• Journal of the Korean Society of Physical Medicine
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• v.4 no.3
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• pp.157-164
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• 2009

Purpose：The purpose of this study was to investigate the effects of angular velocity on muscle strength of biceps brachii. Methods：Subjects was classified into two groups, which were $60^{\circ}/sec$ angular velocity group(n=15) and $240^{\circ}/sec$ angular velocity group(n=15). Each group was applied to perform the isokinetic exercises on flexion muscle group for each 10 times in 3 set(3 days per a week for 2 weeks). Muscle strength was measured using peak torque of biceps brachii. Results：The results were as follows: The peak torque was significantly increased after $60^{\circ}/sec$ angular velocity isokinetic exercise application(p<.05), however, it was not significantly after $240^{\circ}/sec$ angular velocity isokinetic exercise application(p>.05). Conclusions：This study showed that $60^{\circ}/sec$ angular velocity isokinetic exercise application were effective treatment strategy on increase of muscle strength. Therefore, it could be considered as a treatment method in the athlete and patients with musculoskeletal disease.

• Composites Research
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• v.18 no.1
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• pp.38-44
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• 2005

In this paper, the group velocity dispersion curves of the $S_o$ symmetric mode in unidirectional CFRP plate was calculated as varying the propagating direction. The group velocity curve was obtained with the group velocities of the $S_o$ symmetric mode corresponding to 0.2 MHz-mm under the first cut-off frequency in the dispersion curves, and corrected by introducing the slowness curve. The velocities of the $S_o$ symmetric mode in the unidirectional CFRP plate were measured as varying the propagating direction and compared with the col?rotted group velocity curve. The measured velocities were good agreement with the corrected group velocity curve except near the fiber direction which was called the cusp region. It implies that the direction of the group velocities incline toward the fiber direction of the unidirectional CFRP plates when the propagation direction is not accorded with the principal axis. It is supposed that this phenomenon rerults from the preferential propagating the energy toward the direction with the faster propagation velocity.

• Journal of Korean Academy of Nursing
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• v.42 no.4
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• pp.579-588
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• 2012

Purpose: The purpose of this study was to identify the effects of heating on the non-affected hand on blood flow velocity, wound healing, and pain for hand microsurgery patients. Methods: This study was designed using the nonequivalent control group pretest-posttest design. Thirty-nine patients were assigned either to the experimental group (20 patients) or control group (19 patients). Data were analyzed with $x^2$-test, Fisher's exact test, t-test, and repeated measure ANOVA using SPSS/WIN 17.0 program. Results: After treatment in this program, blood flow velocity (F=5.13, p=.008) and wound healing (F=4.11, p=.020) improved significantly in the experimental group compared to the control group. But there was no significant improvement in pain in the experimental group compared to the control group (F=2.40, p=.097). Conclusion: Based upon these results, the non-affected side hand heating was recommended as an independent nursing intervention for the patients who need improvement in blood flow velocity and wound healing such as patients who have microsurgery. As the heating was effective even when applied on the non-affected side, it is the applicable to patients who cannot tolerate any therapy on affected side.

• Journal of International Academy of Physical Therapy Research
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• v.2 no.2
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• pp.288-293
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• 2011

The purpose of this study is to examine the effects of gait training using functional electrical stimulation on the improvement of hemiplegic patients' functions for balance and gait velocity. The subjects of the experiment were determined to be 10 each hemiplegic patients who had been diagnosed with stroke or brain damage six months or longer earlier assigned to an experimental group and a control group respectively. The subjects were evaluated before the experiment using Tetrax and 10M gait tests, received gait training five times a week for four weeks using functional electrical stimulation and were evaluated after the experiment in the same method as used in the evaluation before the experiment. In order to examine differences between the experimental group that received gait training using functional electrical stimulation and the control group that was treated by functional electrical stimulation and received gait training thereafter, differences between before and after the experiment were analyzed using paired sample t-tests and differences in changes after the experiment between the experimental group and the control group were analyzed using independent sample t-tests in order to compare the two groups with each other. Experimental results showed significant differences in weight bearing, balance and gait velocity between before and after the experiment in the experimental group(p<.05). In the control group, whereas weight bearing and gait velocity did not show any significant difference between before and after the experiment(p>.05), balance showed significant differences(p<.05). Weight bearing, balance and gait velocity change rates showed significant differences between the experimental group and the control group(p<.05). In conclusion, it was indicated that gait training using functional electrical stimulation is effective for enhancing stroke patients' weight bearing rates, balance abilities and gait velocity.

