• Title/Summary/Keyword: feed-back control

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Effects of Dietary ${\beta}$-Cyclodextrin on Plasma Lipid and Tissue Cholesterol Content in Swine

  • Park, B.S.;Jang, A.
    • Asian-Australasian Journal of Animal Sciences
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    • v.20 no.1
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    • pp.100-105
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    • 2007
  • This study examined the effects of dietary ${\beta}$-cyclodextrin (${\beta}CD$) on the cholesterol of blood and tissues of swine. Thirty six male castrated swine ($Landrace{\times}Yolkshire{\times}Duroc$) weighing 50 kg were randomly assigned to one of four dietary groups until their weight reached 110 kg. The groups were: basal diet without ${\beta}CD$ (control) and basal diets containing 1.5%, 3.0%, or 5.0% ${\beta}CD$. Diets and water were offered ad libitum. No significant difference was found between treatments in terms of feeding performance measured by daily intake, daily weight gain, and feed efficiency. Addition of ${\beta}CD$ to the diets significantly reduced total lipid, triglyceride and total cholesterol levels in swine blood, particularly in the group receiving 5.0% ${\beta}CD$, which showed decreases (p<0.05) of 21.9%, 55.6% and 27.7%, respectively. Cholesterol levels in back fat, loin, belly and ham portions of swine fed ${\beta}CD$ significantly differed (p<0.05) from controls, especially in the 5.0% ${\beta}CD$-fed group, with reductions of 26.0%, 27.5%, 17.9% and 18.3%, respectively. These results suggested that the addition of ${\beta}CD$ to the diet of swine could reduce their body cholesterol by decreasing the migration of cholesterol through the blood.

GPS/INS Integration using Vector Delay Lock Loop Processing Technique

  • Kim, Hyun-Soo;Bu, Sung-Chun;Jee, Gyu-In
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.2641-2647
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    • 2003
  • Conventional DLLs estimate the delay times of satellite signals individually and feed back these measurements to the VCO independently. But VDLL estimates delay times and user position directly and then estimate the feedback term for VCO using the estimated position changes. In this process, input measurements are treated as vectors and these vectors are used for navigation. First advantage of VDLL is that noise is reduced in all of the tracking channels making them less likely to enter the nonlinear region and fall below threshold. Second is that VDLL can operate successfully when the conventional independent parallel DLL approach fails completely. It means that VDLL receiver can get enough total signal power to track successfully to obtain accurate position estimates under the same conditions where the signal strength from each individual satellite is so low or week that none of the individual scalar DLL can remain in lock when operating independently. To operate VDLL successfully, it needs to know the initial user dynamics and position and prevents total system from the divergence. The suggested integration method is to use the inertial navigation system to provide initial dynamics for VDLL and to maintain total system stable. We designed the GPS/INS integrated navigation system. This new type of integrated system contained the vector pseudorange format generation block, VDLL signal processing block, position estimation block and the conversion block from position change to delay time feedback term aided by INS.

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Analysis of the Chip Shape in Turing (I) -Analysis of the Chip Flow Angle- (선삭가공의 칩형상 해석 (I) -칩흐름각 해석-)

  • 이영문;최수준;우덕진
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.15 no.1
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    • pp.139-144
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    • 1991
  • Chip flow angle is one of the important factors to be determined for the scheme of Chip Control. Up to now, however, a dependable way to predict the chip flow angle in practical cutting has not been established satisfactorily. In this paper a rather simple theoretical prediction of chip flow angle is tried based on some already widely confirmed hypotheses. The developed equation of chip flow angle contains the parameters of depth of cut d, feed rate f, nose radius $r_{n}$ side cutting edge angle $C_{s}$, side rake angle .alpha.$_{s}$ and back rake angle .alpha.$_{b}$. Theoretical results of chip flow angle given by this study bas been shown in a good agreement with experimental ones.s.s.s.s.

