• Journal of Broadcast Engineering
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• v.20 no.4
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• pp.568-579
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• 2015

Recently, mobile devices with touch display panel are widely used. Accuracy and reaction speed of touch signal are very important in touch devices. Therefore, we need to develop an effective algorithm to reduce touch noise quickly and accurately. This paper proposes a touch noise reduction algorithm using Kalman filtering in consideration of signal motion. First, a specific pre-emphasis processing is applied to an input signal so as to maximize the effect of Kalman filtering. In other words, a pure signal in the touch signal increases but noise in the touch signal decreases. Next, motion of the signal is detected. Motion estimation is performed only if motion is detected. If we detect motion by using the only neighborhood of the signal, we can reduce about 75% of the computation in comparison with examining the entire area. Finally, Kalman filtering using the previous state of current signal is performed. Experimental results show that the proposed algorithm suppresses touch noise sufficiently without degradation of the pure signal

• Physical Therapy Korea
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• v.27 no.1
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• pp.70-77
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• 2020

Background: Neck pain can be caused by any structure in the neck, such as intervertebral discs, ligaments, muscles, facet joints, dura mater, and nerve roots. The hyoid bone is a structure that is also related to head and neck posture, neck movement and pain, but there are no studies on hyoid deviation, neck pain, and range of motion (ROM). Objects: The purpose of this study was to investigate the effect of fascia relaxation and mobilization of the hyoid bone on the ROM, pain, and lateral deviation of the hyoid bone. Methods: Twenty-five patients with neck pain identified by the lateral motion test (10 males [35.13 ± 7.67 years, 172.69 ± 3.90 cm, 78.77 ± 6.96 kg] and 15 females [35.13 ± 10.05 years, 161.11 ± 4.09 cm, 52.59 ± 2.98 kg]) was chosen randomly. Baseline values for pain, neck ROM, and lateral deviation in the hyoid bone were recorded using a visual analogue scale (VAS), goniometer, and tape measure. Then, each patient was treated with hyoid fascia relaxation and mobilization, and all results were recorded after intervention. Comparison of the results before and after intervention was analyzed using paird t-test (p < 0.05). Results: Right rotation, extension, VAS, and rotational asymmetry statistically significant differences (p < 0.05). Right rotation and extension increased ROM, rotational asymmetry ratio and VAS decreased. However, there was no significant difference in flexion, left rotation, center point (p > 0.05). Conclusion: Fascia relaxation and hyoid mobilization could improve the ROM of cervical extension, asymmetry of the cervical rotation and neck pain.

• Journal of the Society of Naval Architects of Korea
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• v.50 no.4
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• pp.240-247
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• 2013

Hydrodynamic characteristics of a planing craft are very sensitive to the hull form variations, especially when the craft navigates with high-speed. Therefore, we need to verify hydrodynamic performances of the craft during the process of hull form design. In this paper, motion performances of a 40ft class cruise leisure boat are evaluated by both model tests and theoretical analyses using two different methods. Model tests are carried out at calm sea and regular wave conditions using high speed towing carriage installed in SNU towing tank. Theoretical methods used are a empirical method proposed by Martin (1976) and a potential method based on Rankine panel (DNV, 2010). The results from the theoretical methods are compared with and verified by those of model tests. Results of empirical formula showed somewhat larger motion RAOs and resonant frequencies than those of model tests. Potential based method showed even larger discrepancies with the model test results. From the analyses of comparison results, we could confirm the limitation of each theoretical method and suggest the way of improvement for the better prediction of motion performances.

• Physical Therapy Korea
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• v.26 no.1
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• pp.28-36
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• 2019

Background: Temporomandibular disorder (TMD) is characterized by pain and limited range of motion in the jaw. TMD patients generally prefer to chew on the unaffected or less-affected side, and this tendency often results in asymmetries in masseter muscle thickness and range of mandibular motion. Objects: The purpose of this study was to compare the asymmetries in masseter muscle thickness and range of mandibular motion in subjects with and without temporomandibular disorders. Methods: Thirty-nine subjects were divided into two groups: A TMD group ($n_1=19$) and a control group ($n_2=20$). The jaw opening range and laterotrusion were measured using a digital vernier caliper. The masseter muscle thickness was examined in both the resting state and the maximal clenching state using ultrasonography. The absolute asymmetry indices calculated based on the laterotrusion and masseter muscle thickness of the respective right and left sides. A two-way ANOVA and a Mann-Whitney U test were used for statistical analysis. Results: No significant different was found in the masseter muscle thickness between the TMD and control group. A significant difference was found in the absolute asymmetry indices of mandibular laterotrusion between the TMD and control groups (p<.05). Furthermore, the ranges of jaw opening were significantly different between males and females (p<.05). The absolute asymmetry index values of masseter muscle thickness at rest and during maximal clenching were also significantly different between males and females (p<.05). Conclusion: These results demonstrated that the subjects with TMD had a larger degree of asymmetry in laterotrusion than those without TMD. Therefore, a physiotherapy program needs to be designed to restore normal laterotrusion capacities for TMD subjects. These results also showed that female subjects had greater absolute asymmetry indices in masseter muscle thickness than male subjects. Therefore, more training is needed to promote bilaterally balanced chewing among women.

