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Sample records for rapid control parameters

  1. Contributions of rapid neuromuscular transmission to the fine control of acoustic parameters of birdsong.

    Science.gov (United States)

    Mencio, Caitlin; Kuberan, Balagurunathan; Goller, Franz

    2017-02-01

    Neural control of complex vocal behaviors, such as birdsong and speech, requires integration of biomechanical nonlinearities through muscular output. Although control of airflow and tension of vibrating tissues are known functions of vocal muscles, it remains unclear how specific muscle characteristics contribute to specific acoustic parameters. To address this gap, we removed heparan sulfate chains using heparitinases to perturb neuromuscular transmission subtly in the syrinx of adult male zebra finches (Taeniopygia guttata). Infusion of heparitinases into ventral syringeal muscles altered their excitation threshold and reduced neuromuscular transmission changing their ability to modulate airflow. The changes in muscle activation dynamics caused a reduction in frequency modulation rates and elimination of many high-frequency syllables but did not alter the fundamental frequency of syllables. Sound amplitude was reduced and sound onset pressure was increased, suggesting a role of muscles in the induction of self-sustained oscillations under low-airflow conditions, thus enhancing vocal efficiency. These changes were reversed to preinfusion levels by 7 days after infusion. These results illustrate complex interactions between the control of airflow and tension and further define the importance of syringeal muscle in the control of a variety of acoustic song characteristics. In summary, the findings reported here show that altering neuromuscular transmission can lead to reversible changes to the acoustic structure of song. Understanding the full extent of muscle involvement in song production is critical in decoding the motor program for the production of complex vocal behavior, including our search for parallels between birdsong and human speech motor control. It is largely unknown how fine motor control of acoustic parameters is achieved in vocal organs. Subtle manipulation of syringeal muscle function was used to test how active motor control influences acoustic

  2. Comparing Generic Parameter Controllers for EAs

    NARCIS (Netherlands)

    Karafotias, G.; Hoogendoorn, M.

    2014-01-01

    Parameter controllers for Evolutionary Algorithms (EAs) deal with adjusting parameter values during an evolutionary run. Many ad hoc approaches have been presented for parameter control, but few generic parameter controllers exist and, additionally, no comparisons or in depth analyses of these

  3. CTER—Rapid estimation of CTF parameters with error assessment

    Energy Technology Data Exchange (ETDEWEB)

    Penczek, Pawel A., E-mail: Pawel.A.Penczek@uth.tmc.edu [Department of Biochemistry and Molecular Biology, The University of Texas Medical School, 6431 Fannin MSB 6.220, Houston, TX 77054 (United States); Fang, Jia [Department of Biochemistry and Molecular Biology, The University of Texas Medical School, 6431 Fannin MSB 6.220, Houston, TX 77054 (United States); Li, Xueming; Cheng, Yifan [The Keck Advanced Microscopy Laboratory, Department of Biochemistry and Biophysics, University of California, San Francisco, CA 94158 (United States); Loerke, Justus; Spahn, Christian M.T. [Institut für Medizinische Physik und Biophysik, Charité – Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin (Germany)

    2014-05-01

    In structural electron microscopy, the accurate estimation of the Contrast Transfer Function (CTF) parameters, particularly defocus and astigmatism, is of utmost importance for both initial evaluation of micrograph quality and for subsequent structure determination. Due to increases in the rate of data collection on modern microscopes equipped with new generation cameras, it is also important that the CTF estimation can be done rapidly and with minimal user intervention. Finally, in order to minimize the necessity for manual screening of the micrographs by a user it is necessary to provide an assessment of the errors of fitted parameters values. In this work we introduce CTER, a CTF parameters estimation method distinguished by its computational efficiency. The efficiency of the method makes it suitable for high-throughput EM data collection, and enables the use of a statistical resampling technique, bootstrap, that yields standard deviations of estimated defocus and astigmatism amplitude and angle, thus facilitating the automation of the process of screening out inferior micrograph data. Furthermore, CTER also outputs the spatial frequency limit imposed by reciprocal space aliasing of the discrete form of the CTF and the finite window size. We demonstrate the efficiency and accuracy of CTER using a data set collected on a 300 kV Tecnai Polara (FEI) using the K2 Summit DED camera in super-resolution counting mode. Using CTER we obtained a structure of the 80S ribosome whose large subunit had a resolution of 4.03 Å without, and 3.85 Å with, inclusion of astigmatism parameters. - Highlights: • We describe methodology for estimation of CTF parameters with error assessment. • Error estimates provide means for automated elimination of inferior micrographs. • High computational efficiency allows real-time monitoring of EM data quality. • Accurate CTF estimation yields structure of the 80S human ribosome at 3.85 Å.

  4. Linear Parameter Varying Control of Induction Motors

    DEFF Research Database (Denmark)

    Trangbæk, Klaus

    The subject of this thesis is the development of linear parameter varying (LPV) controllers and observers for control of induction motors. The induction motor is one of the most common machines in industrial applications. Being a highly nonlinear system, it poses challenging control problems...... for high performance applications. This thesis demonstrates how LPV control theory provides a systematic way to achieve good performance for these problems. The main contributions of this thesis are the application of the LPV control theory to induction motor control as well as various contributions...

  5. Examination of aerodynamic parameters of fluid controlled ...

    African Journals Online (AJOL)

    The aerodynamic parameters of fluid controlled mechanical thrust vectoring nozzle have been computed to establish the relationships for improving the nozzle design. While a nozzle with exit Mach number (M) of 3 was used as case study, other values of exit M were also considered for comparison. The maximum deflector ...

  6. Inventory control in case of unknown demand and control parameters

    NARCIS (Netherlands)

    Janssen, E.

    2010-01-01

    This thesis deals with unknown demand and control parameters in inventory control. Inventory control involves decisions on what to order when and in what quantity. These decisions are based on information about the demand. Models are constructed using complete demand information; these models ensure

  7. Rail Vehicle Vibrations Control Using Parameters Adaptive PID Controller

    Directory of Open Access Journals (Sweden)

    Muzaffer Metin

    2014-01-01

    Full Text Available In this study, vertical rail vehicle vibrations are controlled by the use of conventional PID and parameters which are adaptive to PID controllers. A parameters adaptive PID controller is designed to improve the passenger comfort by intuitional usage of this method that renews the parameters online and sensitively under variable track inputs. Sinusoidal vertical rail misalignment and measured real rail irregularity are considered as two different disruptive effects of the system. Active vibration control is applied to the system through the secondary suspension. The active suspension application of rail vehicle is examined by using 5-DOF quarter-rail vehicle model by using Manchester benchmark dynamic parameters. The new parameters of adaptive controller are optimized by means of genetic algorithm toolbox of MATLAB. Simulations are performed at maximum urban transportation speed (90 km/h of the rail vehicle with ±5% load changes of rail vehicle body to test the robustness of controllers. As a result, superior performance of parameters of adaptive controller is determined in time and frequency domain.

  8. Controlled Attenuation Parameter And Alcoholic Hepatic Steatosis

    DEFF Research Database (Denmark)

    Thiele, Maja; Rausch, Vanessa; Fluhr, Gabriele

    2018-01-01

    ≥S2 = 0.78; 0.72-0.83) and severe steatosis with good accuracy (AUC S3 = 0.82; 0.75-0.88). CAP was superior to bright liver echo pattern by regular ultrasound. CAP above 290 dB/m ruled in any steatosis with 88% specificity and 92% positive predictive value, while CAP below 220 dB/m ruled out....... LAY SUMMARY: Controlled attenuation parameter (CAP) is a new ultrasound based technique for measuring fat content in the liver, but has never been tested for fatty liver due to alcohol. We here examine 562 patients in a multicenter setting. We show that CAP highly correlates with liver fat...... detoxification on CAP. METHODS: Cross-sectional, biopsy-controlled, diagnostic study in four European liver centers. Consecutive alcohol-overusing patients underwent concomitant CAP, regular ultrasound and liver biopsy. In addition, we measured CAP before and after admission for detoxification in a separate...

  9. Multi-parameter based coagulant dosing control.

    Science.gov (United States)

    Manamperuma, L; Wei, L; Ratnaweera, H

    2017-05-01

    The required coagulant dosage is strongly related to the quality of raw water or wastewater. Online sensors for most quality parameters are now readily available to treatment facilities, yet remain rarely used in treatment process control. This paper presents the evaluation of an advanced coagulant dosing control system based on online measurements in full-scale processes. The popular multivariate analytical method, partial least square regression, was used to build up the relationship between the coagulant dose and wastewater quality. The system was tested in two wastewater treatment plants (WWTPs) in Norway. Coagulant savings up to 30% in Norwegian plants were observed with feed forward calibrations. The considerable savings reduce sludge production, leading to further cost saving on sludge treatment. This paper presents the method, function and experiences of the full-scale implementation of the system in different WWTPs.

  10. Automatic Control of Personal Rapid Transit Vehicles

    Science.gov (United States)

    Smith, P. D.

    1972-01-01

    The requirements for automatic longitudinal control of a string of closely packed personal vehicles are outlined. Optimal control theory is used to design feedback controllers for strings of vehicles. An important modification of the usual optimal control scheme is the inclusion of jerk in the cost functional. While the inclusion of the jerk term was considered, the effect of its inclusion was not sufficiently studied. Adding the jerk term will increase passenger comfort.

  11. VLSI PARTITIONING ALGORITHM WITH ADAPTIVE CONTROL PARAMETER

    Directory of Open Access Journals (Sweden)

    P. N. Filippenko

    2013-03-01

    Full Text Available The article deals with the problem of very large-scale integration circuit partitioning. A graph is selected as a mathematical model describing integrated circuit. Modification of ant colony optimization algorithm is presented, which is used to solve graph partitioning problem. Ant colony optimization algorithm is an optimization method based on the principles of self-organization and other useful features of the ants’ behavior. The proposed search system is based on ant colony optimization algorithm with the improved method of the initial distribution and dynamic adjustment of the control search parameters. The experimental results and performance comparison show that the proposed method of very large-scale integration circuit partitioning provides the better search performance over other well known algorithms.

  12. Determination Of Adaptive Control Parameter Using Fuzzy Logic Controller

    Directory of Open Access Journals (Sweden)

    Omur Can Ozguney

    2017-08-01

    Full Text Available The robot industry has developed along with the increasing the use of robots in industry. This has led to increase the studies on robots. The most important part of these studies is that the robots must be work with minimum tracking trajectory error. But it is not easy for robots to track the desired trajectory because of the external disturbances and parametric uncertainty. Therefore adaptive and robust controllers are used to decrease tracking error. The aim of this study is to increase the tracking performance of the robot and minimize the trajectory tracking error. For this purpose adaptive control law for robot manipulator is identified and fuzzy logic controller is applied to find the accurate values for adaptive control parameter. Based on the Lyapunov theory stability of the uncertain system is guaranteed. In this study robot parameters are assumed to be unknown. This controller is applied to a robot model and the results of simulations are given. Controller with fuzzy logic and without fuzzy logic are compared with each other. Simulation results show that the fuzzy logic controller has improved the results.

  13. Rapid Prototyping of Nonlinear Controller Designs

    Science.gov (United States)

    1996-03-31

    the Universitä di Roma ) studied two schemes for the adaptive tracking con- trol of MIMO systems with parametric uncertainty in their dynamics. The...problems arise, for example, in highway au- tomation problems, problems of command and control and also more generically in flight control (with many

  14. Determining Key Model Parameters of Rapidly Intensifying Hurricane Guillermo(1997) using the Ensemble Kalman Filter

    CERN Document Server

    Godinez, Humberto C; Fierro, Alexandre O; Guimond, Stephen R; Kao, Jim

    2011-01-01

    In this work we present the assimilation of dual-Doppler radar observations for rapidly intensifying hurricane Guillermo (1997) using the Ensemble Kalman Filter (EnKF) to determine key model parameters. A unique aspect of Guillermo was that during the period of radar observations strong convective bursts, attributable to wind shear, formed primarily within the eastern semicircle of the eyewall. To reproduce this observed structure within a hurricane model, background wind shear of some magnitude must be specified; as well as turbulence and surface parameters appropriately specified so that the impact of the shear on the simulated hurricane vortex can be realized. To first illustrate the complex nonlinear interactions induced by changes in these parameters, an ensemble of 120 simulations have been conducted in which individual members were formulated by sampling the parameters within a certain range via a Latin hypercube approach. Next, data from the 120 simulations and two distinct derived fields of observati...

  15. A computer-based matrix for rapid calculation of pulmonary hemodynamic parameters in congenital heart disease

    Directory of Open Access Journals (Sweden)

    Lopes Antonio

    2009-01-01

    Full Text Available Background : In patients with congenital heart disease undergoing cardiac catheterization for hemodynamic purposes, parameter estimation by the indirect Fick method using a single predicted value of oxygen consumption has been a matter of criticism. Objective : We developed a computer-based routine for rapid estimation of replicate hemodynamic parameters using multiple predicted values of oxygen consumption. Materials and Methods : Using Microsoft ® Excel facilities, we constructed a matrix containing 5 models (equations for prediction of oxygen consumption, and all additional formulas needed to obtain replicate estimates of hemodynamic parameters. Results : By entering data from 65 patients with ventricular septal defects, aged 1 month to 8 years, it was possible to obtain multiple predictions for oxygen consumption, with clear between-age groups ( P < .001 and between-methods ( P < .001 differences. Using these predictions in the individual patient, it was possible to obtain the upper and lower limits of a likely range for any given parameter, which made estimation more realistic. Conclusion : The organized matrix allows for rapid obtainment of replicate parameter estimates, without error due to exhaustive calculations.

  16. A computer-based matrix for rapid calculation of pulmonary hemodynamic parameters in congenital heart disease.

    Science.gov (United States)

    Lopes, Antonio Augusto; Dos Anjos Miranda, Rogério; Gonçalves, Rilvani Cavalcante; Thomaz, Ana Maria

    2009-07-01

    In patients with congenital heart disease undergoing cardiac catheterization for hemodynamic purposes, parameter estimation by the indirect Fick method using a single predicted value of oxygen consumption has been a matter of criticism. We developed a computer-based routine for rapid estimation of replicate hemodynamic parameters using multiple predicted values of oxygen consumption. Using Microsoft® Excel facilities, we constructed a matrix containing 5 models (equations) for prediction of oxygen consumption, and all additional formulas needed to obtain replicate estimates of hemodynamic parameters. By entering data from 65 patients with ventricular septal defects, aged 1 month to 8 years, it was possible to obtain multiple predictions for oxygen consumption, with clear between-age groups (P <.001) and between-methods (P <.001) differences. Using these predictions in the individual patient, it was possible to obtain the upper and lower limits of a likely range for any given parameter, which made estimation more realistic. The organized matrix allows for rapid obtainment of replicate parameter estimates, without error due to exhaustive calculations.

  17. Controlling a Chaotic System through Control Parameter Self-Modulation

    Energy Technology Data Exchange (ETDEWEB)

    Pastor, I.

    1994-07-01

    A method for obtaining active control of a chaotic system based on the modulation of a control parameter by adding to it a small perturbation proportional to one output signal is proposed. From a theoretical point of view, chaos can be stabilized in the framework of this method because small modifications of the vector field controlling the dynamics are allowed, and thus some of the previously oxi sting unstable periodic trajectories can be made stable. The method is much inspired on recent treatments of some related problems, and i t is compared with them. One of its most attractive features is that is should be very easy to implement it on real experiments. The method is tested on a system of ordinary differential equations model ling the coupling of two se If - oscillating electronic circuits (van der Pol oscillators). Some brief comments are made on the no possibility that it could be applied to complex spatio-temporal systems where multiple chaotic structures can coexist for some values of the control parameters. (Author) 28 refs.

  18. Studies on the Process Parameters of Rapid Prototyping Technique (Stereolithography for the Betterment of Part Quality

    Directory of Open Access Journals (Sweden)

    Raju Bangalore Singe Gowda

    2014-01-01

    Full Text Available Rapid prototyping (RP has evolved as frontier technology in the recent times, which allows direct transformation of CAD files into functional prototypes where it tremendously reduces the lead time to produce physical prototypes necessary for design verification, fit, and functional analysis by generating the prototypes directly from the CAD data. Part quality in the rapid prototyping process is a function of build parameters such as hatch cure depth, layer thickness, orientation, and hatch spacing. Thus an attempt was made to identify, study, and optimize the process parameters governing the system which are related to part characteristics using Taguchi experimental design techniques quality. The part characteristics can be divided into physical part and mechanical part characteristics. The physical characteristics are surface finish, dimensional accuracy, distortion, layer thickness, hatch cure, and hatch file, whereas mechanical characteristics are flexural strength, ultimate tensile strength, and impact strength. Thus, this paper proposes to characterize the influence of the physical build parameters over the part quality. An L9 orthogonal array was designed with the minimum number of experimental runs with desired parameter settings and also by analysis tools such as ANOVA (analysis of variance. Establishment of experimentally verified correlations between the physical part characteristics and mechanical part characteristics to obtain an optimal process parameter level for betterment of part quality is obtained. The process model obtained by the empirical relation can be used to determine the strength of the prototype for the given set of parameters that shows the dependency of strength, which are essential for designers and RP machine users.

  19. Control and Estimation of Distributed Parameter Systems

    CERN Document Server

    Kappel, F; Kunisch, K

    1998-01-01

    Consisting of 23 refereed contributions, this volume offers a broad and diverse view of current research in control and estimation of partial differential equations. Topics addressed include, but are not limited to - control and stability of hyperbolic systems related to elasticity, linear and nonlinear; - control and identification of nonlinear parabolic systems; - exact and approximate controllability, and observability; - Pontryagin's maximum principle and dynamic programming in PDE; and - numerics pertinent to optimal and suboptimal control problems. This volume is primarily geared toward control theorists seeking information on the latest developments in their area of expertise. It may also serve as a stimulating reader to any researcher who wants to gain an impression of activities at the forefront of a vigorously expanding area in applied mathematics.

  20. Optimization of process parameters for the rapid biosynthesis of hematite nanoparticles.

    Science.gov (United States)

    Rajendran, Kumar; Sen, Shampa

    2016-06-01

    Hematite (α-Fe2O3) nanoparticles are widely used in various applications including gas sensors, pigments owing to its low cost, environmental friendliness, non-toxicity and high resistance to corrosion. These nanoparticles were generally synthesized by different chemical methods. In the present study, nanoparticles were synthesized rapidly without heat treatment by biosynthesis approach using culture supernatant of Bacillus cereus SVK1. The physiochemical parameters for rapid synthesis were optimized by using UV-visible spectroscopy. The time taken for hematite nanoparticle synthesis was found to increase with the increasing concentration of the precursor. This might be due to the inadequate proportion of quantity of biomolecules present in the culture supernatant to the precursor which led to delayed bioreduction. Greater quantities of culture supernatant with respect to precursor lead to rapid synthesis of hematite nanoparticles. The nucleation of the hematite nucleus happens more easily when the solution pH was less than 10. The optimum parameters identified for the rapid biosynthesis of hematite nanoparticles were pH9, 37°C (temperature) and 1mM ferric chloride as precursor. The particles were well crystallized hexagonal structured hematite nanoparticles and are predominantly (110)-oriented. The synthesized nanoparticles were found to contain predominantly iron (73.47%) and oxygen (22.58%) as evidenced by Energy Dispersive X-ray analysis. Hematite nanoparticles of 15-40nm diameters were biosynthesized in 48h under optimized conditions, compared to 21days before optimization. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Neuromuscular Control of Rapid Linear Accelerations in Fish

    Science.gov (United States)

    2016-06-22

    fish : Final Report Eric D. Tytell Department of Biology , Tufts University, eric.tytell@tufts.edu Abstract In this project, we measured muscle... important aspects of how rapid movements are controlled, but will have to be done using a negative stimulus such as a object accelerating toward the fish ...sunfish, Lepomis macrochirus. Animals with flexible bodies, like fishes , face a tradeoff for rapid movements. To produce high forces, they must

  2. Direct Parametric Image Reconstruction in Reduced Parameter Space for Rapid Multi-Tracer PET Imaging.

    Science.gov (United States)

    Cheng, Xiaoyin; Li, Zhoulei; Liu, Zhen; Navab, Nassir; Huang, Sung-Cheng; Keller, Ulrich; Ziegler, Sibylle; Shi, Kuangyu

    2015-02-12

    The separation of multiple PET tracers within an overlapping scan based on intrinsic differences of tracer pharmacokinetics is challenging, due to limited signal-to-noise ratio (SNR) of PET measurements and high complexity of fitting models. In this study, we developed a direct parametric image reconstruction (DPIR) method for estimating kinetic parameters and recovering single tracer information from rapid multi-tracer PET measurements. This is achieved by integrating a multi-tracer model in a reduced parameter space (RPS) into dynamic image reconstruction. This new RPS model is reformulated from an existing multi-tracer model and contains fewer parameters for kinetic fitting. Ordered-subsets expectation-maximization (OSEM) was employed to approximate log-likelihood function with respect to kinetic parameters. To incorporate the multi-tracer model, an iterative weighted nonlinear least square (WNLS) method was employed. The proposed multi-tracer DPIR (MTDPIR) algorithm was evaluated on dual-tracer PET simulations ([18F]FDG and [11C]MET) as well as on preclinical PET measurements ([18F]FLT and [18F]FDG). The performance of the proposed algorithm was compared to the indirect parameter estimation method with the original dual-tracer model. The respective contributions of the RPS technique and the DPIR method to the performance of the new algorithm were analyzed in detail. For the preclinical evaluation, the tracer separation results were compared with single [18F]FDG scans of the same subjects measured 2 days before the dual-tracer scan. The results of the simulation and preclinical studies demonstrate that the proposed MT-DPIR method can improve the separation of multiple tracers for PET image quantification and kinetic parameter estimations.

  3. Parameters and sensitivity in workload control

    NARCIS (Netherlands)

    Land, M.J.

    2006-01-01

    Both practitioners and scientists have recognized the importance of workload control (WLC) for job shop practices. WLC principles have been integrated into a comprehensive concept, which receives a lot of attention in scientific literature in recent years. Though meant as a robust concept for

  4. Real-time control of beam parameters

    CERN Document Server

    Dehler, M

    2008-01-01

    This article gives an overview of the theory and application of real-time control of accelerator beams. The design and structure of orbit feedbacks are described, going from basic local feedbacks to modern state-of-the art global systems. The time domain behaviour is analysed for the building blocks of the systems as well as from the spectrum of random sources driving the orbit perturbations. The use of predictive ltering is shown for the design of the control algorithm. A second important class is the control of tunes and chromaticities. Advanced tune measurements are performed using a digital phase-locked loop. The feedback systems are typically hybrid, simultaneously working on tune and coupling and chromaticity. Adaptive feed-forward algorithms are shown to be a suitable approach for use in energy ramping. For application in a high-speed bunch-by-bunch feedback system, ef cient low-noise data processing is presented for a digital lter. Also here, predictive ltering is shown to give well-adapted high-order...

  5. Another Look at the EWMA Control Chart with Estimated Parameters

    NARCIS (Netherlands)

    Saleh, N.A.; Mahmoud, M.A.; Jones-Farmer, L.A.; Zwetsloot, I.; Woodall, W.H.

    2015-01-01

    The authors assess the in-control performance of the exponentially weighted moving average (EWMA) control chart in terms of the SDARL and percentiles of the ARL distribution when the process parameters are estimated.

  6. Reward prospect rapidly speeds up response inhibition via reactive control.

    Science.gov (United States)

    Boehler, Carsten N; Schevernels, Hanne; Hopf, Jens-Max; Stoppel, Christian M; Krebs, Ruth M

    2014-06-01

    Response inhibition is an important cognitive-control function that allows for already-initiated or habitual behavioral responses to be promptly withheld when needed. A typical paradigm to study this function is the stop-signal task. From this task, the stop-signal response time (SSRT) can be derived, which indexes how rapidly an already-initiated response can be canceled. Typically, SSRTs range around 200 ms, identifying response inhibition as a particularly rapid cognitive-control process. Even so, it has recently been shown that SSRTs can be further accelerated if successful response inhibition is rewarded. Since this earlier study effectively ruled out differential preparatory (proactive) control adjustments, the reward benefits likely relied on boosted reactive control. Yet, given how rapidly such control processes would need to be enhanced, alternative explanations circumventing reactive control are important to consider. We addressed this question with an fMRI study by gauging the overlap of the brain networks associated with reward-related and response-inhibition-related processes in a reward-modulated stop-signal task. In line with the view that reactive control can indeed be boosted swiftly by reward availability, we found that the activity in key brain areas related to response inhibition was enhanced for reward-related stop trials. Furthermore, we observed that this beneficial reward effect was triggered by enhanced connectivity between task-unspecific (reward-related) and task-specific (inhibition-related) areas in the medial prefrontal cortex (mPFC). The present data hence suggest that reward information can be translated very rapidly into behavioral benefits (here, within ~200 ms) through enhanced reactive control, underscoring the immediate responsiveness of such control processes to reward availability in general.

  7. LPV control of a 2-DOF robot using parameter reduction

    OpenAIRE

    Kwiatkowski, Andreas; Werner, Herbert

    2005-01-01

    This paper demonstrates the benefit of a new method for reducing the number of scheduling parameters of LPV controllers, by applying it to a robot manipulator. A full LPV representation of a planar two-link robot with ten scheduling parameters is considered. The number of parameters can be reduced by applying principal components analysis to typical scheduling trajectories. The proposed method enables a systematic trade-off between the number of reduced parameters and the desired accura...

  8. Addressing model uncertainty through stochastic parameter perturbations within the High Resolution Rapid Refresh (HRRR) ensemble

    Science.gov (United States)

    Wolff, J.; Jankov, I.; Beck, J.; Carson, L.; Frimel, J.; Harrold, M.; Jiang, H.

    2016-12-01

    It is well known that global and regional numerical weather prediction ensemble systems are under-dispersive, producing unreliable and overconfident ensemble forecasts. Typical approaches to alleviate this problem include the use of multiple dynamic cores, multiple physics suite configurations, or a combination of the two. While these approaches may produce desirable results, they have practical and theoretical deficiencies and are more difficult and costly to maintain. An active area of research that promotes a more unified and sustainable system for addressing the deficiencies in ensemble modeling is the use of stochastic physics to represent model-related uncertainty. Stochastic approaches include Stochastic Parameter Perturbations (SPP), Stochastic Kinetic Energy Backscatter (SKEB), Stochastic Perturbation of Physics Tendencies (SPPT), or some combination of all three. The focus of this study is to assess the model performance within a convection-permitting ensemble at 3-km grid spacing across the Contiguous United States (CONUS) when using stochastic approaches. For this purpose, the test utilized a single physics suite configuration based on the operational High-Resolution Rapid Refresh (HRRR) model, with ensemble members produced by employing stochastic methods. Parameter perturbations were employed in the Rapid Update Cycle (RUC) land surface model and Mellor-Yamada-Nakanishi-Niino (MYNN) planetary boundary layer scheme. Results will be presented in terms of bias, error, spread, skill, accuracy, reliability, and sharpness using the Model Evaluation Tools (MET) verification package. Due to the high level of complexity of running a frequently updating (hourly), high spatial resolution (3 km), large domain (CONUS) ensemble system, extensive high performance computing (HPC) resources were needed to meet this objective. Supercomputing resources were provided through the National Center for Atmospheric Research (NCAR) Strategic Capability (NSC) project support

  9. Rapid control prototyping for cylinder pressure indication; Rapid Control Prototyping fuer Zylinderdruckindizierung

    Energy Technology Data Exchange (ETDEWEB)

    Pfluger, Jan [RWTH Aachen Univ. (Germany). Lehrstuhl fuer Verbrennungskraftmaschinen; Andert, Jakob [FEV GmbH, Aachen (Germany). Fahrzeugelektronik/E-Mobilitaet; Ross, Holger; Mertens, Frank [dSpace GmbH, Paderborn (Germany). Rapid Control Prototyping Systems

    2012-11-15

    Cylinder-pressure-based controls that allow cycle-synchronous reactions to events in the combustion chamber are a particularly promising possibility further optimising engine combustion processes. However, the requirements of real-time cylinder indication are fast pushing today's systems up against their limits. The Institute for Combustion Engines at RWTH Aachen University and dSpace together developed a high performance prototype for online indication with cycle-synchronous combustion control. (orig.)

  10. Rapid Control Prototyping Plataform for Didactic Plant Motor DC

    Directory of Open Access Journals (Sweden)

    Cristian Bazán-Orobio

    2013-06-01

    Full Text Available In this paper a design, implementation and validation of a Rapid Control Prototype platform for a plant based on a DC motor is proposed. This low-cost prototype provides of an electronic card (with a motor DC and sensors manipulated by PC with free software tools using Linux, Scilab / Scicos and RTAI-Lab. This RCP System allows developing speed -position control trainings by using different types of PID industrial controllers with anti – wind up and bump less transfer schemes. We develop a speed control application structured in four steps: identification, controller design, simulation and real time control, where there are pedagogical advantages of a platform that not only allows simulation but also real-time control of a plant.

  11. Parameter optimization and stretch enhancement of AISI 316 sheet using rapid prototyping technique

    Science.gov (United States)

    Moayedfar, M.; Rani, A. M.; Hanaei, H.; Ahmad, A.; Tale, A.

    2017-10-01

    Incremental sheet forming is a flexible manufacturing process which uses the indenter point-to-point force to shape the sheet metal workpiece into manufactured parts in batch production series. However, the problem sometimes arising from this process is the low plastic point in the stress-strain diagram of the material which leads the low stretching amount before ultra-tensile strain point. Hence, a set of experiments is designed to find the optimum forming parameters in this process for optimum sheet thickness distribution while both sides of the sheet are considered for the surface quality improvement. A five-axis high-speed CNC milling machine is employed to deliver the proper motion based on the programming system while the clamping system for holding the sheet metal was a blank mould. Finally, an electron microscope and roughness machine are utilized to evaluate the surface structure of final parts, illustrate any defect may cause during the forming process and examine the roughness of the final part surface accordingly. The best interaction between parameters is obtained with the optimum values which lead the maximum sheet thickness distribution of 4.211e-01 logarithmic elongation when the depth was 24mm with respect to the design. This study demonstrates that this rapid forming method offers an alternative solution for surface quality improvement of 65% avoiding the low probability of cracks and low probability of crystal structure changes.

  12. Parameter optimization in AQM controller design to support TCP traffic

    Science.gov (United States)

    Yang, Wei; Yang, Oliver W.

    2004-09-01

    TCP congestion control mechanism has been widely investigated and deployed on Internet in preventing congestion collapse. We would like to employ modern control theory to specify quantitatively the control performance of the TCP communication system. In this paper, we make use of a commonly used performance index called the Integral of the Square of the Error (ISE), which is a quantitative measure to gauge the performance of a control system. By applying the ISE performance index into the Proportional-plus-Integral controller based on Pole Placement (PI_PP controller) for active queue management (AQM) in IP routers, we can further tune the parameters for the controller to achieve an optimum control minimizing control errors. We have analyzed the dynamic model of the TCP congestion control under this ISE, and used OPNET simulation tool to verify the derived optimized parameters of the controllers.

  13. Robust control of UAVs using the parameter space approach

    NARCIS (Netherlands)

    Abdelmoeti, Samer; Carloni, Raffaella

    2016-01-01

    In this paper a robust PID controller for quadrotor unmanned aerial vehicles is proposed that uses the pa- rameter space approach. Stability and robustness analyses are carried out in the controller parameter space to determine a set of stable controller gains that guarantee also robustness against

  14. The Determination of Optimal Parameters of Fuzzy PI Sugeno Controller

    Science.gov (United States)

    Kudinov, Y. I.; Kudinov, I. Yu; Volkova, A. A.; Durgarjan, I. S.; Pashchenko, F. F.

    2017-11-01

    Describe the procedure for determining by means of Matlab and Simulink optimal parameters of the fuzzy PI controller Sugeno, where some indicators of the quality of the transition process in a closed system control with this controller satisfies the specified conditions.

  15. Linear Parameter Varying Control of Doubly Fed Induction Machines

    NARCIS (Netherlands)

    Tien, H. Nguyen; Scherer, Carsten W.; Scherpen, Jacquelien M.A.; Müller, Volkmar

    This paper is concerned with the design of a self-scheduled current controller for doubly fed induction machines. The design is based on the framework of linear parameter-varying systems where the mechanical angular speed is considered to be a measurable time-varying parameter. The objective is to

  16. Parameter Control in Evolutionary Algorithms: Trends and Challenges

    NARCIS (Netherlands)

    Karafotias, Giorgos; Hoogendoorn, Mark; Eiben, A.E.

    2015-01-01

    More than a decade after the first extensive overview on parameter control, we revisit the field and present a survey of the state-of-the-art. We briefly summarize the development of the field and discuss existing work related to each major parameter or component of an evolutionary algorithm. Based

  17. Switching State-Feedback LPV Control with Uncertain Scheduling Parameters

    Science.gov (United States)

    He, Tianyi; Al-Jiboory, Ali Khudhair; Swei, Sean Shan-Min; Zhu, Guoming G.

    2017-01-01

    This paper presents a new method to design Robust Switching State-Feedback Gain-Scheduling (RSSFGS) controllers for Linear Parameter Varying (LPV) systems with uncertain scheduling parameters. The domain of scheduling parameters are divided into several overlapped subregions to undergo hysteresis switching among a family of simultaneously designed LPV controllers over the corresponding subregion with the guaranteed H-infinity performance. The synthesis conditions are given in terms of Parameterized Linear Matrix Inequalities that guarantee both stability and performance at each subregion and associated switching surfaces. The switching stability is ensured by descent parameter-dependent Lyapunov function on switching surfaces. By solving the optimization problem, RSSFGS controller can be obtained for each subregion. A numerical example is given to illustrate the effectiveness of the proposed approach over the non-switching controllers.

  18. Controller parameter tuning of delta robot based on servo identification

    Science.gov (United States)

    Zhao, Qing; Wang, Panfeng; Mei, Jiangping

    2015-03-01

    High-speed pick-and-place parallel robot is a system where the inertia imposed on the motor shafts is real-time changing with the system configurations. High quality of computer control with proper controller parameters is conducive to overcoming this problem and has a significant effect on reducing the robot's tracking error. By taking Delta robot as an example, a method for parameter tuning of the fixed gain motion controller is presented. Having identifying the parameters of the servo system in the frequency domain by the sinusoidal excitation, the PD+feedforward control strategy is proposed to adapt to the varying inertia loads, allowing the controller parameters to be tuned by minimizing the mean square tracking error along a typical trajectory. A set of optimum parameters is obtained through computer simulations and the effectiveness of the proposed approach is validated by experiments on a real prototype machine. Let the traveling plate undergoes a specific trajectory and the results show that the tracking error can be reduced by at least 50% in comparison with the conventional auto-tuning and Z-N methods. The proposed approach is a whole workspace optimization and can be applied to the parameter tuning of fixed gain motion controllers.

  19. Intermittent control of unstable multivariate systems with uncertain system parameters.

    Science.gov (United States)

    Loram, I; Cunningham, R; Zenzeri, J; Gollee, H

    2016-08-01

    Multivariable intermittent control (MIC) combines stability with flexibility in the control of unstable systems. Using an underlying continuous-time optimal control design, MIC uses models of the physical system to generate multivariate open-loop control signals between samples of the observed state. Using accurate model values of physical system parameters, stability of the closed loop system is not dependent upon sample interval. Here we consider the sensitivity of MIC to inaccurate model values of system parameters. The high dimensionality of multiple parameters combined with an unstable open loop system ensures the ratio of hyper-volumes containing good to bad parameter combinations resembles a "needle in a haystack". Is this sensitivity a problem or an asset? Prediction error between open loop and observed states provides the basis for triggering a sampling event but is also sensitive to inaccurate model values. Investigation of the mapping between prediction error and model values of physical parameters illustrates the value of prediction error to identify combinations of parameters giving stable closed loop control with low state error, similar to that provided by accurate values. Sensitivity of prediction error to model inaccuracy is potentially an asset facilitating adaptation and supporting the rationale for MIC to combine control with flexibility.

  20. Space-Filling Curves for Quantum Control Parameters

    Science.gov (United States)

    Shafee, Fariel

    2006-06-01

    We consider the use of space-filling curves (SFC) in scanning control parameters for quantum chemical systems. First we show that a formally exact SFC must be singular in the control parameters, but a finite discrete generalization can be used with no problem. We then make general observations about the relevance of SFCs in preference to linear scans of the parameters. Finally we present a simple magnetic field example relevant in NMR and show from the calculated autocorrelations that a SFC Peano-Hilbert curve gives a smoother sequence than a linear scan.

  1. Reinforcement Learning for Ramp Control: An Analysis of Learning Parameters

    Directory of Open Access Journals (Sweden)

    Chao Lu

    2016-08-01

    Full Text Available Reinforcement Learning (RL has been proposed to deal with ramp control problems under dynamic traffic conditions; however, there is a lack of sufficient research on the behaviour and impacts of different learning parameters. This paper describes a ramp control agent based on the RL mechanism and thoroughly analyzed the influence of three learning parameters; namely, learning rate, discount rate and action selection parameter on the algorithm performance. Two indices for the learning speed and convergence stability were used to measure the algorithm performance, based on which a series of simulation-based experiments were designed and conducted by using a macroscopic traffic flow model. Simulation results showed that, compared with the discount rate, the learning rate and action selection parameter made more remarkable impacts on the algorithm performance. Based on the analysis, some suggestionsabout how to select suitable parameter values that can achieve a superior performance were provided.

  2. Model Predictive Control of Nonlinear Parameter Varying Systems via Receding Horizon Control Lyapunov Functions

    National Research Council Canada - National Science Library

    Sznaier, Mario

    2001-01-01

    .... In this chapter we propose a suboptimal regulator for nonlinear parameter varying, control affine systems based upon the combination of model predictive and control Lyapunov function techniques...

  3. Parameter testing for lattice filter based adaptive modal control systems

    Science.gov (United States)

    Sundararajan, N.; Williams, J. P.; Montgomery, R. C.

    1983-01-01

    For Large Space Structures (LSS), an adaptive control system is highly desirable. The present investigation is concerned with an 'indirect' adaptive control scheme wherein the system order, mode shapes, and modal amplitudes are estimated on-line using an identification scheme based on recursive, least-squares, lattice filters. Using the identified model parameters, a modal control law based on a pole-placement scheme with the objective of vibration suppression is employed. A method is presented for closed loop adaptive control of a flexible free-free beam. The adaptive control scheme consists of a two stage identification scheme working in series and a modal pole placement control scheme. The main conclusion from the current study is that the identified parameters cannot be directly used for controller design purposes.

  4. Analytical one parameter method for PID motion controller settings

    NARCIS (Netherlands)

    van Dijk, Johannes; Aarts, Ronald G.K.M.

    2012-01-01

    In this paper analytical expressions for PID-controllers settings for electromechanical motion systems are presented. It will be shown that by an adequate frequency domain oriented parametrization, the parameters of a PID-controller are analytically dependent on one variable only, the cross-over

  5. Robust Control with Enlaeged Interval of Uncertain Parameters

    Directory of Open Access Journals (Sweden)

    Marek Keresturi

    2002-01-01

    Full Text Available Robust control is advantageous for systems with defined interval of uncertain parameters. This can be substantially enlarged dividing it into a few sub-intervals. Corresponding controllers for each of them may be set after approximate identification of some uncertain plant parameters. The paper deals with application of the pole region assignment method for position control of the crane crab. The same track form is required for uncertain burden mass and approximate value of rope length. Measurement of crab position and speed is supposed, burden deviation angle is observed. Simulation results have verified feasibility of this design procedure.

  6. Quantitative Functional Imaging Using Dynamic Positron Computed Tomography and Rapid Parameter Estimation Techniques

    Science.gov (United States)

    Koeppe, Robert Allen

    Positron computed tomography (PCT) is a diagnostic imaging technique that provides both three dimensional imaging capability and quantitative measurements of local tissue radioactivity concentrations in vivo. This allows the development of non-invasive methods that employ the principles of tracer kinetics for determining physiological properties such as mass specific blood flow, tissue pH, and rates of substrate transport or utilization. A physiologically based, two-compartment tracer kinetic model was derived to mathematically describe the exchange of a radioindicator between blood and tissue. The model was adapted for use with dynamic sequences of data acquired with a positron tomograph. Rapid estimation techniques were implemented to produce functional images of the model parameters by analyzing each individual pixel sequence of the image data. A detailed analysis of the performance characteristics of three different parameter estimation schemes was performed. The analysis included examination of errors caused by statistical uncertainties in the measured data, errors in the timing of the data, and errors caused by violation of various assumptions of the tracer kinetic model. Two specific radioindicators were investigated. ('18)F -fluoromethane, an inert freely diffusible gas, was used for local quantitative determinations of both cerebral blood flow and tissue:blood partition coefficient. A method was developed that did not require direct sampling of arterial blood for the absolute scaling of flow values. The arterial input concentration time course was obtained by assuming that the alveolar or end-tidal expired breath radioactivity concentration is proportional to the arterial blood concentration. The scale of the input function was obtained from a series of venous blood concentration measurements. The method of absolute scaling using venous samples was validated in four studies, performed on normal volunteers, in which directly measured arterial concentrations

  7. Robust linear parameter varying induction motor control with polytopic models

    Directory of Open Access Journals (Sweden)

    Dalila Khamari

    2013-01-01

    Full Text Available This paper deals with a robust controller for an induction motor which is represented as a linear parameter varying systems. To do so linear matrix inequality (LMI based approach and robust Lyapunov feedback controller are associated. This new approach is related to the fact that the synthesis of a linear parameter varying (LPV feedback controller for the inner loop take into account rotor resistance and mechanical speed as varying parameter. An LPV flux observer is also synthesized to estimate rotor flux providing reference to cited above regulator. The induction motor is described as a polytopic model because of speed and rotor resistance affine dependence their values can be estimated on line during systems operations. The simulation results are presented to confirm the effectiveness of the proposed approach where robustness stability and high performances have been achieved over the entire operating range of the induction motor.

  8. Total energy control system autopilot design with constrained parameter optimization

    Science.gov (United States)

    Ly, Uy-Loi; Voth, Christopher

    1990-01-01

    A description is given of the application of a multivariable control design method (SANDY) based on constrained parameter optimization to the design of a multiloop aircraft flight control system. Specifically, the design method is applied to the direct synthesis of a multiloop AFCS inner-loop feedback control system based on total energy control system (TECS) principles. The design procedure offers a structured approach for the determination of a set of stabilizing controller design gains that meet design specifications in closed-loop stability, command tracking performance, disturbance rejection, and limits on control activities. The approach can be extended to a broader class of multiloop flight control systems. Direct tradeoffs between many real design goals are rendered systematic by proper formulation of the design objectives and constraints. Satisfactory designs are usually obtained in few iterations. Performance characteristics of the optimized TECS design have been improved, particularly in the areas of closed-loop damping and control activity in the presence of turbulence.

  9. Effect of Varying Controller Parameters on the Performance of a ...

    African Journals Online (AJOL)

    This paper presents the results of computer simulation studies designed to isolate the effects of the major parameters of a fuzzy logic controller namely the range of the universe of discourse, the extent of overlap of the fuzzy sets, the rules in the rule base and the modes of the output fuzzy sets on the performance of a fuzzy ...

  10. Effective valence as the control parameter of the superconducting ...

    African Journals Online (AJOL)

    In this paper, we have demonstrated that the effective valence of iron can be used as the control parameter to tune the Tc of this family of superconducting materials. This is achieved by postulating that our model of spin fluctuation which has been used to successfully account for the superconductivity in the cuprates in Ref.

  11. Genetic Algorithm Optimizes Q-LAW Control Parameters

    Science.gov (United States)

    Lee, Seungwon; von Allmen, Paul; Petropoulos, Anastassios; Terrile, Richard

    2008-01-01

    A document discusses a multi-objective, genetic algorithm designed to optimize Lyapunov feedback control law (Q-law) parameters in order to efficiently find Pareto-optimal solutions for low-thrust trajectories for electronic propulsion systems. These would be propellant-optimal solutions for a given flight time, or flight time optimal solutions for a given propellant requirement. The approximate solutions are used as good initial solutions for high-fidelity optimization tools. When the good initial solutions are used, the high-fidelity optimization tools quickly converge to a locally optimal solution near the initial solution. Q-law control parameters are represented as real-valued genes in the genetic algorithm. The performances of the Q-law control parameters are evaluated in the multi-objective space (flight time vs. propellant mass) and sorted by the non-dominated sorting method that assigns a better fitness value to the solutions that are dominated by a fewer number of other solutions. With the ranking result, the genetic algorithm encourages the solutions with higher fitness values to participate in the reproduction process, improving the solutions in the evolution process. The population of solutions converges to the Pareto front that is permitted within the Q-law control parameter space.

  12. TCP Congestion Control for the Networks with Markovian Jump Parameters

    Directory of Open Access Journals (Sweden)

    MOMENI, H. R.

    2011-05-01

    Full Text Available This paper is concerned with the problem of TCP congestion control for the class of communication networks with random parameters. The linear dynamic model of TCP New Reno in congestion avoidance mode is considered which contains round trip delays in both state and input. The randomness of link capacity, round trip time delay and the number of TCP sessions is modeled with a continuous-time finite state Markov process. An Active Queue Management (AQM technique is then used to adjust the queue level of the congested link to a predefined value. For this purpose, a dynamic output feedback controller with mode dependent parameters is synthesized to stochastically stabilize the TCP/AQM dynamics. The procedure of the control synthesis is implemented by solving a linear matrix inequality (LMI. The results are tested within a simulation example and the effectiveness of the proposed design method is verified.

  13. Optimal estimation and scheduling in aquifer management using the rapid feedback control method

    Science.gov (United States)

    Ghorbanidehno, Hojat; Kokkinaki, Amalia; Kitanidis, Peter K.; Darve, Eric

    2017-12-01

    Management of water resources systems often involves a large number of parameters, as in the case of large, spatially heterogeneous aquifers, and a large number of "noisy" observations, as in the case of pressure observation in wells. Optimizing the operation of such systems requires both searching among many possible solutions and utilizing new information as it becomes available. However, the computational cost of this task increases rapidly with the size of the problem to the extent that textbook optimization methods are practically impossible to apply. In this paper, we present a new computationally efficient technique as a practical alternative for optimally operating large-scale dynamical systems. The proposed method, which we term Rapid Feedback Controller (RFC), provides a practical approach for combined monitoring, parameter estimation, uncertainty quantification, and optimal control for linear and nonlinear systems with a quadratic cost function. For illustration, we consider the case of a weakly nonlinear uncertain dynamical system with a quadratic objective function, specifically a two-dimensional heterogeneous aquifer management problem. To validate our method, we compare our results with the linear quadratic Gaussian (LQG) method, which is the basic approach for feedback control. We show that the computational cost of the RFC scales only linearly with the number of unknowns, a great improvement compared to the basic LQG control with a computational cost that scales quadratically. We demonstrate that the RFC method can obtain the optimal control values at a greatly reduced computational cost compared to the conventional LQG algorithm with small and controllable losses in the accuracy of the state and parameter estimation.

  14. Simulation of parameters of hydraulic drive with volumetric type controller

    Science.gov (United States)

    Mulyukin, V. L.; Boldyrev, A. V.; Karelin, D. L.; Belousov, A. M.

    2017-09-01

    The article presents a mathematical model of volumetric type hydraulic drive controller that allows to calculate the parameters of forward and reverse motion. According to the results of simulation static characteristics of rod’s speed and the force of the hydraulic cylinder rod were built and the influence of the angle of swash plate of the controller at the characteristics profile is shown. The results analysis showed that the proposed controller allows steplessly adjust the speed□ц of hydraulic cylinder’s rod motion and the force developed on the rod without the use of flow throttling.

  15. Parameter Estimation for Sensorless Controlled Induction Motors using Nonlinear Filters

    Science.gov (United States)

    Hozuki, Takashi; Kawabata, Yoshitaka; Sugimoto, Sueo

    In this paper, we consider parameter estimation of the state variables and unknown parameters of Induction Motors (IMs) using nonlinear filters. Simultaneous estimation is the most general method for sensorless controlled IMs, and at present, by the advance of computer processors, nonlinear filters have been applied to various occasions, so we describe the method for applying nonlinear filters to Induction Motors model, and consider its estimate performance by simulations. Simulation results showed that nonlinear filters have more accuracy estimate performance than the adaptive observer, and the excellent noise immunity.

  16. Lumped Parameter Modeling for Rapid Vibration Response Prototyping and Test Correlation for Electronic Units

    Science.gov (United States)

    Van Dyke, Michael B.

    2013-01-01

    Present preliminary work using lumped parameter models to approximate dynamic response of electronic units to random vibration; Derive a general N-DOF model for application to electronic units; Illustrate parametric influence of model parameters; Implication of coupled dynamics for unit/board design; Demonstrate use of model to infer printed wiring board (PWB) dynamics from external chassis test measurement.

  17. Cavity parameters identification for TESLA control system development

    Energy Technology Data Exchange (ETDEWEB)

    Czarski, T.; Pozniak, K.T.; Romaniuk, R.S. [Warsaw Univ. of Technology (Poland). ELHEP Lab., ISE; Simrock, S. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2005-07-01

    The control system modeling for the TESLA - TeV-Energy Superconducting Linear Accelerator project has been developed for the efficient stabilization of the pulsed, accelerating EM field of the resonator. The cavity parameters identification is an essential task for the comprehensive control algorithm. The TESLA cavity simulator has been successfully implemented by applying very high speed FPGA - Field Programmable Gate Array technology. The electromechanical model of the cavity resonator includes the basic features - Lorentz force detuning and beam loading. The parameters identification bases on the electrical model of the cavity. The model is represented by the state space equation for the envelope of the cavity voltage driven by the current generator and the beam loading. For a given model structure, the over-determined matrix equation is created covering the long enough measurement range with the solution according to the least squares method. A low degree polynomial approximation is applied to estimate the time-varying cavity detuning during the pulse. The measurement channel distortion is considered, leading to the external cavity model seen by the controller. The comprehensive algorithm of the cavity parameters identification has been implemented in the Matlab system with different modes of the operation. Some experimental results have been presented for different cavity operational conditions. The following considerations have lead to the synthesis of the efficient algorithm for the cavity control system predicted for the potential FPGA technology implementation. (orig.)

  18. Rapid convergence of optimal control in NMR using numerically-constructed toggling frames

    Science.gov (United States)

    Coote, Paul; Anklin, Clemens; Massefski, Walter; Wagner, Gerhard; Arthanari, Haribabu

    2017-08-01

    We present a numerical method for rapidly solving the Bloch equation for an arbitrary time-varying spin-1/2 Hamiltonian. The method relies on fast, vectorized computations such as summation and quaternion multiplication, rather than slow computations such as matrix exponentiation. A toggling frame is constructed in which the Hamiltonian is time-invariant, and therefore has a simple analytical solution. The key insight is that constructing this frame is faster than solving the system dynamics in the original frame. Rapidly solving the Bloch equations for an arbitrary Hamiltonian is particularly useful in the context of NMR optimal control. Optimal control theory can be used to design pulse shapes for a range of tasks in NMR spectroscopy. However, it requires multiple simulations of the Bloch equations at each stage of the algorithm, and for each relevant set of parameters (e.g. chemical shift frequencies). This is typically time consuming. We demonstrate that by working in an appropriate toggling frame, optimal control pulses can be generated much faster. We present a new alternative to the well-known GRAPE algorithm to continuously update the toggling-frame as the optimal pulse is generated, and demonstrate that this approach is extremely fast. The use and benefit of rapid optimal pulse generation is demonstrated for 19F fragment screening experiments.

  19. Control of complex dynamics and chaos in distributed parameter systems

    Energy Technology Data Exchange (ETDEWEB)

    Chakravarti, S.; Marek, M.; Ray, W.H. [Univ. of Wisconsin, Madison, WI (United States)

    1995-12-31

    This paper discusses a methodology for controlling complex dynamics and chaos in distributed parameter systems. The reaction-diffusion system with Brusselator kinetics, where the torus-doubling or quasi-periodic (two characteristic incommensurate frequencies) route to chaos exists in a defined range of parameter values, is used as an example. Poincare maps are used for characterization of quasi-periodic and chaotic attractors. The dominant modes or topos, which are inherent properties of the system, are identified by means of the Singular Value Decomposition. Tested modal feedback control schemas based on identified dominant spatial modes confirm the possibility of stabilization of simple quasi-periodic trajectories in the complex quasi-periodic or chaotic spatiotemporal patterns.

  20. Tuning RED parameters in satellite networks using control theory

    Science.gov (United States)

    Sridharan, Mukundan; Durresi, Arjan; Chellappan, Sriram; Ozbay, Hitay; Jain, Raj

    2003-08-01

    Congestion in the Internet results in wasted bandwidth and also stands in the way of guaranteeing QoS. The effect of congestion is multiplied many fold in Satellite networks, where the resources are very expensive. Thus congestion control has a special significance in the performance of Satellite networks. In today's Internet, congestion control is implemented mostly using some form of the de facto standard, RED. But tuning of parameters in RED has been a major problem throughout. Achieving high throughput with corresponding low delays is the main goal in parameter setting. It is also desired to keep the oscillations in the queue low to reduce jitter, so that the QoS guarantees can be improved. In this paper, we use a previously linearized fluid flow model of TCP-RED to study the performance and stability of the Queue in the router. We use classical control tools like Tracking Error minimization and Delay Margin to study the performance, stability of the system. We use the above-mentioned tools to provide guidelines for setting the parameters in RED, such that the throughput, delay and jitter of the system are optimized. Thus we provide guidelines for optimizing satellite IP networks. We apply our results exclusively for optimizing the performance of satellite networks, where the effects of congestion are much pronounced and need for optimization is much important. We use ns simulator to validate our results to support our analysis.

  1. Three-parameter tunable Tilt-Integral-Derivative (TID) controller

    Science.gov (United States)

    Lurie, Boris J. (Inventor)

    1994-01-01

    A feedback control system compensator of the PID type is provided, wherein the proportional component of the compensator is replaced with a tilted component having a transfer function s to the power of -1/n. The resulting transfer function of the entire compensator more closely approximates an optimal transfer function, thereby achieving improved feedback controller. Further, as compared to conventional PID compensators, the TID compensator allows for simpler tuning, better disturbance rejection ratio, and smaller effects of plant parameter variations on closed loop response.

  2. Parameter Identification and Adaptive Control Applied to the Inverted Pendulum

    Directory of Open Access Journals (Sweden)

    Carlos A. Saldarriaga-Cortés

    2012-06-01

    Full Text Available This paper presents a methodology to implement an adaptive control of the inverted pendulum system; which uses the recursive square minimum method for the identification of a dynamic digital model of the plant and then, with its estimated parameters, tune in real time a pole placement control. The plant to be used is an unstable and nonlinear system. This fact, combined with the adaptive controller characteristics, allows the obtained results to be extended to a great variety of systems. The results show that the above methodology was implemented satisfactorily in terms of estimation, stability and control of such a system. It was established that adaptive techniques have a proper performance even in systems with complex features such as nonlinearity and instability.

  3. Estimation of Saxophone Control Parameters by Convex Optimization.

    Science.gov (United States)

    Wang, Cheng-I; Smyth, Tamara; Lipton, Zachary C

    2014-12-01

    In this work, an approach to jointly estimating the tone hole configuration (fingering) and reed model parameters of a saxophone is presented. The problem isn't one of merely estimating pitch as one applied fingering can be used to produce several different pitches by bugling or overblowing. Nor can a fingering be estimated solely by the spectral envelope of the produced sound (as it might for estimation of vocal tract shape in speech) since one fingering can produce markedly different spectral envelopes depending on the player's embouchure and control of the reed. The problem is therefore addressed by jointly estimating both the reed (source) parameters and the fingering (filter) of a saxophone model using convex optimization and 1) a bank of filter frequency responses derived from measurement of the saxophone configured with all possible fingerings and 2) sample recordings of notes produced using all possible fingerings, played with different overblowing, dynamics and timbre. The saxophone model couples one of several possible frequency response pairs (corresponding to the applied fingering), and a quasi-static reed model generating input pressure at the mouthpiece, with control parameters being blowing pressure and reed stiffness. Applied fingering and reed parameters are estimated for a given recording by formalizing a minimization problem, where the cost function is the error between the recording and the synthesized sound produced by the model having incremental parameter values for blowing pressure and reed stiffness. The minimization problem is nonlinear and not differentiable and is made solvable using convex optimization. The performance of the fingering identification is evaluated with better accuracy than previous reported value.

  4. Water column methanotrophy controlled by a rapid oceanographic switch

    Science.gov (United States)

    Steinle, Lea; Graves, Carolyn; Treude, Tina; Biastoch, Arne; Ferré, Bénédicte; Bussmann, Ingeborg; Berndt, Christian; Krastel, Sebastian; James, Rachael H.; Behrens, Erik; Böning, Claus W.; Greinert, Jens; Sapart, Célia-Julia; Sommer, Stefan; Lehmann, Moritz F.; Niemann, Helge

    2015-04-01

    Large amounts of the greenhouse gas methane are released from the seabed to the water column where it may be consumed by aerobic methanotrophic bacteria. This microbial filter is consequently the last marine sink for methane before its liberation into the atmosphere. The size and activity of methanotrophic communities, which determine the capacity of the water column methane filter, are thought to be mainly controlled by nutrient and redox dynamics, but little is known about the effects of ocean currents. Here we show that cold bottom water at methane seeps west of Svalbard, containing a large number of aerobic methanotrophs, was rapidly displaced by warmer water with a considerably smaller methanotrophic community. This community replacement led to a reduction of methane oxidation rates of 60 % and was independent of methane input. Measurements of temperature and salinity, combined with the output of a high-resolution ocean/sea-ice simulation model (VIKING20) showed that this water mass exchange was caused by short-term variations of the West Spitsbergen Current (WSC), which is characterized by two principal modes: The warm core of the WSC either flows along the continental shelf break and thus above the methane seeps (nearshore mode), or it meanders offshore thereby entraining colder shelf water, which then flows over the seeps (offshore mode). We could link the larger community to the colder shelf water during the offshore mode, and the smaller community and lower methane oxidation rates to the presence of the warmer WSC water above the seeps. As a result, the meandering of the WSC can be considered as an oceanographic switch severely reducing methanotrophic activity in the water column. Output from the ORCA12 model showed that strong and fluctuating bottom currents are common features at methane seep systems. We thus argue that the variability of physical water mass transport is a globally important control on the distribution and abundance of methanotrophs and

  5. Metrics for rapid quality control in RNA structure probing experiments.

    Science.gov (United States)

    Choudhary, Krishna; Shih, Nathan P; Deng, Fei; Ledda, Mirko; Li, Bo; Aviran, Sharon

    2016-12-01

    The diverse functionalities of RNA can be attributed to its capacity to form complex and varied structures. The recent proliferation of new structure probing techniques coupled with high-throughput sequencing has helped RNA studies expand in both scope and depth. Despite differences in techniques, most experiments face similar challenges in reproducibility due to the stochastic nature of chemical probing and sequencing. As these protocols expand to transcriptome-wide studies, quality control becomes a more daunting task. General and efficient methodologies are needed to quantify variability and quality in the wide range of current and emerging structure probing experiments. We develop metrics to rapidly and quantitatively evaluate data quality from structure probing experiments, demonstrating their efficacy on both small synthetic libraries and transcriptome-wide datasets. We use a signal-to-noise ratio concept to evaluate replicate agreement, which has the capacity to identify high-quality data. We also consider and compare two methods to assess variability inherent in probing experiments, which we then utilize to evaluate the coverage adjustments needed to meet desired quality. The developed metrics and tools will be useful in summarizing large-scale datasets and will help standardize quality control in the field. The data and methods used in this article are freely available at: http://bme.ucdavis.edu/aviranlab/SPEQC_software CONTACT: saviran@ucdavis.eduSupplementary information: Supplementary data are available at Bioinformatics online. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  6. Control of rock joint parameters on deformation of tunnel opening

    Directory of Open Access Journals (Sweden)

    Suman Panthee

    2016-08-01

    Full Text Available Tunneling in complex rock mass conditions is a challenging task, especially in the Himalayan terrain, where a number of unpredicted conditions are reported. Rock joint parameters such as persistence, spacing and shear strength are the factors which significantly modify the working environments in the vicinity of the openings. Therefore, a detailed tunnel stability assessment is critically important based on the field data collection on the excavated tunnel's face. In this context, intact as well as rock mass strength and deformation modulus is obtained from laboratory tests for each rock type encountered in the study area. Finite element method (FEM is used for stability analysis purpose by parametrically varying rock joint persistence, spacing and shear strength parameters, until the condition of overbreak is reached. Another case of marginally stable condition is also obtained based on the same parameters. The results show that stability of tunnels is highly influenced by these parameters and the size of overbreak is controlled by joint persistence and spacing. Garnetiferous schist and slate characterized using high persistence show the development of large plastic zones but small block size, depending upon joint spacing; whereas low persistence, low spacing and low shear strength in marble and quartzite create rock block fall condition.

  7. Monitoring and control of rf electrical parameters near plasma loads

    Science.gov (United States)

    Rummel, Paul

    1991-03-01

    Today''s semiconductor processing equipment demands accurate and repeatable controls to obtain improved yields of increasingly complex chemistries and smaller geometries. Electrical control of RF induced plasmas has sadly lacked the precision of modern gas flow pressure and chemistry control and hence is a major limiting factor to process repeatability and diagnostics. Present technology which is decades old maintains a constant indicated forward power at the RF source regardless of mismatch reflections transmission line losses non-repeatable impedance matching losses reactor feed losses and RF envelope modulation due to plasma load non-linearities interacting with power source instabilities. Process diagnostics is often reduced to a guessing game once gas flow and pressure controls are checked against each other. Comdel Inc. has produced a new product to remove some of the ''black art'' from RE control and analysis. The RPM-l (Real Power Monitor) is intended to become center of the RE delivery system. Consisting of a sensor unit and a processor unit the RPM-i controls the RE power source based upon real power RF voltage RF current or DC bias at the point where the sensor unit is installed regardless of the load impedance. The user interface to control and read these RE electrical parameters is an ASCII terminal or host computer via an RS- 232 serial port on the processor unit. The RPM-l also calculates and displays on the terminal the plasma load impedance

  8. Rapid Computation of Thermodynamic Properties over Multidimensional Nonbonded Parameter Spaces Using Adaptive Multistate Reweighting.

    Science.gov (United States)

    Naden, Levi N; Shirts, Michael R

    2016-04-12

    We show how thermodynamic properties of molecular models can be computed over a large, multidimensional parameter space by combining multistate reweighting analysis with a linear basis function approach. This approach reduces the computational cost to estimate thermodynamic properties from molecular simulations for over 130,000 tested parameter combinations from over 1000 CPU years to tens of CPU days. This speed increase is achieved primarily by computing the potential energy as a linear combination of basis functions, computed from either modified simulation code or as the difference of energy between two reference states, which can be done without any simulation code modification. The thermodynamic properties are then estimated with the Multistate Bennett Acceptance Ratio (MBAR) as a function of multiple model parameters without the need to define a priori how the states are connected by a pathway. Instead, we adaptively sample a set of points in parameter space to create mutual configuration space overlap. The existence of regions of poor configuration space overlap are detected by analyzing the eigenvalues of the sampled states' overlap matrix. The configuration space overlap to sampled states is monitored alongside the mean and maximum uncertainty to determine convergence, as neither the uncertainty or the configuration space overlap alone is a sufficient metric of convergence. This adaptive sampling scheme is demonstrated by estimating with high precision the solvation free energies of charged particles of Lennard-Jones plus Coulomb functional form with charges between -2 and +2 and generally physical values of σij and ϵij in TIP3P water. We also compute entropy, enthalpy, and radial distribution functions of arbitrary unsampled parameter combinations using only the data from these sampled states and use the estimates of free energies over the entire space to examine the deviation of atomistic simulations from the Born approximation to the solvation free

  9. Computing an operating parameter of a unified power flow controller

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, David G.; Robinett, III, Rush D.

    2017-12-26

    A Unified Power Flow Controller described herein comprises a sensor that outputs at least one sensed condition, a processor that receives the at least one sensed condition, a memory that comprises control logic that is executable by the processor; and power electronics that comprise power storage, wherein the processor causes the power electronics to selectively cause the power storage to act as one of a power generator or a load based at least in part upon the at least one sensed condition output by the sensor and the control logic, and wherein at least one operating parameter of the power electronics is designed to facilitate maximal transmittal of electrical power generated at a variable power generation system to a grid system while meeting power constraints set forth by the electrical power grid.

  10. Control of Linear Parameter Varying Systems with Applications

    CERN Document Server

    Mohammadpour, Javad

    2012-01-01

    Control of Linear Parameter Varying Systems with Applications compiles state-of-the-art contributions on novel analytical and computational methods to address system modeling and identification, complexity reduction, performance analysis and control design for time-varying and nonlinear systems in the LPV framework. The book has an interdisciplinary character by emphasizing techniques that can be commonly applied in various engineering fields. It also includes a rich collection of illustrative applications in diverse domains to substantiate the effectiveness of the design methodologies and provide pointers to open research directions. The book is divided into three parts. The first part collects chapters of a more tutorial character on the background of LPV systems modeling and control. The second part gathers chapters devoted to the theoretical advancement of LPV analysis and synthesis methods to cope with the design constraints such as uncertainties and time delay. The third part of the volume showcases con...

