• International Journal of Naval Architecture and Ocean Engineering
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• v.6 no.2
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• pp.333-346
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• 2014

If we want to analyze the motion of a body in fluid, we should use rigid-body dynamics and fluid dynamics together. Even if the rigid-body and fluid dynamics are each self-consistent, there arises the problem of self-similar structure in the equation of motion when the two dynamics are coupled with each other. When the added mass is greater than the mass of a body, the calculated motion is divergent because of its self-similar structure. This study showed that the above problem is an inherent problem. This problem of self-similar structure may arise in the equation of motion in which the fluid dynamic forces are treated as external forces on the right hand side of the equation. A reconfiguration technique for the equation of motion using pseudo-added-mass was proposed to resolve the self-similar structure problem; specifically for the case when the fluid force is expressed by integration of the fluid pressure.

• Physical Therapy Rehabilitation Science
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• v.10 no.3
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• pp.257-262
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• 2021

Objective: Patients with stroke generally diminished ankle range of motion, which decreases balance and walking ability. This study aimed to determine the effect of ankle self-mobilization with movement (s-MWM) on ankle dorsiflexion passive range of motion, timed up and go test, and dynamic gait index in patients with chronic stroke. Design: Randomized controlled trial design Methods: Twenty-four post-stroke patients participated in this study. The participants were randomized into the control (n = 12) and self-MWM groups (n = 12). Both groups attended standard rehabilitation therapy for 30 minutes per session. In addition, self-MWM group was performed 3 times per week for 8 weeks. All participants have measured ankle dorsiflexion passive range of motion, timed up and go test, and dynamic gait index in before and after the intervention. Results: After 8 weeks of training, self-MWM group showed greater improvement in ankle dorsiflexion passive range of motion, timed up and go test, and dynamic gait index than in the control group (p<0.05). Further, self-MWM group had significantly improvement in all dependent variables compared to the pre-test (p<0.05). Conclusions: Our investigation demonstrates that self-MWM is beneficial for improving functional ability. Also, self-MWM was superior to control with respect to improving ankle dorsiflexion passive range of motion, timed up and go test, and dynamic gait index.

• Journal of The Korean Society of Integrative Medicine
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• v.10 no.1
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• pp.119-128
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• 2022

Purpose : The purpose of this study was to examine the effects of applying occupational therapy that uses motion recognition on the physical self-efficacy, visual-motor integration ability, and play skills of children who have neurodevelopmental disorder before and after treatment. Methods : This The study chose 16 children with neurodevelopmental disorder as research subjects who were randomly and evenly allocated into an experimental group and a control group. The experiment followed a pretest-posttest design. As an intervention, the experimental group received motion recognition-based occupational therapy and a separate sensory integration program. The control group only participated in the separate sensory integration program. The eight-week experiment duration included 24 intervention sessions where the a 50-minute session was implemented three times a week for eight weeks. To compare the physical self-efficacy, visual-motor integration ability, and play skills before and after the intervention, measurement tools including the Physical self efficacy, Beery VMI-6, and Penn interactive peer play scale were used. All measured variables were analyzed and expressed as mean, standard deviation and percentage. Results : The motion recognition-based occupational therapy demonstrated a significant effect on improving the physical self-efficacy, visual-motor integration ability, and play skills of the experimental group. The intervention also caused a significant difference between the experimental group and control group in terms of the physical self-efficacy, visual-motor integration ability, and play skills. Conclusion : We confirmed the possibility motion recognition-based occupational therapy could be effective in improving the physical self-efficacy, visual-motor integration ability, and play skills for patients who have neurodevelopmental disorder. Based on the study result, further future studies are expected based on this study result that prove the application effect of the motion recognition-based occupational therapy using disabled and non- disabled children as subjects are expected in the future.

• Journal of the Korean Society of Physical Medicine
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• v.7 no.4
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• pp.509-514
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• 2012

PURPOSE: This study aims to compare the effects of upper backbone joint mobilization and self-stretching exercise in the patients with chronic neck pain. METHODS: Thirty seven patients with chronic neck pain were divides into self stretching group(SSG, n=18) and mobilization group(MG, n=19). To assess the degree of neck pain, the visual analog scale (VAS) was utilized, and to measure the joint range of motion at the flexion-extension, it was compared and analyzed by using the cervical range of motion (CROM) device. RESULTS: The joint range of motion and visual analog scale of SSG and MG showed significant effects on both groups. In the comparison of groups, there was no significant difference, but it indicated effects on improving the pain and the range of joint motion in MG. CONCLUSION: According to the analysis, not only self-stretching exercise intervening for direct treatment but also upper backbone joint mobilization intervening for indirect treatment are effective to improve the pain and the range of motion.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.1031-1034
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• 2007

The interactions between two-dimensional and three-dimensional stimulus configurations on visually induced self-motion perception (vection) were examined. The experiment revealed that there is no 2D-3D interaction, and vection strength is determined solely by the size of the moving background stimulus, which should be a primary factor in inducing vection.