• Journal of the Korean Society of Physical Medicine
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• v.17 no.4
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• pp.85-92
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• 2022

PURPOSE: This study examined the effects of motion taping during combined lower extremity exercise application on pain, ROM, muscle strength, and WOMAC index in middle-aged women with osteoarthritis of the knee joint METHODS: The subjects were 26 middle-aged women with osteoarthritis in the knee joint. Twenty-six subjects were divided into two groups. Each group contained 13 subjects. Three subjects dropped out in the middle of the experiment. The intervention was six weeks, three times a week. The control group performed traditional physical therapy and lower extremity exercise. The experimental group was motion taping applied to the lower extremity exercise. The measurement factors were knee joint pain, quadriceps muscle strength, and WOMAC index. The pain was measured using the numeric pain scale instrument (NPSI). The quadriceps strength was measured using the 1RM method. RESULTS: In both groups, pain, muscle strength, and WOMAC index showed significant improvement according to the intervention (p < .05). In comparison between groups of the change values pre-post intervention, pain and WOMAC index showed statistically significant differences between the two groups. On the other hand, there was no difference in strength between the two groups. CONCLUSION: When performing a rehabilitation exercise program for middle-aged women with osteoarthritis of the knee, motion taping has a positive effect on pain and the WOMAC index.

• Journal of The Korean Society of Integrative Medicine
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• v.12 no.2
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• pp.33-45
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• 2024

Purpose : This study aimed to compare the effects of spinal manipulation combined with medication on low back pain (LBP), range of motion, and disability in patients with chronic LBP. Methods : Twenty patients with chronic LBP were included in this study. The participants were randomly assigned to the spinal manipulation with medication group (n=10) or the medication only group (n=10). The intervention group received spinal manipulation for 15 minutes, twice a week, and took medication twice a day for eight weeks. The control group received the medication twice daily for eight weeks. Pain intensity assessed using the visual analog scale (VAS), range of motion, and disability due to LBP assessed using the Oswestry disability index were measured before and after the intervention. Results : The intervention group showed a significant improvement in pain intensity compared to the control group (p<.05), and the intervention and control groups significantly improved low back pain after the intervention (p<.05). The intervention group showed a significant improvement in the range of motion in flexion, extension, right lateral flexion, left lateral flexion, and right rotation (p<.05). The intervention group also showed a significant improvement in the change of disability in total score, pain intensity, personal care, lifting and standing compared to the control group (p<.05). Conclusion : This study showed that the combination of spinal manipulation and medication can benefit patients with chronic LBP, as evidenced by significant improvements in pain intensity, ROM, and disability. These findings suggest that utilizing both spinal manipulation and medication can positively affect individuals with chronic LBP. The results of this study should be applied in clinical settings to optimize treatment outcomes in patients with chronic LBP.

• Journal of Korean Physical Therapy Science
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• v.27 no.3
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• pp.45-55
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• 2020

Background: The purpose of this study was to investigate the effects of WBC (whole-body cryotherapy)on the MVIC (maximal voluntary isometric contraction)and active ROM (range of motion) recovery of after EIMD (exercise-induced muscle injury). Design: Randomized Controlled Trial. Methods: Thirty subjects who are student in their 20s at a university participated in this study, these subjects were assigned into three groups, a control group (n=10), experiment group I(n=10), and experiment group II (n=10). The subjects in the experimental group II were intervened by WBC (-130℃, 3 minutes) before induced EIMD, the experimental group were intervened by WBC (-130℃, 3 minutes) after induced EIMD, and the control group weren't by any intervened after induced EIMD. Results: First, In the comparison of the MVIC, there were significant variations with the lapse the time in three groups (p<.001) and there was a significant interaction of time and group (p<.001). In the among group comparison, the MVIC of experimental group II was significantly larger than those of other groups (p<.001). Second, In the comparison of the active extension angle, there were significant variations with the lapse the time in three groups (p<.001) and there was a significant interaction of time and group (p<.001). In the among group comparison, the active extension angle of experimental group II was significantly smaller than those of other groups (p<.001). Third, In the comparison of the active flexion angle, there were significant variations with the lapse the time in three groups (p<.01) and there was a significant interaction of time and group (p<.001). In the among group comparison, the active flexion angle of experimental group II was significantly larger than those of other groups (p<.05). Conclusion: The above results revealed that the WBC intervention after an exercise had a positive effect of muscle function after EIMD. Therefore we can consider the WBC as a considerable intervention method to prevent or reduce an exercise injury.

