• Title/Summary/Keyword: limits of stability

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Effect on Body Balance due to Occlusal Biteplane Splint (교합안정장치가 신체 균형에 미치는 영향)

  • Kim, Jeong-Uk;Park, Min-Chull;Choi, Sung-Min;Lee, Sang-Yeol;Won, Hyeon-Jin
    • The Journal of the Korea Contents Association
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    • v.13 no.4
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    • pp.273-280
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    • 2013
  • This study aims to examine the influences of wearing an occlusal biteplane splint on balance of the body. 10 subjects were selected who had neither impaired occlusion and masticating systems nor difficulty in walking along with no medical history in temporomandibular joint. Measurements were conducted with the Fukuda stepping test, the limits of stability test. The level of significance, ${\alpha}$ to determine the statistical significance was .05. Fukuda stepping test and the limits of stability test were put to the Wilcoxon signed test. As a result of this study, there was a significant difference in the moving distance in the Fukuda stepping test (p<.05). In addition, there were significant differences in the results of the limits of stability test (p<.05). In conclusion, the results of this study suggest that wearing the occlusal biteplane splint has an positive influence on the balance of the boby.

A Study on the Combustion Characteristics of Turbulent Diffusion Flame Stabilized by Bluff Body (보염기에 의해 안정되는 난류확산화염의 연소특성에 관한 연구)

  • An, J.G.;Song, K.K.
    • Journal of the Korean Society of Combustion
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    • v.3 no.1
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    • pp.71-78
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    • 1998
  • The flame stabilization and the combustion characteristics of diffusion flame formed in the wake of a cylindrical bluff body with fuel injection are studied. With the turbulence generator, the flame stability limits and ion currents were measured and analyzed. The results from this experimental study are summarized as follows. The region with highest average value of ion currents in the middle of flame is moved to the upstream side by the turbulent components of main stream. The flame mass with partially active reaction is moved fast for uniform flow and turbulence generator G3, but the flame mass with relatively slow reaction is moved slowly for turbulence generator G1. If the turbulence generator with strong turbulent component is installed, the turbulent time scale is increased with movement from main stream side to recirculation zone as well as the flame stability limits is deteriorated. Though the special dominant frequency is not appeared in the eddy which exists in flame, high frequency characteristics are appeared in uniform flow and turbulence generator G3, and low frequency characteristics are appeared in uniform flow, turbulence generator G3 and G1.

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The Effects of the Proprioceptive Control and Visual Feedback for the Limits of Stability in Patients with Chronic Hemiplegia (고유수용성 조절과 시각적 피드백이 만성 편마비 환자의 안정성 한계에 미치는 영향)

  • Hwang, Byong-Yong
    • The Journal of Korean Physical Therapy
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    • v.19 no.6
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    • pp.37-41
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    • 2007
  • Purpose: Hemiplegic patients usually present with difficulties in maintaining their balance. Balance retraining is a major component of a rehabilitation program for patients with neurological impairments. This study compared the effects of prorpioceptive exercise and visual feedback program on the limits of stability (LOS) in chronic hemiplegia patients. Methods: Thirty subjects (mean age $57.0{\pm}9.8$) were recruited. The subjects were divided into a proprioceptive group and a visual group. The subjects for the proprioceptive group participated in the proprioceptive exercise program for 4 weeks, and the visual group were treated with visual feedback training using a Balance Master. Results: At the 4 week follow-up test, the LOS in the proprioceptive group improved significantly in all directions (p<0.05). However, improvement was only observed in the forward direction in the visual feedback group. Therefore, the proprioceptive control approach improves the LOS in chronic hemiplegia patients. Conclusion: These results suggest that compared with physical therapy alone using a proprioceptive control approach to hemiplegia, there was no additional benefit of visual feedback training, such as Balance Master, when administrated in combination with other physical therapy interventions.

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The Effects of Ankle Strengthening Training and Whole Body Vibration on the Balance of Older Adults Who Have Experienced a Fall

  • Choi, Jung Hyun;An, Ho Jung
    • Journal of International Academy of Physical Therapy Research
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    • v.6 no.2
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    • pp.884-890
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    • 2015
  • This study observed the effects of ankle strengthening exercise and whole body vibration on the balance ability of older adults, thereby intending to provide basic materials for intervention methods aimed at improving older adults' balance ability. The subjects were 20 older adults who had experienced a fall. They were equally divided into two groups. Ankle strengthening training was applied to one group and ankle strengthening training and whole body vibration were applied to the other group, a timed up and go (TUG) test and Tinetti performance oriented mobility assessment (POMA) were performed, and changes in the subjects' limits of stability were observed. The TUG and POMA results significantly differed between before and after the experiment in the angle strengthening training (AST) group and the angle strengthening training with whole body vibration (ASTWV) group. In addition, the interaction between timing and each group was statistically significant. The limits of stability significantly changed after the intervention in both groups. Differences in the posterior and right limits of stability were significant between the AST group and ASTWV group. Therefore, ankle strengthening exercise and whole body vibration improve older adults' balance maintenance and reduce falls or the risk factors for falls in older adults.

Effects of Finite-Rate Chemistry and Film Cooling on Linear Combustion-Stability Limit in Liquid Rocket Engine (액체 로켓엔진에서 선형 연소 안정한계에 미치는 유한화학반응 및 막냉각 효과)

  • Sohn Chae Hoon;Park I-Sun;Moon Yoon Wan;Kim Hong-Jip;Oh Hwa Young;Huh Hwanil
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • v.y2005m4
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    • pp.189-193
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    • 2005
  • Thermal effect of finite-rate chemistry on linear combustion stability and film cooling effect are investigated in sample rocket engine. The flow variables required to evaluate stability limits are obtained from CFD data with finite-rate chemistry adopted in three dimensional chamber. Major flow variables are affected appreciably by finite-rate chemistry and thereby, the calculated stability limits are modified. It is found that finite-rate chemistry contributes to stability enhancement in thermal point of view. And film cooling also has the effect of combustion stabilization.

