• Journal of Korean Ophthalmic Optics Society
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• v.14 no.3
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• pp.43-49
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• 2009

Purpose: The purpose of this study was to obtain the fundamental data of dynamic visual acuity and dynamic stereoacuity. Methods: The subjects were 20 athletes (high school baseball player) and 40 nonathletes (20 male, 20 female). We assessed static visual acuity, dynamic visual acuity, static stereoacuity and dynamic stereoacuity using rotating mirror projection system and computer program. Results: Three groups had similar static visual acuity and static stereoacuity. On the other hand, the dynamic visual acuity and dynamic stereoacuity showed statistically significant differency. The mean dynamic visual acuity for athletes was 174.80${\pm}$28.70 deg/sec, 137.10${\pm}$16.54 deg/sec for male nonathletes and 111.59${\pm}$15.40 deg/sec for female nonathletes. The mean dynamic stereoacuity for athlets was 234.55${\pm}$19.64, 249.05${\pm}$8.86 for male nonathletes and 247.10${\pm}$14.89 for female nonathletes. The group of athletes had better dynamic visual acuity and dynamic stereoacuity. Conclusions: If the result of this study apply to sports, it will be very useful to improve sports performance.

• The Journal of the Korea Contents Association
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• v.9 no.12
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• pp.665-673
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• 2009

This study was conducted to compare the PNF and Trunk Exercise Program has effectiveness on the pain, disability, static and dynamic balance in chronic low back pain patients. To evaluate the effects of exercise, subjects were evaluated by using VAS for pain, Oswestry disability index for disability, One leg stand test for static balance and Balance System for dynamic balance test. Pain, Oswestry disability index, One leg stand test, and Dynamic balance test in PNF had statistical significance than Trunk exercise program(p<0.05). So this results were suggested that the lifting and chopping pattern of PNF was effective on pain, disability and balance in chronic low back pain patients.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.2
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• pp.212-220
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• 2020

This study examines the effects on isometric lumbar extension strength, dynamic balance ability, and range of motion, after administering 8 weeks SEBT exercise (dynamic balance exercise) and Lumbar Stabilizing exercise, to open laser lumbar microdiscectomy patients. Totally, 14 patients who underwent preservation treatment for 6 weeks after undergoing open laser lumbar microdiscectomy, were enrolled for the study. Patients were randomly assigned to the Lumbar Stabilizing Exercise Group (LSG, n=7) and SEBT Exercise + Lumbar Stabilizing Exercise Group (SGLS, n=7). Results indicate that isometric lumbar extension strength ratio significantly decreases after 8 weeks rehabilitation exercise in both the LSG (p=0.007) as well as SLSG (p=0.024) groups. Normalized reach distance of the three directions in the Y-balance test to examine the dynamic balance capability showed a significant increase in both groups. The dynamic balance capability showed significant increase to the left (LSG, p=0.010; SLSG, p=0.002) and right (LSG, p=0.002; SLSG, p=0.002). Moreover, significant increase was also obtained in the range of joint operation, in both LSG (p=0.006) and SLSG (p=0.017) groups. These results indicate that both groups of rehabilitation exercise achieve positive outcomes on the isometric lumbar extension strength, range of motion, and dynamic balance ability. However, some results suggest that the SEBT program is likely to have a better efficacy.

• Journal of the Korea Society of Computer and Information
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• v.27 no.5
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• pp.215-224
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• 2022

The purpose of this study is to analyze how it affects functional movement and dynamic balance applying Czech get up exercise based on the principle of motor development of child for office worker women in 30s and 40s. Through random allocation, an Czech get up exercise group(n=15) and a control group(n=14) were formed to apply exercise for 12 weeks, 3 times a week, and 60 minutes a day, and the control group maintained daily life at the same period. As a result of the study, showed that Deep squat(p<.05), Hurdle step(p<.01), In-line lunge(p<.05), Trunk stability push-up(p<.001), Rotary stability (p<.01), Total score(p<.001), were significantly in the Czech get up Group, and Dynamic Balance of Lower Extremity(p<.001), Right Dynamic Balance of Lower Extremity(p<.001) were also significantly in the Czech get up Group. In conclusion, it is thought that Czech get up exercise based on the principle of motor development of child will have a positive effect on the functional movement and dynamic balance in office women, thereby increasing work efficiency as well as healthy life.

