• 제목/요약/키워드: Limit Of Stability

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BioRescue의 측정자내와 측정자간 신뢰도 (Intra- and Inter-rater Reliability of BioRescue)

  • 김진홍;최보람
    • 한국콘텐츠학회논문지
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    • 제18권11호
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    • pp.348-352
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    • 2018
  • BioRescue($RMIng{\acute{e}}nierie$, Marseille, France)는 대상자가 일어서거나 앉을 때 동적과 정적인 균형을 평가하기 위해 사용하는 장비이다. 이전부터 다양하게 사용되고 있지만 이 장비에 대한 명확한 신뢰도에 대한 연구는 아직 부족한 상태이다. 본 논문은 균형 능력 측정을 위한 BioRescue의 측정자내와 측정자간 신뢰도를 측정했다. 이 연구의 대상자는 34명의 건강한 대상자들과 2명의 물리치료사 평가자들로 구성되었다. BioRescue는 발지표(면적과 압력), 롬버그 검사, 안정성 검사로 구성되어 있다. 발지표의 면적과 안정성 검사는 모든 방향에서 ICC값이 0.60 이상으로 나왔다. 하지만 발지표의 압력과 롬버그 검사는 모든 방향에서 ICC값이 0.60 이하로 나왔다. BioRescue는 균형검사 시 발지표의 면적과 안정성 검사에서 높은 신뢰도를 나타냈다. 하지만, 발지표의 압력과 롬버그 검사의 수치에서 숙련자와 비숙련자의 차이를 보이기 때문에 장비의 정확성을 위해 숙련이 필요하다.

PNF 목 패턴을 병행한 체간안정로봇훈련이 만성 뇌졸중 환자의 체간 안정성 및 균형능력에 미치는 영향 (The Effects of PNF and Trunk Stabilization Robot Training on Trunk Stability and Balance in Patients with Chronic Stroke)

  • 문현민;김동훈
    • PNF and Movement
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    • 제19권1호
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    • pp.67-77
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    • 2021
  • Purpose: The purpose of the study was to identify the effects of proprioceptive neuromuscular facilitation (PNF) training and robot rehabilitation training on trunk stability and standing balance in individuals with chronic stroke. Methods: There were 30 patients with chronic stroke, divided into two groups: 15 subjects who received PNF and robot training (the experimental group) and 15 subjects who received standard conservative training (the control group), that participated. The experimental group received treatment for 60 min: 30 min of conventional physical therapy, 15 min of PNF training, and 15 min of robot training. The control group received conventional physical therapy for 60 min. Trunk stabilization (trunk impairment scale) and standing balance (center of pressure, limit of stability, modified functional reach test, and Berg balance scale) were measured before and after intervention. Results: Within each group, both the experimental and control groups significantly improved after the intervention in all tests; however, the experimental group showed greater improvement in scores on the trunk impairment scale, the center of pressure, the limit of stability, the modified functional reach test, and the Berg balance scale. Conclusion: The study verified that PNF training and robot training had a positive influence on trunk stability and standing balance indices in patients with chronic stroke.

사면안정해석에 있어서의 유한요소법과 한계평형법의 비교 (Comparative study between Finite Element Method and Limit Equilibrium Method on Slope Stability Analysis)

  • 이동엽;유충식
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2002년도 가을 학술발표회 논문집
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    • pp.483-490
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    • 2002
  • This paper presents the results of a comparative study between FEM and LEM on slope stability analysis. For validation, factors of safety were compared between FEM and LEM. The results from the two methods were in good agreement suggesting that the FEM with the shear strength reduction method can be effectively used on slope stability analyses. A series of analysis were then performed using the FEM for various constitutive laws, slope angles, flow rules, and the finite element discretizations. Among the findings, the finite element method in conjunction with the shear strength reduction method can provide reasonable results in terms of factor of safety. Also revealed is that the results of FEM can be significantly affected by the way in which the type of constitutive law and flow rule are selected.

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인공신경망 기반의 한계상태함수를 이용한 사면의 신뢰성해석 (Reliability Analysis of Slopes Using ANN-based Limit-state Function)

  • 조성은;변위용
    • 한국지반공학회논문집
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    • 제23권8호
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    • pp.117-127
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    • 2007
  • 사면안정해석은 지반물성의 불확실성을 포함한 많은 불확실한 요인을 내포하는 지반공학적 문제이다. 본 연구에서는 상업용 유한차분해석 프로그램을 이용하여 확률론적 사면안정해석을 수행할 수 있는 절차를 제시하였다. 이 경우 한계상태함수가 명시적인 형태로 표현되지 않기 때문에 한계상태함수를 근사화하기 위하여 인공신경망기법을 활용한 응답면기법을 이용하였으며 파괴확률을 구하기 위해 일차 및 이차신뢰도법과 Monte Carlo simulation을 이용하였다. 제안된 절차의 적용성을 검토하기 위하여 2층 지반의 사면과 Sugar Creek제방사면에 대한 확률론적 사면안정해석을 수행하였다. 해석결과는 제안된 절차의 적정성과 다른 다양한 지반공학 문제로의 확장 적용의 가능성을 보여준다.