  11. On some inventory control problems with state-dependent parameters

    Directory of Open Access Journals (Sweden)

    Lev Abolnikov

    1987-01-01

    Full Text Available This article analyzes discrete Markov processes that arise in some general control problems of a storage (or a dam with an infinite capacity. Employing a special “step-wise” structure of the transition matrices of these processes, the author obtains conditions for their ergodicity and develops an implementable algorithm for finding the generating function of the corresponding distributions. This algorithm is applied to a dam with a multilevel state-dependent control strategy, according to which parameters of the input and output processes may depend on the amount of the water in the dam. The method is illustrated with a case of a single-level control strategy where explicit results are obtained.

  12. An Improved Method to Control the Critical Parameters of a Multivariable Control System

    Science.gov (United States)

    Subha Hency Jims, P.; Dharmalingam, S.; Wessley, G. Jims John

    2017-10-01

    The role of control systems is to cope with the process deficiencies and the undesirable effect of the external disturbances. Most of the multivariable processes are highly iterative and complex in nature. Aircraft systems, Modern Power Plants, Refineries, Robotic systems are few such complex systems that involve numerous critical parameters that need to be monitored and controlled. Control of these important parameters is not only tedious and cumbersome but also is crucial from environmental, safety and quality perspective. In this paper, one such multivariable system, namely, a utility boiler has been considered. A modern power plant is a complex arrangement of pipework and machineries with numerous interacting control loops and support systems. In this paper, the calculation of controller parameters based on classical tuning concepts has been presented. The controller parameters thus obtained and employed has controlled the critical parameters of a boiler during fuel switching disturbances. The proposed method can be applied to control the critical parameters like elevator, aileron, rudder, elevator trim rudder and aileron trim, flap control systems of aircraft systems.

  13. Investigation of critical parameters controlling the efficiency of associative ionization

    Science.gov (United States)

    Le Padellec, A.; Launoy, T.; Dochain, A.; Urbain, X.

    2017-05-01

    This paper compiles our merged-beam experimental findings for the associative ionization (AI) process from charged reactants, with the aim of guiding future investigations with e.g. the double electrostatic ion storage ring DESIREE in Stockholm. A reinvestigation of the isotopic effect in H-(D-) + He+ collisions is presented, along with a review of {{{H}}}3+ and NO+ production by AI involving ion pairs or excited neutrals, and put in perspective with the mutual neutralization and radiative association reactions. Critical parameters are identified and evaluated for their systematic role in controlling the magnitude of the cross section: isotopic substitution, exothermicity, electronic state density, and spin statistics.

  14. Invariant-Based Inverse Engineering of Crane Control Parameters

    Science.gov (United States)

    González-Resines, S.; Guéry-Odelin, D.; Tobalina, A.; Lizuain, I.; Torrontegui, E.; Muga, J. G.

    2017-11-01

    By applying invariant-based inverse engineering in the small-oscillation regime, we design the time dependence of the control parameters of an overhead crane (trolley displacement and rope length) to transport a load between two positions at different heights with minimal final-energy excitation for a microcanonical ensemble of initial conditions. The analogy between ion transport in multisegmented traps or neutral-atom transport in moving optical lattices and load manipulation by cranes opens a route for a useful transfer of techniques among very different fields.

  15. Control of force during rapid visuomotor force-matching tasks can be described by discrete time PID control algorithms.

    Science.gov (United States)

    Dideriksen, Jakob Lund; Feeney, Daniel F; Almuklass, Awad M; Enoka, Roger M

    2017-08-01

    Force trajectories during isometric force-matching tasks involving isometric contractions vary substantially across individuals. In this study, we investigated if this variability can be explained by discrete time proportional, integral, derivative (PID) control algorithms with varying model parameters. To this end, we analyzed the pinch force trajectories of 24 subjects performing two rapid force-matching tasks with visual feedback. Both tasks involved isometric contractions to a target force of 10% maximal voluntary contraction. One task involved a single action (pinch) and the other required a double action (concurrent pinch and wrist extension). 50,000 force trajectories were simulated with a computational neuromuscular model whose input was determined by a PID controller with different PID gains and frequencies at which the controller adjusted muscle commands. The goal was to find the best match between each experimental force trajectory and all simulated trajectories. It was possible to identify one realization of the PID controller that matched the experimental force produced during each task for most subjects (average index of similarity: 0.87 ± 0.12; 1 = perfect similarity). The similarities for both tasks were significantly greater than that would be expected by chance (single action: p = 0.01; double action: p = 0.04). Furthermore, the identified control frequencies in the simulated PID controller with the greatest similarities decreased as task difficulty increased (single action: 4.0 ± 1.8 Hz; double action: 3.1 ± 1.3 Hz). Overall, the results indicate that discrete time PID controllers are realistic models for the neural control of force in rapid force-matching tasks involving isometric contractions.

  16. Rapid effects of deep brain stimulation reactivation on symptoms and neuroendocrine parameters in obsessive-compulsive disorder.

    Science.gov (United States)

    de Koning, P P; Figee, M; Endert, E; van den Munckhof, P; Schuurman, P R; Storosum, J G; Denys, D; Fliers, E

    2016-01-26

    Improvement of obsessions and compulsions by deep brain stimulation (DBS) for obsessive-compulsive disorder (OCD) is often preceded by a rapid and transient mood elevation (hypomania). In a previous study we showed that improvement of mood by DBS for OCD is associated with a decreased activity of the hypothalamus-pituitary adrenal axis. The aim of our present study was to evaluate the time course of rapid clinical changes following DBS reactivation in more detail and to assess their association with additional neuroendocrine parameters. We included therapy-refractory OCD patients treated with DBS (>1 year) and performed a baseline assessment of symptoms, as well as plasma concentrations of thyroid-stimulating hormone (TSH), prolactin, growth hormone, copeptin and homovanillic acid. This was repeated after a 1-week DBS OFF condition. Next, we assessed the rapid effects of DBS reactivation by measuring psychiatric symptom changes using visual analog scales as well as repeated neuroendocrine measures after 30 min, 2 h and 6 h. OCD, anxiety and depressive symptoms markedly increased during the 1-week OFF condition and decreased again to a similar extent already 2 h after DBS reactivation. We found lower plasma prolactin (41% decrease, P=0.003) and TSH (39% decrease, P=0.003) levels during DBS OFF, which increased significantly already 30 min after DBS reactivation. The rapid and simultaneous increase in TSH and prolactin is likely to result from stimulation of hypothalamic thyrotropin-releasing hormone (TRH), which may underlie the commonly observed transient mood elevation following DBS.

  17. Application of electrical capacitance tomography and artificial neural networks to rapid estimation of cylindrical shape parameters of industrial flow structure

    Directory of Open Access Journals (Sweden)

    Garbaa Hela

    2016-12-01

    Full Text Available A new approach to solve the inverse problem in electrical capacitance tomography is presented. The proposed method is based on an artificial neural network to estimate three different parameters of a circular object present inside a pipeline, i.e. radius and 2D position coordinates. This information allows the estimation of the distribution of material inside a pipe and determination of the characteristic parameters of a range of flows, which are characterised by a circular objects emerging within a cross section such as funnel flow in a silo gravitational discharging process. The main advantages of the proposed approach are explicitly: the desired characteristic flow parameters are estimated directly from the measured capacitances and rapidity, which in turn is crucial for online flow monitoring. In a classic approach in order to obtain these parameters in the first step the image is reconstructed and then the parameters are estimated with the use of image processing methods. The obtained results showed significant reduction of computations time in comparison to the iterative LBP or Levenberg-Marquard algorithms.

  18. Impacts of Earth rotation parameters on GNSS ultra-rapid orbit prediction: Derivation and real-time correction

    Science.gov (United States)

    Wang, Qianxin; Hu, Chao; Xu, Tianhe; Chang, Guobin; Hernández Moraleda, Alberto

    2017-12-01

    Analysis centers (ACs) for global navigation satellite systems (GNSSs) cannot accurately obtain real-time Earth rotation parameters (ERPs). Thus, the prediction of ultra-rapid orbits in the international terrestrial reference system (ITRS) has to utilize the predicted ERPs issued by the International Earth Rotation and Reference Systems Service (IERS) or the International GNSS Service (IGS). In this study, the accuracy of ERPs predicted by IERS and IGS is analyzed. The error of the ERPs predicted for one day can reach 0.15 mas and 0.053 ms in polar motion and UT1-UTC direction, respectively. Then, the impact of ERP errors on ultra-rapid orbit prediction by GNSS is studied. The methods for orbit integration and frame transformation in orbit prediction with introduced ERP errors dominate the accuracy of the predicted orbit. Experimental results show that the transformation from the geocentric celestial references system (GCRS) to ITRS exerts the strongest effect on the accuracy of the predicted ultra-rapid orbit. To obtain the most accurate predicted ultra-rapid orbit, a corresponding real-time orbit correction method is developed. First, orbits without ERP-related errors are predicted on the basis of ITRS observed part of ultra-rapid orbit for use as reference. Then, the corresponding predicted orbit is transformed from GCRS to ITRS to adjust for the predicted ERPs. Finally, the corrected ERPs with error slopes are re-introduced to correct the predicted orbit in ITRS. To validate the proposed method, three experimental schemes are designed: function extrapolation, simulation experiments, and experiments with predicted ultra-rapid orbits and international GNSS Monitoring and Assessment System (iGMAS) products. Experimental results show that using the proposed correction method with IERS products considerably improved the accuracy of ultra-rapid orbit prediction (except the geosynchronous BeiDou orbits). The accuracy of orbit prediction is enhanced by at least 50

  19. Experimental validation of analytical models for a rapid determination of cycle parameters in thermoplastic injection molding

    Science.gov (United States)

    Pignon, Baptiste; Sobotka, Vincent; Boyard, Nicolas; Delaunay, Didier

    2017-10-01

    Two different analytical models were presented to determine cycle parameters of thermoplastics injection process. The aim of these models was to provide quickly a first set of data for mold temperature and cooling time. The first model is specific to amorphous polymers and the second one is dedicated to semi-crystalline polymers taking the crystallization into account. In both cases, the nature of the contact between the polymer and the mold could be considered as perfect or not (thermal contact resistance was considered). Results from models are compared with experimental data obtained with an instrumented mold for an acrylonitrile butadiene styrene (ABS) and a polypropylene (PP). Good agreements were obtained for mold temperature variation and for heat flux. In the case of the PP, the analytical crystallization times were compared with those given by a coupled model between heat transfer and crystallization kinetics.

  20. Parameter Identification and Control Scheme for Monitoring Automatic Thickness Control System with Measurement Delay

    Directory of Open Access Journals (Sweden)

    Xu Yang

    2017-01-01

    Full Text Available The thickness of the steel strip is an important indicator of the overall strip quality. Deviations in thickness are primarily controlled using the automatic gauge control (AGC system of each rolling stand. At the last stand, the monitoring AGC system is usually used, where the deviations in thickness can be directly measured by the X-ray thickness gauge device and used as the input to the AGC system. However, due to the physical distance between the thickness detection device and the rolling stand, time delay is unavoidably present in the thickness control loop, which can affect control performance and lead to system oscillations. Furthermore, the parameters of the system can change due to perturbations from external disturbances. Therefore, this paper proposes an identification and control scheme for monitoring AGC system that can handle time delay and parameter uncertainty. The cross-correlation function is used to estimate the time delay of the system, while the system parameters are identified using a recursive least squares method. The time delay and parameter estimates are then further refined using the Levenberg-Marquardt algorithm, so as to provide the most accurate parameter estimates for the complete system. Simulation results show that, compared with the standard Proportion Integration Differentiation (PID controller approach, the proposed approach is not affected by changes in the time delay and parameter uncertainties.

  1. Parameter Estimation Analysis for Hybrid Adaptive Fault Tolerant Control

    Science.gov (United States)

    Eshak, Peter B.

    Research efforts have increased in recent years toward the development of intelligent fault tolerant control laws, which are capable of helping the pilot to safely maintain aircraft control at post failure conditions. Researchers at West Virginia University (WVU) have been actively involved in the development of fault tolerant adaptive control laws in all three major categories: direct, indirect, and hybrid. The first implemented design to provide adaptation was a direct adaptive controller, which used artificial neural networks to generate augmentation commands in order to reduce the modeling error. Indirect adaptive laws were implemented in another controller, which utilized online PID to estimate and update the controller parameter. Finally, a new controller design was introduced, which integrated both direct and indirect control laws. This controller is known as hybrid adaptive controller. This last control design outperformed the two earlier designs in terms of less NNs effort and better tracking quality. The performance of online PID has an important role in the quality of the hybrid controller; therefore, the quality of the estimation will be of a great importance. Unfortunately, PID is not perfect and the online estimation process has some inherited issues; the online PID estimates are primarily affected by delays and biases. In order to ensure updating reliable estimates to the controller, the estimator consumes some time to converge. Moreover, the estimator will often converge to a biased value. This thesis conducts a sensitivity analysis for the estimation issues, delay and bias, and their effect on the tracking quality. In addition, the performance of the hybrid controller as compared to direct adaptive controller is explored. In order to serve this purpose, a simulation environment in MATLAB/SIMULINK has been created. The simulation environment is customized to provide the user with the flexibility to add different combinations of biases and delays to

  2. Nutritional screening; control of clinical undernutrition with analytical parameters.

    Science.gov (United States)

    de Ulíbarri Pérez, José Ignacio; Fernández, Guillermo; Rodríguez Salvanés, Francisco; Díaz López, Ana María

    2014-01-13

    To update the system for nutritional screening. The high prevalence of nutritional unstability that causes the Clinical Undernutrition (CU), especially within the hospitals and assisted residencies, makes it necessary to use screening tools for the constant control of undernutrition to combat it during its development. CU is not so much due to a nutritional deficiency but to the illness and its treatments. However, the screening systems currently used are aimed at detecting an already established undernutrition rather than at detecting any nutritional risk that may be present. The metabolic changes of the nutritional status that have a trophopathic effect, can be easily and automatically detected in plasma, which allows to make the necessary changes in treatments that might be too aggressive, as well as to apply nutritional support according to each case. The manual screening systems can detect those somatic changes typical of undernutrition only after many days or weeks, which might be too late. Plasma albumin is a very reliable parameter for nutritional control. A lowered amount of it, due to whatever reason, is a clear sign of a possible deficit as well as of a nutritional risk suffered by the cell way before the somatic signs of undernutrition will become apparent. A fast detection of nutritional risk, anticipating undernutrition, offers prognostic abilities, which makes screening tools based on analytic parameters the most useful, ergonomic, reliable and efficient system for nutritional screening and prognosis in the clinical practice. It is necessary to update some concepts, to leave behind old myths and to choose modern screening systems that have proven to be efficient. This is the only way achieving the dream of controlling CU among ill and vulnerable patients. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

  3. Vibrations control of light rail transportation vehicle via PID type fuzzy controller using parameters adaptive method

    OpenAIRE

    METİN, Muzaffer; GÜÇLÜ, Rahmi

    2014-01-01

    In this study, a conventional PID type fuzzy controller and parameter adaptive fuzzy controller are designed to control vibrations actively of a light rail transport vehicle which modeled as 6 degree-of-freedom system and compared performances of these two controllers. Rail vehicle model consists of a passenger seat and its suspension system, vehicle body, bogie, primary and secondary suspensions and wheels. The similarity between mathematical model and real system is shown by compar...

  4. Reaction parameters for controlled sonosynthesis of gold nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez M, A. L. [Universidad Autonoma del Estado de Mexico, Facultad de Quimica, Paseo Colon esq. Paseo Tollocan s/n, 50120 Toluca, Estado de Mexico (Mexico); Cabrera L, L. I. [UNAM-UAEM, Centro Conjunto de Investigacion en Quimica Sustentable, Km 14.5 Carretera Toluca-Atlacomulco, 50200 San Cayetano-Toluca, Estado de Mexico (Mexico)

    2015-07-01

    The synthesis of gold nanoparticles by sonochemical technique has been previously performed with excellent results. The synthesis has been carried out in the presence of citric acid, a strong reducing agent, which allows the nucleation and growth of gold nanoparticles, at the same time that controls particle size. In this work we report the use of sodium tartrate as a mild reducing agent that allows a better understanding of the effect of the reaction parameters during gold nanoparticle synthesis. A conventional sonication bath (37 k Hz) was used for the sonochemical synthesis. This work focuses on the reaction temperature effect and the effect of sodium tartrate concentration. It was confirmed that particle size, and particle morphology is dependent of these two reaction parameters. Equally, colloidal stabilization was related to reaction temperature and sodium tartrate concentration. It was also determined that Ostwald ripening takes place during sonochemical reaction under our conditions, allowing to understand the mechanism that takes place during synthesis. Gold nanoparticles with main particle size of 17 nm were achieved by this method. Characterization techniques used: Fourier transform infrared spectra (Ftir), X-ray diffraction and Atomic Force Microscope was used in order to determine particle size of the synthetic product of reaction M10c by tapping mode. (Author)

  5. The dynamical control of subduction parameters on surface topography

    Science.gov (United States)

    Crameri, F.; Lithgow-Bertelloni, C. R.; Tackley, P. J.

    2017-04-01

    The long-wavelength surface deflection of Earth's outermost rocky shell is mainly controlled by large-scale dynamic processes like isostasy or mantle flow. The largest topographic amplitudes are therefore observed at plate boundaries due to the presence of large thermal heterogeneities and strong tectonic forces. Distinct vertical surface deflections are particularly apparent at convergent plate boundaries mostly due to the convergence and asymmetric sinking of the plates. Having a mantle convection model with a free surface that is able to reproduce both realistic single-sided subduction and long-wavelength surface topography self-consistently, we are now able to better investigate this interaction. We separate the topographic signal into distinct features and quantify the individual topographic contribution of several controlling subduction parameters. Results are diagnosed by splitting the topographic signal into isostatic and residual components, and by considering various physical aspects like viscous dissipation during plate bending. Performing several systematic suites of experiments, we are then able to quantify the topographic impact of the buoyancy, rheology, and geometry of the subduction-zone system to each and every topographic feature at a subduction zone and to provide corresponding scaling laws. We identify slab dip and, slightly less importantly, slab buoyancy as the major agents controlling surface topography at subduction zones on Earth. Only the island-arc high and the back-arc depression extent are mainly controlled by plate strength. Overall, his modeling study sets the basis to better constrain deep-seated mantle structures and their physical properties via the observed surface topography on present-day Earth and back through time.

  6. Control of the spectral parameters of vanadate lasers

    Energy Technology Data Exchange (ETDEWEB)

    Sirotkin, A A; Vlasov, V I; Zagumennyi, A I; Zavartsev, Yu D; Kutovoi, S A; Shcherbakov, I A [A M Prokhorov General Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation)

    2014-01-31

    It is experimentally established that the luminescence spectra of Nd{sup 3+} ions at the {sup 4}F{sub 3/2} – {sup 4}I{sub 11/2} transition in Nd{sup 3+}:YVO{sub 4}, Nd{sup 3+}:GdVO{sub 4}, Nd{sup 3+}:Gd{sub 1-x}Y{sub x}VO{sub 4}, and Nd{sup 3+}:Sc{sub 1-x}Y{sub x}VO{sub 4} vanadate crystals strongly depend on the recording and polarisation angles with respect to the crystallographic axes. Using these angular dependences of luminescence spectra, it is possible to control the gain coefficient for lasers based on vanadate crystals, create broad gain bands for pico- and femtoseconds lasers, and change radiation wavelengths. Efficient operation of a passively Q-switched laser based on a Nd{sup 3+}:GdVO{sub 4} crystal cut at an angle to the a axis (θ = 25°, ψ = 0) is demonstrated for the first time. (control of laser radiation parameters)

  7. The Controlling Parameters for EMIC Wave Scattering of Relativistic Electrons

    Science.gov (United States)

    Zhang, X.; Li, W.; Ma, Q.; Thorne, R. M.; Angelopoulos, V.; Bortnik, J.

    2016-12-01

    Although there is growing support for relativistic electron losses due to precipitation from electromagnetic ion cyclotron (EMIC) wave scattering, this mechanism is yet to be quantified. Such a quantification has been difficult in the past, because equatorial electron measurements simultaneous with EMIC waves have been limited, due to the highly localized presence of EMIC waves in the magnetosphere. In this study, we examine parameters controlling characteristics of EMIC wave induced relativistic (0.3-6 MeV) electron scattering, directly based on simultaneous wave and particle measurements from Van Allen Probes. We first present a case study when relativistic electrons respond differently during two intervals of intense ( 1 nT) EMIC wave observations: one with no scattering signature and one with efficient electron losses at >1.8 MeV. Based on the observed EMIC wave spectra and background plasma conditions, we calculate the wave diffusion rates and model the evolution of electron pitch angle distributions. By comparing the modeled results with local observations of pitch angle distributions, we demonstrate that fpe/fce is critical in controlling the effectiveness of EMIC waves in scattering multi-MeV electrons. We then expand our analysis to explore the conditions (such as fpe/fce, wave frequency spectra, and ring current ion temperature and anisotropy levels) favorable for EMIC wave scattering multi-MeV electrons through multi-event analyses. Our study is important for accurately modeling relativistic electron loss processes in radiation belt electron forecasts.

  8. Moody Music Generator: Characterising Control Parameters Using Crowdsourcing

    DEFF Research Database (Denmark)

    Scirea, Marco; Togelius, Julian; Nelson, Mark

    2015-01-01

    of generated music over the Internet, and to describe the moods with free-text labels. We find that the arousal parameter does roughly map to perceived arousal, but that the nominal “valence” parameter has strong interaction with the arousal parameter, and produces different effects in different parts...

  9. Controlled nanoporous Pt morphologies by varying deposition parameters

    Energy Technology Data Exchange (ETDEWEB)

    Misra, Amit [Los Alamos National Laboratory; Nastasi, Michael A [Los Alamos National Laboratory; Baldwin, J Kevin [Los Alamos National Laboratory; Goodwin, Peter M [Los Alamos National Laboratory; Bhattacharyya, Dhriti [Los Alamos National Laboratory; Antoniou, Antonia [GEROGIA INSTITUTE OF TECH

    2009-01-01

    Typically, dealloying of an alloy can result in an open cell nanoporous structure of the least electrochemically active element. Here, we show that a wider range of nanoporous structures is possible by controlling the composition and deposition parameters of the as-synthesized alloy as a way to provide sites for preferential etching. We demonstrate this by synthesizing nanoporous platinum (np-Pt) through electrochemical dealloying in aqueous HF from co-sputtered Pt{sub x}Si{sub 1-x} amorphous films. For increased Pt fraction of the amorphous alloy, silicon dissolution is favored along pre-existing features of the amorphous film (e.g. column boundaries or surface asperities). The resulting np-Pt depends on the manner in which silicon is preferentially removed. In addition to the expected isotropic open cell structure, columnar and Voronoi (radial) np-Pt are observed. A processing-structure map is developed to correlate np-Pt morphology to the initial composition and thickness of the amorphous Pt{sub x}Si{sub 1-x} film and the negative substrate bias used in magnetron sputtering.

  10. Simulation and sensitivity analysis of controlling parameters in resistance spot welding

    OpenAIRE

    Kim, Euiwhan; Eagar, Thomas W

    2014-01-01

    This study was performed to investigate the fundamental parameters controlling the nugget growth. The parameters were categorized into four groups, i.e. material parameters, electrical parameters, thermal parameters and geometrical parameters. In order to quantify the sensitivity of nugget growth to changes in these parameters, a numerical model which incorporates the electrical, mechanical and thermal contact was developed. As a result, a sensitivity index table was constructed and analyzed ...

  11. Normal Morning Melanin-Concentrating Hormone Levels and No Association with Rapid Eye Movement or Non-Rapid Eye Movement Sleep Parameters in Narcolepsy Type 1 and Type 2.

    Science.gov (United States)

    Schrölkamp, Maren; Jennum, Poul J; Gammeltoft, Steen; Holm, Anja; Kornum, Birgitte R; Knudsen, Stine

    2017-02-15

    Other than hypocretin-1 (HCRT-1) deficiency in narcolepsy type 1 (NT1), the neurochemical imbalance of NT1 and narcolepsy type 2 (NT2) with normal HCRT-1 levels is largely unknown. The neuropeptide melanin-concentrating hormone (MCH) is mainly secreted during sleep and is involved in rapid eye movement (REM) and non-rapid eye movement (NREM) sleep regulation. Hypocretin neurons reciprocally interact with MCH neurons. We hypothesized that altered MCH secretion contributes to the symptoms and sleep abnormalities of narcolepsy and that this is reflected in morning cerebrospinal fluid (CSF) MCH levels, in contrast to previously reported normal evening/afternoon levels. Lumbar CSF and plasma were collected from 07:00 to 10:00 from 57 patients with narcolepsy (subtypes: 47 NT1; 10 NT2) diagnosed according to International Classification of Sleep Disorders, Third Edition (ICSD-3) and 20 healthy controls. HCRT-1 and MCH levels were quantified by radioimmunoassay and correlated with clinical symptoms, polysomnography (PSG), and Multiple Sleep Latency Test (MSLT) parameters. CSF and plasma MCH levels were not significantly different between narcolepsy patients regardless of ICSD-3 subtype, HCRT-1 levels, or compared to controls. CSF MCH and HCRT-1 levels were not significantly correlated. Multivariate regression models of CSF MCH levels, age, sex, and body mass index predicting clinical, PSG, and MSLT parameters did not reveal any significant associations to CSF MCH levels. Our study shows that MCH levels in CSF collected in the morning are normal in narcolepsy and not associated with the clinical symptoms, REM sleep abnormalities, nor number of muscle movements during REM or NREM sleep of the patients. We conclude that morning lumbar CSF MCH measurement is not an informative diagnostic marker for narcolepsy.

  12. Rapid calibaration of the control rod of miniature neutron source ...

    African Journals Online (AJOL)

    An innovative method of combining the well-known computer codes WIMS and CITATION in an interactive Windows environment to calculate the control rod worth and generate the calibration data/curve of single-contr-ol rod miniature source reactor (MNSR) types has been developed and tested. In the scheme, once ...

  13. Prognostic Value of Controlled Attenuation Parameter by Transient Elastography.

    Science.gov (United States)

    Liu, Ken; Wong, Vincent Wai-Sun; Lau, Keith; Liu, Sienna Du; Tse, Yee-Kit; Yip, Terry Cheuk-Fung; Kwok, Raymond; Chan, Alex Yiu-Wa; Chan, Henry Lik-Yuen; Wong, Grace Lai-Hung

    2017-10-31

    Liver stiffness measurement (LSM) by transient elastography (TE) has been shown to predict outcomes in patients with liver disease. While controlled attenuation parameter (CAP) measurement can accurately quantify hepatic steatosis, its prognostic value is unknown. We aim to determine if CAP is predictive for liver-related events (LRE), non-hepatocellular carcinoma (HCC) cancers, and cardiovascular events (CVE). Consecutive patients with both a reliable LSM and ≥10 successful CAP measurements by TE from August 2012 to March 2016 were included in the analysis. LRE were defined as HCC or hepatic decompensation. CVE were defined as acute coronary syndrome (ACS), cerebrovascular accident (CVA), or coronary intervention (stenting or bypass). Of the 5,848 patients that were examined, 4,282 (56.7% male, median age 57 years) had adequate follow-up, reliable LSM (median 6.1 kPa), and ≥10 CAP measurements (median 250 dB/m). Indications for TE were: suspected non-alcoholic fatty liver disease (NAFLD) (40.7%), hepatitis B (HBV) (37.0%), hepatitis C (2.9%), and others (19.4%). During 8,540 patient-years of follow-up, there were 45 patients with LRE (34 HCC, 33 decompensations), 73 with newly diagnosed non-HCC cancers, and 65 with CVE (27 ACS, 25 CVA, and 35 coronary interventions). CAP did not predict LRE, non-HCC cancer, or CVE on univariate analysis. On multivariate analysis, LSM, male sex, platelet count, serum albumin, and HBV etiology independently predicted LRE; age was the only independent predictor of non-HCC cancer; while age, fasting blood glucose, total cholesterol, and creatinine predicted for CVE. Subgroup analyses of viral hepatitis and NAFLD patients revealed similar results. Neither the presence nor the severity of hepatic steatosis as measured by CAP predict LRE, cancer, or CVE in the short term.Am J Gastroenterol advance online publication, 31 October 2017; doi:10.1038/ajg.2017.389.

  14. Optimal supplementary frequency controller design using the wind farm frequency model and controller parameters stability region.

    Science.gov (United States)

    Toulabi, Mohammadreza; Bahrami, Shahab; Ranjbar, Ali Mohammad

    2018-02-03

    In most of the existing studies, the frequency response in the variable speed wind turbines (VSWTs) is simply realized by changing the torque set-point via appropriate inputs such as frequency deviations signal. However, effective dynamics and systematic process design have not been comprehensively discussed yet. Accordingly, this paper proposes a proportional-derivative frequency controller and investigates its performance in a wind farm consisting of several VSWTs. A band-pass filter is deployed before the proposed controller to avoid responding to either steady state frequency deviations or high rate of change of frequency. To design the controller, the frequency model of the wind farm is first characterized. The proposed controller is then designed based on the obtained open loop system. The stability region associated with the controller parameters is analytically determined by decomposing the closed-loop system's characteristic polynomial into the odd and even parts. The performance of the proposed controller is evaluated through extensive simulations in MATLAB/Simulink environment in a power system comprising a high penetration of VSWTs equipped with the proposed controller. Finally, based on the obtained feasible area and appropriate objective function, the optimal values associated with the controller parameters are determined using the genetic algorithm (GA). Copyright © 2018 ISA. Published by Elsevier Ltd. All rights reserved.

  15. Characterization and optimized control by means of multi-parameter controllers

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, Carsten; Hoeg, S.; Thoegersen, A. (Dan-Ejendomme, Hellerup (Denmark)) (and others)

    2009-07-01

    Poorly functioning HVAC systems (Heating, Ventilation and Air Conditioning), but also separate heating, ventilation and air conditioning systems are costing the Danish society billions of kroner every year: partly because of increased energy consumption and high operational and maintenance costs, but mainly due to reduced productivity and absence due to illness because of a poor indoor climate. Typically, the operation of buildings and installations takes place today with traditional build-ing automation, which is characterised by 1) being based on static considerations 2) the individual sensor being coupled with one actuator/valve, i.e. the sensor's signal is only used in one place in the system 3) subsystems often being controlled independently of each other 4) the dynamics in building constructions and systems which is very important to the system and comfort regulation is not being considered. This, coupled with the widespread tendency to use large glass areas in the facades without sufficient sun shading, means that it is difficult to optimise comfort and energy consumption. Therefore, the last 10-20 years have seen a steady increase in the complaints of the indoor climate in Danish buildings and, at the same time, new buildings often turn out to be considerably higher energy consuming than expected. The purpose of the present project is to investigate the type of multi parameter sensors which may be generated for buildings and further to carry out a preliminary evaluation on how such multi parameter controllers may be utilized for optimal control of buildings. The aim of the project isn't to develop multi parameter controllers - this requires much more effort than possible in the present project. The aim is to show the potential of using multi parameter sensors when controlling buildings. For this purpose a larger office building has been chosen - an office building with at high energy demand and complaints regarding the indoor climate. In order to

  16. Parameter space of experimental chaotic circuits with high-precision control parameters

    Energy Technology Data Exchange (ETDEWEB)

    Sousa, Francisco F. G. de; Rubinger, Rero M. [Instituto de Física e Química, Universidade Federal de Itajubá, Itajubá, MG (Brazil); Sartorelli, José C., E-mail: sartorelli@if.usp.br [Universidade de São Paulo, São Paulo, SP (Brazil); Albuquerque, Holokx A. [Departamento de Física, Universidade do Estado de Santa Catarina, Joinville, SC (Brazil); Baptista, Murilo S. [Institute of Complex Systems and Mathematical Biology, SUPA, University of Aberdeen, Aberdeen (United Kingdom)

    2016-08-15

    We report high-resolution measurements that experimentally confirm a spiral cascade structure and a scaling relationship of shrimps in the Chua's circuit. Circuits constructed using this component allow for a comprehensive characterization of the circuit behaviors through high resolution parameter spaces. To illustrate the power of our technological development for the creation and the study of chaotic circuits, we constructed a Chua circuit and study its high resolution parameter space. The reliability and stability of the designed component allowed us to obtain data for long periods of time (∼21 weeks), a data set from which an accurate estimation of Lyapunov exponents for the circuit characterization was possible. Moreover, this data, rigorously characterized by the Lyapunov exponents, allows us to reassure experimentally that the shrimps, stable islands embedded in a domain of chaos in the parameter spaces, can be observed in the laboratory. Finally, we confirm that their sizes decay exponentially with the period of the attractor, a result expected to be found in maps of the quadratic family.

  17. Rapid Prototyping of Polymeric Nanopillars by 3D Direct Laser Writing for Controlling Cell Behavior.

    Science.gov (United States)

    Buch-Månson, Nina; Spangenberg, Arnaud; Gomez, Laura Piedad Chia; Malval, Jean-Pierre; Soppera, Olivier; Martinez, Karen L

    2017-08-23

    Mammalian cells have been widely shown to respond to nano- and microtopography that mimics the extracellular matrix. Synthetic nano- and micron-sized structures are therefore of great interest in the field of tissue engineering, where polymers are particularly attractive due to excellent biocompatibility and versatile fabrication methods. Ordered arrays of polymeric pillars provide a controlled topographical environment to study and manipulate cells, but processing methods are typically either optimized for the nano- or microscale. Here, we demonstrate polymeric nanopillar (NP) fabrication using 3D direct laser writing (3D DLW), which offers a rapid prototyping across both size regimes. The NPs are interfaced with NIH3T3 cells and the effect of tuning geometrical parameters of the NP array is investigated. Cells are found to adhere on a wide range of geometries, but the interface depends on NP density and length. The Cell Interface with Nanostructure Arrays (CINA) model is successfully extended to predict the type of interface formed on different NP geometries, which is found to correlate with the efficiency of cell alignment along the NPs. The combination of the CINA model with the highly versatile 3D DLW fabrication thus holds the promise of improved design of polymeric NP arrays for controlling cell growth.

  18. Evolutionary Tuning Method for PID Controller Parameters of a Cruise Control System Using Metamodeling

    Directory of Open Access Journals (Sweden)

    M. N. Ab Malek

    2009-01-01

    Full Text Available For long time the optimization of controller parameters uses the well-known classical method such as the Ziegler-Nichols and the Cohen-Coon tuning techniques. Despite its effectiveness, these off-line tuning techniques can be time consuming especially for a case of complex nonlinear system. This paper attempts to show a great deal on how Metamodeling techniques can be utilized to tune the PID controller parameters quickly. Note that the plant use in this study is the cruise control system with 2 different models, which are the linear model and the nonlinear model. The difference between both models is that the disturbances were taken into consideration for the nonlinear model, but in the linear model the disturbances were assumed as zero. The Radial Basis Function Neural Network Metamodel is able to prove that it can minimize the time in tuning process as it is able to give a good approximation to the optimum controller parameters in both models of this system.

  19. Coordinated Control of Multi-Agent Systems in Rapidly Varying Environments Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The main objective of this Phase II STTR project is to develop advanced control algorithms that enable multiple autonomous agents to perform complex tasks in rapidly...

  20. The Application of Parameter Space Design Method for Generator Excitation Control

    Science.gov (United States)

    Iki, Hiroyuki; Yoshimura, Shyuta; Uriu, Yosihisa

    Recently, control engineering changes from classical control theory to modern control theory, and analogue to digital. However, as a matter of fact, the sensitivity adjustment of the parameters using Bode diagram require many time and works. In this paper, the tool of Matlab/Simulink that adjusted the AVR control parameter of the PI control type brushless and Thyristor excitation method by using the technique for based on the parameter space planning method by QE was made. Moreover, the adjustment of the sensitivity parameter of the excitation control method intended for the dynamic stability level area in Single Machine Infinite Bus is examined with the tool.

  1. Rapid mapping of compound eye visual sampling parameters with FACETS, a highly automated wide-field goniometer.

    Science.gov (United States)

    Douglass, John K; Wehling, Martin F

    2016-12-01

    A highly automated goniometer instrument (called FACETS) has been developed to facilitate rapid mapping of compound eye parameters for investigating regional visual field specializations. The instrument demonstrates the feasibility of analyzing the complete field of view of an insect eye in a fraction of the time required if using non-motorized, non-computerized methods. Faster eye mapping makes it practical for the first time to employ sample sizes appropriate for testing hypotheses about the visual significance of interspecific differences in regional specializations. Example maps of facet sizes are presented from four dipteran insects representing the Asilidae, Calliphoridae, and Stratiomyidae. These maps provide the first quantitative documentation of the frontal enlarged-facet zones (EFZs) that typify asilid eyes, which, together with the EFZs in male Calliphoridae, are likely to be correlated with high-spatial-resolution acute zones. The presence of EFZs contrasts sharply with the almost homogeneous distribution of facet sizes in the stratiomyid. Moreover, the shapes of EFZs differ among species, suggesting functional specializations that may reflect differences in visual ecology. Surveys of this nature can help identify species that should be targeted for additional studies, which will elucidate fundamental principles and constraints that govern visual field specializations and their evolution.

  2. Dynamic Characteristics of Communication Lines with Distributed Parameters to Control the Throttle-controlled Hydraulic Actuators

    Directory of Open Access Journals (Sweden)

    D. N. Popov

    2015-01-01

    Full Text Available The article considers a mathematical model of the hydraulic line for remote control of electro-hydraulic servo drive (EHSD with throttle control. This type of hydraulic lines is designed as a backup to replace the electrical connections, which are used to control EHSD being remote from the site with devices located to form the control signals of any object. A disadvantage of electric connections is that they are sensitive to magnetic fields and thereby do not provide the required reliability of the remote control. Hydraulic lines have no this disadvantage and therefore are used in aircraft and other industrial systems. However, dynamic characteristics of hydraulic systems still have been investigated insufficiently in the case of transmitting control signals at a distance at which the signal may be distorted when emerging the wave processes.The article results of mathematical simulation, which are verified through physical experimentation, largely eliminate the shortcomings of said information.The mathematical model described in the paper is based on the theory of unsteady pressure compressible fluids. In the model there are formulas that provide calculation of frequency characteristics of the hydraulic lines under hydraulic oscillations of the laminar flow parameters of viscous fluid.A real mock-up of the system under consideration and an experimental ad hoc unit are used to verify the results of mathematically simulated hydraulic systems.Calculated logarithmic amplitude and phase frequency characteristics compared with those obtained experimentally prove, under certain conditions, the proposed theoretical method of calculation. These conditions have to ensure compliance with initial parameters of fluid defined under stationary conditions. The applied theory takes into consideration a non-stationary hydraulic resistance of the line when calculating frequency characteristics.The scientific novelty in the article material is presented in

  3. Use of polydispersity index as control parameter to study melting ...

    Indian Academy of Sciences (India)

    Using polydispersity index as an additional order parameter we investigate freezing/melting transition of Lennard-Jones polydisperse systems (with Gaussian polydispersity in size), especially to gain insight into the origin of the terminal polydispersity. The average inherent structure (IS) energy and root mean square ...

  4. In Vitro Assessment of Quality Control Parameters of Some ...

    African Journals Online (AJOL)

    Purpose: To use specific parameters to evaluate the in vitro quality assurance of ten generics of amlodipine besylate (10mg) tablets commonly sold in the Nigerian drug market. Methods: Organoleptic and physicochemical properties of 10 brands of the amlodipine besylate tablets were assessed according to official and ...

  5. Demographic parameters of individual E.coli within and among controlled environment

    DEFF Research Database (Denmark)

    Jouvet, Lionel; Steiner, Ulrich

    2014-01-01

    In most biodemographic studies, demographic parameters, such as lifespan and reproduction, are quantified from populations without controlling environmental or genetic influences. To accurately quantify the demographic parameters, we need to isolate the system from stochastic extrinsic factors. T...

  6. Structured Control of Affine Linear Parameter Varying Systems

    DEFF Research Database (Denmark)

    Adegas, Fabiano Daher; Stoustrup, Jakob

    2011-01-01

    This paper presents a new procedure to design structured controllers for discrete-time affine linear parametervarying systems (A LPV). The class of control structures includes decentralized of any order, fixed order output feedback, simultaneous plant-control design, among others. A parametervaryin...... non-convex condition for an upper bound on the induced L2-norm performance is solved by an iterative linear matrix inequalities (LMI) optimization algorithm. Numerical examples demostrate the effectiveness of the proposed approach....

  7. Adaptive Linear Parameter Varying Control for Aeroservoelastic Suppression Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Adaptive control offers an opportunity to fulfill aircraft safety objectives though automated vehicle recovery while maintaining performance and stability...

  8. Adaptive Linear Parameter Varying Control for Aeroservoelastic Suppression Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Adaptive control offers an opportunity to fulfill present and future aircraft safety objectives though automated vehicle recovery while maintaining performance and...

  9. Inductively coupled plasma-atomic emission spectroscopy: a computer controlled, scanning monochromator system for the rapid determination of the elements

    Energy Technology Data Exchange (ETDEWEB)

    Floyd, M.A.

    1980-03-01

    A computer controlled, scanning monochromator system specifically designed for the rapid, sequential determination of the elements is described. The monochromator is combined with an inductively coupled plasma excitation source so that elements at major, minor, trace, and ultratrace levels may be determined, in sequence, without changing experimental parameters other than the spectral line observed. A number of distinctive features not found in previously described versions are incorporated into the system here described. Performance characteristics of the entire system and several analytical applications are discussed.

  10. Psychomotor control in a virtual laparoscopic surgery training environment: gaze control parameters differentiate novices from experts.

    Science.gov (United States)

    Wilson, Mark; McGrath, John; Vine, Samuel; Brewer, James; Defriend, David; Masters, Richard

    2010-10-01

    Surgical simulation is increasingly used to facilitate the adoption of technical skills during surgical training. This study sought to determine if gaze control parameters could differentiate between the visual control of experienced and novice operators performing an eye-hand coordination task on a virtual reality laparoscopic surgical simulator (LAP Mentor™). Typically adopted hand movement metrics reflect only one half of the eye-hand coordination relationship; therefore, little is known about how hand movements are guided and controlled by vision. A total of 14 right-handed surgeons were categorised as being either experienced (having led more than 70 laparoscopic procedures) or novice (having performed fewer than 10 procedures) operators. The eight experienced and six novice surgeons completed the eye-hand coordination task from the LAP Mentor basic skills package while wearing a gaze registration system. A variety of performance, movement, and gaze parameters were recorded and compared between groups. The experienced surgeons completed the task significantly more quickly than the novices, but only the economy of movement of the left tool differentiated skill level from the LAP Mentor parameters. Gaze analyses revealed that experienced surgeons spent significantly more time fixating the target locations than novices, who split their time between focusing on the targets and tracking the tools. The findings of the study provide support for the utility of assessing strategic gaze behaviour to better understand the way in which surgeons utilise visual information to plan and control tool movements in a virtual reality laparoscopic environment. It is hoped that by better understanding the limitations of the psychomotor system, effective gaze training programs may be developed.

  11. Controllable pulse parameter transcranial magnetic stimulator with enhanced circuit topology and pulse shaping

    Science.gov (United States)

    Peterchev, Angel V.; DʼOstilio, Kevin; Rothwell, John C.; Murphy, David L.

    2014-10-01

    Objective. This work aims at flexible and practical pulse parameter control in transcranial magnetic stimulation (TMS), which is currently very limited in commercial devices. Approach. We present a third generation controllable pulse parameter device (cTMS3) that uses a novel circuit topology with two energy-storage capacitors. It incorporates several implementation and functionality advantages over conventional TMS devices and other devices with advanced pulse shape control. cTMS3 generates lower internal voltage differences and is implemented with transistors with a lower voltage rating than prior cTMS devices. Main results. cTMS3 provides more flexible pulse shaping since the circuit topology allows four coil-voltage levels during a pulse, including approximately zero voltage. The near-zero coil voltage enables snubbing of the ringing at the end of the pulse without the need for a separate active snubber circuit. cTMS3 can generate powerful rapid pulse sequences (\\lt 10 ms inter pulse interval) by increasing the width of each subsequent pulse and utilizing the large capacitor energy storage, allowing the implementation of paradigms such as paired-pulse and quadripulse TMS with a single pulse generation circuit. cTMS3 can also generate theta (50 Hz) burst stimulation with predominantly unidirectional electric field pulses. The cTMS3 device functionality and output strength are illustrated with electrical output measurements as well as a study of the effect of pulse width and polarity on the active motor threshold in ten healthy volunteers. Significance. The cTMS3 features could extend the utility of TMS as a research, diagnostic, and therapeutic tool.

  12. Modification of piezoelectric vibratory gyroscope resonator parameters by feedback control

    CSIR Research Space (South Africa)

    Loveday, PW

    1998-09-01

    Full Text Available A method for analyzing the effect of feedback control on the dynamics of piezoelectric resonators used in vibratory gyroscopes has been developed. This method can be used to determine the feasibility of replacing the traditional mechanical balancing...

  13. A distributed parameter systems view of control problems in drilling

    OpenAIRE

    Di Meglio, Florent; Aarsnes, Ulf Jakob Flø

    2015-01-01

    We give a detailed view of estimation and control problems raised by the drilling process where the distributed nature of the system cannot be ignored. In particular, we focus on the transport phenomena in Managed Pressure Drilling (MPD) and UnderBalanced Operations (UBO), as well as the time-delay mechanisms of the mechanical stick-slip vibrations. These industrial challenges raise increasingly difficult control questions for hyperbolic systems.

  14. A distributed parameter systems view of control problems in drilling

    OpenAIRE

    Di Meglio, Florent; Aarsnes, Ulf Jakob Flø

    2015-01-01

    We give a detailed view of estimation and control problems raised by the drilling process where the distributed nature of the system cannot be ignored. In particular, we focus on the transport phenomena in Managed Pressure Drilling (MPD) and UnderBalanced Operations (UBO), as well as the time-delay mechanisms of the mechanical stick-slip vibrations. These industrial challenges raise increasingly difficult control questions for hyperbolic systems. This is the authors' accepted and refereed ...

  15. Controlled cooling versus rapid freezing of teratozoospermic semen samples: Impact on sperm chromatin integrity

    Directory of Open Access Journals (Sweden)

    Shivananda N Kalludi

    2011-01-01

    Full Text Available Aim: The present study evaluates the impact of controlled slow cooling and rapid freezing techniques on the sperm chromatin integrity in teratozoospermic and normozoospermic samples. Setting: The study was done in a university infertility clinic, which is a tertiary healthcare center serving the general population. Design: It was a prospective study designed in vitro. Materials and Methods: Semen samples from normozoospermic (N=16 and teratozoospermic (N=13 infertile men were cryopreserved using controlled cooling and rapid freezing techniques. The sperm chromatin integrity was analyzed in fresh and frozen-thawed samples. Statistical Analysis Used: Data were reported as mean and standard error (mean ± SEM of mean. The difference between two techniques was determined by a paired t-test. Results: The freeze-thaw induced chromatin denaturation was significantly (P<0.01 elevated in the post-thaw samples of normozoospermic and teratozoospermic groups. Compared to rapid freezing, there was no difference in the number of red sperms (with DNA damage by the controlled slow cooling method in both normozoospermic and teratozoospermic groups. Freeze-thaw induced sperm chromatin denaturation in teratozoospermic samples did not vary between controlled slow cooling and rapid freezing techniques. Conclusions: Since the controlled slow cooling technique involves the use of expensive instrument and is a time consuming protocol, rapid freezing can be a good alternative technique for teratozoospermic and normozoospermic samples when sperm DNA damage is a concern.

  16. Design parameters to control synthetic gene expression in Escherichia coli.

    Directory of Open Access Journals (Sweden)

    Mark Welch

    Full Text Available BACKGROUND: Production of proteins as therapeutic agents, research reagents and molecular tools frequently depends on expression in heterologous hosts. Synthetic genes are increasingly used for protein production because sequence information is easier to obtain than the corresponding physical DNA. Protein-coding sequences are commonly re-designed to enhance expression, but there are no experimentally supported design principles. PRINCIPAL FINDINGS: To identify sequence features that affect protein expression we synthesized and expressed in E. coli two sets of 40 genes encoding two commercially valuable proteins, a DNA polymerase and a single chain antibody. Genes differing only in synonymous codon usage expressed protein at levels ranging from undetectable to 30% of cellular protein. Using partial least squares regression we tested the correlation of protein production levels with parameters that have been reported to affect expression. We found that the amount of protein produced in E. coli was strongly dependent on the codons used to encode a subset of amino acids. Favorable codons were predominantly those read by tRNAs that are most highly charged during amino acid starvation, not codons that are most abundant in highly expressed E. coli proteins. Finally we confirmed the validity of our models by designing, synthesizing and testing new genes using codon biases predicted to perform well. CONCLUSION: The systematic analysis of gene design parameters shown in this study has allowed us to identify codon usage within a gene as a critical determinant of achievable protein expression levels in E. coli. We propose a biochemical basis for this, as well as design algorithms to ensure high protein production from synthetic genes. Replication of this methodology should allow similar design algorithms to be empirically derived for any expression system.

  17. Three-parameter feedback control of amorphous ribbon magnetization

    Czech Academy of Sciences Publication Activity Database

    Stupakov, Oleksandr; Švec, P.

    2013-01-01

    Roč. 64, č. 3 (2013), s. 166-172 ISSN 0013-578X R&D Projects: GA ČR GP102/09/P108 Institutional support: RVO:68378271 Keywords : magnetic variables measurement * magnetic hysteresis * digital feedback control * amorphous magnetic materials Subject RIV: JB - Sensors, Measurment, Regulation

  18. Social security, self-control problems and unknown preference parameters

    NARCIS (Netherlands)

    Bucciol, A.

    2009-01-01

    We develop a general equilibrium model with overlapping generations to show that Social Security may increase welfare in dynamically efficient economies where agents are affected by self-control problems à la Gul and Pesendorfer (2001, Econometrica 69, 1403). In calibrating the model to the US

  19. A new tool for rapid and automatic estimation of earthquake source parameters and generation of seismic bulletins

    Science.gov (United States)

    Zollo, Aldo

    2016-04-01

    RISS S.r.l. is a Spin-off company recently born from the initiative of the research group constituting the Seismology Laboratory of the Department of Physics of the University of Naples Federico II. RISS is an innovative start-up, based on the decade-long experience in earthquake monitoring systems and seismic data analysis of its members and has the major goal to transform the most recent innovations of the scientific research into technological products and prototypes. With this aim, RISS has recently started the development of a new software, which is an elegant solution to manage and analyse seismic data and to create automatic earthquake bulletins. The software has been initially developed to manage data recorded at the ISNet network (Irpinia Seismic Network), which is a network of seismic stations deployed in Southern Apennines along the active fault system responsible for the 1980, November 23, MS 6.9 Irpinia earthquake. The software, however, is fully exportable and can be used to manage data from different networks, with any kind of station geometry or network configuration and is able to provide reliable estimates of earthquake source parameters, whichever is the background seismicity level of the area of interest. Here we present the real-time automated procedures and the analyses performed by the software package, which is essentially a chain of different modules, each of them aimed at the automatic computation of a specific source parameter. The P-wave arrival times are first detected on the real-time streaming of data and then the software performs the phase association and earthquake binding. As soon as an event is automatically detected by the binder, the earthquake location coordinates and the origin time are rapidly estimated, using a probabilistic, non-linear, exploration algorithm. Then, the software is able to automatically provide three different magnitude estimates. First, the local magnitude (Ml) is computed, using the peak-to-peak amplitude

  20. Control of postharvest pear diseases using Rhodotorula glutinis and its effects on postharvest quality parameters.

    Science.gov (United States)

    Zhang, Hongyin; Wang, Lei; Dong, Ying; Jiang, Song; Zhang, Haihui; Zheng, Xiaodong

    2008-08-15

    Rhodotorula glutinis was evaluated for its activity in reducing postharvest gray mold decay and blue mold decay of pear caused by Botrytis cinerea and Penicillium expansum respectively, and in reducing natural decay development of pear fruits, as well as its effects on postharvest quality of fruits. There was a significant negative correlation between concentrations of the yeast cells and infectivity of the pathogens. At concentrations of R. glutinis at 5x108 CFU/ml, the gray mold decay was completely inhibited after 7 days incubation at 20 degrees C, while the control fruit had 100% disease incidence and 2.15 cm lesion diameter respectively, at challenged with B. cinerea spores suspension of 1x105 spores/ml; No completely control was got to blue mold, when pear fruits stored at 20 degrees C for 7 d (challenged with P. expansum spores suspension of 5x104 spores/ml), but the decay was distinctly prevented with 20% and 0.60 cm of disease incidence and lesion diameter respectively, while the control fruits were 100% and 2.74 cm, respectively. Rapid colonization of the yeast in wounds was observed during the first 1 d at 20 degrees C, and then the populations stabilized for the remaining storage period. On pear wounds kept at 4 degrees C, rapid colonization of the yeast in wounds was observed during the first 3 d, and then the increase in population density of R. glutinis turned slow, which continued over 6 d after application of the antagonist until it reached a high level. Then, the populations stabilized for the remaining storage period. In the test on PDA plates, R. glutinis significantly inhibit the growth of B. cinerea and P. expansum. Spore germination of pathogens in PDB was greatly controlled in the present of living yeast cell suspensions. R. glutinis significantly reduced the natural development of decay of pear following storage at 20 degrees C for 7 days or at 4 degrees C for 30 days followed by 20 degrees C for 5 days, and did not impair quality

  1. 3,5-Diiodo-L-thyronine administration to hypothyroid rats rapidly enhances fatty acid oxidation rate and bioenergetic parameters in liver cells.

    Directory of Open Access Journals (Sweden)

    Alessandro Cavallo

    Full Text Available Growing evidence shows that, among triiodothyronine derivatives, 3,5 diiodo-L-thyronine (T(2 plays an important role in energy metabolism and fat storage. In the present study, short-term effects of T(2 administration to hypothyroid rats on fatty acid oxidation rate and bioenergetic parameters were investigated. Within 1 h following T(2 injection, state 3 and state 4 respiration rates, which were reduced in hypothyroid mitochondria, were noticeably increased particularly in succinate- with respect to glutamate/malate-energized mitochondria. Maximal respiratory activity, observed when glutamate/malate/succinate were simultaneously present in the respiratory medium, was significantly stimulated by T(2 treatment. A T(2-induced increase in respiratory rates was also observed when palmitoyl-CoA or L-palmitoylcarnitine were used as substrates. No significant change in respiratory control index and ADP/O ratio was observed. The activities of the mitochondrial respiratory chain complexes, especially Complex II, were increased in T(2-treated rats. In the latter, Complex V activities, assayed in both ATP synthesis and hydrolysis direction, were enhanced. The rate of fatty acid oxidation, followed by conversion of [(14C]palmitate to CO(2 and ketone bodies, was higher in hepatocytes isolated from T(2-treated rats. This increase occurs in parallel with the raise in the activity of carnitine palmitoyltransferase-I, the rate limiting enzyme of fatty acid β-oxidation, assayed in situ in digitonin-permeabilized hepatocytes. Overall, these results indicate that T(2 rapidly increases the ability of mitochondria to import and oxidize fatty acids. An emerging idea in the literature is the ability of T(2 to reduce adiposity and dyslipidemia and to prevent the development in liver steatosis. The results of the present study, showing a rapid T(2-induced increase in the ability of mitochondria to import and oxidize fatty acids, may contribute to understand the

  2. Parameter Space Techniques for Robust Control System Design.

    Science.gov (United States)

    1980-07-01

    JSEP-NO0014- 79-C-0424 Juergen Ackermann, S. Norman Franklin, Christine FS-78-3633 AFOSR-78-3633 B. Chato, and Douglas P. Looze 9. PERFORMING...Ackermann, S. Norman Franklin, Christine B. Chato, and Douglas P. Looze P DThis work was supported in part by the Joint Services Electronics Program (U.S...example of a crane. In Chapter 5, it will be used to design a dynamic controller for the short period longitudinal mode of an F4-E aircraft with canards

  3. Oxygen diffusion: an enzyme-controlled variable parameter.

    Science.gov (United States)

    Erdmann, Wilhelm; Kunke, Stefan

    2014-01-01

    Previous oxygen microelectrode studies have shown that the oxygen diffusion coefficient (DO₂) increases during extracellular PO₂ decreases, while intracellular PO₂ remained unchanged and thus cell function (spike activity of neurons). Oxygen dependency of complex multicellular organisms requires a stable and adequate oxygen supply to the cells, while toxic concentrations have to be avoided. Oxygen brought to the tissue by convection diffuses through the intercellular and cell membranes, which are potential barriers to diffusion. In gerbil brain cortex, PO₂ and DO₂ were measured by membrane-covered and by bare gold microelectrodes, as were also spike potentials. Moderate respiratory hypoxia was followed by a primary sharp drop of tissue PO₂ that recovered to higher values concomitant with an increase of DO₂. A drop in intracellular PO₂ recovered immediately. Studies on the abdominal ganglion of aplysia californica showed similar results.Heterogeneity is a feature of both normal oxygen supply to tissue and supply due to a wide range of disturbances in oxygen supply. Oxygen diffusion through membranes is variable thereby ensuring adequate intracellular PO₂. Cell-derived glucosamine oxidase seems to regulate the polymerization/depolymerisation ratio of membrane mucopolysaccharides and thus oxygen diffusion.Variability of oxygen diffusion is a decisive parameter for regulating the supply/demand ratio of oxygen supply to the cell; this occurs in highly developed animals as well as in species of a less sophisticated nature. Autoregulation of oxygen diffusion is as important as the distribution/perfusion ratio of the capillary meshwork and as the oxygen extraction ratio in relation to oxygen consumption of the cell. Oxygen diffusion resistance is the cellular protection against luxury oxygen supply (which can result in toxic oxidative species leading to mutagenesis).

  4. Observer-based linear parameter varying H∞ tracking control for hypersonic vehicles

    Directory of Open Access Journals (Sweden)

    Yiqing Huang

    2016-11-01

    Full Text Available This article aims to develop observer-based linear parameter varying output feedback H∞ tracking controller for hypersonic vehicles. Due to the complexity of an original nonlinear model of the hypersonic vehicle dynamics, a slow–fast loop linear parameter varying polytopic model is introduced for system stability analysis and controller design. Then, a state observer is developed by linear parameter varying technique in order to estimate the unmeasured attitude angular for slow loop system. Also, based on the designed linear parameter varying state observer, a kind of attitude tracking controller is presented to reduce tracking errors for all bounded reference attitude angular inputs. The closed-loop linear parameter varying system is proved to be quadratically stable by Lypapunov function technique. Finally, simulation results show that the developed linear parameter varying H∞ controller has good tracking capability for reference commands.

  5. Tuning of the PI Controller Parameters of a PMSG Wind Turbine to Improve Control Performance under Various Wind Speeds

    Directory of Open Access Journals (Sweden)

    Yun-Su Kim

    2015-02-01

    Full Text Available This paper presents a method to seek the PI controller parameters of a PMSG wind turbine to improve control performance. Since operating conditions vary with the wind speed, therefore the PI controller parameters should be determined as a function of the wind speed. Small-signal modeling of a PMSG WT is implemented to analyze the stability under various operating conditions and with eigenvalues obtained from the small-signal model of the PMSG WT, which are coordinated by adjusting the PI controller parameters. The parameters to be tuned are chosen by investigating participation factors of state variables, which simplifies the problem by reducing the number of parameters to be tuned. The process of adjusting these PI controller parameters is carried out using particle swarm optimization (PSO. To characterize the improvements in the control method due to the PSO method of tuning the PI controller parameters, the PMSG WT is modeled using the MATLAB/SimPowerSystems libraries with the obtained PI controller parameters.

  6. The Use of Logistics n the Quality Parameters Control System of Material Flow

    Science.gov (United States)

    Karpova, Natalia P.; Toymentseva, Irina A.; Shvetsova, Elena V.; Chichkina, Vera D.; Chubarkova, Elena V.

    2016-01-01

    The relevance of the research problem is conditioned on the need to justify the use of the logistics methodologies in the quality parameters control process of material flows. The goal of the article is to develop theoretical principles and practical recommendations for logistical system control in material flows quality parameters. A leading…

  7. Environment Parameters Control Based on Wireless Sensor Network in Livestock Buildings

    OpenAIRE

    Zhang, Yu; Chen, Qiyu; Liu, Guanting; Shen, Weizheng; Wang, Guanlin

    2016-01-01

    The products quality and welfare of animals are closely related to the environment parameters in livestock buildings. A monitoring and control method of environment parameters in livestock buildings based on wireless sensor network is proposed in this paper. Temperature, humidity, light, carbon dioxide concentration, ammonia concentration, and hydrogen sulfide concentration can be monitored in real time by this method. The above six parameters will be adjusted and controlled through WLS algor...

  8. Study of Efficiency Control by Hybrid Jet Engine Parameters

    Directory of Open Access Journals (Sweden)

    S. F. Maksimov

    2015-01-01

    Full Text Available The paper analyzes main control aspects of thrust jet engines, which use fuel components in different states of aggregation (solid fuels - liquid oxidant, a solid oxidizer - liquid fuel. Following the analytical review of literature a conclusion has been drawn that it is technically and functionally complicated to provide a process of thrust control by changing the mass flow and the combustion rate of a solid fuel charge.The objective of this work is to give a theoretical prediction of how the thermal knife impacts on the local combustion rate.The paper presents a diagram of interaction between thermal knife and solid fuel. There are three modes, namely: pyrolysis, transition (from pyrolysis to cutting charge, and fuel cut. In the computational model generation it is assumed that the solid fuel combustion rate is not dependent on the combustion direction, and the temperature distribution along the length of the charge (in the direction perpendicular to the face obeys the Michelson dependence without considering a resistance of the heated layer at the surface of the combustion charge. The paper considers mechanical interaction of the thermal knife with the surface of charge. The Hertz formula describes the relationship between the pressing force, the penetration depth and the radius of thermal knife mark in the fuel.Numerical modeling methods and direct calculations allow us to obtain relationships to describe the changing local combustion rate under the action of the thermal knife on a solid fuel charge in its mechanical penetration, depending on the blade geometry, mechanical properties of charge and pressing force.

  9. CRED Rapid Ecological Assessment Line Point Intercept Survey of Benthic Parameter Assessments at Lisianski, Northwestern Hawaiian Islands in 2010

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Line point intercept (LPI) surveys and benthic composition assessments were conducted during Rapid Ecological Assessments (REA) as part of the Pacific Reef...

  10. CRED Rapid Ecological Assessment Line Point Intercept Survey of Benthic Parameter Assessments at Tau, American Samoa in 2012

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Line point intercept (LPI) surveys and benthic composition assessments were conducted during Rapid Ecological Assessments (REA) as part of the Pacific Reef...

  11. CRED Rapid Ecological Assessment Line Point Intercept Survey of Benthic Parameter Assessments at Farallon de Pajaros, Marianas in 2011

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Line point intercept (LPI) surveys and benthic composition assessments were conducted during Rapid Ecological Assessments (REA) as part of the Pacific Reef...

  12. CRED Rapid Ecological Assessment Line Point Intercept Survey of Benthic Parameter Assessments at Rose, American Samoa in 2012

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Line point intercept (LPI) surveys and benthic composition assessments were conducted during Rapid Ecological Assessments (REA) as part of the Pacific Reef...

  13. CRED Rapid Ecological Assessment Line Point Intercept Survey of Benthic Parameter Assessments at Alamagan, Marianas in 2011

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Line point intercept (LPI) surveys and benthic composition assessments were conducted during Rapid Ecological Assessments (REA) as part of the Pacific Reef...

  14. CRED Rapid Ecological Assessment Line Point Intercept Survey of Benthic Parameter Assessments at Howland, Pacific Remote Island Areas in 2012

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Line point intercept (LPI) surveys and benthic composition assessments were conducted during Rapid Ecological Assessments (REA) as part of the Pacific Reef...

  15. CRED Rapid Ecological Assessment Line Point Intercept Survey of Benthic Parameter Assessments at French Frigate, Northwestern Hawaiian Islands in 2010

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Line point intercept (LPI) surveys and benthic composition assessments were conducted during Rapid Ecological Assessments (REA) as part of the Pacific Reef...

  16. CRED Rapid Ecological Assessment Line Point Intercept Survey of Benthic Parameter Assessments at Asuncion, Marianas in 2011

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Line point intercept (LPI) surveys and benthic composition assessments were conducted during Rapid Ecological Assessments (REA) as part of the Pacific Reef...

  17. CRED Rapid Ecological Assessment Line Point Intercept Survey of Benthic Parameter Assessments at Pagan, Marianas in 2011

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Line point intercept (LPI) surveys and benthic composition assessments were conducted during Rapid Ecological Assessments (REA) as part of the Pacific Reef...

  18. CRED Rapid Ecological Assessment Line Point Intercept Survey of Benthic Parameter Assessments at Ofu & Olosega, American Samoa in 2012

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Line point intercept (LPI) surveys and benthic composition assessments were conducted during Rapid Ecological Assessments (REA) as part of the Pacific Reef...

  19. CRED Rapid Ecological Assessment Line Point Intercept Survey of Benthic Parameter Assessments at Molokai, Main Hawaiian Islands in 2010

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Line point intercept (LPI) surveys and benthic composition assessments were conducted during Rapid Ecological Assessments (REA) as part of the Pacific Reef...

