WorldWideScience

Sample records for external control parameter

  1. Adaptive Sliding Mode Control of a 6-DOF RLED Robot Manipulator with Uncertain Parameters and External Disturbances

    Directory of Open Access Journals (Sweden)

    Isro Hutama

    2016-03-01

    Full Text Available This paper addresses the end-effector position and orientation tracking problem of a 6-degrees of freedom (DOF rigid link electrically driven (RLED revolute joint serial robot manipulator with uncertain parameters and external disturbances. System uncertainties and external disturbances are bounded but their upper limits are unknown. The input matrix, which is always invertible and not necessarily a diagonal matrix, is also assumed to be uncertain with a certain bound. An adaptive sliding mode control (ASMC is designed to solve the tracking problem given these uncertainties. Note that the designed control method can be applied to any RLED serial robot manipulator. No regression matrices are required and the uncertainty upper limits are not necessarily known. Furthermore, the controller computation time can be reduced by considering some parts of the system dynamics and the nth time-derivative reference signals of nth order system, in this case desired joint jerk signals, as unknown bounded uncertainties. The desired trajectory is defined in operational space while the designed ASMC works in joint space. The methods to convert the end-effector pose, velocity, acceleration, and jerk from operational space to joint space are also explained. The Lyapunov stability criterion is applied to prove the convergence of the adaptive gain of ASMC, the sliding surface, and system stability. Finally, simulation results verified ASMC performance.

  2. Thermodynamic cost of external control

    Science.gov (United States)

    Barato, Andre C.; Seifert, Udo

    2017-07-01

    Artificial molecular machines are often driven by the periodic variation of an external parameter. This external control exerts work on the system of which a part can be extracted as output if the system runs against an applied load. Usually, the thermodynamic cost of the process that generates the external control is ignored. Here, we derive a refined second law for such small machines that include this cost, which is, for example, generated by free energy consumption of a chemical reaction that modifies the energy landscape for such a machine. In the limit of irreversible control, this refined second law becomes the standard one. Beyond this ideal limiting case, our analysis shows that due to a new entropic term unexpected regimes can occur: the control work can be smaller than the extracted work and the work required to generate the control can be smaller than this control work. Our general inequalities are illustrated by a paradigmatic three-state system.

  3. Stochastic Control - External Models

    DEFF Research Database (Denmark)

    Poulsen, Niels Kjølstad

    2005-01-01

    This note is devoted to control of stochastic systems described in discrete time. We are concerned with external descriptions or transfer function model, where we have a dynamic model for the input output relation only (i.e.. no direct internal information). The methods are based on LTI systems...

  4. Supervised Online Adaptive Control of Inverted Pendulum System Using ADALINE Artificial Neural Network with Varying System Parameters and External Disturbance

    Directory of Open Access Journals (Sweden)

    Sudeep Sharma

    2012-07-01

    Full Text Available Generalized Adaptive Linear Element (GADALINE Artificial Neural Network (ANN as an Artificial Intelligence (AI technique is used in this paper to online adaptive control of a Non-linear Inverted Pendulum (IP system. The ANN controller is designed with specifications as: network type is three (Input, Hidden and Output layered Feed-Forward Network (FFN, training is done by Widrow-Hoffs delta rule or Least Mean Square algorithm (LMS, that updates weight and bias states to minimize the error function. The research is focused on how to adapt the control actions to solve the problem of “parameter variations”. The method is applied to the Nonlinear IP model with the application of some uncertainties, and the experimental results show that the system responds very well to handle those uncertainties.

  5. External synchronization of two dynamical systems with uncertain parameters

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    External synchronization is addressed as two or more dynamical systems with synchronous motions,which is also regarded as master-slave system.In this paper,two dynamical systems,one employs a hysteretic term to model the friction phenomenon,the other involves a hardening stiffness component with the third order of displacement due to flexible deformation,are controlled to converge to the same trajectory.The control strategy is extended from feedback control for all parameters known to adaptive control for linear parameters unknown and all parameters unknown.The slave system can keep synchronous motions with the movements of master via the designed control strategy even all the parameters are not known.The stability of synchronization error,the transient process into synchronization and the effects of parameters on the designed controller using different control strategies are investigated.The simulation results unfold the feasibility and effectiveness of this synchronization method.

  6. Investigation of Inlet Control Parameters for an External-internal-compression Inlet from Mach 2.1 to 3.0

    Science.gov (United States)

    Anderson, B. H.; Bowditch, D. N.

    1958-01-01

    Investigation of the control parameters of an external-internal compression inlet indicates that the cowl-lip shock provides a signal to position the spike and to start the inlet over a Mach number range from 2.1 to 3.0. Use of a single fixed probe position to control the spike over the range of conditions resulted in a 3.7-count loss in total-pressure recovery at Mach 3.0 and 0 deg angle of attack. Three separate shock-sensing-probe positions were required to set the spike for peak recovery from Mach 2.1 to 3.0 and angles of attack from 0 deg to 6 deg. When the inlet was unstarted, an erroneous signal was obtained from the normal-shock control through most of the starting cycle that prevented the inlet from starting. Therefore, it was necessary to over-ride the normal-shock control signal and not allow the control to position the terminal shock until the spike was positioned.

  7. Control of External Kink Instability

    Science.gov (United States)

    Navratil, Gerald

    2004-11-01

    A fundamental pressure and current limiting phenomenon in magnetically confined plasmas for fusion energy is the long wavelength ideal-MHD kink mode. These modes have been extensively studied in tokamak and reversed field pinch (RFP) devices. They are characterized by significant amplitude on the boundary of the confined plasma and can therefore be controlled by manipulation of the external boundary conditions. In the past ten years, the theoretically predicted stabilizing effect of a nearby conducting wall has been documented in experiments, which opens the possibility of a significant increase in maximum stable plasma pressure. While these modes are predicted to remain unstable when the stabilizing wall is resistive, their growth rates are greatly reduced from the hydrodynamic time scale to the time scale of magnetic diffusion through the resistive wall. These resistive wall slowed kink modes have been identified as limiting phenomena in tokamak (DIII-D, PBX-M, HBT-EP, JT-60U, JET, NSTX) and RFP (HBTX, Extrap, T2R) devices. The theoretical prediction of stabilization to nearly the ideal wall pressure limit by toroidal plasma rotation and/or active feedback control using coils has recently been realized experimentally. Sustained, stable operation at double the no-wall pressure limit has been achieved. Discovery of the phenomenon of resonant field amplification by marginally stable kink modes and its role in the momentum balance of rotationally stabilized plasmas has emerged as a key feature. A theoretical framework, based on an extension of the very successful treatment of the n=0 axisymmetric mode developed in the early 1990's, to understand the stabilization mechanisms and model the performance of active feedback control systems is now established. This allows design of kink control systems for burning plasma experiments like ITER.

  8. [External respiration parameters in workers engaged in synthetic detergents production].

    Science.gov (United States)

    Makhon'ko, M N; Trubetskov, A D

    2005-01-01

    The study covers results of thorough clinical and functional examination of workers engaged into contemporary chemical production. The authors studied effects caused in immunity parameters, respiratory organs and skin by sensitizing and irritating chemicals. Findings are that the most significant changes in external respiration parameters and high predisposition to respiratory diseases are associated with specific sensitizing to industrial allergen and with higher IgE levels.

  9. Synchronization of chaotic VCSELs by external chaotic signal parameter modulation

    Institute of Scientific and Technical Information of China (English)

    Wei Wang; Shenghai Zhang; Xingzhong Qian; Yanbin Wang

    2009-01-01

    Synchronization of chaotic vertical-cavity surface-emitting lasers (VCSELs) is achieved by external chaotic signal modulation successfully.Simulation indicates that we can get chaos synchronization if the intensity of external chaotic signal is large enough.First of all,we use direct current modulation to achieve the chaos of VCSELs,and determine the laser's chaotic state by analyzing time series of the output and the corresponding power spectrum.And then we achieve synchronization of the two chaotic systems by external chaotic signal parameter modulation.We also find that the larger the modulation intensity is,the easier it is to achieve synchronization for chaotic VCSELs.This approach can also be applied to systems with a number of modulated lasers.

  10. Externality and locus of control in obese children.

    Science.gov (United States)

    Isbitsky, J R; White, D R

    1981-03-01

    Fifty-nine obese and normal-weight children, aged 8-12 years were compared on two dimensions of "externality," previously examined in obese adults. Significant sex difference indicated that boys generally ate more than girls and held more internal locus of control expectancies. However, obese and normal-weight children were not differentiated by their performance on either a food-related or three nonfood-related measures of external-cue responsiveness, nor by their locus of control expectancies. Furthermore, the various measures were neither strongly nor consistently intercorrelated, providing little support for the notion of a single underlying dimension of "externality." The contribution of physiological, sensory, cognitive-motivational, and sociocultural parameters to the regulation of eating behavior was discussed.

  11. Antisynchronization of a novel hyperchaotic system with parameter mismatch and external disturbances

    Indian Academy of Sciences (India)

    Fei Yu; Chun Hua Wang; Yan Hu; Jin Wen Yin

    2012-07-01

    A novel hyperchaotic system is proposed. It is particularly interesting that the hyperchaotic system has a nonlinear term in the form of an exponential function and has onle one equilibrium. Basic dynamical properties of the hyperchaotic system are investigated. Moreover, antisynchronization of the new hyperchaotic system with parameter mismatch and external disturbances is also studied in this paper by using adaptive control. Numerical simulation results further demonstrate that the proposed methods are effective and robust.

  12. External Cylindrical Nozzle with Controlled Vacuum

    Directory of Open Access Journals (Sweden)

    V. N. Pil'gunov

    2015-01-01

    Full Text Available There is a developed design of the external cylindrical nozzle with a vacuum camera. The paper studies the nozzle controllability of flow rate via regulated connection of the evacuated chamber to the atmosphere through an air throttle. Working capacity of the nozzle with inlet round or triangular orifice are researched. The gap is provided in the nozzle design between the external wall of the inlet orifice and the end face of the straight case in the nozzle case. The presented mathematical model of the nozzle with the evacuated chamber allows us to estimate the expected vacuum amount in the compressed section of a stream and maximum permissible absolute pressure at the inlet orifice. The paper gives experimental characteristics of the fluid flow process through the nozzle for different values of internal diameter of a straight case and an extent of its end face remoteness from an external wall of the inlet orifice. It estimates how geometry of nozzle constructive elements influences on the volume flow rate. It is established that the nozzle capacity significantly depends on the shape of inlet orifice. Triangular orifice nozzles steadily work in the mode of completely filled flow area of the straight case at much more amounts of the limit pressure of the flow. Vacuum depth in the evacuated chamber also depends on the shape of inlet orifice: the greatest vacuum is reached in a nozzle with the triangular orifice which 1.5 times exceeds the greatest vacuum with the round orifice. Possibility to control nozzle capacity through the regulated connection of the evacuated chamber to the atmosphere was experimentally estimated, thus depth of flow rate regulation of the nozzle with a triangular orifice was 45% in comparison with 10% regulation depth of the nozzle with a round orifice. Depth of regulation calculated by a mathematical model appeared to be much more. The paper presents experimental dependences of the flow coefficients of nozzle input orifice

  13. External quality control for embryology laboratories.

    Science.gov (United States)

    Castilla, Jose Antonio; Ruiz de Assín, Rafael; Gonzalvo, Maria Carmen; Clavero, Ana; Ramírez, Juan Pablo; Vergara, Francisco; Martínez, Luis

    2010-01-01

    Participation in external quality control (EQC) programmes is recommended by various scientific societies. Results from an EQC programme for embryology laboratories are presented. This 5-year programme consisted of the annual delivery of (i) materials to test toxicity and (ii) a DVD/CD-ROM with images of zygotes and embryos on days 2 and 3, on the basis of which the participants were asked to judge the embryo quality and to take a clinical decision. A high degree of agreement was considered achieved when over 75% of the laboratories produced similar classifications. With respect to the materials analysed, the specificity was 68% and the sensitivity was 83%. Concerning embryo classification, the proportion of embryos on which a high degree of agreement was achieved increased during this period from 35% to 55%. No improvement was observed in the degree of agreement on the clinical decision to be taken. Day-3 embryos produced a higher degree of agreement (58%) than did day-2 embryos (32%) (Pembryology laboratories.

  14. Sensitivity of detachment extent to magnetic configuration and external parameters

    Science.gov (United States)

    Lipschultz, Bruce; Parra, Felix I.; Hutchinson, Ian H.

    2016-05-01

    Divertor detachment may be essential to reduce heat loads to magnetic fusion tokamak reactor divertor surfaces. Yet in experiments it is difficult to control the extent of the detached, low pressure, plasma region. At maximum extent the front edge of the detached region reaches the X-point and can lead to degradation of core plasma properties. We define the ‘detachment window’ in a given position control variable C (for example, the upstream plasma density) as the range in C within which the front location can be stably held at any position from the target to the X-point; increased detachment window corresponds to better control. We extend a 1D analytic model [1] to determine the detachment window for the following control variables: the upstream plasma density, the impurity concentration and the power entering the scrape-off layer (SOL). We find that variations in magnetic configuration can have strong effects; increasing the ratio of the total magnetic field at the X-point to that at the target, {{B}×}/{{B}t} , (total flux expansion, as in the super-x divertor configuration) strongly increases the detachment window for all control variables studied, thus strongly improving detachment front control and the capability of the divertor plasma to passively accommodate transients while still staying detached. Increasing flux tube length and thus volume in the divertor, through poloidal flux expansion (as in the snowflake or x-divertor configurations) or length of the divertor, also increases the detachment window, but less than the total flux expansion does. The sensitivity of the detachment front location, z h , to each control variable, C, defined as \\partial {{z}h}/\\partial C , depends on the magnetic configuration. The size of the radiating volume and the total divertor radiation increase \\propto {{≤ft({{B}×}/{{B}t}\\right)}2} and \\propto {{B}×}/{{B}t} , respectively, but not by increasing divertor poloidal flux expansion or field line length. We

  15. Spectral control of diode lasers using external waveguide circuits

    NARCIS (Netherlands)

    Oldenbeuving, Ruud

    2013-01-01

    We investigated spectral control of diode lasers using external waveguide circuits. The purpose of this work is to investigate such external control for providing a new class of diode lasers with technologically interesting properties, such as a narrow spectral bandwidth and spectrally tunable

  16. Spectral control of diode lasers using external waveguide circuits

    NARCIS (Netherlands)

    Oldenbeuving, R.M.

    2013-01-01

    We investigated spectral control of diode lasers using external waveguide circuits. The purpose of this work is to investigate such external control for providing a new class of diode lasers with technologically interesting properties, such as a narrow spectral bandwidth and spectrally tunable outpu

  17. EXTERNAL AND INTERNAL CONTROL IN PLANT DEVELOPMENT

    Institute of Scientific and Technical Information of China (English)

    Beáta Oborny

    2003-01-01

    Bodies of plants are modularly organized. Development proceeds by adding new modules to open endings with a potential for branching. Each module is autonomous to some extent. Development relies on the self-organized patterns that emerge from the interactions of individual modules. Interactions include both competition and cooperation, and several types of positive and negative feedback loops are involved. Development can be open to external influences, thus enabling the plant to adjust its form to the environment, for example, to the spatial distribution of ecological resources. This paper provides a review on adaptive plasticity in plants.

  18. External production and control of electrojet irregularities.

    Science.gov (United States)

    Lee, K.; Kaw, P. K.; Kennel, C. F.

    1972-01-01

    Analytical investigation of parametric coupling of a large-amplitude 'pump' wave to a natural plasma mode of the ionospheric E layer. It is shown that the E layer plasma mode can be either stabilized or destabilized by the parametric process. Two necessary conditions for parametric interaction are (1) near frequency matching (i.e., the pump wave frequency should be near the local upper hybrid frequency) and (2) a finite electric field component of the pump wave perpendicular to the background static magnetic field. An investigation of the propagation characteristics of the pump wave in the magnetic equatorial region indicates that an obliquely propagating O mode in the magnetic meridian plane meets the two necessary conditions in an optimal manner. From typical values of ionospheric parameters it is estimated that the required incident energy flux of the pump wave for parametric stabilization or destabilization of the E layer plasma mode (near its natural marginal stability) is much less than 1 mW/sq m. Thus parametric coupling experiments for the ionospheric E layer are technically feasible.

  19. Location of external state financial control in national control system of Ukraine

    National Research Council Canada - National Science Library

    N.G. Vygovska; A.Y. Slavitska

    2016-01-01

    The article estimates the theoretical basis of the external state financial control in Ukraine in the context of defining its place in the formation of the functional areas of internal and external...

  20. 49 CFR 192.463 - External corrosion control: Cathodic protection.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false External corrosion control: Cathodic protection. 192.463 Section 192.463 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) PIPELINE SAFETY TRANSPORTATION OF NATURAL AND OTHER GAS...

  1. Noise-spectroscopy of multiqubit systems: Determining all their parameters by applying an external classical noise

    Energy Technology Data Exchange (ETDEWEB)

    Savel' ev, S., E-mail: S.Saveliev@lboro.ac.uk [Department of Physics, Loughborough University, Leicestershire LE11 3TU (United Kingdom); Advanced Science Institute, RIKEN, Wako-shi, Saitama 351-0198 (Japan); Zagoskin, A.M. [Department of Physics, Loughborough University, Leicestershire LE11 3TU (United Kingdom); Advanced Science Institute, RIKEN, Wako-shi, Saitama 351-0198 (Japan); Omelyanchouk, A.N. [Advanced Science Institute, RIKEN, Wako-shi, Saitama 351-0198 (Japan); B. Verkin Institute for Low Temperature Physics and Engineering, 61103 Kharkov (Ukraine); Nori, Franco [Advanced Science Institute, RIKEN, Wako-shi, Saitama 351-0198 (Japan); Physics Department, University of Michigan, Ann Arbor, MI 48109-1040 (United States)

    2010-10-05

    Imagine that you have several sets of two coupled qubits, but you do not know the parameters of their Hamitonians. How to determine these without resorting to the usual spectroscopy approach to the problem? Based on numerical modeling, we show that all the parameters of a system of two coupled qubits can be determined by applying to it an external classical noise and analyzing the Fourier spectrum of the elements of the system's density matrix. In particular, the interlevel spacings as well as the strength and sign of the qubit-qubit coupling can be determined this way.

  2. Location of external state financial control in national control system of Ukraine

    Directory of Open Access Journals (Sweden)

    N.G. Vygovska

    2016-12-01

    Full Text Available The article estimates the theoretical basis of the external state financial control in Ukraine in the context of defining its place in the formation of the functional areas of internal and external controls in order to eliminate duplication of a single national control system. The authors have investigated the scientific approaches to the interpretation of the concept of «external state financial control», «internal financial control», «public audit» in order to eliminate terminological confusion. It were found the differences between the external and internal financial control on the basis of comparative characteristics of such features as the entity controlling entities, controlled objects, object methods, and direction control. The concept of internal and external controls are considered to expedient to communicate with the system in which this control is identified. «Internal» in this case is identical intra-control, that is located within the executive branch, while an external control is not included in it and is external to the executive bodies of the controlled institution, and is not related to them and, as a consequence, independent. The authors suggest to form a unified system of state financial control, a clear distinction between internal and external powers of species. The authors consider that appropriate in this context will be the adoption of a single legislative act «About State Financial Control», the proposed structure is introduced in the article. Implementation of this law will contribute to the clear division of functional areas of the state control (internal and external, the elimination of departmental conflicts, and promote the formation of a single integrated control system in Ukraine, able to counteract abuses and prevent the possible loss of budgetary funds.

  3. Distributed Time-Varying Formation Robust Tracking for General Linear Multiagent Systems With Parameter Uncertainties and External Disturbances.

    Science.gov (United States)

    Hua, Yongzhao; Dong, Xiwang; Li, Qingdong; Ren, Zhang

    2017-05-18

    This paper investigates the time-varying formation robust tracking problems for high-order linear multiagent systems with a leader of unknown control input in the presence of heterogeneous parameter uncertainties and external disturbances. The followers need to accomplish an expected time-varying formation in the state space and track the state trajectory produced by the leader simultaneously. First, a time-varying formation robust tracking protocol with a totally distributed form is proposed utilizing the neighborhood state information. With the adaptive updating mechanism, neither any global knowledge about the communication topology nor the upper bounds of the parameter uncertainties, external disturbances and leader's unknown input are required in the proposed protocol. Then, in order to determine the control parameters, an algorithm with four steps is presented, where feasible conditions for the followers to accomplish the expected time-varying formation tracking are provided. Furthermore, based on the Lyapunov-like analysis theory, it is proved that the formation tracking error can converge to zero asymptotically. Finally, the effectiveness of the theoretical results is verified by simulation examples.

  4. Clinical evaluation of nares-vocal cord distance and its correlation with various external body parameters

    Directory of Open Access Journals (Sweden)

    Bhuwan Sareen

    2015-01-01

    Full Text Available Background and Aims: The optimal visualisation of vocal cords during fibreoptic intubation may be utilised for the nares-vocal cord distance (NVD estimation. The present study was conducted to measure NVD and to correlate with various external body parameters. Methods: This study was conducted on 50 males and 50 females. We measured NVD and analysed its relationship with height, nares to tragus of ear distance (NED, nares to angle of mandible distance (NMD, sternal length (SL, thyro-mental distance (TMD, sterno-mental distance (SMD and arm span (AS. Results: The mean NVD of the males was 18.5 ± 1.5 cm, and that of the females was 15.9 ± 1.1 cm. The relationship between the NVD and body height (males P = 0.001, r = 0.463, females P = 0.000, r = 0.555, SL (males P = 0.000, r = 0.463, females P < 0.000, r = 0.801 or AS (males P = 0.000, r = 0.561, females P = 0.000, r = 0.499 showed a significant correlation but NED, NMD, TMD, SMD did not. After combining male and female groups, (n = 100, the correlation of NVD with external body parameters is as follows SL (r = 0.887, height (r = 0.791, AS (r = 0.769, weight (r = 0.531, SMD (r = 0.466, NED (r = 0.459, NMD (r = 0.391, TMD (r = 0.379. Conclusion: The relationship of NVD to external body parameters had strong correlation in all parameters in the combined group; whereas when gender was taken into consideration NVD correlated significantly only with SL, height and AS.

  5. Design of control systems with uncertain parameters

    Science.gov (United States)

    Auslander, D. M.; Spear, R. C.; Young, G. E.

    1981-01-01

    A design method for control systems with uncertain parameters is presented. The method utilizes a generalized sensitivity approach which separates the parameter space into regions which produce a system response that satisfies given design criteria and regions which do not. Nonparametric statistics and confidence limits for the binomial distribution are used to determine degree of parameter sensitivity and to locate regions in the parameter space which maximize the probability of producing a desirable system response. In an example it is shown that a given parameter may have to be known to a lesser degree of uncertainty to be able to specify a satisfactory design.

  6. External control of the GAL network in S. cerevisiae: a view from control theory.

    Directory of Open Access Journals (Sweden)

    Ruoting Yang

    Full Text Available While there is a vast literature on the control systems that cells utilize to regulate their own state, there is little published work on the formal application of control theory to the external regulation of cellular functions. This paper chooses the GAL network in S. cerevisiae as a well understood benchmark example to demonstrate how control theory can be employed to regulate intracellular mRNA levels via extracellular galactose. Based on a mathematical model reduced from the GAL network, we have demonstrated that a galactose dose necessary to drive and maintain the desired GAL genes' mRNA levels can be calculated in an analytic form. And thus, a proportional feedback control can be designed to precisely regulate the level of mRNA. The benefits of the proposed feedback control are extensively investigated in terms of stability and parameter sensitivity. This paper demonstrates that feedback control can both significantly accelerate the process to precisely regulate mRNA levels and enhance the robustness of the overall cellular control system.

  7. External control of the GAL network in S. cerevisiae: a view from control theory.

    Science.gov (United States)

    Yang, Ruoting; Lenaghan, Scott C; Wikswo, John P; Zhang, Mingjun

    2011-04-29

    While there is a vast literature on the control systems that cells utilize to regulate their own state, there is little published work on the formal application of control theory to the external regulation of cellular functions. This paper chooses the GAL network in S. cerevisiae as a well understood benchmark example to demonstrate how control theory can be employed to regulate intracellular mRNA levels via extracellular galactose. Based on a mathematical model reduced from the GAL network, we have demonstrated that a galactose dose necessary to drive and maintain the desired GAL genes' mRNA levels can be calculated in an analytic form. And thus, a proportional feedback control can be designed to precisely regulate the level of mRNA. The benefits of the proposed feedback control are extensively investigated in terms of stability and parameter sensitivity. This paper demonstrates that feedback control can both significantly accelerate the process to precisely regulate mRNA levels and enhance the robustness of the overall cellular control system.

  8. A 5-M approach to control external pipeline corrosion

    Energy Technology Data Exchange (ETDEWEB)

    Papavinasam, S.; Doiron, A. [Natural Resources Canada, Ottawa, ON (Canada). CANMET Materials Technology Laboratory

    2009-07-01

    The application of polymeric coatings and cathodic protection (CP) are the general methods of controlling external corrosion of pipelines. Since many pipelines are being operated beyond their original design span, several methods are used to assess their integrity, such as inline inspection (ILI), hydrostatic testing and direct assessment (DA). The 5-M approach to controlling external pipeline corrosion combines the strengths of various methodologies to overcome the weaknesses in any one approach. The 5-M approach includes mitigation, modeling, monitoring, maintenance and management. This paper described the procedures and practices of the 5Ms. The 5-M approach is useful in developing an effective integrity management program by identifying susceptible conditions under which coating deterioration may occur, by establishing priorities for repair or replacement, and by protecting the environment from pipeline leakage and ruptures. A freeware software program has been developed to coordinate various activities of the 5-M approach. The 5-M approach complements the external corrosion direct assessment (ECDA) process of the National Association of Corrosion Engineers (NACE), and provides quantitative scores to the ECDA data. 24 refs., 4 tabs., 2 figs.

  9. Adaptive control of an active magnetic bearing with external disturbance.

    Science.gov (United States)

    Dong, Lili; You, Silu

    2014-09-01

    Adaptive back stepping control (ABC) is originally applied to a linearized model of an active magnetic bearing (AMB) system. Our control goal is to regulate the deviation of the magnetic bearing from its equilibrium position in the presence of an external disturbance and system uncertainties. Two types of ABC methods are developed on the AMB system. One is based on full state feedback, for which displacement, velocity, and current states are assumed available. The other one is adaptive observer based back stepping controller (AOBC) where only displacement output is measurable. An observer is designed for AOBC to estimate velocity and current states of AMB. Lyapunov approach proves the stabilities of both regular ABC and AOBC. Simulation results demonstrate the effectiveness and robustness of two controllers. Copyright © 2013 ISA. Published by Elsevier Ltd. All rights reserved.

  10. Behaviour of the order parameter of the simple magnet in an external field

    Directory of Open Access Journals (Sweden)

    M.P.Kozlovskii

    2005-01-01

    Full Text Available The effect of a homogeneous external field on the three-dimensional uniaxial magnet behaviour near the critical point is investigated within the framework of the nonperturbative collective variables method using the ρ4 model. The research is carried out for the low-temperature region. The analytic explicit expressions for the free energy, average spin moment and susceptibility are obtained for weak and strong fields in comparison with the field value belonging to the pseudocritical line. The calculations are performed on the microscopic level without any adjusting parameters. It is established that the long-wave fluctuations of the order parameter play a crucial role in forming a crossover between the temperature-dependence and field-dependence critical behaviour of the system.

  11. External Thermal Insulation Composite Systems: Critical Parameters for Surface Hygrothermal Behaviour

    Directory of Open Access Journals (Sweden)

    Eva Barreira

    2014-01-01

    Full Text Available External Thermal Insulation Composite Systems (ETICS are often used in Europe. Despite its thermal advantages, low cost, and ease of application, this system has serious problems of biological growth causing the cladding defacement. Recent studies pointed that biological growth is due to high values of surface moisture content, which mostly results from the combined effect of exterior surface condensation, wind-driven rain, and drying process. Based on numerical simulation, this paper points the most critical parameters involved in hygrothermal behaviour of ETICS, considering the influence of thermal and hygric properties of the external rendering, the effect of the characteristics of the façade, and the consequences of the exterior and interior climate on exterior surface condensation, wind-driven rain, and drying process. The model used was previously validated by comparison with the results of an “in situ” campaign. The results of the sensitivity analyses show that relative humidity and temperature of the exterior air, atmospheric radiation, and emissivity of the exterior rendering are the parameters that most influence exterior surface condensation. Wind-driven rain depends mostly on horizontal rain, building’s height, wind velocity, and orientation. The drying capacity is influenced by short-wave absorbance, incident solar radiation, and orientation.

  12. How external magnetic fields alter the parameter dependence of reflectivity in stimulated Raman scattering

    Science.gov (United States)

    Winjum, B. J.; Tableman, A.; Tsung, F. S.; Mori, W. B.

    2016-10-01

    We show the parameter dependence of stimulated Raman scattering (SRS) reflectivity over a range of electron temperatures and densities, laser intensities, and external magnetic field (B0) amplitudes and orientations in particle-in-cell simulations with kλD = 0.2 - 0.4 for the backscatter plasma wave. B0 can modify kinetic SRS by altering the phasespace dynamics of trapped particles. We show how B0 (both in amplitude and in orientation relative to the incident laser wavevector) affects the onset intensity and threshold values for reflectivity. Without an external field, and for constant kλD , lower electron densities have lower reflectivities, since SRS saturates at amplitudes for which the detuning rate due to the nonlinear frequency shift is on the order of the growth rate. Lower reflectivities are also seen for shorter speckle lengths in multi-speckle ensembles. The sensitivity of SRS reflectivity to B0 depends on the underlying kinetic physics, though we comment on generalities and the parameter regimes for which B0 eliminates kinetic SRS reflectivity. Supported under Grant DE-NA0001833; simulations were carried out on the Dawson2 cluster, Edison, Mira, and BlueWaters.

  13. Homeostasis 3: nurses as external agents of control in hypothyroidism.

    Science.gov (United States)

    Clancy, John; McVicar, Andrew

    The role of healthcare practitioners in reversing homeostatic imbalances essentially makes them external agents of homeostatic control-they are replacing the usual assessment, controlling and effector aspects that operate intrinsically in health (homeostasis) but have failed in ill-health (homeostatic imbalances). This article examines the homeostatic imbalance of hypothyroidism, using a case study to draw analogies between the components of homeostatic theory and those of the nursing process. After reading this article, nurses should be able to explain: how the components of homeostasis are associated with health, and how failure of one or more of these components of homeostasis is associated with illness; that illness arises from a cellular, and therefore chemical, homeostatic imbalance; that hypothyroidism is a cellular imbalance of low levels of thyroid hormone, which is identified by signs and symptoms (i.e. other homeostatic imbalances) related to these low levels; and understand how primary care nurses looking after people with hypothyroidism are acting as external agents of homeostatic control.

  14. External stimuli mediate collective rhythms: artificial control strategies.

    Directory of Open Access Journals (Sweden)

    Tianshou Zhou

    Full Text Available The artificial intervention of biological rhythms remains an exciting challenge. Here, we proposed artificial control strategies that were developed to mediate the collective rhythms emerging in multicellular structures. Based on noisy repressilators and by injecting a periodic control amount to the extracellular medium, we introduced two typical kinds of control models. In one, there are information exchanges among cells, where signaling molecules receive the injected stimulus that freely diffuses toward/from the intercellular medium. In the other, there is no information exchange among cells, but signaling molecules also receive the stimulus that directionally diffuses into each cell from the common environment. We uncovered physical mechanisms for how the stimulus induces, enhances or ruins collective rhythms. We found that only when the extrinsic period is close to an integer multiplicity of the averaged intrinsic period can the collective behaviors be induced/enhanced; otherwise, the stimulus possibly ruins the achieved collective behaviors. Such entrainment properties of these oscillators to external signals would be exploited by realistic living cells to sense external signals. Our results not only provide a new perspective to the understanding of the interplays between extrinsic stimuli and intrinsic physiological rhythms, but also would lead to the development of medical therapies or devices.

  15. Application of optical controlling methods for plants under external influence

    Science.gov (United States)

    Timchenko, E. V.; Taskina, L. A.

    2012-10-01

    The experimental study results of spectral characteristic change of different types of plants influenced by external factors (synthetic superficially active substances, salts of heavy metals and nitrate fertilizers) are presented. Differential optical factor was used as the monitored optical parameter that characterizes the chlorophyll concentration change. The differential backscatter method which has high test-sensitivity and provides with the most complete information on the plant condition was the main optical monitoring method. For understanding the mechanisms of external factor accumulation and influence on plants the confocal fluorescent microscopy method providing contrast micrographs of high resolution was used for microscopic analysis in the study. It was revealed that synthetic superficially active substances and heavy metal presence lead to quasilinear decrease of differential backscatter factor with time. It was shown that the presence of salts of heavy metals in a water solution leads to chlorophyll "binding" which is microscopically shown as their «adhesion» near the cell membranes. On the contrary, the presence of synthetic superficially active substances maintains the uniformity of chlorophyll distribution in a cell, but its concentration falls with increasing the concentration in a major emission. The latter depends on the fact that synthetic superficially active substances solubilize the cell membrane proteins, increasing its penetrability. It causes pigment release ("washing away") from a plant, thereby leading to differential optical factor change. It was shown that nitrate fertilizer presence leads to increase of differential backscatter factor with time which is microscopically connected to increase in chlorophyll concentration.

  16. Effects of Differences in Suggestibility within Self- and External-Control Conditions.

    Science.gov (United States)

    Souheaver, Gary T.; Schuldt, W. John

    1978-01-01

    Studied effects of suggestibility on performance within self- and external-control conditions. Subjects were assigned to experimental conditions--self-control, external-control, and no reward. Response rates of self and external groups were highest. Response rates of high-suggestibles in self-control conditions were not significantly different…

  17. Integral evaluation of the external corrosion control system for buried pipelines

    Energy Technology Data Exchange (ETDEWEB)

    Kowalski, A.R. [Asesoria Adiestramiento y Construccion, Caracas (Venezuela)

    1998-12-31

    The External Corrosion Control System of a 16 inch diameter (406 mm), 70 miles long (113 km) pipeline, was evaluated using the Direct Current Voltage Gradient DCVG, Close Interval Potential Survey CIPS and Continuous Soil Resistivity Evaluation CSRE techniques. Sixteen thousand five hundred meters (16,500 meters) of the pipeline were evaluated using the three techniques simultaneously and the rest was inspected separately in previous years. The results from the survey were taken as parameters to classify all defects found on the protective coating. A Defect Severity Classification (DSC) was established and used as an input for a maintenance program for the rehabilitation of the pipeline integrity. The parameters taken to establish the DSC were: (a) Instant Off Potential, (b) %IR, (c) Soil Resistivity, (d) defect shape, (e) Geographic location, (f) Distance from drain point. A Maintenance Program for the Pipeline External Corrosion Control System was designed by implementing the Integral Evaluation of the Corrosion Control System for Buried Pipelines (IEECCSBP). The priority was to achieve pipeline integrity and then, gradually improve the protection level of the system. The implementation of IEECCSBP will help to reduce the frequency of Electromagnetic Metal Loss Inspections, which in the future will serve only as an audit of the External Corrosion Control System performance.

  18. Homeostasis 6: nurses as external control agents in rheumatoid arthritis.

    Science.gov (United States)

    Clancy, John; McVicar, Andrew; Mooney, Janice

    All disorders involve a disturbance of cellular and hence chemical function in the body. Rheumatoid arthritis (RA) is a chronic, systemic, inflammatory disease that usually attacks synovial joints and surrounding ligaments, muscles and their tendons and blood vessels. This article applies the concept of health professionals operating as external agents of homeostatic control (Clancy and McVicar, 20011a; 2011b) to RA and to the care of affected patients, using a case scenario to illustrate attempts to minimize homeostatic imbalances. After reading the article, nurses should be able to understand: how the principles of homeostatic theory apply to skeletomuscular function, in particular to synovial joint function; the skeletomuscular homeostatic role in movement; and that homeostatic failure of reduced mobility, as in RA, is a result of nature-nurture interaction; that illness arises from a cellular, hence chemical, homeostatic imbalance(s) (Clancy and McVicar, 2011a; 2011b; 2011c; 2011d; 2011e). RA is considered a cellular (B-lymphocyte) hence chemical (autoantibody) imbalance that causes the homeostatic imbalances (inflammatory pain, reduced mobility, reduced activities of daily living) associated with the condition. Health professionals are able at act as external agents of homeostatic control to only a limited extent when caring for people with RA because, as with any progressive disorder, they will only be managing signs and symptoms to improve patients' quality of life.

  19. Significance assessment of the external control effects of lecturers

    Directory of Open Access Journals (Sweden)

    Kurbatova Margarita, V.

    2015-06-01

    Full Text Available The state policy regarding higher education has changed in the last decade. These changes were part of the efficiency programs of the public sector. Governments of different countries ruined previously existing system of higher education state regulation and attempted to build the quasi-market structure in the higher education industry. Such transformations served as timely and progressive reforms in the recent studies of the economics of education. Substitution of bureaucratic management mechanisms and modern competition managerial tools are articulated. Economic and institutional and sociological studies on the effects of the introduction of quasi-markets and managerial tools in higher education governance oppose to orthodox market approach. They drew attention to the fact that evaluation methods and improve the effectiveness of organizations and employees that are typical of the private sector often produce results that differ from those in the public sector. To assess the consequences of the introduction of managerial tools of external control activities of university lecturers used a methodology based on the allocation of the individual structural components (effects and building on their basis of a multi-level hierarchical model in the research. Each component of the model (single effect is characterized by a degree of significance (importance and the degree of severity. The results of the systematization and assessment of the significance of the effects of external control activity of lecturers of Russian universities implemented in conditions of quasi-market mechanisms of the higher education system are highlighted in the paper.

  20. The SARS algorithm: detrending CoRoT light curves with Sysrem using simultaneous external parameters

    CERN Document Server

    Ofir, Aviv; Bonomo, Aldo Stefano; Carone, Ludmila; Carpano, Stefania; Samuel, Benjamin; Weingrill, Jorg; Aigrain, Suzanne; Auvergne, Michel; Baglin, Annie; Barge, Pierre; Borde, Pascal; Bouchy, Francois; Deeg, Hans J; Deleuil, Magali; Dvorak, Rudolf; Erikson, Anders; Mello, Sylvio Ferraz; Fridlund, Malcolm; Gillon, Michel; Guillot, Tristan; Hatzes, Artie; Jorda, Laurent; Lammer, Helmut; Leger, Alain; Llebaria, Antoine; Moutou, Claire; Ollivier, Marc; Paetzold, Martin; Queloz, Didier; Rauer, Heike; Rouan, Daniel; Schneider, Jean; Wuchterl, Guenther

    2010-01-01

    Surveys for exoplanetary transits are usually limited not by photon noise but rather by the amount of red noise in their data. In particular, although the CoRoT spacebased survey data are being carefully scrutinized, significant new sources of systematic noises are still being discovered. Recently, a magnitude-dependant systematic effect was discovered in the CoRoT data by Mazeh & Guterman et al. and a phenomenological correction was proposed. Here we tie the observed effect a particular type of effect, and in the process generalize the popular Sysrem algorithm to include external parameters in a simultaneous solution with the unknown effects. We show that a post-processing scheme based on this algorithm performs well and indeed allows for the detection of new transit-like signals that were not previously detected.

  1. Averaged controllability of parameter dependent conservative semigroups

    Science.gov (United States)

    Lohéac, Jérôme; Zuazua, Enrique

    2017-02-01

    We consider the problem of averaged controllability for parameter depending (either in a discrete or continuous fashion) control systems, the aim being to find a control, independent of the unknown parameters, so that the average of the states is controlled. We do it in the context of conservative models, both in an abstract setting and also analysing the specific examples of the wave and Schrödinger equations. Our first result is of perturbative nature. Assuming the averaging probability measure to be a small parameter-dependent perturbation (in a sense that we make precise) of an atomic measure given by a Dirac mass corresponding to a specific realisation of the system, we show that the averaged controllability property is achieved whenever the system corresponding to the support of the Dirac is controllable. Similar tools can be employed to obtain averaged versions of the so-called Ingham inequalities. Particular attention is devoted to the 1d wave equation in which the time-periodicity of solutions can be exploited to obtain more precise results, provided the parameters involved satisfy Diophantine conditions ensuring the lack of resonances.

  2. Externally controlled selective spin transfer through a two-terminal bridge setup

    Science.gov (United States)

    Maiti, Santanu K.

    2015-07-01

    A new way of getting controlled spin dependent transport through a two-terminal bridge setup is explored. The system comprises a magnetic quantum ring which is directly coupled to a magnetic quantum wire and subjected to an in-plane electric field perpendicular to the wire. Without directly changing system parameters, one can regulate spin currents simply by tuning the external electric field under a finite bias drop across the wire. For some particular field strengths a high degree of spin polarization can be achieved and thus the system can essentially be utilized as an externally controlled spin polarized device. A detailed comparison of spin current magnitudes obtained from other bridge setups is also examined to make the present investigation a self contained study.

  3. An on-line calibration algorithm for external parameters of visual system based on binocular stereo cameras

    Science.gov (United States)

    Wang, Liqiang; Liu, Zhen; Zhang, Zhonghua

    2014-11-01

    Stereo vision is the key in the visual measurement, robot vision, and autonomous navigation. Before performing the system of stereo vision, it needs to calibrate the intrinsic parameters for each camera and the external parameters of the system. In engineering, the intrinsic parameters remain unchanged after calibrating cameras, and the positional relationship between the cameras could be changed because of vibration, knocks and pressures in the vicinity of the railway or motor workshops. Especially for large baselines, even minute changes in translation or rotation can affect the epipolar geometry and scene triangulation to such a degree that visual system becomes disabled. A technology including both real-time examination and on-line recalibration for the external parameters of stereo system becomes particularly important. This paper presents an on-line method for checking and recalibrating the positional relationship between stereo cameras. In epipolar geometry, the external parameters of cameras can be obtained by factorization of the fundamental matrix. Thus, it offers a method to calculate the external camera parameters without any special targets. If the intrinsic camera parameters are known, the external parameters of system can be calculated via a number of random matched points. The process is: (i) estimating the fundamental matrix via the feature point correspondences; (ii) computing the essential matrix from the fundamental matrix; (iii) obtaining the external parameters by decomposition of the essential matrix. In the step of computing the fundamental matrix, the traditional methods are sensitive to noise and cannot ensure the estimation accuracy. We consider the feature distribution situation in the actual scene images and introduce a regional weighted normalization algorithm to improve accuracy of the fundamental matrix estimation. In contrast to traditional algorithms, experiments on simulated data prove that the method improves estimation

  4. Energy cost of balance control during walking decreases with external stabilizer stiffness independent of walking speed.

    Science.gov (United States)

    Ijmker, Trienke; Houdijk, Han; Lamoth, Claudine J C; Beek, Peter J; van der Woude, Lucas H V

    2013-09-03

    Human walking requires active neuromuscular control to ensure stability in the lateral direction, which inflicts a certain metabolic load. The magnitude of this metabolic load has previously been investigated by means of passive external lateral stabilization via spring-like cords. In the present study, we applied this method to test two hypotheses: (1) the effect of external stabilization on energy cost depends on the stiffness of the stabilizing springs, and (2) the energy cost for balance control, and consequently the effect of external stabilization on energy cost, depends on walking speed. Fourteen healthy young adults walked on a motor driven treadmill without stabilization and with stabilization with four different spring stiffnesses (between 760 and 1820 Nm(-1)) at three walking speeds (70%, 100%, and 130% of preferred speed). Energy cost was calculated from breath-by-breath oxygen consumption. Gait parameters (mean and variability of step width and stride length, and variability of trunk accelerations) were calculated from kinematic data. On average external stabilization led to a decrease in energy cost of 6% (pwalking speed (p=0.111). These results show that active lateral stabilization during walking involves an energetic cost, which is independent of walking speed. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. Sensor Fault and Delay Tolerant Control for Networked Control Systems Subject to External Disturbances.

    Science.gov (United States)

    Han, Shi-Yuan; Chen, Yue-Hui; Tang, Gong-You

    2017-03-28

    In this paper, the problem of sensor fault and delay tolerant control problem for a class of networked control systems under external disturbances is investigated. More precisely, the dynamic characteristics of the external disturbance and sensor fault are described as the output of exogenous systems first. The original sensor fault and delay tolerant control problem is reformulated as an equivalence problem with designed available system output and reformed performance index. The feedforward and feedback sensor fault tolerant controller (FFSFTC) can be obtained by utilizing the solutions of Riccati matrix equation and Stein matrix equation. Based on the designed fault diagnoser, the proposed FFSFTC is further reconstructed to compensate for the sensor fault and delayed measurement effects. Finally, numerical examples are provided to illustrate the effectiveness of our proposed FFSFTC with different cases with various types of sensor faults, measurement delays and external disturbances.

  6. 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.

  7. Internal versus External Control of Reinforcement: A Review of the Locus of Control Construct

    Science.gov (United States)

    Kormanik, Martin B.; Rocco, Tonette S.

    2009-01-01

    One aspect of personality, perceptions of internal versus external control of reinforcement, shifts under conditions of change. This review of the literature examines the relationship between planned organizational change and locus of control. The review includes literature from the disciplines of clinical and social psychology, adult development,…

  8. Internal versus External Control of Reinforcement: A Review of the Locus of Control Construct

    Science.gov (United States)

    Kormanik, Martin B.; Rocco, Tonette S.

    2009-01-01

    One aspect of personality, perceptions of internal versus external control of reinforcement, shifts under conditions of change. This review of the literature examines the relationship between planned organizational change and locus of control. The review includes literature from the disciplines of clinical and social psychology, adult development,…

  9. Quality control parameters for Tamra (copper) Bhasma.

    Science.gov (United States)

    Jagtap, Chandrashekhar Yuvaraj; Prajapati, Pradeepkumar; Patgiri, Biswajyoti; Shukla, Vinay J

    2012-04-01

    Metallic Bhasmas are highly valued and have their own importance in Ayurvedic formulations. To testify the Bhasmas various parameters have been told in Rasashastra classics. Tamra Bhasma (TB) with its different properties is used in the treatment of various diseases is quiet famous among the Ayurvedic physicians (Vaidyas). The present study was carried out to set up the quality control parameters for the TB by making the use of classical tests along with advanced analytical tools. Copper wire taken for the preparation of Bhasma was first analyzed for its copper content and then subjected to Shodhana, Marana and Amrutikarana procedures as per the classical references. Final product complied with all the classical parameters like Rekhapurnatwa, Varitaratwa etc. After complying with these tests TB was analyzed by advanced analytical techniques like particle size distribution (PSD) analysis, scanning electron microscopy (SEM), and inductive coupled plasma spectrometry (ICP). PSD analysis of TB showed volumetric mean diameter of 28.70 μm, 50% of the material was below 18.40 μm size. Particle size less than 2μm were seen in SEM. 56.24 wt % of copper and 23.06 wt % of sulphur was found in ICP-AES. Heavy metals like cadmium, selenium were not detected while others like arsenic, lead and mercury were present in traces. These observations could be specified as the quality control parameters conforming to all the classical tests under the Bhasma Pariksha.

  10. Parametric optimal bounded feedback control for smart parameter-controllable composite structures

    Science.gov (United States)

    Ying, Z. G.; Ni, Y. Q.; Duan, Y. F.

    2015-03-01

    Deterministic and stochastic parametric optimal bounded control problems are presented for smart composite structures such as magneto-rheological visco-elastomer based sandwich beam with controllable bounded parameters subjected to initial disturbances and stochastic excitations. The parametric controls by actively adjusting system parameters differ from the conventional additive controls by systemic external inputs. The dynamical programming equations for the optimal parametric controls are derived based on the deterministic and stochastic dynamical programming principles. The optimal bounded functions of controls are firstly obtained from the equations with the bounded control constraints based on the bang-bang control strategy. Then the optimal bounded parametric control laws are obtained by the inversion of the nonlinear functions. The stability of the optimally controlled systems is proved according to the Lyapunov method. Finally, the proposed optimal bounded parametric feedback control strategy is applied to single-degree-of-freedom and two-degree-of-freedom dynamic systems with nonlinear parametric bounded control terms under initial disturbances and earthquake excitations and then to a magneto-rheological visco-elastomer based sandwich beam system with nonlinear parametric bounded control terms under stochastic excitations. The effective vibration suppression is illustrated with numerical results. The proposed optimal parametric control strategy is applicable to other smart composite structures with nonlinear controllable parameters.

  11. External Load Affects Ground Reaction Force Parameters Non-uniformly during Running in Weightlessness

    Science.gov (United States)

    DeWitt, John; Schaffner, Grant; Laughlin, Mitzi; Loehr, James; Hagan, R. Donald

    2004-01-01

    Long-term exposure to microgravity induces detrimefits to the musculcskdetal system (Schneider et al., 1995; LeBlanc et al., 2000). Treadmill exercise is used onboard the International Space Station as an exercise countermeasure to musculoskeletal deconditioning due to spaceflight. During locomotive exercise in weightlessness (0G), crewmembers wear a harness attached to an external loading mechanism (EL). The EL pulls the crewmember toward the treadmill, and provides resistive load during the impact and propulsive phases of gait. The resulting forces may be important in stimulating bone maintenance (Turner, 1998). The EL can be applied via a bungee and carabineer clip configuration attached to the harness and can be manipulated to create varying amounts of load levels during exercise. Ground-based research performed using a vertically mounted treadmill found that peak ground reaction forces (GRF) during running at an EL of less than one body weight (BW) are less than those that occur during running in normal gravity (1G) (Davis et al., 1996). However, it is not known how the GRF are affected by the EL in a true OG environment. Locomotion while suspended may result in biomechanics that differ from free running. The purpose of this investigation was to determine how EL affects peak impact force, peak propulsive force, loading rate, and impulse of the GRF during running in 0G. It was hypothesized that increasing EL would result in increases in each GRF parameter.

  12. Influence of pellet seating on the external ballistic parameters of spring-piston air guns.

    Science.gov (United States)

    Werner, Ronald; Schultz, Benno; Frank, Matthias

    2016-09-01

    In firearm examiners' and forensic specialists' casework as well as in air gun proof testing, reliable measurement of the weapon's muzzle velocity is indispensable. While there are standardized and generally accepted procedures for testing the performance of air guns, the method of seating the diabolo pellets deeper into the breech of break barrel spring-piston air guns has not found its way into standardized test procedures. The influence of pellet seating on the external ballistic parameters was investigated using ten different break barrel spring-piston air guns. Test shots were performed with the diabolo pellets seated 2 mm deeper into the breech using a pellet seater. The results were then compared to reference shots with conventionally loaded diabolo pellets. Projectile velocity was measured with a high-precision redundant ballistic speed measurement system. In eight out of ten weapons, the muzzle energy increased significantly when the pellet seater was used. The average increase in kinetic energy was 31 % (range 9-96 %). To conclude, seating the pellet even slightly deeper into the breech of spring-piston air guns might significantly alter the muzzle energy. Therefore, it is strongly recommended that this effect is taken into account when accurate and reliable measurements of air gun muzzle velocity are necessary.

  13. Adaptive tracking control for double-pendulum overhead cranes subject to tracking error limitation, parametric uncertainties and external disturbances

    Science.gov (United States)

    Zhang, Menghua; Ma, Xin; Rong, Xuewen; Tian, Xincheng; Li, Yibin

    2016-08-01

    In a practical application, overhead cranes are usually subjected to system parameter uncertainties, such as uncertain payload masses, cable lengths, frictions, and external disturbances, such as air resistance. Most existing crane control methods treat the payload swing as that of a single-pendulum. However, certain types of payloads and hoisting mechanisms result in double-pendulum dynamics. The double-pendulum effects will make most existing crane control methods fail to work normally. Therefore, an adaptive tracking controller for double-pendulum overhead cranes subject to parametric uncertainties and external disturbances is developed in this paper. The proposed adaptive tracking control method guarantees that the trolley tracking error is always within a prior set of boundary conditions and converges to zero rapidly. The asymptotic stability of the closed-loop system's equilibrium point is assured by Lyapunov techniques and Barbalat's Lemma. Simulation results show that the proposed adaptive tracking control method is robust with respect to system parametric uncertainties and external disturbances.

