• 한국강구조학회 논문집
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• 제14권6호
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• pp.835-843
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• 2002

본 논문은 외부 T스티프너로 보강한 콘크리트 충전각형강관-H형강보 접합부의 응력전달 메카니즘을 유한요소해석을 통해 정확히 이해하고, T스티프너에 관한 설계기본자료를 제공하는데 그 목적이 있다. 따라서 선행된 실대형 접합부의 실험결과와 비선형 유한요소해석의 결과를 비교함으로써 유한요소해석의 신뢰도를 높였다. 유한요소해석에서 접합부의 응력전달 메카니즘을 이해하기 위해 여러 가지의 응력 및 변형도 지수를 사용하였고, 유한요소해석을 통하여 실험에서 발견된 보플랜지와 수평스티프너 접합부의 응력집중을 감소시킬수 있는 방안을 모색하였다.

• Journal of Korean Biological Nursing Science
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• 제13권2호
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• pp.102-108
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• 2011

Purpose: The purpose of this study was to examine the effects of first clinical training on stress, anxiety and changes in autonomic nervous system in nursing students. Methods: Seventy-four nursing students were assigned to the experimental group (n=36) that had two weeks of clinical training, and the control group (n=38) that had only two weeks of regular classes. Perceived stress, state anxiety and heart rate variability (HRV) were measured at the beginning and end of the experiment. Results: Perceived stress in the experimental group was significantly higher than in the control group. However, State anxiety was not significantly different between the two groups. All indices of HRV except LF/HF ratio were significantly different between the two groups. LF norm in the experimental group was significantly higher than in the control group, and HF norm in the experimental group was significantly lower than in the control group. Conclusion: Based on these results, it can be suggested that clinical training increases the perceived stress and affects the changes in autonomic nervous system in nursing students.

• Journal of Korean Biological Nursing Science
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• 제22권2호
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• pp.90-101
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• 2020

Purpose: The purpose of this study was to build and verify a structural model that could predict the severity of irritable bowel syndrome in university students. Methods: Participants were 205 students enrolled in college with irritable bowel syndrome using the irritable bowel syndrome module of the ROME IV Adult Questionnaire. The data were collected using online questionnaires in AprilMay 2019. The data were analyzed using the SPSS WIN 25.0 and AMOS 20.0 programs. Results: 1) The symptom severity that participants experienced were mild (14.6%), moderate (45.4%), and severe (40%). 2) Fit indices of the model were x²= 79.66 (df = 52, p= .009), CFI= .94, TLI= .96, RMSEA= .05, RMR= 1.59, GFI= .94, and TLI= .96.3). The severity of irritable bowel syndrome was influenced directly by anxiety and sleep, and indirectly by family history, perfectionism, social support, coping, and stress. The severity of irritable bowel syndrome was indirectly affected by the following: family history through anxiety; perfectionism through stress, anxiety, and sleep; social support through coping, stress, anxiety, and sleep; coping through stress and anxiety; and stress through anxiety and sleep. Conclusion: Based on the results of this study, a nursing intervention is needed to reduce the anxiety and stress and improve the quality of sleep to improve the health of the college students and manage the symptoms of patients with irritable bowel syndrome.

• Advances in materials Research
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• 제9권2호
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• pp.115-131
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• 2020

Limit elastic speed analysis of Al/SiC-based functionally graded annular disk of uniform thickness has been carried out for two cases, namely: metal-rich and ceramic rich. In the present study, the unknown field variable for radial displacement is solved using variational method wherein the solution was obtained by Galerkin's error minimization principle. One of the objectives was to identify the variation of induced stress in a functionally graded disk of uniform thickness at limit elastic speed using modified rule of mixture by comparing the induced von-Mises stress with the yield stress along the disk radius, thereby locating the yield initiation. Furthermore, limit elastic speed has been reported for a combination of varying grading index (n) and aspect ratios (a/b).Results indicate, limit elastic speed increases with an increase in grading indices. In case of an increase in aspect ratio, limit elastic speed increases up to a critical value beyond which it recedes. Also, the objective was to look at the variation of yield stress corresponding to volume fraction variation within the disk which later helps in material tailoring. The study reveals the qualitative variation of yield stress for FG disk with volume fraction, resulting in the possibility of material tailoring from the processing standpoint, in practice.