  20. CRED Rapid Ecological Assessment Line Point Intercept Survey of Benthic Parameter Assessments at Maug, Marianas in 2011

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Line point intercept (LPI) surveys and benthic composition assessments were conducted during Rapid Ecological Assessments (REA) as part of the Pacific Reef...

  1. CRED Rapid Ecological Assessment Line Point Intercept Survey of Benthic Parameter Assessments at Kingman, Pacific Remote Island Areas in 2012

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Line point intercept (LPI) surveys and benthic composition assessments were conducted during Rapid Ecological Assessments (REA) as part of the Pacific Reef...

  2. CRED Rapid Ecological Assessment Line Point Intercept Survey of Benthic Parameter Assessments at Tutuila, American Samoa in 2012

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Line point intercept (LPI) surveys and benthic composition assessments were conducted during Rapid Ecological Assessments (REA) as part of the Pacific Reef...

  3. CRED Rapid Ecological Assessment Line Point Intercept Survey of Benthic Parameter Assessments at Wake, Pacific Remote Island Areas in 2011

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Line point intercept (LPI) surveys and benthic composition assessments were conducted during Rapid Ecological Assessments (REA) as part of the Pacific Reef...

  4. CRED Rapid Ecological Assessment Line Point Intercept Survey of Benthic Parameter Assessments at Agrihan, Marianas in 2011

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Line point intercept (LPI) surveys and benthic composition assessments were conducted during Rapid Ecological Assessments (REA) as part of the Pacific Reef...

  5. CRED Rapid Ecological Assessment Line Point Intercept Survey of Benthic Parameter Assessments at Lanai, Main Hawaiian Islands in 2010

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Line point intercept (LPI) surveys and benthic composition assessments were conducted during Rapid Ecological Assessments (REA) as part of the Pacific Reef...

  6. CRED Rapid Ecological Assessment Line Point Intercept Survey of Benthic Parameter Assessments at Kure, Northwestern Hawaiian Islands in 2010

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Line point intercept (LPI) surveys and benthic composition assessments were conducted during Rapid Ecological Assessments (REA) as part of the Pacific Reef...

  7. CRED Rapid Ecological Assessment Line Point Intercept Survey of Benthic Parameter Assessments at Rota, Marianas in 2011

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Line point intercept (LPI) surveys and benthic composition assessments were conducted during Rapid Ecological Assessments (REA) as part of the Pacific Reef...

  8. CRED Rapid Ecological Assessment Line Point Intercept Survey of Benthic Parameter Assessments at Hawaii, Main Hawaiian Islands in 2010

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Line point intercept (LPI) surveys and benthic composition assessments were conducted during Rapid Ecological Assessments (REA) as part of the Pacific Reef...

  9. CRED Rapid Ecological Assessment Line Point Intercept Survey of Benthic Parameter Assessments at Kauai, Main Hawaiian Islands in 2010

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Line point intercept (LPI) surveys and benthic composition assessments were conducted during Rapid Ecological Assessments (REA) as part of the Pacific Reef...

  10. CRED Rapid Ecological Assessment Line Point Intercept Survey of Benthic Parameter Assessments at Swains, American Samoa in 2012

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Line point intercept (LPI) surveys and benthic composition assessments were conducted during Rapid Ecological Assessments (REA) as part of the Pacific Reef...

  11. CRED Rapid Ecological Assessment Line Point Intercept Survey of Benthic Parameter Assessments at Guguan, Marianas in 2011

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Line point intercept (LPI) surveys and benthic composition assessments were conducted during Rapid Ecological Assessments (REA) as part of the Pacific Reef...

  12. CRED Rapid Ecological Assessment Line Point Intercept Survey of Benthic Parameter Assessments at Sarigan, Marianas in 2011

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Line point intercept (LPI) surveys and benthic composition assessments were conducted during Rapid Ecological Assessments (REA) as part of the Pacific Reef...

  13. CRED Rapid Ecological Assessment Line Point Intercept Survey of Benthic Parameter Assessments at Johnston, Pacific Remote Island Areas in 2012

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Line point intercept (LPI) surveys and benthic composition assessments were conducted during Rapid Ecological Assessments (REA) as part of the Pacific Reef...

  14. CRED Rapid Ecological Assessment Line Point Intercept Survey of Benthic Parameter Assessments at Aguijan, Marianas in 2011

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Line point intercept (LPI) surveys and benthic composition assessments were conducted during Rapid Ecological Assessments (REA) as part of the Pacific Reef...

  15. CRED Rapid Ecological Assessment Line Point Intercept Survey of Benthic Parameter Assessments at Palmyra, Pacific Remote Island Areas in 2012

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Line point intercept (LPI) surveys and benthic composition assessments were conducted during Rapid Ecological Assessments (REA) as part of the Pacific Reef...

  16. CRED Rapid Ecological Assessment Line Point Intercept Survey of Benthic Parameter Assessments at Tinian, Marianas in 2011

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Line point intercept (LPI) surveys and benthic composition assessments were conducted during Rapid Ecological Assessments (REA) as part of the Pacific Reef...

  17. CRED Rapid Ecological Assessment Line Point Intercept Survey of Benthic Parameter Assessments at Pearl & Hermes, Northwestern Hawaiian Islands in 2010

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Line point intercept (LPI) surveys and benthic composition assessments were conducted during Rapid Ecological Assessments (REA) as part of the Pacific Reef...

  18. CRED Rapid Ecological Assessment Line Point Intercept Survey of Benthic Parameter Assessments at Maui, Main Hawaiian Islands in 2010

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Line point intercept (LPI) surveys and benthic composition assessments were conducted during Rapid Ecological Assessments (REA) as part of the Pacific Reef...

  19. CRED Rapid Ecological Assessment Line Point Intercept Survey of Benthic Parameter Assessments at Guam, Marianas in 2011

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Line point intercept (LPI) surveys and benthic composition assessments were conducted during Rapid Ecological Assessments (REA) as part of the Pacific Reef...

  20. Design of rapid prototype of UAV line-of-sight stabilized control system

    Science.gov (United States)

    Huang, Gang; Zhao, Liting; Li, Yinlong; Yu, Fei; Lin, Zhe

    2018-01-01

    The line-of-sight (LOS) stable platform is the most important technology of UAV (unmanned aerial vehicle), which can reduce the effect to imaging quality from vibration and maneuvering of the aircraft. According to the requirement of LOS stability system (inertial and optical-mechanical combined method) and UAV's structure, a rapid prototype is designed using based on industrial computer using Peripheral Component Interconnect (PCI) and Windows RTX to exchange information. The paper shows the control structure, and circuit system including the inertial stability control circuit with gyro and voice coil motor driven circuit, the optical-mechanical stability control circuit with fast-steering-mirror (FSM) driven circuit and image-deviation-obtained system, outer frame rotary follower, and information-exchange system on PC. Test results show the stability accuracy reaches 5μrad, and prove the effectiveness of the combined line-of-sight stabilization control system, and the real-time rapid prototype runs stable.

  1. Active vibration control of Flexible Joint Manipulator using Input Shaping and Adaptive Parameter Auto Disturbance Rejection Controller

    Science.gov (United States)

    Li, W. P.; Luo, B.; Huang, H.

    2016-02-01

    This paper presents a vibration control strategy for a two-link Flexible Joint Manipulator (FJM) with a Hexapod Active Manipulator (HAM). A dynamic model of the multi-body, rigid-flexible system composed of an FJM, a HAM and a spacecraft was built. A hybrid controller was proposed by combining the Input Shaping (IS) technique with an Adaptive-Parameter Auto Disturbance Rejection Controller (APADRC). The controller was used to suppress the vibration caused by external disturbances and input motions. Parameters of the APADRC were adaptively adjusted to ensure the characteristic of the closed loop system to be a given reference system, even if the configuration of the manipulator significantly changes during motion. Because precise parameters of the flexible manipulator are not required in the IS system, the operation of the controller was sufficiently robust to accommodate uncertainties in system parameters. Simulations results verified the effectiveness of the HAM scheme and controller in the vibration suppression of FJM during operation.

  2. New approach for rapid assessment of trophic status of Yellow Sea and East China Sea using easy-to-measure parameters

    Science.gov (United States)

    Kong, Xianyu; Liu, Yanfang; Jian, Huimin; Su, Rongguo; Yao, Qingzhen; Shi, Xiaoyong

    2017-10-01

    To realize potential cost savings in coastal monitoring programs and provide timely advice for marine management, there is an urgent need for efficient evaluation tools based on easily measured variables for the rapid and timely assessment of estuarine and offshore eutrophication. In this study, using parallel factor analysis (PARAFAC), principal component analysis (PCA), and discriminant function analysis (DFA) with the trophic index (TRIX) for reference, we developed an approach for rapidly assessing the eutrophication status of coastal waters using easy-to-measure parameters, including chromophoric dissolved organic matter (CDOM), fluorescence excitation-emission matrices, CDOM UV-Vis absorbance, and other water-quality parameters (turbidity, chlorophyll a, and dissolved oxygen). First, we decomposed CDOM excitation-emission matrices (EEMs) by PARAFAC to identify three components. Then, we applied PCA to simplify the complexity of the relationships between the water-quality parameters. Finally, we used the PCA score values as independent variables in DFA to develop a eutrophication assessment model. The developed model yielded classification accuracy rates of 97.1%, 80.5%, 90.3%, and 89.1% for good, moderate, and poor water qualities, and for the overall data sets, respectively. Our results suggest that these easy-to-measure parameters could be used to develop a simple approach for rapid in-situ assessment and monitoring of the eutrophication of estuarine and offshore areas.

  3. An exploratory study for rapid estimation of critical source parameters of great subduction-zone earthquakes in Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Singh, S. K; Perez-Campos, X, Iglesias, A; Pacheco, J. F [Instituto de Geofisica, Universidad Nacional Autonoma de Mexico, Mexico D.F. (Mexico)

    2008-10-15

    The rapid and reliable estimation of moment magnitude M{sub w}, location, and size of rupture area, and radiated energy E{sub s} of great Mexican subduction zone earthquakes is critical for a quick assessment of tsunami and/or damage potential of the event and for issuing an early tsunami alert. To accomplish this goal, the Mexican broadband seismic network needs to be supplemented by permanent GPS stations along the Pacific coast, spaced about 65 km apart or less. The data from the GPS network must be transmitted to a central location and processed in near-real time to track the position of the stations. Assuming that this can be implemented, we develop a procedure for near-real time estimation of the critical source parameters. We demonstrate the viability of the procedure by processing near-source GPS data and regional seismograms for the earthquakes of Colima-Jalisco in 1995 (M{sub w}=8.0) and Sumatra-Andaman in 2004 (M{sub w}=9.0-9.3). The procedure yields estimates of M{sub w} and E{sub s} in excellent agreement with those reported from earlier solutions. In the case of the Colima-Jalisco earthquake, the estimated location and size of rupture area agree with that mapped from aftershock locations. Presently, there are 13 permanent GPS stations along the Pacific coast of Mexico with an average spacing of {approx}200 km which operate in an autonomous mode. It is urgent to increase the number of stations to {>=}28 thus decreasing the spacing of stations to {<=}65 km. Data must be transmitted in near-real time to a central station to track the position of the stations, preferably every second. [Spanish] Para una estimacion oportuna del potencial de dano y tsunami asociado a los grandes temblores de subduccion en Mexico, resulta critica la determinacion rapida y confiable de parametros sismologicos como lo son la magnitud de momento (M{sub w}), la energia sismica radiada (E{sub s}) y la localizacion y el tamano de la ruptura. Para alcanzar este objetivo, la red

  4. The Application of PSO-AFSA Method in Parameter Optimization for Underactuated Autonomous Underwater Vehicle Control

    Directory of Open Access Journals (Sweden)

    Chunmeng Jiang

    2017-01-01

    Full Text Available In consideration of the difficulty in determining the parameters of underactuated autonomous underwater vehicles in multi-degree-of-freedom motion control, a hybrid method that combines particle swarm optimization (PSO with artificial fish school algorithm (AFSA is proposed in this paper. The optimization process of the PSO-AFSA method is firstly introduced. With the control simulation models in the horizontal plane and vertical plane, the PSO-AFSA method is elaborated when applied in control parameter optimization for an underactuated autonomous underwater vehicle. Both simulation tests and field trials were carried out to prove the efficiency of the PSO-AFSA method in underactuated autonomous underwater vehicle control parameter optimization. The optimized control parameters showed admirable control quality by enabling the underactuated autonomous underwater vehicle to reach the desired states with fast convergence.

  5. Prioritization and selection of parameters for control chart implementation based on technical criticality and cost criticality

    Directory of Open Access Journals (Sweden)

    Sirintra Tan-intara-art

    2013-07-01

    Full Text Available An important problem in control chart implementation is the availability of resources to collect and analyze data for control charts implementation. This paper proposes a method to prioritize and select final product parameters to control. The prioritization is based on cost of quality and technical criticality of those parameters. The prioritization method is demonstrated by a case study of flexible printed circuit manufacturing.

  6. Simulation and sensitivity analysis of controlling parameters in resistance spot welding

    Science.gov (United States)

    Kim, Euiwhan; Eagar, Thomas W.

    2015-03-01

    This study was performed to investigate the fundamental parameters controlling the nugget growth. The parameters were categorized into four groups, i.e. material parameters, electrical parameters, thermal parameters and geometrical parameters. In order to quantify the sensitivity of nugget growth to changes in these parameters, a numerical model which incorporates the electrical, mechanical and thermal contact was developed. As a result, a sensitivity index table was constructed and analyzed to ascertain the relative importance of these characteristic parameters. It was found that the most important factor in determining the variability of nugget growth behavior is the ratio of contact radius to electrode radius and the ratio of electrode radius to the square of specimen thickness. In general for a variation of 10%, the geometrical parameters are most important, followed by the material parameters. The electrical parameters and the thermal parameters are the least important. The importance of contact at the faying interface is greater for the contact area than for the contact resistance.

  7. Robust and Fault-Tolerant Linear Parameter-Varying Control of Wind Turbines

    DEFF Research Database (Denmark)

    Sloth, Christoffer; Esbensen, Thomas; Stoustrup, Jakob

    2011-01-01

    a robust controller (RC). This controller is able to take into account model uncertainties in the aerodynamic model. The controllers are based on output feedback and are scheduled on an estimated wind speed to manage the parameter-varying nature of the model. Furthermore, the AFTC relies on information...

  8. Simulation and Rapid Prototyping of Adaptive Control Systems using the Adaptive Blockset for Simulink

    DEFF Research Database (Denmark)

    Ravn, Ole

    1998-01-01

    The paper describes the design considerations and implementational aspects of the Adaptive Blockset for Simulink which has been developed in a prototype implementation. The concept behind the Adaptive Blockset for Simulink is to bridge the gap between simulation and prototype controller...... implementation. This is done using the code generation capabilities of Real Time Workshop in combination with C s-function blocks for adaptive control in Simulink. In the paper the design of each group of blocks normally found in adaptive controllers is outlined. The block types are, identification, controller...... design, controller and state variable filter.The use of the Adaptive Blockset is demonstrated using a simple laboratory setup. Both the use of the blockset for simulation and for rapid prototyping of a real-time controller are shown....

  9. Evaluation of a hospice rapid response community service: a controlled evaluation

    Directory of Open Access Journals (Sweden)

    Butler Claire

    2012-07-01

    Full Text Available Abstract Background While most people faced with a terminal illness would prefer to die at home, less than a third in England are enabled to do so with many dying in National Health Service hospitals. Patients are more likely to die at home if their carers receive professional support. Hospice rapid response teams, which provide specialist palliative care at home on a 24/7 on-call basis, are proposed as an effective way to help terminally ill patients die in their preferred place, usually at home. However, the effectiveness of rapid response teams has not been rigorously evaluated in terms of patient, carer and cost outcomes. Methods/Design The study is a pragmatic quasi-experimental controlled trial. The primary outcome for the quantitative evaluation for patients is dying in their preferred place of death. Carers’ quality of life will be evaluated using postal questionnaires sent at patient intake to the hospice service and eight months later. Carers’ perceptions of care received and the patient’s death will be assessed in one to one interviews at 6 to 8 months post bereavement. Service utilisation costs including the rapid response intervention will be compared to those of usual care. Discussion The study will contribute to the development of the evidence base on outcomes for patients and carers and costs of hospice rapid response teams operating in the community. Trial registration: Current controlled trials ISRCTN32119670.

  10. The impact of parameter identification methods on drug therapy control in an intensive care unit

    National Research Council Canada - National Science Library

    Hann, CE; Chase, JG; Ypma, MF; Elfring, J Jos; Nor, NHM; Lawrence, P; Shaw, GM

    2008-01-01

    This paper investigates the impact of fast parameter identification methods, which do not require any forward simulations, on model-based glucose control, using retrospective data in the Christchurch...

  11. Rapid control of male typical behaviors by brain-derived estrogens

    Science.gov (United States)

    Cornil, Charlotte A.; Ball, Gregory F.; Balthazart, Jacques

    2012-01-01

    Beside their genomic mode of action, estrogens also activate a variety of cellular signaling pathways through non-genomic mechanisms. Until recently, little was known regarding the functional significance of such actions in males and the mechanism that control local estrogen concentration with a spatial and time resolution compatible with these non-genomic actions had rarely been examined. Here, we review evidence that estrogens rapidly modulate a variety of behaviors in male vertebrates. Then, we present in vitro work supporting the existence of a control mechanism of local brain estrogen synthesis by aromatase along with in vivo evidence that rapid changes in aromatase activity also occur in a region-specific manner in response to changes in the social or environmental context. Finally, we suggest that the brain estrogen provision may also play a significant role in females. Together these data bolster the hypothesis that brain-derived estrogens should be considered as neuromodulators. PMID:22983088

  12. Statistical analysis of the blast furnace process output parameter using arima control chart with proposed methodology of control limits setting

    Directory of Open Access Journals (Sweden)

    D. Noskievičová

    2009-10-01

    Full Text Available The paper deals with the statistical analysis of the selected parameter of the blast furnace process. It was proved that analyzed measurements have been autocorrelated. ARIMA control chart was selected for their analysis as a very useful statistical process control (SPC method. At first the methodology for control limits setting in ARIMA control charts considering the time series outlier analysis as an integral part of the ARIMA model building was designed. Then this proposal was applied to the statistical analysis of the selected blast furnace process output parameter with the aim to compare two production methods.

  13. Combustion Model and Control Parameter Optimization Methods for Single Cylinder Diesel Engine

    Directory of Open Access Journals (Sweden)

    Bambang Wahono

    2014-01-01

    Full Text Available This research presents a method to construct a combustion model and a method to optimize some control parameters of diesel engine in order to develop a model-based control system. The construction purpose of the model is to appropriately manage some control parameters to obtain the values of fuel consumption and emission as the engine output objectives. Stepwise method considering multicollinearity was applied to construct combustion model with the polynomial model. Using the experimental data of a single cylinder diesel engine, the model of power, BSFC, NOx, and soot on multiple injection diesel engines was built. The proposed method succesfully developed the model that describes control parameters in relation to the engine outputs. Although many control devices can be mounted to diesel engine, optimization technique is required to utilize this method in finding optimal engine operating conditions efficiently beside the existing development of individual emission control methods. Particle swarm optimization (PSO was used to calculate control parameters to optimize fuel consumption and emission based on the model. The proposed method is able to calculate control parameters efficiently to optimize evaluation item based on the model. Finally, the model which added PSO then was compiled in a microcontroller.

  14. An approach to design controllers for MIMO fractional-order plants based on parameter optimization algorithm.

    Science.gov (United States)

    Xue, Dingyü; Li, Tingxue

    2017-04-27

    The parameter optimization method for multivariable systems is extended to the controller design problems for multiple input multiple output (MIMO) square fractional-order plants. The algorithm can be applied to search for the optimal parameters of integer-order controllers for fractional-order plants with or without time delays. Two examples are given to present the controller design procedures for MIMO fractional-order systems. Simulation studies show that the integer-order controllers designed are robust to plant gain variations. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  15. Modeling, Parameters Identification, and Control of High Pressure Fuel Cell Back-Pressure Valve

    Directory of Open Access Journals (Sweden)

    Fengxiang Chen

    2014-01-01

    Full Text Available The reactant pressure is crucial to the efficiency and lifespan of a high pressure PEMFC engine. This paper analyses a regulated back-pressure valve (BPV for the cathode outlet flow in a high pressure PEMFC engine, which can achieve precisely pressure control. The modeling, parameters identification, and nonlinear controller design of a BPV system are considered. The identified parameters are used in designing active disturbance rejection controller (ADRC. Simulations and extensive experiments are conducted with the xPC Target and show that the proposed controller can not only achieve good dynamic and static performance but also have strong robustness against parameters’ disturbance and external disturbance.

  16. Iterative Learning Control with Forgetting Factor for Linear Distributed Parameter Systems with Uncertainty

    Directory of Open Access Journals (Sweden)

    Xisheng Dai

    2014-01-01

    Full Text Available Iterative learning control is an intelligent control algorithm which imitates human learning process. Based on this concept, this paper discussed iterative learning control problem for a class parabolic linear distributed parameter systems with uncertainty coefficients. Iterative learning control algorithm with forgetting factor is proposed and the conditions for convergence of algorithm are established. Combining the matrix theory with the basic theory of distributed parameter systems gives rigorous convergence proof of the algorithm. Finally, by using the forward difference scheme of partial differential equation to solve the problems, the simulation results are presented to illustrate the feasibility of the algorithm.

  17. Validation of Contamination Control in Rapid Transfer Port Chambers for Pharmaceutical Manufacturing Processes

    OpenAIRE

    Shih-Cheng Hu; Angus Shiue; Han-Yang Liu; Rong-Ben Chiu

    2016-01-01

    There is worldwide concern with regard to the adverse effects of drug usage. However, contaminants can gain entry into a drug manufacturing process stream from several sources such as personnel, poor facility design, incoming ventilation air, machinery and other equipment for production, etc. In this validation study, we aimed to determine the impact and evaluate the contamination control in the preparation areas of the rapid transfer port (RTP) chamber during the pharmaceutical manufacturing...

  18. Workstation-Based Simulation for Rapid Prototyping and Piloted Evaluation of Control System Designs

    Science.gov (United States)

    Mansur, M. Hossein; Colbourne, Jason D.; Chang, Yu-Kuang; Aiken, Edwin W. (Technical Monitor)

    1998-01-01

    The development and optimization of flight control systems for modem fixed- and rotary-. wing aircraft consume a significant portion of the overall time and cost of aircraft development. Substantial savings can be achieved if the time required to develop and flight test the control system, and the cost, is reduced. To bring about such reductions, software tools such as Matlab/Simulink are being used to readily implement block diagrams and rapidly evaluate the expected responses of the completed system. Moreover, tools such as CONDUIT (CONtrol Designer's Unified InTerface) have been developed that enable the controls engineers to optimize their control laws and ensure that all the relevant quantitative criteria are satisfied, all within a fully interactive, user friendly, unified software environment.

  19. A temperature control method for shortening thermal cycling time to achieve rapid polymerase chain reaction (PCR) in a disposable polymer microfluidic device

    DEFF Research Database (Denmark)

    Bu, Minqiang; Perch-Nielsen, Ivan R.; Sørensen, Karen Skotte

    2013-01-01

    We present a temperature control method capable of effectively shortening the thermal cycling time of polymerase chain reaction (PCR) in a disposable polymer microfluidic device with an external heater and a temperature sensor. The method employs optimized temperature overshooting and undershooting...... steps to achieve a rapid ramping between the temperature steps for DNA denaturation, annealing and extension. The temperature dynamics within the microfluidic PCR chamber was characterized and the overshooting and undershooting parameters were optimized using the temperature-dependent fluorescence...

  20. A novel temperature control method for shortening thermal cycling time to achieve rapid polymerase chain reaction (PCR) in a disposable polymer microfluidic device

    DEFF Research Database (Denmark)

    Bu, Minqiang; R. Perch-Nielsen, Ivan; Sørensen, Karen Skotte

    We present a new temperature control method capable of effectively shortening the thermal cycling time of polymerase chain reaction (PCR) in a disposable polymer microfluidic device with external heater and temperature sensor. The method employs optimized temperature overshooting and undershooting...... steps to achieve a rapid ramping between the temperature steps for DNA denaturation, annealing and extension. The temperature dynamics within the microfluidic PCR chamber was characterized and the overshooting and undershooting parameters were optimized using the temperature dependent fluorescence...

  1. Rapid Automatized Naming in Children with Dyslexia: Is Inhibitory Control Involved?

    Science.gov (United States)

    Bexkens, Anika; van den Wildenberg, Wery P M; Tijms, Jurgen

    2015-08-01

    Rapid automatized naming (RAN) is widely seen as an important indicator of dyslexia. The nature of the cognitive processes involved in rapid naming is however still a topic of controversy. We hypothesized that in addition to the involvement of phonological processes and processing speed, RAN is a function of inhibition processes, in particular of interference control. A total 86 children with dyslexia and 31 normal readers were recruited. Our results revealed that in addition to phonological processing and processing speed, interference control predicts rapid naming in dyslexia, but in contrast to these other two cognitive processes, inhibition is not significantly associated with their reading and spelling skills. After variance in reading and spelling associated with processing speed, interference control and phonological processing was partialled out, naming speed was no longer consistently associated with the reading and spelling skills of children with dyslexia. Finally, dyslexic children differed from normal readers on naming speed, literacy skills, phonological processing and processing speed, but not on inhibition processes. Both theoretical and clinical interpretations of these results are discussed. Copyright © 2014 John Wiley & Sons, Ltd.

  2. Minimal-Learning-Parameter Technique Based Adaptive Neural Sliding Mode Control of MEMS Gyroscope

    Directory of Open Access Journals (Sweden)

    Bin Xu

    2017-01-01

    Full Text Available This paper investigates an adaptive neural sliding mode controller for MEMS gyroscopes with minimal-learning-parameter technique. Considering the system uncertainty in dynamics, neural network is employed for approximation. Minimal-learning-parameter technique is constructed to decrease the number of update parameters, and in this way the computation burden is greatly reduced. Sliding mode control is designed to cancel the effect of time-varying disturbance. The closed-loop stability analysis is established via Lyapunov approach. Simulation results are presented to demonstrate the effectiveness of the method.

  3. Dynamic parameter identification of robot arms with servo-controlled electrical motors

    Science.gov (United States)

    Jiang, Zhao-Hui; Senda, Hiroshi

    2005-12-01

    This paper addresses the issue of dynamic parameter identification of the robot manipulator with servo-controlled electrical motors. An assumption is made that all kinematical parameters, such as link lengths, are known, and only dynamic parameters containing mass, moment of inertia, and their functions need to be identified. First, we derive dynamics of the robot arm with a linear form of the unknown dynamic parameters by taking dynamic characteristics of the motor and servo unit into consideration. Then, we implement the parameter identification approach to identify the unknown parameters with respect to individual link separately. A pseudo-inverse matrix is used for formulation of the parameter identification. The optimal solution is guaranteed in a sense of least-squares of the mean errors. A Direct Drive (DD) SCARA type industrial robot arm AdeptOne is used as an application example of the parameter identification. Simulations and experiments for both open loop and close loop controls are carried out. Comparison of the results confirms the correctness and usefulness of the parameter identification and the derived dynamic model.

  4. Parameters Sensitivity Analysis of Position-Based Impedance Control for Bionic Legged Robots’ HDU

    Directory of Open Access Journals (Sweden)

    Kaixian Ba

    2017-10-01

    Full Text Available For the hydraulic drive unit (HDU on the joints of bionic legged robots, this paper proposes the position-based impedance control method. Then, the impedance control performance is tested by a HDU performance test platform. Further, the method of first-order sensitivity matrix is proposed to analyze the dynamic sensitivity of four main control parameters under four working conditions. To research the parameter sensitivity quantificationally, two sensitivity indexes are defined, and the sensitivity analysis results are verified by experiments. The results of the experiments show that, when combined with corresponding optimization strategies, the dynamic compliance composition theory and the results from sensitivity analysis can compensate for the control parameters and optimize the control performance in different working conditions.

  5. Investigation on sense of control parameters for joystick interface in remote operated container crane application

    Science.gov (United States)

    Abdullah, U. N. N.; Handroos, H.

    2017-09-01

    Introduction: This paper presents the study of sense of control parameters to improve the lack of direct motion feeling through remote operated container crane station (ROCCS) joystick interface. The investigations of the parameters in this study are important to develop the engineering parameters related to the sense of control goal in the next design process. Methodology: Structured interviews and observations were conducted to obtain the user experience data from thirteen remote container crane operators from two international terminals. Then, interview analysis, task analysis, activity analysis and time line analysis were conducted to compare and contrast the results from interviews and observations. Results: Four experience parameters were identified to support the sense of control goal in the later design improvement of the ROCC joystick interface. The significance of difficulties to control, unsynchronized movements, facilitate in control and decision making in unexpected situation as parameters to the sense of control goal were validated by' feedbacks from operators as well as analysis. Contribution: This study provides feedback directly from end users towards developing a sustainable control interface for ROCCS in specific and remote operated off-road vehicles in general.

  6. Add-in macros for rapid and versatile calculation of non-compartmental pharmacokinetic parameters on Microsoft Excel spreadsheets.

    Science.gov (United States)

    Sato, H; Sato, S; Wang, Y M; Horikoshi, I

    1996-06-01

    We developed a package of macro programs (named PK_MOMENT) to automatically calculate non-compartmental pharmacokinetic parameters on Microsoft Excel spreadsheets. These macros include rigorous algorithms to execute moment calculations in a comprehensive manner. An optimum number of terminal data points for infinite-time extrapolation can be calculated with one of these macros so that automatic calculation of infinite moment parameters is possible. The moment calculation with PK_MOMENT provided satisfactory results using the hybrid (mixed linear-logarithmic) trapezoidal method rather than the conventional linear trapezoidal method. The macro-aided pharmacokinetic analyses turned out to be useful in that the macro-containing cells can be easily copied and pasted to analyze other data sets and that powerful tools of Excel can be utilized. The use of our macros will be significantly time-saving for routine pharmacokinetic analyses, considering that pharmacokinetic data are usually stored in a spreadsheet format, typically with Excel.

  7. Oscillation regimes produced by an alto saxophone: Influence of the control parameters and the bore inharmonicity.

    Science.gov (United States)

    Doc, Jean-Baptiste; Vergez, Christophe

    2015-04-01

    The aim of this work is to highlight experimentally how inharmonicity of the bore resonance frequencies of an alto saxophone influences the nature of the oscillation regimes. A variable volume branching from the neck of an alto sax at an appropriate position allows one to change the frequency of the first resonance independently from the second. A blowing machine with artificial lips is used to make the saxophone play while controlling independently the control parameters: the blowing pressure and an embouchure parameter. Values of these parameters are estimated experimentally through the measurement of the nonlinear characteristics linking the mean air flow blown into the instrument to the static pressure difference across the reed. Experiments with different values of the control parameters as well as of the inharmonicity produce different kinds of oscillation regimes. These regimes are categorized through the analysis of the pressure signal inside the mouthpiece. The resulting maps demonstrate that the emergence of quasi-periodic regimes, and their extent, depend on the level of inharmonicity, but also on the values of the control parameters. Periodic regimes playable by choosing appropriate values of the control parameters also differ according to the level of inharmonicity, a higher inharmonicity facilitating the emergence of the third register.

  8. Fractional order sliding-mode control based on parameters auto-tuning for velocity control of permanent magnet synchronous motor.

    Science.gov (United States)

    Zhang, BiTao; Pi, YouGuo; Luo, Ying

    2012-09-01

    A fractional order sliding mode control (FROSMC) scheme based on parameters auto-tuning for the velocity control of permanent magnet synchronous motor (PMSM) is proposed in this paper. The control law of the proposed F(R)OSMC scheme is designed according to Lyapunov stability theorem. Based on the property of transferring energy with adjustable type in F(R)OSMC, this paper analyzes the chattering phenomenon in classic sliding mode control (SMC) is attenuated with F(R)OSMC system. A fuzzy logic inference scheme (FLIS) is utilized to obtain the gain of switching control. Simulations and experiments demonstrate that the proposed FROSMC not only achieve better control performance with smaller chatting than that with integer order sliding mode control, but also is robust to external load disturbance and parameter variations. Copyright © 2012 ISA. Published by Elsevier Ltd. All rights reserved.

  9. A New Controller for PMSM Servo Drive Based on the Sliding Mode Approach with Parameter Adaptation

    Science.gov (United States)

    Gjini, Orges; Kaneko, Takayuki; Ohsawa, Hiroshi

    A novel controller based on the Sliding Mode (SM) approach is designed for controlling a permanent magnet synchronous motor (PMSM) in a servo drive. After analyzing the classical SM controller, changes are made in the controller design such that its performance is substantially improved. To improve the controller performance in steady state (zero error positioning) an integral block is added to the controller resulting in a new controller configuration, which we call Sliding Mode Integral (SMI) controller. The new controller is tuned based on the results from parameter identification of the motor and the working machine. To cope with model parameter variations, especially unpredictable friction changes, gain scheduling and fuzzy based adaptive techniques are used in the control algorithm. Experiments and simulations are carried out and their results show a high performance control. The new controller offers very good tracking; it is highly robust, reaches the final position very fast and has a large stall torque. Furthermore the application of the SM ensures reduction of the system order by one. For comparison, the new controller's performance is compared with that of a PI controller. From the experimental results it is obvious the superiority of the new proposed controller.

  10. Closed-loop Identification for Control of Linear Parameter Varying Systems

    DEFF Research Database (Denmark)

    Bendtsen, Jan Dimon; Trangbæk, Klaus

    2014-01-01

    This paper deals with system identification for control of linear parameter varying systems. In practical applications, it is often important to be able to identify small plant changes in an incremental manner without shutting down the system and/or disconnecting the controller; unfortunately, cl...

  11. Rapid evolution of regulatory element libraries for tunable transcriptional and translational control of gene expression

    Directory of Open Access Journals (Sweden)

    Erqing Jin

    2017-12-01

    Full Text Available Engineering cell factories for producing biofuels and pharmaceuticals has spurred great interests to develop rapid and efficient synthetic biology tools customized for modular pathway engineering. Along the way, combinatorial gene expression control through modification of regulatory element offered tremendous opportunity for fine-tuning gene expression and generating digital-like genetic circuits. In this report, we present an efficient evolutionary approach to build a range of regulatory control elements. The reported method allows for rapid construction of promoter, 5′UTR, terminator and trans-activating RNA libraries. Synthetic overlapping oligos with high portion of degenerate nucleotides flanking the regulatory element could be efficiently assembled to a vector expressing fluorescence reporter. This approach combines high mutation rate of the synthetic DNA with the high assembly efficiency of Gibson Mix. Our constructed library demonstrates broad range of transcriptional or translational gene expression dynamics. Specifically, both the promoter library and 5′UTR library exhibits gene expression dynamics spanning across three order of magnitude. The terminator library and trans-activating RNA library displays relatively narrowed gene expression pattern. The reported study provides a versatile toolbox for rapidly constructing a large family of prokaryotic regulatory elements. These libraries also facilitate the implementation of combinatorial pathway engineering principles and the engineering of more efficient microbial cell factory for various biomanufacturing applications.

  12. Intelligent tuning method of PID parameters based on iterative learning control for atomic force microscopy.

    Science.gov (United States)

    Liu, Hui; Li, Yingzi; Zhang, Yingxu; Chen, Yifu; Song, Zihang; Wang, Zhenyu; Zhang, Suoxin; Qian, Jianqiang

    2018-01-01

    Proportional-integral-derivative (PID) parameters play a vital role in the imaging process of an atomic force microscope (AFM). Traditional parameter tuning methods require a lot of manpower and it is difficult to set PID parameters in unattended working environments. In this manuscript, an intelligent tuning method of PID parameters based on iterative learning control is proposed to self-adjust PID parameters of the AFM according to the sample topography. This method gets enough information about the output signals of PID controller and tracking error, which will be used to calculate the proper PID parameters, by repeated line scanning until convergence before normal scanning to learn the topography. Subsequently, the appropriate PID parameters are obtained by fitting method and then applied to the normal scanning process. The feasibility of the method is demonstrated by the convergence analysis. Simulations and experimental results indicate that the proposed method can intelligently tune PID parameters of the AFM for imaging different topographies and thus achieve good tracking performance. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Homogeneous light field model for interactive control of viewing parameters of integral imaging displays.

    Science.gov (United States)

    Xu, Yin; Wang, XiaoRui; Sun, Yan; Zhang, JianQi

    2012-06-18

    A novel model for three dimensional (3D) interactive control of viewing parameters of integral imaging systems is established in this paper. Specifically, transformation matrices are derived in an extended homogeneous light field coordinate space based on interactive controllable requirement of integral imaging displays. In this model, new elemental images can be synthesized directly from the ones captured in the record process to display 3D images with expected viewing parameters, and no extra geometrical information of the 3D scene is required in the synthesis process. Computer simulation and optical experimental results show that the reconstructed 3D scenes with depth control, lateral translation and rotation can be achieved.

  14. Rapid evolution meets invasive species control: The potential for pesticide resistance in sea lamprey

    Science.gov (United States)

    Dunlop, Erin S.; McLaughlin, Robert L.; Adams, Jean V.; Jones, Michael L.; Birceanu, Oana; Christie, Mark R.; Criger, Lori A.; Hinderer, Julia L.M.; Hollingworth, Robert M.; Johnson, Nicholas; Lantz, Stephen R.; Li, Weiming; Miller, James R.; Morrison, Bruce J.; Mota-Sanchez, David; Muir, Andrew M.; Sepulveda, Maria S.; Steeves, Todd B.; Walter, Lisa; Westman, Erin; Wirgin, Isaac; Wilkie, Michael P.

    2018-01-01

    Rapid evolution of pest, pathogen and wildlife populations can have undesirable effects; for example, when insects evolve resistance to pesticides or fishes evolve smaller body size in response to harvest. A destructive invasive species in the Laurentian Great Lakes, the sea lamprey (Petromyzon marinus) has been controlled with the pesticide 3-trifluoromethyl-4-nitrophenol (TFM) since the 1950s. We evaluated the likelihood of sea lamprey evolving resistance to TFM by (1) reviewing sea lamprey life history and control; (2) identifying physiological and behavioural resistance strategies; (3) estimating the strength of selection from TFM; (4) assessing the timeline for evolution; and (5) analyzing historical toxicity data for evidence of resistance. The number of sea lamprey generations exposed to TFM was within the range observed for fish populations where rapid evolution has occurred. Mortality from TFM was estimated as 82-90%, suggesting significant selective pressure. However, 57 years of toxicity data revealed no increase in lethal concentrations of TFM. Vigilance and the development of alternative controls are required to prevent this aquatic invasive species from evolving strategies to evade control.

  15. Longitudinal control of aircraft dynamics based on optimization of PID parameters

    Science.gov (United States)

    Deepa, S. N.; Sudha, G.

    2016-03-01

    Recent years many flight control systems and industries are employing PID controllers to improve the dynamic behavior of the characteristics. In this paper, PID controller is developed to improve the stability and performance of general aviation aircraft system. Designing the optimum PID controller parameters for a pitch control aircraft is important in expanding the flight safety envelope. Mathematical model is developed to describe the longitudinal pitch control of an aircraft. The PID controller is designed based on the dynamic modeling of an aircraft system. Different tuning methods namely Zeigler-Nichols method (ZN), Modified Zeigler-Nichols method, Tyreus-Luyben tuning, Astrom-Hagglund tuning methods are employed. The time domain specifications of different tuning methods are compared to obtain the optimum parameters value. The results prove that PID controller tuned by Zeigler-Nichols for aircraft pitch control dynamics is better in stability and performance in all conditions. Future research work of obtaining optimum PID controller parameters using artificial intelligence techniques should be carried out.

  16. Hands-on parameter search for neural simulations by a MIDI-controller.

    Directory of Open Access Journals (Sweden)

    Hubert Eichner

    Full Text Available Computational neuroscientists frequently encounter the challenge of parameter fitting--exploring a usually high dimensional variable space to find a parameter set that reproduces an experimental data set. One common approach is using automated search algorithms such as gradient descent or genetic algorithms. However, these approaches suffer several shortcomings related to their lack of understanding the underlying question, such as defining a suitable error function or getting stuck in local minima. Another widespread approach is manual parameter fitting using a keyboard or a mouse, evaluating different parameter sets following the users intuition. However, this process is often cumbersome and time-intensive. Here, we present a new method for manual parameter fitting. A MIDI controller provides input to the simulation software, where model parameters are then tuned according to the knob and slider positions on the device. The model is immediately updated on every parameter change, continuously plotting the latest results. Given reasonably short simulation times of less than one second, we find this method to be highly efficient in quickly determining good parameter sets. Our approach bears a close resemblance to tuning the sound of an analog synthesizer, giving the user a very good intuition of the problem at hand, such as immediate feedback if and how results are affected by specific parameter changes. In addition to be used in research, our approach should be an ideal teaching tool, allowing students to interactively explore complex models such as Hodgkin-Huxley or dynamical systems.

  17. Calculation of PID controller parameters by using a fuzzy neural network.

    Science.gov (United States)

    Lee, Ching-Hung; Teng, Ching-Cheng

    2003-07-01

    In this paper, we use the fuzzy neural network (FNN) to develop a formula for designing the proportional-integral-derivative (PID) controller. This PID controller satisfies the criteria of minimum integrated absolute error (IAE) and maximum of sensitivity (Ms). The FNN system is used to identify the relationship between plant model and controller parameters based on IAE and Ms. To derive the tuning rule, the dominant pole assignment method is applied to simplify our optimization processes. Therefore, the FNN system is used to automatically tune the PID controller for different system parameters so that neither theoretical methods nor numerical methods need be used. Moreover, the FNN-based formula can modify the controller to meet our specification when the system model changes. A simulation result for applying to the motor position control problem is given to demonstrate the effectiveness of our approach.

  18. Adaptive Model Predictive Vibration Control of a Cantilever Beam with Real-Time Parameter Estimation

    Directory of Open Access Journals (Sweden)

    Gergely Takács

    2014-01-01

    Full Text Available This paper presents an adaptive-predictive vibration control system using extended Kalman filtering for the joint estimation of system states and model parameters. A fixed-free cantilever beam equipped with piezoceramic actuators serves as a test platform to validate the proposed control strategy. Deflection readings taken at the end of the beam have been used to reconstruct the position and velocity information for a second-order state-space model. In addition to the states, the dynamic system has been augmented by the unknown model parameters: stiffness, damping constant, and a voltage/force conversion constant, characterizing the actuating effect of the piezoceramic transducers. The states and parameters of this augmented system have been estimated in real time, using the hybrid extended Kalman filter. The estimated model parameters have been applied to define the continuous state-space model of the vibrating system, which in turn is discretized for the predictive controller. The model predictive control algorithm generates state predictions and dual-mode quadratic cost prediction matrices based on the updated discrete state-space models. The resulting cost function is then minimized using quadratic programming to find the sequence of optimal but constrained control inputs. The proposed active vibration control system is implemented and evaluated experimentally to investigate the viability of the control method.

  19. Adaptive multiparameter control: application to a Rapid Thermal Processing process; Commande Adaptative Multivariable: Application a un Procede de Traitement Thermique Rapide

    Energy Technology Data Exchange (ETDEWEB)

    Morales Mago, S.J.

    1995-12-20

    In this work the problem of temperature uniformity control in rapid thermal processing is addressed by means of multivariable adaptive control. Rapid Thermal Processing (RTP) is a set of techniques proposed for semiconductor fabrication processes such as annealing, oxidation, chemical vapour deposition and others. The product quality depends on two mains issues: precise trajectory following and spatial temperature uniformity. RTP is a fabrication technique that requires a sophisticated real-time multivariable control system to achieve acceptable results. Modelling of the thermal behaviour of the process leads to very complex mathematical models. These are the reasons why adaptive control techniques are chosen. A multivariable linear discrete time model of the highly non-linear process is identified on-line, using an identification scheme which includes supervisory actions. This identified model, combined with a multivariable predictive control law allows to prevent the controller from systems variations. The control laws are obtained by minimization of a quadratic cost function or by pole placement. In some of these control laws, a partial state reference model was included. This reference model allows to incorporate an appropriate tracking capability into the control law. Experimental results of the application of the involved multivariable adaptive control laws on a RTP system are presented. (author) refs

  20. Adaptive control based on an on-line parameter estimation of an upper limb exoskeleton.

    Science.gov (United States)

    Riani, Akram; Madani, Tarek; Hadri, Abdelhafid El; Benallegue, Abdelaziz

    2017-07-01

    This paper presents an adaptive control strategy for an upper-limb exoskeleton based on an on-line dynamic parameter estimator. The objective is to improve the control performance of this system that plays a critical role in assisting patients for shoulder, elbow and wrist joint movements. In general, the dynamic parameters of the human limb are unknown and differ from a person to another, which degrade the performances of the exoskeleton-human control system. For this reason, the proposed control scheme contains a supplementary loop based on a new efficient on-line estimator of the dynamic parameters. Indeed, the latter is acting upon the parameter adaptation of the controller to ensure the performances of the system in the presence of parameter uncertainties and perturbations. The exoskeleton used in this work is presented and a physical model of the exoskeleton interacting with a 7 Degree of Freedom (DoF) upper limb model is generated using the SimMechanics library of MatLab/Simulink. To illustrate the effectiveness of the proposed approach, an example of passive rehabilitation movements is performed using multi-body dynamic simulation. The aims is to maneuver the exoskeleton that drive the upper limb to track desired trajectories in the case of the passive arm movements.

  1. Adaptive Control Parameters for Dispersal of Multi-Agent Mobile Ad Hoc Network (MANET) Swarms

    Energy Technology Data Exchange (ETDEWEB)

    Kurt Derr; Milos Manic

    2013-11-01

    A mobile ad hoc network is a collection of independent nodes that communicate wirelessly with one another. This paper investigates nodes that are swarm robots with communications and sensing capabilities. Each robot in the swarm may operate in a distributed and decentralized manner to achieve some goal. This paper presents a novel approach to dynamically adapting control parameters to achieve mesh configuration stability. The presented approach to robot interaction is based on spring force laws (attraction and repulsion laws) to create near-optimal mesh like configurations. In prior work, we presented the extended virtual spring mesh (EVSM) algorithm for the dispersion of robot swarms. This paper extends the EVSM framework by providing the first known study on the effects of adaptive versus static control parameters on robot swarm stability. The EVSM algorithm provides the following novelties: 1) improved performance with adaptive control parameters and 2) accelerated convergence with high formation effectiveness. Simulation results show that 120 robots reach convergence using adaptive control parameters more than twice as fast as with static control parameters in a multiple obstacle environment.

  2. A Taguchi approach on optimal process control parameters for HDPE pipe extrusion process

    Science.gov (United States)

    Sharma, G. V. S. S.; Rao, R. Umamaheswara; Rao, P. Srinivasa

    2017-12-01

    High-density polyethylene (HDPE) pipes find versatile applicability for transportation of water, sewage and slurry from one place to another. Hence, these pipes undergo tremendous pressure by the fluid carried. The present work entails the optimization of the withstanding pressure of the HDPE pipes using Taguchi technique. The traditional heuristic methodology stresses on a trial and error approach and relies heavily upon the accumulated experience of the process engineers for determining the optimal process control parameters. This results in setting up of less-than-optimal values. Hence, there arouse a necessity to determine optimal process control parameters for the pipe extrusion process, which can ensure robust pipe quality and process reliability. In the proposed optimization strategy, the design of experiments (DoE) are conducted wherein different control parameter combinations are analyzed by considering multiple setting levels of each control parameter. The concept of signal-to-noise ratio ( S/ N ratio) is applied and ultimately optimum values of process control parameters are obtained as: pushing zone temperature of 166 °C, Dimmer speed at 08 rpm, and Die head temperature to be 192 °C. Confirmation experimental run is also conducted to verify the analysis and research result and values proved to be in synchronization with the main experimental findings and the withstanding pressure showed a significant improvement from 0.60 to 1.004 Mpa.

  3. The need for control of magnetic parameters for energy efficient performance of magnetic tunnel junctions

    Science.gov (United States)

    Farhat, I. A. H.; Gale, E.; Alpha, C.; Isakovic, A. F.

    2017-07-01

    Optimizing energy performance of Magnetic Tunnel Junctions (MTJs) is the key for embedding Spin Transfer Torque-Random Access Memory (STT-RAM) in low power circuits. Due to the complex interdependencies of the parameters and variables of the device operating energy, it is important to analyse parameters with most effective control of MTJ power. The impact of threshold current density, Jco , on the energy and the impact of HK on Jco are studied analytically, following the expressions that stem from Landau-Lifshitz-Gilbert-Slonczewski (LLGS-STT) model. In addition, the impact of other magnetic material parameters, such as Ms , and geometric parameters such as tfree and λ is discussed. Device modelling study was conducted to analyse the impact at the circuit level. Nano-magnetism simulation based on NMAGTM package was conducted to analyse the impact of controlling HK on the switching dynamics of the film.

  4. PI Stabilization for Congestion Control of AQM Routers with Tuning Parameter Optimization

    Directory of Open Access Journals (Sweden)

    S. Chebli

    2016-09-01

    Full Text Available In this paper, we consider the problem of stabilizing network using a new proportional- integral (PI based congestion controller in active queue management (AQM router; with appropriate model approximation in the first order delay systems, we seek a stability region of the controller by using the Hermite- Biehler theorem, which isapplicable to quasipolynomials. A Genetic Algorithm technique is employed to derive optimal or near optimal PI controller parameters.

  5. Rapid Mechanistic Evaluation and Parameter Estimation of Putative Inhibitors in a Single-Step Progress-Curve Analysis: The Case of Horse Butyrylcholinesterase

    Directory of Open Access Journals (Sweden)

    Jure Stojan

    2017-07-01

    Full Text Available Highly efficient and rapid lead compound evaluation for estimation of inhibition parameters and type of inhibition is proposed. This is based on a single progress-curve measurement in the presence of each candidate compound, followed by the simultaneous analysis of all of these curves using the ENZO enzyme kinetics suite, which can be implemented as a web application. In the first step, all of the candidate ligands are tested as competitive inhibitors. Where the theoretical curves do not correspond to the experimental data, minimal additional measurements are added, with subsequent processing according to modified reaction mechanisms.

  6. Rapid Mechanistic Evaluation and Parameter Estimation of Putative Inhibitors in a Single-Step Progress-Curve Analysis: The Case of Horse Butyrylcholinesterase.

    Science.gov (United States)

    Stojan, Jure

    2017-07-26

    Highly efficient and rapid lead compound evaluation for estimation of inhibition parameters and type of inhibition is proposed. This is based on a single progress-curve measurement in the presence of each candidate compound, followed by the simultaneous analysis of all of these curves using the ENZO enzyme kinetics suite, which can be implemented as a web application. In the first step, all of the candidate ligands are tested as competitive inhibitors. Where the theoretical curves do not correspond to the experimental data, minimal additional measurements are added, with subsequent processing according to modified reaction mechanisms.

  7. Parameters identification for Interior Permanent Magnet Synchronous Motor driven by sensorless control

    OpenAIRE

    Kosaka, Manabu; Uda, Hiroshi

    2013-01-01

    [Abstract] In this paper, a new parameter identification method for Interior Permanent Magnet Synchronous Motor (IPMSM) driven by sensorless control is proposed. Noise and vibration in mechanical plant becomes larger if rotor position estimation error occurs. Furthermore, the rotor position estimation error cause noise and vibration. When a load torque and a reference motor speed are constant, and phase voltages and phase currents in multiple stationary states are measured, motor parameters c...

  8. Noninvasive assessment of liver steatosis in children: the clinical value of controlled attenuation parameter

    OpenAIRE

    Ferraioli, Giovanna; Calcaterra, Valeria; Lissandrin, Raffaella; Guazzotti, Marinella; Maiocchi, Laura; Tinelli, Carmine; De Silvestri, Annalisa; Regalbuto, Corrado; Pelizzo, Gloria; Larizza, Daniela; Filice, Carlo

    2017-01-01

    Background To assess the clinical validity of controlled attenuation parameter (CAP) in the diagnosis of hepatic steatosis in a series of overweight or obese children by using the imperfect gold standard methodology. Methods Consecutive children referred to our institution for auxological evaluation or obesity or minor elective surgery were prospectively enrolled. Anthropometric and biochemical parameters were recorded. Ultrasound (US) assessment of steatosis was carried out using ultrasound ...

  9. Algorithms of control parameters selection for automation of FDM 3D printing process

    Directory of Open Access Journals (Sweden)

    Kogut Paweł

    2017-01-01

    Full Text Available The paper presents algorithms of control parameters selection of the Fused Deposition Modelling (FDM technology in case of an open printing solutions environment and 3DGence ONE printer. The following parameters were distinguished: model mesh density, material flow speed, cooling performance, retraction and printing speeds. These parameters are independent in principle printing system, but in fact to a certain degree that results from the selected printing equipment features. This is the first step for automation of the 3D printing process in FDM technology.

  10. Raman scattering of light and photoinduced control of the parameters of high temperature superconductors

    Science.gov (United States)

    Dovgii, Ia. O.; Kityk, I. V.; Lutsiv, R. V.; Malinich, S. Z.

    1992-01-01

    Results of a comprehensive study of changes in the parameters of high temperature superconductors induced by UV laser irradiation are reported. With reference to results obtained for YBa2Cu3O(6.2) specimens, the possibility of controlling the parameters of high temperature superconductors by exposing then to nitrogen laser radiation at the liquid helium temperature is demonstrated. Good correlation is obtained between structural parameters and Raman modes 115 and 505/cm, which opens the possibility of the remote monitoring of photostructural changes in high temperature superconductors.

  11. Controlled precipitation for enhanced dissolution rate of flurbiprofen: development of rapidly disintegrating tablets.

    Science.gov (United States)

    Essa, Ebtessam A; Elmarakby, Amira O; Donia, Ahmed M A; El Maghraby, Gamal M

    2017-09-01

    The aim of this work was to investigate the potential of controlled precipitation of flurbiprofen on solid surface, in the presence or absence of hydrophilic polymers, as a tool for enhanced dissolution rate of the drug. The work was extended to develop rapidly disintegrated tablets. This strategy provides simple technique for dissolution enhancement of slowly dissolving drugs with high scaling up potential. Aerosil was dispersed in ethanolic solution of flurbiprofen in the presence and absence of hydrophilic polymers. Acidified water was added as antisolvent to produce controlled precipitation. The resultant particles were centrifuged and dried at ambient temperature before monitoring the dissolution pattern. The particles were also subjected to FTIR spectroscopic, X-ray diffraction and thermal analyses. The FTIR spectroscopy excluded any interaction between flurbiprofen and excipients. The thermal analysis reflected possible change in the crystalline structure and or crystal size of the drug after controlled precipitation in the presence of hydrophilic polymers. This was further confirmed by X-ray diffraction. The modulation in the crystalline structure and size was associated with a significant enhancement in the dissolution rate of flurbiprofen. Optimum formulations were successfully formulated as rapidly disintegrating tablet with subsequent fast dissolution. Precipitation on a large solid surface area is a promising strategy for enhanced dissolution rate with the presence of hydrophilic polymers during precipitation process improving the efficiency.

  12. Hyperspectral Imaging as a Rapid Quality Control Method for Herbal Tea Blends

    Directory of Open Access Journals (Sweden)

    Majolie Djokam

    2017-03-01

    Full Text Available In South Africa, indigenous herbal teas are enjoyed due to their distinct taste and aroma. The acclaimed health benefits of herbal teas include the management of chronic diseases such as hypertension and diabetes. Quality control of herbal teas has become important due to the availability of different brands of varying quality and the production of tea blends. The potential of hyperspectral imaging as a rapid quality control method for herbal tea blends from rooibos (Aspalathus linearis, honeybush (Cyclopia intermedia, buchu (Agathosma Betulina and cancerbush (Sutherlandia frutescens was investigated. Hyperspectral images of raw materials and intact tea bags were acquired using a sisuChema shortwave infrared (SWIR hyperspectral pushbroom imaging system (920–2514 nm. Principal component analysis (PCA plots showed clear discrimination between raw materials. Partial least squares discriminant analysis (PLS-DA models correctly predicted the raw material constituents of each blend and accurately determined the relative proportions. The results were corroborated independently using ultra-high performance liquid chromatography coupled to mass spectrometry (UHPLC-MS. This study demonstrated the application of hyperspectral imaging coupled with chemometric modelling as a reliable, rapid and non-destructive quality control method for authenticating herbal tea blends and to determine relative proportions in a tea bag.

  13. Rapid evolution leads to differential population dynamics and top-down control in resurrectedDaphniapopulations.

    Science.gov (United States)

    Goitom, Eyerusalem; Kilsdonk, Laurens J; Brans, Kristien; Jansen, Mieke; Lemmens, Pieter; De Meester, Luc

    2018-01-01

    There is growing evidence of rapid genetic adaptation of natural populations to environmental change, opening the perspective that evolutionary trait change may subsequently impact ecological processes such as population dynamics, community composition, and ecosystem functioning. To study such eco-evolutionary feedbacks in natural populations, however, requires samples across time. Here, we capitalize on a resurrection ecology study that documented rapid and adaptive evolution in a natural population of the water flea Daphnia magna in response to strong changes in predation pressure by fish, and carry out a follow-up mesocosm experiment to test whether the observed genetic changes influence population dynamics and top-down control of phytoplankton. We inoculated populations of the water flea D. magna derived from three time periods of the same natural population known to have genetically adapted to changes in predation pressure in replicate mesocosms and monitored both Daphnia population densities and phytoplankton biomass in the presence and absence of fish. Our results revealed differences in population dynamics and top-down control of algae between mesocosms harboring populations from the time period before, during, and after a peak in fish predation pressure caused by human fish stocking. The differences, however, deviated from our a priori expectations. An S-map approach on time series revealed that the interactions between adults and juveniles strongly impacted the dynamics of populations and their top-down control on algae in the mesocosms, and that the strength of these interactions was modulated by rapid evolution as it occurred in nature. Our study provides an example of an evolutionary response that fundamentally alters the processes structuring population dynamics and impacts ecosystem features.

  14. Prediction Model of Battery State of Charge and Control Parameter Optimization for Electric Vehicle

    Directory of Open Access Journals (Sweden)

    Bambang Wahono

    2015-07-01

    Full Text Available This paper presents the construction of a battery state of charge (SOC prediction model and the optimization method of the said model to appropriately control the number of parameters in compliance with the SOC as the battery output objectives. Research Centre for Electrical Power and Mechatronics, Indonesian Institute of Sciences has tested its electric vehicle research prototype on the road, monitoring its voltage, current, temperature, time, vehicle velocity, motor speed, and SOC during the operation. Using this experimental data, the prediction model of battery SOC was built. Stepwise method considering multicollinearity was able to efficiently develops the battery prediction model that describes the multiple control parameters in relation to the characteristic values such as SOC. It was demonstrated that particle swarm optimization (PSO succesfully and efficiently calculated optimal control parameters to optimize evaluation item such as SOC based on the model.

  15. Parameters-tuning of PID controller for automatic voltage regulators using the African buffalo optimization.

    Science.gov (United States)

    Odili, Julius Beneoluchi; Mohmad Kahar, Mohd Nizam; Noraziah, A

    2017-01-01

    In this paper, an attempt is made to apply the African Buffalo Optimization (ABO) to tune the parameters of a PID controller for an effective Automatic Voltage Regulator (AVR). Existing metaheuristic tuning methods have been proven to be quite successful but there were observable areas that need improvements especially in terms of the system's gain overshoot and steady steady state errors. Using the ABO algorithm where each buffalo location in the herd is a candidate solution to the Proportional-Integral-Derivative parameters was very helpful in addressing these two areas of concern. The encouraging results obtained from the simulation of the PID Controller parameters-tuning using the ABO when compared with the performance of Genetic Algorithm PID (GA-PID), Particle-Swarm Optimization PID (PSO-PID), Ant Colony Optimization PID (ACO-PID), PID, Bacteria-Foraging Optimization PID (BFO-PID) etc makes ABO-PID a good addition to solving PID Controller tuning problems using metaheuristics.

  16. Anti-Synchronization of Tigan and Li Systems with Unknown Parameters via Adaptive Control

    Directory of Open Access Journals (Sweden)

    Sundarapandian VAIDYANATHAN

    2012-01-01

    Full Text Available In this paper, the adaptive nonlinear control method has been deployed to derive new resultsfor the anti-synchronization of identical Tigan systems (2008, identical Li systems (2009 and nonidenticalTigan and Li systems. In adaptive anti-synchronization of identical chaotic systems, theparameters of the master and slave systems are unknown and the feedback control law has been derivedusing the estimates of the system parameters. In adaptive anti-synchronization of non-identical chaoticsystems, the parameters of the master system are known, but the parameters of the slave system areunknown and accordingly, the feedback control law has been derived using the estimates of theparameters of the slave system. Our adaptive synchronization results derived in this paper for theuncertain Tigan and Li systems are established using Lyapunov stability theory. Numerical simulationsare shown to demonstrate the effectiveness of the adaptive anti-synchronization schemes for theuncertain chaotic systems addressed in this paper.

  17. Rapid Size- Controlled Synthesis of Dextran-Coated, Copper-Doped Iron Oxide Nanoparticles

    Science.gov (United States)

    Wong, Ray M.

    2011-12-01

    Development of dual modality probes enabled for magnetic resonance imaging (MRI) and positron emission tomography (PET) has been on the rise in recent years due to the potential for these probes to facilitate combining the complementary high resolution of MRI and the high sensitivity of PET. The efficient synthesis of multimodal probes that include the radiolabels for PET can be hindered due to prolonged reaction times during radioisotope incorporation, and the resulting decay of the radiolabel. Along with a time-efficient synthesis, one also needs an optimal synthesis that yields products in a desirable size range (between 20-100 nm) to increase blood retention time. In this work, we describe a novel, rapid, microwave-based synthesis of dextran-coated iron oxide nanoparticles doped with copper (DIO/Cu). Traditional methods for synthesizing dextran-coated iron oxide particles require refluxing for 2 hours and result in approximately 50 nm particles. We demonstrate that microwave synthesis can produce 50 nm nanoparticles in 5 minutes of heating. We discuss the various parameters used in the microwave synthesis protocol to vary the size distribution of DIO/Cu, and demonstrate the successful incorporation of copper into these particles with the aim of future use for rapid 64Cu incorporation.

  18. Robust PID Steering Control in Parameter Space for Highly Automated Driving

    Directory of Open Access Journals (Sweden)

    Mümin Tolga Emirler

    2014-01-01

    Full Text Available This paper is on the design of a parameter space based robust PID steering controller. This controller is used for automated steering in automated path following of a midsized sedan. Linear and nonlinear models of this midsized sedan are presented in the paper. Experimental results are used to validate the longitudinal and lateral dynamic models of this vehicle. This paper is on automated steering control and concentrates on the lateral direction of motion. The linear model is used to design a PID steering controller in parameter space that satisfies D-stability. The PID steering controller that is designed is used in a simulation study to illustrate the effectiveness of the proposed method. Simulation results for a circular trajectory and for a curved trajectory are presented and discussed in detail. This study is part of a larger research effort aimed at implementing highly automated driving in a midsized sedan.

  19. Determinants of rapid weight gain during infancy: baseline results from the NOURISH randomised controlled trial

    Directory of Open Access Journals (Sweden)

    Mihrshahi Seema

    2011-11-01

    Full Text Available Abstract Background Rapid weight gain in infancy is an important predictor of obesity in later childhood. Our aim was to determine which modifiable variables are associated with rapid weight gain in early life. Methods Subjects were healthy infants enrolled in NOURISH, a randomised, controlled trial evaluating an intervention to promote positive early feeding practices. This analysis used the birth and baseline data for NOURISH. Birthweight was collected from hospital records and infants were also weighed at baseline assessment when they were aged 4-7 months and before randomisation. Infant feeding practices and demographic variables were collected from the mother using a self administered questionnaire. Rapid weight gain was defined as an increase in weight-for-age Z-score (using WHO standards above 0.67 SD from birth to baseline assessment, which is interpreted clinically as crossing centile lines on a growth chart. Variables associated with rapid weight gain were evaluated using a multivariable logistic regression model. Results Complete data were available for 612 infants (88% of the total sample recruited with a mean (SD age of 4.3 (1.0 months at baseline assessment. After adjusting for mother's age, smoking in pregnancy, BMI, and education and infant birthweight, age, gender and introduction of solid foods, the only two modifiable factors associated with rapid weight gain to attain statistical significance were formula feeding [OR = 1.72 (95%CI 1.01-2.94, P = 0.047] and feeding on schedule [OR = 2.29 (95%CI 1.14-4.61, P = 0.020]. Male gender and lower birthweight were non-modifiable factors associated with rapid weight gain. Conclusions This analysis supports the contention that there is an association between formula feeding, feeding to schedule and weight gain in the first months of life. Mechanisms may include the actual content of formula milk (e.g. higher protein intake or differences in feeding styles, such as feeding to schedule

  20. Rapid implementation of the repair-misrepair-fixation (RMF) model facilitating online adaption of radiosensitivity parameters in ion therapy

    Science.gov (United States)

    Kamp, F.; Carlson, D. J.; Wilkens, J. J.

