• Title/Summary/Keyword: Quantitative Feedback

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Robust QFT(Quantitative Feedback Theory) Controller Design of Parallel Link (평행링크 매니퓰레이터의 강인한 QFT(Quantitative Feedback Theory)제어기 설계)

  • Kang, Min-Goo;Byun, Gi-Sik
    • Proceedings of the KIEE Conference
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    • 2001.07d
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    • pp.2249-2251
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    • 2001
  • This paper proposes that it minimizes interference between link at high speed trajectory tracking of 2-degree parallel link manipulator and QFT(Quantitative Feedback Theory) controller which robust structure uncertainty and disturbance of plant. And using ICD(Individual Channel Design), it separates two channel from multivariable system, parallel link manipulator and designs robust controller with applying MISO QFT to each channel. Finally, we make sure of robustness and excellence of QFT controller through simulation and experiment.

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Incentivizing User Contributions in Idea Crowdsourcing through Quantitative and Qualitative Feedback : A Field Experiment

  • Cho, Sook-Hyun;Lee, Sang-Min;Moon, Jae Yun
    • Journal of Information Technology Applications and Management
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    • v.21 no.3
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    • pp.19-33
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    • 2014
  • Crowdsourcing is a popular tool for firms to harness external knowledge and resources. One variation of crowdsourcing entails the use of corporate channels in social network services (SNS) such as Twitter to hold public idea competitions. This study examined the role of feedback interaction between participants of idea competitions. More specifically, the study examined the impact of incentives to provide feedback on other participants' ideas. We found that idea competitions where explicit incentives were introduced to elicit crowdsourced feedback in the form of qualitative comments resulted in improved idea generation performance-with more ideas generated overall, and more ideas generated through participant collaborations, through increased comment-posting activities. Based on the findings, implications for theory and practice are discussed.

A Design of the Robust Controller for Stabilization of the Unstable System Using QFT(Quantitative Feedback Theory) (QFT(Quantitative Feedback Theory)를 이용한 불안정한 시스템의 안정화를 위한 강인 제어기 설계)

  • 강민구;변기식
    • Journal of the Institute of Convergence Signal Processing
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    • v.2 no.3
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    • pp.57-64
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    • 2001
  • This paper propose a robust control method to achieve a desired system performance in spite of system uncertainty and disturbance uncertainty. The procedures of the robust controller based on QFT(Quantitative Feedback Theory) make template, bound and loop shaping which are considered by system parameter variations and performance specifications. To prove the efficiency, the designed controller is applied for an inverted pendulum which is so sensitive to the parameter variation and has a highly nonlinear and unstable characteristics. It is shown that the simulation and experimental results from the proposed controller are efficient in robustness of parameter variation and disturbance.

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Direct multivariable quantitative feedback theory (직접식 다변수 정량적 피드백 이론)

  • Park, Myoung-Soo;Lee, Jae-Won
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.22 no.3
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    • pp.562-568
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    • 1998
  • During the past three decades, several techniques have been suggested for robust performance design of multivariable systems within the framework of Quantitative Feedback Theory. They are all characterized and limited by the use of loop transmission inversion. A new approach within framework is described which leads to a design tehnique without loop transmission inversion. Complete sequential design algorithms are derived for performance specifications in terms of plant input disturbance, sensitivity, complimentary sensitivity and control effort.

Study for Position Control of Two-degree Parallel Link Robot Using QFT(Quantitative Feedback Theory) (QFT(Quantitative Feedback Theory)를 이용한 2 자유도 평행 링크 로봇의 위치 제어에 관한 연구)

  • 강민구;변기식;최연욱;황용연
    • Proceedings of the Korea Institute of Convergence Signal Processing
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    • 2001.06a
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    • pp.97-100
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    • 2001
  • This paper introduces that it minimizes interference between links at high speed trajectory tracking of 2-degree parallel link robot. And in spite of system uncertainty, it introduces controller design method which is satisfied with performance specification. To do these, we separate two channels from parallel link robot through ICD(Individual Channel Design) and design controller of each channel using QFT(Quantitative Feedback Theory). Finally, we make sure of robustness and excellence of QFT control1er through simulation and experiment.

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Design of Quantitative Feedback Control System for the Three Axes Hydraulic Road Simulator (3축 유압 도로 시뮬레이터의 정량적 피드백 제어 시스템 설계)

  • Kim, Jin-Wan;Xuan, Dong-Ji;Kim, Young-Bae
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.32 no.3
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    • pp.280-289
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    • 2008
  • This paper presents design of the quantitative feedback control system of the three axes hydraulic road simulator with respect to the dummy wheel for uncertain multiple input-output(MIMO) feedback systems. This simulator has the uncertain parameters such as fluid compressibility, fluid leakage, electrical servo components and nonlinear mechanical connections. This works have reproduced the random input signal to implement the real road vibration's data in the lab. The replaced $m^2$ MISO equivalent control systems satisfied the design specifications of the original $m^*m$ MIMO control system and developed the mathematical method using quantitative feedback theory based on schauder's fixed point theorem. This control system illustrates a tracking performance of the closed-loop controller with low order transfer function G(s) and pre-filter F(s) having the minimum bandwidth for parameters of uncertain plant. The efficacy of the designed controller is verified through the dynamic simulation with combined hydraulic model and Adams simulator model. The Matlab simulation results to connect with Adams simulator model show that the proposed control technique works well under uncertain hydraulic plant system. The designed control system has satisfied robust performance with stability bounds, tracking bounds and disturbance. The Hydraulic road simulator consists of the specimen, hydraulic pump, servo valve, hydraulic actuator and its control equipments