  14. 49 CFR 195.559 - What coating material may I use for external corrosion control?

    Science.gov (United States)

    2010-10-01

    ... corrosion control? 195.559 Section 195.559 Transportation Other Regulations Relating to Transportation...) PIPELINE SAFETY TRANSPORTATION OF HAZARDOUS LIQUIDS BY PIPELINE Corrosion Control § 195.559 What coating material may I use for external corrosion control? Coating material for external corrosion control...

  15. Intelligent Control of Diesel Generators Using Gain-Scheduling Based on Online External-Load Estimation

    DEFF Research Database (Denmark)

    Mai, Christian; Jepsen, Kasper Lund; Yang, Zhenyu;

    2014-01-01

    keep a consistent performance for a wide range of operating conditions. Technically, a general nonlinear dynamic model is firstly developed based on fundamental principles of diesel generators. Then, the system parameters of this model can be identified experimentally or partially retrieved from...... the data-sheet for a specific unit. By combining an online external-load estimation with this specific units model, finally an intelligent control using the online gain scheduling strategy is proposed. The proposed solution is verified and analyzed based on a lab-sized emulator of a diesel generator, where...... a controlled AC-motor is employed to emulate a diesel engine. The testing results clearly show that the proposed control solution can lead to a better overall system performance than most existing solutions do, especially subject to widely diverse operating conditions....

  16. 49 CFR 195.561 - When must I inspect pipe coating used for external corrosion control?

    Science.gov (United States)

    2010-10-01

    ... corrosion control? 195.561 Section 195.561 Transportation Other Regulations Relating to Transportation...) PIPELINE SAFETY TRANSPORTATION OF HAZARDOUS LIQUIDS BY PIPELINE Corrosion Control § 195.561 When must I inspect pipe coating used for external corrosion control? (a) You must inspect all external pipe...

  17. A novel tetracycline-controlled transactivator-transrepressor system enables external control of oncolytic adenovirus replication.

    Science.gov (United States)

    Fechner, H; Wang, X; Srour, M; Siemetzki, U; Seltmann, H; Sutter, A P; Scherübl, H; Zouboulis, C C; Schwaab, R; Hillen, W; Schultheiss, H-P; Poller, W

    2003-09-01

    The use of restricted replication-competent adenoviruses (RRCAs) inducing tumor cell-specific lysis is a promising approach in cancer gene therapy. However, the use of RRCAs in humans carries considerable risk, since after injection into the patient, further regulation or inhibition of virus replication from the outside is impossible. Therefore, we have developed a novel system allowing external pharmacological control of RRCA replication. We show here that a tumor-selective E1B-deleted RRCA can be tightly regulated by use of doxycycline (dox)-controlled adenoviral E1A gene expression, which in turn determines vector replication. RRCA replication is switched on by addition and switched off by withdrawal of dox. The system results in efficient tumor cell killing after induction by dox, whereas cells are unaffected by the uninduced system. It was also employed for efficient external control of transgene expression from cotransfected replication-deficient adenovectors. Furthermore, the use of a liver cell-specific human alpha1-antitrypsin (hAAT)-promoter driving a tetracycline-controlled transcriptional silencer allowed specific protection of cells with hAAT-promoter activity in the absence of dox in vitro and in vivo, delineating a new principle of 'tissue protective' gene therapy. The concept of external control of RRCAs may help to improve the safety of cancer gene therapy.

  18. Active Vibration Control of a Nonlinear Beam with Self- and External Excitations

    Directory of Open Access Journals (Sweden)

    J. Warminski

    2013-01-01

    Full Text Available An application of the nonlinear saturation control (NSC algorithm for a self-excited strongly nonlinear beam structure driven by an external force is presented in the paper. The mathematical model accounts for an Euler-Bernoulli beam with nonlinear curvature, reduced to first mode oscillations. It is assumed that the beam vibrates in the presence of a harmonic excitation close to the first natural frequency of the beam, and additionally the beam is self-excited by fluid flow, which is modelled by a nonlinear Rayleigh term for self-excitation. The self- and externally excited vibrations have been reduced by the application of an active, saturation-based controller. The approximate analytical solutions for a full structure have been found by the multiple time scales method, up to the first-order approximation. The analytical solutions have been compared with numerical results obtained from direct integration of the ordinary differential equations of motion. Finally, the influence of a negative damping term and the controller's parameters for effective vibrations suppression are presented.

  19. Determination of Optimized Parameters for the Flexible Operation of a Biomass-Fueled, Microscale Externally Fired Gas Turbine (EFGT

    Directory of Open Access Journals (Sweden)

    Mathhar Bdour

    2016-10-01

    Full Text Available Biomass as a source of renewable energy is a promising solution for current problems in energy supply. Olive waste is considered as an interesting option, especially for Mediterranean countries. Within this paper, a microscale externally fired gas turbine (EFGT technology is presented as a decentralized power plant, within the range of 15 kWth, based on olive residues. It was modeled by Aspen Plus 8.6 software to provide a sufficient technical study for such a plant. Optimized parameters for pressure ratio and turbine air-mass flow have been mapped for several loads to provide information for process control. For all cases, mechanical output, efficiency curves, and back-work ratio have been calculated. Using this information, typical plant sizes and an example of power production are discussed. Additionally, achievable energy production from olive waste is estimated on the basis of this data. The results of this study show that such a plant has an electrical efficiency of 5%–17%. This variation is due to the examination being performed under several combustion temperatures, actual load, heat exchanger temperatures, and heat transfer efficiency. A cost estimation of the discussed system showed an estimated capital cost of 33,800 to 65,300 € for a 15 kWth system.

  20. Elimination of the soil moisture effect on the spectra for reflectance prediction of soil salinity using external parameter orthogonalization method

    Science.gov (United States)

    Peng, Xiang; Xu, Chi; Zeng, Wenzhi; Wu, JingWei; Huang, JieSheng

    2016-01-01

    Soil salinization is a common desertification process, especially in arid lands. Hyperspectral remote sensing of salinized soil is favored for its advantages of being efficient and inexpensive. However, soil moisture often jointly has a great influence on the soil reflectance spectra under field conditions. It is a challenge to establish a model to eliminate the effect of soil moisture and quantitatively estimate the salinity contents of slightly and moderately salt-affected soil. A controlled laboratory experiment was conducted by way of continuously monitoring changes of soil moisture and salt content, which was mainly focused on the slightly and moderately salt-affected soil. We investigated the external parameter orthogonalization (EPO) method to remove the effect of soil moisture (4 to 36% in weight base) by preprocessing soil spectral reflectance and establishing the partial least squares regression after EPO preprocessing model (EPO-PLS) to predict soil salt content. Through comparing PLS with EPO-PLS model, R2 and ratio of prediction to deviation rose from 0.604 and 1.063, respectively, to 0.874 and 2.865 for validation data. Root mean square error and bias were, respectively, reduced from 1.163 and 0.141 g/100 g to 0.718 and 0.044 g/100 g. The performance of the model after EPO algorithm preprocessing was improved significantly.

  1. Control of Compact-Toroid Characteristics by External Copper Shell

    Science.gov (United States)

    Matsumoto, T.; Sekiguchi, J.; Asai, T.; Gota, H.; Roche, T.; Allfrey, I.; Cordero, M.; Garate, E.; Kinley, J.; Valentine, T.; Waggoner, W.; the TAE Team

    2015-11-01

    A collaborative research project by Tri Alpha Energy and Nihon University has been conducted for several years, which led to the development of a new compact toroid (CT) injector for efficient FRC particle refueling in the C-2U experiment. The CT is formed by a magnetized coaxial plasma gun (MCPG), consisting of coaxial cylindrical electrodes. In CT formation via MCPG, the magnetic helicity content of the generated CT is one of the critical parameters. A bias coil is inserted into the inner electrode to generate a poloidal flux. The resultant bias magnetic field is spread out of MCPG with time due to its low-frequency bias current. To obtain a more effectively distributed bias magnetic field as well as to improve the voltage breakdown between electrodes, the MCPG incorporates a novel ~ 1 mm thick copper shell mounted outside of the outer electrode. This allows for reliable and controlled operation and more robust CT generation. A detailed discussion of the copper shell and experimental test results will be presented.

  2. 25 CFR 23.46 - Financial management, internal and external controls and other assurances.

    Science.gov (United States)

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Financial management, internal and external controls and....46 Financial management, internal and external controls and other assurances. Grantee financial... required by the grantee's financial management system. The Secretary or his/her designee may review the...

  3. 49 CFR 195.573 - What must I do to monitor external corrosion control?

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false What must I do to monitor external corrosion... SAFETY TRANSPORTATION OF HAZARDOUS LIQUIDS BY PIPELINE Corrosion Control § 195.573 What must I do to monitor external corrosion control? (a) Protected pipelines. You must do the following to...

  4. 49 CFR 192.455 - External corrosion control: Buried or submerged pipelines installed after July 31, 1971.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false External corrosion control: Buried or submerged... SAFETY STANDARDS Requirements for Corrosion Control § 192.455 External corrosion control: Buried or... against external corrosion, including the following: (1) It must have an external protective...

  5. Automated Microscopy: Macro Language Controlling a Confocal Microscope and its External Illumination: Adaptation for Photosynthetic Organisms.

    Science.gov (United States)

    Steinbach, Gábor; Kaňa, Radek

    2016-04-01

    Photosynthesis research employs several biophysical methods, including the detection of fluorescence. Even though fluorescence is a key method to detect photosynthetic efficiency, it has not been applied/adapted to single-cell confocal microscopy measurements to examine photosynthetic microorganisms. Experiments with photosynthetic cells may require automation to perform a large number of measurements with different parameters, especially concerning light conditions. However, commercial microscopes support custom protocols (through Time Controller offered by Olympus or Experiment Designer offered by Zeiss) that are often unable to provide special set-ups and connection to external devices (e.g., for irradiation). Our new system combining an Arduino microcontroller with the Cell⊕Finder software was developed for controlling Olympus FV1000 and FV1200 confocal microscopes and the attached hardware modules. Our software/hardware solution offers (1) a text file-based macro language to control the imaging functions of the microscope; (2) programmable control of several external hardware devices (light sources, thermal controllers, actuators) during imaging via the Arduino microcontroller; (3) the Cell⊕Finder software with ergonomic user environment, a fast selection method for the biologically important cells and precise positioning feature that reduces unwanted bleaching of the cells by the scanning laser. Cell⊕Finder can be downloaded from http://www.alga.cz/cellfinder. The system was applied to study changes in fluorescence intensity in Synechocystis sp. PCC6803 cells under long-term illumination. Thus, we were able to describe the kinetics of phycobilisome decoupling. Microscopy data showed that phycobilisome decoupling appears slowly after long-term (>1 h) exposure to high light.

  6. 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.

  7. 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.

  8. 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.

  9. Internal-External Control and Others' Susceptibility to Influence as Determinants of Interpersonal Attraction.

    Science.gov (United States)

    Davis, William L.; Taylor, Alan L.

    The relationship between internal-external control of reinforcement and attraction to others who vary in susceptibility to persuasion was investigated. Internals are defined as persons who believe that reinforcement is contingent on their behavior, while externals are those who believe that reinforcement is independent of their actions and is…

  10. Linear Parameter Varying Control of Induction Motors

    DEFF Research Database (Denmark)

    Trangbæk, Klaus

    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...... to the field of LPV control theory itself...

  11. Antisynchronization of a novel hyperchaotic system with parameter mismatch and external disturbances

    Indian Academy of Sciences (India)

    Fei Yu; Chunhua Wang; Yan Hu; Jinwen Yin

    2013-12-01

    In our recent publication (Pramana – J. Phys. 79, 81 (2012), DOI: 10.1007/s12043-012-0285-6), our statement on adaptive antisynchronization (AS) controller design is incorrect. In this erratum we propose a correct control law. The corresponding proof is also given to demonstrate the effectiveness of the proposed control strategy.

  12. 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.

  13. External Verification of SCADA System Embedded Controller Firmware

    Science.gov (United States)

    2012-03-01

    2 HMI human machine interface . . . . . . . . . . . . . . . . . . . . . . . . . 5 RTU remote terminal unit... ISA International Society for Automation . . . . . . . . . . . . . . . . . . . 18 DOE Department of Energy...interface (HMI). Field devices, such as are either PLCs or remote terminal units ( RTUs ), automate physical system operation by implementing digital control

  14. Active Vibration Control of Laminated Composite Plates by using External Patches

    Directory of Open Access Journals (Sweden)

    N. S. Sunil Varma

    2017-05-01

    Full Text Available The concept of suppressing vibrations caused by external or internal stimulus has been evolving from a long time and there have been several techniques to suppress these vibrations involving spring mass dampeners and inertial mass actuators but the technique of active vibration control is more efficient in its ability to reduce vibrations to great extent. The field applications that active vibration control can be employed in, are vast ranging from structures like automobile engines, vehicle chassis, to airplane wings. The key significant improvement in using this technique is that the actuatosr placed reduces the vibrations of all modal frequencies more efficiently compared to other techniques that are efficient only in suppressing high-frequency modes. The main points to be considered in this technique are the positioning, number and the size of actuator/patch. In this study we used ANSYS 15.0 to analyse the impact of patch position, size and number on the natural frequency and displacement of the actual host structure (in our case laminated composite plate by observing the strain values and root occurrence in case of the host structure. We used Piezo ceramic as an actuator/patch to suppress vibrations. The positional influence is shown to have a profound impact on reducing host structure deformation to a significant extent. The Analysis we have done paves a way for using active vibration control technique efficiently; since it involves the study of all the key parameters that helps in attenuating the vibrations.

  15. [Development of external quality control protocol for CyberKnife beams dosimetry: preliminary tests multicentre].

    Science.gov (United States)

    Guinement, L; Marchesi, V; Veres, A; Lacornerie, T; Buchheit, I; Peiffert, D

    2013-01-01

    To develop an external quality control procedure for CyberKnife(®) beams. This work conducted in Nancy, has included a test protocol initially drawn by the medical physicist of Nancy and Lille in collaboration with Equal-Estro Laboratory. A head and neck anthropomorphic phantom and a water-equivalent homogeneous cubic plastic test-object, so-called "MiniCube", have been used. Powder and solid thermoluminescent dosimeters as well as radiochromic films have been used to perform absolute and relative dose studies, respectively. The comparison between doses calculated by Multiplan treatment planning system and measured doses have been studied in absolute dose. The dose distributions measured with films and treatment planning system calculations have been compared via the gamma function, configured with different tolerance criteria. This work allowed, via solid thermoluminescent dosimeter measurements, verifying the beam reliability with a reproducibility of 1.7 %. The absolute dose measured in the phantom irradiated by the seven participating centres has shown an error inferior to the standard tolerance limits (± 5 %), for most of participating centres. The relative dose measurements performed at Nancy and by the Equal-Estro laboratory allowed defining the most adequate parameters for gamma index (5 %/2mm--with at least 95 % of pixels satisfying acceptability criteria: γsoftware. This work allowed defining a dosimetric external quality control for CyberKnife(®) systems, based on a reproducible irradiation plan through measurements performed with thermoluminescent dosimeters and radiochromic films. This protocol should be validated by a new series of measurement and taking into account the lessons of this work. Copyright © 2013 Société française de radiothérapie oncologique (SFRO). Published by Elsevier SAS. All rights reserved.

  16. Total heart volume as a function of clinical and anthropometric parameters in a population of external beam radiation therapy patients

    Science.gov (United States)

    Nadège Ilembe Badouna, Audrey; Veres, Cristina; Haddy, Nadia; Bidault, François; Lefkopoulos, Dimitri; Chavaudra, Jean; Bridier, André; de Vathaire, Florent; Diallo, Ibrahima

    2012-01-01

    The aim of this paper was to determine anthropometric parameters leading to the least uncertain estimate of heart size when connecting a computational phantom to an external beam radiation therapy (EBRT) patient. From computed tomography images, we segmented the heart and calculated its total volume (THV) in a population of 270 EBRT patients of both sexes, aged 0.7-83 years. Our data were fitted using logistic growth functions. The patient age, height, weight, body mass index and body surface area (BSA) were used as explanatory variables. For both genders, good fits were obtained with both weight (R2 = 0.89 for males and 0.83 for females) and BSA (R2 = 0.90 for males and 0.84 for females). These results demonstrate that, among anthropometric parameters, weight plays an important role in predicting THV. These findings should be taken into account when assigning a computational phantom to a patient.

  17. A research on adaptive control to stabilize and synchronize a hyperchaotic system with uncertain parameters

    Directory of Open Access Journals (Sweden)

    Israr Ahmad

    2015-07-01

    Full Text Available This paper addresses the chaos control and synchronization problems of a hyperchaotic system. It is assumed that the parameters of the hyperchaotic system are unknown and the system is perturbed by the external disturbance. Based on the Lyapunov stability theory and the adaptive control theory, suitable nonlinear controllers are designed for the asymptotic stability of the closed-loop system both for stabilization of hyperchaos at the origin and complete synchronization of two identical hyperchaotic systems. Accordingly, suitable update laws are proposed to estimate the fully uncertain parameters. All simulation results are carried out to validate the effectiveness of the theoretical findings. The effect of external disturbance is under our discussion.

  18. 49 CFR 195.557 - Which pipelines must have coating for external corrosion control?

    Science.gov (United States)

    2010-10-01

    ... corrosion control? 195.557 Section 195.557 Transportation Other Regulations Relating to Transportation...) PIPELINE SAFETY TRANSPORTATION OF HAZARDOUS LIQUIDS BY PIPELINE Corrosion Control § 195.557 Which pipelines must have coating for external corrosion control? Except bottoms of aboveground breakout tanks,...

  19. Barchan dune corridors: Field characterization and investigation of control parameters

    Science.gov (United States)

    Elbelrhiti, H.; Andreotti, B.; Claudin, P.

    2008-06-01

    The structure of the barchan field located between Tarfaya and Laayoune (Atlantic Sahara, Morocco) is quantitatively investigated and compared to that in La Pampa de la Joya (Arequipa, Peru). On the basis of field measurements, we show how the volume, the velocity, and the output sand flux of a dune can be computed from the value of its body and horn widths. The dune size distribution is obtained from the analysis of aerial photographs. It shows that these fields are in a statistically homogeneous state along the wind direction and present a "corridor" structure in the transverse direction, in which the dunes have a rather well selected size. Investigating the possible external parameters controlling these corridors, we demonstrate that none among topography, granulometry, wind, and sand flux is relevant. We finally discuss the dynamical processes at work in these fields (collisions and wind fluctuations) and investigate the way they could regulate the size of the dunes. Furthermore, we show that the overall sand flux transported by a dune field is smaller than the maximum transport that could be reached in the absence of dunes, i.e., in saltation over the solid ground.

  20. Temperature insensitive prediction of glucose concentration in turbid medium using multivariable calibration based on external parameter orthogonalization

    Science.gov (United States)

    Han, Tongshuai; Zhang, Ziyang; Sun, Cuiying; Guo, Chao; Sun, Di; Liu, Jin

    2016-10-01

    The measurement accuracy of non-invasive blood glucose concentration (BGC) sensing with near-infrared spectroscopy is easily affected by the temperature variation in tissue because it would induce an unacceptable spectrum variation and the consequent prediction deviation. We use a multivariable correction method based on external parameter orthogonalization (EPO) to calibrate the spectral data recorded at different temperature values to reduce the spectral variation. The tested medium is a kind of tissue phantom, the Intralipid aqueous solution. The calibration uses a projection matrix to get the orthogonal spectral space to the variable of external parameter, i.e. temperature, and then the useful spectral information relative to glucose concentration has been reserved. Even more, training the projection matrix can be separated to building the calibration matrix for the prediction of glucose concentration as it only uses the representative samples' data with temperature variation. The method presents a lower complexity than modeling a robust prediction matrix, which can be built from comprehensive spectral data involved the all variables both of BGC and temperature. In our test, the calibrated spectra with the same glucose concentration but different temperature values show a significantly improved repeatability. And then the glucose concentration prediction results show a lower root mean squared error of prediction (RMSEP) than that using the robust calibration model, which has considered the two variables. We also discuss the rationality of the representative samples chosen by EPO. This research may be referenced to the temperature calibration for in vivo BGC sensing.

  1. Novel Parameter Predicting Grade 2 Rectal Bleeding After Iodine-125 Prostate Brachytherapy Combined With External Beam Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Shiraishi, Yutaka, E-mail: shiraishi@rad.med.keio.ac.jp [Department of Radiology, Keio University School of Medicine, Tokyo (Japan); Hanada, Takashi; Ohashi, Toshio [Department of Radiology, Keio University School of Medicine, Tokyo (Japan); Yorozu, Atsunori; Toya, Kazuhito [Department of Radiology, National Hospital Organization Tokyo Medical Center, Tokyo (Japan); Saito, Shiro [Department of Urology, National Hospital Organization Tokyo Medical Center, Tokyo (Japan); Shigematsu, Naoyuki [Department of Radiology, Keio University School of Medicine, Tokyo (Japan)

    2013-09-01

    Purpose: To propose a novel parameter predicting rectal bleeding on the basis of generalized equivalent uniform doses (gEUD) after {sup 125}I prostate brachytherapy combined with external beam radiation therapy and to assess the predictive value of this parameter. Methods and Materials: To account for differences among radiation treatment modalities and fractionation schedules, rectal dose–volume histograms (DVHs) of 369 patients with localized prostate cancer undergoing combined therapy retrieved from corresponding treatment planning systems were converted to equivalent dose-based DVHs. The gEUDs for the rectum were calculated from these converted DVHs. The total gEUD (gEUD{sub sum}) was determined by a summation of the brachytherapy and external-beam radiation therapy components. Results: Thirty-eight patients (10.3%) developed grade 2+ rectal bleeding. The grade 2+ rectal bleeding rate increased as the gEUD{sub sum} increased: 2.0% (2 of 102 patients) for <70 Gy, 10.3% (15 of 145 patients) for 70-80 Gy, 15.8% (12 of 76 patients) for 80-90 Gy, and 19.6% (9 of 46 patients) for >90 Gy (P=.002). Multivariate analysis identified age (P=.024) and gEUD{sub sum} (P=.000) as risk factors for grade 2+ rectal bleeding. Conclusions: Our results demonstrate gEUD to be a potential predictive factor for grade 2+ late rectal bleeding after combined therapy for prostate cancer.

  2. Optimal control of nonsmooth distributed parameter systems

    CERN Document Server

    Tiba, Dan

    1990-01-01

    The book is devoted to the study of distributed control problems governed by various nonsmooth state systems. The main questions investigated include: existence of optimal pairs, first order optimality conditions, state-constrained systems, approximation and discretization, bang-bang and regularity properties for optimal control. In order to give the reader a better overview of the domain, several sections deal with topics that do not enter directly into the announced subject: boundary control, delay differential equations. In a subject still actively developing, the methods can be more important than the results and these include: adapted penalization techniques, the singular control systems approach, the variational inequality method, the Ekeland variational principle. Some prerequisites relating to convex analysis, nonlinear operators and partial differential equations are collected in the first chapter or are supplied appropriately in the text. The monograph is intended for graduate students and for resea...

  3. [Analysis of the results of the SEIMC External Quality Control Program. Year 2008].

    Science.gov (United States)

    Serrano, María del Remedio Guna; Mira, Nieves Orta; de Gopegui, Enrique Ruiz; Ovies, María Rosario; Cardona, Concepción Gimeno; Pérez, José L

    2010-01-01

    The External Quality Control Program of the Spanish Society of Infectious Diseases and Clinical Microbiology (SEIMC) include controls for bacteriology, serology, mycology, parasitology, mycobacteria and virology. This article present the most relevant conclusions and lessons from the 2008 controls. As a whole, the results obtained in 2008 confirm the excellent skill and good technical standards of the microbiology laboratories in Spain found in previous editions. However, a few deviations can be obtained in any laboratory, even in clinically relevant determinations. Once again, the results of this program highlighted the need to implement both internal an external controls in order to assure the maximal quality of the microbiological tests.

  4. [Analysis of the results of the SEIMC External Quality Control Program. Year 2012].

    Science.gov (United States)

    de Gopegui Bordes, Enrique Ruiz; Guna Serrano, M del Remedio; Orta Mira, Nieves; Ovies, María Rosario; Poveda, Marta; Gimeno Cardona, Concepción

    2014-02-01

    The External Quality Control Program of the Spanish Society of Infectious Diseases and Clinical Microbiology (SEIMC) include controls for bacteriology, serology, mycology, parasitology, mycobacteria, virology and molecular microbiology. This article presents the most relevant conclusions and lessons from the 2012 controls. As a whole, the results obtained in 2012 confirm the excellent skill and good technical standards found in previous editions. However, erroneous results can be obtained in any laboratory and in clinically relevant determinations. Once again, the results of this program highlighted the need to implement both internal and external controls in order to assure the maximal quality of the microbiological tests.

  5. [Analysis of the results of the SEIMC External Quality Control Program. Year 2014].

    Science.gov (United States)

    Gopegui Bordes, Enrique Ruiz de; Guna Serrano, M Del Remedio; Orta Mira, Nieves; Medina González, Rafael; Rosario Ovies, María; Poveda, Marta; Gimeno Cardona, Concepción

    2016-07-01

    The External Quality Control Program of the Spanish Society of Infectious Diseases and Clinical Microbiology (SEIMC) include controls for bacteriology, serology, mycology, parasitology, mycobacteria, virology and molecular microbiology. This article presents the most relevant conclusions and lessons from the 2014 controls. As a whole, the results obtained in 2014 confirm the excellent skill and good technical standards found in previous editions. However, erroneous results can be obtained in any laboratory and in clinically relevant determinations. Once again, the results of the SEIMC program highlighted the need to implement both internal and external controls in order to assure the maximal quality of the microbiological tests.

  6. Engineering challenges of BioNEMS: the integration of microfluidics, micro- and nanodevices, models and external control for systems biology.

    Science.gov (United States)

    Wikswo, J P; Prokop, A; Baudenbacher, F; Cliffel, D; Csukas, B; Velkovsky, M

    2006-08-01

    Systems biology, i.e. quantitative, postgenomic, postproteomic, dynamic, multiscale physiology, addresses in an integrative, quantitative manner the shockwave of genetic and proteomic information using computer models that may eventually have 10(6) dynamic variables with non-linear interactions. Historically, single biological measurements are made over minutes, suggesting the challenge of specifying 10(6) model parameters. Except for fluorescence and micro-electrode recordings, most cellular measurements have inadequate bandwidth to discern the time course of critical intracellular biochemical events. Micro-array expression profiles of thousands of genes cannot determine quantitative dynamic cellular signalling and metabolic variables. Major gaps must be bridged between the computational vision and experimental reality. The analysis of cellular signalling dynamics and control requires, first, micro- and nano-instruments that measure simultaneously multiple extracellular and intracellular variables with sufficient bandwidth; secondly, the ability to open existing internal control and signalling loops; thirdly, external BioMEMS micro-actuators that provide high bandwidth feedback and externally addressable intracellular nano-actuators; and, fourthly, real-time, closed-loop, single-cell control algorithms. The unravelling of the nested and coupled nature of cellular control loops requires simultaneous recording of multiple single-cell signatures. Externally controlled nano-actuators, needed to effect changes in the biochemical, mechanical and electrical environment both outside and inside the cell, will provide a major impetus for nanoscience.

  7. Investment and emission control under technology and pollution externalities

    Energy Technology Data Exchange (ETDEWEB)

    Heal, Geoffrey [Graduate School of Business, Columbia University, 616 Uris Hall, New York, NY 10027 (United States); Tarui, Nori [Department of Economics, University of Hawaii at Manoa, 2424 Maile Way, Honolulu, HI 96822 (United States)

    2010-01-15

    This paper studies incentives to develop advanced pollution abatement technology when technology may spillover across agents and pollution abatement is a public good. We are motivated by a variety of pollution control issues where solutions require the development and implementation of new pollution abatement technologies. We show that at the Nash equilibrium of a simultaneous-move game with R and D investment and emission abatement, whether the free rider effect prevails and under-investment and excess emissions occur depends on the degree of technology spillovers and the effect of R and D on the marginal abatement costs. There are cases in which, contrary to conventional wisdom, Nash equilibrium investments in emissions reductions exceed the first-best case. (author)

  8. [Analysis of the results of the SEIMC External Quality Control Program. Year 2013].

    Science.gov (United States)

    de Gopegui Bordes, Enrique Ruiz; Orta Mira, Nieves; Del Remedio Guna Serrano, M; Medina González, Rafael; Rosario Ovies, María; Poveda, Marta; Gimeno Cardona, Concepción

    2015-07-01

    The External Quality Control Program of the Spanish Society of Infectious Diseases and Clinical Microbiology (SEIMC) include controls for bacteriology, serology, mycology, parasitology, mycobacteria, virology, molecular microbiology and HIV-1, HCV and HBV viral loads. This manuscript presents the analysis of results obtained of the participants from the 2013 SEIMC External Quality Control Programme, except viral loads controls, that they are summarized in a manuscript abroad. As a whole, the results obtained in 2013 confirm the excellent skill and good technical standards found in previous editions. However, erroneous results can be obtained in any laboratory and in clinically relevant determinations. Once again, the results of this program highlighted the need to implement both internal and external controls in order to assure the maximal quality of the microbiological tests.

  9. Control of a Bose-Einstein condensate on a chip by external optical and magnetic potentials

    Energy Technology Data Exchange (ETDEWEB)

    Maluckov, A. [Vinca Institute of Nuclear Sciences, University of Belgrade, P.O. Box 522, 11001 Belgrade (Serbia); Petrovic, J., E-mail: jovanap@vin.bg.ac.rs [Vinca Institute of Nuclear Sciences, University of Belgrade, P.O. Box 522, 11001 Belgrade (Serbia); Laboratory for Nonlinear Spectroscopy, Via Nello Carrara 1, 50019 Firenze (Italy); Gligoric, G. [Vinca Institute of Nuclear Sciences, University of Belgrade, P.O. Box 522, 11001 Belgrade (Serbia); Max-Planck-Institut fuer Physik Complexer Systeme, Noethnitzer St. 38, D-01187 Dresden (Germany); Hadzievski, Lj. [Vinca Institute of Nuclear Sciences, University of Belgrade, P.O. Box 522, 11001 Belgrade (Serbia); Lombardi, P. [Laboratory for Nonlinear Spectroscopy, Via Nello Carrara 1, 50019 Firenze (Italy); Dipartimento di Fisica e Astronomia, Universita di Firenze via Sansone 1, 50019 Sesto F.no (Italy); Schaefer, F. [Laboratory for Nonlinear Spectroscopy, Via Nello Carrara 1, 50019 Firenze (Italy); Cataliotti, F.S. [Laboratory for Nonlinear Spectroscopy, Via Nello Carrara 1, 50019 Firenze (Italy); Dipartimento di Energetica ' Sergio Stecco' , Universita di Firenze via S. Marta 3, 50139 Firenze (Italy)

    2012-09-15

    In this paper we explore the possibilities of control of a Bose-Einstein condensate on an atom chip by the use of potentials generated by photonic and magnetic components. We show that the fields produced by both types of components can be modelled by a generic exponential potential and derive analytic expressions that allow for an easy assessment of their impact on a trapped condensate. Using dynamical numerical simulations we study the transport of the condensate between the control structures on a chip. We study in detail different regimes of the condensate behaviour in an evanescent light potential generated by a photonic structure in the vicinity of the condensate and in magnetic potentials generated by a wire or a coil. The calculations are based on the reported parameters of atom chip setups and available photonic and magnetic components. Finally, the model is verified by an experiment with a condensate on an atom chip and a coil. - Highlights: Black-Right-Pointing-Pointer Generic potential used to describe both the optical evanescent and magnetic fields. Black-Right-Pointing-Pointer An analytic closed form solution found for the impact of a generic potential on a BEC. Black-Right-Pointing-Pointer BEC dynamics calculated for potential time sequences attainable in experiments. Black-Right-Pointing-Pointer Conditions for BEC transfer by an external field identified. Black-Right-Pointing-Pointer Exponential-potential model validated by a BEC-on-chip experiment.

  10. 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.

  11. Novel Rigid External Distraction Device Improves Stability and Controls the Vector During Midfacial Advancement.

    Science.gov (United States)

    Resnick, Cory M; Rottgers, Stephen Alex; Langenfeld, Christopher C; Mulliken, John B; Padwa, Bonnie L

    2016-06-01

    The major limitation of the rigid external devices currently used for midfacial distraction after subcranial Le Fort III osteotomies is the ductile wire that connects the midface to the device, which makes it difficult to control the vector and force during distraction. The authors describe a novel external appliance that addresses this and other problems of contemporary devices, and application of a custom cranial template that facilitates precise placement of the device to achieve the planned vector of distraction.

  12. External Contamination Control of Attached Payloads on the International Space Station

    Science.gov (United States)

    Soares, Carlos E.; Mikatarian, Ronald R.; Olsen, Randy L.; Huang, Alvin Y.; Steagall, Courtney A.; Schmidl, William D.; Wright, Bruce D.; Koontz, Steven

    2012-01-01

    The International Space Station (ISS) is an on-orbit platform for science utilization in low Earth orbit with multiple sites for external payloads with exposure to the natural and induced environments. Contamination is one of the induced environments that can impact performance, mission success and science utilization on the vehicle. This paper describes the external contamination control requirements and integration process for externally mounted payloads on the ISS. The external contamination control requirements are summarized and a description of the integration and verification process is detailed to guide payload developers in the certification process of attached payloads on the vehicle. A description of the required data certification deliverables covers the characterization of contamination sources. Such characterization includes identification, usage and operational data for each class of contamination source. Classes of external contamination sources covered are vacuum exposed materials, sources of leakage, vacuum venting and thrusters. ISS system level analyses are conducted by the ISS Space Environments Team to certify compliance with external contamination control requirements. This paper also addresses the ISS induced contamination environment at attached payload sites, both at the requirements level as well as measurements made on ISS.

  13. Optimizing wind turbine control system parameters

    Energy Technology Data Exchange (ETDEWEB)

    Schluter, L.L. [Sandia National Labs., Albuquerque, NM (United States); Vachon, W.A. [Vachon (W.A.) and Associates, Inc., Manchester, MA (United States)

    1993-08-01

    The impending expiration of the levelized period in the Interim Standard Offer Number 4 (ISO4) utility contracts for purchasing wind-generated power in California mandates, more than ever, that windplants be operated in a cost-effective manner. Operating plans and approaches are needed that maximize the net revenue from wind parks--after accounting for operation and maintenance costs. This paper describes a design tool that makes it possible to tailor a control system of a wind turbine (WT) to maximize energy production while minimizing the financial consequences of fatigue damage to key structural components. Plans for code enhancements to include expert systems and fuzzy logic are discussed, and typical results are presented in which the code is applied to study the controls of a generic Danish 15-m horizontal axis wind turbine (HAWT).

  14. The Control Anticipation Parameter for Augmented Aircraft.

    Science.gov (United States)

    1981-05-15

    time delay - sec Te2 - Pitch rate numerator time constant - sec-i V - Freestream velocity - ft/sec Z~ eZw - Normal force stability derivative due to...reference (f)) SHORT PERIOD CHARACTERISTICS CONTROL - 18.5 g/RAD "la 50 g/RAD SYSTEM V 1d 250 KT Vind350 KT CHARACTERISTICS t/;ir d - 1.25 SECI 1/t-,p

  15. An active optimal control strategy of rotor vibrations using external forces

    Science.gov (United States)

    Zhu, W.; Castelazo, I.; Nelson, H. D.

    1989-01-01

    An active control strategy for lateral rotor vibrations using external forces is proposed. An extended state observer is used to reconstruct the full states and the unbalance distribution. An optimal controller which accommodates persistent unbalance excitation is derived with feedback of estimated states and unbalances. Numerical simulations were conducted for two separate four degree of freedom rotor systems. These simulations indicated that the proposed strategy can achieve almost complete vibration cancellation. This was shown to be true even when the number of external control forces was less than the system order so long as coordinate coupling was present. Both steady state and transient response at a constant speed are presented.

  16. Multiple nonlinear parameter estimation using PI feedback control

    NARCIS (Netherlands)

    Lith, van P. F.; Witteveen, H.; Betlem, B.H.L.; Roffel, B.

    2001-01-01

    Nonlinear parameters often need to be estimated during the building of chemical process models. To accomplish this, many techniques are available. This paper discusses an alternative view to parameter estimation, where the concept of PI feedback control is used to estimate model parameters. The appr

  17. 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.

  18. Positive Emotion, Negative Emotion, and Emotion Control in the Externalizing Problems of School-Aged Children

    Science.gov (United States)

    Kim, Geunyoung; Walden, Tedra; Harris, Vicki; Karrass, Jan; Catron, Thomas

    2007-01-01

    The present study examined the role of emotion and emotion control in children's externalizing problems. Third- to sixth-grade children were administered a self-report measure of positive emotion, negative emotion, and emotion control. Peer- and teacher-reported adjustment problems were assessed. Structural equations modeling revealed that…

  19. Stainless steel surface wettability control via laser ablation in external electric field

    Science.gov (United States)

    Serkov, A. A.; Shafeev, G. A.; Barmina, E. V.; Loufardaki, A.; Stratakis, E.

    2016-12-01

    Laser ablation of stainless steel in external electric field (up to 10 kV/cm) is experimentally studied. The dependencies of both morphology and chemical properties of surface structures on laser parameters and electric field strength are investigated. Surface wettability properties of the laser-treated samples are considered by means of contact angle measurement. It is shown that under certain conditions laser irradiation in external electric field can render the surface superhydrophobic. Influence of electric field on the laser surface treatment is discussed on basis of its impact on melt solidification and oxidation processes.

  20. Robust mechanical system swith mechatronic devices: parameters identification and vibration control

    OpenAIRE

    Chovnyuk, Yurii; Dikterjuk, Mykhailo

    2015-01-01

    The disturbance estimated with the help of advanced mechatronic devices is used for realization of robust mechanical system, such as agricultural machines. In the actual application, the estimated disturbance is effective not only for the disturbance compensation but also for the parameter identification in the mechanical system. The identified external force is applicable to sensorless force feed-back control in mechanical system and is utilized for a realization of mechanical vibration cont...

  1. Foucault imaging and small-angle electron diffraction in controlled external magnetic fields.

    Science.gov (United States)

    Nakajima, Hiroshi; Kotani, Atsuhiro; Harada, Ken; Ishii, Yui; Mori, Shigeo

    2016-12-01

    We report a method for acquiring Foucault images and small-angle electron diffraction patterns in external magnetic fields using a conventional transmission electron microscope without any modification. In the electron optical system that we have constructed, external magnetic fields parallel to the optical axis can be controlled using the objective lens pole piece under weak excitation conditions in the Foucault mode and the diffraction mode. We observe two ferromagnetic perovskite-type manganese oxides, La0.7Sr0.3MnO3 (LSMO) and Nd0.5Sr0.5MnO3, in order to visualize magnetic domains and their magnetic responses to external magnetic fields. In rhombohedral-structured LSMO, pinning of magnetic domain walls at crystallographic twin boundaries was found to have a strong influence on the generation of new magnetic domains in external applied magnetic fields.

  2. Controlling three-dimensional vortices using multiple and moving external fields

    Science.gov (United States)

    Das, Nirmali Prabha; Dutta, Sumana

    2017-08-01

    Spirals or scroll wave activities in cardiac tissues are the cause of lethal arrhythmias. The external control of these waves is thus of prime interest to scientists and physicians. In this article, we demonstrate the spatial control of scroll waves by using external electric fields and thermal gradients in experiments with the Belousov-Zhabotinsky reaction. We show that a scroll ring can be made to trace cyclic trajectories under a rotating electric field. Application of a thermal gradient in addition to the electric field deflects the motion and changes the nature of the trajectory. Our experimental results are analyzed and corroborated by numerical simulations based on an excitable reaction diffusion model.

  3. Visual Servoing of a Conventional CNC Machine Using an External Axis Controller

    Directory of Open Access Journals (Sweden)

    Daniel Hanafi

    2003-04-01

    Full Text Available This paper presents the implementation of an external axis control system on a conventional CNC machine so that the machine can be actively controlled in response to sensors such as vision and force. The controller that runs on an external computer has direct access to the CNC controller for machine position sensing. The control signals to the machine are sent through purpose built circuitry via the machine's manual pulse generator (MPG inputs. To demonstrate the accuracy and performance of the control system, it was used to visually track the profile of a mandrel used for shear spinning. The implemented system eliminates the parallax error and the need to use an accurate pixel resolution. The raw tracking data is processed by a curvature detection algorithm that detects linear and circular segments and segment transitions. The results show that the visual tracking system provides accurate tracking results that are well within the tolerances used in the industry.

  4. Moody Music Generator: Characterising Control Parameters Using Crowdsourcing

    DEFF Research Database (Denmark)

    Scirea, Marco; Togelius, Julian; Nelson, Mark

    2015-01-01

    We characterise the expressive effects of a music generator capable of varying its moods through two control parameters. The two control parameters were constructed on the basis of existing work on valence and arousal in music, and intended to provide control over those two mood factors....... In this paper we conduct a listener study to determine how people actually perceive the various moods the generator can produce. Rather than directly attempting to validate that our two control param- eters represent arousal and valence, instead we conduct an open-ended study to crowd-source labels...... 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...

  5. INVARIAN AUTOMATIC CONTROL SYSTEM, USING THE INTERMEDIATE-FREQUENCY SIGNALS OF HEAT POWER PARAMETERS

    Directory of Open Access Journals (Sweden)

    G. T. Kulakov

    2015-01-01

    Full Text Available The usage of digital micro-processing automatic means allow to use design methods (technique of automatic control systems  more wider, and also to apply optimal ways of control, for example, it is possible to combine the Method of structural-parameter optimization and invariance theory. This method allow to increase essential system speed in processing of task jump and to reduce operation time of outside external disturbance up to two  values of regulated influence, and the usage of invariance principle is based on an additional measuring of the most dangerous perturbation influence and in connection with it the improvement of regulation quality is achieved.In this article the principle of invariance is applied in order to improve greatly external disturbance attack by consumption of over-heated steam. Compensation of disturbance influence on regulated value is achieving by introduction of additional signal on input of correction regulator from output of compensation device, measuring the external disturbance by consumption of over-heated steam.Modeling results of transient processes of cascade system of automatic control (CSAC, on the base of which were realized the unity of these methods, demonstrated the fact that, in processing of external disturbance by consumption of steam, the reduction of maximal dynamic regulation error is six times and cutting of regulation time by 30 % in comparison with CSAC without compensation device of external disturbance. And that is why it leads to the further reduction of maximal dynamic regulation error in processing of external disturbance by consumption of steam, and this allows to improve the quality of control.

  6. Trends in Control Area of PLC Reliability and Safety Parameters

    Directory of Open Access Journals (Sweden)

    Juraj Zdansky

    2008-01-01

    Full Text Available Extension of the PLC application possibilities is closely related to increase of reliability and safety parameters. If the requirement of reliability and safety parameters will be suitable, the PLC could by implemented to specific applications such the safety-related processes control. The goal of this article is to show the way which producers are approaching to increase PLC`s reliability and safety parameters. The second goal is to analyze these parameters for range of present choice and describe the possibility how the reliability and safety parameters can be affected.

  7. External Periodic Force Control of a Single-Degree-of-Freedom Vibroimpact System

    Directory of Open Access Journals (Sweden)

    Jingyue Wang

    2013-01-01

    Full Text Available A single-degree-of-freedom mechanical model of vibro-impact system is established. Bifurcation and chaos in the system are revealed with the time history diagram, phase trajectory map, and Poincaré map. According to the bifurcation and chaos of the actual vibro-impact system, the paper puts forward external periodic force control strategy. The method of controlling chaos by external periodic force feedback controller is developed to guide chaotic motions towards regular motions. The stability of the control system is also analyzed especially by theory. By selecting appropriate feedback coefficients, the unstable periodic orbits of the original chaotic orbit can be stabilized to the stable periodic orbits. The effectiveness of this control method is verified by numerical simulation.

  8. UPFC control parameter identification for effective power oscillation damping

    Energy Technology Data Exchange (ETDEWEB)

    Pandey, R.K.; Singh, N.K. [Dept. of Electrical Engineering, Institute of Technology, Banaras Hindu University, Varanasi, UP 22100 (India)

    2009-07-15

    This paper presents UPFC control parameter identification for effective power oscillation damping (POD). A comparative analysis with minimum singular value (MSV), Hankel singular value (HSV), direct component of torque (DCT) and residue has been proposed for finding the most appropriate control input parameters of unified power flow controller (UPFC) for damping power system oscillations. The basic objective of the paper is to identify the control parameters of UPFC in order to provide adequate damping in power network with changing system conditions. The results presented in this paper are studied widely on single machine infinite bus. The test has also been carried for two area systems and same trend has been observed. The results show the suitability of this approach in identification of UPFC control parameters. (author)

  9. Stability and accuracy control of k · p parameters

    Science.gov (United States)

    Bastos, Carlos M. O.; Sabino, Fernando P.; Faria Junior, Paulo E.; Campos, Tiago; Da Silva, Juarez L. F.; Sipahi, Guilherme M.

    2016-10-01

    The k · p method is a successful approach to obtain band structure, optical and transport properties of semiconductors and it depends on external parameters that are obtained either from experiments, tight binding or ab initio calculations. Despite the widespread use of the k · p method, a systematic analysis of the stability and the accuracy of its parameters is not usual in the literature. In this work, we report a theoretical framework to determine the k · p parameters from state-of-the-art hybrid density functional theory including spin-orbit coupling, providing a calculation where the gap and spin-orbit energy splitting are in agreement with the experimental values. The accuracy of the set of parameters is enhanced by fitting over several directions at once, minimizing the overall deviation from the original data. This strategy allows us to systematically evaluate the stability, preserving the accuracy of the parameters, providing a tool to determine optimal parameters for specific ranges around the Γ-point. To prove our concept, we investigate the zinc blende GaAs that shows results in excellent agreement with the most reliable data in the literature.

  10. Energy cost of balance control during walking decreases with external stabilizer stiffness independent of walking speed

    NARCIS (Netherlands)

    Ijmker, Trienke; Houdijk, Han; Lamoth, Claudine J. C.; Beek, Peter J.; van der Woude, Lucas H. V.

    2013-01-01

    Human walking requires active neuromuscular control to ensure stability in the lateral direction, which inflicts a certain metabolic load. The magnitude of this metabolic load has previously been investigated by means of passive external lateral stabilization via spring-like cords. In the present

  11. The Association of External Locus of Control, Nonverbal Processing Difficulties, and Emotional Disturbance.

    Science.gov (United States)

    Nowicki, Stephen, Jr.; DiGirolamo, Ann

    1989-01-01

    The study with 20 emotionally disturbed and 20 nondisturbed subjects (ages 9-11) found that an external locus of control and poorer performance in decoding voice tone and facial expression were associated with emotional disturbance. Implications for teaching and remediation are discussed. (Author/DB)

  12. Parental Control is Not Unconditionally Detrimental for Externalizing Behaviors in Early Childhood

    Science.gov (United States)

    Akcinar, Berna; Baydar, Nazli

    2014-01-01

    The association of three different strategies of maternal control (behavioral, psychological, and physical), and maternal warmth with children's externalizing behaviors were analyzed in an observational study of 3-year-old children in Turkey ("N" = 123). The results indicated that (i) mothers exercised all three types of control…

  13. Gargamelle in the West Area - control room for the external electronic detectors

    CERN Multimedia

    1977-01-01

    Four electronic detectors complementing Gargamelle were installed in 1977, among them the external muon identifier (EMI), consisting of two arrays of multiwire proportional chambers separated by an iron wall (see Annual Report 1977 p. 84). The photo shows the control room close to the West Gargamelle Hall (Bld. 185).

  14. Port controlled Hamiltonian representation of distributed parameter systems

    NARCIS (Netherlands)

    Maschke, B.M.; van der Schaft, Arjan

    2000-01-01

    A port controlled Hamiltonian formulation of the dynamics of distributed parameter systems is presented, which incorporates the energy flow through the boundary of the domain of the system, and which allows to represent the system as a boundary control Hamiltonian system. This port controlled

  15. Orbit control of a stratospheric satellite with parameter uncertainties

    Science.gov (United States)

    Xu, Ming; Huo, Wei

    2016-12-01

    When a stratospheric satellite travels by prevailing winds in the stratosphere, its cross-track displacement needs to be controlled to keep a constant latitude orbital flight. To design the orbit control system, a 6 degree-of-freedom (DOF) model of the satellite is established based on the second Lagrangian formulation, it is proven that the input/output feedback linearization theory cannot be directly implemented for the orbit control with this model, thus three subsystem models are deduced from the 6-DOF model to develop a sequential nonlinear control strategy. The control strategy includes an adaptive controller for the balloon-tether subsystem with uncertain balloon parameters, a PD controller based on feedback linearization for the tether-sail subsystem, and a sliding mode controller for the sail-rudder subsystem with uncertain sail parameters. Simulation studies demonstrate that the proposed control strategy is robust to uncertainties and satisfies high precision requirements for the orbit flight of the satellite.

  16. Use of two-axis joystick for control of externally powered shoulder disarticulation prostheses

    Directory of Open Access Journals (Sweden)

    Robert D. Lipschutz, BSME, CP

    2011-07-01

    Full Text Available We explored a new method for simple and accurate control of shoulder movement for externally powered shoulder disarticulation prostheses with a two-axis joystick. We tested 10 subjects with intact shoulders and arms to determine the average amount of shoulder motion and force available to control an electronic input device. We then applied this information to two different input strategies to examine their effectiveness: (1 a traditional rocker potentiometer and a pair of force-sensing resistors and (2 a two-axis joystick. Three nondisabled subjects and two subjects with shoulder disarticulation amputations attempted to control an experimental externally powered shoulder using both control strategies. Two powered arms were tested, one with powered flexion/extension and humeral rotation and one with powered flexion/extension and adduction/abduction. Overwhelmingly, the subjects preferred the joystick control, because it was more intuitively linked with their shoulder movement. Additionally, two motions (one in each axis could be controlled simultaneously. This pilot study provides valuable insight into an effective means of controlling high-level, externally powered prostheses with a two-axis joystick.

  17. Use of two-axis joystick for control of externally powered shoulder disarticulation prostheses.

    Science.gov (United States)

    Lipschutz, Robert D; Lock, Blair; Sensinger, Jonathon; Schultz, Aimee E; Kuiken, Todd A

    2011-01-01

    We explored a new method for simple and accurate control of shoulder movement for externally powered shoulder disarticulation prostheses with a two-axis joystick. We tested 10 subjects with intact shoulders and arms to determine the average amount of shoulder motion and force available to control an electronic input device. We then applied this information to two different input strategies to examine their effectiveness: (1) a traditional rocker potentiometer and a pair of force-sensing resistors and (2) a two-axis joystick. Three nondisabled subjects and two subjects with shoulder disarticulation amputations attempted to control an experimental externally powered shoulder using both control strategies. Two powered arms were tested, one with powered flexion/extension and humeral rotation and one with powered flexion/extension and adduction/abduction. Overwhelmingly, the subjects preferred the joystick control, because it was more intuitively linked with their shoulder movement. Additionally, two motions (one in each axis) could be controlled simultaneously. This pilot study provides valuable insight into an effective means of controlling high-level, externally powered prostheses with a two-axis joystick.

