• 제목/요약/키워드: stable condition

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로보트의 Compliance 제어에서의 안정성:이론 (Stability of the Robot Compliant Motion Control, Part 1 : Theory)

  • Sung-Kwun Kim
    • 대한전기학회논문지
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    • 제38권11호
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    • pp.941-949
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    • 1989
  • This two-part paper presents a control method that allows for stable interaction of a robot manipulator with environment. In part 1, we focus on the input output relationships (unstructured modeling) of the robot and environment dynamics. This analysis leads to a general condition for stability of the robot and environment taken as a whole. This stability condition, for stable maneuver, prescribes a finite sensitivity for robot and environment where sensitivity of the robot (or the environment) is defined as a mapping forces into displacement. According to this stability condition, smaller sensitivity either in robot or in environment leads to narrower stability range. In the limit, when both systems have zero sensitivity, stability cannot be guaranteed. These models do not have any particular structure, yet they can model a wide variety of industrial and research robot manipulators and environment dynamic behavior. Although this approach of modeling may not lead to and design procedure, it will allow us to understand the fundamental issues in stability when a robot interacts with an environment.

지연요소를 갖는 시스템의 안정화 방법 (Feedback stabilization of linear systems with delay in control by receding horizon)

  • 권욱현
    • 전기의세계
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    • 제28권5호
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    • pp.44-48
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    • 1979
  • For ordinary systems the receding horizon method has beer proved by the author as a very useful and easy tool to find stable feedback controls. In this paper an open-loop optimal control which minimizes the control energy with a suitable upper limit and terminal control and state constraints is derived and then transformed to the closed-loop control. The stable feedback control law is obtained from the closed-loop control. The stable feedback control law is obtained from the closed-loop control by the receding horizon concept. It is shown by the Lyapunov method that the control law derived from the receding, horizon concept is asymtotically stable under the complete controllability condition. The stable feedback control which is similar to but more general than the receding horizon control is presented in this paper To the author's knowledge the control laws in this paper are easiest to stabilize systems with delay in control.

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C1-STABLE INVERSE SHADOWING CHAIN COMPONENTS FOR GENERIC DIFFEOMORPHISMS

  • Lee, Man-Seob
    • 대한수학회논문집
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    • 제24권1호
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    • pp.127-144
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    • 2009
  • Let f be a diffeomorphism of a compact $C^{\infty}$ manifold, and let p be a hyperbolic periodic point of f. In this paper we introduce the notion of $C^1$-stable inverse shadowing for a closed f-invariant set, and prove that (i) the chain recurrent set $\cal{R}(f)$ of f has $C^1$-stable inverse shadowing property if and only if f satisfies both Axiom A and no-cycle condition, (ii) $C^1$-generically, the chain component $C_f(p)$ of f associated to p is hyperbolic if and only if $C_f(p)$ has the $C^1$-stable inverse shadowing property.

Stabilizing Unstable Matching because of a Varied Preference List in Distributed Stable Marriage Problem

  • Kinjo, Hideki;Nakamura, Morikazu;Onaga, Kenji
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2000년도 ITC-CSCC -2
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    • pp.1033-1036
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    • 2000
  • A distributed stable marriage problem in extended in this paper. The traditional approach related to the stable matching problem assume that preference lists are fixed. However, in decentralized version this assumption is not reasonable because of the autonomy of members. In this paper, we consider the situation that a preference list can be varied at some stable matching and show the condition to be broken the stability of the original matching. Moreover, we propose a stabilization algorithm to obtain a stable matching by execution with a minimal set of members.

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Comparison of Activity of the Muscles around the Shoulders during Push Up and Push Up Plus Exercises under Diverse Stabilization Conditions

  • Lee, Han Ki;Lee, Jun Cheol;Yoon, Seong Min
    • 국제물리치료학회지
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    • 제6권1호
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    • pp.815-823
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    • 2015
  • This study aimed to examine the most effective exercise method for shoulder joint rehabilitation by comparatively observing activity of shoulder stabilizer muscles during push up and push up plus exercises under diverse stable conditions. The subjects were 20 healthy adults students who went to M university. While the subjects conducted push up and push up plus exercises under diverse stable conditions(a stable surface, a support of 25cm height, a support of 30 cm height and a balance pad), activities of the upper trapezius muscle, pectoralis major muscle, serratus anterior muscle, and triceps brachii muscle were recorded. During push up and push up plus exercises, activities of the stabilizer muscles were higher when the stable condition was changed rather than on the stable surface. In particular, when the support of 30cm height and balance pads were applied, activity of the shoulder stabilizer was highest. There were significant differences in the upper trapezius muscle and triceps brachii muscle during the push up exercise(p<.05) and in the serratus anterior muscle during the push up plus exercise(p<.05). Activities of the shoulder stabilizers were higher when the upper and lower limbs' surface stable conditions were changed than the stable surface. Therefore, when programs for rehabilitation of shoulder joints are applied, provision of diverse stable conditions according to patients' conditions will be effective methods.