    2017-07-01

    Introduction: Treatment planning for ion therapy must account for physical properties of the beam as well as differences in the relative biological effectiveness (RBE) of ions compared to photons. In this work, we present a fast RBE calculation approach, based on the decoupling of physical properties and the αx / βx ratio commonly used to describe the radiosensitivity of irradiated cells or organs. Material and methods: In the framework of the mechanistic repair-misrepair-fixation (RMF) model, the biological modeling can be decoupled from the physical dose. This was implemented into a research treatment planning system for carbon ion therapy. Results: The presented implementation of the RMF model is very fast, allowing online changes of αx / βx . For example, a change of αx / βx including a complete biological modeling and a recalculation of RBE for 2.9\\cdot 105 voxel takes 4 ms on a 4 CPU, 3.2 GHz workstation. Discussion and conclusion: The derived decoupling within the RMF model allows fast changes in αx / βx , facilitating online adaption by the user. This provides new options for radiation oncologists, facilitating online variations of the radiobiological input parameters during the treatment plan evaluation process as well as uncertainty and sensitivity analyses.

  1. Sky view factor as a parameter in applied climatology rapid estimation by the SkyHelios model

    Directory of Open Access Journals (Sweden)

    Andreas Matzarakis

    2011-02-01

    Full Text Available Graphic processors can be integrated in simulation models computing e.g. three-dimensional flow visualization or radiation estimation. Going a step further it is even possible to use modern graphics hardware as general-purpose array processors. These ideas and approaches use a cheap mass production technology to solve specific problems. This technology can be applied for modelling climate conditions or climate-relevant parameters on the micro-scale or with respect to urban areas. To illustrate this we present the simulation of the continuous sky view factor (SVF, thus the calculation of the SVF for each point of a complex area. Digital elevation models (DEM, data concerning urban obstacles (OBS or other digital files can serve as a data base in order to quantify relevant climatic conditions in urban and complex areas. The following benefits are provided by the new model: (a short computing time (b short development time and (c low costs due to the use of open source frameworks. The application of the developed model will be helpful to estimate radiation fluxes and the mean radiant temperature in urban and complex situations accurately, especially in combination with an urban microclimate model, e.g. the RayMan model.

  2. Fractional Order Controller Designing with Firefly Algorithm and Parameter Optimization for Hydroturbine Governing System

    Directory of Open Access Journals (Sweden)

    Li Junyi

    2015-01-01

    Full Text Available A fractional order PID (FOPID controller, which is suitable for control system designing for being insensitive to the variation in system parameter, is proposed for hydroturbine governing system in the paper. The simultaneous optimization for several parameters of controller, that is, Ki, Kd, Kp, λ, and μ, is done by a recently developed metaheuristic nature-inspired algorithm, namely, the firefly algorithm (FA, for the first time, where the selecting, moving, attractiveness behavior between fireflies and updating of brightness, and decision range are studied in detail to simulate the optimization process. Investigation clearly reveals the advantages of the FOPID controller over the integer controllers in terms of reduced oscillations and settling time. The present work also explores the superiority of FA based optimization technique in finding optimal parameters of the controller. Further, convergence characteristics of the FA are compared with optimum integer order PID (IOPID controller to justify its efficiency. What is more, analysis confirms the robustness of FOPID controller under isolated load operation conditions.

  3. Application of a PID controller based on fuzzy logic to reduce variations in the control parameters in PWR reactors

    Energy Technology Data Exchange (ETDEWEB)

    Vasconcelos, Wagner Eustaquio de; Lira, Carlos Alberto Brayner de Oliveira; Brito, Thiago Souza Pereira de; Afonso, Antonio Claudio Marques, E-mail: wagner@unicap.br, E-mail: cabol@ufpe.br, E-mail: afonsofisica@gmail.com, E-mail: thiago.brito86@yahoo.com.br [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Centro de Tecnologia e Geociencias. Departamento de Energia Nuclear; Cruz Filho, Antonio Jose da; Marques, Jose Antonio, E-mail: antonio.jscf@gmail.com, E-mail: jamarkss@uol.com.br [Universidade Catolica de Pernambuco (CCT/PUC-PE), Recife, PE (Brazil). Centro de Ciencias e Tecnologia; Teixeira, Marcello Goulart, E-mail: marcellogt@dcc.ufrj.br [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil). Instituto de Matematica. Dept. de Matematica

    2013-07-01

    Nuclear reactors are in nature nonlinear systems and their parameters vary with time as a function of power level. These characteristics must be considered if large power variations occur in power plant operational regimes, such as in load-following conditions. A PWR reactor has a component called pressurizer, whose function is to supply the necessary high pressure for its operation and to contain pressure variations in the primary cooling system. The use of control systems capable of reducing fast variations of the operation variables and to maintain the stability of this system is of fundamental importance. The best-known controllers used in industrial control processes are proportional-integral-derivative (PID) controllers due to their simple structure and robust performance in a wide range of operating conditions. However, designing a fuzzy controller is seen to be a much less difficult task. Once a Fuzzy Logic controller is designed for a particular set of parameters of the nonlinear element, it yields satisfactory performance for a range of these parameters. The objective of this work is to develop fuzzy proportional-integral-derivative (fuzzy-PID) control strategies to control the level of water in the reactor. In the study of the pressurizer, several computer codes are used to simulate its dynamic behavior. At the fuzzy-PID control strategy, the fuzzy logic controller is exploited to extend the finite sets of PID gains to the possible combinations of PID gains in stable region. Thus the fuzzy logic controller tunes the gain of PID controller to adapt the model with changes in the water level of reactor. The simulation results showed a favorable performance with the use to fuzzy-PID controllers. (author)

  4. Simple Design of a PID Controller and Tuning of Its Parameters Using LabVIEW Software

    Directory of Open Access Journals (Sweden)

    Subrata CHATTOPADHYAY

    2011-06-01

    Full Text Available Feedback control system with PID Controller is an important technique that is widely used in the process industries. Their main advantage is that corrective action occurs as soon as the controlled variable deviates from the set point, regardless of the source and type of disturbance. Again if process conditions change, retuning the controller usually produces satisfactory control. The degree of convergence of the output waveform of PID controller is depending upon proper tuning of the controller. In this paper the control parameters (KP, KI, KD of a PID controller are tuned to their optimum value. The controller algorithm is simulated by using LabVIEW (G language software and usefulness of this controller for controlling different process variables is studied using proper tuning. The designed virtual instrument includes all the necessary components and facilities necessary for PID controller to function properly and to control any linear process. All the issues related to integral windup, derivative overrun, output signal limits and sampling interval ∆t are well considered. The created Sub VI program may be used as a controller in a closed loop which is able to control a process.

  5. Impulse control disorder and rapid eye movement sleep behavior disorder in Parkinson's disease.

    Science.gov (United States)

    Bayard, Sophie; Dauvilliers, Yves; Yu, Huan; Croisier-Langenier, Muriel; Rossignol, Alexia; Charif, Mahmoud; Geny, Christian; Carlander, Bertrand; Cochen De Cock, Valérie

    2014-12-01

    The relationship between ICD and RBD is still not yet understood and the results from the current literature are contradictory in PD. We aimed to explore the association between rapid eye movement (REM) sleep behavior disorder (RBD) and impulse control disorder in Parkinson's disease. Ninety-eight non-demented patients with Parkinson's disease underwent one night of video-polysomnography recording. The diagnosis of RBD was established according to clinical and polysomnographic criteria. Impulse control disorders were determined by a gold standard, semi-structured diagnostic interview. Half of the patients (n = 49) reported clinical history of RBD while polysomnographic diagnosis of RBD was confirmed in 31.6% of the patients (n = 31). At least one impulse control disorder was identified in 21.4% of patients, 22.6% with RBD and 20.9% without. Logistic regression controlling for potential confounders indicated that both clinical RBD (OR = 0.34, 95% CI = 0.07-1.48, P = 0.15) and polysomnographic confirmed RBD diagnoses (OR = 0.1.28, 95% CI = 0.31-5.33, P = 0.34) were not associated with impulse control disorder. In Parkinson's disease, REM Sleep Behavior Disorder is not associated with impulse control disorder. The results of our study do not support the notion that PSG-confirmed RBD and ICD share a common pathophysiology. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Virtual Simulator for Autonomous Mobile Robots Navigation System Using Concepts of Control Rapid Prototyping

    Directory of Open Access Journals (Sweden)

    Leonimer Flavio de Melo

    2013-09-01

    Full Text Available This work presents the proposal of virtual environment implementation for project simulation and conception of supervision and control systems for mobile robots, that are capable to operate and adapting in different environments and conditions. This virtual system has as purpose to facilitate the development of embedded architecture systems, emphasizing the implementation of tools that allow the simulation of the kinematic conditions, dynamic and control, with real time monitoring of all important system points. For this, open control architecture is proposal, integrating the two main techniques of robotic control implementation in the hardware level: systems microprocessors and reconfigurable hardware devices. The implemented simulator system is composed of a trajectory generating module, a kinematic and dynamic simulator module and of a analysis module of results and errors. The kinematic and dynamic simulator module makes all simulation of the mobile robot following the pre-determined trajectory of the trajectory generator. All the kinematic and dynamic results shown during the simulation can be evaluated and visualized in graphs and tables formats, in the results analysis module, allowing an improvement in the system, minimizing the errors with the necessary adjustments optimization. For controller implementation in the embedded system, it uses the rapid prototyping, which is the technology that allows, in set with the virtual simulation environment, the development of a controller project for mobile robots. The validation and tests had been accomplishing with nonholonomics mobile robots models with differential transmission.

  7. Monitoring of β-d-Galactosidase Activity as a Surrogate Parameter for Rapid Detection of Sewage Contamination in Urban Recreational Water

    Directory of Open Access Journals (Sweden)

    Ingun Tryland

    2016-02-01

    Full Text Available Simple, automated methods are required for rapid detection of wastewater contamination in urban recreational water. The activity of the enzyme β-d-galactosidase (GAL can rapidly (<2 h be measured by field instruments, or a fully automated instrument, and was evaluated as a potential surrogate parameter for estimating the level of fecal contamination in urban waters. The GAL-activity in rivers, affected by combined sewer overflows, increased significantly during heavy rainfall, and the increase in GAL-activity correlated well with the increase in fecal indicator bacteria. The GAL activity in human feces (n = 14 was high (mean activity 7 × 107 ppb MU/hour and stable (1 LOG10 variation, while the numbers of Escherichia coli and intestinal enterococci varied by >5 LOG10. Furthermore, the GAL-activity per gram feces from birds, sheep and cattle was 2–3 LOG10 lower than the activity from human feces, indicating that high GAL-activity in water may reflect human fecal pollution more than the total fecal pollution. The rapid method can only be used to quantify high levels of human fecal pollution, corresponding to about 0.1 mg human feces/liter (or 103 E. coli/100 mL, since below this limit GAL-activity from non-fecal environmental sources may interfere.

  8. Position and Speed Sensorless Control System of Permanent Magnet Synchronous Motor with Parameter Identification

    Science.gov (United States)

    Morimoto, Shigeo; Shimmei, Akihide; Sanada, Masayuki; Takeda, Yoji

    The model parameters of permanent magnet synchronous motor (PMSM) are required for a high-performance control and a model based sensorless control. This paper proposes the sensorless control system of PMSM that doesn't need parametric information beforehand. The parameters of PMSM drive system including inverter are identified at standstill and operating condition. At first, the initial rotor position is estimated by a signal injection sensorless scheme, in which the machine parameters are not required. After the initial position has been estimated, the resistance including on-resistance of IGBT, the voltage error caused by dead-time of inverter, d-axis and q-axis inductances are identified at standstill. After the motor starts by the signal injection sensorless control, the sensorless scheme changes to an extended EMF estimation based scheme. The estimated parameters of resistance, d-axis and q-axis inductances are used in such sensorless control. The magnet flux-linkage, which can not be estimated at standstill, is identified under the sensorless operation at medium and high speeds. The effectiveness of the proposed method is verified by several experimental results.

  9. Design of Parameter Independent, High Performance Sensorless Controllers for Permanent Magnet Synchronous Machines

    DEFF Research Database (Denmark)

    Xie, Ge

    The Permanent Magnet Synchronous Machine (PMSM) has become an attractive candidate for various industrial applications due to its high efficiency and torque density. In the PMSM drive system, simple and robust control methods play an important role in achieving satisfactory drive performances......, a generalized, universal sensorless controller that can be used for different types of PMSMs is desired. It is highly preferred that there should be no machine parameters involved in the sensorless controller. The understanding of the PM machine model is a foremost requirement for the machine control...

  10. Flux qubit interaction with rapid single-flux quantum logic circuits: Control and readout

    Science.gov (United States)

    Klenov, N. V.; Kuznetsov, A. V.; Soloviev, I. I.; Bakurskiy, S. V.; Denisenko, M. V.; Satanin, A. M.

    2017-07-01

    We present the results of an analytical study and numerical simulation of the dynamics of a superconducting three-Josephson-junction (3JJ) flux qubit magnetically coupled with rapid single-flux quantum (RSFQ) logic circuit, which demonstrate the fundamental possibility of implementing the simplest logic operations at picosecond times, as well as rapid non-destructive readout. It is shown that when solving optimization problems, the qubit dynamics can be conveniently interpreted as a precession of the magnetic moment vector around the direction of the magnetic field. In this case, the role of magnetic field components is played by combinations of the Hamiltonian matrix elements, and the role of the magnetic moment is played by the Bloch vector. Features of the 3JJ qubit model are discussed during the analysis of how the qubit is affected by exposure to a short control pulse, as are the similarities between the Bloch and Landau-Lifshitz-Gilbert equations. An analysis of solutions to the Bloch equations made it possible to develop recommendations for the use of readout RSFQ circuits in implementing an optimal interface between the classical and quantum parts of the computer system, as well as to justify the use of single-quantum logic in order to control superconducting quantum circuits on a chip.

  11. Rapid fabrication method of a microneedle mold with controllable needle height and width.

    Science.gov (United States)

    Lin, Yen-Heng; Lee, I-Chi; Hsu, Wei-Chieh; Hsu, Ching-Hong; Chang, Kai-Ping; Gao, Shao-Syuan

    2016-10-01

    The main issue of transdermal drug delivery is that macromolecular drugs cannot diffuse through the stratum corneum of skin. Many studies have pursued micro-sized needles encapsulated with drugs to overcome this problem, as these needles can pierce the stratum corneum and allow drugs to enter the circulatory system of the human body. However, most microneedle fabrication processes are time-consuming and require expensive equipment. In this study, we demonstrate a rapid method for fabricating a microneedle mold using drawing lithography and a UV-cured resin. The mold was filled with a water-soluble material, polyvinylpyrrolidone (PVP), which was then demolded to produce a water-soluble microneedle array. The results of an in vitro skin insertion test using PVP microneedles and pig ear skin demonstrated the feasibility of the microneedle mold. In addition, by controlling the viscosity of the UV-cured resin through various heat treatments, microneedles with different heights and aspect ratios were produced. Compared with other methods, this technology significantly simplifies and accelerates the mold fabrication process. In addition, the required equipment is relatively simple and inexpensive. Through this technology, we can rapidly fabricate microneedle molds with controllable dimensions for various applications.

  12. Research of energy efficiency evaluation parameters for power quality control device based on IGBT module

    Science.gov (United States)

    Xu, Jieyan; Liu, Yang; Mao, Yongqiu; Chen, Zheng; Jia, Rongda; Zhao, Caiyi; Yang, Xi

    2017-01-01

    In this paper, the energy efficiency evaluation parameters for power quality control device based on IGBT modules have been discussed. First of all, energy consumption of the typical power quality control equipment, such as SVG, APF and MEC, under the rated conditions, have been analyzed to identify the main energy-consuming parts. Then, energy loss mechanism and energy saving path of IGBT module have been discussed. And the energy saving improvement direction of the power quality control equipment based on IGBT module is identified at the same time. At last, the applicable energy efficiency evaluation parameters for power quality control device have been selected, based on the research of the product performances for energy efficiency of power grid.

  13. Design and fabrication of magnetically functionalized flexible micropillar arrays for rapid and controllable microfluidic mixing

    KAUST Repository

    Zhou, BingPu

    2015-03-25

    Magnetically functionalized PDMS-based micropillar arrays have been successfully designed, fabricated and implanted for controllable microfluidic mixing. The arrangement of PDMS micropillar arrays inside the microchannel can be flexibly controlled by an external magnetic field. As a consequence, the flow fields inside the microchannel can be regulated at will via magnetic activation conveniently. When a microchannel is implanted with such micropillar arrays, two microstreams can be mixed easily and controllably upon the simple application of an on/off magnetic signal. Mixing efficiencies based on micropillar arrays with different densities were investigated and compared. It was found that micropillar arrays with higher density (i.e. smaller pillar pitch) would render better mixing performance. Our microfluidic system is capable of generating highly reproducible results within many cycles of mixing/non-mixing conversion. We believe that the simple mixing-triggering method together with rapid and controllable mixing control will be extraordinarily valuable for various biological or chemical applications in the future. This journal is © The Royal Society of Chemistry 2015.

  14. Speed Control of Separately Excited D.C. Motor using Self-Tuned Parameters of PID Controller

    Directory of Open Access Journals (Sweden)

    A. K. Mansoor

    2013-05-01

    Full Text Available This paper presents a simulation and hardware implementation of a closed loop control of a separately excited D.C. motor using a self-tuning PID controller. The PID controller design is based on using the Field Programmable Analog Array (FPAA technology. Parameters tuning of the PID controller is achieved by using the genetic algorithm (GA. The FPAA controller based technology gives the advantage of low power, no quantization noise, high bandwidth and high speed response. The practical results show that a self-tuning controller can outperform a hand-tuned solution and demonstrate adaptability to plant drift; also it gives very acceptable results in the reduction of overshoot, stability time and the steady-state transient response of the controlled plant.

  15. Optimizing the control process parameters for the induction soldering of aluminium alloy waveguide paths1

    Science.gov (United States)

    Tynchenko, V. S.; Murygin, A. V.; Petrenko, V. E.; Emilova, O. A.; Bocharov, A. N.

    2017-10-01

    The paper describes the problem of selecting the optimal initial values of algorithm parameters for the process of the induction soldering of aluminium alloy waveguide paths. The authors consider some factors influencing the quality of waveguide soldered joint elements. These factors depend on the correct choice of initial values for control parameters. The problem of optimizing such parameters for further analytical and numerical studies is researched by authors. For solving the stated task, the random search method is selected, allowing for an acceptable field study within the stated time to solve the problem of control optimization with the level of accuracy required by the technological process. Therefore, optimal initial values of the induction soldering technological process were found for three sizes of waveguide tubes and flanges.

  16. Robust control design for active driver assistance systems a linear-parameter-varying approach

    CERN Document Server

    Gáspár, Péter; Bokor, József; Nemeth, Balazs

    2017-01-01

    This monograph focuses on control methods that influence vehicle dynamics to assist the driver in enhancing passenger comfort, road holding, efficiency and safety of transport, etc., while maintaining the driver’s ability to override that assistance. On individual-vehicle-component level the control problem is formulated and solved by a unified modelling and design method provided by the linear parameter varying (LPV) framework. The global behaviour desired is achieved by a judicious interplay between the individual components, guaranteed by an integrated control mechanism. The integrated control problem is also formalized and solved in the LPV framework. Most important among the ideas expounded in the book are: application of the LPV paradigm in the modelling and control design methodology; application of the robust LPV design as a unified framework for setting control tasks related to active driver assistance; formulation and solution proposals for the integrated vehicle control problem; proposal for a re...

  17. Robust H infinity control design for the space station with structured parameter uncertainty

    Science.gov (United States)

    Byun, Kuk-Whan; Wie, Bong; Geller, David; Sunkel, John

    1992-01-01

    A robust H-infinity control design methodology and its application to a Space Station attitude and momentum control problem are presented. This new approach incorporates nonlinear multi-parameter variations in the state-space formulation of H-infinity control theory. An application of this robust H-infinity control synthesis technique to the Space Station control problem yields a remarkable result in stability robustness with respect to the moments-of-inertia variation of about 73% in one of the structured uncertainty directions. The performance and stability of this new robust H-infinity controller for the Space Station are compared to those of other controllers designed using a standard linear-quadratic-regulator synthesis technique.

  18. effect of varying controller parameters on the performance of a fuzzy

    African Journals Online (AJOL)

    Dr Obe

    Abstract. This paper presents the results of computer simulation studies designed to isolate the effects of the major parameters of a fuzzy logic controller namely the range of the universe of discourse, the extent of overlap of the fuzzy sets, the rules in the rule base and the modes of the output fuzzy sets on the performance of ...

  19. In vitro evaluation of the quality control parameters of five brands of ...

    African Journals Online (AJOL)

    In this study, the quality control parameters of five brands of metronidazole tablets produced in Nigeria were assessed to ascertain their pharmacopeial compliance. The potency of the active drug content and other tablet properties were assessed using HPLC and the British Pharmacopeia methods respectively. Results ...

  20. LMI-based gain scheduled controller synthesis for a class of linear parameter varying systems

    DEFF Research Database (Denmark)

    Bendtsen, Jan Dimon; Anderson, Brian; Lanzon, Alexander

    2006-01-01

    This paper presents a novel method for constructing controllers for a class of single-input multiple-output (SIMO) linear parameter varying (LPV) systems. This class of systems encompasses many physical systems, in particular systems where individual components vary with time, and is therefore...

  1. Application of the Morris method for screening the influential parameters of fuzzy controllers applied to WWTPs

    DEFF Research Database (Denmark)

    Ruano, M.V.; Ribes, J.; Ferrer, J,

    2011-01-01

    In this paper,we evaluate the application of a sensitivity analysis to help fine-tuning a fuzzy controller for a biological nitrogen and phosphorus removal (BNPR) plant. The Morris Screeningmethod is proposed and evaluated as a prior step to obtain the parameter significance ranking. First, an it...

  2. DETERMINE THE RANGE OF VARIATION OF THE CONTROL SUBSYSTEM OUTPUT PARAMETERS

    Directory of Open Access Journals (Sweden)

    M. A. Bobrin

    2015-01-01

    Full Text Available For the evaluation of the tolerance of output parameters of the controls functional subsystem the hydraulic system under different operating conditions and phases of flight are given mathematical relationships and the results obtained in Mathcad are given in graphical form.

  3. History of malaria control in Tajikistan and rapid malaria appraisal in an agro-ecological setting.

    Science.gov (United States)

    Matthys, Barbara; Sherkanov, Tohir; Karimov, Saifudin S; Khabirov, Zamonidin; Mostowlansky, Till; Utzinger, Jürg; Wyss, Kaspar

    2008-10-26

    Reported malaria cases in rice growing areas in western Tajikistan were at the root of a rapid appraisal of the local malaria situation in a selected agro-ecological setting where only scarce information was available. The rapid appraisal was complemented by a review of the epidemiology and control of malaria in Tajikistan and Central Asia from 1920 until today. Following a resurgence in the 1990s, malaria transmission has been reduced considerably in Tajikistan as a result of concerted efforts by the government and international agencies. The goal for 2015 is transmission interruption, with control interventions and surveillance currently concentrated in the South, where foci of Plasmodium vivax and Plasmodium falciparum persist. The rapid malaria appraisal was carried out in six communities of irrigated rice cultivation during the peak of malaria transmission (August/September 2007) in western Tajikistan. In a cross-sectional survey, blood samples were taken from 363 schoolchildren and examined for Plasmodium under a light microscope. A total of 56 farmers were interviewed about agricultural activities and malaria. Potential Anopheles breeding sites were characterized using standardized procedures. A literature review on the epidemiology and control of malaria in Tajikistan was conducted. One case of P. vivax was detected among the 363 schoolchildren examined (0.28%). The interviewees reported to protect themselves against mosquito bites and used their own concepts on fever conditions, which do not distinguish between malaria and other diseases. Three potential malaria vectors were identified, i.e. Anopheles superpictus, Anopheles pulcherrimus and Anopheles hyrcanus in 58 of the 73 breeding sites examined (79.5%). Rice paddies, natural creeks and man-made ponds were the most important Anopheles habitats. The presence of malaria vectors and parasite reservoirs, low awareness of, and protection against malaria in the face of population movements and inadequate

  4. History of malaria control in Tajikistan and rapid malaria appraisal in an agro-ecological setting

    Directory of Open Access Journals (Sweden)

    Utzinger Jürg

    2008-10-01

    Full Text Available Abstract Background Reported malaria cases in rice growing areas in western Tajikistan were at the root of a rapid appraisal of the local malaria situation in a selected agro-ecological setting where only scarce information was available. The rapid appraisal was complemented by a review of the epidemiology and control of malaria in Tajikistan and Central Asia from 1920 until today. Following a resurgence in the 1990s, malaria transmission has been reduced considerably in Tajikistan as a result of concerted efforts by the government and international agencies. The goal for 2015 is transmission interruption, with control interventions and surveillance currently concentrated in the South, where foci of Plasmodium vivax and Plasmodium falciparum persist. Methods The rapid malaria appraisal was carried out in six communities of irrigated rice cultivation during the peak of malaria transmission (August/September 2007 in western Tajikistan. In a cross-sectional survey, blood samples were taken from 363 schoolchildren and examined for Plasmodium under a light microscope. A total of 56 farmers were interviewed about agricultural activities and malaria. Potential Anopheles breeding sites were characterized using standardized procedures. A literature review on the epidemiology and control of malaria in Tajikistan was conducted. Results One case of P. vivax was detected among the 363 schoolchildren examined (0.28%. The interviewees reported to protect themselves against mosquito bites and used their own concepts on fever conditions, which do not distinguish between malaria and other diseases. Three potential malaria vectors were identified, i.e. Anopheles superpictus, Anopheles pulcherrimus and Anopheles hyrcanus in 58 of the 73 breeding sites examined (79.5%. Rice paddies, natural creeks and man-made ponds were the most important Anopheles habitats. Conclusion The presence of malaria vectors and parasite reservoirs, low awareness of, and protection against

  5. History of malaria control in Tajikistan and rapid malaria appraisal in an agro-ecological setting

    Science.gov (United States)

    Matthys, Barbara; Sherkanov, Tohir; Karimov, Saifudin S; Khabirov, Zamonidin; Mostowlansky, Till; Utzinger, Jürg; Wyss, Kaspar

    2008-01-01

    Background Reported malaria cases in rice growing areas in western Tajikistan were at the root of a rapid appraisal of the local malaria situation in a selected agro-ecological setting where only scarce information was available. The rapid appraisal was complemented by a review of the epidemiology and control of malaria in Tajikistan and Central Asia from 1920 until today. Following a resurgence in the 1990s, malaria transmission has been reduced considerably in Tajikistan as a result of concerted efforts by the government and international agencies. The goal for 2015 is transmission interruption, with control interventions and surveillance currently concentrated in the South, where foci of Plasmodium vivax and Plasmodium falciparum persist. Methods The rapid malaria appraisal was carried out in six communities of irrigated rice cultivation during the peak of malaria transmission (August/September 2007) in western Tajikistan. In a cross-sectional survey, blood samples were taken from 363 schoolchildren and examined for Plasmodium under a light microscope. A total of 56 farmers were interviewed about agricultural activities and malaria. Potential Anopheles breeding sites were characterized using standardized procedures. A literature review on the epidemiology and control of malaria in Tajikistan was conducted. Results One case of P. vivax was detected among the 363 schoolchildren examined (0.28%). The interviewees reported to protect themselves against mosquito bites and used their own concepts on fever conditions, which do not distinguish between malaria and other diseases. Three potential malaria vectors were identified, i.e. Anopheles superpictus, Anopheles pulcherrimus and Anopheles hyrcanus in 58 of the 73 breeding sites examined (79.5%). Rice paddies, natural creeks and man-made ponds were the most important Anopheles habitats. Conclusion The presence of malaria vectors and parasite reservoirs, low awareness of, and protection against malaria in the face of

  6. A novel abutment construction technique for rapid bridge construction : controlled low strength Materials (CLSM) with full-height concrete panels.

    Science.gov (United States)

    2012-01-01

    One of the major obstacles facing rapid bridge construction for typical span type bridges is the time required to construct bridge abutments and foundations. This can be remedied by using the controlled low strength materials (CLSM) bridge abutment. ...

  7. A novel high-throughput multi-parameter flow cytometry based method for monitoring and rapid characterization of microbiome dynamics in anaerobic systems.

    Science.gov (United States)

    Dhoble, Abhishek S; Bekal, Sadia; Dolatowski, William; Yanz, Connor; Lambert, Kris N; Bhalerao, Kaustubh D

    2016-11-01

    A novel multidimensional flow cytometry based method has been demonstrated to monitor and rapidly characterize the dynamics of the complex anaerobic microbiome associated with perturbations in external environmental factors. While community fingerprinting provides an estimate of the meta genomic structure, flow cytometry provides a fingerprint of the community morphology including its autofluorescence spectrum in a high-throughput manner. Using anaerobic microbial consortia perturbed with the controlled addition of various carbon sources, it is possible to quantitatively discriminate between divergent microbiome analogous to community fingerprinting techniques using automated ribosomal intergenic spacer analysis (ARISA). The utility of flow cytometry based method has also been demonstrated in a fully functional industry scale anaerobic digester to distinguish between microbiome composition caused by varying hydraulic retention time (HRT). This approach exploits the rich multidimensional information from flow cytometry for rapid characterization of the dynamics of microbial communities. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Dual mode adaptive fractional order PI controller with feedforward controller based on variable parameter model for quadruple tank process.

    Science.gov (United States)

    Roy, Prasanta; Roy, Binoy Krishna

    2016-07-01

    The Quadruple Tank Process (QTP) is a well-known benchmark of a nonlinear coupled complex MIMO process having both minimum and nonminimum phase characteristics. This paper presents a novel self tuning type Dual Mode Adaptive Fractional Order PI controller along with an Adaptive Feedforward controller for the QTP. The controllers are designed based on a novel Variable Parameter Transfer Function model. The effectiveness of the proposed model and controllers is tested through numerical simulation and experimentation. Results reveal that the proposed controllers work successfully to track the reference signals in all ranges of output. A brief comparison with some of the earlier reported similar works is presented to show that the proposed control scheme has some advantages and better performances than several other similar works. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

  9. Intelligent Controller Design for Quad-Rotor Stabilization in Presence of Parameter Variations

    Directory of Open Access Journals (Sweden)

    Oualid Doukhi

    2017-01-01

    Full Text Available The paper presents the mathematical model of a quadrotor unmanned aerial vehicle (UAV and the design of robust Self-Tuning PID controller based on fuzzy logic, which offers several advantages over certain types of conventional control methods, specifically in dealing with highly nonlinear systems and parameter uncertainty. The proposed controller is applied to the inner and outer loop for heading and position trajectory tracking control to handle the external disturbances caused by the variation in the payload weight during the flight period. The results of the numerical simulation using gazebo physics engine simulator and real-time experiment using AR drone 2.0 test bed demonstrate the effectiveness of this intelligent control strategy which can improve the robustness of the whole system and achieve accurate trajectory tracking control, comparing it with the conventional proportional integral derivative (PID.

  10. Adaptive nonlinear model predictive control design of a flexible-link manipulator with uncertain parameters

    Science.gov (United States)

    Schnelle, Fabian; Eberhard, Peter

    2017-06-01

    This paper presents a novel adaptive nonlinear model predictive control design for trajectory tracking of flexible-link manipulators consisting of feedback linearization, linear model predictive control, and unscented Kalman filtering. Reducing the nonlinear system to a linear system by feedback linearization simplifies the optimization problem of the model predictive controller significantly, which, however, is no longer linear in the presence of parameter uncertainties and can potentially lead to an undesired dynamical behaviour. An unscented Kalman filter is used to approximate the dynamics of the prediction model by an online parameter estimation, which leads to an adaptation of the optimization problem in each time step and thus to a better prediction and an improved input action. Finally, a detailed fuzzy-arithmetic analysis is performed in order to quantify the effect of the uncertainties on the control structure and to derive robustness assessments. The control structure is applied to a serial manipulator with two flexible links containing uncertain model parameters and acting in three-dimensional space.

  11. Parameters Online Detection and Model Predictive Control during the Grain Drying Process

    Directory of Open Access Journals (Sweden)

    Lihui Zhang

    2013-01-01

    Full Text Available In order to improve the grain drying quality and automation level, combined with the structural characteristics of the cross-flow circulation grain dryer designed and developed by us, the temperature, moisture, and other parameters measuring sensors were placed on the dryer, to achieve online automatic detection of process parameters during the grain drying process. A drying model predictive control system was set up. A grain dry predictive control model at constant velocity and variable temperature was established, in which the entire process was dried at constant velocity (i.e., precipitation rate per hour is a constant and variable temperature. Combining PC with PLC, and based on LabVIEW, a system control platform was designed.

  12. A Survey on Gain-Scheduled Control and Filtering for Parameter-Varying Systems

    Directory of Open Access Journals (Sweden)

    Guoliang Wei

    2014-01-01

    Full Text Available This paper presents an overview of the recent developments in the gain-scheduled control and filtering problems for the parameter-varying systems. First of all, we recall several important algorithms suitable for gain-scheduling method including gain-scheduled proportional-integral derivative (PID control, H2, H∞ and mixed H2/H∞ gain-scheduling methods as well as fuzzy gain-scheduling techniques. Secondly, various important parameter-varying system models are reviewed, for which gain-scheduled control and filtering issues are usually dealt with. In particular, in view of the randomly occurring phenomena with time-varying probability distributions, some results of our recent work based on the probability-dependent gain-scheduling methods are reviewed. Furthermore, some latest progress in this area is discussed. Finally, conclusions are drawn and several potential future research directions are outlined.

  13. Optimization of Allelic Combinations Controlling Parameters of a Peach Quality Model.

    Science.gov (United States)

    Quilot-Turion, Bénédicte; Génard, Michel; Valsesia, Pierre; Memmah, Mohamed-Mahmoud

    2016-01-01

    Process-based models are effective tools to predict the phenotype of an individual in different growing conditions. Combined with a quantitative trait locus (QTL) mapping approach, it is then possible to predict the behavior of individuals with any combinations of alleles. However the number of simulations to explore the realm of possibilities may become infinite. Therefore, the use of an efficient optimization algorithm to intelligently explore the search space becomes imperative. The optimization algorithm has to solve a multi-objective problem, since the phenotypes of interest are usually a complex of traits, to identify the individuals with best tradeoffs between those traits. In this study we proposed to unroll such a combined approach in the case of peach fruit quality described through three targeted traits, using a process-based model with seven parameters controlled by QTL. We compared a current approach based on the optimization of the values of the parameters with a more evolved way to proceed which consists in the direct optimization of the alleles controlling the parameters. The optimization algorithm has been adapted to deal with both continuous and combinatorial problems. We compared the spaces of parameters obtained with different tactics and the phenotype of the individuals resulting from random simulations and optimization in these spaces. The use of a genetic model enabled the restriction of the dimension of the parameter space toward more feasible combinations of parameter values, reproducing relationships between parameters as observed in a real progeny. The results of this study demonstrated the potential of such an approach to refine the solutions toward more realistic ideotypes. Perspectives of improvement are discussed.

  14. LINEAR RELATIONSHIPS TO ASSIST IN PARAMETER SELECTION OF A CUSUM CONTROL CHART

    Directory of Open Access Journals (Sweden)

    Michael Anthony Arnold Cox

    2012-06-01

    Full Text Available The cumulative sum (CUSUM chart is widely employed in quality control. These charts are designed to exhibit acceptable average run lengths (ARL both when the process is in and out of control. For such a chart, for specified ARLs, this paper introduces a technique employing a simple linear approximation for parameter selection. Graphs are produced to provide the coefficients for the fit. The simplicity of this approach should encourage its adoption as an additional tool in the statistical process control kit.

  15. The DNA 'comet assay' as a rapid screening technique to control irradiated food.

    Science.gov (United States)

    Cerda, H; Delincée, H; Haine, H; Rupp, H

    1997-04-29

    The exposure of food to ionizing radiation is being progressively used in many countries to inactivate food pathogens, to eradicate pests, and to extend shelf-life, thereby contributing to a safer and more plentiful food supply. To ensure free consumer choice, irradiated food will be labelled as such, and to enforce labelling, analytical methods to detect the irradiation treatment in the food product itself are desirable. In particular, there is a need for simple and rapid screening methods for the control of irradiated food. The DNA comet assay offers great potential as a rapid tool to detect whether a wide variety of foodstuffs have been radiation processed. In order to simplify the test, the agarose single-layer set-up has been chosen, using a neutral protocol. Interlaboratory blind trials have been successfully carried out with a number of food products, both of animal and plant origin. This paper presents an overview of the hitherto obtained results and in addition the results of an intercomparison test with seeds, dried fruits and spices are described. In this intercomparison, an identification rate of 95% was achieved. Thus, using this novel technique, an effective screening of radiation-induced DNA fragmentation is obtained. Since other food treatments also may cause DNA fragmentation, samples with fragmented DNA suspected to have been irradiated should be analyzed by other validated methods for irradiated food, if such treatments which damage DNA cannot be excluded.

  16. The DNA `comet assay` as a rapid screening technique to control irradiated food

    Energy Technology Data Exchange (ETDEWEB)

    Cerda, H. [Department of Radioecology, The Swedish University of Agricultural Sciences, Uppsala (Sweden); Delincee, H. [Institute of Nutritional Physiology, Federal Research Centre for Nutrition, Karlsruhe (Germany); Haine, H. [Campden and Chorleywood Food Research Association, Chipping Campden, Gloucestershire (United Kingdom); Rupp, H. [Swiss Federal Office of Public Health, Section of Food Chemistry, Berne (Switzerland)

    1997-04-29

    The exposure of food to ionizing radiation is being progressively used in many countries to inactivate food pathogens, to eradicate pests, and to extend shelf-life, thereby contributing to a safer and more plentiful food supply. To ensure free consumer choice, irradiated food will be labelled as such, and to enforce labelling, analytical methods to detect the irradiation treatment in the food product itself are desirable. In particular, there is a need for simple and rapid screening methods for the control of irradiated food. The DNA comet assay offers great potential as a rapid tool to detect whether a wide variety of foodstuffs have been radiation processed. In order to simplify the test, the agarose single-layer set-up has been chosen, using a neutral protocol. Interlaboratory blind trials have been successfully carried out with a number of food products, both of animal and plant origin. This paper presents an overview of the hitherto obtained results and in addition the results of an intercomparison test with seeds, dried fruits and spices are described. In this intercomparison, an identification rate of 95% was achieved. Thus, using this novel technique, an effective screening of radiation-induced DNA fragmentation is obtained. Since other food treatments also may cause DNA fragmentation, samples with fragmented DNA suspected to have been irradiated should be analyzed by other validated methods for irradiated food, if such treatments which damage DNA cannot be excluded.

  17. SOAR telescope control system: a rapid prototype and development in LabVIEW

    Science.gov (United States)

    Ashe, Michael C.; Schumacher, German

    2000-06-01

    A Rapid Prototype and full development plan of the SOAR TCS is reviewed to show advances in: (1) Prototyping speed, which makes implementation and test of features faster than specification under older methods. This allows the development environment and prototype modules to become partners with and part of the specification documents. (2) Real-Time performance and reliability through use of RT Linux. (3) Visually Rich GUI development that allows an emphasis on `seeing' versus `reading'. (4) Long-Term DataLogging and Internet subscription service of all desired variables with instant recall of historical trend data. (5) A `plug-in' software architecture which enables rapid reconfiguration and reuse of the system and/or plug-ins utilizing LabVIEW graphical modules, a scripting language engine (in LabVIEW) and encapsulation of interfaces in `instrument-driver' style `plug-in' modules. (6) A platform- independent development environment and distributed architecture allowing secure internet observation and control via every major OS and hardware platform.

  18. Vibration control of a flexible rotor on variable parameter squeeze film damper

    Science.gov (United States)

    Wang, Chuanfa; Zhang, Azhou; Huang, Taiping

    1993-03-01

    In this paper, the effectiveness of VPSFD (Variable Parameter Squeeze Film Damper) parameter change on control of resonant amplitude of a simple rotor system, which has one disk at the center of the span on one squirrel-cage elastic bearing with VPSFD, is investigated. On the basis of steady state tests, the vibration suppression of the rotor through the first two critical speeds has been done. The results show that the first two resonant amplitudes will be greatly decreased and the rotor system will run smoothly through the first two critical speeds.

  19. Analysis of Inverse Modelling Procedures For The Estimation of Parameters Controlling Macropore Flow

    Science.gov (United States)

    Roulier, S.; Jarvis, N.

    Because they are objective, reproducible, and unambiguous, inverse modelling pro- cedures are increasingly used to identify water flow and solute transport parameters. This study focused on the development and testing of inverse methods to estimate transfer parameters in simulation models which account for rapid non-equilibrium flow in soil macropores. The dual-porosity/dual-permeability model of water flow and solute transport MACRO was linked with the inverse modelling package SUFI. The Bayesian approach followed by SUFI is stable, converging, and is not affected by the usual issues of initial values and local minima. A theoretical study was carried out using the combined tool SUFI/MACRO to assess data requirements for robust param- eter estimation in macropore flow models. Generated "dummy" data were used for this purpose, representing transient state leaching experiments for tracers and pesticides in small soil columns (20 cm height). General issues related to inverse modelling, such as internal correlation and sensitivity, were investigated. Attention was also focused on the significance of experimental and model errors, the degree of macropore flow in the system, and the availability of resident and flux concentrations. The study showed reliable results, especially in the case of strong macropore flow, but both resident and flux concentrations were needed. Errors (up to 30% for the pesticide concentrations) did not affect the robustness of the tool. SUFI linked to MACRO appeared thus to be well suited for global optimisation of the system parameters in soils affected by macropore flow.

  20. Rapid identification of genes controlling virulence and immunity in malaria parasites

    KAUST Repository

    Abkallo, Hussein M.

    2017-07-13

    Identifying the genetic determinants of phenotypes that impact disease severity is of fundamental importance for the design of new interventions against malaria. Here we present a rapid genome-wide approach capable of identifying multiple genetic drivers of medically relevant phenotypes within malaria parasites via a single experiment at single gene or allele resolution. In a proof of principle study, we found that a previously undescribed single nucleotide polymorphism in the binding domain of the erythrocyte binding like protein (EBL) conferred a dramatic change in red blood cell invasion in mutant rodent malaria parasites Plasmodium yoelii. In the same experiment, we implicated merozoite surface protein 1 (MSP1) and other polymorphic proteins, as the major targets of strain-specific immunity. Using allelic replacement, we provide functional validation of the substitution in the EBL gene controlling the growth rate in the blood stages of the parasites.

  1. Controls on valley spacing in landscapes subject to rapid base-level fall

    Science.gov (United States)

    McGuire, Luke; Pelletier, John D.

    2015-01-01

    What controls the architecture of drainage networks is a fundamental question in geomorphology. Recent work has elucidated the mechanisms of drainage network development in steadily uplifting landscapes, but the controls on drainage-network morphology in transient landscapes are relatively unknown. In this paper we exploit natural experiments in drainage network development in incised Plio-Quaternary alluvial fan surfaces in order to understand and quantify drainage network development in highly transient landscapes, i.e. initially unincised low-relief surfaces that experience a pulse of rapid base-level drop followed by relative base-level stasis. Parallel drainage networks formed on incised alluvial-fan surfaces tend to have a drainage spacing that is approximately proportional to the magnitude of the base-level drop. Numerical experiments suggest that this observed relationship between the magnitude of base-level drop and mean drainage spacing is the result of feedbacks among the depth of valley incision, mass wasting and nonlinear increases in the rate of colluvial sediment transport with slope gradient on steep valley side slopes that lead to increasingly wide valleys in cases of larger base-level drop. We identify a threshold magnitude of base-level drop above which side slopes lengthen sufficiently to promote increases in contributing area and fluvial incision rates that lead to branching and encourage drainage networks to transition from systems of first-order valleys to systems of higher-order, branching valleys. The headward growth of these branching tributaries prevents the development of adjacent, ephemeral drainages and promotes a higher mean valley spacing relative to cases in which tributaries do not form. Model results offer additional insights into the response of initially unincised landscapes to rapid base-level drop and provide a preliminary basis for understanding how varying amounts of base-level change influence valley network morphology.

  2. Leader-follower formation control of underactuated surface vehicles based on sliding mode control and parameter estimation.

    Science.gov (United States)

    Sun, Zhijian; Zhang, Guoqing; Lu, Yu; Zhang, Weidong

    2017-12-05

    This paper studies the leader-follower formation control of underactuated surface vehicles with model uncertainties and environmental disturbances. A parameter estimation and upper bound estimation based sliding mode control scheme is proposed to solve the problem of the unknown plant parameters and environmental disturbances. For each of these leader-follower formation systems, the dynamic equations of position and attitude are analyzed using coordinate transformation with the aid of the backstepping technique. All the variables are guaranteed to be uniformly ultimately bounded stable in the closed-loop system, which is proven by the distribution design Lyapunov function synthesis. The main advantages of this approach are that: first, parameter estimation based sliding mode control can enhance the robustness of the closed-loop system in presence of model uncertainties and environmental disturbances; second, a continuous function is developed to replace the signum function in the design of sliding mode scheme, which devotes to reduce the chattering of the control system. Finally, numerical simulations are given to demonstrate the effectiveness of the proposed method. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  3. Rapid size-controlled synthesis of dextran-coated, 64Cu-doped iron oxide nanoparticles.

    Science.gov (United States)

    Wong, Ray M; Gilbert, Dustin A; Liu, Kai; Louie, Angelique Y

    2012-04-24

    Research into developing dual modality probes enabled for magnetic resonance imaging (MRI) and positron emission tomography (PET) has been on the rise recently due to the potential to combine the high resolution of MRI and the high sensitivity of PET. Current synthesis techniques for developing multimodal probes is largely hindered in part by prolonged reaction times during radioisotope incorporation--leading to a weakening of the radioactivity. Along with a time-efficient synthesis, the resulting products must fit within a critical size range (between 20 and 100 nm) to increase blood retention time. In this work, we describe a novel, rapid, microwave-based synthesis technique to grow dextran-coated iron oxide nanoparticles doped with copper (DIO/Cu). Traditional methods for coprecipitation of dextran-coated iron oxide nanoparticles require refluxing for 2 h and result in approximately 50 nm diameter particles. We demonstrate that microwave synthesis can produce 50 nm nanoparticles with 5 min of heating. We discuss the various parameters used in the microwave synthesis protocol to vary the size distribution of DIO/Cu and demonstrate the successful incorporation of (64)Cu into these particles with the aim of future use for dual-mode MR/PET imaging.

  4. Effects of sleep bruxism on functional and occlusal parameters: a prospective controlled investigation.

    Science.gov (United States)

    Ommerborn, Michelle Alicia; Giraki, Maria; Schneider, Christine; Fuck, Lars Michael; Handschel, Jörg; Franz, Matthias; Hans-Michael Raab, Wolfgang; Schäfer, Ralf

    2012-09-01

    This study was conducted to verify the results of a preceding retrospective pilot study by means of a prospective controlled investigation including a larger sample size. Therefore, the aim of this clinical investigation was to analyze the relationship between sleep bruxism and several functional and occlusal parameters. The null hypothesis of this study was that there would be no differences among sleep bruxism subjects and non-sleep bruxism controls regarding several functional and occlusal parameters. Fifty-eight sleep bruxism subjects and 31 controls participated in this study. The diagnosis sleep bruxism was based on clinical criteria of the American Academy of Sleep Medicine. Sixteen functional and occlusal parameters were recorded clinically or from dental study casts. Similar to the recently published retrospective pilot study, with a mean slide of 0.77 mm (s.d., 0.69 mm) in the sleep bruxism group and a mean slide of 0.4 mm (s.d., 0.57 mm) in the control group, the evaluation of the mean comparison between the two groups demonstrated a larger slide from centric occlusion to maximum intercuspation in sleep bruxism subjects (Mann-Whitney U-test; P=0.008). However, following Bonferroni adjustment, none of the 16 occlusal and functional variables differed significantly between the sleep bruxism subjects and the non-sleep bruxism controls. The present study shows that the occlusal and functional parameters evaluated do not differ between sleep bruxism subjects and non-sleep bruxism subjects. However, as the literature reveals a possible association between bruxism and certain subgroups of temporomandibular disorders, it appears advisable to incorporate the individual adaptive capacity of the stomatognathic system into future investigations.

  5. Effects of sleep bruxism on functional and occlusal parameters: a prospective controlled investigation

    Science.gov (United States)

    Alicia Ommerborn, Michelle; Giraki, Maria; Schneider, Christine; Michael Fuck, Lars; Handschel, Jörg; Franz, Matthias; Hans-Michael Raab, Wolfgang; Schäfer, Ralf

    2012-01-01

    This study was conducted to verify the results of a preceding retrospective pilot study by means of a prospective controlled investigation including a larger sample size. Therefore, the aim of this clinical investigation was to analyze the relationship between sleep bruxism and several functional and occlusal parameters. The null hypothesis of this study was that there would be no differences among sleep bruxism subjects and non-sleep bruxism controls regarding several functional and occlusal parameters. Fifty-eight sleep bruxism subjects and 31 controls participated in this study. The diagnosis sleep bruxism was based on clinical criteria of the American Academy of Sleep Medicine. Sixteen functional and occlusal parameters were recorded clinically or from dental study casts. Similar to the recently published retrospective pilot study, with a mean slide of 0.77 mm (s.d., 0.69 mm) in the sleep bruxism group and a mean slide of 0.4 mm (s.d., 0.57 mm) in the control group, the evaluation of the mean comparison between the two groups demonstrated a larger slide from centric occlusion to maximum intercuspation in sleep bruxism subjects (Mann–Whitney U-test; P=0.008). However, following Bonferroni adjustment, none of the 16 occlusal and functional variables differed significantly between the sleep bruxism subjects and the non-sleep bruxism controls. The present study shows that the occlusal and functional parameters evaluated do not differ between sleep bruxism subjects and non-sleep bruxism subjects. However, as the literature reveals a possible association between bruxism and certain subgroups of temporomandibular disorders, it appears advisable to incorporate the individual adaptive capacity of the stomatognathic system into future investigations. PMID:22935746

  6. The Parameters Controlling the Burning Efficiency of In-Situ Burning of Crude Oil on Water

    DEFF Research Database (Denmark)

    van Gelderen, Laurens; Jomaas, Grunde

    2017-01-01

    Parameters that control the burning efficiency of in-situ burning of crude oil on water were identified by studying the influence of the initial slick thickness, vaporization order, oil slick diameter, weathering state of the oil, heat losses to the water layer and heat flux to the fuel surface...... on the burning efficiency for light and heavy crude oils. These parameters were studied in several small scale and intermediate scale experimental setups. The results showed that the heat losses to the water layer increase with increasing burning time because the components in a crude oil evaporate from volatile...... oil. It can be concluded that the pool fire diameter is the key parameter that determines the burning efficiency of crude oil fires on water, which was partially attributed to the increasing heat flux (in kW/m2) to the fuel surface with increasing diameter. Increasing the heat flux to the fuel surface...

  7. Auto-tuning of PID controller parameters with supervised receding horizon optimization.

    Science.gov (United States)

    Xu, Min; Li, Shaoyuan; Qi, Chenkun; Cai, Wenjian

    2005-10-01

    In this paper, a novel two-layer online auto-tuning algorithm is presented for a nonlinear time-varying system. The lower layer consists of a conventional proportional-integral-derivative (PID) controller and a plant process, while the upper layer is composed of identification and tuning modules. The purpose of the upper layer is to find a set of optimal PID parameters for the lower layer via an online receding horizon optimization approach, which result in a time-varying PID controller. Through mathematical analysis, the proposed system performance is equivalent to that of a standard generalized predictive control. Simulation and experiment demonstrate that the new method has a better control system performance compared with conventional PID controllers.

  8. A Novel SHLNN Based Robust Control and Tracking Method for Hypersonic Vehicle under Parameter Uncertainty

    Directory of Open Access Journals (Sweden)

    Chuanfeng Li

    2017-01-01

    Full Text Available Hypersonic vehicle is a typical parameter uncertain system with significant characteristics of strong coupling, nonlinearity, and external disturbance. In this paper, a combined system modeling approach is proposed to approximate the actual vehicle system. The state feedback control strategy is adopted based on the robust guaranteed cost control (RGCC theory, where the Lyapunov function is applied to get control law for nonlinear system and the problem is transformed into a feasible solution by linear matrix inequalities (LMI method. In addition, a nonfragile guaranteed cost controller solved by LMI optimization approach is employed to the linear error system, where a single hidden layer neural network (SHLNN is employed as an additive gain compensator to reduce excessive performance caused by perturbations and uncertainties. Simulation results show the stability and well tracking performance for the proposed strategy in controlling the vehicle system.

  9. The Influence of Controller Parameters on the Quality of the Train Converter Current

    Directory of Open Access Journals (Sweden)

    M. Brenna

    2011-01-01

    Full Text Available This paper presents a stability analysis of train converters in order to evaluate how the controller parameters affect the absorbed current. The new dynamic model presented in this paper is capable of considering the time-variant nature of the system for the correct tuning of the feedback proportional-integral PI controller, applying a current controlled modulation technique never used in high-power traction converters. The reduction of the harmonic content of the current absorbed by a converter employed at the input stage onboard high-speed trains is really important, considering the interaction with the signaling system set up for traffic control. A computer model of the converter, considering both the power and the control structure, has also been implemented in order to deliver a validated tool for the developed theoretical analysis.

  10. Parameter Optimization of MIMO Fuzzy Optimal Model Predictive Control By APSO

    Directory of Open Access Journals (Sweden)

    Adel Taieb

    2017-01-01

    Full Text Available This paper introduces a new development for designing a Multi-Input Multi-Output (MIMO Fuzzy Optimal Model Predictive Control (FOMPC using the Adaptive Particle Swarm Optimization (APSO algorithm. The aim of this proposed control, called FOMPC-APSO, is to develop an efficient algorithm that is able to have good performance by guaranteeing a minimal control. This is done by determining the optimal weights of the objective function. Our method is considered an optimization problem based on the APSO algorithm. The MIMO system to be controlled is modeled by a Takagi-Sugeno (TS fuzzy system whose parameters are identified using weighted recursive least squares method. The utility of the proposed controller is demonstrated by applying it to two nonlinear processes, Continuous Stirred Tank Reactor (CSTR and Tank system, where the proposed approach provides better performances compared with other methods.

  11. Temporal parameter change of human postural control ability during upright swing using recursive least square method

    Science.gov (United States)

    Goto, Akifumi; Ishida, Mizuri; Sagawa, Koichi

    2010-01-01

    The purpose of this study is to derive quantitative assessment indicators of the human postural control ability. An inverted pendulum is applied to standing human body and is controlled by ankle joint torque according to PD control method in sagittal plane. Torque control parameters (KP: proportional gain, KD: derivative gain) and pole placements of postural control system are estimated with time from inclination angle variation using fixed trace method as recursive least square method. Eight young healthy volunteers are participated in the experiment, in which volunteers are asked to incline forward as far as and as fast as possible 10 times over 10 [s] stationary intervals with their neck joint, hip joint and knee joint fixed, and then return to initial upright posture. The inclination angle is measured by an optical motion capture system. Three conditions are introduced to simulate unstable standing posture; 1) eyes-opened posture for healthy condition, 2) eyes-closed posture for visual impaired and 3) one-legged posture for lower-extremity muscle weakness. The estimated parameters Kp, KD and pole placements are applied to multiple comparison test among all stability conditions. The test results indicate that Kp, KD and real pole reflect effect of lower-extremity muscle weakness and KD also represents effect of visual impairment. It is suggested that the proposed method is valid for quantitative assessment of standing postural control ability.

  12. Controller Parameters Tuning Based on Transfer Matrix Method for Multibody Systems

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    Hossam Hendy

    2014-01-01

    Full Text Available Transfer matrix method for multibody systems (MS-TMM is a rife method to multi-rigid-flexible-body systems dynamics model deduction due to that there are no needs to establish the global dynamics equations of the system. Its basic idea is transferring a state vector between the body input(s and output(s; this idea is close to the linear theories in control analysis and design. In this paper, three controllers’ parameters tuning techniques for the proposed system model using MS-TMM are utilized; one technique is applied to get the stability regions via the frequency response of MS-TMM derived model. Another technique considers a classical PID controller design through the analysis of step input response of the system, and the last technique can be applied in both time and frequency domains if the model has a known mathematical model. A car suspension system is considered to represent modeling and tuning problems. In-depth study of MS-TMM with control techniques and defining the controllers’ parameters stability regions provide an opportunity to formulate a relationship between MS-TMM and control design for novel control applications due to the powerful strength of MS-TMM dealing with more complex problems of the controlled multibody systems.

  13. Robust control design with real parameter uncertainty using absolute stability theory. Ph.D. Thesis

    Science.gov (United States)

    How, Jonathan P.; Hall, Steven R.

    1993-01-01

    The purpose of this thesis is to investigate an extension of mu theory for robust control design by considering systems with linear and nonlinear real parameter uncertainties. In the process, explicit connections are made between mixed mu and absolute stability theory. In particular, it is shown that the upper bounds for mixed mu are a generalization of results from absolute stability theory. Both state space and frequency domain criteria are developed for several nonlinearities and stability multipliers using the wealth of literature on absolute stability theory and the concepts of supply rates and storage functions. The state space conditions are expressed in terms of Riccati equations and parameter-dependent Lyapunov functions. For controller synthesis, these stability conditions are used to form an overbound of the H2 performance objective. A geometric interpretation of the equivalent frequency domain criteria in terms of off-axis circles clarifies the important role of the multiplier and shows that both the magnitude and phase of the uncertainty are considered. A numerical algorithm is developed to design robust controllers that minimize the bound on an H2 cost functional and satisfy an analysis test based on the Popov stability multiplier. The controller and multiplier coefficients are optimized simultaneously, which avoids the iteration and curve-fitting procedures required by the D-K procedure of mu synthesis. Several benchmark problems and experiments on the Middeck Active Control Experiment at M.I.T. demonstrate that these controllers achieve good robust performance and guaranteed stability bounds.

  14. Metodology of identification parameters of models control objects of automatic trailing system

    Directory of Open Access Journals (Sweden)

    I.V. Zimchuk

    2017-04-01

    Full Text Available The determining factor for the successful solution of the problem of synthesis of optimal control systems of different processes are adequacy of mathematical model of control object. In practice, the options can differ from the objects taken priori, causing a need to clarification of them. In this context, the article presents the results of the development and application of methods parameters identification of mathematical models of control object of automatic trailing system. The stated problem in the article is solved provided that control object is fully controlled and observed, and a differential equation of control object is known a priori. The coefficients of this equation to be determined. Identifying quality criterion is to minimize the integral value of squared error of identification. The method is based on a description of the dynamics of the object in space state. Equation of identification synthesized using the vector-matrix representation of model. This equation describes the interconnection of coefficients of matrix state and control with inputs and outputs of object. The initial data for calculation are the results of experimental investigation of the reaction of phase coordinates of control object at a typical input signal. The process of calculating the model parameters is reduced to solving the system of equations of the first order each. Application the above approach is illustrated in the example identification of coefficients transfer function of control object first order. Results of digital simulation are presented, they are confirming the justice of set out mathematical calculations. The approach enables to do the identification of models of one-dimensional and multidimensional objects and does not require a large amount of calculation for its implementation. The order of identified model is limited capabilities of measurement phase coordinates of corresponding control object. The practical significance of the work is

  15. Controlling the Radiation Parameters of a Resonant Medium Excited by a Sequence of Ultrashort Superluminal Pulses

    Science.gov (United States)

    Arkhipov, R. M.; Arkhipov, M. V.; Belov, P. A.; Babushkin, I.; Tolmachev, Yu. A.

    2016-03-01

    We investigate the possibility of controlling the radiation parameters of a spatially periodic one-dimensional medium consisting of classical harmonic oscillators by means of a sequence of ultrashort pulses that propagate through the medium with a superluminal velocity. We show that, in the spectrum of the transient process, in addition to the radiation at a resonant frequency of oscillators, new frequencies arise that depend on the period of the spatial distribution of the oscillator density, the excitation velocity, and the angle of observation. We have examined in detail the case of excitation of the medium by a periodic sequence of ultrashort pulses that travel with a superluminal velocity. We show that it is possible to excite oscillations of complex shapes and to control the radiation parameters of the resonant medium by changing the relationship between the pulse repetition rate, the medium resonant frequency, and the new frequency.

  16. Control Parameters for Boundary-Layer Instabilities in Unsteady Shock Interactions

    Directory of Open Access Journals (Sweden)

    LaVar King Isaacson

    2012-01-01

    Full Text Available This article presents the computation of a set of control parameters for the deterministic prediction of laminar boundary-layer instabilities induced by an imposed unsteady shock interaction. The objective of the study is exploratory in nature by computing a supersonic flight environment for flow over a blunt body and the deterministic prediction of the spectral entropy rates for the boundary layer subjected to an unsteady pressure disturbance. The deterministic values for the spectral entropy rate within the instabilities are determined for each control parameter. Computational results imply that the instabilities are of a span-wise vortex form, that the maximum vertical velocity wave vector components are produced in the region nearest the wall and that extended transient coherent structures are produced in the boundary layer at a vertical location slightly below the mid-point of the boundary layer.

  17. Linear parameter-varying and time-delay systems analysis, observation, filtering & control

    CERN Document Server

    Briat, Corentin

    2015-01-01

    This book provides an introduction to the analysis and control of Linear Parameter-Varying Systems and Time-Delay Systems and their interactions. The purpose is to give the readers some fundamental theoretical background on these topics and to give more insights on the possible applications of these theories. This self-contained monograph is written in an accessible way for readers ranging from undergraduate/PhD students to engineers and researchers willing to know more about the fields of time-delay systems, parameter-varying systems, robust analysis, robust control, gain-scheduling techniques in the LPV fashion and LMI based approaches. The only prerequisites are basic knowledge in linear algebra, ordinary differential equations and (linear) dynamical systems. Most of the results are proved unless the proof is too complex or not necessary for a good understanding of the results. In the latter cases, suitable references are systematically provided. The first part pertains on the representation, analysis and ...

  18. Research progress in controlled attenuation parameter for assessment of fatty liver disease

    OpenAIRE

    LU Jiafa

    2015-01-01

    Controlled attenuation parameter (CAP) is a noninvasive, quantitative, fast, and reliable novel tool for the assessment of fatty liver disease (FLD), and it has been a hotspot in the noninvasive diagnosis of FLD. This paper introduces factors associated with CAP assessing FLD, the cut-off value for the diagnosis of liver steatosis, and the causes of the failure of CAP measurement and unreliable CAP measurement. The paper believes that even though the noninvasive and quantitative diagnosis of ...

  19. Usefulness of the Controlled Attenuation Parameter for Detecting Liver Steatosis in Health Checkup Examinees

    OpenAIRE

    Kim, Ja Kyung; Lee, Kwan Sik; Choi, Jung Ran; Chung, Hyun Jung; Jung, Da Hyun; Lee, Kyung Ah; Lee, Jung Il

    2015-01-01

    Background/Aims The controlled attenuation parameter (CAP) implemented in FibroScan? is reported to be a non-invasive means of detecting steatosis (>10% steatosis). We aimed to evaluate the usefulness of CAP in detecting steatosis among health checkup examinees and to assess its correlation with ultrasonography (US). Methods Consecutive CAP results were retrospectively collected. A total of 280 subjects were included. Results Fatty liver was detected in 119 subjects (42.5%) by US, whereas it ...

  20. Parameters-tuning of PID controller for automatic voltage regulators using the African buffalo optimization.

    Directory of Open Access Journals (Sweden)

    Julius Beneoluchi Odili

    Full Text Available In this paper, an attempt is made to apply the African Buffalo Optimization (ABO to tune the parameters of a PID controller for an effective Automatic Voltage Regulator (AVR. Existing metaheuristic tuning methods have been proven to be quite successful but there were observable areas that need improvements especially in terms of the system's gain overshoot and steady steady state errors. Using the ABO algorithm where each buffalo location in the herd is a candidate solution to the Proportional-Integral-Derivative parameters was very helpful in addressing these two areas of concern. The encouraging results obtained from the simulation of the PID Controller parameters-tuning using the ABO when compared with the performance of Genetic Algorithm PID (GA-PID, Particle-Swarm Optimization PID (PSO-PID, Ant Colony Optimization PID (ACO-PID, PID, Bacteria-Foraging Optimization PID (BFO-PID etc makes ABO-PID a good addition to solving PID Controller tuning problems using metaheuristics.

  1. Parameters-tuning of PID controller for automatic voltage regulators using the African buffalo optimization

    Science.gov (United States)

    Mohmad Kahar, Mohd Nizam; Noraziah, A.

    2017-01-01

    In this paper, an attempt is made to apply the African Buffalo Optimization (ABO) to tune the parameters of a PID controller for an effective Automatic Voltage Regulator (AVR). Existing metaheuristic tuning methods have been proven to be quite successful but there were observable areas that need improvements especially in terms of the system’s gain overshoot and steady steady state errors. Using the ABO algorithm where each buffalo location in the herd is a candidate solution to the Proportional-Integral-Derivative parameters was very helpful in addressing these two areas of concern. The encouraging results obtained from the simulation of the PID Controller parameters-tuning using the ABO when compared with the performance of Genetic Algorithm PID (GA-PID), Particle-Swarm Optimization PID (PSO-PID), Ant Colony Optimization PID (ACO-PID), PID, Bacteria-Foraging Optimization PID (BFO-PID) etc makes ABO-PID a good addition to solving PID Controller tuning problems using metaheuristics. PMID:28441390

  2. Economic Model Predictive Control of Bihormonal Artificial Pancreas System Based on Switching Control and Dynamic R-parameter.