  18. Linear Parameter Varying Control of Doubly Fed Induction Machines

    NARCIS (Netherlands)

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

    2016-01-01

    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 o

  19. A Novel Parameter Tuning Algorithm for AQM-PI Controllers

    Directory of Open Access Journals (Sweden)

    Ma XiaoYan

    2012-01-01

    Full Text Available AQM is recognized as an active queue management mechanism to solve network congestion. As an easily implemented algorithm, PI controllers can effectively control the queue length of router. Based on indepth analysis of classical design methodologies towards PI controllers, this paper explicitly introduces a novel PI parameter tuning algorithm, which takes advantage of the relationship between PI parameters and control systems’ damping ratios and employs recursive bisection searching approaches to achieve an optimum damping ratio in terms of both steady-state and accuracy; performances of controlled queue length, thereby obtaining the best parameters of PI controllers. An experimental study is carried out to demonstrate the effectiveness of the proposed algorithm.

  20. PD-type iterative learning control for nonlinear time-delay system with external disturbance

    Institute of Scientific and Technical Information of China (English)

    Zhang Baolin; Tang Gongyou; Zheng Shi

    2006-01-01

    The PD-type iterative learning control design of a class of affine nonlinear time-delay systems with external disturbances is considered. Sufficient conditions guaranteeing the convergence of the n-norm of the tracking error are derived. It is shown that the system outputs can be guaranteed to converge to desired trajectories in the absence of external disturbances and output measurement noises. And in the presence of state disturbances and measurement noises, the tracking error will be bounded uniformly. A numerical simulation example is presented to validate the effectiveness of the proposed scheme.

  1. Pull-in control due to Casimir forces using external magnetic fields

    CERN Document Server

    Esquivel-Sirvent, R; Cocoletzi, G H

    2009-01-01

    We present a theoretical calculation of the pull-in control in capacitive micro switches actuated by Casimir forces, using external magnetic fields. The external magnetic fields induces an optical anisotropy due to the excitation of magneto plasmons, that reduces the Casimir force. The calculations are performed in the Voigt configuration, and the results show that as the magnetic field increases the system becomes more stable. The detachment length for a cantilever is also calculated for a cantilever, showing that it increases with increasing magnetic field. At the pull-in separation, the stiffness of the system decreases with increasing magnetic field.

  2. [Analysis of the results of the SEIMC External Quality Control Program. Year 2011].

    Science.gov (United States)

    Ruiz de Gopegui Bordes, Enrique; Guna Serrano, M del Remedio; Orta Mira, Nieves; Ovies, María Rosario; Poveda, Marta; Gimeno Cardona, Concepción

    2013-02-01

    The External Quality Control Program of the Spanish Society of Infectious Diseases and Clinical Microbiology (Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica [SEIMC]) includes controls for bacteriology, serology, mycology, parasitology, mycobacteria, virology, and molecular microbiology. This article presents the most relevant conclusions and lessons from the 2011 controls. Overall, the results obtained in 2011 confirm the excellent skill and good technical standards found in previous years. Nevertheless, erroneous results can be obtained in any laboratory and in clinically relevant determinations. The results of this program highlight the need to implement both internal and external controls, such as those offered by the SEIMC program, in order to ensure maximal quality of microbiological tests. Copyright © 2013 Elsevier España, S.L. All rights reserved.

  3. Adaptive Fuzzy Control for Nonlinear Fractional-Order Uncertain Systems with Unknown Uncertainties and External Disturbance

    OpenAIRE

    2015-01-01

    In this paper, the problem of robust control of nonlinear fractional-order systems in the presence of uncertainties and external disturbance is investigated. Fuzzy logic systems are used for estimating the unknown nonlinear functions. Based on the fractional Lyapunov direct method and some proposed Lemmas, an adaptive fuzzy controller is designed. The proposed method can guarantee all the signals in the closed-loop systems remain bounded and the tracking errors converge to an arbitrary small ...

  4. Control of Groundwater Remediation Process as Distributed Parameter System

    Directory of Open Access Journals (Sweden)

    Mendel M.

    2014-12-01

    Full Text Available Pollution of groundwater requires the implementation of appropriate solutions which can be deployed for several years. The case of local groundwater contamination and its subsequent spread may result in contamination of drinking water sources or other disasters. This publication aims to design and demonstrate control of pumping wells for a model task of groundwater remediation. The task consists of appropriately spaced soil with input parameters, pumping wells and control system. Model of controlled system is made in the program MODFLOW using the finitedifference method as distributed parameter system. Control problem is solved by DPS Blockset for MATLAB & Simulink.

  5. Design of Digital Imaging System for Optimization of Control Parameters

    Institute of Scientific and Technical Information of China (English)

    SONG Yong; HAO Qun; YANG Guang; SUN Hong-wei

    2007-01-01

    The design of experimental system of digital imaging system for control parameter is discussed in detail. Signal processing of digital CCD imaging system is first analyzed. Then the real time control of CCD driver and digital processing circuit and man-machine interaction are achieved by the design of digital CCD imaging module and control module. Experimental results indicate that the image quality of CCD experimental system makes a good response to the change of control parameters. The system gives an important base for improving image quality and the applicability of micro imaging system in complex environment.

  6. Molecules Near Absolute Zero and External Field Control of Atomic and Molecular Dynamics

    CERN Document Server

    Krems, R V

    2005-01-01

    This article reviews the current state of the art in the field of cold and ultracold molecules and demonstrates that chemical reactions, inelastic collisions and dissociation of molecules at subKelvin temperatures can be manipulated with external electric or magnetic fields. The creation of ultracold molecules may allow for spectroscopy measurements with extremely high precision and tests of fundamental symmetries of nature, quantum computation with molecules as qubits, and controlled chemistry. The probability of chemical reactions and collisional energy transfer can be very large at temperatures near zero Kelvin. The collision energy of ultracold atoms and molecules is much smaller than perturbations due to interactions with external electric or magnetic fields available in the laboratory. External fields may therefore be used to induce dissociation of weakly bound molecules, stimulate forbidden electronic transitions, suppress the effect of centrifugal barriers in outgoing reaction channels or tune Feshbac...

  7. SWR 1000 severe accident control through in-vessel melt retention by external RPV cooling

    Energy Technology Data Exchange (ETDEWEB)

    Kolev, N.I. [Framatome Advanced Nuclear Power, NDSI, Erlangen (Germany)

    2001-07-01

    Framatome Advanced Nuclear Power is being designing a new generation NPP with boiling water reactor SWR1000. Besides of various of modern passive and active safety features the system is also designed for controlling of a postulated severe accident with extreme low probability of occurrence. This work presents the rationales behind the decision to select the external cooling as a safety management strategy during severe accident. Bounding scenery are analyzed regarding the core melting, melt-water interaction during relocation of the melt from the core region into the lower head and the external coolability of the lower head. The conclusion is reached that the external cooling for the SWR1000 is a valuable strategy for accident management during postulated severe accidents. (authors)

  8. Controller Parameter Tuning of Delta Robot Based on Servo Identification

    Institute of Scientific and Technical Information of China (English)

    ZHAO Qing; WANG Panfeng; MEI Jiangping

    2015-01-01

    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.

  9. 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.

  10. Autonomous attitude coordinated control for spacecraft formation with input constraint, model uncertainties, and external disturbances

    Institute of Scientific and Technical Information of China (English)

    Zheng Zhong; Song Shenmin

    2014-01-01

    To synchronize the attitude of a spacecraft formation flying system, three novel auton-omous control schemes are proposed to deal with the issue in this paper. The first one is an ideal autonomous attitude coordinated controller, which is applied to address the case with certain mod-els and no disturbance. The second one is a robust adaptive attitude coordinated controller, which aims to tackle the case with external disturbances and model uncertainties. The last one is a filtered robust adaptive attitude coordinated controller, which is used to overcome the case with input con-straint, model uncertainties, and external disturbances. The above three controllers do not need any external tracking signal and only require angular velocity and relative orientation between a space-craft and its neighbors. Besides, the relative information is represented in the body frame of each spacecraft. The controllers are proved to be able to result in asymptotical stability almost every-where. Numerical simulation results show that the proposed three approaches are effective for atti-tude coordination in a spacecraft formation flying system.

  11. 49 CFR 192.457 - External corrosion control: Buried or submerged pipelines installed before August 1, 1971.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false External corrosion control: Buried or submerged... SAFETY STANDARDS Requirements for Corrosion Control § 192.457 External corrosion control: Buried or... areas in which active corrosion is found: (1) Bare or ineffectively coated transmission lines. (2)...

  12. External and semi-internal controls for PCR amplification of homologous sequences in mixed templates

    DEFF Research Database (Denmark)

    Kalle, Elena; Gulevich, Alexander; Rensing, Christopher Günther T

    2013-01-01

    in a single template assay. Yet, multi-template PCR has been used without appropriate attention to quality control and assay validation, in spite of the fact that such practice diminishes the reliability of results. External and internal amplification controls became obligatory elements of good laboratory...... practice in different PCR assays. We propose the inclusion of an analogous approach as a quality control system for multi-template PCR applications. The amplification controls must take into account the characteristics of multi-template PCR and be able to effectively monitor particular assay performance...

  13. 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.

  14. Shape control of distributed parameter reflectors using sliding mode control

    Science.gov (United States)

    Andoh, Fukashi; Washington, Gregory N.; Utkin, Vadim

    2001-08-01

    Sliding mode control has become one of the most powerful control methods for variable structure systems, a set of continuous systems with an appropriate switching logic. Its robustness properties and order reduction capability have made sliding mode control one of the most efficient tools for relatively higher order nonlinear plants operating under uncertain conditions. Piezo-electric materials possess the property of creating a charge when subjected to a mechanical strain, and of generating a strain when subjected to an electric field. Piezo-electric actuators are known to have a hysteresis due to the thermal motion and Coulomb interaction of Weiss domains. Because of the thermal effect the hysteresis of piezo-electric actuators is reproducible only with some uncertainty in experiments. The robustness of sliding mode control under uncertain conditions has an advantage in handling the hysteresis of piezo-electric actuators. In this research sliding mode control is used to control the shape of one- and two-dimensionally curved adaptive reflectors with piezo-electric actuators. Four discrete linear actuators for the one-dimensionally curved reflector and eight actuators for the two-dimensionally curved reflector are assumed.

  15. Forcing a unitary transformation by an external field comparing two approaches based on optimal control theory

    CERN Document Server

    Palao, J P; Palao, Jose P.; Kosloff, Ronnie

    2002-01-01

    A quantum gate is realized by specific unitary transformations operating on states representing qubits. Considering a quantum system employed as an element in a quantum computing scheme, the task is therefore to enforce the pre-specified unitary transformation. This task is carried out by an external time dependent field. Optimal control theory has been suggested as a method to compute the external field which alters the evolution of the system such that it performs the desire unitary transformation. This study compares two recent implementations of optimal control theory to find the field that induces a quantum gate. The first approach is based on the equation of motion of the unitary transformation. The second approach generalizes the state to state formulation of optimal control theory. This work highlight the formal relation between the two approaches.

  16. Adolescent externalizing behaviour, psychological control, and peer rejection: Transactional links and dopaminergic moderation.

    Science.gov (United States)

    Janssens, Annelies; Van Den Noortgate, Wim; Goossens, Luc; Verschueren, Karine; Colpin, Hilde; Claes, Stephan; Van Heel, Martijn; Van Leeuwen, Karla

    2017-09-01

    This study investigated (1) reciprocal links among parental psychological control, peer rejection, and adolescent externalizing (aggressive and rule-breaking behaviour), and (2) the moderating effect of an adolescent genetic factor (biologically informed polygenic score for dopamine signalling). Three-year longitudinal data from 1,116 adolescents (51% boys; M age = 13.79) and their parents included psychological measures (adolescent-reported psychological control, peer-reported rejection, and parent-reported aggressive and rule-breaking behaviour). Cross-lagged analyses showed bidirectional effects between psychological control and both aggressive and rule-breaking behaviour and a unidirectional effect of peer rejection on both forms of problem behaviour over time. Multigroup structural equation modelling revealed genetic moderation only for rule-breaking behaviour: for adolescents with intermediate levels of dopamine signalling significant environmental effects were present, whereas adolescent effects of rule-breaking behaviour on psychological control were significant for adolescents with both intermediate and high profiles and effects on peer rejection only for adolescents with high dopamine profiles. Statement of contribution What is already known on this subject? Parental psychological control is related to adolescent externalizing problems. Experiencing peer rejection reinforces aggressive and rule-breaking behaviour. Single-gene studies show that dopaminergic genes influence externalizing problems directly or in interaction with the environment. What does this study add? Parental psychological control and adolescent aggressive and rule-breaking behaviour exacerbate one another longitudinally. Longitudinal associations between peer rejection and both subtypes of externalizing behaviour are unidirectional. With a polygenic approach, dopaminergic moderation is present for rule-breaking behaviour only. © 2017 The British Psychological Society.

  17. The order parameter and susceptibility of the 3D Ising-like system in an external field near the phase transition point

    Directory of Open Access Journals (Sweden)

    M.P. Kozlovskii

    2010-01-01

    Full Text Available The present work is devoted to the investigation of the 3D Ising-like model in the presence of an external field in the vicinity of critical point. The method of collective variables is used. General expressions for the order parameter and susceptibility are calculated as functions of temperature and the external field as well as scaling functions of that are explicitly obtained. The results are compared with the ones obtained within the framework of parametric representation of the equation of state and Monte Carlo simulations. New expression for the exit point from critical regime of the order parameter fluctuations is proposed and used for the calculation.

  18. Real-Time Control of Humanoid Robots Considering External Forces on Upper Part of the Body

    Science.gov (United States)

    Inomata, Kentaro; Shigemori, Yo; Uchimura, Yutaka

    Recently, the demand for the practical use of service robots has risen significantly because of acceleration of demographic aging, and a humanoid robot is one of the promising form factors of service robots. When a humanoid robot is used by a human in a real environment, the robot needs to be designed by taking into account the various external forces that act on the robot. Thus far, most of the walking humanoid robots have been mainly controlled by the conventional ZMP method to maintain a stable walking posture. However, the conventional ZMP method can not be used to handle the various external forces that act on the upper part of the humanoid robot body. To overcome these problems, in this paper, we propose a novel control method, which we called 3DZMP and pZMP, for a humanoid robot to react to the external force on the upper part of the body. The 3DZMP is defined as the point in three-dimensional space at which the moment about all axes is zero. 3DZMP can prevent the rotation of a humanoid robot. The pZMP is defined as the point corresponding to the orthographic projection of the 3DZMP on a plane. pZMP is used to evaluate the stability of 3DZMP. We implemented the proposed method on a prototype robot and verified that the robot gained the capability to react to external forces that could not be handled by the conventional ZMP method.

  19. External and semi-internal controls for PCR amplification of homologous sequences in mixed templates.

    Science.gov (United States)

    Kalle, Elena; Gulevich, Alexander; Rensing, Christopher

    2013-11-01

    In a mixed template, the presence of homologous target DNA sequences creates environments that almost inevitably give rise to artifacts and biases during PCR. Heteroduplexes, chimeras, and skewed template-to-product ratios are the exclusive attributes of mixed template PCR and never occur in a single template assay. Yet, multi-template PCR has been used without appropriate attention to quality control and assay validation, in spite of the fact that such practice diminishes the reliability of results. External and internal amplification controls became obligatory elements of good laboratory practice in different PCR assays. We propose the inclusion of an analogous approach as a quality control system for multi-template PCR applications. The amplification controls must take into account the characteristics of multi-template PCR and be able to effectively monitor particular assay performance. This study demonstrated the efficiency of a model mixed template as an adequate external amplification control for a particular PCR application. The conditions of multi-template PCR do not allow implementation of a classic internal control; therefore we developed a convenient semi-internal control as an acceptable alternative. In order to evaluate the effects of inhibitors, a model multi-template mix was amplified in a mixture with DNAse-treated sample. Semi-internal control allowed establishment of intervals for robust PCR performance for different samples, thus enabling correct comparison of the samples. The complexity of the external and semi-internal amplification controls must be comparable with the assumed complexity of the samples. We also emphasize that amplification controls should be applied in multi-template PCR regardless of the post-assay method used to analyze products.

  20. 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.

  1. Analytical one parameter method for PID motion controller settings

    NARCIS (Netherlands)

    Dijk, van J.; Aarts, R.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 fre

  2. Study on a magnetic spiral-type wireless capsule endoscope controlled by rotational external permanent magnet

    Energy Technology Data Exchange (ETDEWEB)

    Ye, Bo, E-mail: yebo@hubu.edu.cn [School of Mechanical Science & Engineering, Huazhong University of Science & Technology, Wuhan 430074 (China); School of Computer Science and Information Engineering, HuBei University, Wuhan 430062 (China); Zhang, Wei [Department of Mechanical Engineering, Hubei University of Automotive Technology, Shiyan 442002 (China); Sun, Zhen-jun [School of Mechanical Science & Engineering, Huazhong University of Science & Technology, Wuhan 430074 (China); Guo, Lin [School of Computer Science and Information Engineering, HuBei University, Wuhan 430062 (China); Deng, Chao [School of Mechanical Science & Engineering, Huazhong University of Science & Technology, Wuhan 430074 (China); Chen, Ya-qi [Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030 (China); Zhang, Hong-hai [School of Mechanical Science & Engineering, Huazhong University of Science & Technology, Wuhan 430074 (China); Liu, Sheng [School of Power and Mechanical Engineering, Wuhan University, Wuhan 430072 (China)

    2015-12-01

    In this paper, the authors propose rotating an external permanent magnet (EPM) to manipulate the synchronous rotation of a magnetic spiral-type wireless capsule endoscope (WCE), and the synchronous rotation of the WCE is converted to its translational motion in intestinal tract. In order to preliminarily verify the feasibility of this method, a handheld actuator (HA) controlled by micro controller unit, a magnetic spiral-type WCE and a bracket were fabricated, theoretical analysis and simulations about the control distance of this method were performed, and in ex-vivo tests were examined in porcine small intestine to verify the control distance and control performances of this method. It was demonstrated that this method showed good performances in controlling the translational motion of the magnetic spiral-type WCE, and this method has great potential to be used in clinical application. - Highlights: • A new magnetic control method for spiral-type wireless capsule endoscope is proposed. • Wireless capsule endoscope rotates synchronously with external permanent magnet. • The method controls the wireless capsule endoscope well in porcine small intestine. • Long control distance makes the method may be used in future medical application. • Experimental setup has great advantages: high cost performance and easy operation.

  3. Minnowbrook VI: 2009 Workshop on Flow Physics and Control for Internal and External Aerodynamics

    Science.gov (United States)

    LaGraff, John E.; Povinelli, Louis A.; Gostelow, J. Paul; Glauser, Mark

    2010-01-01

    Topics covered include: Flow Physics and control for Internal and External Aerodynamics (not in TOC...starts on pg13); Breaking CFD Bottlenecks in Gas-Turbine Flow-Path Design; Streamwise Vortices on the Convex Surfaces of Circular Cylinders and Turbomachinery Blading; DNS and Embedded DNS as Tools for Investigating Unsteady Heat Transfer Phenomena in Turbines; Cavitation, Flow Structure and Turbulence in the Tip Region of a Rotor Blade; Development and Application of Plasma Actuators for Active Control of High-Speed and High Reynolds Number Flows; Active Flow Control of Lifting Surface With Flap-Current Activities and Future Directions; Closed-Loop Control of Vortex Formation in Separated Flows; Global Instability on Laminar Separation Bubbles-Revisited; Very Large-Scale Motions in Smooth and Rough Wall Boundary Layers; Instability of a Supersonic Boundary-Layer With Localized Roughness; Active Control of Open Cavities; Amplitude Scaling of Active Separation Control; U.S. Air Force Research Laboratory's Need for Flow Physics and Control With Applications Involving Aero-Optics and Weapon Bay Cavities; Some Issues Related to Integrating Active Flow Control With Flight Control; Active Flow Control Strategies Using Surface Pressure Measurements; Reduction of Unsteady Forcing in a Vaned, Contra-Rotating Transonic Turbine Configuration; Active Flow Control Stator With Coanda Surface; Controlling Separation in Turbomachines; Flow Control on Low-Pressure Turbine Airfoils Using Vortex Generator Jets; Reduced Order Modeling Incompressible Flows; Study and Control of Flow Past Disk, and Circular and Rectangular Cylinders Aligned in the Flow; Periodic Forcing of a Turbulent Axisymmetric Wake; Control of Vortex Breakdown in Critical Swirl Regime Using Azimuthal Forcing; External and Turbomachinery Flow Control Working Group; Boundary Layers, Transitions and Separation; Efficiency Considerations in Low Pressure Turbines; Summary of Conference; and Final Plenary Session

  4. Implementation and evaluation of a National External Quality Control Program for Cervical Cytology in Mexico

    Directory of Open Access Journals (Sweden)

    Flisser Ana

    2002-01-01

    Full Text Available Objective. To evaluate cytology laboratories and the performance of cytotechnologists for establishing efficient external quality control for Mexico's National Program for the Prevention and Control of Cervical Cancer. Material and Methods. During January and February 1998, an on-site evaluation of all cytology laboratories of the Ministry of Health found that only 70% of the microscopes were in adequate working conditions, reagents were out of date, and working conditions were sub-optimal. A program for external quality control based on proficiency testing was established for cytotechnologists. Fifty slide sets with 20 Papanicolaou slides and 10 photographic slides were prepared. The sets were given to the cytotechnologists for evaluation and again one year later by courier. Results. Twenty-one percent of microscopes were repaired and 9% replaced; reagents were distributed and laboratory facilities improved. Only 16% of cytotechnologists passed the initial proficiency test. Cytotechnologists received a refresher training course: one year later 67% of them passed the proficiency test. To ascertain that each slide was correctly diagnosed, 41 sets were rescreened by expert cytopathologists or cytologists and their diagnoses compared to the original ones. Thirty-seven sets had 86% to 96% concordance. Conclusions. This new system for external quality control of cervical cytology allowed the opportune and reliable evaluation of the performance of cytotechnologists.

  5. Externally controlled triggered-release of drug from PLGA micro and nanoparticles.

    Directory of Open Access Journals (Sweden)

    Xin Hua

    Full Text Available Biofilm infections are extremely hard to eradicate and controlled, triggered and controlled drug release properties may prolong drug release time. In this study, the ability to externally control drug release from micro and nanoparticles was investigated. We prepared micro/nanoparticles containing ciprofloxacin (CIP and magnetic nanoparticles encapsulated in poly (lactic-co-glycolic acid PLGA. Both micro/nanoparticles were observed to have narrow size distributions. We investigated and compared their passive and externally triggered drug release properties based on their different encapsulation structures for the nano and micro systems. In passive release studies, CIP demonstrated a fast rate of release in first 2 days which then slowed and sustained release for approximately 4 weeks. Significantly, magnetic nanoparticles containing systems all showed ability to have triggered drug release when exposed to an external oscillating magnetic field (OMF. An experiment where the OMF was turned on and off also confirmed the ability to control the drug release in a pulsatile manner. The magnetically triggered release resulted in a 2-fold drug release increase compared with normal passive release. To confirm drug integrity following release, the antibacterial activity of released drug was evaluated in Pseudomonas aeruginosa biofilms in vitro. CIP maintained its antimicrobial activity after encapsulation and triggered release.

  6. Identification and robust control of linear parameter-varying systems

    Science.gov (United States)

    Lee, Lawton Hubert

    This dissertation deals with linear parameter-varying (LPV) systems: linear dynamic systems that depend on time-varying parameters. These systems appear in gain scheduling problems, and much recent research has been devoted to their prospective usefulness for systematic gain scheduling. We primarily focus on robust control of uncertain LPV systems and identification of LPV systems that are modelable as linear-fractional transformations (LFTs). Using parameter-dependent quadratic Lyapunov functions, linear matrix inequalities (LMIs), and scaled small-gain arguments, we define notions of stability and induced-{cal L}sb2 performance for uncertain LPV systems whose parameters and rates of parameter variation satisfy given bounds. The performance criterion involves integral quadratic constraints and implies naturally parameter-dependent induced-{cal L}sb2 norm bounds. We formulate and solve an {cal H}sb{infty}-like control problem for an LPV plant with measurable parameters and an "Output/State Feedback" structure: the feedback outputs include some noiselessly measured states. Necessary and sufficient solvability conditions reduce to LMIs that can be solved approximately using finite-dimensional convex programming. Reduced-order LPV controllers are constructed from the LMI solutions. A D-K iteration-like procedure provides robustness to structured, time-varying, parametric uncertainty. The design method is applied to a motivating example: flight control for the F-16 VISTA throughout its subsonic flight envelope. Parameter-dependent weights and {cal H}sb{infty} design principles describe the performance objectives. Closed-loop responses exhibited by nonlinear simulations indicate satisfactory flying qualities. Identification of linear-fractional LPV systems is treated using maximum-likelihood parameter estimation. Computing the gradient and Hessian of a maximum-likelihood cost function reduces to simulating one LPV filter per identified parameter. We use nonlinear

  7. Linear, Parameter-Varying Control of Aeroservoelastic Systems

    Science.gov (United States)

    Moreno Chicunque, Claudia Patricia

    Modern aircraft designers are adopting light-weight, high-aspect ratio flexible wings to improve performance and reduce operation costs. A technical challenge associated with these designs is that the large deformations in flight of the wings lead to adverse interactions between the aircraft aerodynamic forces and structural forces. These adverse interactions produce excessive vibrations that can degrade flying qualities and may result in severe structural damages or catastrophic failure. This dissertation is focused on the application of multivariable robust control techniques for suppression of these adverse interactions in flexible aircraft. Here, the aircraft coupled nonlinear equations of motion are represented in the linear, parameter-varying framework. These equations account for the coupled aerodynamics, rigid body dynamics, and deformable body dynamics of the aircraft. Unfortunately, the inclusion of this coupled dynamics results in high-order models that increase the computational complexity of linear, parameter-varying control techniques. This dissertation addresses three key technologies for linear, parameter-varying control of flexible aircraft: (i) linear, parameter-varying model reduction; (ii) selection of actuators and sensors for vibration suppression; and (iii) design of linear, parameter-varying controllers for vibration suppression. All of these three technologies are applied to an experimental research platform located at the University of Minnesota. The objective of this dissertation is to provide to the flight control community with a set of design methodologies to safely exploit the benefits of light-weight flexible aircraft.

  8. Human ECG signal parameters estimation during controlled physical activity

    Science.gov (United States)

    Maciejewski, Marcin; Surtel, Wojciech; Dzida, Grzegorz

    2015-09-01

    ECG signal parameters are commonly used indicators of human health condition. In most cases the patient should remain stationary during the examination to decrease the influence of muscle artifacts. During physical activity, the noise level increases significantly. The ECG signals were acquired during controlled physical activity on a stationary bicycle and during rest. Afterwards, the signals were processed using a method based on Pan-Tompkins algorithms to estimate their parameters and to test the method.

  9. Actively controlled tuning of an external cavity diode laser by polarization spectroscopy.

    Science.gov (United States)

    Führer, Thorsten; Stang, Denise; Walther, Thomas

    2009-03-30

    We report on an universal method to achieve and sustain a large mode-hop free tuning range of an external cavity diode laser. By locking one of the resonators using a closed loop control based on polarization spectroscopy while tuning the laser we achieved mode-hop free tuning of up to 130 GHz with a non AR-coated, off-the-shelf laser diode.

  10. Multiobjective insensitive design of airplane control systems with uncertain parameters

    Science.gov (United States)

    Schy, A. A.; Giesy, D. P.

    1981-01-01

    A multiobjective computer-aided design algorithm has been developed which minimizes the sensitivity of the design objectives to uncertainties in system parameters. The more important uncertain parameters are described by a gaussian random vector with known covariance matrix, and a vector sensitivity objective function is defined as the probabilities that the design objectives will violate specified requirements constraints. Control system parameters are found which minimize the sensitivity vector in a Pareto-optimal sense, using constrained minimization algorithms. Example results are shown for lateral stability augmentation system (SAS) design for three Shuttle flight conditions.

  11. QUALITY CONTROL PARAMETERS OF BRIHAT DASHAMULA TAILA: A PRELIMINARY STUDY

    Directory of Open Access Journals (Sweden)

    Sharma Vinay

    2011-05-01

    Full Text Available Standard analytical parameters of a number of Ayurvedic oils have been described in API. Brihat Dashamula Taila is one of the most commonly used oil by Ayurvedic Physicians. But there no standard analytical parameters are available in any authentic texts. Therefore this study aimed to set the quality control parameters with SOP of Brihat Dashamula Taila and found values like Refractive index (1.47 at 400C, specific gravity (0.923 at 250C Acid value (1.2, Iodine value (92.6 and Saponification value (86.34 may be considered as standard.

  12. Terminal sliding mode control for coordinated motion of a space rigid manipulator with external disturbance

    Institute of Scientific and Technical Information of China (English)

    GUO Yi-shen; CHEN Li

    2008-01-01

    The control problem of coordinated motion of a free-floating space rigid manipulator with external disturbance is discussed. By combining linear momentum conversion and the Lagrangian approach, the full-control dynamic equation and the Jacobian relation of a free-floating space rigid manipulator are established and then inverted to the state equation for control design. Based on the terminal sliding mode control (SMC) technique, a mathematical expression of the terminal sliding surface is proposed. The terminal SMC scheme is then developed for coordinated motion between the base's attitude and the end-effect or of the free-floating space manipulator with external disturbance. This proposed control scheme not only guarantees the existence of the sliding phase of the closed-loop system, but also ensures that the output tracking error converges to zero in finite time. In addition, because the initial system state is always at the terminal sliding surface, the control scheme can eliminate reaching phase of the SMC and guarantee global robustness and stability of the closed-loop system. A planar free-floating space rigid manipulator is simulated to verify the feasibility of the proposed control scheme.

  13. Use of a Two-Axis Joystick for Control of Externally Powered, Shoulder Disarticulation Prostheses

    Science.gov (United States)

    Lipschutz, Robert D.; Lock, Blair; Sensinger, Jonathon; Schultz, Aimee E.; Kuiken, Todd A.

    2015-01-01

    We explored a new method for simple and accurate control of shoulder movement for externally powered shoulder disarticulation prostheses using a two-axis joystick. Ten subjects with intact shoulders and arms were tested to determine the average amount of shoulder motion and force available for control of an electronic input device. This information was then applied to two different input strategies in order to examine their effectiveness: (1) a traditional strategy implemented with a rocker potentiometer and a pair of force-sensing resistors (FSRs), and (2) a strategy implemented with a two-axis joystick. Three able-bodied subjects and two subjects with shoulder disarticulation amputations attempted to control an experimental powered shoulder using both control strategies. Two powered arms were tested, one with powered flexion/extension and humeral rotation, and one with powered flexion/extension and adduction/abduction. Overwhelmingly, the subjects preferred the joystick control, as it was more intuitively linked with their shoulder movement. Additionally, two motions (one in each axis) could be controlled simultaneously. This pilot study provides valuable insight into an effective means of controlling high-level, externally powered prostheses via a two-axis joystick. PMID:21938653

  14. 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.

  15. Application of Improved Genetic Algorithm in PID Controller Parameters Optimization

    Directory of Open Access Journals (Sweden)

    Ying Chen

    2013-01-01

    Full Text Available Ying Chen, Yong-jie Ma, Wen-xia Yun College of Physics and Electronic Engineering, Northwest Normal University, Anning Road no.967 ,Lanzhou,China,0931-7971503 e-mail:chenying1386685@126.com Abstract The setting and optimization of Proportion Integration Differentiation(PID parameters have been always the important study topics in the automatic control field. The current optimization design methods are often difficult to consider the system requirements for quickness ,reliability and robustness .So a method of PID controller parameters optimization based on Improved Genetic Algorithm(IGA is presented .Simulations with Matlab have proved that the control performance index based on IGA is better than that of the GA method and Z-N method, and is a method which has good practical value of the PID parameter setting and optimization .

  16. Structured Linear Parameter Varying Control of Wind Turbines

    DEFF Research Database (Denmark)

    Adegas, Fabiano Daher; Sloth, Christoffer; Stoustrup, Jakob

    2012-01-01

    is presented. We specifically consider variable-speed, variable-pitch wind turbines with faults on actuators and sensors. Linear parameter-varying (LPV) controllers can be designed by a proposed method that allows the inclusion of faults in the LPV controller design. Moreover, the controller structure can......High performance and reliability are required for wind turbines to be competitive within the energy market. To capture their nonlinear behavior, wind turbines are often modeled using parameter-varying models. In this chapter, a framework for modelling and controller design of wind turbines...... be arbitrarily chosen: static output feedback, dynamic (reduced order) output feedback, decentralized, among others. The controllers are scheduled on an estimated wind speed to manage the parametervarying nature of the model and on information from a fault diagnosis system. The optimization problems involved...

  17. Study on a magnetic spiral-type wireless capsule endoscope controlled by rotational external permanent magnet

    Science.gov (United States)

    Ye, Bo; Zhang, Wei; Sun, Zhen-jun; Guo, Lin; Deng, Chao; Chen, Ya-qi; Zhang, Hong-hai; Liu, Sheng

    2015-12-01

    In this paper, the authors propose rotating an external permanent magnet (EPM) to manipulate the synchronous rotation of a magnetic spiral-type wireless capsule endoscope (WCE), and the synchronous rotation of the WCE is converted to its translational motion in intestinal tract. In order to preliminarily verify the feasibility of this method, a handheld actuator (HA) controlled by micro controller unit, a magnetic spiral-type WCE and a bracket were fabricated, theoretical analysis and simulations about the control distance of this method were performed, and in ex-vivo tests were examined in porcine small intestine to verify the control distance and control performances of this method. It was demonstrated that this method showed good performances in controlling the translational motion of the magnetic spiral-type WCE, and this method has great potential to be used in clinical application.

  18. Control of a Modular Multilevel Converter STATCOM under internal and external unbalances

    DEFF Research Database (Denmark)

    Tsolaridis, Georgios; Kontos, E.; Parikh, Harsh;

    2016-01-01

    This paper develops a complete control scheme for the Modular Multilevel Converter (MMC) in a STATCOM application. The focus is laid on the internal balancing of the converter and its reliable operation under internal mismatches as well as under external unbalanced conditions. The leg energy...... controller ensures that the sum of the capacitor voltages of each phase are equal. An intuitive arm energy controller is also implemented which allows the decoupled control of the energy levels of every arm. The control performance of the STATCOM was evaluated under asymmetrical grid faults...... and the simulation results verified the capability to provide maximum reactive power to the AC grid while maintaining internal balance through the individual control of each arm energy level....

  19. Control of a Modular Multilevel Converter STATCOM under internal and external unbalances

    DEFF Research Database (Denmark)

    Tsolaridis, Georgios; Kontos, E.; Parikh, Harsh

    2016-01-01

    This paper develops a complete control scheme for the Modular Multilevel Converter (MMC) in a STATCOM application. The focus is laid on the internal balancing of the converter and its reliable operation under internal mismatches as well as under external unbalanced conditions. The leg energy...... and the simulation results verified the capability to provide maximum reactive power to the AC grid while maintaining internal balance through the individual control of each arm energy level....... controller ensures that the sum of the capacitor voltages of each phase are equal. An intuitive arm energy controller is also implemented which allows the decoupled control of the energy levels of every arm. The control performance of the STATCOM was evaluated under asymmetrical grid faults...

  20. Modeling and Simulation of Quay Crane Control System for PID Controller Optimal Parameters Determination

    OpenAIRE

    Tomas Eglynas; Audrius Senulis; Marijonas Bogdevičius; Arūnas Andziulis; Mindaugas Jusis

    2016-01-01

    The main control object of Quay crane, which is operating in seaport intermodal terminal cargo loading and unloading process, is the crane trolley. One of the main frequent problem, which occurs, is the swinging of the container. This swinging is caused not only by external forces but also by the movement of the trolley. The research results of recent years produced various types of control algorithms by the other researchers. The control algorithms are solving separate control problems of Qu...

  1. 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.

  2. Control of chaos in an external-cavity multi-quantum-well laser subjected to dual-wedges and optical dual-feedback

    Institute of Scientific and Technical Information of China (English)

    YAN SenLin

    2009-01-01

    A multi-parameter chaos-control method used to control chaos in an external cavity multi-quantum-well (MQW) laser via the dual-wedges and external delayed optical dual-feedback is presented. The physical model of the laser dynamic is established under the conditions of the dual-wedges and dual-feedback light control. The frequency detuning and stable ranges of the control system are theoretically demon-strated. The optical-length of the feedback light may be adjusted by shifting horizontally or sliding the dual-wedges relatively in the external optical road, which will alter the delaying time and feedback in-tensity of the dual-feedback light. Accordingly, the multi-parameter chaos-control of the optical dual-feedback may be achieved physically. The numerical simulations approve that the chaotic laser may be controlled into a stable state, a single-periodic state and multi-periodic states, and the con-trolled periodic pulse power may be increased.

  3. Locus of control of behaviour: is high externality associated with substance misuse?

    Science.gov (United States)

    Haynes, P; Ayliffe, G

    1991-09-01

    Personal control and responsibility are key themes in the therapeutic use of 'motivational interviewing'. This popular method of counselling has suggested that clients need to believe they have a significant degree of control over their behaviour if they are to make progress. Using a well validated psychological test on locus of control of behaviour, our research sought to establish whether active misusers really believed they had less personal control than non-misusers. To establish this a sample of misusers was tested and compared with three diverse, comparable groups. Possible confounding factors such as age, sex and class were controlled for. T tests established a significant difference between the active misusers and the other sampled groups. Further, a regression analysis of variance, calculated to explain the differing external scores offered no reasonable explanation as far as age, sex and class were concerned. Alternatively, self diagnosed substance misuse accounted for 23% of the variation in scores. We concluded, therefore, that high externality scores are a good indicator of active misusing behaviour and that beliefs about personal control are important to address, if one is to increase the chances of a positive client outcome.

  4. Externalizing behavior and impulsivity in the children of alcoholics: A case-control study

    Directory of Open Access Journals (Sweden)

    Ayyanar Sugaparaneetharan

    2016-01-01

    Full Text Available Context: Reduced behavioural inhibition, characterized by impulsivity and disruptive behaviour disorders, has been identified as a developmental precursor of alcoholism with a considerable genetic component. Aims: The present study aimed to assess whether children of fathers with alcohol dependence have high impulsivity and externalizing behaviours. Setting and Design: Observational case-control study, done in a tertiary care teaching hospital of Southern India. Materials and Methods: The present case-control study recruited 50 children aged 7 to 14 years of fathers with alcohol dependence and 50 age- and gender-matched children of fathers without alcohol dependence. The two groups were compared using the DSM-IV-TR criteria for ADHD, the Barratt Impulsivity Scale (BIS and the Child Behaviour Checklist (CBCL. Statistical Analysis Used: Descriptive statistics used to summarise the study findings. Cases and controls were compared on BIS and CBCL scores using a general linear model (GLM. All analyses were two tailed and test P value <0.05 was considered significant. Results: The children of fathers with alcohol dependence were more likely to meet criteria for ADHD (30% versus 10%, χ2 = 6.250, P = 0.012. After controlling for age and gender, impulsivity scores on the BIS tended to be higher in the cases (F = 2.410, P = 0.055 than controls, mainly in the non-planning domains (F = 3.650, P = 0.008. Similarly, externalizing behaviours on CBCL were more common in the cases than controls (F = 2.817, P = 0.029. Conclusions: Children of fathers with alcohol dependence had greater impulsivity and externalizing behaviours. This may represent a behavioural phenotype as well as a potential target for early intervention.

  5. Distributed Coordination Control of First- and Second-Order Multiagent Systems with External Disturbances

    Directory of Open Access Journals (Sweden)

    Lipo Mo

    2015-01-01

    Full Text Available This paper is devoted to the coordination control problem of heterogeneous first- and second-order multiagent systems with external disturbances. First, by applying the theory of eigenvalue and the method of model transformation, the consensus state of heterogeneous multiagent systems is obtained. Then, based on the consensus state, the control output is defined, and sufficient conditions are derived to make all agents reach consensus with H∞ performance. Finally, simulation results are provided to demonstrate the effectiveness of the presented results.

  6. Robust H-infinity control in CD players to suppress external disturbances and defects on the disk

    DEFF Research Database (Denmark)

    Vidal, E.; Andersen, B.; Karlsson, R.V.

    2000-01-01

    This paper deals with the design and implementation of robust H8 controllers in order to suppress external disturbances and defects on the disk. Due to the conflictive requirements concerning the bandwidth of the closed loop to suppress external disturbances and defects on the disk, two independent...... H8 controllers are designed where norm-bounded uncertainties are assumed. The controllers are evaluated through an experiment showing better performance than a classical PID controller...

  7. Robust H-infinity control in CD players to suppress external disturbances and defects on the disk

    DEFF Research Database (Denmark)

    Vidal, E.; Andersen, B.; Karlsson, R.V.

    2000-01-01

    This paper deals with the design and implementation of robust H8 controllers in order to suppress external disturbances and defects on the disk. Due to the conflictive requirements concerning the bandwidth of the closed loop to suppress external disturbances and defects on the disk, two independe...... H8 controllers are designed where norm-bounded uncertainties are assumed. The controllers are evaluated through an experiment showing better performance than a classical PID controller...

  8. Social Self Control, Externalizing Behavior, and Peer Liking Among Children with ADHD-CT: A Mediation Model.

    Science.gov (United States)

    Rosen, Paul J; Vaughn, Aaron J; Epstein, Jeffery N; Hoza, Betsy; Arnold, L Eugene; Hechtman, Lily; Molina, Brooke S G; Swanson, James M

    2014-05-01

    This study investigated the role of externalizing behavior as a mediator of the relation between social self-control and peer liking among children with Attention-Deficit/Hyperactivity Disorder-Combined Type (ADHD-CT). A model was proposed whereby externalizing behavior would fully statistically account for the direct relation of social self-control to peer liking. One hundred seventy two children ages 7.0-9.9 years with ADHD-CT were rated by their teachers regarding their social self-control and by their parents and teachers regarding their rates of externalizing behavior. Same-sex classmates provided ratings of overall liking. Structural Equation Modeling (SEM) was used to assess the proposed model. Results supported the proposed model of externalizing behavior as fully statistically accounting for the relation of social self-control to peer liking. This study demonstrated the crucial role that externalizing behaviors play in the social impairment commonly seen among children with ADHD-CT.

  9. Extracting Chaos Control Parameters from Time Series Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Santos, R B B [Centro Universitario da FEI, Avenida Humberto de Alencar Castelo Branco 3972, 09850-901, Sao Bernardo do Campo, SP (Brazil); Graves, J C, E-mail: rsantos@fei.edu.br [Instituto Tecnologico de Aeronautica, Praca Marechal Eduardo Gomes 50, 12228-900, Sao Jose dos Campos, SP (Brazil)

    2011-03-01

    We present a simple method to analyze time series, and estimate the parameters needed to control chaos in dynamical systems. Application of the method to a system described by the logistic map is also shown. Analyzing only two 100-point time series, we achieved results within 2% of the analytical ones. With these estimates, we show that OGY control method successfully stabilized a period-1 unstable periodic orbit embedded in the chaotic attractor.

  10. Phase Synchronization as a Mechanism of Controlling Spatiotemporal Chaos via External Periodic Signal

    Institute of Scientific and Technical Information of China (English)

    SANG Hai-Bo; HE Kai-Fen

    2004-01-01

    @@ We find that phase synchronization (PS) is a mechanism in which the spatiotemporal chaos (STC) can be suppressed to a spatially regular (SR) state by applying an external periodic signal in a one-dimensional driven drift-wave system. In the driving wave coordinate, the nonlinear system can be transformed to a set of coupled oscillators moving in a periodic potential. In this multi-dimensional system, the internal modes are slaved one by one through PS by the control signal. Two types of responses of the internal modes to the external periodic signal are observed. For some modes, the stabilization is through frequency-locking; while for the other modes,a special kind of PS without frequency-locking, namely multi-looping PS, is developed.

  11. Different configurations of laser vibrometry for quality control of electric motors with external rotor

    Science.gov (United States)

    Chiariotti, P.; Ciarmatori, R.; Castellini, P.; Bastari, A.; Paone, N.

    2012-06-01

    When designing a test bench for vibration based diagnostics of machines with external rotating parts, such as electric motors having a rotating external rotor, one may choose among single point vibrometry, rotational vibrometry or in-plane vibrometry. The paper discusses these different options, taking the assumption that the minimum number of measuring instruments is preferred when instrumenting a quality control system and provides an insight into advantages and limitations of each instrument. In particular the following issues are discussed: a) possible installation lay-outs; b) alignment problems (and possible advantages for diagnostics), c) typical signals and diagnostic features which can be observed. The research presented refers to electric motors for home appliances, but potentially has wider application fields to other rotating machines.

  12. Fuzzy Control of Nitrate Recirculation and External Carbon Addition in A/O Nitrogen Removal Process

    Institute of Scientific and Technical Information of China (English)

    马勇; 彭永臻; 王淑莹; 王晓莲

    2005-01-01

    Nitrogen and phosphorous concentrations of effluent water must be taken into account for the design and operation of wastewater treatment plants. In addition, the requirement for effluent quality is becoming strict.Therefore, intelligent control approaches are recently required in removing biological nutrient. In this study, fuzzy control has been successfully applied to improve the nitrogen removal. Experimental results showed that a close relationship between nitrate concentration and oxidation-reduction potential (ORP) at the end of anoxic zone was found for anoxic/oxic (A/O) nitrogen removal process treating synthetic wastewater. ORP can be used as online fuzzy control parazneter of nitrate recirculation and external carbon addition. The established fuzzy logic controller that includes two inputs and one output can maintain ORP value at-86 mV and -90 mV by adjusting the nitrate recirculation flow and external carbon dosage respectively to realize the optimal control of nitrogen removal, improving the effluent quality and reducing the operating cost.

  13. 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.

  14. Observer-based approximate optimal tracking control for time-delay systems with external disturbances

    Science.gov (United States)

    Su, Hao; Tang, Gong-You

    2016-09-01

    This paper proposes a successive approximation design approach of observer-based optimal tracking controllers for time-delay systems with external disturbances. To solve a two-point boundary value problem with time-delay and time-advance terms and obtain the optimal tracking control law, two sequences of vector differential equations are constructed first. Second, the convergence of the sequences of the vector differential equations is proved to guarantee the existence and uniqueness of the control law. Third, a design algorithm of the optimal tracking control law is presented and the physically realisable problem is addressed by designing a disturbance state observer and a reference input state observer. An example of an industrial electric heater is given to demonstrate the efficiency of the proposed approach.

  15. 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.

  16. A measurement system of magnetism parameters for motion control

    Institute of Scientific and Technical Information of China (English)

    WANG Xiao-ming; HUANG Xu-yan; LEI Tao

    2007-01-01

    Magnetism parameters vary with the position and the speed of electromagnetic actuator's motion parts. The measurement unit presented in the paper can be applied to get the position and the speed feedback information from the measurement of electromagnetism parameters, and can constitute the untouched feedback sensing unit in the closed-loop motion control, and it adapts to the diversified feedback control of electromagnetic actuator. The digital miniaturization meter, based on MSP430 single chip processor, which can do the multiformance evaluation and improvement, and also the online quality control in production process. Both real-time data graph and data table can be displayed in the meter. The paper presents the system's structure, describes the principle, discusses the working modes, and shows the software flowchart and the measuring results.

  17. Vascular inward rectifier K+ channels as external K+ sensors in the control of cerebral blood flow.

    Science.gov (United States)

    Longden, Thomas A; Nelson, Mark T

    2015-04-01

    For decades it has been known that external K(+) ions are rapid and potent vasodilators that increase CBF. Recent studies have implicated the local release of K(+) from astrocytic endfeet-which encase the entirety of the parenchymal vasculature-in the dynamic regulation of local CBF during NVC. It has been proposed that the activation of KIR channels in the vascular wall by external K(+) is a central component of these hyperemic responses; however, a number of significant gaps in our knowledge remain. Here, we explore the concept that vascular KIR channels are the major extracellular K(+) sensors in the control of CBF. We propose that K(+) is an ideal mediator of NVC, and discuss KIR channels as effectors that produce rapid hyperpolarization and robust vasodilation of cerebral arterioles. We provide evidence that KIR channels, of the KIR 2 subtype in particular, are present in both the endothelial and SM cells of parenchymal arterioles and propose that this dual positioning of KIR 2 channels increases the robustness of the vasodilation to external K(+), enables the endothelium to be actively engaged in NVC, and permits electrical signaling through the endothelial syncytium to promote upstream vasodilation to modulate CBF.

  18. Optimization of control parameters for petroleum waste composting

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Composting is being widely employed in the treatment of petroleum waste. The purpose of this study was to find the optimum control parameters for petroleum waste in-vessel composting. Various physical and chemical parameters were monitored to evaluate their influence on the microbial communities present in composting. The CO2 evolution and the number of microorganisms were measured as theactivity of composting. The results demonstrated that the optimum temperature, pH and moisture content were 56.5-59.5, 7.0-8.5 and 55%-60%, respectively. Under the optimum conditions, the removal efficiency of petroleum hydrocarbon reached 83.29% after 30 days composting.

  19. Stabilization of parameters of asynchronous electric drive with vector control

    Directory of Open Access Journals (Sweden)

    N.J. Khlopenko

    2015-03-01

    Full Text Available A problem of stabilization of parameters of the asynchronous electric drive vector control system is considered. Usually such systems have two control channels. The synthesis of stabilizing controllers is made for every control channel. The evaluation of variables of system status is made by observer. The problem of stabilizing controllers and observer synthesis consists in calculation of state feedback intensification. Its solution is based on existing approaches form vector control theories, matrix inequalities and Lyapunov stability. Several synthesis methods of stabilizing controllers have been proposed. Structural scheme of vector control system and observer has been built. The simulation of transient processes in the vector control system is carried out with MATLAB computing environment. The most important property of obtained solution is Lyapunov stability of control loops closed-looped by state vectors. Transient processes have been investigated on the particular example. Graphs confirming stability of such processes that flow in the vector control system in minimal period of time have been plotted down.

  20. Improvements in springback control by external force laser-assisted sheet bending of titanium and aluminum alloys

    Science.gov (United States)

    Gisario, A.; Barletta, M.; Venettacci, S.

    2016-12-01

    The present investigation deals with an external-force laser assisted bending process of Grade 2 CP titanium and AA 7075 T6 aluminum sheets. High bending angles, sharp fillet radii and control of springback were achieved by tuning the contact pressure of a hydraulically driven tool with the local and selective heating of the bending zone by irradiation with a high power diode laser. First, the role of laser operational parameters, namely power, scanning speed and number of passes, in metal bending was investigated, allowing to identify the most suitable processing window. Second, a custom-built equipment to measure the bending angle during the forming process, together with the metal temperature, was implemented. Real-time monitoring of the bending angle and temperature allowed to evaluate the continuous evolution of the geometry of the metal substrates during the external force laser-assisted bending process. Experimental results showed both metal sheets could be bent to high angles with very low fillet radii by the appropriate combination of the tooling contact pressure and selective laser heating of the bending zone. Laser heating also reduces the risk of rupture in both metals during bending at high angles, limits the springback extent up to 10 times on titanium and 30 times on aluminum in comparison with conventional bending process and does not affect significantly the visual appearance of the bending zone.

  1. The impact of cognitive control, incentives, and working memory load on the P3 responses of externalizing prisoners.

    Science.gov (United States)

    Baskin-Sommers, Arielle R; Krusemark, Elizabeth A; Curtin, John J; Lee, Christopher; Vujnovich, Aleice; Newman, Joseph P

    2014-02-01

    The P3 amplitude reduction is one of the most common correlates of externalizing. However, few studies have used experimental manipulations designed to challenge different cognitive functions in order to clarify the processes that impact this reduction. To examine factors moderating P3 amplitude in trait externalizing, we administered an n-back task that manipulated cognitive control demands, working memory load, and incentives to a sample of male offenders. Offenders with high trait externalizing scores did not display a global reduction in P3 amplitude. Rather, the negative association between trait externalizing and P3 amplitude was specific to trials involving inhibition of a dominant response during infrequent stimuli, in the context of low working memory load, and incentives for performance. In addition, we discuss the potential implications of these findings for externalizing-related psychopathologies. The results complement and expand previous work on the process-level dysfunction contributing to externalizing-related deficits in P3.

