• Korea-Australia Rheology Journal
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• 제17권4호
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• pp.171-180
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• 2005

We present numerical results for inertialess elliptic particle suspensions in a Newtonian fluid subject to simple shear flow, using the sliding bi-periodic frame concept of Hwang et al. (2004) such that a particulate system with a small number of particles could represent a suspension system containing a large number of particles. We report the motion and configurational change of elliptic particles in simple shear flow and discuss the inter-relationship with the bulk shear stress behaviors through several example problems of a single, two-interacting and ten particle problems in a sliding bi-periodic frame. The main objective is to check the feasibility of the direct simulation method for understanding the relationship between the microstructural evolution and the bulk material behaviors.

• Computers and Concrete
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• 제28권6호
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• pp.621-634
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• 2021

For the reliable strut-and-tie model (STM) design of disturbed regions of concrete members, structural designers must accurately determine the strength of concrete struts to check the strength conditions of a selected STM el and the anchorage of reinforcing bars in nodal zones. In this study, the author proposed a consistent numerical method for strut strength, applicable to all two-dimensional STMs. The proposed method includes the effects of a biaxial stress state associated with tensile strains in reinforcing bars crossing a strut, deviation angle between strut orientation and compressive principal stress flow, and degree of confinement provided by reinforcement. The author examined the method's validity through the STM prediction of the ultimate strengths of 517 reinforced concrete (RC) deep beams, 24 RC panels, and 258 RC corbels, all tested to failure.

• 대한설비공학회지:설비저널
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• 제6권4호
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• pp.262-266
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• 1977

A new computer system for the stress analysis and design of piping network has been devlo-ped in this study. For the stress analysis, the system utilizes the finite element technique in which the frontal technique is used as the equation solver. The element library of the system has (1) Pipe Element (2) Beam Element, (3) Hanger Element and (4) Spring Element which should be sufficient to model the entire piping system including flexible supports, joints, piping rack and hangers. Based on the element stresses, code check has been performed and the safety factor for each element is calculated.

• 대한간호학회지
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• 제36권6호
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• pp.976-982
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• 2006

Purpose: The purpose of this study was to compare the feeling state guided imagery(FSGI) and end state guided imagery(ESGI) on stress and performance of an intramuscular injection of nursing students. Method: The design was a time series with a nonequivalent control group pretest-posttest study. Data was collected from the 23 rd to the 25th of Nov. 2004. The subjects of this study were 40 female sophomores (21 for the ESGI, 19 for the FSGI). The instruments used in this study were the Visual Analogue Scale for Stress and the Nursing Skill Performance Check-list on Intramuscular Injection developed by the researchers(10 items). Guided imagery was provided through audiotapes for 8 minutes. A pretest was given before applying the guided imagery, posttest 1 was performed after the intervention, posttest 2 was performed before the intramuscular injection and then evaluation of the performance of the intramuscular injection was done. Data was analyzed using t-test, and Repeated Measures ANOVA. Result: The level of stress for those who received the ESGI and FEGI was not significant and the level of the nursing skill performance for those who received the ESGI was significantly higher than that of students who received the FEGI. Conclusion: The use of ESGI has an effect on learning psychomotor nursing skills and further research is needed on stress.

• 동의생리병리학회지
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• 제28권4호
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• pp.396-402
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• 2014

This study is designed to investigate cytoprotective effects of Platycodon grandiflorus (Jacq.) A.DC on C6 glioma cell apoptosis by oxidative stress. Experimental C6 glioma cells were classified into four groups as follows: normal group, PGE group, chemical groups, PGE+chemical groups. Oxidative stress that caused by chemicals in the C6 glioma cell, check the impact to Chemical group was administered normal group. Apoptotic effect protecting in order to observe the chemical group was administered PGE. We to observe effects of PGE on SOD inhibition, total glutathione production in C6 glioma cells were administered PGE. In case of administration PGE, apoptosis induced by Paraquat was significantly decreased. In case of administration PGE, apoptosis induced by SNP was significantly decreased. In case of administration PGE, apoptosis induced by $H_2O_2$ was significantly decreased. In case of administration PGE, apoptosis induced by Rotenone was decreased, but the statistical significance was not. In case of administration PGE, SOD inhibition activities significantly decreased. In case of administration PGE, Total glutathione did not affect the content. These results suggest that PGE is able to treat a disease caused by oxidative stress and prevent a aging. These results suggest that PGE is a disease caused by oxidative stress and aging, the prevention and treatment of food shall be able to be applied.

• Journal of the Korean Wood Science and Technology
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• 제23권2호
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• pp.47-54
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• 1995

This study was to measure the properties of logs and classify them by non-destructive methods. The purpose of this experiment was focused at mensurability of logs by non-destructive methods. The non-destructive instrument, Stress-Wave Timer 239A which was made by Metriguard in U.S.A., was used. The stress wave velocities of log's cross direction were measured and compared with three different methods; 1. with hammer, 2. with hammer and D.B.H. meter, 3. with manufactured instrument. Number of used logs were seven logs, which were classified by naked eye into six groups; very severe rot, severe rot, mild rot & knot, mild rot & check, mild rot, sound log, and in diameter were into three groups; large(57.4cm), medium(36~41.2cm), small(28.9cm) log. The results, which were classified by mensurability with non-destructive methods, were followed; 1. The stress wave velocities were very different between rot and sound log. So it meant the possibility of mensurability of logs by non-destructive method even if high standard error. 2. The stress wave velocities decreased with checks more than with rots, which meant the checks affected speeds more. 3. The stress wave velocities increased with knot. 4. The velocities with manufactured instrument showed lower standard error, so more accurate results than other methods. Especially the required labour decreased from 3~4 to 2 persons. 5. Finally, the mensurability showed more accurate results and made the classification of logs scientific.

