National Research Council Canada - National Science Library
Sundarapandian Vaidyanathan
2011-01-01
...).Explicitly, new state feedback control laws regulating the output of the modified Arneodo chaotic systemhave been derived so as to regulate the output of the modified Arneodo chaotic system have been...
Lotfi, Babak; Wang, Qiuwang
2013-07-01
The performance of thermal control systems has, in recent years, improved in numerous ways due to developments in control theory and information technology. The shell-and-tube heat exchanger (STHX) is a medium where heat transfer process occurred. The accuracy of the heat exchanger depends on the performance of both elements. Therefore, both components need to be controlled in order to achieve a substantial result in the process. For this purpose, the actual dynamics of both shell and tube of the heat exchanger is crucial. In this paper, optimal reliability-based multi-objective Pareto design of robust state feedback controllers for a STHX having parameters with probabilistic uncertainties. Accordingly, the probabilities of failure of those objective functions are also considered in the reliability-based design optimization (RBDO) approach. A new multi-objective uniform-diversity genetic algorithm (MUGA) is presented and used for Pareto optimum design of linear state feedback controllers for STHX problem. In this way, Pareto front of optimum controllers is first obtained for the nominal deterministic STHX using the conflicting objective functions in time domain. Such Pareto front is then obtained for STHX having probabilistic uncertainties in its parameters using the statistical moments of those objective functions through a Hammersley Sequence Sampling (HSS) approach. It is shown that multi-objective reliability-based Pareto optimization of the robust state feedback controllers using MUGA includes those that may be obtained by various crisp threshold values of probability of failures and, thus, remove the difficulty of selecting suitable crisp values. Besides, the multi-objective Pareto optimization of such robust feedback controllers using MUGA unveils some very important and informative trade-offs among those objective functions. Consequently, some optimum robust state feedback controllers can be compromisingly chosen from the Pareto frontiers.
DEFF Research Database (Denmark)
Federico, de Bosio; de Sousa Ribeiro, Luiz Antonio; Freijedo Fernandez, Francisco Daniel
2016-01-01
In stand-alone microgrids based on voltage source inverters state feedback coupling between the capacitor voltage and inductor current degrades significantly the dynamics performance of voltage and current regulators. The decoupling of the controlled states is proposed, considering the limitations...... introduced by system delays. Moreover, a proportional resonant voltage controller is designed according to Nyquist criterion taking into account application requirements. Experimental tests performed in compliance with the UPS standards verify the theoretical analysis....
State Feedback H∞ Control of Power Units Based on an Improved Particle Swarm Optimization
Directory of Open Access Journals (Sweden)
Zhongqiang Wu
2015-01-01
Full Text Available A new state feedback H∞ control scheme is presented used in the boiler-turbine power units based on an improved particle swarm optimizing algorithm. Firstly, the nonlinear system is transformed into a linear time-varying system; then the H∞ control problem is transformed into the solution of a Riccati equation. The control effect of H∞ controller depends on the selection of matrix P, so an improved particle swarm optimizing (PSO algorithm by introducing differential evolution algorithm is used to solve the Riccati equation. The main purpose is that mutation and crossover are introduced for a new population, and the population diversity is improved. It is beneficial to eliminate stagnation caused by premature convergence, and the algorithm convergence rate is improved. Finally, the real-time optimizing of the controller parameters is realized. Theoretical analysis and simulation results show that a state feedback H∞ controller can be obtained, which can ensure asymptotic stability of the system, and the double objectives of stabilizing system and suppressing the disturbance are got. The system can work well over a large range working point.
H_2-Optimal Decentralized Control over Posets: A State-Space Solution for State-Feedback
Shah, Parikshit
2011-01-01
We develop a complete state-space solution to H_2-optimal decentralized control of poset-causal systems with state-feedback. Our solution is based on the exploitation of a key separability property of the problem, that enables an efficient computation of the optimal controller by solving a small number of uncoupled standard Riccati equations. Our approach gives important insight into the structure of optimal controllers, such as controller degree bounds that depend on the structure of the poset. A novel element in our state-space characterization of the controller is a remarkable pair of transfer functions, that belong to the incidence algebra of the poset, are inverses of each other, and are intimately related to prediction of the state along the different paths on the poset. The results are illustrated by a numerical example.
Robust state feedback controller design of STATCOM using chaotic optimization algorithm
Directory of Open Access Journals (Sweden)
Safari Amin
2010-01-01
Full Text Available In this paper, a new design technique for the design of robust state feedback controller for static synchronous compensator (STATCOM using Chaotic Optimization Algorithm (COA is presented. The design is formulated as an optimization problem which is solved by the COA. Since chaotic planning enjoys reliability, ergodicity and stochastic feature, the proposed technique presents chaos mapping using Lozi map chaotic sequences which increases its convergence rate. To ensure the robustness of the proposed damping controller, the design process takes into account a wide range of operating conditions and system configurations. The simulation results reveal that the proposed controller has an excellent capability in damping power system low frequency oscillations and enhances greatly the dynamic stability of the power systems. Moreover, the system performance analysis under different operating conditions shows that the phase based controller is superior compare to the magnitude based controller.
Energy Technology Data Exchange (ETDEWEB)
Bienert, W. [Kraftwerk Pleinting der Bayernwerk AG Konventionelle Waermekraftwerke GmbH (Germany). Abt. Elektro- und Leittechnik; Mann, J. [Siemens AG, Karlsruhe (Germany). Bereich Energieerzeugung (KWU)
1998-12-31
During a boiler construction change at the power station Pleinting Unit 2 the heating surfaces of the superheater were enlarged. Due to these changes in the temperature control loop, the temperature deviations could no longer be regulated satisfactorily by the hitherto installed conventional controllers. Using state feedback controllers thereafter, these deviations were reduced considerably. The configuring and parameter setting of the used state feedback controllers was extremely easy because only one tuning factor was needed. So further optimizations with customer benefits could be worked out: The state feedback control was supplemented by an enthalpy calculation with subordinate mass flow control. Thus, it has become possible to inject water into saturated steam during start-ups in case of high temperature deviations. The achieved results are verified by time trends measured at the plant. (orig.) [Deutsch] Bei einem Kesselumbau im Kraftwerk Pleinting Block 2 wurden die Heizflaechen der Ueberhitzer und damit die Aufwaermspannen vergroessert. Aufgrund der dadurch veraenderten Temperaturregelstrecke konnten die Temperaturstoerungen mit der konventionellen Regelung nicht mehr zufriedenstellend ausgeregelt werden. Mit dem Einsatz von Zustandsreglern wurden diese Regelabweichungen wesentlich verringert. Die Projektierung und Parametrierung der verwendeten Zustandsregler gestaltete sich durch die Verwendung von nur einem Einstellfaktor aeusserst einfach. So konnte dann das Augenmerk auf weiteres Optimierungspotential mit Kundennutzen gelegt werden: Die Zustandsregelung wurde um eine Enthalpie-Rechnung mit unterlagerter Massenstromregelung ergaenzt, um waehrend des Anfahrens bei hohen Temperaturbweichungen in Sattdampf einspritzen zu koennen. Die erzielten Ergebnisse sind durch in der Anlage gemessene Kurven belegt. (orig.)
Numerical static state feedback laws for closed-loop singular optimal control
Graaf, de S.C.; Stigter, J.D.; Straten, van G.
2005-01-01
Singular and non-singular control trajectories of agricultural and (bio) chemical processes may need to be recalculated from time to time for use in closed-loop optimal control, because of unforeseen changes in state values and noise. This is time consuming. As an alternative, in this paper,
Directory of Open Access Journals (Sweden)
A.R Alfi
2012-06-01
Full Text Available This paper presents an intelligent optimal design control strategy for current and voltage of boost DC-DC convertors in fuel cell power systems by considering detailed model for different operating points. The proposed control strategy is designed based on a state feedback whereas the controllability and the stability region are analyzed. Moreover, in order to determine of the optimal coefficients of state feedback and zero steady state error in voltage signal, in the core of the proposed control method a heuristic algorithm namely Particle Swarm Optimization (PSO is utilized. The results are presented in the different load conditions. In order to show the feasibility of the proposed control strategy, the controller is implemented both average model and detailed model of convertor and the results are compared.
Institute of Scientific and Technical Information of China (English)
无
2007-01-01
This paper develops a unified methodology for a real-time speed control of brushless direct-current motor drive systems in the presence of measurement noise and load torque disturbance. First, the mathematical model and hardware structure of system is established. Next, an optimal state feed back controller using the Kalman filter state estimation technique is derived.This is followed by an adaptive control algorithm to compensate for the effects of noise and disturbance. Those two algorithms working together can provide a very-high-speed regulation and dynamic response over a wide range of operating conditions.Simulated responses are presented to highlight the effectiveness of the proposed control strategy.
THE INVERSE PROBLEM OF OPTIMAL REGULATORS AND ITS AP PLICATION
Institute of Scientific and Technical Information of China (English)
无
2000-01-01
This paper presents a new solution to the inverse problem of linear optimal regulators to minimize a cost function and meet the requirements of relative stability in the presence of a constant but unknown disturbance. A state feedback matrix is developed using Lyapunov's second method. Moreover, the relationships between the state feedback matrix and the cost function are obtained, and a formula to solve the weighting matrices is suggest ed. The developed method is applied successfully to design the horizontal loops in the inertial navigation system.
Functional observer and state feedback
Energy Technology Data Exchange (ETDEWEB)
Zhang, S.Y.
1986-01-01
In this paper, we show the relation between state space approach and transfer function approach for functional observer and state feedback design. Two approaches can be transformed into each other, based on this result. More importantly, we find that the state space approach introduces some severe, unnecessary restrictions in solving the problem. The restrictions are, however, reduced to be a trivial condition in transfer function approach. It is believed that the result presented in this paper will be useful in developing both approaches, and motivate some new results for solving the problem.
Nonlinear H-ininity state feedback controllers:
DEFF Research Database (Denmark)
Cromme, Marc; Møller-Pedersen, Jens; Pagh Petersen, Martin
1997-01-01
From a general point of view the state feedback H∞ suboptimal control problem is reasonably well understood. Important problems remain with regard to a priori information of the size of the neighbourhood where the local state feedback H∞ problem is solvable. This problem is solved regionally (sem...
Robustness Results for State Feedback Regulators,
1979-08-31
CCT - DDT (11) KB = 1 - (/2 - C)D Proof. This is again a direct application of the circle criterion in combination with the Kalman-Yakubovich-Popov...right-hand side is nonnegative, and the following inequality results: (I G (-iw))I p(I - G(iW)) < I p (7). A straight-forward application of the circle ... criterion then implies the desired stability for 1 K,= , K2 =any finite K. It is obvious that the best possible lower bound K1 without restrictions on
Semiglobal H-infinity State Feedback Control
DEFF Research Database (Denmark)
Cromme, Marc; Stoustrup, Jakob
1996-01-01
Semi-global set-stabilizing H-infinity controlis a local within some given compact set such that all statetrajectories are bounded inside the set, and are approaching an openloop invariant subset as time approaches infinity. Sufficientconditions for the existence of a continuous state feedback law...
Comparison of the domain and frequency domain state feedbacks
Energy Technology Data Exchange (ETDEWEB)
Zhang, S.Y.
1986-01-01
In this paper, we present explicitly the equivalence of the time domain and frequency domain state feedbacks, as well as the dynamic state feedback and a modified frequency domain state feedback, from the closed-loop transfer function point of view. The difference of the two approaches is also shown.
Gibson, J. S.; Rosen, I. G.
1988-01-01
An abstract approximation framework is developed for the finite and infinite time horizon discrete-time linear-quadratic regulator problem for systems whose state dynamics are described by a linear semigroup of operators on an infinite dimensional Hilbert space. The schemes included the framework yield finite dimensional approximations to the linear state feedback gains which determine the optimal control law. Convergence arguments are given. Examples involving hereditary and parabolic systems and the vibration of a flexible beam are considered. Spline-based finite element schemes for these classes of problems, together with numerical results, are presented and discussed.
Geometric Structures of Stable Time-Variant State Feedback Systems
Institute of Scientific and Technical Information of China (English)
ZHONG Feng-wei; SUN Hua-fei; ZHANG Zhen-ning
2007-01-01
A new technique for considering the stabilizing time-variant state feedback gains is proposed from the viewpoint of information geometry. First, parametrization of the set of all stabilizing time-variant state feedback gains is given. Moreover, a diffeomorphic structure between the set of stabilizing time-variant state feedback gains and the Cartesian product of positive definite matrix and skew symmetric matrix satisfying certain algebraic conditions is constructed. Furth ermore, an immersion and some results about the eigenvalue locations of stable state feedback systems are derived.
H-INFINITY-CONTROL BY STATE-FEEDBACK FOR PLANTS WITH ZEROS ON THE IMAGINARY AXIS
SCHERER, C
1992-01-01
Algebraic tests are derived for the suboptimality of some parameter in the H(infinity)-optimization problem by state-feedback, where the finite zero structure of the plant is not restricted. As an application of these characterizations, a quadratically convergent algorithm for the computation of the
Speech production as state feedback control.
Houde, John F; Nagarajan, Srikantan S
2011-01-01
Spoken language exists because of a remarkable neural process. Inside a speaker's brain, an intended message gives rise to neural signals activating the muscles of the vocal tract. The process is remarkable because these muscles are activated in just the right way that the vocal tract produces sounds a listener understands as the intended message. What is the best approach to understanding the neural substrate of this crucial motor control process? One of the key recent modeling developments in neuroscience has been the use of state feedback control (SFC) theory to explain the role of the CNS in motor control. SFC postulates that the CNS controls motor output by (1) estimating the current dynamic state of the thing (e.g., arm) being controlled, and (2) generating controls based on this estimated state. SFC has successfully predicted a great range of non-speech motor phenomena, but as yet has not received attention in the speech motor control community. Here, we review some of the key characteristics of speech motor control and what they say about the role of the CNS in the process. We then discuss prior efforts to model the role of CNS in speech motor control, and argue that these models have inherent limitations - limitations that are overcome by an SFC model of speech motor control which we describe. We conclude by discussing a plausible neural substrate of our model.
Speech production as state feedback control
Directory of Open Access Journals (Sweden)
John F Houde
2011-10-01
Full Text Available Spoken language exists because of a remarkable neural process. Inside a speaker’s brain, an intended message gives rise to neural signals activating the muscles of the vocal tract. The process is remarkable because these muscles are activated in just the right way that the vocal tract produces sounds a listener understands as the intended message. What is the best approach to understanding the neural substrate of this crucial motor control process? One of the key recent modeling developments in neuroscience has been the use of state feedback control (SFC theory to explain the role of the CNS in motor control. SFC postulates that the CNS controls motor output by (1 estimating the current dynamic state of the thing (e.g., arm being controlled, and (2 generating controls based on this estimated state. SFC has successfully predicted a great range of non-speech motor phenomena, but as yet has not received attention in the speech motor control community. Here, we review some of the key characteristics of speech motor control and what they say about the role of the CNS in the process. We then discuss prior efforts to model the role of CNS in speech motor control, and argue that these models have inherent limitations – limitations that are overcome by an SFC model of speech motor control which we describe. We conclude by discussing a plausible neural substrate of our model.
DEFF Research Database (Denmark)
Federico, de Bosio; Pastorelli, Michele; Antonio DeSouza Ribeiro, Luiz
2016-01-01
State feedback coupling between the capacitor voltage and inductor current deteriorates notably the performance during transients of voltage and current regulators in stand-alone systems based on voltage source inverters. A decoupling technique is proposed, considering the limitations introduced ...... by system delays. Laboratory experiments were executed in compliance with the normative for Uninterruptible Power Supply systems to prove the developed analysis....
Unpower aerocraft augmented state feedback tracking guaranteed cost control
Institute of Scientific and Technical Information of China (English)
无
2008-01-01
Aimed at designing the unpower aerocraft attitude control system in a simple and practical way,the guaranteed cost control is adopted.To eliminate the steady-error,a novel tracking control approach-augmented state feedback tracking guaranteed cost control is proposed.Firstly,the unpower aerocraft is modeled as a linear system with norm bounded parameter uncertain,then the linear matrix inequality based state feedback gnaranteed cost control law is combined with the augmented state feedback tracking control from a new point of view.The sufficient condition of the existence of the augmented state feedback tracking guaranteed cost control is derived and converted to the feasible problem of the linear matrix inequality.Finally,the proposed approach is applied to a specified unpower aerocraft.The six dimensions of freedom simulation results show that the proposed approach is effective and feasible.
State feedback design for singularly perturbed system using unified approach
Institute of Scientific and Technical Information of China (English)
Chenxiao CAI; Yun ZOU; Duanjin ZHANG
2004-01-01
The state feedback design for singularly perturbed systems described in Delta operator is considered.The composite state feedback controller for slow and fast subsystems is designed by using the direct method.The obtained results can bring previous conclusions of continuous and discrete time systems into the unified Delta framework.A simulation example is presented to demonstrate the validity and efficiency of the design.
PSO Based State Feedback Controller Design for SVC to Enhance the Stability of Power System
Directory of Open Access Journals (Sweden)
Saeid Jalilzadeh
2012-08-01
Full Text Available SVC is one of the most significant devices in FACTS technology, which is used in parallel compensation, enhancing the transient stability, limiting the low frequency oscillations and, etc. designing a proper controller is effective in operation of SVC. In this paper, a simplified analysis of the effect of a SVC on the stability of a Single Machine Infinite Bus (SMIB system is presented. The SVC which is located at the terminal of the generator has the state feedback controller in which the coefficients of state feedback are optimized by the Particle Swarm Optimization (PSO algorithm in order to damp the Low Frequency Oscillations (LFO. The equations that describe the proposed system have been linearized, and then the optimum state feedback controller has been designed for SVC which its optimal coefficients have been earned by PSO algorithm. The system with proposed controller has been simulated for a special disturbance in nominal loading condition. Thereafter, for three states viz light loading condition, normal loading condition and heavy loading condition, to show the robustness of the proposed controller, the previous disturbance has been applied again. Then the dynamic responses of the generator have been presented. The simulation results showed that the system composed with proposed controller has a suitable operation in fast damping of oscillations of the power system. to ensure stability and tracking. Simulations is carried out to verify the theoretical results.
Interference Alignment with Analog Channel State Feedback
Ayach, Omar El
2010-01-01
Interference alignment (IA) is a multiplexing gain optimal transmission strategy for the interference channel with an arbitrary number of users. While the achieved sum rate with IA is much higher than previously thought possible, the improvement comes at the cost of requiring network channel state information at the transmitters. This can be achieved by explicit feedback, a flexible yet costly approach that incurs large overhead and limits throughput. We propose using analog feedback as an alternative to limited feedback or reciprocity based alignment. We show that the full multiplexing gain observed with perfect channel knowledge is preserved by analog feedback and the mean loss in sum rate is bounded by a constant when signal-to-noise ratio is comparable in both forward and feedback channels. When such feedback quality is not quite possible, a fraction of the degrees of freedom is achieved. We consider the overhead of training and feedback and use this framework to optimize the system's effective throughput...
Corruption and optimal regulation under common agency
Directory of Open Access Journals (Sweden)
Pedro Hemsley
2016-05-01
Full Text Available I show that it is optimal to separate non-benevolent regulators when regulated projects are large. Separation prevents regulators from coordinating to appropriate all of the agent's informational rent when they know the type of the latter; therefore, there is a trade-off between saving on informational rent and efficiency, since the game between the regulators induced by separation causes further distortions when compared to the allocation under one regulator. When the informational rent at stake is large due to the size of the project, separation is the optimal institutional answer.
Sampled-Data State Feedback Stabilization of Boolean Control Networks.
Liu, Yang; Cao, Jinde; Sun, Liangjie; Lu, Jianquan
2016-04-01
In this letter, we investigate the sampled-data state feedback control (SDSFC) problem of Boolean control networks (BCNs). Some necessary and sufficient conditions are obtained for the global stabilization of BCNs by SDSFC. Different from conventional state feedback controls, new phenomena observed the study of SDSFC. Based on the controllability matrix, we derive some necessary and sufficient conditions under which the trajectories of BCNs can be stabilized to a fixed point by piecewise constant control (PCC). It is proved that the global stabilization of BCNs under SDSFC is equivalent to that by PCC. Moreover, algorithms are given to construct the sampled-data state feedback controllers. Numerical examples are given to illustrate the efficiency of the obtained results.
Gaalman, G.J.C.
2006-01-01
A 'proportional' order-up-to policy reacting to ARMA demand is analyzed using stochastic optimal control theory. This policy is compared with a full-state-feedback order-up-to policy. Necessary conditions for an optimum of a weighted sum of the inventory and the ordering variances for both policies
Gaalman, G.J.C.
A 'proportional' order-up-to policy reacting to ARMA demand is analyzed using stochastic optimal control theory. This policy is compared with a full-state-feedback order-up-to policy. Necessary conditions for an optimum of a weighted sum of the inventory and the ordering variances for both policies
State-feedback control of LPV sampled-data systems
Directory of Open Access Journals (Sweden)
K. Tan
2000-01-01
norm of such sampled-data LPV systems using parameter-dependent Lyapunov functions. Based on these analysis results, the sampled-data state-feedback control synthesis problems are examined. Both analysis and synthesis conditions are formulated in terms of linear matrix inequalities that can be solved via efficient interior-point algorithms.
State-feedback control of LPV sampled-data systems
Directory of Open Access Journals (Sweden)
Tan K.
2000-01-01
Full Text Available In this paper, we address the analysis and the state-feedback synthesis problems for linear parameter-varying (LPV sampled-data control systems. We assume that the state-space data of the plant and the sampling interval depend on parameters that are measurable in real-time and vary in a compact set with bounded variation rates. We explore criteria such as the stability, the energy-to-energy gain (induced L 2 norm and the energy-to-peak gain (induced L 2 -to- L ∞ norm of such sampled-data LPV systems using parameter-dependent Lyapunov functions. Based on these analysis results, the sampled-data state-feedback control synthesis problems are examined. Both analysis and synthesis conditions are formulated in terms of linear matrix inequalities that can be solved via efficient interior-point algorithms.
Engineering applications of a dynamical state feedback chaotification method
Şahin, Savaş; Güzeliş, Cüneyt
2012-09-01
This paper presents two engineering applications of a chaotification method which can be applied to any inputstate linearizable (nonlinear) system including linear controllable ones as special cases. In the used chaotification method, a reference chaotic and linear system can be combined into a special form by a dynamical state feedback increasing the order of the open loop system to have the same chaotic dynamics with the reference chaotic system. Promising dc motor applications of the method are implemented by the proposed dynamical state feedback which is based on matching the closed loop dynamics to the well known Chua and also Lorenz chaotic systems. The first application, which is the chaotified dc motor used for mixing a corn syrup added acid-base mixture, is implemented via a personal computer and a microcontroller based circuit. As a second application, a chaotified dc motor with a taco-generator used in the feedback is realized by using fully analog circuit elements.
Optimal Bank Regulation and Monetary Policy
John J. Seater
2000-01-01
A unified model of monetary policy and bank regulation is presented. In accordance with modern banking theory, banks not only intermediate loans and deposits but also provide a financial service affecting aggregate output. Optimal parameter settings for monetary and regulatory policy are derived. New results are that monetary policy affects the expected level as well as the variance of output, bank regulation should change continually in response to the state of the economy, and bank regulati...
A Design Method for a State Feedback Microcomputer Controller of a Wide Bandwidth Analog Plant.
1983-12-01
METHOD . . . .... 16 1. State Feedback Control System . . . . . . 16 2. Microcomputer Controller Design with Time Delay . . . . . . . . . . . . . . . . 18...90 C. DESIGN OF STATE FEEDBACK CONTROL SYSTEM WITH MICROCOMPUTER . . . . . . . . . . . . . . . . 91 1. Control Algorithm...FIGURES 2.1 Signal Flow Diagram of State Feedback System . . 17 2.2 Feedback Control System with PD Control . . . . 18 2.3 Bode Diagram of Eqn. 2.7
Disturbance Attenuation State-Feedback Control for Uncertain Interconnected Systems
Institute of Scientific and Technical Information of China (English)
无
2002-01-01
This paper studies the problem of robust H∞ control design for a class of uncertain interconnected systems viastate feedback. This class of systems are described by a state space model, which contains unknown nonlinear interactionand time-varying norm-bounded parametric uncertainties in state equation. Using the Riccati-equation-based approach wedesign state feedback control laws, which guarantee the decentralized stability with disturbance attenuation for the inter-connected uncertain systems. A simple example of an interconnected uncertain linear system is presented to illustrate theresults.
State Feedback with Memory for Constrained Switched Positive Linear Systems
Directory of Open Access Journals (Sweden)
Jinjin Liu
2015-04-01
Full Text Available In this paper, the stabilization problem in switched linear systems with time-varying delay under constrained state and control is investigated. The synthesis of bounded state-feedback controllers with memory ensures that a closed-loop state is positive and stable. Firstly, synthesis with a sign-restricted (nonnegative and negative control is considered for general switched systems; then, the stabilization issue under bounded controls including the asymmetrically bounded controls and states constraints are addressed. In addition, the results are extended to systems with interval and polytopic uncertainties. All the proposed conditions are solvable in term of linear programming. Numerical examples illustrate the applicability of the results.
Regulatory Risk under Optimal Incentive Regulation
Strausz, Roland
2009-01-01
The paper provides a tractable, analytical framework to study regulatory risk under optimal incentive regulation. Regulatory risk is captured by uncertainty about the policy variables in the regulator’s objective function: weights attached to profits and costs of public funds. Results are as follows: 1) The regulator’s reaction to regulatory risk depends on the curvature of the aggregate demand function. 2) It yields a positive information rent effect exactly when demand is convex. 3) Firms b...
Multiobjective controller synthesis via eigenstructure assignment with state feedback
Li, Zhao; Lam, James
2016-10-01
A general parameter scheme for multiobjective controller synthesis via eigenstructure assignment with state feedback is proposed. The scheme provides total pole configurability, that is, pole assignment constraints, partial pole assignment constraints, generalised regional pole assignment constraints can be dealt with simultaneously without introducing essential conservatism. The scheme is derived from the pole assignment approach using Sylvester equations, and the parameter space is the Cartesian product of some subspaces characterising the free parameters. Under the scheme, the controller design problems are formulated as nonlinear optimisation problems with both objectives and constraints being differentiable and can be solved by derivative-based nonlinear programming technique. Numerical examples are given to illustrate the efficiency of the proposed method.
Improved decoding of limb-state feedback from natural sensors.
Wagenaar, J B; Ventura, V; Weber, D J
2009-01-01
Limb state feedback is of great importance for achieving stable and adaptive control of FES neuroprostheses. A natural way to determine limb state is to measure and decode the activity of primary afferent neurons in the limb. The feasibility of doing so has been demonstrated by [1] and [2]. Despite positive results, some drawbacks in these works are associated with the application of reverse regression techniques for decoding the afferent neuronal signals. Decoding methods that are based on direct regression are now favored over reverse regression for decoding neural responses in higher regions in the central nervous system [3]. In this paper, we apply a direct regression approach to decode the movement of the hind limb of a cat from a population of primary afferent neurons. We show that this approach is more principled, more efficient, and more generalizable than reverse regression.
Regulation of Viable and Optimal Cohorts
Energy Technology Data Exchange (ETDEWEB)
Aubin, Jean-Pierre, E-mail: aubin.jp@gmail.com [VIMADES (Viabilité, Marchés, Automatique, Décisions) (France)
2015-10-15
This study deals with the evolution of (scalar) attributes (resources or income in evolutionary demography or economics, position in traffic management, etc.) of a population of “mobiles” (economic agents, vehicles, etc.). The set of mobiles sharing the same attributes is regarded as an instantaneous cohort described by the number of its elements. The union of instantaneous cohorts during a mobile window between two attributes is a cohort. Given a measure defining the number of instantaneous cohorts, the accumulation of the mobile attributes on a evolving mobile window is the measure of the cohort on this temporal mobile window. Imposing accumulation constraints and departure conditions, this study is devoted to the regulation of the evolutions of the attributes which are1.viable in the sense that the accumulations constraints are satisfied at each instant;2.and, among them, optimal, in the sense that both the duration of the temporal mobile window is maximum and that the accumulation on this temporal mobile window is the largest viable one. This value is the “accumulation valuation” function. Viable and optimal evolutions under accumulation constraints are regulated by an “implicit Volterra integro-differential inclusion” built from the accumulation valuation function, solution to an Hamilton–Jacobi–Bellman partial differential equation under constraints which is constructed for this purpose.
Improved State Feedback H∞ Control for Flexible Air-Breathing Hypersonic Vehicles on LMI Approach
Directory of Open Access Journals (Sweden)
Zhang Xue
2017-01-01
Full Text Available Focusing on a nonlinear longitudinal dynamical model for Air-breathing Hypersonic Flight Vehicles (AHFV, a linearized model on a nominal trim condition is proposed. To stabilize the flight of an AHFV in the presence of external disturbances and actuator uncertainties, a state feedback H∞ control is designed. With bounds on the uncertainties, a feedback stabilization problem is converted to an optimal control problem and the cost function is minimized by solving a set of linear matrix inequalities. Since uncertainties in the design of AHFV are inevitable, to make a comparison, a general H∞ robust controller is constructed by only considering the disturbances firstly. Then the results are extended by incorporating the actual existing uncertainties as well as the external disturbances in the AHFV system. Numerical simulation shows that the controller, which takes both disturbances and uncertainties into account, can effectively stabilize the AHFV system.
Memory State Feedback RMPC for Multiple Time-Delayed Uncertain Linear Systems with Input Constraints
Directory of Open Access Journals (Sweden)
Wei-Wei Qin
2014-01-01
Full Text Available This paper focuses on the problem of asymptotic stabilization for a class of discrete-time multiple time-delayed uncertain linear systems with input constraints. Then, based on the predictive control principle of receding horizon optimization, a delayed state dependent quadratic function is considered for incorporating MPC problem formulation. By developing a memory state feedback controller, the information of the delayed plant states can be taken into full consideration. The MPC problem is formulated to minimize the upper bound of infinite horizon cost that satisfies the sufficient conditions. Then, based on the Lyapunov-Krasovskii function, a delay-dependent sufficient condition in terms of linear matrix inequality (LMI can be derived to design a robust MPC algorithm. Finally, the digital simulation results prove availability of the proposed method.
State feedback control of switched linear systems: An LMI approach
Montagner, V. F.; Leite, V. J. S.; Oliveira, R. C. L. F.; Peres, P. L. D.
2006-10-01
This paper addresses the problem of state feedback control of continuous-time switched linear systems with arbitrary switching rules. A quadratic Lyapunov function with a common matrix is used to derive a stabilizing switching control strategy that guarantees: (i) the assignment of all the eigenvalues of each linear subsystem inside a chosen circle in the left-hand half of the complex plane; (ii) a minimum disturbance attenuation level for the closed-loop switched system. The proposed design conditions are given in terms of linear matrix inequalities that encompass previous results based on quadratic stability conditions with fixed control gains. Although the quadratic stability based on a fixed Lyapunov matrix has been widely used in robust control design, the use of this condition to provide a convex design method for switching feedback gains has not been fully investigated. Numerical examples show that the switching control strategy can cope with more stringent design specifications than the fixed gain strategy, being useful to improve the performance of this class of systems.
The Quadratic Matrix Inequality in Singular H∞ Control with State Feedback
Stoorvogel, A.A.; Trentelman, H.L.
1990-01-01
In this paper the standard H∞ control problem using state feedback is considered. Given a linear, time-invariant, finite-dimensional system, this problem consists of finding a static state feedback such that the resulting closed-loop transfer matrix has H∞ norm smaller than some a priori given upper
Optimal Price Regulation for Natural and Legal Monopolies
Ingo Vogelsang
1999-01-01
Optimal price regulation for natural and legal monopolies is an impossible task. The still difficult .task of good price regulation can be systematized by considering separately price level and price structure of the regulated firm. Various methods of price level and price structure regulation are evaluated and then considered for the regulation of electricity transmission, both in the context of an independent transmission company and of vertical integration between transmission and most of ...
Incentive Mechanism Design for Public Goods Provision: Price Cap Regulation and Optimal Regulation
Institute of Scientific and Technical Information of China (English)
ZHENG Jun-jun; YIN Hong; WANG Xian-jia
2005-01-01
This paper studies the mechanism design that induces firms to provide public goods under two regulatory means: price cap regulation and optimal regulation, respectively. We first outline two models of monopoly regulation with unobservable marginal costs and effort, which can be regard as an optimal problem with dual restrictions. By solving this problem, we get the two optimal regulatory mechanisms to induce the provision of public goods. Further, by comparative statics, the conclusion is drawn that the welfare loss associated with price cap regulation, with respective to optimal regulation, increases more with increase of the expense of public goods.
ℋ∞ constant gain state feedback stabilization of stochastic hybrid systems with Wiener process
Directory of Open Access Journals (Sweden)
E. K. Boukas
2004-01-01
Full Text Available This paper considers the stabilization problem of the class of continuous-time linear stochastic hybrid systems with Wiener process. The ℋ∞ state feedback stabilization problem is treated. A state feedback controller with constant gain that does not require access to the system mode is designed. LMI-based conditions are developed to design the state feedback controller with constant gain that stochastically stabilizes the studied class of systems and, at the same time, achieve the disturbance rejection of a desired level. The minimum disturbance rejection is also determined. Numerical examples are given to show the usefulness of the proposed results.
H∞ State Feedback Delay-dependent Control for Discrete Systems with Multi-time-delay
Institute of Scientific and Technical Information of China (English)
Bai-Da Qu
2005-01-01
In this paper,H∞ state feedback control with delay information for discrete systems with multi-time-delay is discussed. Making use of linear matrix inequality (LMI) approach, a time-delay-dependent criterion for a discrete system with multi-time-delay to satisfy H∞ performance indices is induced, and then a strategy for H∞ state feedback control with delay values for plant with multi-time-delay is obtained. By solving corresponding LMI, a delay-dependent state feedback controller satisfying H∞ performance indices is designed. Finally, a simulation example demonstrates the validity of the proposed approach.
The Optimal Regulation of Product Quality under Monopoly
Hans Zenger
2006-01-01
This paper characterizes the optimal quality regulation of a monopolist when quality is observable. In contrast to Sheshinski (1976) it is shown that a minimum quality standard may be desirable even if it induces the firm to reduce output.
On optimal output regulation for linear systems
Saberi, Ali; Stoorvogel, Anton A.; Sannuti, Peddapullaiah; Shi, Guoyong
2003-01-01
The classical output regulation problem formulation for linear systems has a number of shortcomings; among them a primary one is that it does not take into account the transient response. Although this problem has been studied since the 1970s, a complete picture has not emerged yet. We formulate and
Arousal state feedback as a potential physiological generator of the ultradian REM/NREM sleep cycle.
