• Title/Summary/Keyword: Stability and stabilization

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Effects of Sensorimotor Training on Postural Stability and Pain in Patients with Chronic Low Back Pain

  • Kang, Kwonyoung
    • Journal of International Academy of Physical Therapy Research
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    • v.12 no.2
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    • pp.2314-2322
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    • 2021
  • Background: Back pain is associated with a high risk of recurrence. Various physical therapy techniques for back pain have been studied, including reprogramming the central nervous system by integrating sensation and motion with sensory exercise training. Objectives: To aimed verify the effectiveness of sensorimotor training in improving postural stability and pain levels. Design: A randomized controlled trial. Methods: The study population was randomized into a sensory exercise training group and trunk stabilization training group and treated three times a week for 4 weeks. Each group took part in sensorimotor training for 15 minutes or lumbar stabilization exercise for 15 minutes. Results: After the intervention both groups showed Improvements in the variables. There was a significant difference in the dynamic postural stability, limit of stability, and modified visual analog scale scores in the sensorimotor training group compared to the lumbar stabilization exercise group (P<.05). Conclusion: Sensorimotor training appears to be an effective physical therapy exercise program that can be applied in patients with low back pain to improve muscle control ability.

Stability Rating of KSR-III Rocket Engine (KSR-III 로켓엔진의 연소 안정성 평가)

  • Sohn, Chae-Hoon;Kim, Young-Mog
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.32 no.3
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    • pp.95-101
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    • 2004
  • Stability rating of KSR-III rocket engine is conducted based on stability rating tests in the course of development of KSR-III rocket engine. Rocket engine is approved to have combustion stabilization ability when it can suppress the external perturbation or pressure oscillation with finite amplitude and recover the original stable combustion. Rocket engine in flight may be perturbed by unexpectedly large-amplitude pressure oscillation and thus a designer should not only assure combustion stabilization ability of the engine but also quantify the stabilization capacity. For this, principal quantitative parameters and their evaluation are introduced. To verify dynamic stability of KSR-III rocket engine, six stability rating tests have been conducted. Based on these test results, such parameters are quantified and thereby, the stabilization capacity of KSR-III rocket engine is evaluated.

Comparison of the Effects of Massage, Stretching Exercise and Scapular Stabilization Exercise in Patients with Upper Trapezius Myofascial Pain Syndrome (상승모근 근막동통증후군 환자에 대한 마사지, 신장운동, 견갑골 안정화운동의 효과 비교)

  • Park, Young-Soek;Kim, Suhn-Yeop;Oh, Duck-Won;Choi, Duk-Jong;Bae, Ho-Won;Seo, Young-Joo
    • The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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    • v.17 no.1
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    • pp.1-8
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    • 2011
  • Background: The purpose of this study was to determine the effects of massage, stretching exercise, and scapular stabilization exercise in patients with upper trapezius myofascial pain syndrome (MPS). Methods: Twenty-three female patients with upper trapezius MPS were randomly allocated to three groups: massage, stretching exercise, and scapular stability exercise groups. Therapeutic intervention for all groups included general therapy such as hot pack, transcutaneous electrical nerve stimulation and ultrasound. Patients in the massage group (n=8), stretching group (n=7), and stabilization exercise group (n=8) received their respective therapy program after general therapy for 15 minutes. Therapeutic intervention for each group was performed three times per week for six weeks. All groups were tested four times: prior to the test, at three weeks, at six weeks, and at nine weeks. Results: Pain levels decreased significantly in the stretching and stabilization exercise groups over time (p<.05). The rate of change in pain level was significantly different among all groups (p<.01), and the stability exercise group experienced the lowest pain level. Pressure-pain level increased significantly in the stabilization exercise group over time (p<.05). The rate of change in pressure-pain level was significantly different among all groups (p<.01), and the stability exercise group had the highest pressure-pain level. The level of upper-extremity stability increased significantly in the stability exercise group over time (p<.05). The rate of change in the upper-extremity stabilization level was significantly different among all groups (p<.01), and the stability exercise group had the highest upper-extremity stability level. Conclusions: Scapular stabilization exercises proved to be the most effective therapy for MPS patients.

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Stability Rating of Liquid Propellant Rocket Engine (액체 로켓엔진의 연소 안정성 평가)

  • 손채훈;김영목
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2003.10a
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    • pp.73-77
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    • 2003
  • Stability rating of KSR-III rocket engine is conducted based on stability rating tests in the course of development of KSR-III rocket engine. Rocket engine is approved to have combustion stabilization ability when it can suppress the external perturbation or pressure oscillation with finite amplitude and recover the original stable combustion. Rocket engine in flight nay be perturbed with unexpectedly large amplitude and thus a designer should not only assure combustion stabilization ability of the engine but also quantify the stabilization capacity. For this, several quantitative parameters and their evaluation are introduced. To verify dynamic stability of KSR-III rocket engine, five stability rating tests have been conducted. Based on these test results, such parameters are quantified and thereby, the stabilization capacity of KSR-III rocket engine is evaluated.

