• Title, Summary, Keyword: Balance

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Vibration Characteristics of High Pressure Multi-Stage Pump with Anti-Swirl Injection Balance Sleeve (역스월 유로 입력을 가지는 밸런스 슬리브를 적용한 고압 다단 펌프의 진동 특성)

  • 곽현덕;이용복;김창호;이봉주
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.214-219
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    • 2002
  • As the tangential flow inside the clearance of tribe elements such as bearings and seals is increased as the shaft speed increases, the system stability will be decreased due to the increment of the instability parameter. To reduce the tangential flow inside the clearance of the balance sleeve, anti-swirl injection mechanism is applied. The balance sleeve is used in resisting the axial force induced by impeller in high pressure multi-stage pump. In this paper, total three cases are experimentally investigated; original balance steeve, anti-swirl injection balance steeve with 0 axial degree and anti-swirl injection balance sleeve with 30 axial degree. Experiments are focused in the comparison of vibration level and leakage flow rate. The results clearly shows that the anti-swirl injection balance sleeve with 0 axial degree improves the vibration characteristics. However, the anti-swirl injection balance sleeve with 30 degree aggravates the vibration characteristics. In the standpoint of leakage performance, both anti-swirl injection balance sleeves show the better result than the original balance sleeve.

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The Effect of Visual Biofeedback Exercise on the Recovery of Balance in Stroke Patients (시각적 바이오피드백 균형 훈련이 뇌졸중 환자의 균형 회복에 미치는 영향)

  • Kim, Jae-Yong;Kim, Dae-Kyung
    • PNF and Movement
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    • v.15 no.2
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    • pp.201-208
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    • 2017
  • Purpose: The purpose of this study is to determine the effects of visual biofeedback training on the recovery of balance function in stroke patients. Methods: A total of 30 patients with stroke were chosen as the subjects of this study. The subjects were randomly divided into either the visual biofeedback balance training group (experimental group; n=15) or the general balance training group (control group; n=15). The visual biofeedback balance training and general balance training were implemented for 30 minutes a day, three times a week, for a total of four weeks. The subjects' balance ability was measured before and after the interventions. Results: The shift length and surface area of the center of the body decreased in both the experimental group and the control group, with the difference being statistically significant. The shift length and surface area of the center of the body both decreased more in the experimental group than in the control group, and there was a statistically significant between-group difference. Conclusion: The experimental group showed a greater improvement in terms of the balance ability of patients with stroke than the control group. Therefore, we believe that visual biofeedback balance training can be effectively applied for the improvement of balance ability in patients with stroke.

A Study on Generating Process of Regional Balance Point Temperature for Heating Degree-days in Korea (국내 난방도일의 지역별 균형점온도 산정 과정에 관한 연구)

  • Park, So Min;Song, Doo Sam
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.29 no.9
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    • pp.482-495
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    • 2017
  • Degree-days are practically used as a tool to estimate energy consumption for heating and cooling. Degree-days are calculated by summing differences of balance point temperature and outside temperature for the analyzed period. Determining balance point temperature is a key point in calculating accurate degree-days. However, ASHRAE standards are used for balance point temperature in Korea because balance point temperature considering climate conditions and building thermal performance is not proposed in Korea. This study proposes the process to generate balance point temperature for heating degree-days considering Korean climate and building conditions. Also, a new balance point temperature for three regions in Korea will be suggested in this study. Balance point temperature of Seoul is approximately $15.0^{\circ}C$, lower than the current standard of $18.3^{\circ}C$. Balance point temperature of Seoul considering climate conditions and building performance can be different from the ASHRAE suggested value ($18.3^{\circ}C$). Results revealed the current standard for balance point temperature should be changed considering climate and building conditions in Korea.

Effects of Weight Distribution and Balance with Foot Orthotics in Hemiplegic Patients (편마비 환자에서 발 교정구의 적용이 체중분포과 균형에 미치는 영향)

  • Park, Seung-Kyu;Kang, Yang-Hun
    • The Journal of Korean Physical Therapy
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    • v.24 no.4
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    • pp.241-246
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    • 2012
  • Purpose: We investigated the effect of postural stability and balance with foot orthotics in hemiplegic patients. Methods: The subjects enrolled in this study were 16 hemiplegic patients who were examined for balance ability, weight distribution, and limits of stability with or without foot orthotics insole. Balance was measured according to a stance position by BIORESCUE: static balance open eyes (SEO), static balance close eyes (SEC), dynamic balance open eyes (DEO), dynamic balance close eyes (DEC), right and left weight distribution (RLWD), anterior and posterior weight distribution (APWD) and limit of stability (LOS). The data were analyzed with SPSS window version 18.0 (IBM Co., Armonk, NY, USA). Results: The results were of significant changes to the SEO (p<0.05), RLWD (p<0.05), APWD (p<0.05), and LOS (p<0.05). The SEC, DEO and DEC were not found to be statistically significant. Conclusion: It was found that foot orthotics affected the balance for hemiplegic patients. Therefore, it is thought to help fall prevention to measure the balance ability.