  2. Control of light polarization using optically spin-injected vertical external cavity surface emitting lasers

    Energy Technology Data Exchange (ETDEWEB)

    Frougier, J., E-mail: julien.frougier@thalesgroup.com; Jaffrès, H.; Deranlot, C.; George, J.-M. [Unité Mixte de Physique CNRS-Thales and Université Paris Sud 11, 1 av. Fresnel, 91767 Palaiseau (France); Baili, G.; Dolfi, D. [Thales Research and Technology, 1 av. Fresnel, 91767 Palaiseau (France); Alouini, M. [Institut de Physique de Rennes, 263 Avenue Général Leclerc, 35042 Rennes (France); Sagnes, I. [Laboratoire de Photonique et de Nanostructures, Route de Nozay, 91460 Marcoussis (France); Garnache, A. [Institut d' électronique du Sud CNRS UMR5214, Université Montpellier 2 Place Eugene Bataillon, 34095 Montpellier (France)

    2013-12-16

    We fabricated and characterized an optically pumped (100)-oriented InGaAs/GaAsP multiple quantum well Vertical External Cavity Surface Emitting Laser (VECSEL). The structure is designed to allow the integration of a Metal-Tunnel-Junction ferromagnetic spin-injector for future electrical injection. We report here the control at room temperature of the electromagnetic field polarization using optical spin injection in the active medium of the VECSEL. The switching between two highly circular polarization states had been demonstrated using an M-shaped extended cavity in multi-modes lasing. This result witnesses an efficient spin-injection in the active medium of the LASER.

  3. Kink topology control by high-frequency external forces in nonlinear Klein-Gordon models

    Science.gov (United States)

    Alvarez-Nodarse, R.; Quintero, N. R.; Mertens, F. G.

    2014-10-01

    A method of averaging is applied to study the dynamics of a kink in the damped double sine-Gordon equation driven by both external (nonparametric) and parametric periodic forces at high frequencies. This theoretical approach leads to the study of a double sine-Gordon equation with an effective potential and an effective additive force. Direct numerical simulations show how the appearance of two connected π kinks and of an individual π kink can be controlled via the frequency. An anomalous negative mobility phenomenon is also predicted by theory and confirmed by simulations of the original equation.

  4. Kink topology control by high-frequency external forces in nonlinear Klein-Gordon models.

    Science.gov (United States)

    Alvarez-Nodarse, R; Quintero, N R; Mertens, F G

    2014-10-01

    A method of averaging is applied to study the dynamics of a kink in the damped double sine-Gordon equation driven by both external (nonparametric) and parametric periodic forces at high frequencies. This theoretical approach leads to the study of a double sine-Gordon equation with an effective potential and an effective additive force. Direct numerical simulations show how the appearance of two connected π kinks and of an individual π kink can be controlled via the frequency. An anomalous negative mobility phenomenon is also predicted by theory and confirmed by simulations of the original equation.

  5. H Infinity Control of Magnetic Bearings to Ensure Both System and External Periodic Disturbance Robustness

    Science.gov (United States)

    Jiang, Yuhong; Zmood, R. B.

    1996-01-01

    Both self-excited and forced disturbances often lead to severe rotor vibrations in a magnetic bearing systems with long slender shafts. This problem has been studied using the H-infinity method, and stability with good robustness can be achieved for the linearized model of a magnetic bearing when small transient disturbances are applied. In this paper, the H-infinity control method for self-excited and forced disturbances is first reviewed. It is then applied to the control of a magnetic bearing rotor system. In modelling the system, the shaft is first discretized into 18 finite elements and then three levels of condensation are applied. This leads to a system with three masses and three compliant elements which can be described by six state variable coordinates. Simulation of the resultant system design has been performed at speeds up to 10,000 rpm. Disturbances in terms of different initial displacements, initial impulses, and external periodic inputs have been imposed. The simulation results show that good stability can be achieved under these different transient disturbances using the proposed controller while at the same time reducing the sensitivity to external periodic disturbances.

  6. 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.

  7. Control synthesis of linear distributed parameter switched systems

    Institute of Scientific and Technical Information of China (English)

    Leping Bao; Shumin Fei; Lin Chai

    2015-01-01

    The control synthesis for switched systems is extended to distributed parameter switched systems in Hilbert space. Based on semigroup and operator theory, by means of multiple Lyapunov method incorporated average dwel time approach, sufficient con-ditions are derived in terms of linear operator inequalities frame-work for distributed parameter switched systems. Being applied to one dimensional heat propagation switched systems, these lin-ear operator inequalities are reduced to linear matrix inequalities subsequently. In particular, the state feedback gain matrices and the switching law are designed, and the state decay estimate is explicitly given whose decay coefficient completely depends on the system’s parameter and the boundary condition. Final y, two numerical examples are given to il ustrate the proposed method.

  8. Scale Control and Quality Management of Printed Image Parameters

    Science.gov (United States)

    Novoselskaya, O. A.; Kolesnikov, V. L.; Solov'eva, T. V.; Nagornova, I. V.; Babluyk, E. B.; Trapeznikova, O. V.

    2017-06-01

    The article provides a comparison of the main valuation techniques for a regulated parameter of printability of the offset paper by current standards GOST 24356 and ISO 3783: 2006. The results of development and implementation of a complex test scale for management and control the quality of printed production are represented. The estimation scale is introduced. It includes normalized parameters of print optical density, print uniformity, picking out speed, the value of dot gain, print contrast with the added criteria of minimizing microtexts, a paper slip, resolution threshold and effusing ability of paper surface. The results of analysis allow directionally form surface properties of the substrate to facilitate achieving the required quality of the printed image parameters, i. e. optical density of a print at a predetermined level not less than 1.3, the print uniformity with minimal deviation of dot gain about the order of 10 per cents.

  9. Optimal vibration control of curved beams using distributed parameter models

    Science.gov (United States)

    Liu, Fushou; Jin, Dongping; Wen, Hao

    2016-12-01

    The design of linear quadratic optimal controller using spectral factorization method is studied for vibration suppression of curved beam structures modeled as distributed parameter models. The equations of motion for active control of the in-plane vibration of a curved beam are developed firstly considering its shear deformation and rotary inertia, and then the state space model of the curved beam is established directly using the partial differential equations of motion. The functional gains for the distributed parameter model of curved beam are calculated by extending the spectral factorization method. Moreover, the response of the closed-loop control system is derived explicitly in frequency domain. Finally, the suppression of the vibration at the free end of a cantilevered curved beam by point control moment is studied through numerical case studies, in which the benefit of the presented method is shown by comparison with a constant gain velocity feedback control law, and the performance of the presented method on avoidance of control spillover is demonstrated.

  10. Evaluation of control parameters of the activated sludge process

    Energy Technology Data Exchange (ETDEWEB)

    Stall, T.R.; Sherrard, J.H.

    1978-03-01

    The evaluation of control parameters of the activated sludge process was effected with a laboratory-scale, completely mixed process employing internal cell recycle and an artificial wasterwater over a wide spectrum of conditions at full-scale facilities. The parameters: food-microorganism ratio, specific utilization rate, COD or BOD sludge age, and aeration and total system mean cell residence time can all be used to control an activated sludge wastewater treatment plant. Because of the sensitivity of the COD or BOD sludge age (when compared with measures of mean cell residence time), its use may be of limited value. The aeration basin cell residence time may be favored over the total system mean cell residence time because of the ease in measuring aeration basin solids and the difficulty in measuring solids concentration at the bottom of the secondary clarifier and in the recycle line.

  11. 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.

  12. Control rod drive WWER 1000 – tuning of input parameters

    OpenAIRE

    Markov P.; Valtr O.

    2007-01-01

    The article picks up on the contributions presented at the conferences Computational Mechanics 2005 and 2006, in which a calculational model of an upgraded control rod linear stepping drive for the reactors WWER 1000 (LKP-M/3) was described and results of analysis of dynamical response of its individual parts when moving up- and downwards were included. The contribution deals with the tuning of input parameters of the 3rd generation drive with the objective of reaching its running as smooth a...

  13. Limiting Behaviour in Parameter Optimal Iterative Learning Control

    Institute of Scientific and Technical Information of China (English)

    David H. Owens; Maria Tomas-Rodriguez; Jari J. Hat(o)nen

    2006-01-01

    This paper analyses the concept of a Limit Set in Parameter Optimal Iterative Learning Control (ILC). We investigate the existence of stable and unstable parts of Limit Set and demonstrates that they will often exist in practice.This is illustrated via a 2-dimensional example where the convergence of the learning algorithm is analyzed from the error's dynamic behaviour. These ideas are extended to the N-dimensional cases by analogy and example.

  14. Robust parameter design for automatically controlled systems and nanostructure synthesis

    Science.gov (United States)

    Dasgupta, Tirthankar

    2007-12-01

    This research focuses on developing comprehensive frameworks for developing robust parameter design methodology for dynamic systems with automatic control and for synthesis of nanostructures. In many automatically controlled dynamic processes, the optimal feedback control law depends on the parameter design solution and vice versa and therefore an integrated approach is necessary. A parameter design methodology in the presence of feedback control is developed for processes of long duration under the assumption that experimental noise factors are uncorrelated over time. Systems that follow a pure-gain dynamic model are considered and the best proportional-integral and minimum mean squared error control strategies are developed by using robust parameter design. The proposed method is illustrated using a simulated example and a case study in a urea packing plant. This idea is also extended to cases with on-line noise factors. The possibility of integrating feedforward control with a minimum mean squared error feedback control scheme is explored. To meet the needs of large scale synthesis of nanostructures, it is critical to systematically find experimental conditions under which the desired nanostructures are synthesized reproducibly, at large quantity and with controlled morphology. The first part of the research in this area focuses on modeling and optimization of existing experimental data. Through a rigorous statistical analysis of experimental data, models linking the probabilities of obtaining specific morphologies to the process variables are developed. A new iterative algorithm for fitting a Multinomial GLM is proposed and used. The optimum process conditions, which maximize the above probabilities and make the synthesis process less sensitive to variations of process variables around set values, are derived from the fitted models using Monte-Carlo simulations. The second part of the research deals with development of an experimental design methodology, tailor

  15. Parameters determination and bolting control of gateway floor

    Institute of Scientific and Technical Information of China (English)

    GOU Pan-feng; XlN Ya-jun

    2011-01-01

    Gateway floor heave control is the key to guarantee mine safe and efficient production.Through analysis of floor instability characteristics and bolting control,gateway floor strata show second level stress under abutment pressure,which causes plastic flow failure in floor strata; gateway floor instability shows mainly shear-break slippage of “triangle sliding body”.Mechanics of floor bolting is mainly a function of connection and combination.Main area of bolting control lies in two gateway floor angles.The paper analyzes mechanics principle of gateway floor instability,constructs stability mechanics model of gateway floor bolting,obtains gateway floor stability criterion of different bolting angles and optimum formula of bolting parameters,carries out the engineering example,and guides better field application.It provides theoretical base for bolting gateway floor instability control.

  16. 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.

  17. Linear parameter-varying control for engineering applications

    CERN Document Server

    White, Andrew P; Choi, Jongeun

    2013-01-01

    The objective of this brief is to carefully illustrate a procedure of applying linear parameter-varying (LPV) control to a class of dynamic systems via a systematic synthesis of gain-scheduling controllers with guaranteed stability and performance. The existing LPV control theories rely on the use of either H-infinity or H2 norm to specify the performance of the LPV system.  The challenge that arises with LPV control for engineers is twofold. First, there is no systematic procedure for applying existing LPV control system theory to solve practical engineering problems from modeling to control design. Second, there exists no LPV control synthesis theory to design LPV controllers with hard constraints. For example, physical systems usually have hard constraints on their required performance outputs along with their sensors and actuators. Furthermore, the H-infinity and H2 performance criteria cannot provide hard constraints on system outputs. As a result, engineers in industry could find it difficult to utiliz...

  18. Relevant parameters in models of cell division control

    Science.gov (United States)

    Grilli, Jacopo; Osella, Matteo; Kennard, Andrew S.; Lagomarsino, Marco Cosentino

    2017-03-01

    A recent burst of dynamic single-cell data makes it possible to characterize the stochastic dynamics of cell division control in bacteria. Different models were used to propose specific mechanisms, but the links between them are poorly explored. The lack of comparative studies makes it difficult to appreciate how well any particular mechanism is supported by the data. Here, we describe a simple and generic framework in which two common formalisms can be used interchangeably: (i) a continuous-time division process described by a hazard function and (ii) a discrete-time equation describing cell size across generations (where the unit of time is a cell cycle). In our framework, this second process is a discrete-time Langevin equation with simple physical analogues. By perturbative expansion around the mean initial size (or interdivision time), we show how this framework describes a wide range of division control mechanisms, including combinations of time and size control, as well as the constant added size mechanism recently found to capture several aspects of the cell division behavior of different bacteria. As we show by analytical estimates and numerical simulations, the available data are described precisely by the first-order approximation of this expansion, i.e., by a "linear response" regime for the correction of size fluctuations. Hence, a single dimensionless parameter defines the strength and action of the division control against cell-to-cell variability (quantified by a single "noise" parameter). However, the same strength of linear response may emerge from several mechanisms, which are distinguished only by higher-order terms in the perturbative expansion. Our analytical estimate of the sample size needed to distinguish between second-order effects shows that this value is close to but larger than the values of the current datasets. These results provide a unified framework for future studies and clarify the relevant parameters at play in the control of

  19. The Czech External Quality Control system in medical microbiology and parasitology.

    Science.gov (United States)

    Slosárek, M; Kríz, B

    2000-11-01

    The External Quality Control (EQC) system in activities of laboratories engaged in medical microbiology and parasitology was established in the Czech Republic in 1993 when to the first laboratories which applied coded serum samples were sent for diagnosis of viral hepatitis and bacterial strains for identification. In the course of years the number of control areas increased and in 2000 there were 31 and the number of those interested in participation in EQC increased from 79 in 1993 to 434 in 2000. This year a total of 13,239 samples will be sent to laboratories. Gradually thus almost all microbiological and parasitological laboratories concerned with examination of clinical material became involved. Seven-year experience with EQC in the Czech Republic revealed that gradually the results of various examinations became more accurate, that methods became standardized and the most suitable examination sets are used.

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

    Institute of Scientific and Technical Information of China (English)

    Suman Panthee; P.K. Singh; Ashutosh Kainthola; T.N. Singh

    2016-01-01

    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 defor-mation 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 persis-tence, 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.

  1. External corrosion control of northern pipelines : influence of construction conditions on the performance of coatings

    Energy Technology Data Exchange (ETDEWEB)

    Papavinasam, S.; Doiron, A.

    2008-09-15

    Risk management is a key consideration in the construction of northern pipelines operating in harsh environments with extreme temperature conditions and ground movement. As such, it is important to acquire information on the properties of construction materials, including the steel itself, the girth welds that are made in the field and the coating and cathodic protection (CP) that will protect the pipes from corrosion and degradation. The use of polymeric coatings and CP are standard procedures for controlling external corrosion on buried or submerged metallic piping systems. When both systems fail, the pipeline is susceptible to stress corrosion cracking (SCC). This paper described methodologies to evaluate both external coatings under conditions anticipated during construction of the pipelines and to simulate the influence of freeze-thaw settlements on coating. The performance of an external pipeline coating depends on the events that occur during the 5 stages of the coating lifetime, notably manufacture, application, transportation, installation and operation. This paper reported on laboratory experiments that were conducted for 0, 4, 8 and 12 months to simulate 4 months of Canadian winter conditions in which samples were exposed to temperatures as low as -45 degrees C. Cathodic disbondment, impact resistance, flexibility, peel resistance, shearing and soil adhesion were tested. Field experiments were also carried out at Devon and Norman Wells for 0, 12, 24 and 36 months to investigate impact resistance and the squeeze test. The studies showed that Canadian Standards Association (CSA) standards CSA Z662, CSA Z245.20 and CSA Z245.21 adequately cover evaluation of coatings for northern pipelines. However, the pipelines specimens should be exposed for at least 4 months in order to evaluate the effects of low temperatures. 21 refs., 10 tabs., 25 figs., 4 appendices.

  2. 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...

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

    Science.gov (United States)

    Wilson, David G; Robinett, III, Rush D

    2015-01-06

    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.

  4. SDRE Based Attitude Control Using Modified Rodriguez Parameters

    CERN Document Server

    Doruk, R Ozgur

    2011-01-01

    The purpose of this paper is to present an application of the State Dependent Riccati Equation (SDRE) method to satellite attitude control where the satellite kinematics is modeled by Modified Rodriguez Parameters (MRP). The SDRE methodology is applicable on special forms of nonlinear systems where satellite model is one of the candidates. It is not easy to find an analytical solution from the SDRE. Thus point wise solutions are interpolated with respect to the operating conditions. The point wise solutions are obtained from the MATLAB algorithms which are derived from the positive definite solutions of the SDRE. The global stability analysis is difficult due to the nature of the methodology. The resultant attitude controllers outside the breakpoints (the selected operating conditions for interpolation) are suboptimal. The performance of the designs is examined by simulations on MATLAB - Simulink environment. The simulation results show that, the designed attitude controllers are working satisfactorily even i...

  5. 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.

  6. Global Multivariable Control of Permanent Magnet Synchronous Motor for Mechanical Elastic Energy Storage System under Multiclass Nonharmonic External Disturbances

    Directory of Open Access Journals (Sweden)

    Yang Yu

    2014-01-01

    Full Text Available For the technology of mechanical elastic energy storage utilizing spiral torsion springs as the energy storage media presented previously, a global multivariable control algorithm based on nonlinear internal model principle under multiclass external disturbances is proposed. The nonlinear external disturbances with nonharmonic periodic characteristics are generated by multiclass nonlinear external systems. New equations of nonlinear internal model are designed to estimate the multiclass external disturbances. On the basis of constructing the control law of nominal system, a state feedback controller is designed to guarantee the closed-loop system globally uniformly bounded, and a Lyapunov function is constructed to theoretically prove the global uniform boundedness of the multivariable closed-loop system signals. The simulation results verify the correctness and effectiveness of the presented algorithm.

  7. Controllability of brushite structural parameters using an applied magnetic field.

    Science.gov (United States)

    Kuznetsov, V N; Yanovska, A A; Stanislavov, A S; Danilchenko, S N; Kalinkevich, A N; Sukhodub, L F

    2016-03-01

    The paper studies the influence of low intensity static magnetic field on brushite structural and microstructural parameters using the X-ray diffraction and the transmission electron microscopy. This effect was shown to have various influences on DCPD (Dicalcium Phosphate Dihydrate) structure depending on a magnetic field configuration or time of synthesis, which allows achieving controllability of the main properties of an obtained material. The influence of the magnetic field leads mostly to the decrease of crystallite sizes with no impact on the crystal lattice parameters. In (0 2 0) and (1 5 0) planes the growth of crystallite sizes is observed after 2 and 3 days of crystallization, respectively. The analysis of different contributions to peak broadening in [0 b 0] direction showed a similar trend for the crystallite sizes with the lower lattice microstrains after 2 days of synthesis. The effect similar to the preferred orientation was observed and classified with the Harris method.

  8. Quantum dynamics of tight-binding networks coherently controlled by external fields

    Institute of Scientific and Technical Information of China (English)

    YANG Shuo; SONG Zhi; SUN Chang-pu

    2007-01-01

    With some reviews on the investigations on the schemes for quantum state transfer based on spin systems,we discuss the quantum dynamics of magnetically-controlled networks for Bloch electrons. The networks are constructed by connecting several tight-binding chains with uniform nearest-neighbor hopping integrals. The external magnetic field and the connecting hopping integrals can be used to control the intrinsic properties of the networks. For several typical networks, rigorous results are shown for some specific values of external magnetic field and the connecting hopping integrals: a complicated network can be reduced into a virtual network, which is a direct sum of some independent chains with uniform nearest-neighbor hopping integrals. These reductions are due to the fermionic statistics and the Aharonov-Bohm effects. In application, we study the quantum dynamics of wave packet motion of Bloch electrons in such networks. For various geometrical configurations, these networks can function as some optical devices,such as beam splitters, switches and interferometers. When the Bloch electrons as Gaussian wave packets input these devices, various quantum coherence phenomena can be observed, e.g., the perfect quantum state transfer without reflection in a Y-shaped beam, the multi-mode entanglers of electron wave by star-shaped network, magnetically controlled switches, and Bloch electron interferometer with the lattice Aharonov-Bohm effects. With these quantum coherent features, the networks are expected to be used as quantum information processors for the fermion system based on the possible engineered solid state systems, such as the array of quantum dots that can be implemented experimentally.

  9. The Impact of Externalization of Migration Controls on the Rights of Asylum Seekers and Other Migrants

    Directory of Open Access Journals (Sweden)

    Bill Frelick

    2016-12-01

    Full Text Available Wars, conflict, and persecution have forced more people to flee their homes and seek refuge and safety elsewhere than at any time since the end of World War II. As displaced people and other migrants increasingly move out of the conflict-ridden and less developed regions of their displacement and into relatively rich and stable regions of the world, the countries of destination are increasingly working to contain and even stem the migration flow before it reaches their shores. Perversely, countries that have developed generally rights-sensitive standards and procedures for assessing protection claims of asylum seekers within their jurisdictions have simultaneously established barriers that prevent migrants, including asylum seekers, from setting foot on their territories or otherwise triggering protection obligations. Consequently, those who would otherwise have been able to avail themselves of asylum procedures, social support, and decent reception conditions are often relegated to countries of first arrival or transit that have comparatively less capacity to ensure protection of human rights in accordance with international standards.This paper seeks to develop a working definition of the externalization of migration controls and how such externalization of the border implicates the human rights of migrants, and asylum seekers in particular. Although the majority of those migrants seeking legal protections stay in countries neighboring their own, hundreds of thousands continue their journeys in search of protection and stability in more distant states, including in the European Union, the United States, and Australia. In response to the significant increase in asylum seekers arriving at their borders, all three entities have significantly increased deterrence measures with the hopes of keeping new arrivals from entering. This paper will thus highlight a number of the most troubling externalization strategies used by the European Union, the

  10. Dynamic control for nanostructures through slowly ramping parameters

    Science.gov (United States)

    Yoo, Jaeyun; Blick, Robert; Ahn, Kang-Hun

    2016-06-01

    We propose a nanostructure control method which uses slowly ramping parameters. We demonstrate the dynamics of this method in both a nonlinear classical system and a quantum system. When a quantum mechanical two-level atom (quantum dot) is irradiated by an electric field with a slowly increasing frequency, there exists a sudden transition from ground (excited) to excited (ground) state. This occurs when the ramping rate is smaller than the square of the Rabi frequency. The transition arises when its "instant frequency"—the time derivative of the driving field phase—matches the resonance frequency, satisfying the Fermi golden rule. We also find that the parameter ramping is an efficient control manner for classical nanomechanical shuttles. For ramping of driving amplitudes, the shuttle's mechanical oscillation is amplified and even survives when the ramping is stopped outside the original oscillation region. This strange oscillation is due to the entrance into a multistable dynamic region in phase space. For ramping of driving frequencies, an onset of oscillation arises when the instant frequency enters the oscillation region. Thus, regardless of being classical or quantum, the instant frequency is physically relevant. We discuss in which conditions the dynamic control is efficient.

  11. Online Verification of Control Parameter Calculations in Communication Based Train Control System

    CERN Document Server

    Bu, Lei; Wang, Linzhang; Li, Xuandong

    2011-01-01

    Communication Based Train Control (CBTC) system is the state-of-the-art train control system. In a CBTC system, to guarantee the safety of train operation, trains communicate with each other intensively and adjust their control modes autonomously by computing critical control parameters, e.g. velocity range, according to the information they get. As the correctness of the control parameters generated are critical to the safety of the system, a method to verify these parameters is a strong desire in the area of train control system. In this paper, we present our ideas of how to model and verify the control parameter calculations in a CBTC system efficiently. - As the behavior of the system is highly nondeterministic, it is difficult to build and verify the complete behavior space model of the system online in advance. Thus, we propose to model the system according to the ongoing behavior model induced by the control parameters. - As the parameters are generated online and updated very quickly, the verification...

  12. 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.

  13. Control rod drive WWER 1000 – tuning of input parameters

    Directory of Open Access Journals (Sweden)

    Markov P.

    2007-10-01

    Full Text Available The article picks up on the contributions presented at the conferences Computational Mechanics 2005 and 2006, in which a calculational model of an upgraded control rod linear stepping drive for the reactors WWER 1000 (LKP-M/3 was described and results of analysis of dynamical response of its individual parts when moving up- and downwards were included. The contribution deals with the tuning of input parameters of the 3rd generation drive with the objective of reaching its running as smooth as possible so as to get a minimum wear of its parts as a result and hence to achieve maximum life-time.

  14. Airport Casualties: Non-Admission and Return Risks at Times of Internalized/Externalized Border Controls

    Directory of Open Access Journals (Sweden)

    Maybritt Jill Alpes

    2015-09-01

    Full Text Available This article analyzes what can happen to forced returnees upon arrival in their country of nationality. Subjective configurations of state agents in the Global South have created return risks, which in turn transform subjectivities of post-colonial citizens. The article contributes to this Special Issue by tracing repercussions of the externalization and internalization of border controls. In the case of Cameroon, these connections have resulted in the criminalization of emigration. Aspiring migrants are prosecuted if their departure projects fail to respect the entry requirements of countries in the Global North. The article is based on research conducted in Douala, Cameroon, in the form of discussions with control agents at the international airport, investigations at a prison, a review of related case law, police registers and interviews with Cameroonians returnees (November 2013–January 2014. Border controls and connected anti-fraud programs suppress family-based forms of solidarity and allow only for subjectivities rooted in state-managed forms of national identity. The article illustrates how efforts to combat fraud fuel corruption in returnees’ social networks, whereby, instead of receiving remittances, families in emigration countries have to mobilize financial resources in order to liberate returnees from police stations or prison complexes. Migration related detention of nationals in the Global South highlights the growing significance of exit controls in migration management.

  15. [External quality control system in medical microbiology and parasitology in the Czech Republic].

    Science.gov (United States)

    Slosárek, M; Petrás, P; Kríz, B

    2004-11-01

    The External Quality Control System (EQAS) of laboratory activities in medical microbiology and parasitology was implemented in the Czech Republic in 1993 with coded sera samples for diagnosis of viral hepatitis and bacterial strains for identification distributed to first participating laboratories. The number of sample types reached 31 in 2003 and the number of participating laboratories rised from 79 in 1993 to 421 in 2003. As many as 15.130 samples were distributed to the participating laboratories in 2003. Currently, almost all microbiology and parasitology laboratories in the Czech Republic involved in examination of clinical material participate in the EQAS. Based on the 11-year experience gained with the EQAS in the Czech Republic, the following benefits were observed: higher accuracy of results in different tests, standardisation of methods and the use of most suitable test kits.

  16. Repetitive transcranial magnetic stimulator with controllable pulse parameters

    Science.gov (United States)

    Peterchev, Angel V.; Murphy, David L.; Lisanby, Sarah H.

    2011-06-01

    The characteristics of transcranial magnetic stimulation (TMS) pulses influence the physiological effect of TMS. However, available TMS devices allow very limited adjustment of the pulse parameters. We describe a novel TMS device that uses a circuit topology incorporating two energy storage capacitors and two insulated-gate bipolar transistor (IGBT) modules to generate near-rectangular electric field pulses with adjustable number, polarity, duration, and amplitude of the pulse phases. This controllable pulse parameter TMS (cTMS) device can induce electric field pulses with phase widths of 10-310 µs and positive/negative phase amplitude ratio of 1-56. Compared to conventional monophasic and biphasic TMS, cTMS reduces energy dissipation up to 82% and 57% and decreases coil heating up to 33% and 41%, respectively. We demonstrate repetitive TMS trains of 3000 pulses at frequencies up to 50 Hz with electric field pulse amplitude and width variability less than the measurement resolution (1.7% and 1%, respectively). Offering flexible pulse parameter adjustment and reduced power consumption and coil heating, cTMS enhances existing TMS paradigms, enables novel research applications and could lead to clinical applications with potentially enhanced potency.

  17. Chimeric External Control to Quantify Cell Free DNA in Plasma Samples by Real Time PCR

    Science.gov (United States)

    Eini, Maryam; Behzad-Behbahani, Abbas; Takhshid, Mohammad Ali; Ramezani, Amin; Rafiei Dehbidi, Gholam Reza; Okhovat, Mohammad Ali; Farhadi, Ali; Alavi, Parniyan

    2016-01-01

    Background: DNA isolation procedure can significantly influence the quantification of DNA by real time PCR specially when cell free DNA (cfDNA) is the subject. To assess the extraction efficiency, linearity of the extraction yield, presence of co-purified inhibitors and to avoid problems with fragment size relevant to cfDNA, development of appropriate External DNA Control (EDC) is challenging. Using non-human chimeric nucleotide sequences, an EDC was developed for standardization of qPCR for monitoring stability of cfDNA concentration in blood samples over time. Methods: A0 DNA fragment of 167 bp chimeric sequence of parvovirus B19 and pBHA designated as EDC fragment was designed. To determine the impact of different factors during DNA extraction processing on quantification of cfDNA, blood samples were collected from normal subjects and divided into aliquots with and without specific treatment. In time intervals, the plasma samples were isolated. The amplicon of 167 bp EDC fragment in final concentration of 1.1 pg/500 μl was added to each plasma sample and total DNA was extracted by an in house method. Relative and absolute quantification real time PCR was performed to quantify both EDC fragment and cfDNA in extracted samples. Results: Comparison of real time PCR threshold cycle (Ct) for cfDNA fragment in tubes with and without specific treatment indicated a decrease in untreated tubes. In contrast, the threshold cycle was constant for EDC fragment in treated and untreated tubes, indicating the difference in Ct values of the cfDNA is because of specific treatments that were made on them. Conclusions: Spiking of DNA fragment size relevant to cfDNA into the plasma sample can be useful to minimize the bias due to sample preparation and extraction processing. Therefore, it is highly recommended that standard external DNA control be employed for the extraction and quantification of cfDNA for accurate data analysis. PMID:27141267

  18. Exploring control parameters of two photon processes in solutions

    Indian Academy of Sciences (India)

    Debabrata Goswami; Amit Nag

    2012-01-01

    Two-photon microscopy depends extensively on the two-photon absorption cross-sections of biologically relevant chromophores. High repetition rate (HRR) lasers are essential in multiphoton microscopy for generating satisfactory signal to noise at low average powers. However, HRR lasers generate thermal distortions in samples even with the slightest single photon absorption. We use an optical chopper with HRR lasers to intermittently `blank’ irradiation and effectively minimize thermal effects to result in a femtosecond z-scan setup that precisely measures the two-photon absorption (TPA) cross-sections of chromophores. Though several experimental factors impact such TPA measurements, a systematic effort to modulate and influence TPA characteristics is yet to evolve. Here, we present the effect of several control parameters on the TPA process that are independent of chromophore characteristics for femtosecond laser pulse based measurements; and demonstrate how the femtosecond laser pulse repetition rate, chromophore environment and incident laser polarization can become effective control parameters for such nonlinear optical properties.

  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. Five years of experience with a national external quality control program for the culture and identification of Neisseria gonorrhoeae.

    OpenAIRE

    Griffin, C W; Mehaffey, M A; Cook, E C

    1983-01-01

    In response to a need for monitoring the proficiency of public health laboratories in isolating and identifying Neisseria gonorrhoeae, a national external quality control program was developed. Essentially, three types of freeze-dried samples, representing different levels of challenge for identification, were sent to laboratories for testing. The quality of the samples was confirmed by external reference laboratories, and stability of the samples was confirmed by thermal degradation tests be...

  1. Data-Driven H∞ Control for Nonlinear Distributed Parameter Systems.

    Science.gov (United States)

    Luo, Biao; Huang, Tingwen; Wu, Huai-Ning; Yang, Xiong

    2015-11-01

    The data-driven H∞ control problem of nonlinear distributed parameter systems is considered in this paper. An off-policy learning method is developed to learn the H∞ control policy from real system data rather than the mathematical model. First, Karhunen-Loève decomposition is used to compute the empirical eigenfunctions, which are then employed to derive a reduced-order model (ROM) of slow subsystem based on the singular perturbation theory. The H∞ control problem is reformulated based on the ROM, which can be transformed to solve the Hamilton-Jacobi-Isaacs (HJI) equation, theoretically. To learn the solution of the HJI equation from real system data, a data-driven off-policy learning approach is proposed based on the simultaneous policy update algorithm and its convergence is proved. For implementation purpose, a neural network (NN)- based action-critic structure is developed, where a critic NN and two action NNs are employed to approximate the value function, control, and disturbance policies, respectively. Subsequently, a least-square NN weight-tuning rule is derived with the method of weighted residuals. Finally, the developed data-driven off-policy learning approach is applied to a nonlinear diffusion-reaction process, and the obtained results demonstrate its effectiveness.

  2. Aging and balance control in response to external perturbations: role of anticipatory and compensatory postural mechanisms.

    Science.gov (United States)

    Kanekar, Neeta; Aruin, Alexander S

    2014-06-01

    The ability to maintain balance deteriorates with increasing age. Anticipatory and compensatory postural adjustments (APAs and CPAs, respectively), both, are known to be affected in the elderly. We examined the effect of aging on the ability of older adults to utilize APAs and its effect on subsequent control of posture (CPAs). Ten elderly individuals were exposed to external predictable and unpredictable perturbations applied to the upper body in the sagittal plane. Body kinematics, electromyographic activity of 13 muscles, and ground reaction forces were analyzed during the anticipatory and compensatory phases of postural control. The elderly were capable of recognizing an upcoming predictable perturbation and activated muscles prior to it. However, the older adults used different muscle strategies and sequence of muscle recruitment than that reported in young adults. Additionally, when the perturbations were unpredictable, no APAs were seen which resulted in large CPAs and greater peak displacements of the center of pressure (COP) and center of mass (COM) following perturbations. As opposed to this, when the perturbations were predictable, APAs were seen in older adults resulting in significantly smaller CPAs. The presence and utilization of APAs in older adults also improved postural stability following the perturbation as seen by significantly smaller COP and COM peak displacements. Using APAs in older adults significantly reduces the need for large CPAs, resulting in greater postural stability following a perturbation. The results provide a foundation for investigating the role of training in improving the interplay between anticipatory and compensatory postural control in older adults.

  3. 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.

  4. Nutritional screening: control of clinical undernutrition with analytical parameters

    Directory of Open Access Journals (Sweden)

    José Ignacio de Ulíbarri Pérez

    2014-04-01

    Full Text Available Objective: 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. Conclusion: 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.

  5. Advanced Instrumentation, Information, and Control Systems Technologies Pathway: FY 2016 External Review

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, Kenneth David [Idaho National Lab. (INL), Idaho Falls, ID (United States); Hallbert, Bruce Perry [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-11-01

    This report describes an External Review conducted by the LWRS Program Advanced Instrumentation, Information, and Control (II&C) Systems Technologies Pathway to solicit feedback on the topics and results of the ongoing II&C research program. This review was held in conjunction with the Nuclear Energy Institute (NEI) Digital I&C Working Group meeting that was held at Idaho National Laboratory (INL) on August 9-10, 2016. Given the opportunity to visit INL and see the pathway research projects, NEI agreed that the Working Group would serve as the External Review panel for the purpose of obtaining expert input on the value and timing of the research projects. This consisted of demonstrations in the Human Systems Simulation Laboratory followed by presentations on the II&C research program in general as well as the five technology development areas. Following the meeting, the presentations were sent to each of the attendees so they could review them in more detail and refer to them in completing the feedback form. Follow-up activities were conducted with the attendees following the meeting to obtain the completed feedback forms. A total of 13 forms were returned. The feedback forms were reviewed by the pathway to compile the data and comments received, which are documented in the report. In all, the feedback provided by the External Review participants is taken to be a strong endorsement of the types of projects being conducted by the pathway, the value they hold for the nuclear plants, and the general timing of need. The feedback aligns well with the priorities, levels of efforts allocated for the research projects, and project schedules. The feedback also represents realistic observations on the practicality of some aspects of implementing these technologies. In some cases, the participants provided thoughtful challenges to certain assumptions in the formulation of the technologies or in deployment plans. These deserve further review and revision of plans if warranted

  6. Resistance to temptation: the interaction of external and internal control on alcohol use during residential treatment for alcohol use disorder.

    Science.gov (United States)

    Soravia, Leila M; Schläfli, Katrin; Stutz, Sonja; Rösner, Susanne; Moggi, Franz

    2015-11-01

    There is evidence that drinking during residential treatment is related to various factors, such as patients' general control beliefs and self-efficacy, as well as to external control of alcohol use by program's staff and situations where there is temptation to drink. As alcohol use during treatment has been shown to be associated with the resumption of alcohol use after discharge from residential treatment, we aimed to investigate how these variables are related to alcohol use during abstinence-oriented residential treatment programs for alcohol use disorders (AUD). In total, 509 patients who entered 1 of 2 residential abstinence-oriented treatment programs for AUD were included in the study. After detoxification, patients completed a standardized diagnostic procedure including interviews and questionnaires. Drinking was assessed by patients' self-report of at least 1 standard drink or by positive breathalyzer testing. The 2 residential programs were categorized as high or low control according to the average number of tests per patient. Regression analysis revealed a significant interaction effect between internal and external control suggesting that patients with high internal locus of control and high frequency of control by staff demonstrated the least alcohol use during treatment (16.7%) while patients with low internal locus of control in programs with low external control were more likely to use alcohol during treatment (45.9%). No effects were found for self-efficacy and temptation. As alcohol use during treatment is most likely associated with poor treatment outcomes, external control may improve treatment outcomes and particularly support patients with low internal locus of control, who show the highest risk for alcohol use during treatment. High external control may complement high internal control to improve alcohol use prevention while in treatment. Copyright © 2015 The Authors. Alcoholism: Clinical and Experimental Research published by Wiley

  7. 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.

  8. 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.

  9. Nonlinear model predictive control using parameter varying BP-ARX combination model

    Science.gov (United States)

    Yang, J.-F.; Xiao, L.-F.; Qian, J.-X.; Li, H.

    2012-03-01

    A novel back-propagation AutoRegressive with eXternal input (BP-ARX) combination model is constructed for model predictive control (MPC) of MIMO nonlinear systems, whose steady-state relation between inputs and outputs can be obtained. The BP neural network represents the steady-state relation, and the ARX model represents the linear dynamic relation between inputs and outputs of the nonlinear systems. The BP-ARX model is a global model and is identified offline, while the parameters of the ARX model are rescaled online according to BP neural network and operating data. Sequential quadratic programming is employed to solve the quadratic objective function online, and a shift coefficient is defined to constrain the effect time of the recursive least-squares algorithm. Thus, a parameter varying nonlinear MPC (PVNMPC) algorithm that responds quickly to large changes in system set-points and shows good dynamic performance when system outputs approach set-points is proposed. Simulation results in a multivariable stirred tank and a multivariable pH neutralisation process illustrate the applicability of the proposed method and comparisons of the control effect between PVNMPC and multivariable recursive generalised predictive controller are also performed.

  10. Opportunism of University Lecturers As a Way to Adaptate the External Control Activities Strengthening

    Directory of Open Access Journals (Sweden)

    Margarita V. Kurbatova

    2016-09-01

    Full Text Available At the present the Russian government is undertaking a higher education system reform actively introducing management tools of new public management. Implementation of these instruments is accompanied by the transformation of universities in the customer-oriented organizations and lecturers into the employees. There is a substitution of incentives based on the existing informal norms of academic standards and reputation mechanisms of control to the incentives based on the quasi-market conditions artificially generated by the state and corresponding to the mechanisms of external assessment and monitoring. Practices changing used by lecturers to follow their interests is the inevitable result and more widespread form is opportunism. The purpose of the paper is to characterize the forms of manifestation of opportunistic behavior of university lecturers emerging as a result of changes in the nature of lecturers’ contract in the conditions of university governance managerisation. The main forms of lecturers’ opportunism and assesses of its degree based on data analysis of the two waves of the expert survey on the problems of assessing the impact of implementation mechanisms of external evaluation of their activities and the questionnaire survey of lecturers more than 40 Russian universities of different status are described as well as lecturers’ strategy of behavior, which are presented as a combination of different severity practices used by opportunistic behavior is highlighted. It shows the relation between the non-observance of academic freedom and the choice of lecturers’ strategies conduct. It is proved that the lecturers of Russian universities depending on the accumulated stocks of human and social capital as well as the resource capacity of separate universities are choosing different strategies to follow their own interests, which differ in the level of shirking in different areas of activity. All this is accompanied by

  11. Immobilization in External Rotation Versus Internal Rotation After Primary Anterior Shoulder Dislocation: A Meta-analysis of Randomized Controlled Trials.

    Science.gov (United States)

    Whelan, Daniel B; Kletke, Stephanie N; Schemitsch, Geoffrey; Chahal, Jaskarndip

    2016-02-01

    The recurrence rate after primary anterior shoulder dislocation is high, especially in young, active individuals. Recent studies have suggested external rotation immobilization as a method to reduce the rate of recurrent shoulder dislocation in comparison to traditional sling immobilization. To assess and summarize evidence from randomized controlled trials on the effect of internal rotation versus external rotation immobilization on the rate of recurrence after primary anterior shoulder dislocation. Meta-analysis. PubMed, MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials, and abstracts from recent proceedings were searched for eligible studies. Two reviewers selected studies for inclusion, assessed methodological quality, and extracted data. Six randomized controlled trials (632 patients) were included in this review. Demographic and prognostic variables measured at baseline were similar in the pooled groups. The average age was 30.1 years in the pooled external rotation group and 30.3 years in the pooled internal rotation group. Two studies found that external rotation immobilization reduced the rate of recurrence after initial anterior shoulder dislocation compared with conventional internal rotation immobilization, whereas 4 studies failed to find a significant difference between the 2 groups. This meta-analysis suggested no overall significant difference in the rate of recurrence among patients treated with internal rotation versus external rotation immobilization (risk ratio, 0.69; 95% CI, 0.42-1.14; P = .15). There was no significant difference in the rate of compliance between internal and external rotation immobilization (P = .43). The Western Ontario Shoulder Instability Index scores were pooled across 3 studies, and there was no significant difference between the 2 groups (P = .54). Immobilization in external rotation is not significantly more effective in reducing the recurrence rate after primary anterior shoulder dislocation than

  12. The Effects of Internal-External Locus of Control and Selected Demographic Variables on Rational-Irrational Beliefs.

    Science.gov (United States)

    Martin, Janice E.; And Others

    This study evaluated whether or not locus of control mediates rational-irrational beliefs. Data were generated investigating the impact of an internal-external orientation and selected demographic variables (age, race, gender, education, and occupation) on rational-irrational beliefs. Independent variables were locus of control and demographic…

  13. Does Parental Psychological Control Relate to Internalizing and Externalizing Problems in Early Childhood? An Examination Using the Berkeley Puppet Interview

    Science.gov (United States)

    Stone, Lisanne L.; Otten, Roy; Janssens, Jan M. A. M.; Soenens, Bart; Kuntsche, Emmanuel; Engels, Rutger C. M. E.

    2013-01-01

    Parental psychological control has been linked to symptoms of psychopathology in adolescence, yet less is known about its correlates in childhood. The current study is among the first to address whether psychological control is related to internalizing and externalizing problems in early childhood. A community sample of 298 children aged 7.04…

  14. Simulation studies on the effect of a buffer layer on the external parameters of hydrogenated amorphous silicon –– solar cells

    Indian Academy of Sciences (India)

    K Rajeev Kumar; M Zeman

    2008-10-01

    Device modeling of –– junction amorphous silicon solar cells has been carried out using the amorphous semiconductor analysis (ASA) simulation programme. The aim of the study was to explain the role of a buffer layer in between the - and -layers of the –– solar cell on the external parameters such as dark current density and open circuit voltage. Investigations based on the simulation of dark – characteristics revealed that as the buffer layer thickness increases the dark current for a given voltage decreases.

  15. A parameter-tuned genetic algorithm for statistically constrained economic design of multivariate CUSUM control charts: a Taguchi loss approach

    Science.gov (United States)

    Niaki, Seyed Taghi Akhavan; Javad Ershadi, Mohammad

    2012-12-01

    In this research, the main parameters of the multivariate cumulative sum (CUSUM) control chart (the reference value k, the control limit H, the sample size n and the sampling interval h) are determined by minimising the Lorenzen-Vance cost function [Lorenzen, T.J., and Vance, L.C. (1986), 'The Economic Design of Control Charts: A Unified Approach', Technometrics, 28, 3-10], in which the external costs of employing the chart are added. In addition, the model is statistically constrained to achieve desired in-control and out-of-control average run lengths. The Taguchi loss approach is used to model the problem and a genetic algorithm, for which its main parameters are tuned using the response surface methodology (RSM), is proposed to solve it. At the end, sensitivity analyses on the main parameters of the cost function are presented and their practical conclusions are drawn. The results show that RSM significantly improves the performance of the proposed algorithm and the external costs of applying the chart, which are due to real-world constraints, do not increase the average total loss very much.

  16. Adaptive tracking control of leader-following linear multi-agent systems with external disturbances

    Science.gov (United States)

    Lin, Hanquan; Wei, Qinglai; Liu, Derong; Ma, Hongwen

    2016-10-01

    In this paper, the consensus problem for leader-following linear multi-agent systems with external disturbances is investigated. Brownian motions are used to describe exogenous disturbances. A distributed tracking controller based on Riccati inequalities with an adaptive law for adjusting coupling weights between neighbouring agents is designed for leader-following multi-agent systems under fixed and switching topologies. In traditional distributed static controllers, the coupling weights depend on the communication graph. However, coupling weights associated with the feedback gain matrix in our method are updated by state errors between neighbouring agents. We further present the stability analysis of leader-following multi-agent systems with stochastic disturbances under switching topology. Most traditional literature requires the graph to be connected all the time, while the communication graph is only assumed to be jointly connected in this paper. The design technique is based on Riccati inequalities and algebraic graph theory. Finally, simulations are given to show the validity of our method.

  17. Development of semi-active hydraulic damper as active interaction control device to withstand external excitation

    Indian Academy of Sciences (India)

    Ming-Hsiang Shih; Wen-Pei Sung

    2014-02-01

    Semi-automatic control systems have the characteristics of being adaptable and requiring low energy. The objective of this research was to study the performance of an improved DSHD (Displacement Semi-Active Hydraulic Damper) by converting it to AIC (Active Interaction Control Device) with the addition of an accumulator. The prototype was tested using full-scale elements for examining the structural displacement, and typical responses of the interacting interface element developed in this research, the pressure variation of the pressure storage device, and the energy dissipation hysteresis loop when the structure installed with these elements is subjected to external force of various magnitude. The laboratory results confirm that the device developed in this research is capable of applying the energy dissipation characteristics of DSHD so that these elements are appropriate for developing the proposed AIC. The mutual interaction between the subordinate structure and the main structure to be protected is capable of transforming the quake energy applied to the main structure to the subordinate structure so that the objective of minimizing the deformation of main structural can be achieved.

  18. Aeroelastic passive control optimization of supersonic composite wing with external stores

    Science.gov (United States)

    Sulaeman, E.; Abdullah, N. A.; Kashif, S. M.

    2017-03-01

    This paper provides a study on passive aeroelastic control optimization, by means of aeroelastic tailoring, of a composite supersonic wing equipped with external stores. The objective of the optimization is to minimize wing weight by considering the aeroelastic flutter and divergence instability speeds as constraints at several flight altitudes. The optimization variables are the composite ply angle and skin thickness of the wing box, wing rib and its control surfaces. The aeroelastic instability speed is set as constraint such that it should be higher than the flutter speed of a metallic base line model of supersonic wing having previously published. A finite element analysis is applied to determine the stiffness and mass matric of the wing and its multi stores. The boundary element method in the form of doublet lattice method is used to model the unsteady aerodynamic load. The results indicate that, for the present wing configuration, the high modulus Graphite/Epoxy composite provides a desired higher flutter speed and lower wing weight compare to that of Kevlar/Epoxy composite as well as the base line metallic wing materials. The aeroelastic boundary thus can be enlarged to higher speed zone and in the same time reduce the structural weight which is important for a further optimization process.

  19. Key parameters controlling the performance of catalytic motors

    Science.gov (United States)

    Esplandiu, Maria J.; Afshar Farniya, Ali; Reguera, David

    2016-03-01

    The development of autonomous micro/nanomotors driven by self-generated chemical gradients is a topic of high interest given their potential impact in medicine and environmental remediation. Although impressive functionalities of these devices have been demonstrated, a detailed understanding of the propulsion mechanism is still lacking. In this work, we perform a comprehensive numerical analysis of the key parameters governing the actuation of bimetallic catalytic micropumps. We show that the fluid motion is driven by self-generated electro-osmosis where the electric field originates by a proton current rather than by a lateral charge asymmetry inside the double layer. Hence, the surface potential and the electric field are the key parameters for setting the pumping strength and directionality. The proton flux that generates the electric field stems from the proton gradient induced by the electrochemical reactions taken place at the pump. Surprisingly the electric field and consequently the fluid flow are mainly controlled by the ionic strength and not by the conductivity of the solution, as one could have expected. We have also analyzed the influence of the chemical fuel concentration, electrochemical reaction rates, and size of the metallic structures for an optimized pump performance. Our findings cast light on the complex chemomechanical actuation of catalytic motors and provide important clues for the search, design, and optimization of novel catalytic actuators.

  20. 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)

  1. Physiological parameters controlling plant-atmosphere ammonia exchange

    Science.gov (United States)

    Schjoerring, Jan K.; Husted, Søren; Mattsson, Marie

    Recent advances in characterizing the influence of different physiological and environmental parameters on NH 3 exchange between plants and the atmosphere are presented. A central parameter in controlling the rate and direction of NH 3 fluxes is the NH 3 compensation point. It may vary from below 1 to over 20 nmol NH 3 mol -1 air. High compensation points seem to be a result of high tissue N status, rapid absorption of NH +4 from the root medium and/or low activity of glutamine synthetase, a key enzyme in NH +4 assimilation. These conditions cause the NH +4 concentration in leaf apoplast and leaf cells to increase. The NH 3 compensation point also depends on plant developmental stage with peaks in NH 3 emission related to leaf senescence and N remobilization. The leaf temperature has a profound influence on the NH 3 compensation point: an increase in temperature from 15 to 30°C may cause a plant to switch from being a strong sink for atmospheric NH 3 to being a significant NH 3 source. Stomatal conductance for NH 3 relative to that of water vapour increases with tissue N status and with leaf senescence. At a given leaf temperature, the NH 3 compensation point can be successfully predicted on basis of the pH and NH +4 concentration in the apoplast of the mesophyll cells.

  2. [Impact of formulation and process parameters on the properties of chitosan-based microspheres prepared by external ionic gelation].

    Science.gov (United States)

    Kubánková, Romana; Vysloužil, Jakub; Kejdušová, Martina; Vetchý, David; Dvořáčková, Kateřina

    2014-06-01

    The aim of this experimental study was to optimize a preparation of microspheres from high viscosity chitosan by external ion gelation and to evaluate selected aspects of their preparation. For drug-free microparticles, the concentration of chitosan dispersions was chosen as a formulation variable; the position of instrument for a dispersion extrusion (horizontal vs. vertical) was evaluated as a process variable. On the basis of sphericity and equivalent diameter results, three different concentrations of chitosan dispersions were used for 5-aminosalicylic acid (5-ASA) encapsulation with the extrusion instrument in horizontal position, which was considered as the optimal. In consequent drug-loaded microparticle preparation, the influence of the concentration of chitosan dispersions and composition of hardening solution (10% sodium tripolyphosphate (TPP) vs. 10% TPP containing drug) was evaluated. In prepared 5-ASA microspheres it was found that the equivalent diameter increased with increasing chitosan concentration. In the case of sphericity, significant differences were not found. Samples prepared with the drug in both chitosan dispersion and hardening solution had a higher drug content, a smaller equivalent diameter and they showed a faster in vitro drug release in comparison with the samples prepared with the drug in chitosan dispersion only.