Phillips, A J K; Robinson, P A; Klerman, E B
2013-02-21
Human sleep episodes are characterized by an approximately 90-min ultradian oscillation between rapid eye movement (REM) and non-REM (NREM) sleep stages. The source of this oscillation is not known. Pacemaker mechanisms for this rhythm have been proposed, such as a reciprocal interaction network, but these fail to account for documented homeostatic regulation of both sleep stages. Here, two candidate mechanisms are investigated using a simple model that has stable states corresponding to Wake, REM sleep, and NREM sleep. Unlike other models of the ultradian rhythm, this model of sleep dynamics does not include an ultradian pacemaker, nor does it invoke a hypothetical homeostatic process that exists purely to drive ultradian rhythms. Instead, only two inputs are included: the homeostatic drive for Sleep and the circadian drive for Wake. These two inputs have been the basis for the most influential Sleep/Wake models, but have not previously been identified as possible ultradian rhythm generators. Using the model, realistic ultradian rhythms are generated by arousal state feedback to either the homeostatic or circadian drive. For the proposed 'homeostatic mechanism', homeostatic pressure increases in Wake and REM sleep, and decreases in NREM sleep. For the proposed 'circadian mechanism', the circadian drive is up-regulated in Wake and REM sleep, and is down-regulated in NREM sleep. The two mechanisms are complementary in the features they capture. The homeostatic mechanism reproduces experimentally observed rebounds in NREM sleep duration and intensity following total sleep deprivation, and rebounds in both NREM sleep intensity and REM sleep duration following selective REM sleep deprivation. The circadian mechanism does not reproduce sleep state rebounds, but more accurately reproduces the temporal patterns observed in a normal night of sleep. These findings have important implications in terms of sleep physiology and they provide a parsimonious explanation for the
Quadratic Optimal Regulator Design of a Pneumatic Control Valve
Directory of Open Access Journals (Sweden)
Mohammad Heidari
2013-01-01
Full Text Available Pneumatic control valves are still the most used devices in the process industries, due to their low cost and simplicity. This paper presents a regulator for pneumatic control valves using pole-placement method, optimal control, full-order state observer, and minimum-order state observer and their responses will be compared with each other. Bondgraph method has been used to model the control valve. Simulation results have been made for four models of regulator. The results show that minimum overshoot and settling time are achieved using optimal regulator of pneumatic valve.
Stabilizing State-Feedback Design via the Moving Horizon Method.
1982-01-01
aide if necessary and identify by block number) Stabilizing control design; linear time varying systems; fixed depth horizon; index optimization methods...dual system. 20. ABSTRACT (Continue an reverse side If necessary and Identify by block number) Li _ A stabilizing control design for general linear...Apprvyed for pb~ ~~* 14 ~dl Stri but ion uni imit Oe, ABSTRACT A stabilizing control design for general linear time vary- invariant systems through
Linear-Quadratic-Gaussian Regulator Developed for a Magnetic Bearing
Choi, Benjamin B.
2002-01-01
Linear-Quadratic-Gaussian (LQG) control is a modern state-space technique for designing optimal dynamic regulators. It enables us to trade off regulation performance and control effort, and to take into account process and measurement noise. The Structural Mechanics and Dynamics Branch at the NASA Glenn Research Center has developed an LQG control for a fault-tolerant magnetic bearing suspension rig to optimize system performance and to reduce the sensor and processing noise. The LQG regulator consists of an optimal state-feedback gain and a Kalman state estimator. The first design step is to seek a state-feedback law that minimizes the cost function of regulation performance, which is measured by a quadratic performance criterion with user-specified weighting matrices, and to define the tradeoff between regulation performance and control effort. The next design step is to derive a state estimator using a Kalman filter because the optimal state feedback cannot be implemented without full state measurement. Since the Kalman filter is an optimal estimator when dealing with Gaussian white noise, it minimizes the asymptotic covariance of the estimation error.
H{sup {infinity}} State Feedback Control for Generalized Continuous/Discrete Time Delay System
Energy Technology Data Exchange (ETDEWEB)
Kim, J.H.; Lee, S.K.; Park, H.B. [Kyungpook National University, Taegu (Korea, Republic of); Jeung, E.T. [Changwon National University, Changwon (Korea, Republic of)
1998-04-01
In this paper, we consider the problem of designing H{sup {infinity}} state feedback controller for the generalized time delay systems with delayed states and control inputs in continuous and discrete time cases, respectively. The generalized time delay system problems are solved on the basis of LMI(linear matrix inequality) technique considering time delays. The sufficient condition for the existence of controller and H{sup {infinity}} state feedback controller design methods are presented. Also, using some changes of variables and Schur complements, the obtained sufficient condition can be rewritten as a LMI form in terms of transformed variables. The proposed controller design method can be extended into the problem of robust H{sup {infinity}} state feedback controller design method easily. (author). 15 refs.
Stabilization of nonlinear sandwich systems via state feedback-Discrete-time systems
Wang, Xu; Stoorvogel, Anton A.; Saberi, Ali; Grip, H°avard Fjær; Sannuti, Peddapullaiah
2011-01-01
A recent paper (IEEE Trans. Aut. Contr. 2010; 55(9):2156–2160) considered stabilization of a class of continuous-time nonlinear sandwich systems via state feedback. This paper is a discrete-time counterpart of it. The class of nonlinear sandwich systems consists of saturation elements sandwiched bet
A new algorithm for pole assignment of single-input linear systems using state feedback
Institute of Scientific and Technical Information of China (English)
QIAN Jiang; CHENG Mingsong; XU Shufang
2005-01-01
In this paper we present a new algorithm for the single-input pole assignment problem using state feedback. This algorithm is based on the Schur decomposition of the closed-loop system matrix, and the numerically stable unitary transformations are used whenever possible, and hence it is numerically reliable.The good numerical behavior of this algorithm is also illustrated by numerical examples.
Stabilization of three-dimensional chaotic systems via single state feedback controller
Energy Technology Data Exchange (ETDEWEB)
Yu Wenguang, E-mail: smilewgyu@163.co [School of Statistics and Mathematics, Shandong Economic University, Jinan 250014 (China)
2010-03-29
This Letter investigates the stabilization of three-dimensional chaotic systems, and proposes a novel simple adaptive-feedback controller for chaos control. In comparison with previous methods, the present controller which only contains single state feedback, to our knowledge, is the simplest control scheme for controlling the three-dimensional chaotic system. The results are validated using numerical simulations.
Yang, Tao; Stoorvogel, Anton A.; Saberi, Ali; Johansson, Karl H.
2013-01-01
It is known that for single-input neutrally stable planar systems, there exists a class of saturated globally stabilizing linear state feedback control laws. The goal of this paper is to characterize the dynamic behavior for such a system under arbitrary locally stabilizing linear state feedback con
Yang, Tao; Stoorvogel, Antonie Arij; Saberi, Ali; Johansson, Karl H.
2013-01-01
It is known that for single-input neutrally stable planar systems, there exists a class of saturated globally stabilizing linear state feedback control laws. The goal of this paper is to characterize the dynamic behavior for such a system under arbitrary locally stabilizing linear state feedback
Optimal Down Regulation of mRNA Translation
Zarai, Yoram; Margaliot, Michael; Tuller, Tamir
2017-01-01
Down regulation of mRNA translation is an important problem in various bio-medical domains ranging from developing effective medicines for tumors and for viral diseases to developing attenuated virus strains that can be used for vaccination. Here, we study the problem of down regulation of mRNA translation using a mathematical model called the ribosome flow model (RFM). In the RFM, the mRNA molecule is modeled as a chain of n sites. The flow of ribosomes between consecutive sites is regulated by n + 1 transition rates. Given a set of feasible transition rates, that models the outcome of all possible mutations, we consider the problem of maximally down regulating protein production by altering the rates within this set of feasible rates. Under certain conditions on the feasible set, we show that an optimal solution can be determined efficiently. We also rigorously analyze two special cases of the down regulation optimization problem. Our results suggest that one must focus on the position along the mRNA molecule where the transition rate has the strongest effect on the protein production rate. However, this rate is not necessarily the slowest transition rate along the mRNA molecule. We discuss some of the biological implications of these results.
Optimal Down Regulation of mRNA Translation
Zarai, Yoram; Margaliot, Michael; Tuller, Tamir
2017-01-01
Down regulation of mRNA translation is an important problem in various bio-medical domains ranging from developing effective medicines for tumors and for viral diseases to developing attenuated virus strains that can be used for vaccination. Here, we study the problem of down regulation of mRNA translation using a mathematical model called the ribosome flow model (RFM). In the RFM, the mRNA molecule is modeled as a chain of n sites. The flow of ribosomes between consecutive sites is regulated by n + 1 transition rates. Given a set of feasible transition rates, that models the outcome of all possible mutations, we consider the problem of maximally down regulating protein production by altering the rates within this set of feasible rates. Under certain conditions on the feasible set, we show that an optimal solution can be determined efficiently. We also rigorously analyze two special cases of the down regulation optimization problem. Our results suggest that one must focus on the position along the mRNA molecule where the transition rate has the strongest effect on the protein production rate. However, this rate is not necessarily the slowest transition rate along the mRNA molecule. We discuss some of the biological implications of these results. PMID:28120903
Analysis of stability of a Power System by using Delay Static State Feedback
Directory of Open Access Journals (Sweden)
Sindy Paola Amaya
2012-12-01
Full Text Available This article presents the analysis of stability of a power system modeled as Infinite Bus Connected Generator with delay static state feedback. The model of the power system is described by nonlinear differential- algebraic equations. For controller design, we linealize the nonlinear differential-algebraic model around an operation point to obtain a lineal differential-algebraic model. As of this model obtains the Kronecker -Weierstrass model which designs the controller. To obtain the K gain of the controller outline inequalities matrix lineal (LMI's . Then it makes a study of the maximum delay that it supports in the state feedback. At the end of the article present the results and the conclusions.
Yu, Jue; Zhuang, Jian; Yu, Dehong
2015-01-01
This paper concerns a state feedback integral control using a Lyapunov function approach for a rotary direct drive servo valve (RDDV) while considering parameter uncertainties. Modeling of this RDDV servovalve reveals that its mechanical performance is deeply influenced by friction torques and flow torques; however, these torques are uncertain and mutable due to the nature of fluid flow. To eliminate load resistance and to achieve satisfactory position responses, this paper develops a state feedback control that integrates an integral action and a Lyapunov function. The integral action is introduced to address the nonzero steady-state error; in particular, the Lyapunov function is employed to improve control robustness by adjusting the varying parameters within their value ranges. This new controller also has the advantages of simple structure and ease of implementation. Simulation and experimental results demonstrate that the proposed controller can achieve higher control accuracy and stronger robustness. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.
Optimal Control of Active Recoil Mechanisms
1977-02-01
pressures in different chambers, rod pull are available and can be plotted. A linear state feedback control system is proposed to adapt this...desirable. A linear state feedback control system with variable gains is proposed in the report. A separate control law is designed for each...optimization algorithm to choose a feasible solution. 27 3.3 Results for M-37 Recoil Mechanism The linear state feedback control system and
State-Feedback Control for Fractional-Order Nonlinear Systems Subject to Input Saturation
Directory of Open Access Journals (Sweden)
Junhai Luo
2014-01-01
Full Text Available We give a state-feedback control method for fractional-order nonlinear systems subject to input saturation. First, a sufficient condition is derived for the asymptotical stability of a class of fractional-order nonlinear systems. Then based on Gronwall-Bellman lemma and a sector bounded condition of the saturation function, a linear state-feed back controller is designed. Finally, two simulation examples are presented to show the validity of the proposed method.
Delay-dependent state feedback robust stabilization for uncertain singular time-delay systems
Institute of Scientific and Technical Information of China (English)
Gao Huanli; Xu Bugong
2008-01-01
The problem of robust stabilization for uncertain singular time-delay systems is studied.First,a new delay-dependent asymptotic stability criteria for normal singular time-delay systems is given,which is less conservative.Using this result,the problem of state feedback robust stabilization for uncertain singular time-delay systems is discussed.Finally,two examples are given to illustrate the effectiveness of the results.
Model-Based State Feedback Controller Design for a Turbocharged Diesel Engine with an EGR System
Directory of Open Access Journals (Sweden)
Tianpu Dong
2015-05-01
Full Text Available This paper describes a method for the control of transient exhaust gas recirculation (EGR systems. Firstly, a state space model of the air system is developed by simplifying a mean value model. The state space model is linearized by using linearization theory and validated by the GT-Power data with an operating point of the diesel engine. Secondly, a state feedback controller based on the intake oxygen mass fraction is designed for EGR control. Since direct measurement of the intake oxygen mass fraction is unavailable on the engine, the estimation method for intake oxygen mass fraction has been proposed in this paper. The control strategy is analyzed by using co-simulation with the Matlab/Simulink and GT-Powers software. Finally, the whole control system is experimentally validated against experimental data of a turbocharged diesel engine. The control effect of the state feedback controller compared with PID controller proved to be further verify the feasibility and advantages of the proposed state feedback controller.
ROBUST STABILIZATION AND OPTIMIZATION OF FLIGHT CONTROL SYSTEM WITH STATE FEEDBACK AND FUZZY LOGICS
Directory of Open Access Journals (Sweden)
Marta M. Komnatska
2009-04-01
Full Text Available This paper deals with combination of two powerful and modern control tools as linear matrix inequality that is used for synthesis a ‘crisp’ controller and a fuzzy control approach for designing a soft controller. The control design consists of two stages. The first stage investigates the problem of a robust an controller design with parameters uncertainties of the handled plant in the presence of external disturbances. Stability conditions are obtained via a quadratic Lyapunov function and represented in the form of linear matrix inequalities. The second stage consists of the outer loop controller construction based on fuzzy inference system that utilizes for altitude hold mode. The parameters of the fuzzy controller are adjusted with a gradient descent method in order to improve the performance of the overall system. The case study illustrates the efficiency of the proposed approach to the flight control of small Unmanned Aerial Vehicle
An optimal velocity for online limb-target regulation processes?
Tremblay, Luc; Crainic, Valentin A; de Grosbois, John; Bhattacharjee, Arindam; Kennedy, Andrew; Hansen, Steve; Welsh, Timothy N
2017-01-01
The utilization of visual information for the control of ongoing voluntary limb movements has been investigated for more than a century. Recently, online sensorimotor processes for the control of upper-limb reaches were hypothesized to include a distinct process related to the comparison of limb and target positions (i.e., limb-target regulation processes: Elliott et al. in Psychol Bull 136:1023-1044. doi: 10.1037/a0020958 , 2010). In the current study, this hypothesis was tested by presenting participants with brief windows of vision (20 ms) when the real-time velocity of the reaching limb rose above selected velocity criteria. One experiment tested the perceptual judgments of endpoint bias (i.e., under- vs. over-shoot), and another experiment tested the shifts in endpoint distributions following an imperceptible target jump. Both experiments revealed that limb-target regulation processes take place at an optimal velocity or "sweet spot" between movement onset and peak limb velocity (i.e., 1.0 m/s with the employed movement amplitude and duration). In contrast with pseudo-continuous models of online control (e.g., Elliott et al. in Hum Mov Sci 10:393-418. doi: 10.1016/0167-9457(91)90013-N , 1991), humans likely optimize online limb-target regulation processes by gathering visual information at a rather limited period of time, well in advance of peak limb velocity.
Optimal Distributed Voltage Regulation in Power Distribution Networks
Lam, Albert Y S; Dominguez-Garcia, Alejandro; Tse, David
2012-01-01
In this paper, we address the problem of voltage regulation in power distribution networks with deep-penetration of distributed energy resources (DERs), e.g., renewable-based generation, and storage-capable loads such as plug-in hybrid electric vehicles. We cast the problem as an optimization program, where the objective is to minimize the losses in the network subject to constraints on bus voltage magnitudes, limits on active and reactive power injections, transmission line thermal limits and losses. We provide sufficient conditions under which the optimization problem can be solved via its convex relaxation. Using data from existing networks, we show that the conditions are expected to be satisfied by most networks. We also provide an efficient distributed algorithm to solve the problem. The algorithm is asynchronous, with a communication topology that is the same as the electrical network topology. We illustrate the algorithm's performance in the IEEE 34-bus and the 123-bus feeder test systems.
State feedback control of surge oscillations of two-point mooring system
Mitra, R. K.; Banik, A. K.; Chatterjee, S.
2017-01-01
Stability analysis of surge oscillations of two-point mooring system under state feedback control with time-delay is investigated. The two-point mooring system is harmonically excited and essentially represents a strongly nonlinear Duffing oscillator. In this paper, a frequency domain based method viz. incremental harmonic balance method along with arc-length continuation technique (IHBC) is first employed to identify the primary and higher order subharmonic responses which may be present in such system. The IHBC is then reformulated in a manner to treat two-point mooring system under state feedback control with time-delay and is applied to obtain control of responses in an efficient and systematic way. The stability of uncontrolled responses for primary and higher order subharmonic oscillations is obtained by Floquet's theory using Hsu' scheme; whereas the stability of controlled responses is obtained by applying semi-discretization method for delay differential equation. The study focussed on the controlling primary, higher order subharmonics and chaotic responses by considering appropriate feedback gains and delay by way of (i) appreciable reduction of primary, subharmonic responses, (ii) exclusion of all higher order subharmonics 2T, 3T, 5T and 9T (1/n subharmonics or period-n solutions), and (iii) reduction of the extent of domain of all instability phenomena represented by various type of bifurcation of solutions, jump phenomena, chaotic responses etc. In the study, negative velocity feedback is observed to be much effective than state feedback for better controlling of surge oscillation of two-point mooring system. Also, the effect of larger gain values is investigated by an extensive parametric study for vibration control with different delay values.
Chaotifying a stable linear controllable system by single input state feedback
Institute of Scientific and Technical Information of China (English)
Wu Zheng-Mao; Lu Jun-Guo; Xie Jian-Ying
2007-01-01
In this paper, an approach for chaotifying a stable controllable linear system via single input state-feedback is presented. The overflow function of the system states is designed as the feedback controller, which can make the fixed point of the closed-loop system to be a snap-back repeller, thereby yields chaotic dynamics. Based on the Marotto theorem, it proves theoretically that the closed-loop system is chaotic in the sense of Li and Yorke. Finally, the simulation results are used to illustrate the effectiveness of the proposed method.
Institute of Scientific and Technical Information of China (English)
陈宁; 桂卫华; 谢永芳
2004-01-01
Decentralized H∞ control was studied for a class of interconnected uncertain systems with multiple delays in the state and control and time varying but norm-bounded parametric uncertainties. A sufficient condition which makes the closed--loop system decentralized asymptotically stable with H∞ performance was derived based on Lyapunov stability theorem. This condition is expressed as the solvability problem of linear matrix inequalities. The method overcomes the limitations of the existing algebraic Riccati equation method. Finally, a numerical example was given to demonstrate the design procedure for the decentralized H∞ state feedback controller.
Stabilizability of linear quadratic state feedback for uncertain fuzzy time-delay systems.
Wang, Rong-Jyue; Lin, Wei-Wei; Wang, Wen-June
2004-04-01
This paper investigates the problem of designing a fuzzy state feedback controller to stabilize an uncertain fuzzy system with time-varying delay. Based on Lyapunov criterion and Razumikhin theorem, some sufficient conditions are derived under which the parallel-distributed fuzzy control can stabilize the whole uncertain fuzzy time-delay system asymptotically. By Schur complement, these sufficient conditions can be easily transformed into the problem of LMIs. Furthermore, the tolerable bound of the perturbation is also obtained. A practical example based on the continuous stirred tank reactor (CSTR) model is given to illustrate the control design and its effectiveness.
Zhang, Dongkai; Wang, Chaoli; Wei, Guoliang; Zhang, Hengjun; Chen, Hua
2014-07-01
The stabilising problem of stochastic non-holonomic mobile robots with uncertain parameters based on visual servoing is addressed in this paper. The model of non-holonomic mobile robots based on visual servoing is extended to the stochastic case, where their forward velocity and angular velocity are both subject to some stochastic disturbances. Based on backstepping technique, state-feedback stabilising controllers are designed for stochastic non-holonomic mobile robots. A switching control strategy for the original system is presented. The proposed controllers guarantee that the closed-loop system is asymptotically stabilised at the zero equilibrium point in probability.
Partial state feedback control of chaotic neural network and its application
Energy Technology Data Exchange (ETDEWEB)
He Guoguang [Aihara Complexity Modelling Project, ERATO, JST, Tokyo 153-8505 (Japan); Department of Physics, College of Science, Zhejiang University, Hangzhou 310027 (China); Institute of Industrial Science, University of Tokyo, Tokyo 153-8505 (Japan)], E-mail: gghe@aihara.jst.go.jp; Shrimali, Manish Dev; Aihara, Kazuyuki [Aihara Complexity Modelling Project, ERATO, JST, Tokyo 153-8505 (Japan); Institute of Industrial Science, University of Tokyo, Tokyo 153-8505 (Japan)
2007-11-12
The chaos control in the chaotic neural network is studied using the partial state feedback with a control signal from a few control neurons. The controlled CNN converges to one of the stored patterns with a period which depends on the initial conditions, i.e., the set of control neurons and other control parameters. We show that the controlled CNN can distinguish between two initial patterns even if they have a small difference. This implies that such a controlled CNN can be feasibly applied to information processing such as pattern recognition.
Orun, Bilal; Basdogan, Cagatay; Guvenc, Levent
2012-01-01
We adjust the transient dynamics of a piezo-actuated bimorph Atomic Force Microscopy (AFM) probe using a state feedback controller. This approach enables us to adjust the quality factor and the resonance frequency of the probe simultaneously. First, we first investigate the effect of feedback gains on dynamic response of the probe and then show that the time constant of the probe can be reduced by reducing its quality factor and/or increasing its resonance frequency to reduce the scan error in tapping mode AFM.
Nonlinear robust control of proton exchange membrane fuel cell by state feedback exact linearization
Energy Technology Data Exchange (ETDEWEB)
Li, Q.; Chen, W. [School of Electrical Engineering, Southwest Jiaotong University, Chengdu 610031, Sichuan Province (China); Wang, Y.; Jia, J. [School of Electrical and Electronic Engineering, Nanyang Technological University, Nanyang Avenue 639798, Singapore (Singapore); Han, M. [School of Engineering, Temasek Polytechnic, Tampines 529757, Singapore (Singapore)
2009-10-20
By utilizing the state feedback exact linearization approach, a nonlinear robust control strategy is designed based on a multiple-input multiple-output (MIMO) dynamic nonlinear model of proton exchange membrane fuel cell (PEMFC). The state feedback exact linearization approach can achieve the global exact linearization via the nonlinear coordinate transformation and the dynamic extension algorithm such that H{sub {infinity}} robust control strategy can be directly utilized to guarantee the robustness of the system. The proposed dynamic nonlinear model is tested by comparing the simulation results with the experimental data in Fuel Cell Application Centre in Temasek Polytechnic. The comprehensive results of simulation manifest that the dynamic nonlinear model with nonlinear robust control law has better transient and robust stability when the vehicle running process is simulated. The proposed nonlinear robust controller will be very useful to protect the membrane damage by keeping the pressure deviations as small as possible during large disturbances and prolong the stack life of PEMFC. (author)
A switched state feedback law for the stabilization of LTI systems.
Energy Technology Data Exchange (ETDEWEB)
Santarelli, Keith R.
2009-09-01
Inspired by prior work in the design of switched feedback controllers for second order systems, we develop a switched state feedback control law for the stabilization of LTI systems of arbitrary dimension. The control law operates by switching between two static gain vectors in such a way that the state trajectory is driven onto a stable n - 1 dimensional hyperplane (where n represents the system dimension). We begin by briefly examining relevant geometric properties of the phase portraits in the case of two-dimensional systems to develop intuition, and we then show how these geometric properties can be expressed as algebraic constraints on the switched vector fields that are applicable to LTI systems of arbitrary dimension. We then derive necessary and sufficient conditions to ensure stabilizability of the resulting switched system (characterized primarily by simple conditions on eigenvalues), and describe an explicit procedure for designing stabilizing controllers. We then show how the newly developed control law can be applied to the problem of minimizing the maximal Lyapunov exponent of the corresponding closed-loop state trajectories, and we illustrate the closed-loop transient performance of these switched state feedback controllers via multiple examples.
Mahmoodabadi, M J; Taherkhorsandi, M; Bagheri, A
2014-01-01
An optimal robust state feedback tracking controller is introduced to control a biped robot. In the literature, the parameters of the controller are usually determined by a tedious trial and error process. To eliminate this process and design the parameters of the proposed controller, the multiobjective evolutionary algorithms, that is, the proposed method, modified NSGAII, Sigma method, and MATLAB's Toolbox MOGA, are employed in this study. Among the used evolutionary optimization algorithms to design the controller for biped robots, the proposed method operates better in the aspect of designing the controller since it provides ample opportunities for designers to choose the most appropriate point based upon the design criteria. Three points are chosen from the nondominated solutions of the obtained Pareto front based on two conflicting objective functions, that is, the normalized summation of angle errors and normalized summation of control effort. Obtained results elucidate the efficiency of the proposed controller in order to control a biped robot.
Rudra, Shubhobrata; Maitra, Madhubanti
2017-01-01
This book presents a novel, generalized approach to the design of nonlinear state feedback control laws for a large class of underactuated mechanical systems based on application of the block backstepping method. The control law proposed here is robust against the effects of model uncertainty in dynamic and steady-state performance and addresses the issue of asymptotic stabilization for the class of underactuated mechanical systems. An underactuated system is defined as one for which the dimension of space spanned by the configuration vector is greater than that of the space spanned by the control variables. Control problems concerning underactuated systems currently represent an active field of research due to their broad range of applications in robotics, aerospace, and marine contexts. The book derives a generalized theory of block backstepping control design for underactuated mechanical systems, and examines several case studies that cover interesting examples of underactuated mechanical systems. The math...
Stabilization of generalized fractional order chaotic systems using state feedback control
Energy Technology Data Exchange (ETDEWEB)
Ahmad, Wajdi M. E-mail: wajdi@sharjah.ac.ae; El-Khazali, Reyad E-mail: khazali@ece.ac.ae; Al-Assaf, Yousef E-mail: yassaf@aus.ac.ae
2004-10-01
In this paper, we address the problem of chaos control of three types of fractional order systems using simple state feedback gains. Electronic chaotic oscillators, mechanical 'jerk' systems, and the Chen system are investigated when they assume generalized fractional orders. We design the static gains to place the eigenvalues of the system Jacobian matrices in a stable region whose boundaries are determined by the orders of the fractional derivatives. We numerically demonstrate the effectiveness of the controller in eliminating the chaotic behavior from the state trajectories, and driving the states to the nearest equilibrium point in the basin of attraction. For the recently introduced Chen system, in particular, we demonstrate that with a proper choice of model parameters, chaotic behavior is preserved when the system order becomes fractional. Both state and output feedback controllers are then designed to stabilize a generalized fractional order Chen system.
Mixed H2/H∞ State Feedback Attitude Control of Microsatellite Based on Extended LMI Method
Institute of Scientific and Technical Information of China (English)
Keke Shi; Chuang Liu; Feng Wang∗; Zhaowei Sun
2016-01-01
For the appearance of the additive perturbation of controller gain when the controller parameter has minute adjustment at the initial running stage of system, to avoid the adverse effects, this paper investigates the mixed H2/H∞ state feedback attitude control problem of microsatellite based on extended LMI method. Firstly, the microsatellite attitude control system is established and transformed into corresponding state space form. Then, without the equivalence restriction of the two Lyapunov variables of H2 and H∞ performance, this paper introduces additional variables to design the mixed H2/H∞ control method based on LMI which can also reduce the conservatives. Finally, numerical simulations are analyzed to show that the proposed method can make the satellite stable within 20 s whether there is additive perturbation of the controller gain or not. The comparative analysis of the simulation results between extended LMI method and traditional LMI method also demonstrates the effectiveness and feasibility of the proposed method in this paper.
Fundamental and Subharmonic Resonances of Harmonically Oscillation with Time Delay State Feedback
Directory of Open Access Journals (Sweden)
A.F. EL-Bassiouny
2006-01-01
Full Text Available Time delays occur in many physical systems. In particular, when automatic control is used with structural or mechanical systems, there exists a delay between measurement of the system state and corrective action. The concept of an equivalent damping related to the delay feedback is proposed and the appropriate choice of the feedback gains and the time delay is discussed from the viewpoint of vibration control. We investigate the fundamental resonance and subharmonic resonance of order one-half of a harmonically oscillation under state feedback control with a time delay. By using the multiple scale perturbation technique, the first order approximation of the resonances are derived and the effect of time delay on the resonances is investigated. The fixed points correspond to a periodic motion for the starting system and we show the external excitation-response and frequency-response curves. We analyze the effect of time delay and the other different parameters on these oscillations.
State Feedback Consensus for Multi-Agent System with Multiple Time-Delays
Directory of Open Access Journals (Sweden)
Jia Wei
2013-09-01
Full Text Available In this paper, we study the multi-agent system to achieve a faster consensus with multiple time-delays under a directed asymmetric information exchange topology. We first assume that an agent processes its own state information with self-delay and receives state information from its neighbors with communication delays. Based on state proportion derivative feedback, the improved consensus protocol can accelerate the system to achieve a consensus. A sufficient condition for reaching consensus is then derived based on the Nyquist stability criterion and frequency domain analysis. In addition, a specific form of consensus equilibrium is obtained which is influenced by the initial states of agents, time-delays and state feedback intensity. Finally, simulations are presented to verify the validity of the theoretical results.
Park, Seong-Jin; Cho, Kwang-Hyun
2011-12-01
This article addresses a modular state feedback supervisory control problem where two local controllers should achieve a common control objective against another local controller. Each local controller has its own control objective described as a predicate. This article also addresses a nonblocking modular control problem in which a discrete event system controlled by three local controllers tends to reach the common marked states of two local controllers that are, however, prohibited by the third local controller. For a case study, we apply the proposed theory to an oligopolistic market composed of two firms and one government. Two oligopolistic firms have a common objective to maximise their total profit through collusion. However, the government prevents them from engaging in collusion. We show that the modular supervisory control theory presented in this article can be used to solve the problem of 'how can the firms maximise their total profit against the intervention of government'?
Chinese Speech Recognition Model Based on Activation of the State Feedback Neural Network
Institute of Scientific and Technical Information of China (English)
李先志; 孙义和
2001-01-01
This paper proposes a simplified novel speech recognition model, the state feedback neuralnetwork activation model (SFNNAM), which is developed based on the characteristics of Chinese speechstructure. The model assumes that the current state of speech is only a correction of the last previous state.According to the "C-V"(Consonant-Vowel) structure of the Chinese language, a speech segmentation methodis also implemented in the SFNNAM model. This model has a definite physical meaning grounded on thestructure of the Chinese language and is easily implemented in very large scale integrated circuit (VLSI). In thespeech recognition experiment, less calculations were need than in the hidden Markov models (HMM) basedalgorithm. The recognition rate for Chinese numbers was 93.5% for the first candidate and 99.5% for the firsttwo candidates.``
Gettman, Chang-Ching L.; Adams, Neil; Bedrossian, Nazareth; Valavani, Lena
1993-01-01
This paper demonstrates an approach to nonlinear control system design that uses linearization by state feedback to allow faster maneuvering of payloads by the Shuttle Remote Manipulator System (SRMS). A nonlinear feedback law is defined to cancel the nonlinear plant dynamics so that a linear controller can be designed for the SRMS. First a nonlinear design model was generated via SIMULINK. This design model included nonlinear arm dynamics derived from the Lagrangian approach, linearized servo model, and linearized gearbox model. The current SRMS position hold controller was implemented on this system. Next, a trajectory was defined using a rigid body kinematics SRMS tool, KRMS. The maneuver was simulated. Finally, higher bandwidth controllers were developed. Results of the new controllers were compared with the existing SRMS automatic control modes for the Space Station Freedom Mission Build 4 Payload extended on the SRMS.
Energy Technology Data Exchange (ETDEWEB)
Boukhezzar, B
2006-02-15
The research work is dealing with variable speed wind turbines modelling and control design, in order to achieve the objectives of maximizing the extracted energy from the wind, below the rated power area in the one hand and in the other hand regulating the electric power production, above the rated power area, while reducing mechanical transient loads. For this purpose, we have studied various control strategies from linear to nonlinear based. some of the controllers that we have developed, herein appear for the first time in the relevant domain, the remaining others are an adaptation of well know controllers to the adopted wind turbine models. as matter of fact, we have derived two wind turbine models as well as a wind speed estimator. Indeed, the estimator allows obtaining the effective wind speed which cannot be measured, since the wind profile around the rotor is variable in time and space. As results, it has been shown that single input control by means of pitch angle or generator control cannot succeed to simultaneously drive the electric power output regulation and the rotor speed reference tracking. So then, our idea is to combine nonlinear dynamic state feedback torque control and pitch linear based control which turns out to be the best strategy. In addition, the validation of the controllers performance, using a high turbulence wind speed profile, has been performed through wind turbine simulators provided by nrel (national renewable energy laboratory, golden, co), has confirmed the theoretical results and has led to quite satisfactory conclusions in terms of energy capture optimization, power regulation and disturbances strong rejection as well. (author)
An optimized, chemically regulated gene expression system for Chlamydomonas.
Directory of Open Access Journals (Sweden)
Paola Ferrante
Full Text Available BACKGROUND: Chlamydomonas reinhardtii is a model system for algal and cell biology and is used for biotechnological applications, such as molecular farming or biological hydrogen production. The Chlamydomonas metal-responsive CYC6 promoter is repressed by copper and induced by nickel ions. However, induction by nickel is weak in some strains, poorly reversible by chelating agents like EDTA, and causes, at high concentrations, toxicity side effects on Chlamydomonas growth. Removal of these bottlenecks will encourage the wide use of this promoter as a chemically regulated gene expression system. METHODOLOGY: Using a codon-optimized Renilla luciferase as a reporter gene, we explored several strategies to improve the strength and reversibility of CYC6 promoter induction. Use of the first intron of the RBCS2 gene or of a modified TAP medium increases the strength of CYC6 induction up to 20-fold. In the modified medium, induction is also obtained after addition of specific copper chelators, like TETA. At low concentrations (up to 10 microM TETA is a more efficient inducer than Ni, which becomes a very efficient inducer at higher concentrations (50 microM. Neither TETA nor Ni show toxicity effects at the concentrations used. Unlike induction by Ni, induction by TETA is completely reversible by micromolar copper concentrations, thus resulting in a transient "wave" in luciferase activity, which can be repeated in subsequent growth cycles. CONCLUSIONS: We have worked out a chemically regulated gene expression system that can be finely tuned to produce temporally controlled "waves" in gene expression. The use of cassettes containing the CYC6 promoter, and of modified growth media, is a reliable and economically sustainable system for the temporally controlled expression of foreign genes in Chlamydomonas.