The Effect of a Rollator on Plantar Pressure and Foot Balance during Gait in old-aged Adults (노인의 보행 시 Rollator 사용이 족저압 및 균형에 미치는 영향)

  • Koo, Hyung-Mo;Kim, Min-Hee
    • The Journal of Korean Physical Therapy
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    • v.22 no.5
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    • pp.71-76
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    • 2010
  • Purpose: The present study was designed to investigate the effect of a Rollator on plantar pressure and foot balance during gait in older adults. Methods: Twenty consecutive subjects (8 men, 12 women; age: $69.9{\pm}8.9$) had the following measurements done: plantar pressure in 10 areas of the foot, foot balance including heel rotation, foot balance, forefoot balance, medial forefoot balance, and meta loading during gait with or without a Rollator. Results: Significant differences in plantar pressure were observed in the areas of toes 2-5 or etatarsal areas 1, 4, 5 during gait with and without a Rollator. There were no significant differences in other areas of the foot. Regarding foot balance during gait with or without a Rollator, there were statistically significant differences in heel rotation, forefoot balance, medial forefoot balance, and meta loading. Conclusion: For older adults, the use of a Rollator can decrease plantar pressure and increase foot balance in various foot areas.

Can Functional Assessment Tools Reflect Balance Abilities at 3 Months after Total hip Arthroplasty?

  • Kim, Min-Woo;Ryu, Young-Uk
    • Journal of the Korean Society of Physical Medicine
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    • v.13 no.4
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    • pp.51-58
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    • 2018
  • PURPOSE: This study was conducted to determine if the Harrison hip score (HHS), a tool for assessing hip joint function, and the Burg balance scale (BBS), a general balance assessment tool, actually reflect the balance ability of total hip arthroplasty (THA) patients 3 months after surgery. In addition, this study investigated the initial weight distribution strategy for bilateral lower extremity after THA surgery to understand the balance of THA patients. METHODS: Fourteen 3-month THA patients performed static dual standing and sit-to-stand (STS) tasks. Ground reaction forces on each leg were collected to calculate the weight distribution symmetricity (SWD), and the HHS, functional HHS (f-HHS), and BBS were evaluated. Correlation analyses between SWD and the HHS (also f-HHS) and BBS were then applied to the THA patients. RESULTS: The correlations between functional evaluation tools (HHS, f-HHS, BBS) and SWD were weak strength for the static balance task, but moderate for the dynamic STS task. Among the evaluation tools used in the present study, f-HHS was most useful for evaluation of dynamic balance ability. CONCLUSION: The results suggest that use of HHS, f-HHS, and BBS as functional evaluation tools does not provide meaningful information regarding balance ability, but that they are useful for evaluating dynamic balance ability of THA patients. The dynamic balance ability at 3 months after THA seems to be under development.

Vibration Characteristics of High Pressure Multi-stage Pump with Anti-swirl Injection Balance Sleeve (역스월 유로 입력을 가지는 밸런스 슬리브를 적용한 고압 다단 펌프의 진동 특성)

  • 곽현덕;이용복;김창호;이봉주
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.12 no.8
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    • pp.632-638
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    • 2002
  • As the tangential flow inside the clearance of tribo elements such as bearings and seals is increased as the shaft speed increases, the system stability will be decreased due to the increment of the instability parameter. To reduce the tangential flow inside the clearance of the balance sleeve, anti-swirl injection mechanism is applied. The balance sleeve is used in resisting the axial force induced by impeller in high pressure multi-stage pump. In this paper, total three cases are experimentally investigated; original balance sleeve, anti-swirl injection balance sleeve with 0 axial degree and anti-swirl injection balance sleeve with 30 axial degree. Experiments are focused in the comparison of vibration level and leakage flow rate. The results clearly shows that the anti-swirl injection balance sleeve with 0 axial degree improves the vibration characteristics. However, the anti-swirl injection balance sleeve with 30 degree aggravates the vibration characteristics. In the standpoint of leakage performance, both anti-swirl injection balance sleeves show the better result than the original balance sleeve.

