• Title/Summary/Keyword: stabilization method

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Reliability Study of Measuring Range of Motion Glenohumeral Joint Internal Rotation With Pressure Biofeedback Stabilization

  • Hwang, Ui-jae;Ha, Sung-min;Jeon, In-chul;Jung, Sung-hoon;Choi, Kyu-hwan;Kim, Su-jung;Kwon, Oh-yun
    • Physical Therapy Korea
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    • v.22 no.4
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    • pp.62-70
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    • 2015
  • The aims of the current study were to assess reliability of range of motion (ROM) measurement of glenohumeral internal rotation (GIR) with a pressure biofeedback stabilization (PBS) method and to compare the reliability between manual stabilization (MS) and the PBS method. In measurement of pure glenohumeral joint motion, scapular stabilization is necessary. The MS method in GIR ROM measurement was used to restrict scapular motion by pressing the palm of the tester's hand over the subject's clavicle, coracoid process, and humeral head. The PBS method was devised to maintain consistent pressure for scapular stabilization during GIR ROM measurement by using a pressure biofeedback unit. GIR ROM was measured by 2 different stabilization methods in 32 subjects with GIR deficit using a smartphone clinometer application. Repeated measurements were performed in two test sessions by two testers to confirm inter- and intra-rater reliability. After tester A performed measurements in test session 1, tester B's measurements were conducted one hour later on the same day to assess the inter-rater reliability and then tester A performed again measurements in test session 2 for confirming the intra-rater reliability. Intra-class correlation coefficient (ICC) (2,1) was applied to assess the inter-rater reliability and ICC (3,1) was applied to determine the intra-rater reliability of the two methods. In the PBS method, the intra-rater reliability was excellent (ICC=.91) and the inter-rater reliability was good (ICC=.84). The inter-rater and intra-rater reliability of the PBS method was higher than in the MS method. The PBS method could regulate manual scapular stabilization pressure in inter- and intra-rater measuring GIR ROM. Results of the current study recommend that the PBS method can provide reliable measurement data on GIR ROM.

An Implementation of Stabilizing Controller for 2-Axis Platform using Adaptive Fuzzy Control and DSP

  • Ryu, Gi-Seok;Kim, Jin-Kyu;Park, Jang-Ho;Kim, Dae-Young;Kim, Jong-Hwa
    • 제어로봇시스템학회:학술대회논문집
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    • 2001.10a
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    • pp.71.3-71
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    • 2001
  • Passive Stabilization method and active stabilization method are mainly used to comprise a control system of platform stabilizer. Passive Stabilization method has demerits because of size and weight except that control structure is simple while active stabilization method using sensors can reduce size and weight, it requires high sensor technique and control algorithm. In this paper, a stabilizing controller using adaptive fuzzy control technique and floating-point processor(DSP) is suggested.

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Oxidative Stabilization Behaviors of Petroleum-based Isotropic Pitch Fiber Spun by Melt-blown Method

  • Kim, Chan;Lee, Su-Hyun;Kim, Young-Min;Yang, Kap-Seung
    • Carbon letters
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    • v.2 no.3_4
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    • pp.170-175
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    • 2001
  • A petroleum-based isotropic pitch fiber spun by melt-blown method was oxidized in air flow at various conditions. The oxidized pitch fiber obtained was tested for its infusibility and its elemental composition during the process of stabilization. The structural changes were traced by using solvent solubility, FT-IR spectroscopy, and elemental analysis. The samples showed a gradual increase in weight with increasing the oxidization temperature. The weight gain of sample oxidized at $320^{\circ}C$ for 10 min was about 4.5%. The concentration of the pyridine and toluene soluble fraction decreased with an increase in stabilization temperatures. The oxygen uptaken in the stabilization process converted aliphatic side chains into the carbonyl groups. As stabilization proceeded, the more ether and carboxylic acid groups were formed through the oxidations of aldehyde and primary alcohol, and then the carboxylic acid was dehydrated to be aromatic anhydride.

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Performance Investigation of Attitude Determination Control for Cube Satellite Using Permanent Magnet Stabilization Method (영구자석 안정화 방식을 적용한 극초소형 위성의 자세제어 성능분석)

  • Ha, Heonwoo;Oh, Hyun-Ung
    • Journal of Aerospace System Engineering
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    • v.7 no.1
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    • pp.44-49
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    • 2013
  • Passive attitude stabilization method has been widely used for attitude determination and control of cube satellite due to its advantage of system simplicity. In this paper, permanent magnet stabilization method for application of cube satellite attitude control has been introduced and its performance with and without hysteresis damper system has been investigated through a numerical simulation. The simulation results indicate that the permanent magnet stabilization combined with hysteresis damper shows much higher stabilization performance than the system without damper system.

Spurious mode distinguish by eigensystem realization algorithm with improved stabilization diagram

  • Qu, Chun-Xu;Yi, Ting-Hua;Yang, Xiao-Mei;Li, Hong-Nan
    • Structural Engineering and Mechanics
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    • v.63 no.6
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    • pp.743-750
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    • 2017
  • Modal parameter identification plays a key role in the structural health monitoring (SHM) for civil engineering. Eigensystem realization algorithm (ERA) is one of the most popular identification methods. However, the complex environment around civil structures can introduce the noises into the measurement from SHM system. The spurious modes would be generated due to the noises during ERA process, which are usually ignored and be recognized as physical modes. This paper proposes an improved stabilization diagram method in ERA to distinguish the spurious modes. First, it is proved that the ERA can be performed by any two Hankel matrices with one time step shift. The effect of noises on the eigenvalues of structure is illustrated when the choice of two Hankel matrices with one time step shift is different. Then, a moving data diagram is proposed to combine the traditional stabilization diagram to form the improved stabilization diagram method. The moving data diagram shows the mode variation along the different choice of Hankel matrices, which indicates whether the mode is spurious or not. The traditional stabilization diagram helps to determine the concerned truncated order before moving data diagram is implemented. Finally, the proposed method is proved through a numerical example. The results show that the proposed method can distinguish the spurious modes.