Control of Forward converter by state feedback linearization%Forward变换器的精确线性化控制
Institute of Scientific and Technical Information of China (English)
李昂
2013-01-01
In order to improve the control performance of the Forward converter, exact linearization design approach is proposed to apply to converter control. Firstly, the affine nonlinear system models for differential geometry methods are established with the switching function and average switch period operator. Then, the models are proved in theory to meet conditions for exact linearization. For the linear system of nonlinear coordinate transformation, quadratic optimal control strategy is used. The nonlinear state feedback control laws are deduced. The corresponding experiment results show that the system has good static and dynamic performance, and the effectiveness and correctness of the control method are verified.%为了提高Forward变换器非线性系统的控制性能,采用了精确线性化控制方法.首先采用开关函数和开关周期平均算子建立适合微分几何方法的仿射非线性系统模型.从理论上证明了该模型满足系统精确线性化的条件.对非线性坐标变换后得到的线性系统,利用二次型最优控制策略推导出非线性状态反馈控制律.实验结果表明,系统具有良好的静态和动态性能,验证了该控制方法的有效性和正确性.
Robust State Feedback H∞Control for Dynamic Biped Robot Based on T-S Fuzzy Model
Institute of Scientific and Technical Information of China (English)
HUAI Chuangfeng; FANG Yuefa
2006-01-01
T-S fuzzy model was applied to describe nonlinear system and global fuzzy model was expressed by the form of uncertain system. Based on robust state feedback H∞control strategy, designed a global asymptotic steady fuzzy model. This control system can use the experimental input-output data pairs for the biped robot learning and walking with dynamic balance. It is proved by simulation result that robust state feedback H∞ control method based on T-S fuzzy model can effectively restrain the effect of model uncertainties and external disturbance acting on biped robot. From these works, we showed the satisfactory performance of joint tracking without any chattering.
Gao, Fangzheng; Wu, Yuqiang
2015-03-01
This paper considers the problem of global stabilization by state feedback for a class of high-order nonlinear systems with time-varying delays. Comparing with the existing relevant literature, the systems under investigation allow more uncertainties, to which the existing control methods are inapplicable. By introducing sign function and necessarily modifying the method of adding a power integrator, a state feedback controller is successfully constructed to preserve the equilibrium at the origin and guarantee the global asymptotic stability of the resulting closed-loop system. Finally, two simulation examples are provided to illustrate the effectiveness of the proposed approach.
A SURVEY: PID OPTIMIZATION FOR AUTOMATIC VOLTAGE REGULATOR
Ajay Dixit*, Miss.Pragati Joshi, Mr.Mahesh Lokhande
2016-01-01
This paper presents on survey paper of PSO and automatic voltage regulator for synchronous generator. It is used to obtain for regulation and stability of any electrical equipment. There are many technology/methods were used in automatic voltage regulator as well as different controller used for improving robustness, overshoot, rise time and voltage control but problem is about to survey on Automatic Voltage Regulator. Comparisons studies which are based on PID Controller are performed to sh...
Global view of Hopf bifurcations of a van der Pol oscillator with delayed state feedback
Institute of Scientific and Technical Information of China (English)
无
2010-01-01
This paper presents both analytical and numerical studies on the global view of Hopf bifurcations of a van der Pol oscillator with delayed state feedback.Based on a detailed analysis of the stability switches of the trivial equilibrium of the system,the stability charts are given in a parameter space consisting of the time delay and the feedback gains.The center manifold reduc-tion and the normal form method are used to study Hopf bifurcations with respect to the time delay.To gain an insight into the persistence of a Hopf bifurcation as the time delay varies farther away from its critical value,the method of multiple scales is used to obtain the global view of Hopf bifurcations with respect to the time delay.Both the analytical results of Hopf bifurca-tions and global view of those bifurcations are validated via a collocation scheme implemented on DDE-Biftool.The most important discovery in this paper is the well-structured global view of Hopf bifurcations for the system of concern,showing the generality of the persistence of Hopf bifurcations.
Dominant pole and eigenstructure assignment for positive systems with state feedback
Li, Zhao; Lam, James
2016-09-01
In this paper, the dominant pole assignment problem, the dominant eigenstructure assignment problem and the robust dominant pole assignment problem for linear time-invariant positive systems with state feedback are considered. The dominant pole assignment problem is formulated as a linear programming problem, and the dominant eigenstructure problem is formulated as a quasiconvex optimisation problem with linear constraints. The robust dominant pole assignment problem is formulated as a non-convex optimisation problem with non-linear constraints which is solved using particle swarm optimisation (PSO) with an efficient scheme which employs the dominant eigenstructure assignment technique to accelerate the convergence of the PSO procedure. Each of the three problems can be further constrained by requiring that the controller has a pre-specified structure, or the gain matrix have both elementwise upper and lower bounds. These constraints can be incorporated into the proposed scheme without increasing the complexity of the algorithms. Both the continuous-time case and the discrete-time case are treated in the paper.
Optimal Regulation of Structural Systems with Uncertain Parameters.
1981-02-02
0, of the associated deterministic plant regulation problem . Then, within the above restrictions, the problem is to determine a K (such that K is real...deterministic plant regulation problem we here obtain the stronger assurance of second moment stability. This is indirectly a consequence of the use of
Hydrodynamic Optimization Method and Design Code for Stall-Regulated Hydrokinetic Turbine Rotors
Energy Technology Data Exchange (ETDEWEB)
Sale, D.; Jonkman, J.; Musial, W.
2009-08-01
This report describes the adaptation of a wind turbine performance code for use in the development of a general use design code and optimization method for stall-regulated horizontal-axis hydrokinetic turbine rotors. This rotor optimization code couples a modern genetic algorithm and blade-element momentum performance code in a user-friendly graphical user interface (GUI) that allows for rapid and intuitive design of optimal stall-regulated rotors. This optimization method calculates the optimal chord, twist, and hydrofoil distributions which maximize the hydrodynamic efficiency and ensure that the rotor produces an ideal power curve and avoids cavitation. Optimizing a rotor for maximum efficiency does not necessarily create a turbine with the lowest cost of energy, but maximizing the efficiency is an excellent criterion to use as a first pass in the design process. To test the capabilities of this optimization method, two conceptual rotors were designed which successfully met the design objectives.
Jointly optimal regulation of bank capital and maturity structure
Ansgar Walther
2014-01-01
Banks create excessive systemic risk through leverage and maturity mismatch, as financial constraints introduce welfare-reducing pecuniary externalities. Macroprudential regulators can achieve efficiency with simple linear constraints on banks' balance sheets, which require less information than Pigouvian taxes. These can be implemented using the Liquidity Coverage and Net Stable Funding ratios of Basel III. When bank failures are socially costly, microprudential regulation of leverage is als...
Institute of Scientific and Technical Information of China (English)
Zongyao SUN; Yungang LIU
2007-01-01
In this paper, a new approach is successfully addressed to design the state-feedback adaptive stabilizing control law for a class of high-order nonlinear systems in triangular form and with unknown and nonidentical control coefficients, whose stabilizing control has been investigated recently under the knowledge that the lower bounds of the control coefficients are exactly known. In the present paper,without any knowledge of the lower bounds of the control coefficients, based on the adaptive technique and appropriately choosing design parameters, we give the recursive design procedure of the stabilizing control law by utilizing the approach of adding a power integrator together with tuning functions. The state-feedback adaptive control law designed not only preserves the equilibrium at the origin, but also guarantees the global asymptotic stability of the closed-loop states and the uniform boundedness of all the other closed-loop signals.
Yang, Xinsong; Cao, Jinde; Ho, Daniel W C
2015-04-01
This paper investigates drive-response synchronization for a class of neural networks with time-varying discrete and distributed delays (mixed delays) as well as discontinuous activations. Strict mathematical proof shows the global existence of Filippov solutions to neural networks with discontinuous activation functions and the mixed delays. State feedback controller and impulsive controller are designed respectively to guarantee global exponential synchronization of the neural networks. By using Lyapunov function and new analysis techniques, several new synchronization criteria are obtained. Moreover, lower bound on the convergence rate is explicitly estimated when state feedback controller is utilized. Results of this paper are new and some existing ones are extended and improved. Finally, numerical simulations are given to verify the effectiveness of the theoretical results.
A new approach on designing l1 optimal regulator with minimum order for SISO linear systems
Institute of Scientific and Technical Information of China (English)
Xiang LIU
2006-01-01
For a SISO linear discrete-time system with a specified input signal, a novel method to realize optimal l1 regulation control is presented. Utilizing the technique of converting a polynomial equation to its corresponding matrix equation, a linear programming problem to get an optimal l1 norm of the system output error map is developed which includes the first term and the last term of the map sequence in the objective function and the right vector of its constraint matrix equation, respectively. The adjustability for the width of the constraint matrix makes the trade-off between the order of the optimal regulator and the value of the minimum objective norm become possible, especially for achieving the optimal regulator with minimum order. By norm scaling rules for the constraint matrix equation, the optimal solution can be scaled directly or be obtained by solving a linear programming problem with l1 norm objective.
Institute of Scientific and Technical Information of China (English)
段广仁; 张彪
2007-01-01
Based on a general parametric eigenstructure assignment result proposed for descriptor linear systems via proportional plus partial derivative state feedback and a result for generalized eigenvalue sensitivity problem of matrix pairs, parametric representation of the closed-loop eigenvalue sensitivities to the perturbed elements in the open-loop system matrices is obtained. An effective algorithm for eigenvalue assignment with minimum sensitivity in descriptor linear systems via proportional plus partial derivative be conveniently optimized within desired regions. An example demonstrates its effectiveness and simplicity.
Cost benefit theory and optimal design of gene regulation functions
Kalisky, Tomer; Dekel, Erez; Alon, Uri
2007-12-01
Cells respond to the environment by regulating the expression of genes according to environmental signals. The relation between the input signal level and the expression of the gene is called the gene regulation function. It is of interest to understand the shape of a gene regulation function in terms of the environment in which it has evolved and the basic constraints of biological systems. Here we address this by presenting a cost-benefit theory for gene regulation functions that takes into account temporally varying inputs in the environment and stochastic noise in the biological components. We apply this theory to the well-studied lac operon of E. coli. The present theory explains the shape of this regulation function in terms of temporal variation of the input signals, and of minimizing the deleterious effect of cell-cell variability in regulatory protein levels. We also apply the theory to understand the evolutionary tradeoffs in setting the number of regulatory proteins and for selection of feed-forward loops in genetic circuits. The present cost-benefit theory can be used to understand the shape of other gene regulatory functions in terms of environment and noise constraints.
The Optimal Linear Quadratic Feedback State Regulator Problem for Index One Descriptor Systems
Engwerda, J.C.; Salmah, Y.; Wijayanti, I.E.
2008-01-01
In this note we present both necessary and sufficient conditions for the existence of a linear static state feedback controller if the system is described by an index one descriptor system. A priori no definiteness restrictions are made w.r.t. the quadratic performance criterium. It is shown that in
Franchise Values, Regulatory Monitoring, and Capital Requirements in Optimal Bank Regulation
DEFF Research Database (Denmark)
Andersen, Thomas Barnebeck; Harr, Thomas
2008-01-01
This paper demonstrates that financial deregulation is likely to make standard prudential regulatory instruments less effective in curbing excessive risk-taking incentives among banks. This has interesting implications for optimal bank regulation. When there is an increase in competition......, the optimal capital requirement should increase, whereas regulatory auditing should decrease. In contrast, when there is an increase in gambling yields, auditing should always increase, whereas the optimal capital requirement may increase or decrease....
Optimization of Regulation Valve Location for Heating System
Institute of Scientific and Technical Information of China (English)
LIU Ling-ling; CHEN Hong-bing; LI De-ying
2009-01-01
This paper mainly studied how to determine the best location of the self-operated flow control valve at the heating system entrance.Since the location of regulating valve directly affects the pipe network per-formance,the simulation and analysis of pressure change in heating system WaS carried out with ComputationalFluid Dynamics(CFD)software.The study shows the best location of regulating valve varies with the change of the supply and return pipe length when the heating area of each user is small,and when the heating area of each user is large(2000000～3000000m2),the best location is on the supply pipe.
Systemic Model for Optimal Regulation in Public Service
Directory of Open Access Journals (Sweden)
Lucica Matei
2006-05-01
Full Text Available The current paper inscribes within those approaching the issue of public services from the interdisciplinary perspective. Public service development and imposing standards of efficiency and effectiveness, as well as for citizens’ satisfaction bring in front line the systemic modelling and establishing optimal policies for organisation and functioning of public services. The issue under discussion imposes an interface with powerful determinations of social nature. Consequently, the most adequate modelling might be that with a probabilistic and statistic nature. The fundamental idea of this paper, that obviously can be broadly developed, starts with assimilating the way of organisation and functioning of a public service with a waiting thread, to which some hypotheses are associated concerning the order of provision, performance measurement through costs or waiting time in the system etc. We emphasise the openness and dynamics of the public service system, as well as modelling by turning into account the statistic knowledge and researches, and we do not make detailed remarks on the cybernetic characteristics of this system. The optimal adjustment is achieved through analysis on the feedback and its comparison with the current standards or good practices.
Energy Technology Data Exchange (ETDEWEB)
Hope, E.
1994-06-01
The report discusses the organization and behaviour of grid monopolies in the Norwegian power trade and relations to the socio-economic effectiveness. The main attention is laid on analyzing regulation mechanisms and measures leading to an efficient short-term operation and to the investment of optimum production capacity in a long run. Regarding the management, measures are discussed for increasing the efficiency of total power trade by evaluating the existing marketing function of Statnett. Some basic conditions are accounted concerning the regulation problem of grid monopolies with a particular attention to asymmetric information between the authority and the monopoly. In addition, forms of regulation and regulation mechanisms together with the incentive characteristics of these, are discussed. The existing profit regulation principles in relation to an alternative system design such as maximum price regulation combined with standard regulation, are evaluated. 16 refs., 7 figs.
DEFF Research Database (Denmark)
Zhang, Baohua; Hu, Weihao; Chen, Zhe
2015-01-01
As modern wind farmshave the ability to provideregulation service for the power system, wind power plant operators may be motivated to participate in the regulating market to maximize their profit.In this paper, anoptimal regulation servicestrategy for a wind farm to participate in the regulating......As modern wind farmshave the ability to provideregulation service for the power system, wind power plant operators may be motivated to participate in the regulating market to maximize their profit.In this paper, anoptimal regulation servicestrategy for a wind farm to participate...... in the stochastic optimization to deal with the uncertainty of the up regulation price and the up regulation activation of the power system.The Danish short-term electricity market and a wind farm in western Denmark are chosen to evaluate the effect of the proposed strategy. Simulation results showthe proposed...
Balas, Mark J.; Thapa Magar, Kaman S.; Frost, Susan A.
2013-01-01
A theory called Adaptive Disturbance Tracking Control (ADTC) is introduced and used to track the Tip Speed Ratio (TSR) of 5 MW Horizontal Axis Wind Turbine (HAWT). Since ADTC theory requires wind speed information, a wind disturbance generator model is combined with lower order plant model to estimate the wind speed as well as partial states of the wind turbine. In this paper, we present a proof of stability and convergence of ADTC theory with lower order estimator and show that the state feedback can be adaptive.
Directory of Open Access Journals (Sweden)
Lin Chai
2013-01-01
Full Text Available Stabilization of a class of systems with time delay is studied using adaptive control. With the help of the “error to error” technique and the separated “descriptor form” technique, the memory state-feedback controller is designed. The adaptive controller designed can guarantee asymptotical stability of the closed-loop system via a suitable Lyapunov-Krasovskii functional. Some sufficient conditions are derived for the stabilization together with the linear matrix inequality (LMI design approach. Finally, the effectiveness of the proposed control design methodology is demonstrated in numerical simulations.
Institute of Scientific and Technical Information of China (English)
无
2001-01-01
This paper focuses on the H∞ controller design for linear systems with time-varying delays and norm bounded parameter perturbetions in the system state and control/disturbance. On the existence of delayed/undelayed full state feedback controllers, we present a sufficient condition and give a design method in the form of Riccati equation. The controller can not only stabilize the time-delay system, but also make the H∞ norm of the closed-loop system be less than a given bound. This result practically generalizes the related results in current literature.
Xiao, Qizhen; Dai, Binxiang
2015-10-01
In this paper, we analyze a general predator-prey model with state feedback impulsive harvesting strategies in which the prey species displays a strong Allee effect. We firstly show the existence of order-1 heteroclinic cycle and order-1 positive periodic solutions by using the geometric theory of differential equations for the unperturbed system. Based on the theory of rotated vector fields, the order-1 positive periodic solutions and heteroclinic bifurcation are studied for the perturbed system. Finally, some numerical simulations are provided to illustrate our main results. All the results indicate that the harvesting rate should be maintained at a reasonable range to keep the sustainable development of ecological systems.
Non-fragile state feedback H-infinity control for discrete-time systems with quantized signals
Institute of Scientific and Technical Information of China (English)
Weiwei CHE; Guanghong YANG
2009-01-01
This paper presents a study on the problem of non-fragile state feedback H-infinity controller design for linear discrete-time systems with quantized signals.The quantizers considered here are dynamic and time-varying.With the consideration of controller gain variations and quantized signals at the same time,a new non-fragile H-infinity control strategy is proposed with updating quantizer's parameters,such that the quantized closed-loop system is asymptotically stable and with a prescribed H-infinity performance bound.An example is presented to illustrate the effectiveness of the proposed control strategy.
Energy Technology Data Exchange (ETDEWEB)
Lee, Sang Hoon; Chang, Soon Hong; Kang, Kee Sik; Paek, Won Phil; Kim, Han Gon; Chang, Hyeon Seop [Korea Association for Nuclear Technology, Taejon (Korea, Republic of)
1995-12-15
This project consists of the three phase as follow : define the RBR(Risk Based Regulation) concept and analysis of state of art to RBR to NRC, EPRI etc., develop the application area and guideline of RBR to the selected area, develop the regulatory guideline with considering the plant specific conditions in detail. For the first year of this study elementary work for risk based regulation concept was analysed and performed as follows : state of the art of RBR research status, methodology establishment for usage of PSA(Probabilistic Safety Assessment), establishment of the methodology of risk based regulation, and application area for RBR.
Wong, Hong; Kapila, Vikram
2004-01-01
In this paper, we present a method for trajectory generation and adaptive full-state feedback control to facilitate spacecraft formation flying near the Sun-Earth L2 Lagrange point. Specifically, the dynamics of a spacecraft in the neighborhood of a Halo orbit reveals that there exist quasi-periodic orbits surrounding the Halo orbit. Thus, a spacecraft formation is created by placing a leader spacecraft on a desired Halo orbit and placing follower spacecraft on desired quasi-periodic orbits. To produce a formation maintenance controller, we first develop the nonlinear dynamics of a follower spacecraft relative to the leader spacecraft. We assume that the leader spacecraft is on a desired Halo orbit trajectory and the follower spacecraft is to track a desired quasi-periodic orbit surrounding the Halo orbit. Then, we design an adaptive, full-state feedback position tracking controller for the follower spacecraft providing an adaptive compensation for the unknown mass of the follower spacecraft. The proposed control law is simulated for the case of the leader and follower spacecraft pair and is shown to yield global, asymptotic convergence of the relative position tracking errors.
Directory of Open Access Journals (Sweden)
Muhamad Zalani Daud
2014-01-01
Full Text Available This paper presents an evaluation of an optimal DC bus voltage regulation strategy for grid-connected photovoltaic (PV system with battery energy storage (BES. The BES is connected to the PV system DC bus using a DC/DC buck-boost converter. The converter facilitates the BES power charge/discharge to compensate for the DC bus voltage deviation during severe disturbance conditions. In this way, the regulation of DC bus voltage of the PV/BES system can be enhanced as compared to the conventional regulation that is solely based on the voltage-sourced converter (VSC. For the grid side VSC (G-VSC, two control methods, namely, the voltage-mode and current-mode controls, are applied. For control parameter optimization, the simplex optimization technique is applied for the G-VSC voltage- and current-mode controls, including the BES DC/DC buck-boost converter controllers. A new set of optimized parameters are obtained for each of the power converters for comparison purposes. The PSCAD/EMTDC-based simulation case studies are presented to evaluate the performance of the proposed optimized control scheme in comparison to the conventional methods.
Directory of Open Access Journals (Sweden)
Esha Gupta
2016-01-01
Full Text Available This paper presents an application of the recently introduced Antlion Optimizer (ALO to find the parameters of primary governor loop of thermal generators for successful Automatic Generation Control (AGC of two-area interconnected power system. Two standard objective functions, Integral Square Error (ISE and Integral Time Absolute Error (ITAE, have been employed to carry out this parameter estimation process. The problem is transformed in optimization problem to obtain integral gains, speed regulation, and frequency sensitivity coefficient for both areas. The comparison of the regulator performance obtained from ALO is carried out with Genetic Algorithm (GA, Particle Swarm Optimization (PSO, and Gravitational Search Algorithm (GSA based regulators. Different types of perturbations and load changes are incorporated to establish the efficacy of the obtained design. It is observed that ALO outperforms all three optimization methods for this real problem. The optimization performance of ALO is compared with other algorithms on the basis of standard deviations in the values of parameters and objective functions.
Daud, Muhamad Zalani; Mohamed, Azah; Hannan, M A
2014-01-01
This paper presents an evaluation of an optimal DC bus voltage regulation strategy for grid-connected photovoltaic (PV) system with battery energy storage (BES). The BES is connected to the PV system DC bus using a DC/DC buck-boost converter. The converter facilitates the BES power charge/discharge to compensate for the DC bus voltage deviation during severe disturbance conditions. In this way, the regulation of DC bus voltage of the PV/BES system can be enhanced as compared to the conventional regulation that is solely based on the voltage-sourced converter (VSC). For the grid side VSC (G-VSC), two control methods, namely, the voltage-mode and current-mode controls, are applied. For control parameter optimization, the simplex optimization technique is applied for the G-VSC voltage- and current-mode controls, including the BES DC/DC buck-boost converter controllers. A new set of optimized parameters are obtained for each of the power converters for comparison purposes. The PSCAD/EMTDC-based simulation case studies are presented to evaluate the performance of the proposed optimized control scheme in comparison to the conventional methods.
Long Series Multi-objectives Optimal Operation of Water And Sediment Regulation
Bai, T.; Jin, W.
2015-12-01
Secondary suspended river in Inner Mongolia reaches have formed and the security of reach and ecological health of the river are threatened. Therefore, researches on water-sediment regulation by cascade reservoirs are urgent and necessary. Under this emergency background, multi-objectives water and sediment regulation are studied in this paper. Firstly, multi-objective optimal operation models of Longyangxia and Liujiaxia cascade reservoirs are established. Secondly, based on constraints handling and feasible search space techniques, the Non-dominated Sorting Genetic Algorithm (NSGA-II) is greatly improved to solve the model. Thirdly, four different scenarios are set. It is demonstrated that: (1) scatter diagrams of perato front are obtained to show optimal solutions of power generation maximization, sediment maximization and the global equilibrium solutions between the two; (2) the potentiality of water-sediment regulation by Longyangxia and Liujiaxia cascade reservoirs are analyzed; (3) with the increasing water supply in future, conflict between water supply and water-sediment regulation occurred, and the sustainability of water and sediment regulation will confront with negative influences for decreasing transferable water in cascade reservoirs; (4) the transfer project has less benefit for water-sediment regulation. The research results have an important practical significance and application on water-sediment regulation by cascade reservoirs in the Upper Yellow River, to construct water and sediment control system in the whole Yellow River basin.
An Improved Multi-Objective Artificial Bee Colony Optimization Algorithm with Regulation Operators
Directory of Open Access Journals (Sweden)
Jiuyuan Huo
2017-02-01
Full Text Available To achieve effective and accurate optimization for multi-objective optimization problems, a multi-objective artificial bee colony algorithm with regulation operators (RMOABC inspired by the intelligent foraging behavior of honey bees was proposed in this paper. The proposed algorithm utilizes the Pareto dominance theory and takes advantage of adaptive grid and regulation operator mechanisms. The adaptive grid technique is used to adaptively assess the Pareto front maintained in an external archive and the regulation operator is used to balance the weights of the local search and the global search in the evolution of the algorithm. The performance of RMOABC was evaluated in comparison with other nature inspired algorithms includes NSGA-II and MOEA/D. The experiments results demonstrated that the RMOABC approach has better accuracy and minimal execution time.
State Feedback Decoupling with In-Loop Lead Compensator in Stand-Alone VSIs
DEFF Research Database (Denmark)
Federico, de Bosio; Pastorelli, Michele; de Sousa Ribeiro, Luiz Antonio
2016-01-01
The performance of current and voltage regulators during transients and steady-state is of primary concern for power converters intended for stand-alone applications. Dynamics performance and command tracking capability are enhanced by actively decoupling the controlled states variables. To furth...... requiring even more a proper anti-wind up scheme to avoid saturation of the integral term during demanding transients. Lab-tests are performed in accordance with standards imposed to uninterruptible power supplies, verifying the theoretical analysis.......The performance of current and voltage regulators during transients and steady-state is of primary concern for power converters intended for stand-alone applications. Dynamics performance and command tracking capability are enhanced by actively decoupling the controlled states variables. To further...
Energy Technology Data Exchange (ETDEWEB)
Santos Coelho, Leandro dos [Pontifical Catholic University of Parana, PUCPR Industrial and Systems Engineering Graduate Program, LAS/PPGEPS Imaculada Conceicao, 1155, Zip code 80215-901, Curitiba, Parana (Brazil)], E-mail: leandro.coelho@pucpr.br
2009-02-28
Despite the popularity, the tuning aspect of proportional-integral-derivative (PID) controllers is a challenge for researchers and plant operators. Various controllers tuning methodologies have been proposed in the literature such as auto-tuning, self-tuning, pattern recognition, artificial intelligence, and optimization methods. Chaotic optimization algorithms as an emergent method of global optimization have attracted much attention in engineering applications. Chaotic optimization algorithms, which have the features of easy implementation, short execution time and robust mechanisms of escaping from local optimum, is a promising tool for engineering applications. In this paper, a tuning method for determining the parameters of PID control for an automatic regulator voltage (AVR) system using a chaotic optimization approach based on Lozi map is proposed. Since chaotic mapping enjoys certainty, ergodicity and the stochastic property, the proposed chaotic optimization introduces chaos mapping using Lozi map chaotic sequences which increases its convergence rate and resulting precision. Simulation results are promising and show the effectiveness of the proposed approach. Numerical simulations based on proposed PID control of an AVR system for nominal system parameters and step reference voltage input demonstrate the good performance of chaotic optimization.
Directory of Open Access Journals (Sweden)
C. Oktay Azeloglu
2015-01-01
Full Text Available This paper studies the design of a linear matrix inequality (LMI based mixed H2/H∞ state-feedback controller for vibration attenuation problem of seismic-excited container cranes. In order to show effectiveness of the designed controller, a six-degree-of-freedom container crane structural system is modeled using a spring-mass-damper subsystem. The system is then simulated against the real ground motion of El Centro and Northridge earthquakes. Finally, the time history of the crane parts displacements, accelerations, control forces, and frequency responses of both uncontrolled and controlled cases are presented. Additionally, the performance of the designed controller is also compared with a nominal state-feedback H∞ controller performance. Simulations of the designed controller show better seismic performance than a nominal state-feedback H∞ controller. Simulation results show that the designed controller is all effective in reducing vibration amplitudes of crane parts.
Directory of Open Access Journals (Sweden)
OBINABO, EDWIN CHUKWUDI
2010-12-01
Full Text Available This study proposes an optimal control law for a linear constant energy renewal multivariable system supplying power to protection and signaling circuits for switchgears and substation operations. The energy storage mechanism creates a control source that dictates the frequency of the pow er supply voltage. The entire analysis was based essentially on the use of a vector of inputs and outputs, and a matrix of operations characterizing the storage mechanism, assuming the system is both controllable and observable under arbitrary state feedback. The property of the output regulator which was desirable from the view point of feedback control design was clarified.
Institute of Scientific and Technical Information of China (English)
FU Yu-sun; TIAN Zuo-hua; SHI Song-jiao
2001-01-01
The paper is concerned with the reliable H∞ state feedback control and controller parameterization problem for nonlinear systems with strictly redundant actuators. Based on Hamilton-Jacobi inequality,the sufficient condition is presented such that the reliable control problem is resolved, and a family of controllers is given such that the resulting closed-loop systems are asymptotically stable and their L2-gain is limitable not only when all actuators are operational but also when any one, but only one of actuators experiences an outage. The results of this paper provide a deep insight into the synthesis of the reliable nonlinear H∞ state-feedback.
An Optimization-Based Impedance Approach for Robot Force Regulation with Prescribed Force Limits
Directory of Open Access Journals (Sweden)
R. de J. Portillo-Vélez
2015-01-01
Full Text Available An optimization based approach for the regulation of excessive or insufficient forces at the end-effector level is introduced. The objective is to minimize the interaction force error at the robot end effector, while constraining undesired interaction forces. To that end, a dynamic optimization problem (DOP is formulated considering a dynamic robot impedance model. Penalty functions are considered in the DOP to handle the constraints on the interaction force. The optimization problem is online solved through the gradient flow approach. Convergence properties are presented and the stability is drawn when the force limits are considered in the analysis. The effectiveness of our proposal is validated via experimental results for a robotic grasping task.
Optimal Output Regulation for Heterogeneous Multiagent Systems via Adaptive Dynamic Programming.
Zhang, Huaguang; Liang, Hongjing; Wang, Zhanshan; Feng, Tao
2017-01-01
In this paper, the optimal output regulation problem for partially model-free heterogeneous linear multiagent systems with disturbance generated by an exosystem is addressed by using adaptive dynamic programming and double compensator method. The topology graph for the information exchange of the agents has a spanning tree. The dynamic of individual agent is assumed to be nonidentical and of different dimensions. One distributed compensator is designed to deal with the nonidentical agents, and the other compensator is used to handle the optimal performance index. By constructing the double compensator, the distributed feedback control laws are designed to make the output of each agent synchronize with the reference output and minimize the energy of the output error simultaneously. To overcome the lack of the dynamics knowledge of each agent, a novel online policy iteration algorithm is developed to obtain the optimal feedback gain matrix. Finally, two examples are presented to illustrate the effectiveness of our results.
Directory of Open Access Journals (Sweden)
Gao Dexin
2012-10-01
Full Text Available This paper concentrates on the solution of state feedback exact linearization zero steady-state error optimal control problem for nonlinear systems affected by external disturbances. Firstly, the nonlinear system model with external disturbances is converted to quasi-linear system model by differential homeomorphism. Using Internal Model Optional Control (IMOC, the disturbances compensator is designed, which exactly offset the impact of external disturbances on the system. Taking the system and the disturbances compensator in series, a new augmented system is obtained. Then the zero steady-state error optimal control problem is transformed into the optimal regulator design problem of an augmented system, and the optimal static error feedback control law is designed according to the different quadratic performance index. At last, the simulation results show the effectiveness of the method.
Directory of Open Access Journals (Sweden)
Thair M. Al-Taiee
2013-05-01
Full Text Available To obtain optimal operating rules for storage reservoirs, large numbers of simulation and optimization models have been developed over the past several decades, which vary significantly in their mechanisms and applications. Rule curves are guidelines for long term reservoir operation. An efficient technique is required to find the optimal rule curves that can mitigate water shortage in long term operation. The investigation of developed Genetic Algorithm (GA technique, which is an optimization approach base on the mechanics of natural selection, derived from the theory of natural evolution, was carried out to through the application to predict the daily rule curve of Mosul regulating reservoir in Iraq. Record daily inflows, outflow, water level in the reservoir for 19 year (1986-1990 and (1994-2007 were used in the developed model for assessing the optimal reservoir operation. The objective function is set to minimize the annual sum of squared deviation from the desired downstream release and desired storage volume in the reservoir. The decision variables are releases, storage volume, water level and outlet (demand from the reservoir. The results of the GA model gave a good agreement during the comparison with the actual rule curve and the designed rating curve of the reservoir. The simulated result shows that GA-derived policies are promising and competitive and can be effectively used for daily reservoir operation in addition to the rational monthly operation and predicting also rating curve of reservoirs.
Directory of Open Access Journals (Sweden)
Yujian Guo
2016-01-01
Full Text Available A design strategy of optimal output regulators for dual-rate discrete-time systems, whose output sampling period is an integer multiple of the input updating period, is proposed. At first, by using the discrete lifting technique, the dual-rate discrete-time system is converted to a single-rate augmented system in form and the lifted state-space model is constructed. Correspondingly, the performance index of the original system is modified to the performance index of the single-rate augmented system. And the original problem is transformed into an output regulation problem for the augmented system. Then, according to the optimal regulator theory, an optimal output regulator for the dual-rate discrete-time system is derived. In the meantime, the existence conditions of the optimal output regulator are discussed. Finally, a numerical example is included to illustrate the effectiveness of the proposed method.
Hueschen, R. M.
1984-01-01
The Digital Integrated Automatic Landing System (DIALS) is discussed. The DIALS is a modern control theory design performing all the maneuver modes associated with current autoland systems: localizer capture and track, glideslope capture and track, decrab, and flare. The DIALS is an integrated full-state feedback system which was designed using direct-digital methods. The DIALS uses standard aircraft sensors and the digital Microwave Landing System (MLS) signals as measurements. It consists of separately designed longitudinal and lateral channels although some cross-coupling variables are fed between channels for improved state estimates and trajectory commands. The DIALS was implemented within the 16-bit fixed-point flight computers of the ATOPS research aircraft, a small twin jet commercial transport outfitted with a second research cockpit and a fly-by-wire system. The DIALS became the first modern control theory design to be successfully flight tested on a commercial-type aircraft. Flight tests were conducted in late 1981 using a wide coverage MLS on Runway 22 at Wallops Flight Center. All the modes were exercised including the capture and track of steep glidescopes up to 5 degrees.
Directory of Open Access Journals (Sweden)
Mahesh Nagarkar
2016-04-01
Full Text Available In this paper, a genetic algorithm (GA based in an optimization approach is presented in order to search the optimum weighting matrix parameters of a linear quadratic regulator (LQR. A Macpherson strut quarter car suspension system is implemented for ride control application. Initially, the GA is implemented with the objective of minimizing root mean square (RMS controller force. For single objective optimization, RMS controller force is reduced by 20.42% with slight increase in RMS sprung mass acceleration. Trade-off is observed between controller force and sprung mass acceleration. Further, an analysis is extended to multi-objective optimization with objectives such as minimization of RMS controller force and RMS sprung mass acceleration and minimization of RMS controller force, RMS sprung mass acceleration and suspension space deflection. For multi-objective optimization, Pareto-front gives flexibility in order to choose the optimum solution as per designer’s need.