BLDC Feed back Control System Under Open Circuit Accident (개방 사고시 BLDC 피드백 제어 시스템)

  • Im, Che-Young;Lim, Jin-Woo;Lee, Dong-Su;Lee, Jin-Woo;Lee, Seung-Ho;Woo, Dae-Hyun;Kim, Ju-Young;Kim, Nam-Hyun;Jung, Sang-Yong
    • Proceedings of the KIEE Conference
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    • 2009.07a
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    • pp.2221_2222
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    • 2009
  • 본 논문에서는 BLDC 운전 중 각 상의 결상 사고에 따른 토크 및 속도의 최적화에 대해 연구하였다. BLDC 모터의 구동을 위하여 ATmega16이 사용되었으며 제어기법으로는 PWM(Pulse Width Modulation) 기법이 사용된다. 속도 제어는 Hall Sensor의 검출 속도에 따라 Duty비를 제어하여 이루어지며 회전자 위치는 Hall Sensor 검출 방식을 통하여 이루어진다. 이러한 BLDC 모터를 이용하여 예기치 못한 결상 상황의 발생 시 토크의 감소로 인한 급제동에 대비하여 부하에 상응하는 토크를 최대한 낼 수 있도록 알고리즘을 구현하였다.

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Development of Clamping Force Estimation Algorithm and Clamp-force Sensor Calibration on Electromechanical Brake Systems (전동식 브레이크 시스템의 클램핑력 센서 교정 및 클램핑력 추정 알고리즘 개발)

  • Park, Giseo;Choi, Seibum;Hyun, Dongyoon
    • Transactions of the Korean Society of Automotive Engineers
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    • v.24 no.3
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    • pp.365-371
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    • 2016
  • The electromechanical brake (EMB) is one of future brake systems due to its many advantages. For implementation of the EMB, the correct feed back about clamping force is necessary. Keeping commercialization of the EMB in mind, it is strongly demanded that an expensive load cell measuring the clamping force is replaced with an estimation algorithm. In addition, an estimation of the kissing point where the brake pads start to come into contact with a disk wheel is proposed in this paper. With these estimation algorithms, the clamping force can be expressed as a polynomial characteristic curve versus the motor angle. Also, a method for calibration of measured values by the load cell is proposed and used for an actual characteristic curve. Lastly, the performance of the proposed algorithms is evaluated in comparison with the actual curve on a developed EMB test bench.

A cause analysis of Noise & Vibration of Gas Heater (가스히터의 소음 진동 원인 분석)

  • Koh, Jae-Pil;You, Hyun-Seok
    • Journal of the Korean Institute of Gas
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    • v.13 no.1
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    • pp.9-13
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    • 2009
  • A cause of noise and vibration which come from a Combustion of gas heater are a combustion roar and Combustion oscillation. A character of a combustion roar is that sound pressure is distribute with broad band frequency. otherwise, The presence of combustion oscillation caused by positive Feed Back in Combustion Chamber break out a noise and vibration. Accordingly, The method that be solved a noise and vibration is to make each natural frequency different frequency. first, in order to solve problem, we control ratio of fuel and air. that is, Keep away resonance. second, in order to changing natural frequency of Combustion Chamber, We changed the shape of Economizer.

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Neural Network Modeling of PECVD SiN Films and Its Optimization Using Genetic Algorithms

  • Han, Seung-Soo
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.1 no.1
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    • pp.87-94
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    • 2001
  • Silicon nitride films grown by plasma-enhanced chemical vapor deposition (PECVD) are useful for a variety of applications, including anti-reflecting coatings in solar cells, passivation layers, dielectric layers in metal/insulator structures, and diffusion masks. PECVD systems are controlled by many operating variables, including RF power, pressure, gas flow rate, reactant composition, and substrate temperature. The wide variety of processing conditions, as well as the complex nature of particle dynamics within a plasma, makes tailoring SiN film properties very challenging, since it is difficult to determine the exact relationship between desired film properties and controllable deposition conditions. In this study, SiN PECVD modeling using optimized neural networks has been investigated. The deposition of SiN was characterized via a central composite experimental design, and data from this experiment was used to train and optimize feed-forward neural networks using the back-propagation algorithm. From these neural process models, the effect of deposition conditions on film properties has been studied. A recipe synthesis (optimization) procedure was then performed using the optimized neural network models to generate the necessary deposition conditions to obtain several novel film qualities including high charge density and long lifetime. This optimization procedure utilized genetic algorithms, hybrid combinations of genetic algorithm and Powells algorithm, and hybrid combinations of genetic algorithm and simplex algorithm. Recipes predicted by these techniques were verified by experiment, and the performance of each optimization method are compared. It was found that the hybrid combinations of genetic algorithm and simplex algorithm generated recipes produced films of superior quality.