  3. The ploidy level of Synechocystis sp. PCC 6803 is highly variable and is influenced by growth phase and by chemical and physical external parameters.

    Science.gov (United States)

    Zerulla, Karolin; Ludt, Katharina; Soppa, Jörg

    2016-05-01

    Synechocystis sp. PCC 6803 is a cyanobacterial model strain widely used to study many biological processes and is also applied for the production of biopolymers. Recently, it was reported that two of its substrains are highly polyploid. To test whether this can be generalized to the whole strain, six substrains were selected and their ploidy levels quantified. The ploidy levels of all substrains were highly growth phase regulated and the copy number was on average about 20 at an OD750 of 0.1 and about 4 at an OD750 of 2.5. In addition to growth phase, external conditions were found to influence the ploidy level, i.e. the copy number was elevated at lower light intensity and at higher phosphate concentrations (53 and 35 copies, respectively). In the absence of external phosphate, considerable growth was observed, although growth rate and growth yield were much lower than in the presence of either orthophosphate or genomic DNA as external source of phosphate. A rapid reduction in genome copy number was observed during growth in the absence of phosphate, indicating that replication ceased and genomes were distributed to the daughter cells. During prolonged incubation of stationary-phase cultures in the absence of phosphate, the cells eventually became monoploid. Taking the data together, the ploidy level of Synechocystis sp. PCC 6803 is extremely variable and is influenced by both growth phase and physical and chemical environmental parameters.

  4. Self-Determination of Academic Standards by Children: Toward Freedom from External Control

    Science.gov (United States)

    Flexibrod, Jeffrey J.; O'Leary, K. Daniel

    1974-01-01

    With contingency reinforcement, students with externally imposed or self-determined academic standards did comparable work. When contingent reinforcement was dropped in an extinction phase, external imposition subjects tended to outperform self-determination subjects. Experiment serves to demonstrate the utility of self-management as an…

  5. Teaching social skills to adults with intellectual disabilities: a comparison of external control and problem-solving interventions.

    Science.gov (United States)

    O'Reilly, Mark F; Lancioni, Giulio E; Sigafoos, Jeff; O'Donoghue, Deirdre; Lacey, Claire; Edrisinha, Chaturi

    2004-01-01

    We compared the effectiveness of a problem-solving and an external control intervention to teach social skills to five adults with mild intellectual disabilities. The social skills of "responding to corrective feedback" and "managing conflict" were targeted for intervention. Each participant received the problem-solving intervention with one social skill and the external control intervention with the other social skill. The comparative effectiveness of the social skills training protocol was evaluated using individual participant alternating treatments designs. Little difference between the intervention protocol was observed in terms of acquisition, generalization, and maintenance of the social skills. Limitations of the current study and suggestions for future research are discussed.

  6. Numerical Investigation of Vortex Generator Flow Control for External-Compression Supersonic Inlets

    Science.gov (United States)

    Baydar, Ezgihan

    Vortex generators (VGs) within external-compression supersonic inlets for Mach 1.6 were investigated to determine their ability to increase total pressure recovery and reduce total pressure distortion. Ramp and vane-type VGs were studied. The geometric factors of interest included height, length, spacing, angle-of-incidence, and positions upstream and downstream of the inlet terminal shock. The flow through the inlet was simulated numerically through the solution of the steady-state, Reynolds-averaged Navier-Stokes equations on multi-block, structured grids using the Wind-US flow solver. The inlet performance was characterized by the inlet total pressure recovery and the radial and circumferential total pressure distortion indices at the engine face. Previous research of downstream VGs in the low-boom supersonic inlet demonstrated improvement in radial distortion up to 24% while my work on external-compression supersonic inlets improved radial distortion up to 86%, which is significant. The design of experiments and statistical analysis methods were applied to quantify the effect of the geometric factors of VGs and search for optimal VG arrays. From the analysis, VG angle-of-incidence and VG height were the most influential factors in increasing total pressure recovery and reducing distortion. The study on the two-dimensional external-compression inlet determined which passive flow control devices, such as counter-rotating vanes or ramps, reduce high distortion levels and improve the health of the boundary layer, relative to the baseline. Downstream vanes demonstrate up to 21% improvement in boundary layer health and 86% improvement in radial distortion. Upstream vanes demonstrated up to 3% improvement in boundary layer health and 9% improvement in radial distortion. Ramps showed no improvement in boundary layer health and radial distortion. Micro-VGs were preferred for their reduced viscous drag and improvement in total pressure recovery at the AIP. Although

  7. Homeostasis 5: nurses as external agents of control in breast cancer.

    Science.gov (United States)

    Clancy, John; McVicar, Andrew

    Breast cancer is caused by a homeostatic imbalance of cell division. Healthcare practitioners need to understand cellular activities to appreciate the physiological basis of health (homeostasis), the pathophysiological basis of illness and the physiological rationale of healthcare. Cells are the 'basic unit of life' (Clancy and McVicar, 2011a). This article describes normal cell division and the anatomy and physiology of the breast and, using a case study, will show how breast cancer is a homeostatic imbalance of cell division. There are analogies between the components of homeostasis and the components of the nursing (healthcare) process (Clancy and McVicar, 2011b) in the condition of breast cancer. After reading this article, nurses should be able to: understand that breast cancer is a cellular hence chemical imbalance that causes uncontrollable mitotic division of breast cells; understand how the cell cycle of cancer cells differs from that of normal cells; identify nature-nurture interactions involved in the aetiology of breast cancer; understand that when caring for people with breast cancer, health professionals including oncology nurses are acting as external agents of homeostatic control as the patient 'recovers' from breast cancer, and also to some extent when reducing signs and symptoms, hence quality of life, by providing palliative care.

  8. The response of nonlinear controlled system under an external excitation via time delay state feedback

    Directory of Open Access Journals (Sweden)

    A.M. Elnaggar

    2016-01-01

    Full Text Available An analysis of primary, superharmonic of order five, and subharmonic of order one-three resonances for non-linear s.d.o.f. system with two distinct time-delays under an external excitation is investigated. The method of multiple scales is used to determine two first order ordinary differential equations which describe the modulation of the amplitudes and the phases. Steady-state solutions and their stabilities in each resonance are studied. Numerical results are obtained by using the Software of Mathematica, which presented in a group of figures. The effect of the feedback gains and time-delays on the non-linear response of the system is discussed and it is found that: an appropriate feedback can enhance the control performance. A suitable choice of the feedback gains and time-delays can enlarge the critical force amplitude, and reduce the peak amplitude of the response (or peak amplitude of the free oscillation term for the case of primary resonance (superharmonic resonance. Furthermore, a proper feedback can eliminate saddle-node bifurcation, thereby eliminating jump and hysteresis phenomena taking place in the corresponding uncontrolled system. For subharmonic resonance, an adequate feedback can reduce the regions of subharmonic resonance response.

  9. Melnikov analysis and chaos control of nonlinear dispersive KdV equation under external periodic perturbation

    Science.gov (United States)

    Yin, J. L.; Xing, Q. Q.; Tian, L. X.

    2015-03-01

    The behavior of non-smooth solitary waves switching to chaos is studied. Firstly, we present some singular homoclinic orbits of an unperturbed system. These singular homoclinic orbits correspond to non-smooth solutions. Secondly, we find that the peculiar solitary waves are more likely to be chaos by using the Melnikov theory. Finally, chaos thresholds under different amplitudes and frequencies of a periodic perturbation are given. One interesting finding is that there exists a peculiar perturbation frequency, which has significant effect on the system. The system is not well-controlled under this frequency. However, the system can be well controlled, when the frequency of the perturbation surpasses the peculiar perturbation frequency with fixed parameters of the unperturbed system.

  10. Warm Parenting and Effortful Control in Toddlerhood: Independent and Interactive Predictors of School-Age Externalizing Behavior.

    Science.gov (United States)

    Reuben, Julia D; Shaw, Daniel S; Neiderhiser, Jenae M; Natsuaki, Misaki N; Reiss, David; Leve, Leslie D

    2016-08-01

    Externalizing symptoms, such as aggression, impulsivity, and inattention, represent the most common forms of childhood maladjustment (Campbell et al. Development and Psychopathology, 12, 467-488, 2000). Several dimensions of parenting behavior, including overreactive and warm parenting, have been linked to children's conduct problems. However, the majority of these studies involve biologically-related family members, thereby limiting understanding of the role of genetic and/or environmental underpinnings of parenting on child psychopathology. This study extends previous research by exploring associations between overreactive and warm parenting during toddlerhood and school-age externalizing problems, as well as the potential moderating effects of child effortful control (EC) on such associations using a longitudinal adoption design. The sample consisted of 225 adoption-linked families (adoptive parents, adopted child [124 male and 101 female] and birth parent[s]), thereby allowing for a more precise estimate of environmental influences on the association between parenting and child externalizing problems. Adoptive mothers' warm parenting at 27 months predicted lower levels of child externalizing problems at ages 6 and 7. Child EC moderated this association in relation to teacher reports of school-age externalizing problems. Findings corroborate prior research with biological families that was not designed to unpack genetic and environmental influences on associations between parenting and child externalizing problems during childhood, highlighting the important role of parental warmth as an environmental influence.

  11. Control of soliton characteristics of the condensate by an arbitrary x-dependent external potential

    Institute of Scientific and Technical Information of China (English)

    Yang Ru-Shu; Yao Chun-Mei; Chen Ri-Xin

    2009-01-01

    This paper presents a family of soliton solutions of the one-dimensional nonlinear Schrodinger equation which describes the dynamics of the dark solitons in Bose-Einstein condensates with an arbitrary x-dependent external potential. The obtained results show that the external potential has an important effect on the dark soliton dynamical characteristics of the condensates. The amplitude,width,and velocity of the output soliton are relative to the source position of the external potential. The smaller the amplitude of the soliton is,the narrower its width is,and the slower the soliton propagates. The collision of two dark solitons is nearly elastic.

  12. It's beyond my control: a cross-temporal meta-analysis of increasing externality in locus of control, 1960-2002.

    Science.gov (United States)

    Twenge, Jean M; Zhang, Liqing; Im, Charles

    2004-01-01

    Two meta-analyses found that young Americans increasingly believe their lives are controlled by outside forces rather than their own efforts. Locus of control scores became substantially more external (about.80 standard deviations) in college student and child samples between 1960 and 2002. The average college student in 2002 had a more external locus of control than 80% of college students in the early 1960s. Birth cohort/time period explains 14% of the variance in locus of control scores. The data included 97 samples of college students (n = 18,310) and 41 samples of children ages 9 to 14 (n = 6,554) gathered from dissertation research. The results are consistent with an alienation model positing increases in cynicism, individualism, and the self-serving bias. The implications are almost uniformly negative, as externality is correlated with poor school achievement, helplessness, ineffective stress management, decreased self-control, and depression.

  13. GENETIC ALGORITHM BASED PARAMETER TUNING OF PID CONTROLLER FOR COMPOSITION CONTROL SYSTEM

    Directory of Open Access Journals (Sweden)

    Bhawna Tandon

    2011-08-01

    Full Text Available A Composition control system is discussed in this paper in which the PID controller is tuned using Genetic Algorithm & Ziegler-Nichols Tuning Criteria. Tuning methods for PID controllers are very importantfor the process industries. Traditional methods such as Ziegler-Nichols method often do not provide adequate tuning. Genetic Algorithm (GA as an intelligent approach has also been widely used to tune the parameters of PID. Genetic algorithms are used to create an objective function that can evaluate the optimum PID gains based on the controlled systems overall error.

  14. Implementation of client versus care-provider strategies to improve external cephalic version rates: a cluster randomized controlled trial

    NARCIS (Netherlands)

    Vlemmix, F.; Rosman, A.N.; Rijnders, M.E.; Beuckens, A.; Opmeer, B.C.; Mol, B.W.J.; Kok, M.; Fleuren, M.A.H.

    2015-01-01

    Onjective: To determine the effectiveness of a client or care-provider strategy to improve the implementation of external cephalic version. Design: Cluster randomized controlled trial.Setting: Twenty-five clusters; hospitals and their referring midwifery practices randomly selected in the Netherland

  15. Longitudinal Relations of Children's Effortful Control, Impulsivity, and Negative Emotionality to Their Externalizing, Internalizing, and Co-Occurring Behavior Problems

    Science.gov (United States)

    Eisenberg, Nancy; Valiente, Carlos; Spinrad, Tracy L.; Cumberland, Amanda; Liew, Jeffrey; Reiser, Mark; Zhou, Qing; Losoya, Sandra H.

    2009-01-01

    The purpose of the study was to examine the relations of effortful control (EC), impulsivity, and negative emotionality to at least borderline clinical levels of symptoms and change in maladjustment over four years. Children's (N = 214; 77% European American; M age = 73 months) externalizing and internalizing symptoms were rated by parents and…

  16. Validation and standardization of gene expression data for microarray and real time quantitative PCR using universal external RNA controls

    Science.gov (United States)

    This presentation will introduce newly developed universal external ribonucleic acid (RNA) controls and their applications on different platforms of microarray and quantitative real time polymerase chain reaction (qRT-PCR) including SYBR Green® and TaqMan® probe-based chemistries. Data obtained fro...

  17. Credit Card Misuse, Money Attitudes, and Compulsive Buying Behaviors: A Comparison of Internal and External Locus of Control (LOC) Consumers

    Science.gov (United States)

    Watson, Stevie

    2009-01-01

    This study examined attitudinal and behavioral differences between internal and external locus of control (LOC) consumers on credit card misuse, the importance of money, and compulsive buying. Using multiple analysis of variance and separate analyses of variance, internal LOC consumers were found to have lower scores on credit card misuse and…

  18. Credit Card Misuse, Money Attitudes, and Compulsive Buying Behaviors: A Comparison of Internal and External Locus of Control (LOC) Consumers

    Science.gov (United States)

    Watson, Stevie

    2009-01-01

    This study examined attitudinal and behavioral differences between internal and external locus of control (LOC) consumers on credit card misuse, the importance of money, and compulsive buying. Using multiple analysis of variance and separate analyses of variance, internal LOC consumers were found to have lower scores on credit card misuse and…

  19. [The significance of the relationship between external/internal locus of control and adolescent substance use in behavioral medicine].

    Science.gov (United States)

    Pikó, Bettina; Kovács, Eszter; Kriston, Pálma

    2011-02-27

    Prevention and treatment of the addictions are key public health priorities in modern society. In medical practice, in relation to the biochemical processes, mapping the addiction-prone personality traits, like external/internal locus of control are getting more and more attention. Individuals with high level on internal locus of control, for example, tend to take care of their health behavior; the lack of it, on the other hand, may worsen the effectiveness of stress release which may increase the likelihood of turning to substance use. The main goal of the present study was to investigate the relationship between adolescent substance use (both lifetime prevalence and the actual substance user status) and external/internal locus of control). The data collection of the questionnaire survey was going on among 656 high school students in Szeged (age range between 14-21 years, mean = 16.5 years, S.D. = 1.5 years of age, 49.1% of the sample was female). Associations between indicators of substance use (as dependent variables) and scale points of external/internal locus of control (as independent variables) were assessed using odds ratios calculated by logistic regression analyses, whereas gender was used as a controlling variable. Among boys, scale points of external, among girls, those of internal locus of control showed higher values. External locus of control increased, whereas internal locus of control decreased the risk of substance use, however, the relative role of external/internal locus of control was different according to the type of substance use and the prevalence values. In terms of smoking, lifetime prevalence, whereas in terms of marijuana use, the actual user status was influenced. In addition, while the latter one was also affected by gender, it did not play a role at all in the previous one. All these findings suggest that behavioral control may play a particularly important role in prevention of adolescent substance use. For developing this, methods

  20. On Optimization Control Parameters in an Adaptive Error-Control Scheme in Satellite Networks

    Directory of Open Access Journals (Sweden)

    Ranko Vojinović

    2011-09-01

    Full Text Available This paper presents a method for optimization of control parameters of an adaptive GBN scheme in error-prone satellite channel. Method is based on the channel model with three state, where channel have the variable noise level.

  1. External validity of randomized controlled trials in older adults, a systematic review

    Science.gov (United States)

    van Deudekom, Floor J.; Postmus, Iris; van der Ham, Danielle J.; Pothof, Alexander B.; Broekhuizen, Karen; Blauw, Gerard J.; Mooijaart, Simon P.

    2017-01-01

    Background To critically assess the external validity of randomized controlled trials (RCTs) it is important to know what older adults have been enrolled in the trials. The aim of this systematic review is to study what proportion of trials specifically designed for older patients report on somatic status, physical and mental functioning, social environment and frailty in the patient characteristics. Methods PubMed was searched for articles published in 2012 and only RCTs were included. Articles were further excluded if not conducted with humans or only secondary analyses were reported. A random sample of 10% was drawn. The current review analyzed this random sample and further selected trials when the reported mean age was ≥ 60 years. We extracted geriatric assessments from the population descriptives or the in- and exclusion criteria. Results In total 1396 trials were analyzed and 300 trials included. The median of the reported mean age was 66 (IQR 63–70) and the median percentage of men in the trials was 60 (IQR 45–72). In 34% of the RCTs specifically designed for older patients somatic status, physical and mental functioning, social environment or frailty were reported in the population descriptives or the in- and exclusion criteria. Physical and mental functioning was reported most frequently (22% and 14%). When selecting RCTs on a mean age of 70 or 80 years the report of geriatric assessments in the patient characteristics was 46% and 85% respectively but represent only 5% and 1% of the trials. Conclusion Somatic status, physical and mental functioning, social environment and frailty are underreported even in RCTs specifically designed for older patients published in 2012. Therefore, it is unclear for clinicians to which older patients the results can be applied. We recommend systematic to transparently report these relevant characteristics of older participants included in RCTs. PMID:28346503

  2. Chaos Synchronization on Parameters Adaptive Control for Chen Chaotic System

    Institute of Scientific and Technical Information of China (English)

    ZHOU Ping

    2003-01-01

    Chaos synchronization of Chen chaotic system for parameters unknown is discussed in this paper using a scalar output. Using the concept of conditional Lyapunov exponents, the negativity of all Lyapunov exponents shows the synchronization of transmitter systems with receiver systems even though system parametes are not known to receiver systems.

  3. The Different Faces of Controlling Teaching: Implications of a Distinction between Externally and Internally Controlling Teaching for Students' Motivation in Physical Education

    Science.gov (United States)

    De Meyer, Jotie; Soenens, Bart; Aelterman, Nathalie; De Bourdeaudhuij, Ilse; Haerens, Leen

    2016-01-01

    Background: In Self-Determination Theory (SDT), a well-validated macro-theory on human motivation, a distinction is made between internally controlling teaching practices (e.g. guilt-induction and shaming) and externally controlling practices (e.g. threats and punishments, commands). While both practices are said to undermine students' motivation,…

  4. Design of nonlinear discrete-time controllers using a parameter space sampling procedure

    Science.gov (United States)

    Young, G. E.; Auslander, D. M.

    1983-01-01

    The design of nonlinear discrete-time controllers is investigated where the control algorithm assumes a special form. State-dependent control actions are obtained from tables whose values are the design parameters. A new design methodology capable of dealing with nonlinear systems containing parameter uncertainty is used to obtain the controller design. Various controller strategies are presented and illustrated through an example.

  5. Damage control orthopaedics: Variability of construct design for external fixation of the lower extremity and implications on cost.

    Science.gov (United States)

    Logan, Catherine; Hess, Arthur; Kwon, John Y

    2015-08-01

    To evaluate relative cost of external fixator constructs applied for damage control purposes in a cohort of advanced orthopaedic trainees and orthopaedic staff traumatologists. We also sought to evaluate physicians' understanding of component cost. Participants were asked to apply an external fixator for three separate fracture patterns in damage control fashion. A total of 19 physicians (nine PGY-4 residents, five PGY-5 residents, two orthopaedic trauma fellows and three orthopaedic staff traumatologists) participated. Total construct cost was calculated. Participants provided an estimate of the cost of each component in a fill-in format survey. Main outcome measures included cost of external fixator construct applied and the estimated cost of external fixator components. Average whole sale cost of an external fixator construct was $5252 (±$1798). Of the three fracture types examined, the tibial plafond fracture external fixator construct on average cost the most, followed by the tibial plateau fracture and the femur fracture construct. The large ex-fix combination clamp was the major contributor to cost for each construct. The combination clamp may be substituted for a multi-pin clamp, resulting in significant cost savings. The self-drilling Schanz pin and the large ex-fix combination clamp were most highly underestimated (25% and 22% of their actual cost, respectively). Innumerous construct designs exist and even small changes can significantly impact cost. Knowledge of component cost is low among staff and trainees. Education of component cost is vital to allow adequate consideration of construct design prior to fixator application. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. 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%.

  7. 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

  8. Parameter Identification for the Valve Control Cylinder System of a Hydraulic Manipulator

    Institute of Scientific and Technical Information of China (English)

    XIE Qing-hua; PEI Wen-kai; JIANG Bin; ZHANG Qi

    2006-01-01

    In mechanical, hydraulic and electronic systems, the determination of system parameters is often challenging because liquid parameters often change significantly, due to variations in working and environmental conditions. Therefore, it is of significant practical importance to identify those parameters through experimental procedures. A systematic approach to identifying parameters in the valve controlling cylinder system of hydraulic manipulators is provided. It first derives the transfer function of the system, and then uses P control of PID control to predict system parameters. The predicted parameters are further validated using PID control. The prediction through simulation using MatLab language is utilized, which agrees well with experimental results.

  9. Application of Time Scale to Parameters Tuning of Active Disturbance Rejection Controller for Induction Motor

    Institute of Scientific and Technical Information of China (English)

    SHAO Li-wei; LIAO Xiao-zhong; ZHANG Yu-he

    2007-01-01

    Active disturbance rejection controller (ADRC) has good performance in induction motor (IM) control system, but controller parameter is difficult to tune. A method of tuning ADRC parameter by time scale is analyzed. The IM time scale is obtained by theoretical analysis. Combining the relations between scale time and ADRC parameters, ADRC parameter tuning in IM vector control based stator flux oriented is obtained. This parameter tuning method is validated by simulations and it provides a new technique for tuning of ADRC parameters of IM.

  10. 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.

  11. Ensemble control of linear systems with parameter uncertainties

    Science.gov (United States)

    Kou, Kit Ian; Liu, Yang; Zhang, Dandan; Tu, Yanshuai

    2016-07-01

    In this paper, we study the optimal control problem for a class of four-dimensional linear systems based on quaternionic and Fourier analysis. When the control is unconstrained, the optimal ensemble controller for this linear ensemble control systems is given in terms of prolate spheroidal wave functions. For the constrained convex optimisation problem of such systems, the quadratic programming is presented to obtain the optimal control laws. Simulations are given to verity the effectiveness of the proposed theory.

  12. The dangers of damage control orthopedics: a case report of vascular injury after femoral fracture external fixation

    Directory of Open Access Journals (Sweden)

    Staeheli Gregory R

    2012-03-01

    Full Text Available Abstract Background Placement of external fixation frames is an expedient and minimally invasive method of achieving bone and joint stability in the setting of severe trauma. Although anatomic safe zones are established for placement of external fixation pins, neurovascular structures may be at risk in the setting of severe trauma. Case report We present a case of a 21-year-old female involved in a high speed motorcycle accident who sustained a Type IIIB open segmental femur fracture with significant thigh soft tissue injury. Damage control orthopedic principals were applied and a spanning external fixator placed for provisional femoral stabilization. Intraoperative vascular examination noted absent distal pulses, however an intraoperative angiogram showed arterial flow distal to the trifurcation. Immediately postoperatively the dorsalis pedis pulse was detected using Doppler ultrasound but was then non-detectable over the preceding 12-hours. Femoral artery CT angiogram revealed iatrogenic superficial femoral artery occlusion due to kinking of the artery around an external fixator pin. Although the pin causing occlusion was placed under direct visualization, the degree of soft tissue injury altered the appearance of the local anatomy. The pin was subsequently revised allowing the artery to travel in its anatomic position, restoring perfusion. Conclusion This case highlights the dangers associated with damage control orthopedics, especially when severe trauma alters normal local anatomy. Careful assessment of external fixator pin placement is crucial to avoiding iatrogenic injury. We recommend a thorough vascular examination pre-operatively and prior to leaving the operating room, which allows any abnormalities to be further evaluated while the patient remains in a controlled environment. When an unrecognized iatrogenic injury occurs, serial postoperative neurovascular examinations allow early recognition and corrective actions.

  13. Controlled structuring of binary hard-disk mixtures via a periodic, external potential.

    Science.gov (United States)

    Franzrahe, K; Nielaba, P

    2009-05-01

    Ordering phenomena on surfaces or in monolayers can be successfully studied by model systems as binary hard-disk mixtures, the influence of a substrate being modeled by an external potential. For the field-free case the thermodynamic stability of space-filling lattice structures for binary hard-disk mixtures is studied by Monte Carlo computer simulations. As these structures prove to be thermodynamically stable only in high pressure environments, the phase behavior of an equimolar binary mixture with a diameter ratio of sigma_{B}/sigma_{A}=0.414 exposed to an external, one-dimensional, periodic potential is analyzed in detail. The underlying ordering mechanisms and the resulting order differ considerably, depending on which components of the mixture interact with the external potential. The simulations show that slight deviations in the concentration of large particles x_{A} or the diameter ratio sigma_{B}/sigma_{A} have no impact on the occurrence of the various field-induced phenomena as long as the mixture stays in the relevant regime of the packing fraction eta . Furthermore the importance of the commensurability of the external potential to the S1(AB) square lattice for the occurrence of the induced ordering is discussed.

  14. Control of the external photoluminescent quantum yield of emitters coupled to nanoantenna phased arrays

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Ke; Verschuuren, Marc A. [Philips Research Laboratories, High Tech Campus 4, 5656 AE Eindhoven (Netherlands); Lozano, Gabriel [Center for Nanophotonics, FOM Institute AMOLF, c/o Philips Research Laboratories, High Tech Campus 4, 5656 AE Eindhoven (Netherlands); Gómez Rivas, Jaime, E-mail: J.Gomez@amolf.nl [Center for Nanophotonics, FOM Institute AMOLF, c/o Philips Research Laboratories, High Tech Campus 4, 5656 AE Eindhoven (Netherlands); COBRA Research Institute, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven (Netherlands)

    2015-08-21

    Optical losses in metals represent the largest limitation to the external quantum yield of emitters coupled to plasmonic antennas. These losses can be at the emission wavelength, but they can be more important at shorter wavelengths, i.e., at the excitation wavelength of the emitters, where the conductivity of metals is usually lower. We present accurate measurements of the absolute external photoluminescent quantum yield of a thin layer of emitting material deposited over a periodic nanoantenna phased array. Emission and absorptance measurements of the sample are performed using a custom-made setup including an integrating sphere and variable angle excitation. The measurements reveal a strong dependence of the external quantum yield on the angle at which the optical field excites the sample. Such behavior is attributed to the coupling between far-field illumination and near-field excitation mediated by the collective resonances supported by the array. Numerical simulations confirm that the inherent losses associated with the metal can be greatly reduced by selecting an optimum angle of illumination, which boosts the light conversion efficiency in the emitting layer. This combined experimental and numerical characterization of the emission from plasmonic arrays reveals the need to carefully design the illumination to achieve the maximum external quantum yield.

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

    Science.gov (United States)

    de Sousa, Francisco F. G.; Rubinger, Rero M.; Sartorelli, José C.; Albuquerque, Holokx A.; Baptista, Murilo S.

    2016-08-01

    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.

  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. Modern control concepts in hydrology. [parameter identification in adaptive stochastic control approach

    Science.gov (United States)

    Duong, N.; Winn, C. B.; Johnson, G. R.

    1975-01-01

    Two approaches to an identification problem in hydrology are presented, based upon concepts from modern control and estimation theory. The first approach treats the identification of unknown parameters in a hydrologic system subject to noisy inputs as an adaptive linear stochastic control problem; the second approach alters the model equation to account for the random part in the inputs, and then uses a nonlinear estimation scheme to estimate the unknown parameters. Both approaches use state-space concepts. The identification schemes are sequential and adaptive and can handle either time-invariant or time-dependent parameters. They are used to identify parameters in the Prasad model of rainfall-runoff. The results obtained are encouraging and confirm the results from two previous studies; the first using numerical integration of the model equation along with a trial-and-error procedure, and the second using a quasi-linearization technique. The proposed approaches offer a systematic way of analyzing the rainfall-runoff process when the input data are imbedded in noise.

  18. Development of linear parameter varying control system for autonomous underwater vehicle

    OpenAIRE

    Sutarto, Herman; Budiyono, Agus

    2011-01-01

    The development and application of Linear Parameter Varying (LPV) control system for robust longitudinal control system on an Autonomous Underwater Vehicle (AUV) are presented. The LPV system is represented as Linear Fractional Transformation (LFT) on its parameter set. The LPV control system combines LPV theory based upon Linear Matrix Inequalities (LMIs) and - synthesis to form a robust LPV control system. The LPV control design is applied for a pitch control of the AUV to fulfill control...

  19. 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 parametervarying...

  20. Parameters monitoring and control for flueric actuators testing syste

    Directory of Open Access Journals (Sweden)

    Tiberiu Adrian SALAORU

    2014-04-01

    Full Text Available A wide range of air supply parameters is needed for the flueric actuators testing in order to find their optimum working regime. A system for conditioning these parameters, namely pressure, temperature, mass and volume flow rate has been built for this purpose. The measured values are continuously stored on the PC hard drive and are checked automatically for keeping them in the normal operating range. In case any of them are going out of this range, this system warns the operator and performs automatic actions for limiting or partially or totally shutting down the system.

  1. Multiplicity Control in Structural Equation Modeling: Incorporating Parameter Dependencies

    Science.gov (United States)

    Smith, Carrie E.; Cribbie, Robert A.

    2013-01-01

    When structural equation modeling (SEM) analyses are conducted, significance tests for all important model relationships (parameters including factor loadings, covariances, etc.) are typically conducted at a specified nominal Type I error rate ([alpha]). Despite the fact that many significance tests are often conducted in SEM, rarely is…

  2. Parameter self-adaptive synchronization control for a kind of financial chaotic systems

    Institute of Scientific and Technical Information of China (English)

    PU Xing-cheng; WANG Hai-ying

    2009-01-01

    A parameter adaptive control approach was applied to a kind of financial chaotic systems. According to Lyapunov stability theorem, synchronization of two financial chaotic systems with different certain parameters or the same uncertain parameters were implemented through designing proper control functions and using parameters self-adaptive control principle. The sufficient synchronization conditions of the two financial systems were obtained. Under the situation of the same uncertain parameters, the synchronization system has simpler controller and better performance. Numerical simulations show the effectiveness of the method.

  3. Control of internal and external short circuits in lithium batteries using a composite thermal switch

    Science.gov (United States)

    Mcdonald, Robert C.; Pickett, Jerome; Goebel, Franz

    1991-01-01

    A composite material has been developed, consisting of a blend of metal and fluorocarbon particles, which behaves as an electronic conductor at room temperature and which abruptly becomes an insulator at a predetermined temperature. This switching behavior results from the difference in thermal expansion coefficients between the conductive and non-conductive portions of the composite. This material was applied as a thin film between the carbon cathode in Li/SOCl2 cells, and the metallic cathode current collector. Using test articles incorporating this feature it was shown that lithium cells externally heated or internally heated during a short circuit lost rate capability and the ability to overheat well below the melting point of lithium (180 C). Thus, during an internal or external cell short circuit, the potential for thermal runaway involving reactions of molten lithium is avoided.

  4. 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...

  5. Stability and optimal parameters for continuous feedback chaos control.

    Science.gov (United States)

    Kouomou, Y Chembo; Woafo, P

    2002-09-01

    We investigate the conditions under which an optimal continuous feedback control can be achieved. Chaotic oscillations in the single-well Duffing model, with either a positive or a negative nonlinear stiffness term, are tuned to their related Ritz approximation. The Floquet theory enables the stability analysis of the control. Critical values of the feedback control coefficient fulfilling the optimization criteria are derived. The influence of the chosen target orbit, of the feedback coefficient, and of the onset time of control on its duration is discussed. The analytic approach is confirmed by numerical simulations.

  6. 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...

  7. Ruthenium-based olefin metathesis catalysts bearing pH-responsive ligands: External control of catalyst solubility and activity

    Science.gov (United States)

    Balof, Shawna Lynn

    2011-12-01

    Sixteen novel, Ru-based olefin metathesis catalysts bearing pH responsive ligands were synthesized. The pH-responsive groups employed with these catalysts included dimethylamino (NMe2) modified NHC ligands as well as N-donor dimethylaminopyridine (DMAP) and 3-(o-pyridyl)propylidene ligands. These pH-responsive ligands provided the means by which the solubility and/or activity profiles of the catalysts produced could be controlled via acid addition. The main goal of this dissertation was to design catalyst systems capable of performing ring opening metathesis (ROMP) and ring closing metathesis (RCM) reactions in both organic and aqueous media. In an effort to quickly gain access to new catalyst structures, a template synthesis for functionalized NHC ligand precursors was designed, in addition to other strategies, to obtain ligand precursors with ancillary NMe2 groups. Kinetic studies for the catalysts produced from these precursors showed external control of catalyst solubility was afforded via protonation of the NMe2 groups of their NHC ligands. Additionally, this protonation afforded external control of catalyst propagation rates for several catalysts. This is the first known independent external control for the propagation rates of ROMP catalysts. The incorporation of pH-responsive N-donor ligands into catalyst structures also provided the means for the external control of metathesis activity, as the protonation of these ligands resulted in an increased initiation rate based on their fast and irreversible dissociation from the metal center. The enhanced external control makes these catalysts applicable to a wide range of applications, some of which have been explored by us and/or through collaboration. Three of the catalysts designed showed remarkable metathesis activity in aqueous media. These catalysts displayed comparable RCM activity in aqueous media to a class of water-soluble catalysts reported by Grubbs et al., considered to be the most active catalyst for

  8. Reduced Order Adaptive Controllers for Distributed Parameter Systems

    Science.gov (United States)

    2005-09-01

    Adaptation in the Presence of Input Constraints, Submitted to IEEE Transactions on Automatic Control , 2003. J7. E. Lavretsky, N. Hovakimyan, Positive p...Dynamics Using Delayed Outputs and Feedforward Neural Networks, IEEE Transactions on Automatic Control , vol. 48 (9), pp.1606-1610, 2003. J14. N. Hovakimyan

  9. High Performance Controllers Based on Real Parameters to Account for Parameter Variations due to Iron Saturation

    Science.gov (United States)

    2013-08-22

    Shaft Surface PMSM Interior PMSM UNCLASSIFIED UNCLASSIFIED Three phase model 22 August 2013  abM ...transformation matrix: • To transform from 3 phase abc to 3 equivalent axes dq0: • Under balanced condition zero sequence quantities are...d qi i    * *,d qi i regulator PI * *,d qv v Inverse Park’s * abcvabc dq dq abc  DYNAMOMETER OR ENGINE Controller UNCLASSIFIED UNCLASSIFIED

  10. Determination of the Critical Parameters for Remote Microscope Control

    Science.gov (United States)

    Hahn, R. C.; Herbach, B. A.; Johnston, J. C.; Bethea, M.

    1991-01-01

    As part of a program to determine the capabilities of Telescience as applied to Microgravity Materials Science the need for a remotely controlled microscope was recognized. For this purpose we equipped a microscope with an X-Y-Z positioning device and motors on the zoom and focus controls. Computer control of these devices allowed remote operation. A standard TV camera was mounted to the computer controlled video board which could compress the image in resolution and grey scale. The operator control console was programmed to display three still video pictures as well as provide command access. A standard data transfer network was used to transmit the video data files and the command interaction was via a high speed phone modem. This system, with the microscope in the Microgravity Materials Science Laboratory (MMSL) at LeRC and the control at RPI, was used to determine the accuracy of setting, time required to achieve setting and the operator ease factor. It was found that the focus setting could be established well within the resolution limit of the TV system and that each motion took about 50 seconds and approximately 12 minutes was required to reach ?best? focus. These times could be reduced significantly with operator experience. The operators were provided with ancillary equipment which provided assistance in making the necessary decisions and they reported satisfaction with the control.

  11. Parameter Optimization of Linear Quadratic Controller Based on Genetic Algorithm

    Institute of Scientific and Technical Information of China (English)

    LI Jimin; SHANG Chaoxuan; ZOU Minghu

    2007-01-01

    The selection of weighting matrix in design of the linear quadratic optimal controller is an important topic in the control theory. In this paper, an approach based on genetic algorithm is presented for selecting the weighting matrix for the optimal controller. Genetic algorithm is adaptive heuristic search algorithm premised on the evolutionary ideas of natural selection and genetic. In this algorithm, the fitness function is used to evaluate individuals and reproductive success varies with fitness. In the design of the linear quadratic optimal controller, the fitness function has relation to the anticipated step response of the system. Not only can the controller designed by this approach meet the demand of the performance indexes of linear quadratic controller, but also satisfy the anticipated step response of close-loop system. The method possesses a higher calculating efficiency and provides technical support for the optimal controller in engineering application. The simulation of a three-order single-input single-output (SISO) system has demonstrated the feasibility and validity of the approach.

  12. Implementation of electro-optic amplitude modulator in the external cavity of semiconductor laser for generation of periodic sates and chaos control

    Directory of Open Access Journals (Sweden)

    Kh Mabhouti

    2016-12-01

    Full Text Available In this paper, by placing the electro optical modulator (EOM into the external cavity of the semiconductor laser (SL and amplitude modulation of the optical feedback, the dynamical variation of the output intensity  of the laser has been studied. This is analyzed numerically via bifurcation and time series diagrams with respect to the applied amplitude modulation index, and modulation voltage frequency of the EOM. It has been shown that, by modulating the amplitude of the optical feedback beam, various changes in the types of the dynamics of  can be observed, and various periodic states can be generated. This makes it possible to receive the desired dynamics without any variations in the main parameters of the SL. Also, in present study, a method of chaos control in the SL has been presented based on EOM in the external cavity. The obtained results confirm that based on this method the chaotic dynamics can be controlled single-periodic dynamics

  13. 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...

  14. Influence of Control Parameters on the Competition Between Spiral Waves and Target Waves

    Institute of Scientific and Technical Information of China (English)

    钱郁; 李伟; 黄晓东; 弭元元; 张朝阳

    2012-01-01

    In this paper we systematically investigate the influence of control parameters on the competition results between spiral waves and target waves. Driving frequency f, amplitude A and injection area n of the input signals are three important parameters and the competition results between spiral waves and target waves are influenced by these three parameters remarkably. Based on these understandings we can control spiral waves effectively by suitable combination these parameters to generate faster target waves. And the effective controllable parameter regions are also studied.

  15. Structural modelling and control design under incomplete parameter information: The maximum-entropy approach

    Science.gov (United States)

    Hyland, D. C.

    1983-01-01

    A stochastic structural control model is described. In contrast to the customary deterministic model, the stochastic minimum data/maximum entropy model directly incorporates the least possible a priori parameter information. The approach is to adopt this model as the basic design model, thus incorporating the effects of parameter uncertainty at a fundamental level, and design mean-square optimal controls (that is, choose the control law to minimize the average of a quadratic performance index over the parameter ensemble).

  16. Investigation of Synthetic Jets Efficiency to Control Cavity Flotation with Subsonic External Flow by High-Resolution RANS / ILES Method

    Directory of Open Access Journals (Sweden)

    D. A. Lyubimov

    2015-01-01

    Full Text Available Cavities often found in airplanes: a niche for the landing gear, various weapons, etc. Reducing fluctuations of pressure and temperature in the cavity is a relevant practical problem. The article presents simulation results of external subsonic flow around the cavity (M = 0.85, T = 300K. . Calculations were performed using the high-resolution RANS/ILES (Reynolds Averaged Navier-Stokes - RANS, Implicit Large Eddy Simulation - ILES method. To control flow the authors propose to use synthetic jets. Synthetic jets are produced by periodic ejection and suction of fluid from a slot induced by the movement of a diaphragm (generator of synthetic jets inside a cavity. They are compact and efficient and do not require a special working body and the ways for its supply. Instead of calculating the flow in the synthetic jet generator was used the modified boundary condition on the wall where the output slots was positioned. Under consideration there were two variants of slots for synthetic jets output: in front of the cavity and inside the cavity on the front wall. The frequency and amplitude values of the synthetic jet specified a mode of each jet. For a jet inside the cavity two modes have been reviewed, namely: 100 Hz and 50m/s, 200Hz and 50m/s. For jet in front of the cavity three modes have been reviewed, specifically: 20Hz and 20m/s, 100Hz and 50m/s, 200Hz and 50m/s. Analysis of calculation results showed that for all modes under examination, the synthetic jets reduced fluctuation of static pressure and temperature on the bottom and back walls of the cavity. The mode with parameters 200Hz, 50 m/s and synthetic jet located in front of the cavity was the most efficient. Furthermore, we compared the results of calculations for two-and three-dimensional cavities, which have the same length and depth. Research has shown that the simplified quasi-two-dimensional calculations cannot be used to evaluate the pressure and temperature fluctuations. This is due to

  17. Search Space Calculation to Improve Parameter Estimation of Excitation Control Systems

    Directory of Open Access Journals (Sweden)

    Andrés J. Saavedra-Montes

    2013-11-01

    Full Text Available A method to calculate the search space for each parameter in an excitation control system is presented in this paper. The calculated search space is intended to reduce the number of parameter solution sets that can be found by an estimation algorithm, reducing its processing time. The method considers a synchronous generator time constant range between 4s and 10s, an excitation control system performance index, a controller design technique, and the excitation control system model structure. When the obtained search space is used to estimate the parameters, less processing time is used by the algorithm. Also the estimated parameters are closer to the reference ones.

  18. Moody Music Generator: Characterising Control Parameters Using Crowdsourcing

    DEFF Research Database (Denmark)

    Scirea, Marco; Togelius, Julian; Nelson, Mark

    2015-01-01

    . In this paper we conduct a listener study to determine how people actually perceive the various moods the generator can produce. Rather than directly attempting to validate that our two control param- eters represent arousal and valence, instead we conduct an open-ended study to crowd-source labels...

  19. CUSUM Charts with Controlled Conditional Performance Under Estimated Parameters

    NARCIS (Netherlands)

    Saleh, N.A.; Zwetsloot, I.M.; Mahmoud, M.A.; Woodall, W.H.

    2016-01-01

    We study the effect of the Phase I estimation error on the cumulative sum (CUSUM) chart. Impractically large amounts of Phase I data are needed to sufficiently reduce the variation in the in-control average run lengths (ARL) between practitioners. To reduce the effect of estimation error on the char

  20. CUSUM Chart with Controlled Conditional Performance Under Estimated Parameters

    NARCIS (Netherlands)

    Saleh, N.A.; Zwetsloot, I.M.; Mahmoud, M.A.; Woodall, W.H.

    2016-01-01

    We study the effect of the Phase I estimation error on the cumulative sum (CUSUM) chart. Impractically large amounts of Phase I data are needed to sufficiently reduce the variation in the in-control average run lengths (ARL) between practitioners. To reduce the effect of estimation error on the char

  1. Moody Music Generator: Characterising Control Parameters Using Crowdsourcing

    DEFF Research Database (Denmark)

    Scirea, Marco; Togelius, Julian; Nelson, Mark

    2015-01-01

    . In this paper we conduct a listener study to determine how people actually perceive the various moods the generator can produce. Rather than directly attempting to validate that our two control param- eters represent arousal and valence, instead we conduct an open-ended study to crowd-source labels...

  2. Internal/external locus of control, self-esteem, and parental verbal interaction of at-risk black male adolescents.

    Science.gov (United States)

    Enger, J M; Howerton, D L; Cobbs, C R

    1994-06-01

    We investigated the relationship between three factors--internal/external locus of control, self-esteem, and parental verbal interaction--for at-risk Black male adolescents in the United States. Forty-two male students in Grades 6, 7, and 8 who had been identified by their teachers as being at risk completed the Locus of Control Scale for Children (Nowicki & Strickland, 1973), the Self-Esteem Inventory (Coopersmith, 1967), and the Verbal Interaction Questionnaire (Blake, 1991). A moderate positive relationship found between self-esteem and parental verbal interaction was consistent with a previous finding for White high school students. A moderate negative relationship found between locus of control and self-esteem differed from a previous finding of no significant relationship for Black elementary children. A weak, yet significant, negative relationship was found between locus of control and parental verbal interaction.

  3. The Effect of External Apple Vinegar Application on Varicosity Symptoms, Pain, and Social Appearance Anxiety: A Randomized Controlled Trial

    Directory of Open Access Journals (Sweden)

    Derya Atik

    2016-01-01

    Full Text Available Aim. We aimed to determine the effect of external apple vinegar application on the symptoms and social appearance anxiety of varicosity patients who were suggested conservative treatment. Method. The study was planned as an experimental, randomized, and controlled study. 120 patients were randomly selected and then were randomly allocated to either experimental or control group by simple blind random sampling method. In the collection of research data, a questionnaire questioning sociodemographic and clinical characteristics, the Visual Analog Scale (VAS for pain, and the Social Appearance Anxiety Scale (SAAS were used. The patients in the study group were suggested to apply apple vinegar to the area of the leg with varicosity alongside the treatment suggested by the doctor. The patients in the control group received no intervention during the study. Results. The sociodemographic and clinic characteristics of both groups were found to be similar (p>0.05. The patients were evaluated with regard to cramps, pain, leg fatigue perception, edema, itching, pigmentation, and weight feelings in the leg, VAS, and SAAS averages in the second evaluation; the control group had a decrease in such symptoms (p>0.05 although the decrease in the application group was higher and statistically meaningful (p<0.05. Conclusion. We determined that the external application of apple vinegar on varicosity patients, which is a very easy application, increased the positive effects of conservative treatment.

  4. Beta tricalcium phosphate ceramics with controlled crystal orientation fabricated by application of external magnetic field during the slip casting process.

    Science.gov (United States)

    Hagio, Takeshi; Yamauchi, Kazushige; Kohama, Takenori; Matsuzaki, Toshiya; Iwai, Kazuhiko

    2013-07-01

    Beta tricalcium phosphate (β-TCP) is a resorbable bioceramic that has hitherto been utilized in the medical field. Since it crystallizes in the anisotropic hexagonal system, properties such as chemical and physical ones are expected to depend on its crystal axis direction and/or on its crystal plane (anisotropy). Control of crystal orientation is thus important when used in polycrystalline form. Meanwhile, application of a strong magnetic field has been found to be a promising technique to control crystal orientation of anisotropic shape or structured crystals. In this work, we attempted to fabricate β-TCP ceramics with controlled crystal orientation by applying an external magnetic field during the slip casting process and subsequently sintering them at 1050°C, below the β-α transition temperature. Application of a vertical magnetic field increased intensities of planes perpendicular to c-plane on the top surface, while a horizontal one with simultaneous mechanical mold rotation decreased it. These results indicated that crystal orientation of β-TCP ceramics were successfully controlled by the external magnetic field and together that the magnetic susceptibility of β-TCP is χ(c[perpendicular])>χ(c//).

  5. Beam Parameter Measurement and Control at the SNS Target

    CERN Document Server

    Plum, Michael; McManamy, Tom

    2005-01-01

    The spallation neutron production target at the SNS facility is designed for 1.4 MW beam power. Both beam position and profile must be carefully controlled within narrow margins to avoid damage to the target. The position must be within 2 mm of the target center, and 90% of the beam must be within the nominal 70 mm x 200 mm spot size, without exceeding 0.18 A/m2

  6. Nutritional screening: control of clinical undernutrition with analytical parameters

    OpenAIRE

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

    2014-01-01

    Objective: 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 alre...

  7. Relevant parameters in models of cell division control

    CERN Document Server

    Grilli, Jacopo; Kennard, Andrew S; Lagomarsino, Marco Cosentino

    2016-01-01

    A recent burst of dynamic single-cell growth-division data makes it possible to characterize the stochastic dynamics of cell division control in bacteria. Different modeling frameworks were used to infer specific mechanisms from such data, but the links between frameworks are poorly explored, with relevant consequences for how well any particular mechanism can be supported by the data. Here, we describe a simple and generic framework in which two common formalisms can be used interchangeably: (i) a continuous-time division process described by a hazard function and (ii) a discrete-time equation describing cell size across generations (where the unit of time is a cell cycle). In our framework, this second process is a discrete-time Langevin equation with a simple physical analogue. By perturbative expansion around the mean initial size (or inter-division time), we show explicitly how this framework describes a wide range of division control mechanisms, including combinations of time and size control, as well a...

  8. Optimum Self Tuning of PID Controller Parameters for Level Control System against Parameter Variations by Neural Network trained with GA Optimized Data

    Directory of Open Access Journals (Sweden)

    N.Ramesh Raju

    2015-10-01

    Full Text Available PID controller is mostly used in process plants to control the system performance by properly choosing its parameters. The optimum PID parameters can be obtained in offline using genetic algorithm if the mathematical model of the system is exactly known. In all process plants the process parameters such as properties of materials like thermal conductivity, electrical conductivity, physical dimensions such as diameter, length of the pipes, parameters of valves and pumps will change as time runs. This happens due to corrosion, scaling, aging, repairs during the maintenance, wear and tear. When the system is robust these changes slightly affect the performance of the system. When the system is not robust they make the system performance worst. Due to above reasons the process plant parameters changes as time runs. It is not easy to measure the changes in system parameters while plant is running and could not be evaluated optimum PID parameters through mathematical model. In this paper a new approach using genetic algorithm and neural network is established for optimum self tuning of PID parameters by observing the time response of the system at any time while plant is running.

  9. Tuning the defect mode in ternary photonic crystal with external voltage for designing a controllable optical filter

    Science.gov (United States)

    Jamshidi-Ghaleh, Kazem; Rashidi, Shiva; Vahedi, Ali

    2015-09-01

    In this work, behavior of defect mode in one-dimensional ternary photonic crystal (1DTPC) structure with arrangement of (MgF2/Ag/TiO2)5LiNbO3(TiO2/Ag/MgF2)5 was investigated under the applied external electric dc voltage. The defect layer is lithium niobate (LiNbO3), an electro-optical (EO) material whose refractive index is voltage-dependent with high EO coefficient. In comparison, magnesium fluoride (MgF2) and titanium dioxide (TiO2) layers have very low EO coefficients. A narrow localized defect mode with perfect transmittance was appeared inside the photonic band gap. Under applying the positive or negative biases, red shift and blue shift was observed in the defect mode, respectively. More than 120 nm tunability was obtained under externally applied voltage in the range of -200 V to 200 V. The physical interpretation is very simple. Change in optical path-length displaces the localized wavelength of the defect mode due to Bragg interface condition. The externally tunable localized mode can be employed in designing a controllable optical filter, one of the essential devices for new-generation all-optical integrated circuits.

  10. Can Findings from Randomized Controlled Trials of Social Skills Training in Autism Spectrum Disorder Be Generalized? The Neglected Dimension of External Validity

    Science.gov (United States)

    Jonsson, Ulf; Olsson, Nora Choque; Bölte, Sven

    2016-01-01

    Systematic reviews have traditionally focused on internal validity, while external validity often has been overlooked. In this study, we systematically reviewed determinants of external validity in the accumulated randomized controlled trials of social skills group interventions for children and adolescents with autism spectrum disorder. We…

  11. Experimental Evidence for Differential Susceptibility: Dopamine D4 Receptor Polymorphism (DRD4 VNTR) Moderates Intervention Effects on Toddlers' Externalizing Behavior in a Randomized Controlled Trial

    Science.gov (United States)

    Bakermans-Kranenburg, Marian J.; Van Ijzendoorn, Marinus H.; Pijlman, Femke T. A.; Mesman, Judi; Juffer, Femmie

    2008-01-01

    In a randomized controlled trial we tested the role of genetic differences in explaining variability in intervention effects on child externalizing behavior. One hundred fifty-seven families with 1- to 3-year-old children screened for their relatively high levels of externalizing behavior participated in a study implementing Video-feedback…

  12. Trajectory Tracking Control of Underactuated USV with Model Perturbation and External Interference

    Directory of Open Access Journals (Sweden)

    Liu Jinbiao

    2016-01-01

    Full Text Available This paper presents an improved trajectory tracking controller based backstepping control algorithm to address the trajectory tracking problem of an underactuated Unmanned Surface Vessel (USV. A Three Degree of Freedom (DOF underactuated maneuvering motion model for water-jet-propelled USV is established, and controller can track both straight line trajectory and curve trajectory with relatively high accuracy. The stability of USV system is proved by BIBO (bounded-input-bounded-output stable characteristics, then simulation experiments are carried out to demonstrate the robustness and precise control performance of the controller.