Short-Term State Forecasting-Based Optimal Voltage Regulation in Distribution Systems: Preprint
Energy Technology Data Exchange (ETDEWEB)
Yang, Rui; Jiang, Huaiguang; Zhang, Yingchen
2017-05-17
A novel short-term state forecasting-based optimal power flow (OPF) approach for distribution system voltage regulation is proposed in this paper. An extreme learning machine (ELM) based state forecaster is developed to accurately predict system states (voltage magnitudes and angles) in the near future. Based on the forecast system states, a dynamically weighted three-phase AC OPF problem is formulated to minimize the voltage violations with higher penalization on buses which are forecast to have higher voltage violations in the near future. By solving the proposed OPF problem, the controllable resources in the system are optimally coordinated to alleviate the potential severe voltage violations and improve the overall voltage profile. The proposed approach has been tested in a 12-bus distribution system and simulation results are presented to demonstrate the performance of the proposed approach.
State Feedback Stabilzation for a Class of Time-delay Nonlinear Systems%一类非线性时滞系统的状态反馈镇定
Institute of Scientific and Technical Information of China (English)
张宪福; 程兆林
2005-01-01
The problem of global stabilization by state feedback for a class of time-delay nonlinear system is considered. By constructing the appropriate Lyapunov-Krasovskii functionals (LKF) and using the backstepping design, a linear state feedback controller making the closed-loop system globally asymptotically stable is constructed.
Is transcriptional regulation of metabolic pathways an optimal strategy for fitness?
Directory of Open Access Journals (Sweden)
Carl Troein
Full Text Available BACKGROUND: Transcriptional regulation of the genes in metabolic pathways is a highly successful strategy, which is virtually universal in microorganisms. The lac operon of E. coli is but one example of how enzyme and transporter production can be made conditional on the presence of a nutrient to catabolize. METHODOLOGY: With a minimalist model of metabolism, cell growth and transcriptional regulation in a microorganism, we explore how the interaction between environmental conditions and gene regulation set the growth rate of cells in the phase of exponential growth. This in silico model, which is based on biochemical rate equations, does not describe a specific organism, but the magnitudes of its parameters are chosen to match realistic values. Optimizing the parameters of the regulatory system allows us to quantify the fitness benefit of regulation. When a second nutrient and its metabolic pathway are introduced, the system must further decide whether and how to activate both pathways. CONCLUSIONS: Even the crudest transcriptional network is shown to substantially increase the fitness of the organism, and this effect persists even when the range of nutrient levels is kept very narrow. We show that maximal growth is achieved when pathway activation is a more or less steeply graded function of the nutrient concentration. Furthermore, we predict that bistability of the system is a rare phenomenon in this context, but outline a situation where it may be selected for.
Cost-optimal levels of minimum energy performance requirements in the Danish Building Regulations
Energy Technology Data Exchange (ETDEWEB)
Aggerholm, S.
2013-09-15
The purpose of the report is to analyse the cost optimality of the energy requirements in the Danish Building Regulations 2010, BR10 to new building and to existing buildings undergoing major renovation. The energy requirements in the Danish Building Regulations have by tradition always been based on the cost and benefits related to the private economical or financial perspective. Macro economical calculations have in the past only been made in addition. The cost optimum used in this report is thus based on the financial perspective. Due to the high energy taxes in Denmark there is a significant difference between the consumer price and the macro economical for energy. Energy taxes are also paid by commercial consumers when the energy is used for building operation e.g. heating, lighting, ventilation etc. In relation to the new housing examples the present minimum energy requirements in BR 10 all shows gaps that are negative with a deviation of up till 16 % from the point of cost optimality. With the planned tightening of the requirements to new houses in 2015 and in 2020, the energy requirements can be expected to be tighter than the cost optimal point, if the costs for the needed improvements don't decrease correspondingly. In relation to the new office building there is a gap of 31 % to the point of cost optimality in relation to the 2010 requirement. In relation to the 2015 and 2020 requirements there are negative gaps to the point of cost optimality based on today's prices. If the gaps for all the new buildings are weighted to an average based on mix of building types and heat supply for new buildings in Denmark there is a gap of 3 % in average for the new building. The excessive tightness with today's prices is 34 % in relation to the 2015 requirement and 49 % in relation to the 2020 requirement. The component requirement to elements in the building envelope and to installations in existing buildings adds up to significant energy efficiency
Aranza, M. F.; Kustija, J.; Trisno, B.; Hakim, D. L.
2016-04-01
PID Controller (Proportional Integral Derivative) was invented since 1910, but till today still is used in industries, even though there are many kind of modern controllers like fuzz controller and neural network controller are being developed. Performance of PID controller is depend on on Proportional Gain (Kp), Integral Gain (Ki) and Derivative Gain (Kd). These gains can be got by using method Ziegler-Nichols (ZN), gain-phase margin, Root Locus, Minimum Variance dan Gain Scheduling however these methods are not optimal to control systems that nonlinear and have high-orde, in addition, some methods relative hard. To solve those obstacles, particle swarm optimization (PSO) algorithm is proposed to get optimal Kp, Ki and Kd. PSO is proposed because PSO has convergent result and not require many iterations. On this research, PID controller is applied on AVR (Automatic Voltage Regulator). Based on result of analyzing transient, stability Root Locus and frequency response, performance of PID controller is better than Ziegler-Nichols.
DEFF Research Database (Denmark)
He, Guannan; Chen, Qixin; Kang, Chongqing
2016-01-01
Large-scale battery storage will become an essential part of the future smart grid. This paper investigates the optimal bidding strategy for battery storage in power markets. Battery storage could increase its profitability by providing fast regulation service under a performance-based regulation...... degree. Thus, we incorporate a battery cycle life model into a profit maximization model to determine the optimal bids in day-ahead energy, spinning reserve, and regulation markets. Then a decomposed online calculation method to compute cycle life under different operational strategies is proposed...
Energy Technology Data Exchange (ETDEWEB)
Benitez R, J.S. [ININ, 52750 La Marquesa, Estado de Mexico (Mexico); Perez C, J.H. [CINVESTAV, IPN, A.P. 14740 07000 Mexico D.F. (Mexico); Rivero G, T. [ITT, 50140 Metepec, Estado de Mexico (Mexico)
2008-07-01
In this paper a novel procedure for power regulation in a TRIGA Mark III nuclear reactor is presented. The control scheme combines state variable feedback with a first order predictor, which is incorporated to speed up the power response of the reactor without exceeding the safety requirement imposed by the reactor period. The simulation results using the proposed control strategy attains different values of steady-state power from different values of initial power in short time, complying at all times with the safety restriction imposed on the reactor period. The predictor, derived from the theory of first order numerical integration, produces very good results during the ascent of power. These results include a fast response and independence of the wide variety of potential operating conditions something not easy and even impossible to obtain with other procedures. By using this control scheme, the reactor period is maintained within safety limits during the start up of the reactor, which is normally the operating condition where an occurrence of a period scram is common. However, the predictor can not be used when the power is reaching the desired power level because the instantaneous power increases far above the desired level. Thus, when the power increases above certain power level, the state feedback gain is set constant to a predefined value. This causes some oscillations that decrease in a few seconds. Afterwards, the power response smoothly approaches, with a small overshoot, the desired power. This constraint on the use of the predictor prevents the unbounded increase of the neutron power. The control law proposed requires all the system's state variables. Since only the neutron power is available, it is necessary the estimation of the non measurable states. The key issue of the existence of a solution to this problem has been previously considered. One of the conclusions is that the point kinetic equations are observable under certain restrictions
Zhang, Yuanxing
Some high value proteins and vaccines for medical and veterinary applications by animal cell culture have an increasing market in China. In order to meet the demands of large-scale productions of proteins and vaccines, animal cell culture technology has been widely developed. In general, an animal cell culture process can be divided into two stages in a batch culture. In cell growth stage a high specific growth rate is expected to achieve a high cell density. In production stage a high specific production rate is stressed for the expression and secretion of qualified protein or replication of virus. It is always critical to maintain high cell viability in fed-batch and perfusion cultures. More concern has been focused on two points by the researchers in China. First, the cell metabolism of substrates is analyzed and the accumulation of toxic by-products is decreased through regulating cell metabolism in the culture process. Second, some important factors effecting protein expression are understood at the molecular level and the production ability of protein is improved. In pace with the rapid development of large-scale cell culture for the production of vaccines, antibodies and other recombinant proteins in China, the medium design and process optimization based on cell metabolism regulation and protein expression improvement will play an important role. The chapter outlines the main advances in metabolic regulation of cell and expression improvement of protein in animal cell culture in recent years.
Directory of Open Access Journals (Sweden)
Åshild Ergon
2017-02-01
Full Text Available Seasonal growth patterns of perennial plants are linked to patterns of acclimation and de-acclimation to seasonal stresses. The timing of cold acclimation (development of freezing resistance and leaf growth cessation in autumn, and the timing of de-acclimation and leaf regrowth in spring, is regulated by seasonal cues in the environment, mainly temperature and light factors. Warming will lead to new combinations of these cues in autumn and spring. Extended thermal growing seasons offer a possibility for obtaining increased yields of perennial grasses at high latitudes. Increased productivity in the autumn may not be possible in all high latitude regions due to the need for light during cold acclimation and the need for accumulating a carbohydrate storage prior to winter. There is more potential for increased yields in spring due to the availability of light, but higher probability of freezing events in earlier springs would necessitate a delay of de-acclimation, or an ability to rapidly re-acclimate. In order to optimize the balance between productivity and overwintering in the future, the regulation of growth and acclimation processes may have to be modified. Here, the current knowledge on the coordinated regulation of growth and freezing resistance in perennial grasses is reviewed.
Zhu, Houjuan; Fang, Yuan; Miao, Qingqing; Qi, Xiaoying; Ding, Dan; Chen, Peng; Pu, Kanyi
2017-09-26
Development of optical nanotheranostics for the capability of photodynamic therapy (PDT) provides opportunities for advanced cancer therapy. However, most nanotheranostic systems fail to regulate their generation levels of reactive oxygen species (ROS) according to the disease microenvironment, which can potentially limit their therapeutic selectivity and increase the risk of damage to normal tissues. We herein report the development of hybrid semiconducting polymer nanoparticles (SPNs) with self-regulated near-infrared (NIR) photodynamic properties for optimized cancer therapy. The SPNs comprise a binary component nanostructure: a NIR-absorbing semiconducting polymer acts as the NIR fluorescent PDT agent, while nanoceria serves as the smart intraparticle regular to decrease and increase ROS generation at physiologically neutral and pathologically acidic environments, respectively. As compared with nondoped SPNs, the NIR fluorescence imaging ability of nanoceria-doped SPNs is similar due to the optically inactive nature of nanoceria; however, the self-regulated photodynamic properties of nanoceria-doped SPN not only result in dramatically reduced nonspecific damage to normal tissue under NIR laser irradiation but also lead to significantly enhanced photodynamic efficacy for cancer therapy in a murine mouse model. This study thus provides a simple yet effective hybrid approach to modulate the phototherapeutic performance of organic photosensitizers.
Control, regulation and storage systems to optimize the integration of wind power
Energy Technology Data Exchange (ETDEWEB)
Gasco, Manuel [Universidad de Alicante (Spain). Area de Ingenieria Electrica; Rios, Alberto [Universidad Europea de Madrid (Spain). Area de Ingenieria Electrica
2012-07-01
Increasing integration of a wind energy into the power system increases the importance of its control and regulation. The new wind energy technologies and smart grid technologies substantially modify the power.system, acquiring this way a great amount of active elements. New devices in the grid become more important; power storage systems, regulation systems and control systems are described in this paper. When talking about power storage systems, nowadays the most important are pump and turbine systems which are used in the power grid and the electric vehicle connected to the grid. Regarding the power control, the systems applied are tap transformers and capacitor banks. However, FACTS devices are becoming increasingly important, whether they are connected in series or in parallel, they combine conventional systems, power electronics and microelectronics, together with modern telecommunication systems. Finally, the demand management systems enable us to determine the cost of energy for the consumers on the real time basis. This way the user can decide when and for how much money he wants to consume the energy. If different types of technologies integrated in the power grid are compared, different behaviors are observed. Therefore, it is possible to select those devices of control, regulation and management that should be applied to optimize the power grid. (orig.)
Control, regulation and storage systems to optimize the integration of solar power
Energy Technology Data Exchange (ETDEWEB)
Gasco, Manuel [Universidad de Alicante (Spain). Area de Ingenieria Electrica; Rios, Alberto [Universidad Europea de Madrid (Spain). Area de Ingenieria Electrica
2012-07-01
Increasing integration of a solar energy into the power system increases the importance of its control and regulation. The new solar energy technologies and smart grid technologies substantially modify the power system, acquiring this way a great amount of active elements. New devices in the grid become more important; power storage systems, regulation systems and control systems are described in this paper. When talking about power storage systems, nowadays the most important are pump and turbine systems which are used in the power grid and the electric vehicle connected to the grid. Regarding the power control, the systems applied are tap transformers and capacitor banks. However, FACTS devices are becoming increasingly important, whether they are connected in series or in parallel, they combine conventional systems, power electronics and microelectronics, together with modern telecommunication systems. Finally, the demand management systems enable us to determine the cost of energy for the consumers on the real time basis. This way the user can decide when and for how much money he wants to consume the energy. If different types of technologies integrated in the power grid are compared, different behaviors are observed. Therefore, it is possible to select those devices of control, regulation and management that should be applied to optimize the power grid. (orig.)
Zhang, Yuanxing
2009-01-01
Some high value proteins and vaccines for medical and veterinary applications by animal cell culture have an increasing market in China. In order to meet the demands of large-scale productions of proteins and vaccines, animal cell culture technology has been widely developed. In general, an animal cell culture process can be divided into two stages in a batch culture. In cell growth stage a high specific growth rate is expected to achieve a high cell density. In production stage a high specific production rate is stressed for the expression and secretion of qualified protein or replication of virus. It is always critical to maintain high cell viability in fed-batch and perfusion cultures. More concern has been focused on two points by the researchers in China. First, the cell metabolism of substrates is analyzed and the accumulation of toxic by-products is decreased through regulating cell metabolism in the culture process. Second, some important factors effecting protein expression are understood at the molecular level and the production ability of protein is improved. In pace with the rapid development of large-scale cell culture for the production of vaccines, antibodies and other recombinant proteins in China, the medium design and process optimization based on cell metabolism regulation and protein expression improvement will play an important role. The chapter outlines the main advances in metabolic regulation of cell and expression improvement of protein in animal cell culture in recent years.
Institute of Scientific and Technical Information of China (English)
无
2010-01-01
In this paper, a class of simplified Type-IV predator-prey system with linear state feedback is investigated. We prove the boundedness of the positive solutions to this system, and analyze the quality of the equilibria and the existence of limit cycles of the system surrounding the positive equilibra. By Hopf bifurcation theory, the result of having two limit cycles to the system is obtained.
Directory of Open Access Journals (Sweden)
Chuanjun Dai
2012-01-01
Full Text Available The dynamic complexities of a prey-predator system in the presence of alternative prey with impulsive state feedback control are studied analytically and numerically. By using the analogue of the Poincaré criterion, sufficient conditions for the existence and stability of semitrivial periodic solutions can be obtained. Furthermore, the corresponding bifurcation diagrams and phase diagrams are investigated by means of numerical simulations which illustrate the feasibility of the main results.
Li, Huiping; Shi, Yang
2012-10-01
This article focuses on the state-feedback ℋ∞ control problem for the stochastic nonlinear systems with state and disturbance-dependent noise and time-varying state delays. Based on the maxmin optimisation approach, both the delay-independent and the delay-dependent Hamilton-Jacobi-inequalities (HJIs) are developed for synthesising the state-feedback ℋ∞ controller for a general type of stochastic nonlinear systems. It is shown that the resulting control system achieves stochastic stability in probability and the prescribed disturbance attenuation level. For a class of stochastic affine nonlinear systems, the delay-independent as well as delay-dependent matrix-valued inequalities are proposed; the resulting control system satisfies global asymptotic stability in the mean-square sense and the required disturbance attenuation level. By modelling the nonlinearities as uncertainties in corresponding stochastic time-delay systems, the sufficient conditions in terms of a linear matrix inequality (LMI) and a bilinear matrix inequality (BMI) are derived to facilitate the design of the state-feedback ℋ∞ controller. Finally, two numerical examples are provided to illustrate the effectiveness of the proposed methods.
Linear systems optimal and robust control
Sinha, Alok
2007-01-01
Introduction Overview Contents of the Book State Space Description of a Linear System Transfer Function of a Single Input/Single Output (SISO) System State Space Realizations of a SISO System SISO Transfer Function from a State Space Realization Solution of State Space Equations Observability and Controllability of a SISO System Some Important Similarity Transformations Simultaneous Controllability and Observability Multiinput/Multioutput (MIMO) Systems State Space Realizations of a Transfer Function Matrix Controllability and Observability of a MIMO System Matrix-Fraction Description (MFD) MFD of a Transfer Function Matrix for the Minimal Order of a State Space Realization Controller Form Realization from a Right MFD Poles and Zeros of a MIMO Transfer Function Matrix Stability Analysis State Feedback Control and Optimization State Variable Feedback for a Single Input System Computation of State Feedback Gain Matrix for a Multiinput System State Feedback Gain Matrix for a Multi...
Determination of optimal gains for constrained controllers
Energy Technology Data Exchange (ETDEWEB)
Kwan, C.M.; Mestha, L.K.
1993-08-01
In this report, we consider the determination of optimal gains, with respect to a certain performance index, for state feedback controllers where some elements in the gain matrix are constrained to be zero. Two iterative schemes for systematically finding the constrained gain matrix are presented. An example is included to demonstrate the procedures.
Energy Technology Data Exchange (ETDEWEB)
Sandvig, J.
2009-11-15
The project's overall objective has been to use methods in model-based control and online optimization to increase industrial energy efficiency. Model-based regulation is a relatively new technology that combines knowledge of processes and systems, theoretical methods and computer processing power in intelligent, advanced control solutions and methods. The methods have so far been successfully applied in some of the largest process industries, but virtually not in small and medium-sized industries. A major reason for this is that no standard solutions have existed, and therefore it has required significant resources to develop and implement. The goal of this project is to contribute to model-based control being disseminated among the SMEs. This can be done by finding out whether it is possible to adjust and standardize the methods so that they are suitable for deployment in these segments. (ln)
On the Model Study of Multiobjective Optimization for Regulating Regional Economy
Institute of Scientific and Technical Information of China (English)
LUO Zhi-hui
2001-01-01
Based on different equation of Cobb-Douglas production function, the model of regulating regional economy on the multiobjective optimization of efficiency and equity is set up, with the spatial distribution strategy of capital and labour force as the controlling variable. Two basic conclusions drawn from the model are strictly demonstrated: ① A country＇s economic development is decided by the consistency between the regional distributive strategy of increment investment and the regional difference in marginal investment revenue. ② The couple targets of efficiency and equity are strictly in conflict with each other, if and only if the marginal investment revenue in the developed regions is higher than in the undeveloped,otherwise the targets are consistent.
Directory of Open Access Journals (Sweden)
S. Chaine
2015-09-01
Full Text Available This work presents a methodology to optimize the controller parameters of doubly fed induction generator modeled for frequency regulation in interconnected two-area wind power integrated thermal power system. The gains of integral controller of automatic generation control loop and the proportional and derivative controllers of doubly fed induction generator inertial control loop are optimized in a coordinated manner by employing the multi-objective non-dominated sorting genetic algorithm-II. To reduce the numbers of optimization parameters, a sensitivity analysis is done to determine that the above mentioned three controller parameters are the most sensitive among the rest others. Non-dominated sorting genetic algorithm-II has depicted better efficiency of optimization compared to the linear programming, genetic algorithm, particle swarm optimization, and cuckoo search algorithm. The performance of the designed optimal controller exhibits robust performance even with the variation in penetration levels of wind energy, disturbances, parameter and operating conditions in the system.
ORACLS- OPTIMAL REGULATOR ALGORITHMS FOR THE CONTROL OF LINEAR SYSTEMS (CDC VERSION)
Armstrong, E. S.
1994-01-01
This control theory design package, called Optimal Regulator Algorithms for the Control of Linear Systems (ORACLS), was developed to aid in the design of controllers and optimal filters for systems which can be modeled by linear, time-invariant differential and difference equations. Optimal linear quadratic regulator theory, currently referred to as the Linear-Quadratic-Gaussian (LQG) problem, has become the most widely accepted method of determining optimal control policy. Within this theory, the infinite duration time-invariant problems, which lead to constant gain feedback control laws and constant Kalman-Bucy filter gains for reconstruction of the system state, exhibit high tractability and potential ease of implementation. A variety of new and efficient methods in the field of numerical linear algebra have been combined into the ORACLS program, which provides for the solution to time-invariant continuous or discrete LQG problems. The ORACLS package is particularly attractive to the control system designer because it provides a rigorous tool for dealing with multi-input and multi-output dynamic systems in both continuous and discrete form. The ORACLS programming system is a collection of subroutines which can be used to formulate, manipulate, and solve various LQG design problems. The ORACLS program is constructed in a manner which permits the user to maintain considerable flexibility at each operational state. This flexibility is accomplished by providing primary operations, analysis of linear time-invariant systems, and control synthesis based on LQG methodology. The input-output routines handle the reading and writing of numerical matrices, printing heading information, and accumulating output information. The basic vector-matrix operations include addition, subtraction, multiplication, equation, norm construction, tracing, transposition, scaling, juxtaposition, and construction of null and identity matrices. The analysis routines provide for the following
ORACLS- OPTIMAL REGULATOR ALGORITHMS FOR THE CONTROL OF LINEAR SYSTEMS (DEC VAX VERSION)
Frisch, H.
1994-01-01
This control theory design package, called Optimal Regulator Algorithms for the Control of Linear Systems (ORACLS), was developed to aid in the design of controllers and optimal filters for systems which can be modeled by linear, time-invariant differential and difference equations. Optimal linear quadratic regulator theory, currently referred to as the Linear-Quadratic-Gaussian (LQG) problem, has become the most widely accepted method of determining optimal control policy. Within this theory, the infinite duration time-invariant problems, which lead to constant gain feedback control laws and constant Kalman-Bucy filter gains for reconstruction of the system state, exhibit high tractability and potential ease of implementation. A variety of new and efficient methods in the field of numerical linear algebra have been combined into the ORACLS program, which provides for the solution to time-invariant continuous or discrete LQG problems. The ORACLS package is particularly attractive to the control system designer because it provides a rigorous tool for dealing with multi-input and multi-output dynamic systems in both continuous and discrete form. The ORACLS programming system is a collection of subroutines which can be used to formulate, manipulate, and solve various LQG design problems. The ORACLS program is constructed in a manner which permits the user to maintain considerable flexibility at each operational state. This flexibility is accomplished by providing primary operations, analysis of linear time-invariant systems, and control synthesis based on LQG methodology. The input-output routines handle the reading and writing of numerical matrices, printing heading information, and accumulating output information. The basic vector-matrix operations include addition, subtraction, multiplication, equation, norm construction, tracing, transposition, scaling, juxtaposition, and construction of null and identity matrices. The analysis routines provide for the following
Institute of Scientific and Technical Information of China (English)
李宁; 王树青
2011-01-01
The structural vibration control of offshore platform under random wave loading by using Tuned Mass Damper (TMD) is investigated. The model of offshore platform -TMD is established. Tuned Mass Damper (TMD) is installed on the offshore platform for sharing the energy of main structure* so that vibration of the main structure can be controlled. Optimal TMD parameters can be determined by analyzing the energy dissipation and transmission of the structure-TMD. Meanwhile, states feedback is introduced in the structure -TMD. Optimal controlling force is determined based on feedback from structural responses. By use of pole assignment method, feedback gain is selected suitably. The vibration could be reduced further.%研究了随机波浪载荷作用下海洋平台的TMD振动控制,建立了TMD-海洋平台振动模型,从TMD能量分析的角度对TMD参数进行了优化设计;同时将状态反馈引入系统,依据结构响应的反馈信息确定控制力,运用极点配置法,选取适当的反馈增益K,从而进一步达到控制结构振动的目的.
Carver, Charles S.; Scheier, Michael F.; Segerstrom, Suzanne C.
2010-01-01
Optimism is an individual difference variable that reflects the extent to which people hold generalized favorable expectancies for their future. Higher levels of optimism have been related prospectively to better subjective well-being in times of adversity or difficulty (i.e., controlling for previous well-being). Consistent with such findings, optimism has been linked to higher levels of engagement coping and lower levels of avoidance, or disengagement, coping. There is evidence that optimism is associated with taking proactive steps to protect one's health, whereas pessimism is associated with health-damaging behaviors. Consistent with such findings, optimism is also related to indicators of better physical health. The energetic, task-focused approach that optimists take to goals also relates to benefits in the socioeconomic world. Some evidence suggests that optimism relates to more persistence in educational efforts and to higher later income. Optimists also appear to fare better than pessimists in relationships. Although there are instances in which optimism fails to convey an advantage, and instances in which it may convey a disadvantage, those instances are relatively rare. In sum, the behavioral patterns of optimists appear to provide models of living for others to learn from. PMID:20170998
Pearce, Charles
2009-01-01
Focuses on mathematical structure, and on real-world applications. This book includes developments in several optimization-related topics such as decision theory, linear programming, turnpike theory, duality theory, convex analysis, and queuing theory.
DEFF Research Database (Denmark)
Federico, de Bosio; de Sousa Ribeiro, Luiz Antonio; Freijedo Fernandez, Francisco Daniel
2016-01-01
provided. A proportional resonant voltage controller is designed according to Nyquist criterion taking into account application requirements. For this purpose, a mathematical expression based on root locus analysis is proposed to find the minimum value of the fundamental resonant gain. Experimental tests...... on the state feedback decoupling path in order to compensate for system delays. Practical implementation issues are discussed with reference to both the decoupling techniques. A design methodology for the voltage loop, that considers the closed loop transfer functions developed for the inner loop, is also...... performed in accordance to UPS standards verify the theoretical analysis....
Model of Stochastic Automation Asymptotically Optimal Behavior for Inter-budget Regulation
Directory of Open Access Journals (Sweden)
Elena D. Streltsova
2013-01-01
Full Text Available This paper is focused on the topical issue of inter-budget control in the structure ↔ by applying econometric models. To create the decision-making model, mathematical tool of the theory of stochastic automation, operating in random environments was used. On the basis of the application of this mathematical tool, the adaptive training economic and mathematical model, able to adapt to the environment, maintained by the income from the payment of federal and regional taxes and fees, payable to the budget of the constituent entity of the RF and paid to the budget of a lower level in the form of budget regulation was developed. The authors have developed the structure of the machine, described its behavior in a random environment and introduced the expression for the final probabilities of machine in each of its states. The behavioral aspect of the machine by means of a mathematically rigorous proof of the theorem on the feasibility of behavior and the asymptotic optimality of the proposed design of the machine were presented.
Key Economic Parameters for an Optimal Pharmacy Network in a Regulated Environment
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Franjo MLINARIC
2016-10-01
Full Text Available Pharmacies are an integral part of the modern healthcare system which strives for a holistic and effi cient care. General practitioners and pharmacists are held in high esteem among local communities as they are the fi rst point of contact when people have health issues. However, a strong demand for health services in developed countries and its present fi nancing schemes undermined the sustainability of the whole health system (8.9% of GDP in 2013 and growing. According to WHO and EU recommendations, the whole healthcare system shall accept a holistic approach and focus on education, prevention and proper medicine consume. Part of this strategy is a seamless care concept, where medical doctors and pharmacists build a team around the well-being of a patient. Financing scheme incentives and KPI’s (key performance indicators will be focused on keeping people healthy, instead of paying for procedures. The future healthcare ecosystem obliges pharmacists to optimize network coverage and to extend health services. Nevertheless, their growth strategy needs to be gradual, considering the present level of network coverage, the low pace of private and public expenditures for medicine and services, and the fact that a new fi nancing model for pharmacies is still unknown. Thus, we expect the development of pharmacy network in regulated environment to be fi nanced predominantly from retained earnings in publicly owned pharmacies and by awarding pharmacy concessions.
Heilmann, Silja; Krishna, Sandeep; Kerr, Benjamin
2015-01-01
Many bacteria secrete compounds which act as public goods. Such compounds are often under quorum sensing (QS) regulation, yet it is not understood exactly when bacteria may gain from having a public good under QS regulation. Here, we show that the optimal public good production rate per cell as a function of population size (the optimal production curve, OPC) depends crucially on the cost and benefit functions of the public good and that the OPC will fall into one of two categories: Either it is continuous or it jumps from zero discontinuously at a critical population size. If, e.g., the public good has accelerating returns and linear cost, then the OPC is discontinuous and the best strategy thus to ramp up production sharply at a precise population size. By using the example of public goods with accelerating and diminishing returns (and linear cost) we are able to determine how the two different categories of OPSs can best be matched by production regulated through a QS signal feeding back on its own production. We find that the optimal QS parameters are different for the two categories and specifically that public goods which provide accelerating returns, call for stronger positive signal feedback.
Zhang, Xi; Miao, Lingjuan; Shao, Haijun
2016-05-02
If a Kalman Filter (KF) is applied to Global Positioning System (GPS) baseband signal preprocessing, the estimates of signal phase and frequency can have low variance, even in highly dynamic situations. This paper presents a novel preprocessing scheme based on a dual-filter structure. Compared with the traditional model utilizing a single KF, this structure avoids carrier tracking being subjected to code tracking errors. Meanwhile, as the loop filters are completely removed, state feedback values are adopted to generate local carrier and code. Although local carrier frequency has a wide fluctuation, the accuracy of Doppler shift estimation is improved. In the ultra-tight GPS/Inertial Navigation System (INS) integration, the carrier frequency derived from the external navigation information is not viewed as the local carrier frequency directly. That facilitates retaining the design principle of state feedback. However, under harsh conditions, the GPS outputs may still bear large errors which can destroy the estimation of INS errors. Thus, an innovative integrated navigation filter is constructed by modeling the non-negligible errors in the estimated Doppler shifts, to ensure INS is properly calibrated. Finally, field test and semi-physical simulation based on telemetered missile trajectory validate the effectiveness of methods proposed in this paper.
Output Regulation of the Arneodo Chaotic System
Sundarapandian Vaidyanathan
2010-01-01
This paper solves the problem of regulating the output of the Arneodo chaotic system (1981), which is one of the paradigms of chaotic dynamical systems. Explicitly, using the state feedback control laws, the output of the Arneodo chaotic system is regulated so as to track constant reference signals as well as to track periodic reference signals. The control laws are derived using the regulator equations of Byrnes and Isidori (1990), which provide the solution of the output regulation problem ...
Control design for robust stability in linear regulators: Application to aerospace flight control
Yedavalli, R. K.
1986-01-01
Time domain stability robustness analysis and design for linear multivariable uncertain systems with bounded uncertainties is the central theme of the research. After reviewing the recently developed upper bounds on the linear elemental (structured), time varying perturbation of an asymptotically stable linear time invariant regulator, it is shown that it is possible to further improve these bounds by employing state transformations. Then introducing a quantitative measure called the stability robustness index, a state feedback conrol design algorithm is presented for a general linear regulator problem and then specialized to the case of modal systems as well as matched systems. The extension of the algorithm to stochastic systems with Kalman filter as the state estimator is presented. Finally an algorithm for robust dynamic compensator design is presented using Parameter Optimization (PO) procedure. Applications in a aircraft control and flexible structure control are presented along with a comparison with other existing methods.
Chen, Zhihuan; Yuan, Yanbin; Yuan, Xiaohui; Huang, Yuehua; Li, Xianshan; Li, Wenwu
2015-05-01
A hydraulic turbine regulating system (HTRS) is one of the most important components of hydropower plant, which plays a key role in maintaining safety, stability and economical operation of hydro-electrical installations. At present, the conventional PID controller is widely applied in the HTRS system for its practicability and robustness, and the primary problem with respect to this control law is how to optimally tune the parameters, i.e. the determination of PID controller gains for satisfactory performance. In this paper, a kind of multi-objective evolutionary algorithms, named adaptive grid particle swarm optimization (AGPSO) is applied to solve the PID gains tuning problem of the HTRS system. This newly AGPSO optimized method, which differs from a traditional one-single objective optimization method, is designed to take care of settling time and overshoot level simultaneously, in which a set of non-inferior alternatives solutions (i.e. Pareto solution) is generated. Furthermore, a fuzzy-based membership value assignment method is employed to choose the best compromise solution from the obtained Pareto set. An illustrative example associated with the best compromise solution for parameter tuning of the nonlinear HTRS system is introduced to verify the feasibility and the effectiveness of the proposed AGPSO-based optimization approach, as compared with two another prominent multi-objective algorithms, i.e. Non-dominated Sorting Genetic Algorithm II (NSGAII) and Strength Pareto Evolutionary Algorithm II (SPEAII), for the quality and diversity of obtained Pareto solutions set. Consequently, simulation results show that this AGPSO optimized approach outperforms than compared methods with higher efficiency and better quality no matter whether the HTRS system works under unload or load conditions.
Directory of Open Access Journals (Sweden)
Mikhail Matveev
2008-10-01
Full Text Available In this study the metabolic network of cell energetics are investigated as a self-regulating system, the control which is described with non-classical variation method - the Bellman's equation (also known as a dynamic programming equation, on the basis of the thermodynamics of irreversible processes and the kinetics of the biochemical reactions.
Directory of Open Access Journals (Sweden)
S. Chaine
2017-06-01
Full Text Available Controllers in some power system problems are required to satisfy different performance objectives, which could be conflicting with one another. Therefore in the process of their gain tuning, when the problem is formulated within an optimization framework, it becomes necessary to achieve multiple objectives with a method multi-objective optimization method. This work presents a new method of multi-objective optimization method to optimize several controller parameters. The problem deals with optimization of controllers of doubly fed induction generator modeled for frequency regulation in an interconnected two-area wind power integrated thermal power system. The gains of integral controller of automatic generation control loop and the proportional and derivative controllers of doubly fed induction generator inertial control loop are optimized in a coordinated manner by employing a multi-objective non-dominated sorting based Cuckoo search algorithm. The algorithm is formed by synthesizing the parallel searching abilities of Cuckoo search algorithm (CSA with the non dominated sorting methodology adopted in Non dominated sorting genetic algorithm (NSGA-II. Based on the set of selected instances, the algorithm termed as non dominated sorting Cuckoo search (NSCS, exhibits better efficiency of optimization compared to the NSGA-II, CSA, genetic algorithm, and particle swarm optimization. The performance of the designed controller is further compared with the performance obtained with a modified version of NSCS, which includes the method of archiving in it. The designed set of controllers perform robustly even with the variation in disturbances, parameter and operating conditions in the system.
Discrete Optimal Multirate Techniques for Excitation Controller Design of a Synchronous Machine
Directory of Open Access Journals (Sweden)
D. I. Pappas
2016-02-01
Full Text Available An optimal control strategy based on Two-Point-Multirate Controllers (TPMRCs, is used to design a desirable excitation controller of a hydrogenerator system, in order to enhance its dynamic stability characteristics. In the TPMRCs based scheme, the control is constrained to a certain piecewise constant signal, while each of the controlled plant outputs is detected many times over a fundamental sampling period T0. On the basis on this strategy, the original problem is reduced to an associate discrete-time linear quadratic (LQ regulation problem for the performance index with cross product terms, for which a fictitious static state feedback controller is needed to be computed. Simulation results for the actual 117 MVA synchronous generator with conventional exciter supplying line to an infinite grid show the effectiveness of the proposed method which has a quite satisfactory performance.
