• Wind and Structures
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• v.5 no.6
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• pp.543-562
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• 2002

The main purpose of this study is to discuss the design wind loads for the structural frames of single-layer latticed domes with long spans. First, wind pressures are measured simultaneously at many points on dome models in a wind tunnel. Then, the dynamic response of several models is analyzed in the time domain, using the pressure data obtained from the wind tunnel experiment. The nodal displacements and the resultant member stresses are computed at each time step. The results indicate that the dome's dynamic response is generally dominated by such vibration modes that contribute to the static response significantly. Furthermore, the dynamic response is found to be almost quasi-static. Then, a series of quasi-static analyses, in which the inertia and damping terms are neglected, is made for a wide range of the dome's geometry. Based on the results, a discussion is made of the design wind load. It is found that a gust effect factor approach can be used for the load estimation. Finally, an empirical formula for the gust effect factor and a simple model of the pressure coefficient distribution are provided.

• Composites Research
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• v.22 no.4
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• pp.1-12
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• 2009

In this paper, quasi-static crushing tests of composite circular tubes under axial compression load are conducted to investigate the energy absorption characteristics. Circular tubes used for this experiment are glass/epoxy (GFRP) composite tubes which are fabricated by the filament winding method. One edge of the composite tube is chamfered to reduce the initial peak load and to prevent catastrophic failure during crushing process. Energy absorption characteristics vary significantly according to the constituent materials, fabrication conditions, tube geometry and test condition. In tube geometry, according as inner diameter increase, unstable crush mode is caused by local buckling of delamination, but control of the fiber orientation should help composite tubes get stable crush mode.

• Journal of Korean Home Economics Education Association
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• v.19 no.1 s.43
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• pp.65-79
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• 2007

The purpose of this study was to test the effects of practical reasoning home economics instruction on middle school students' views of home economics. Thomas(1986) categorized six alternative views of home economics as education for women, manual training, application of science, household management, family development, and an intervention. This study carried a quasi-experiment research with an independent variable of types of instruction and a dependent variable of views of home economics. The experiment was carried with the sample of 137 8th grade students in Gwangju area for ten class hours. Paired t-test was performed to examine the pretest-posttest differences of each experiment group and comparison group. The results showed that practical reasoning instruction improved level of the view of home economics as an intervention, and decreased level of the view of home economics as manual training. From the results of this study, conclusion can be made that practical reasoning home economics instruction is effective in changing to the appropriate views of home economics. Also it is expected that current Korean home economics textbook can lead to the views of home economics as household management and as family development.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.50 no.7
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• pp.465-470
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• 2022

This paper studied the high-velocity impact behavior characteristics of metal materials by crosschecking the high-velocity impact analysis with the high-velocity impact experiment results of aluminul 6061. The coefficients of the Huh-Kang material model and the Johnson-Cook fracture model were calculated through quasi-static using MTS-810 and dynamic experimenting using the Hopkinson bar equipment for high-velocity impact analysis. The penetration velocity and shape were predicted through high-velocity impact analysis using the LS-DYNA. The resultes were compared with the experiment results using a high-velocit experiment equipment. It is intended to be used the containment evaluation research for aircraft gas turbine engine blade.

• Journal of International Academy of Physical Therapy Research
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• v.10 no.4
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• pp.1873-1878
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• 2019

Background: Walking is a complex activity. The main components of walking include balance, coordination, and symmetrical posture. The characteristics of walking patterns of stroke patients include slow walking, measured by gait cycle and walking speed. This is an important factor that reflects post-stroke quality of life and walking ability. Objective: This study aimed to examine the effect of deep lumbar muscle stabilization exercise on the spatiotemporal walking ability of stroke patients. Design: Quasi-experial study Methods: The experiment was conducted 5 times per week for 4 weeks, with 30 minutes per session, on 10 subjects in the experimental group who performed the deep lumbar muscle stabilization exercise and 10 subjects in the control group who performed a regular exercise. Variables that represent the spatiotemporal walking ability (step length, stride length, step rate, and walking speed) were measured using GAITRrite before and after the experiment and were analyzed. Results: There was a significant difference in the pre- and post-exercise spatiotemporal walking ability between the two groups (p<.05). Furthermore, there was a significant difference in the step rate and walking speed between the two groups (p<.05). Conclusions: Deep lumbar muscle stabilization exercise is effective in improving the walking ability of stroke patients. Therefore, its application will help improve the spatiotemporal walking ability of stroke patients.