  13. Optimal Parameter Tuning in a Predictive Nonlinear Control Method for a Mobile Robot

    Directory of Open Access Journals (Sweden)

    D. Hazry

    2006-01-01

    Full Text Available This study contributes to a new optimal parameter tuning in a predictive nonlinear control method for stable trajectory straight line tracking with a non-holonomic mobile robot. In this method, the focus lies in finding the optimal parameter estimation and to predict the path that the mobile robot will follow for stable trajectory straight line tracking system. The stability control contains three parameters: 1 deflection parameter for the traveling direction of the mobile robot 2 deflection parameter for the distance across traveling direction of the mobile robot and 3 deflection parameter for the steering angle of the mobile robot . Two hundred and seventy three experimental were performed and the results have been analyzed and described herewith. It is found that by using a new optimal parameter tuning in a predictive nonlinear control method derived from the extension of kinematics model, the movement of the mobile robot is stabilized and adhered to the reference posture

  14. 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.

  15. Adaptive Backstepping Controller and Synchronizer Design for Arneodo Chaotic System With Unknown Parameters

    OpenAIRE

    Sundarapandian Vaidyanathan

    2013-01-01

    In this paper, we apply backstepping control method to derive new results for the adaptive controller andsynchronizer design for the Arneodo chaotic system (1980), when the system parameters are unknown.First, we design an adaptive backstepping controller to stabilize the Arneodo system to its unstableequilibrium at the origin. Next, we design an adaptive backstepping controller to achieve global chaossynchronization of the identical Arneodo chaotic systems with unknown parameters. MATLAB sim...

  16. Search Space Calculation to Improve Parameter Estimation of Excitation Control Systems

    OpenAIRE

    2013-01-01

    A method to calculate the search space for each parameter in an excitation control system is presented in this paper. The calculated search space is intended to reduce the number of parameter solution sets that can be found by an estimation algorithm, reducing its processing time. The method considers a synchronous generator time constant range between 4s and 10s, an excitation control system performance index, a controller design technique, and the excitation control system model structure. ...

  17. Real-Time Control of the Embedded Waveform for External Defibrillation

    Science.gov (United States)

    2001-10-25

    Additional such possibilities may be useful for development a new electrotherapy methods, as electrochemotherapy for cancer treatment [6]. II...5] B.E. Gliner, T.D. Lyster, C.S. Cole, D.J. Powers and C.B. Morgan, “ Electrotherapy method utilizing patient dependent electrical parameters,” US

  18. 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.

  19. Fuzzy Controller Parameters´ Proposal in Matlab Enviroment

    Directory of Open Access Journals (Sweden)

    Štefan Koprda

    2015-10-01

    Full Text Available  In this paper we deal with the creation and design of fuzzy controller using Matlab. As the founder of fuzzy theory is considered Azerbaijani Prof. Lotfi Zadeh. In his article in 1965 is first time specified term "fuzzy" [8]. Defining of Zadeh fuzzy sets is based on the efforts of experts to build multivalued logic. Multivalued logic (Lukasiewicz logic allows to work with imprecise (vague terms and eliminates gaps of "classical" two-valued logic that we utilized in the art since ancient times. The use of vague terms can not be avoided especially when describing the behavior of complex systems. Their exact analytical description would be technically infeasible or prohibitively complicated, and therefore for realization very expensive. Cause of fuzzy theory can also be formulated by means of the so-called Law incompatibility (incompatibility by Druckmüller [2].

  20. 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.

  1. A Further Study of the {t}_{{Burst}} of GRBs: Rest-frame Properties, External Plateau Contributions, and Multiple Parameter Analysis

    Science.gov (United States)

    Gao, He; Ren, An-Bing; Lei, Wei-Hua; Zhang, Bin-Bin; Lü, Hou-Jun; Li, Ye

    2017-08-01

    Zhang et al. propose to redefine the true γ-ray burst (GRB) central engine activity duration, {t}{burst}, by considering the contributions from the prompt γ-ray emission, X-ray flare, and internal plateau features. With a comprehensive study of a large sample of Swift GRBs, it is shown that the {t}{burst} distribution in the observer frame consists of a bimodal feature, suggesting the existence of a new population of ultra-long GRBs. In this work, we make a series of further studies on {t}{burst}: we update the Swift GRB sample up to 2016 June; we investigate the properties of {t}{burst} distribution in the rest frame; we redefine {t}{burst} by involving external plateau contributions; and we make a multiple parameter analysis to investigate whether the bursts within the ultra-long population are statistically different in the sense of other features besides the duration distribution. We find that for all situations, the distribution of {t}{burst} requires two normal distributions in logarithmic space to provide a good fit both in the observer frame and in the rest frame. Considering the observational gap effect would not completely erase the bimodal distribution feature. However, the bursts within the ultra-long population may have no statistical difference in the sense of other features besides the duration term. We thus suggest that if the ultra-long population of GRBs indeed exists, their central engine and radiation mechanisms should be similar to those of the normal population, but they have a longer central engine activity timescale.

  2. Predictors of urinary and rectal toxicity after external conformed radiation therapy in prostate cancer: Correlation between clinical, tumour and dosimetric parameters and radical and postoperative radiation therapy.

    Science.gov (United States)

    Martínez-Arribas, C M; González-San Segundo, C; Cuesta-Álvaro, P; Calvo-Manuel, F A

    2017-06-15

    To determine rectal and urinary toxicity after external beam radiation therapy (EBRT), assessing the results of patients who undergo radical or postoperative therapy for prostate cancer (pancreatic cancer) and their correlation with potential risk factors. A total of 333 patients were treated with EBRT. Of these, 285 underwent radical therapy and 48 underwent postoperative therapy (39 cases of rescue and 9 of adjuvant therapy). We collected clinical, tumour and dosimetric variable to correlate with toxicity parameters. We developed decision trees based on the degree of statistical significance. The rate of severe acute toxicity, both urinary and rectal, was 5.4% and 1.5%, respectively. The rate of chronic toxicity was 4.5% and 2.7%, respectively. Twenty-seven patients presented haematuria, and 9 presented haemorrhagic rectitis. Twenty-five patients (7.5%) presented permanent limiting sequela. The patients with lower urinary tract symptoms prior to the radiation therapy presented poorer tolerance, with greater acute bladder toxicity (P=0.041). In terms of acute rectal toxicity, 63% of the patients with mean rectal doses >45Gy and anticoagulant/antiplatelet therapy developed mild toxicity compared with 37% of the patients with mean rectal doses <45 Gy and without anticoagulant therapy. We were unable to establish predictors of chronic toxicity in the multivariate analysis. The long-term sequelae were greater in the patients who underwent urological operations prior to the radiation therapy and who were undergoing anticoagulant therapy. The tolerance to EBRT was good, and severe toxicity was uncommon. Baseline urinary symptoms constitute the predictor that most influenced the acute urinary toxicity. Rectal toxicity is related to the mean rectal dose and with anticoagulant/antiplatelet therapy. There were no significant differences in severe toxicity between radical versus postoperative radiation therapy. Copyright © 2017 AEU. Publicado por Elsevier España, S

  3. Stabilizing Unstable Equilibrium Point of Unified Chaotic Systems with Unknown Parameter Using Sliding Mode Control

    Institute of Scientific and Technical Information of China (English)

    GUAN Xin-Ping; HE Yan-Hui

    2004-01-01

    @@ The control problem of a unified chaos is considered. Stabilizing unstable equilibrium point is achieved by a sliding mode controller based on parameter identification. The observer is applied to identify the unknown parameter of a unified chaotic system. Simulations are made and the results verify the validity of the proposed method.

  4. 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…

  5. Systems and Methods for Parameter Dependent Riccati Equation Approaches to Adaptive Control

    Science.gov (United States)

    Kim, Kilsoo (Inventor); Yucelen, Tansel (Inventor); Calise, Anthony J. (Inventor)

    2015-01-01

    Systems and methods for adaptive control are disclosed. The systems and methods can control uncertain dynamic systems. The control system can comprise a controller that employs a parameter dependent Riccati equation. The controller can produce a response that causes the state of the system to remain bounded. The control system can control both minimum phase and non-minimum phase systems. The control system can augment an existing, non-adaptive control design without modifying the gains employed in that design. The control system can also avoid the use of high gains in both the observer design and the adaptive control law.

  6. Chattering-Free Adaptive Sliding Mode Control for Attitude Tracking of Spacecraft with External Disturbance

    Directory of Open Access Journals (Sweden)

    Xuxi Zhang

    2014-01-01

    Full Text Available The attitude tracking problem of spacecraft in the presence of unknown disturbance is investigated. By using the adaptive control technique and the Lyapunov stability theory, a chattering-free adaptive sliding mode control law is proposed for the attitude tracking problem of spacecraft with unknown disturbance. Simulation results are employed to demonstrate the effectiveness of the proposed control design technique in this paper.

  7. An Adaptive Tracking Control of Fractional-Order Chaotic Systems with Uncertain System Parameter

    OpenAIRE

    Ping Zhou; Rui Ding

    2011-01-01

    An adaptive tracking control scheme is presented for fractional-order chaotic systems with uncertain parameter. It is theoretically proved that this approach can make the uncertain parameter fractional-order chaotic system track any given reference signal and the uncertain system parameter is estimated through the adaptive tracking control process. Furthermore, the reference signal may belong to other integer-orders chaotic system or belong to different fractional-order chaotic system with di...

  8. Electrospinning of nickel oxide nanofibers: Process parameters and morphology control

    Energy Technology Data Exchange (ETDEWEB)

    Khalil, Abdullah, E-mail: akhalil@masdar.ac.ae; Hashaikeh, Raed, E-mail: rhashaikeh@masdar.ac.ae

    2014-09-15

    In the present work, nickel oxide nanofibers with varying morphology (diameter and roughness) were fabricated via electrospinning technique using a precursor composed of nickel acetate and polyvinyl alcohol. It was found that the diameter and surface roughness of individual nickel oxide nanofibers are strongly dependent upon nickel acetate concentration in the precursor. With increasing nickel acetate concentration, the diameter of nanofibers increased and the roughness decreased. An optimum concentration of nickel acetate in the precursor resulted in the formation of smooth and continuous nickel oxide nanofibers whose diameter can be further controlled via electrospinning voltage. Beyond an optimum concentration of nickel acetate, the resulting nanofibers were found to be ‘flattened’ and ‘wavy’ with occasional cracking across their length. Transmission electron microscopy analysis revealed that the obtained nanofibers are polycrystalline in nature. These nickel oxide nanofibers with varying morphology have potential applications in various engineering domains. - Highlights: • Nickel oxide nanofibers were synthesized via electrospinning. • Fiber diameter and roughness depend on nickel acetate concentration used. • With increasing nickel acetate concentration the roughness of nanofibers decreased. • XRD and TEM revealed a polycrystalline structure of the nanofibers.

  9. Controlling external corrosion of oil and gas pipelines : the PreCaution program

    Energy Technology Data Exchange (ETDEWEB)

    Doiron, A.; Papavinasam, S. [Natural Resources Canada, Ottawa, ON (Canada). CANMET Materials Technology Laboratory

    2009-07-01

    Strategies to maintain the integrity of the pipeline coating can be developed using information available from laboratory tests, field operating conditions, above-ground survey, and below-ground measurements. The materials assessment team at Natural Resources Canada has developed a PreCaution software program to predict the external corrosion and stress-corrosion cracking (SCC) rate of oil and gas pipelines. The PreCaution software program predicts the corrosion rate using the following 4 different input data: (1) projection, based on laboratory evaluation, (2) adaptation, based on field operating conditions, (3) validation, based on above-ground survey, and (4) verification, based on below-ground measurements from field excavation. The four steps are meant to be used in sequence, but can be used independently through certain sections. Within each step, there are 5 categories that consider the most useful properties of pipeline coatings for comparing laboratory test results and field performance. These include adhesion; resistance to soil stresses; chemical and physical stability; resistance to impact; and resistance to cathodic disbonding. Each of these properties are assigned a score based on a specific set of criteria. A category score is then determined from the property scores. The software program can be used to predict the corrosion rate and the lifetime of a pipe. Although a corrosion rate is predicted for each step, only 1 lifetime prediction is made based on the most accurate steps. 18 refs., 1 tab., 5 figs.

  10. Two-Valued Control for a Second-Order Plant with Additive External Disturbance

    Directory of Open Access Journals (Sweden)

    Alejandro Rincon

    2012-01-01

    Full Text Available In this work a two-valued state feedback control for a plant of second order with known constant coefficients and an additive bounded disturbance is designed. In this controller the control signal can take only two possible values. The controller design is based on Lyapunov-like function method, achieving the convergence of the tracking error to a user-defined residual set. A boundedness condition for the user-defined reference signal is defined, which is necessary to allow out-put tracking. The developed scheme avoids large commutation rate of the control input. The controller design and stability analysis have important contributions with respect to closely related controllers based on the direct Lyapunov method, namely, (i conditions to guarantee the expected convergence of the tracking error are established. These conditions are imposed on the reference signal and the extreme values of the control input. The stability analysis is developed by means of the Lyapunov-like function method and the Barbalat's Lemma and includes (ii the bounded nature of the Lyapunov function, (iii the monotonic convergence of the Lyapunov function to a residual set, and (iv the asymptotic convergence of the tracking error to a residual set of user-defined size.

  11. 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

    as a function of estimated wind speed. The dynamic control law is based on LPV controller synthesis with general parameter dependency by gridding the parameter space.The controller construction can, for medium- to large-scale systems, be difficult from a numerical point of view, because the involved matrix......This paper considers the design of linear parameter varying (LPV) controllers for wind turbines in order to obtain a multivariable control law that covers the entire nominal operating trajectory.The paper first presents a controller structure for selecting a proper operating trajectory...... 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...

  12. Fault tolerant synchronization of chaotic heavy symmetric gyroscope systems versus external disturbances via Lyapunov rule-based fuzzy control.

    Science.gov (United States)

    Farivar, Faezeh; Shoorehdeli, Mahdi Aliyari

    2012-01-01

    In this paper, fault tolerant synchronization of chaotic gyroscope systems versus external disturbances via Lyapunov rule-based fuzzy control is investigated. Taking the general nature of faults in the slave system into account, a new synchronization scheme, namely, fault tolerant synchronization, is proposed, by which the synchronization can be achieved no matter whether the faults and disturbances occur or not. By making use of a slave observer and a Lyapunov rule-based fuzzy control, fault tolerant synchronization can be achieved. Two techniques are considered as control methods: classic Lyapunov-based control and Lyapunov rule-based fuzzy control. On the basis of Lyapunov stability theory and fuzzy rules, the nonlinear controller and some generic sufficient conditions for global asymptotic synchronization are obtained. The fuzzy rules are directly constructed subject to a common Lyapunov function such that the error dynamics of two identical chaotic motions of symmetric gyros satisfy stability in the Lyapunov sense. Two proposed methods are compared. The Lyapunov rule-based fuzzy control can compensate for the actuator faults and disturbances occurring in the slave system. Numerical simulation results demonstrate the validity and feasibility of the proposed method for fault tolerant synchronization.

  13. 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

    Objetivo: Actualizar el cribado nutricional. La alta prevalencia del desequilibrio nutricional que genera la Desnutrición Clínica (DC), especialmente en hospitales y residencias asistidas, obliga al uso de herramientas de cribado y a controlar su evolución para combatirla sobre la marcha. La DC deriva menos de la carencia nutricional que de los efectos de la enfermedad y sus tratamientos, pero los actuales sistemas de cribado buscan más la desnutrición ya establecida que el riesgo nutricional existente. Las alteraciones metabólicas del equilibrio nutricional que constituyen la trofopatía se pueden captar en el plasma sin demoras, automáticamente, permitiendo rectificar actitudes terapéuticas demasiado agresivas o complementarlas con el adecuado soporte nutricional. Con los sistemas manuales de cribado, solo pasados días o semanas se evidenciarán, tardíamente, los cambios somáticos expresivos de esa desnutrición. La concentración de la albúmina plasmática es un parámetro muy valioso en el control nutricional. Su disminución, cualquiera que sea la causa, expresa un posible déficit pero también el riesgo nutricional a que se ve sometida la célula, antes de que la desnutrición se manifieste somáticamente. La precocidad de la detección del riesgo nutricional, anticipándose a la desnutrición y su gran capacidad pronóstica hacen de las herramientas basadas en parámetros analíticos, el procedimiento más útil, ergonómico, seguro y eficiente para el cribado y pronóstico nutricional en el entorno clínico. Conclusión: es hora de actualizar conceptos, deshacer mitos y optar por sistemas modernos de cribado eficientes, única manera de alcanzar el sueño de controlar la DC en nuestras poblaciones enfermas y frágiles.

  14. Pipeline integrity management: integration of geotechnical and mechanical assessment to control potential risks due to external forces

    Energy Technology Data Exchange (ETDEWEB)

    Malpartida Moya, John E.; Sota, Giancarlo Massucco de la; Seri, Walter [Compania Operadora de Gas del Amazonas, Lima (Peru)

    2009-07-01

    Every pipeline integrity management system evaluates and controls various threats. On pipelines which have particular characteristics as it is the case of the Andean pipelines and pipelines crossing jungles, one of the main threats are the external forces. Even, this threat causes a greater number of failures than other threats like corrosion or the third part damage. Facing this situation, the pipeline integrity management system of TgP has achieved an important development in the use and suitable handling of the information provided by diverse techniques of pipeline mechanical inspection and geotechnical inspection of the right-of-way (ROW). This document presents our methodology, which interrelate information of the in-line inspection, information of geotechnical inspections of the ROW, instrumentation (Strain Gages), topographic monitoring, among others. All this information is supported in a Geographic Information System (GIS) which allows us to integrate the information. By means of the pipeline integrity management system we control potential risks due to external forces, we have been able to act before events become critical, with no occurrence of failures. This system allows us simultaneously to optimize efforts and preserve the mechanical integrity of our pipelines, not producing neither personal nor environmental nor economical affectation. (author)

  15. Levenson's IPC (Internal-External Control) Scale: A Comparison of Chinese and American Students

    Science.gov (United States)

    Lao, Rosina C.

    1978-01-01

    The results of this study, taken together and compared with data from previous studies, suggest that the locus of control variable may be tapping some basic psychological dimension common to both Chinese and American cultures. (Author/AM)

  16. Chaos control and synchronization of two neurons exposed to ELF external electric field

    Energy Technology Data Exchange (ETDEWEB)

    Wang Jiang [School of Electrical and Automation Engineering, Tianjin University, Tianjin 300072 (China)]. E-mail: jiangwang@tju.edu.cn; Zhang Ting [School of Electrical and Automation Engineering, Tianjin University, Tianjin 300072 (China); Che Yanqiu [School of Electrical and Automation Engineering, Tianjin University, Tianjin 300072 (China)

    2007-11-15

    Chaos control and synchronization of two unidirectional coupled neurons exposed to ELF electrical field via nonlinear control technique is investigated. Based on results of space-time characteristics of trans-membrane voltage, the variation of cell trans-membrane voltage exposed to extremely low frequency (ELF) electric field is analyzed. The dynamical behaviors of the modified Hodgkin-Huxley (HH) model are identified under the periodic ELF electric field using both analytical and numerical analysis. Then, using the results of the analysis, a nonlinear feedback linearization control scheme and a modified adaptive control strategy are designed to synchronize the two unidirectional coupled neurons and stabilize the chaotic trajectory of the slave system to desired periodic orbit of the master system. The simulation results demonstrated the efficiency of the proposed algorithms.

  17. Increasing Elbow Torque Output of Stroke Patients by EMG-Controlled External Torque

    Science.gov (United States)

    2007-11-02

    Myoelectric signal processing: optimal estimation applied to electromyography � part 1: derivation of the optimal myprocessor,� IEEE Trans. Biomed...stroke patients. The control signal to the manipulator is the difference between the weighted biceps and triceps EMG, so that the system moves with the...EMG of biceps and triceps. Contrary to the many attempts in the past that used EMG signal for switch control, in the current study, we used EMG

  18. Development of Active External Network Topology Module for Floodlight SDN Controller

    Directory of Open Access Journals (Sweden)

    A. A. Noskov

    2015-01-01

    Full Text Available Traditional network architecture is inflexible and complicated. This observation has led to a paradigm shift towards software-defined networking (SDN, where network management level is separated from data forwarding level. This change was made possible by control plane transfer from the switching equipment to software modules that run on a dedicated server, called the controller (or network operating system, or network applications, that work with this controller. Methods of representation, storage and communication interfaces with network topology elements are the most important aspects of network operating systems available to SDN user because performance of some key controller modules is heavily dependent on internal representation of the network topology. Notably, firewall and routing modules are examples of such modules. This article describes the methods used for presentation and storage of network topologies, as well as interface to the corresponding Floodlight modules. An alternative algorithm has been suggested and developed for message exchange conveying network topology alterations between the controller and network applications. Proposed algorithm makes implementation of module alerting based on subscription to the relevant events. API for interaction between controller and network applications has been developed. This algorithm and API formed the base for Topology Tracker module capable to inform network applications about the changes that had occurred in the network topology and also stores compact representation of the network to speed up the interaction process.

  19. Levenberg – Marquardt’s Algorithm used for PID Controller Parameters Optimization

    OpenAIRE

    Ahmed S. Abd El-Hamid; Ahmed H. Eissa; Aly M. Radwan

    2015-01-01

    The determination of parameters of controllers is an important problem in automatic control systems. In this paper, the Levenberg Marquardt (LM) Algorithm is used to effectively solve this problem with reasonable computational effort. The Levenberg Marquardt (LM) Algorithm for optimization of three term (PID) controller parameters with dynamic model of pH neutralization process is presented. The main goal is to show the merits of Levenberg Marquardt algorithm optimizat...

  20. 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.

  1. External control of the public water supply in 29 Brazilian cities

    Directory of Open Access Journals (Sweden)

    Suzely Adas Saliba Moimaz

    2012-02-01

    Full Text Available The fluoridation of public water supplies is considered the most efficient public health measure for dental caries prevention. However, fluoride levels in the public water supply must be kept constant and adequate for the population to gain preventive benefit. The aim of this study was to analyze fluoride levels in the public water supply of 29 Brazilian municipalities during a 48-month period from November 2004 to October 2008. Three collection sites were defined for each source of municipal public water supply. Water samples were collected monthly and analyzed at the Research Laboratory of the Nucleus for Public Health (NEPESCO, Public Health Postgraduate Program, Araçatuba Dental School (UNESP. Of the 6862 samples analyzed, the fluoride levels of 53.5% (n = 3671 were within the recommended parameters, those of 30.4% (n = 2084 were below these parameters, and those of 16.1% (n = 1107 were above recommended values. Samples from the same collection site showed temporal variability in fluoride levels. Variation was also observed among samples from collection sites with different sources within the same municipality. Although 53.5% of the samples contained the recommended fluoride levels, these findings reinforce the importance of monitoring to minimize the risk of dental fluorosis and to achieve the maximum benefit in the prevention of dental caries.

  2. Adaptive Control and Synchronization of Sprott J System With Estimation Of Fully Unknown Parameters

    Directory of Open Access Journals (Sweden)

    Islam Mitul

    2015-06-01

    Full Text Available This communication develops an adaptive scheme for control and synchronization of Sprott J system with fully unknown parameters. The scheme provides an elegant strategy of designing estimators for identification of the unknown parameters of the underlying dynamical system. Adaptive control and update laws are proposed to globally stabilize the chaotic Sprott J system. A pair of identical Sprott J systems with un- known parameters are globally synchronized with the help of adaptive control and parameter update laws. The results are established using LaSalle invariance principle, which lays down weaker restrictions on the derivatives of the Lyapunov function, and producing more general results. All the results obtained in the paper are global in nature. Numerical simulations are performed to illustrate the validity and effectiveness of the proposed adaptive control and synchronization scheme in the context of the Sprott J system. The parameter identification capability of the scheme is also explored.

  3. 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...... the parameters are varying, with the degree of stability related directly to a bound on the average rate of allowable parameter variations. Thus, if knowledge of the parameter variations is available, the conservativeness of the design can be kept at a minimum. The construction of the controller is formulated...

  4. Energetics and control of ultracold isotope-exchange reactions between heteronuclear dimers in external fields

    CERN Document Server

    Tomza, Michał

    2015-01-01

    We show that isotope-exchange reactions between ground-state alkali-metal, alkaline-earth-metal, and lanthanide heteronuclear dimers consisting of two isotopes of the same atom are exothermic with an energy change in the range of 1-8000$\\,$MHz thus resulting in cold or ultracold products. For these chemical reactions there are only one rovibrational and at most several hyperfine possible product states. The number and energetics of open and closed reactive channels can be controlled by the laser and magnetic fields. The exothermic isotope-exchange reactions can be tuned to become endothermic by employing a laser-induced state-selective Stark shift control thus providing a ground for testing models of the chemical reactivity. The present proposal opens the way for studying the state-to-state dynamics of ultracold chemical reactions beyond the universal limit with a meaningful control over quantum states of both reactants and products.

  5. Energetics and Control of Ultracold Isotope-Exchange Reactions between Heteronuclear Dimers in External Fields

    Science.gov (United States)

    Tomza, Michał

    2015-08-01

    We show that isotope-exchange reactions between ground-state alkali-metal, alkaline-earth-metal, and lanthanide heteronuclear dimers consisting of two isotopes of the same atom are exothermic with an energy change in the range of 1-8000 MHz, thus resulting in cold or ultracold products. For these chemical reactions, there are only one rovibrational and at most several hyperfine possible product states. The number and energetics of open and closed reactive channels can be controlled by the laser and magnetic fields. We suggest a laser-induced isotope- and state-selective Stark shift control to tune the exothermic isotope-exchange reactions to become endothermic, thus providing the ground for testing models of the chemical reactivity. The present proposal opens the way for studying the state-to-state dynamics of ultracold chemical reactions beyond the universal limit with a meaningful control over the quantum states of both reactants and products.

  6. External validity of a randomised controlled trial on the treatment of severe infections caused by MRSA

    Science.gov (United States)

    Paul, Mical; Bronstein, Ella; Yahav, Dafna; Goldberg, Elad; Bishara, Jihad; Leibovici, Leonard

    2015-01-01

    Objectives To assess the external validity of a pragmatic, investigator-initiated RCT on treatment of severe infections caused by methicillin-resistant Staphylococcus aureus (MRSA), we compared patient characteristics and treatment effect estimates for patients included in the RCT versus those excluded. Participants and outcomes The RCT included hospitalised patients with documented or highly-probable invasive MRSA infections who were randomised to vancomycin versus trimethoprim-sulfamethoxazole (TMP-SMX) treatment, between 2007 and 2014. A concomitant observational study prospectively included all consecutive patients, between 2008 and 2011, who were excluded from the RCT due to no consent, meningitis, left-sided endocarditis, severe neutropaenia, chronic renal dialysis or treatment with study medications for longer than 48 h. The primary outcomes were clinical failure at day 7 and 30-day mortality for both studies. We compared baseline and infection characteristics, outcome rates and treatment effect estimates for included versus excluded patients. Results The RCT included 252 patients who were compared with 220 excluded patients who were observed. Inability to provide informed consent was the main reason for patient exclusion. Excluded patients’ functional and cognitive performance was significantly poorer than that of included patients. Sepsis was more severe among excluded patients (higher rates of mechanical ventilation, indwelling catheters, septic shock and organ failure). Clinical failure occurred in 83/252 (32.9%) versus 175/220 (79.5%) and deaths in 32 (12.7%) versus 64 (29.1%) for included versus excluded patients, p<0.001 for both comparisons. Comparing vancomycin to TMP-SMX, in the RCT mortality, was non-significantly lower with vancomycin (OR 0.76, 95% CIs 0.36 to 1.62), while in the observational analysis of excluded patients, mortality was significantly higher with vancomycin (OR 2.63, 1.04 to 6.65), p=0.04 for the difference. Conclusions

  7. Data acquisition and real-time control using spreadsheets: interfacing Excel with external hardware.

    Science.gov (United States)

    Aliane, Nourdine

    2010-07-01

    Spreadsheets have become a popular computational tool and a powerful platform for performing engineering calculations. Moreover, spreadsheets include a macro language, which permits the inclusion of standard computer code in worksheets, and thereby enable developers to greatly extend spreadsheets' capabilities by designing specific add-ins. This paper describes how to use Excel spreadsheets in conjunction to Visual Basic for Application programming language to perform data acquisition and real-time control. Afterwards, the paper presents two Excel applications with interactive user interfaces developed for laboratory demonstrations and experiments in an introductory course in control.

  8. Numerical modeling and passive thermal control of external lighting systems for Space Station Freedom

    Science.gov (United States)

    Buck, Gregory A.; Li, Weiming; Tong, Timothy W.

    1993-01-01

    Consideration is given to three generic families of luminaries with lamp power ranging from 11 to 150 watts. A concept of an equivalent radiation node boundary temperature was used to impose worst hot and cold environments, and transient finite difference models were developed to study the effects of geometry and optical properties of thermal control coatings. Minimum and maximum transient temperatures were computed at the critical location during 90 minute orbit and were compared with allowable limits. Results show that with the proper choice of optical properties, the luminaries can be passively controlled to within acceptable limits.

  9. External Carbon Source Addition as a Means to Control an Activated Sludge Nutrient Removal Process

    DEFF Research Database (Denmark)

    Isaacs, Steven Howard; Henze, Mogens; Søeberg, Henrik

    1994-01-01

    In alternating type activated sludge nutrient removal processes, the denitrification rate can be limited by the availability of readily-degradable carbon substrate. A control strategy is proposed by which an easily metabolizable COD source is added directly to that point in the process at which...... denitrification momentarily occurs. This approach serves to increase the denitrification rate on demand, thereby allowing the accumulation of nitrate and nitrite during periods of peak nitrogen loading to be reduced or avoided. A pilot plant demonstration of the control strategy using acetate as COD source...

  10. A simulation-based approach to the design of control systems with uncertain parameters

    Science.gov (United States)

    Auslander, D. M.; Spear, R. C.; Young, G. E.

    1982-01-01

    A design method for control systems with uncertain parameters is presented. The method utilizes a generalized sensitivity approach which separates the parameter space into regions which produce a system response that satisfies given design criteria and regions which do not. Nonparametric statistics and confidence limits for the binomial distribution are used to determine degree of parameter sensitivity and to locate regions in the parameter space which maximize the probability of producing a desirable system response. In an example it is shown that a given parameter may have to be known to a lesser degree of uncertainty to be able to specify a satisfactory design.

  11. Control of open-loop neutrally stable systems subject to actuator saturation and external disturbances

    NARCIS (Netherlands)

    Wang, Xu; Saberi, Ali; Grip, H°avard Fjær; Stoorvogel, Antonie Arij

    2013-01-01

    In this paper, we study the disturbance response of open-loop neutrally stable linear systems with saturating linear feedback controller. It is shown that the closed-loop states remain bounded if the disturbances con- sists of those signals that do not have large sustained frequency components

  12. Internalizing versus Externalizing Control: Different Ways to Perform a Time-Based Prospective Memory Task

    Science.gov (United States)

    Huang, Tracy; Loft, Shayne; Humphreys, Michael S.

    2014-01-01

    "Time-based prospective memory" (PM) refers to performing intended actions at a future time. Participants with time-based PM tasks can be slower to perform ongoing tasks (costs) than participants without PM tasks because internal control is required to maintain the PM intention or to make prospective-timing estimates. However, external…

  13. digital control of external devices through the parallel port of a ...

    African Journals Online (AJOL)

    2012-11-03

    Nov 3, 2012 ... causes the computer port to generate an actuating signal (the controlling voltage of 5V) which drives an ... order to provide faster execution. In [11], the ... Visual Basic (VB) is a simple and powerful high-level .... Most port can.

  14. Internalizing versus Externalizing Control: Different Ways to Perform a Time-Based Prospective Memory Task

    Science.gov (United States)

    Huang, Tracy; Loft, Shayne; Humphreys, Michael S.

    2014-01-01

    "Time-based prospective memory" (PM) refers to performing intended actions at a future time. Participants with time-based PM tasks can be slower to perform ongoing tasks (costs) than participants without PM tasks because internal control is required to maintain the PM intention or to make prospective-timing estimates. However, external…

  15. Relations Among Positive Parenting, Children's Effortful Control, and Externalizing Problems: A Three-Wave Longitudinal Study

    Science.gov (United States)

    Eisenberg, Nancy; Zhou, Qing; Spinrad, Tracy L.; Valiente, Carlos; Fabes, Richard A.; Liew, Jeffrey

    2005-01-01

    In a 3-wave longitudinal study (with assessments 2 years apart) involving 186 early adolescents (M ages of approximately 9.3, 11.4, and 13.4), the hypothesis that parental warmth/positive expressivity predicts children's effortful control (EC) (a temperamental characteristic contributing to emotion regulation) 2 years later, which in turn predicts…

  16. Design, control, and sensory feedback of externally powered hand prostheses: a literature review.

    Science.gov (United States)

    Cloutier, Aimee; Yang, James

    2013-01-01

    In recent years, there has been a steep rise in the quality of prostheses for patients with upper limb amputations. Researchers have begun to identify methods of making prosthetic hands both functional and cosmetically appealing, in contrast to past designs. Many improvements have occurred because of novel design strategies, such as the use of underactuated mechanisms, which allow for more degrees of freedom (DOF) or help reduce the weight of the prosthesis. The increase in functionality is also due in large part to advancements in control strategies for prosthetic hands. One common control method, using electromyographic (EMG) signals generated by muscle contractions, has allowed for an increase in the DOF of hand designs and a larger number of available grip patterns with little added complexity for the wearer. Another recent improvement in prosthetic hand design instead employs electroneurographic (ENG) signals, requiring an interface directly with the peripheral nervous system (PNS) or the central nervous system (CNS). Despite the recent progress in design and control strategies, however, prosthetic hands are still far more limited than the actual human hand. This review outlines the recent progress in the development of electrode-based prosthetic hands, detailing advancements in the areas of design, sensory feedback, and control through EMG and ENG signals (with a particular focus on interfaces with the PNS). The potential benefits and limitations of both control strategies, in terms of signal classification, invasiveness, and sensory feedback, are discussed. Finally, a brief overview of interfaces with the CNS is provided, and potential future developments for prosthetic hand design are discussed.

  17. High-density mammalian cell cultures in stirred-tank bioreactor without external pH control.

    Science.gov (United States)

    Xu, Sen; Chen, Hao

    2016-08-10

    Maintaining desired pH is a necessity for optimal cell growth and protein production. It is typically achieved through a two-sided pH control loop on the bioreactor controller. Here we investigated cell culture processes with minimum or no pH control and demonstrated that high-density mammalian cell cultures could be maintained for long-term protein production without pH control. The intrinsic interactions between pCO2, lactate, and pH were leveraged to maintain culture pH. Fed-batch cultures at the same lower pH limit of 6.75 but different upper pH limits (7.05, 7.30, 7.45, 7.65) were evaluated in the 3L bioreactors and comparable results were obtained. Neither CO2 sparging nor base addition was required to control pH in the pH range of 6.75-7.65. The impact of sparger configurations (drilled hole sparger vs. frit sparger) and scales (3L vs. 200L) on CO2 accumulation and culture pH was also demonstrated. The same principle was applied in two perfusion cultures with steady state cell densities at 42.5±3.3 or 68.3±6.0×10(6)cells/mL with low cell specific perfusion rates (15±2 to 23±3pL/cell/day), achieving up to 1.9±0.1g/L/day bioreactor productivity. Culture pH level in the 3L perfusion bioreactors was steadily maintained by controlling the residual lactate and pCO2 levels without the requirement of external pH control for up to 40days with consistent productivity and product quality. Furthermore, culture pH could be potentially modulated via adjusting residual glucose levels and CO2 stripping capability in perfusion cultures. To the best of our knowledge, this is the first time a systematic study was performed to evaluate the long-term cell cultivation and protein production in stirred-tank bioreactors without external pH control.

  18. Intelligent, Robust Control of Deteriorated Turbofan Engines via Linear Parameter Varying Quadratic Lyapunov Function Design

    Science.gov (United States)

    Turso, James A.; Litt, Jonathan S.

    2004-01-01

    A method for accommodating engine deterioration via a scheduled Linear Parameter Varying Quadratic Lyapunov Function (LPVQLF)-Based controller is presented. The LPVQLF design methodology provides a means for developing unconditionally stable, robust control of Linear Parameter Varying (LPV) systems. The controller is scheduled on the Engine Deterioration Index, a function of estimated parameters that relate to engine health, and is computed using a multilayer feedforward neural network. Acceptable thrust response and tight control of exhaust gas temperature (EGT) is accomplished by adjusting the performance weights on these parameters for different levels of engine degradation. Nonlinear simulations demonstrate that the controller achieves specified performance objectives while being robust to engine deterioration as well as engine-to-engine variations.

  19. Refractoriness in sustained visuo-manual control: is the refractory duration intrinsic or does it depend on external system properties?

    Science.gov (United States)

    van de Kamp, Cornelis; Gawthrop, Peter J; Gollee, Henrik; Loram, Ian D

    2013-01-01

    Researchers have previously adopted the double stimulus paradigm to study refractoriness in human neuromotor control. Currently, refractoriness, such as the Psychological Refractory Period (PRP) has only been quantified in discrete movement conditions. Whether refractoriness and the associated serial ballistic hypothesis generalises to sustained control tasks has remained open for more than sixty years. Recently, a method of analysis has been presented that quantifies refractoriness in sustained control tasks and discriminates intermittent (serial ballistic) from continuous control. Following our recent demonstration that continuous control of an unstable second order system (i.e. balancing a 'virtual' inverted pendulum through a joystick interface) is unnecessary, we ask whether refractoriness of substantial duration (~200 ms) is evident in sustained visual-manual control of external systems. We ask whether the refractory duration (i) is physiologically intrinsic, (ii) depends upon system properties like the order (0, 1(st), and 2(nd)) or stability, (iii) depends upon target jump direction (reversal, same direction). Thirteen participants used discrete movements (zero order system) as well as more sustained control activity (1(st) and 2(nd) order systems) to track unpredictable step-sequence targets. Results show a substantial refractory duration that depends upon system order (250, 350 and 550 ms for 0, 1(st) and 2(nd) order respectively, n=13, p<0.05), but not stability. In sustained control refractoriness was only found when the target reverses direction. In the presence of time varying actuators, systems and constraints, we propose that central refractoriness is an appropriate control mechanism for accommodating online optimization delays within the neural circuitry including the more variable processing times of higher order (complex) input-output relations.

  20. Refractoriness in sustained visuo-manual control: is the refractory duration intrinsic or does it depend on external system properties?

    Directory of Open Access Journals (Sweden)

    Cornelis van de Kamp

    Full Text Available Researchers have previously adopted the double stimulus paradigm to study refractoriness in human neuromotor control. Currently, refractoriness, such as the Psychological Refractory Period (PRP has only been quantified in discrete movement conditions. Whether refractoriness and the associated serial ballistic hypothesis generalises to sustained control tasks has remained open for more than sixty years. Recently, a method of analysis has been presented that quantifies refractoriness in sustained control tasks and discriminates intermittent (serial ballistic from continuous control. Following our recent demonstration that continuous control of an unstable second order system (i.e. balancing a 'virtual' inverted pendulum through a joystick interface is unnecessary, we ask whether refractoriness of substantial duration (~200 ms is evident in sustained visual-manual control of external systems. We ask whether the refractory duration (i is physiologically intrinsic, (ii depends upon system properties like the order (0, 1(st, and 2(nd or stability, (iii depends upon target jump direction (reversal, same direction. Thirteen participants used discrete movements (zero order system as well as more sustained control activity (1(st and 2(nd order systems to track unpredictable step-sequence targets. Results show a substantial refractory duration that depends upon system order (250, 350 and 550 ms for 0, 1(st and 2(nd order respectively, n=13, p<0.05, but not stability. In sustained control refractoriness was only found when the target reverses direction. In the presence of time varying actuators, systems and constraints, we propose that central refractoriness is an appropriate control mechanism for accommodating online optimization delays within the neural circuitry including the more variable processing times of higher order (complex input-output relations.

  1. Generalized synchronization with uncertain parameters of nonlinear dynamic system via adaptive control.

    Science.gov (United States)

    Yang, Cheng-Hsiung; Wu, Cheng-Lin

    2014-01-01

    An adaptive control scheme is developed to study the generalized adaptive chaos synchronization with uncertain chaotic parameters behavior between two identical chaotic dynamic systems. This generalized adaptive chaos synchronization controller is designed based on Lyapunov stability theory and an analytic expression of the adaptive controller with its update laws of uncertain chaotic parameters is shown. The generalized adaptive synchronization with uncertain parameters between two identical new Lorenz-Stenflo systems is taken as three examples to show the effectiveness of the proposed method. The numerical simulations are shown to verify the results.

  2. Chaotic Synchronization of Two Electrical Coupled Neurons with Unknown Parameters Based on Adaptive Control

    Institute of Scientific and Technical Information of China (English)

    WANG Xing-Yuan; REN Xiao-Li

    2011-01-01

    @@ Chaotic synchronization of two electrical coupled FitzHugh-Nagumo(FHN) neurons with unknown parameters via adaptive control is investigated.Based on the Lyapunov stability theory,an adaptive controller and a parameter update law are designed,which can achieve the synchronization of the two gap junction coupled FHN neurons when the individual neuron is chaotic,without considering the coupling strength.Moreover,the unknown parameters are identified successfully and the controller is robust to the random noise.The numerical simulation results confirm the effectiveness of the designed controller.%Chaotic synchronization of two electrical coupled FitzHugh-Nagumo (FHN) neurons with unknown parameters via adaptive control is investigated. Based on the Lyapunov stability theory, an adaptive controller and a parameter update law are designed, which can achieve the synchronization of the two gap junction coupled FHN neurons when the individual neuron is chaotic, without considering the coupling strength. Moreover, the unknown parameters are identified successfully and the controller is robust to the random noise. The numerical simulation results confirm the effectiveness of the designed controller.

  3. PID Controller Parameters Tuning Based-on Satisfaction for Superheated Steam Temperature of Power Station Boiler

    Directory of Open Access Journals (Sweden)

    Benxian Xiao

    2014-06-01

    Full Text Available Proposed the PID controller parameters tuning method based-on New Luus-Jaakola (NLJ algorithm and satisfaction idea. According to the different requirements of each performance index, designed the satisfaction function with fuzzy constraint attributes, and then determined the comprehensive satisfaction function for PID tuning by NLJ algorithm. Provided the steps of PID controller parameters tuning based on the NLJ algorithm and satisfaction, and applied this tuning method to the cascade control system of superheated steam temperature for Power Station Boiler. Finally the simulation and experiment results have shown the proposed method has good dynamic and static control performances for this complicated superheated steam temperature control system.

  4. Medicinal plants used to control internal and external parasites in goats

    Directory of Open Access Journals (Sweden)

    Marcia Sanhokwe

    2016-03-01

    Full Text Available The use of medicinal plants plays a major role in the primary health care of animals in South Africa. A survey was conducted to document medicinal plants used to control parasites in goats in Kwezi and Ntambethemba villages in the Eastern Cape Province, South Africa. Information from 50 farmers and 3 herbalists was obtained through the use of a structured questionnaire, and a snowball sampling technique was used to identify key informants. The obtained data were analysed using PROC FREQ of SAS (2003, and fidelity level values were determined to estimate the healing potential of the mentioned plants. The survey revealed nine plant species belonging to eight families that were used to control parasites in goats. Asphodelaceae (22.22% was the most frequently used plant family. Leaves were the most used plant parts, constituting 60.38%. They were prepared either as infusions or decoctions of single plants or in mixtures. Aloe ferox, Acokanthera oppositifolia and Elephantorrhiza elephantina were the plants having the highest fidelity level for their use to control parasites, each scoring 100%, followed by Albuca setosa (83.33%. The study revealed low knowledge about ethnoveterinary medicine in the study area. It also revealed that information on ethno-veterinary medicine in this area is mostly confined to older people and there is danger that this knowledge can be lost before being passed on to other generations. Therefore, there is an urgent need to document information on these plant species so that the future generation can benefit. Further investigation should be carried out to validate the efficacy and safety of the above-mentioned plants so as to provide cheap alternative ways of controlling parasites.Keywords: ailments; ethno-veterinary practices; small ruminant; traditional medicine

  5. Medicinal plants used to control internal and external parasites in goats.

    Science.gov (United States)

    Sanhokwe, Marcia; Mupangwa, Johnfisher; Masika, Patrick J; Maphosa, Viola; Muchenje, Voster

    2016-04-29

    The use of medicinal plants plays a major role in the primary health care of animals in South Africa. A survey was conducted to document medicinal plants used to control parasites in goats in Kwezi and Ntambethemba villages in the Eastern Cape Province, South Africa. Information from 50 farmers and 3 herbalists was obtained through the use of a structured questionnaire, and a snowball sampling technique was used to identify key informants. The obtained data were analysed using PROC FREQ of SAS (2003), and fidelity level values were determined to estimate the healing potential of the mentioned plants. The survey revealed nine plant species belonging to eight families that were used to control parasites in goats. Asphodelaceae (22.22%) was the most frequently used plant family. Leaves were the most used plant parts, constituting 60.38%. They were prepared either as infusions or decoctions of single plants or in mixtures. Aloe ferox, Acokanthera oppositifolia and Elephantorrhiza elephantina were the plants having the highest fidelity level for their use to control parasites, each scoring 100%, followed by Albuca setosa (83.33%). The study revealed low knowledge about ethnoveterinary medicine in the study area. It also revealed that information on ethno-veterinary medicine in this area is mostly confined to older people and there is danger that this knowledge can be lost before being passed on to other generations. Therefore, there is an urgent need to document information on these plant species so that the future generation can benefit. Further investigation should be carried out to validate the efficacy and safety of the above-mentioned plants so as to provide cheap alternative ways of controlling parasites.

  6. Perceived parental control of food intake is related to external, restrained and emotional eating in 7-12-year-old boys and girls.

    Science.gov (United States)

    van Strien, Tatjana; Bazelier, Francien G

    2007-11-01

    This study examined the prevalence of external, restrained and emotional eating and the relationship of these disturbed types of eating behaviours with perceived parental control of food intake (pressure to eat and restriction) in a group of 7- to 12-year-old boys and girls (n = 596). External eating turned out to be the most prevalent disturbed eating behaviour for boys and girls, followed by restrained eating and emotional eating. Sex differences were found in external and restrained eating. For the boys, perceived pressure to eat was positively related to emotional and external eating. For both sexes, perceived restriction to eat was negatively related to emotional and external eating and positively related to restrained eating. This led to the conclusion that perceived pressure to eat has a disruptive effect on a child's self-regulating mechanism of food intake, particularly so for boys, whereas perceived restriction can also have a positive effect.

  7. Amnioinfusion for women with a singleton breech presentation and a previous failed external cephalic version: a randomized controlled trial.

    Science.gov (United States)

    Diguisto, Caroline; Winer, Norbert; Descriaud, Celine; Tavernier, Elsa; Weymuller, Victoire; Giraudeau, Bruno; Perrotin, Franck

    2017-03-09

    Purpose Our trial aimed to assess the effectiveness of amnioinfusion for a second attempt at external cephalic version (ECV). Material and methods This open randomized controlled trial was planned with a sequential design. Women at a term ≥ 36 weeks of gestation with a singleton fetus in breech presentation and a first unsuccessful ECV were recruited in two level-3 maternity units. They were randomly allocated to transabdominal amnioinfusion with a 500-mL saline solution under ultrasound surveillance or no amnioinfusion before the second ECV attempt. Trained senior obstetricians performed all procedures. The primary outcome was the cephalic presentation rate at delivery. Analyses were conducted according to intention to treat (NCT00465712) Result Recruitment difficulties led to stopping the trial after a 57-month period, 119 women were randomized: 59 allocated to amnioinfusion + ECV and 60 to ECV only. Data were analyzed without applying the sequential feature of the design. The rate of cephalic presentation at delivery did not differ significantly according to whether the second version attempt was or was not preceded by amnioinfusion (20% vs 12%, p = 0.20). Premature rupture of the membranes occurred for 15% of the women in the amnioinfusion group. Conclusion Amnioinfusion before a second attempt to external version does not significantly increase the rate of cephalic presentation at delivery.

  8. Optimum control of the active magnetic bearing for various parameters of the program movement

    Science.gov (United States)

    Majorov, S. V.; Makhova, N. N.

    2017-08-01

    We consider the mathematical model of stabilization of the situation of a rotor is given in an active magnetic bearing. Also various options of control system are considered Investigated influence of the program movement and free controller parameters on quality of control process.

  9. Synchronization of hyperchaotic Rossler system with uncertain parameters via nonlinear control

    Institute of Scientific and Technical Information of China (English)

    DONG En-zeng; CHEN Zeng-qiang; YUAN Zhu-zhi

    2006-01-01

    @@ Based on the Lyapunov stability theory,a new method for synchronization of hyperchaotic Rossler system with uncertain parameters is proposed.By this method,choosing appropriate control law and adaptive update law of uncertain parameters,all the errors of system variable synchronization and of uncertain parameter track are asymptotically stable.The theoretical analysis and the numerical simulations prove the effectiveness of the proposed method.

  10. A Nanostructured Composites Thermal Switch Controls Internal and External Short Circuit in Lithium Ion Batteries

    Science.gov (United States)

    McDonald, Robert C.; VanBlarcom, Shelly L.; Kwasnik, Katherine E.

    2013-01-01

    A document discusses a thin layer of composite material, made from nano scale particles of nickel and Teflon, placed within a battery cell as a layer within the anode and/or the cathode. There it conducts electrons at room temperature, then switches to an insulator at an elevated temperature to prevent thermal runaway caused by internal short circuits. The material layer controls excess currents from metal-to-metal or metal-to-carbon shorts that might result from cell crush or a manufacturing defect

  11. [Analysis of the results of the 2010 External Quality Control Program of the Spanish Society of Infectious Diseases and Clinical Microbiology].

    Science.gov (United States)

    Ruiz de Gopegui Bordes, Enrique; Serrano, M del Remedio Guna; Orta Mira, Nieves; Ovies, María Rosario; Poveda, Marta; Cardona, Concepción Gimeno

    2011-12-01

    The External Quality Control Program of the Spanish Society of Infectious Diseases and Clinical Microbiology includes controls for bacteriology, serology, mycology, parasitology, mycobacteria, virology and molecular microbiology. This article presents the most important conclusions and lessons of the 2010 controls. As a whole, the results obtained in 2010 confirm the excellent skill and good technical standards found in previous years. However, erroneous results can be obtained in any laboratory and in clinically relevant determinations. The results of this program highlight the need to implement both internal and external controls to ensure maximal quality of microbiological tests(1).

  12. LPV Control for a Semi-Active Suspension Quarter of Car-One Parameter Case

    Directory of Open Access Journals (Sweden)

    Lozoya SantosJorge de Jesús

    2016-01-01

    Full Text Available The actual semi-active suspension control systems with a balance between comfort and road holding goals are not optimal because in these solutions one goal or the other always dominates in the suspension performance. This paper is centered in a new proposal to control an automotive semi-active suspension to achieve the comfort and maintain the road holding.The output in the control strategy is the electric current. A nonlinear quarter of vehicle model simulation compares and validates the proposal versus different controllers. The controller is designed with the H∞ criteria and the Linear Varying Parameter (LPV considering the saturation and sigmoid shape of the F-V characteristic diagram. Unlike the solutions in literature, which use at least two scheduling parameters, the proposed LPV controller scheme for a semi-active suspension uses only one scheduling parameter.