Directory of Open Access Journals (Sweden)
Chein-Shan Liu
2013-11-01
Full Text Available Starting from a quadratic invariant manifold in terms of the residual vector ${extbf r}={extbf B}{extbf x}-{extbf b}$ for an $n$-dimensional ill-posed linear algebraic equations system ${extbf B}{extbf x}={extbf b}$, we derive an ODEs system for ${extbf x}$ which is equipped with a state feedback controller to enforce the orbit of the state vector ${extbf x}$ on a specified manifold, whose residual-norm is exponentially decayed. To realize the above idea we develop a very powerful implicit scheme based on the novel $GL(n,{mathbb R}$ Lie-group method to integrate the resultant differential algebraic equation (DAE. Through numerical tests of inverse problems we find that the present Lie-group DAE algorithm can significantly accelerate the convergence speed, and is robust enough against the random noise.
Energy Technology Data Exchange (ETDEWEB)
Pop, E.; Coroescu, T.; Poanta, A.; Pop, M.
1978-01-01
Uncontrollable dynamic operating regime of a combine has a negative effect. A consequence of the uncontrolled change in productivity and rate during cutting is total decrease in productivity. The cutters of the cutting mechanism are prematurely worn out. The quality of the coal decreases. Complications with combine control reduce productivity. The motor is exposed to the maximum loads, its service life decreases, and there is an inefficient consumption of electricity. Studies of the optimal automatic regulation of the cutting process were made by the method of modeled analysis on digital and analog machines. The method uses an electronic-automatic device with integrating circuit of domestic production (A-741, A-723). This device controls and regulates the current parameters of the acting motor. The device includes primarily an element of information type of the Hall TH traductor type, the regulating element is an electronic relay, electronic power distributor, etc.
面向长周期的交通状态反馈诱导策略%Traffic state feedback guidance strategy under long update intervals
Institute of Scientific and Technical Information of China (English)
贺正冰; 关伟
2013-01-01
Update intervals for guidance strategies used in variable message signs have to be long due to limitations of detectors and display format of broadcasting guidance information. A guidance strategy is introduced based on the traffic state instead of travel time. A traffic state feedback guidance strategy is obtained by utilizing relative stability of traffic state. A hybrid strategy considering travel time and traffic state is proposed as a solution of conflict between time-varying demand and long intervals. Simulation results show that the traffic state feedback strategy is able to meet the practical requirement both in the stability and accuracy under long update intervals, and the hybrid strategy further improves the accuracy.% 受检测器和诱导信息板显示形式的限制，诱导信息更新周期通常较长。为此，根据备选路径交通状态而非行驶时间制定诱导策略，利用交通状态相对稳定的特点，进一步提出状态反馈诱导策略；为减少长周期与时变交通需求间的矛盾及其他误差，提出了状态与时间反馈策略相结合的混合策略。仿真实验表明，面对长周期时，状态反馈策略可以满足稳定性和准确性的双重要求，混合策略则进一步提高了诱导的准确性。
Application of non-linear discretetime feedback regulators with assignable closed-loop dynamics
Directory of Open Access Journals (Sweden)
Dubljević Stevan
2003-01-01
Full Text Available In the present work the application of a new approach is demonstrated to a discrete-time state feedback regulator synthesis with feedback linearization and pole-placement for non-linear discrete-time systems. Under the simultaneous implementation of a non-linear coordinate transformation and a non-linear state feedback law computed through the solution of a system of non-linear functional equations, both the feedback linearization and pole-placement design objectives were accomplished. The non-linear state feedback regulator synthesis method was applied to a continuous stirred tank reactor (CSTR under non-isothermal operating conditions that exhibits steady-state multiplicity. The control objective was to regulate the reactor at the middle unstable steady state by manipulating the rate of input heat in the reactor. Simulation studies were performed to evaluate the performance of the proposed non-linear state feedback regulator, as it was shown a non-linear state feedback regulator clearly outperformed a standard linear one, especially in the presence of adverse disturbance under which linear regulation at the unstable steady state was not feasible.
An internal model approach to (optimal) frequency regulation in power grids
Buerger, Mathias; De Persis, Claudio; Trip, Sebastian
2014-01-01
The power grid can be regarded as a large interconnected network of different subsystems, called control area’s. In order to guarantee reliable operation the frequency is tightly regulated around its nominal value, e.g. 50 Hz. Automatic regulation of the frequency in power grid is traditionally achi
Institute of Scientific and Technical Information of China (English)
田杰; 解学军
2008-01-01
An adaptive state-feedback stabilization is inves-tigated for a class of high-order stochastic nonlinear systems in which the upper bound of the function fi(·) depends on the state xi+1 besides the states x1,…,xi and z.A smooth adaptive state-feedback controller is designed, which guarantees that the cloeed-loop system has an almost surely unique solution, and the equilibrium is globally stable in probability. A numerical simu-lation example is given to show the systematic design and the effectiveness of controller.
Regulation of Renewable Energy Sources to Optimal Power Flow Solutions Using ADMM
Energy Technology Data Exchange (ETDEWEB)
Dall-Anese, Emiliano [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Zhang, Yijian [Iowa State University; Hong, Mingyi [Iowa State University; Dhople, Sairaj [University of Minnesota; Xu, Zi [Shanghai University
2017-07-03
This paper considers power distribution systems featuring renewable energy sources (RESs), and develops a distributed optimization method to steer the RES output powers to solutions of AC optimal power flow (OPF) problems. The design of the proposed method leverages suitable linear approximations of the AC-power flow equations, and is based on the Alternating Direction Method of Multipliers (ADMM). Convergence of the RES-inverter output powers to solutions of the OPF problem is established under suitable conditions on the stepsize as well as mismatches between the commanded setpoints and actual RES output powers. In a broad sense, the methods and results proposed here are also applicable to other distributed optimization problem setups with ADMM and inexact dual updates.
Regulation of Renewable Energy Sources to Optimal Power Flow Solutions Using ADMM: Preprint
Energy Technology Data Exchange (ETDEWEB)
Zhang, Yijian; Hong, Mingyi; Dall' Anese, Emiliano; Dhople, Sairaj; Xu, Zi
2017-03-03
This paper considers power distribution systems featuring renewable energy sources (RESs), and develops a distributed optimization method to steer the RES output powers to solutions of AC optimal power flow (OPF) problems. The design of the proposed method leverages suitable linear approximations of the AC-power flow equations, and is based on the Alternating Direction Method of Multipliers (ADMM). Convergence of the RES-inverter output powers to solutions of the OPF problem is established under suitable conditions on the stepsize as well as mismatches between the commanded setpoints and actual RES output powers. In a broad sense, the methods and results proposed here are also applicable to other distributed optimization problem setups with ADMM and inexact dual updates.
Institute of Scientific and Technical Information of China (English)
Chen Kaiyan; Si Junhong; Zhou Fubao; Zhang Renwei; Shao He; Zhao Hongmei
2015-01-01
In mine ventilation networks, the reasonable airflow distribution is very important for the production safety and economy. Three basic problems of the natural, full-controlled and semi-controlled splitting were reviewed in the paper. Aiming at the high difficulty semi-controlled splitting problem, the general nonlinear multi-objectives optimization mathematical model with constraints was established based on the theory of mine ventilation networks. A new algorithm, which combined the improved differential evaluation and the critical path method (CPM) based on the multivariable separate solution strategy, was put forward to search for the global optimal solution more efficiently. In each step of evolution, the feasible solutions of air quantity distribution are firstly produced by the improved differential evolu-tion algorithm, and then the optimal solutions of regulator pressure drop are obtained by the CPM. Through finite steps iterations, the optimal solution can be given. In this new algorithm, the population of feasible solutions were sorted and grouped for enhancing the global search ability and the individuals in general group were randomly initialized for keeping diversity. Meanwhile, the individual neighbor-hood in the fine group which may be closely to the optimal solutions were searched locally and slightly for achieving a balance between global searching and local searching, thus improving the convergence rate. The computer program was developed based on this method. Finally, the two ventilation networks with single-fan and multi-fans were solved. The results show that this algorithm has advantages of high effectiveness, fast convergence, good robustness and flexibility. This computer program could be used to solve large-scale generalized ventilation networks optimization problem in the future.
Directory of Open Access Journals (Sweden)
DINAKAR eCHALLABATHULA
2016-02-01
results indicated the importance of AOX pathway in optimizing photosynthesis under both hyper-osmotic stress and sub-optimal temperatures. Regulation of ROS through redox couples related to malate valve and antioxidant system by AOX pathway to optimize photosynthesis under these stresses are discussed.
Li, Zhihai; Li, Hui; Chen, Songjie; Froehlich, Toni; Yi, Chenyi; Schönenberger, Christian; Calame, Michel; Decurtins, Silvio; Liu, Shi-Xia; Borguet, Eric
2014-06-25
We report a novel strategy for the regulation of charge transport through single molecule junctions via the combination of external stimuli of electrode potential, internal modulation of molecular structures, and optimization of anchoring groups. We have designed redox-active benzodifuran (BDF) compounds as functional electronic units to fabricate metal-molecule-metal (m-M-m) junction devices by scanning tunneling microscopy (STM) and mechanically controllable break junctions (MCBJ). The conductance of thiol-terminated BDF can be tuned by changing the electrode potentials showing clearly an off/on/off single molecule redox switching effect. To optimize the response, a BDF molecule tailored with carbodithioate (-CS2(-)) anchoring groups was synthesized. Our studies show that replacement of thiol by carbodithioate not only enhances the junction conductance but also substantially improves the switching effect by enhancing the on/off ratio from 2.5 to 8.
Chen, Yuhang; Schellekens, Michiel; Zhou, Shiwei; Cadman, Joseph; Li, Wei; Appleyard, Richard; Li, Qing
2011-08-01
Tissue scaffolds aim to provide a cell-friendly biomechanical environment for facilitating cell growth. Existing studies have shown significant demands for generating a certain level of wall shear stress (WSS) on scaffold microstructural surfaces for promoting cellular response and attachment efficacy. Recently, its role in shear-induced erosion of polymer scaffold has also drawn increasing attention. This paper proposes a bi-directional evolutionary structural optimization (BESO) approach for design of scaffold microstructure in terms of the WSS uniformity criterion, by downgrading highly-stressed solid elements into fluidic elements and/or upgrading lowly-stressed fluidic elements into solid elements. In addition to this, a computational model is presented to simulate shear-induced erosion process. The effective stiffness and permeability of initial and optimized scaffold microstructures are characterized by the finite element based homogenization technique to quantify the variations of mechanical properties of scaffold during erosion. The illustrative examples show that a uniform WSS is achieved within the optimized scaffold microstructures, and their architectural and biomechanical features are maintained for a longer lifetime during shear-induced erosion process. This study provides a mathematical means to the design optimization of cellular biomaterials in terms of the WSS criterion towards controllable shear-induced erosion.
Directory of Open Access Journals (Sweden)
Julia Steinbach
2015-06-01
Full Text Available Parents’ attitudes towards self-regulated learning and their influence on children’s learning behav-ior have been a rather neglected area of research. One reason for this is very likely the lack of a suitable measurement instrument. We adapted a measurement instrument designed to assess prima-ry teachers’ attitudes towards self-regulated learning for use with parents and validated it on a sample of 664 parents and their primary-school children. The instrument measures parents’ attitudes towards various cognitive and metacognitive strategies that have been shown to be particularly effective in self-regulated learning processes of primary-school children. In a first step, the factor structure and the theoretical appropriateness of the instrument was verified via a confirmatory factor analysis. In a second step, the validity of the scale was tested with a structural equation model. Parents’ attitudes towards self-regulated learning predicted how they facilitated the learning environment of their children; we measured parents’ learning-environment facilitation with two scales: parental autonomy support during learning and setting up children’s homework workspaces. The path between attitudes towards self-regulated learning and learning-environment facilitation was mediated by parents’ self-efficacy regarding learning support. The criterion variable, parents’ learning-environment facilitation, then, in turn, predicted students’ school achievement as assessed with grades and a standardized test. These initial results suggest that the adapted instrument is useful for assessing parents’ attitudes towards self-regulated learning and that these attitudes seem to influence the kind of learning environment parents create.
Institute of Scientific and Technical Information of China (English)
Xiao-xiao LI; Xuan-yin WANG; Fu-shang LI
2008-01-01
With the analysis on regulating system in 200 MW steam turbine, the necessity of appending the fast-opening function to the original system is set forth and a new type of fast-opening mechanism is devised. The mathematical model of system is built up. With the use of AMESIM software, the displacement curve of the piston, the force curve of the cartridge valve spool, the pressure curve and the flux curve in the regulation process are obtained based on simulation. The performances of three fast-opening systems composed of cartridge valves with different diameters are compared. Based on the analysis on factors that affect the execution time of fast-opening, the dead zone of the fast-opening system is put forward, To overcome the defect, different operation modes are adopted for different zones. The result shows that with the increase of the valve diameter, the regulating time in the dead zone significantly exceeds the fast-opening time in the whole journey. Accordingly, the optimization operation tactic in the dead zone and the qualification conditions are brought forward. The fast-opening system composed of 32 mm cartridge valves is taken as an example with use of the tactic. The simulation result shows that the maximum regulating time is shortened by 509 ms.
Mooij, Ton; Dijkstra, Elma; Walraven, Amber; Kirschner, Paul A.
2014-01-01
At the start of preschool, four-year-old pupils differ in their development, including the capacity to self-regulate their playing and learning. In preschool and primary school, educational processes are generally adapted to the mean age of the pupils in class. The same may apply to ICT-based
Mooij, Ton; Dijkstra, Elma; Walraven, Amber; Kirschner, Paul A.
2014-01-01
At the start of preschool, four-year-old pupils differ in their development, including the capacity to self-regulate their playing and learning. In preschool and primary school, educational processes are generally adapted to the mean age of the pupils in class. The same may apply to ICT-based pupil-
Trip, Sebastian; Buerger, Mathias; De Persis, Claudio
2016-01-01
This paper studies the problem of frequency regulation in power grids under unknown and possible time-varying load changes, while minimizing the generation costs. We formulate this problem as an output agreement problem for distribution networks and address it using incremental passivity and distrib
Directory of Open Access Journals (Sweden)
Katerina Peterková
2011-03-01
Full Text Available This paper was presented at the first meeting of the NSU study group “Conceptions of ethical and social values in post-secular society: Towards a new ethical imagination in a cosmopolitan world society”, held on January 28-30, 2011 at Copenhagen Business School. First, this paper examines the voluntary (ethical v. mandatory (legal basis of corporate social responsibility (CSR. Second, it examines the relationship between CSR, law and business ethics. Third, it tries to answer the question if there is a need for a hard[2] legal regulation of CSR within international supply relationships or if ethical norms, e.g. expressed in the form of self-regulation, may better serve the purpose. And finally, it suggests possible ways for the future development of suitable regulatory methods for enhancing social standards within international supply chains. The questions are approached solely from the perspectives of legal theory and socio-legal analysis.
An Optimization Model for Urban Readjustment and Subdivision Regulations in Turkey
Kucukmehmetoglu, Mehmet; Geymen, Abdurrahman
2014-01-01
Rapid urbanization in Turkey has resulted in various problems in urban spaces such as squatter houses, substandard subdivisions, and low-quality urban environment. In order to facilitate self-motivated developments, government has enacted various laws and bylaws and made amendments in current legal frameworks. The 18th Article (Dough Rule) of the Land and Building Development Law (İmar Kanunu) has various and extensive applications in regulating and restructuring cadastral properties. One of ...
Optimal Transmission Capacity under Nodal Pricing and Incentive Regulation for Transco
Tanaka, Makoto
2005-01-01
This paper examines regulatory incentive mechanisms for efficient investment in the transmission network, taking into account both technological externalities among transmission lines and information asymmetry between the regulator and the transmission company (Transco). First, by adding extra constraints associated with the power flow, we develop an extended price cap mechanism that can internalize technological externalities among transmission lines. We show that this new mechanism induces ...
Sahoo, Avimanyu; Jagannathan, Sarangapani
2017-02-01
In this paper, an event-driven stochastic adaptive dynamic programming (ADP)-based technique is introduced for nonlinear systems with a communication network within its feedback loop. A near optimal control policy is designed using an actor-critic framework and ADP with event sampled state vector. First, the system dynamics are approximated by using a novel neural network (NN) identifier with event sampled state vector. The optimal control policy is generated via an actor NN by using the NN identifier and value function approximated by a critic NN through ADP. The stochastic NN identifier, actor, and critic NN weights are tuned at the event sampled instants leading to aperiodic weight tuning laws. Above all, an adaptive event sampling condition based on estimated NN weights is designed by using the Lyapunov technique to ensure ultimate boundedness of all the closed-loop signals along with the approximation accuracy. The net result is event-driven stochastic ADP technique that can significantly reduce the computation and network transmissions. Finally, the analytical design is substantiated with simulation results.
Franklin, Nicholas T; Frank, Michael J
2015-12-25
Convergent evidence suggests that the basal ganglia support reinforcement learning by adjusting action values according to reward prediction errors. However, adaptive behavior in stochastic environments requires the consideration of uncertainty to dynamically adjust the learning rate. We consider how cholinergic tonically active interneurons (TANs) may endow the striatum with such a mechanism in computational models spanning three Marr's levels of analysis. In the neural model, TANs modulate the excitability of spiny neurons, their population response to reinforcement, and hence the effective learning rate. Long TAN pauses facilitated robustness to spurious outcomes by increasing divergence in synaptic weights between neurons coding for alternative action values, whereas short TAN pauses facilitated stochastic behavior but increased responsiveness to change-points in outcome contingencies. A feedback control system allowed TAN pauses to be dynamically modulated by uncertainty across the spiny neuron population, allowing the system to self-tune and optimize performance across stochastic environments.
Chiou, J.-S.; Liu, M.-T.
2008-02-01
As a powerful machine-learning approach to pattern recognition problems, the support vector machine (SVM) is known to easily allow generalization. More importantly, it works very well in a high-dimensional feature space. This paper presents a nonlinear active suspension controller which achieves a high level performance by compensating for actuator dynamics. We use a linear quadratic regulator (LQR) to ensure optimal control of nonlinear systems. An LQR is used to solve the problem of state feedback and an SVM is used to address the question of the estimation and examination of the state. These two are then combined and designed in a way that outputs feedback control. The real-time simulation demonstrates that an active suspension using the combined SVM-LQR controller provides passengers with a much more comfortable ride and better road handling.
Banks, H. T.; Ito, K.
1991-01-01
A hybrid method for computing the feedback gains in linear quadratic regulator problem is proposed. The method, which combines use of a Chandrasekhar type system with an iteration of the Newton-Kleinman form with variable acceleration parameter Smith schemes, is formulated to efficiently compute directly the feedback gains rather than solutions of an associated Riccati equation. The hybrid method is particularly appropriate when used with large dimensional systems such as those arising in approximating infinite-dimensional (distributed parameter) control systems (e.g., those governed by delay-differential and partial differential equations). Computational advantages of the proposed algorithm over the standard eigenvector (Potter, Laub-Schur) based techniques are discussed, and numerical evidence of the efficacy of these ideas is presented.
Wei, Yuquan; Zhao, Yue; Wang, Huan; Lu, Qian; Cao, Zhenyu; Cui, Hongyang; Zhu, Longji; Wei, Zimin
2016-12-01
The study was conducted to investigate the influence of biochar and/or phosphate-solubilizing bacteria (PSB) inoculants on microbial biomass, bacterial community composition and phosphorus (P) fractions during kitchen waste composting amended with rock phosphate (RP). There were distinct differences in the physic-chemical parameters, the proportion of P fractions and bacterial diversity in different treatments. The contribution of available P fractions increased during composting especially in the treatment with the addition of PSB and biochar. Redundancy analysis showed that bacterial compositions were significantly influenced by P content, inoculation and biochar. Variance partitioning further showed that synergy of inoculated PSB and indigenous bacterial communities and the joint effect between biochar and bacteria explained the largest two proportion of the variation in P fractions. Therefore, the combined application of PSB and biochar to improve the inoculation effect and an optimized regulating method were suggested based on the distribution of P fractions.
Response of a quarter car model with optimal magnetorheological damper parameters
Prabakar, R. S.; Sujatha, C.; Narayanan, S.
2013-04-01
In this paper, the control of the stationary response of a quarter car model to random road excitation with a Magnetorheological (MR) damper as a semi-active suspension device is considered. The MR damper is a hypothetical analytical damper whose parameters are determined optimally using a multi-objective optimization technique Non-dominated Sorting Genetic Algorithm II (NSGA II). The hysteretic behaviour of the MR damper is characterized using Bingham and modified Bouc-Wen models. The multi-objective optimization problem is solved by minimizing the difference between the root mean square (rms) sprung mass acceleration, suspension stroke and the road holding responses of the quarter car model with the MR damper and those of the active suspension system based on linear quadratic regulator (LQR) control with the constraint that the MR damper control force lies between ±5 percent of the LQR control force. It is observed that the MR damper suspension systems with optimal parameters perform an order of magnitude better than the passive suspension and perform as well as active suspensions with limited state feedback and closer to the performance of fully active suspensions.
Current control loop design and analysis based on resonant regulators for microgrid applications
DEFF Research Database (Denmark)
Federico, de Bosio; Pastorelli, Michelle; de Sousa Ribeiro, Luiz Antonio
2015-01-01
Voltage and current control loops play an important role in the performance of microgrids employing power electronics voltage source inverters. Correct design of feedback loops is essential for the proper operation of these systems. This paper analyzes the influence of state feedback cross......-coupling in the design of resonant regulators for inner current loops in power converters operating in standalone microgrids. It is also demonstrated that the effect of state feedback cross-coupling degrades the performance of the control loops by increasing the steady-state error. Different resonant regulators...... structures are analyzed and compared, performing experimental tests to validate the results of the theoretical analysis....
Directory of Open Access Journals (Sweden)
Mohammad Hosein Rezaei
2011-10-01
Full Text Available Transformers perform many functions such as voltage transformation, isolation and noise decoupling. They are indispensable components in electric power distribution system. However, at low frequencies (50 Hz, they are one of the heaviest and the most expensive equipment in an electrical distribution system. Nowadays, electronic power transformers are used instead of conventional power transformers that do voltage transformation and power delivery in power system by power electronic converter. In this paper, the structure of distribution electronic power transformer (DEPT are analized and then paid attention on the design of a linear-quadratic-regulator (LQR with integral action to improve dynamic performance of DEPT with voltage unbalance, voltage sags, voltage harmonics and voltage ﬂicker. The presentation control strategy is simulated by MATLAB/SIMULINK. In addition, the results that are in terms of dc-link reference voltage, input and output voltages clearly show that a better dynamic performance can be achieved by using the LQR method when compared to other techniques.
Periphyton: an important regulator in optimizing soil phosphorus bioavailability in paddy fields.
Wu, Yonghong; Liu, Junzhuo; Lu, Haiying; Wu, Chenxi; Kerr, Philip
2016-11-01
Periphyton is ubiquitous in paddy field, but its importance in influencing the bioavailability of phosphorus (P) in paddy soil has been rarely recognized. A paddy field was simulated in a greenhouse to investigate how periphyton influences P bioavailability in paddy soil. Results showed that periphyton colonizing on paddy soil greatly reduced P content in paddy floodwater but increased P bioavailability of paddy soil. Specifically, all the contents of water-soluble P (WSP), readily desorbable P (RDP), algal-available P (AAP), and NaHCO3-extractable P (Olsen-P) in paddy soil increased to an extent compared to the control (without periphyton) after fertilization. In particular, Olsen-P was the most increased P species, up to 216 mg kg(-1) after fertilization, accounting for nearly 60 % of total phosphorus (TP) in soil. The paddy periphyton captured P up to 1.4 mg g(-1) with Ca-P as the dominant P fraction and can be a potential crop fertilizer. These findings indicated that the presence of periphyton in paddy field benefited in improving P bioavailability for crops. This study provides valuable insights into the roles of periphyton in P bioavailability and migration in a paddy ecosystem and technical support for P regulation.
Masani, Mat Yunus Abdul; Noll, Gundula; Parveez, Ghulam Kadir Ahmad; Sambanthamurthi, Ravigadevi; Prüfer, Dirk
2013-09-01
Oil palm protoplasts are suitable as a starting material for the production of oil palm plants with new traits using approaches such as somatic hybridization, but attempts to regenerate viable plants from protoplasts have failed thus far. Here we demonstrate, for the first time, the regeneration of viable plants from protoplasts isolated from cell suspension cultures. We achieved a protoplast yield of 1.14×10(6) per gram fresh weight with a viability of 82% by incubating the callus in a digestion solution comprising 2% cellulase, 1% pectinase, 0.5% cellulase onuzuka R10, 0.1% pectolyase Y23, 3% KCl, 0.5% CaCl2 and 3.6% mannitol. The regeneration of protoplasts into viable plants required media optimization, the inclusion of plant growth regulators and the correct culture technique. Microcalli derived from protoplasts were obtained by establishing agarose bead cultures using Y3A medium supplemented with 10μM naphthalene acetic acid, 2μM 2,4-dichlorophenoxyacetic acid, 2μM indole-3-butyric acid, 2μM gibberellic acid and 2μM 2-γ-dimethylallylaminopurine. Small plantlets were regenerated from microcalli by somatic embryogenesis after successive subculturing steps in medium with limiting amounts of growth regulators supplemented with 200mg/l ascorbic acid.
Directory of Open Access Journals (Sweden)
Liping Xiong
2015-08-01
Full Text Available Sustained molecular oscillations are ubiquitous in biology. The obtained oscillatory patterns provide vital functions as timekeepers, pacemakers and spacemarkers. Models based on control theory have been introduced to explain how specific oscillatory behaviors stem from protein interaction feedbacks, whereas the energy dissipation through the oscillating processes and its role in the regulatory function remain unexplored. Here we developed a general framework to assess an oscillator's regulation performance at different dissipation levels. Using the Escherichia coli MinCDE oscillator as a model system, we showed that a sufficient amount of energy dissipation is needed to switch on the oscillation, which is tightly coupled to the system's regulatory performance. Once the dissipation level is beyond this threshold, unlike stationary regulators' monotonic performance-to-cost relation, excess dissipation at certain steps in the oscillating process damages the oscillator's regulatory performance. We further discovered that the chemical free energy from ATP hydrolysis has to be strategically assigned to the MinE-aided MinD release and the MinD immobilization steps for optimal performance, and a higher energy budget improves the robustness of the oscillator. These results unfold a novel mode by which living systems trade energy for regulatory function.
Brooks, Steven S
2017-06-01
Physician-inventors are in a unique position to identify unserved patient needs, and innovate solutions to clinical problems. These solutions may also have associated commercial opportunities. The logistics of developing these medical products, however, can seem a daunting task. One of the primary barriers in the United States is the regulatory process of the Food and Drug Administration (FDA). In this article, we will explore the risk-based approach used by the FDA which forms a framework to consider the regulatory pathway and the process to gain regulatory clearance or approval for medical devices. Inherent device properties and the procedural risk of the devices will determine the rigor with which they are scrutinized by FDA, and the evidentiary requirements to legally market them. Data and evidentiary development will vary depending on risk and regulatory precedent and may or may not require clinical data This regulatory paradigm will determine into which risk-based device class they fit, and whether they are regulated under the 510(k) or premarket approval application pathways. The FDA, although gatekeeper of the US market and tasked with determining which products are safe and effective, can be a powerful ally for product development. They have significant scientific and medical expertise, and mechanisms to both provide guidance, and also to consider novel approaches to product development and evidence development. Early interaction for routine and novel products alike can result in expedited and efficient development. This collaborative approach can be best practice to most expeditiously develop the next generation of products, getting them into the hands of US doctors and into the treatment of US patients. Copyright © 2017. Published by Elsevier Inc.
Institute of Scientific and Technical Information of China (English)
蒋朝辉; 桂卫华; 谢永芳; 阳春华
2009-01-01
In this paper, the problem of delay-dependent stabilization for singular linear continuous-time systems with multiple internal incommensurate constant point delays (SLCS-MIID) is investigated. The condition when a singular system subject to point delays is regular independent of time delays is given and it can be easily tested with numerical or algebraic methods. Based on the Lyapunov-Krasovskii functional approach and the descriptor integral-inequality lemma, a sufficient condition for delay-dependent stability is obtained. The main idea is to design multiple memory state feedback control laws such that the resulting closed-loop system is regular independently of time delays, impulse free, and asymptotically stable via solving some strict linear matrix inequalities (LMIs) problem. An explicit expression for the desired memory state feedback control law is also given. Finally, a numerical example illustrates effectiveness and availability for the proposed method.
Chauhan, Manvendra S; Kumar, Anil; Pathak, Kamla
2012-12-01
A nondisintegrating, floating asymmetric membrane capsule (FAMC) was developed to achieve site-specific osmotic flow of a highly water-soluble drug, ranitidine hydrochloride (RHCl), in a controlled manner. Solubility suppression of RHCl was achieved by the common ion effect, using optimized coated sodium chloride as a formulation component. The capsular wall of FAMC was prepared by the phase inversion process wherein the polymeric membrane was precipitated on glass pins by dipping them in a solution of cellulose acetate followed by quenching. Central composite design was utilized to investigate the influence of independent variables, namely, level(s) of membrane former, pore former, and osmogen, on percent cumulative drug release (response). The release mechanism of RHCl through FAMC was confirmed as osmotic pumping. The asymmetry of the membrane was characterized by scanning electron microscopy that revealed a dense nonporous outer region of membrane supported by an inner porous region. Differential scanning calorimetry indicated no incompatibility between the drug and excipients. In vitro drug release in three biorelevant media, pH 2.5 (low fed), pH 4.5 (intermediate fed), and pH 6.5 (high fed), demonstrated pH-independent release of RHCl (P > 0.05). Floating ability for 12 h of the optimized FAMC9 was visually examined during the in vitro release studies that showed maximal drug release with zero-order kinetics (r (2) = 0.9991). Thus, a novel osmotically regulated floating capsular system was developed for site-specific delivery of RHCl.
Optimal Control for a Class of Chaotic Systems
Directory of Open Access Journals (Sweden)
Jianxiong Zhang
2012-01-01
Full Text Available This paper proposes the optimal control methods for a class of chaotic systems via state feedback. By converting the chaotic systems to the form of uncertain piecewise linear systems, we can obtain the optimal controller minimizing the upper bound on cost function by virtue of the robust optimal control method of piecewise linear systems, which is cast as an optimization problem under constraints of bilinear matrix inequalities (BMIs. In addition, the lower bound on cost function can be achieved by solving a semidefinite programming (SDP. Finally, numerical examples are given to illustrate the results.
Gestsdottir, Steinunn; Geldhof, G. John; Paus, Tomáš; Freund, Alexandra M.; Adalbjarnardottir, Sigrun; Lerner, Jacqueline V.; Lerner, Richard M.
2015-01-01
We address how to conceptualize and measure intentional self-regulation (ISR) among adolescents from four cultures by assessing whether ISR (conceptualized by the SOC model of Selection, Optimization, and Compensation) is represented by three factors (as with adult samples) or as one "adolescence-specific" factor. A total of 4,057 14-…
Output Regulation of the Arneodo Chaotic System
Directory of Open Access Journals (Sweden)
Sundarapandian Vaidyanathan
2010-08-01
Full Text Available This paper solves the problem of regulating the output of the Arneodo chaotic system (1981, which is one of the paradigms of chaotic dynamical systems. Explicitly, using the state feedback control laws, the output of the Arneodo chaotic system is regulated so as to track constant reference signals as well as to track periodic reference signals. The control laws are derived using the regulator equations of Byrnes and Isidori (1990, which provide the solution of the output regulation problem for nonlinear control systems involving neutrally stable exosystem dynamics. Numerical results are shown to verify the results.
Haro-Monteagudo, David; Solera, Abel; Andreu, Joaquín
2017-01-01
Droughts are a major threat to water resources systems management. Timely anticipation results crucial to defining strategies and measures to minimise their effects. Water managers make use of monitoring systems in order to characterise and assess drought risk by means of indices and indicators. However, there are few systems currently in operation that are capable of providing early warning with regard to the occurrence of a drought episode. This paper proposes a novel methodology to support and complement drought monitoring and early warning in regulated water resources systems. It is based in the combined use of two models, a water resources optimization model and a stochastic streamflow generation model, to generate a series of results that allow evaluating the future state of the system. The results for the period 1998-2009 in the Jucar River Basin (Spain) show that accounting for scenario change risk can be beneficial for basin managers by providing them with information on the current and future drought situation at any given moment. Our results show that the combination of scenario change probabilities with the current drought monitoring system can represent a major advance towards improved drought management in the future, and add a significant value to the existing national State Index (SI) approach for early warning purposes.
DEFF Research Database (Denmark)
Møller, Michael
2013-01-01
I begyndelsen af 2012 nedsatte regeringen et udvalg, ”Udvalg om systemisk Vigtige Finansielle Institutter i Danmark”, som afgav rapport i marts 2013. I denne artikel ses indledningsvis på de overvejelser, man som udvalg må gøre sig i forbindelse med det kommissorium, man får. Derefter ses dels på...
DEFF Research Database (Denmark)
Justinussen, Jessica; Holm, A; Kornum, B R
2015-01-01
The hypocretin/orexin system regulates, among other things, sleep and energy homeostasis. The system is likely regulated by both homeostatic and circadian mechanisms. Little is known about local differences in the regulation of hypocretin activity. The aim of this study was to establish an optimi......The hypocretin/orexin system regulates, among other things, sleep and energy homeostasis. The system is likely regulated by both homeostatic and circadian mechanisms. Little is known about local differences in the regulation of hypocretin activity. The aim of this study was to establish...... an optimized peptide quantification method for hypocretin-1 extracted from different mouse brain areas and use this method for investigating circadian fluctuations of hypocretin-1 levels in these areas. The results show that hypocretin-1 peptide can be extracted from small pieces of intact tissue......, with sufficient yield for measurements in a standard radioimmunoassay. Utilizing the optimized method, it was found that prepro-hypocretin mRNA and peptide show circadian fluctuations in the mouse brain. This study further demonstrates that the hypocretin-1 peptide level in the frontal brain peaks during dark...
Energy Technology Data Exchange (ETDEWEB)
Didriksen, H.; Sandvig Nielsen, J.; Weel Hansen, M.
