• Korean Journal of Applied Biomechanics
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• v.19 no.1
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• pp.67-75
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• 2009

The purpose of this study is to analyze the effects of target position on the bowling motion. Four female high school athletes with more than four years of bowling experiences were recruited to this study. The major results of this study are as follows; When a subject treats the 1st pin, The spin angle of a coxa for the target position is largely kept from the downswing to the backswing peak point. When a subject treats the 7th pin, As the 7th pin exists at the left side for the right shoulder axis of the thrower, the movement of the ball center of the thrower from side to side is the lowest. In addition, the time required and horizontal speed appear the highest in the release section. The slant angle of a shoulder is largely increased as she moves from the backswing peak point to the release section. The twist angle of a shoulder also appears small as a throw motion is made toward the left side. When a subject treats the 10th pin, The spin angle of a shoulder and the twist angle of a body in motion appear the largest in the release section. So, there are the effects of target position on the bowling motion.

• Journal of Korean Physical Therapy Science
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• v.18 no.2
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• pp.41-49
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• 2011

Purpose: The purpose of this study is to acknowledge the effects that have the strength exercise done only on the neck extensor, only on the thoracic extensor, and both the neck and the thoracic extensor on forward head posture(FHP) and cervical range of motion. Also is to discover which of the exercise is the most effective. Method: This experiment will be done by selecting 40 people who have 16cm or more FHP and they will be divided into four groups: three experimental groups and a control group. The first experimental group will do only the neck extensor strength exercise(NESE). The second experimental group will do only the thoracic extensorstrength exercise(TESE) and the third experimental group will do both the NESE and the TESE. The experimental groups will make a day three times each ten sets of extensor isometric strength exercise but the time will be increased from 4 to 6 and8 seconds until it will be done the ten sets. Then after four weeks, they will be compared which had the best results for the FHP and the cervical range of motion. Result: After the experiment, it was compared the experimental groups with the control group. Every experimental group had an improvement on their FHP and cervical range of motion. However, the only NESE and the only TESE did not have a significantly difference(p>.05). Only the group who did both the NESE and the TESE had a sign ificantly improvement compared to the control group. Conclusion: 1. The only NESE and the only TESE seem that had a positive effect on FHP and cervical range of motion. However, it cannot be conclude that it is effective. 2. When both the NESE and the TESE are done, it is showed statistically a significant difference(p<.05) on FHP and cervical range of motion. The refore, it would be note worthy if this exercise is used to improve the FHP and the cervical range of motion.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.4
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• pp.759-768
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• 2015

The ground motions of large dimensional structures such as long span bridges at different stations during an earthquake, are inevitably different, which is known as the ground motion spatial variation effect. There are many causes that may result in the spatial variability in seismic ground motion, e.g., the wave passage effect due to the different arrival times of waves at different locations; the loss of coherency due to seismic waves scattering in the heterogeneous medium of the ground; the site amplification effect owing to different local soil properties. In previous researches, the site amplification effects have not been considered or considered by a single-layered soil model only. In this study, however, the ground motion amplification and filtering effects are evaluated by multi-layered soil model. Spatially varying ground motion at the sites with different number of layers, depths, and soil characteristics are generated and the variation characteristics of ground motion time histories according to the correlation of coherency loss function and soil conditions are evaluated. For the bridge system composed of two unit bridges, seismic behavior characteristics are analyzed using the generated seismic waves as input ground motion. Especially, relative displacement due to coherency loss and site effect which can cause the unseating and pounding between girders are evaluated. As a result, considering the soil conditions of each site are always important and should not be neglected for an accurate structural response analysis.