    Science.gov (United States)

    Tang, Fengna; Wang, Youqing

    2017-11-01

    Blood glucose (BG) regulation is a long-term task for people with diabetes. In recent years, more and more researchers have attempted to achieve automated regulation of BG using automatic control algorithms, called the artificial pancreas (AP) system. In clinical practice, it is equally important to guarantee the treatment effect and reduce the treatment costs. The main motivation of this study is to reduce the cure burden. The dynamic R-parameter economic model predictive control (R-EMPC) is chosen to regulate the delivery rates of exogenous hormones (insulin and glucagon). It uses particle swarm optimization (PSO) to optimize the economic cost function and the switching logic between insulin delivery and glucagon delivery is designed based on switching control theory. The proposed method is first tested on the standard subject; the result is compared with the switching PID and the switching MPC. The effect of the dynamic R-parameter on improving the control performance is illustrated by comparing the results of the EMPC and the R-EMPC. Finally, the robustness tests on meal change (size and timing), hormone sensitivity (insulin and glucagon), and subject variability are performed. All results show that the proposed method can improve the control performance and reduce the economic costs. The simulation results verify the effectiveness of the proposed algorithm on improving the tracking performance, enhancing robustness, and reducing economic costs. The method proposed in this study owns great worth in practical application.

  3. Infants in control: rapid anticipation of action outcomes in a gaze-contingent paradigm.

    Directory of Open Access Journals (Sweden)

    Quan Wang

    Full Text Available Infants' poor motor abilities limit their interaction with their environment and render studying infant cognition notoriously difficult. Exceptions are eye movements, which reach high accuracy early, but generally do not allow manipulation of the physical environment. In this study, real-time eye tracking is used to put 6- and 8-month-old infants in direct control of their visual surroundings to study the fundamental problem of discovery of agency, i.e. the ability to infer that certain sensory events are caused by one's own actions. We demonstrate that infants quickly learn to perform eye movements to trigger the appearance of new stimuli and that they anticipate the consequences of their actions in as few as 3 trials. Our findings show that infants can rapidly discover new ways of controlling their environment. We suggest that gaze-contingent paradigms offer effective new ways for studying many aspects of infant learning and cognition in an interactive fashion and provide new opportunities for behavioral training and treatment in infants.

  4. Quality controls in cellular immunotherapies: rapid assessment of clinical grade dendritic cells by gene expression profiling.

    Science.gov (United States)

    Castiello, Luciano; Sabatino, Marianna; Zhao, Yingdong; Tumaini, Barbara; Ren, Jiaqiang; Ping, Jin; Wang, Ena; Wood, Lauren V; Marincola, Francesco M; Puri, Raj K; Stroncek, David F

    2013-02-01

    Cell-based immunotherapies are among the most promising approaches for developing effective and targeted immune response. However, their clinical usefulness and the evaluation of their efficacy rely heavily on complex quality control assessment. Therefore, rapid systematic methods are urgently needed for the in-depth characterization of relevant factors affecting newly developed cell product consistency and the identification of reliable markers for quality control. Using dendritic cells (DCs) as a model, we present a strategy to comprehensively characterize manufactured cellular products in order to define factors affecting their variability, quality and function. After generating clinical grade human monocyte-derived mature DCs (mDCs), we tested by gene expression profiling the degrees of product consistency related to the manufacturing process and variability due to intra- and interdonor factors, and how each factor affects single gene variation. Then, by calculating for each gene an index of variation we selected candidate markers for identity testing, and defined a set of genes that may be useful comparability and potency markers. Subsequently, we confirmed the observed gene index of variation in a larger clinical data set. In conclusion, using high-throughput technology we developed a method for the characterization of cellular therapies and the discovery of novel candidate quality assurance markers.

  5. New Active Control Method Based on Using Multiactuators and Sensors Considering Uncertainty of Parameters

    Directory of Open Access Journals (Sweden)

    Babak Karimpour

    2014-01-01

    Full Text Available New approach is presented for controlling the structural vibrations. The proposed active control method is based on structural dynamics theories in which multiactuators and sensors are utilized. Each actuator force is modeled as an equivalent viscous damper so that several lower vibration modes are damped critically. This subject is achieved by simple mathematical formulation. The proposed method does not depend on the type of dynamic load and it could be applied to control structures with multidegrees of freedom. For numerical verification of proposed method, several criterions such as maximum displacement, maximum kinetic energy, maximum drift, and time history of controlled force and displacement are evaluated in two- , five- , and seven-story shear buildings, subjected to the harmonic load, impact force, and the Elcentro base excitation. This study shows that the proposed method has suitable efficiency for reducing structural vibrations. Moreover, the uncertainty effect of different parameters is investigated here.

  6. Sliding Mode Observer and Control Design with Adaptive Parameter Estimation for a Supersonic Flight Vehicle

    Directory of Open Access Journals (Sweden)

    M. Bahrami

    2010-01-01

    Full Text Available Design and synthesis of a nonlinear generic supersonic flight vehicle longitudinal dynamics control for angle-of-attack, AOA, output tracking in the atmospheric flight is presented based on sliding mode control. A sliding mode observer is invoked to estimate AOA which is difficult to measure in practice. Large parameter uncertainties accommodation envisaged by designing adaptive mechanisms for both the control and observer and high chattering authority due to large deviations of aerodynamic coefficients arising from wind-tunnel measurements are inhibited. The employed method enables the sliding mode control design to exhibit the desired dynamic properties during the entire output-tracking process. Simulations results are presented to demonstrate the performance, robustness, and stability.

  7. Uncertainty analysis for parameters of CFAST in the main control room fire scenario

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Wanhong; Guo, Yun; Peng, Changhong [Univ. of Science and Technology of China No. 96, Anhui (China). School of Nuclear Science and Technology

    2017-07-15

    The fire accident is one of important initial events in the nuclear power plant. Moreover, the fire development process is extremely difficult and complex to predict accurately. As a result, the plant internal fire accidents have become one of the most realistic threat on the safety of the nuclear power plants. The main control room contains all the control and monitoring equipment that operators need. Once it is on fire, hostile environments would greatly impact on the safety of human operations. Therefore, fire probability safety analysis on the main control room has become a significant task. By using CFAST and Monte Carlo sampling method as a tool for fire modeling to simulate main control room on fire, we can examine uncertainty analysis for the important parameters of CFAST.

  8. Controller Parameter Optimization for Nonlinear Systems Using Enhanced Bacteria Foraging Algorithm

    Directory of Open Access Journals (Sweden)

    V. Rajinikanth

    2012-01-01

    Full Text Available An enhanced bacteria foraging optimization (EBFO algorithm-based Proportional + integral + derivative (PID controller tuning is proposed for a class of nonlinear process models. The EBFO algorithm is a modified form of standard BFO algorithm. A multiobjective performance index is considered to guide the EBFO algorithm for discovering the best possible value of controller parameters. The efficiency of the proposed scheme has been validated through a comparative study with classical BFO, adaptive BFO, PSO, and GA based controller tuning methods proposed in the literature. The proposed algorithm is tested in real time on a nonlinear spherical tank system. The real-time results show that, EBFO tuned PID controller gives a smooth response for setpoint tracking performance.

  9. Rapid evaluation and quality control of next generation sequencing data with FaQCs.

    Science.gov (United States)

    Lo, Chien-Chi; Chain, Patrick S G

    2014-11-19

    Next generation sequencing (NGS) technologies that parallelize the sequencing process and produce thousands to millions, or even hundreds of millions of sequences in a single sequencing run, have revolutionized genomic and genetic research. Because of the vagaries of any platform's sequencing chemistry, the experimental processing, machine failure, and so on, the quality of sequencing reads is never perfect, and often declines as the read is extended. These errors invariably affect downstream analysis/application and should therefore be identified early on to mitigate any unforeseen effects. Here we present a novel FastQ Quality Control Software (FaQCs) that can rapidly process large volumes of data, and which improves upon previous solutions to monitor the quality and remove poor quality data from sequencing runs. Both the speed of processing and the memory footprint of storing all required information have been optimized via algorithmic and parallel processing solutions. The trimmed output compared side-by-side with the original data is part of the automated PDF output. We show how this tool can help data analysis by providing a few examples, including an increased percentage of reads recruited to references, improved single nucleotide polymorphism identification as well as de novo sequence assembly metrics. FaQCs combines several features of currently available applications into a single, user-friendly process, and includes additional unique capabilities such as filtering the PhiX control sequences, conversion of FASTQ formats, and multi-threading. The original data and trimmed summaries are reported within a variety of graphics and reports, providing a simple way to do data quality control and assurance.

  10. Computer controlled automated assay for comprehensive studies of enzyme kinetic parameters.

    Directory of Open Access Journals (Sweden)

    Felix Bonowski

    Full Text Available Stability and biological activity of proteins is highly dependent on their physicochemical environment. The development of realistic models of biological systems necessitates quantitative information on the response to changes of external conditions like pH, salinity and concentrations of substrates and allosteric modulators. Changes in just a few variable parameters rapidly lead to large numbers of experimental conditions, which go beyond the experimental capacity of most research groups. We implemented a computer-aided experimenting framework ("robot lab assistant" that allows us to parameterize abstract, human-readable descriptions of micro-plate based experiments with variable parameters and execute them on a conventional 8 channel liquid handling robot fitted with a sensitive plate reader. A set of newly developed R-packages translates the instructions into machine commands, executes them, collects the data and processes it without user-interaction. By combining script-driven experimental planning, execution and data-analysis, our system can react to experimental outcomes autonomously, allowing outcome-based iterative experimental strategies. The framework was applied in a response-surface model based iterative optimization of buffer conditions and investigation of substrate, allosteric effector, pH and salt dependent activity profiles of pyruvate kinase (PYK. A diprotic model of enzyme kinetics was used to model the combined effects of changing pH and substrate concentrations. The 8 parameters of the model could be estimated from a single two-hour experiment using nonlinear least-squares regression. The model with the estimated parameters successfully predicted pH and PEP dependence of initial reaction rates, while the PEP concentration dependent shift of optimal pH could only be reproduced with a set of manually tweaked parameters. Differences between model-predictions and experimental observations at low pH suggest additional protonation

  11. The rapid control of interactions in a two-component Fermi gas

    Science.gov (United States)

    Stites, Ronald William Donald

    In this dissertation, we describe a variety of experiments having application to ultra-cold atomic gases. While the majority of the experimental results focus on the development of a novel laser source for cooling and manipulating a gas of fermionic 6Li atoms, we also report on a preliminary investigation of rapidly controlling interactions in a two-component Fermi gas. One of the primary tools for our ultra-cold atomic physics experiments is 671 nm laser light nearly resonant with the D1 and D2 spectroscopic lines of ultracold fermionic 6Li atoms. Traditionally, this light is generated using dye lasers or tapered amplifier systems. Here we describe a diode pumped solid state ring laser system utilizing a Nd:YVO 4 gain crystal. Nd:YVO4 has a 4F 3/2 → 4I13/2 emission line at 1342 nm. This wavelength is double the 671 nm needed for our experiments. As a part of this investigation, we also measured the Verdet constant of undoped Y3Al5O12 in the near infrared for constructing a Faraday rotator used to drive unidirectional operation of our ring laser. As an alternative method to achieve unidirectional, single-frequency operation of the laser, we developed a novel scheme of "self-injection locking" where a small portion of the output beam is coupled back into the cavity to break the symmetry. This technique is useful for high-power, single-frequency operation of a ring laser because lossy elements needed for frequency selection and unidirectional operation of the laser can be removed from the internal cavity. In addition to our laser experiments, we also drive Raman transitions between different magnetic hyperfine states within 6Li atoms. For atoms in the two lowest hyperfine states, there exists a broad Feshbach resonance at 834.1 Gauss whereby the s-wave scattering length diverges, resulting in strong interactions between the two species. By using two phase locked lasers to drive a transition from a strongly interacting state to a weakly interacting state, we can

  12. Linear parameter-varying modeling and control of the steam temperature in a Canadian SCWR

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Peiwei, E-mail: sunpeiwei@mail.xjtu.edu.cn; Zhang, Jianmin; Su, Guanghui

    2017-03-15

    Highlights: • Nonlinearity of Canadian SCWR is analyzed based on step responses and Nyquist plots. • LPV model is derived through Jacobian linearization and curve fitting. • An output feedback H{sub ∞} controller is synthesized for the steam temperature. • The control performance is evaluated by step disturbances and wide range operation. • The controller can stabilize the system and reject the reactor power disturbance. - Abstract: The Canadian direct-cycle Supercritical Water-cooled Reactor (SCWR) is a pressure-tube type SCWR under development in Canada. The dynamics of the steam temperature have a high degree of nonlinearity and are highly sensitive to reactor power disturbances. Traditional gain scheduling control cannot theoretically guarantee stability for all operating regions. The control performance can also be deteriorated when the controllers are switched. In this paper, a linear parameter-varying (LPV) strategy is proposed to solve such problems. Jacobian linearization and curve fitting are applied to derive the LPV model, which is verified using a nonlinear dynamic model and determined to be sufficiently accurate for control studies. An output feedback H{sub ∞} controller is synthesized to stabilize the steam temperature system and reject reactor power disturbances. The LPV steam temperature controller is implemented using a nonlinear dynamic model, and step changes in the setpoints and typical load patterns are carried out in the testing process. It is demonstrated through numerical simulation that the LPV controller not only stabilizes the steam temperature under different disturbances but also efficiently rejects reactor power disturbances and suppresses the steam temperature variation at different power levels. The LPV approach is effective in solving control problems of the steam temperature in the Canadian SCWR.

  13. Effect of clinical parameters on the control of myoelectric robotic prosthetic hands.

    Science.gov (United States)

    Atzori, Manfredo; Gijsberts, Arjan; Castellini, Claudio; Caputo, Barbara; Hager, Anne-Gabrielle Mittaz; Elsig, Simone; Giatsidis, Giorgio; Bassetto, Franco; Müller, Henning

    2016-01-01

    Improving the functionality of prosthetic hands with noninvasive techniques is still a challenge. Surface electromyography (sEMG) currently gives limited control capabilities; however, the application of machine learning to the analysis of sEMG signals is promising and has recently been applied in practice, but many questions still remain. In this study, we recorded the sEMG activity of the forearm of 11 male subjects with transradial amputation who were mentally performing 40 hand and wrist movements. The classification performance and the number of independent movements (defined as the subset of movements that could be distinguished with >90% accuracy) were studied in relationship to clinical parameters related to the amputation. The analysis showed that classification accuracy and the number of independent movements increased significantly with phantom limb sensation intensity, remaining forearm percentage, and temporal distance to the amputation. The classification results suggest the possibility of naturally controlling up to 11 movements of a robotic prosthetic hand with almost no training. Knowledge of the relationship between classification accuracy and clinical parameters adds new information regarding the nature of phantom limb pain as well as other clinical parameters, and it can lay the foundations for future "functional amputation" procedures in surgery.

  14. Controller design for wind turbine load reduction via multiobjective parameter synthesis

    Science.gov (United States)

    Hoffmann, A. F.; Weiβ, F. A.

    2016-09-01

    During the design process for a wind turbine load reduction controller many different, sometimes conflicting requirements must be fulfilled simultaneously. If the requirements can be expressed as mathematical criteria, such a design problem can be solved by a criterion-vector and multi-objective design optimization. The software environment MOPS (Multi-Objective Parameter Synthesis) supports the engineer for such a design optimization. In this paper MOPS is applied to design a multi-objective load reduction controller for the well-known DTU 10 MW reference wind turbine. A significant reduction in the fatigue criteria especially the blade damage can be reached by the use of an additional Individual Pitch Controller (IPC) and an additional tower damper. This reduction is reached as a trade-off with an increase of actuator load.

  15. Backstepping Controller with Intelligent Parameters Selection for Stabilization of Quadrotor Helicopter

    Directory of Open Access Journals (Sweden)

    Mohd Ariffanan Mohd Basri

    2016-07-01

    Full Text Available In this paper, the dynamic model of quadrotor helicopter has been mathematically formulated. Then, an intelligent backstepping controller (IBC is designed for the quadrotor altitude and attitude stabilization in the existence of external disturbances and measurement noise. The designed controller consists of a backstepping controller which can automatically select its parameters on-line by a fuzzy supervisory mechanism. The stability criterion for the stabilization of the quadrotor is proven by the Lyapunov theorem. Several numerical simulations using the dynamic model of a four degree of freedom (DOF quadrotor helicopter show the effectiveness of the approach. Besides, the simulation results indicate that the proposed design techniques can stabilize the quadrotor helicopter with better performance than established linear design techniques.

  16. Critical parameters controlling mechanical stability of NaCl under irradiation

    Science.gov (United States)

    Vainshtein, D. I.; Hartog, H. W. Den; Dubinko, V. I.; Turkin, A. A.

    A new concept of the radiation-induced microstructural evolution in ionic crystals has been verified experimentally by phenomena observed in heavily irradiated NaCl, such as the formation of large vacancy voids followed by a sudden explosion-like fracture of crystalline samples. The new concept can be a prototype of an adequate description of the long-term behavior of important insulating materials in intense radiation fields, which can be employed for an evaluation of the critical effects expected under conditions of storage of high level nuclear waste and development of radiation resistant materials. In this paper, we present some new data on the microstructural parameters of materials doped with different impurities and summarize the critical microstructural, irradiation and material parameters that control mechanical stability of rock salt materials under irradiation.

  17. Variation of UPFC Controllable Parameters during Power Swing and their Impacts on Distance Relay

    DEFF Research Database (Denmark)

    Khodaparast, Jalal; Khederzadeh, Mojtaba; Silva, Filipe Miguel Faria da

    2017-01-01

    Unified power flow controller (UPFC) has impact on the performance of distance relay during power swing. Generally, power system's parameters oscillate during power swing and since UPFC operation depends on some of these parameters (bus voltage, active and reactive power), the UPFC injects...... oscillated series voltage and draws oscillated shunt current. These oscillating series voltage and shunt current influence distance relays, as the impedance seen by a distance relay during power swing changes in UPFC-compensated lines. This study shows how and why series voltage and shunt current change...... during power swing. Moreover, the admittance swing characteristic is proposed in this study and effects of series and shunt branches of UPFC on the admittance seen by a distance relay during power swing have been examined....

  18. Control of deterministic and stochastic systems with several small parameters - A survey

    Directory of Open Access Journals (Sweden)

    Vasile Dragan

    2009-07-01

    Full Text Available The past three decades of research on multiparametric singularly perturbed systems are reviewed, including recent results. Particular attention is paid to stability analysis, control, filtering problems and dynamic games. First, a parameter-independent design methodology is summarized, which employs a two-time-scale and descriptor system approach without information on the small parameters. Further, variational computational algorithms are included to avoid ill-conditioned systems : the exact slow-fast decomposition method, the recursive algorithm and Newton's method are considered in particular. Convergence results are presented and the existence and uniqueness of the solutions are discussed. Second, the new results obtained via the stochastic approach are presented. Finally, the results of a simulation of a practical power system are presented to validate the efficiency of the considered design methods.

  19. Prevention and Control of Cardiovascular Disease in the Rapidly Changing Economy of China.

    Science.gov (United States)

    Wu, Yangfeng; Benjamin, Emelia J; MacMahon, Stephen

    2016-06-14

    With one-fifth of the world's total population, China's prevention and control of cardiovascular disease (CVD) may affect the success of worldwide efforts to achieve sustainable CVD reduction. Understanding China's current cardiovascular epidemic requires awareness of the economic development in the past decades. The rapid economic transformations (industrialization, marketization, urbanization, globalization, and informationalization) contributed to the aging demography, unhealthy lifestyles, and environmental changes. The latter have predisposed to increasing cardiovascular risk factors and the CVD pandemic. Rising CVD rates have had a major economic impact, which has challenged the healthcare system and the whole society. With recognition of the importance of health, initial political steps and national actions have been taken to address the CVD epidemic. Looking to the future, we recommend that 4 priorities should be taken: pursue multisectorial government and nongovernment strategies targeting the underlying causes of CVD (the whole-of-government and whole-of-society policy); give priority to prevention; reform the healthcare system to fit the nature of noncommunicable diseases; and conduct research for evidence-based, low-cost, simple, sustainable, and scalable interventions. By pursuing the 4 priorities, the pandemic of CVD and other major noncommunicable diseases in China will be reversed and the global sustainable development goal achieved. © 2016 American Heart Association, Inc.

  20. A large Legionnaires' disease outbreak in Pamplona, Spain: early detection, rapid control and no case fatality.

    Science.gov (United States)

    Castilla, J; Barricarte, A; Aldaz, J; García Cenoz, M; Ferrer, T; Pelaz, C; Pineda, S; Baladrón, B; Martín, I; Goñi, B; Aratajo, P; Chamorro, J; Lameiro, F; Torroba, L; Dorronsoro, I; Martínez-Artola, V; Esparza, M J; Gastaminza, M A; Fraile, P; Aldaz, P

    2008-06-01

    An outbreak of Legionnaire's disease was detected in Pamplona, Spain, on 1 June 2006. Patients with pneumonia were tested to detect Legionella pneumophila antigen in urine (Binax Now; Binax Inc., Scarborough, ME, USA), and all 146 confirmed cases were interviewed. The outbreak was related to district 2 (22 012 inhabitants), where 45% of the cases lived and 50% had visited; 5% lived in neighbouring districts. The highest incidence was found in the resident population of district 2 (3/1000 inhabitants), section 2 (14/1000). All 31 cooling towers of district 2 were analysed. L. pneumophila antigen (Binax Now) was detected in four towers, which were closed on 2 June. Only the strain isolated in a tower situated in section 2 of district 2 matched all five clinical isolates, as assessed by mAb and two genotyping methods, AFLP and PFGE. Eight days after closing the towers, new cases ceased appearing. Early detection and rapid coordinated medical and environmental actions permitted immediate control of the outbreak and probably contributed to the null case fatality.

  1. Validation of Contamination Control in Rapid Transfer Port Chambers for Pharmaceutical Manufacturing Processes.

    Science.gov (United States)

    Hu, Shih-Cheng; Shiue, Angus; Liu, Han-Yang; Chiu, Rong-Ben

    2016-11-12

    There is worldwide concern with regard to the adverse effects of drug usage. However, contaminants can gain entry into a drug manufacturing process stream from several sources such as personnel, poor facility design, incoming ventilation air, machinery and other equipment for production, etc. In this validation study, we aimed to determine the impact and evaluate the contamination control in the preparation areas of the rapid transfer port (RTP) chamber during the pharmaceutical manufacturing processes. The RTP chamber is normally tested for airflow velocity, particle counts, pressure decay of leakage, and sterility. The air flow balance of the RTP chamber is affected by the airflow quantity and the height above the platform. It is relatively easy to evaluate the RTP chamber's leakage by the pressure decay, where the system is charged with the air, closed, and the decay of pressure is measured by the time period. We conducted the determination of a vaporized H₂O₂ of a sufficient concentration to complete decontamination. The performance of the RTP chamber will improve safety and can be completely tested at an ISO Class 5 environment.

  2. Validation of Contamination Control in Rapid Transfer Port Chambers for Pharmaceutical Manufacturing Processes

    Directory of Open Access Journals (Sweden)

    Shih-Cheng Hu

    2016-11-01

    Full Text Available There is worldwide concern with regard to the adverse effects of drug usage. However, contaminants can gain entry into a drug manufacturing process stream from several sources such as personnel, poor facility design, incoming ventilation air, machinery and other equipment for production, etc. In this validation study, we aimed to determine the impact and evaluate the contamination control in the preparation areas of the rapid transfer port (RTP chamber during the pharmaceutical manufacturing processes. The RTP chamber is normally tested for airflow velocity, particle counts, pressure decay of leakage, and sterility. The air flow balance of the RTP chamber is affected by the airflow quantity and the height above the platform. It is relatively easy to evaluate the RTP chamber′s leakage by the pressure decay, where the system is charged with the air, closed, and the decay of pressure is measured by the time period. We conducted the determination of a vaporized H2O2 of a sufficient concentration to complete decontamination. The performance of the RTP chamber will improve safety and can be completely tested at an ISO Class 5 environment.

  3. A novel case-control subsampling approach for rapid model exploration of large clustered binary data.

    Science.gov (United States)

    Wright, Stephen T; Ryan, Louise M; Pham, Tung

    2017-12-11

    In many settings, an analysis goal is the identification of a factor, or set of factors associated with an event or outcome. Often, these associations are then used for inference and prediction. Unfortunately, in the big data era, the model building and exploration phases of analysis can be time-consuming, especially if constrained by computing power (ie, a typical corporate workstation). To speed up this model development, we propose a novel subsampling scheme to enable rapid model exploration of clustered binary data using flexible yet complex model set-ups (GLMMs with additive smoothing splines). By reframing the binary response prospective cohort study into a case-control-type design, and using our knowledge of sampling fractions, we show one can approximate the model estimates as would be calculated from a full cohort analysis. This idea is extended to derive cluster-specific sampling fractions and thereby incorporate cluster variation into an analysis. Importantly, we demonstrate that previously computationally prohibitive analyses can be conducted in a timely manner on a typical workstation. The approach is applied to analysing risk factors associated with adverse reactions relating to blood donation. Copyright © 2017 John Wiley & Sons, Ltd.

  4. Rapid Deposition of Uniform Polydopamine Coatings on Nanoparticle Surfaces with Controllable Thickness.

    Science.gov (United States)

    Orishchin, Nazar; Crane, Cameron C; Brownell, Matthew; Wang, Tengjiao; Jenkins, Samuel; Zou, Min; Nair, Arun; Chen, Jingyi

    2017-06-20

    Polydopamine is a bioinspired, versatile material that can adhere to bulk and nanoscale surfaces made of disparate materials to improve their physical and chemical properties in many applications. The typical methods to coat polydopamine on the nanoparticle substrates usually take several hours to a day. This work successfully applies a dispersion method to form a controllable, uniform coating on a nanoparticle surface within minutes. Using plasmonic Ag nanoparticles as a substrate, the coating thickness can be monitored using a spectroscopic method based on the extinction peak shifts of the Ag nanoparticles. The deposition rate increases with dopamine concentration; however, too much excess dopamine leads to the formation of free dopamine particles. The optimized concentration of dopamine (i.e., ∼6 mM) can be applied to other nanoparticles by normalizing the number of particles to maintain a constant concentration of dopamine per unit surface area (i.e., 1.70 × 10(4) dopamine/nm(2)). The molecular dynamics simulation reveals that the amount of hydrogen bonding increases with water content, suggesting that sufficient mixing using the dispersion tool facilitates the formation of hydrogen bonding, thus rapidly depositing PDA on the nanoparticle surface. The physical and chemical properties (e.g., pH response and thermal stability) can be tailored by varying the coating thickness due to the changes in the number of hydrogen bonds and the conformation of π-π interactions. This dispersion method provides a facile means to control the PDA coating thickness on nanoparticle surfaces and thus the surface properties of nanoparticles toward various applications.

  5. Asymmetric rapid maxillary expansion in true unilateral crossbite malocclusion: a prospective controlled clinical study.

    Science.gov (United States)

    Ileri, Zehra; Basciftci, Faruk Ayhan

    2015-03-01

    To investigate the short-term effects of the asymmetric rapid maxillary (ARME) appliance on the vertical, sagittal, and transverse planes in patients with true unilateral posterior crossbite. Subjects were divided into two groups. The treatment group was comprised of 21 patients with unilateral posterior crossbite (mean age  =  13.3 ± 2.1 years). Members of this group were treated with the ARME appliance. The control group was comprised of 17 patients with Angle Class I who were kept under observation (mean age  =  12.3 ± 0.8 years). Lateral and frontal cephalograms were taken before the expansion (T1), immediately after expansion (T2), and at postexpansion retention (T3) in the treatment group and at preobservation (T1) and postobservation (T2) in the control group. A total of 34 measurements were assessed on cephalograms. For statistical analysis, the Wilcoxon test and analysis of covariance were used. The ARME appliance produced significant increases in nasal, maxillary base, upper arch, and lower arch dimensions (P ARME appliance created asymmetric increments in the transversal dimensions of the nose, maxilla, and upper arch in the short term. Asymmetric expansion therapy for subjects with unilateral maxillary deficiency may provide satisfactory outcomes in adolescents, with the exception of mandibular arch expansion. The triangular pattern of expansion caused clockwise rotation of the mandible and the occlusal plane and produced significant alterations in the vertical facial dimensions, whereas it created no displacement in maxilla in the sagittal plane.

  6. Mandibular response after rapid maxillary expansion in class II growing patients: a pilot randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Roberta Lione

    2017-11-01

    Full Text Available Abstract Background The aim of this pilot randomized controlled trial (RCT was to evaluate the sagittal mandibular response induced by rapid maxillary expansion (RME therapy in mixed dentition patients with class II malocclusion, comparing the effects of bonded RME and banded RME with a matched untreated class II control group. Methods This RCT was designed in parallel with an allocation ratio of 1:1:1. The sample consisted of 30 children with a mean age of 8.1 ± 0.6 years who were randomly assigned to three groups: group 1 treated with bonded RME, group 2 treated with banded RME, and group 3 the untreated control group. All patients met the following inclusion criteria: early mixed dentition, class II molar relationship, transverse discrepancy ≥ 4 mm, overjet ≥ 5 mm, and prepubertal skeletal maturity stage (CS1–CS2. The expansion screw was activated one quarter of a turn per day (0.25 mm until overcorrection was reached. For each subject, lateral cephalograms and plaster casts were obtained before treatment (T1 and after 1 year (T2. A randomization list was created for the group assignment, with an allocation ratio of 1:1:1. The observer who performed all the measurements was blinded to group assignment. The study was single-blinded in regard to statistical analysis. Results RME was effective in the correction of maxillary deficiency. Class II patients treated with both types of RME showed no significant improvement of the anteroposterior relationship of the maxilla and the mandible at both skeletal and occlusal levels. The acrylic splint RME had significant effects on reducing the skeletal vertical dimension and the gonial angle. Conclusions The orthopedic expansion did not affect the sagittal relationship of class II patients treated in the early mixed dentition when compared with the untreated control group. Additional studies with a larger sample are warranted to elucidate individual variations in dento-skeletal mandibular

  7. Mandibular response after rapid maxillary expansion in class II growing patients: a pilot randomized controlled trial.

    Science.gov (United States)

    Lione, Roberta; Brunelli, Valerio; Franchi, Lorenzo; Pavoni, Chiara; Quiroga Souki, Bernardo; Cozza, Paola

    2017-11-06

    The aim of this pilot randomized controlled trial (RCT) was to evaluate the sagittal mandibular response induced by rapid maxillary expansion (RME) therapy in mixed dentition patients with class II malocclusion, comparing the effects of bonded RME and banded RME with a matched untreated class II control group. This RCT was designed in parallel with an allocation ratio of 1:1:1. The sample consisted of 30 children with a mean age of 8.1 ± 0.6 years who were randomly assigned to three groups: group 1 treated with bonded RME, group 2 treated with banded RME, and group 3 the untreated control group. All patients met the following inclusion criteria: early mixed dentition, class II molar relationship, transverse discrepancy ≥ 4 mm, overjet ≥ 5 mm, and prepubertal skeletal maturity stage (CS1-CS2). The expansion screw was activated one quarter of a turn per day (0.25 mm) until overcorrection was reached. For each subject, lateral cephalograms and plaster casts were obtained before treatment (T1) and after 1 year (T2). A randomization list was created for the group assignment, with an allocation ratio of 1:1:1. The observer who performed all the measurements was blinded to group assignment. The study was single-blinded in regard to statistical analysis. RME was effective in the correction of maxillary deficiency. Class II patients treated with both types of RME showed no significant improvement of the anteroposterior relationship of the maxilla and the mandible at both skeletal and occlusal levels. The acrylic splint RME had significant effects on reducing the skeletal vertical dimension and the gonial angle. The orthopedic expansion did not affect the sagittal relationship of class II patients treated in the early mixed dentition when compared with the untreated control group. Additional studies with a larger sample are warranted to elucidate individual variations in dento-skeletal mandibular response to the maxillary expansion protocol in class

  8. Effect of Process Parameter in Laser Cutting of PMMA Sheet and ANFIS Modelling for Online Control

    Directory of Open Access Journals (Sweden)

    Hossain Anamul

    2016-01-01

    Full Text Available Laser beam machining (LBM is a promising and high accuracy machining technology in advanced manufacturing process. In LBM, crucial machining qualities of the end product include heat affected zone, surface roughness, kerf width, thermal stress, taper angle etc. It is essential for industrial applications especially in laser cutting of thermoplastics to acquire output product with minimum kerf width. The kerf width is dependent on laser input parameters such as laser power, cutting speed, standoff distance, assist gas pressure etc. However it is difficult to get a functional relationship due to the high uncertainty among these parameters. Hence, total 81 sets of full factorial experiment were conducted, representing four input parameters with three different levels. The experiments were performed by a continuous wave (CW CO2 laser with the mode structure of TEM01 named Zech laser machine that can provide maximum laser power up to 500 W. The polymethylmethacrylate (PMMA sheet with thickness of 3.0 mm was used for this experiment. Laser power, cutting speed, standoff distance and assist gas pressure were used as input parameters for the output named kerf width. Standoff distance, laser power, cutting speed and assist gas pressure have the dominant effect on kerf width, respectively, although assist gas has some significant effect to remove the harmful gas. ANFIS model has been developed for online control purposes. This research is considered important and helpful for manufacturing engineers in adjusting and decision making of the process parameters in laser manufacturing industry of PMMA thermoplastics with desired minimum kerf width as well as intricate shape design purposes.

  9. Controlled attenuation parameter (CAP) for the diagnosis of steatosis: a prospective study of 5323 examinations.

    Science.gov (United States)

    de Lédinghen, Victor; Vergniol, Julien; Capdepont, Maylis; Chermak, Faiza; Hiriart, Jean-Baptiste; Cassinotto, Christophe; Merrouche, Wassil; Foucher, Juliette; Brigitte, Le Bail

    2014-05-01

    Controlled attenuation parameter (CAP) evaluated with transient elastography (FibroScan®) is a recent method for non-invasive assessment of steatosis. Its usefulness in clinical practice is unknown. We prospectively investigated the determinants of CAP failure and the relationships between CAP and clinical or biological parameters in a large cohort of consecutive patients. All CAP examinations performed in adult patients with suspected chronic liver disease were included. CAP failure was defined as zero valid shot. The following factors were analyzed for their influence on CAP value and the relationships between CAP and clinico-biological parameters: age, gender, body mass index, waist circumference, hypertension, diabetes, metabolic syndrome, alcohol use, liver stiffness measurement, indication, and different biological parameters. CAP failure occurred in 7.7% of 5323 examinations. By multivariate analysis, factors independently associated with CAP measurement failure were female gender, BMI, and metabolic syndrome. By multivariate analysis, factors significantly associated with elevated CAP were BMI [25-30]kg/m(2), BMI >30kg/m(2), metabolic syndrome, alcohol >14 drink/week and liver stiffness >6kPa. CAP increased with the number of parameters of metabolic syndrome, BMI, waist circumference, the presence of diabetes or hypertension, and the cause of the disease. In the 440 patients with liver biopsy, for the diagnosis of steatosis >10%, steatosis >33%, and steatosis >66%, AUROCs of CAP were 0.79 (95% CI 0.74-0.84, pCAP provides an immediate assessment of steatosis simultaneously with liver stiffness measurement. The strong association of CAP with the metabolic syndrome and alcohol use could be of interest for the follow-up of NAFLD or alcoholic patients. Copyright © 2014 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

  10. Assessment of the reliability of neutronic parameters of Ghana Research Reactor-1 control systems

    Energy Technology Data Exchange (ETDEWEB)

    Amponsah-Abu, E.O., E-mail: edwardabu2002@yahoo.com [National Nuclear Research Institute, Ghana Atomic Energy Commission, P.O. Box LG. 80, Legon-Accra (Ghana); Gbadago, J.K. [National Nuclear Research Institute, Ghana Atomic Energy Commission, P.O. Box LG. 80, Legon-Accra (Ghana); Akaho, E.H.K.; Akoto-Bamford, S. [School of Nuclear and Allied Sciences, University of Ghana (Ghana); Gyamfi, K.; Asamoah, M.; Baidoo, I.K. [National Nuclear Research Institute, Ghana Atomic Energy Commission, P.O. Box LG. 80, Legon-Accra (Ghana)

    2015-01-15

    Highlights: • The reliability of neutronics parameters of GHARR-I was assessed. • The reactor was operated at different power levels of 5–30 kW. • The pre-set flux was compared with the flux in the inner irradiation site. • Decrease in the core reactivity caused difference in flux on the meters and site. • Neutronic parameters become reliable when operation is done at reactivity of 4 mk. - Abstract: The Ghana Research Reactor-1 (GHARR-1) has been in operation for the past 19 years using a Micro-Computer Closed Loop System (MCCLS) and Control Console (CC) as the control systems. The two control systems were each coupled separately with a micro-fission chamber to measure the current pulses of the neutron fluxes in the core at excess reactivity of 4 mk. The MCCLS and CC meter readings at a pre-set flux of 5.0 × 10{sup 11} n/cm{sup 2} s were 6.42 × 10{sup 11} n/cm{sup 2} s and 5.0 × 10{sup 11} n/cm{sup 2} s respectively. Due to ageing and obsolescence, the MCCLS and some components that control the sensitivity and the reading mechanism of the meters were replaced. One of the fission chambers was also removed and the two control systems were coupled to one fission chamber. The reliability of the neutronic parameters of the control systems was assessed after the replacement. The results showed that when the reactor is operated at different power levels of 5–30 kW using one micro-fission chamber, the pre-set neutron fluxes at the control systems is 1.6 times the neutron fluxes obtained using a flux monitor at the inner irradiation site two of the reactor. The average percentage deviations of the obtained fluxes from the pre-set values of 1.67 × 10{sup 11}–1.0 × 10{sup 12} n/cm{sup 2} s were 36.5%. This compares very well with the decrease in core excess reactivity of 36.3% of the nominal value of 4 mk, after operating the reactor at critical neutron flux of 1.0 × 10{sup 9} n/cm{sup 2} s.

  11. Feasibility of creating a normative database of colour Doppler imaging parameters in glaucomatous eyes and controls.

    Science.gov (United States)

    Rusia, Deepam; Harris, Alon; Pernic, Allison; Williamson, Kathleen M; Moss, Adam M; Shoshani, Yochai Z; Siesky, Brent

    2011-09-01

    Colour Doppler imaging (CDI) is a frequently cited methodology for quantifying ocular blood flow velocities. This investigation reviews the feasibility of creating a normative database of CDI parameters in glaucoma patients and controls. A literature search was conducted for CDI studies involving glaucomatous eyes. Using data from these studies, a weighted mean was derived for the peak systolic velocity, end diastolic velocity and Pourcelot's resistive index in the ophthalmic, central retinal and posterior ciliary arteries. A multivariate analysis was performed to identify whether methodological characteristics contributed to the inter-study variance in CDI values. Data from 3061 glaucoma patients and 1072 controls were included. The mean values for glaucomatous eyes were within one standard deviation of the values for controls for most CDI parameters. Gender mix (p=0.043), intraocular pressure status (p=0.017), frequency of the ultrasound transducer (p=0.02) and whether the patients were on antihypertensive therapy (p=0.004) contributed to the variance. Methodological differences create inter-study variance in CDI values, complicating the construction of a normative database and limiting its utility. Because the mean values for glaucomatous and normal eyes have overlapping ranges, caution should be used when classifying glaucoma status based on a single CDI measurement.

  12. Development of a Quadrotor Test Bed — Modelling, Parameter Identification, Controller Design and Trajectory Generation

    Directory of Open Access Journals (Sweden)

    Wei Dong

    2015-02-01

    Full Text Available In this paper, a quadrotor test bed is developed. The technical approach for this test bed is firstly proposed by utilizing a commercial quadrotor, a Vicon motion capture system and a ground station. Then, the mathematical model of the quadrotor is formulated considering aerodynamic effects, and the parameter identification approaches for this model are provided accordingly. Based on the developed model and identified parameters, a simulation environment that is consistent with the real system is developed. Subsequently, a flight control strategy and a trajectory generation method, both of which are conceptually and computationally lightweight, are developed and tested in the simulation environment. The developed algorithms are then directly transplanted to the real system, and the experimental results show that their responses in the real-time flights match well with those from the simulations. This indicates that the control algorithms developed for the quadrotor can be preliminarily verified and refined though simulations, and then directly implemented to the real system, which could significantly reduce the experimental risks and costs. Meanwhile, real-time experiments show that the developed flight controller can efficiently stabilize the quadrotor when external disturbances exist, and the trajectory generation approach can provide safe guidance for the quadrotor to fly smoothly through cluttered environments with obstacle rings. All of these features are valuable for real applications, thus demonstrating the feasibility of further development.

  13. Damage control operations in non-trauma patients: defining criteria for the staged rapid source control laparotomy in emergency general surgery.

    Science.gov (United States)

    Becher, Robert D; Peitzman, Andrew B; Sperry, Jason L; Gallaher, Jared R; Neff, Lucas P; Sun, Yankai; Miller, Preston R; Chang, Michael C

    2016-01-01

    The staged laparotomy in the operative management of emergency general surgery (EGS) patients is an extension of trauma surgeons operating on this population. Indications for its application, however, are not well defined, and are currently based on the lethal triad used in physiologically-decompensated trauma patients. This study sought to determine the acute indications for the staged, rapid source control laparotomy (RSCL) in EGS patients. All EGS patients undergoing emergent staged RSCL and non-RSCL over 3 years were studied. Demographics, physiologic parameters, perioperative variables, outcomes, and survival were compared. Logistic regression models determined the influence of physiologic parameters on mortality and postoperative complications. EGS-RSCL indications were defined. 215 EGS patients underwent emergent laparotomy; 53 (25 %) were staged RSCL. In the 53 patients who underwent a staged RSCL based on the lethal triad, adjusted multivariable regression analysis shows that when used alone, no component of the lethal triad independently improved survival. Staged RSCL may decrease mortality in patients with preoperative severe sepsis / septic shock, and an elevated lactate (≥3); acidosis (pH ≤ 7.25); elderly (≥70); male gender; and multiple comorbidities (≥3). Of the 162 non-RSCL emergent laparotomies, 27 (17 %) required unplanned re-explorations; of these, 17 (63 %) had sepsis preoperatively and 9 (33 %) died. The acute physiologic indicators that help guide operative decisions in trauma may not confer a similar survival advantage in EGS. To replace the lethal triad, criteria for application of the staged RSCL in EGS need to be defined. Based on these results, the indications should include severe sepsis / septic shock, lactate, acidosis, gender, age, and pre-existing comorbidities. When correctly applied, the staged RSCL may help to improve survival in decompensated EGS patients.

  14. Aromatherapy for reducing colonoscopy related procedural anxiety and physiological parameters: a randomized controlled study.

    Science.gov (United States)

    Hu, Pei-Hsin; Peng, Yen-Chun; Lin, Yu-Ting; Chang, Chi-Sen; Ou, Ming-Chiu

    2010-01-01

    Colonoscopy is generally tolerated, some patients regarding the procedure as unpleasant and painful and generally performed with the patient sedated and receiving analgesics. The effect of sedation and analgesia for colonoscopy is limited. Aromatherapy is also applied to gastrointestinal endoscopy to reduce procedural anxiety. There is lack of information about aromatherapy specific for colonoscopy. In this study, we aimed to performed a randomized controlled study to investigate the effect of aromatherapy on relieve anxiety, stress and physiological parameters of colonoscopy. A randomized controlled trail was carried out and collected in 2009 and 2010. The participants were randomized in two groups. Aromatherapy was then carried out by inhalation of Sunflower oil (control group) and Neroli oil (Experimental group). The anxiety index was evaluated by State Trait Anxiety Inventory-state (STAI-S) score before aromatherapy and after colonoscopy as well as the pain index for post-procedural by visual analogue scale (VAS). Physiological indicators, such as blood pressure (systolic and diastolic blood pressure), heart rate and respiratory rate were evaluated before and after aromatherapy. Participates in this study were 27 subjects, 13 in control group and 14 in Neroli group with average age 52.26 +/- 17.79 years. There was no significance of procedural anxiety by STAI-S score and procedural pain by VAS. The physiological parameters showed a significant lower pre- and post-procedural systolic blood pressure in Neroli group than control group. Aromatic care for colonoscopy, although with no significant effect on procedural anxiety, is an inexpensive, effective and safe pre-procedural technique that could decrease systolic blood pressure.

  15. Approximation Methods for the Identification and Control of Distributed Parameter Systems.

    Science.gov (United States)

    1987-11-20

    Computacional , 5 (1986), 139-168. 12. The Identification of a Distributed Parameter Model for a Flexible Structure, (with H.T. Banks, S.S. Gates and Y. Wang...Science and Engineering, NASA Langley Research Center, Hampton, VA, and Mat. Applicada e Computacional , 5 (1986). [7] H.T. Banks and P.L. Daniel (Lamm...Bericht 83-26, Techn. Universitat Graz, December 1983; Mat. Aplicada e Computacional 4 (1985), pp. 95-124. [27] J.L. Lions, Optimal Control of

  16. Parameter Estimation of Dynamic Multi-zone Models for Livestock Indoor Climate Control

    DEFF Research Database (Denmark)

    Wu, Zhuang; Stoustrup, Jakob; Heiselberg, Per

    2008-01-01

    , the livestock, the ventilation system and the building on the dynamic performance of indoor climate. Some significant parameters employed in the climate model as well as the airflow interaction between each conceptual zone are identified with the use of experimental time series data collected during spring...... and winter at a real scale livestock building in Denmark. The obtained comparative results between the measured data and the simulated output confirm that a very simple multi-zone model can capture the salient dynamical features of the climate dynamics which are needed for control purposes....

  17. Rapid Airplane Parametric Input Design (RAPID)

    Science.gov (United States)

    Smith, Robert E.

    1995-01-01

    RAPID is a methodology and software system to define a class of airplane configurations and directly evaluate surface grids, volume grids, and grid sensitivity on and about the configurations. A distinguishing characteristic which separates RAPID from other airplane surface modellers is that the output grids and grid sensitivity are directly applicable in CFD analysis. A small set of design parameters and grid control parameters govern the process which is incorporated into interactive software for 'real time' visual analysis and into batch software for the application of optimization technology. The computed surface grids and volume grids are suitable for a wide range of Computational Fluid Dynamics (CFD) simulation. The general airplane configuration has wing, fuselage, horizontal tail, and vertical tail components. The double-delta wing and tail components are manifested by solving a fourth order partial differential equation (PDE) subject to Dirichlet and Neumann boundary conditions. The design parameters are incorporated into the boundary conditions and therefore govern the shapes of the surfaces. The PDE solution yields a smooth transition between boundaries. Surface grids suitable for CFD calculation are created by establishing an H-type topology about the configuration and incorporating grid spacing functions in the PDE equation for the lifting components and the fuselage definition equations. User specified grid parameters govern the location and degree of grid concentration. A two-block volume grid about a configuration is calculated using the Control Point Form (CPF) technique. The interactive software, which runs on Silicon Graphics IRIS workstations, allows design parameters to be continuously varied and the resulting surface grid to be observed in real time. The batch software computes both the surface and volume grids and also computes the sensitivity of the output grid with respect to the input design parameters by applying the precompiler tool

  18. Output-feedback sampled-data control design for linear parameter-varying systems with delay

    Science.gov (United States)

    Ramezanifar, Amin; Mohammadpour, Javad; Grigoriadis, Karolos M.

    2014-12-01

    In this paper, we address the sampled-data output-feedback control design problem for continuous-time linear parameter-varying systems with time-varying delay in the system states. Due to the combination of the plant's continuous-time dynamics and the controller's discrete-time dynamics connected through A/D and D/A converter devices, the closed-loop system is a hybrid system. In order to analyse this hybrid system from stability and performance perspectives we use the input-delay approach to map the closed-loop system into the continuous-time domain with delay in the states. This results in a closed-loop system containing two types of delays, the system internal delay and the one imposed by the mapping. Next, we use delay-dependent conditions for analysis of stability and ?-norm performance which result in a sampled-data control synthesis procedure. The proposed output-feedback sampled-data controller is obtained based on the solution to a linear matrix inequality optimisation problem using a set of appropriately defined slack variables. A numerical example of a milling machine is presented to demonstrate the viability of the proposed sampled-data control design method to satisfy the stability and performance objectives even with a varying sampling rate.

  19. Robust control and linear parameter varying approaches application to vehicle dynamics

    CERN Document Server

    Gaspar, Peter; Bokor, József

    2013-01-01

    Vehicles are complex systems (non-linear, multi-variable) where the abundance of embedded controllers should ensure better security. This book aims at emphasizing the interest and potential of Linear Parameter Varying methods within the framework of vehicle dynamics, e.g.   ·          proposed control-oriented model, complex enough to handle some system non linearities but still simple for control or observer design,   ·          take into account the adaptability of the vehicle's response to driving situations, to the driver request and/or to the road sollicitations,   ·          manage interactions between various actuators to optimize the dynamic behavior of vehicles.   This book results from the 32th International Summer School in Automatic that held in Grenoble, France, in September 2011, where recent methods (based on robust control and LPV technics), then applied to the control of vehicle dynamics, have been presented. After some theoretical background and a view on so...

  20. The measurement, control, and validation of critical parameters in an electron beam sterilization facility

    Science.gov (United States)

    Burns, P.; Drewell, N. H.; McKeown, J.

    1996-06-01

    The delivery and validation of a specified dose to a medical device are key concerns of operators of electron beam irradiation facilities. In an IMPELA-based irradiator , four of the parameters that directly influence the absorbed dose distribution in the product are controllable in real time — the electron energy, average beam current, scanned area, and the product exposure time. The 10 MeV accelerator operates at 50 kW with a stream of 200 μs wide, 100 mA pulses at a repetition rate of 250 Hz. The combination of short-term intra-pulse regulation with long-term pulse-to-pulse stability makes the IMPELA output attractive for the sterilization of medical products. The measurement and closed-loop control techniques used in the IMPELA design with be described with reference to facilitating compliance with medical sterilization standards. IMPELA is a registered trademark of Atomic Energy of Canada Ltd.

  1. Robust output feedback cruise control for high-speed train movement with uncertain parameters

    Science.gov (United States)

    Li, Shu-Kai; Yang, Li-Xing; Li, Ke-Ping

    2015-01-01

    In this paper, the robust output feedback cruise control for high-speed train movement with uncertain parameters is investigated. The dynamic of a high-speed train is modeled by a cascade of cars connected by flexible couplers, which is subject to rolling mechanical resistance, aerodynamic drag and wind gust. Based on Lyapunov’s stability theory, the sufficient condition for the existence of the robust output feedback cruise control law is given in terms of linear matrix inequalities (LMIs), under which the high-speed train tracks the desired speed, the relative spring displacement between the two neighboring cars is stable at the equilibrium state, and meanwhile a small prescribed H∞ disturbance attenuation level is guaranteed. One numerical example is given to illustrate the effectiveness of the proposed methods. Project supported by the Fundamental Research Funds for the Central Universities of Ministry of Education of China (Grant No.2014JBM150).

  2. Modified preparation and rapid quality control test for technetium-99m-tetrofosmin.

    Science.gov (United States)

    Patel, M; Owunwanne, A; Tuli, M; al-Za'abi, K; al-Mohannadi, S; Sa'ad, M; Jahan, S; Jacob, A; al-Bunny, A

    1998-12-01

    The objectives of this study were to: modify the preparation of 99mTc-tetrofosmin by using twice the amount of 99mTcO4- recommended by the manufacturer; evaluate the use of miniaturized rapid paper chromatography (MRPC) for quality control (QC) testing; and determine the in vitro stability of the modified preparation using MRPC. Two preparations of 99mTc-tetrofosmin were made: one with 4.4-8.8 GBq (120-240 mCi) and the other with 13.9-17.6 GBq (380-480 mCi) 99mTcO4-, referred to as regular and modified preparations, respectively. Routine QC tests were performed using MRPC and instant thin-layer chromatography/silica-gel (ITLC/SG) systems. The preparations were injected into 58 patients. Planar and SPECT images of stress and rest studies were obtained. The technical quality of the SPECT images was graded visually by four observers. Heart-to-lung and heart-to-background ratios were calculated from the planar images. The QC testing procedure took 4.18 +/- 0.15 min with MRPC and 54 +/- 5.3 min with ITLC/SG systems. The percent labeling efficiency, as determined by both techniques, ranged from 95.6 +/- 1.6 to 97.2% +/- 0.8%. Both preparations were stable up to 6 hr after reconstitution. There was no difference between the cardiac-to-lung and cardiac-to-background ratios of the two preparations. The results indicate that MRPC is a faster and effective chromatographic technique for routine QC testing of 99mTc-tetrofosmin. Doubling the amount of 99mTcO4- used in preparing 99mTc-tetrofosmin did not affect its in vitro stability, its efficacious use in patients or the technical quality of the images.

  3. Estimation of Gravitation Parameters of Saturnian Moons Using Cassini Attitude Control Flight Data

    Science.gov (United States)

    Krening, Samantha C.

    2013-01-01

    A major science objective of the Cassini mission is to study Saturnian satellites. The gravitational properties of each Saturnian moon is of interest not only to scientists but also to attitude control engineers. When the Cassini spacecraft flies close to a moon, a gravity gradient torque is exerted on the spacecraft due to the mass of the moon. The gravity gradient torque will alter the spin rates of the reaction wheels (RWA). The change of each reaction wheel's spin rate might lead to overspeed issues or operating the wheel bearings in an undesirable boundary lubrication condition. Hence, it is imperative to understand how the gravity gradient torque caused by a moon will affect the reaction wheels in order to protect the health of the hardware. The attitude control telemetry from low-altitude flybys of Saturn's moons can be used to estimate the gravitational parameter of the moon or the distance between the centers of mass of Cassini and the moon. Flight data from several low altitude flybys of three Saturnian moons, Dione, Rhea, and Enceladus, were used to estimate the gravitational parameters of these moons. Results are compared with values given in the literature.

  4. OLIVE PASTE CONSISTENCY AS A CONTROL PARAMETER FOR OIL EXTRACTION: A PRELIMINARY APPROACH

    Directory of Open Access Journals (Sweden)

    Piernicola Masella

    2008-09-01

    Full Text Available Malaxation is a critical step of olive oil extraction process as it can largely affect the extraction yield along with product quality. At present, malaxation control is based upon accumulated empirical results and the experience of the operators. There are evidences that this method rarely point out the olive-paste state suitable for oil extraction. The paper reports the results of a laboratory investigation aimed to verify the feasibility of using the olive paste consistency variation during malaxation as a parameter representing the right state for oil extraction. Olive pastes consistency evaluation was performed with a rotational rheometer. Oil extraction yield was evaluated by means of an extractability index (EI determined by laboratory centrifugation of the paste. The effect of different malaxation time and pastes humidity was investigated. Both malaxation time and humidity increments involve significant decrements of paste consistency and a simultaneous increase of EI. A good linear correlation among paste consistency and EI has been found, i.e. a large proportion of EI variance, about 90%, can be explained in terms of paste consistency variation during malaxation. The availability of a measurable parameter representing the paste state suitable for oil extraction could allow to implement a “closed-loop” control system for extraction yield maximization.

  5. Electrotransfer parameters as a tool for controlled and targeted gene expression in skin

    Directory of Open Access Journals (Sweden)

    Spela Kos

    2016-01-01

    Full Text Available Skin is an attractive target for gene electrotransfer. It consists of different cell types that can be transfected, leading to various responses to gene electrotransfer. We demonstrate that these responses could be controlled by selecting the appropriate electrotransfer parameters. Specifically, the application of low or high electric pulses, applied by multi-electrode array, provided the possibility to control the depth of the transfection in the skin, the duration and the level of gene expression, as well as the local or systemic distribution of the transgene. The influence of electric pulse type was first studied using a plasmid encoding a reporter gene (DsRed. Then, plasmids encoding therapeutic genes (IL-12, shRNA against endoglin, shRNA against melanoma cell adhesion molecule were used, and their effects on wound healing and cutaneous B16F10 melanoma tumors were investigated. The high-voltage pulses resulted in gene expression that was restricted to superficial skin layers and induced a local response. In contrast, the low-voltage electric pulses promoted transfection into the deeper skin layers, resulting in prolonged gene expression and higher transgene production, possibly with systemic distribution. Therefore, in the translation into the clinics, it will be of the utmost importance to adjust the electrotransfer parameters for different therapeutic approaches and specific mode of action of the therapeutic gene.

  6. A Comprehensive Analysis of Multiscale Field-Aligned Currents: Characteristics, Controlling Parameters, and Relationships

    Science.gov (United States)

    McGranaghan, Ryan M.; Mannucci, Anthony J.; Forsyth, Colin

    2017-12-01

    We explore the characteristics, controlling parameters, and relationships of multiscale field-aligned currents (FACs) using a rigorous, comprehensive, and cross-platform analysis. Our unique approach combines FAC data from the Swarm satellites and the Advanced Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE) to create a database of small-scale (˜10-150 km, 250 km) FACs. We examine these data for the repeatable behavior of FACs across scales (i.e., the characteristics), the dependence on the interplanetary magnetic field orientation, and the degree to which each scale "departs" from nominal large-scale specification. We retrieve new information by utilizing magnetic latitude and local time dependence, correlation analyses, and quantification of the departure of smaller from larger scales. We find that (1) FACs characteristics and dependence on controlling parameters do not map between scales in a straight forward manner, (2) relationships between FAC scales exhibit local time dependence, and (3) the dayside high-latitude region is characterized by remarkably distinct FAC behavior when analyzed at different scales, and the locations of distinction correspond to "anomalous" ionosphere-thermosphere behavior. Comparing with nominal large-scale FACs, we find that differences are characterized by a horseshoe shape, maximizing across dayside local times, and that difference magnitudes increase when smaller-scale observed FACs are considered. We suggest that both new physics and increased resolution of models are required to address the multiscale complexities. We include a summary table of our findings to provide a quick reference for differences between multiscale FACs.

  7. Control of HPNS in humans during rapid compression with trimix to 650 m (2131 ft).

    Science.gov (United States)

    Bennett, P B; Coggin, R; Roby, J

    1981-06-01

    In 1978 a series of deep trimix (He-N2-O2) dives was initiated to establish the relationship between a given nitrogen percentage and the rate of compression required to prevent the high pressure nervous syndrome (HPNS) at 460 m (1509 ft) and to determine the effects of inspired gas density, hydrostatic pressure, and narcosis o various circulatory and respiratory parameter, including the presence of dyspnea. In 1979, three human subjects were compressed to 460 m in 12 h 20 min with 5% N2 in He-O2. This resulted in nausea, vomiting, fatigue, tremors, and other signs and symptoms of HPNS that were especially prominent on arrival at that depth but had much improved by Day 2. In March 1980 the same profile was repeated but with 10% N2 in He-O2. The divers arrived at 460 m with virtually no symptoms of HPNS, but the psychometric performance, as for Atlantis I, still was decreased by some 40% on Day 1 and recovered to some 15% by Day 2. After 5-6 days at 460 m further extension of the dive to 650 m (2132 ft) with a 7.7% N2 mixture for 24 h showed similar control of symptoms of HPNS, although inspiratory resting dyspnea was present in one subject. The results are discussed in relation to the interactions of nitrogen percentage and rate of compression.

  8. Genetic algorithm–based varying parameter linear quadratic regulator control for four-wheel independent steering vehicle

    Directory of Open Access Journals (Sweden)

    Linlin Gao

    2015-11-01

    Full Text Available From the perspective of vehicle dynamics, the four-wheel independent steering vehicle dynamics stability control method is studied, and a four-wheel independent steering varying parameter linear quadratic regulator control system is proposed with the help of expert control method. In the article, a four-wheel independent steering linear quadratic regulator controller for model following purpose is designed first. Then, by analyzing the four-wheel independent steering vehicle dynamic characteristics and the influence of linear quadratic regulator control parameters on control performance, a linear quadratic regulator control parameter adjustment strategy based on vehicle steering state is proposed to achieve the adaptive adjustment of linear quadratic regulator control parameters. In addition, to further improve the control performance, the proposed varying parameter linear quadratic regulator control system is optimized by genetic algorithm. Finally, simulation studies have been conducted by applying the proposed control system to the 8-degree-of-freedom four-wheel independent steering vehicle dynamics model. The simulation results indicate that the proposed control system has better performance and robustness and can effectively improve the stability and steering safety of the four-wheel independent steering vehicle.

  9. Enhanced Photoelectrochemical Behavior of H-TiO2 Nanorods Hydrogenated by Controlled and Local Rapid Thermal Annealing.

    Science.gov (United States)

    Wang, Xiaodan; Estradé, Sonia; Lin, Yuanjing; Yu, Feng; Lopez-Conesa, Lluis; Zhou, Hao; Gurram, Sanjeev Kumar; Peiró, Francesca; Fan, Zhiyong; Shen, Hao; Schaefer, Lothar; Braeuer, Guenter; Waag, Andreas

    2017-12-01

    Recently, colored H-doped TiO2 (H-TiO2) has demonstrated enhanced photoelectrochemical (PEC) performance due to its unique crystalline core-disordered shell nanostructures and consequent enhanced conduction behaviors between the core-shell homo-interfaces. Although various hydrogenation approaches to obtain H-TiO2 have been developed, such as high temperature hydrogen furnace tube annealing, high pressure hydrogen annealing, hydrogen-plasma assisted reaction, aluminum reduction and electrochemical reduction etc., there is still a lack of a hydrogenation approach in a controlled manner where all processing parameters (temperature, time and hydrogen flux) were precisely controlled in order to improve the PEC performance of H-TiO2 and understand the physical insight of enhanced PEC performance. Here, we report for the first time a controlled and local rapid thermal annealing (RTA) approach to prepare hydrogenated core-shell H-TiO2 nanorods grown on F:SnO2 (FTO) substrate in order to address the degradation issue of FTO in the typical TiO2 nanorods/FTO system observed in the conventional non-RTA treated approaches. Without the FTO degradation in the RTA approach, we systematically studied the intrinsic relationship between the annealing temperature, structural, optical, and photoelectrochemical properties in order to understand the role of the disordered shell on the improved photoelectrochemical behavior of H-TiO2 nanorods. Our investigation shows that the improvement of PEC performance could be attributed to (i) band gap narrowing from 3.0 to 2.9 eV; (ii) improved optical absorption in the visible range induced by the three-dimensional (3D) morphology and rough surface of the disordered shell; (iii) increased proper donor density; (iv) enhanced electron-hole separation and injection efficiency due to the formation of disordered shell after hydrogenation. The RTA approach developed here can be used as a suitable hydrogenation process for TiO2 nanorods/FTO system for

  10. Blade Fault Diagnosis in Small Wind Power Systems Using MPPT with Optimized Control Parameters

    Directory of Open Access Journals (Sweden)

    Jui-Ho Chen

    2015-08-01

    Full Text Available A systematic experiment verification of Chaos Embedded Sliding Mode Extremum Seeking Control for maximum power point tracking and a method for detecting possible faults in small wind turbine systems in advance are proposed in this paper. The chaotic logistic map is used to replace the random function in the particle swarm optimization algorithm for faster searching the optimal control parameter . From the experimental results, it is verified that the Chaos Embedded Sliding Mode Extremum Seeking Control scheme has a better dynamic response than traditional Extremum Seeking Control scheme and Hill-Climbing Search scheme for maximum power point tracking. In the proposed scheme for fault detection, a chaotic synchronization method is used to transform the maximum power point tracking signal into a chaos synchronization error distribution diagram. It is then taken as the characteristic for fault diagnosis purposes. Finally, an extension theory pattern recognition technique is applied to diagnose the fault. Notably, the use of the chaotic dynamic errors as the fault diagnosis characteristic reduces the number of extracted features required, and therefore greatly reduces both the computation time and the hardware implementation cost. From the experimental results, it is shown that the fault diagnosis rate of the proposed method exceeds 98% not only in non-real-time but also in real-time of faults detection of the blades.

  11. Experimental Active Vibration Control in Truss Structures Considering Uncertainties in System Parameters

    Directory of Open Access Journals (Sweden)

    Douglas Domingues Bueno

    2008-01-01

    Full Text Available This paper deals with the study of algorithms for robust active vibration control in flexible structures considering uncertainties in system parameters. It became an area of enormous interest, mainly due to the countless demands of optimal performance in mechanical systems as aircraft, aerospace, and automotive structures. An important and difficult problem for designing active vibration control is to get a representative dynamic model. Generally, this model can be obtained using finite element method (FEM or an identification method using experimental data. Actuators and sensors may affect the dynamics properties of the structure, for instance, electromechanical coupling of piezoelectric material must be considered in FEM formulation for flexible and lightly damping structure. The nonlinearities and uncertainties involved in these structures make it a difficult task, mainly for complex structures as spatial truss structures. On the other hand, by using an identification method, it is possible to obtain the dynamic model represented through a state space realization considering this coupling. This paper proposes an experimental methodology for vibration control in a 3D truss structure using PZT wafer stacks and a robust control algorithm solved by linear matrix inequalities.

