• Steel and Composite Structures
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• v.28 no.1
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• pp.51-61
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• 2018

A new I-girder consisted of top concrete-filled tubular flange and corrugated web has been proved to have high resistance to both global buckling of the entire girder and local buckling of the web. This study carries out theoretical analysis and experimental tests for this new I-girder to investigate the stress distribution in the flanges and in the corrugated web. Based on some reasonable assumptions, theoretical equations for calculating the normal stress in the flanges and the shear stress in the corrugated web are presented. To verify the accuracy of the presented equations, experimental tests on two specimens were carried out, and the experimental results of stress distribution were used to assess the theoretical prediction. Comparison between the two results indicates that the presented theoretical equations have enough accuracy for calculating the stress in the new I-girder, and thus they can be used reliably in the design stage.

• Journal of Korean Academy of Nursing
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• v.27 no.4
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• pp.912-922
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• 1997

The purpose of this study was to examine the effect of supportive nursing on stress reaction of breast cancer patients undergoing chemotherapy. The nonequivalent control group pre-test/post-test design was used for this experimental study. The subjects were 32 patients who were receiving chemotherapy after mastectomies at K hospital in Taegu from June, 1994 to June 1995. Among 32 subjects, 16 were placed in the experimental group and 16 in the control group. The experimental and control groups were tested for general characteristics, trait anxiety, health locus of control, family support, state anxiety, hopelessness, physical stress, and anxiety behavior. Collected data was analized by means of a chisquare test and a t-test for the comparative analysis of the general characteristics and homogeneity of subjects. ANOVA, and MANOVA were used for testing the hypothesis. Reliability of the tools were analyzed using the Pearson Correlation coefficient. The results of this study were as follows : 1. The hypothesis : The stress reaction of the experimental group which took supportive nursing was lower than the stress reaction of the control group : this was supported statistically. The main variable influenced in stress reaction was hopelessness. Supportive nursing for breast cancer patients, who are receiving chemotherapy, was especially effective in the reduction of hopelessness compared to state anxiety, physical stress, and anxiety behavior. 2. An analysis of the difference on stress reaction, according to the frequency of supportive nursing between the control and experimental group, showed the level of hopelessness of the experimental group was lower than the control group after four supportive meeting sessions. But there was no statistical difference in state anxiety, physical stress, and anxiety behavior. In conclusion, this study supported utilization of supportive care as well as demonstrating the effectiveness of the System-Developmental Stress Model developed by Chrisman and Riehl-Sisca.

• Journal of Korean Academy of Nursing
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• v.22 no.3
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• pp.271-296
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• 1992

The purposes of this study were 1) to identify patterns and trends of studies of anxiety and stress and 2) to provide direction on which to base further research. Research studies of anxiety and stress were selected from journals of medical and nursing schools, the Korean Nurse, the Korean Nurses' Academic Society Journal, the Central Journal of Medicine, the New Medical Journal, Monthly Nurse, and from theses and dissertations, which had been conducted for the 20 years from 1970 to 1990. The total population of the studies numbered 463. Seven studies were excluded from the analysis because of duplication, so that 252 studies of anxiety and 204 of stress were analyzed. These studies were analyzed for 1) time of publication or presentation, 2) research design, 3) characteristics of subjects used in each study, 4) types of correlated variables, and 5) types of nursing interventions. Findings obtained in the study were as follows : 1. The number of studies related to anxiety and stress has increased rapidly since the early 1980's. 2. The studies were primarily descriptive throughout the 20 years. However, correlational studies, comparative studies and experimental studies slowly increased. 3. Anxiety studies tend to be conducted more on patients and stress studies with normal subjects in non - experimental research. However, experimental studies were conducted more with patients than with normal subjects. 4. In correlational studies, the trend was to study physical conditions in relation to anxiety, and coping and adaptation in relation to stress. 5. In experimental studies, teaching and information therapy and relaxation were the most popular interventions for anxiety, and supportive care for stress. On the bases of these findings, the following recommendations were made : 1. These patterns of studies related to anxiety and stress in Korea need to be compared with studies conducted in other countries. 2. More attention is needed in terms of research design, reliability and validity of tools, and results of statistical analysis. 3. Meta -analysis should be done to analyze and integrate the results of various studies. 4. For theory testing and identification of useful intervention methods, experimintal studies with the same protocols must be conducted rather than more descriptive studies.

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.12
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• pp.3105-3114
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• 1993

previously, several basic studies in the experimental analysis of stress intensity factors of cracks by slab analogy have been presented by authors. But, for the application of above mentioned method to the analysis of the arbitrarily distributed cracks, there still is several bottlenecks to be overcome in terms of its experimental process and data treatment. Moreover, authors recently proposed an improved experimental method to use the fixed slab analogy device which has promised more accurate measurement of S.I.F. of small cracks. In this paper, for the completion of slab analogy analysis of distributed cracks, a grating imaginary rotation method is introduced. And, to prove its validity, this combined method is applied to the determination of stress intensity factors of theoretically known distributed cracks. The results show good agreement with the existing theoretical solutions and physical crack propagation tendencies.