• Korean Journal of Applied Biomechanics
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• v.16 no.2
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• pp.97-108
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• 2006

C. H. OH, S. N. CHOI, T. G. NAM, The Kinematic Analysis of the Tennis Flat Serve Motion, Korean Jiurnal of Sports Biomechanics, Vol. 16, No. 2, pp. 97-108, 2006. By the comparison and the analysis of the different factors during the tennis flat serve motion such as the required time per section, the movement displacement of the racket, the velocity of the upper limbs joints, the physical center of gravity, and the angle and the angular velocity of the upper limbs joints between an ace player and a mediocre player, these following results were drawn. First, the experiment result of the total time required per section in a tennis flat serve motion showed that an ace player was faster than a mediocre player by 0.4 seconds. This result suggested that it was required to increase the speed of the racket head by a swift swing to perform an effective flat serve motion. Second, the experiment result of the movement displacement of the racket in the tennis flat serve motion showed that an ace player greatly moved toward the left side on an x-axis. But both an ace and a mediocre player were shown to be at the similar points on a y-axis at the moment of the impact of the racket. An ace player was also shown to be located at a higher position on a z-axis by 0.23m. Third, the velocity of the center of gravity of an ace player was faster in every phase than that of a mediocre player in a tennis flat serve motion. Fourth, the velocity of the upper limb joints of an ace player was faster in every phase than that of a mediocre player in a tennis flat serve motion. Fifth, the experiment result of the speed of the racket head in tennis flat serve motion showed that a mediocre player was faster than an ace player in the first phase, but the latter was faster than the former in the second, third, and the fourth phases. Sixth, at the moment of impact of a tennis flat serve, an ace player had greater flexion of the angle of the wrist joints by an 11.8 degree than a mediocre player. An ace player also had greater extension of the angle of the elbow joint and the shoulder joint respectively by a 5.2 degree and a 1.4 degree with a mediocre player. Seventh, an ace player had greater angular velocity of the upper limb joints and the hip joints than a mediocre player at the moment of the impact of tennis flat serve. Eighth, an ace player was shown to have a greater change of the forward and the backward inclination (or the anterior and posterior inclination) of the upper body

• Journal of the Earthquake Engineering Society of Korea
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• v.24 no.6
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• pp.293-303
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• 2020

Seismic fragility was assessed for non-seismic reinforced concrete shear walls in Korean high-rise apartment buildings in order to implement an earthquake damage prediction system. Seismic hazard was defined with an earthquake scenario, in which ground motion intensity was varied with respect to prescribed seismic center distances given an earthquake magnitude. Ground motion response spectra were computed using Korean ground motion attenuation equations to match accelerograms. Seismic fragility functions were developed using nonlinear static and dynamic analysis for comparison. Differences in seismic fragility between damage state criteria including inter-story drifts and the performance of individual structural members were investigated. The analyzed building had an exceptionally long period for the fundamental mode in the longitudinal direction and corresponding contribution of higher modes because of a prominently insufficient wall quantity in such direction. The results showed that nonlinear static analyses based on a single mode tend to underestimate structural damage. Moreover, detailed assessments of structural members are recommended for seismic fragility assessment of a relatively low performance level such as collapse prevention. On the other hand, inter-story drift is a more appropriate criterion for a relatively high performance level such as immediate occupancy.

• Wind and Structures
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• v.26 no.3
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• pp.179-190
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• 2018

Translation of tornadoes is an important feature in replicating the near-ground tornado flow field which has been simulated in previous studies based on Ward-type tornado simulators using relative motion of the ground plane. In this laboratory investigation, effects of translation on the near-ground tornado flow field were studied using the ISU Tornado Simulator that can physically translate over a ground plane. Two translation speeds, 0.15 m/s and 0.50 m/s, that scale up to those corresponding to slowly-moving tornadoes in the field were selected for this study. Compared with the flow field of a stationary tornado, the simulated tornado with translation had an influence on the spatial distribution and magnitude of the horizontal velocities, early reversal of the radial inflow, and expansion of the core radius. Maximum horizontal velocities were observed to occur behind the center of the translating tornado and on the right side of its mean path. An increase in translation speed, resulted in reduction of maximum horizontal velocities at all heights. Comparison of the results with previous studies that used relative motion of the ground plane for simulating translating tornadoes, showed that translation has similar effects on the flow field at smaller radial distances (~2 core radius), but different effects at larger radial distances (~4 core radius). Further, it showed that the effect of translation on velocity profiles is noticeable at and above an elevation of ~0.6 core radius, unlike those in studies based on the relative motion of the ground plane.