• Biomedical Science Letters
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• v.11 no.4
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• pp.435-439
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• 2005

To determine the appropriate concentration of papaverine hydrochloride(PPV) for therapeutic intraarterial infusion against cerebral vasospasm and to measure the mean blood flow velocity of the middle cerebral artery in rabbits. Vasospasm was induced in the experimental groups (3 days after infusion; group 1, n=3, 7 days after infusion; group 2, n=3) and a control group (n=l) by placing a blood clot in the subarachnoid space around the top of the internal carotid siphon. PPV (5 mg/kg) was infused into the internal carotid artery. The vascular diameters of the internal carotid artery (ICA) and middle cerebral artery (MCA) were measured on angiograms before and after infusion. The mean blood flow velocity in the MCA was measured on transcranial doppler sonograms before and 24 hours after infusion. After fixation, the MCA was dissected out, stained, and examined microscopically. After PPV infusion in both groups, vascular dilatation of about $20\%$ was seen. The mean increase in blood flow velocity in the group $1(30\%)$ was smaller than in the group $2(70\%)$. The mean blood flow velocity in the MCA decreased by about $30\%$ in both groups, but increased again after 24 hours nearly to the level before PPV infusion. PPV infusion may be more effective in early stages of vasospasm when vascular walls have fewer histologic changes.

• Korean Journal of Applied Biomechanics
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• v.23 no.4
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• pp.327-333
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• 2013

The purpose of this study was to investigate the effects of different types of attentional focus(internal focus vs. external focus) on the dart throwing mechanics. Seven expert dart throwing athletes were assigned to an internal focus group and other seven athletes were assigned to an external focus group. Each group was asked to throw dart either under verbal instruction or without instruction. During dart throwing, accuracy(radial error), consistency(bivariate variable error), dart velocity, acceleration, elbow joint ROM, elbow joint angular velocity, EMD(electromechanical delay), iEMG of biceps brachii and triceps brachii, and CI(coactivation index) were collected and analyzed. Nither instruction type nor instruction itself affected in accuracy and consistency. However, in dart velocity and acceleration, there was an interaction between instruction and attentional focus types. Velocity and acceleration increased in the internal condition, where as they decreased in the external condition. The ROM of elbow joint did not affected by instruction and attention type. However, similar to dart velocity and acceleration, angular velocity increased in internal focus group, while it decreased in external focus group. EMG showed no difference with any condition. In conclusion, internal focus is better than external focus for dart throwing.

• Journal of Oral Medicine and Pain
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• v.20 no.2
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• pp.291-306
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• 1995