• Journal of Digital Convergence
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• v.11 no.4
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• pp.361-368
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• 2013

The aim of this study was to identify influence that integrated PNF(IPNF) on sprinter and skater pattern exercise had an effect on static and dynamic balance in chronic low back pain elderly adult. The subjects of this study were 34 and they were divided into two groups: IPNF exercise group(n=17), swiss ball exercise group(n=17). They were measured static balance ability using Good Balance System (GBS) and dynamic balance ability using functional reaching test(FRT) and timed up and go (TUG) during pre and post exercise. The results of this study were significant differences in groups about pre and post static and dynamic balance tests the greater part(p<.05). There were significant differences in groups according to exercises(p<.05). The above results from this study indicated that integrated patterns of PNF have improved the static and dynamic balance ability. This study will be enough to provide the basic raw material using a integrated PNF.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.10 no.2
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• pp.64-72
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• 1998

Dynamic response analysis is carried out for slender marine structures such as tensioned risers and tethers of tension leg platform, which are subjected to floating vessel motions as well as environmental forces arising from ocean waves. A mumerical analysis procedure is developed by using finite element model of the structural member. Dynamic analses are performed in the time domain for regular waves. Parameter studies are carried out to highlight the effects of surface vessel motions on the lateral dynamics of the structures. Example results of displacements, bending stresses are compared for various in water depth, environmental condition and vessel motion. Some instability conditions of the structures due to time-varying tension by vessel heave motion are discussed through the example analyses. As the results, the interaction between vessel surge and heave motions amplifies the total structural response of a riser. In the case of a tether, the effect of vessel heave motion during heavy storm is seemed to be quite significant to lateral response of the structure.

• Journal of Korean Society of Steel Construction
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• v.29 no.6
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• pp.401-410
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• 2017

This study deals with dynamic instability of a tendon moored submerged floating tunnel (SFT) due to tendon slack. In general, environmental loadings such as wave and current govern SFT design. Especially, the wave force, whose amplitude and direction continuously change, directly induces the dynamic behavior of the SFT. The motion of the floating tube, induced by the wave force, leads dynamic response of the attached tendons and the dynamic change of internal forces of the tendons significantly affects to the fatigue design as well as the structural strength design. When the severe motion of the SFT occurs due to significant waves, tendons might lose their tension and slack so that the floating tube can be transiently instable. In this study, the characteristics of dynamic instability of the SFT due to tendon slack are investigated performing hydrodynamic analysis. In addition, the effects of draft, buoyancy-weight ratio, and tendon inclination on tendon slack and dynamic instability behavior are analytically investigated.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.9
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• pp.2509-2515
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• 2009

This study compared the relative effectiveness of trunk stability exercise with general balance exercise on dynamic balance for patients with chronic patients. Thirty eight subjects were recruited and randomly divided into two groups. One group was trained trunk stability exercise and the other group was trained general balance exercise. This process was carried out three times a week for seven weeks. Dynamic balance was measured prior to commencement of the exercise programs, and again after seven weeks, when the programs were completed, in order to establish the effectiveness of both exercise programs. Both the trunk stability exercise and the general balance exercise increased BBS and TUG(p<.001). The trunk stability exercise was more effective at increasing BBS(p<.05). We suggest that trunk stability exercise is effective in the improvement of balance ability in the persons with chronic stroke. Therefore, the trunk stability exercise is considered to important when the stroke patients are trained. Further studies of effectiveness of trunk stability exercise should be carried out to increase our understanding of this area of study.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2004.04a
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• pp.285-290
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• 2004

Wave exciting force and moment generate the motions of a ship in waves. Since ship motion exerts the negative influences on a crew's operability, the safety of cargos, passenger's comfort, etc, the anti-rolling devices may be required to reduce such motion. In this paper, the dynamics of the anti-rolling devices such as passive and active moving weight stabilizer and anti-rolling tank, and fin stabilizer are mathematically modeled. While the effect of the motion of the anti-rolling device on a ship was taken into consideration in roll mode only in the past, the 6 DOF coupled equations of motion between a ship and the anti-rolling devices are constituted. Finally the motion of a ship with anti-rolling devices in waves is simulated through the developed simulation program.

• Journal of Power System Engineering
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• v.16 no.3
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• pp.57-63
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• 2012

본 논문은 작업공간상에서 로봇 운동과 힘의 통합제어를 구현할 수 있는 플랫폼의 구현에 초점을 두고 있다. 조립 또는 디버링 같은 접촉작업에서의 매니플레이터 효율성 제고나 친 인간 환경에서의 휴머노이드 로봇의 안정성을 위해서는 종래의 PID 제어나 관절공간상에서의 CTM(Computed Torque Method) 제어보다는 작업공간상에서의 운동과 힘의 통합제어를 실시해야 한다. 이것을 위해서는 작업공간상에서의 엔드이펙트(end-effector, E-E)에 대한 동역학식과 자코비안(jacobian)을 도출해야 하며 이를 위해서는 각종 동적파라미터의 정확한 동정이 중요하다. 본 논문에서는 3D CAD 모델링, MATLAB, 동역학 시뮬레이터를 활용하여 로봇 모델링, 동역학식과 동적 파라미터 추출, 운동과 힘의 실시간 통합제어 시뮬레이션등을 쉽고 일관되게 진행할 수 있는 플랫폼을 구현하였고 적용예로써 JS-10로봇을 택해서 그 효용성을 입증하였다.