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A BLMS Adaptive Receiver for Direct-Sequence Code Division Multiple Access Systems

  • Hamouda Walaa;McLane Peter J.
    • Journal of Communications and Networks
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    • v.7 no.3
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    • pp.243-247
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    • 2005
  • We propose an efficient block least-mean-square (BLMS) adaptive algorithm, in conjunction with error control coding, for direct-sequence code division multiple access (DS-CDMA) systems. The proposed adaptive receiver incorporates decision feedback detection and channel encoding in order to improve the performance of the standard LMS algorithm in convolutionally coded systems. The BLMS algorithm involves two modes of operation: (i) The training mode where an uncoded training sequence is used for initial filter tap-weights adaptation, and (ii) the decision-directed where the filter weights are adapted, using the BLMS algorithm, after decoding/encoding operation. It is shown that the proposed adaptive receiver structure is able to compensate for the signal-to­noise ratio (SNR) loss incurred due to the switching from uncoded training mode to coded decision-directed mode. Our results show that by using the proposed adaptive receiver (with decision feed­back block adaptation) one can achieve a much better performance than both the coded LMS with no decision feedback employed. The convergence behavior of the proposed BLMS receiver is simulated and compared to the standard LMS with and without channel coding. We also examine the steady-state bit-error rate (BER) performance of the proposed adaptive BLMS and standard LMS, both with convolutional coding, where we show that the former is more superior than the latter especially at large SNRs ($SNR\;\geq\;9\;dB$).

Structural Layout Design for Concrete Structures Based on the Repeated Control Method by Using Micro Lattice Truss Model (마이크로 격자트러스모델을 이용한 반복강성제어법에 의한 콘크리트 구조형태의 최적화)

  • Choi, Ik-Chang;Ario, Ichiro
    • Journal of the Korea Concrete Institute
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    • v.20 no.6
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    • pp.705-712
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    • 2008
  • This study carried out simulation for structural layout design for concrete structures by using the models of the ground structure method. The micro lattice truss is modeled as assemblage of a number of unit cells. The progress of analysis repeat to undergo finite element analysis to feed-back results of stress to the stiffness of each member. Through the repeated this analysis, truss model is represented to form the topological materials and the structural shape with the use of the local stress condition without mathematical optimum tools. It is successful to analyse the shape-layout problem as numerical samples on the lattice truss model.

The Effect of Visual Feedback Squat on Q-angle with Patellofemoral Pain Syndrome (시각적 피드백 스쿼트가 슬개대퇴 통증 증후군이 있는 성인의 대퇴사두근 각에 미치는 영향)

  • Kim, Gi-Chul
    • The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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    • v.19 no.1
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    • pp.41-47
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    • 2013
  • Background: The purpose of this study is to examine the effects of visual feedback squat exercise on the young adults with Patellofemoral pain syndrome. Methods: The subjects of this study were 22 female and 8 male who were equally and randomly allocated to a visual feedback exercise group (VSEG), an experimental group, and squat exercise group (SEG), a control group. Both did so for 30 minutes three times per week over a six-week period. Using Dartfish, their static Q-angle (SQA) and dynamic Q-angle (DQA) were evaluated. Results: The static Q-angle was significantly reduced in both groups of VSEG and SEG and in the comparison of difference values before and after exercise between groups, VSEG had more significant effect than SEG but in the comparison of the effects of dynamic Q-angle both VSEG and SEG had significant effects and in the comparison of difference values before and after exercise between groups, VSEG had more significant effect than SEG. Conclusion: Visual feedback squat exercise may be applied as a method to correct the lower extremity alignment with PFPS.

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