• 제목/요약/키워드: Balance Analysis

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질량신정의 구현을 위한 NPL 와트발란스 나이프에지의 기계적 특성 분석 (An Analysis of the Mechanical Characteristics of the Knife Edges used in the NPL Watt Balance)

  • 최인묵;;우삼용
    • 한국정밀공학회지
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    • 제25권4호
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    • pp.61-68
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    • 2008
  • Of the seven base units of the international system of units, only the kilogram is still defined in terms of a material artifact. One of the experimental approaches opening the way to a new definition of the kilogram is the watt balance To improve the performance of the NPL watt balance, we need to quantify and reduce hysteresis effects in the balance knives. In this paper, we discuss the mechanical characteristics of the knife edges used in the NPL watt balance. The hysteresis mechanism is analyzed using the finite element method. It is found that the cause of hysteresis is not normal stress but shear, and the deformation of the flat, rather than the knife, is an important factor in the hysteresis mechanism. The study presented here, using finite element analysis, suggests that parameters such as material property, tip radius and knife straightness can be more important than others, such as friction coefficient, tip angle, etc.

Activities-Specific Balance Confidence(ABC)척도에 대한 라쉬분석의 적용 (Application of Rasch Analysis to the Activities-Specific Balance Confidence (ABC) Scale)

  • 황수진;이충휘;박소연
    • 한국전문물리치료학회지
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    • 제14권1호
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    • pp.37-45
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    • 2007
  • This study was designed to examine, applying Rasch analysis based on item response theory, the questionnaires of the Activities-Specific Balance Confidence (ABC) scale for the elderly. The subjects were 99 institutional older adults and clients of social welfare facilities. The subjects (17 men, 72 women) ranged in age from 65 to 94 years (mean age 76.5 yrs). The Winsteps software was used to assess whether the ABC scale fits the Rasch model, to estimate the score and to refine the rating scale. The results are as follows. Twenty-two subjects were excluded as misfit persons. Four items were found to be misfits and the order of difficulty of the remaining 12 items was rearranged. Their balance confidence is indicated by -.64~1.12 logit, and the transformation formula is score=[(logit score+2.76)/(2.76+3.48)]${\times}$100. The most difficult item was "Walk outside in icy sidewalks" and the easiest item was "Walk around house." In conclusion, the ABC scale for the elderly has been proven reliable and valid. Therefore, it is expected to be used as an effective examination tool for treatment planning and screening for older adults.

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Dynamic Analysis of Harmonically Excited Non-Linear Structure System Using Harmonic Balance Method

  • 문병영;강범수;김병수
    • Journal of Mechanical Science and Technology
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    • 제15권11호
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    • pp.1507-1516
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    • 2001
  • An analytical method is presented for evaluation of the steady state periodic behavior of nonlinear structural systems. This method is based on the substructure synthesis formulation and a harmonic balance procedure, which is applied to the analysis of nonlinear responses. A complex nonlinear system is divided into substructures, of which equations are approximately transformed to modal coordinates including nonlinear term under the reasonable procedure. Then, the equations are synthesized into the overall system and the nonlinear solution for the system is obtained. Based on the harmonic balance method, the proposed procedure reduces the size of large degrees-of-freedom problem in the solving nonlinear equations. Feasibility and advantages of the proposed method are illustrated using the study of the nonlinear rotating machine system as a large mechanical structure system. Results obtained are reported to be an efficient approach with respect to nonlinear response prediction when compared with other conventional methods.

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Family 금형 제작에서의 유동 밸런스 및 휨특성에 관한 연구 (A Study on flow Balance and Warpage Characteristics in Manufacturing of Plastic Injection Family Mould)

  • 김기환;송동주;권창오;이성희;허영무;김무연
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2005년도 금형가공,미세가공,플라스틱가공 공동 심포지엄
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    • pp.141-146
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    • 2005
  • In the present study, the characteristic of warpage and flow balance for family mould, which is able to mold parts with different shapes in a mold, is considered. To obtain an optimal gate and runner system, plastic injection molding analysis with commercial code is performed. Design and manufacturing of family mould is then carried out on the basis of this computer aided engineering result. Flow balance and warpage comparisons between experiment and numerical analysis give good agreement with each other. However, it was shown that results of warpage measured by CMM was about $20\~55\%$ lower than those of numerical analysis.

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A Prediction of Work-life Balance Using Machine Learning

  • Youngkeun Choi
    • Asia pacific journal of information systems
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    • 제34권1호
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    • pp.209-225
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    • 2024
  • This research aims to use machine learning technology in human resource management to predict employees' work-life balance. The study utilized a dataset from IBM Watson Analytics in the IBM Community for the machine learning analysis. Multinomial dependent variables concerning workers' work-life balance were examined, categorized into continuous and categorical types using the Generalized Linear Model. The complexity of assessing variable roles and their varied impact based on the type of model used was highlighted. The study's outcomes are academically and practically relevant, showcasing how machine learning can offer further understanding of psychological variables like work-life balance through analyzing employee profiles.

균형능력 향상을 위한 종아리 서포터 개발에 관한 연구 (A Study on the Development of a Calf Supporter for Improving Balance Capacity)

  • 황선규;박진희;김주용
    • 패션비즈니스
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    • 제25권1호
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    • pp.39-50
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    • 2021
  • The purpose of this study was to investigate how wearing calf support and applying of electronic muscle simulation(EMS) affected the ability to balance. In this study, the one leg standing test for static balance and the Y balance test for dynamic balance were used to assess balance. At this time, the pressure of the calf support was different to produce two supporters, and a difference between wearing the support before, after, and after applying EMS was evaluated. Seven men in their 20s with healthy bodies were measured five times each with a five-minute break, taking into account muscle fatigue, and the difference between each variable was analyzed through a follow-up test using nonparametric statistical analysis. Studies have shown more difference from supporter B with a more appropriate pressure (mmgh) for increasing balance capability than from supporter A. In addition, it was confirmed that the use of EMS electrostimulation and support before measuring the balance capability resulted in a greater difference. The proper pressure (mmgh) supporters and EMS can increase the ability to balance, and these results can be expected to improve the balance ability of ordinary people in their daily lives.