• Journal of Sensor Science and Technology
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• v.31 no.2
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• pp.79-84
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• 2022

Self-powered sensors play an important role in everyday life, and they cover a wide range of topics. These sensors are meant to measure the amount of relevant motion and transform the biomechanical activities into electrical signals using triboelectric nanogenerators (TENGs) since they are sensitive to external stimuli such as pressure, temperature, wetness, and motion. The present advancement of TENGs-based self-powered wearable, implantable, and patchable sensors for healthcare monitoring, human body motion, and medication delivery systems was carefully emphasized in this study. The use of TENG technology to generate electrical energy in real-time using self-powered sensors has been the topic of considerable research among various leading scholars. TENGs have been used in a variety of applications, including biomedical and healthcare physical sensors, wearable devices, biomedical, human-machine interface, chemical and environmental monitoring, smart traffic, smart cities, robotics, and fiber and fabric sensors, among others, as efficient mechanical-to-electric energy conversion technologies. In this evaluation, the progress accomplished by TENG in several areas is extensively reviewed. There will be a discussion on the future of self-powered sensors.

• Bulletin of the Korean Mathematical Society
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• v.53 no.5
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• pp.1327-1339
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• 2016

Self-organizing systems arise very naturally in artificial intelligence, and in physical, biological and social sciences. In this paper, we modify the classic Cucker-Smale model at both microscopic and macroscopic levels by taking the target motion pattern driving forces into consideration. Such target motion pattern driving force functions are properly defined for the line-shaped motion pattern and the ball-shaped motion pattern. For the modified Cucker-Smale model with the prescribed line-shaped motion pattern, we have analytically shown that there is a flocking pattern with an asymptotic flocking velocity. This is illustrated by numerical simulations using both symmetric and non-symmetric pairwise influence functions. For the modified Cucker-Smale model with the prescribed ball-shaped motion pattern, our simulations suggest that the solution also converges to the prescribed motion pattern.

• Journal of computational fluids engineering
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• v.16 no.2
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• pp.24-29
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• 2011

Immersed boundary lattice Boltzmann method has been applied to analyze the characteristics of the self-propelled fish motion swimming robot. The airfoil NACA0012 with caudal fin stroke model was considered to examine the characteristics. The foil in steady forward motion and a combination of steady-state harmonic deformation produces thrust through the formation of a flow downstream from the trailing edge. The harmonic motion of the foil causes unsteady shedding of vorticity from the trailing edge, while forming the vortices at the leading edge as well. The resultant thrust is developed by the pressure difference formed on the upper and lower surface of the airfoil. and the time averaged thrust coefficient increases as Re increase in the region of $Re{\leqq}700$. The suggested numerical method is suitable to develop the fish-motion model to control the swimming robot, however It would need to extend in 3D analysis to examine the higher Re and to determine the more detail mechanism of thrust production.

• Bulletin of the Korean Mathematical Society
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• v.57 no.3
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• pp.547-568
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• 2020

In this paper, we introduce the linear self-attracting diffusion driven by a weighted fractional Brownian motion with weighting exponent a > -1 and Hurst index |b| < a + 1, 0 < b < 1, which is analogous to the linear fractional self-attracting diffusion. For the 1-dimensional process we study its convergence and the corresponding weighted local time. As a related problem, we also obtain the renormalized intersection local time exists in L² if max{a₁ + b₁, a₂ + b₂} < 0.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2013.05a
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• pp.589-590
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• 2013

The fast development of electronic devices towards wireless, portable and multi-functionality desperately needs the self-powered and low maintenance power sources. The possibility to coupling the nanogenerator to wearable and portable electronic device facilitates the self powered device with independent and self sustained power source. Nanogenerator has ability to convert the low frequency mechanical vibration to electrical energy which is utilized to drive the electronic device [1]. The self powered power source has the ability to generate the power from environment and human activity has attracted much interest because of place and time independent. The human body motion based energy harvesting has created huge impact for future self powered electronics device applications. The power generated from the human body motion is enough to operate the future electronic devices. The energy harvesting from human body motion based on triboelectric effect has simple, cost-effective method [2, 3] and meet the required power density of devices. However, its output is still insufficient to driving electronic devices in continues manner so new technology and new device architecture required to meet required power. In the present work, we have fabricated the triboelectric nanogenerator using PDMS polymer. We have studied detail about the power output of the device with respect to different polymer thickness and varied separation distance.