• 한국간호교육학회지
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• 제28권1호
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• pp.70-79
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• 2022

Purpose: The purposes of this study were to develop and test a model for the effects of grit, gratitude disposition, and stress on the psychological well-being of nursing students during the Coronavirus-2019 pandemic. Methods: The data were collected from June 9 to June 27, 2021. A total of 286 nursing students responded to an online questionnaire. In the hypothesis's model, the exogenous variables were grit and gratitude disposition, and the endogenous variables were nursing students' stress and psychological well-being. Data were analyzed using the SPSS/WIN and AMOS programs. Results: The final model showed the following indices of goodness of fit: χ²=78.30, χ²/df=3.01, GFI=.95, CFI=.96, TLI=.94, SRMR=.05, and RMSEA=.08. Nursing students' psychological well-being was explained by their grit, gratitude disposition, and stress directly and indirectly, with these three variables explaining 56% of psychological well-being. Conclusion: This study identified factors affecting the psychological well-being of nursing students in a state of increased stress due to the COVID-19 pandemic. The results of this study can be a basis for developing and applying a program to enhance nursing students' psychological well-being.

• 통합자연과학논문집
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• 제9권4호
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• pp.241-248
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• 2016

Corticotropin-releasing factor receptors (CRFRs) activate the hypothalamic-pituitary-adrenal axis, which is an integral part of the fight or flight response to stress. Increase in CRH level is observed in Alzheimer's disease and major depression and hypoglycemia. Here, we report on the relevant physicochemical parameters required for the CRFR inhibitors. Comparative molecular similarity indices analysis (CoMSIA) was performed with the derivatives of 8-substituted-2-aryl-5-alkylaminoquinolinesas CRFR inhibitors. The best predictions were obtained for the best CoMSIA model with a $q^2$ of 0.576 with 6 components and $r^2$ of 0.977. The statistical parameters from the generated CoMSIA models indicated that the data are well fitted and have high predictive ability. CoMSIA contour maps could be useful in the designing of more potent and novel CRFR derivatives.

• 조명전기설비학회논문지
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• 제23권11호
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• pp.76-83
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• 2009

In today's competitive power market, electric power utilities have strived to provide energy at an acceptable level of quality due to increased expectations from customers. For this reason, electric power utilities have invested in electric equipment and new techniques. That is the Distribution Automation System (DAS). A merit of DAS is the ability to reduce outage time because of fast service restoration. However, DAS is usually installed in outdoor environments. Therefore, their efficiency is affected by the external conditions. Lightning creates varying degrees of physical stress on DAS. This paper focuses on the reliability of DAS for lightning. Four application studies were performed to compare the reliability indices.

• 대한수의학회지
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• 제47권4호
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• pp.483-488
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• 2007

To determine the effects of anesthesia to clove oil on the secondary stress indices, changes in haematological and blood chemistry were monitored in healthy crucian carps (Carassius auratus). 24 fishes were divided into three groups, and blood was collected before anaesthesia (control group), immediately after anaesthesia at a concentration of 30 mg/l clove oil (anesthetized group), and 24 h after anaesthesia (recovered group). The anesthesia to clove oil significantly increased glucose in anaesthetized group, and constantly decreased lactate dehydrogenase in anaesthetized group and recovered group. However, clove oil had not effect on other biochemical indices. These results suggests that the anesthetic use of clove oil at a concentration of 30 mg/l does not cause irreversible damage in carp.

• Journal of Electrical Engineering and Technology
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• 제8권4호
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• pp.694-703
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• 2013

In electric power system, the line stability indices adopted in most of the instances laid stress on variation of reactive power than real power variation of the transmission line. In this paper, a proposal is made with the formulation of a New Voltage Stability Index (NVSI) which originates from the equation of a two bus network, neglecting the resistance of transmission line, resulting in appreciable variations in both real and reactive loading. The efficacy of the index and fuzzy based load flow are validated with IEEE 30 bus and Tamil Nadu Electricity Board (TNEB) 69 bus system, a practical system in India. The results could prove that the identification of weak bus and critical line in both systems is effectively done. The weak area of the practical system and the contingency ranking with overloading either line or generator outages are found by conducting contingency analysis using NVSI.

• Korea-Australia Rheology Journal
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• 제16권3호
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• pp.129-134
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• 2004

The aggregation characteristics of red blood cells (RBCs) were measured using a newly developed light-transmission slit rheometer. Conventional methods of RBC disaggregation such as the rotational Couette system were replaced with a pressure-driven slit flow system with a vibrational mechanism. Using a vibration generator, one can disaggregate the RBC aggregates stored in the slit. While shear stress decreases exponentially, instantaneous pressure and the transmitted light intensity were measured over time. Applying an abrupt shearing flow after disaggregation caused a rapid elongation of the RBCs followed by loss of elongation with the decreasing shear stress. While the shear stress is further decreasing, the RBCs start to re-aggregate and the corresponding transmitted intensity increases with time, from which the aggregation indices can be obtained using a curve-fitting program.