• Bulletin of the Korean Chemical Society
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• 제12권3호
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• pp.309-315
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• 1991

The thermal transport coefficients-the self-diffusion coefficient, shear viscosity, and thermal conductivity-of liquid argon at 94.4 K and 1 atm are calculated by non-equilibrium molecular dynamics (NEMD) simulations of a Lennard-Jones potential and compared with those obtained from Green-Kubo relations using equilibrium molecular dynamics (EMD) simulations and with experimental data. The time-correlation functions-the velocity, pressure, and heat flux auto-correlation functions-of liquid argon obtained from the EMD simulations show well-behaved smooth curves which are not oscillating and decaying fast around 1.5 ps. The calculated self-diffusion coefficient from our NEMD simulation is found to be approximately 40% higher than the experimental result. The Lagrange extrapolated shear viscosity is in good agreement with the experimental result and the asymptotic formula of the calculated shear viscosities seems to be an exponential form rather than the square-root form predicted by other NEMD studies of shear viscosity. The agreement for thermal conductivity between the simulation results (NEMD and EMD) and the experimental result is within statistical error. In conclusion, through our NEMD and EMD simulations, the overall agreement is quite good, which means that the Green-Kubo relations and the NEMD algorithms of thermal transport coefficients for simple liquids are valid.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2000년도 추계 학술발표회 논문집 Proceedings of EESK Conference-Fall 2000
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• pp.389-396
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• 2000

Fatigue behavior of shear joints between combined reinforced concrete(RC) and reinforced steel fiber concrete(RSFC) specimens has been experimentally investigated. Experimental parameters used are the amount of steel fiber and the type of shear joint. 6 specimens have been tested under static load, and 8 specimens have been subjected to the fatigue load in a range of 50% and 5 % of the ultimate static load. The purpose of this research is to propose an empirical formula for fatigue shear behavior of combined RC and RSFC structures on the basic of experimental result. It can be observed from experimental result that addition of steel fibers to concrete specimen increases the static ultimate load by approximately 25%, enhances the fatigue behavior, and also reduces vertical and lateral displacements at the shear joint for a given load cycle after the occurrence of first crack.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2003년도 춘계전력전자학술대회 논문집(1)
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• pp.49-53
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• 2003

In this paper, to analyze efficiency characteristic, one of important factors in design of DC-DC converter prototype, theoretically derived power loss of individual components generating in DC-DC converter and compared theoretical results with experimental results. For evaluation of results, active clamp type Forward DC-DC converter with synchronous rectifier was composed of experimental converter. Efficiency result measured in experimental converter was compared with theoretical efficiency result derived in this paper. In comparative results, a fact that derived theoretical value and experimental value comparatively correspond have been able to verify.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 춘계학술대회논문집
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• pp.816-820
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• 2003

The objective of this paper is to develop an experimental technique to measure the in-plane vibration intensity of a plate. In order to measure the in-plane vibration intensity at a data point, the frequency response functions for the 2 components of an acceleration vector are measured at each point of 4 points in the neighborhood of the data point. This experimental technique has been implemented to measure the in-plane vibration intensity of a plate. The experimental result has been compared with a theoretical result. It showed that the experimental technique can be effectively used to measure the in-plane vibration intensity of plates.

• 대한조선학회논문집
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• 제45권3호
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• pp.309-314
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• 2008

An experimental method to estimate the added mass of a marine propeller has been developed for the axial rigid body motion in still water, and the experiments have been carried out. The experimental result has been compared to the theoretical result by PRODAS based on the unsteady lifting surface theory. The experimental method developed in this research and the theoretical method by PRODAS have been validated by confirming good agreements between the experimental results and the theoretical ones. Also the comparison to the results by empirical formula has been made and discussed.

• 한국세라믹학회지
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• 제44권4호
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• pp.235-239
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• 2007

For the pressure compaction process of the ceramic powder, the density distribution is very important for the uniform shrinkages at the sintered body. In this paper, we fabricated alumina green body using compaction process and simulated about same condition. Then comparison of simulation and experimental result confirmed that accuracy of simulation. On the average density of top and lower part was each $2.41g/cm^3,\;2.27g/cm^3$ and deviation at final step was calculated with 0.06 in simulation. Also, experiments show that total density of top and lower part was each $2.59g/cm^3,\;2.36g/cm^3$, and deviation was 0.09. Conclusion, that was not a difference to the simulation and experimental result. The application using the finite element simulation method is possible optimization of the compressing process, predict generated part of cracks and there is a possibility of getting result of more fast, more accurate then existing experience method.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 추계학술대회
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• pp.1631-1636
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• 2003

