• Structural Engineering and Mechanics
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• 제40권6호
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• pp.801-811
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• 2011

A new experimental technique was developed on the plate-inserted welded tubular joints of spatial grid structures. In the experimental technique, a microcomputer controlling instrument of moire intervention (MCIMI) was adopted. A test was designed on the plate-inserted welded tubular joints of spatial grid structures to show the effectiveness of the MCIMI technique. Both traditional electrical measuring technique and MCIMI technique were employed in the test. The test results showed that the MCIMI technique was feasible in the case of the complicated tests on steel structures. The MCIMI technique not only implemented the limitation of traditional electrical measuring technique, but also improved the accuracy of the test. According to the test results, we further examined the plate-inserted welded tubular joints in the cable-stayed spatial grids of the Binhai International Convention & Exhibition in Tianjin, China. The analysis showed the joints are safely designed with adequate conservatism. The research provided a new application of MCIMI in the field of large-scale structure engineering.

• Journal of the Optical Society of Korea
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• 제16권3호
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• pp.215-220
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• 2012

In an earlier work, we proposed the chromatic dispersion monitoring technique of non-return to zero (NRZ) signal based on clock-frequency component (CFC) through numerical simulations. However, we have not yet shown any experimental demonstration or analytic derivation of it. In this paper, we show an experimental demonstration and analytic derivation of the proposed chromatic dispersion monitoring technique. We confirm that the experimental results and the analytic results correspond with the simulation results. We also demonstrate that monitoring range and accuracy can be improved by using a simple clock-extraction method.

• 대한기계학회논문집A
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• 제24권6호
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• pp.1427-1437
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• 2000

In the authors＇ preceeding paper, an improved component mode synthesis (CMS) technique in which experimental data as well as finite-element data are available in sub-systems has been proposed. Thi s technique, called an improved experimental free-interface method (IEFIM), has been proved to be more accurate and more efficient than the conventional experimental CMS method based on McNeal's formulation. It is due to the facts that dynamic residual terms as well as static ones are compensated from experimentally obtained FRFs and that FRFs measured on any frequencies can be used for the compensation. In this paper, the technique is applied to the component mode synthesis of a car body structure. As a result, the applicability of the technique to a large structure is demonstrated.

• 대한물리치료과학회지
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• 제31권1호
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• pp.1-15
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• 2024

Background: This study was conducted to apply active release techniques to male youth basketball players to help improve physical development and damage prevention and improve performance through improved balance and functional movement. Design: Randomized control trial. Methods: The subjects included 33 youth basketball players who were randomly assigned to the experimental group (n=17) and the control group (n=16). For the experimental group, the active release technique was applied to the hip muscles, calf muscles, posterior thigh muscles based on the distribution of injuries surveyed in youth basketball players in the Korean Basksetball League. The Y-balance test and the functional reach test (FRT) were used to assess balance and the Functional Movement Screen (FMS) was used to assess functional movement. Interventions were conducted twice a week for 4 weeks at 40 minutes per session. The experimental group was the active release technique group, and static stretching, a common exercise therapy technique, and self-myofascial release using a foam roller were applied for 20 minutes. The control group received general exercise therapy and placebo active release technique. The placebo active release technique applies pressure only. results:The experimental group showed a greater improvement in balance, as evidenced by the FRT, compared to the control group, which received general exercise treatment. However, there was no statistically significant difference in improvement between the 2 groups. In the case of the experimental group, the difference in the Y balance test before and after the intervention was larger than that of the control group, but there was no statistically significant difference. Significant improvement was found in functional movement, as evidence by the FMS, for the trunk stability test (p < 0.05), in-line lunge test (p < 0.05), rotational stability test (p < 0.05), total score (p < 0.05). Conclusion: In this study, the active release technique improved the balance and functional movement of young basketball players more than general exercise therapy. The application of the active release technique is therefore expected to assist in physical development, prevent damage, and improve the performance of youth basketball players.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 1998년도 춘계 학술대회논문집
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• pp.1-14
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• 1998

Underwater explosion properties for TNT, an ideal explosive, and DXD-04, a nonideal explosive, were numerically modeled with a one-dimensional Lagrangian hydrodynamic code. The equation of state parameters for detonation products for TNT and DXD-04 were obtained from the BKW code, assuming complete reaction. Burn of TNT was modeled by using the Chapman-Jouguet(CJ) volume burn technique, a programmed-burn technique, assuming instantaneous detonation reaction. Burn of DXD-04 was modeled by using the same technique and by using the reaction rate calibrated from two-dimensional steady-state detonation experiments. The calculations for TNT reproduced the experimental peak pressure of the shock wave propagating through water with an error of $3.0\%$ and the experimental oscillation period of the bubble formed of detonation products with an error of $2.3\%$. For DXD-04, the CJ volume burn technique could not reproduce the experimental observations. When the reaction rate calibrated from two-dimensional steady-state detonation experimental data, the calculated peak pressure was slightly higher by $7.3\%$ than the experimental data, but the calculated shock profile was in good agreement. The bubble period was reproduced with an error of $1.8\%$. These results demonstrated that underwater explosion properties for an ideal explosive can be predicted by using a programmed burn technique, and that, however, those for a nonideal explosive can be predicted only when a well-calibrated reaction rate is used.