• Physical Therapy Korea
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• v.27 no.4
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• pp.227-232
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• 2020

Background: Hallux valgus (HV) is a foot deformity developed by mediolateral deviation of the first metatarsophalangeal joint. Although various foot-toe orthoses were used to correct the HV angle, verification of the effects of kinetics variables such as ground reaction force (GRF) through three-dimensional (3D) gait analysis according to the various type of orthoses for HV is insufficient. Objects: This study aimed to investigate the effect of soft and hard types of foot and toe orthoses to correct HV deformity on the GRF in individuals with HV using 3D motion analysis system during walking. Methods: Twenty-six subjects participated in the experiment. Participants had HV angle of more than 15° in both feet. Two force platforms were used to obtain 3D GRF data for both feet and a 3D motion capture system with six infrared cameras was used to measure exact stance phase point such as heel strike or toe off period. Total walk trials of each participant were 8 to 10, the walkway length was 6 m. Two-way repeated measures ANOVA was used to determine the effects of each orthosis condition on the various GRF values. Results: The late anteroposterior maximal force and a first vertical peak force of the GRF showed that the hard type orthosis condition significantly increased GRF compared to the other orthosis conditions (p < 0.05). Conclusion: There were significant effects in GRF values when wearing the hard type foot orthosis. However, the hard type foot orthosis was uncomfortable to wear during walking. Therefore, it is necessary to develop a new foot-toe orthosis that can compensate for these disadvantages.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.10 no.1
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• pp.37-45
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• 1990

An analytical procedure is proposed for the seismic analysis of a soil-structure interaction system with besemat uplift, including the effects of concurrent vertical seismic ground motion, nonlinear distribution of bearing soil pressure under the basemat, and 3-dimensional behavior of the system. The soil-structure interaction system is assumed to have rectangular-shaped basemat on elastic half-space. Nonlinearity of soil spring constants and soil damping coefficients induced by the base mat uplift is modeled by considering not only the reduction of contact area between soil and structure but also the effects of rigid body rotational motion of the superstructure, and the shift in the point of action of the resultant reaction on the basemat. Throught various parametric studies. it has been confirmed that the seismic responses of the superstructure reduce notably while response at the basemat increases considerably. The results also show that the effects of concurrent vertical ground motion. nonlinear soil pressure distribution under basemat, and 3-dimensional behavior of the system shall be included in uplift analysis in order to obtain the correct structural responses.

• Journal of International Academy of Physical Therapy Research
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• v.3 no.2
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• pp.413-421
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• 2012

Few studies address the use of manual muscle stretching to improve spinal active range of motion(AROM). There is evidence that' Hold-Relax'(HR) is effective for increasing ROM in the extremities, which leads the researchers to anticipate similar benefits in the spine. The purpose of this study is to investigate the effects of HR(trunk flexors) and active thoracic flexion and extension on thoracic mobility, specifically flexion and extension in healthy individuals. A convenience sample of 30 physical therapy students(22-38 years) were randomly assigned to intervention sequence 'A-B' or 'B-A', with at least 7 days between interventions. Intervention' A' consisted of HR of the ventral trunk musculature while 'B' consisted of thoracic flexion-extension AROM. Thoracic flexion and extension AROM were measured before and after each intervention using the double inclinometer method. Paired t-tests were used to compare AROM pre and post-intervention for both groups, and to test for carry-over and learning effects. There was a statistically significant increase(mean=$3^{\circ}$ ; p=0.006) in thoracic extension following HR of the trunk flexors. There were no significant changes in thoracic flexion following HR, or in flexion or extension following the AROM intervention. No carryover or learning effects were identified. HR may be an effective tool for improving AROM in the thoracic spine in pain free individuals. Further investigation is warranted with symptomatic populations and to define the minimal clinical difference(MCD) for thoracic spine mobility.

• Wind and Structures
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• v.23 no.3
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• pp.231-251
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• 2016

This paper presents the experimental results of the wind tunnel tests for three symmetric, rectangular, tall building models on a typical open terrain considering the torsional motion-induced vibrations. The time histories of the wind pressure on these models under different reduced wind speeds and torsional amplitudes are obtained through the multiple point synchronous scanning pressure technique. Thereafter, the characteristics of both the Root Mean Square (RMS) coefficients and the spectra of the base shear/torque in the along-wind, across-wind, and torsional directions, respectively, are discussed. The results show that the RMS coefficients of the base shear/torque vary in the three directions with both the reduced wind speeds and the torsional vibration amplitudes. The variation of the RMS coefficients in the along-wind direction results mainly from the change of the aerodynamic forces, but sometimes from aeroelastic effects induced by torsional vibration. However, the variations of the RMS coefficients in the across-wind and torsional directions are caused by more equal weights of both the aerodynamic forces and the aeroelastic effects. As such, for the typical tall buildings, the modification of the aerodynamic forces in the along-wind, across-wind, and torsional directions, respectively, and the aeroelastic effects in the across-wind and torsional directions should be considered. It is identified that the torsional vibration amplitudes and the reduced wind speeds are two significant parameters for the aerodynamic forces on the structures in the three directions.