The purpose of this study is to analyze the phenomena of the thermally-induced vibration for the flexible space structure due to abrupt change of radiation heating circumstance using the numerical analyze and experiment test. In order to verify this structure, numerical approaches on the simplified flexible tube were compared with experimental test results at the ground experimental facility In this analyze, it was found that the thermal deformation occurs firstly due to fast radiation heating of flexible structure and then the thermally-induced vibration would be induced due to small periodic change of temperature. According to comparison of numerical and experimental result, in case of no tip mass, the first mode vibration by the numerical analyze was O.78Hz same as that of the experimental result However in case of increase tip-masses of 8g l6g, 50g and 100g, the first modes vibration theoretical analyze were 1.75Hz, 1.3Hz, 0.87Hz and O.73Hz, in decrease trend respectively and those by experimental test were 234Hz, 1.5Hz, O.78Hz and O.78Hz in decrease trend respectively Although using the simpled equation for the estimation, the estimation results were similar to experimental results.

• The Journal of Korean Physical Therapy
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• 제11권3호
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• pp.97-106
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• 1999

The purpose of this study was to examine the effect of transcutaneous electrical nerve stimulation(TENS) in the patients of dysmenorrhea. A total of thirty subjects were assigned randomly to one of the two experimental groups or to a control group : 1) an Experimental group I received high-frequency TENS(100pps with a 100-microsecond pluse width), 2) an Experimental group II received low-frequency TENS(2pps with a 100-microsecond pulse width), 3) a Control group received medication(Acetaminophen 600mg). All subjects completed visual analogue scale(VAS) pre-treatment; after post-treatment; 1, 2, 3, 4, and 6 hours post-treatment; and the next morning. The results of study were as follows; 1. The mean pain scores decreased in thru groups. 2. The experimental group II and the control group exhibited a significant decrease in pain post - treatment. 3. The experimental group I had the pain relief obtained after three hours post - treatment. The experimental group II had the pain relief obtained immediately after the post - treatment Control group had the pain relief obtained immediately after the post - treatment, but increased pain after four hours of post-treatment. Finally. this result suggests that TENS can reduce significantly the pain of dysmenorrhea. Besides. low-frequency TENS provided a good result to the excellent subjective pain relief in the subject, compared with high-frequency TENS and medication.

• 대한지구과학교육학회지
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• 제4권1호
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• pp.57-65
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• 2011

The purposes of this study investigated the effects of placement of analogy on the conceptual changes of air of elementary students, while learning the air conceptions. The subjects consisted of 108 students who are in the sixth grade classes in an elementary school in Busan city. For this study, comparative group(37 members), experimental group I(37 members), and experimental group II(34 memgers) were selected. A pre-test and a post-test on the air conception were done both for the comparative group and the experimental groups. The results are as follows. First, the averages of experiment group I and II are statistically higher than comparative group's. By the way, it just has a small gap between the comparative group and the experimental II. In other words, activity of analogy does not keep always constant to change of air conceptions of elementary students. Therefore, it has a different reason that only before or after during the analogy. Second, it shows that experimental group I has effected on a more change of air conceptions as compared with experimental group II. Then, the first group's result shows better than the other group's result. From this result, six grade students showed a change of air conceptions very well by analogy. It means if the analogy is given to students at the beginning state of chapter, they can understand scientific concepts easily.

• 대한물리의학회지
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• 제16권1호
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• pp.93-101
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• 2021

PURPOSE: This study examined the effects of a myofascial release technique with preservation physical therapy on low back pain, range of motion, and physical function of patients in acute traffic accidents METHODS: Twelve patients with traffic accidents were divided randomly into two groups of six patients each who met the selection criteria. The training was conducted for 45 minutes each time, for two weeks and four times per week. The experimental group received four myofascial release techniques and with preservation physical therapy. The control group received only preservation physical therapy. RESULTS: The VAS test result was statistically significant after the intervention in both groups (p < .05). After the intervention, there was no significant difference between the experimental group and control group. The Schober test result was statistically significant after the intervention in both the experimental and control groups (p < .05), and there was a significant difference between the experimental group and control group after the intervention (p < .05). The KODI assessment result was significant after the intervention in both the experimental and control groups (p < .05), and there was a significant difference between the experimental group and control group after the intervention (p < .05). CONCLUSION: The myofascial release technique with preservation physical therapy had a positive effect on low back pain, range of motion, and body function in acute traffic accident patients.