• Journal of Korea Foundry Society
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• v.13 no.1
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• pp.81-93
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• 1993

It is well-known that the analysis of elasto-plastic thermal stress and deformation are substantially important in optimal design of metal casting mould. The unsteady state thermal stress and deformation generated during the solidification process of ingot and mould have been analyzed by two dimensional thermal elasto-plastic theories. Distributions of temperature, stress and relative displacement of the mould are calculated by the finite element method and compared with experimental results. In the elasto-plastic thermal stress analysis, compressive stress occurred at the inside wall of the mould whereas tensile stress occurred at outside wall. A coincidence between the analytical and experimental results is found to be fairly good, showing that the proposed analytical method is reliable.

• Journal of Korean Biological Nursing Science
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• v.14 no.1
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• pp.41-48
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• 2012

Purpose: This experimental research explored the effects of aroma inhalation on blood pressure, pulse, sleep, stress, and anxiety in patients with essential hypertension who are taking antihypertensive medication. Methods: A pilot survey, pre-test and post-test were conducted. The data were collected from August to October, 2009. The participants were 44 patients randomly assigned to an experimental group (22 people) and a control group (22 people). The experimental group received individual instruction for aroma inhalation, which lasted for 3 minutes. They inhaled blended oils of Lavender, Majoram and Ylang Ylang (The mixed ratio was 4:3:3), three times a day, for two weeks. Data from 36 patients were used for the final analysis (20 from the experimental group, 16 from the control group). Data were analyzed using SPSS version 13.0. Results: Sleep disturbance decreased in the experimental group (t=-2.258, $p$=.030). Blood pressure, pulse, stress, and anxiety were not significantly different between the two groups ($p$ >.05). Additional analysis of the experimental group showed that physical stress and psychological stress were significantly lowered. Conclusion: Aroma inhalation is an effective paramedical intervention for patients with essential hypertension.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.23 no.6 s.165
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• pp.988-1000
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• 1999

An experimental study is presented for the effect of number of terms of a pewee series type stress function on stress analysis around a hole in tensile loaded plate. The hybrid method coupling photoelastsic data inputs and complex variable formulations involving conformal mappings and analytical continuity is used to calculate tangential stress on the boundary of the hole in uniaxially loaded, finite width tensile plate. In order to measure isochromatic data accurately, actual photoelastic fringe patterns are two times multiplied and sharpened by digital image processing. For qualitative comparison, actual fringes are compared with calculated ones. For quantitative comparison, percentage errors and standard deviations with respect to percentage errors are caculated for all measured points by changing the number of terms of stress function. The experimental results indicate that stress concentration factors analyzed by the hybrid method are accurate within three percent compared with ones obtained by theoretical and finite element analysis.

• Journal of Welding and Joining
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• v.16 no.5
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• pp.67-75
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• 1998

This study aimed at he experimental and finite element analytic investigation of the effect of preheating on he residual stress of weldment. In this study, an autogenous arc welding was used on type 304 stainless steel and MARC as F.E.M. common code was utilized in analysis The analyses include transient and moving heat source and thermal properties as function of temperature. During welding, the thermal cycles of four locations in the weldment were recorded to investigate of the behavior of thermal stress and residual stress. The experimental and analytic results had good coincidence and show that there are two factors influencing the formation of welding residual stress in preheat process. One is the elevation of welding equilibrium temperature and the other is the increase of amount of heat input. The former decrease welding residual stress and the latter increase welding residual stress. Therefore, the cumulative effects result in the welding residual stress not being improved significantly with preheating in 304 stainless steel.

• Journal of Korea Foundry Society
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• v.11 no.3
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• pp.245-253
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• 1991

It is known that the analysis of thermal stresses is substantially important in optimal design of casting mould. In this paper unsteady state thermal stresses generated in ingot and mould during the solidification process are analyzed by the two dimensional thermal elasto-plastic analysis. Distribution of temperature and stress of the mould is calculated using the finite element method and compared with experimental result. The significant results obtained in this study are as follows. At the early stage of the casting process, abrupt temperature change was shown in the vicinity of the inner surface of the mould. The largest temperature gradient is occurred at the corner of the mould. In the thermal stress analysis, compressible stress occurred in the inside wall of the mould where as tensile stress on outside wall. Smaller thermal stress is observed at the rounded corner. It is also observed that the shown is influenced by the thickness of the wall. A fairly good coincidence is found between analytical and experimental results, showing that the proposed analytical methodology is reliable.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.1
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• pp.1-7
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• 2003

The optimal design for the shape of MIL-S-46119 ring obturator under the high pressure using parameter stud:』 on the stress analysis considering effects of design variable is presented, and it is compared to experimental results. The trends of parametric study are in good agreement with the experimental results. The more thickness the higher stress. The more taper the higher stress. And maximum stress of circumferential surface is larger than maximum stress of forward surface. The design variable!; are such as thickness, taper, radius of shape of the obturator. In order to optimize the shape of obturation ring, the weight is maximized subject to maximum stress of the obturator within allowable stress. The design constraints are geometric elements of design variables.