  13. Controlling hyperchaotic complex systems with unknown parameters based on adaptive passive method

    Institute of Scientific and Technical Information of China (English)

    Gamal M.Mahmoud; Emad E.Mahmoud; Ayman A.Arafa

    2013-01-01

    The aim of this paper is to study the control of hyperchaotic complex nonlinear systems with unknown parameters using passive control theory.An approach is stated to design the passive controller and estimate the unknown parameters based on the property of the passive system.The feasibility and effectiveness of the proposed approach is demonstrated through its application to the hyperchaotic complex Lü system,as an example.The estimated values of the unknown parameters are calculated.The analytical form of the complex controller is derived and used in the numerical simulation to control the hyperchaotic attractors of this example.Block diagrams of this example using Matlab/Simulink are constructed after and before the control to ensure the validity of the analytical results.Other examples of hyperchaotic complex nonlinear systems can be similarly treated.

  14. The Effect of External Apple Vinegar Application on Varicosity Symptoms, Pain, and Social Appearance Anxiety: A Randomized Controlled Trial.

    Science.gov (United States)

    Atik, Derya; Atik, Cem; Karatepe, Celalettin

    2016-01-01

    Aim. We aimed to determine the effect of external apple vinegar application on the symptoms and social appearance anxiety of varicosity patients who were suggested conservative treatment. Method. The study was planned as an experimental, randomized, and controlled study. 120 patients were randomly selected and then were randomly allocated to either experimental or control group by simple blind random sampling method. In the collection of research data, a questionnaire questioning sociodemographic and clinical characteristics, the Visual Analog Scale (VAS) for pain, and the Social Appearance Anxiety Scale (SAAS) were used. The patients in the study group were suggested to apply apple vinegar to the area of the leg with varicosity alongside the treatment suggested by the doctor. The patients in the control group received no intervention during the study. Results. The sociodemographic and clinic characteristics of both groups were found to be similar (p > 0.05). The patients were evaluated with regard to cramps, pain, leg fatigue perception, edema, itching, pigmentation, and weight feelings in the leg, VAS, and SAAS averages in the second evaluation; the control group had a decrease in such symptoms (p > 0.05) although the decrease in the application group was higher and statistically meaningful (p apple vinegar on varicosity patients, which is a very easy application, increased the positive effects of conservative treatment.

  15. Center of mass acceleration feedback control of standing balance by functional neuromuscular stimulation against external postural perturbations.

    Science.gov (United States)

    Nataraj, Raviraj; Audu, Musa L; Triolo, Ronald J

    2013-01-01

    This study investigated the use of center of mass (COM) acceleration feedback for improving performance of a functional neuromuscular stimulation control system to restore standing function to a subject with complete, thoracic-level spinal cord injury. The approach for linearly relating changes in muscle stimulation to changes in COM acceleration was verified experimentally and subsequently produced data to create an input-output map driven by sensor feedback. The feedback gains were systematically tuned to reduce upper extremity (UE) loads applied to an instrumented support device while resisting external postural disturbances. Total body COM acceleration was accurately estimated (>89% variance explained) using 3-D outputs of two accelerometers mounted on the pelvis and torso. Compared to constant muscle stimulation employed clinically, feedback control of stimulation reduced UE loading by 33%. COM acceleration feedback is advantageous in constructing a standing neuroprosthesis since it provides the basis for a comprehensive control synergy about a global, dynamic variable and requires minimal instrumentation. Future work should include tuning and testing the feedback control system during functional reaching activity that is more indicative of activities of daily living.

  16. Fuzzy Backstepping Torque Control Of Passive Torque Simulator With Algebraic Parameters Adaptation

    Science.gov (United States)

    Ullah, Nasim; Wang, Shaoping; Wang, Xingjian

    2015-07-01

    This work presents fuzzy backstepping control techniques applied to the load simulator for good tracking performance in presence of extra torque, and nonlinear friction effects. Assuming that the parameters of the system are uncertain and bounded, Algebraic parameters adaptation algorithm is used to adopt the unknown parameters. The effect of transient fuzzy estimation error on parameters adaptation algorithm is analyzed and the fuzzy estimation error is further compensated using saturation function based adaptive control law working in parallel with the actual system to improve the transient performance of closed loop system. The saturation function based adaptive control term is large in the transient time and settles to an optimal lower value in the steady state for which the closed loop system remains stable. The simulation results verify the validity of the proposed control method applied to the complex aerodynamics passive load simulator.

  17. Self-Adaptive Differential Evolution Algorithm With Zoning Evolution of Control Parameters and Adaptive Mutation Strategies.

    Science.gov (United States)

    Fan, Qinqin; Yan, Xuefeng

    2016-01-01

    The performance of the differential evolution (DE) algorithm is significantly affected by the choice of mutation strategies and control parameters. Maintaining the search capability of various control parameter combinations throughout the entire evolution process is also a key issue. A self-adaptive DE algorithm with zoning evolution of control parameters and adaptive mutation strategies is proposed in this paper. In the proposed algorithm, the mutation strategies are automatically adjusted with population evolution, and the control parameters evolve in their own zoning to self-adapt and discover near optimal values autonomously. The proposed algorithm is compared with five state-of-the-art DE algorithm variants according to a set of benchmark test functions. Furthermore, seven nonparametric statistical tests are implemented to analyze the experimental results. The results indicate that the overall performance of the proposed algorithm is better than those of the five existing improved algorithms.

  18. The influence of change software of engine control unit on chosen parameters of its work

    Directory of Open Access Journals (Sweden)

    Piotr GUSTOF

    2007-01-01

    Full Text Available In this work was presented the influence of changes software of engine control unit Fiat Stilo 1,9 JTD on chosen parameters of its work: maximum power, engine torque, acceleration, maximum speed and average fuel consumption.

  19. A new ball launching system with controlled flight parameters for catching experiments.

    Science.gov (United States)

    d'Avella, A; Cesqui, B; Portone, A; Lacquaniti, F

    2011-03-30

    Systematic investigations of sensorimotor control of interceptive actions in naturalistic conditions, such as catching or hitting a ball moving in three-dimensional space, requires precise control of the projectile flight parameters and of the associated visual stimuli. Such control is challenging when air drag cannot be neglected because the mapping of launch parameters into flight parameters cannot be computed analytically. We designed, calibrated, and experimentally validated an actuated launching apparatus that can control the average spatial position and flight duration of a ball at a given distance from a fixed launch location. The apparatus was constructed by mounting a ball launching machine with adjustable delivery speed on an actuated structure capable of changing the spatial orientation of the launch axis while projecting balls through a hole in a screen hiding the apparatus. The calibration procedure relied on tracking the balls with a motion capture system and on approximating the mapping of launch parameters into flight parameters by means of polynomials functions. Polynomials were also used to estimate the variability of the flight parameters. The coefficients of these polynomials were obtained using the launch and flight parameters of 660 launches with 65 different initial conditions. The relative accuracy and precision of the apparatus were larger than 98% for flight times and larger than 96% for ball heights at a distance of 6m from the screen. Such novel apparatus, by reliably and automatically controlling desired ball flight characteristics without neglecting air drag, allows for a systematic investigation of naturalistic interceptive tasks.

  20. Trajectory control of PbSe-γ-Fe2O3 nanoplatforms under viscous flow and an external magnetic field

    Science.gov (United States)

    Etgar, Lioz; Nakhmani, Arie; Tannenbaum, Allen; Lifshitz, Efrat; Tannenbaum, Rina

    2010-04-01

    The flow behavior of nanostructure clusters, consisting of chemically bonded PbSe quantum dots and magnetic γ-Fe2O3 nanoparticles, has been investigated. The clusters are regarded as model nanoplatforms with multiple functionalities, where the γ-Fe2O3 magnets serve as transport vehicles, manipulated by an external magnetic field gradient, and the quantum dots act as fluorescence tags within an optical window in the near-infrared regime. The clusters' flow was characterized by visualizing their trajectories within a viscous fluid (mimicking a blood stream), using an optical imaging method, while the trajectory pictures were analyzed by a specially developed processing package. The trajectories were examined under various flow rates, viscosities and applied magnetic field strengths. The results revealed a control of the trajectories even at low magnetic fields (<1 T), validating the use of similar nanoplatforms as active targeting constituents in personalized medicine.

  1. An assessment of overall "gain" of the O2-feedback control system with and without external dead space breathing.

    Science.gov (United States)

    Masuyama, H; Hayashi, F; Honda, Y

    1983-01-01

    Overall gain of the O2-ventilation feedback control system (GO2) was determined in 9 male and one female healthy subjects. GO2 progressively increased with decreasing end-tidal PO2 (PETO2). This value did not exceed the overall gain of the CO2-ventilation feedback system (GCO2) even at a PETO2 level of 40 mmHg, suggesting that hypoxic stimulation did not become predominant in the present experimental condition. With addition of 250 ml of external dead space, PETO2 decrement (delta PETO2 X actual) was experimentally observed. The delta PETO2 X actual thus obtained was found to be in good agreement with the PETO2 decrement deduced from GO2 (delta PETO2 X expected). This result was similar to that found in the PETCO2 change previously seen in normoxia.

  2. Trajectory control of PbSe-gamma-Fe2O3 nanoplatforms under viscous flow and an external magnetic field.

    Science.gov (United States)

    Etgar, Lioz; Nakhmani, Arie; Tannenbaum, Allen; Lifshitz, Efrat; Tannenbaum, Rina

    2010-04-30

    The flow behavior of nanostructure clusters, consisting of chemically bonded PbSe quantum dots and magnetic gamma-Fe(2)O(3) nanoparticles, has been investigated. The clusters are regarded as model nanoplatforms with multiple functionalities, where the gamma-Fe(2)O(3) magnets serve as transport vehicles, manipulated by an external magnetic field gradient, and the quantum dots act as fluorescence tags within an optical window in the near-infrared regime. The clusters' flow was characterized by visualizing their trajectories within a viscous fluid (mimicking a blood stream), using an optical imaging method, while the trajectory pictures were analyzed by a specially developed processing package. The trajectories were examined under various flow rates, viscosities and applied magnetic field strengths. The results revealed a control of the trajectories even at low magnetic fields (<1 T), validating the use of similar nanoplatforms as active targeting constituents in personalized medicine.

  3. Free-flight investigation of the stability and control characteristics of a STOL model with an externally blown jet flap

    Science.gov (United States)

    Parlett, L. P.; Emerling, S. J.; Phelps, A. E., III

    1974-01-01

    The stability and control characteristics of a four-engine turbofan STOL transport model having an externally blown jet flap have been investigated by means of the flying-model technique in the Langley full-scale tunnel. The flight characteristics of the model were investigated under conditions of symmetric and asymmetric (one engine inoperative) thrust at lift coefficients up to 9.5 and 5.5, respectively. Static characteristics were studied by conventional power-on force tests over the flight-test angle-of-attack range including the stall. In addition to these tests, dynamic longitudinal and lateral stability calculations were performed for comparison with the flight-test results and for use in correlating the model results with STOL handling-qualities criteria.

  4. Study On The External Gas-Assisted Mold Temperature Control For Thin Wall Injection Molding

    Directory of Open Access Journals (Sweden)

    ThanhTrung Do

    2017-03-01

    Full Text Available Dynamic mold surface temperature control (DMTC has many advantages in micro-injection molding as well as thin-wall molding product. In this paper, DMTC will be applied for the thin-wall molding part with the observation of the weldline appearance and the weldline strength. The heating step of DMTC will be achieved by the hot air flow directly to the weldline area. The results show that the heating rate could be reached to 4.5C/s, which could raising the mold surface from 30C to over 120C within 15 s. The melt filling was operated with high temperature at the weldline area; therefore, the weldline appearance was eliminated. In addition, the weldline strength was also improved. The results show that the thinner part had the higher strength of the weldline

  5. Externally controlled drug release using a gold nanorod contained composite membrane.

    Science.gov (United States)

    Kim, Kibeom; Jo, Min-Chul; Jeong, Sundo; Palanikumar, L; Rotello, Vincent M; Ryu, Ja-Hyoung; Park, Myoung-Hwan

    2016-06-09

    Versatile drug delivery devices using nanoporous membranes consisting of gold nanorods and dendrimers have been demonstrated to provide light-triggered on-demand pulsatile release from a reservoir containing highly enriched therapeutics for a real patient's needs. The drug release rate is directly correlated with the temperature increase and irradiated energy of a near-IR laser in both static and fluidic devices. This biocompatible platform for on-demand control was further confirmed by in vitro experiments. Interestingly, different responses to stimuli were obtained from each drug in the absence and presence of NIR light, indicating the versatile potential of our on-demand drug delivery system in less-invasive therapies requiring multi-drug delivery strategies. The enhanced delivery system will improve therapeutic efficacy and reduce side effects through regulation of plasma drug profiles.

  6. Externally controlled drug release using a gold nanorod contained composite membrane

    Science.gov (United States)

    Kim, Kibeom; Jo, Min-Chul; Jeong, Sundo; Palanikumar, L.; Rotello, Vincent M.; Ryu, Ja-Hyoung; Park, Myoung-Hwan

    2016-06-01

    Versatile drug delivery devices using nanoporous membranes consisting of gold nanorods and dendrimers have been demonstrated to provide light-triggered on-demand pulsatile release from a reservoir containing highly enriched therapeutics for a real patient's needs. The drug release rate is directly correlated with the temperature increase and irradiated energy of a near-IR laser in both static and fluidic devices. This biocompatible platform for on-demand control was further confirmed by in vitro experiments. Interestingly, different responses to stimuli were obtained from each drug in the absence and presence of NIR light, indicating the versatile potential of our on-demand drug delivery system in less-invasive therapies requiring multi-drug delivery strategies. The enhanced delivery system will improve therapeutic efficacy and reduce side effects through regulation of plasma drug profiles.Versatile drug delivery devices using nanoporous membranes consisting of gold nanorods and dendrimers have been demonstrated to provide light-triggered on-demand pulsatile release from a reservoir containing highly enriched therapeutics for a real patient's needs. The drug release rate is directly correlated with the temperature increase and irradiated energy of a near-IR laser in both static and fluidic devices. This biocompatible platform for on-demand control was further confirmed by in vitro experiments. Interestingly, different responses to stimuli were obtained from each drug in the absence and presence of NIR light, indicating the versatile potential of our on-demand drug delivery system in less-invasive therapies requiring multi-drug delivery strategies. The enhanced delivery system will improve therapeutic efficacy and reduce side effects through regulation of plasma drug profiles. Electronic supplementary information (ESI) available. See DOI: 10.1039/c6nr00362a

  7. 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.

  8. 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.

  9. Aquatic therapy for boys with Duchenne muscular dystrophy (DMD): an external pilot randomised controlled trial.

    Science.gov (United States)

    Hind, Daniel; Parkin, James; Whitworth, Victoria; Rex, Saleema; Young, Tracey; Hampson, Lisa; Sheehan, Jennie; Maguire, Chin; Cantrill, Hannah; Scott, Elaine; Epps, Heather; Main, Marion; Geary, Michelle; McMurchie, Heather; Pallant, Lindsey; Woods, Daniel; Freeman, Jennifer; Lee, Ellen; Eagle, Michelle; Willis, Tracey; Muntoni, Francesco; Baxter, Peter

    2017-01-01

    Standard treatment of Duchenne muscular dystrophy (DMD) includes regular physiotherapy. There are no data to show whether adding aquatic therapy (AT) to land-based exercises helps maintain motor function. We assessed the feasibility of recruiting and collecting data from boys with DMD in a parallel-group pilot randomised trial (primary objective), also assessing how intervention and trial procedures work. Ambulant boys with DMD aged 7-16 years established on steroids, with North Star Ambulatory Assessment (NSAA) score ≥8, who were able to complete a 10-m walk test without aids or assistance, were randomly allocated (1:1) to 6 months of either optimised land-based exercises 4 to 6 days/week, defined by local community physiotherapists, or the same 4 days/week plus AT 2 days/week. Those unable to commit to a programme, with >20% variation between NSAA scores 4 weeks apart, or contraindications to AT were excluded. The main outcome measures included feasibility of recruiting 40 participants in 6 months from six UK centres, clinical outcomes including NSAA, independent assessment of treatment optimisation, participant/therapist views on acceptability of intervention and research protocols, value of information (VoI) analysis and cost-impact analysis. Over 6 months, 348 boys were screened: most lived too far from centres or were enrolled in other trials; 12 (30% of the targets) were randomised to AT (n = 8) or control (n = 4). The mean change in NSAA at 6 months was -5.5 (SD 7.8) in the control arm and -2.8 (SD 4.1) in the AT arm. Harms included fatigue in two boys, pain in one. Physiotherapists and parents valued AT but believed it should be delivered in community settings. Randomisation was unattractive to families, who had already decided that AT was useful and who often preferred to enrol in drug studies. The AT prescription was considered to be optimised for three boys, with other boys given programmes that were too extensive and insufficiently

  10. 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.

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

    DEFF Research Database (Denmark)

    Sloth, Christoffer; Esbensen, Thomas; Stoustrup, Jakob

    2011-01-01

    , designed using a proposed method that allows the inclusion of both faults and uncertainties in the LPV controller design. We specifically consider a 4.8 MW, variable-speed, variable-pitch wind turbine model with a fault in the pitch system. We propose the design of a nominal controller (NC), handling...... the parameter variations along the nominal operating trajectory caused by nonlinear aerodynamics. To accommodate the fault in the pitch system, an active fault-tolerant controller (AFTC) and a passive fault-tolerant controller (PFTC) are designed. In addition to the nominal LPV controller, we also propose...... 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...

  12. Externally Controlled Injection of Electrons by a Laser Pulse in a Laser Wakefield Electron Accelerator

    CERN Document Server

    Chen Szu Yuan; Chen Wei Ting; Chien, Ting-Yei; Lee, Chau-Hwang; Lin, Jiunn-Yuan; Wang, Jyhpyng

    2005-01-01

    Spatially and temporally localized injection of electrons is a key element for development of plasma-wave electron accelerator. Here we report the demonstration of two different schemes for electron injection in a self-modulated laser wakefield accelerator (SM-LWFA) by using a laser pulse. In the first scheme, by implementing a copropagating laser prepulse with proper timing, we are able to control the growth of Raman forward scattering and the production of accelerated electrons. We found that the stimulated Raman backward scattering of the prepulse plays the essential role of injecting hot electrons into the fast plasma wave driven by the pump pulse. In the second scheme, by using a transient density ramp we achieve self-injection of electrons in a SM-LWFA with spatial localization. The transient density ramp is produced by a prepulse propagating transversely to drill a density depression channel via ionization and expansion. The same mechanism of injection with comparable efficiency is also demonstrated wi...

  13. Pose control of the chain composed of magnetic particles using external uniform and gradient magnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, J. F., E-mail: zhoujianfeng@njtech.edu.cn; Shao, C. L.; Gu, B. Q. [Nanjing Tech University, School of Mechanical and Power Engineering (China)

    2016-01-15

    Magnetic particles (MPs) are known to respond to a magnetic field and can be moved by magnetic force, which make them good carriers in bioengineering and pharmaceutical engineering. In this paper, a pose control method for the straight chain composed of MPs is proposed, and the chain with one pose can be moved to another position with another pose using alternately employed uniform and gradient magnetic fields. Based on computer simulations, it is revealed that in the uniform magnetic field, the MPs form a straight chain with the same separation space along the field lines, and once the uniform magnetic field rotates, the chain also rotates with the field. In the gradient magnetic field, the MPs move toward the higher field so that the translation of the chain can be realized. The simulation results indicate that while the uniform magnetic field is rotating, there exists certain hysteresis between the chain and the field, and the chain is not straight anymore. So the uniform magnetic field should rest at the target angle for a period to make the chain fully relax to be straight. For nanoMP, its magnetic moment directly determines the gradient magnetic force which is much smaller than the dipole–dipole force among MPs. Therefore, the translation of the chain is much more time-consuming than rotation. To enlarge the translational velocity, it is suggested to increase the size of MPs or the magnetic field gradient.

  14. 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.

  15. An Adaptive Tracking Control of Fractional-Order Chaotic Systems with Uncertain System Parameter

    Directory of Open Access Journals (Sweden)

    Ping Zhou

    2011-01-01

    Full Text Available An adaptive tracking control scheme is presented for fractional-order chaotic systems with uncertain parameter. It is theoretically proved that this approach can make the uncertain parameter fractional-order chaotic system track any given reference signal and the uncertain system parameter is estimated through the adaptive tracking control process. Furthermore, the reference signal may belong to other integer-orders chaotic system or belong to different fractional-order chaotic system with different fractional orders. Two examples are presented to demonstrate the effectiveness of the proposed method.

  16. Blackness coefficients, effective diffusion parameters, and control rod worths for thermal reactors - methods

    Energy Technology Data Exchange (ETDEWEB)

    Bretscher, M.M.

    1984-01-01

    Simple diffusion theory cannot be used to evaluate control rod worths in thermal neutron reactors because of the strongly absorbing character of the control material. However, reliable control rod worths can be obtained within the framework of diffusion theory if the control material is characterized by a set of mesh-dependent effective diffusion parameters. For thin slab absorbers the effective diffusion parameters can be expressed as functions of a suitably-defined pair of blackness coefficients. Methods for calculating these blackness coefficients in the P/sub 1/, P/sub 3/, and P/sub 5/ approximations, with and without scattering, are presented. For control elements whose geometry does not permit a thin slab treatment, other methods are needed for determining the effective diffusion parameters. One such method, based on reaction rate ratios, is discussed.

  17. THE STUDY ON A KIND OF CONTROL SYSTEM WITH NONLINEAR PARABOLIC DISTRIBUTED PARAMETERS

    Institute of Scientific and Technical Information of China (English)

    周建军; 徐燕侯

    2002-01-01

    The modelling of one kind of nonlinear parabolic distributed parameter control system with moving boundary, which had extensive applications was presented. Two methods were used to investigate the basic characteristics of the system: 1 ) transforming the system in the variable domain into that in the fixed domain; 2) transforming the distributed parameter system into the lumped parameter system. It is found that there are two critical values for the control variable: the larger one determines whether or not the boundary would move, while the smaller one determines whether or not the boundary would stop automatically. For one-dimensional system of planar, cylindrical and spherical cases the definite solution problem can be expressed as a unified form. By means of the computer simulation the open-loop control system and close-cycle feedback control system have been investigated. Numerical results agree well with theoretical results. The computer simulation shows that the system is well posed, stable, measurable and controllable.

  18. Tuning a PD Controller Based on an SVR for the Control of a Biped Robot Subject to External Forces and Slope Variation

    Directory of Open Access Journals (Sweden)

    João P. Ferreira

    2014-03-01

    The ZMP is calculated by reading four force sensors placed under each of the robot’s feet. The gait implemented in this biped is similar to a human gait, which is acquired and adapted to the robot’s size. The main contribution of this paper is the fine-tuning of the ZMP controller based on the SVR. To implement and test this, the biped robot was subjected to external forces and slope variation. Some experiments are presented and the results show that the implemented gait combined with the correct tuning of the SVR controller is appropriate for use with this biped robot. The SVR controller runs at 0.2 ms, which is about 50 times faster than a corresponding first- order TSK neural-fuzzy network.

  19. CONTROL OF LASER RADIATION PARAMETERS: Enhancement of the efficiency and control of emission parameters of an unstable-resonator chemical oxygen—iodine laser

    Science.gov (United States)

    Boreisho, A. S.; Lobachev, V. V.; Savin, A. V.; Strakhov, S. Yu; Trilis, A. V.

    2007-07-01

    The outlook is considered for the development of a high-power supersonic flowing chemical oxygen—iodine laser operating as an amplifier and controlled by radiation from a master oscillator by using an unstable resonator with a hole-coupled mirror. The influence of the seed radiation intensity, the coupling-hole diameter, the active-medium length, and the magnification factor on the parameters of laser radiation is analysed. It is shown that the use of such resonators is most advisable in medium-power oxygen—iodine lasers for which classical unstable resonators are inefficient because of their low magnification factors. The use of unstable resonators with a hole-coupled mirror and injection provides the control of radiation parameters and a considerable increase in the output power and brightness of laser radiation.

  20. Dose-volume histogram parameters and local tumor control in magnetic resonance image-guided cervical cancer brachytherapy.

    Science.gov (United States)

    Dimopoulos, Johannes C A; Lang, Stefan; Kirisits, Christian; Fidarova, Elena F; Berger, Daniel; Georg, Petra; Dörr, Wolfgang; Pötter, Richard

    2009-09-01

    To investigate the value of dose-volume histogram (DVH) parameters for predicting local control in magnetic resonance (MR) image-guided brachytherapy (IGBT) for patients with cervical cancer. Our study population consists of 141 patients with cervical cancer (Stages IB-IVA) treated with 45-50 Gy external beam radiotherapy plus four times 7 Gy IGBT with or without cisplatin. Gross tumor volume (GTV), high-risk clinical target volume (HRCTV), and intermediate-risk clinical target volume (IRCTV) were contoured, and DVH parameters (minimum dose delivered to 90% of the volume of interest [D90] and D100) were assessed. Doses were converted to the equivalent dose in 2 Gy (EQD2) by applying the linear quadratic model (alpha/beta = 10 Gy). Groups were defined for patients with or without local recurrence (LR) in the true pelvis for tumor size at diagnosis (GTV at diagnosis [GTVD] of 2-5 cm (Group 1) or greater than 5 cm (Group 2) and for tumor size response at IGBT (HRCTV) of 2-5 cm (Group 2a) or greater than 5 cm (Group 2b). Eighteen LRs were observed. The most important DVH parameters correlated with LR were the D90 and D100 for HRCTV. Mean D90 and D100 values for HRCTV were 86 +/- 16 and 65 +/- 10 Gy, respectively. The D90 for HRCTV greater than 87 Gy resulted in an LR incidence of 4% (3 of 68) compared with 20% (15 of 73) for D90 less than 87 Gy. The effect was most pronounced in the tumor group (Group 2b). We showed an increase in local control in IGBT in patients with cervical cancer with the dose delivered, which can be expressed by the D90 and D100 for HRCTV. Local control rates greater than 95% can be achieved if the D90 (EQD2) for HRCTV is 87 Gy or greater.

  1. Asymmetry of short-term control of spatio-temporal gait parameters during treadmill walking

    Science.gov (United States)

    Kozlowska, Klaudia; Latka, Miroslaw; West, Bruce J.

    2017-03-01

    Optimization of energy cost determines average values of spatio-temporal gait parameters such as step duration, step length or step speed. However, during walking, humans need to adapt these parameters at every step to respond to exogenous and/or endogenic perturbations. While some neurological mechanisms that trigger these responses are known, our understanding of the fundamental principles governing step-by-step adaptation remains elusive. We determined the gait parameters of 20 healthy subjects with right-foot preference during treadmill walking at speeds of 1.1, 1.4 and 1.7 m/s. We found that when the value of the gait parameter was conspicuously greater (smaller) than the mean value, it was either followed immediately by a smaller (greater) value of the contralateral leg (interleg control), or the deviation from the mean value decreased during the next movement of ipsilateral leg (intraleg control). The selection of step duration and the selection of step length during such transient control events were performed in unique ways. We quantified the symmetry of short-term control of gait parameters and observed the significant dominance of the right leg in short-term control of all three parameters at higher speeds (1.4 and 1.7 m/s).

  2. External validation of a COPD prediction model using population-based primary care data: a nested case-control study

    Science.gov (United States)

    Nwaru, Bright I; Simpson, Colin R; Sheikh, Aziz; Kotz, Daniel

    2017-01-01

    Emerging models for predicting risk of chronic obstructive pulmonary disease (COPD) require external validation in order to assess their clinical value. We validated a previous model for predicting new onset COPD in a different database. We randomly drew 38,597 case-control pairs (total N = 77,194) of individuals aged ≥35 years and matched for sex, age, and general practice from the United Kingdom Clinical Practice Research Datalink database. We assessed accuracy of the model to discriminate between COPD cases and non-cases by calculating area under the receiver operator characteristic (ROCAUC) for the prediction scores. Analogous to the development model, ever smoking (OR 6.70; 95%CI 6.41–6.99), prior asthma (OR 6.43; 95%CI 5.85–7.07), and higher socioeconomic deprivation (OR 2.90; 95%CI 2.72–3.09 for highest vs. lowest quintile) increased the risk of COPD. The validated prediction scores ranged from 0–5.71 (ROCAUC 0.66; 95%CI 0.65–0.66) for males and 0–5.95 (ROCAUC 0.71; 95%CI 0.70–0.71) for females. We have confirmed that smoking, prior asthma, and socioeconomic deprivation are key risk factors for new onset COPD. Our model seems externally valid at identifying patients at risk of developing COPD. An impact assessment now needs to be undertaken to assess whether this prediction model can be applied in clinical care settings. PMID:28304375

  3. To whom do the results of the multicenter, randomized, controlled INSECT trial (ISRCTN 24023541 apply? - assessment of external validity

    Directory of Open Access Journals (Sweden)

    Fischer Lars

    2012-02-01

    Full Text Available Abstract A response to Seiler et al: Interrupted or continuous slowly absorbable sutures for closure of primary elective midline abdominal incisions: a multicenter randomized trial (INSECT: ISRCTN24023541. Ann Surg 2009, 249(4:576-582. Background Existing evidence suggests that the transfer of results of randomized controlled trials into clinical practice may be limited. Potential reasons can be attributed to aspects of external validity. The aim of this study is to investigate issues related to the external validity of the INSECT trial. Methods All participating surgical departments were categorized and the clinical and baseline characteristics of randomized patients were evaluated. In addition, demographic and clinical data of all screened and randomized patients at the Departments of Surgery in Heidelberg and Erlangen were analyzed. Results Twenty-five centers enrolled a total of 625 patients. These centers included eight primary, 11 secondary, and six tertiary care centers. The tertiary care centers enrolled the most patients (n = 237, 38% followed by the primary care centers (n = 199, 32% and the secondary care centers (n = 189 patients; 30%. The mean number and baseline data of randomized patients did not differ between the three types of care centers (p = 0.09. Overall, the treatment according to protocol was at least 92%. At the Department of Surgery, University of Heidelberg, 307 patients were screened and 60 out of 130 eligible patients were randomized. There were no differences in demographic and clinical baseline data between included and non-included patients. In Erlangen, 351 patients were screened and 57 out of 106 eligible patients randomized. Conclusions Results of the INSECT trial are applicable to a broad spectrum of patients treated at different hospital levels.

  4. The Prevention Program for Externalizing Problem Behavior (PEP) Improves Child Behavior by Reducing Negative Parenting: Analysis of Mediating Processes in a Randomized Controlled Trial

    Science.gov (United States)

    Hanisch, Charlotte; Hautmann, Christopher; Plück, Julia; Eichelberger, Ilka; Döpfner, Manfred

    2014-01-01

    Background: Our indicated Prevention program for preschool children with Externalizing Problem behavior (PEP) demonstrated improved parenting and child problem behavior in a randomized controlled efficacy trial and in a study with an effectiveness design. The aim of the present analysis of data from the randomized controlled trial was to identify…

  5. The Prevention Program for Externalizing Problem Behavior (PEP) Improves Child Behavior by Reducing Negative Parenting: Analysis of Mediating Processes in a Randomized Controlled Trial

    Science.gov (United States)

    Hanisch, Charlotte; Hautmann, Christopher; Plück, Julia; Eichelberger, Ilka; Döpfner, Manfred

    2014-01-01

    Background: Our indicated Prevention program for preschool children with Externalizing Problem behavior (PEP) demonstrated improved parenting and child problem behavior in a randomized controlled efficacy trial and in a study with an effectiveness design. The aim of the present analysis of data from the randomized controlled trial was to identify…

  6. Control of Comfort Parameters in Interior of Railway Coach Using ANN and RFID Tasks

    Science.gov (United States)

    Beinarts, Ivars; Levchenkov, Anatoly

    2009-01-01

    The main idea of this paper is to use methods of ANN (artificial neural network) and RFID (radio frequency identification) to create an algorithm and coordination mechanism for climate parameters control in the railway passengers' coach to save an electrical energy and keep a high comfort level in the passengers' interior of railway coach. The article presents mathematical problem using intelligent control of HVAC (heating, ventilation and air conditioning) systems for microclimate parameters optimal control. The methods of the problem solving and the structure of problem solving algorithm are given in the article.

  7. Robust H∞ control for aseismic structures With uncertainties in model parameters

    Institute of Scientific and Technical Information of China (English)

    Song Gang; Lin Jiahao; Zhao Yan; W.Paul Howson; Fred W Williams

    2007-01-01

    This paper presents a robust H∞ output feedback control approach for structural systems with uncertainties in model parameters by using available acceleration measurements and proposes conditions for the existence of such a robust ontput feedback controller.The uncertainties of structural stiffness,damping and mass parameters are assumed to be norm-bounded.The proposed control approach is formulated within the framework of linear matrix inequalities,for which existing convex optimization techniques,such as the LMI toolbox in MATLAB,can be used effectively and conveniently.To illustrate the effectiveness of the proposed robust H∞ strategy,a six-story building was subjected both to the 1940 El Centro earthquake record and to a suddenly applied Kanai-Tajimi filtered white noise random excitation.The results show that the proposed robust H∞ controller provides satisfactory results with or without variation of the structural stiffness,damping and mass parameters.

  8. External control of fluoridation of public water supplies of the city of Jaguaribara, Ceará, Brazil

    Directory of Open Access Journals (Sweden)

    Daniel Fernandes Peixoto

    2012-09-01

    Full Text Available Objective: To monitor the levels of fluoride (F in public water supplies in the city of Jaguaribara, Ceará, Brazil. Methods: Water samples were collected from the urban area, at three different points. Samples were collected twice a month, from August 2010 to July 2011. The samples were analyzed in triplicate, using the combined electrode connected to a meter, previously calibrated with standards containing 0.2 to 6.4 ppm F, with Tisab II. Data was analyzed by three criteria: I (Brazil, 1975, II (Ramires et al., 2006 and III (Technical Consensus, 2011. results: Among a total of 72 water samples, we observed an average of 0.55 (± 0.19 ppm F, median of 0.61. According to Criterion I, acceptable levels of fluoride were found in 47.2% of samples, while 44,4% were underfluoridated ( 0.84 ppm F. Based on criterion III, 25% of samples showed negligible risk and benefits concerning dental fluorosis and prevention of dental caries, while 11.1% of the samples presented low risk and benefit and 63.9% pointed to low risk and maximum benefit. Conclusions: Altered levels of fluoride were observed in public water supplies in the studied period. It is suggested the need to improve operational control and also the external control of water fluoridation in Jaguaribara, Ceará, Brazil.

  9. Efficacy of oxytetracycline hydrochloride bath immersion to control external columnaris disease on walleye and channel catfish fingerlings

    Science.gov (United States)

    Rach, J.J.; Johnson, Aaron H.; Rudacille, J.B.; Schleis, S.M.

    2008-01-01

    The efficacy of oxytetracycline hydrochloride (OTC-HCl) in controlling external columnaris disease caused by Flavobacterium columnare on fingerling walleyes Sander vitreus and channel catfish Ictalurus punctatus was evaluated in two on-site hatchery trials. Microscopic examination of skin scrapings before treatment confirmed the presence of bacteria with characteristics indicative of F. columnare.in separate trials, walleyes (4.4 g) and channel catfish (1.5 g) were exposed to 60-min static bath treatments of OTC-HCl at 0, 10, and 20 mg/L (walleyes) or 0, 10, 20, and 40 mg/L (channel catfish) on three consecutive days. Each treatment regimen was tested in triplicate, and each replicate contained either 30 walleyes or 55 channel catfish. Posttreatment presumptive disease diagnosis indicated that F. columnare was the disease agent causing the mortality in both species of fish. Walleye survival at 10 d posttreatment was greater in the 10- and 20-mg/L treatment groups than in the control group; however, only the 10-mg/L treatment significantly (P catfish trial, survival at 10 d posttreatment was significantly (P catfish infected with F. columnare. ?? Copyright by the American Fisheries Society 2008.

  10. Control of wake and vortex shedding behind a porous circular obstacle by exerting an external magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Bovand, M. [Department of Mechanical Engineering, Ferdowsi University of Mashhad, P.O. Box 91775-1111, Mashhad (Iran, Islamic Republic of); Rashidi, S., E-mail: samanrashidi3983@gmail.com [Department of Mechanical Engineering, Ferdowsi University of Mashhad, P.O. Box 91775-1111, Mashhad (Iran, Islamic Republic of); Dehghan, M. [Faculty of Mechanical Engineering, Semnan University, P.O. 35131-19111, Semnan (Iran, Islamic Republic of); Esfahani, J.A. [Department of Mechanical Engineering, Ferdowsi University of Mashhad, P.O. Box 91775-1111, Mashhad (Iran, Islamic Republic of); Valipour, M.S. [Faculty of Mechanical Engineering, Semnan University, P.O. 35131-19111, Semnan (Iran, Islamic Republic of)

    2015-07-01

    In this article the finite volume method (FVM) is carried out to simulate the flow around and through a two-dimensional porous cylinder. An external magnetic field is used to control the wake behind the bluff body and also to suppress the vortex shedding phenomena. The Darcy–Brinkman–Forchheimer model has been used for modeling the flow in the porous medium. Effects of Stuart (N), Reynolds (Re) and Darcy (Da) numbers on the flow behavior have been investigated. The results show that the critical Stuart number for suppress vortex shedding decreases with increasing the Darcy numbers. Also, the Stuart number for disappearance the re-circulating wake increases with increased Reynolds number for both porous and solid cylinders. - Highlights: • The formation and shedding of wakes behind a porous bluff-body are investigated. • Effects of a magnetic field on controlling the wake formation is explored. • Roles of Darcy, Reynolds and Stuart numbers on the flow behavior are analyzed. • Flow patterns change with Reynolds number and Darcy numbers. • The critical Stuart number decreases with increased Darcy numbers.

  11. 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.

  12. Can findings from randomized controlled trials of social skills training in autism spectrum disorder be generalized? The neglected dimension of external validity.

    Science.gov (United States)

    Jonsson, Ulf; Choque Olsson, Nora; Bölte, Sven

    2016-04-01

    Systematic reviews have traditionally focused on internal validity, while external validity often has been overlooked. In this study, we systematically reviewed determinants of external validity in the accumulated randomized controlled trials of social skills group interventions for children and adolescents with autism spectrum disorder. We extracted data clustered into six overarching themes: source population, included population, context, treatment provider, treatment intervention, and outcome. A total of 15 eligible randomized controlled trials were identified. The eligible population was typically limited to high-functioning school-aged children with autism spectrum disorder, and the included population was predominantly male and Caucasian. Scant information about the recruitment of participants was provided, and details about treatment providers and settings were sparse. It was not evident from the trials to what extent acquired social skills were enacted in everyday life and maintained over time. We conclude that the generalizability of the accumulated evidence is unclear and that the determinants of external validity are often inadequately reported. At this point, more effectiveness-oriented randomized controlled trials of equally high internal and external validity are needed. More attention to the determinants of external validity is warranted when this new generation of randomized controlled trials are planned and reported. We provide a tentative checklist for this purpose.

  13. 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.

  14. Increased external hip-rotation strength relates to reduced frontal-plane knee control during drop jumping in recreational female athletes: paradox or adaptation?

    DEFF Research Database (Denmark)

    Bandholm, Thomas; Thorborg, Kristian; Andersson, Elin;

    2011-01-01

    The purpose of the present study was to examine the relationship between hip muscle strength (abduction and external rotation) and frontal-plane knee control during drop jumping in recreational female athletes. Thirty-three healthy young recreational female athletes were included. Maximal isometric...... hip abduction and external rotation torque were measured using hand-held dynamometry, and frontal-plane knee control during drop jumping was assessed using three-dimensional motion analysis. Frontal-plane knee control during drop jumping was expressed as the absolute (cm) and relative (cm/cm body...... in knee marker distance during drop jumping. Maximal hip-abduction torque did not correlate with the absolute (r=0.18, P=0.31) or relative (r=0.19, P=0.29) change in knee marker distance during drop jumping. Contrary to our expectations, greater maximal external hip-rotation torque was related to greater...

  15. Assessment of Governor Control Parameter Settings of a Submarine Diesel Engine

    Science.gov (United States)

    2013-03-01

    University of Technology 15. Ogata , K. (1997) Modern control engineering. Upper Saddle River, NJ, Prentice-Hall 16. DiStephano, J., Stubberud, A. and...UNCLASSIFIED Assessment of Governor Control Parameter Settings of a Submarine Diesel Engine Peter Hield and Michael Newman...generators to provide power for propulsion and the hotel load. The governor, often a proportional-integral controller , attempts to maintain a constant

  16. 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.

  17. 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.

  18. 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

    2016-12-01

    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.

  19. Determining Relative Importance and Effective Settings for Genetic Algorithm Control Parameters.

    Science.gov (United States)

    Mills, K L; Filliben, J J; Haines, A L

    2015-01-01

    Setting the control parameters of a genetic algorithm to obtain good results is a long-standing problem. We define an experiment design and analysis method to determine relative importance and effective settings for control parameters of any evolutionary algorithm, and we apply this method to a classic binary-encoded genetic algorithm (GA). Subsequently, as reported elsewhere, we applied the GA, with the control parameter settings determined here, to steer a population of cloud-computing simulators toward behaviors that reveal degraded performance and system collapse. GA-steered simulators could serve as a design tool, empowering system engineers to identify and mitigate low-probability, costly failure scenarios. In the existing GA literature, we uncovered conflicting opinions and evidence regarding key GA control parameters and effective settings to adopt. Consequently, we designed and executed an experiment to determine relative importance and effective settings for seven GA control parameters, when applied across a set of numerical optimization problems drawn from the literature. This paper describes our experiment design, analysis, and results. We found that crossover most significantly influenced GA success, followed by mutation rate and population size and then by rerandomization point and elite selection. Selection method and the precision used within the chromosome to represent numerical values had least influence. Our findings are robust over 60 numerical optimization problems.

  20. 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.

  1. 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.

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

    DEFF Research Database (Denmark)

    Bendtsen, Jan Dimon; Trangbæk, Klaus

    2014-01-01

    , closed- loop system identification is more difficult than open-loop identification. In this paper we prove that the so-called Hansen Scheme, a technique known from linear time-invariant systems theory for transforming closed-loop system identification problems into open-loop-like problems, can......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...... be extended to accommodate linear parameter varying systems as well. We investigate the identified subsystem’s parameter dependency and observe that, under mild assumptions, the identified subsystem is affine in the parameter vector. Various identification methods are compared in direct and Hansen Scheme...

  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. Controllability of air conditioning systems. Components and control parameters; Klimaanlaegs reguleringsegenskaber. Komponenter og reguleringsparametre

    Energy Technology Data Exchange (ETDEWEB)

    Pilgaard Schmidt, T.

    1993-12-31

    The purpose was to investigate the factors affecting the controllability of air condition systems by evaluating the influence of the components and by developing an improved method of adjustment for controllers. A system consisting of a heat coil with constant water flow and temperature control was used for the purposes of the investigation. The following conditions give the best controllability: A short pipe length, e g 1m, and a shunt length of 0.5 m, a sensor time constant of 1 second, exponential valve characteristics and a motor running time of 3 seconds. Shares of valve pressure drop between 60% and 98% gives small changes in controllability, 2% hysteresis in the connection between the valve and the motor gives poorer such. in the case of 4-row heat coil and a series connection of two 4-row coils, a 100% increase in water flow proportional to the water flow at the design load, and a k{sub v}s value chosen from the design load conditions, improves controllability. The controllability of a series connection of two 4-row coils is poorer compared with one 4-row heat coil. PID control improves controllability compared to PI control. Controllability with optimal controller settings is considerably better than with controller settings indicated by the Zeigler-Nichols step response method. (AB) 51 refs.

  5. Robust adaptive control for a nonholonomic mobile robot with unknown parameters

    Institute of Scientific and Technical Information of China (English)

    Jinbo WU; Guohua XU; Zhouping YIN

    2009-01-01

    A robust adaptive controller for a nonholonomic mobile robot with unknown kinematic and dynamic parameters is proposed. A kinematic controller whose output is the input of the relevant dynamic controller is provided by using the concept of backstepping. An adaptive algorithm is developed in the kinematic controller to approximate the unknown kinematic parameters, and a simple single-layer neural network is used to express the highly nonlinear robot dynamics in terms of the known and unknown parameters. In order to attenuate the effects of the uncertainties and disturbances on tracking performance, a sliding mode control term is added to the dynamic controller. In the deterministic design of feedback controllers for the uncertain dynamic systems, upper bounds on the norm of the uncertainties are an important clue to guarantee the stability of the closed-loop system. However, sometimes these upper bounds may not be easily obtained because of the complexity of the structure of the uncertainties. Thereby, simple adaptation laws are proposed to approximate upper bounds on the norm of the uncertainties to address this problem. The stability of the proposed control system is shown through the Lyapunov method. Lastly, a design example for a mobile robot with two actuated wheels is provided and the feasibility of the controller is demonstrated by numerical simulations.

  6. The antecedents of women's external locus of control: Associations with characteristics of their parents and their early childhood.

    Science.gov (United States)

    Golding, Jean; Gregory, Steven; Iles-Caven, Yasmin; Nowicki, Stephen

    2017-01-01

    Locus of control (LOC) measures individuals' expectancies regarding their ability to affect what happens to them based on how they behave. The more they believe their behaviour has something to do with what happens to them the more internal they are. In contrast the more they perceive that what happens to them is beyond their control and determined by luck, fate, chance or powerful others the more external they are. Copious research findings suggest that external LOC (ELOC) is associated with many adverse personal, social, academic and health outcomes. In spite of its importance in so many areas of human behaviour relatively little is known about the features of the early background of individuals that contributes to these expectancies. This is the first in a number of studies that will suggest possible antecedents and consequences of having a high ELOC. The study takes advantage of the data collected in the Avon Longitudinal Study of Parents and Children (ALSPAC), which started by studying pregnancies in 1991-1992 of residents in an area of south-west England. Over 12000 of the women who enrolled during pregnancy completed a set of questions in mid-pregnancy from which an LOC score was computed. ELOC was defined as a score greater than the median. The relationships with characteristics of the women's parents and her early childhood (<6 years) are considered first as unadjusted odds ratios and then as adjusted after analysis using hierarchical sets of stepwise logistic regressions. The relative contributions to the women's ELOC was measured using a goodness-of-fit (GOF) measure. The analyses demonstrated the independent importance of maternal and paternal backgrounds as well as features of her early childhood (<6 years). The final model identified nine independent features (each with P < 0.0001): year of birth of her mother, maternal and paternal education levels, father smoked, mother smoked when pregnant, year of birth of study woman, the number of older siblings

  7. ADAPTIVE NONLINEAR FEEDBACK CONTROL OF CHAOTIC SYSTEMSBASED ON REDUCED PARAMETER QUADRATIC PREDICTORS

    Institute of Scientific and Technical Information of China (English)

    张家树; 肖先赐; 万继宏

    2001-01-01

    An adaptive nonlinear feedback-control method is proposed to control continuous-time chaotic dynamical systems,where the adaptive nonlinear controller acts on only one-dimensional error signals between the desired state and the observed chaotic state of a system. The reduced parameter adaptive quadratic predictor used in adaptive feedback cancellation of the nonlinear terms can control the system at any desired state. Computer simulation results on the Lorenz system are shown to demonstrate the effectiveness of this feedback-control method.

  8. 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.

  9. 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)

  10. Control of effect on the nucleation rate for hen egg white lysozyme crystals under application of an external ac electric field.

    Science.gov (United States)

    Koizumi, H; Uda, S; Fujiwara, K; Nozawa, J

    2011-07-05

    The effect of an external ac electric field on the nucleation rate of hen egg white lysozyme crystals increased with an increase in the concentration of the precipitant used, which enabled the design of an electric double layer (EDL) formed at the inner surface of the drop in the oil. This is attributed to the thickness of the EDL controlled by the ionic strength of the precipitant used. Control of the EDL formed at the interface between the two phases is important to establishing this novel technique for the crystallization of proteins under the application of an external ac electric field. © 2011 American Chemical Society

  11. Quantum correlations responsible for remote state creation: strong and weak control parameters

    Science.gov (United States)

    Doronin, S. I.; Zenchuk, A. I.

    2017-03-01

    We study the quantum correlations between the two remote qubits (sender and receiver) connected by the transmission line (homogeneous spin-1/2 chain) depending on the parameters of the sender's and receiver's initial states (control parameters). We consider two different measures of quantum correlations: the entanglement (a traditional measure) and the informational correlation (based on the parameter exchange between the sender and receiver). We find the domain in the control parameter space yielding (i) zero entanglement between the sender and receiver during the whole evolution period and (ii) non-vanishing informational correlation between the sender and receiver, thus showing that the informational correlation is responsible for the remote state creation. Among the control parameters, there are the strong parameters (which strongly effect the values of studied measures) and the weak ones (whose effect is negligible), therewith the eigenvalues of the initial state are given a privileged role. We also show that the problem of small entanglement (concurrence) in quantum information processing is similar (in certain sense) to the problem of small determinants in linear algebra. A particular model of 40-node spin-1/2 communication line is presented.

  12. A new analytic method with a convergence-control parameter for solving nonlinear problems

    CERN Document Server

    Zhang, Xiaolong

    2016-01-01

    In this paper, a new analytic method with a convergence-control parameter $c$ is first proposed. The parameter $c$ is used to adjust and control the convergence region and rate of the resulting series solution. It turns out that the convergence region and rate can be greatly enlarged by choosing a proper value of $c$. Furthermore, a numerical approach for finding the optimal value of the convergence-control parameter is given. At the same time, it is found that the traditional Adomian decomposition method is only a special case of the new method. The effectiveness and applicability of the new technique are demonstrated by several physical models including nonlinear heat transfer problems, nano-electromechanical systems, diffusion and dissipation phenomena, and dispersive waves. Moreover, the ideas proposed in this paper may offer us possibilities to greatly improve current analytic and numerical techniques.

  13. 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.

  14. Parameter optimization of controllable local degree of freedom for reducing vibration of flexible manipulator

    Institute of Scientific and Technical Information of China (English)

    Bian Yushu; Gao Zhihui

    2013-01-01

    Parameter optimization of the controllable local degree of freedom is studied for reducing vibration of the flexible manipulator at the lowest possible cost.The controllable local degrees of freedom are suggested and introduced to the topological structure of the flexible manipulator,and used as an effective way to alleviate vibration through dynamic coupling.Parameters introduced by the controllable local degrees of freedom are analyzed and their influences on vibration reduction are investigated.A strategy to optimize these parameters is put forward and the corresponding optimization method is suggested based on Particle Swarm Optimization (PSO).Simulations are conducted and results of case studies confirm that the proposed optimization method is effective in reducing vibration of the flexible manipulator at the lowest possible cost.

  15. 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.

  16. Parameter Tuning via Genetic Algorithm of Fuzzy Controller for Fire Tube Boiler

    Directory of Open Access Journals (Sweden)

    Osama I. Hassanein

    2012-04-01

    Full Text Available The optimal use of fuel energy and water in a fire tube boiler is important in achieving economical system operation, precise control system design required to achieve high speed of response with no overshot. Two artificial intelligence techniques, fuzzy control (FLC and genetic-fuzzy control (GFLC applied to control both of the water/steam temperature and water level control loops of boiler. The parameters of the FLC are optimized to locating the optimal solutions to meet the required performance objectives using a genetic algorithm. The parameters subject to optimization are the width of the membership functions and scaling factors. The performance of the fire tube boiler that fitted with GFLC has reliable dynamic performance as compared with the system fitted with FLC.

  17. 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.

  18. Controllability of air conditioning systems. Components and control parameters. Appendix; Klimaanlaegs reguleringsegenskaber. Komponenter og reguleringsparameter. Appendiks

    Energy Technology Data Exchange (ETDEWEB)

    Pilgaard Schmidt, T.