• 한국육종학회지
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• 제43권5호
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• pp.391-398
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• 2011

Physiological responses to salinity stress were evaluated in six rice genotypes differing in their tolerance to salinity at the seedling stage. Susceptible genotypes ('Dongjingbyeo', 'Hwayeongbyeo', and 'IR29') showed salt injury symptoms (mean 8.8) and higher visual score under salt stress than that of tolerant ones ('Pokkali', 'IR74009', and 'IR73571'). As salinity affects growth and physiological parameters, the six genotypes thus showed significant reduction because of salt stress. Tolerant Japonica/Indica bred lines ('IR74009', 'IR73571') showed lower reduction, 33.9%, 34.5%, and 50%, respectively, in plant seedling height, dry shoot weight and dry root weight than those of the susceptible Japonica varieties ('Dongjingbyeo', 'Hwayeongbyeo'), and the highest reduction under salt stress was observed in dry root weight, followed by dry shoot weight and seedling height, respectively. Shoot $Na^+$ concentration of IR74099 and IR73571 was lower than that of the susceptible varieties, 'Dongjinbyeo' and 'Hwayeongbyeo'. There were no significant differences among genotypes in root $Na^+$ concentration. Shoot $K^+$ concentration showed a reverse tendency compared to shoot $Na^+$ concentration. IR74009 and IR73571 had considerably lower ratio compared to 'Dongjinbyeo' and 'Hwayeongbyeo' in $Na^+/K^+$ ratio of their shoot and was not different the tolerant check, 'Pokkali'.

• 보건교육건강증진학회지
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• 제24권2호
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• pp.77-91
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• 2007

Purpose: The purpose of this study was to investigate the relationship among health behavior, obesity and QOL, and to identify factors affecting QOL of University Students in rural area, to provide the basic data for health promoting program in order to improve the QOL. Methods: The subjects of this study were 991 university students. The collected data was analyzed using descriptive statistics, t-test, ANOVA, Scheffe's test, Pearson correlation coefficient and Stepwise multiple regression with SAS. Results: In the degree of the obesity were 13.4% of the underweight group, 48.9% of the normal weight group, and 37.6% of the overweight group. The average item score for the QOL was 3.19; the highest score on the subscale was physical domains(M=3.25) with the lowest environmental domains. In the degree of health behavior performance were 15.3% of regular health check, 27.5% of exercise, 45.1% of no-smoking, 32.4% of no-drinking alcohol, 53.1% of sleeping 7-hour, 49.7% of weight care, 56.1% of stress management, and 44.4% of breakfast. The score of QOL was statistically significant difference according to age, occupation of father, the number of brothers, total income, level of life, perceived health status, and admission of hospital. The score of QOL correlated positively with health behavior(r=.2521, p<.0001), and the scores of health behavior correlated positively with obesity(r=.0915, p=.0039). Stepwise multiple regression analysis for QOL revealed that the most powerful predictor was level of life. Stress management, perceived health status, sleeping 7-hour, regular health check, admission of hospital, total income, and weight care explained 13.2% of the variance. Conclusions: Therefore, it is necessary to develop health behavior promotion program in order to enhance the quality of life of university students. Future studies need to be pursued to find significant influencing factors for QOL of university students.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2009년도 추계학술대회 논문집
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• pp.245-249
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• 2009

According to the increase of intelligent vehicles many automotive electric components are installed. The wire harness which connects those also increases. The crimping process for compressing the copper wire bundle into the terminal is a key process to assure the good quality of wire harness. For the case of inadequate forming condition many shape failures such as less-filling, over-filling are happen in the crimping process. Even though the quality of crimping shape is satisfactory the quality check for electrical resistance of wire harness is sometime not satisfied the qualification due to large variation of electrical resistance of wire harness under climate test. This large variation is thought to be related with the malfunction automotive electric system and caused by the internal stress of wire, which occurred during the crimping process. In this paper we develop the 3D-FEM simulation scheme and design methodology of optimum terminal shape. Also the effect of terminal shape on the residual stress is discussed.

• 한국소음진동공학회논문집
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• 제22권1호
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• pp.81-87
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• 2012

This paper establishes a modeling and simulation procedure for structural response and reliability of a cylindrical array sensor on submarines under the shock generated by underwater explosion. The structural reliability of SONAR is important because the submarine could get out of combat ability by the structural damage of the SONAR upon explosion. A cylindrical array sensor was first modeled using the finite element method. Modal analysis was then performed for the check of the reliability of the modeling. The shock resistance simulations were performed for the responses to the structural shock waves and for the responses to the directly applied underwater shock waves, according to BV-043 and MIL-STD-901D, respectively. The stresses of the structure were evaluated with von-Mises scheme. Vulnerable regions were exposed through mapping the maximum stress to the structural model. Maximum stress of the SONAR was compared with the yield stress of the material to examine the structural reliability.