Mandibular movement is composed of border movement and functional movement. Border movement such as maximal mouth opening, hinge opening ad lateral eccentric movement has good reproducibility, but functional movement such as chewing, swallowing and speech has also reproducibility. Especially for chewing movement, individual reproducibility has been confirmed by many studies. Study of chewing pattern is still in controversy. In new approach for raising the diagnostic value, numeric parameters and morphologic characteristics could be used for evaluation of chewing pattern. This study was performed to investigate the differences between chewing pattern in controls and in patients with temporomandibular disorders. Sixty-three patients with temporomandibular disorders participated in this study, and they were divided into unilaterally affected subjects or bilaterally affected subjects. Then unilaterally affected subjects were classified into closed lock group, disk displacement with reduction group, and degenerative joint disease group. For recording of chewing pattern, subjects were asked to chew one piece of presoftened chewing gum on both sides, and the chewing movement was recorded with the Electrognatho- Graphy(Bio-Research Associates Inc., U.S.A.). Tooth contact pattern for occlusal stability (Total left-right statistics )was also recorded with T-Scan(Tekscan Co., U.S.A.). The dta related to chewing pattern and total left-right statistics were statistically analyzed by SAS/stat program. The obtained results were as follows : 1. In patient group, mean value of A-P distance and the ratio of A-P distance to vertical distance were larger than control group, but the value of lateral distance in affected side and the closing velocity in unaffected side were smaller than that of control group, respectively. 2. In case of unilateral affected patients, chewing pattern of other side had tendency to restricted movement and slow velocity in closed lock group or degenerative joint disease group than control group or disk displacement with reduction group. 3. In bilateral degenerative joint disease patients, contralateral side had tendency to large range of motion and slow chewing velocity than preferred chewing side. 4. The patients with restricted mouth opening below than 35mm had higher value of total left-right statistics than patient group mouth opening above 35mm. Also closed lock group had higher total left-right statistics than disk displacement with reduction group, degenerative joint disease group and control group. 5. There was some difference in morphologic characteristics of chewing pattern between in control group and in affected side of unilateral patient group, but no difference between control group and unaffected side of unilateral patient group. 6. There were positive correlations between vertical distance and A-P distance, between vertical distance and chewing velocity, between A-P distance and chewing velocity, and between opening velocity and closing velocity in unilateral affected patients.

• Journal of electromagnetic engineering and science
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• v.3 no.1
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• pp.67-71
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• 2003

In this paper, frequency modulated(FM) reflectometry is proposed to measure group velocity of microwave transmission line Various microwave transmission lines such as periodically loaded conducting posts in a waveguide and nonradiative dielectric(NRD) guide are adopted to measure their group velocity The result compared with that from network analyzer shows good agreement, indicating the validity of our measurement method.

• Steel and Composite Structures
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• v.42 no.3
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• pp.397-405
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• 2022

The existing researches on the dynamics of the fluid-conveying pipes only focus on stability and vibration problems, and there is no literature report on the wave propagation of the fluid-conveying pipes. Therefore, the purpose of this paper is to explore the propagation characteristics of longitudinal and flexural waves in the fluid-conveying pipes. First, it is assumed that the material properties of the fluid-conveying pipes vary based on a power function of the thickness. In addition, it is assumed that the material properties of both the fluid and the pipes are closely depended on temperature. Using the Euler-Bernoulli beam equation and based on the linear theory, the motion equations considering the thermal-mechanical-fluid coupling is derived. Then, the exact expressions of phase velocity and group velocity of longitudinal waves and bending waves in the fluid-conveying pipes are obtained by using the eigenvalue method. In addition, we also studied the free vibration frequency characteristics of the fluid-conveying pipes. In the numerical analysis, we successively studied the influence of temperature, functional gradient index and liquid velocity on the wave propagation and vibration problems. It is found that the temperature and functional gradient exponent decrease the phase and group velocities, on the contrary, the liquid flow velocity increases the phase and group velocities. However, for vibration problems, temperature, functional gradient exponent parameter, and fluid velocity all reduce the natural frequency.

• Journal of the Korean earth science society
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• v.37 no.5
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• pp.286-294
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• 2016

Using a method suggested by Yanovskaya, we obtained Rayleigh wave group velocities with a resolution of $1.0^{\circ}{\times}1.0^{\circ}$ in a period range between 10 and 80 s in and around the Korean peninsula. Both regional and distant earthquake data sets were used together in analysis of group velocities. The resolution of the group velocity maps has been remarkably enhanced by the method, especially in the sparse/non-station region in the northern Korean peninsula. Some qualitative geophysical information was inferred from the group velocity maps. In the East Sea, the slow group velocities at periods longer than 40 s suggest the existence of an oceanic lithosphere at depths of 50-70 km, assuming 4 km/s of S wave velocity at a period of 40 s. On the other hand, a thick lithosphere can be inferred in the continental area from the fast group velocities at periods longer than 50 s. For most periods, the group velocities change rapidly over a short distance of about 200 km across the eastern coast of Korean peninsula, which may suggest a rapid change in the thickness of lithosphere in this area.