    1993-12-31

    This appendix to the document of the same title gives details on system identification (determination of the mathematical model for a system and estimation of the parameters in the model based on registered input and output data) and presents mathematical models for the laminated heat surfaces, the piping, for pipe joints, pumps and laminated heat surfaces. (AB) 51 refs.

  19. Temporal stability of network centrality in control and default mode networks: Specific associations with externalizing psychopathology in children and adolescents.

    Science.gov (United States)

    Sato, João Ricardo; Biazoli, Claudinei Eduardo; Salum, Giovanni Abrahão; Gadelha, Ary; Crossley, Nicolas; Satterthwaite, Theodore D; Vieira, Gilson; Zugman, André; Picon, Felipe Almeida; Pan, Pedro Mario; Hoexter, Marcelo Queiroz; Anés, Mauricio; Moura, Luciana Monteiro; Del'aquilla, Marco Antonio Gomes; Amaro, Edson; McGuire, Philip; Lacerda, Acioly L T; Rohde, Luis Augusto; Miguel, Euripedes Constantino; Jackowski, Andrea Parolin; Bressan, Rodrigo Affonseca

    2015-12-01

    Abnormal connectivity patterns have frequently been reported as involved in pathological mental states. However, most studies focus on "static," stationary patterns of connectivity, which may miss crucial biological information. Recent methodological advances have allowed the investigation of dynamic functional connectivity patterns that describe non-stationary properties of brain networks. Here, we introduce a novel graphical measure of dynamic connectivity, called time-varying eigenvector centrality (tv-EVC). In a sample 655 children and adolescents (7-15 years old) from the Brazilian "High Risk Cohort Study for Psychiatric Disorders" who were imaged using resting-state fMRI, we used this measure to investigate age effects in the temporal in control and default-mode networks (CN/DMN). Using support vector regression, we propose a network maturation index based on the temporal stability of tv-EVC. Moreover, we investigated whether the network maturation is associated with the overall presence of behavioral and emotional problems with the Child Behavior Checklist. As hypothesized, we found that the tv-EVC at each node of CN/DMN become more stable with increasing age (P < 0.001 for all nodes). In addition, the maturity index for this particular network is indeed associated with general psychopathology in children assessed by the total score of Child Behavior Checklist (P = 0.027). Moreover, immaturity of the network was mainly correlated with externalizing behavior dimensions. Taken together, these results suggest that changes in functional network dynamics during neurodevelopment may provide unique insights regarding pathophysiology.

  20. Routine internal- and external-quality control data in clinical laboratories for estimating measurement and diagnostic uncertainty using GUM principles.

    Science.gov (United States)

    Magnusson, Bertil; Ossowicki, Haakan; Rienitz, Olaf; Theodorsson, Elvar

    2012-05-01

    Healthcare laboratories are increasingly joining into larger laboratory organizations encompassing several physical laboratories. This caters for important new opportunities for re-defining the concept of a 'laboratory' to encompass all laboratories and measurement methods measuring the same measurand for a population of patients. In order to make measurement results, comparable bias should be minimized or eliminated and measurement uncertainty properly evaluated for all methods used for a particular patient population. The measurement as well as diagnostic uncertainty can be evaluated from internal and external quality control results using GUM principles. In this paper the uncertainty evaluations are described in detail using only two main components, within-laboratory reproducibility and uncertainty of the bias component according to a Nordtest guideline. The evaluation is exemplified for the determination of creatinine in serum for a conglomerate of laboratories both expressed in absolute units (μmol/L) and relative (%). An expanded measurement uncertainty of 12 μmol/L associated with concentrations of creatinine below 120 μmol/L and of 10% associated with concentrations above 120 μmol/L was estimated. The diagnostic uncertainty encompasses both measurement uncertainty and biological variation, and can be estimated for a single value and for a difference. This diagnostic uncertainty for the difference for two samples from the same patient was determined to be 14 μmol/L associated with concentrations of creatinine below 100 μmol/L and 14 % associated with concentrations above 100 μmol/L.

  1. Visualization of magnetic microcapsules in liquid by optical coherent tomography and control of their arrangement via external magnetic field

    Science.gov (United States)

    Kolesnikova, T. A.; Akchurin, Ga G.; Portnov, S. A.; Khomutov, G. B.; Akchurin, Ge G.; Naumova, O. G.; Sukhorukov, G. B.; Gorin, D. A.

    2012-09-01

    Optical coherence tomography (OCT) is a new, non-invasive, noncontact in vivo imaging technology. We demonstrated that the OCT can be used as a sufficient technique for nanocomposite microcapsule visualization in a liquid medium. As a model system we choose a water/glycerol mixture with viscosity in a variable range from 1.01 to 1.41×103 mPa s, including viscosity of a blood plasma. We have found that tomography spatial resolution is enough to visualize capsules and their aggregates in liquids and to estimate their concentration via two-dimensional (2D) tomography scan analysis. In our experimental conditions microcapsule concentration measured by OCT was 3.9×107 cm-3 and this value correlated well with the concentration measured in a counting chamber (1.9×107 cm-3). We also demonstrated the possibility to control capsule spatial distribution in glycerol solutions by external magnetic field and determined the dependence of capsule sedimentation time on the liquid medium viscosity.

  2. A Study of Transmission Control Method for Distributed Parameters Measurement in Large Factories and Storehouses

    Directory of Open Access Journals (Sweden)

    Shujing Su

    2015-01-01

    Full Text Available For the characteristics of parameters dispersion in large factories, storehouses, and other applications, a distributed parameter measurement system is designed that is based on the ring network. The structure of the system and the circuit design of the master-slave node are described briefly. The basic protocol architecture about transmission communication is introduced, and then this paper comes up with two kinds of distributed transmission control methods. Finally, the reliability, extendibility, and control characteristic of these two methods are tested through a series of experiments. Moreover, the measurement results are compared and discussed.

  3. Output feedback robust model predictive control with unmeasurable model parameters and bounded disturbance☆

    Institute of Scientific and Technical Information of China (English)

    Baocang Ding; Hongguang Pan

    2016-01-01

    The output feedback model predictive control (MPC), for a linear parameter varying (LPV) process system including unmeasurable model parameters and disturbance (all lying in known polytopes), is considered. Some previously developed tools, including the norm-bounding technique for relaxing the disturbance-related constraint handling, the dynamic output feedback law, the notion of quadratic boundedness for specifying the closed-loop stability, and the el ipsoidal state estimation error bound for guaranteeing the recursive feasibility, are merged in the control design. Some previous approaches are shown to be the special cases. An example of continuous stirred tank reactor (CSTR) is given to show the effectiveness of the proposed approaches.

  4. Creep crack growth analysis using C{sub t}-parameter for internal circumferential and external axial surface cracks in a pressurized cylinder

    Energy Technology Data Exchange (ETDEWEB)

    Tun, Nwe Ni; Yang, Hee Seung; Yu, Jong Min; Yoon, Kee Bong [Dept. of Mechanical Engineering, Chung Ang University, Seoul (Korea, Republic of)

    2016-12-15

    Creep crack growth at elevated temperatures is a critical consideration in estimating the remaining life of high temperature structural components and in deciding their inspection interval. In this study, creep crack growth analyses for external radial-axial and internal radial-circumferential surface cracks in a pressurized cylinder were conducted by an analytical method. The effect of crack depth and crack length on the variations in Ct and remaining life predictions were investigated for surface cracks with various initial aspect ratios. It was observed that the remaining life of an internal radial-circumferential surface crack was approximately 53 times longer than that of an external radial-axial surface crack for the same crack size and loading conditions with 316 stainless steel material. It was also observed that the variations in remaining life, crack propagations, and the Ct values were considerably sensitive to the crack location and crack depth. Convergence of crack aspect ratio was not observed when the crack depth ratio was increased. Since the method is independent of material properties and location of the crack geometries, it can be extended to various material properties and various locations of the surface crack geometries.

  5. On oscillation reduction in feedback control for processes with an uncertain dead time and internal-external disturbances.

    Science.gov (United States)

    Zhang, Yuqiong; Li, Donghai; Gao, Zhiqiang; Zheng, Qinling

    2015-11-01

    This paper aims to find a practical solution to reduce oscillation on the Smith Predictor (SP) based design with the dead time (DT) uncertainty, making it less sensitive to DT change and more effective in disturbance rejection. First, a conditional feedback mechanism is introduced in SP to reduce the amount of oscillation caused by the model inaccuracies in the DT parameter. Then, to address the oscillation caused by the phase lag in traditional PI controller and uncertain dynamics, this conditional SP is combined with active disturbance rejection control (ADRC), assisted by the knowledge of process dynamics. A practical tuning method is provided for the practicing engineers. The proposed approach is validated in extensive simulation studies with different types of plants and in frequency domain analysis. The simulation results show significant improvements in performance robustness and transient response.

  6. Experimental determination of mechanical parameters in sensorless vector-controlled induction motor drive

    Indian Academy of Sciences (India)

    V S S PAVAN KUMAR HARI; AVANISH TRIPATHI; G NARAYANAN

    2017-08-01

    High-performance industrial drives widely employ induction motors with position sensorless vector control (SLVC). The state-of-the-art SLVC is first reviewed in this paper. An improved design procedure for current and flux controllers is proposed for SLVC drives when the inverter delay is significant. The speed controller design in such a drive is highly sensitive to the mechanical parameters of the induction motor. These mechanical parameters change with the load coupled. This paper proposes a method to experimentally determine the moment of inertia and mechanical time constant of the induction motor drive along with the load driven. The proposed method is based on acceleration and deceleration of the motor under constant torque, which is achieved using a sensorless vector-controlled drive itself. Experimental results from a 5-hp induction motor drive are presented.

  7. An extended harmonic balance method based on incremental nonlinear control parameters

    Science.gov (United States)

    Khodaparast, Hamed Haddad; Madinei, Hadi; Friswell, Michael I.; Adhikari, Sondipon; Coggon, Simon; Cooper, Jonathan E.

    2017-02-01

    A new formulation for calculating the steady-state responses of multiple-degree-of-freedom (MDOF) non-linear dynamic systems due to harmonic excitation is developed. This is aimed at solving multi-dimensional nonlinear systems using linear equations. Nonlinearity is parameterised by a set of 'non-linear control parameters' such that the dynamic system is effectively linear for zero values of these parameters and nonlinearity increases with increasing values of these parameters. Two sets of linear equations which are formed from a first-order truncated Taylor series expansion are developed. The first set of linear equations provides the summation of sensitivities of linear system responses with respect to non-linear control parameters and the second set are recursive equations that use the previous responses to update the sensitivities. The obtained sensitivities of steady-state responses are then used to calculate the steady state responses of non-linear dynamic systems in an iterative process. The application and verification of the method are illustrated using a non-linear Micro-Electro-Mechanical System (MEMS) subject to a base harmonic excitation. The non-linear control parameters in these examples are the DC voltages that are applied to the electrodes of the MEMS devices.

  8. Parameters Controlling Dimensional Accuracy of Aluminum Extrusions Formed in Stretch Bending

    Science.gov (United States)

    Baringbing, Henry Ako; Welo, Torgeir

    2007-04-01

    For stretch formed components used in the automotive industry, such as bumper beams, it is of primary importance to control parameters affecting dimensional accuracy. The variations in geometry and mechanical properties induced in extrusion and stretch forming lead to subsequent dimensional inaccuracy of the final product. In this work, tensile and compression samples were taken at three different positions along AA7108W extruded profiles in order to determine material parameters for a constitutive model particularly suited for strong texture materials. In addition, geometry were measured and analyzed statistically in order to study its impact on local cross sectional distortions (sagging) and springback in stretch bending of a bumper beam. These full scale experiments were combined with analytical and numerical simulations to quantify the impact of each basic parameter on product quality. It is concluded that this methodology provides a means to systematically control the product quality by focusing on reducing the acceptance limits of the main parameters controlling basic mechanisms in stretch forming. Despite the assumptions and simplifications made in order to make the analytical expressions solvable, the approach has proven its capability in establishing accurate closed-form expressions including the main influential parameters.

  9. 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...

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

    OpenAIRE

    Vaidyanathan, Sundarapandian; Rajagopal, Karthikeyan

    2012-01-01

    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 chaoticsystem...

  11. Comparative Analysis of Control Coefficients on the Performance of CNTFET Under Different Parameters

    Science.gov (United States)

    Imam, Safayat-Al; Kalam, Nasheen; Abdullah, Sharmin

    2016-02-01

    This paper deals with the performance of both gate and drain control coefficients to analyze the behavior of carbon nanotube field effect transistors (CNTFETs) under ballistic conditions and based on the change of different parameter value, such as oxide thickness of structure and temperature variation. A thorough study of both gate and drain control coefficient effects on the performance of CNTFETs has been conducted under different temperature and oxide layers and the output of the device has been analyzed through different parameters. Higher values of control coefficient help to attain larger transconductance by the increasing temperatures. For a fixed value of control coefficient, 4nm thickness of oxide has a transconductance of ˜ 4.5 × 10-5 S/m. Smaller oxide layer thickness has higher slope of increment in transconductance value. ON-state current to leakage current ratio shows a steady state response toward increment of gate control coefficient. Also, increment of oxide thickness has an adverse effect on current ratio, while a linear decay of current ratio is observed with the increased value of drain controlled one. Drain-induced battery lowering (DIBL) effect decreases with the value of gate control one and increases with the drain control coefficient. In this way, the optimum value for both the control coefficients has to be considered in order to perform well.

  12. Optimization of control parameters of CdZnTe ACRT-Bridgman single crystal growth

    Institute of Scientific and Technical Information of China (English)

    LIU Juncheng

    2004-01-01

    The CdZnTe vertical Bridgman single crystal process with accelerated crucible rotation technique (ACRT) has been simulated. Effects have been investigated of the ACRT wave parameters on the solid-liquid interface concavity and the solute segregation of the crystal. The results show that ACRT can result in the increase of both the solid-liquid interface concavity and the temperature gradient of the melt in the front of the solid-liquid interface, of which the magnitude varies from small to many times when the ACRT wave parameters change. Of the ACRT wave parameters, the increase of the crucible maximum rotation rate can hardly improve the radial solute segregation of the crystal, but the variation of the crucible acceleration time, the keep time at the maximum rotation rate, and the crucible deceleration time can affect the solute segregation of the single crystal extraordinarily. With suitable wave parameters, ACRT greatly decreases the radial solute segregation of the crystal, and even makes it disappear completely. However, it increases both the axial solute segregation and the radial one notably with bad wave parameters. An excellent single crystal could be gotten, of which a majority part is with no segregation, with ACRT-Bridgman method by adjusting both the ACRT wave parameters and the crystal growth control parameters, such as the initial temperature of the melt, the temperature gradient, and the crucible withdrawal rate, etc.

  13. Active control and parameter updating techniques for nonlinear thermal network models

    Science.gov (United States)

    Papalexandris, M. V.; Milman, M. H.

    The present article reports on active control and parameter updating techniques for thermal models based on the network approach. Emphasis is placed on applications where radiation plays a dominant role. Examples of such applications are the thermal design and modeling of spacecrafts and space-based science instruments. Active thermal control of a system aims to approximate a desired temperature distribution or to minimize a suitably defined temperature-dependent functional. Similarly, parameter updating aims to update the values of certain parameters of the thermal model so that the output approximates a distribution obtained through direct measurements. Both problems are formulated as nonlinear, least-square optimization problems. The proposed strategies for their solution are explained in detail and their efficiency is demonstrated through numerical tests. Finally, certain theoretical results pertaining to the characterization of solutions of the problems of interest are also presented.

  14. Non-probabilistic stability reliability measure for active vibration control system with interval parameters

    Science.gov (United States)

    Li, Yunlong; Wang, Xiaojun; Wang, Lei; Fan, Weichao; Qiu, Zhiping

    2017-01-01

    A systematic non-probabilistic reliability analysis procedure for structural vibration active control system with unknown-but-bounded parameters is proposed. The state-space representation of active vibration control system with uncertain parameters is presented. Compared with the robust control theory, which is always over-conservative, the reliability-based analysis method is more suitable to deal with uncertain problem. Stability is the core of the closed-loop feedback control system design, so stability criterion is adopted to act as the limited state function for reliability analysis. The uncertain parameters without enough samples are modeled as interval variables. Interval perturbation method is employed to estimate the interval bounds of eigenvalues, which can be used to characterize the stability of the closed-loop active control system. Formulation of defining the reliability of active control system based on stability is discussed. A novel non-probabilistic reliability measurement index is discussed and used to determine the probability of the stability based on the area ratio. The feasibility and efficiency of the proposed method are demonstrated by two numerical examples.

  15. Control of Rhagoletis indifferents using Thiamethoxam and Spinosad baits under external fly pressure and its relation to rapidity of kill and residual bait activity

    Science.gov (United States)

    Control of western cherry fruit fly (Rhagoletis indifferens Curran) using thiamethoxam in sucrose bait and spinosad bait in cherry orchards under external fly pressure and its relation to rapidity of kill and residual bait activity were studied in Washington and Utah in 2010 and 2011. Thiamethoxam ...

  16. Child Effortful Control as a Mediator of Parenting Practices on Externalizing Behavior: Evidence for a Sex-Differentiated Pathway across the Transition from Preschool to School

    Science.gov (United States)

    Chang, Hyein; Olson, Sheryl L.; Sameroff, Arnold J.; Sexton, Holly R.

    2011-01-01

    An explanatory model for children's development of disruptive behavior across the transition from preschool to school was tested. It was hypothesized that child effortful control would mediate the effects of parenting on children's externalizing behavior and that child sex would moderate these relations. Participants were 241 children (123 boys)…

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

    African Journals Online (AJOL)

    Dr Obe

    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 ... rule-based expert system, which is a logical.

  18. 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...... (WWTP) applications....

  19. 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.

  20. 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...

  1. Multidimensional Z-Matrix with Control Parameters and Its Applications in Image Encryption

    Institute of Scientific and Technical Information of China (English)

    ZHAO Liang; LIAO Xiao-Feng; XIANG Tao; XIAO Di

    2009-01-01

    An n-dimensional Z-matrix with control parameters is presented,and its periodicity and chaos are testified.Experimental results show that the proposed Z-matrix has a long period and changeable periodicity with different dimensions.Some examples of image encryption with a Z-matrix of different dimensions are listed for demonstrating its appfications.

  2. 模糊控制A/O脱氮工艺内循环回流量和外碳源投加量%Fuzzy Control of Nitrate Recirculation and External Carbon Addition in A/O Nitrogen Removal Process

    Institute of Scientific and Technical Information of China (English)

    马勇; 彭永臻; 王淑莹; 王晓莲

    2005-01-01

    Nitrogen and phosphorous concentrations of effluent water must be taken into account for the design and operation of wastewater treatment plants. In addition, the requirement for effluent quality is becoming strict.Therefore, intelligent control approaches are recently required in removing biological nutrient. In this study, fuzzy control has been successfully applied to improve the nitrogen removal. Experimental results showed that a close relationship between nitrate concentration and oxidation-reduction potential (ORP) at the end of anoxic zone was found for anoxic/oxic (A/O) nitrogen removal process treating synthetic wastewater. ORP can be used as online fuzzy control parameter of nitrate recirculation and external carbon addition. The established fuzzy logic controller that includes two inputs and one output can maintain ORP value at -86 mV and -90 mV by adjusting the nitrate recirculation flow and external carbon dosage respectively to realize the optimal control of nitrogen removal, improving the effluent quality and reducing the operating cost.

  3. 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.

  4. Seroprevalence of Cutaneous Human Papillomaviruses and the Risk of External Genital Lesions in Men: A Nested Case-Control Study

    Science.gov (United States)

    Rahman, Shams; Rollison, Dana E.; Pierce Campbell, Christine M.; Waterboer, Tim; Michel, Angelika; Pawlita, Michael; Villa, Luisa L.; Lazcano Ponce, Eduardo; Wang, Wei; Borenstein, Amy R.; Giuliano, Anna R.

    2016-01-01

    Background A variety of cutaneous human papillomaviruses (HPV) are detectable in genital epithelial lesions in men and non-melanoma skin cancer patients. It remains unclear whether these viruses are associated causally with skin lesions. To date, no study has prospectively examined the association between cutaneous HPV seropositivity and development of external genital lesions (EGLs) in men. Objectives To examine the association between seropositivity to cutaneous HPV types and the risk of subsequent development of EGLs. Methods A nested case-control study including 163 incident EGL cases and 352 EGL-free controls in the HPV Infection in Men (HIM) Study cohort was conducted. Cases were ascertained at each of up to 10 biannual clinical visits and verified through biopsy and pathological diagnoses. EGLs were categorized as condyloma, suggestive of condyloma, penile intraepithelial neoplasia (PeIN), and other EGLs. Archived serum specimens collected at baseline were tested for antibodies against 14 cutaneous HPV types (β types (5, 8, 12, 14, 17, 22, 23, 24, 38, and 47), α type 27, γ type 4, μ type 1, and ν type 41) using a GST L1-based multiplex serology assay. Socio-demographic and sexual behavior data were collected through a questionnaire. Using logistic regression, adjusted odds ratios (AOR) and 95% confidence intervals (CI) were estimated. Results Overall, seropositivity to ≥1 cutaneous HPV type (any-HPV) and ≥1 β types (any-β) was 58.3% and 37.5% among other EGL cases, 71.6% and 46.8% among condyloma, 66.8% and 50.0% among PeIN, and 71.9% and 38.4% among controls, respectively. Type-specific seropositivity was most common for ɤ-HPV 4, μ-HPV 1, and β-HPV 8. No statistically significant association was observed between any-HPV, any-β, and type-specific HPV seropositivity and subsequent development of EGLs across all pathological diagnoses. Conclusions Overall, seropositivity to cutaneous HPV was common among men; however, it appears that cutaneous

  5. International Space Station (ISS) External Thermal Control System (ETCS) Loop A Pump Module (PM) Jettison Options Assessment

    Science.gov (United States)

    Murri, Daniel G.; Dwyer Cianciolo, Alicia; Shidner, Jeremy D.; Powell, Richard W.

    2014-01-01

    On December 11, 2013, the International Space Station (ISS) experienced a failure of the External Thermal Control System (ETCS) Loop A Pump Module (PM). To minimize the number of extravehicular activities (EVA) required to replace the PM, jettisoning the faulty pump was evaluated. The objective of this study was to independently evaluate the jettison options considered by the ISS Trajectory Operations Officer (TOPO) and to provide recommendations for safe jettison of the ETCS Loop A PM. The simulation selected to evaluate the TOPO options was the NASA Engineering and Safety Center's (NESC) version of Program to Optimize Simulated Trajectories II (POST2) developed to support another NESC assessment. The objective of the jettison analysis was twofold: (1) to independently verify TOPO posigrade and retrograde jettison results, and (2) to determine jettison guidelines based on additional sensitivity, trade study, and Monte Carlo (MC) analysis that would prevent PM recontact. Recontact in this study designates a propagated PM trajectory that comes within 500 m of the ISS propagated trajectory. An additional simulation using Systems Tool Kit (STK) was run for independent verification of the POST2 simulation results. Ultimately, the ISS Program removed the PM jettison option from consideration. However, prior to the Program decision, the retrograde jettison option remained part of the EVA contingency plan. The jettison analysis presented showed that, in addition to separation velocity/direction and the atmosphere conditions, the key variables in determining the time to recontact the ISS is highly dependent on the ballistic number (BN) difference between the object being jettisoned and the ISS.

  6. Vibration suppression of distributed parameter flexible structures by Integral Consensus Control

    Science.gov (United States)

    Omidi, Ehsan; Mahmoodi, S. Nima

    2016-03-01

    Integral Consensus Control (ICC) is proposed and implemented in this paper for the first time, as a novel approach for vibration control in distributed parameter flexible structures. The ICC consists of multiple parallel first-order lossy integrators, with the goal of targeting all major participating resonant modes in the oscillation of the structure. The vibration control design is taken to a different level, by integrating the concept of consensus control design into the new dynamics. Each control patch on the flexible structure is considered as a node of a network, and a communication topology with consensus control terms are augmented in the controller design dynamics. The result is an effective vibration controller, which is also robust to failures and inconsistencies in the control system. A cantilever is used as a sample flexible structure to investigate the control method. Multi-agent representation of the system, state estimator dynamics and the ICC model are designed for the structure. Extensive numerical simulations have been conducted to show the suppression performance of the ICC under different input disturbances. A comparative study is presented to show the advantage of the decentralized design over the conventional centralized approach. The new consensus control design provides new possibilities to vibration control problems, where an effective, robust and synchronized suppression is needed.

  7. Linear Parameter Varying Model Identification for Control of Rotorcraft-based UAV

    CERN Document Server

    Budiyono, Agus

    2008-01-01

    A rotorcraft-based unmanned aerial vehicle exhibits more complex properties compared to its full-size counterparts due to its increased sensitivity to control inputs and disturbances and higher bandwidth of its dynamics. As an aerial vehicle with vertical take-off and landing capability, the helicopter specifically poses a difficult problem of transition between forward flight and unstable hover and vice versa. The LPV control technique explicitly takes into account the change in performance due to the real-time parameter variations. The technique therefore theoretically guarantees the performance and robustness over the entire operating envelope. In this study, we investigate a new approach implementing model identification for use in the LPV control framework. The identification scheme employs recursive least square technique implemented on the LPV system represented by dynamics of helicopter during a transition. The airspeed as the scheduling of parameter trajectory is not assumed to vary slowly. The exclu...

  8. Robust model-reference control for descriptor linear systems subject to parameter uncertainties

    Institute of Scientific and Technical Information of China (English)

    Guangren DUAN; Biao ZHANG

    2007-01-01

    Robust model-reference control for descriptor linear systems with structural parameter uncertainties is investigated. A sufficient condition for existing a model-reference zero-error asymptotic tracking controller is given. It is shown that the robust model reference control problem can be decomposed into two subproblems: a robust state feedback stabilization problem for descriptor systems subject to parameter uncertainties and a robust compensation problem. The latter aims to find three coefficient matrices which satisfy four matrix equations and simultaneously minimize the effect of the uncertainties to the tracking error. Based on a complete parametric solution to a class of generalized Sylvester matrix equations, the robust compensation problem is converted into a minimization problem with quadratic cost and linear constraints. A numerical example shows the effect of the proposed approach.

  9. 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.

  10. 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.

  11. Controllability, Observability and Parameter Identification of two coupled spin 1's

    CERN Document Server

    D'Alessandro, D K

    2003-01-01

    In this paper, we study the control theoretic properties of a couple of interacting spin 1's driven by an electro-magnetic field. In particular, we assume that it is possible to observe the expectation value of the total magnetization and we study controllability, observability and parameter identification of these systems. We give conditions for controllability and observability and characterize the classes of equivalent models which have the same input-output behavior. The analysis is motivated by the recent interest in three level systems in quantum information theory and quantum cryptography as well as by the problem of modeling molecular magnets as spin networks.

  12. External control strategies for self-propelled particles: Optimizing navigational efficiency in the presence of limited resources

    Science.gov (United States)

    Haeufle, Daniel F. B.; Bäuerle, Tobias; Steiner, Jakob; Bremicker, Lena; Schmitt, Syn; Bechinger, Clemens

    2016-07-01

    We experimentally and numerically study the dependence of different navigation strategies regarding the effectivity of an active particle to reach a predefined target area. As the only control parameter, we vary the particle's propulsion velocity depending on its position and orientation relative to the target site. By introducing different figures of merit, e.g., the time to target or the total consumed propulsion energy, we are able to quantify and compare the efficiency of different strategies. Our results suggest that each strategy to navigate towards a target has its strengths and weaknesses, and none of them outperforms the other in all regards. Accordingly, the choice of an ideal navigation strategy will strongly depend on the specific conditions and the figure of merit which should be optimized.

  13. External control strategies for self-propelled particles: optimizing navigational efficiency in the presence of limited resources

    CERN Document Server

    Haeufle, Daniel F B; Steiner, Jakob; Bremicker, Lena; Schmitt, Syn; Bechinger, Clemens

    2016-01-01

    We experimentally and numerically study the dependence of different navigation strategies regarding the effectivity of an active particle to reach a predefined target area. As the only control parameter, we vary the particle's propulsion velocity depending on its position and orientation relative to the target site. By introducing different figures of merit, e.g. the time to target or the total consumed propulsion energy, we are able to quantify and compare the efficiency of different strategies. Our results suggest, that each strategy to navigate towards a target, has its strengths and weaknesses and none of them outperforms the other in all regards. Accordingly, the choice of an ideal navigation strategy will strongly depend on the specific conditions and the figure of merit which should be optimized.

  14. Identifying dominant controls on hydrologic parameter transfer from gauged to ungauged catchments: a comparative hydrology approach

    Science.gov (United States)

    Singh, R.; Archfield, S.A.; Wagener, T.

    2014-01-01

    Daily streamflow information is critical for solving various hydrologic problems, though observations of continuous streamflow for model calibration are available at only a small fraction of the world’s rivers. One approach to estimate daily streamflow at an ungauged location is to transfer rainfall–runoff model parameters calibrated at a gauged (donor) catchment to an ungauged (receiver) catchment of interest. Central to this approach is the selection of a hydrologically similar donor. No single metric or set of metrics of hydrologic similarity have been demonstrated to consistently select a suitable donor catchment. We design an experiment to diagnose the dominant controls on successful hydrologic model parameter transfer. We calibrate a lumped rainfall–runoff model to 83 stream gauges across the United States. All locations are USGS reference gauges with minimal human influence. Parameter sets from the calibrated models are then transferred to each of the other catchments and the performance of the transferred parameters is assessed. This transfer experiment is carried out both at the scale of the entire US and then for six geographic regions. We use classification and regression tree (CART) analysis to determine the relationship between catchment similarity and performance of transferred parameters. Similarity is defined using physical/climatic catchment characteristics, as well as streamflow response characteristics (signatures such as baseflow index and runoff ratio). Across the entire US, successful parameter transfer is governed by similarity in elevation and climate, and high similarity in streamflow signatures. Controls vary for different geographic regions though. Geology followed by drainage, topography and climate constitute the dominant similarity metrics in forested eastern mountains and plateaus, whereas agricultural land use relates most strongly with successful parameter transfer in the humid plains.

  15. An Improved Self-adaptive Control Parameter of Differential Evolution for Global Optimization

    Science.gov (United States)

    Jia, Liyuan; Gong, Wenyin; Wu, Hongbin

    Differential evolution (DE), a fast and robust evolutionary algorithm for global optimization, has been widely used in many areas. However, the success of DE for solving different problems mainly depends on properly choosing the control parameter values. On the other hand, DE is good at exploring the search space and locating the region of global minimum, but it is slow at exploiting the solution. In order to alleviate these drawbacks of DE, this paper proposes an improved self-adaptive control parameter of DE, referred to as ISADE, for global numerical optimization. The proposed approach employs the individual fitness information to adapt the parameter settings. Hence, it can exploit the information of the individual and generate the promising offspring efficiently. To verify the viability of the proposed ISADE, 10 high-dimensional benchmark problems are chosen from literature. Experiment results indicate that this approach is efficient and effective. It is proved that this approach performs better than the original DE in terms of the convergence rate and the quality of the final solutions. Moreover, ISADE obtains faster convergence than the original self-adaptive control parameter of DE (SADE).

  16. Robust H∞ Control for a Class of Nonlinear Distributed Parameter Systems via Proportional-Spatial Derivative Control Approach

    Directory of Open Access Journals (Sweden)

    Cheng-Dong Yang

    2014-01-01

    Full Text Available This paper addresses the problem of robust H∞ control design via the proportional-spatial derivative (P-sD control approach for a class of nonlinear distributed parameter systems modeled by semilinear parabolic partial differential equations (PDEs. By using the Lyapunov direct method and the technique of integration by parts, a simple linear matrix inequality (LMI based design method of the robust H∞ P-sD controller is developed such that the closed-loop PDE system is exponentially stable with a given decay rate and a prescribed H∞ performance of disturbance attenuation. Moreover, a suboptimal H∞ controller is proposed to minimize the attenuation level for a given decay rate. The proposed method is successfully employed to address the control problem of the FitzHugh-Nagumo (FHN equation, and the achieved simulation results show its effectiveness.

  17. External beam radiotherapy for basal cell carcinoma. Local control and cosmetic outcome; Strahlentherapie des Basalzellkarzinoms. Lokale Kontrolle und kosmetisches Ergebnis

    Energy Technology Data Exchange (ETDEWEB)

    Seegenschmiedt, M.H.; Oberste-Beulmann, S.; Guntrum, F.; Olschewski, T. [Krankenhaus Essen (Germany). Klinik fuer Radioonkologie, Strahlentherapie und Nuklearmedizin; Lang, E.; Lang, B. [Praxis fuer Dermatologie, Essen (Germany)

    2001-05-01

    Background: The basal cell carcinoma which is often occurring in the elderly can be well treated by surgery. For large and recurrent lesions and in cosmetically difficult locations external beam radiotherapy provides an equally effective treatment alternative. Patients and Methods: From 1986 to 1999, 60 females and 39 males received primary radiotherapy for a total of 127 histologically verified basal cell carcinoma lesions. Tumors were mostly localized in the face at the temple, nose and forehead. Radiotherapy was applied with orthovoltage equipment and energies of up to 100 kV. Single doses ranged from 2 to 5 Gy related to the 80%-isodose depth. Weekly doses ranged from 8 to 25 Gy and total doses from 25 to 60 Gy. The mean follow-up period was 36{+-}21 months. The acute sequelae were scored according to CTC criteria. Radiogenic late effects as single events were related to the radiation portal. Results: 3 months after treatment all besides one patient (99%) experienced complete tumor remission (CR). In all cases, acute radiation reaction occurred within the radiation portal: CTC Grade 1 in 100%, CTC Grade 2 in 54% and CTC Grade 3 in 30% of the cases. All side effects regressed under simple local measures without further complications. Late sequelae were observed in three cases. Overall cosmetic outcome was good to excellent in almost all patients (98%). In two cases (2%) a local recurrence was observed 6 and 20 months after radiotherapy. Conclusion: External beam (orthovoltage) radiotherapy is very effective and yields high tumor control rates and good cosmetic results in long-term follow-up. Former dermatological treatment concepts should be replaced by an ICRU-based radiophysical dose prescription and should respect the newer radiobiological fractionation principles. (orig.) [German] Hintergrund: Das Basaliom oder Basalzellkarzinom ist ein im Alter haeufig vorkommender Hauttumor, der chirurgisch gut behandelbar ist. Bei grossen und rezidivierenden Tumoren und

  18. 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

  19. 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.

  20. 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.

  1. Composite control method for stabilizing spacecraft attitude in terms of Rodrigues parameters

    Institute of Scientific and Technical Information of China (English)

    Sun Haibin; Li Shihua

    2013-01-01

    In this paper,the attitude stabilization problem of a rigid spacecraft described by Rodrigues parameters is investigated via a composite control strategy,which combines a feedback control law designed by a finite time control technique with a feedforward compensator based on a linear disturbance observer (DOB) method.By choosing a suitable coordinate transformation,the spacecraft dynamics can be divided into three second-order subsystems.Each subsystem includes a certain part and an uncertain part.By using the finite time control technique,a continuous finite time controller is designed for the certain part.The uncertain part is considered to be a lumped disturbance,which is estimated by a DOB,and a corresponding feedforward design is then implemented to compensate the disturbance.Simulation results are employed to confirm the effectiveness of the proposed approach.

  2. A Unified Approach to Nonlinear Dynamic Inversion Control with Parameter Determination by Eigenvalue Assignment

    Directory of Open Access Journals (Sweden)

    Yu-Chi Wang

    2015-01-01

    Full Text Available This paper presents a unified approach to nonlinear dynamic inversion control algorithm with the parameters for desired dynamics determined by using an eigenvalue assignment method, which may be applied in a very straightforward and convenient way. By using this method, it is not necessary to transform the nonlinear equations into linear equations by feedback linearization before beginning control designs. The applications of this method are not limited to affine nonlinear control systems or limited to minimum phase problems if the eigenvalues of error dynamics are carefully assigned so that the desired dynamics is stable. The control design by using this method is shown to be robust to modeling uncertainties. To validate the theory, the design of a UAV control system is presented as an example. Numerical simulations show the performance of the design to be quite remarkable.

  3. Multivariable norm optimal and parameter optimal iterative learning control: a unified formulation

    Science.gov (United States)

    Owens, D. H.

    2012-08-01

    This article investigates the two paradigms of norm optimal iterative learning control (NOILC) and parameter optimal iterative learning control (POILC) for multivariable (MIMO) ℓ-input, m-output linear discrete-time systems. The main result is a proof that, despite their algebraic and conceptual differences, they can be unified using linear quadratic multi-parameter optimisation techniques. In particular, whilst POILC has been naturally regarded as an approximation to NOILC, it is shown that the NOILC control law can be generated from a suitable choice of control law parameterisation and objective function in a multi-parameter MIMO POILC problem. The form of this equivalence is used to propose a new general approach to the construction of POILC problems for MIMO systems that approximates the solution of a given NOILC problem. An infinite number of such approximations exist. This great diversity is illustrated by the derivation of new convergent algorithms based on time interval and gradient partition that extend previously published work.

  4. 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

  5. The effects of user mobility on usage parameter control (UPC) in wireless ATM systems

    Energy Technology Data Exchange (ETDEWEB)

    Sholander, P.; Martinez, L.; Tolendino, L. [Sandia National Labs., Albuquerque, NM (United States); Mah, B.A. [Sandia National Labs., Livermore, CA (United States)

    1997-07-01

    Wireless Asynchronous Transfer Mode (WATM) networks pose new traffic management problems. One example is the effect of user mobility on Usage Parameter Control (UPC). If the UPC algorithm resets after each handoff between wireless-cells, then users can cheat on their traffic contract. This paper derives explicit relationships between a user`s traffic parameters (Peak Cell Rate, Sustained Cell Rate and Maximum Burst Size), their transit time per wireless-cell, their maximum sustained cheating-rate and the Generic Cell Rate Algorithm`s (GCRA`s) Limit (L) parameter. It also shows that the GCRA can still effectively police Constant Bit Rate (CBR) traffic, but not some types of realistic Variable Bit Rate (VBR) traffic.

  6. Optimisasi Parameter Interline Power Flow Controller (IPFC Menggunakan Imperialist Competitive Algorithm (ICA

    Directory of Open Access Journals (Sweden)

    Muhammad Siddiq Basid

    2012-09-01

    Full Text Available Interline Power Flow Controller (IPFC merupakan alat kendali daya aktif dan reaktif antara beberapa saluran dengan mentransfer daya dari saluran yang mengalami kelebihan beban (overload ke saluran yang kekurangan beban (underload. IPFC menggunakan dua buah Voltage Sourced Converters (VSCs yang dihubungkan dengan saluran DC (DC link. Pada penelitian ini dilakukan optimisasi parameter pada IPFC dengan menggunakan Imperialist Competitive Algorithm (ICA berdasarkan model steady state untuk meminimalkan rugi-rugi transmisi pada jaring. Simulasi yang dilakukan adalah penerapan optimisasi parameter IPFC dengan menggunakan ICA pada sistem kelistrikan Jawa Bali 500 kV. Pada simulasi tersebut dibandingkan antara kinerja sistem tanpa IPFC, sistem dengan IPFC tapi tanpa optimisasi, dan dengan sistem yang menggunakan IPFC yang telah dioptimisasi dengan menggunakan ICA. Hasil simulasi menunjukkan bahwa penerapan ICA pada optimisasi parameter IPFC dapat meminimalkan rugi-rugi transmisi pada jaringan.

  7. Development of a parameter optimization technique for the design of automatic control systems

    Science.gov (United States)

    Whitaker, P. H.

    1977-01-01

    Parameter optimization techniques for the design of linear automatic control systems that are applicable to both continuous and digital systems are described. The model performance index is used as the optimization criterion because of the physical insight that can be attached to it. The design emphasis is to start with the simplest system configuration that experience indicates would be practical. Design parameters are specified, and a digital computer program is used to select that set of parameter values which minimizes the performance index. The resulting design is examined, and complexity, through the use of more complex information processing or more feedback paths, is added only if performance fails to meet operational specifications. System performance specifications are assumed to be such that the desired step function time response of the system can be inferred.

  8. 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.

  9. Rate control system algorithm developed in state space for models with parameter uncertainties

    Directory of Open Access Journals (Sweden)

    Adilson Jesus Teixeira

    2011-09-01

    Full Text Available Researching in weightlessness above the atmosphere needs a payload to carry the experiments. To achieve the weightlessness, the payload uses a rate control system (RCS in order to reduce the centripetal acceleration within the payload. The rate control system normally has actuators that supply a constant force when they are turned on. The development of an algorithm control for this rate control system will be based on the minimum-time problem method in the state space to overcome the payload and actuators dynamics uncertainties of the parameters. This control algorithm uses the initial conditions of optimal trajectories to create intermediate points or to adjust existing points of a switching function. It associated with inequality constraint will form a decision function to turn on or off the actuators. This decision function, for linear time-invariant systems in state space, needs only to test the payload state variables instead of spent effort in solving differential equations and it will be tuned in real time to the payload dynamic. It will be shown, through simulations, the results obtained for some cases of parameters uncertainties that the rate control system algorithm reduced the payload centripetal acceleration below μg level and keep this way with no limit cycle.

  10. Flexible-link Robot Control Using a Linear Parameter Varying Systems Methodology

    Directory of Open Access Journals (Sweden)

    Houssem Halalchi

    2014-03-01

    Full Text Available This paper addresses the issues of the Linear Parameter Varying (LPV modelling and control of flexible-link robot manipulators. The LPV formalism allows the synthesis of nonlinear control laws and the assessment of their closed-loop stability and performances in a simple and effective manner, based on the use of Linear Matrix Inequalities (LMI. Following the quasi-LPV modelling approach, an LPV model of a flexible manipulator is obtained, starting from the nonlinear dynamic model stemming from Euler-Lagrange equations. Based on this LPV model, which has a rational dependence in terms of the varying parameters, two different methods for the synthesis of LPV controllers are explored. They guarantee the asymptotic stability and some level of closed-loop L2-gain performance on a bounded parametric set. The first method exploits a descriptor representation that simplifies the rational dependence of the LPV model, whereas the second one manages the troublesome rational dependence by using dilated LMI conditions and taking the particular structure of the model into account. The resulting controllers involve the measured state variables only, namely the joint positions and velocities. Simulation results are presented that illustrate the validity of the proposed control methodology. Comparisons with an inversion-based nonlinear control method are performed in the presence of velocity measurement noise, model uncertainties and high-frequency inputs.

  11. THE BUBNOV–GALERKIN PROCEDURE IN PROBLEMS OF MOBILE (SCANNING CONTROL FOR SYSTEMS WITH DISTRIBUTED PARAMETERS

    Directory of Open Access Journals (Sweden)

    Arakelyan Sh. Kh.

    2015-09-01

    Full Text Available We suggest to apply the Bubnov–Galerkin procedure to solve scanning control problems for systems with distributed parameters. The algorithm is described in details for three-dimensional linear heat equation It allows to reduce the solution of control problem to finite-dimensional nonlinear moments problem. The procedure of derivation of moments problem is illustrated in details on the example of one-dimensional equation of thermal conductivity. The solution of obtained moments problem is found in a particular case. Based on obtained results a computer simulation is done using COMSOL Multiphysics platform in one-dimensional case for a rod. The main dependences of control function against input data of the problem are revealed. The state of the rod for several (constant values of the source intensity is expressed in terms of graphs and illustrations. Corresponding illustrations are brought in case of control absence (null-power source for comparison. An effective numerical scheme for solving the obtained system of nonlinear constraints is suggested in the case of extended class of admissible controls. Calculation of control parameters is reduced to the simplest problem of nonlinear programming.

  12. Dependences of spin polarization on the control parameters in the spin-polarized injection through the magnetic p-n junction

    Institute of Scientific and Technical Information of China (English)

    Zhang Lei; Deng Ning; Ren Min; Dong Hao; Chen Pei-Yi

    2007-01-01

    Effective spin-polarized injection from magnetic semiconductor (MS) to nonmagnetic semiconductor (NMS) has been highlighted in recent years. In this paper we study theoretically the dependence of nonequilibrium spin polarization (NESP) in NMS during spin-polarized injection through the magnetic p-n junction. Based on the theory in semiconductor physics, a model is established and the boundary conditions are determined in the case of no external spin-polarized injection and low bias. The control parameters that may influence the NESP in NMS are indicated by calculating the distribution of spin polarization. They are the doping concentrations, the equilibrium spin polarization in MS and the bias. The effective spin-polarized injection can' be realized more easily by optimizing the above parameters.

  13. Optimization and effect of controlling parameters on AJM using Taguchi technique

    Directory of Open Access Journals (Sweden)

    Jukti Prasad Padhy

    2014-03-01

    Full Text Available Abrasive Jet Machining (AJM is a non-conventional machining process where a high-pressure air stream with small abrasive particles to impinge the work surface through a nozzle. A model of AJM was designed by using CATIA. This model was implemented to design a workable AJM. In this paper drilling experiment was done on glass as the work piece and aluminum oxide (Al2O3 as abrasive powder on AJM. The air pressure and stand-off-distance (SOD are considering control parameter. The effect of Overcut (OC and Material Removal Rate (MRR of glass material was finding by using L9 Orthogonal Array (OA based on Taguchi design. And the influence of these controlling parameters is analyzed. Individual main effect of air pressure and SOD are plotted and optimized. Analysis of variance (ANOVA results were performed implementing Taguchi technique.

  14. 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 ...

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

    DEFF Research Database (Denmark)

    Khodaparast, Jalal; Silva, Filipe Miguel Faria da; Bak, Claus Leth

    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 paper shows how and why series voltage and shunt current change...... during power swing. Moreover, the admittance swing characteristic is proposed in this paper and effects of series and shunt branches of UPFC on the admittance seen by a distance relay during power swing have been examined. keywords:Admittance, Distance relay, Power Swing, Unified Power Flow Controller...

  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. Improvement of Quality of a Modern Commercial Silk Mill through effective Process and Machine Control Parameters

    Directory of Open Access Journals (Sweden)

    Dr. Swapan Kumar Ghosh

    2016-08-01

    Full Text Available This paper deals with international and national scenario of commercial production and market share of silk fabrics with particular reference to process along with machine control parameters followed by adoption of good practices in the preparatory stages during production of the silk fabric in a commercial Silk Mill. An observatory report has been presented here for starting from yarn to the fabric stage, which indicates the major technical reasons for deterioration in the quality of the silk products affecting the cost factor and environment to some extent. This paper delineates an effective monitoring and controlling process variables along with machine parameters at every step of production of silk fabric from its filament yarn stage, particularly during the modern high speed silk twisting process, enhancing the quality of the finished product on one hand and minimizing wastage along with the cost of production and adverse environmental impact on the other

  18. External quality assessment/proficiency testing and internal quality control for the PFA-100 and PFA-200: an update.

    Science.gov (United States)

    Favaloro, Emmanuel J; Bonar, Roslyn

    2014-03-01

    Platelet function testing is an essential component of comprehensive hemostasis evaluation within the framework of bleeding and/or bruising investigations, and it may also be performed to evaluate antiplatelet medication effects. Globally, the platelet function analyzer (PFA)-100 (Siemens Healthcare, Marburg, Germany) is the most used primary hemostasis-screening instrument and has also been recently remodeled/upgraded to the PFA-200. The PFA-100 is sensitive to a wide range of associated disorders, including platelet function defects and von Willebrand disease (VWD), as well as to various antiplatelet medications. The PFA-100 is also useful in therapy monitoring, especially in VWD. External quality assessment (EQA) (or proficiency testing) and internal quality control (IQC) are critical to ensuring quality of test practice, inclusive of all hemostasis tests. However, both EQA and IQC for platelet function testing, including the PFA-100, is logistically challenging, given theoretical requirements for production, storage, and shipment of large volumes of "stabilized" normal and pathological blood/platelets covering both normal function plus a wide variety of potential defects. We accordingly describe the development and testing of novel feasible approaches to both EQA and IQC of PFA-100/PFA-200 instruments, whereby a range of formulated "platelet function antagonist" materials are utilized. For EQA purposes, these are distributed to participants, and citrated normal whole blood collected on site is then added locally, thereby creating test material that can be locally evaluated. Several exercises have been conducted by the Royal College of Pathologists of Australasia Quality Assurance Program (RCPAQAP) over the past 6 years. A total of 26 challenges, with most designed to mimic moderate to severe primary hemostasis defects, have been tested in 26 to 50 laboratories depending on the year of dispatch. Numerical results for PFA-100/PFA-200 closure times (CTs) and

  19. Parameter optimisation of real-time control strategies for urban wastewater systems.

    Science.gov (United States)

    Schütze, M; Butler, D; Beck, M B

    2001-01-01

    Real-time control (RTC) of wastewater systems has been a topic of research and application for over two decades. Attempts so far have mainly focused on one of the parts of the urban wastewater system: either the sewer system, or the treatment plant or the river. Approaches to integrate these subsystems and considering them jointly for control purposes have been pursued only recently. Control of the systems aims at pursuing one (or several concomitant) objectives, which are expressed, for example, in terms of overflow volumes, loads, effluent concentrations, receiving water quality or monetary costs, to name just a few. This paper provides a general and formal definition of the problem to define a real time control algorithm for a given urban wastewater system. A general mathematical optimization problem is formulated, which describes the task of finding an (in some sense) optimum control algorithm. Since this optimization problem is, in the general case, highly non-linear with only limited information available about the objective function itself, optimization methods appropriate for this type of problem are identified. Here, the similarity of the problem to find a control algorithm and of the parameter estimation problem common in mathematical modelling becomes apparent. Hence, methods (and problems encountered) in parameter estimation can be transferred to the problem of determining optimum RTC algorithms. This parallelism is outlined in the paper. As an application of the parameterisation and optimization of control strategies, integrated control of an urban wastewater system is discussed. Since the analysis of integrated control as just described poses certain requirements on a simulation engine, a novel modelling tool, called SYNOPSIS, is utilized here. This simulation tool, comprising of modules simulating water quantity and quality processes in all parts of the urban wastewater system, is embedded into a suite of optimization procedures. An integrated RTC

  20. Frost formation and defrost control parameters for open multideck refrigerated food display cabinets

    Energy Technology Data Exchange (ETDEWEB)

    Tassou, S.A.; Datta, D. [Brunel Univ., Dept. of Mechanical Engineering, Uxbridge (United Kingdom); Marriott, D. [Safeway Stores plc, Hayes (United Kingdom)

    2001-04-03

    In order to achieve the required air and product temperatures in refrigerated food display cabinets, the evaporator coils, which are normally located in the base of the cabinets, operate at temperatures below the freezing point of water. The air which is circulated over the evaporator coil is cooled below its dew point and water vapour present in the air condenses and eventually freezes on the coil surface. With continuous operation of the coil, frost will accumulate on the coil surface leading to a decrease both in the air flowrate and in the overall heat transfer coefficient. In order to maintain satisfactory performance, evaporator coils are defrosted periodically. Although different defrost control strategies can be employed, for simplicity and cost considerations, defrosting in supermarket refrigeration systems is usually controlled by a pre-set time cycle. It is widely acknowledge, however, that time-based defrost may cause a number of unnecessary defrost cycles and this reduces the energy efficiency of the refrigeration systems as well as the accuracy of temperature control of the cabinets. Implementing defrost only when it is needed or on 'demand' should reduce the number of defrost cycles and lead to savings in energy and improved product quality. This paper reports on field and experimental investigations on the processes of frosting and defrosting of medium-temperature display cabinet evaporator coils. The results show that for medium-temperature refrigeration applications where the environment temperature is kept reasonably constant, the store humidity is the primary parameter influencing the rate of frost formation. Using relative humidity as a control parameter the defrost frequency can be reduced considerably without affecting cabinet performance and product integrity. Alongside the effect of relative humidity, the paper also considers the effects of other performance parameters on the processes of frosting and defrosting such as cooling