2001-06-01
The aim of the project is to present a procedure to optimize existing drying processes. The optimization deals with energy consumption, capacity utilization and product quality. Other factors can also be included in the optimization, e.g. minimization of volume of discharged air. The optimization of existing drying processes will use calculation tool based on a mathematical simulation model for the process to calculate the most optimum operation situation on the basis of given conditions. In the project mathematical models have been developed precisely with this aim. The calculation tools have been developed with a user interface so that the tools can be used by technical staff in industrial companies and by consultants. The project also illustrates control of drying processes. Based on the developed models, the effect of using different types of control strategies by means of model simulations is illustrated. Three types of drying processes are treated: drum dryers, disc dryers and drying chambers. The work with the development of the simulation models has been very central in the project, as these have to be the basis for the optimization of the processes. The work is based on a large amount of information from academical literature and knowledge and experience about modelling thermal processes at dk-TEKNIK. The models constitute the core in the simulation programmes. The models describe the most important physical effects in connection with mass and energy transfer and transport under the drying for the three treated drying technologies. (EHS)
管制消费的最优替代政策%Optimal Replacement Policy of Regulation Consumption
Institute of Scientific and Technical Information of China (English)
李贺明; 张勤; 李进伟
2013-01-01
Since reform and opening up, China has let go of the controls in the areas of the economy, and the vitality of market is constantly enhancing. Socialist development mode with Chinese characteristics is emerging as a growth engine of the global economy. But in recent years, as the economic growth and more and more serious resource environment contradictions, Government carried out more and more restrictions on the micro-economic consumer behavior and abuse. This article starts from the perspective of improving public services, and proposes theoretical basis for transforming government functions and creating a service-oriented government and the optimal replacement policy of regulation consumption.%改革开放以来，我国在经济领域不断放开管制，市场主体活力不断增强，有中国特色的社会主义发展模式逐步成为全球经济的增长引擎之一。但近年来，随着经济增长和资源环境的矛盾越来越突出，政府对微观经济体的消费行为限制及弊端也越来越多。本文从改进政府公共服务的角度出发，提出转变政府职能、创建服务型政府的理论依据和管制消费的替代政策。
基于扩张状态观测器的航天器时延状态反馈控制%Spacecraft time-delay state feedback control based on extended state observer
Institute of Scientific and Technical Information of China (English)
史小平; 毕显婷; 杨婧
2016-01-01
研究了刚性航天器的时延姿态稳定控制问题。首先建立了基于修正罗德里格斯参数（modified ro-drigues parameters，MRPs）的航天器非线性状态模型，具有确定上界的时延项在状态反馈控制律中体现。通过构造Lyapunov-Krasovskii 泛函进行稳定性分析，由此得到保证系统渐近稳定的线性矩阵不等式，依此设计状态反馈控制系数矩阵。考虑到航天器三轴间的耦合非线性项，利用扩张状态观测器（extended state observer，ESO）方法，设计了二阶非线性扩张状态观测器，以获得航天器系统内部状态向量并用于状态反馈控制律。为便于工程实际应用，仿真中将 MRPs 响应输出转换为欧拉角响应，仿真结果表明，本文所设计的控制系统能保证航天器三轴姿态稳定。%This paper researches the problem of rigid body spacecraft time-delay attitude stabilization. Firstly,the spacecraft nonlinear state model based on modified rodrigues parameters (MRPs)is established,the time delay term with certain upper boundary is modeled in state feedback control law.Lyapunov-Krasovskii functional is constructed for this nonlinear time-delay system to achieve asymptotic stabilization,linear matrix inequalities are accordingly obtained and the state feedback control coefficients matrixes are thereby computed with.Concerning the three-axis coupling nonlinear terms in spacecraft,the extended state observer (ESO) method is used to design a two rank nonlinear ESO,the spacecraft system internal state vector is therefore ac-quired and used in the aforementioned state feedback control law.For the convenience of engineering applica-tion,the MRPs state vector is converted to Euler angles in simulation.The simulation results show the efficient of the state feedback control law with three-axis attitude asymptotic stabilization achieved.
Institute of Scientific and Technical Information of China (English)
赵立纯; 荆海英; 陶凤梅
2001-01-01
The permanent problem for four-species Lotka-Volterra models is investigated, some sufficient and necessary conditions for a model to be permanent are obtained by using linear state feedback.%本文研究了四种群Lotka-Volterra模型的永久持续生存问题，给出了通过线性状态反馈使四种群Lotka-Volterra模型永久持续生存的一些充分和必要条件.
Output tracking and regulation of nonlinear system based on Takagi-Sugeno fuzzy model.
Ma, X J; Sun, Z Q
2000-01-01
On the basis of the Takagi-Sugeno (TS) fuzzy model, this paper discusses in detail the following three problems: (1) output tracking of the nonlinear system; (2) output regulation of the nonlinear system via a state feedback; (3) output regulation of the nonlinear system via a error feedback. Numerical simulations are given to illustrate the soundness of these results and the effectiveness of the new methodology solving the output tracking and regulation problem of the nonlinear system.
Institute of Scientific and Technical Information of China (English)
苗建明; 孟军
2011-01-01
目前,海上地震石油勘探系统中实际使用的拖缆自动定深器大多采用PID控制算法,以及采用压力传感器实时采集压力来进行深度闭环控制.本文在建立自动定深器状态反馈方程的基础上,设计了带全维状态观测器的状态反馈控制系统,并且对该系统进行了仿真分析.结果表明,利用本文所设计的控制器,该系统的动态特性明显优于经典控制器,可以为后续拖缆深度控制系统控制算法的优化提供参考.%The depth controller of the marine seismic towed system mostly adopts the depth closed loop with PID control arithmetic currently, the state feedback control system based on the state feedback equations of the depth controller is designed in this paper,then the simulation is carried out. The result show that making use of the controller designed in this paper, the dynamic characteristic surpasses the classic controller obviously,the method of the towed cable depth control system provide a reference for the follow-up.
Wang, Liang; Liu, Zunying; Zhao, Yuanhui; Dong, Shiyuan; Zeng, Mingyong; Yang, HuiCheng
2014-01-01
Three freezing-point regulators (glycine, sodium chloride and D-sorbitol) were employed to optimize thermophysical properties of Pacific white shrimp (Litopenaeus vannamei) using response surface methodology (RSM). The independent variables were glycine content (0.250–1.250 %), sodium chloride content (0.500–2.500 %) and D-sorbitol content (0.125–0.625 %) and analysis of variance showed that the effects of glycine, sodium chloride and D-sorbitol on the thermophysical properties were statistic...
Wang, Chongwen; Yu, Xiao; Lan, Weiyao
2014-10-01
To improve transient performance of output response, this paper applies composite nonlinear feedback (CNF) control technique to investigate semi-global output regulation problems for linear systems with input saturation. Based on a linear state feedback control law for a semi-global output regulation problem, a state feedback CNF control law is constructed by adding a nonlinear feedback part. The extra nonlinear feedback part can be applied to improve the transient performance of the closed-loop system. Moreover, an observer is designed to construct an output feedback CNF control law that also solves the semi-global output regulation problem. The sufficient solvability condition of the semi-global output regulation problem by CNF control is the same as that by linear control, but the CNF control technique can improve the transient performance. The effectiveness of the proposed method is illustrated by a disturbance rejection problem of a translational oscillator with rotational actuator system.
Institute of Scientific and Technical Information of China (English)
刘艳; 蒋卫生; 黄发伦
2004-01-01
It has been observed that for many stable feedback control systems, the introduction of arbitrarily small delays into the loop causes instability. Therefore, robustness of stablility with respect to small delays is of great importance. The authors study the robustness with respect to small delays for exponential stability of Pritchard-Salamon systems with admissible state feedback,i.e. the exponential stability of the following systems are equivalent:(x(t)=S(t)x0+∫t0S(t-s)ds)(u(t)=Fx(t),x0∈V,t≥0)(x(t)=S(t)x0+∫t0S(t-s)BFx(s-r)ds)(u(t)=Fx(t-r),x0∈V,t≥0)and obtain a mumber of necessary and sufficient conditions,particularly,frepuency domain characterization for robustness with respect to small delays for exponential stability.
Institute of Scientific and Technical Information of China (English)
孙林; 郑煜; 姚娟
2011-01-01
Robust non-fragile H∞ state feedback control for uncertainty discrete singular systems was investigated, and the necessary and sufficient condition for the existence of controller was obtained. Furthermore, the desired controller was presented via linear matrix inequality. Finally, a numerical simulation illustrated this effectiveness of the proposed method.%研究了不确定离散奇异系统的鲁棒非脆弱H∞状态反馈控制,得到了控制器存在的充要条件.并通过线性矩阵不等式进一步给出了控制器的具体设计,最后利用数值仿真验证了本文方法的有效性.
Institute of Scientific and Technical Information of China (English)
张东凯; 王朝立; 陈华
2012-01-01
Based on the backstepping approach,an adaptive state-feedback backstepping controller is designed for stochastic nonholonomic systems with uncertain nonlinear terms and uncertain nonlinear coefficients.A switching control strategy for the original system is developed which can guarantee that the closed-loop system is almost asymptotically stable at the zero equilibrium in probability.A simulation example is provided to illustrate the effectiveness of the controller.%基于反步技术,对带有不确定非线性项和不确定非线性系数的随机非完整链式系统,设计了自适应状态反馈镇定器.给出了能够保证系统依概率几乎渐近稳定到平衡点的切换控制.最后用仿真验证了控制器的有效性.
车辆悬挂系统的状态反馈控制稳定性分析%Analysis of State Feedback Control Stability of a Vehicle Suspension System
Institute of Scientific and Technical Information of China (English)
杨杭旭
2014-01-01
Theoretical analysis of the active suspension closed-loop system of vehicles with a state feedback control adopted is made, the conditions required to realize system feedback gain are given, which provides an effective stability identification method for the study of the active suspension system of vehicles.%对采用状态反馈控制的车辆主动悬挂闭环系统进行理论分析，给出了使系统稳定反馈增益应满足的条件，为车辆主动悬挂系统研究提供了有效的稳定性判别方法。
利用时间延迟状态反馈实现异步电机的混沌合成%Chaos Synthesis of Asynchronous Motor by Time-Delayed State Feedback
Institute of Scientific and Technical Information of China (English)
李卫东; 唐斌
2012-01-01
为了在三相交流异步电机的运行过程中实现混沌合成,采用非线性系统的微分几何理论和时间延迟反馈控制的方法,设计了混沌合成控制器.该控制器通过对三相交流异步电机模型的简化分析,并利用非线性控制理论的状态反馈精确线性化方法来设计.应该此控制器即可得到异步电机运行时的混沌合成.应用Matlab软件中Simulink 工具进行仿真分析,仿真结果说明利用时间延迟状态反馈设计的控制器实现异步电机的混沌合成是完全合理可行的,运行结果也是满足要求的.%The chaos synthesis controller is designed using the method of differential geometry theory of nonlinear systems and time-delayed feedback control to realize chaos synthesis in running process of three-phase alternating current (AC) asynchronous motor. The exact linearization approach by state feedback of nonlinear control theory is used for controller design and through simplified analysis on the model of three-phase AC asynchronous motor. Chaos synthesis is got when asynchronous motor running by this controller. Simulink tool in Matlab software is used for Simulation analysis. The simulation results show that the time-delayed state feedback method designed controller implementing chaos synthesis of asynchronous motor is feasible and the control result is satisfied.
Directory of Open Access Journals (Sweden)
Beier Markus
2007-08-01
Full Text Available Abstract Background Genetic variants in immune regulator genes have been associated with numerous diseases, including allergies and cancer. Increasing evidence suggests a substantially elevated disease risk in individuals who carry a combination of disease-relevant single nucleotide polymorphisms (SNPs. For the genotyping of immune regulator genes, such as cytokines, chemokines and transcription factors, an oligonucleotide microarray for the analysis of 99 relevant SNPs was established. Since the microarray design was based on a platform that permits flexible in situ oligonucleotide synthesis, a set of optimally performing probes could be defined by a selection approach that combined computational and experimental aspects. Results While the in silico process eliminated 9% of the initial probe set, which had been picked purely on the basis of potential association with disease, the subsequent experimental validation excluded more than twice as many. The performance of the optimized microarray was demonstrated in a pilot study. The genotypes of 19 hay-fever patients (aged 40–44 with high IgE levels against inhalant antigens were compared to the results obtained with 19 age- and sex-matched controls. For several variants, allele-frequency differences of more than 10% were identified. Conclusion Based on the ability to improve empirically a chip design, the application of candidate-SNP typing represents a viable approach in the context of molecular epidemiological studies.
Gordillo, Luis F
2014-06-01
To determine optimal sterile insect release policies in area-wide integrated pest management is a challenge that users of this pest control method inevitably confront. In this note we provide approximations to best policies of release through the use of simulated annealing. The discrete time model for the population dynamics includes the effects of sterile insect release and density dependence in the pest population. Spatial movement is introduced through integrodifference equations, which allow the use of the stochastic search in cases where movement is described through arbitrary dispersal kernels. As a byproduct of the computations, an assessment of appropriate control zone sizes is possible.
Directory of Open Access Journals (Sweden)
Chaojun Wu
2015-01-01
Full Text Available An efficient approach of inverse optimal control and adaptive control is developed for global asymptotic stabilization of a novel fractional-order four-wing hyperchaotic system with uncertain parameter. Based on the inverse optimal control methodology and fractional-order stability theory, a control Lyapunov function (CLF is constructed and an adaptive state feedback controller is designed to achieve inverse optimal control of a novel fractional-order hyperchaotic system with four-wing attractor. Then, an electronic oscillation circuit is designed to implement the dynamical behaviors of the fractional-order four-wing hyperchaotic system and verify the satisfactory performance of the controller. Comparing with other fractional-order chaos control methods which may have more than one nonlinear state feedback controller, the inverse optimal controller has the advantages of simple structure, high reliability, and less control effort that is required and can be implemented by electronic oscillation circuit.
Wang, Liang; Liu, Zunying; Zhao, Yuanhui; Dong, Shiyuan; Zeng, Mingyong; Yang, Huicheng
2015-08-01
Three freezing-point regulators (glycine, sodium chloride and D-sorbitol) were employed to optimize thermophysical properties of Pacific white shrimp (Litopenaeus vannamei) using response surface methodology (RSM). The independent variables were glycine content (0.250-1.250 %), sodium chloride content (0.500-2.500 %) and D-sorbitol content (0.125-0.625 %) and analysis of variance showed that the effects of glycine, sodium chloride and D-sorbitol on the thermophysical properties were statistically significant (P < 0.05). The coefficient of determination, R (2) values for initial freezing point (T i ), unfreezable water mass fraction (W u ), apparent specific heat (C app ) and Enthalpy (H) were 0.896 ~ 0.999. The combined effects of these independent variables on T i , W u , C app and H were investigated. The results indicated that T i , C app and H varied curvilinearly with increasing of glycine, sodium chloride and D-sorbitol content whereas W u increased nearly linearly. Based on response plots and desirability functions, the optimum combination of process variables for Pacific white shrimp previously treated with freezing-point regulators were 0.876 % for glycine content, 2.298 % for sodium chloride content and 0.589 % for D-sorbitol content, correspondently the optimized thermophysical properties were T i , - 5.086 °C; W u , 17.222 %; C app , 41.038 J/g °C and H, 155.942 J/g, respectively. Briefly, the application of freezing-point regulators depressed T i and obtained the optimum W u , C app and H, which would be obviously beneficial for the exploitation of various thermal processing and food storage.
Directory of Open Access Journals (Sweden)
S. J. Sadati
2012-01-01
Full Text Available A fractional-order controller will be proposed to regulate the inlet oxygen into the heart-lung machine. An analytical approach will be explained to satisfy some requirements together with practical implementation of some restrictions for the first time. Primarily a nonlinear single-input single-output (SISO time-delay model which was obtained previously in the literature is introduced for the oxygen generation process in the heart-lung machine system and we will complete it by adding some new states to control it. Thereafter, the system is linearized using the state feedback linearization approach to find a third-order time-delay dynamics. Consequently classical PID and fractional order controllers are gained to assess the quality of the proposed technique. A set of optimal parameters of those controllers are achieved through the genetic algorithm optimization procedure through minimizing a cost function. Our design method focuses on minimizing some famous performance criterions such as IAE, ISE, and ITSE. In the genetic algorithm, the controller parameters are chosen as a random population. The best relevant values are achieved by reducing the cost function. A time-domain simulation signifies the performance of controller with respect to a traditional optimized PID controller.
Institute of Scientific and Technical Information of China (English)
李家伟
2015-01-01
With control optimizing of the rotational speed of the wind turbine, improve the output power and the power trans-mission efficiency of the wind turbine, the interference of magnetic loss coupling by the wind turbine rotor blade in the con-trol, it is difficult to achieve effective speed regulation, The algorithm has the defects of nonlinear distortion. A wind turbine of PID based on optimal control of rotating speed adjustment optimization, analysis of rotating speed adjusting parameter model of wind turbine, the wind turbine rotor blade speed adjustment control optimization objective function, the design of three layers PID neural network, the PID variable structure control, wind turbine speed shaft connected with the rotor axis the gear box, the aerodynamic excitation brake operation, speed regulation, effectively restrain the interference of wind tur-bine rotor blade control strong coupling magnetic loss, improve the speed of rotation to adjust the output control perfor-mance of wind turbine. The simulation results show that, the method can effectively realize the wind turbine speed control, it can improve the wind turbine efficiency and output gain.%通过对风机转动速度的优化控制调节,提高风机的输出功率和电能传输效率,风机转子叶片控制中受到强耦合的磁损耗的干扰,难以实现有效的转速调节,提出一种基于PID优化控制的风机转动速度调节优化算法,分析风机转动速度调节控制参数模型,构建风机转子叶片速度调节的优化控制目标函数,设计三层前向PID神经网络,通过PID变结构控制,风机的低速轴将转子轴心与齿轮箱连接,激发空气动力闸的运行,进行转速调节,有效地抑制了风机转子叶片控制中强耦合磁损耗的干扰,提高了风机转动速度调节输出控制性能.仿真结果表明,采用该方法能有效实现风机转速调节控制,提高风机运行效率和输出增益.
Institute of Scientific and Technical Information of China (English)
孙纯军; 倪春花; 窦晓波
2016-01-01
文中储能系统功率优化分配以一阶惯性滤波系统为基础，介绍了滤波系数的确定方法，首先提出了基于频谱分析的混合储能系统功率分配方法，根据频谱分析结果，确定波动功率在蓄电池与超级电容之间的分配；在频谱分析的基础上，进一步提出了基于SOC状态反馈的混合储能系统功率优化分配方法，并采用模糊控制，根据储能系统荷电状态SOC的值实时调整系统的滤波时间参数，从而实现超级电容－蓄电池储能系统的长期有效运行。最后，在PSCAD／EMTDC中搭建微电网仿真模型，并设计仿真方案，通过仿真验证所提混合储能系统功率优化分配策略的有效性。%Energy storage system has an important significance for reliable and stable operation of micro-grids.Con-sidering the lack of single form of energy storage, ultra-capacitor-battery hybrid energy storage system is used in this paper.Strategies of power distribution of energy storage system are based on first order inertial filter system, and the method to determine the filter coefficients are introduced.Firstly, a method based on spectrum analysis is proposed to distribute the fluctuated power between the battery and ultra-capacitor.Next, a power distribution strategy of hybrid energy storage system based on SOC feedback is proposed.And fuzzy control method is adopted to adjust system pa-rameters in real time according to the state of charge of the storage system, thus achieving the long term operation of hybrid energy storage system.Finally, the models are built in PSCAD /EMTDC to verify the effectiveness of the pow-er distribution strategies through simulation according to the designed projects.
Sui, Jinliang; Cotard, Shakira; Andersen, Jennifer; Zhu, Ping; Staunton, Jane; Lee, Margaret; Lin, Stephen
2010-12-01
Cystic fibrosis is an inherited, life-threatening disease associated with mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. The most common mutation, F508del CFTR, is found in 90% of CF patients. The loss of a single amino acid (phenylalanine at position 508) results in malformed CFTR with defective trafficking to the plasma membrane and impaired channel function. A functional assay with cells expressing F508del CFTR has been previously described by others using genetically engineered halide-sensitive yellow fluorescent protein to screen for CFTR modulators. We adapted this yellow fluorescent protein assay to 384-well plate format with a high-throughput screening plate reader, and optimized the assay in terms of data quality, resolution, and throughput, with target-specific protocols. The optimized assay was validated with reference compounds from cystic fibrosis foundation therapeutics. On the basis of the Z-factor range (≥0.5) and the potential productivity, this assay is well suited for high-throughput screening. It was successfully used to screen for active single agent and synergistic combinations of single agent modulators of F508del CFTR from a library collection of current active pharmaceutical ingredients (supported by Cystic Fibrosis Foundation Therapeutics).
Directory of Open Access Journals (Sweden)
Kumare Vinodh
2016-03-01
Full Text Available This paper presents an analytical approach for solving the weighting matrices selection problem of a linear quadratic regulator (LQR for the trajectory tracking application of a magnetic levitation system. One of the challenging problems in the design of LQR for tracking applications is the choice of Q and R matrices. Conventionally, the weights of a LQR controller are chosen based on a trial and error approach to determine the optimum state feedback controller gains. However, it is often time consuming and tedious to tune the controller gains via a trial and error method. To address this problem, by utilizing the relation between the algebraic Riccati equation (ARE and the Lagrangian optimization principle, an analytical methodology for selecting the elements of Q and R matrices has been formulated. The novelty of the methodology is the emphasis on the synthesis of time domain design specifications for the formulation of the cost function of LQR, which directly translates the system requirement into a cost function so that the optimal performance can be obtained via a systematic approach. The efficacy of the proposed methodology is tested on the benchmark Quanser magnetic levitation system and a detailed simulation and experimental results are presented. Experimental results prove that the proposed methodology not only provides a systematic way of selecting the weighting matrices but also significantly improves the tracking performance of the system.
Zheng, Qiong; Xing, Feng; Li, Xianfeng; Ning, Guiling; Zhang, Huamin
2016-08-01
Vanadium flow battery holds great promise for use in large scale energy storage applications. However, the power density is relatively low, leading to significant increase in the system cost. Apart from the kinetic and electronic conductivity improvement, the mass transport enhancement is also necessary to further increase the power density and reduce the system cost. To better understand the mass transport limitations, in the research, the space-varying and time-varying characteristic of the mass transport polarization is investigated based on the analysis of the flow velocity and reactant concentration in the bulk electrolyte by modeling. The result demonstrates that the varying characteristic of mass transport polarization is more obvious at high SoC or high current densities. To soften the adverse impact of the mass transport polarization, a new rectangular plug flow battery with a plug flow and short flow path is designed and optimized based on the mass transport polarization regulation (reducing the mass transport polarization and improving its uniformity of distribution). The regulation strategy of mass transport polarization is practical for the performance improvement in VFBs, especially for high power density VFBs. The findings in the research are also applicable for other flow batteries and instructive for practical use.
Based on the Geomagnetic-aided Inertial Navigation System of State Feedback%基于地磁辅助惯性导航的状态反馈系统研究
Institute of Scientific and Technical Information of China (English)
唐志勇; 艾文娟; 刘岩
2015-01-01
According to the characteristics of low precision of the inertial sensor of MEMS technology,a high precision of integrated navigation algorithm is put forward, adopt geomagnetic aided navigation with closed-loop correction, and the deviation of the magnetic and heading Angle of the observation is in order to achieve high precision of inertial navi-gation and a higher dynamic performance .Experiments show that state feedback of inertial navigation system can over-come the error accumulation of inertial navigation,greatly improve the anti-interference ability of the geomagnetic navi-gation,get better navigation accuracy.%针对MEMS技术的惯性传感器低精度的特点,提出一种高精度的组合导航算法,采用地磁辅助导航进行闭环校正,并对地磁的自差和航向角进行观测,以达到较高的惯性导航精度和更高的动态性能.实验证明,状态反馈的惯性导航系统能很好地克服惯导的误差累积,大幅度提高了地磁导航的抗干扰能力,得到较好的导航精度.
Vishwakarma, Abhaypratap; Tetali, Sarada Devi; Selinski, Jennifer; Scheibe, Renate; Padmasree, Kollipara
2015-09-01
The importance of the alternative oxidase (AOX) pathway, particularly AOX1A, in optimizing photosynthesis during de-etiolation, under elevated CO2, low temperature, high light or combined light and drought stress is well documented. In the present study, the role of AOX1A in optimizing photosynthesis was investigated when electron transport through the cytochrome c oxidase (COX) pathway was restricted at complex III. Leaf discs of wild-type (WT) and aox1a knock-out mutants of Arabidopsis thaliana were treated with antimycin A (AA) under growth-light conditions. To identify the impact of AOX1A deficiency in optimizing photosynthesis, respiratory O2 uptake and photosynthesis-related parameters were measured along with changes in redox couples, reactive oxygen species (ROS), lipid peroxidation and expression levels of genes related to respiration, the malate valve and the antioxidative system. In the absence of AA, aox1a knock-out mutants did not show any difference in physiological, biochemical or molecular parameters compared with WT. However, after AA treatment, aox1a plants showed a significant reduction in both respiratory O2 uptake and NaHCO3-dependent O2 evolution. Chlorophyll fluorescence and P700 studies revealed that in contrast to WT, aox1a knock-out plants were incapable of maintaining electron flow in the chloroplastic electron transport chain, and thereby inefficient heat dissipation (low non-photochemical quenching) was observed. Furthermore, aox1a mutants exhibited significant disturbances in cellular redox couples of NAD(P)H and ascorbate (Asc) and consequently accumulation of ROS and malondialdehyde (MDA) content. By contrast, WT plants showed a significant increase in transcript levels of CSD1, CAT1, sAPX, COX15 and AOX1A in contrast to aox1a mutants. These results suggest that AOX1A plays a significant role in sustaining the chloroplastic redox state and energization to optimize photosynthesis by regulating cellular redox homeostasis and ROS
Robust output regulation problem for linear time-delay systems
Lu, Maobin; Huang, Jie
2015-06-01
In this paper, we study the robust output regulation problem for linear systems with input time-delay. By extending the internal model design method to linear time-delay systems, we have established solvability conditions for the problem by both dynamic state feedback control and dynamic output feedback control. The advantages of internal model approach over the feedforward design approach are that it can handle perturbations of the uncertain parameters in the plant and the control law, and it does not need to solve the regulator equations.
Enhanced current and voltage regulators for stand-alone applications
DEFF Research Database (Denmark)
Federico, de Bosio; Pastorelli, Michele; Antonio DeSouza Ribeiro, Luiz
2016-01-01
State feedback decoupling permits to achieve a better dynamic response for Voltage Source in stand-alone applications. The design of current and voltage regulators is performed in the discrete-time domain since it provides better accuracy and allows direct pole placement. As the attainable...... bandwidth of the current loop is mainly limited by computational and PWM delays, a lead compensator structure is proposed to overcome this limitation. The design of the voltage regulator is based on the Nyquist criterion, verifying to guarantee a high sensitivity peak. Discrete-time domain implementation...
Semiglobal H-infty state feedback control
DEFF Research Database (Denmark)
Cromme, Marc
1997-01-01
semi-global set-stabilizing H-infty control is local H-infty control within some given compact set O such that all state trajectories are bounded inside O, and are approaching an open loop invariant set S subset O as t -> infinity. Sufficient conditions for the existance of a continuous statefeed...
On Output Regulation in Systems with Differential Variational Inequalities (Long Version)
Tanwani, Aneel; Brogliato, Bernard; Prieur, Christophe
2014-01-01
International audience; We consider the problem of designing state feedback control laws for output regulation in a class of dynamical systems which are described by variational inequalities and ordinary differential equations. In our setup, these variational inequalities are used to model state trajectories constrained to evolve within time-varying, closed, and convex sets, and systems with complementarity relations. We first derive conditions to study the existence and uniqueness of solutio...
基于监管的保险公司最优比例再保险策略%OPTIMAL PROPORTIONAL REINSURANCE POLICY BASED ON REGULATIONS
Institute of Scientific and Technical Information of China (English)
曾燕; 李仲飞
2009-01-01
According to regulations, an insurance company must convert a certain level of reserve. In view of this, the insurer must keep its surplus no less than this reserve level. In this paper, the "ruin" time is denned as the first time to achieve the reserve level, and the target is to minimize the "ruin" probability of the insurer. It is assumed that the surplus process is described by a diffusion model, the insurer can purchase proportional reinsurance and its surplus is appreciated according to continuous compound interest with a constant force of interest. By using the stochastic dynamic programming approach, explicit expressions of the optimal value function and the optimal proportional reinsurance policy are obtained via solving the corresponding HJB equation. Finally, some economical explanations and a numerical example are provided.%根据监管规定,保险公司必须提存一定水平的准备金.鉴于此,保险公司必须保持盈余不低于这个准备金水平.将保险公司盈余首达该准备金水平的时刻定义为"破产"时刻,以最小化"破产"概率为目标;假设保险公司可购买比例再保险,其盈余过程由扩散模型刻画且盈余按连续复利方式计算利息,其中利力为常数;借助随机动态规划方法,通过求解相应的HJB方程得到了最优值函数与最优比例再保险策略的解析式.最后给出了经济解释与数值算例.
Forcato, Diego; Posada, Velia; Beaugé, Luis; Berberián, Graciela
2010-11-05
In inside-out bovine heart sarcolemmal vesicles, p-chloromercuribenzenesulfonate (PCMBS) and n-ethylmaleimide (NEM) fully inhibited MgATP up-regulation of the Na(+)/Ca(2+) exchanger (NCX1) and abolished the MgATP-dependent PtdIns-4,5P2 increase in the NCX1-PtdIns-4,5P2 complex; in addition, these compounds markedly reduced the activity of the PtdIns(4)-5kinase. After PCMBS or NEM treatment, addition of dithiothreitol (DTT) restored a large fraction of the MgATP stimulation of the exchange fluxes and almost fully restored PtdIns(4)-5kinase activity; however, in contrast to PCMBS, the effects of NEM did not seem related to the alkylation of protein SH groups. By itself DTT had no effect on the synthesis of PtdIns-4,5P2 but affected MgATP stimulation of NCX1: moderate inhibition at 1mM MgATP and 1μM Ca(2+) and full inhibition at 0.25mM MgATP and 0.2μM Ca(2+). In addition, DDT prevented coimmunoprecipitation of NCX1 and PtdIns(4)-5kinase. These results indicate that, for a proper MgATP up-regulation of NCX1, the enzyme responsible for PtdIns-4,5P2 synthesis must be (i) functionally competent and (ii) set in the NCX1 microenvironment closely associated to the exchanger. This kind of supramolecular structure is needed to optimize binding of the newly synthesized PtdIns-4,5P2 to its target region in the exchanger protein.
流域系统优化调控的新模型与应用%A new model for optimal watershed system regulation and its application
Institute of Scientific and Technical Information of China (English)
郭怀成; 伊璇; 周丰; 陈国贤; 高伟
2012-01-01
流域系统具有复合性和非线性特征,其机理过程的数值描述本身也存在随机和认知不确定性.在此前提下,如何优化调控流域系统,实现水质改善和水生态系统健康成为当前水资源、水环境及水生态领域亟待解决的突出问题.本文提出了贝叶斯递归回归树模型和区间不确定性的风险决策分析方法,与强化区间线性规划结合形成了新的不确定性＂模拟-优化＂间接耦合模型,实现流域系统优化调控及风险决策方案.上述方法将应用于美国佛杰尼亚州Chesterfield县Swift Creek水库营养盐TMDL分配方案,确定8个子流域的最小负荷分配以实现叶绿素a浓度达标.结果表明该耦合模型既能表征流域系统特征,也能兼顾不确定性模拟的准确度、计算效率以及不确定性优化与风险决策的解空间全局最优性、绝对可行性,为流域系统优化调控及其未来非线性系统的预测与最优控制提供了新的计算工具.%Watershed systems are complex and nonlinear,and stochastic and cognitive uncertainties exist in the numerical description of their scheme.In this context,optimizing watershed systems for improving water quality and ecological health is essential for integrated watershed management.To support watershed system regulation and its risk-based decision-making,Bayesian Recursive Regression Tree model (BRRT) and risk-based decision-making analysis under interval-uncertainty were proposed,which coupled with Enhanced-Interval Linear Programming (EILP) formed a new indirect coupled "simulation-optimization" model.The proposed approach was applied to the Swift Creek Reservoir's nutrient TMDL allocation (Chesterfield County,VA) to identify the minimum nutrient load allocations required from eight sub-watersheds to ensure compliance with user-specified chlorophyll-a criteria.The results indicated that the proposed model is able to represent watershed system characteristics
基于模型的变门限状态反馈事件触发控制%Model-based event-triggered state feedback control with variable threshold
Institute of Scientific and Technical Information of China (English)
李国梁; 张合新; 周鑫; 惠俊军
2016-01-01
针对基于模型的事件触发状态反馈控制系统,提出一种触发门限可变的触发机制.该触发机制能够在被控对象面临变化较大且快的干扰时,自动调整触发门限变大,避免频繁的事件触发导致网络通信资源浪费;能够在被控对象面临变化较小的干扰时,通过定时触发,避免长时间没有事件发生导致的通信网闲置,同时自动调整触发门限变小,提升控制性能.仿真结果表明,较固定门限触发机制,所提出的触发机制能利用更少的通信资源实现整体控制性能的提升.%An event-triggering mechanism with variable threshold for model-based event-triggered state-feedback control system is propoesd.When strong and fast varying disturbances act on the plant,this event-triggering mechanism can enlarge the threshold automatically to mitigate the unnecessary waste of communication resources.When slowly varying disturbances act on the plant,this event-triggering mechanism can avoid the communication network lies idle by using a timetriggering mechanism.Meanwhile,this event-triggering mechanism can also decrease the threshold automatically to improve the control performance.Simulation results show that,compared with the fixed threshold event-triggering mechanism,the proposed variable threshold event-triggering mechanism consumes less communication resources,but makes better whole performance.
LMI-Based Fuzzy Optimal Variance Control of Airfoil Model Subject to Input Constraints
Swei, Sean S.M.; Ayoubi, Mohammad A.
2017-01-01
This paper presents a study of fuzzy optimal variance control problem for dynamical systems subject to actuator amplitude and rate constraints. Using Takagi-Sugeno fuzzy modeling and dynamic Parallel Distributed Compensation technique, the stability and the constraints can be cast as a multi-objective optimization problem in the form of Linear Matrix Inequalities. By utilizing the formulations and solutions for the input and output variance constraint problems, we develop a fuzzy full-state feedback controller. The stability and performance of the proposed controller is demonstrated through its application to the airfoil flutter suppression.
Mixed H2／H∞ Optimal Guaranteed Cost Control of Uncertain Linear Systems
Institute of Scientific and Technical Information of China (English)
GuodingChen; MayingYang; LiYu
2004-01-01
The mixed H2/H∞ guaranteed cost control problem via state feedback control laws is considered in this paper for linear systems with norm-bounded parameter uncertainty. Based on the linear matrix inequality (LMI) approach, sufficient conditions are derived for the existence of guaranteed cost controllers whihc guarantee not only a prespecified H∞ disturbance attenuation level on one controlled output for all admissible parameter uncertainties, but also the worst-case H2 performance index on the other controlled output to be no more than a specified bound. Furthermore, a convex optimization problem is formulated to design an optimal H2/H∞ guaranteed cost controller.