  12. Rapid prototyping of nano- and micro-patterned substrates for the control of cell neuritogenesis by topographic and chemical cues

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Ajay V.; Gailite, Lasma; Vyas, Varun [European School of Molecular Medicine (SEMM), IFOM-IEO Campus, Via Adamello 16, I-20139 Milano (Italy); CIMAINA and Dipartimento di Fisica, Universita di Milano, via Celoria 16, I-20133 Milano (Italy); Lenardi, Cristina, E-mail: cristina.lenardi@mi.infn.it [CIMAINA and Dipartimento di Scienze Molecolari Applicate ai Biosistemi, Universita di Milano, via Trentacoste 2, I-20134 Milano (Italy); Fondazione Filarete, viale Ortles 22/4, I-20139 Milano (Italy); Forti, Stefania [CIMAINA and Dipartimento di Fisica, Universita di Milano, via Celoria 16, I-20133 Milano (Italy); Matteoli, Michela [Dipartimento di Farmacologia, Chemioterapia e Tossicologia Medica, Universita di Milano, via Vanvitelli 32, I-20139 Milano (Italy); Fondazione Filarete, viale Ortles 22/4, I-20139 Milano (Italy); Milani, Paolo, E-mail: paolo.milani@mi.infn.it [CIMAINA and Dipartimento di Fisica, Universita di Milano, via Celoria 16, I-20133 Milano (Italy); Fondazione Filarete, viale Ortles 22/4, I-20139 Milano (Italy)

    2011-07-20

    Rapid prototyping of titania substrates with micro and nanofeatures is obtained by combining nanosphere lithography with supersonic cluster beam deposition on protein-functionalized glass supports. The proliferation and differentiation of PC12 cells were studied on these substrates. The facile control and modification of the substrate structure at the micro- and nanoscale allowed us to characterize the role of functional and structural features on neuritogenesis and to control this phenomenon by identifying the optimal topography.

  13. Dried Plasmodium falciparum-infected samples as positive controls for malaria rapid diagnostic tests

    Directory of Open Access Journals (Sweden)

    Aidoo Michael

    2012-07-01

    Full Text Available Abstract Background Rapid diagnostic tests (RDTs are central to fulfilling the WHO’s recommendation for parasitologic confirmation of all suspected cases of malaria. RDT performance may be compromised when exposed to the high temperature conditions typical of most malaria endemic regions. However, a systematic method to monitor RDT quality and performance in endemic countries is lacking at the present time. Current methods to monitor RDT performance in the field include comparing results from RDTs to diagnoses made by light microscopy and observing health workers perform tests. These methods are not substitutes for direct quality control. In this study, the suitability of dried Plasmodium falciparum-infected blood as quality control samples for malaria RDTs was evaluated. Methods Three cultured strains of P. falciparum at 200 and 2,000 parasites/μl were tested on 10 brands of RDT. After baseline testing to determine initial reactivity, aliquots of parasite-infected blood were air dried, stored at 35°C, room temperature (~25°C or 4°C for one, four and 12 weeks and were then tested on the 10 RDTs after rehydration. Extended stability testing of dried blood stored at 4°C was done using P. falciparum strain 3D7 at 1,000 and 2,000 parasites/μl. Results All dried blood samples at 2,000 parasites/μl retained reactivity (100% sensitivity at all three temperatures and time points for all nine RDT brands that detect histidine-rich protein-2 (HRP2. The dried blood samples with 200 parasites/μl were detected by six of the nine HRP2-based RDTs at all storage temperatures and time points. The sensitivity for two of the three remaining HRP2-based RDTs was 100% up to four weeks of storage at all temperatures but dropped to 87.5% at week 12. Of the four RDTs that detect plasmodium lactate dehydrogenase (pLDH in a pan-specific manner, alone or in combination with HRP2, the detection of pLDH in samples with 2,000 parasites/μL was 100% for two RDTs and

  14. A double-blind, placebo-controlled, prophylaxis study of lamotrigine in rapid-cycling bipolar disorder. Lamictal 614 Study Group.

    Science.gov (United States)

    Calabrese, J R; Suppes, T; Bowden, C L; Sachs, G S; Swann, A C; McElroy, S L; Kusumakar, V; Ascher, J A; Earl, N L; Greene, P L; Monaghan, E T

    2000-11-01

    Patients with rapid-cycling bipolar disorder are often treatment refractory. This study examined lamotrigine as maintenance monotherapy for rapid-cycling bipolar disorder. Lamotrigine was added to patients' current psychotropic regimens and titrated to clinical effect during an open-label treatment phase. Stabilized patients were tapered off other psychotropics and randomly assigned to lamotrigine or placebo monotherapy for 6 months. Time to additional pharmacotherapy for emerging symptoms was the primary outcome measure. Secondary efficacy measures included survival in study (time to any premature discontinuation), percentage of patients stable without relapse for 6 months, and changes in the Global Assessment Scale and Clinical Global Impressions-Severity scale. Safety was assessed from adverse event, physical examination, and laboratory data. 324 patients with rapid-cycling bipolar disorder (DSM-IV criteria) received open-label lamotrigine, and 182 patients were randomly assigned to the double-blind maintenance phase. The difference between the treatment groups in time to additional pharmacotherapy did not achieve statistical significance in the overall efficacy population. However, survival in study was statistically different between the treatment groups (p = .036). Analyses also indicated a 6-week difference in median survival time favoring lamotrigine. Forty-one percent of lamotrigine patients versus 26% of placebo patients (p = .03) were stable without relapse for 6 months of monotherapy. Lamotrigine was well tolerated; there were no treatment-related changes in laboratory parameters, vital signs, or body weight. No serious rashes occurred. This was the largest and only prospective placebo-controlled study of rapid-cycling bipolar disorder patients to date; results indicate lamotrigine monotherapy is a useful treatment for some patients with rapid-cycling bipolar disorder.

  15. A methodology for modeling photocatalytic reactors for indoor pollution control using previously estimated kinetic parameters

    Energy Technology Data Exchange (ETDEWEB)

    Passalia, Claudio; Alfano, Orlando M. [INTEC - Instituto de Desarrollo Tecnologico para la Industria Quimica, CONICET - UNL, Gueemes 3450, 3000 Santa Fe (Argentina); FICH - Departamento de Medio Ambiente, Facultad de Ingenieria y Ciencias Hidricas, Universidad Nacional del Litoral, Ciudad Universitaria, 3000 Santa Fe (Argentina); Brandi, Rodolfo J., E-mail: rbrandi@santafe-conicet.gov.ar [INTEC - Instituto de Desarrollo Tecnologico para la Industria Quimica, CONICET - UNL, Gueemes 3450, 3000 Santa Fe (Argentina); FICH - Departamento de Medio Ambiente, Facultad de Ingenieria y Ciencias Hidricas, Universidad Nacional del Litoral, Ciudad Universitaria, 3000 Santa Fe (Argentina)

    2012-04-15

    Highlights: Black-Right-Pointing-Pointer Indoor pollution control via photocatalytic reactors. Black-Right-Pointing-Pointer Scaling-up methodology based on previously determined mechanistic kinetics. Black-Right-Pointing-Pointer Radiation interchange model between catalytic walls using configuration factors. Black-Right-Pointing-Pointer Modeling and experimental validation of a complex geometry photocatalytic reactor. - Abstract: A methodology for modeling photocatalytic reactors for their application in indoor air pollution control is carried out. The methodology implies, firstly, the determination of intrinsic reaction kinetics for the removal of formaldehyde. This is achieved by means of a simple geometry, continuous reactor operating under kinetic control regime and steady state. The kinetic parameters were estimated from experimental data by means of a nonlinear optimization algorithm. The second step was the application of the obtained kinetic parameters to a very different photoreactor configuration. In this case, the reactor is a corrugated wall type using nanosize TiO{sub 2} as catalyst irradiated by UV lamps that provided a spatially uniform radiation field. The radiative transfer within the reactor was modeled through a superficial emission model for the lamps, the ray tracing method and the computation of view factors. The velocity and concentration fields were evaluated by means of a commercial CFD tool (Fluent 12) where the radiation model was introduced externally. The results of the model were compared experimentally in a corrugated wall, bench scale reactor constructed in the laboratory. The overall pollutant conversion showed good agreement between model predictions and experiments, with a root mean square error less than 4%.

  16. A Simple Attitude Control of Quadrotor Helicopter Based on Ziegler-Nichols Rules for Tuning PD Parameters

    Directory of Open Access Journals (Sweden)

    ZeFang He

    2014-01-01

    Full Text Available An attitude control strategy based on Ziegler-Nichols rules for tuning PD (proportional-derivative parameters of quadrotor helicopters is presented to solve the problem that quadrotor tends to be instable. This problem is caused by the narrow definition domain of attitude angles of quadrotor helicopters. The proposed controller is nonlinear and consists of a linear part and a nonlinear part. The linear part is a PD controller with PD parameters tuned by Ziegler-Nichols rules and acts on the quadrotor decoupled linear system after feedback linearization; the nonlinear part is a feedback linearization item which converts a nonlinear system into a linear system. It can be seen from the simulation results that the attitude controller proposed in this paper is highly robust, and its control effect is better than the other two nonlinear controllers. The nonlinear parts of the other two nonlinear controllers are the same as the attitude controller proposed in this paper. The linear part involves a PID (proportional-integral-derivative controller with the PID controller parameters tuned by Ziegler-Nichols rules and a PD controller with the PD controller parameters tuned by GA (genetic algorithms. Moreover, this attitude controller is simple and easy to implement.

  17. Clinical implications of controlled attenuation parameter in a health check-up cohort.

    Science.gov (United States)

    Kwak, Min-Sun; Chung, Goh Eun; Yang, Jong In; Yim, Jeong Yoon; Chung, Su Jin; Jung, Se Young; Kim, Joo Sung

    2017-09-21

    Evaluation of the controlled attenuation parameter (CAP) is a promising noninvasive method for assessing hepatic steatosis. Despite the increasing reliability of the CAP for assessing steatosis in subjects with chronic liver disease, few studies have evaluated the CAP in asymptomatic subjects without overt liver disease. Therefore, we aimed to evaluate the usefulness of the CAP for a health check-up population. We enrolled subjects who underwent abdominal ultrasonography (US), FibroScan (Echosens, France) and blood sampling during medical health check-ups. The CAP was measured using FibroScan, and increased CAP was defined as CAP ≥ 222 dB/m. A total of 1133 subjects were included; 589 subjects (52.0%) had fatty liver based on US, and 604 subjects (53.3%) had increased CAP. Increased CAP was significantly associated with metabolic abnormalities, including higher body mass index (BMI)[odds ratio (OR) = 1.33;95% confidence interval (CI),1.24-1.43; P parameters among three groups (normal vs no fatty liver by US but increased CAP vs fatty liver based on US) revealed that metabolic parameters, including blood pressure, BMI, waist circumference, aspartate aminotransferase (AST), ALT, triglycerides, fasting glucose, uric acid, insulin, homeostasis model assessment-estimated insulin resistance and liver stiffness measurements, gradually increased across the three groups (all P < .001). In conclusion, increased CAP could be an early indicator of fatty liver disease with metabolic abnormalities that manifests even before a sonographic fatty change appears. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  18. Architectural setup for online monitoring and control of process parameters in robot-based ISF

    Science.gov (United States)

    Störkle, Denis Daniel; Thyssen, Lars; Kuhlenkötter, Bernd

    2017-10-01

    This article describes new developments in an incremental, robot-based sheet metal forming process (Roboforming) for the production of sheet metal components for small lot sizes and prototypes. The dieless kinematic-based generation of the shape is implemented by means of two industrial robots, which are interconnected to a cooperating robot system. Compared to other incremental sheet forming (ISF) machines, this system offers high geometrical design flexibility without the need of any part-dependent tools. However, the industrial application of ISF is still limited by certain constraints, e.g. the low geometrical accuracy. Responding to these constraints, the authors introduce a new architectural setup extending the current one by a superordinate process control. This sophisticated control consists of two modules, i.e. the compensation of the two industrial robots' low structural stiffness as well as a combined force/torque control. It is assumed that this contribution will lead to future research and development projects in which the authors will thoroughly investigate ISF process parameters influencing the geometric accuracy of the forming results.

  19. Insight into the Physical and Dynamical Processes that Control Rapid Increases in Total Flash Rate

    Science.gov (United States)

    Schultz, Christopher J.; Carey, Lawrence D.; Schultz, Elise V.; Blakeslee, Richard J.; Goodman, Steven J.

    2015-01-01

    Rapid increases in total lightning (also termed "lightning jumps") have been observed for many decades. Lightning jumps have been well correlated to severe and hazardous weather occurrence. The main focus of lightning jump work has been on the development of lightning algorithms to be used in real-time assessment of storm intensity. However, in these studies it is typically assumed that the updraft "increases" without direct measurements of the vertical motion, or specification of which updraft characteristic actually increases (e.g., average speed, maximum speed, or convective updraft volume). Therefore, an end-to-end physical and dynamical basis for coupling rapid increases in total flash rate to increases in updraft speed and volume must be understood in order to ultimately relate lightning occurrence to severe storm metrics. Herein, we use polarimetric, multi-Doppler, and lightning mapping array measurements to provide physical context as to why rapid increases in total lightning are closely tied to severe and hazardous weather.

  20. Very-low speed control of PMSM based on EKF estimation with closed loop optimized parameters.

    Science.gov (United States)

    Xu, Dong; Zhang, Shaoguang; Liu, Jingmeng

    2013-11-01

    When calculating the speed from the position of permanent magnet synchronous motor (PMSM), the accuracy and real-time are limited by the precision of the sensor. This problem causes crawling and jitter at very-low speed. Using the angle from the position sensor, an extended Kalman filter (EKF) designed in dq-coordinate is presented to solve this problem. The usage of position sensor simplifies the model and improves the accuracy of speed estimation. Specially, a closed loop optimal (CLO) method is devised to overcome the difficulty to adjust the parameters of the EKF. The EKF is the feedback link of speed control, CLO method is derived from the perspective of the speed step response to optimize the measurement covariance matrix and the system covariance matrix of EKF. Simulation and experimental results, comparing the low-speed performance of the EKF and sensor feedback methods, prove the effectiveness of the method to adjust the parameters of EKF and the advantages in eliminating the low speed jitter. © 2013 ISA. Published by ISA. All rights reserved.

  1. Controlled attenuation parameter for the diagnosis of steatosis in non-alcoholic fatty liver disease.

    Science.gov (United States)

    de Lédinghen, Victor; Wong, Grace Lai-Hung; Vergniol, Julien; Chan, Henry Lik-Yuen; Hiriart, Jean-Baptiste; Chan, Anthony Wing-Hung; Chermak, Faiza; Choi, Paul Cheung-Lung; Foucher, Juliette; Chan, Carmen Ka-Man; Merrouche, Wassil; Chim, Angel Mei-Ling; Le Bail, Brigitte; Wong, Vincent Wai-Sun

    2016-04-01

    Controlled attenuation parameter (CAP) evaluated with transient elastography (FibroScan) is a recent method for non-invasive assessment of steatosis. Its usefulness in non-alcoholic fatty liver disease (NAFLD) is unknown. We prospectively investigated the performance of CAP for the diagnosis of steatosis in NAFLD, factors associated with discordances between CAP and steatosis grades, and relationships between CAP and clinical or biological parameters. All CAP examinations performed in NAFLD patients with a liver biopsy performed within 1 week of CAP measurement were included. Liver biopsies were assessed for activity and fibrosis stage, NAFLD activity score, and steatosis graded as follows: S0, steatosis 66%. Two hundred sixty-one patients (59% male, age 56 years) from two ethnic groups were included. No patient had steatosis  310 dB/m. The association of CAP with steatosis, especially in patients with non-alcoholic steatohepatitis, and with elevated BMI could be useful for the diagnosis and follow-up of NAFLD patients. © 2015 Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd.

  2. Optimization of Sample Preparation and Instrumental Parameters for the Rapid Analysis of Drugs of Abuse in Hair samples by MALDI-MS/MS Imaging

    Science.gov (United States)

    Flinders, Bryn; Beasley, Emma; Verlaan, Ricky M.; Cuypers, Eva; Francese, Simona; Bassindale, Tom; Clench, Malcolm R.; Heeren, Ron M. A.

    2017-08-01

    Matrix-assisted laser desorption/ionization-mass spectrometry imaging (MALDI-MSI) has been employed to rapidly screen longitudinally sectioned drug user hair samples for cocaine and its metabolites using continuous raster imaging. Optimization of the spatial resolution and raster speed were performed on intact cocaine contaminated hair samples. The optimized settings (100 × 150 μm at 0.24 mm/s) were subsequently used to examine longitudinally sectioned drug user hair samples. The MALDI-MS/MS images showed the distribution of the most abundant cocaine product ion at m/z 182. Using the optimized settings, multiple hair samples obtained from two users were analyzed in approximately 3 h: six times faster than the standard spot-to-spot acquisition method. Quantitation was achieved using longitudinally sectioned control hair samples sprayed with a cocaine dilution series. A multiple reaction monitoring (MRM) experiment was also performed using the `dynamic pixel' imaging method to screen for cocaine and a range of its metabolites, in order to differentiate between contaminated hairs and drug users. Cocaine, benzoylecgonine, and cocaethylene were detectable, in agreement with analyses carried out using the standard LC-MS/MS method. [Figure not available: see fulltext.

  3. Mathematical Modelling and Parameter Identification of an Electro-Magneto-Mechanical Actuator for Vibration Control

    DEFF Research Database (Denmark)

    Darula, Radoslav; Stein, George Juraj; Kallesøe, Carsten Skovmose

    2012-01-01

    Electromechanical systems for vibration control exhibit complex non-linear behaviour. Therefore advanced mathematical tools and appropriate simplifications are required for their modelling. To properly understand the dynamics of such a non-linear system, it is necessary to identify the parameters...... of the electromagnetic circuit in its various operational regimes. The parametric identification supplements mathematical derivations. The analyzed mechanical system is essentially a Single Degree-Of-Freedom (SDOF) oscillatory system augmented by magnetic force influence. The additional magnetic force is generated...... by an electromagnet with armature. The electromagnet is energized by a constant voltage source. The SDOF system is excited by a harmonic force causing vibration of the armature. Due to the reluctance variation of the air gap of the magnetic circuit alternating voltage is generated across the coil terminals...

  4. Adding randomness controlling parameters in GRASP method applied in school timetabling problem

    Directory of Open Access Journals (Sweden)

    Renato Santos Pereira

    2017-09-01

    Full Text Available This paper studies the influence of randomness controlling parameters (RCP in first stage GRASP method applied in graph coloring problem, specifically school timetabling problems in a public high school. The algorithm (with the inclusion of RCP was based on critical variables identified through focus groups, whose weights can be adjusted by the user in order to meet the institutional needs. The results of the computational experiment, with 11-year-old data (66 observations processed at the same high school show that the inclusion of RCP leads to significantly lowering the distance between initial solutions and local minima. The acceptance and the use of the solutions found allow us to conclude that the modified GRASP, as has been constructed, can make a positive contribution to this timetabling problem of the school in question.

  5. The outcome of tactile touch on stress parameters in intensive care: a randomized controlled trial.

    Science.gov (United States)

    Henricson, Maria; Ersson, Anders; Määttä, Sylvia; Segesten, Kerstin; Berglund, Anna-Lena

    2008-11-01

    The study aimed to investigate the effects of a five-day tactile touch intervention in order to find new and unconventional measures to moderate the detrimental influence of patients' stressors during intensive care. The hypothesis was that tactile touch would decrease stress indicators such as anxiety, glucose metabolism, blood pressure, heart rate and requirements of sedative drugs and noradrenalin. A randomized controlled trial was undertaken with 44 patients, which were assigned either to tactile touch or standard treatment (a rest hour). Observations of the stress indicators were made before, during and after the intervention or standard treatment. The study showed that tactile touch led to significantly lower levels of anxiety. The circulatory parameters suggested increased circulatory stability indicated by a reduction in noradrenalin requirement. The results need to be further validated through studies with larger sample sizes.

  6. Diagnostic performance of controlled attenuation parameter for predicting steatosis grade in chronic hepatitis B.

    Science.gov (United States)

    Cardoso, Ana C; Beaugrand, Michel; de Ledinghen, Victor; Douvin, Catherine; Poupon, Raoul; Trinchet, Jean-Claude; Ziol, Marianne; Bedossa, Pierre; Marcellin, Patrick

    2015-01-01

    A novel controlled attenuation parameter (CAP) using the signals acquired by the FibroScan® has been developed as a method for evaluating steatosis. The aim of this study is to assess the performance of the CAP for the detection and quantification of steatosis in patients with chronic hepatitis B (CHB). 136 subjects with CHB underwent liver biopsy and FibroScan® within 60 days. CAP was evaluated retrospectively using raw FibroScan® data. Steatosis was graded as follows: S0 (steatosis CAP correlated with steatosis (τ = 0.38, P CAP were: 0.82 (0.73-0.92), 0.82 (0.69-0.95), and 0.97 (0.84-1.00) for ≥ S1, ≥ S2 and S3 steatosis, respectively. In conclusión CAP is a novel, accurate non-invasive tool and may be suitable for detecting and quantifying steatosis in CHB patients.

  7. Research progress in controlled attenuation parameter for assessment of fatty liver disease

    Directory of Open Access Journals (Sweden)

    LU Jiafa

    2015-05-01

    Full Text Available Controlled attenuation parameter (CAP is a noninvasive, quantitative, fast, and reliable novel tool for the assessment of fatty liver disease (FLD, and it has been a hotspot in the noninvasive diagnosis of FLD. This paper introduces factors associated with CAP assessing FLD, the cut-off value for the diagnosis of liver steatosis, and the causes of the failure of CAP measurement and unreliable CAP measurement. The paper believes that even though the noninvasive and quantitative diagnosis of FLD by CAP has been confirmed by many studies, most of the results were obtained with a limited sample size. Therefore, the factors associated with the cut-off value for CAP diagnosing liver steatosis and factors influencing the measurement results still need validation with larger samples and multi-centered research reports.

  8. Controlled attenuation parameter for evaluating liver steatosis in chronic viral hepatitis.

    Science.gov (United States)

    Ferraioli, Giovanna; Tinelli, Carmine; Lissandrin, Raffaella; Zicchetti, Mabel; Dal Bello, Barbara; Filice, Gaetano; Filice, Carlo

    2014-06-07

    To assess the performance of controlled attenuation parameter (CAP) in patients with chronic viral hepatitis. CAP is a new technique that measures the attenuation in the liver of an ultrasound beam, which is directly related to lipid accumulation. Consecutive patients undergoing liver biopsy for chronic viral hepatitis were studied using the M probe of FibroScan device (Echosens, Paris, France). The device estimates liver steatosis in decibel per meter (dB/m). An expert operator performed all measurements. Steatosis was graded according to Kleiner's classification. Pearson or Spearman rank coefficient was used to test correlation between two study variables. Linear regression was used for multivariate model to assess the association between CAP and other variables. Receiver operating characteristic curve analysis was performed to calculate area under the curve (AUROC) for S0 vs S1-S3 and S0-S1 vs S2-S3. 115 subjects (85 males and 30 females) were prospectively studied. The mean values of CAP were 227.1 ± 43.1 for S0; 254.6 ± 38.9 for S1; 297.8 ± 49.4 dB/m for S2-S3. In univariate analysis CAP showed a significant correlation with age, body mass index (BMI), degree of steatosis, and cholesterol. Multivariate regression analysis confirmed the correlation with the degree of steatosis [coefficient, 1.2 (0.60-1.83); P Controlled attenuation parameter could be a useful tool in the clinical management of patients with chronic viral hepatitis for detecting liver steatosis.

  9. Speed Sensorless Field Oriented Control of an Induction Motor at zero speed with identification of inverter parameters

    DEFF Research Database (Denmark)

    Rasmussen, Henrik; Vadstrup, P.; Børsting, H.

    2002-01-01

    Using adaptive Lyapunov design a new approach for the design of an observer for speed sensorless control is developed. The resulting scheme leads to a nonlinear full order observer for the motor states and for the motor and inverter parameters including the rotor speed. Assuming motor parameters...

  10. Identification of critical parameters for PEMFC stack performance characterization and control strategies for reliable and comparable stack benchmarking

    DEFF Research Database (Denmark)

    Mitzel, Jens; Gülzow, Erich; Kabza, Alexander

    2016-01-01

    This paper is focused on the identification of critical parameters and on the development of reliable methodologies to achieve comparable benchmark results. Possibilities for control sensor positioning and for parameter variation in sensitivity tests are discussed and recommended options for the ...

  11. Modelling and multiparameter control applied to a fast annealing furnace; Modelisation et Commande Multivariable Appliquee a un Four de Recuit Rapide

    Energy Technology Data Exchange (ETDEWEB)

    Bardon, B.

    1995-01-31

    Rapid Thermal Processing (RTP) technology is a delicate field to the control engineer. Its compatibility to single-wafer processing is well suited for performing thermal steps in the state-of-the-art integrated circuit (IC) manufacturing. Control of the wafer temperature during the processing is essential. The main problem in the scalar (SISO) approach is due to the steady-state temperature uniformity. A solution to this problem is to vary the spatial energy flux distribution radiating to the wafer. To achieve this requirement, one approach is the use a multivariable (MIMO) control law to manipulate independently the different lamps banks. Thermal process are highly non linear and distributed in nature. Besides, these non-linearities implies process dynamics variations. In this work, after physically describing our process about a reference value of the power and temperature, we present an off-line identification procedure (in the aim of devising a linear multivariable model) using input/output data for different reference values from real experiences and multi-variable least square algorithm. Afterwards, particular attention is devoted to the structure parameter determination of the linear model. Based on the linear model, a multivariable PID controller is designed. The controller coupled with the least mean square identification algorithm is tested under real conditions. The performances of the MIMO adaptive controller is also evaluated in tracking as well as in regulation. (author) refs.

  12. Validity criteria for the diagnosis of fatty liver by M probe-based controlled attenuation parameter.

    Science.gov (United States)

    Wong, Vincent Wai-Sun; Petta, Salvatore; Hiriart, Jean-Baptiste; Cammà, Calogero; Wong, Grace Lai-Hung; Marra, Fabio; Vergniol, Julien; Chan, Anthony Wing-Hung; Tuttolomondo, Antonino; Merrouche, Wassil; Chan, Henry Lik-Yuen; Le Bail, Brigitte; Arena, Umberto; Craxì, Antonio; de Lédinghen, Victor

    2017-09-01

    Controlled attenuation parameter (CAP) can be performed together with liver stiffness measurement (LSM) by transient elastography (TE) and is often used to diagnose fatty liver. We aimed to define the validity criteria of CAP. CAP was measured by the M probe prior to liver biopsy in 754 consecutive patients with different liver diseases at three centers in Europe and Hong Kong (derivation cohort, n=340; validation cohort, n=414; 101 chronic hepatitis B, 154 chronic hepatitis C, 349 non-alcoholic fatty liver disease, 37 autoimmune hepatitis, 49 cholestatic liver disease, 64 others; 277 F3-4; age 52±14; body mass index 27.2±5.3kg/m(2)). The primary outcome was the diagnosis of fatty liver, defined as steatosis involving ≥5% of hepatocytes. The area under the receiver-operating characteristics curve (AUROC) for CAP diagnosis of fatty liver was 0.85 (95% CI 0.82-0.88). The interquartile range (IQR) of CAP had a negative correlation with CAP (r=-0.32, pCAP would be an inappropriate validity parameter. In the derivation cohort, the IQR of CAP was associated with the accuracy of CAP (AUROC 0.86, 0.89 and 0.76 in patients with IQR of CAP CAP in the validation cohort was 0.90 and 0.77 in patients with IQR of CAP CAP in detecting grade 2 and 3 steatosis was lower among patients with body mass index ≥30kg/m(2) and F3-4 fibrosis. The validity of CAP for the diagnosis of fatty liver is lower if the IQR of CAP is ≥40dB/m. Lay summary: Controlled attenuation parameter (CAP) is measured by transient elastography (TE) for the detection of fatty liver. In this large study, using liver biopsy as a reference, we show that the variability of CAP measurements based on its interquartile range can reflect the accuracy of fatty liver diagnosis. In contrast, other clinical factors such as adiposity and liver enzyme levels do not affect the performance of CAP. Copyright © 2017 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

  13. Effect of Acarbose on Control of Metabolic Parameters in Patients with Diabetes Type 1

    Directory of Open Access Journals (Sweden)

    A. Ziaee

    2012-07-01

    Full Text Available Introduction & Objective: Acarbose is an intestinal alpha-glucosidase inhibitor that delays absorption of carbohydrates. Findings of some studies show that it has been effective in better control of blood glucose in patients with diabetes type 1. The goal of this study is to investigate the effect of administration of acarbose on glycemic & lipid parameters and daily insulin requirements and tolerability in type 1 diabetic patient.Materials & Methods: This was a clinical trial randomized double blind placebo controlled study. Performed on patients with history of at least 1 year diabetes type 1 and had HbA1c≥7.5%. Patients with Cr≥2, partial GI obstruction or IBD were excluded from the study. 45 patients were randomized to be administered acarbose or placebo for 12 weeks. Initial dose of acarbose was 25 mg T.D.S for 2 weeks, and then it was increased to 50 mg T.D.S for 10 weeks. BMI, FBS, 2hpp, HbA1c, Total cholesterol, HDL, LDL, TG and Insulin dosage were investigated monthly.Results: The values of BMI, FBS, 2hpp, HbA1c, Total cholesterol, and TG & Insulin requirements decreased significantly in the case group compared to the controls (P=0.003, P=0.005, P<0.001, P=0.001, P=0.003, P<0.001, P<0.001, respectively; but no significant changes were observed in HDL &LDL levels. Conclusion: Administration of acarbose together with insulin to type 1 diabetic patient can be valuable in improving metabolic control (BMI, FBS, 2hpp, HbA1c, Total cholesterol and TG.(Sci J Hamadan Univ Med Sci 2012;19(2:5-10

  14. Rapid Debris Analysis Project Task 3 Final Report - Sensitivity of Fallout to Source Parameters, Near-Detonation Environment Material Properties, Topography, and Meteorology

    Energy Technology Data Exchange (ETDEWEB)

    Goldstein, Peter [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2014-01-24

    This report describes the sensitivity of predicted nuclear fallout to a variety of model input parameters, including yield, height of burst, particle and activity size distribution parameters, wind speed, wind direction, topography, and precipitation. We investigate sensitivity over a wide but plausible range of model input parameters. In addition, we investigate a specific example with a relatively narrow range to illustrate the potential for evaluating uncertainties in predictions when there are more precise constraints on model parameters.

  15. Relevant parameters for construction of a radon controlled chamber; Parametros relevantes para construcao de uma camara controlada de radonio

    Energy Technology Data Exchange (ETDEWEB)

    Estrada, Julio J.S.; Matta, Luiz E.S.C. [Instituto de Radioprotecao e Dosimetria (IRD), Rio de Janeiro, RJ (Brazil); Alves, Rex N. [Instituto Militar de Engenharia (IME), Rio de Janeiro, RJ (Brazil)

    1997-10-01

    This work intends to discuss important parameters to be considered during the construction of a controlled radon chamber. Based on the review of different chambers, it was noticed that some characteristics such as size, shape, volume, and source activity are dependent on the chamber applications. Parameters such as aerosol generation, humidity, temperature and pressure inside the chamber are also discussed. A design of a multipurpose controlled radon chamber is suggested. (author). 10 refs., 2 figs., 1 tab.

  16. Threshold-crossing statistics in diffusion with a time-dependent control parameter

    Science.gov (United States)

    Balakrishnan, V.

    2006-11-01

    We study two important aspects of the diffusion of a free particle in the presence of a time- dependent control parameter. The latter is represented by a friction coefficient that is a given function of time. We solve the stochastic Liouville equation (the Fokker-Planck equation) for the probability density of the particle in phase space, i. e., in both position and velocity. The exact solution is then used to analyze the behavior of (i) the variance in the position, a global charac- terizer of the system; and (ii) the mean rate of crossings of an arbitrary threshold in the position, a local characterizer. The former is the more conventional descriptor of diffusive processes, but the latter provides valuable complementary information on the dynamical behavior. Depending on the long-time behavior of the friction coefficient, the asymptotic behaviors of both these char- acterizers vary, and exhibit several cross-overs. This helps elucidate the nature of the interplay between the destabilizing effects of the noise and the stabilizing tendency of the damping, as the latter undergoes a controlled variation in time.

  17. Methane conversion efficiency as a simple control parameter for an anaerobic digester at high loading rates.

    Science.gov (United States)

    Charles, W; Carnaje, N P; Cord-Ruwisch, R

    2011-01-01

    The anaerobic digestion process is globally applied to the treatment of highly concentrated wastes such as industrial and rural effluents, and sewage sludge. However, it is known to be relatively unstable. When loaded with high concentrations of organic material, unwanted volatile fatty acids (VFA) are often produced rather than methane (CH4) gas which can lead to digester acidification and failure. This study investigated digester behaviour under high loading rates, testing the usefulness of stoichiometric methane conversion efficiency as a digester control parameter at high loading rates. Our results show that, in general, the CH4 production rate was proportional to the feed rate (loading rate). However, at very high loading rates, the CH4 production rate was not proportional to the increase in the feeding rate. Consequently, VFA accumulated and the H2 partial pressure increased. The proportionality of the loading rate and gas production rate is stoichiometrically expressed as the conversion efficiency. We found that conversion efficiency was a useful indicator as an early warning of digester imbalance. The digester remained stable at conversion efficiencies above 75%. Dropping below 70% signified the onset of digester failure. As loading rate and methane production data are readily available on-line in most anaerobic digestion plants, the conversion efficiency can be monitored on-line and used as an efficient control technique to maintain safe operation of anaerobic digesters at high loading rates.

  18. Transient spark: a dc-driven repetitively pulsed discharge and its control by electric circuit parameters

    Science.gov (United States)

    Janda, Mario; Martišovitš, Viktor; Machala, Zdenko

    2011-06-01

    The paper presents an analysis of electrical characteristics of streamer-to-spark transition discharge in air at atmospheric pressure named transient spark (TS). The TS is applicable for flue gas cleaning or bio-decontamination and has potential in plasma shielding, combustion and flow control applications. Despite the dc applied voltage, TS has a pulsed character with short (~10-100 ns) high current (>1 A) pulses, with repetitive frequencies 1-20 kHz. Estimation of the temporal evolution of electron density shows that ne ≈ 1016 cm-3 at maximum and ~1011 cm-3 on average are reached using relatively low power delivered to the plasma (0.2-3 W). Thanks to the high repetition frequency, ne between two current pulses does not fall below a critical value and therefore plasma exists during the whole time. A detailed analysis of the TS control by electrical circuit parameters is presented. With appropriate circuit components, the current pulse tail (>1 mA) can be extended and the electron density can be held above ~1013 cm-3 for several tens of μs.

  19. Transient spark: a dc-driven repetitively pulsed discharge and its control by electric circuit parameters

    Energy Technology Data Exchange (ETDEWEB)

    Janda, Mario; Martisovits, Viktor; Machala, Zdenko, E-mail: janda@fmph.uniba.sk [Division of Environmental Physics, Faculty of Mathematics, Physics and Informatics, Comenius University, Mlynska dolina F2, 84248 Bratislava (Slovakia)

    2011-06-15

    The paper presents an analysis of electrical characteristics of streamer-to-spark transition discharge in air at atmospheric pressure named transient spark (TS). The TS is applicable for flue gas cleaning or bio-decontamination and has potential in plasma shielding, combustion and flow control applications. Despite the dc applied voltage, TS has a pulsed character with short ({approx}10-100 ns) high current (>1 A) pulses, with repetitive frequencies 1-20 kHz. Estimation of the temporal evolution of electron density shows that n{sub e} {approx} 10{sup 16} cm{sup -3} at maximum and {approx}10{sup 11} cm{sup -3} on average are reached using relatively low power delivered to the plasma (0.2-3 W). Thanks to the high repetition frequency, n{sub e} between two current pulses does not fall below a critical value and therefore plasma exists during the whole time. A detailed analysis of the TS control by electrical circuit parameters is presented. With appropriate circuit components, the current pulse tail (>1 mA) can be extended and the electron density can be held above {approx}10{sup 13} cm{sup -3} for several tens of {mu}s.

  20. Influence of controller parameters on the life of ball screw feed drives

    Directory of Open Access Journals (Sweden)

    Stefano Mauro

    2015-08-01

    Full Text Available The ball screws are the machine component most frequently used for transforming rotational into linear motion of a feed drive, to position the machine tool components carrying the cutting tool to the desired location. A failure of the ball screw usually leads to a total breakdown of the axis; therefore, the attainable life of this component is an important issue concerning the availability and productivity of modern machine tools. This article presents an approach to evaluate the influence of control parameters on the fatigue life of ball screws based on simulation, by means of a numerical model of a machine tool servo-axis. Ball screw life was evaluated with different conditions, varying the position loop main proportional gain and the kinematic limit conditions for trajectory generation. Furthermore, the mathematical model was used to evaluate optimal control gain and trajectory conditions for a machine tool based on the achievable life span of the ball screw feed drive system, with regard to the desirable performances, such as position accuracy, promptness, and cutoff frequency.

  1. Individual patient data meta-analysis of controlled attenuation parameter (CAP) technology for assessing steatosis.

    Science.gov (United States)

    Karlas, Thomas; Petroff, David; Sasso, Magali; Fan, Jian-Gao; Mi, Yu-Qiang; de Lédinghen, Victor; Kumar, Manoj; Lupsor-Platon, Monica; Han, Kwang-Hyub; Cardoso, Ana C; Ferraioli, Giovanna; Chan, Wah-Kheong; Wong, Vincent Wai-Sun; Myers, Robert P; Chayama, Kazuaki; Friedrich-Rust, Mireen; Beaugrand, Michel; Shen, Feng; Hiriart, Jean-Baptiste; Sarin, Shiv K; Badea, Radu; Jung, Kyu Sik; Marcellin, Patrick; Filice, Carlo; Mahadeva, Sanjiv; Wong, Grace Lai-Hung; Crotty, Pam; Masaki, Keiichi; Bojunga, Joerg; Bedossa, Pierre; Keim, Volker; Wiegand, Johannes

    2017-05-01

    The prevalence of fatty liver underscores the need for non-invasive characterization of steatosis, such as the ultrasound based controlled attenuation parameter (CAP). Despite good diagnostic accuracy, clinical use of CAP is limited due to uncertainty regarding optimal cut-offs and the influence of covariates. We therefore conducted an individual patient data meta-analysis. A review of the literature identified studies containing histology verified CAP data (M probe, vibration controlled transient elastography with FibroScan®) for grading of steatosis (S0-S3). Receiver operating characteristic analysis after correcting for center effects was used as well as mixed models to test the impact of covariates on CAP. The primary outcome was establishing CAP cut-offs for distinguishing steatosis grades. Data from 19/21 eligible papers were provided, comprising 3830/3968 (97%) of patients. Considering data overlap and exclusion criteria, 2735 patients were included in the final analysis (37% hepatitis B, 36% hepatitis C, 20% NAFLD/NASH, 7% other). Steatosis distribution was 51%/27%/16%/6% for S0/S1/S2/S3. CAP values in dB/m (95% CI) were influenced by several covariates with an estimated shift of 10 (4.5-17) for NAFLD/NASH patients, 10 (3.5-16) for diabetics and 4.4 (3.8-5.0) per BMI unit. Areas under the curves were 0.823 (0.809-0.837) and 0.865 (0.850-0.880) respectively. Optimal cut-offs were 248 (237-261) and 268 (257-284) for those above S0 and S1 respectively. CAP provides a standardized non-invasive measure of hepatic steatosis. Prevalence, etiology, diabetes, and BMI deserve consideration when interpreting CAP. Longitudinal data are needed to demonstrate how CAP relates to clinical outcomes. There is an increase in fatty liver for patients with chronic liver disease, linked to the epidemic of the obesity. Invasive liver biopsies are considered the best means of diagnosing fatty liver. The ultrasound based controlled attenuation parameter (CAP) can be used instead

  2. Parameter-less remote real-time control for the adjustment of pressure in water distribution systems

    CSIR Research Space (South Africa)

    Page, Philip R

    2017-09-01

    Full Text Available ; and either better or worse than two established controllers with the luxury of an optimally tuned parameter. Additional novel aspects of this work are highlighted in the Conclusion section. 2 Review of PCV P-controllers PCVs can be used to maintain a set... values of the CN pressure very near to the set-point, with its ∆ a factor of 2.7 improvement on the parameter-less LCF. In addition, the ∆ for LVF it is just within ∆’s obtained in the effective range for DCF, which has the luxury of a tunable parameter...

  3. Rapid control of a methicillin resistant Staphylococcus aureus (MRSA) outbreak in a medical surgical intensive care unit (ICU).

    Science.gov (United States)

    Khan, Anjum; Lampitoc, Marianita; Salaripour, Maryam; McKernan, Patricia; Devlin, Roslyn; Muller, Matthew P

    2009-01-01

    Outbreaks of methicillin resistant Staphylococcus aureus in the intensive care unit setting can be prolonged and difficult to control. This report describes the rapid control of an outbreak of methicillin resistant Staphylococcus aureus in a 24-bed open-concept medical surgical intensive care unit with a baseline methicillin resistant Staphylococcus aureus acquisition rate of 1.5 cases per 1000 patient days. This institution's infection control policy mandates an outbreak investigation if two cases of hospital-acquired methicillin resistant Staphylococcus aureus colonization or infection are identified in an intensive care unit within a four-week period. In July 2007, methicillin resistant Staphylococcus aureus was identified in the sputum of two patients within a one-week period. Screening of all patients in the intensive care unit identified one additional case and a fourth case was identified from a clinical specimen before control measures were implemented. Initial control measures included healthcare worker education, enhanced surveillance, patient cohorting, and enhanced environmental cleaning. Despite these measures, three more cases occurred. All patients were then placed in contact isolation, healthcare workers were screened, and the nursing staff was cohorted. After two weeks without a case, two additional cases were identified. Decolonization of all positive patients was initiated. No further cases occurred over a five-week period and the outbreak was declared over. The outbreak resulted in nine cases of methicillin resistant Staphylococcus aureus colonization (n = 8) or infection (n = 1) over an 11-week period. Only one of 175 healthcare workers was colonized and it was not the outbreak strain. Early detection and the stepwise addition of infection control measures resulted in the rapid control of an outbreak of methicillin resistant Staphylococcus aureus in a medical surgical intensive care unit without unit closure. A low threshold of suspicion and

  4. Radiobiological hypoxia, histological parameters of tumour microenvironment and local tumour control after fractionated irradiation.

    Science.gov (United States)

    Yaromina, Ala; Thames, Howard; Zhou, Xuanjing; Hering, Sandra; Eicheler, Wolfgang; Dörfler, Annegret; Leichtner, Thomas; Zips, Daniel; Baumann, Michael

    2010-07-01

    To investigate the relationships between radiobiological hypoxic fraction (rHF), pimonidazole hypoxic fraction (pHF) as well as other histological parameters of the tumour microenvironment, and local tumour control after fractionated irradiation in human squamous cell carcinomas (hSCCs). Ten different hSCC cell lines were transplanted into nude mice and rHF was calculated from local tumour control rates after single dose irradiation under normal or clamped blood flow conditions. In parallel, tumours were irradiated with 30 fractions within 6 weeks. Radiation response was quantified as dose required to cure 50% of tumours (TCD(50)). Unirradiated tumours were excised for histological evaluation including relative hypoxic area (pHF), relative vascular area (RVA), and fraction of perfused vessels (PF). A weak but significant positive correlation between rHF (R(2)=0.6, p=0.014) and TCD(50) after fractionated irradiation was found. The pHF did not correlate with rHF but was significantly associated with the TCD(50) after single dose clamp (R(2)=0.8, p=0.003) and showed a trend for an association with TCD(50) after fractionated irradiation (R(2)=0.4, p=0.067). Relative vascular area and fraction of perfused vessels did not show an association with rHF or TCD(50) after fractionated irradiation. Our data suggest that radiobiological hypoxia contributes to the response after fractionated irradiation but that also other radiobiological mechanisms are involved. In the present study, pimonidazole labelling does not reflect rHF and has a limited value to predict local tumour control after fractionated irradiation. The association between pHF and TCD(50) after single dose clamp warrants further investigation. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.

  5. Dried Plasmodium falciparum-infected samples as positive controls for malaria rapid diagnostic tests

    OpenAIRE

    Aidoo Michael; Patel Jaymin C; Barnwell John W

    2012-01-01

    Abstract Background Rapid diagnostic tests (RDTs) are central to fulfilling the WHO’s recommendation for parasitologic confirmation of all suspected cases of malaria. RDT performance may be compromised when exposed to the high temperature conditions typical of most malaria endemic regions. However, a systematic method to monitor RDT quality and performance in endemic countries is lacking at the present time. Current methods to monitor RDT performance in the field include comparing results fro...

  6. Effect of brief daily resistance training on rapid force development in painful neck and shoulder muscles: randomized controlled trial.

    Science.gov (United States)

    Jay, Kenneth; Schraefel, Mc; Andersen, Christoffer H; Ebbesen, Frederik S; Christiansen, David H; Skotte, Jørgen; Zebis, Mette K; Andersen, Lars L

    2013-09-01

    To determine the effect of small daily amounts of progressive resistance training on rapid force development of painful neck/shoulder muscles. 198 generally healthy adults with frequent neck/shoulder muscle pain (mean: age 43.1 years, computer use 93% of work time, 88% women, duration of pain 186 day during the previous year) were randomly allocated to 2- or 12 min of daily progressive resistance training with elastic tubing or to a control group receiving weekly information on general health. A blinded assessor took measures at baseline and at 10-week follow-up; participants performed maximal voluntary contractions at a static 90-degree shoulder joint angle. Rapid force development was determined as the rate of torque development and maximal muscle strength was determined as the peak torque. Compared with the control group, rate of torque development increased 31.0 Nm s(-1) [95% confidence interval: (1.33-11.80)] in the 2-min group and 33.2 Nm s(-1) (1.66-12.33) in the 12-min group from baseline to 10-week follow-up, corresponding to an increase of 16.0% and 18.2% for the two groups, respectively. The increase was significantly different compared to controls (Pmuscle strength increased only ~5-6% [mean and 95% confidence interval for 2- and 12-min groups to control, respectively: 2.5 Nm (0.05-0.73) and 2.2 Nm (0.01-0.70)]. No significant differences between the 2- and 12-min groups were evident. A weak but significant relationship existed between changes in rapid force development and pain (r = 0.27, Pmuscle strength and pain. Small daily amounts of progressive resistance training in adults with frequent neck/shoulder pain increases rapid force development and, to a less extent, maximal force capacity. © 2013 The Authors Clinical Physiology and Functional Imaging © 2013 Scandinavian Society of Clinical Physiology and Nuclear Medicine.

  7. Effect of glycemic control on self-perceived oral health, periodontal parameters, and alveolar bone loss among patients with prediabetes.

    Science.gov (United States)

    Javed, Fawad; Thafeed Alghamdi, Ali Saad; Mikami, Toshinari; Mehmood, Abid; Ahmed, Hameeda Bashir; Samaranayake, Lakshman P; Tenenbaum, Howard C

    2014-02-01

    The effect of glycemic control on severity of periodontal inflammatory parameters in patients with prediabetes is unknown. The aim of the present study is to assess the effects of glycemic control on self-perceived oral health, periodontal parameters, and marginal bone loss (MBL) in patients with prediabetes. A total of 303 individuals were included. Hemoglobin A1c (HbA1c) and fasting blood glucose levels (FBGLs) were recorded. Participants were divided into three groups: 1) group A: 75 patients with prediabetes (FBGLs = 100 to 125 mg/dL [HbA1c ≥5%]); 2) group B: 78 individuals previously considered prediabetic but having FBGLs control; and 3) control group: 150 medically healthy individuals. Self-perceived oral health, socioeconomic status, and education status were determined using a questionnaire. Plaque index (PI), bleeding on probing (BOP), probing depth (PD), and clinical attachment loss (AL) were recorded. Premolar and molar MBLs were measured on panoramic radiographs. Periodontal parameters (PI, BOP, PD, and AL) (P perceived gingival bleeding (P pain on chewing (P perceived oral symptoms among patients with prediabetes in group B and healthy controls. Self-perceived oral health, severity of periodontal parameters, and MBL are worse in patients with prediabetes than controls. Glycemic control significantly reduces the severity of these parameters as well as the state of prediabetes in affected individuals.

  8. Novel Design Integrating a Microwave Applicator into a Crystallizer for Rapid Temperature Cycling. A Direct Nucleation Control Study

    Science.gov (United States)

    2017-01-01

    The control of nucleation in crystallization processes is a challenging task due to the often lacking knowledge on the process kinetics. Inflexible (predetermined) control strategies fail to grow the nucleated crystals to the desired quality because of the variability in the process conditions, disturbances, and the stochastic nature of crystal nucleation. Previously, the concept of microwave assisted direct nucleation control (DNC) was demonstrated in a laboratory setup to control the crystal size distribution in a batch crystallization process by manipulating the number of particles in the system. Rapid temperature cycling was used to manipulate the super(under)saturation and hence the number of crystals. The rapid heating response achieved with the microwave heating improved the DNC control efficiency, resulting in halving of the batch time. As an extension, this work presents a novel design in which the microwave applicator is integrated in the crystallizer, hence avoiding the external loop though the microwaves oven. DNC implemented in the 4 L unseeded crystallizer, at various count set points, resulted in strong efficiency enhancement of DNC, when compared to the performance with a slow responding system. The demonstrated crystallizer design is a basis for extending the enhanced process control opportunity to other applications. PMID:28729813

  9. Rapid quality control for coal seams by gamma ray transmission technique

    CERN Document Server

    Raja-Sekhar, N; Nageswara-Rao, A S

    1999-01-01

    The quality of coal expressed as useful heat value (UHV) depends on various parameters such as fixed carbon, volatiles, ash and moisture. These factors have been assessed and the detailed dependence of UHV on these parameters has been studied for samples of coal from a local mine. The samples were subjected to collimated low energy gamma beams and correlation was obtained between the attenuation coefficient and UHV. The method is reliable, fast and non-destructive and can be used in the field for estimating UHV.

  10. Quantification of parameters controlling the carbon stocks in German agricultural soils

    Science.gov (United States)

    Vos, Cora; Don, Axel; Freibauer, Annette; Heidkamp, Arne; Prietz, Roland

    2016-04-01

    Within the framework of UNFCCC, Germany is obligated to report on its greenhouse gas emissions from soils. This also includes the emissions in the agricultural sector. Changes in soil carbon stocks are a major source of CO2 that need to be reported. Until now there are only regional inventories of the soil carbon stocks in the agricultural sector while for the forestry sector a repeated national inventory exists. In order to report on changes in soil carbon stocks in agricultural soils, a consistent, representative and quantitative dataset of agricultural soil properties, especially on carbon stocks and management data is necessary. In the course of the German Agricultural Soil Inventory 3109 agricultural sites are examined. Up to January 2016, 2450 sites were sampled. The sites are sampled in five depth increments and all samples are analyzed in the same laboratory. Of the sampled sites the laboratory analyses are completed for 1312 sites. The samples of all depth increments were analyzed for their texture, bulk density, pH, electric conductivity, stone and root content, organic and inorganic carbon content and nitrogen content. The data are coupled with management data covering the past ten years and with climate data. They are analyzed with multivariate statistical techniques (e.g. mixed effects models, additive models, random forest) to quantify the parameters that control the carbon stocks in German agricultural soils. First descriptive results show that the mean soil carbon stocks down to a depth of 100 cm are 126.1 t ha-1 (range 8.9-1158.9 t ha-1). The mean stocks only for croplands are 102.6 t ha-1 (range 8.9-1158.9 t ha-1), while for grasslands the mean stock is 184.1 t ha-1 (range 19.4-937.8 t ha-1). In total the soil scientists found a surprisingly high proportion of disturbed and unusual soil profiles, indicating intensive human modifications of agricultural soils through e.g. deep ploughing. The data set of the German Agricultural Soil Inventory is the

  11. Utility of controlled attenuation parameter measurement for assessing liver steatosis in Japanese patients with chronic liver diseases.

    Science.gov (United States)

    Masaki, Keiichi; Takaki, Shintaro; Hyogo, Hideyuki; Kobayashi, Tomoki; Fukuhara, Takayuki; Naeshiro, Noriaki; Honda, Yoji; Nakahara, Takashi; Ohno, Atsushi; Miyaki, Daisuke; Murakami, Eisuke; Nagaoki, Yuko; Kawaoka, Tomokazu; Tsuge, Masataka; Hiraga, Nobuhiko; Hiramatsu, Akira; Imamura, Michio; Kawakami, Yoshiiku; Aikata, Hiroshi; Ochi, Hidenori; Takahashi, Shoichi; Arihiro, Koji; Chayama, Kazuaki

    2013-11-01

    Steatosis is a common histological feature of chronic liver disease, especially alcoholic and non-alcoholic fatty liver disease, as well as chronic hepatitis C. A recent study showed that evaluating the controlled attenuation parameter (CAP) with transient elastography was an efficient way of non-invasively determining the severity of hepatic steatosis. The objective of this study was to prospectively evaluate the utility of CAP for diagnosing steatosis in patients with chronic liver disease. One hundred and fifty-five consecutive patients with suspected chronic liver disease underwent steatosis diagnosis using CAP, blood sample analyses, computed tomography for assessing the liver/spleen ratio and liver biopsy. Steatosis was graded according to the percentage of fat-containing hepatocytes: S0, less than 5%; S1, 5-33%; S2, 34-66%; and S3: more than 66%. The CAP was significantly correlated with steatosis grade, and there were significant differences between the CAP value of the S0 patients and those of the patients with other grades of steatosis. S0 and S1-3 hepatic steatosis were considered to represent mild and significant steatosis, respectively. The CAP values of the patients with mild and significant steatosis were significantly different (P CAP for diagnosing significant steatosis was 0.878 (95% confidence interval, 0.818-0.939), and the optimal CAP cut-off value for detecting significant steatosis was 232.5 db/m. In multivariate analysis, the CAP (P = 0.0002) and the liver to spleen ratio (P = 0.004) were found to be significantly associated with significant steatosis. The CAP is a promising tool for rapidly and non-invasively diagnosing steatosis. © 2013 The Japan Society of Hepatology.

  12. "Slave" metabolites and enzymes. A rapid way of delineating metabolic control.

    NARCIS (Netherlands)

    Teusink, B.; Westerhoff, H.V.

    2000-01-01

    Although control of fluxes and concentrations tends to be distributed rather than confined to a single rate-limiting enzyme, the extent of control can differ widely between enzymes in a metabolic network. In some cases, there are enzymes that lack control completely. This paper identifies one

  13. Controlled auto-ignition characteristics of methane-air mixture in a rapid intake compression and expansion machine

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Gyubaek; Jeong, Dongsoo [Engine Research Team, Eco-Machinery Research Division, Korea Institute of Machinery and Materials, 104 Sinseongno, Yuseong-gu, Daejeon 305-701 (Korea); Moon, Gunfeel [Department of Clean Environmental system, University of Science and Technology, 52 Eoeun-dong, Yuseong-gu, Daejeon (Korea); Bae, Choongsik [Engine Laboratory, Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, 373-1 GuSeong-Dong, Yuseong-Gu, Daejeon 305-701 (Korea)

    2010-10-15

    The characteristics of controlled auto-ignition (CAI) were investigated with a methane-air mixture and simulated residual gas, that represents internal exhaust gas recirculation (IEGR). Supply systems were additionally installed on the conventional rapid compression machine (RCM), and this modified machine - a rapid intake compression and expansion machine (RICEM) - was able to simulate an intake stroke for the evaluation of controlled auto-ignition with fuel-air mixture. The fuel-air mixture and the simulated residual gas were introduced separately into the combustion chamber through the spool valves. Various IEGR rates and temperatures of the IEGR gas were tested. The initial reaction and the development in controlled auto-ignition combustion were compared with spark-ignited combustion by visualization with a high-speed digital camera. Under the controlled auto-ignition operation, multi-point ignition and faster combustion were observed. With increasing the temperature of IEGR gas, the auto-ignition timing was advanced and burning duration was shortened. The higher rate of IEGR had the same effects on the combustion of the controlled auto-ignition. However, this trend was reversed with more than 47 per cent of IEGR. (author)

  14. Real-time adjustment of pressure to demand in water distribution systems: Parameter-less P-controller algorithm

    CSIR Research Space (South Africa)

    Page, Philip R

    2016-08-01

    Full Text Available Remote real-time control is currently the most advanced form of pressure management. Here the parameters describing pressure control valves (or pumps) are changed in real-time in such a way to provide the most optimal pressure in the water...

  15. Hydrodynamic parameters estimation from self-potential data in a controlled full scale site

    Science.gov (United States)

    Chidichimo, Francesco; De Biase, Michele; Rizzo, Enzo; Masi, Salvatore; Straface, Salvatore

    2015-03-01

    A multi-physical approach developed for the hydrodynamic characterization of porous media using hydrogeophysical information is presented. Several pumping tests were performed in the Hydrogeosite Laboratory, a controlled full-scale site designed and constructed at the CNR-IMAA (Consiglio Nazionale delle Ricerche - Istituto di Metodologia per l'Analisi Ambientale), in Marsico Nuovo (Basilicata Region, Southern Italy), in order to obtain an intermediate stage between laboratory experiments and field survey. The facility consists of a pool, used to study water infiltration processes, to simulate the space and time dynamics of subsurface contamination phenomena, to improve and to find new relationship between geophysical and hydrogeological parameters, to test and to calibrate new geophysical techniques and instruments. Therefore, the Hydrogeosite Laboratory has the advantage of carrying out controlled experiments, like in a flow cell or sandbox, but at field comparable scale. The data collected during the experiments have been used to estimate the saturated hydraulic conductivity ks [ms-1] using a coupled inversion model working in transient conditions, made up of the modified Richards equation describing the water flow in a variably saturated porous medium and the Poisson equation providing the self-potential ϕ [V], which naturally occurs at points of the soil surface owing to the presence of an electric field produced by the motion of underground electrolytic fluids through porous systems. The result obtained by this multi-physical numerical approach, which removes all the approximations adopted in previous works, makes a useful instrument for real heterogeneous aquifer characterization and for predictive analysis of its behavior.

  16. Controlled attenuation parameter for the detection of hepatic steatosis in patients with chronic hepatitis B.

    Science.gov (United States)

    Chen, Jing; Wu, Dongbo; Wang, Menglan; Chen, Enqiang; Bai, Lang; Liu, Cong; Liao, Juan; Tang, Hong

    2016-09-01

    Controlled attenuation parameter (CAP) is a non-invasive method for diagnosing liver steatosis based on vibration-controlled transient elastography. The primary objective of this study was to assess CAP performance and determine the cut-off values for the diagnosis of hepatic steatosis in patients with chronic hepatitis B (CHB) using liver biopsy as a gold standard. The second objective was to apply the cut-off values found in the first cohort to a larger cohort to compare the performance of CAP and ultrasonography. Overall, 189 patients with CHB who underwent liver biopsy and CAP detection and 1707 patients with CHB and CAP who underwent abdominal ultrasonography were prospectively enrolled. The performance of CAP for evaluating hepatic steatosis compared with liver biopsy was calculated using the area under the receiver operating characteristic curve (AUROC). In the 189 patients who underwent liver biopsy, the cut-offs for the CAP with steatosis S ≥ 1, S ≥ 2 and S ≥ 3 were 222 dB/m, 247 dB/m and 274 dB/m, respectively, and the AUROC were 0.88 (95% confidence interval [CI] = 0.82-0.95), 0.92 (95% CI = 0.87-0.97) and 0.94 (95% CI = 0.90-0.99), respectively. After applying the cut-offs above to the 1707 patients, it was found that CAP had a good concordance with abdominal ultrasonography with steatosis grade > S2. On multivariate analysis, body mass index (p CAP. CAP had high diagnostic performance for evaluating hepatic steatosis in patients with CHB and had a good concordance with abdominal ultrasonography.

  17. Association Between Hepatic Steatosis, Measured by Controlled Attenuation Parameter, and Fibrosis Burden in Chronic Hepatitis B.

    Science.gov (United States)

    Seto, Wai-Kay; Hui, Rex Wh; Mak, Lung-Yi; Fung, James; Cheung, Ka-Shing; Liu, Kevin Sh; Wong, Danny Ka-Ho; Lai, Ching-Lung; Yuen, Man-Fung

    2017-09-29

    The interaction between chronic hepatitis B (CHB) and hepatic steatosis is poorly understood. We investigated whether measurement of controlled attenuation parameter (CAP), a non-invasive method to quantify steatosis, can assist in monitoring patients with CHB. We performed transient elastography, to measure liver stiffness, and made CAP measurements in 1606 patients with CHB (898 treated with nucleoside analogues, for a median 75.4 months) in Hong Kong, from January 2015 through September 2016. We also collected information on patients' medical history, current treatment, and smoking and alcohol habits, anthropometric measurements. We obtained and analyzed fasting blood samples. Severe liver fibrosis was defined, according to guidelines, as a liver stiffness measurement greater than 9.0 kPa in patients with normal level of alanine aminotransferase (ALT) or greater than 12.0 kPa in patients with a level of ALT 1-5-fold the upper limit of normal. Steatosis was defined as a CAP measurement of 248 dB/m or more, and severe steatosis as a CAP measurement or 280 dB/m more. We performed multivariate analysis to identify factors associated with severe fibrosis. The prevalence of steatosis, severe steatosis, and severe fibrosis in our cohort were 40.8%, 22.6% and 14.1% respectively. A higher proportion of patients with severe steatosis had severe fibrosis (21.4% vs 11.9% in the overall cohort; PCAP value of 10 dB/m, the risk of severe fibrosis increased by 15% in treatment-naïve patients and by 7%-8% in patients receiving treatment. Severe steatosis, determined by CAP measurement, is associated with severe fibrosis in treatment-naïve patients with CHB and in patients receiving treatment. Longitudinal studies are required to investigate if steatosis control, in addition to antiviral treatment, can reduce the burden fibrosis in patients with CHB. Copyright © 2017 AGA Institute. Published by Elsevier Inc. All rights reserved.

  18. Detection of hepatic steatosis using the controlled attenuation parameter: a comparative study with liver biopsy.

    Science.gov (United States)

    Yilmaz, Yusuf; Yesil, Atakan; Gerin, Fatma; Ergelen, Rabia; Akin, Hakan; Celikel, Çigdem Ataizi; Imeryuz, Nese

    2014-05-01

    Measurements of controlled attenuation parameter (CAP) with transient elastography (FibroScan®; EcoSens SA, Paris, France) may provide an accurate noninvasive assessment of hepatic steatosis. Herein, we prospectively determined the accuracy of liver fat quantification with CAP values in patients with chronic liver diseases and compare the results with those of histological assessment of steatosis as reference standard. We enrolled 50 Turkish patients with various forms of chronic liver diseases. All patients underwent both CAP assessment and ultrasonography-guided liver biopsy. On liver biopsy, 16 (32%) patients had S0, 12 (24%) had S1, 9 (18%) had S2, and 13 (26%) had S3. The CAP values increased significantly (pliver biopsy: S0, 222 dB/m; S1, 250 dB/m; S2, 270 dB/m; and S3, 318 dB/m. A cutoff value of 257 dB/m could distinguish significant steatosis (S2-S3) from S0 (Sn 89%, Sp 83%, positive likelihood ratio 5.33, negative likelihood ratio 0.13, AUROC=0.93). Multivariable analysis indicated that neither liver fibrosis (p=0.58) nor disease etiology (p=0.96) had a significant impact on the association between CAP and the stage of steatosis. The determination of CAP using transient elastography can represent an important step forward toward the goal of an "imaging liver biopsy".

  19. Comparison of Controlled Attenuation Parameter and Liver Biopsy to Assess Hepatic Steatosis in Pediatric Patients.

    Science.gov (United States)

    Desai, Nirav K; Harney, Sarah; Raza, Roshan; Al-Ibraheemi, Alyaa; Shillingford, Nick; Mitchell, Paul D; Jonas, Maureen M

    2016-06-01

    To assess whether the degree of steatosis as determined by controlled attenuation parameter (CAP) measurements correlates with that observed on liver biopsies in a single-center pediatric and young adult cohort. This cross-sectional study included patients undergoing liver biopsy as part of standard clinical care between January 25, 2012, and April 1, 2015, at Boston Children's Hospital. Eligible patients, with a variety of liver diseases, had CAP measurements within 1 year of biopsy. CAP values were compared across histologic steatosis grades using ANOVA. Sixty-nine patients (mean age, 16.0 ± 2.9 years; 62% male) were studied. CAP measurements were obtained at a median of 1.3 months (IQR, 0.5-3.2) after biopsy. Of the 69 subjects, 23 had steatosis on biopsy. Mean CAP value (dB/m) for subjects with no steatosis was 198 ± 37 vs 290 ± 47 for subjects with steatosis (P < .0001). There were statistically significant differences between CAP values in individuals with no steatosis vs mild/moderate steatosis (P < .0001), no steatosis vs marked steatosis (P < .0001), and mild/moderate vs marked steatosis (P = .004). This study demonstrated a difference in CAP between no steatosis and steatosis, and between grades of steatosis. CAP may be a useful noninvasive tool to detect hepatic steatosis in children. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. A lumped parameter model of cerebral blood flow control combining cerebral autoregulation and neurovascular coupling.