Effects of Gait Training Using a Shoulder-Back Orthosis on Balance and Gait in Patients with Stroke

  • Han-Byul Youn;Jong-Kyung Lee;Yu-Min Ko;Ji-Won Park
    • The Journal of Korean Physical Therapy
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    • 제35권6호
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    • pp.200-205
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    • 2023
  • Purpose: The purpose of this study is to find out how gait training with shoulder-back assistive device affects dynamic and static balance, gait of patients with stroke and to help improve body alignment, balance, and gait ability in stroke patients. Methods: Measurements were taken of the 20 subjects before intervention without shoulder-back assistive device, after intervention with device, and follow up after an hour compared. Berg balance scale used to evaluate dynamic balance; wii balance board was used to measure static balance; and gait ability were measured by timed up and go test and 10-meter walk test. To analyze the results, a one-way repeated measures analysis of variance was implemented to compare the measurements. Results: The results showed that, after wearing the shoulder-back assistive device, the subjects' dynamic balance statistically significantly improved; no statistically significant difference was observed in static balance, although their balance ability was enhanced; and their increase in gait ability was statistically significant. Conclusion: This study proved that gait training combined with a shoulder-back assistive device positively impacted dynamic and static balance, gait of patients with stroke.

Effects of Sling Exercise on Balance and Gait in Patients with Stroke: Meta-Analysis of Studies in Korea

  • Cho, Woonsu;Lee, Seongjin;Kim, Byeonggeun
    • 국제물리치료학회지
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    • 제11권3호
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    • pp.2164-2172
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    • 2020
  • Background: Stroke patients have multiple disorders, but most have problems with balance and gait. Post-stroke rehabilitation exercise has been shown to be very important for functional recovery. Objectives: To systematically review and meta-analyze the effects of sling exercise (SE) on patients with stroke in studies published in Korea. Design: Meta-analysis. Methods: Five databases, namely, RISS, KISS, NDSL, DBpia and Earticle, were used to collect articles on vibration. Keywords such as "Stroke," "Hemiplegia," "Sling," and "Sling Exercise" were used in the search for published articles. Interventions and comparisons were SE and other exercise (OE). Outcome measures were berg balance scale (BBS) and timed up and go (TUG). Consequently, eight studies were selected in the second screening using meta-analyses. Results: Based on the results of the meta-analysis, SE was effective for BBS in the comparison of SE and OE [2.71, 95% CI (1.42, 4.01)]. It was effective for TUG in the comparison of SE and OE [-1.89, 95% CI (-3.01, -0.77)]. Conclusion: Based on eight limited studies, SE improved BBS and TUG over OE, suggesting improved stroke balance and gait. Therefore, more studies and large-scale sample randomized controlled trials are needed to confirm clinical application.

MOBA 게임 뉴시즌 Update를 위한 게임 만족 및 밸런스 연구 (A Study on Game Satisfaction and Game Balance of MOBA Game in New Season Update)

  • 이정;조동민
    • 한국멀티미디어학회논문지
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    • 제24권8호
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    • pp.1161-1170
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    • 2021
  • The MOBA game is updated every year with a new season, the new season update brings fun to the game users and also makes them feel unfamiliar with the new gameplay. In order to let game users better adapt to the new season, this study will extract the new season balance evaluation factors. Firstly, we used one-on-one review to collect the unbalanced factors that game users had encountered at the beginning of the new season of the MOBA game, and secondly, we organized the collected review data into a questionnaire and conducted a survey. The first step of the experiment was to filter out the lower factors through exploratory factor analysis and extract the balance evaluation factors of the MOBA game new season. The second step of the experiment was to examine the correlation between the factors through confirmatory factor analysis, as well as to confirm the appropriateness and explanatory value of the factors. The analysis resulted in "Game character experience", "Game view's expression", "Game level", and "Composition of the game setting" are the four factors. Finally, through correlation analysis, the most relevant factor for game satisfaction is the "Game character experience", and each factor is correlated with each other.

코어 프로그램이 20대 여성의 정적균형에 미치는 영향 (Effects of Core Program Exercise on Static Balance of Females in Their Twenties)

  • 황성준;조남정;이정우
    • 대한임상전기생리학회지
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    • 제8권1호
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    • pp.31-36
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    • 2010
  • Purpose : The purpose of this study was to investigate the effects of core exercise on the static balance for females in their twenties. Methods : The core exercise program was conducted 3 times per week for 4 weeks. The result is based on the analysis of measuring static balance before and after the core exercise program. By using the GOOD BALANCE system, the assessment of the static balance ability was made before and after the exercise of 6 postures: normal standing, one left leg?and one right leg standing with eyes open and closed respectively. For each case, the experimental data were obtained in 3 items: mean X speed, mean Y speed, and velocity moment. Statistical analysis was performed using SPSS/Win(10.0) version and Willcoxon signed rank test. Results : From the result of this study, we found that mean X speed, mean Y speed and velocity moment of total postures significantly increased after the 4 week program of core exercises. Conclusion : These finding indicate that core exercises could be beneficial to females in their twenties due to the effect of increasing static balance.