• Journal of Electrical Engineering and Technology
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• 제10권3호
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• pp.916-924
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• 2015

Electromagnetic Interference (EMI) is a system to system or environment to system phenomenon. The literature survey proved that the Randomized Pulse Width Modulation (RPWM) technique is a promising technique to reduce EMI. A new Constant Trailing Edge, Randomized Pulse Width Modulation (CTERPWM) technique is proposed in this paper. The effect of the proposed RPWM technique for mitigation of conducted-EMI on Cuk converter operating in Continuous Conduction Mode (CCM) is simulated and tested. In this paper, the analytical expressions for the Power Spectral Density (PSD) are derived for the proposed RPWM technique and are validated by experimental measurements. The effectiveness of the proposed RPWM technique on the mitigation of conducted-EMI is verified comparing simulation and experimental results and it is identified that both the results are almost similar with allowable experimental deviations. The comparative investigation proves that the proposed RPWM technique can mitigate and spread the dominant peaks of conducted-EMI over the complete spectrum for the Cuk converter. Based on the investigation the CTERPWM technique is recommended for adoption.

• 소성∙가공
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• 제11권7호
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• pp.614-619
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• 2002

For an accurate measurement of the material behavior of small structures, a new optical experimental technique is proposed to measure the deformation. The test method uses the dual microscope that can measure the relative deformation of two adjacent regions. The magnified view is captured by CCD cameras and the relative deformation can be measured by the pattern matching and tracing method. Using this experimental technique, the deformation of solder joints in electronic packaging and the strain of the nickel thin film are measured.

• 기본간호학회지
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• 제6권1호
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• pp.7-17
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• 1999

This study investigated the degree of knowledge achievement and self-confidence in aseptic technique as a part of the fundamental nursing practice classes. The subjects were 220 nursing students in a junior college in Chonnam and an applied Quasi-experimental research methodology was used thirty of them comprised an experimental group to examine learning according to the teaching method. Wata were collected over 80 days, from April to June 1988, analyzed using descriptive statistics, percentages, means, t-test, one way ANOVA, Pearson's correlation coefficient and stepwise multiple regression with the SAS program. The conclusions are as follows. 1. The mean score of the degree of knowledge achievement of aseptic technique of the 220 students was 0.68(possible score 1.0) before the lecture but was 0.88 after lecture(p=.000). 2. The mean score for aseptic technique of the 220 students was 3.41(possible score 5.0) before practice but was 4.27 after practice(p=.000). 3. The correlation of self-confidence before and after practice was relatively low(r=.25, p=.000). 4. The mean score of the degree of knowledge achievement of aseptic technique in the experimental group(selected 30 students) was 0.72 before the lecture but was 0.90 after the lecture. 5. The mean score of self-confidence on aseptic technique in the experimental group(selected 30 students) was 3.18 before practice but was 4.32 after practice(p=.000). 6. The mean score of learning according to the type of teaching to aseptic technique for the experimental group(selected 30 students) was 23.2(possibel score 34) after lecture and presentation, was 27.3 after learning through video tape, was 31.7 after presentation through practice, was 33.7 after first practical training, and was 34 after secondary practical training. As a result of this study, learning methods in the education of fundamental nursing skill effective for knowledge achievement and competence in practicing skill.

• PNF and Movement
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• 제21권2호
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• pp.185-192
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• 2023

Purpose: This study aimed to confirm the effectiveness of the diaphragm stretching technique as a treatment method for low back pain by evaluating maximum inspiratory pressure, maximum expiratory pressure, and changes in back mobility in patients with low back pain. Methods: Thirty-four patients with low back pain were randomly divided into two groups: an experimental group and a control group. The diaphragm stretching technique was conducted in the experimental group, and the placebo intervention was conducted in the control group. The diaphragm stretching technique was conducted once, maintaining tension for 7 min. The placebo intervention was conducted in the same position as the diaphragm stretching technique, but with only light contact maintained without pressure. Maximum inspiratory pressure, maximum expiratory pressure, and back mobility were measured before and after the intervention, and the changes were compared and analyzed. A paired sample t-test was used to compare measurements within the group before and after the intervention. An independent t-test was used to compare the experimental and control groups. Statistical significance (α) was set at 0.05. Results: In the experimental group, maximum inspiratory pressure, maximum expiratory pressure, and back mobility increased significantly after the intervention (p < 0.05). However, there was no significant difference in the changes in all areas of the control (p > 0.05). As a result of comparative analysis of changes before and after the intervention, there were significant differences in maximum inspiratory pressure, maximum expiratory pressure, and back mobility only in the experimental group (p < 0.05). Conclusion: The diaphragm stretching technique improved maximum inspiratory pressure, maximum expiratory pressure, and back mobility compared to the placebo intervention. Therefore, the diaphragm stretching technique can be recommended as a physical therapy intervention to improve pain in patients with LBP.

• Interaction and multiscale mechanics
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• 제1권2호
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• pp.177-190
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• 2008

In this paper, both experimental measurement and theoretical analysis are used to investigate the out-of-plane resonant characteristics of a cantilevered piezoceramic plate in air and three different kinds of fluid. The experimental method, amplitude-fluctuation electronic speckle pattern interferometry (AF-ESPI), is the major technique used in this study to measure the resonant characteristics of the cantilivered piezoceramic plate. Both resonant frequencies and full-field mode shapes are obtained from this experimental technique. Numerical computations based on the finite element analysis are presented for comparison with the experimental results. Good quality of mode shapes for the cantilevered piezoceramic plate in air is obtained from the AF-ESPI technique. However, the quality decreases as the viscosity of fluids increases. From the results provided from experimental measurements and numerical computations, it is indicated that the resonant frequencies of the cantilevered piezoceramic plate in fluid decrease with the increase of the viscosity of fluids. Good agreements between the experimental measured data and the numerical calculated results are found for both resonant frequencies and mode shapes of the cantilevered piezoceramic plate in fluid.