    Science.gov (United States)

    Spronck, Bart; Martens, Esther G H J; Gommer, Erik D; van de Vosse, Frans N

    2012-11-01

    Cerebral blood flow regulation is based on a variety of different mechanisms, of which the relative regulatory role remains largely unknown. The cerebral regulatory system expresses two regulatory properties: cerebral autoregulation and neurovascular coupling. Since partly the same mechanisms play a role in cerebral autoregulation and neurovascular coupling, this study aimed to develop a physiologically based mathematical model of cerebral blood flow regulation combining these properties. A lumped parameter model of the P2 segment of the posterior cerebral artery and its distal vessels was constructed. Blood flow regulation is exerted at the arteriolar level by vascular smooth muscle and implements myogenic, shear stress based, neurogenic, and metabolic mechanisms. In eight healthy subjects, cerebral autoregulation and neurovascular coupling were challenged by squat-stand maneuvers and visual stimulation using a checkerboard pattern, respectively. Cerebral blood flow velocity was measured using transcranial Doppler, whereas blood pressure was measured by finger volume clamping. In seven subjects, the model proposed fits autoregulation and neurovascular coupling measurement data well. Myogenic regulation is found to dominate the autoregulatory response. Neurogenic regulation, although only implemented as a first-order mechanism, describes neurovascular coupling responses to a great extent. It is concluded that our single, integrated model of cerebral blood flow control may be used to identify the main mechanisms affecting cerebral blood flow regulation in individual subjects.

  1. The relationship between visceral obesity and hepatic steatosis measured by controlled attenuation parameter.

    Science.gov (United States)

    Lee, Hye Won; Kim, Kwang Joon; Jung, Kyu Sik; Chon, Young Eun; Huh, Ji Hye; Park, Kyeong Hye; Chung, Jae Bock; Kim, Chang Oh; Han, Kwang-Hyub; Park, Jun Yong

    2017-01-01

    Nonalcoholic fatty liver disease (NAFLD) is closely related with obesity. However, obese subjects, generally represented by high BMI, do not always develop NAFLD. A number of possible causes of NAFLD have been studied, but the exact mechanism has not yet been elucidated. A total of 304 consecutive subjects who underwent general health examinations including abdominal ultrasonography, transient elastography and abdominal fat computed tomography were prospectively enrolled. Significant steatosis was diagnosed by ultrasonography and controlled attenuation parameter (CAP) assessed by transient elastography. Visceral fat area (VFA) was significantly related to hepatic steatosis assessed by CAP, whereas body mass index (BMI) was related to CAP only in univariate analysis. In multiple logistic regression analysis, VFA (odds ratio [OR], 1.010; 95% confidence interval [CI], 1.001-1.019; P = 0.028) and triglycerides (TG) (OR, 1.006; 95% CI, 1.001-1.011; P = 0.022) were independent risk factors for significant hepatic steatosis. The risk of significant hepatic steatosis was higher in patients with higher VFA: the OR was 4.838 (P200 cm2, compared to patients with a VFA ≤100 cm2. Our data demonstrated that VFA and TG is significantly related to hepatic steatosis assessed by CAP not BMI. This finding suggests that surveillance for subjects with NAFLD should incorporate an indicator of visceral obesity, and not simply rely on BMI.

  2. Usefulness of the controlled attenuation parameter for detecting liver steatosis in health checkup examinees.

    Science.gov (United States)

    Kim, Ja Kyung; Lee, Kwan Sik; Choi, Jung Ran; Chung, Hyun Jung; Jung, Da Hyun; Lee, Kyung Ah; Lee, Jung Il

    2015-05-23

    The controlled attenuation parameter (CAP) implemented in FibroScan® is reported to be a noninvasive means of detecting steatosis (>10% steatosis). We aimed to evaluate the usefulness of CAP in detecting steatosis among health checkup examinees and to assess its correlation with ultrasonography (US). Consecutive CAP results were retrospectively collected. A total of 280 subjects were included. Fatty liver was detected in 119 subjects (42.5%) by US, whereas it was detected in 160 subjects (57.1%) by the CAP. The numbers of subjects with S0S1S2S3 steatosis according to the CAP value were 120595843, respectively. The mean CAP values were 203.34±28.39 dB/m for S0, 248.83±6.14 dB/m for S1, 274.33±8.53 dB/m for S2, and 322.35±22.20 dB/m for S3. CAP values were correlated with body weight (r=0.404, pCAP. The CAP seems to be useful for detecting very low-grade hepatic steatosis in health checkup examinees. Its role in predicting subjects with a risk of metabolic derangement needs to be evaluated.

  3. Interobserver reproducibility of the controlled attenuation parameter (CAP) for quantifying liver steatosis.

    Science.gov (United States)

    Ferraioli, Giovanna; Tinelli, Carmine; Lissandrin, Raffaella; Zicchetti, Mabel; Rondanelli, Mariangela; Perani, Guido; Bernuzzi, Stefano; Salvaneschi, Laura; Filice, Carlo

    2014-10-01

    This study was conducted to prospectively investigate the interobserver reproducibility of controlled attenuation parameter (CAP) measurements and the relationship among the CAP and body mass index (BMI), gender and age. Consecutive subjects were studied using the M+ probe of the FibroScan device (Echosens, Paris, France). Measurements were performed by two raters (rater1 and rater2). Interobserver agreement was assessed by using the concordance correlation coefficient (CCC). The Pearson r coefficient was used to test correlation between two study variables, and linear regression was used for the multivariate model. Three hundred fifty-one subjects (227 males and 124 females) were prospectively studied. The CCC was 0.82 (95 % CI 0.78-0.85) overall, 0.80 (95 % CI 0.75-0.85) for BMI CAP values ≤240 dB/m and 0.72 (95 % CI 0.65-0.79) for CAP values >240 dB/m. In univariate analysis, age and BMI by gender were correlated with the CAP. Multiple regression analysis confirmed the relationship of the CAP with age and BMI, but not with gender. The results of this study show that the interreader agreement in CAP measurement is good. In healthy volunteers, the CAP is strongly correlated with age and BMI.

  4. Effect of fixed orthodontic appliances on salivary microbial parameters at 6 months: a controlled observational study

    Directory of Open Access Journals (Sweden)

    Delphine MARET

    2014-01-01

    Full Text Available Objective: The aim of this study was to assess the microbial changes in children with fixed orthodontic appliances compared with a control group of children without orthodontic treatment. Material and Methods: Ninety-five children, aged between 12 and 16 years, participated in this study. Forty-eight subjects were fitted with fixed orthodontic appliances and forty-seven were free of any such appliances. The follow-up was 6 months for all children. The association between orthodontic appliances and high levels of Streptococcus mutans and Lactobacillus spp was assessed with logistic regression models, taking age, sex, pH and buffer capacity into account. Results: Differences at baseline between the two groups were not statistically significant. We found that wearing a fixed orthodontic appliance was associated with high levels of Streptococcus mutans and Lactobacillus spp (adjusted OR: 6.65, 95% CI [1.98-22.37]; 9.49, 95% CI [2.57-35.07], respectively, independently of other variables. Conclusion: The originality of the present epidemiological study was to evaluate the evolution of salivary microbial parameters in a population of children with fixed orthodontic appliances. Our results show an increase of Streptococcus mutans and Lactobacillus spp values during the follow-up. The whole dental workforce should be aware that preventive measures are of paramount importance during orthodontic treatment.

  5. Tailoring Crystallinity of Electrospun Plla Fibres by Control of Electrospinning Parameters

    Directory of Open Access Journals (Sweden)

    Olubayode Ero-Phillips

    2012-06-01

    Full Text Available Poly(L-lactic acid (PLLA fibers were fabricated by electrospinning. The effects of various electrospinning process parameters on the thermal properties, especially the crystallinity of the electrospun fibers were investigated. Thermal analysis of the fibers revealed that they exhibited degree of crystallinity ranging from 23% to 46% while that for the as-received granules was approximately 37%, suggesting that the crystallinity of electrospun PLLA fibres can be controlled by optimizing the electrospinning process. This finding is very important because crystallinity affects polymer properties such as degradation, stiffness, yield stress, modulus and tensile strength, solubility, optical and electrical properties which will in turn affect the behavior of these materials when they are utilized in energy, environment, defense and security applications. The results presented in this paper show that the degree of crystallinity of the electrospun fibers decreased with increasing the polymer solution concentration. Furthermore, an optimum electrospinning voltage at which maximum degree of crystallinity can be obtained was observed. At voltages higher or lower than the optimum electrospinning voltage, the degree of crystallinity will decrease or increase, respectively. The effect of the needle tip to collector distance (NTCD on the degree of crystallinity follows no predictable and consistent pattern.

  6. Tropical Fruit Pulps: Processing, Product Standardization and Main Control Parameters for Quality Assurance

    Directory of Open Access Journals (Sweden)

    Carlos Eduardo de Farias Silva

    2017-05-01

    Full Text Available ABSTRACT Fruit pulp is the most basic food product obtained from fresh fruit processing. Fruit pulps can be cold stored for long periods of time, but they also can be used to fabricate juices, ice creams, sweets, jellies and yogurts. The exploitation of tropical fruits has leveraged the entire Brazilian fruit pulp sector due mainly to the high acceptance of their organoleptic properties and remarkable nutritional facts. However, several works published in the last decades have pointed out unfavorable conditions regarding the consumption of tropical fruit pulps. This negative scenario has been associated with unsatisfactory physico-chemical and microbiological parameters of fruits pulps as outcomes of little knowledge and improper management within the fruit pulp industry. There are protocols for delineating specific identity and quality standards (IQSs and standardized good manufacturing practices (GMP for fruit pulps, which also embrace standard operating procedures (SOPs and hazard analysis and critical control points (HACCP, although this latter is not considered mandatory by the Brazilian legislation. Unfortunately, the lack of skilled labor, along with failures in complying established protocols have impaired quality of fruit pulps. It has been necessary to collect all information available with the aim to identify the most important hazards within fruit pulp processing lines. Standardizing methods and practices within the Brazilian fruit pulp industry would assurance high quality status to tropical fruit pulps and the commercial growth of this vegetal product towards international markets.

  7. A rapid chromatographic method for quality control of technetium-99m-bicisate.

    Science.gov (United States)

    Amin, K C; Saha, G B; Go, R T

    1997-03-01

    The purpose of this work was to develop a simple and rapid method to determine the radiochemical purity of 99mTc-bicisate. A rapid paper chromatographic (PC) method was developed to determine the radiochemical purity of 99mTc-bicisate and compare the results with those of the manufacturer's recommended method. The present PC method included Whatman 3MM paper as the solid phase and ethyl acetate as the solvent. The time for chromatography by this technique was 4-5 min compared to about 23 min by the manufacturer's method. The Rf value of 99mTc-bicisate (Rf = 0.9-1.0) was widely different from those of 99mTcO4- and reduced 99mTc (Rf = 0.0 for both) so the chromatographic strip after development could be readily cut into two segments, in order to determine the labeling yield. No significant difference in labeling yields was found between the present method and the manufacturer's method. The PC method using Whatman 3MM paper and ethyl acetate is a simple and fast technique to determine the radiochemical purity of 99mTc-bicisate and may be substituted for the manufacturer's recommended method to save time.

  8. Controlled attenuation parameter for the detection and quantification of hepatic steatosis in nonalcoholic fatty liver disease.

    Science.gov (United States)

    Chan, Wah-Kheong; Nik Mustapha, Nik Raihan; Mahadeva, Sanjiv

    2014-01-01

    Controlled attenuation parameter (CAP) has been suggested as a noninvasive method for detection and quantification of hepatic steatosis. We aim to study the diagnostic performance of CAP in nonalcoholic fatty liver disease (NAFLD) patients. Transient elastography was performed in consecutive NAFLD patients undergoing liver biopsy and non-NAFLD controls. The accuracy of CAP for the detection and quantification of hepatic steatosis was assessed based on histological findings according to the Nonalcoholic Steatohepatitis Clinical Research Network Scoring System. Data for 101 NAFLD patients (mean age 50.3 ± 11.3 years old, 51.5% male) and 60 non-NAFLD controls were analyzed. CAP was associated with steatosis grade (odds ratio [OR] = 29.16, P CAP for steatosis grades S0, S1, S2, and S3 were 184 dB/m, 305 dB/m, 320 dB/m, and 324 dB/m, respectively. The areas under receiver operating characteristics curves (AUROC) for estimation of steatosis grades ≥ S1, S2, and S3 were 0.97, 0.86, and 0.75, respectively. The optimal CAP cutoffs for estimation of steatosis grades ≥ S1, S2, and S3 were 263 dB/m, 281 dB/m, and 283 dB/m, respectively. Among non-obese patients, the AUROC for estimation of steatosis grades ≥ S1 and S2 were 0.99 and 0.99, respectively. Among obese patients, the AUROC for estimation of steatosis grades ≥ S1, S2, and S3 were 0.92, 0.64, and 0.58, respectively. CAP is excellent for the detection of significant hepatic steatosis. However, its accuracy is impaired by an increased BMI, and it is less accurate to distinguish between the different grades of hepatic steatosis. © 2014 Journal of Gastroenterology and Hepatology Foundation and Wiley Publishing Asia Pty Ltd.

  9. Noninvasive assessment of liver steatosis in children: the clinical value of controlled attenuation parameter.

    Science.gov (United States)

    Ferraioli, Giovanna; Calcaterra, Valeria; Lissandrin, Raffaella; Guazzotti, Marinella; Maiocchi, Laura; Tinelli, Carmine; De Silvestri, Annalisa; Regalbuto, Corrado; Pelizzo, Gloria; Larizza, Daniela; Filice, Carlo

    2017-05-04

    To assess the clinical validity of controlled attenuation parameter (CAP) in the diagnosis of hepatic steatosis in a series of overweight or obese children by using the imperfect gold standard methodology. Consecutive children referred to our institution for auxological evaluation or obesity or minor elective surgery were prospectively enrolled. Anthropometric and biochemical parameters were recorded. Ultrasound (US) assessment of steatosis was carried out using ultrasound systems. CAP was obtained with the FibroScan 502 Touch device (Echosens, Paris, France). Pearson's or Spearman's rank correlation coefficient were used to test the association between two study variables. Optimal cutoff of CAP for detecting steatosis was 249 dB/m. The diagnostic performance of dichotomized CAP, US, body mass indexes (BMI), fatty liver index (FLI) and hepatic steatosis index (HSI) was analyzed using the imperfect gold standard methodology. Three hundred five pediatric patients were enrolled. The data of both US and CAP were available for 289 children. Steatosis was detected in 50/289 (17.3%) children by US and in 77/289 (26.6%) by CAP. A moderate to good correlation was detected between CAP and BMI (r = 0.53), FLI (r = 0.55) and HSI (r = 0.56). In obese children a moderate to good correlation between CAP and insulin levels (r = 0.54) and HOMA-IR (r = 0.54) was also found. Dichotomized CAP showed a performance of 0.70 (sensitivity, 0.72 [0.64-0.79]; specificity, 0.98 [0.97-0.98], which was better than that of US (performance, 0.37; sensitivity, 0.46 [0.42-0.50]; specificity, 0.91 [0.89-0.92]), BMI (performance, 0.22; sensitivity, 0.75 [0.73-0.77]; specificity, 0.57 [0.55-0.60]) and FLI or HSI. For the evaluation of liver steatosis in children CAP performs better than US, which is the most widely used imaging technique for screening patients with a suspicion of liver steatosis. A cutoff value of CAP of 249 dB/m rules in liver steatosis with a very high

  10. Controlled attenuation parameter for non-invasive assessment of hepatic steatosis: does etiology affect performance?

    Science.gov (United States)

    Kumar, Manoj; Rastogi, Archana; Singh, Tarandeep; Behari, Chhagan; Gupta, Ekta; Garg, Hitendra; Kumar, Ramesh; Bhatia, Vikram; Sarin, Shiv K

    2013-07-01

    Hepatic steatosis is an important parameter to assess in chronic liver disease patients. The controlled attenuation parameter (CAP) assesses liver steatosis using transient elastography. To determine the accuracy of CAP for evaluation of hepatic steatosis in chronic hepatitis B virus (CHBV)-infected, chronic hepatitis C virus (CHCV)-infected, and non-alcoholic fatty liver disease (NAFLD) patients and to determine the influence of etiology on the diagnostic accuracy of CAP. One hundred forty-six CHBV patients, 108 CHCV-infected patients and 63 patients with NAFLD, who underwent both liver biopsy and successful CAP measurements within the study period, were assessed. Area under the receiver operating characteristics was used to evaluate performance of CAP for diagnosing steatosis compared with biopsy. Multivariate analysis found that CAP correlated with body mass index (odds ratio, 95% confidence interval = 4.09 [1.2-6.8] for CHBV; 4.7 [1.1-8.4] for CHCV, and 16.2 [9.1-24.5] for NAFLD patients respectively) and hepatic steatosis score on biopsy (odds ratio, 95% confidence interval = 30.7 [19.2-42.2] for CHBV; 24.2 [11.5-37.3] for CHCV, and 21.8 [10.1-45.0] for NAFLD patients respectively). Area under the receiver operating characteristics for CAP was 0.683 (0.601-0.757) for steatosis (S) ≥ 6%, 0.793 (0.718-0.856) for S > 33%, and 0.841 (0.771-0.896) for S > 66% respectively for CHBV-infected patients. There was no difference in accuracy of CAP for assessing liver fat among CHBV, CHCV, and NAFLD patients. CAP is a novel, non-invasive tool that can detect and quantify steatosis accurately among CHBV, CHCV, and NAFLD patients, the accuracy being similar for all the three groups of patients. © 2013 Journal of Gastroenterology and Hepatology Foundation and Wiley Publishing Asia Pty Ltd.

  11. Effects of Hydrotherapy on postural control and electromyography parameters in men with chronic non-specific low back pain

    OpenAIRE

    Mahdi Mahjur; Seyed Ali Akbar Hashemi Javaheri; Hossein Soltani; Nahid KHoshraftar Yazdi

    2016-01-01

    The aim of this study was to evaluate effects of hydrotherapy on postural control and electromyography parameters in men with chronic non-specific low back pain. Thirty men with chronic non-specific LBP divided into two hydrotherapy and control groups, randomly and equally. Electromyographic activity of erector spinae muscles and balance measured for both of groups before and after intervention. Hydrotherapy program was consisted of 24 sessions. Subjects in control group didn’t ha...

  12. Rapid and controllable a-Si:H-to-nc-Si:H transition induced by a high-density plasma route

    Science.gov (United States)

    Zhou, H. P.; Xu, M.; Xu, S.; Xu, L. X.; Ji, H.; Xiao, S. Q.; Feng, Y. Y.

    2017-09-01

    The low-temperature rapid solid phase crystallization route of amorphous silicon is fundamentally and technologically significant. Micrometer thick hydrogenated amorphous silicon (a-Si:H) films were exposed to a low-frequency inductively coupled hydrogen plasma under a low substrate temperature of 300 °C. The plasma treated a-Si:H was completely crystallized within half an hour. The evolution of microstructures, optical and electric properties with respect to plasma exposure duration deterministically demonstrates that the present low-temperature rapid crystallization process enables the controllable phase transition from amorphous to nanocrystalline (nc) silicon. The crystallization mechanism is discussed in terms of the unique characteristics of low-frequency inductively coupled plasma (LFICP) and the LFICP-grown precursor a-Si:H film itself. The crucial role of hydrogen atoms in the phase transition is also discussed.

  13. Lethal and pre-lethal effects of a fungal biopesticide contribute to substantial and rapid control of malaria vectors.

    Directory of Open Access Journals (Sweden)

    Simon Blanford

    Full Text Available Rapidly emerging insecticide resistance is creating an urgent need for new active ingredients to control the adult mosquitoes that vector malaria. Biopesticides based on the spores of entomopathogenic fungi have shown considerable promise by causing very substantial mortality within 7-14 days of exposure. This mortality will generate excellent malaria control if there is a high likelihood that mosquitoes contact fungi early in their adult lives. However, where contact rates are lower, as might result from poor pesticide coverage, some mosquitoes will contact fungi one or more feeding cycles after they acquire malaria, and so risk transmitting malaria before the fungus kills them. Critics have argued that 'slow acting' fungal biopesticides are, therefore, incapable of delivering malaria control in real-world contexts. Here, utilizing standard WHO laboratory protocols, we demonstrate effective action of a biopesticide much faster than previously reported. Specifically, we show that transient exposure to clay tiles sprayed with a candidate biopesticide comprising spores of a natural isolate of Beauveria bassiana, could reduce malaria transmission potential to zero within a feeding cycle. The effect resulted from a combination of high mortality and rapid fungal-induced reduction in feeding and flight capacity. Additionally, multiple insecticide-resistant lines from three key African malaria vector species were completely susceptible to fungus. Thus, fungal biopesticides can block transmission on a par with chemical insecticides, and can achieve this where chemical insecticides have little impact. These results support broadening the current vector control paradigm beyond fast-acting chemical toxins.

  14. ANFIS-based estimation of PV module equivalent parameters: application to a stand-alone PV system with MPPT controller

    OpenAIRE

    KULAKSIZ, Ahmet Afşin

    2012-01-01

    The performance and system cost of photovoltaic (PV) systems can be improved by employing high-efficiency power conditioners with maximum power point tracking (MPPT) methods. Fast implementation and accurate operation of MPPT controllers can be realized by modeling the characteristics of PV modules, obtaining equivalent parameters. In this study, adaptive neuro-fuzzy inference systems (ANFISs) have been used to obtain 3 of the parameters in a single-diode model of PV cells, namely serie...

  15. Field Testing of Rapid Electrokinetic Nanoparticle Treatment for Corrosion Control of Steel in Concrete

    Science.gov (United States)

    Cardenas, Henry E.; Alexander, Joshua B.; Kupwade-Patil,Kunal; Calle, Luz Marina

    2009-01-01

    This work field tested the use of electrokinetics for delivery of concrete sealing nanoparticles concurrent with the extraction of chlorides. Several cylinders of concrete were batched and placed in immersion at the Kennedy Space Center Beach Corrosion Test Site. The specimens were batched with steel reinforcement and a 4.5 wt.% (weight percent) content of sodium chloride. Upon arrival at Kennedy Space Center, the specimens were placed in the saltwater immersion pool at the Beach Corrosion Test Site. Following 30 days of saltwater exposure, the specimens were subjected to rapid chloride extraction concurrent with electrokinetic nanoparticle treatment. The treatments were operated at up to eight times the typical current density in order to complete the treatment in 7 days. The findings indicated that the short-term corrosion resistance of the concrete specimens was significantly enhanced as was the strength of the concrete.

  16. Apparatus for use in rapid and accurate controlled-potential coulometric analysis

    Science.gov (United States)

    Frazzini, Thomas L.; Holland, Michael K.; Pietri, Charles E.; Weiss, Jon R.

    1981-01-01

    An apparatus for controlled-potential coulometric analysis of a solution includes a cell to contain the solution to be analyzed and a plurality of electrodes to contact the solution in the cell. Means are provided to stir the solution and to control the atmosphere above it. A potentiostat connected to the electrodes controls potential differences among the electrodes. An electronic circuit connected to the potentiostat provides analog-to-digital conversion and displays a precise count of charge transfer during a desired chemical process. This count provides a measure of the amount of an unknown substance in the solution.

  17. Fatty liver and light manual labor: an epidemiological survey in Tianjin by controlled attenuation parameter

    Directory of Open Access Journals (Sweden)

    LI Hai

    2015-07-01

    Full Text Available Objective To investigate the incidence and possible related factors for fatty liver among workers engaged in light manual labor in Tianjin, China. Methods Among 800 healthy workers engaged in light manual labor randomly selected from a company in Tianjin, a total of 602 healthy workers completed physical examination and data collection. The content of fat and liver stiffness were determined by controlled attenuation parameter (CAP using FibroScan, and the disease history, body mass, height, blood pressure, and living habits in all subjects were investigated. The possible related factors for different degrees of fatty liver were analyzed. Between-group comparison of continuous data was performed using the Kruskal-Wallis H test, and comparison of categorical data was performed using χ2 test with row×column tables. Pairwise comparison was performed using χ2 segmentation method, and the agreement between CAP and color ultrasound was analyzed using the Kappa coefficient. Results Among the 602 subjects, there were 180 (29.9%, 195 (32.3%, and 227 (37.7% subjects with severe fatty liver, moderate fatty liver, and no fatty liver, respectively. There were significant differences in age, body mass index, waist-hip ratio, smoking, drinking, history of diabetes, and family history between the above three groups according to CAP (P<0.05 for all. With higher sensitivity, CAP achieved a significantly higher detection rate of fatty liver than traditional color ultrasound (62.3% vs 44.0%, P=0.000. The agreement between two methods was poor (Kappa value <0.4. Conclusion Among the so-called “healthy people” engaged in light manual labor, the incidence of fatty liver has exceeded 60%, which is associated with body mass index, waist-hip ratio, bad living habits, history of diabetes, and family history of fatty liver. CAP can noninvasively detect fatty liver with higher sensitivity and less time; however, its clinical significance needs further studies.

  18. Controlled attenuation parameter for diagnosing steatosis in bariatric surgery candidates with suspected nonalcoholic fatty liver disease.

    Science.gov (United States)

    Naveau, Sylvie; Voican, Cosmin S; Lebrun, Amandine; Gaillard, Martin; Lamouri, Karima; Njiké-Nakseu, Micheline; Courie, Rodi; Tranchart, Hadrien; Balian, Axel; Prévot, Sophie; Dagher, Ibrahim; Perlemuter, Gabriel

    2017-09-01

    Steatosis in patients with nonalcoholic fatty liver disease (NAFLD) is often benign, but may progress to fibrosis. The accurate diagnosis of hepatic steatosis is therefore important for clinical decision-making and prognostic assessments. The controlled attenuation parameter (CAP), a noninvasive measurement obtained with Fibro-Scan, has been developed for liver steatosis assessment. CAP performs poorly in patients with high BMI. The XL probe was initially developed for measuring liver stiffness in overweight patients. We assessed the diagnostic value of CAP in candidates for bariatric surgery with suspected NAFLD examined with the XL probe. For the retrospective group, raw ultrasonic radiofrequency signals were stored prospectively in the Fibro-Scan examination file for offline CAP calculation in 194 consecutive obese patients undergoing liver stiffness measurement in the 15 days before liver biopsy. For the prospective group, CAP was calculated automatically and prospectively from the XL probe in 123 obese patients. In the retrospective group, the diagnostic accuracy of CAP was satisfactory for differentiating S3 from S0-S1-S2 (0.79±0.03; 95% confidence interval: 0.71-0.84) and S3 from S0 (0.85±0.05; 95% confidence interval: 0.73-0.92). The Obuchowski measure demonstrated a very good discriminatory performance: 0.87±0.02 in the retrospective group and 0.91±0.02 in the prospective group. CAP calculations from XL probe measurements efficiently detected severe steatosis in morbidly obese patients with suspected NAFLD. However, the cutoff values should now be confirmed in a larger prospective cohort.

  19. Non-invasive diagnosis of liver steatosis using controlled attenuation parameter (CAP) and transient elastography.

    Science.gov (United States)

    de Lédinghen, Victor; Vergniol, Julien; Foucher, Juliette; Merrouche, Wassil; le Bail, Brigitte

    2012-07-01

    Recently, a study showed that Controlled Attenuation Parameter (CAP), evaluated with transient elastography, could efficiently separate steatosis grades. The aim of this study was to prospectively evaluate the performance of CAP for the diagnosis of steatosis in patients with chronic liver disease. Consecutive patients with chronic liver disease had steatosis diagnosis using CAP, blood sample and liver biopsy. Steatosis was graded as the percentage of hepatocytes with fat: S0 ≤ 10%, S1: 11 ~ 33%, S2: 34 ~ 66%, S3 ≥ 67%. Characteristics of the 112 patients included were as follows: age 54 years, BMI 26 kg m(-) ², HCV 36%, NAFLD 25%. Steatosis repartition was: S0 52%, S1 19%, S2 14%, S3 15%. CAP was significantly correlated with SteatoTest, Fatty Liver Index (FLI), percentage of steatosis on liver biopsy, steatosis grade and slightly with liver stiffness, but not with fibrosis and activity grade on liver biopsy. Using CAP vs SteatoTest vs FLI score, Area Under the Receiver-Operating Characteristics (ROC) curves (AUROC)s were 0.84 vs 0.72 vs 0.72 for the diagnosis of steatosis ≥ S1, 0.86 vs 0.73 vs 0.71 for the diagnosis of steatosis ≥ S2, and 0.93 vs 0.73 vs 0.75 for the diagnosis of steatosis S3 respectively. For a sensitivity ≥ 90%, cut-offs of CAP were 215 dB m(-1) for S ≥ 1, 252 dB m(-1) for S ≥ 2, and 296 dB m(-1) for S3. CAP is very efficient to detect even low grade steatosis. CAP being implemented on FibroScan(®) (Echosens, Paris, France), both steatosis and fibrosis can be evaluated simultaneously, enlarging the spectrum of non-invasive techniques for the management of chronic liver diseases. © 2012 John Wiley & Sons A/S.

  20. [Value of controlled attenuation parameter in diagnosis of fatty liver using FibroScan].

    Science.gov (United States)

    Xu, Liang; Li, Ping; Lu, Wei; Shi, Qiyu; Shi, Ruifang; Zhang, Xiaoying; Liu, Yonggang; Wang, Qiujing; Fan, Jangao; Mi, Yuqiang

    2016-02-01

    To investigate the value of controlled attenuation parameter (CAP) in the diagnosis of fatty liver using FibroScan in patients with chronic liver disease (CLD). A prospective cohort study was performed for the patients with chronic hepatitis B (CHB), chronic hepatitis C (CHC), and non-alcoholic fatty liver disease (NAFLD) who underwent liver pathological examination followed by CAP measurement within 1 week in The Second People's Hospital of Tianjin from February 2013 to May 2014. According to related guidelines, hepatocyte steatosis was classified as S0: CAP. A total of 427 patients were enrolled, consisting of 19 patients (4.4%) with NAFLD, 383 (89.7%) with CHB, and 25 (5.9%) with CHC. The optimal cut-off values for CAP in the diagnosis of steatosis ≥5%, ≥34%, and ≥67% were 230 dB/m, 252 dB/m, and 283 dB/m, respectively, and the areas under the ROC curve were 0.803, 0.942, and 0.938, respectively (Z = 14.194, 28.385, and 16.486, respectively, all P CAP differentiated S0 from S1, S1 from S2, S0 from S2, S0 from S3, and S1 from S3 (Z = 10.109, 10.224, 47.81, 29.917, and 10.999, all P CAP. The coincidence rates between CAP and liver pathological diagnosis were 77.4%, 81.0%, and 96.2% for S0, S3, and ≥S2, respectively. CAP has a good value in the diagnosis of fatty liver in CLD patients, and can well differentiate between all stages of fatty liver except S2 and S3. CAP is influenced by BMI, but is not found to be associated with liver fibrosis, inflammation, liver stiffness measurement, and etiology.

  1. Diagnostic value of controlled attenuation parameter for liver steatosis in patients with chronic hepatitis B.

    Science.gov (United States)

    Wang, Chun-Yan; Lu, Wei; Hu, Dong-Sheng; Wang, Guang-Dong; Cheng, Xiao-Jing

    2014-08-14

    To study the diagnostic value of controlled attenuation parameter (CAP), evaluated by transient elastography, for liver steatosis in patients with chronic hepatitis B (CHB). Eighty-eight patients with CHB were enrolled in this study. All of the patients were subjected to transient elastography to determine CAP. These patients also underwent liver biopsy in the same period. Using liver biopsy as a reference, we determined receiver operating characteristic (ROC) curves for different endpoints. Areas under the ROC curves (AUCs) were used to evaluate the diagnostic importance of CAP for liver steatosis in patients with CHB. A positive correlation was observed between the AUCs of CAP and liver pathological stage (r = 0.582, P CAP was not correlated with inflammation degree and fibrosis degree (r = -0.025, P > 0.05; r = 0. 068, P > 0.05). The mean CAP value at S0 was 209.59 ± 41.25 dB/m, 223.84 ± 35.28 dB/m at S1, 274.17 ± 43.69 dB/m at S2, and 312.50 ± 25.44 dB/m at S3. CAP values among S0, S1, S2, and S3 were significantly different (F = 17.79, P CAP were 0.711 (0.592-0.870), 0.868 (0.748-0.989), and 0.974 (0.922-1.026) for S1, S2, and S3, respectively. The optimal cut-off values were 219.5, 230.0, and 283.5 dB/m. CAP is a novel tool that can be used to assess the degree of steatosis.

  2. Controlled attenuation parameter for assessment of hepatic steatosis grades: a diagnostic meta-analysis.

    Science.gov (United States)

    Wang, Yuee; Fan, Qingqi; Wang, Ting; Wen, Jia; Wang, Hong; Zhang, Tiansong

    2015-01-01

    to evaluate the performance and accuracy of Controlled attenuation parameter CAP for hepatic steatosis detection. PubMed, EBSCO, Elsevier Science, Ovid, and Wiley were selected to search studies until August 31, 2014. Quality Assessment of Diagnostic Accuracy Studies checklist was used to assess the quality of included studies. Heterogeneity was evaluated using Q test. Sensitivity, specificity, diagnostic odds ratio (DOR), and the area under curve (AUC) with its 95% confidence intervals (CIs) were calculated to evaluate the accuracy of CAP for assessment of hepatic steatosis stage (≥ S1, ≥ S2 and ≥ S3). Totally 11 studies (13 cohorts) with high methodological qualities were identified. The summary point estimations with 95% CIs of sensitivity, specificity, AUC and DORs were 0.78 (0.71, 0.84), 0.79 (0.70, 0.86), 0.86 (0.82, 0.88), and 14 (7, 27) for ≥ S1; 0.82 (0.74, 0.88), 0.79 (0.73, 0.85), 0.88 (0.85, 0.90) and 18 (10, 30) for ≥ S2; 0.86 (0.82, 0.89), 0.89 (0.86, 0.92), 0.94 (0.91, 0.96) and 51 (35, 76) for ≥ S3. Significant heterogeneity was found among the studies in ≥ S1 and ≥ S3. Threshold effect was existed in ≥ S3, but not in ≥ S1 and ≥ S2. Publication bias was not existed in ≥ S1 and ≥ S2 except ≥ S3. CAP provides good sensitivity and specificity for detection of ≥ S1, ≥ S2, and ≥ S3 steatosis. However, future studies with large samples are still necessary to confirm the clinical application.

  3. Controlled attenuation parameter for non-invasive assessment of hepatic steatosis in Chinese patients.

    Science.gov (United States)

    Shen, Feng; Zheng, Rui-Dan; Mi, Yu-Qiang; Wang, Xiao-Ying; Pan, Qin; Chen, Guang-Yu; Cao, Hai-Xia; Chen, Ming-Li; Xu, Liang; Chen, Jian-Neng; Cao, Yi; Zhang, Rui-Nan; Xu, Lei-Ming; Fan, Jian-Gao

    2014-04-28

    To evaluate the performance of a novel non-invasive controlled attenuation parameter (CAP) to assess liver steatosis. This was a multi-center prospective cohort study. Consecutive patients (aged ≥ 18 years) who had undergone percutaneous liver biopsy and CAP measurement were recruited from three Chinese liver centers. Steatosis was categorized as S0: CAP and liver stiffness measurement values simultaneously. Receiver operating characteristic curves were plotted, and the areas under the curves were calculated to determine the diagnostic efficacy. The accuracy of the CAP values at the optimal thresholds was defined by maximizing the sum of sensitivity and specificity (maximum Youden index). A total of 152 patients were recruited, including 52 (34.2%) patients with NAFLD and 100 (65.8%) with chronic hepatitis B (CHB) virus infection. After adjustment, the steatosis grade (OR = 37.12; 95%CI: 21.63-52.60, P CAP by multivariate linear regression analysis. CAP was not influenced by inflammation, fibrosis or aetiology. The median CAP values and interquartile ranges among patients with S0, S1, S2 and S3 steatosis were 211 (181-240) dB/m, 270 (253-305) dB/m, 330 (302-360) dB/m, and 346 (313-363) dB/m, respectively. The cut-offs for the CAP values in all patients with steatosis ≥ 5%, ≥ 34% and ≥ 67% were 253 dB/m, 285 dB/m and 310 dB/m, respectively. The areas under the curves were 0.92, 0.92 and 0.88 for steatosis ≥ 5%, ≥ 34% and ≥ 67%, respectively. No significant differences were found in the CAP values between the NAFLD group and the CHB group in each steatosis grade. CAP appears to be a promising tool for the non-invasive detection and quantification of hepatic steatosis, but is limited by BMI.

  4. [Aedes albopictus (Diptera: Culicidae) in Rome: experimental study of relevant control strategy parameters].

    Science.gov (United States)

    Pombi, M; Costantini, C; della Torre, A

    2003-06-01

    Since 1997, Aedes albopictus has colonised and then rapidly invaded the city of Rome (Italy) and its peripheral areas. Presently, the control of this mosquito in Italy relies mainly on larvicidal treatment of street storm sewer catch basins with the organophosphate temephos. We have therefore obtained baseline data on the susceptibility to temephos of the Roman Ae. albopictus population by laboratory bioassays on F1 fourth-instar larvae following standard WHO protocols. Estimated lethal concentrations were 0.014 mg/l (LC50) and 0.022 mg/l (LC90) indicating a lack of resistance to this compound. The persistence of temephos in sewer catch basins was evaluated by follow-up of catch basins treated with a dose of 1.5 mg of active ingredient. Mosquito larvae were recovered in 10% and 50% of the treated basins at 9 and 18 days posttreatment, respectively. In order to understand the relative contribution of this larval habitat to adult populations, we conducted a survey in the Zoo of Rome to estimate the larval density of mosquitoes breeding in sewer catch basins. A complete census of a 16.5 ha area mapped 243 catch basins, but only 25 (10.3%) contained water; of the latter 8 (32.0%) hosted mosquito larvae. All positive catch basins contained larvae of Culex pipiens, which were associated with Culiseta longiareolata and/or Ae. albopictus in 6 and 3 cases, respectively. A longitudinal survey of one catch basin over 4 months showed that the mean larval density of Ae. albopictus was markedly lower than that of Cx pipiens and Cs. Iongiareolata, ranging between 0 and 1.3 larvae/dip as compared to 0-33.2 and 0-22.7 larvae/dip, respectively. However, adult densities of Ae. albopictus in this area estimated during the same period with 20 ovitraps showed consistently high values (proportion of positive ovitraps around 100%). These preliminary observations suggest that whenever alternative larval biotopes other than sewer catch basins are widely available, they might be more

  5. Damage control operations in non-trauma patients: defining criteria for the staged rapid source control laparotomy in emergency general surgery

    OpenAIRE

    Becher, Robert D.; Peitzman, Andrew B.; Sperry, Jason L.; Jared R Gallaher; Neff, Lucas P.; Sun, Yankai; Miller, Preston R.; Chang, Michael C.

    2016-01-01

    Background The staged laparotomy in the operative management of emergency general surgery (EGS) patients is an extension of trauma surgeons operating on this population. Indications for its application, however, are not well defined, and are currently based on the lethal triad used in physiologically-decompensated trauma patients. This study sought to determine the acute indications for the staged, rapid source control laparotomy (RSCL) in EGS patients. Methods All EGS patients undergoing eme...

  6. Parameter estimation and interval type-2 fuzzy sliding mode control of a z-axis MEMS gyroscope.

    Science.gov (United States)

    Fazlyab, Mahyar; Pedram, Maysam Zamani; Salarieh, Hassan; Alasty, Aria

    2013-11-01

    This paper reports a hybrid intelligent controller for application in single axis MEMS vibratory gyroscopes. First, unknown parameters of a micro gyroscope including unknown time varying angular velocity are estimated online via normalized continuous time least mean squares algorithm. Then, an additional interval type-2 fuzzy sliding mode control is incorporated in order to match the resonant frequencies and to compensate for undesired mechanical couplings. The main advantage of this control strategy is its robustness to parameters uncertainty, external disturbance and measurement noise. Consistent estimation of parameters is guaranteed and stability of the closed-loop system is proved via the Lyapunov stability theorem. Finally, numerical simulation is done in order to validate the effectiveness of the proposed method, both for a constant and time-varying angular rate. Copyright © 2013 ISA. Published by Elsevier Ltd. All rights reserved.

  7. Gas dwell time control for rapid and long lifetime growth of single-walled carbon nanotube forests.

    Science.gov (United States)

    Yasuda, Satoshi; Futaba, Don N; Yamada, Takeo; Yumura, Motoo; Hata, Kenji

    2011-09-14

    The heat history (i.e., "dwell time") of the carbon source gas was demonstrated as a vital parameter for very rapid single-walled carbon nanotube (SWNT) forest growth with long lifetime. When the dwell time was raised to 7 s from the 4 s used for standard growth, the growth rate increased to 620 μm/min: a benchmark for SWNT forest growth on substrates. Importantly, the increase in growth rate was achieved without decreasing either the growth lifetime or the quality of the SWNTs. We interpret that the conversion rate of the carbon feedstock into CNTs was selectively increased (versus catalyst deactivation) by delivering a thermally decomposed carbon source with the optimum thermal history to the catalyst site.

  8. Rapid manufacturing of polyethylene parts with controlled pore size gradients using selective laser sintering

    Directory of Open Access Journals (Sweden)

    Gean Vitor Salmoria

    2007-06-01

    Full Text Available In this study HDPE specimens were fabricated by selective laser sintering using different particle sizes to obtain controlled variations in the porosity. Electron microscopy, density measurements and mechanical analyses were conducted for the characterization of the specimens. Parts with controlled pore gradients were also manufactured and characterized. The specimens with larger particle sizes had a high sintering degree and a significant level of close pores, as shown by microscopy and density analyses. However, the mechanical properties of specimens prepared with large particles had low values due to the limited density of union points, i.e., low neck number/area. HDPE parts with pore gradients were prepared by selective laser sintering demonstrating that this technique can be used to easily control the structure and the properties of the parts manufactured. This technology may have applications in areas such as drug delivery devices and scaffolds for tissue engineering.

  9. Job demands and decision control predicted return to work: the rapid-RTW cohort study

    Directory of Open Access Journals (Sweden)

    Lise Aasen Haveraaen

    2017-02-01

    Full Text Available Abstract Background In order to help workers with long-term sickness absence return to work (RTW, it is important to understand factors that either impede or facilitate employee’s reintegration into the labour force. The aim of this study was therefore to examine the impact of psychological work characteristics on time-to first RTW in sick listed employees in Norway. Methods The study was designed as a cohort study of 543 employees participating in 50 different RTW programmes. The Job Content Questionnaire (JCQ was used to gather information on the psychological work conditions. The participants were followed for up to 18 months after they started treatment in the RTW programme. Survival analyses were used to investigate the association between psychological work conditions and time-to first RTW. Results Having high psychological job demands (HR = .654; 95% CI: .513–.832 and low decision control (HR = 1.297; 95% CI: 1.010–1.666 were both independent predictors of delayed RTW. Employees in low-strain jobs (low demands/high control (HR = 1.811; 95% CI: 1.287–2.549 and passive jobs (low demands/low control (HR = 1.599; 95% CI: 1.107–2.309, returned to work earlier compared to employees in high-strain jobs (high demands/low control. No difference was found for active jobs (high demands/high control. Conclusion This study revealed that high psychological demands, low control, and being in a high strain job reduced the probability of early RTW in sick listed employees. RTW programmes should therefore increase the focus on these issues.

  10. Bidirectional Control of Generalized Epilepsy Networks via Rapid Real-Time Switching of Firing Mode.

    Science.gov (United States)

    Sorokin, Jordan M; Davidson, Thomas J; Frechette, Eric; Abramian, Armen M; Deisseroth, Karl; Huguenard, John R; Paz, Jeanne T

    2017-01-04

    Thalamic relay neurons have well-characterized dual firing modes: bursting and tonic spiking. Studies in brain slices have led to a model in which rhythmic synchronized spiking (phasic firing) in a population of relay neurons leads to hyper-synchronous oscillatory cortico-thalamo-cortical rhythms that result in absence seizures. This model suggests that blocking thalamocortical phasic firing would treat absence seizures. However, recent in vivo studies in anesthetized animals have questioned this simple model. Here we resolve this issue by developing a real-time, mode-switching approach to drive thalamocortical neurons into or out of a phasic firing mode in two freely behaving genetic rodent models of absence epilepsy. Toggling between phasic and tonic firing in thalamocortical neurons launched and aborted absence seizures, respectively. Thus, a synchronous thalamocortical phasic firing state is required for absence seizures, and switching to tonic firing rapidly halts absences. This approach should be useful for modulating other networks that have mode-dependent behaviors. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. THE CHOICE OF PARAMETERS AND CRITERIA FOR AUTOMATIZATION OF CONTROL TONE TRACK CIRCUITS

    Directory of Open Access Journals (Sweden)

    I. O. Romantsev

    2009-12-01

    Full Text Available Based on the analysis of existing methods of checking the tonal frequency track circuits, the choice of parameters and options for check automation of tonal frequency track circuits is conducted.

  12. Rapid toxicity detection in water quality control utilizing automated multispecies biomonitoring for permanent space stations

    Science.gov (United States)

    Morgan, E. L.; Young, R. C.; Smith, M. D.; Eagleson, K. W.

    1986-01-01

    The objective of this study was to evaluate proposed design characteristics and applications of automated biomonitoring devices for real-time toxicity detection in water quality control on-board permanent space stations. Simulated tests in downlinking transmissions of automated biomonitoring data to Earth-receiving stations were simulated using satellite data transmissions from remote Earth-based stations.

  13. Construction of cryptographic information protection in automated control systems for rapid reaction military forces

    Directory of Open Access Journals (Sweden)

    Sergey Petrovich Evseev

    2012-04-01

    Full Text Available New approaches to realizations of military operations are analyzed. The main factors that directly affect the construction and operation of information security subsystems in prospective automated command and control military systems are described. Possible ways of the construction of cryptographic subsystems of information protection in automated operation management systems for united military force groups are investigated.

  14. A rapidly converging filtered-error algorithm for multichannel active noise control

    NARCIS (Netherlands)

    Berkhoff, Arthur P.; Nijsse, G.

    2006-01-01

    In this paper, a multichannel adaptive control algorithm is described which has good convergence properties while having relatively small computational complexity. This complexity is similar to that of the filtered-error algorithm. In order to obtain these properties, the algorithm is based on a

  15. A Design Methodology for Rapid Implementation of Active Control Systems Across Lean Direct Injection Combustor Platforms

    Science.gov (United States)

    Baumann, William T.; Saunders, William R.; Vandsburger, Uri; Saus, Joseph (Technical Monitor)

    2003-01-01

    The VACCG team is comprised of engineers at Virginia Tech who specialize in the subject areas of combustion physics, chemical kinetics, dynamics and controls, and signal processing. Currently, the team's work on this NRA research grant is designed to determine key factors that influence combustion control performance through a blend of theoretical and experimental investigations targeting design and demonstration of active control for three different combustors. To validiate the accuracy of conclusions about control effectiveness, a sequence of experimental verifications on increasingly complex lean, direct injection combustors is underway. During the work period January 1, 2002 through October 15, 2002, work has focused on two different laboratory-scale combustors that allow access for a wide variety of measurements. As the grant work proceeds, one key goal will be to obtain certain knowledge about a particular combustor process using a minimum of sophisticated measurements, due to the practical limitations of measurements on full-scale combustors. In the second year, results obtained in the first year will be validated on test combustors to be identified in the first quarter of that year. In the third year, it is proposed to validate the results at more realistic pressure and power levels by utilizing the facilities at the Glenn Research Center.

  16. An Educational Laboratory for Digital Control and Rapid Prototyping of Power Electronic Circuits

    Science.gov (United States)

    Choi, Sanghun; Saeedifard, M.

    2012-01-01

    This paper describes a new educational power electronics laboratory that was developed primarily to reinforce experimentally the fundamental concepts presented in a power electronics course. The developed laboratory combines theoretical design, simulation studies, digital control, fabrication, and verification of power-electronic circuits based on…

  17. Control System of 3 GeV Rapid Cycling Synchrotron at J-PARC

    CERN Document Server

    Takahashi, Hiroki; Kato, Yuko; Kawase, Masato; Sakaki, Hironao; Sako, Hiroyuki; Sugimoto, Makoto; Yoshikawa, Hiroshi

    2005-01-01

    Since the 3GeV RCS produces huge beam power of 1 MW, extreme cares must be taken to design the control system in order to minimize radiation due to beam loss. Another complexity appears in the control system, because each beam bunch of 25 Hz is required to be injected either into the MLF* or into the 50GeV MR.** Therefore, each bunch of 25 Hz must be operated separately, and the data acquisition system must collect synchronized data within each pulse. To achieve these goals, a control system via reflective memory and wave endless recorders has been developed. EPICS is adopted in the control system. Since the number of devices is huge, the management of EPICS records and their configurations require huge amount of time and man power. To reduce this work significantly, a RDB*** for static machine information has been developed. This RDB stores (1) EPICS related information of devices, interfaces, and IOC's**** with a capability to generate EPICS records automatically, and (2) machine geometrical information wit...

  18. A Rapid Assessment Tool for Space Access Vehicle Configurations in Guidance and Control Performance (Preprint)

    Science.gov (United States)

    2006-08-01

    following equations from Roskam :3 Ixx = W g (kx b)2 (1) Iyy = W g (ky l)2 (2) Izz = W g (kz b+ l 2 )2 (3) The non-dimensional radii of gyration (k...Proceedings of the 2003 AIAA Guidance Navigation and Control Conference, AIAA 2003-5738, August 2003. 3Roskam, J., Airplane Design, Roskam Aviation

  19. Establishing Relationships between Parameters of the Controlled Compaction Soil by Using Various In-Situ Tests

    Science.gov (United States)

    Wyroslak, Mariusz

    2017-10-01

    The aim of research was evaluating reliable correlations between chosen soil parameters describing state of surface layers of soil. The paper presents site comparative tests based on the light falling weight deflectometer (LFWD), the static plate load tester (VSS), the dynamic probing light tester (DPL) and the bearing ratio tester (CBR in-situ) with relationships between soil state parameters. All featured in-situ tests were conducted based on Polish experiences and Standards used in engineering practice.

  20. Parameter optimization of thermal-model-oriented control law for PEM fuel cell stack via novel genetic algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Li Xi, E-mail: lixi@hust.edu.cn [Department of Control Science and Engineering, Key Laboratory of Education, Ministry for Image Processing and Intelligent Control, Huazhong University of Science and Technology, Wuhan 430074 (China); Deng Zhonghua, E-mail: ldarmy@126.com [Department of Control Science and Engineering, Key Laboratory of Education, Ministry for Image Processing and Intelligent Control, Huazhong University of Science and Technology, Wuhan 430074 (China); Wei Dong [Department of Automation, China Jiliang University, Hangzhou 310018, Zhejiang (China); Xu Chunshan; Cao Guangyi [Institute of Fuel Cell, Shanghai Jiao Tong University, Shanghai 200240 (China)

    2011-10-15

    Highlights: {yields}We build up the thermal expressions of PEMFC stack. {yields} The expressions are converted into the affine state space control-oriented model for the VSC strategy. {yields} The NGA is developed to optimize the parameter of thermal-model-oriented control law. {yields} Numerical results demonstrate the effectiveness and rationality of the method proposed. - Abstract: It is critical to understand and manage the thermal effects in optimizing the performance and durability of proton exchange membrane fuel cell (PEMFC) stack. And building up the control-oriented thermal model of PEMFC stack is necessary. The thermal model, a set of differential equations, is established according to the conservation equations of mass and energy, which can be used to reflect truly the actual temperature response of PEMFC stack, however, the expressions of the model are too complicated to be used in the design of control. For this reason, the expressions are converted into the affine state space control-oriented model in detail for the variable structure control (VSC) strategy. Meanwhile, the accurate model must be established for the VSC and the parameters of VSC laws should be optimized. Consequently, a novel genetic algorithm (NGA) is developed to optimize the parameter of thermal-model-oriented control law for PEMFC stack. Finally, numerical test results demonstrate the effectiveness and rationality of the method proposed in this paper. It lays the foundation for the realization of online thermal management of PEMFC stack based on VSC.

  1. Stomatal control and leaf thermal and hydraulic capacitances under rapid environmental fluctuations.

    Directory of Open Access Journals (Sweden)

    Stanislaus J Schymanski

    Full Text Available Leaves within a canopy may experience rapid and extreme fluctuations in ambient conditions. A shaded leaf, for example, may become exposed to an order of magnitude increase in solar radiation within a few seconds, due to sunflecks or canopy motions. Considering typical time scales for stomatal adjustments, (2 to 60 minutes, the gap between these two time scales raised the question whether leaves rely on their hydraulic and thermal capacitances for passive protection from hydraulic failure or over-heating until stomata have adjusted. We employed a physically based model to systematically study effects of short-term fluctuations in irradiance on leaf temperatures and transpiration rates. Considering typical amplitudes and time scales of such fluctuations, the importance of leaf heat and water capacities for avoiding damaging leaf temperatures and hydraulic failure were investigated. The results suggest that common leaf heat capacities are not sufficient to protect a non-transpiring leaf from over-heating during sunflecks of several minutes duration whereas transpirative cooling provides effective protection. A comparison of the simulated time scales for heat damage in the absence of evaporative cooling with observed stomatal response times suggested that stomata must be already open before arrival of a sunfleck to avoid over-heating to critical leaf temperatures. This is consistent with measured stomatal conductances in shaded leaves and has implications for water use efficiency of deep canopy leaves and vulnerability to heat damage during drought. Our results also suggest that typical leaf water contents could sustain several minutes of evaporative cooling during a sunfleck without increasing the xylem water supply and thus risking embolism. We thus submit that shaded leaves rely on hydraulic capacitance and evaporative cooling to avoid over-heating and hydraulic failure during exposure to typical sunflecks, whereas thermal capacitance provides

  2. Amorphous calcium carbonate controls avian eggshell mineralization: A new paradigm for understanding rapid eggshell calcification.

    Science.gov (United States)

    Rodríguez-Navarro, Alejandro B; Marie, Pauline; Nys, Yves; Hincke, Maxwell T; Gautron, Joel

    2015-06-01

    Avian eggshell mineralization is the fastest biogenic calcification process known in nature. How this is achieved while producing a highly crystalline material composed of large calcite columnar single crystals remains largely unknown. Here we report that eggshell mineral originates from the accumulation of flat disk-shaped amorphous calcium carbonate (ACC) particles on specific organic sites on the eggshell membrane, which are rich in proteins and sulfated proteoglycans. These structures known as mammillary cores promote the nucleation and stabilization of a amorphous calcium carbonate with calcitic short range order which predetermine the calcite composition of the mature eggshell. The amorphous nature of the precursor phase was confirmed by the diffuse scattering of X-rays and electrons. The nascent calcitic short-range order of this transient mineral phase was revealed by infrared spectroscopy and HRTEM. The ACC mineral deposited around the mammillary core sites progressively transforms directly into calcite crystals without the occurrence of any intermediate phase. Ionic speciation data suggest that the uterine fluid is equilibrated with amorphous calcium carbonate, throughout the duration of eggshell mineralization process, supporting that this mineral phase is constantly forming at the shell mineralization front. On the other hand, the transient amorphous calcium carbonate mineral deposits, as well as the calcite crystals into which they are converted, form by the ordered aggregation of nanoparticles that support the rapid mineralization of the eggshell. The results of this study alter our current understanding of avian eggshell calcification and provide new insights into the genesis and formation of calcium carbonate biominerals in vertebrates. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. Cast Off expansion plan by rapid improvement through Optimization tool design, Tool Parameters and using Six Sigma’s ECRS Technique

    Science.gov (United States)

    Gopalakrishnan, T.; Saravanan, R.

    2017-03-01

    Powerful management concepts step-up the quality of the product, time saving in producing the product thereby increase the production rate, improves tools and techniques, work culture, work place and employee motivation and morale. In this paper discussed about the case study of optimizing the tool design, tool parameters to cast off expansion plan according ECRS technique. The proposed designs and optimal tool parameters yielded best results and meet the customer demand without expansion plan. Hence the work yielded huge savings of money (direct and indirect cost), time and improved the motivation and more of employees significantly.

  4. [A clinical study of the association between hepatic controlled attenuation parameter and metabolic syndrome].

    Science.gov (United States)

    Sun, W L; Sun, C G; Chen, G Y; Pan, Q; Zeng, J; Shan, P P; Fan, J G

    2017-02-20

    Objective: To investigate the association between hepatic controlled attenuation parameter (CAP) and metabolic syndrome (MetS) and the correlation of CAP and its changes with the incidence of MetS. Methods: A total of 2461 subjects who underwent physical examination from July 2013 to September 2015 were enrolled. Spearman correlation analysis was used to investigate the correlation of CAP with the number of MetS components and each MetS component, and the chi-square test was used to investigate the prevalence rates of MetS and each component under different CAP levels. Logistic regression analysis was used to analyze the odds ratio (95% confidence interval (CI)) of MetS under different CAP levels. A total of 230 subjects without baseline MetS were selected; in a prospective cohort study, these subjects were divided into groups according to the baseline CAP, change in CAP, and percent change in CAP, and the chi-square test was performed to compare the incidence of MetS. The Cox regression analysis was used to analyze the values of baseline CAP, change in CAP, and percent change in CAP in predicting MetS. Results: CAP was positively correlated with the number of MetS components (r = 0.309, P CAP levels (CAP levels of 238-258 dB/m, 259-291 dB/m, and ≥292 dB/m were 1.784 (1.369-2.325), 2.936 (2.292-3.760), and 4.363 (3.435-5.543), respectively (all P CAP > 238 dB/m, change in CAP > 30 dB/m, and percent change in CAP > 25.0% were 3.337 (1.163-9.569), 7.732 (2.453-24.366), and 11.656 (3.329-40.813), respectively (all P CAP is closely associated with MetS and its components. CAP and its change can be used to predict the risk of MetS.

  5. Diagnostic Accuracy of Controlled Attenuation Parameter for Detecting Hepatic Steatosis in Patients with Chronic Liver Disease.

    Science.gov (United States)

    Andrade, Patrícia; Rodrigues, Susana; Rodrigues-Pinto, Eduardo; Gaspar, Rui; Lopes, Joanne; Lopes, Susana; Macedo, Guilherme

    2017-07-01

    Controlled attenuation parameter (CAP), measured by transient elastography, has been suggested as a noninvasive method for the detection and quantification of steatosis. We aimed to assess the accuracy of CAP to detect steatosis in patients with chronic liver disease (CLD) compared with liver histology and to evaluate factors that correlate with the CAP value. Patients with CLD who underwent liver biopsy and simultaneous CAP determination were consecutively enrolled. CAP was measured using the M probe of FibroScan® (Echosens, Paris, France). Histologically, steatosis was categorized as absent (S0: 66% of all hepatocytes). We analyzed 159 patients with CLD (61% men, mean age 47.9 ± 12.9 years). We found a positive correlation between CAP and steatosis in histology (rs = 0.869, p total cholesterol (rs = 0.442, p 25 (odds ratio [OR] 48.4, 95% confidence interval [CI] 23.78-72.95, p total cholesterol (OR 3.803, 95% CI 2.203-13.889, p = 0.008), and NAFLD etiology (OR 40.8, 95% CI 15.01-66.66, p = 0.002) were independently associated with higher CAP values. We did not find any significant correlation between CAP and the grade of necroinflammatory activity (rs = 0.063, p = 0.808) or fibrosis (rs = 0.071, p = 0.713) in histology and with alanine aminotransferase (rs = 0.190, p = 0.356) or aspartate aminotransferase (rs = 0.117, p = 0.142). Optimal CAP cutoff values for detecting steatosis ≥S1, ≥S2, and ≥S3 were 206.5, 232.5, and 282.5 dB/m, respectively. CAP performance was 0.822, 0.956, and 0.976 for diagnosing steatosis ≥S1, ≥S2, and ≥S3, respectively. CAP had an excellent diagnostic accuracy for the detection of steatosis in diverse CLD patients. A CAP value cutoff of <282.5 dB/m excludes severe steatosis ≥S3 with an accuracy of 98%.

  6. IMC based boundary control of a thermal process with parameter uncertainty

    NARCIS (Netherlands)

    Vajta, Miklos

    2009-01-01

    The aim of this paper is to present a control scheme for controlling the temperature in a slab which is not directly measurable. The process can only be controlled by manipulating the ambient temperature (boundary control). We describe the physical process and derive its (distributed) transfer

  7. Allometric or lean body mass scaling of propofol pharmacokinetics: towards simplifying parameter sets for target-controlled infusions.

    Science.gov (United States)

    Coetzee, Johan Francois

    2012-03-01

    Uncertainty exists as to the most suitable pharmacokinetic parameter sets for propofol target-controlled infusions (TCI). The pharmacokinetic parameter sets currently employed are clearly not universally applicable, particularly when patient attributes differ from those of the subjects who participated in the original research from which the models were derived. Increasing evidence indicates that the pharmacokinetic parameters of propofol can be scaled allometrically as well as in direct proportion to lean body mass (LBM). Appraisal of hitherto published studies suggests that an allometrically scaled pharmacokinetic parameter set may be applicable to a wide range of patients ranging from children to obese adults. On the other hand, there is evidence that propofol pharmacokinetic parameters, scaled linearly to LBM, provide improved dosing in normal and obese adults. The 'Schnider' pharmacokinetic parameter set that has been programmed into commercially available TCI pumps cannot be employed at present for morbidly obese patients (body mass index >40 kg/m2), because of anomalous behaviour of the equation used to calculate LBM, resulting in administration of excessive amounts of propofol. Simulations of TCI using improved equations to calculate LBM indicate that the Schnider model delivers similar amounts of propofol to morbidly obese patients as do the allometrically scaled pharmacokinetic parameter sets. These hypotheses deserve further investigation. To facilitate further investigation, researchers are encouraged to make their data freely available to the WorldSIVA Open TCI Initiative (http://opentci.org).

  8. Rapid and tunable method to temporally control gene editing based on conditional Cas9 stabilization.

    Science.gov (United States)

    Senturk, Serif; Shirole, Nitin H; Nowak, Dawid G; Corbo, Vincenzo; Pal, Debjani; Vaughan, Alexander; Tuveson, David A; Trotman, Lloyd C; Kinney, Justin B; Sordella, Raffaella

    2017-02-22

    The CRISPR/Cas9 system is a powerful tool for studying gene function. Here, we describe a method that allows temporal control of CRISPR/Cas9 activity based on conditional Cas9 destabilization. We demonstrate that fusing an FKBP12-derived destabilizing domain to Cas9 (DD-Cas9) enables conditional Cas9 expression and temporal control of gene editing in the presence of an FKBP12 synthetic ligand. This system can be easily adapted to co-express, from the same promoter, DD-Cas9 with any other gene of interest without co-modulation of the latter. In particular, when co-expressed with inducible Cre-ER T2 , our system enables parallel, independent manipulation of alleles targeted by Cas9 and traditional recombinase with single-cell specificity. We anticipate this platform will be used for the systematic characterization and identification of essential genes, as well as the investigation of the interactions between functional genes.

  9. A Rapid Prototyping Tool for Embedded, Real-Time Hierarchical Control Systems

    Directory of Open Access Journals (Sweden)

    Hugo Andrade

    2008-12-01

    Full Text Available Laboratory Virtual Instrumentation and Engineering Workbench (LabVIEW is a graphical programming tool based on the dataflow language G. Recently, runtime support for a hard real-time environment has become available for LabVIEW, which makes it an option for embedded systems prototyping. Due to its characteristics, the environment presents itself as an ideal tool for both the design and implementation of embedded software. In this paper, we study the design and implementation of embedded software by using G as the specification language and the LabVIEW RT real-time platform. One of the main advantages of this approach is that the environment leads itself to a very smooth transition from design to implementation, allowing for powerful cosimulation strategies (e.g., hardware in the loop, runtime modeling. We characterize the semantics and formal model of computation of G. We compare it to other models of computation and develop design rules and algorithms to propose sound embedded design in the language. We investigate the specification and mapping of hierarchical control systems in LabVIEW and G. Finally, we describe the development of a state-of-the-art embedded motion control system using LabVIEW as the specification, simulation and implementation tool, using the proposed design principles. The solution is state-of-the-art in terms of flexibility and control performance.

  10. A Rapid Prototyping Tool for Embedded, Real-Time Hierarchical Control Systems

    Directory of Open Access Journals (Sweden)

    Ramamoorthy Subramanian

    2008-01-01

    Full Text Available Abstract Laboratory Virtual Instrumentation and Engineering Workbench (LabVIEW is a graphical programming tool based on the dataflow language G. Recently, runtime support for a hard real-time environment has become available for LabVIEW, which makes it an option for embedded systems prototyping. Due to its characteristics, the environment presents itself as an ideal tool for both the design and implementation of embedded software. In this paper, we study the design and implementation of embedded software by using G as the specification language and the LabVIEW RT real-time platform. One of the main advantages of this approach is that the environment leads itself to a very smooth transition from design to implementation, allowing for powerful cosimulation strategies (e.g., hardware in the loop, runtime modeling. We characterize the semantics and formal model of computation of G. We compare it to other models of computation and develop design rules and algorithms to propose sound embedded design in the language. We investigate the specification and mapping of hierarchical control systems in LabVIEW and G. Finally, we describe the development of a state-of-the-art embedded motion control system using LabVIEW as the specification, simulation and implementation tool, using the proposed design principles. The solution is state-of-the-art in terms of flexibility and control performance.

  11. Anti-synchronization of fractional order chaotic and hyperchaotic systems with fully unknown parameters using modified adaptive control

    Directory of Open Access Journals (Sweden)

    Al-Sawalha M. Mossa

    2016-01-01

    Full Text Available The objective of this article is to implement and extend applications of adaptive control to anti-synchronize different fractional order chaotic and hyperchaotic dynamical systems. The sufficient conditions for achieving anti–synchronization are derived by using the Lyapunov stability theory and an analytic expression of the controller with its adaptive laws of parameters is shown. Theoretical analysis and numerical simulations are shown to verify the results.