• Journal of The Korean Society of Integrative Medicine
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• v.10 no.3
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• pp.233-246
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• 2022

Purpose : The study aims to determine the effects of virtual and non-virtual realities in a normal person's mirror walk on gait characteristics. Methods : Twenty male adults (Age: 27.8 ± 5.8 years) participated in the study. Reflection markers were attached to the subjects for motion analysis, and they walked in virtual reality environments with mirrors by wearing goggles that showed them the virtual environments. After walking in virtual environments, the subjects walked in non-virtual environments with mirrors a certain distance away after taking a 5 min break. To prevent the order effect caused by the experiential difference of gait order, the subjects were randomly classified into groups of 10 and the order was differentiated. During each walk, an infrared camera was used to detect motion and the marker positions were saved in real time. Results : Comparison between the virtual and non-virtual reality mirror walks showed that the movable range of the leg joints (ankle, knee, and hip joints), body joints (sacroiliac and atlantoaxial joints), and arm joints (shoulder and wrist joints) significantly differed. Temporal characteristics showed that compared to non-virtual gaits, the virtual gaits were slower and the cycle time and double limb support time of virtual gaits were longer. Furthermore, spacial characteristics showed that compared to non-virtual gaits, virtual gaits had shorter steps and stride lengths and longer stride width and horizontally longer center of movement. Conclusion : The reduction in the joint movement in virtual reality compared to that in non-virtual reality is due to adverse effects on balance and efficiency during walking. Moreover, the spatiotemporal characteristics change based on the gait mechanisms for balance, exhibiting that virtual walks are more demanding than non-virtual walks. However, note that the subject group is a normal group with no abnormalities in gait and balance and it is unclear whether the decrease in performance is due to the environment or fear. Therefore, the effects of the subject group's improvement and fear on the results need to be analyzed in future studies.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.7
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• pp.709-716
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• 2009

Thermal condition according to the operation attitude of a satellite in orbit would be essential to be known because the orbit attitude is a dominant factor to affect satellite thermal design. In this paper, the change in space thermal environment and the thermal effect in thermal design are studied for a low earth orbit satellite according to the yaw motion. The present satellite retains sun-pointing attitude during daylight due to the fixed type solar arrays. And it also moves along the orbit with constant yaw motion in a longitudinal axis so that a star tracker which is a star sensor for satellite's attitude control always looks into the deep space. This attitude is considered in its better visibility to the stars for a successful mission operation. Also, it is required to access the corresponding thermal effects due to the yaw motion. Therefore, we try to verify these by the thermal analysis for the satellite thermal model with the yaw motion.

• The Journal of the Korea Contents Association
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• v.6 no.9
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• pp.124-131
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• 2006

Motion graphic is also developing into its own genre in graphic design by establishing individual industrial fields. images and graphics but also recognize even motions and sounds as communication elements delivering a message. Nevertheless, web communication designers have yet to experimentally test the visual motion priniciples or the audio sound expressions in terms of technology. If the dance are used, they may be new communication approaches in the age of multi-media, which allows for communication of visual and audio information or images. With such conceptions in mind, this study was aimed at reviewing the structural relationship between visual motion principles of the kinetic and the sound images to combine the audio and video effects. To this end, the basic structure of dance and music were substituted into the dance to determine their relevancy, and thereupon, examine the effective sound expression methods and techniques depending on movements of the objects in the monitor. Thus, this study, by inquiring into the uniqueness of choreography in motion graphic, presents the possibility of limitless expression of designer creation and inner world, and the ultimate goal lies in assuring the artistic value of motion graphic and its position as a synthetic art.