Effect of Neuro-Feedback Training and Transcutaneous Electrical Nerve Stimulation (TENS) in Stress, Quantitative Sensory Threshold, Pain on Tension Type Headache

  • Lee, Young-Sin;Lee, Dong-Jin;Han, Sang-Wan;Kim, Kyeong-Tae
    • The Journal of Korean Physical Therapy
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    • v.26 no.6
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    • pp.442-448
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    • 2014
  • Purpose: The objective of this study is to evaluate the effect of neuro-feedback training and transcutaneous electrical nerve stimulation (TENS) on stress, quantitative sensory threshold and pain in patients suffering from tension type headache. Methods: 22 participants who passed the preliminary evaluation were enrolled in the study and 11 participants were randomly assigned to each group. The control group (n=11) was subject to the TENS treatment of which was composed of a 20-minute session for 5 times a week during 4 weeks, and the experimental group (n=11) was subject to both neuro feedback training and TENS treatment for 10 minutes a day and 5 days a week during 4 weeks. The Perceived Stress Scale (PSS) was used to measure a level of stress and the quantitative sensory testing (QST) was used for the measurement of cold pain threshold (CPT) and heat pain threshold (HPT); A degree of pain was evaluated through the headache impact test-6 (HIT-6). Results: In comparision of all dependent variables between the control and subject groups, there were significant differences in stress, quantitative sensory threshold and pain after the treatment (p<0.05), and the experimental group showed significant differences in stress, CPT, HPT and pain (p<0.05) and the control group showed only a significant difference in HPT (p<0.05). Conclusion: Findings of this study demonstrate that the concomitant administration of the TENS treatment and neuro feedback training is effective on alleviation of stress, quantitative sensory threshold and pain in patients with tension type headache.

Common Rail Pressure Control Algorithm for Passenger Car Diesel Engines Using Quantitative Feedback Theory (QFT를 이용한 디젤엔진의 커먼레일 압력 제어알고리즘 설계 연구)

  • Shin, Jaewook;Hong, Seungwoo;Park, Inseok;Sunwoo, Myoungho
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.38 no.2
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    • pp.107-114
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    • 2014
  • This paper proposes a common rail pressure control algorithm for passenger car diesel engines. For handling the parameter-varying characteristics of common rail systems, the quantitative feedback theory (QFT) is applied to the design of a robust rail pressure control algorithm. The driving current of the pressure control valve and the common rail pressure are used as the input/output variables for the common rail system model. The model parameter uncertainty ranges are identified through experiments. Rail pressure controller requirements in terms of tracking performance, robust stability, and disturbance rejection are defined on a Nichols chart, and these requirements are fulfilled by designing a compensator and a prefilter in the QFT framework. The proposed common rail pressure control algorithm is validated through engine experiments. The experimental results show that the proposed rail pressure controller has a good degree of consistency under various operating conditions, and it successfully satisfies the requirements for reference tracking and disturbance rejection.

The Influence of Different Quantitative Knowledge of Results on Performance Error During Lumbar Proprioceptive Sensation Training (양적 결과지식의 종류가 요추의 고유수용성감각 훈련에 미치는 영향)

  • Cynn, Won-Suk;Choi, Houng-Sik;Kim, Tack-Hoon;Roh, Jung-Suk;Yi, Jin-Bock
    • Physical Therapy Korea
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    • v.11 no.3
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    • pp.11-18
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    • 2004
  • This study is aimed at investigating the influence of different quantitative knowledge of results on the measurement error during lumbar proprioceptive sensation training. Twenty-eight healthy adult men participated and subjects were randomly assigned into four different feedback groups(100% relative frequency with an angle feedback, 50% relative frequency with an angle feedback, 100% relative frequency with a length feedback, 50% relative frequency with a length feedback). An electrogoniometer was used to determine performance error in an angle, and the Schober test with measurement tape was used to determine performance error in a length. Each subject was asked to maintain an upright position with both eyes closed and both upper limbs stabilized on their pelvis. Lumbar vertebrae flexion was maintained at $30^{\circ}$ for three seconds. Different verbal knowledge of results was provided in four groups. After lumbar flexion was performed, knowledge of results was offered immediately. The resting period between the sessions per block was five seconds. Training consisted of 6 blocks, 10 sessions per one block, with a resting period of one minute. A resting period of five minutes was provided between 3 blocks and 4 blocks. A retention test was performed between 10 minutes and 24 hours later following the training block without providing knowledge of results. To determine the training effects, a two-way analysis of variance and a one-way analysis of variance were used with SPSS Ver. 10.0. A level of significance was set at .05. A significant block effect was shown for the acquisition phase (p<.05), and a significant feedback effect was shown in the immediate retention phase (p>.05). There was a significant feedback effect in the delayed retention phase (p<.05), and a significant block effect in the first acquisition phase and the last retention phase (p<.05). In conclusion, it is determined that a 50% relative frequency with a length feedback is the most efficient feedback among different feedback types.

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