and the number of the delaminations but also on the mode number and boundary conditions. Kirchhoff based model have higher natural frequency than Mindlin based model and natural frequency of the presented model is closed to Mindlin based model.

• Korea-Australia Rheology Journal
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• v.21 no.2
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• pp.103-108
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• 2009

Hemorheological properties are easily modified by glucose-induced oxidation and glycation. Carnosine, a naturally occurring dipeptide ($\beta$-alanyl-LFull-size image-histidine), has been recently proposed to act as an antioxidant as well as a free-radical scavenger. In the present study, we investigate its protective and rejuvenating effects in erythrocytes that are exposed to glucose-rich plasma. Erythrocytes that were incubated in glucose solutions were treated with different concentrations of carnosine and for different incubation times. Their hemorheological alterations were examined. The results reveal that the presence of carnosine effectively prevented these rheological alterations in a concentration-dependent manner in glucose-rich media. It is proposed that moderate concentrations of carnosine might be further explored as potential therapeutic agents for pathologies that involve hemorheological modification.

• Journal of the Korean housing association
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• v.8 no.1
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• pp.37-48
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• 1997

The purpose of this study supply data that can make a living room a more comfortable space by using a plan of furniture usage, that is to say more affective to human's mental and physical character. For this purpose made experiment with slide film on 39 representative descriptions. The object of this research was female university students and to analyze the data. factor analysis. One-way ANOVA and scheffe-test were used by running SPSS PC+ program. The major results are as follows. In experiment with slide film for grasping spatial effect and evaluation on the 39 representative descriptions, three dimensions(clearness. openness. variety) extracted as the result of factor analysis. Especially the result of this study - sizes of space put independent valuables and each demotion put dependent valuables - shows differences according to space’ size.

• Journal of Power System Engineering
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• v.8 no.2
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• pp.53-58
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• 2004

In this paper, the semi active mount featuring Magneto rheological fluid(MR Fluid) is proposed. MR fluid is suspension of micro sized magnetizable particles in a fluid medium, and its apparent viscosity can be varied by the applied strength of magnetic field. When the controllable MR fluid is applied to mechanical devices, the devices provide simple, rapid response interfaces between electronic controls and mechanical systems. The MR fluid is applied in the conventional fluid mount for improving its performance of the mount's isolation effect. A appropriate size of the MR mount is designed and manufactured on the basis of Bingham model of MR fluid. In addition, the field dependent damping forces of MR mount are evaluated with respect to the input frequency variation.

• Tribology and Lubricants
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• v.18 no.3
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• pp.228-234
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• 2002

Generally, space structures are subjected to severe situations, such as, sublimation, strong evaporation of lubricants, thermal stresses, high temperature gradients, irradiation, impacts by microscopic meteorites, and other factors. Recent]y, various kinds of coatings are applied to the parts under heavy contact stresses, in order to insure long wear-free lives and/or reduce friction coefficients. In space structures, molybdenum disulfide is using frequently. Moreover TiN, Al$_2$O$_3$, PTFE(Poly Tetra Fluor Ethylene) are introduced recently for space structure. In this part we are going to apply the partial model method, developed in reference[11] to analyze part with coated layer. In referencer[l1], we compute the reasonable size of partial model and aspect ratio. Using these data, we analyze the structures coated with TiN, Al$_2$O$_3$, PTFE under contact load, temperature and crack model . Beside, we consider the stress analysis under time dependent load and transient thermal effect.