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Stabilization of pressure solutions in four-node quadrilateral elements

  • Lee, Sang-Ho;Kim, Sang-Hyo
    • Structural Engineering and Mechanics
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    • v.6 no.6
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    • pp.711-725
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    • 1998
  • Mixed finite element formulations for incompressible materials show pressure oscillations or pressure modes in four-node quadrilateral elements. The criterion for the stability in the pressure solution is the so-called Babu$\check{s}$ka-Brezzi stability condition, and the four-node elements based on mixed variational principles do not appear to satisfy this condition. In this study, a pressure continuity residual based on the pressure discontinuity at element edges proposed by Hughes and Franca is used to study the stabilization of pressure solutions in bilinear displacement-constant pressure four-node quadrilateral elements. Also, a solid mechanics problem is presented by which the stability of mixed elements can be studied. It is shown that the pressure solutions, although stable, are shown to exhibit sensitivity to the stabilization parameters.

A Stabilization algorithm for Fuzzy Systems with Singleton Consequents

  • Michio Sugeno;Lee, Chang-Hoon
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 1998.06a
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    • pp.36-41
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    • 1998
  • This paper presents a stabilization algorithm for a class of fuzzy systems with singleton consequect. To this aim, we introduce two canonical forms of an unforced fuzzy system and a stability theorem. A design example is shown to verify the stabilization algorithm.

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Characteristics of Flame Stabilization of the LFG Mixing Gas (LFG 혼합 연료의 화염 안정화 특성)

  • Kim, Sun-Ho;Oh, Chang-Bo;Lee, Chang-Eon;Lee, In-Dae
    • 한국연소학회:학술대회논문집
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    • 1999.10a
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    • pp.165-172
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    • 1999
  • Landfill gas has merely half heating value compared with liquified natural gas but can be greatly utilized as a commercial fuel. The authors have examined emission characteristics as well as measured burning velocity of LFG mixed gas which contains plenty of $CO_{2}$. With the viewpoint of fuel utilization, flame stability could be one of important characteristics of LFG. In this study, the comparison experiments are conducted between $CH_{4}$ and LFG for searching the region of flame stabilization based upon the flame blowout at maximum fuel stream velocity. As a result, it is found that stabilization region of LFG is not improved with that of $CH_{4}$ in non-swirl/or weak swirl jet diffusion flame. However, it is also known that flame stability is hardly affected by inert gas in the strong swirl with considering widened flame stabilization region of LFG rather than LNG.

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Lumbo-pelvic stabilization approach for lower back dysfunction (요통의 요골반부 안정화(lumbo-pelvic stabilization) 접근법)

  • Kim, Suhn-Yeop
    • The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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    • v.4 no.1
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    • pp.7-20
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    • 1998
  • Activity of the trunk muscles is essential for maintaining stability of the lumbar spine because of the unstable structure of that portion of the spine. The central nervous system deals with stabilization of the spine by contraction of the abdominal and multifidus muscles in anticipations of reactive forces produced by limb movement. Recent evidence indicates that the lumbar multifidus muscle and transversus abdominis muscle may be involved in controlling spinal stability. Stabilization training in neutral spine is an integrated approach of education in proper posture and body mechanics along with exercise to improve strength, flexibility, muscular and cardiovascular endurance, and coordination of movement.

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Robust D-Stability and D-Stabilization of Dynamic Interval Systems

  • Mao, Wei-Jie;Chu, Jian
    • International Journal of Control, Automation, and Systems
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    • v.5 no.5
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    • pp.594-600
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    • 2007
  • A sufficient condition for the robust D-stability of dynamic interval systems is proposed in this paper. This D-stability condition is based on a parameter-dependent Lyapunov function obtained from the feasibility of a set of matrix inequalities defined at a series of partial-vertex-based interval matrices other than the total vertex matrices as previous results. This condition is also extended to the robust D-stabilization problem of dynamic interval systems, which supplies an effective synthesis procedure for any LMI D-region. The proposed conditions can be simplified to a set of LMIs, which can be solved by efficient interior point methods in polynomial time.

A Pressure Stabilization Technique for Incompressible Materials (비압축성 물체의 수치해 안정화 기법)

  • Lee, Sang-Ho;Kim, Sang-Hyo
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1995.10a
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    • pp.153-160
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    • 1995
  • Mixed finite element formulations for incompressible materials show pressure oscillations or pressure modes in four-node quadrilateral elements. The criterion for the stability in the pressure solution is the so-called Babufka-Brezzi stability condition, and the four-node elements based on mixed variational principles do not appear to satisfy this condition. In this study, a pressure continuity residual based on the pressure discontinuity at element edges is used to study the stabilization of pressure solutions in bilinear displacement-constant pressure four-node quadrilateral elements. It is shown that the pressure solutions, although stable, exhibit sensitivity to the stabilization parameters.

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