자발광 계측을 통한 모사 SNG 수소함량에 따른 이중선회 버너의 화염 안정화 특성 (Flame Stability of Dual Swirl Combustor with variable SNG composition using the Chemiluminescence Measurement)

  • 최인찬;오광철;이기만
    • 한국연소학회:학술대회논문집
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    • 한국연소학회 2014년도 제49회 KOSCO SYMPOSIUM 초록집
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    • pp.147-148
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    • 2014
  • This article describes an investigation of flame stability characteristics with various compositions of synthetic natural gas (SNG) in dual swirl combustor. The objective of this study is to investigate the flame stabilization, flame structure, fuel compatibility using chemiluminescence measurement in SNG with varying fuel compositions. As experimental conditions, hydrogen content was adjusted from 0 to 11%. Experimental results show that the addition of hydrogen has a major effect on flame behavior due to the higher burning rates associated with hydrogen consequently, The higher reaction activity of hydrogen has extended lean blow-off limit. Especially, DI flame limit has improved more 12.1%.

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하중전이를 고려한 앵커보강사면의 안정해석 (Stability Analysis of Anchored Slope Considering Load Transfer)

  • 김낙경;윤승권;김성규;주용선;박종식
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2009년도 춘계 학술발표회
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    • pp.1113-1124
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    • 2009
  • The limit equilibrium method and finite element method have been commonly used to assess the stability of anchored slope. However, the existing limit equilibrium methods do not consider the load transfer of anchor and, if the potential failure surface crosses the bonded zone of anchors, the anchor loads are not included in computing the factor of safety. In this paper, simplified bishop method, one among several methods based on the limit equilibrium is used to develope the Excel Sheet program and the working load of anchor along the failure surface is calculated by Flamant's formula, proposed by Morlier and Tenier(1982). Additionally, the finite element analysis of anchored slope considering the load transfer is performed in order to compare with the result from the limit equilibrium analysis and analyze the reinforced effect of anchor. From this study, new modelling method that limits the reinforcing range and considers the load transfer is proposed and Excel Sheet program is developed. The factor of safety for several cases between PC STABL and Excel Sheet program is also compared for verification of the program.

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스크롤 압축기에서 축방향 순응하는 고정부재의 안정성 (Stability of the axially compliant fixed scroll in scroll compressors)

  • 김현진;이원학
    • 설비공학논문집
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    • 제9권2호
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    • pp.93-103
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    • 1997
  • This study presents a way of improving the stability of fixed scroll in scroll compressors. For the scroll compressor whose fixed scroll is designed to move in the axial direction for the axial compliance, the fixed scroll is under the influence of the overturning moment produced by internal gas forces. Unless the overturning moment is properly compensated by the moments of reaction forces at the suspension of the fixed scroll to the compressor frame, the fixed scroll would exhibit wobbling motion, increasing gas leakage through the gap induced by the wobbling of the fixed scroll between the two scroll members. The conditions on which the wobbling motion can be suppressed have been found analytically; The axial position of the fixed scroll suspension should be made within a certain range. The upper limit of this range is the axial location for the o-rings which are inserted between the fixed scroll and the back pressure chamber to promote sealing for the gas in the back pressure chamber. And the lower limit is mainly determined by the magnitude of the axial sealing force. As long as the axial sealing force is not negative over all crank angles, the lower limit is not above the mid-height of the scroll wrap. Larger axial sealing force lower the lower limit.

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풍력발전의 전력계통 동적 수용한계 산정 및 BESS 적용방안 분석 (Study on Calculation of Dynamic Penetration Limit of WTG and Applications of BESS in Power Systems)

  • Gwon, Han Na;Choi, Woo Yeong;Kook, Kyugn Soo
    • KEPCO Journal on Electric Power and Energy
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    • 제1권1호
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    • pp.29-32
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    • 2015
  • 풍력발전기와 같은 신재생에너지원은 기존 동기화력발전기의 특성과 매우 다르기 때문에, 상정고장과 같은 가혹한 상황에서는 주파수 변동에 신속히 대응하지 못하므로 주파응답성능을 저하시킬 수 밖에 없다. 특히, 풍력발전의 수용률이 높은 상황에서 상정고장이 발생한 경우, 전력계통에 안정화를 위해서 풍력발전의 수용이 더욱 제한될 가능성이 잠재되어 있다. 이를 위해, 본 논문에서는 풍력발전의 전력계통 동적 수용한계를 산정하는 절차를 구현하고, 산출된 결과로부터 풍력발전의 동적 수용한계를 증대시키기 위한 BESS의 적용방안을 모색하였다.

건설전원용량에 따른 신설전원의 안정도특성 (The Stability Dependency of New Generator on the Existing System Capacity)

  • Nam, Sang-Cheon
    • 대한전기학회논문지
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    • 제35권7호
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    • pp.285-295
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    • 1986
  • This study is to investigate the stability of expanded new generator plant depending on the capacity of existing system. We examined the transmitting power limit to the existing system as its capacity increase for the various system configuration with fixed location of plants and substations. The results show that the stability has decreasing tendency when the existing source capacity increase. Thus it can be concluded that new generator has little stability problem when it connected to small system, whereas large existing system capacity gives remarkable difficulty in adopting new generator.

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변형된 선합성수 디지털 필터의 안정도 해석 (Stability Analysis of Modified Coupled-Form Digital Filter Using a Constructive Algorithm)

  • 남부희;김남호
    • 대한전기학회논문지
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    • 제34권11호
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    • pp.430-435
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    • 1985
  • Using the constructive algorithm proposed by Brayton and Tong, we analyze the stability of a modified coupled-form digital filter with quantization and overflow nonlinearities, and find the regions in the parameter plane where the filter is globally asymptotically stable. In these regions, the absence of zero-input limit cycles is ensured. This constructive algorithm gives less conservative stability results than the application of Jury-Lee stability criterion does.

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