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A study on the ATC(Available Transfer Capabilily) calculation using an Energy Function Method (에너지함수법을 이용한 가용송전용량(ATC) 계산에 관한 연구)

  • Kim, Jae-Hyeon;Jeong, Sung-Won;Kim, Yong-Il
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.22 no.2
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    • pp.94-100
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    • 2008
  • Available transfer capability(ATC) quantifies the viable increase in real power transfer from one point to another in a power system. ATC calculation has predominantly focussed on steady-state viability. But ATC assessment with transient stability constraints has a dominant part in overall ATC calculation. ATC assessment requires a reputation of (n-1) security assessment with constraints of thermal limits, voltage stability and dynamic stability. An estimation of determinant contingency screening method is used for computing eigenvalue of Jacobian matrix. This paper proposed a methods to ATC calculation using energy function. Constraints is used thermal limits, voltage stability and transient stability.

Effects of Finite-Rate Chemistry and Film Cooling on Linear Combustion-Stability Limit in Liquid Rocket Engine (액체 로켓엔진에서 선형 연소 안정한계에 미치는 유한화학반응 및 막냉각 효과)

  • Son, Chae-Hun;Kim, Hong-Jip;Heo, Hwan-Il;Park, Lee-Seon;Mun, Yun-Wan
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.34 no.2
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    • pp.75-81
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    • 2006
  • Thermal effect of finite-rate chemistry on linear combustion stability and film-cooling effect are investigated in sample rocket engines. The flow variables required to evaluate stability limits are obtained from CFD data with finite-rate chemistry adopted in three dimensional chamber. Major flow variables are affected appreciably by finite--rate chemistry and thereby, the calculated stability limits are modified. It is found that finite-rate chemistry contributes to stability enhancement in thermal point of view. And film cooling also has the effect of combustion stabilization.

SOLUTION AND STABILITY OF AN n-VARIABLE ADDITIVE FUNCTIONAL EQUATION

  • Govindan, Vediyappan;Lee, Jung Rye;Pinelas, Sandra;Noorsaba, Abdul Rahim;Balasubramanian, Ganapathy
    • Korean Journal of Mathematics
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    • v.28 no.3
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    • pp.613-621
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    • 2020
  • In this paper, we investigate the general solution and the Hyers-Ulam stability of n-variable additive functional equation of the form $${\Im}\(\sum\limits_{i=1}^{n}(-1)^{i+1}x_i\)=\sum\limits_{i=1}^{n}(-1)^{i+1}{\Im}(x_i)$$, where n is a positive integer with n ≥ 2, in Banach spaces by using the direct method.

Effects of Active Craniocervical Movement Training Using a Cognitive Game on Stroke Patients' Balance (인지적 게임을 이용한 능동적 두경부 움직임 훈련이 뇌졸중 환자의 균형에 미치는 영향)

  • Kim, Mi-sun;Choi, Woo-sung;Choi, Jong-Duk
    • Physical Therapy Korea
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    • v.28 no.1
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    • pp.47-52
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    • 2021
  • Background: Compared with normal people, stroke patients have decreased voluntary craniocervical motion, which affects their balance. Objects: This study was conducted in order to examine the effects of active craniocervical movement training using a cognitive game on stroke patient's cervical movement control ability, balance, and functional mobility. Methods: The subject of this study were 29chronic stroke patients who were randomly allocated to either an experimental, cognitive game group (n = 15), or control group (n = 14), to which only neuro-developmental treatment (NDT) was applied. The intervention was conducted 5 times per week, 30 minutes per each time, for a total of 4 weeks. Active angle reproduction test, static stability test, limits of stability test, and Time up and Go (TUG) test, respectively, were carried out in order to evaluate cervical movement control ability, static balance, dynamic balance, and functional mobility. Paired t-test was used in order to compare differences between prior to after the intervention, along with an independent-test in order to compare prior to and after-intervention differences between the two groups. Results: After the craniocervical training with a body-driven cognitive game, the experimental group showed significant differences in flexion, extension, and lateral flexion on the affected side, and rotation on the affected side in the active angle reproduction test. The experimental group indicated significant differences in sway length both with eyes-open and with eyesclosed in the static stability test and in limits of stability test and TUG test. The control group to which NDT was applied had significant differences in flexion in the active angle reproduction test and in limits of stability test and TUG test. Conclusion: The above results mean that craniocervical training using a body-driven cognitive game positively influences stroke patient's cervical movement control ability and as a result their balance and functional mobility.

The Optimal Power Flow Algorithm Considering Load Power Factor Limits (부하역률 제약조건을 고려한 최적 급전 알고리즘)

  • 김광욱;조종만;김진오
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.53 no.9
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    • pp.494-499
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    • 2004
  • This paper presents to compute the power economic dispatch, an optimal power flow (OPF) computation algorithm, considering the load power factor limits constraint in developed. Efficient reactive power planning enhances economic operation as well as system security. Accordingly, an adequate level of power factor limits for the load busesshould be evaluated for economic operation. In this paper, the ranges of acceptable load power factors are portrayed as bandwidths of load power factor expressed as a function of load level. The load power factor limits are included and described into the OPF's objective function. The method Proposed is applied to IEEE 26 bus system.