• Nuclear Engineering and Technology
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• v.54 no.8
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• pp.2898-2914
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• 2022

When evaluating energy balance and temperature in reduced-scale fire experiments, which are conducted as an alternative to full-scale fire experiments, it is important to consider the similarity in the scale among these experiments. In this paper, a method considering the similarity of energy balance is proposed for setting the conditions for reduced-scale experiments of mechanically ventilated compartment fires. A small-scale fire experiment consisting of various cases with different compartment geometries (aspect ratios between 0.2 and 4.7) and heights of vents and fire sources was conducted under mechanical ventilation, and the energy balance in the quasi-steady state was evaluated. The results indicate the following: (1) although the compartment geometry varies the energy balance in a mechanically ventilated compartment, the variation in the energy balance can be evaluated irrespective of the compartment size and geometry by considering scaling factor F (∝h_effA_wR_T, where h_eff is the effective heat transfer coefficient, A_w is the total wall area, and R_T is the ratio of the spatial mean gas temperature to the exhaust temperature); (2) the value of R_T, which is a part of F, reflects the effects of the compartment geometry and corresponds to the distributions of the gas temperature and wall heat loss.

• Research in Community and Public Health Nursing
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• v.25 no.2
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• pp.146-157
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• 2014

Purpose: The objective of this study is to analyze systematically the trends of experimental researches in the area of community health nursing. Methods: This is a study based on literature review, which analyzed 137 experimental research papers in the Journal of Korean Academy of Community Health Nursing, from the first issue in 1989 to those in 2012. Results: 1) The proportion of experimental researches in the total published papers was 14.9%. 2) The mainly used research method was quasi-experiment, which was 60.6% of them, and there was no RCT. 3) Convenient sampling was used in 95.6% of the researches. 4) Only 5.1% were reviewed for keeping the ethical standards for the study objects by the IRB. 5 When classified by the Omaha Classification System, psycho-social researches were most frequent, which were followed by physiological, health-related behavioral, and environmental ones in order of frequency. Conclusion: This study found that the proportion of experimental research papers was increasing in the 2000s and ethical standards were required more rigorously. However, it was suggested that the research design be more elaborated and sampling methods be manifested to reduce research bias and errors.

• Korean Journal of Adult Nursing
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• v.19 no.5
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• pp.115-126
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• 2007

Purpose: The present study is a quasi-experimental research for examining the effects of imagery on stress, anxiety and immune cells in acute leukemia patients receiving chemotherapy and utilizing the therapy for their self control and stress management. Methods: The subjects were 60 patients who were diagnosed with acute leukemia and scheduled to receive chemotherapy at A hospital in Seoul during the period from November 2006 to March 2007. After the start of chemotherapy, the experimental group received imagery for 4 weeks, three sessions a week, so a total of 12 sessions and 156 minutes. Results: The decrease of stress was larger in the experimental group than in the control group. Systolic blood pressure decreased significantly more in the experimental group than in the control group. In the experimental group, state anxiety decreased significantly in the 2nd week of the experiment and after the final stage of the experiment. The total number of white blood cells, and the absolute number of neutrophils and lymphocytes were showing significant differences between the time points. Conclusion: Imagery is an effective intervention for reducing stress and state anxiety and stabilizing blood pressure in acute leukemia patients receiving chemotherapy.

• Nuclear Engineering and Technology
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• v.54 no.7
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• pp.2540-2549
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• 2022

For a pressurized water reactor power plant, the reactor coolant pump (RCP) is a kernel component. And for a canned motor RCP, the rotor system's properties determines its safety. The liquid coolant inside the canned motor RCP fills clearance between the metal shields of rotor and stator, forming a lengthy clearance flow. The influence of inlet preswirl on rotordynamic coefficients of clearance flow in canned motor RCP and their effects on the rotordynamic characteristics of the pump are numerically and experimentally investigated in this work. A quasi-steady state computational fluid dynamics (CFD) method has been used to investigate the influence of inlet preswirl. A vertical experiment rig has also been established for this purpose. Rotordynamic coefficients on different inlet preswirl ratios (IR) are obtained through CFD and experiment. Results show that the cross-coupled stiffness of the clearance flow would change significantly with inlet preswirl, but other rotordynamic coefficients would not change significantly with inlet preswirl. For the case of clearance flow between the stator and rotor cans, influence of inlet preswirl is not so significant as the IR is not large enough.

• The International Journal of Costume Culture
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• v.9 no.2
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• pp.94-103
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• 2006

The purposes of this study were to found out the effects of appearance variables in fashion coordination cues of a male stimulus person and perceiver's traits on the liking of the stimulus person with person perception theory as the research background. The study consisted of a survey and a quasi-experiment. The experimental materials used for this study were 18 stimuli and instruments to measure fashion interest, liking toward the stimulus, and gender body ideology. The sampling method was a convenient sampling. The subjects consisted of 940 male and female undergraduate students aged from 18 to 51, in three areas including Daejoen, Cheongyang and Nonsan provinces. The data collection was conducted between May 1 and June 30, 2004. The validity of the measuring instruments were confirmed by pre-tests and judge group discussions, and reliability was evaluated by Cronbach' alpha analysis. The results showed that Clothing formality, make-up, hair style of stimulus person, and traits of subjects meaningfully affected on the liking toward the stimulus person. The result of the study will serve as a basic information on total fashion coordination for young male adults.