A Study on Determination of PID Coefficients by Deriving Temperature Stabilization Transfer Function and it's Simulation (온도 안정화 전달함수 도출 및 이의 시뮬레이션에 의한 PID 계수 결정에 관한 연구)

  • Eom, Jinseob
    • Journal of Sensor Science and Technology
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    • v.24 no.6
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    • pp.412-418
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    • 2015
  • In this paper, a new method for obtaining PID coefficients which are essential to a temperature stabilization process has been proposed. This method starts from measuring the open loop transfer function of the module, then the closed loop transfer function embodying PID control can be produced based on this. Finally, the simulations using a few PID coefficients and the performance analysis for those results provide the best PID coefficients which are effective in a fast setting to a target temperature, a less current needed, and less deviation from steady state. The measurement using the derived PID coefficients, $K_p=1.6$,$K_i=0.8$,$K_d=0.3$ showed $T_s=7.4[sec]$, %OS = 16, and stabilization within ${\pm}0.02[^{\circ}C]$ for several hours. In addition to light sources like SOA, the proposed method can be utilized for any device needs temperature stabilization.

A Modeling and Optimal Site of SMES for Power System Stabilization (계통안정화를 위한 SMES의 모델링과 적정위치 선정)

  • Kim, Jeong-Hun;Im, Jae-Yun;Lee, Jong-Pil
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.48 no.5
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    • pp.494-501
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    • 1999
  • In this research, ANN modeling method of SMES unit is developed for stability analysis, and the optimal site is selected to maximize stabilization effect of SMES unit. The ANN is trained by learning data which is obtained through the application of complex test function into the traditional mathematical mode. In order to verify the validity of proposed modeling method, fault data of sample power system is applied to both the traditional and the ANN models. When the response of traditional and proposed models are compared, the average error for the active and reactive power are 2.51[%], and 0.24[%], respectively. From the comparison, the relevance of proposed method is validated. For the transient stability analysis, an application method of the proposed model is presented, and the transient stability performance index, which describes system stabilization effect of SMES at disturbance, is also suggested, and optimal site selection method of SMES is presented. In the viewpoint of the voltage stability, system stabilization criterion of local bus is presented from P­V curve, and then optimal site which can maximize the voltage stabilization of the whole power system, is decided from the proposed voltage stability performance index.

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A Study on the Optimal Mixture Ratio for Stabilization of Surface Layer on Ultra-soft Marine Clay (초연약 해성점토의 표층고화처리를 위한 최적배합에 관한 연구)

  • 천병식;고경환;김진춘;한유찬;문성우
    • Proceedings of the Korean Geotechical Society Conference
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    • 2002.03a
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    • pp.731-738
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    • 2002
  • Recently, as large constructions on the coast are performed frequently, surface layer stabilization method which Is one of the improvement methods for dredged soft clay has been applied. However, there have been few studies about the surface layer stabilization method. The purpose of this study is to clarify characteristics of ultra-soft marine clay and hardening agent. Also, optimal mixture ratio of hardening agent was verified through the laboratory tests such as statistical analysis and pilot tests. Laboratory tests were performed with proper hardening agent and test soil and standard mixing tables of hardening agent were determined according to ground conditions through statistical analysis. Also, applicability of surface layer stabilization method to field was verified by pilot tests. From the results of the tests, it was found that hardening agent materials such as cement, slag, fly-ash, inorganic salts, arwin, gypsum etc. affect on the appearing compressive strength. It was defined optimal mixture ratio which satisfies the required compressive strength from the statistical analysis. Also, It was compared the effect of ground improvement by cements and hardening agents through the pilot tests. This study will serve as data for design or construction criteria of stabilization of surface layer on ultra-soft marine clay.

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A method of robust stabilization of the interval plants with a PID controller (PID 제어기를 갖는 구간 플랜트의 강인안정화 기법)

  • 강환일
    • Journal of the Korean Institute of Telematics and Electronics S
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    • v.34S no.10
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    • pp.52-58
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    • 1997
  • In this paper, we consider methods of robust stabilization of the interval plant with a PID controller. Suppose that we know apriori a sign of the coefficients of the numerator of the PID controller. Under this condition, it sufficies to make eight polynomials stable for robust stabilization of the interval plant with a minimum phase PID controller. In addition, with a nonminimum phase PID controller, it suffices to make different eight polynomials stable. Especially, with the nonminimum phase PID controller it is shown that stabilization of eight plants is necessary and sufficient for robust stabilization of the interval plants.

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Numerical Investigation of On-orbit Thermal Characteristics for Cube Satellite with Permanent Magnet Attitude Stabilization Method (영구자석 안정화 자세제어 방식이 적용된 큐브위성의 열적 특성분석)

  • Kang, Soo-JIn;Jung, Hyun-Mo;Oh, Hyun-Ung
    • Journal of Aerospace System Engineering
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    • v.7 no.3
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    • pp.26-32
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    • 2013
  • Passive attitude stabilization method has been widely usde for attitude determination and control of cube satellite due to its advantage of system simplicity. The permanent magnet installed on the cube satellite passively controls the attitude of the satellite such that the satellite is aligned with the earth magnetic field. In this paper, on-orbit thermal behavior of the cube satellite with the permanent magnet attitude stabilization method has been investigated through on-orbit thermal analysis. THe orbit profile obtained from the aforementioned attitude control method has been reflected in the analysis. The analysis results indicate that the thermal design proposed in this study is effective for satisfying the temperature requirements of the commericial mission equipments.