Aktiv regulering: Optimering af effektregulering
DEFF Research Database (Denmark)
Bindner, H.
1999-01-01
(Technical Univ. of Denmark) and Risø National Laboratory. The objective of the project is to investigate the application of active control of a wind turbine and analyse the interaction with the wind turbinedynamics in order to optimise energy production, improve power control and minimise structural laods......The current report is part of the reporting of the work executed as part of the project 'Active Control and Wind Turbine Dynamics'. The project has been supported by the Danish Energy Agency under contract EFP91, ENS j.nr. 1364/91-0003. Projectparticipants were Vestas Wind Systems A/S, DTU...... of the existing PI-controller is investigated through measurements with respect to powercontrol. In the second phase a model for control purposes of a pitch controlled wind turbine is formulated. It is applied in the optimisation process of the PI-controllers. The results of optimisation are tested on the real...
Optimal Control Design with Limited Model Information
Farokhi, F; Johansson, K H
2011-01-01
We introduce the family of limited model information control design methods, which construct controllers by accessing the plant's model in a constrained way, according to a given design graph. We investigate the achievable closed-loop performance of discrete-time linear time-invariant plants under a separable quadratic cost performance measure with structured static state-feedback controllers. We find the optimal control design strategy (in terms of the competitive ratio and domination metrics) when the control designer has access to the local model information and the global interconnection structure of the plant-to-be-controlled. At last, we study the trade-off between the amount of model information exploited by a control design method and the best closed-loop performance (in terms of the competitive ratio) of controllers it can produce.
Optimal periodic disturbance reduction for active noise cancelation
Kinney, C. E.; de Callafon, R. A.; Dunens, E.; Bargerhuff, R.; Bash, C. E.
2007-08-01
The design of an optimal internal model-based (IMB) controller by extending standard discrete time optimal control theory for IMB controllers is described. The optimal observer and state feedback gains of the IMB controller are given via the solution of discrete time algebraic Riccati equations. The design method is applied to an acoustic system that is subjected to disturbances from a server fan. Periodic disturbances from the server fan appear as harmonics of the fundamental frequency of the fan. Parametric models for the plant and non-periodic part of the disturbance are identified from experimental data. An internal model is designed in discrete time and the internal model principle is used to design a feedback controller that rejects periodic disturbances in the acoustic system. The controller is implemented in real-time and successfully attenuates the first four harmonics of the fan noise.
Optimal Multilevel Control for Large Scale Interconnected Systems
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Ahmed M. A. Alomar,
2014-04-01
Full Text Available A mathematical model of the finishing mill as an example of a large scale interconnected dynamical system is represented. First the system response due to disturbance only is presented. Then,the control technique applied to the finishing hot rolling steel mill is the optimal multilevel control using state feedback. An optimal controller is developed based on the integrated system model, but due to the complexity of the controllers and tremendous computational efforts involved, a multilevel technique is used in designing and implementing the controllers .The basis of the multilevel technique is described and a computational algorithm is discussed for the control of the finishing mill system . To reduce the mass storage , memory requirements and the computational time of the processor, a sub-optimal multilevel technique is applied to design the controllers of the finishing mill . Comparison between these controllers and conclusion is presented.
Multi-objective optimization framework for networked predictive controller design.
Das, Sourav; Das, Saptarshi; Pan, Indranil
2013-01-01
Networked Control Systems (NCSs) often suffer from random packet dropouts which deteriorate overall system's stability and performance. To handle the ill effects of random packet losses in feedback control systems, closed over communication network, a state feedback controller with predictive gains has been designed. To achieve improved performance, an optimization based controller design framework has been proposed in this paper with Linear Matrix Inequality (LMI) constraints, to ensure guaranteed stability. Different conflicting objective functions have been optimized with Non-dominated Sorting Genetic Algorithm-II (NSGA-II). The methodology proposed in this paper not only gives guaranteed closed loop stability in the sense of Lyapunov, even in the presence of random packet losses, but also gives an optimization trade-off between two conflicting time domain control objectives.
Directory of Open Access Journals (Sweden)
Oscar D. Montoya-Giraldo
2014-01-01
Full Text Available This paper presents the design and simulation of a global controller for the Reaction Wheel Pendulum system using energy regulation and extended linearization methods for the state feedback. The proposed energy regulation is based on the gradual reduction of the energy of the system to reach the unstable equilibrium point. The signal input for this task is obtained from the Lyapunov stability theory. The extended state feedback controller design is used to get a smooth nonlinear function that extends the region of operation to a bigger range, in contrast with the static linear state feedback obtained through the method of approximate linearization around an operating point. The general designed controller operates with a switching between the two control signals depending upon the region of operation; perturbations are applied in the control signal and the (simulated measured variables to verify the robustness and efficiency of the controller. Finally, simulations and tests using the model of the reaction wheel pendulum system, allow to observe the versatility and functionality of the proposed controller in the entire operation region of the pendulum.
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Guohua Cui
2015-01-01
Full Text Available This paper proposes a redundantly actuated parallel manipulator 4-UPS-S that is applicable for orientation adjustment in the gathering process of solar power. A thorough analysis involving the kinematic issues is performed. Inverse kinematic problems are solved in the close-loop. The Jacobian matrix and some performance indexes are analytically derived. The multiobjective optimization model is established, and the determinacy optimization is completed on the basis of previous research works. Six-Sigma robust analysis is performed on the basis of the determinacy optimal solution. Results show that 4-UPS-S does not satisfy the quality requirement. Therefore, it is necessary to implement Six-Sigma robust optimization, and select optimial solution of robustness to complete the nondeterminacy optimization. The research results show that the proposed methodology has a simple operation and high optimization efficiency. The methodology commodiously obtains robustness parallel manipulator that satisfies the quality requirement.
Pullen, A.J.J.; Cabello-Medina, Carmen; de Weerd-Nederhof, Petronella C.; Visscher, Klaasjan; Groen, Arend J.; Tschirky, H.; Herstatt, C.; Probert, D.; Gemunden, H.G.; Colombo, M.G.; Durand, T.; de Weerd-Nederhof, P.C.; Schweisfurth, T.
2010-01-01
Rapid development and commercialization of new products is of vital importance for small and medium sized enterprises (SME) in regulated sectors. Due to strict regulations, competitive advantage can hardly be achieved through the effectiveness of product concepts only. If an SME in a highly regulate
Optimal guaranteed cost control for fuzzy descriptor systems with time-varying delay
Institute of Scientific and Technical Information of China (English)
Tian Weihua; Zhang Huaguang
2008-01-01
Based on the delay-independent rule, the problem of optimal guaranteed cost control for a class of Takagi-Sugeno (T-S) fuzzy descriptor systems with time-varying delay is studied. A linear quadratic cost function is considered as the performance index of the closed-loop system. Sufficient conditions for the existence of guaranteed cost controllers via state feedback are given in terms of linear matrix inequalities (LMIs), and the design of an optimal guaranteed cost controller can be reduced to a convex optimization problem. It is shown that the designed controller not only guarantees the asymptotic stability of the closed-loop fuzzy descriptor delay system, but also provides an optimized upper bound of the guaranteed cost. At last, a numerical example is given to illustrate the effectiveness of the proposed method and the perfect performance of the optimal guaranteed cost controller.
Optimally Stopped Optimization
Vinci, Walter; Lidar, Daniel A.
2016-11-01
We combine the fields of heuristic optimization and optimal stopping. We propose a strategy for benchmarking randomized optimization algorithms that minimizes the expected total cost for obtaining a good solution with an optimal number of calls to the solver. To do so, rather than letting the objective function alone define a cost to be minimized, we introduce a further cost-per-call of the algorithm. We show that this problem can be formulated using optimal stopping theory. The expected cost is a flexible figure of merit for benchmarking probabilistic solvers that can be computed when the optimal solution is not known and that avoids the biases and arbitrariness that affect other measures. The optimal stopping formulation of benchmarking directly leads to a real-time optimal-utilization strategy for probabilistic optimizers with practical impact. We apply our formulation to benchmark simulated annealing on a class of maximum-2-satisfiability (MAX2SAT) problems. We also compare the performance of a D-Wave 2X quantum annealer to the Hamze-Freitas-Selby (HFS) solver, a specialized classical heuristic algorithm designed for low-tree-width graphs. On a set of frustrated-loop instances with planted solutions defined on up to N =1098 variables, the D-Wave device is 2 orders of magnitude faster than the HFS solver, and, modulo known caveats related to suboptimal annealing times, exhibits identical scaling with problem size.
Optimization and Optimal Control
Chinchuluun, Altannar; Enkhbat, Rentsen; Tseveendorj, Ider
2010-01-01
During the last four decades there has been a remarkable development in optimization and optimal control. Due to its wide variety of applications, many scientists and researchers have paid attention to fields of optimization and optimal control. A huge number of new theoretical, algorithmic, and computational results have been observed in the last few years. This book gives the latest advances, and due to the rapid development of these fields, there are no other recent publications on the same topics. Key features: Provides a collection of selected contributions giving a state-of-the-art accou
Less Conservative Optimal Robust Control of a 3-DOF Helicopter
Directory of Open Access Journals (Sweden)
L. F. S. Buzachero
2015-01-01
Full Text Available This work proposes an improved technique for design and optimization of robust controllers norm for uncertain linear systems, with state feedback, including the possibility of time-varying the uncertainty. The synthesis techniques used are based on LMIs (linear matrix inequalities formulated on the basis of Lyapunov’s stability theory, using Finsler’s lemma. The design has used the addition of the decay rate restriction, including a parameter γ in the LMIs, responsible for decreasing the settling time of the feedback system. Qualitative and quantitative comparisons were made between methods of synthesis and optimization of the robust controllers norm, seeking alternatives with lower cost and better performance that meet the design restrictions. A practical application illustrates the efficiency of the proposed method with a failure purposely inserted in the system.
Institute of Scientific and Technical Information of China (English)
范辉; 张宇文
2009-01-01
超空化航行器由于航行过程中大部分被空泡包裹,必然面临着航行器与空泡剧烈非线性滑行力带来的稳定控制困难.适当设计的线性控制律一般可得到航行器高频有限振幅振荡运动或阻尼振荡运动的控制结果;而在反馈中引入非线性,虽控制结果理想,但要求对滑行力精确可知,这在实际情况下很难做到.针对以上问题,文章以Dzielski提出的超空化航行器模型为研究对象,基于圆判据定理通过线性状态反馈方法,使航行器系统对所有非线性滑行力特性达到全局绝对稳定.文中首先对原模型进行变换和局部抽取,使之适用于圆判据定理的应用条件;接着给出了通过极点配置方法构建线性状态反馈控制律而达到系统绝对稳定的条件;最后结合系统参数,分析了系统局部和全局绝对稳定情况下稳定域的估计,并给出了仿真验证.%Aim. The two control methods proposed by John Dzielski et al in Ref.2 are, in our opinion, both not practicable. Using Ref.2′s model, we propose a control method that is simple but practicable. Section 1 of the full paper briefs circle criterion and that, if any one of three sets of conditions are satisfied, the system is absolutely stable according to the circle criterion. Subsection 2.1, through transformation, converts eq. (2), which corresponds to Ref.2′s model, into eq. (6), which is suitable for circle criterion. Section 2.2 derives eq. (8) as the control law of a supercavitating vehicle; in practice, the second set of conditions are easily satisfied and therefore, according to circle criterion, the global and absolute stability of the supercavitating vehicle is ensured when using the control law eq. (8). Finally, section 4 gives two simulation examples, whose results are presented in Figs.8, 9 and 11; these results and their analysis show preliminarily that our state feedback control method for a supercavitating vehicle is simple but
Institute of Scientific and Technical Information of China (English)
江道灼; 张振华
2011-01-01
单相H桥级联静止同步补偿器（static synchronous compemator，STATCOM）n7以快速补偿电力机车这种单相整流的波动性负荷所需的无功，但静止同步补偿器是一个强耦合、非线性系统，为对有功和无功进行解耦，引入反馈线性化方法，通过坐标变化和状态反馈，获得精确线性化模型，并使有功、无功完全解耦，设计完成闭环控制器。为保持H桥直流侧电容电压均衡，采用电压外环和独立均压控制相结合的方法，使电容电压维持在设定值。同时，采用载波相移正弦脉宽调制策略（carrier phase－shifted sinusoidal pulsewidth modulation，CPS—SPWM），在较低的器件开关频率下实现较高等效开关频率。数值仿真结果表明，本文采用控制策略正确有效，系统有功和无功功率可独立调节，动态性能良好，电容电压能稳定在设定值。%Electric locomotive is a kind of single-phase rectified and fluctuating load, and single-phase H-bridge cascaded static synchronous compensator （STATCOM）, which is a strongly coupled nonlinear system, can be applied to electrical railway system to compensate reactive power. To decouple active and reactive power, through leading in feedback linearization method and by means of coordinate transformation and state feedback, active and reactive power are completely decoupled and an precise linearization model is attianed, and a closed-loop controller is developed. To keep capacitance voltage balancing at DC side of H-bridge, the outer voltage loop is combined with individual balancing control to make capacitance voltage keeping its set value. Meanwhile, adopting the strategy of carrier phase-shifted sinusoidal pulse-width modulation （CPS-SPWM）, a higher equivalent switching frequency is implememted under lower device switching frequency. Numerical simulation results show that the proposed control strategy is correct and effect; active and reactive
The Application of Time-Delay Dependent H∞ Control Model in Manufacturing Decision Optimization
Directory of Open Access Journals (Sweden)
Haifeng Guo
2015-01-01
Full Text Available This paper uses a time-delay dependent H∞ control model to analyze the effect of manufacturing decisions on the process of transmission from resources to capability. We establish a theoretical framework of manufacturing management process based on three terms: resource, manufacturing decision, and capability. Then we build a time-delay H∞ robust control model to analyze the robustness of manufacturing management. With the state feedback controller between manufacturing resources and decision, we find that there is an optimal decision to adjust the process of transmission from resources to capability under uncertain environment. Finally, we provide an example to prove the robustness of this model.
Output regulation problem for a class of regular hyperbolic systems
Xu, Xiaodong; Dubljevic, Stevan
2016-01-01
This paper investigates the output regulation problem for a class of regular first-order hyperbolic partial differential equation (PDE) systems. A state feedback and an error feedback regulator are considered to force the output of the hyperbolic PDE plant to track a periodic reference trajectory generated by a neutrally stable exosystem. A new explanation is given to extend the results in the literature to solve the regulation problem associated with the first-order hyperbolic PDE systems. Moreover, in order to provide the closed-loop stability condition for the solvability of the regulator problems, the design of stabilising feedback gain and its dual problem design of stabilising output injection gain are considered in this paper. This paper develops an easy method to obtain an adjustable stabilising feedback gain and stabilising output injection gain with the aid of the operator Riccati equation.
Output regulation for linear multi-agent systems with unmeasurable nodes
Liang, Hong-Jing; Zhang, Hua-Guang; Wang, Zhan-Shan; Wang, Jun-Yi
2014-01-01
The output regulation of linear multi-agent systems with partial unmeasurable agents is investigated in this paper. All the agents except the exosystem can be classified into two groups. Agents in the first group can be measured by themselves and their neighbors. State variables are not fully accessible for direct communication and full order Luenberger observers are constructed for the unmeasurable agents. We give a state feedback control law to solve the output regulation problem under the communication topologies based on both measurable and unmeasurable agents. The heterogeneous agents' synchronization problem is a general case of our results. Finally, examples are utilized to show the effectiveness of the obtained results.
Linear Robust Output Regulation in a Class of Switched Power Converters
Directory of Open Access Journals (Sweden)
Josep M. Olm
2010-01-01
Full Text Available This article addresses the robust output regulation problem for a class of nonlinear switched power converters after its linearization by means of a change of the control vector variable. The methodology employs a dynamic state feedback control law and considers parametric uncertainty due to unknown values of resistive loads. Restrictions arising from the fact that the control gains exhibit fixed values are taken into account. The proposed technique is exemplified with the output voltage regulation of a Noninverting Buck-Boost converter and tested through realistic numerical simulations.
Pullen, A.J.J.; Cabello-Medina, Carmen; de Weerd-Nederhof, Petronella C.; Visscher, Klaasjan; Groen, Arend J.; Tschirky, H.; Herstatt, C.; Probert, D.; Gemunden, H.G.; Colombo, M.G.; Durand, T.; de Weerd-Nederhof, P.C.; Schweisfurth, T.
2010-01-01
Rapid development and commercialization of new products is of vital importance for small and medium sized enterprises (SME) in regulated sectors. Due to strict regulations, competitive advantage can hardly be achieved through the effectiveness of product concepts only. If an SME in a highly
Design of Optimal Sparse Feedback Gains via the Alternating Direction Method of Multipliers
Lin, Fu; Jovanović, Mihailo R
2011-01-01
We design sparse and block sparse feedback gains that minimize the $H_2$ norm of distributed systems. Our approach consists of two steps. First, we identify sparsity patterns of the feedback gains by incorporating sparsity-promoting penalty functions into the $H_2$ problem, where the added terms penalize the number of communication links in the distributed controller. Second, we optimize the state feedback gains subject to the structural constraints determined by the identified sparsity patterns. This polishing step improves the $H_2$ performance of the distributed controllers. In the first step, we identify sparsity structure of the feedback gains using the alternating direction method of multipliers, which is a powerful algorithm well-suited to large optimization problems. This method alternates between optimizing the sparsity and optimizing the closed-loop $H_2$ norm, which allows us to exploit the structure of the corresponding objective functions. In particular, we take advantage of the separability of t...
Directory of Open Access Journals (Sweden)
Oleksandra OSADETS
2016-07-01
Full Text Available In the presented scientific practical research we considered and explored the role and problems of state regulation and supervision of the financial sector of Ukraine, in particular of credit unions because they are inalienable participants in the financial market. In current conditions that have been established during the inancial crisis, one of the most urgent problems is the effective functioning of the regulation and supervision of the financial sector. The crisis that negatively affected the activities of financial sector participants discovered the discrepancy of regulation and supervision of them, which caused the negative trend of development of financial market of Ukraine, as evidenced by official data of the National Commission, which performs state regulation in the sphere of financial services. In the presented scientific practical research we identified the strengths and weaknesses of the modern system of state regulation and supervision in the financial sector of Ukraine, particularly in the sector of credit cooperation, and we formed suggestions on improving its model in the context of the concentration of regulatory and supervisory efforts in state financial regulators
Directory of Open Access Journals (Sweden)
Oleksandra OSADETS
2016-07-01
Full Text Available In the presented scientific practical research we considered and explored the role and problems of state regulation and supervision of the financial sector of Ukraine, in particular of credit unions because they are inalienable participants in the financial market. In current conditions that have been established during the financial crisis, one of the most urgent problems is the effective functioning of the regulation and supervision of the financial sector. The crisis that negatively affected the activities of financial sector participants discovered the discrepancy of regulation and supervision of them, which caused the negative trend of development of financial market of Ukraine, as evidenced by official data of the National Commission, which performs state regulation in the sphere of financial services. In the presented scientific practical research we identified the strengths and weaknesses of the modern system of state regulation and supervision in the financial sector of Ukraine, particularly in the sector of credit cooperation, and we formed suggestions on improving its model in the context of the concentration of regulatory and supervisory efforts in state financial regulators.
Cooperative Control for Uncertain Multiagent Systems via Distributed Output Regulation
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Lu Yu
2013-01-01
Full Text Available The distributed robust output regulation problem for multiagent systems is considered. For heterogeneous uncertain linear systems and a linear exosystem, the controlling aim is to stabilize the closed-loop system and meanwhile let the regulated outputs converge to the origin asymptotically, by the help of local interaction. The communication topology considered is directed acyclic graphs, which means directed graphs without loops. With distributed dynamic state feedback controller and output feedback controller, respectively, the solvability of the problem and the algorithm of controller design are both investigated. The solvability conditions are given in terms of linear matrix inequalities (LMIs. It is shown that, for polytopic uncertainties, the distributed controllers constructed by solving LMIs can satisfy the requirements of output regulation property.
Institute of Scientific and Technical Information of China (English)
张磊; 赵进文
2012-01-01
Hot money speculations have a large impact on our country' s macro - market' s operation mechanism and the stability of people' s living. In order to stabilize the price level and to regulate the market mechanism, local governments at all levels are active on establishing and implementing the regulation measures towards the hot money speculations. This paper put forward a dynamic game mechanism between the governments and the speculators, analyzed the governments' optimal regulation strategies on the equilibrium path. And discussed the inhibition effects of the government' s regulations to the speculation scale on the disequilibrium path, combined the featured of the governments regulation regime in our country nowadays. Applied the numerical stimulation methods to verify the features of the government's equilibrium regulation mechanism.%热钱的投机炒作对我国宏观市场运行机制和居民生活稳定产生了严重冲击.为稳定物价水平和规范市场机制,全国各级地方政府正在积极制定和实施对热钱投机的监管措施.构建了一个政府与投机者之间的动态博弈结构,分析了均衡路径上的政府最优监管策略,并结合我国当前的政府监管制度特点,讨论了非均衡路径上的政府监管对投机规模的抑制效应.最后采用数值模拟方法对均衡的政府监管机制的特征进行了验证.
Energy Technology Data Exchange (ETDEWEB)
Boedeker, K.; Moebus, H.; Senkbeil, H. [eds.
1998-12-31
A manual for electrical trade with the following topics: New buissiness sectors, installation and building engineering, standards, tasks and responsibility of qualified personnel in electrical engineering, safety of electrical devices installed and an optimal management of electrical companies.(GL) [Deutsch] Ein Handbuch fuer das Elektrohandwerk mit folgenden Schwerpunkten: Neue Geschaeftsfelder, Installations- und Haustechnik, Normen, Aufgaben und Verantwortung der Elektrofachkraefte, Sicherheit beim Einbau von Anlagen sowie die optimale Betriebsfuehrung in der Elektrobranche.(GL)
Institute of Scientific and Technical Information of China (English)
刘莉; 王长林
2013-01-01
A mathematic model of train operation regulation was built based on the characteristics of train operation organization in this article.This model involved many constraints,had strong limitation of real time and delay spread,so the question was difficult to be solved.The Particle Swarm Optimization had advantages of fast calculation speed and strong convergence,so it was suitable for this model.The Particle Swarm Optimization was applied in this article to solve the train operation regulation problem and implement the high effective solution.%依据列车行车组织的特点,对列车运行调整策略进行研究,建立了列车运行调整模型.模型中涉及的约束条件较多,对实时性和延迟传播有着严格的限制,从而使问题的求解成为难题.在模型的求解过程中,粒子群算法有计算速度快、收敛性强的特点,满足模型实时性的要求.因此在列车运行调整中采用了粒子群算法,实现了列车运行调整的高效求解.
Modeling and optimal vibration control of conical shell with piezoelectric actuators
Institute of Scientific and Technical Information of China (English)
Wang Weiyuan; Wei Yingjie; Wang Cong; Zou Zhenzhu
2008-01-01
In this paper numerical simulations of active vibration control for conical shell structure with distributed piezoelectric actuators is presented. The dynamic equations of conical shell structure are derived using the finite element model (FEM) based on Mindlin's plate theory. The results of modal calculations with FEM model are accurate enough for engineering applications in comparison with experiment results. The Electromechanical influence of distributed piezoelectric actuators is treated as a boundary condition for estimating the control force. The independent modal space control (IMSC) method is adopted and the optimal linear quadratic state feedback control is implemented so that the best control performance with the least control cost can be achieved. Optimal control effects are compared with controlled responses with other non-optimal control parameters. Numerical simulation results are given to demonstrate the effectiveness of the control scheme.
Control design variable linking for optimization of structural/control systems
Jin, Ik Min; Schmit, Lucien A.
1993-01-01
A method is presented to integrate the design space of structural/control system optimization problems in the case of linear state feedback control. Conventional structural sizing variables and elements of the feedback gain matrix are both treated as strictly independent design variables in optimization by extending design variable linking concepts to the control gains. Several approximation concepts including new control design variable linking schemes are used to formulate the integrated structural/control optimization problem as a sequence of explicit nonlinear mathematical programming problems. Examples which involve a variety of behavior constraints, including constraints on dynamic stability, damped frequencies, control effort, peak transient displacement, acceleration, and control force limits, are effectively solved by using the method presented.
Two neural network algorithms for designing optimal terminal controllers with open final time
Plumer, Edward S.
1992-01-01
Multilayer neural networks, trained by the backpropagation through time algorithm (BPTT), have been used successfully as state-feedback controllers for nonlinear terminal control problems. Current BPTT techniques, however, are not able to deal systematically with open final-time situations such as minimum-time problems. Two approaches which extend BPTT to open final-time problems are presented. In the first, a neural network learns a mapping from initial-state to time-to-go. In the second, the optimal number of steps for each trial run is found using a line-search. Both methods are derived using Lagrange multiplier techniques. This theoretical framework is used to demonstrate that the derived algorithms are direct extensions of forward/backward sweep methods used in N-stage optimal control. The two algorithms are tested on a Zermelo problem and the resulting trajectories compare favorably to optimal control results.
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lastuti abubakar Gani
2016-04-01
Full Text Available Objectives - The development of Islamic insurance in Indonesia contributed to economic growth in 2014. The principle of mutual cooperation and tabarru contract is a characteristic of Islamic insurance. The Opportunity to increase the role of Islamic insurance as an economic entity is done by utilizing various aspects of human resource readiness. Human Resource are required to have a comprehensive understanding of Islamic insurance in order to create compliance with Islamic principles for product and services offered.It can provide legal protection against the Takaful participants. Issues to be examined is how the readiness of the relevant regulatory certification and how Regulatory model certification appropriate human resources in order to develop Islamic insurance in Indonesia. Methods -The method used is a normative juridical that through the efforts of an inventory of rules and descriptive analytical. To obtain the appropriate regulatory models, a legal comparison method is employed.Results - Based on the research results, the regulation of certification is required and should include the human resources, starting from a selling agent to the management as a decision maker. This regulation will push the entire human resources involved in the Islamic insurance industry to has the capacity and capability in providing services to the public, and to ensure and guarantee that the services offered comply with Islamic principles. Association of Islamic Insurance Indonesia was initiated concerning certification provisions, but has not been followed by a strong regulations readiness as a legal basis.Conclusion -Therefore we need a comprehensive regulation and it must be issued by Indonesian Financial Services Authority.
Institute of Scientific and Technical Information of China (English)
高爽; 魏也华; 陈雯
2012-01-01
Environmental regulation has become one of the most important driving forces underlying sustainable development and the transformation of the pattern of economic development. The water pollution incident in Lake Taihu(2007), called Lake Taihu Water Crisis, has provided a typical study case to reveal the relationship between environmental regulation and economic development. First, through the case study of Lake Taihu Water Crisis, this study compared the approaches and policies of environmental regulation before and after the Lake Taihu Water Crisis. Second, this study summarized the existing literature and developed a new theoretical framework focusing on the impacts of environmental regulation on the optimization and performance of manufacturing industries. Finally, such a new framework was validated based on a quantitative assessment of the relative strengths of environmental regulation policies and an analysis of factors affecting industrial performance. The quantitative assessment of the strengths of environmental regulation policies showed that, after Lake Taihu Water Crisis, during 2007 - 2009, the environmental regulation has been gradually stronger. The average strengths of government regulation, technological regulation, marketing regulation and social regulation during 2007 and 2009 increased by 2.2,1.0, 2.6, 0.7 times than the average strengths during 2001 -2006. The government not only used administrative commands(government regulation), but also tried to employ market-based regulation approaches on pollution control. However, the environmental regulation is still focused on the governmental regulation approach which has not been changed. Regression results showed that the environmental regulation manifested by the constrains of enterprises' entering in pollution sectors and the encouragement of high-efficiency technologies, has resulted in the optimization of manufacturing industries and the productivity improvement in Wuxi, which also countered the
Distributed output regulation for multi-agent systems with norm-bounded uncertainties
Yu, Lu; Wang, Jinzhi
2014-11-01
In this paper, we consider the distributed robust output regulation problem for multi-agent systems (MASs). It is involved with a group of heterogeneous high-order linear uncertain systems and an linear exosystem. The regulated output is a combination of the output of MAS and the exosystem, which is defined based on controlling demands. Distributed controllers are designed to ensure that the regulated output converges to the origin and meanwhile the closed-loop MAS is stable. The sufficient conditions for the solvability of distributed output regulation problem are given in terms of linear matrix inequalities. And algorithms are proposed to design distributed dynamic controllers with state feedback and output feedback, via the help of internal models. It is shown that, for any time-invariant norm-bounded uncertainties, the given controllers can realise the objective of output regulation.
Directory of Open Access Journals (Sweden)
L. I. Rozonoer
1999-01-01
Full Text Available Necessary and sufficient conditions for existence of optimal control for all initial data are proved for LQ-optimization problem. If these conditions are fulfilled, necessary and sufficient conditions of optimality are formulated. Basing on the results, some general hypotheses on optimal control in terms of Pontryagin's maximum condition and Bellman's equation are proposed.
Energy Technology Data Exchange (ETDEWEB)
Talhouk, R.S.
1988-01-01
A long term bovine mammary cell culture system that maintains normal mammary cell function was established and optimized to study milk protein synthesis and secretion and mammary differentiation. This culture system used bovine mammary acini isolated from developing or lactating mammary gland by enzymatic dissociation, and cryopreserved until thawed and plated for growth in vitro for these studies. Cells in M199 with lactogenic hormones {plus minus} fetal calf serum (FCS) were cultured on plastic, 100ul and 500ul type I collagen, and Matrigel, or embedded within type I collagen. Cell morphology, cell number, and total TCA-precipitable {sup 35}S-labelled proteins were monitored. Milk protein ({alpha}{sub s,1}-casein, lactoferrin (LF), {alpha}-lactalbumin, and {beta}-lactoglobulin) secretion and intracellular levels were determined by an ELISA assay.
Barkhausen, J; Schoenfelder, D; Nagel, H D; Stöblen, F; Müller, R D
1999-11-01
Evaluation of radiation exposure and image quality during fluoroscopy using a new vascular X-ray system. The measurements were made on an Integris V 3000 X-ray system with MRC tube and SpectraBeam technology (Philips Medical Systems, Hamburg). Entrance dose rates were measured with phantoms for the three fluoroscopy levels (1-3) which differed with regard to beam filtering and image intensiver entrance exposure rate. We evaluated 132 diagnostic and interventional angiographic studies. The angiographic investigators were asked to start with level 1 and to change to the next fluoroscopy level only in the case of insufficient image quality. Entrance dose rate is reduced by approx. 74% at fluoroscopy level 1 and by approx. 46% at level 2 relative to level 3 which is comparable to angiographic X-ray systems without MRC tube and SpectraBeam technology. Because level 1 ensured a sufficient image quality in 92% of the diagnostic and 60% of the interventional angiographic procedures a change to higher fluoroscopy levels was not necessary. Reduction of the intensifier exposure rate and the optimization of beam filtering enabled us to reduce the radiation exposure considerably. The procedure was well accepted by the angiographic investigators due to the diagnostically sufficient image quality of the fluoroscopy level 1.
Bees Algorithm and Its Application to Optimal Regulation of Hydropower Stations%蜜蜂算法及其在水电站优化调度中的应用
Institute of Scientific and Technical Information of China (English)
余敏
2015-01-01
The principle and method of BA is introduced, and the ability to attain global optimum solution is discussed.Taking op-timal long-term regulation problem of hydropower stations for example, BA, SPSO, SAPSO and GAPSO are used to solve the prob-lem simultaneous.Results show that BA has fast astringency and better ability to attain global optimum solution.Thus, an additional method is proposed for solving optimal regulation of hydropower stations.%详细阐述了蜜蜂算法的优化原理及实现方法，并对算法的求解速度和全局寻优能力进行详细讨论。在此基础上，以国内广泛开展的复杂高维、非线性、多约束水库中长期优化调度问题为例，同时应用蜜蜂、基本粒子群、退火粒子群和交叉粒子群四种现代群智能优化算法进行分别求解。应用情况的对比分析表明，蜜蜂算法具有比上述其它几种算法更快的求解速度和全局寻优能力。此外，论文的研究成果也为水电站中长期发电优化调度问题提供了一种新的求解途径。
Liou, Luen-Woei; Ray, Asok
1991-01-01
A state feedback control law for integrated communication and control systems (ICCS) is formulated by using the dynamic programming and optimality principle on a finite-time horizon. The control law is derived on the basis of a stochastic model of the plant which is augmented in state space to allow for the effects of randomly varying delays in the feedback loop. A numerical procedure for synthesizing the control parameters is then presented, and the performance of the control law is evaluated by simulating the flight dynamics model of an advanced aircraft. Finally, recommendations for future work are made.
Laird, Philip
1992-01-01
We distinguish static and dynamic optimization of programs: whereas static optimization modifies a program before runtime and is based only on its syntactical structure, dynamic optimization is based on the statistical properties of the input source and examples of program execution. Explanation-based generalization is a commonly used dynamic optimization method, but its effectiveness as a speedup-learning method is limited, in part because it fails to separate the learning process from the program transformation process. This paper describes a dynamic optimization technique called a learn-optimize cycle that first uses a learning element to uncover predictable patterns in the program execution and then uses an optimization algorithm to map these patterns into beneficial transformations. The technique has been used successfully for dynamic optimization of pure Prolog.
Schneider, Johannes J
2007-01-01
This book addresses stochastic optimization procedures in a broad manner. The first part offers an overview of relevant optimization philosophies; the second deals with benchmark problems in depth, by applying a selection of optimization procedures. Written primarily with scientists and students from the physical and engineering sciences in mind, this book addresses a larger community of all who wish to learn about stochastic optimization techniques and how to use them.
2015-07-06
consider a probabilistically-constrained portfolio optimization problem [16] to determine a minimum cost distribution of a unit investment among n assets...present a branching technique (Section 5). Through computational experiments on the probabilistic portfolio optimization problem (3) and an optimal ...at one. 15 DISTRIBUTION A: Distribution approved for public release. 6.2 Probabilistic Portfolio Optimization The first class of instances we test
Institute of Scientific and Technical Information of China (English)
Huaibin TANG; Zhen WU
2009-01-01
In this paper, the authors first study two kinds of stochastic differential equations (SDEs)cesses, the authors proceed to study a stochastic linear quadratic (LQ) optimal control problem with One kind of new stochastic Riccati equation that involves equality and inequality constraints is derived from the idea of square completion and its solvability is proved to be sufficient for the well-posedness and the existence of optimal control which can be of either state feedback or open-loop form of the LQ problems. Moreover, the authors obtain the existence and uniqueness of the solution to the Riccati equation for some special cases. Finally, two examples are presented to illustrate these theoretical results.