Effects of Transcranial Direct Current Stimulation on the Static Balance Ability of Patients with Back Pain

  • Oh, Seung Keun;Kim, Yong Nam
    • The Journal of Korean Physical Therapy
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    • v.31 no.5
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    • pp.328-332
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    • 2019
  • Purpose: This study examined the effects of transcranial direct current stimulation (tDCS) on the static balance ability of patients with back pain. Methods: The subjects comprised of 30 males and females in their 20s, who were divided into two groups with and without tDCS. The balance posture ratio score was calculated to determine the changes in balance ability before and after the application of tDCS using balance equipment. A paired t-test was conducted to determine the changes over time, and an independent t-test was performed to determine the changes between the groups. The significance level was set to ${\alpha}=0.05$. Results: A significant difference in the changes in the static balance ability of CTDCSG between before and after applying tDCS was observed while the subjects' eyes were open (p<0.05). A comparison between the groups after the experiments revealed significantly increased changes in CTDCSG compared to STDCSE (p<0.05). The changes in static balance ability were not significant when the subjects' eyes were closed (p>0.05). Conclusion: The application of tDCS positively changed the static balance ability of patients with back pain. The results of this study showed that tDCS could be used as an intervention to increase the static balance ability of patients with back pain in the clinical field. The study results could be used further as foundational data for future studies on tDCS.

Relationship between Gait, Static Balance, and Pelvic Inclination in Patients with Chronic Stroke

  • Choe, Yu-Won;Kim, Kyu-Ryeong;Kim, Myoung-Kwon
    • Journal of the Korean Society of Physical Medicine
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    • v.16 no.1
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    • pp.17-22
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    • 2021
  • PURPOSE: This study examined the correlations between gait, static balance, and pelvic inclination in patients with chronic stroke. METHODS: Twenty-two chronic stroke patients were included in this study. The subjects participated in gait, static balance, and pelvic inclination tests. In the gait measurement, the cadence and gait velocity were measured, and the average of three trials was calculated and recorded. The static balance was measured using a force platform. The data was captured for ten seconds, and five successful trials were recorded. Pelvic inclination in the sagittal plane was measured using a palpation meter. For data processing, a KolmogorovSmirnov test was used to determine the type of distribution for all variables. Pearson's correlation coefficient was used for correlation analysis. The correlations among the gait, static balance, and pelvic inclination was calculated. The level of significance was .05. RESULTS: Significant negative correlations were observed between the gait variables (cadence, velocity) and static balance variables (COP path length, COP average velocity, and 95% confidence ellipse area) (p < .05). On the other hand, there was no significant correlation between pelvic inclination and gait or between the pelvic inclination and static balance variables. CONCLUSION: Significant correlations were observed between the gait function and static balance. On the other hand, there were no significant correlations between the pelvic inclination and gait and static balance. These results suggest that the pelvic inclination is not an important consideration for increasing the gait function and static balance.

Evaluation of Balance in Diabetes Patients With Peripheral Neuropathy (당뇨병성 신경병증 환자의 균형기능 평가)

  • Weon, Jong-Hyuck;Lee, Young-Hee;Yi, Chung-Hwi;Cho, Sang-Hyun
    • Physical Therapy Korea
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    • v.5 no.3
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    • pp.11-20
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    • 1998
  • The purposes of this study were to determine the effect of different degrees of severity of diabetic neuropathy on balance function, and to evaluate dynamic balance and functional performance in diabetes patients. Twenty-four subjects with diabetes mellitus were divided into three groups according to results of sensory nerve conduction study. All subjects were evaluated for dynamic balance which was measured using computerized dynamic posturography, and functional performance which was measured using the Berg balance scale. One-way analysis of variance was used to determine whether there were any statistically differences of dynamic balance function and functional performance among the three groups. The Spearrnan's rank correlation was used to determine statistical significance between dynamic balance and age. The results were as follows: 1. Dynamic balance measured using computerized dynamic posturography was significantly lower in the no response group than in the normal amplitude group (p<0.05). 2. Functional performance tested by the Berg balance scale was not statistically different among the three groups (p>0.05). 3. an inverse relationship was found between dynamic balance measured using computerized dynamic posturography and age (r=-0.68, p<0.05). These results suggest that patients with severe diabetic neuropathy have loss of dynamic balance function. Therefore, patients with severe diabetic neuropathy need to have their balance evaluated and receive appropriate education.

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