콘크리트의 안정-불안정 거동에 관한 연구 (A Study on Stable-Unstable Behavior in Concrete)

  • 송하원;전재홍;변근주
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1996년도 가을 학술발표회 논문집
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    • pp.459-465
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    • 1996
  • This paper is about unstable behavior in concrete during the localized deformation and the crack growths in concrete. By modeling the strain localization phenomenon of concrete, the stability condition of the localization is obtained and analyzed. And the stability and bifurcation condition of crack growths in two parallel cracks under different loading conditions are derived and discussed.

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원위치 제조 액상 Ferrate(VI)와 안정화 Ferrate(VI)를 이용한 2,4,6-tribromophenol의 제거 비교연구 (Comparison of 2,4,6-tribromophenol removal using in-situ liquid ferrate(VI) and stable ferrate(VI))

  • ;정선영;김일규
    • 상하수도학회지
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    • 제32권2호
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    • pp.123-130
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    • 2018
  • This paper provided the information related to the removal of 2,4,6-tribromophenol using in-situ and stable liquid ferrates(VI). This research's goal was to observe the differences of oxidation power between in-situ liquid ferrate(VI) and stable liquid ferrate(VI). The in-situ liquid ferrate(VI) ($FeO_4{^{2-}}$) has been successfully produced with the concentration 42,000 ppm (Fe) after 11 minutes of reaction time. The stable liquid ferrate(VI) was also successfully produced following the modification method by Sharma with the produced concentrations 7,000 ppm. The stable liquid ferrate(VI) was stable for 44 days and slightly decreased afterwards. This research has been carried out using 2,4,6-tribromophenol as the representative compound. Both of ferrates(VI) have the highest oxidation capability at the neutral condition. Furthermore, the stable liquid ferrate(VI) has higher oxidation power than the in-situ liquid ferrate(VI).

임상시험 중 수면행위가 심박변이도에 미치는 영향 분석 (Assessment of covariate-effect of sleeping behavior on heart rate variability during a clinical trial)

  • 이전;오달석;이혜정;최선미;김종열
    • 한국한의학연구원논문집
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    • 제13권3호
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    • pp.97-103
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    • 2007
  • The object of this study is to evaluate confounding effect of sleeping behavior on heart rate variability (HRV) in healthy volunteers during a randomized clinical trial. From 6 healthy volunteer, we acquired circadian electrocardiography(ECG) with a Holter monitoring device(DigiTrak Plus, Philips). The compatible analytical program, Zymed, was used for calculation of RR intervals of 24h ECG signal. Then, we generated HRV signals and calculated 9 HRV parameters in time domain and frequency domain for every 30 minute with Matlab 6.x software. We also encoded participants' activities as follows; stable condition(1), sleeping behavior(2), eating behavior(3), and undefined condition(4). Using SPSS 12.0, we tested if there was any difference between HRV parameters of day-time and night-time and between those of a subject in stable condition and in sleeping behavior. As a result, one of the most important parameter-LF/HF ratio, which indicates the autonomic balance between sympathetic and parasympathetic nervous systems, as same the other parameters, showed large inter-individual variations in circadian profiles. And, the mean LF/HF ratio of each participant was different between in stable condition and in sleeping behavior (p<.05). Consequently, the effect of sleeping behavior must be considered when one or more of HRV parameters, especially LF/HF ratio, are used as assessment index in clinical studies.

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장애물 주위의 비뉴턴 유체의 유동특성에 관한 수치적 연구 (NUMERICAL STUDY ON THE CHARACTERISTICS OF NON-NEWTONIAN FLUID FLOW OVER OBSTACLE)

  • 김형민
    • 한국전산유체공학회지
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    • 제19권4호
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    • pp.61-67
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    • 2014
  • Since the most of the existing non-Newtonian models are not adequate to apply to the lattmce Boltzmann method, it is a challenging task from both the theoretical and the numerical points of view. In this research the hydro-kinetic model was modified and applied to the 3-D moving sphere in the circular channel flow and the characteristics of the shear thinning effect by the HK-model was evaluated and the condition of ${\Gamma}$ in the model was suggested for the stable simulation to generate non-trivial prediction in three dimension strong shear flows. On the wall boundaries of circular channel the curved wall surface treatment with constant velocity condition was applied and the bounceback condition was applied on the sphere wall to simulate the relative motion of the sphere. The condition is adequate at the less blockage than 0.7 but It may need to apply a multi-scale concept of grid refinement at the narrow flow region. to obtain the stable numerical results.