  12. Anti-synchronization of fractional order chaotic and hyperchaotic systems with fully unknown parameters using modified adaptive control

    Science.gov (United States)

    Al-Sawalha, M. Mossa; Al-Sawalha, Ayman

    2016-01-01

    The objective of this article is to implement and extend applications of adaptive control to anti-synchronize different fractional order chaotic and hyperchaotic dynamical systems. The sufficient conditions for achieving anti-synchronization are derived by using the Lyapunov stability theory and an analytic expression of the controller with its adaptive laws of parameters is shown. Theoretical analysis and numerical simulations are shown to verify the results.

  13. Advances in distributed parameter approach to the dynamics and control of activated sludge processes for wastewater treatment.

    Science.gov (United States)

    Lee, T T; Wang, F Y; Newell, R B

    2006-03-01

    This paper presents a review of modelling and control of biological nutrient removal (BNR)-activated sludge processes for wastewater treatment using distributed parameter models described by partial differential equations (PDE). Numerical methods for solution to the BNR-activated sludge process dynamics are reviewed and these include method of lines, global orthogonal collocation and orthogonal collocation on finite elements. Fundamental techniques and conceptual advances of the distributed parameter approach to the dynamics and control of activated sludge processes are briefly described. A critical analysis on the advantages of the distributed parameter approach over the conventional modelling strategy in this paper shows that the activated sludge process is more adequately described by the former and the method is recommended for application to the wastewater industry.

  14. Performance Analysis of DTC-SVM Sliding Mode Controllers-Based Parameters Estimator of Electric Motor Speed Drive

    Directory of Open Access Journals (Sweden)

    Fatma Ben Salem

    2014-01-01

    Full Text Available This paper is concerned with a framework which unifies direct torque control space vector modulation (DTC-SVM and variable structure control (VSC. The result is a hybrid VSC-DTC-SVM controller design which eliminates several major limitations of the two individual controls and retains merits of both controllers. It has been shown that obtained control laws are very sensitive to variations of the stator resistance, the rotor resistance, and the mutual inductance. This paper discusses the performances of adaptive controllers of VSC-DTC-SVM monitored induction motor drive in a wide speed range and even in the presence of parameters uncertainties and mismatching disturbances. Better estimations of the stator resistance, the rotor resistance, and the mutual inductance yield improvements of induction motor performances using VSC-DTC-SVM, thereby facilitating torque ripple minimization. Simulation results verified the performances of the proposed approach.

  15. Rapid determination of thermodynamic parameters from one-dimensional programmed-temperature gas chromatography for use in retention time prediction in comprehensive multidimensional chromatography.

    Science.gov (United States)

    McGinitie, Teague M; Ebrahimi-Najafabadi, Heshmatollah; Harynuk, James J

    2014-01-17

    A new method for estimating the thermodynamic parameters of ΔH(T0), ΔS(T0), and ΔCP for use in thermodynamic modeling of GC×GC separations has been developed. The method is an alternative to the traditional isothermal separations required to fit a three-parameter thermodynamic model to retention data. Herein, a non-linear optimization technique is used to estimate the parameters from a series of temperature-programmed separations using the Nelder-Mead simplex algorithm. With this method, the time required to obtain estimates of thermodynamic parameters a series of analytes is significantly reduced. This new method allows for precise predictions of retention time with the average error being only 0.2s for 1D separations. Predictions for GC×GC separations were also in agreement with experimental measurements; having an average relative error of 0.37% for (1)tr and 2.1% for (2)tr. Copyright © 2013 Elsevier B.V. All rights reserved.

  16. Dual-harmonic auto voltage control for the rapid cycling synchrotron of the Japan Proton Accelerator Research Complex

    Directory of Open Access Journals (Sweden)

    Fumihiko Tamura

    2008-07-01

    Full Text Available The dual-harmonic operation, in which the accelerating cavities are driven by the superposition of the fundamental and the second harmonic rf voltage, is useful for acceleration of the ultrahigh intensity proton beam in the rapid cycling synchrotron (RCS of Japan Proton Accelerator Research Complex (J-PARC. However, the precise and fast voltage control of the harmonics is necessary to realize the dual-harmonic acceleration. We developed the dual-harmonic auto voltage control system for the J-PARC RCS. We describe details of the design and the implementation. Various tests of the system are performed with the RCS rf system. Also, a preliminary beam test has been done. We report the test results.

  17. Parameters Designing of Slide Mode Variable Structure Controller of Bus Voltage of DC Microgrid Based on Proportion Switching Function

    Directory of Open Access Journals (Sweden)

    Sun Zhenchuan

    2017-01-01

    Full Text Available Constant value control of the DC-bus voltage is a essential problem of the control system of the DC microgrids. DC-DC converters are applied in parallel to realize the transform of energy from the distributed generations (DGs to the DC-bus. Droop control methods are applied to the DC-bus voltage while PI controllers are used in controlling the duty ratios of the converters. This method may bring out the slow response speed of the system accompanied by the large ripple of the voltage. The slide mode variable structure control can speed up the response and reduce the ripple of the voltage as well. In the traditional slide mode control based on the proportion switching function, the denominator of the transfer function of the controlled plant is a second-order characteristic polynomial without the constant term. The denominators of the transfer functions of the buck DC-DC converters contain the constant terms. The designing of the parameters of the slide mode control based on the proportion switching function is analyzed based on mathematics deductions. Simulation results show that the selected parameters can not only speed up the response of the system but also greatly reduce the ripple of the voltage.

  18. The use of plasmapheresis for rapid hormonal control in severe hyperthyroidism caused by a partial molar pregnancy.

    Science.gov (United States)

    Adali, Ertan; Yildizhan, Recep; Kolusari, Ali; Kurdoglu, Mertihan; Turan, Nedim

    2009-04-01

    The hormone human chorionic gonadotropin (hCG), secreted by molar tissue, is structurally similar to thyroid-stimulating hormone (TSH). Hyperthyroidism in trophoblastic disease is thought to be the result of TSH receptor activation by extremely elevated levels of hCG. Significant elevations in hCG levels are less common in cases of partial moles. We describe a patient with partial molar pregnancy in which the levels of hCG and thyroid hormones were significantly high. It was not possible to decrease the elevated thyroid hormone concentrations to safer levels using medical treatment strategies only. Since the patient's vaginal bleeding increased gradually, plasmapheresis was used to rapidly control the thyroid hormones during the preoperative preparation of the patient for anesthesia and surgery. After the evacuation of the molar tissue, the levels of the thyroid hormones detected after the plasmapheresis started to decrease even further. Plasmapheresis may be used as an alternative to antithyroid medication for the rapid control of thyroid hormones in cases of severe hyperthyroidism caused by molar pregnancy.

  19. Rotor Position Sensorless Control and Its Parameter Sensitivity of Permanent Magnet Motor Based on Model Reference Adaptive System

    Science.gov (United States)

    Ohara, Masaki; Noguchi, Toshihiko

    This paper describes a new method for a rotor position sensorless control of a surface permanent magnet synchronous motor based on a model reference adaptive system (MRAS). This method features the MRAS in a current control loop to estimate a rotor speed and position by using only current sensors. This method as well as almost all the conventional methods incorporates a mathematical model of the motor, which consists of parameters such as winding resistances, inductances, and an induced voltage constant. Hence, the important thing is to investigate how the deviation of these parameters affects the estimated rotor position. First, this paper proposes a structure of the sensorless control applied in the current control loop. Next, it proves the stability of the proposed method when motor parameters deviate from the nominal values, and derives the relationship between the estimated position and the deviation of the parameters in a steady state. Finally, some experimental results are presented to show performance and effectiveness of the proposed method.

  20. Formulation and experimental evaluation of closed-form control laws for the rapid maneuvering of reactor neutronic power

    Energy Technology Data Exchange (ETDEWEB)

    Bernard, J.A. (Massachusetts Inst. of Tech., Cambridge, MA (USA). Nuclear Reactor Lab.)

    1989-09-01

    This report describes both the theoretical development and the experimental evaluation of a novel, robust methodology for the time-optimal adjustment of a reactor's neutronic power under conditions of closed-loop digital control. Central to the approach are the MIT-SNL Period-Generated Minimum Time Control Laws' which determine the rate at which reactivity should be changed in order to cause a reactor's neutronic power to conform to a specified trajectory. Using these laws, reactor power can be safely raised by five to seven orders of magnitude in a few seconds. The MIT-SNL laws were developed to facilitate rapid increases of neutronic power on spacecraft reactors operating in an SDI environment. However, these laws are generic and have other applications including the rapid recovery of research and test reactors subsequent to an unanticipated shutdown, power increases following the achievement of criticality on commercial reactors, power adjustments on commercial reactors so as to minimize thermal stress, and automated startups. The work reported here was performed by the Massachusetts Institute of Technology under contract to the Sandia National Laboratories. Support was also provided by the US Department of Energy's Division of University and Industry Programs. The work described in this report is significant in that a novel solution to the problem of time-optimal control of neutronic power was identified, in that a rigorous description of a reactor's dynamics was derived in that the rate of change of reactivity was recognized as the proper control signal, and in that extensive experimental trials were conducted of these newly developed concepts on actual nuclear reactors. 43 refs., 118 figs., 11 tabs.

  1. Performance of the Priority Control Strategies for Bus Rapid Transit: Comparative Study from Scenario Microsimulation Using VISSIM

    Directory of Open Access Journals (Sweden)

    Min Yang

    2013-01-01

    Full Text Available Bus rapid transit (BRT has a great potential to improve the service level of transit system and has been implemented in many Chinese cities. However, the priority it can provide to buses has not been explored fully. Therefore, this study mainly investigated two advanced control strategies (signal priority using advanced detection and transit speed control. Signal priority using advanced detection is a strategy which detects one cycle ahead of buses’ arrival in order to adapt a more flexible control algorithm to provide signal priority for buses. Another is transit speed control, which provides priority at intersections for buses by controlling the speed of them and predicting their arrival at certain intersection. These two advanced strategies were modeled and evaluated using simulation software VISSIM and presented better performance than other three scenarios (base case, exclusive bus lane, and conventional transit signal priority. Only the eastbound direction would be researched as its traffic flow and bus volume are much larger than those of the other direction. Data used in this model was collected in Yingtan City. It is also shown that both the operation of BRT and the efficiency of private traffic can be much improved by applying the two strategies proposed above.

  2. Ebola virus disease outbreak in Nigeria: transmission dynamics and rapid control

    OpenAIRE

    Althaus, Christian L.; Gsteiger, Sandro; Musa, Emmanuel O.; Shuaib, Faisal; Low, Nicola

    2014-01-01

    International air travel has already spread Ebola virus disease (EVD) to major cities as part of the unprecedented epidemic that started in Guinea in December 2013. An infected airline passenger arrived in Nigeria on July 20, 2014 and caused an outbreak in Lagos and then Port Harcourt. After a total of 20 reported cases, including 8 deaths, Nigeria was declared EVD free on October 20, 2014. We quantified the impact of early control measures in preventing further spread of EVD in Nigeria and c...

  3. Improved finite-control-set model predictive control for active front-end rectifiers with simplified computational approach and on-line parameter identification.

    Science.gov (United States)

    Liu, Xing; Wang, Dan; Peng, Zhouhua

    2017-07-01

    In this paper, an improved finite-control-set model predictive control method is proposed for active front-end rectifiers where the computational effort and parameter mismatch problems are taken into account simultaneously. Specifically, a desired voltage vector which only requires one exploration is directly selected by using a single cost function, and the process of selection of the desired voltage vector is optimized by using a sector distribution method. Meanwhile, a model reference adaptive system-based online parameter identification approach is presented to alleviate the parameter mismatch problem. The advantages of the proposed method summarized as follows: First, the proposed algorithm reduces the eight possible voltage vectors to one. The exhaustive exploration can be avoided while the control performance is not deteriorated. Second, the proposed controller can mitigate performance degradation caused by the model parameter mismatch. Simulation results under various parameters operating conditions are presented to demonstrate the efficacy of the proposed method. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  4. Estimation of the parameters of quality control test of professional competence of staff

    OpenAIRE

    Oleksandra Bakanova; Andriy Yegorov; Tetiana Zakhvatova; Klavdiia Nekrasova

    2015-01-01

    Purpose: to develop a method for estimating the reliability of the control of functional competencies of staff with limited test sample. Material and Methods: statistical process control, sampling by attributes. Results: the dependence of the reliability of the sampling of the sample size and the population of test questions, the control plan, methodical error sampling with a given probability. Conclusions: the proposed method of selecting control plan that allows correct (with a given probab...

  5. Rate bounded linear parameter varying control of a wind turbine in full load operation

    DEFF Research Database (Denmark)

    Østergaard, Kasper Zinck; Stoustrup, Jakob; Brath, Per

    2008-01-01

    This paper considers the control of wind turbines using an LPV design technique. The controller design is done by a combination of a method that uses elimination of controller variables and a method using a congruent transformation followed by a change of variables. An investigation is performed ...

  6. Wheeled vehicle deceleration as estimation parameter of adaptive brake control system state

    Directory of Open Access Journals (Sweden)

    Turenko A.

    2012-06-01

    Full Text Available The method of stability estimation of adaptive control system with signal adjustment based on Lyapunov’s direct method that allows to take into account the nonstationarity of the basic system and non-linearity in the form of limitation on control action restriction as well as error control is stated.

  7. On the necessity of identifying the true parameter in adaptive LQ control

    NARCIS (Netherlands)

    Polderman, Jan W.

    1986-01-01

    In adaptive control problems one may drop the requirement of identifying the true system in order to simplify the problem of control. It will be shown that in the adaptive LQ control problem this does not at all lead to an easier problem.

  8. Method for rapid, controllable growth and thickness, of epitaxial silicon films

    Science.gov (United States)

    Wang, Qi [Littleton, CO; Stradins, Paul [Golden, CO; Teplin, Charles [Boulder, CO; Branz, Howard M [Boulder, CO

    2009-10-13

    A method of producing epitaxial silicon films on a c-Si wafer substrate using hot wire chemical vapor deposition by controlling the rate of silicon deposition in a temperature range that spans the transition from a monohydride to a hydrogen free silicon surface in a vacuum, to obtain phase-pure epitaxial silicon film of increased thickness is disclosed. The method includes placing a c-Si substrate in a HWCVD reactor chamber. The method also includes supplying a gas containing silicon at a sufficient rate into the reaction chamber to interact with the substrate to deposit a layer containing silicon thereon at a predefined growth rate to obtain phase-pure epitaxial silicon film of increased thickness.

  9. Origin of a rapidly evolving homeostatic control system programming testis function.

    Science.gov (United States)

    Bu, Pengli; Yagi, Shintaro; Shiota, Kunio; Alam, S M Khorshed; Vivian, Jay L; Wolfe, Michael W; Rumi, M A Karim; Chakraborty, Damayanti; Kubota, Kaiyu; Dhakal, Pramod; Soares, Michael J

    2017-08-01

    Mammals share common strategies for regulating reproduction, including a conserved hypothalamic-pituitary-gonadal axis; yet, individual species exhibit differences in reproductive performance. In this report, we describe the discovery of a species-restricted homeostatic control system programming testis growth and function. Prl3c1 is a member of the prolactin gene family and its protein product (PLP-J) was discovered as a uterine cytokine contributing to the establishment of pregnancy. We utilized mouse mutagenesis of Prl3c1 and revealed its involvement in the regulation of the male reproductive axis. The Prl3c1-null male reproductive phenotype was characterized by testiculomegaly and hyperandrogenism. The larger testes in the Prl3c1-null mice were associated with an expansion of the Leydig cell compartment. Prl3c1 locus is a template for two transcripts (Prl3c1-v1 and Prl3c1-v2) expressed in a tissue-specific pattern. Prl3c1-v1 is expressed in uterine decidua, while Prl3c1-v2 is expressed in Leydig cells of the testis. 5'RACE, chromatin immunoprecipitation and DNA methylation analyses were used to define cell-specific promoter usage and alternative transcript expression. We examined the Prl3c1 locus in five murid rodents and showed that the testicular transcript and encoded protein are the result of a recent retrotransposition event at the Mus musculus Prl3c1 locus. Prl3c1-v1 encodes PLP-J V1 and Prl3c1-v2 encodes PLP-J V2. Each protein exhibits distinct intracellular targeting and actions. PLP-J V2 possesses Leydig cell-static actions consistent with the Prl3c1-null testicular phenotype. Analysis of the biology of the Prl3c1 gene has provided insight into a previously unappreciated homeostatic setpoint control system programming testicular growth and function. © 2017 Society for Endocrinology.

  10. In vitro evaluation of the quality control parameters of six brands of ...

    African Journals Online (AJOL)

    ±0.5˚C in 900 ml of phosphate buffer for 8 h. A 5 mL of sample was withdrawn at hourly intervals and analyzed using UV spectrophotometer at 275 nm. Results show that physical parameters of the respective brands of nifedipine tablets studied ...

  11. Biological control of the Mediterranean fruit fly in Israel: biological parameters of imported parasitoid wasps

    Science.gov (United States)

    Three braconid species that parasitize the Mediterranean fruit fly (medfly), CERATITIS CAPITATA (Wiedemann) were recently imported into Israel. Several of their key biological parameters were studied. The longevities of the egg-attacking parasitoids FOPIUS ARISANUS and FOPIUS CERATITIVORUS, and t...

  12. Analysis of controlling parameters for shear behavior of rock joints with FLAC3D

    Science.gov (United States)

    Tiwari, Prasoon

    The research investigation is conducted to perform an analysis of sensitivity of parameters affecting the strength of joints in rock mass. Friction angle, normal stiffness, shear stiffness and shear displacement are the parameters analyzed with respect to shear strength of rock joints. Discontinuities have an important influence on the deformational behavior of rock systems; hence, proper consideration of the physical and mechanical properties of discontinuities is necessary during experimental investigation, in order to correctly evaluate the shear behavior. These parameters are utilized to simulate the in situ stress condition in numerical modeling, which is important for safe and economical design of various engineering constructions. These concerns require accurate quantification of shear strength of unfilled and in-filled joints, proper understanding of the basic mechanics of discontinuity and the principals involved in their shear deformation. This can be achieved through laboratory testing on natural rock core samples. In the present work, the detailed account of test results of direct shear tests performed on rock joints is presented. Rock samples are obtained by core drilling in an underground mine, in Nevada. These rock samples, containing joint, are used to perform direct shear strength test. Calibration of numerical model is done on average values obtained from direct shear strength test. Analysis of sensitivity of parameters effecting shear strength of rock is done in FLAC3D shear test environment. A numerical parametric study is done, according to the Mohr-Coulomb constitutive model, and results obtained are plotted to estimate performance of rock joints.

  13. House thermal model parameter estimation method for Model Predictive Control applications

    NARCIS (Netherlands)

    van Leeuwen, Richard Pieter; de Wit, J.B.; Fink, J.; Smit, Gerardus Johannes Maria

    In this paper we investigate thermal network models with different model orders applied to various Dutch low-energy house types with high and low interior thermal mass and containing floor heating. Parameter estimations are performed by using data from TRNSYS simulations. The paper discusses results

  14. The method for controlling electric machine parameters based on the analysis of starting currents

    Directory of Open Access Journals (Sweden)

    Remezovsky V.M.

    2015-03-01

    Full Text Available The theoretical and experimental analysis of the electric machine technical condition by studying activate currents has been carried out. It has been shown that by means of express-methods it is possible to estimate the electric engine parameters with sufficient degree of accuracy

  15. Completion report for Early Detection Rapid Response Projects : Inventory and control of yellow toadflax (Linaria vulgaris) on Kulm Wetland Management District

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Completion report for Early Detection Rapid Response Project (EDRR) "Inventory and control of yellow toadflax (Linaria vulgaris) on Kulm Wetland Management District"...

  16. Dynamic Fuzzy Logic Parameter Tuning for ACO and Its Application in the Fuzzy Logic Control of an Autonomous Mobile Robot

    Directory of Open Access Journals (Sweden)

    Oscar Castillo

    2013-01-01

    Full Text Available Ant Colony Optimization (ACO is a population-based constructive meta-heuristic that exploits a form of past performance memory inspired by the foraging behaviour of real ants. The behaviour of the ACO algorithm is highly dependent on the values defined for its parameters. Adaptation and parameter control are recurring themes in the field of bio-inspired algorithms. The present paper explores a new approach to diversity control in ACO. The central idea is to avoid or slow down full convergence through the dynamic variation of certain parameters. The performance of different variants of the ACO algorithm was observed to choose one as the basis for the proposed approach. A convergence fuzzy logic controller with the objective of maintaining diversity at some level to avoid premature convergence was created. Encouraging results have been obtained on its application to the design of fuzzy controllers. In particular, the optimization of membership functions for a unicycle mobile robot trajectory control is presented with the proposed method.

  17. [Metabolic parameters in patients with steatosis non alcoholic liver and controlled diabetes type 2 versus uncontrolled diabetes type 2].

    Science.gov (United States)

    Miranda Manrique, Gonzalo

    2016-01-01

    Non-alcoholic fatty liver (NASH) is widely distributed around the world and is more common in subjects with dyslipidemia, metabolic syndrome obese and DM2 (34-74%). However, the prevalence of cirrhosis by NASH in general population is unknown which is still subject of research. To determine if there are significant differences between metabolic parameters of non-alcoholic fatty liver in controlled versus uncontrolled diabetes type 2 of recent diagnosis. retrospective case-control study, performed in the Hospital Guillermo Almenara Irigoyen, Lima, Peru from November 2014 to February 2015.This study included 231 patients: 147 patients (NASH with DM2 of recent diagnosis and poor control) and 84 patients (NASH with DM2 ofrecent diagnosis and adequate control). Levene test for evaluating homogeneity of variances intra groups and parametric test for independent samples. After applying Levene test of homogeneity and student test, significant metabolic parameters were the triglycerides, HbA1C level, metformin dose and gender. It is important in diabetic patients to diagnose NASH early for a tighter control, not only of glucose but other metabolic parameters mainly triglycerides which strongly supports existing concept of "multiple hits" which considers NASH affects glucose homeostasis, and it could be the starting point of new research to improve interventions for decreasing progression from to cirrhosis in diabetic patients and also to delay progression of diabetes mellitus in patients with non alcoholic steatohepatitis.

  18. Estimation of the parameters of quality control test of professional competence of staff

    Directory of Open Access Journals (Sweden)

    Oleksandra Bakanova

    2015-06-01

    Full Text Available Purpose: to develop a method for estimating the reliability of the control of functional competencies of staff with limited test sample. Material and Methods: statistical process control, sampling by attributes. Results: the dependence of the reliability of the sampling of the sample size and the population of test questions, the control plan, methodical error sampling with a given probability. Conclusions: the proposed method of selecting control plan that allows correct (with a given probability decision criterion to choose the implementation of process control professional competencies of staff with limited test sample.

  19. Robust Adaptive Sliding Mode Control for Generalized Function Projective Synchronization of Different Chaotic Systems with Unknown Parameters

    Directory of Open Access Journals (Sweden)

    Xiuchun Li

    2013-01-01

    Full Text Available When the parameters of both drive and response systems are all unknown, an adaptive sliding mode controller, strongly robust to exotic perturbations, is designed for realizing generalized function projective synchronization. Sliding mode surface is given and the controlled system is asymptotically stable on this surface with the passage of time. Based on the adaptation laws and Lyapunov stability theory, an adaptive sliding controller is designed to ensure the occurrence of the sliding motion. Finally, numerical simulations are presented to verify the effectiveness and robustness of the proposed method even when both drive and response systems are perturbed with external disturbances.

  20. PID-Type Fuzzy Control for Anti-Lock Brake Systems with Parameter Adaptation

    Science.gov (United States)

    Chen, Chih-Keng; Shih, Ming-Chang

    In this research, a platform is built to accomplish a series of experiments to control the Antilock Brake System (ABS). A commercial ABS module controlled by a controller is installed and tested on the platform. The vehicle and tire models are deduced and simulated by a personal computer for real time control. An adaptive PID-type fuzzy control scheme is used. Two on-off conversion methods: pulse width modulation (PWM) and conditional on-off, are used to control the solenoid valves in the ABS module. With the pressure signal feedbacks in the caliper, vehicle dynamics and wheel speeds are computed during braking. Road surface conditions, vehicle weight and control schemes are varied in the experiments to study braking properties.

  1. Optimizing the Attitude Control of Small Satellite Constellations for Rapid Response Imaging

    Science.gov (United States)

    Nag, S.; Li, A.

    2016-12-01

    Distributed Space Missions (DSMs) such as formation flight and constellations, are being recognized as important solutions to increase measurement samples over space and time. Given the increasingly accurate attitude control systems emerging in the commercial market, small spacecraft now have the ability to slew and point within few minutes of notice. In spite of hardware development in CubeSats at the payload (e.g. NASA InVEST) and subsystems (e.g. Blue Canyon Technologies), software development for tradespace analysis in constellation design (e.g. Goddard's TAT-C), planning and scheduling development in single spacecraft (e.g. GEO-CAPE) and aerial flight path optimizations for UAVs (e.g. NASA Sensor Web), there is a gap in open-source, open-access software tools for planning and scheduling distributed satellite operations in terms of pointing and observing targets. This paper will demonstrate results from a tool being developed for scheduling pointing operations of narrow field-of-view (FOV) sensors over mission lifetime to maximize metrics such as global coverage and revisit statistics. Past research has shown the need for at least fourteen satellites to cover the Earth globally everyday using a LandSat-like sensor. Increasing the FOV three times reduces the need to four satellites, however adds image distortion and BRDF complexities to the observed reflectance. If narrow FOV sensors on a small satellite constellation were commanded using robust algorithms to slew their sensor dynamically, they would be able to coordinately cover the global landmass much faster without compensating for spatial resolution or BRDF effects. Our algorithm to optimize constellation satellite pointing is based on a dynamic programming approach under the constraints of orbital mechanics and existing attitude control systems for small satellites. As a case study for our algorithm, we minimize the time required to cover the 17000 Landsat images with maximum signal to noise ratio fall

  2. Development of a model system for rapid assessment of insect mortality in heated controlled atmosphere quarantine treatments.

    Science.gov (United States)

    Neven, Lisa G

    2008-04-01

    The development of postharvest quarantine treatments can be both expensive and time-consuming. It is necessary to determine the species and stage of the pest most tolerant to the treatment, if more than one species is the target of the treatment. Initial laboratory studies often include infesting the commodity with various egg and larval stages of the pest and performing treatments and evaluations of the fruit. In collaboration with others, I have previously developed combination high temperature under controlled atmosphere treatments against two quarantine pests in apples (Malus spp.) and peaches and nectarines (both Prunus spp.). I decided to develop an artificial system that can be used for these initial tests without the need for infesting large quantities of the fruit. I tested the system on the immature stages of the pests under regular air and controlled atmospheres by using the controlled atmosphere water bath system. This system can be used for rapid assessment of the most tolerant stage and species of a pest to a combination heat and controlled atmosphere treatment without the expense of infesting, treating, and evaluating the commodity.

  3. A Case Study on the Application of a Structured Experimental Method for Optimal Parameter Design of a Complex Control System

    Science.gov (United States)

    Torres-Pomales, Wilfredo

    2015-01-01

    This report documents a case study on the application of Reliability Engineering techniques to achieve an optimal balance between performance and robustness by tuning the functional parameters of a complex non-linear control system. For complex systems with intricate and non-linear patterns of interaction between system components, analytical derivation of a mathematical model of system performance and robustness in terms of functional parameters may not be feasible or cost-effective. The demonstrated approach is simple, structured, effective, repeatable, and cost and time efficient. This general approach is suitable for a wide range of systems.

  4. Ebola virus disease outbreak in Nigeria: Transmission dynamics and rapid control.

    Science.gov (United States)

    Althaus, C L; Low, N; Musa, E O; Shuaib, F; Gsteiger, S

    2015-06-01

    International air travel has already spread Ebola virus disease (EVD) to major cities as part of the unprecedented epidemic that started in Guinea in December 2013. An infected airline passenger arrived in Nigeria on July 20, 2014 and caused an outbreak in Lagos and then Port Harcourt. After a total of 20 reported cases, including 8 deaths, Nigeria was declared EVD free on October 20, 2014. We quantified the impact of early control measures in preventing further spread of EVD in Nigeria and calculated the risk that a single undetected case will cause a new outbreak. We fitted an EVD transmission model to data from the outbreak in Nigeria and estimated the reproduction number of the index case at 9.0 (95% confidence interval [CI]: 5.2-15.6). We also found that the net reproduction number fell below unity 15 days (95% CI: 11-21 days) after the arrival of the index case. Hence, our study illustrates the time window for successful containment of EVD outbreaks caused by infected air travelers. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

  5. Ebola virus disease outbreak in Nigeria: Transmission dynamics and rapid control

    Directory of Open Access Journals (Sweden)

    C.L. Althaus

    2015-06-01

    Full Text Available International air travel has already spread Ebola virus disease (EVD to major cities as part of the unprecedented epidemic that started in Guinea in December 2013. An infected airline passenger arrived in Nigeria on July 20, 2014 and caused an outbreak in Lagos and then Port Harcourt. After a total of 20 reported cases, including 8 deaths, Nigeria was declared EVD free on October 20, 2014. We quantified the impact of early control measures in preventing further spread of EVD in Nigeria and calculated the risk that a single undetected case will cause a new outbreak. We fitted an EVD transmission model to data from the outbreak in Nigeria and estimated the reproduction number of the index case at 9.0 (95% confidence interval [CI]: 5.2–15.6. We also found that the net reproduction number fell below unity 15 days (95% CI: 11–21 days after the arrival of the index case. Hence, our study illustrates the time window for successful containment of EVD outbreaks caused by infected air travelers.

  6. tRNA integrity is a prerequisite for rapid CCA addition: implication for quality control.

    Science.gov (United States)

    Dupasquier, Marcel; Kim, Sangbumn; Halkidis, Konstantine; Gamper, Howard; Hou, Ya-Ming

    2008-06-06

    CCA addition to the 3' end is an essential step in tRNA maturation. High-resolution crystal structures of the CCA enzymes reveal primary enzyme contact with the tRNA minihelix domain, consisting of the acceptor stem and T stem-loop. RNA and DNA minihelices are efficient substrates for CCA addition in steady-state kinetics. However, in contrast to structural models and steady-state experiments, we show here by single-turnover kinetics that minihelices are insufficient substrates for the Escherichia coli CCA enzyme and that only the full-length tRNA is kinetically competent. Even a nick in the full-length tRNA backbone in the T loop, or as far away from the minihelix domain as in the anticodon loop, prevents efficient CCA addition. These results suggest a kinetic quality control provided by the CCA enzyme to inspect the integrity of the tRNA molecule and to discriminate against nicked or damaged species from further maturation.

  7. Adaptive Control for Revolute Joints Robot Manipulator with Uncertain/Unknown Dynamic Parameters and in Presence of Disturbance in Control Input

    DEFF Research Database (Denmark)

    Seyed Sakha, Masoud; Shaker, Hamid Reza

    2017-01-01

    This paper presents an effective adaptive controller for revolute joints robot manipulator where the control input is accompanied with a random disturbance (with unknown PSD). It is clear that, disturbance can compromise the overall performance of the system. To cope with this problem, a control...... technique is proposed which uses the concept of exponential practical stability. Unlike other counterparts, the proposed method does not need information such as the physical parameters of robot and gravitational acceleration. The results show that the proposed controller achieves an excellent performance...

  8. Linear parameter varying control of wind turbines covering both partial load and full load conditions

    DEFF Research Database (Denmark)

    Østergaard, Kasper Zinck; Stoustrup, Jakob; Brath, Per

    2009-01-01

    operations tend to be ill-conditioned. The paper proposes a controller construction algorithm together with various remedies for improving the numerical conditioning the algorithm.The proposed algorithm is applied to the design of a LPV controller for wind turbines, and a comparison is made with a controller...... designed using classical techniques to conclude that an improvement in performance is obtained for the entire operating envelope....

  9. Effect of controlled-release Periochip™ on clinical and microbiological parameters in patients of chronic periodontitis

    Science.gov (United States)

    Puri, Komal; Dodwad, Vidya; Bhat, Kishore; Puri, Nikhil

    2013-01-01

    Background: The aim of the present study was to evaluate and compare the clinical and microbiological effectiveness of Periochip™ as an adjunct to scaling and root planing (SRP) with SRP alone in patients with chronic periodontitis. Materials and Methods: This randomized, split mouth, 3-month clinical and microbiological trial included 30 sites in 15 patients aged 30-50 years diagnosed with chronic periodontitis. In each patient, two bilateral pockets probing 5-7 mm were randomly assigned to test and control groups. The test group received SRP plus Periochip™, whereas the control group received SRP alone. Clinical indices and anaerobic culture analysis was done at baseline, 1 month, and 3 months interval. Total bacterial count and analysis of four major periodontopathogenic bacteria Porphyromonas gingivalis (Pg), Prevotella intermedia (Pi), Aggregatibacter actinomycetemcomitans (Aa), and Fusobacterium nucleatum (Fn) was done. Results: Significant improvement was obtained in all clinical variables in the test group as compared to the control group over the study period. Total colony counts were significantly reduced in the test group as compared to control over the period of time. At baseline Aa was recovered from 4 test group sites and 5 control group sites, Pg from 15 test group and 14 control group sites, Pi from 5 test group and 2 control group sites, Fn from 7 test and 7 control group sites. At 3 months, Aa was recovered from 1 test group and 4 control group sites, Pg from 4 test group and 8 control group sites, Pi from 1 test group and 1 control group site, Fn from 3 test and 4 control group sites. Conclusion: Periochip™ placement as an adjunct to SRP, showed promising results, when compared to SRP alone. Healthy microflora can be maintained for a longer period of time and delay in the repopulation by periodontopathic microorganisms was observed. PMID:24174754

  10. An automated image-based method of 3D subject-specific body segment parameter estimation for kinetic analyses of rapid movements.

    Science.gov (United States)

    Sheets, Alison L; Corazza, Stefano; Andriacchi, Thomas P

    2010-01-01

    Accurate subject-specific body segment parameters (BSPs) are necessary to perform kinetic analyses of human movements with large accelerations, or no external contact forces or moments. A new automated topographical image-based method of estimating segment mass, center of mass (CM) position, and moments of inertia is presented. Body geometry and volume were measured using a laser scanner, then an automated pose and shape registration algorithm segmented the scanned body surface, and identified joint center (JC) positions. Assuming the constant segment densities of Dempster, thigh and shank masses, CM locations, and moments of inertia were estimated for four male subjects with body mass indexes (BMIs) of 19.7-38.2. The subject-specific BSP were compared with those determined using Dempster and Clauser regression equations. The influence of BSP and BMI differences on knee and hip net forces and moments during a running swing phase were quantified for the subjects with the smallest and largest BMIs. Subject-specific BSP for 15 body segments were quickly calculated using the image-based method, and total subject masses were overestimated by 1.7-2.9%.When compared with the Dempster and Clauser methods, image-based and regression estimated thigh BSP varied more than the shank parameters. Thigh masses and hip JC to thigh CM distances were consistently larger, and each transverse moment of inertia was smaller using the image-based method. Because the shank had larger linear and angular accelerations than the thigh during the running swing phase, shank BSP differences had a larger effect on calculated intersegmental forces and moments at the knee joint than thigh BSP differences did at the hip. It was the net knee kinetic differences caused by the shank BSP differences that were the largest contributors to the hip variations. Finally, BSP differences produced larger kinetic differences for the subject with larger segment masses, suggesting that parameter accuracy is more

  11. Controlling Morphological Parameters of Anodized Titania Nanotubes for Optimized Solar Energy Applications

    Directory of Open Access Journals (Sweden)

    Michael Hu

    2012-10-01

    Full Text Available Anodized TiO2 nanotubes have received much attention for their use in solar energy applications including water oxidation cells and hybrid solar cells [dye-sensitized solar cells (DSSCs and bulk heterojuntion solar cells (BHJs]. High surface area allows for increased dye-adsorption and photon absorption. Titania nanotubes grown by anodization of titanium in fluoride-containing electrolytes are aligned perpendicular to the substrate surface, reducing the electron diffusion path to the external circuit in solar cells. The nanotube morphology can be optimized for the various applications by adjusting the anodization parameters but the optimum crystallinity of the nanotube arrays remains to be realized. In addition to morphology and crystallinity, the method of device fabrication significantly affects photon and electron dynamics and its energy conversion efficiency. This paper provides the state-of-the-art knowledge to achieve experimental tailoring of morphological parameters including nanotube diameter, length, wall thickness, array surface smoothness, and annealing of nanotube arrays.

  12. Investigation of parameters controlling the dielectrophoretic assembly of carbon nanotubes on microelectrodes

    DEFF Research Database (Denmark)

    Dimaki, Maria; Bøggild, Peter

    2008-01-01

    Networks of single-walled carbon nanotubes were assembled onto microelectrodes by dielectrophoresis. The dependence of the obtained networks on several assembly parameters such as bias voltage, field application time, frequency, electrode geometry and the nanotube solvent were investigated both...... structurally and electrically. Reproducible differences in morphological and electrical properties were observed for the parameters investigated. Application of a bias voltage above 10 V for more than 30 seconds with nanotubes in an SDS solution, resulted in dense networks with a relatively low resistance...... in the 10 k Omega regime. On the other hand, individual nanotubes and bundles were assembled with lower voltages applied for less than 10 seconds and with other nanotubes solutions. The experimental results were combined with theoretical calculations in order to find a geometry and voltage independent...

  13. Rapid Endolysosomal Escape and Controlled Intracellular Trafficking of Cell Surface Mimetic Quantum-Dots-Anchored Peptides and Glycopeptides.

    Science.gov (United States)

    Tan, Roger S; Naruchi, Kentaro; Amano, Maho; Hinou, Hiroshi; Nishimura, Shin-Ichiro

    2015-09-18

    A novel strategy for the development of a high performance nanoparticules platform was established by means of cell surface mimetic quantum-dots (QDs)-anchored peptides/glycopeptides, which was developed as a model system for nanoparticle-based drug delivery (NDD) vehicles with defined functions helping the specific intracellular trafficking after initial endocytosis. In this paper, we proposed a standardized protocol for the preparation of multifunctional QDs that allows for efficient cellular uptake and rapid escaping from the endolysosomal system and subsequent cytoplasmic molecular delivery to the target cellular compartment. Chemoselective ligation of the ketone-functionalized hexahistidine derivative facilitated both efficient endocytic entry and rapid endolysosomal escape of the aminooxy/phosphorylcholine self-assembled monolayer-coated QDs (AO/PCSAM-QDs) to the cytosol in various cell lines such as human normal and cancer cells, while modifications of these QDs with cell-penetrating arginine-rich peptides showed poor cellular uptake and induced self-aggregation of AO/PCSAM-QDs. Combined use of hexahistidylated AO/PCSAM-QDs with serglycine-like glycopeptides, namely synthetic proteoglycan initiators (PGIs), elicited the entry and controlled intracellular trafficking, Golgi localization, and also excretion of these nanoparticles, which suggested that the present approach would provide an ideal platform for the design of high performance NDD systems.

  14. A randomised controlled trial comparing Rapid Rhino Mannheim and Netcell series 5000 packs following routine nasal surgery.

    Science.gov (United States)

    McDonald, S E; Slater, J; Powell, R; Khalil, H S; Garth, R J N

    2009-03-01

    To determine whether there is a difference in discomfort between Netcell Series 5000 and Rapid Rhino Mannheim 8.0 cm (Cat. No. 800) packs used after routine nasal surgery, whilst in situ and during removal. This was tested in a single blind, randomised controlled trial at the ENT Department, Royal Devon & Exeter Hospital. Adults aged 16-65 undergoing nasal septal surgery and trimming of inferior turbinates. Patients were excluded if they were undergoing revision surgery, taking anticoagulants, or had a history of sino-nasal disease or trauma. Thirty nine entered and 32 completed the study. The intervention was a different nasal pack in each side of the nose, removed the morning after surgery. Pain experienced by patients while packs are in situ and on removal as recorded on a standard unmarked 100 mm visual analogue scale. There was no difference in the pain scores whilst in situ. Rapid Rhino Mannheim was more painful on removal (difference = 10.6 mm, p Mannheim packs do not confer a benefit over Netcell Series 5000 packs after routine nasal surgery.

  15. The largest reference range study for hematological parameters from Turkey: A case control study

    OpenAIRE

    Nilgün Tekkeşin; Hüseyin Bekoz; Faruk Tükenmez

    2015-01-01

    Objectives: Accurate, reliable laboratory reference ranges are essential for effective clinical evaluation and monitoring. We present robust reference ranges established for hematology parameters using the Sysmex XT2000i analyzer. Methods: Blood samples were taken from 17409 healthy adults (19 to 49 years, 51.4% men and 48.6% women) and routine hematology analysis performed. Patients were assessed as healthy on the basis of a medical history and routine medical examinations. Serum hematini...

  16. Ecient Parameter Estimation and Control Based on a Modified LOS Guidance System of an Underwater Vehicle

    Directory of Open Access Journals (Sweden)

    Elías Revestido Herrero

    2017-12-01

    Full Text Available In this work, a methodology is proposed for the improvement of the parameter estimation effciency of a non-linear manoeuvring model of a torpedo shaped unmanned underwater vehicle. For this purpose, data from different tests, were carried out with the aforementioned vehicle at the facilities of the Canal de Experiencias Hidrodinámicas del Pardo, Madrid. In the proposed methodology, the following aspects are taken into account in order to improve the parameter estimation effciency: selection of the sampling period, smoothing of the data acquired in the tests considering a compromise between variance and bias of the smoothing filter to be applied, analysis of the classical linear regression model proposed in each trial, from the statistical point of view for the estimation of the parameters. Improvements in effciency are verified by graphical and statistical methods. In addition, a modification of the conventional LOS method is proposed which provides satisfactory results in the presence of ocean currents by performing a simple procedure.

  17. Control of the parameters of attention in basketball at the stage of preliminary basic preparation

    Directory of Open Access Journals (Sweden)

    Olena Mitova

    2015-10-01

    Full Text Available Purpose: to determine the parameters of attention of basketball players aged 13–14 years old before and after the exercises of various kinds. Material and Methods: the study involved 3 teams of basketball players aged 13–14 years old from training groups. The total number of investigated people is 50. The study was carried out on the basis of Sports Children and Youth Olympic school № 5 in Dnepropetrovsk. We used the methods of theoretical analysis and synthesis of the literature, the method of analysis of documentary materials, pedagogical supervision, psychological testing, pulsometry, methods of mathematical statistics.The following techniques were used to determine the parameters of attention: «Mixed up line», proofreading test with Landoldt rings, proofreading test with letters. Results: during our research there was defined the predominantly low level of attention of basketball players at the stage of preliminary basic preparation. It was found out the specific nature of the load influences the decrease of the parameters in a greater degree, especially concentration, switching, and stability decline, the number of errors increases. Conclusions: on the basis of studies arises the necessity to improve monitoring systems in the Sports Children and Youth schools with usage of tests to determine the components of psychological readiness

  18. Model of parameters controlling resistance of pipeline steels to hydrogen-induced cracking

    KAUST Repository

    Traidia, Abderrazak

    2014-01-01

    NACE MR0175/ISO 15156-2 standard provides test conditions and acceptance criteria to evaluate the resistance of carbon and low-alloy steels to hydrogen-induced cracking (HIC). The second option proposed by this standard offers a large flexibility on the choice of test parameters (pH, H2S partial pressure, and test duration), with zero tolerance to HIC initiation as an acceptance condition. The present modeling work is a contribution for a better understanding on how the test parameters and inclusion size can influence HIC initiation, and is therefore of potential interest for both steel makers and endusers. A model able to link the test operating parameters (pH, partial pressure of H2S, and temperature) to the maximum hydrogen pressure generated in the microstructural defects is proposed. The model results are then used to back calculate the minimum fracture toughness below which HIC extends. A minimum fracture toughness of 400 MPa√mm, at the segregation zone, prevents HIC occurrence and leads to successfully pass the HIC qualification test, even under extreme test conditions. The computed results show that the maximum generated pressure can reach up to 1,500 MPa. The results emphasize that the H2S partial pressure and test temperature can both have a strong influence on the final test results, whereas the influence of the pH of the test solution is less significant. © 2014, NACE International.

  19. CPG-Based Locomotion Control of a Robotic Fish : Using Linear Oscillators and Reducing Control Parameters via PSO

    NARCIS (Netherlands)

    Wang, Chen; Xie, G.; Wang, L.; Cao, M.

    The aim of the present study is to investigate the locomotion control of a robotic fish. To achieve this goal, we design a control architecture based on a novel central pattern generator (CPG) and implement it as a system of coupled linear oscillators. This design differs significantly from the

  20. Parameters Tuning Approach for Proportion Integration Differentiation Controller of Magnetorheological Fluids Brake Based on Improved Fruit Fly Optimization Algorithm

    Directory of Open Access Journals (Sweden)

    Xinhua Liu

    2017-07-01

    Full Text Available In order to improve the response performance of a proportion integration differentiation (PID controller for magnetorheological fluids (MRF brake and to reduce the braking fluctuation rate, an improved fruit fly optimization algorithm for PID controller parameters tuning of MRF brake is proposed. A data acquisition system for MRF brake is designed and the transfer function of MRF brake is identified. Moreover, an improved fruit fly optimization algorithm (IFOA through integration of PID control strategy and cloud model algorithm is proposed to design a PID controller for MRF brake. Finally, the simulation and experiment are carried out. The results show that IFOA, with a faster response output and no overshoot, is superior to the conventional PID and fruit fly optimization algorithm (FOA PID controller.

  1. Optimization of Process Parameters of Edge Robotic Deburring with Force Control

    Directory of Open Access Journals (Sweden)

    Burghardt A.

    2016-12-01

    Full Text Available The issues addressed in the paper present a part of the scientific research conducted within the framework of the automation of the aircraft engine part manufacturing processes. The results of the research presented in the article provided information in which tolerances while using a robotic control station with the option of force control we can make edge deburring.

  2. Optimization of Process Parameters of Edge Robotic Deburring with Force Control

    Science.gov (United States)

    Burghardt, A.; Szybicki, D.; Kurc, K.; Muszyńska, M.

    2016-12-01

    The issues addressed in the paper present a part of the scientific research conducted within the framework of the automation of the aircraft engine part manufacturing processes. The results of the research presented in the article provided information in which tolerances while using a robotic control station with the option of force control we can make edge deburring.

  3. Salivary and microbiological parameters of chronic periodontitis subjects with and without type 2 diabetes mellitus: a case-control study

    Directory of Open Access Journals (Sweden)

    José Roberto CORTELLI

    Full Text Available Background: Several studies have investigated the differences in salivary parameters and microbial composition between diabetic and non-diabetic patients, however, specific differences are still not clear mainly due to the effects of confounder. Aim: The aim of this case-control study was to evaluate the salivary and microbial parameters of chronic periodontitis subjects with and without type 2 diabetes mellitus. Material and method: This case-control study included 60 chronic periodontitis subjects, 30 diabetics (case group and 30 non-diabetics (control group, paired according to periodontitis severity, gender and age. Stimulated whole saliva was collected from all volunteers to measure the salivary pH and the salivary flow rate. Bacterial samples were collected with paper points from periodontal sites showing the deepest periodontal pocket depth associated with the highest clinical attachment loss. The frequency of A. actinomycetemcomitans, P. intermedia, P. gingivalis, T. forsythia and C. rectus was evaluated by PCR. Data was statistically analyzed by Student's t, Mann-Whitney and Chi-square (p<0.05. Result: Diabetic subjects showed higher salivary glucose levels and lower stimulated flow rates in comparison to non-diabetic controls. P. gingivalis and T. forsythia were the most frequent pathogens (p<0.05. Bacterial frequency did not differ between case and control groups. Conclusion: Diabetes status influenced salivary glucose levels and flow rate. Within the same severity of chronic periodontitis, diabetic subjects did not show higher frequency of periodontal pathogens in comparison to their paired controls.

  4. Modelling the Pan-Spectral Energy Distribution of Starburst Galaxies: II. Control of the H II Region Parameters

    Energy Technology Data Exchange (ETDEWEB)

    Dopita, M A; Fischera, J; Sutherland, R S; Kewley, L J; Tuffs, R J; Popescu, C C; van Breugel, W; Groves, B A; Leitherer, C

    2006-03-01

    We examine from a theoretical viewpoint how the physical parameters of H II regions are controlled both in normal galaxies and in starburst environments. These parameters are the H II region luminosity function, the time-dependent size, the covering fraction of molecular clouds, the pressure in the ionized gas and the ionization parameter. The factors which control them are the initial mass function of the exciting stars, the cluster mass function, the metallicity and the mean pressure in the surrounding interstellar medium. We investigate the sensitivity of the H{alpha} luminosity to the IMF, and find that this can translate to about 30% variation in derived star formation rates. The molecular cloud dissipation timescale is estimated from a case study of M17 to be {approx} 1 Myr. Based upon H II luminosity function fitting for nearby galaxies, we propose that the cluster mass function has a log-normal form peaking at {approx} 185M{sub {circle_dot}}. This suggests that the cluster mass function is the continuation of the stellar IMF to higher mass. The pressure in the H II regions is controlled by the mechanical luminosity flux from the central cluster. Since this is closely related to the ionizing photon flux, we show that the ionization parameter is not a free variable, and that the diffuse ionized medium may be composed of many large, faint and old H II regions. Finally, we derive theoretical probability distributions for the ionization parameter as a function of metallicity and compare these to those derived for SDSS galaxies.

  5. Denture-frame modifications in class III patients treated with rapid palatal expansion and facemask: a prospective controlled study.

    Science.gov (United States)

    Migliorati, M; Signori, A; Isaia, L; Menini, A; Rubiano, R; Aonzo, E; Silvestrini Biavati, A

    2015-06-01

    The aim of this prospective controlled investigation was to analyze the short-term cephalometric treatment outcomes, according to the denture frame analysis proposed by Sato, of rapid palatal expansion (RPE) and facial mask (FM) therapy. A group of 21 patients with Class III malocclusion treated with the RPE and FM (TG) was compared with untreated Class III controls (CG). The mean age of treatment group was 8.8 years; treatment consisted of 4 weeks of RPE activation (0.20 mm/die) followed by 14 hours wear of the FM for a mean of 333.1 days. As CG were used the data published by Tanaka and Sato. Pre- and post-treatment cephalometric values were compared and statistical analyzed with one-sample t-test. A P-value plane (POC) values some differences compared to control group were found but they were not statistically significant (P=0.067) while for aterior occlusal plane (POA) no differences where noticed. This study revealed an increase in inter-jaw angle during treatment with FM and RPE, an increase in the inclination of the posterior occlusal plane with respect to the Frankfurt plane and a posterior and lower adaptation of the mandible.

  6. Transverse effects on the nasomaxillary complex one year after rapid maxillary expansion as the only intervention: A controlled study

    Directory of Open Access Journals (Sweden)

    Carolina da Luz Baratieri

    2014-10-01

    Full Text Available The aim of this study was to assess by means of cone-beam computed tomography (CBCT scans the transverse effects on the nasomaxillary complex in patients submitted to rapid maxillary expansion (RME using Haas expander in comparison to untreated individuals. This prospective controlled clinical study assessed 30 subjects (18 boys and 12 girls with mixed dentition and during pubertal growth. The treated group was submitted to RME with Haas expander, retention for six months and a six-month follow-up after removal. The control group matched the treated group in terms of age and sex distribution. CBCT scans were taken at treatment onset and one year after the expander was activated. Maxillary first molars (U6 width, right and left U6 angulation, maxillary alveolar width, maxillary basal width, palatal alveolar width, palatal base width, right and left alveolar angulation, palatal area, nasal base width, nasal cavity width and inferior nasal cavity area on the posterior, middle and anterior coronal slices were measured with Dolphin Imaging Software(r 11.5, except for the first two variables which were performed only on the posterior slice. All transverse dimensions increased significantly (P 0.05. Results suggest that increase of molar, maxillary, palatal and nasal transverse dimensions was stable in comparison to the control group one year after treatment with RME.

  7. Influence of Control Structures and Load Parameters on Performance of a Pseudo Direct Drive

    Directory of Open Access Journals (Sweden)

    Mohammed Bouheraoua

    2014-07-01

    Full Text Available The paper describes an in-depth and systematic analysis of a pseudo direct drive permanent magnet machine in closed loop control. Due to the torque being transmitted from the high-speed rotor (HSR to the low-speed rotor (LSR, through a relatively low stiffness magnetic gear with non-linear characteristics, speed oscillations appear in the drive output with a conventional proportional integral (PI controller. Therefore two candidate controllers have been proposed as an alternative to the PI control and all controllers have been optimally tuned with a genetic algorithm against a defined criterion. Furthermore, closed loop models are established in the complex frequency domain to determine the system damping and the cause of the oscillations. Consequently, the best controller structure that improves the dynamic behaviour of the system in terms of speed tracking and disturbance rejection could be identified, based on the frequency domain analysis. Experimental results are presented to validate the analysis and the proposed control technique.

  8. Parameter Identification of Long Stroke and Short Stroke MR Damper for its Use in Semi-Active Vibration Control

    Science.gov (United States)

    Bharathi Priya, C.; Gopalakrishnan, N.

    2016-12-01

    Magnetorheological (MR) dampers are devices that can be used for structural vibration reduction under seismic excitation. These devices are used in semi-active control which require less power compared to active devices and offer high reliability compared to passive devices. Despite the advantages of MR damper, use of these dampers in an effective way in a structure is highly challenging and a precise modelling is required as these dampers are highly non-linear. Among the parametric models available, Bouc-Wen model is widely used because of its effective modelling of the hysteretic force-velocity curve of MR damper. The parameters of Bouc-Wen model are damper dependent and hence need to be identified before utilising the damper for further simulation studies. In this work, the parametric identification of Bouc-Wen model for commercially available long stroke and short stroke MR damper (RD 8040-1 and RD 8041-1) is done. For this, experimental characterization of the dampers are carried out using hydraulic actuators mounted on a self-restraining frame. The damper is driven harmonically in the testing setup at various combinations of frequency, amplitude, current and displacement. Using the experimental characterization, parameters of Bouc-Wen model are identified by Levenberg-Marquardt optimization Algorithm (LMA). The identified parameters are validated by comparing with the experimental results. The identified parameters are believed to be worthwhile for the use of these MR dampers in further studies of real-time semi-active vibration control of structures.

  9. Assessing the Effects of Urban Morphology Parameters on Microclimate in Singapore to Control the Urban Heat Island Effect

    Directory of Open Access Journals (Sweden)

    Hong Jin

    2018-01-01

    Full Text Available It is important to alleviate the “heat island effect” in urban areas, especially tropical cities. Microclimate is normally affected by the urban morphology parameters. The objective of this work is to investigate the correlation between air temperature variations and urban morphology parameters in tropical cities. Field measurement was carried out to record the air temperature at 27 points within an 8 km2 urban area continuously in Singapore for one year. Geographical information system was applied to extract the urban morphology parameters. Generally, the maximum and minimum air temperature spatial differences in the study area ranged from 3.2 to 6.5 °C, indicating the significant effects of urban morphology on the air temperatures. Based on the fitting results of created multilinear regression models, parametric study has been performed to investigate the specific effects of urban morphology parameters on air temperatures. This work has proposed a much more precise regression model to predict the air temperature with various urban morphology parameters. In addition, meaningful value of reference has been offered for urban planners and landscape designers to effectively control the air temperature in tropical cities such as Singapore.

  10. Optimization of technology and boiler control to improve economical and environmental parameters

    Energy Technology Data Exchange (ETDEWEB)

    Stosek, V.; Neuman, P.; Mechura, V.; Masek, Z. [EGU Prague (Czechoslovakia)

    1995-12-01

    For cutting emissions NO{sub x} and CO in the Czech Republic are mostly applied primary measurers. At the same time measuring and control systems are innovated. Analog control systems are replaced by digital and computer network is developed in the power energy generation. It enables application of sophisticated information and diagnostic systems. It is shown how the EGU designs modification of technology equipment, measurement and control systems to increase efficiency and cut NO{sub x} emission levels at 110 MWe units at Prunerov power station and 200 MWe units at Tusimice before and after reconstruction are presented.

  11. Quantifying Effects of Pharmacological Blockers of Cardiac Autonomous Control Using Variability Parameters.

    Science.gov (United States)

    Miyabara, Renata; Berg, Karsten; Kraemer, Jan F; Baltatu, Ovidiu C; Wessel, Niels; Campos, Luciana A

    2017-01-01

    Objective: The aim of this study was to identify the most sensitive heart rate and blood pressure variability (HRV and BPV) parameters from a given set of well-known methods for the quantification of cardiovascular autonomic function after several autonomic blockades. Methods: Cardiovascular sympathetic and parasympathetic functions were studied in freely moving rats following peripheral muscarinic (methylatropine), β1-adrenergic (metoprolol), muscarinic + β1-adrenergic, α1-adrenergic (prazosin), and ganglionic (hexamethonium) blockades. Time domain, frequency domain and symbolic dynamics measures for each of HRV and BPV were classified through paired Wilcoxon test for all autonomic drugs separately. In order to select those variables that have a high relevance to, and stable influence on our target measurements (HRV, BPV) we used Fisher's Method to combine the p-value of multiple tests. Results: This analysis led to the following best set of cardiovascular variability parameters: The mean normal beat-to-beat-interval/value (HRV/BPV: meanNN), the coefficient of variation (cvNN = standard deviation over meanNN) and the root mean square differences of successive (RMSSD) of the time domain analysis. In frequency domain analysis the very-low-frequency (VLF) component was selected. From symbolic dynamics Shannon entropy of the word distribution (FWSHANNON) as well as POLVAR3, the non-linear parameter to detect intermittently decreased variability, showed the best ability to discriminate between the different autonomic blockades. Conclusion: Throughout a complex comparative analysis of HRV and BPV measures altered by a set of autonomic drugs, we identified the most sensitive set of informative cardiovascular variability indexes able to pick up the modifications imposed by the autonomic challenges. These indexes may help to increase our understanding of cardiovascular sympathetic and parasympathetic functions in translational studies of experimental diseases.

  12. The modern instrumentation used for monitoring and controlling the main parameters of the regenerative electro-mechano-hydraulic drive systems

    Science.gov (United States)

    Cristescu, Corneliu; Drumea, Petrin; Krevey, Petrica

    2009-01-01

    In this work is presented the modern instrumentation used for monitoring and controlling the main parameters for one regenerative drive system, used to recovering the kinetic energy of motor vehicles, lost in the braking phase, storing and using this energy in the starting or accelerating phases. Is presented a Romanian technical solution for a regenerative driving system, based on a hybrid solution containing a hydro-mechanic module and an existing thermal motor drive, all conceived as a mechatronics system. In order to monitoring and controlling the evolution of the main parameters, the system contains a series of sensors and transducers that provide the moment, rotation, temperature, flow and pressure values. The main sensors and transducers of the regenerative drive system, their principal features and tehnical conecting solutions are presented in this paper, both with the menaging electronic and informational subsystems.

  13. Analysis of influence on back-EMF based sensorless control of PMSM due to parameter variations and measurement errors

    DEFF Research Database (Denmark)

    Wang, Z.; Lu, K.; Ye, Y.

    2011-01-01

    and flux saturation, current and voltage errors due to measurement uncertainties, and signal delay caused by hardwares. This paper reveals some inherent principles for the performance of the back-EMF based sensorless algorithm embedded in a surface mounted PMSM system adapting vector control strategy......To achieve better performance of sensorless control of PMSM, a precise and stable estimation of rotor position and speed is required. Several parameter uncertainties and variable measurement errors may lead to estimation error, such as resistance and inductance variations due to temperature......, gives mathematical analysis and experimental results to support the principles, and quantify the effects of each. It may be a guidance for designers to minify the estimation error and make proper on-line parameter estimations....

  14. Determination of combined hardening material parameters under strain controlled cyclic loading by using the genetic algorithm method

    Energy Technology Data Exchange (ETDEWEB)

    Badnava, H. [Islamic Azad Univ., Ahvaz (Iran, Islamic Republic of); Pezeshki, S. M.; Fallah Najad, Kh.; Farhoudi, H. R. [Bu Ali Sina Univ., Hamedan (Iran, Islamic Republic of)

    2012-10-15

    In this paper, experimental and numerical investigations on mechanical behaviors of SS304 stainless steel under fully reversed straincontrolled, relaxation, ratcheting and multiple step strain-controlled cyclic loading have been performed. The kinematic and isotropic hardening theories based on the Chaboche model are used to predict the plastic behavior. An iterative method is utilized to analyze the mechanical behavior under cyclic loading conditions based on the Chaboche hardening model. A set of kinematic and isotropic parameters was obtained by using the genetic algorithm optimization approach. In order to analyze the effectiveness of this optimization procedure, numerical and experimental results for an SS304 stainless steel are compared. Finally, the results of this research show that by using the material parameters optimized based on the strain controlled and relaxation data, good agreement with the experimental data for ratcheting is achieved.

  15. Optimization of the Process Parameters for Controlling Residual Stress and Distortion in Friction Stir Welding

    DEFF Research Database (Denmark)

    Tutum, Cem Celal; Schmidt, Henrik Nikolaj Blicher; Hattel, Jesper Henri

    2008-01-01

    , is investigated. The welding process is simulated in 2-dimensions with a sequentially coupled transient thermo-mechanical model using ANSYS. The numerical optimization problem is implemented in modeFRONTIER and solved using the Multi-Objective Genetic Algorithm (MOGA-II). An engineering-wise evaluation or ranking......In the present paper, numerical optimization of the process parameters, i.e. tool rotation speed and traverse speed, aiming minimization of the two conflicting objectives, i.e. the residual stresses and welding time, subjected to process-specific thermal constraints in friction stir welding...

  16. CONTROL PARAMETERS FOR UNDERSTANDING AND PREVENTING PROCESS IMBALANCES IN BIOGAS PLANTS. EMPHAS IS ON VFA DYNAMICS

    DEFF Research Database (Denmark)

    Bangsø Nielsen, Henrik

    H. The experiments were carried out in lab-scale thermophilic continuously stirred tank reactors (CSTR) treating livestock waste. The imbalances included inhibition by long chain fatty acids (LCFA), inhibition by ammonia, organic overloading with proteins and organic overloading with industrial waste, i.e. meat...... and bone meal and lipids. During the main part of the experiments one reactor was connected to an online VFA sensor giving a detailed profile of the VFA dynamics during the process imbalances. Based on the results it was concluded, that propionate was the most reliable single parameter for indication...

  17. Mixed H2/H(infinity)-Control with an output-feedback compensator using parameter optimization

    Science.gov (United States)

    Schoemig, Ewald; Ly, Uy-Loi

    1992-01-01

    Among the many possible norm-based optimization methods, the concept of H-infinity optimal control has gained enormous attention in the past few years. Here the H-infinity framework, based on the Small Gain Theorem and the Youla Parameterization, effectively treats system uncertainties in the control law synthesis. A design approach involving a mixed H(sub 2)/H-infinity norm strives to combine the advantages of both methods. This advantage motivates researchers toward finding solutions to the mixed H(sub 2)/H-infinity control problem. The approach developed in this research is based on a finite time cost functional that depicts an H-infinity bound control problem in a H(sub 2)-optimization setting. The goal is to define a time-domain cost function that optimizes the H(sub 2)-norm of a system with an H-infinity-constraint function.

  18. Mixed H(2)/H(sub infinity): Control with output feedback compensators using parameter optimization

    Science.gov (United States)

    Schoemig, Ewald; Ly, Uy-Loi

    1992-01-01

    Among the many possible norm-based optimization methods, the concept of H-infinity optimal control has gained enormous attention in the past few years. Here the H-infinity framework, based on the Small Gain Theorem and the Youla Parameterization, effectively treats system uncertainties in the control law synthesis. A design approach involving a mixed H(sub 2)/H-infinity norm strives to combine the advantages of both methods. This advantage motivates researchers toward finding solutions to the mixed H(sub 2)/H-infinity control problem. The approach developed in this research is based on a finite time cost functional that depicts an H-infinity bound control problem in a H(sub 2)-optimization setting. The goal is to define a time-domain cost function that optimizes the H(sub 2)-norm of a system with an H-infinity-constraint function.

  19. Control and Estimation of Distributed Parameter Systems. Volume 126, International Conference in Vorau (Austria)

    Science.gov (United States)

    1998-01-01

    E.: Controlabilite approchee de l’equation de la chaleur semi-lineaire. C. R. Acad. Sei. Paris, t. 315, Serie I, pp. 807-812, (1992). J.I. Diaz and...iden- tification problem is formulated as an optimal control problem where the unknown heat exchange function plays the part of the control. The...34). For practical applications it is often easy to bound the maximal growth of the heat exchange coefficient with respect to the temperature. The

  20. Adaptive control and parameter identification of a doubly-fed induction generator for wind power

    OpenAIRE

    Orfanos-Pepainas, Stamatios

    2011-01-01

    Approved for public release; distribution is unlimited. The use of Doubly-Fed Induction Generators (DFIG) for wind energy conversion is addressed in this thesis. It is well known that when the stator is connected to the electric grid, the rotor voltage can control both mechanical torque and reactive electric power. To guarantee efficient wind energy conversion, it is important to research and design more advanced control schemes. In this thesis, we first review the basic theory behind ...