Institute of Scientific and Technical Information of China (English)
Tao CHENG; Frank L.LEWIS
2007-01-01
In this paper,neural networks are used to approximately solve the finite-horizon constrained input H-infiniy state feedback control problem.The method is based on solving a related Hamilton-Jacobi-Isaacs equation of the corresponding finite-horizon zero-sum game.The game value function is approximated by a neural network wlth timevarying weights.It is shown that the neural network approximation converges uniformly to the game-value function and the resulting almost optimal constrained feedback controller provides closed-loop stability and bounded L2 gain.The result is an almost optimal H-infinity feedback controller with time-varying coefficients that is solved a priori off-line.The effectiveness of the method is shown on the Rotational/Translational Actuator benchmark nonlinear control problem.
Sensorless DC motor drive via optimal observer-based servo control
Energy Technology Data Exchange (ETDEWEB)
Thananchai Keephakpreeda [Thammasat University (Thailand). School of Industrial and Mechanical Engineering
2002-07-01
This paper proposes an alternative design of a sensorless DC motor drive via optimal observer-based servo control. Without the speed sensor, the extended Luenberger observer is implemented to estimate the rotor speed of the DC motor in the presence of the disturbance torque. With this knowledge of the speed estimated from the observer, the servo state-feedback controller can drive such a rotor speed to follow the desired one. The stability and performance of the DC drive system can be guaranteed by the optimal control which minimizes the H{sub 2} norm of the closed-loop feedback control and observer system. The simulation and experimental studies are demonstrated for the effectiveness of the proposed control methodology in a practical approach for the sensorless DC drive. (author)
Approximate design of optimal tracking controller for time-delay systems
Institute of Scientific and Technical Information of China (English)
TANG Gongyou; LI Chao; ZHAO Yandong
2006-01-01
Successive approximate design of the optimal tracking controller for linear systems with time-delay is developed. By applying the successive approximation theory of differential equations, the two-point boundary value (TPBV) problem with both time-delay and time-advance terms derived from the original optimal tracking control (OTC) problem is transformed into a sequence of linear TPBV problems without delay and advance terms. The solution sequence of the linear TPBV problems uniformly converges to the solution of the original OTC problem. The obtained OTC law consists of analytic state feedback terms and a compensation term which is the limit of the adjoint vector sequence. The compensation term can be obtained from an iteration formula of adjoint vectors. By using a finite term of the adjoint vector sequence, a suboptimal tracking control law is revealed. Numerical examples show the effectiveness of the algorithm.
Institute of Scientific and Technical Information of China (English)
刘红岭; 蔡建章; 蔡华祥
2015-01-01
During dry water period, contradiction between the utilization of water quality and control of water level is concerned for the uncertainty of reservoir inflow, which is more significant for the limited regulation ability of quarterly and below regulating hydro￣power stations. In this paper, to utilize inflow energy and storage energy comprehensively, the loss of water level is represented with the loss of inflow energy and the objective of high efficient utilization is constructed, and a new optimal operation mode of hydropow￣er station during dry water period is proposed. Through the comparison between loss of inflow energy and utilization of storage ener￣gy, loss of water level is represented with the loss of inflow energy and the objective of high efficient utilization is constructed, and a new optimal operation mode of hydropower station during dry water period is proposed. Through the comparison between loss of in￣flow energy and utilization of storage energy, optimal water level reduction plan is determined, and can provide decision reference for the coordination control on the utilization of water quality and water level.%水库入流的不确定性使得水电站在枯水期调度运行时面临着水量利用与水头控制间的协调矛盾，而季调节及以下调节能力的水电站由于调节能力的限制使得这种矛盾更加突出。本文从综合利用来流能与水库蓄能的角度出发，提出以来流能损失表示水头的损失，以水库蓄能的高效利用为目标确定水电站枯水期最佳调度运行方式。通过来流能损失与一定水库蓄能利用效率下的动用蓄能的比较分析，优化确定枯水期水位控制方案，为实现枯水期水量与水头利用的协调控制提供调度决策依据。
Malachová, Alexandra; Sulyok, Michael; Beltrán, Eduardo; Berthiller, Franz; Krska, Rudolf
2014-10-01
An LC-MS/MS "dilute and shoot" method for the determination of 295 fungal and bacterial metabolites was optimized and validated according to the guidelines established in the Directorate General for Health and Consumer Affairs of the European Commission (SANCO) document No. 12495/2011. Four different types of food matrices were chosen for validation: apple puree for infants (high water content), hazelnuts (high fat content), maize (high starch and low fat content) and green pepper (difficult or unique matrix). Method accuracy and precision was evaluated using spiked samples in five replicates at two concentration levels. Method trueness was demonstrated through participation in various proficiency tests. Although the method covers a total number of 331 analytes, validation data were acquired only for 295 analytes, either due to the non-availability of analytical standards or due other reasons described in this paper. Concerning the apparent recovery, the percentage of 295 analytes matching the acceptable recovery range of 70-120% lied down by SANCO varied from 21% in green pepper to 74% in apple puree at the highest spiking level. At the levels close to limit of quantification only 20-58% of the analytes fulfilled this criterion. The extent of matrix effects was strongly dependent on the analyte/matrix combination. In general, the lowest matrix effects were observed in apple puree (59% of analytes were not influenced by enhancement/suppression at all at the highest validation level). The highest matrix effects were observed in green pepper, where only 10% of analytes did not suffer from signal suppression/enhancement. The repeatability of the method was acceptable (RSD≤20) for 97% of all analytes in apple puree and hazelnuts, for 95% in maize and for 89% in green pepper. Concerning the trueness of the method, Z-scores were generally between -2 and 2, despite a broad variety of different matrices. Based on these results it can be concluded that quantitative
Institute of Scientific and Technical Information of China (English)
姚伟; 肖付伟
2016-01-01
核电机组一次调频在保证核电的安全运行等方面起着重要的作用，因此，研究一次调频动作对汽轮机和反应堆带来何种危害是十分有必要的。针对机组在满功率状态情况下，研究一次调频动作的风险并对其进行分析、仿真，最后提出相应的优化方法。这种研究对核电机组避免此种情况下一次调频带来的动作风险有一定的指导意义，有利于核电的安全运行以及提高电网频率质量和安全稳定运行水平。%Primary frequency regulation of nuclear power unit is very important in ensuring the safe operation of nuclear power. Therefore, it is very necessary to study the effect of primary frequency modulation on steam turbine and the reactor. On the condition that nuclear power unit is in full power state, the risk of primary frequency regulation is analyzed and simulated, and the corresponding optimization methods are proposed. This study has a certain guiding significance in helping the nuclear power unit to avoid the risk of primary frequency regulation, and is conductive to the safe operation of nuclear power and improve the safe and stable operation of power grid frequence quality .
Park, Myoungryoul
2010-09-28
The R2R3-type OsMyb4 transcription factor of rice has been shown to play a role in the regulation of osmotic adjustment in heterologous overexpression studies. However, the exact composition and organization of its underlying transcriptional network has not been established to be a robust tool for stress tolerance enhancement by regulon engineering. OsMyb4 network was dissected based on commonalities between the global chilling stress transcriptome and the transcriptome configured by OsMyb4 overexpression. OsMyb4 controls a hierarchical network comprised of several regulatory sub-clusters associated with cellular defense and rescue, metabolism and development. It regulates target genes either directly or indirectly through intermediary MYB, ERF, bZIP, NAC, ARF and CCAAT-HAP transcription factors. Regulatory sub-clusters have different combinations of MYB-like, GCC-box-like, ERD1-box-like, ABRE-like, G-box-like, as1/ocs/TGA-like, AuxRE-like, gibberellic acid response element (GARE)-like and JAre-like cis-elements. Cold-dependent network activity enhanced cellular antioxidant capacity through radical scavenging mechanisms and increased activities of phenylpropanoid and isoprenoid metabolic processes involving various abscisic acid (ABA), jasmonic acid (JA), salicylic acid (SA), ethylene and reactive oxygen species (ROS) responsive genes. OsMyb4 network is independent of drought response element binding protein/C-repeat binding factor (DREB/CBF) and its sub-regulons operate with possible co-regulators including nuclear factor-Y. Because of its upstream position in the network hierarchy, OsMyb4 functions quantitatively and pleiotrophically. Supra-optimal expression causes misexpression of alternative targets with costly trade-offs to panicle development. © 2010 Blackwell Publishing Ltd.
Park, Myoung-Ryoul; Yun, Kil-Young; Mohanty, Bijayalaxmi; Herath, Venura; Xu, Fuyu; Wijaya, Edward; Bajic, Vladimir B; Yun, Song-Joong; De Los Reyes, Benildo G
2010-12-01
The R2R3-type OsMyb4 transcription factor of rice has been shown to play a role in the regulation of osmotic adjustment in heterologous overexpression studies. However, the exact composition and organization of its underlying transcriptional network has not been established to be a robust tool for stress tolerance enhancement by regulon engineering. OsMyb4 network was dissected based on commonalities between the global chilling stress transcriptome and the transcriptome configured by OsMyb4 overexpression. OsMyb4 controls a hierarchical network comprised of several regulatory sub-clusters associated with cellular defense and rescue, metabolism and development. It regulates target genes either directly or indirectly through intermediary MYB, ERF, bZIP, NAC, ARF and CCAAT-HAP transcription factors. Regulatory sub-clusters have different combinations of MYB-like, GCC-box-like, ERD1-box-like, ABRE-like, G-box-like, as1/ocs/TGA-like, AuxRE-like, gibberellic acid response element (GARE)-like and JAre-like cis-elements. Cold-dependent network activity enhanced cellular antioxidant capacity through radical scavenging mechanisms and increased activities of phenylpropanoid and isoprenoid metabolic processes involving various abscisic acid (ABA), jasmonic acid (JA), salicylic acid (SA), ethylene and reactive oxygen species (ROS) responsive genes. OsMyb4 network is independent of drought response element binding protein/C-repeat binding factor (DREB/CBF) and its sub-regulons operate with possible co-regulators including nuclear factor-Y. Because of its upstream position in the network hierarchy, OsMyb4 functions quantitatively and pleiotrophically. Supra-optimal expression causes misexpression of alternative targets with costly trade-offs to panicle development.
Institute of Scientific and Technical Information of China (English)
卫晓贤; 刘德有; 黄时峰; 王丰
2013-01-01
取水泵站优化运行调度研究对泵站节能具有较好的指导意义.针对取水泵站的工作特点,以取水泵站日运行耗电费最小为目标,考虑峰谷电价及清水池调节容积对取水泵站日运行耗电费的影响,建立了含定速泵或双速泵的取水泵站优化运行调度数学模型,并利用基于动态规划法的求解策略对该数学模型进行了求解.最后通过实例计算结果表明:在原有泵型不变且同等满足供水要求的情况下,该取水泵站采用优化后的运行方案较目前实际的运行方案,可有效地实现充分利用清水池调节容积应对峰谷电价进行错峰运行,泵站运行耗电费可明显降低,这验证了所建立的优化调度数学模型是合理、有效的,对类似的取水泵站节能运行具有良好的指导意义.%Studying the optimal operation of the intake pumping water station has a guiding significance for pump station energy-saving. In regard to the operational characteristics of intake pumping water stations, a model including constant speed or two-speed pumps is applied for the optimal operation of the intake pumping water stations. The model is established with the minimum day total operational cost as objective functioa The effect of peak-valley price and regulation of clearwells on the day total operational cost of the intake pumping water station are taken into consideration in the optimal operation. The model is computed with the method of dynamic planning . Finally, the calculation results of the practical example show that the intake pumping water station after optimal operation can be effectively achieved to run with peak shifting and the full advantage of regulation of clearwells to respond to the peak-valley price in the case of the unchanged types of the original pumps and meeting the requirements of water suppy equally. And the daily total operational cost of the intake pumping water station decreases significantly. This verifies the
Blum, Kenneth; Badgaiyan, Rajendra D.; Braverman, Eric R.; Dushaj, Kristina; Li, Mona; Thanos, Peter K.; Demetrovics, Zsolt; Febo, Marcelo
2017-01-01
Unlike other drugs of abuse such as alcohol, nicotine, opiates/opioids, the FDA has not approved any agent to treat psychostimulant dependence. Certainly, it is widely acceptable that dopaminergic signaling is a key factor in both the initiation and continued motivation to abuse this class of stimulant substances. It is also well accepted that psychostimulants such as cocaine affect not only the release of neuronal dopamine at the nucleus accumbens (NAc), but also has powerful inhibitory actions on the dopamine transporter system. Understandably, certain individuals are at high risk and very vulnerable to abuse this class of substances. Trace-amine-associated receptor 1 (TAAR1) is a G -protein coupled receptor activated by trace amines. The encoded protein responds little or not at all to dopamine, serotonin, epinephrine, or histamine, but responds well to beta-phenylethylamine, p-tyramine, octopamine, and tryptamine. This gene is thought to be intronless. TAAR1 agonists reduce the neurochemical effects of cocaine and amphetamines as well as attenuate addiction and abuse associated with these two psychostimulants. The mechanism involves blocking the firing rate of dopamine in the limbic system thereby decreasing a hyperdopaminergic trait/state, whereby the opposite is true for TAAR1 antagonists. Based on many studies, it is accepted that in Reward Deficiency Syndrome (RDS), there is weakened tonic and improved phasic dopamine discharge leading to a hypodopaminergic/glutamatergic trait. The dopamine pro-complex mixture KB220, following many clinical trials including neuroimaging studies, has been shown to enhance resting state functional connectivity in humans (abstinent heroin addicts), naïve rodent models, and regulates extensive theta action in the cingulate gyrus of abstinent psychostimulant abusers. In this article, we are hypothesizing that KB220 may induce its action on resting state functional connectivity, for example, by actually balancing (optimizing
Blum, Kenneth; Badgaiyan, Rajendra D; Braverman, Eric R; Dushaj, Kristina; Li, Mona; Thanos, Peter K; Demetrovics, Zsolt; Febo, Marcelo
2016-01-01
Unlike other drugs of abuse such as alcohol, nicotine, opiates/opioids, the FDA has not approved any agent to treat psychostimulant dependence. Certainly, it is widely acceptable that dopaminergic signaling is a key factor in both the initiation and continued motivation to abuse this class of stimulant substances. It is also well accepted that psychostimulants such as cocaine affect not only the release of neuronal dopamine at the nucleus accumbens (NAc), but also has powerful inhibitory actions on the dopamine transporter system. Understandably, certain individuals are at high risk and very vulnerable to abuse this class of substances. Trace-amine-associated receptor 1 (TAAR1) is a G -protein coupled receptor activated by trace amines. The encoded protein responds little or not at all to dopamine, serotonin, epinephrine, or histamine, but responds well to beta-phenylethylamine, p-tyramine, octopamine, and tryptamine. This gene is thought to be intronless. TAAR1 agonists reduce the neurochemical effects of cocaine and amphetamines as well as attenuate addiction and abuse associated with these two psychostimulants. The mechanism involves blocking the firing rate of dopamine in the limbic system thereby decreasing a hyperdopaminergic trait/state, whereby the opposite is true for TAAR1 antagonists. Based on many studies, it is accepted that in Reward Deficiency Syndrome (RDS), there is weakened tonic and improved phasic dopamine discharge leading to a hypodopaminergic/glutamatergic trait. The dopamine pro-complex mixture KB220, following many clinical trials including neuroimaging studies, has been shown to enhance resting state functional connectivity in humans (abstinent heroin addicts), naïve rodent models, and regulates extensive theta action in the cingulate gyrus of abstinent psychostimulant abusers. In this article, we are hypothesizing that KB220 may induce its action on resting state functional connectivity, for example, by actually balancing (optimizing
Ruszczynski, Andrzej
2011-01-01
Optimization is one of the most important areas of modern applied mathematics, with applications in fields from engineering and economics to finance, statistics, management science, and medicine. While many books have addressed its various aspects, Nonlinear Optimization is the first comprehensive treatment that will allow graduate students and researchers to understand its modern ideas, principles, and methods within a reasonable time, but without sacrificing mathematical precision. Andrzej Ruszczynski, a leading expert in the optimization of nonlinear stochastic systems, integrates t
Directory of Open Access Journals (Sweden)
James W Vaupel
Full Text Available Semelparous organisms have a simple life cycle characterized by immediate death after reproduction. We assume that semelparous life histories can be separated into a juvenile non-reproductive period followed by an adult period during which reproduction is possible. We derive formulae for the optimal age and size at reproduction and for the optimal size of the offspring (e.g., seeds. Our main contribution is to determine the conditions under which the optimal size of the offspring does not depend on the optimal size at reproduction and vice versa.
King, Andrew
2008-01-01
Remember when an optimized website was one that merely didn't take all day to appear? Times have changed. Today, website optimization can spell the difference between enterprise success and failure, and it takes a lot more know-how to achieve success. This book is a comprehensive guide to the tips, techniques, secrets, standards, and methods of website optimization. From increasing site traffic to maximizing leads, from revving up responsiveness to increasing navigability, from prospect retention to closing more sales, the world of 21st century website optimization is explored, exemplified a
On regulators with a prescribed degree of stability. M.S. Thesis
Ng, P. T. P.
1981-01-01
Several important aspects of the Regulator with a Prescribed Degree of Stability (RPDS) methodology and its applications are considered. The solution of the time varying RPDS problem as well as the characterization of RPDS closed loop eigenstructure properties are obtained. Based on the asymptotic behavior of RPDS root loci, a one step algorithm for designing Regulators with Prescribed Damping Ratio (RPDR) is developed. The robustness properties of RPDS are characterized in terms of the properties of the return difference and the inverse return difference matrices for the RPDS state feedback loop. This class of regulators is found to possess excellent multiloop margins with respect to stability and degree of stability properties. The ability of RPDS design to tolerate changing operating conditions and unmodelled dynamics are illustrated with a multiterminal dc/ac power system example. The output feedback realization of RPDS requires the use of Linear Quadratic Gaussian (LQG) methodology.
DEFF Research Database (Denmark)
Birkholm, Klavs
2010-01-01
En undersøgelse af anvendelsen af medicin til optimering af koncentration, hukommelse og følelsestonus. Efterfulgt af etiske overvejelser og anbefalinger til det politiske system......En undersøgelse af anvendelsen af medicin til optimering af koncentration, hukommelse og følelsestonus. Efterfulgt af etiske overvejelser og anbefalinger til det politiske system...
DEFF Research Database (Denmark)
A. Kristensen, Anders Schmidt; Damkilde, Lars
2007-01-01
. A way to solve the initial design problem namely finding a form can be solved by so-called topology optimization. The idea is to define a design region and an amount of material. The loads and supports are also fidefined, and the algorithm finds the optimal material distribution. The objective function...... dictates the form, and the designer can choose e.g. maximum stiness, maximum allowable stresses or maximum lowest eigenfrequency. The result of the topology optimization is a relatively coarse map of material layout. This design can be transferred to a CAD system and given the necessary geometrically...... refinements, and then remeshed and reanalysed in other to secure that the design requirements are met correctly. The output of standard topology optimization has seldom well-defined, sharp contours leaving the designer with a tedious interpretation, which often results in less optimal structures. In the paper...
Carver, Charles S.; Scheier, Michael F.
2014-01-01
Optimism is a cognitive construct (expectancies regarding future outcomes) that also relates to motivation: optimistic people exert effort, whereas pessimistic people disengage from effort. Study of optimism began largely in health contexts, finding positive associations between optimism and markers of better psychological and physical health. Physical health effects likely occur through differences in both health-promoting behaviors and physiological concomitants of coping. Recently, the scientific study of optimism has extended to the realm of social relations: new evidence indicates that optimists have better social connections, partly because they work harder at them. In this review, we examine the myriad ways this trait can benefit an individual, and our current understanding of the biological basis of optimism. PMID:24630971
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严干贵; 冯晓东; 李军徽; 穆钢; 谢国强; 董效辰; 王芝茗; 杨凯
2012-01-01
利用大规模电池储能系统对电网负荷“削峰填谷”,减少日负荷波动幅度,可以缓解发电机组对负荷追踪调控负担,使电网具备更多向下调节容量来接纳风电.基于给定的负荷特性,分析储能系统配置容量与其改善负荷波动水平之间的关系,以储能系统投资成本、经济效益为约束,以综合效益最大为目标,提出一种用于松弛调峰瓶颈的大规模储能系统容量优化配置方法.针对2010年某省电网接纳风电受限现状,利用该方法对其进行改善,分析了储能系统运行年限、投资成本对其容量配置的影响,算例结果验证了所提出方法的可行性.%Using large-scale battery energy storage systems for load shifting and peak smoothing can decrease the fluctuation of daily load and reduce load tracking regulation burden of generator units, and enlarge down-regulate space to accommodate wind power. Based on a given load characteristics, the relationship between the energy storage system allocation capacity and improvement of load fluctuations was analyzed. By making energy storage system's investment costs and economic benefits as constraints, and by maximizing the comprehensive benefits as the object, an optimal capacity-allocation method was proposed for large-scale energy storage systems to relax peak-regulation bottleneck. For the limitation of wind power accommodation of a province in China in 2010, the method was applied to improve the situation and the impact of the life cycle and investment cost of the energy storage system on its capacity configuration. Case study results verified the feasibility of the proposed method.
Non-fragile memory state feedback H_∞ control for discrete-time systems%具有扇区有界非线性时变时延离散系统的非脆弱H_∞控制
Institute of Scientific and Technical Information of China (English)
杨晓芳; 杨维; 刘建昌
2011-01-01
研究具有扇区有界非线性时变时延离散系统的非脆弱非线性记忆状态反馈H∞控制器的设计问题.提出一种具有更一般性的控制器增益不确定,并采用Lyapunov-Krasovskii泛函及线性矩阵不等式技术给出了控制器设计的一个时滞依赖的充分条件.最后通过一个例子验证了所提出方法的有效性.%For a class of discrete-time systems with simultaneous sector-bounded nonlinearities and varying time delay,the design problem of non-fragile nonlinear memory state feedback H∞ controller is investigated.A more general controller gain variations is proposed.A sufficient delay dependent condition for the existence of non-fragile controller is obtained by using appropriate Lyapunov-Krasovskii functional approach and linear matrix inequality（LMI） technique.Finally,a numerical example demonstrates the effectiveness of the proposed design method.
Optimal design of funded pension schemes
Bovenberg, A.L.; Mehlkopf, R.J.
2014-01-01
This article reviews the literature on the optimal design and regulation of funded pension schemes. We first characterize optimal saving and investment over an individual’s life cycle. Within a stylized modeling framework, we explore optimal individual saving and investing behavior. Subsequently, va
Multiobjective Optimization Based Vessel Collision Avoidance Strategy Optimization
Directory of Open Access Journals (Sweden)
Qingyang Xu
2014-01-01
Full Text Available The vessel collision accidents cause a great loss of lives and property. In order to reduce the human fault and greatly improve the safety of marine traffic, collision avoidance strategy optimization is proposed to achieve this. In the paper, a multiobjective optimization algorithm NSGA-II is adopted to search for the optimal collision avoidance strategy considering the safety as well as economy elements of collision avoidance. Ship domain and Arena are used to evaluate the collision risk in the simulation. Based on the optimization, an optimal rudder angle is recommended to navigator for collision avoidance. In the simulation example, a crossing encounter situation is simulated, and the NSGA-II searches for the optimal collision avoidance operation under the Convention on the International Regulations for Preventing Collisions at Sea (COLREGS. The simulation studies exhibit the validity of the method.
SUMO: regulating the regulator
Directory of Open Access Journals (Sweden)
Bossis Guillaume
2006-06-01
Full Text Available Abstract Post-translational modifiers of the SUMO (Small Ubiquitin-related Modifier family have emerged as key regulators of protein function and fate. While the past few years have seen an enormous increase in knowledge on SUMO enzymes, substrates, and consequences of modification, regulation of SUMO conjugation is far from being understood. This brief review will provide an overview on recent advances concerning (i the interplay between sumoylation and other post-translational modifications at the level of individual targets and (ii global regulation of SUMO conjugation and deconjugation.
Inverse optimal sliding mode control of spacecraft with coupled translation and attitude dynamics
Pukdeboon, Chutiphon
2015-10-01
This paper proposes two robust inverse optimal control schemes for spacecraft with coupled translation and attitude dynamics in the presence of external disturbances. For the first controller, an inverse optimal control law is designed based on Sontag-type formula and the control Lyapunov function. Then a robust inverse optimal position and attitude controller is designed by using a new second-order integral sliding mode control method to combine a sliding mode control with the derived inverse optimal control. The global asymptotic stability of the proposed control law is proved by using the second method of Lyapunov. For the other control law, a nonlinear H∞ inverse optimal controller for spacecraft position and attitude tracking motion is developed to achieve the design conditions of controller gains that the control law becomes suboptimal H∞ state feedback control. The ultimate boundedness of system state is proved by using the Lyapunov stability theory. Both developed robust inverse optimal controllers can minimise a performance index and ensure the stability of the closed-loop system and external disturbance attenuation. An example of position and attitude tracking manoeuvres is presented and simulation results are included to show the performance of the proposed controllers.
Root Placement With Transfer Function Methods (Full State Feedback)
1988-12-01
sient time response of the system can be easily controlled and adjusted. 2. The sensitivity of the system to plant parameter variation is reduced. 3...is less than ten times the real part of the dominant roots, but, is probably acceptable. F-or this plant, the --iidefines are worl ,11In. B. PLANT 2
Robust State Feedback Control of Wind-Excited Tall Buildings
Institute of Scientific and Technical Information of China (English)
无
2001-01-01
The introduction of robust control theory into structure control, as well as design procedure of stabilizing controllers for structures with parameter uncertainty and model error is discussed. A stability bound is derived from the polar decomposition of the nominal system matrix. In addition, our study shows that application of Iow pass filters avoids spillover by eliminating the unconsidered high frequency compo nents. It is demonstrated, via an example, our approach leads to excellent control result and offers far better robustness than previous solutions.
Robust control of robots via linear estimated state feedback
Berghuis, Harry; Nijmeijer, Henk
1994-01-01
In this note we propose a robust tracking controller for robots that requires only position measurements. The controller consists of two parts: a linear observer part that generates an estimated error state from the error on the joint position and a linear feedback part that utilizes this estimated
Frajtova-Michalikova, Katarina; Spuchľakova, Erika; Misankova, Maria
2015-01-01
In this paper Portfolio Optimization techniques were used to determine the most favorable investment portfolio. In particular, stock indices of three companies, namely Microsoft Corporation, Christian Dior Fashion House and Shevron Corporation were evaluated. Using this data the amounts invested in each asset when a portfolio is chosen on the efficient frontier were calculated. In addition, the Portfolio with minimum variance, tangency portfolio and optimal Markowitz portfolio are presented.
CONTROL SYSTEM OF MAGNETIC BEARINGS BASED ON LINEAR QUADRATIC METHOD OF OPTIMAL CONTROL STRATEGY
Institute of Scientific and Technical Information of China (English)
Zhu Huangqiu
2005-01-01
A state equation for radical 4-degree-of-freedom active magnetic bearings is built, and the approach on how to use linear quadratic method of optical control theory to design a centralized and decentralized parameters control system is introduced, and also Matlab language is used to simulate and analyze. The simulation results have proved that the differences are small between centralized parameters and decentralized parameters control system. The conclusions of experiments have shown that decentralized controllers designed from optimal state feedback theory meet the requirements of active magnetic bearing system. The vibration amplitude of the rotor is about 20 μm when the speed of the rotor runs between 0 to 60 000 r/min. This method may be used in the study and design of controllers of magnetic bearings.
Cooperative control of multi-agent systems optimal and adaptive design approaches
Lewis, Frank L; Hengster-Movric, Kristian; Das, Abhijit
2014-01-01
Task complexity, communication constraints, flexibility and energy-saving concerns are all factors that may require a group of autonomous agents to work together in a cooperative manner. Applications involving such complications include mobile robots, wireless sensor networks, unmanned aerial vehicles (UAVs), spacecraft, and so on. In such networked multi-agent scenarios, the restrictions imposed by the communication graph topology can pose severe problems in the design of cooperative feedback control systems. Cooperative control of multi-agent systems is a challenging topic for both control theorists and practitioners and has been the subject of significant recent research. Cooperative Control of Multi-Agent Systems extends optimal control and adaptive control design methods to multi-agent systems on communication graphs. It develops Riccati design techniques for general linear dynamics for cooperative state feedback design, cooperative observer design, and cooperative dynamic output feedback design. B...
Watershed water ecological carrying capacity and optimizing regulation model%流域水生态承载力理论与优化调控模型方法
Institute of Scientific and Technical Information of China (English)
彭文启
2013-01-01
Watershed management is changing from single factor management of environment and re-sources to aquatic ecological protection integrated management. Water resources carrying capacity and water en-vironment carrying capacity have not fully adapted to this situation. Therefore,it is necessary to build a new car-rying capacity theory to solve the current aquatic problems. According to the demands of watershed water ecolog-ical integrity protection management,based on water ecological carrying capacity concept model,water ecologi-cal carrying capacity concept,which reveals its basic connotation of“partition,staging”property and“quanti-ty,quality,order”progressive comprehensive constraint effects,was put forward in this paper. Then the paper analyzed its key optimal regulation variables,and established the water ecological carrying capacity partition coupling concept model using eco-regions as elements. Considering the communication of water flow and water quality among eco-regions,the system dynamics simulation model of Taizi River basin water ecological carrying capacity was established,the water ecological carrying capacity of 8 eco-regions were simulated,and optional regulation schemes of each eco-regions were determined,which can provide a scientific basis for the sustainable development of the watershed.% 流域管理正在从环境及资源的单一要素管理向流域水生态系统综合管理转变，流域水生态承载力是流域水生态系统综合管理的基本理论。针对流域水生态完整性保护管理需求，建立了流域水生态承载力概念模型，提出了流域水生态承载力概念，揭示其“分区、分期”属性和“量、质、序”递进综合约束作用等基本内涵，通过分析其优化调控特性及优化调控关键变量，建立了流域水生态承载力分区耦合概念模型，形成了基于系统动力学方法的流域水生态承载力分区分期耦合模型方法，并以辽河
An optimal state estimation model of sensory integration in human postural balance
Kuo, Arthur D.
2005-09-01
We propose a model for human postural balance, combining state feedback control with optimal state estimation. State estimation uses an internal model of body and sensor dynamics to process sensor information and determine body orientation. Three sensory modalities are modeled: joint proprioception, vestibular organs in the inner ear, and vision. These are mated with a two degree-of-freedom model of body dynamics in the sagittal plane. Linear quadratic optimal control is used to design state feedback and estimation gains. Nine free parameters define the control objective and the signal-to-noise ratios of the sensors. The model predicts statistical properties of human sway in terms of covariance of ankle and hip motion. These predictions are compared with normal human responses to alterations in sensory conditions. With a single parameter set, the model successfully reproduces the general nature of postural motion as a function of sensory environment. Parameter variations reveal that the model is highly robust under normal sensory conditions, but not when two or more sensors are inaccurate. This behavior is similar to that of normal human subjects. We propose that age-related sensory changes may be modeled with decreased signal-to-noise ratios, and compare the model's behavior with degraded sensors against experimental measurements from older adults. We also examine removal of the model's vestibular sense, which leads to instability similar to that observed in bilateral vestibular loss subjects. The model may be useful for predicting which sensors are most critical for balance, and how much they can deteriorate before posture becomes unstable.
Institute of Scientific and Technical Information of China (English)
Qiangde WANG; Chunling WEI; Yuqiang WU
2009-01-01
A robust partial-state feedback asymptotic regulating control scheme is developed for a class of cascade systems with both nonlinear uncertainties and unknown control directions.A parameter separation technique is introduced to separate the time-varying uncertainty and the unmeasurable state from nonlinear functions.Then,the Nussbaum-type gain method together with the idea of changing supply functions is adopted in the design of a smooth partial-state regulator that can ensure all the signals of the closed-loop system are globally uniformly bounded.Especially,the system state asymptotically converges to zero.The design procedure is illustrated through an example and the simulation results show that the controller is feasible and effective.
Institute of Scientific and Technical Information of China (English)
周丽娜; 刘晓华
2013-01-01
The problem of robust and non-fragile stabilization and robust non-fragile H∞ control for a class of neutral stochastic time-delay systems with norm-bounded parameter uncertainties was studied.The sufficient conditions ensuring the closed-loop system mean-square asymptotically stable were established With the additive and multiplicative gain uncertainty in the controller,based on the Lyapunov functional,Ito formula and Schur theory.Furthermore,the sufficient conditions were obtained for the solvability of robust non-fragile H∞ control of the uncertain system.The memory state feedback non-fragile H∞ controllers of the stochastic neutral delay system were designed by solving linear matrix inequality.The numerical example was provided to illustrate the effectiveness of the proposed design method.%研究了一类具有参数不确定性的中立型随机时滞系统的鲁棒非脆弱镇定和鲁棒非脆弱H∞控制问题.在控制器增益分别具有加法式摄动和乘法式摄动的情形下,通过构造Lyapunov泛函,利用Ito公式和Schur补原理,建立了用线性矩阵不等式表示的保证闭环系统随机均方渐近稳定的充分条件；给出了不确定系统鲁棒非脆弱H∞控制可解性的充分条件；通过求解线性矩阵不等式,设计了随机时滞系统的记忆状态反馈非脆弱H∞控制器.数值仿真证明了该方法的有效性.
DEFF Research Database (Denmark)
Frandsen, P. E.; Jonasson, K.; Nielsen, Hans Bruun
1999-01-01
This lecture note is intended for use in the course 04212 Optimization and Data Fitting at the Technincal University of Denmark. It covers about 25% of the curriculum. Hopefully, the note may be useful also to interested persons not participating in that course. The aim of the note is to give...... an introduction to algorithms for unconstrained optimization. We present Conjugate Gradient, Damped Newton and Quasi Newton methods together with the relevant theoretical background. The reader is assumed to be familiar with algorithms for solving linear and nonlinear system of equations, at a level corresponding...
DEFF Research Database (Denmark)
Frandsen, P. E.; Jonasson, K.; Nielsen, Hans Bruun
1999-01-01
This lecture note is intended for use in the course 04212 Optimization and Data Fitting at the Technincal University of Denmark. It covers about 25% of the curriculum. Hopefully, the note may be useful also to interested persons not participating in that course. The aim of the note is to give...... an introduction to algorithms for unconstrained optimization. We present Conjugate Gradient, Damped Newton and Quasi Newton methods together with the relevant theoretical background. The reader is assumed to be familiar with algorithms for solving linear and nonlinear system of equations, at a level corresponding...
Optimal guidance for reentry vehicles based on indirect Legendre pseudospectral method
Tian, Bailing; Zong, Qun
2011-04-01
Development of a feasible guidance scheme for reentry vehicles is a challenge because of its significant nonlinearity and multi-constraints. A method for the implementation of three-degree-of-freedom guidance for constrained reentry vehicle is presented in the paper. First, the constrained trajectory is generated by Legendre pseudospectral method (LPM) and then the feasibily of the trajectory is validated. Based on the obtained reference trajectory, the guidance problem is converted into a trajectory state regulation problem which is a linear time varying system. A robust state feedback guidance law is generated in real time using indirect Legendre pseudospectral feedback method. Finally, simulation results illustrate that the overall guidance scheme can lead to a very accurately controlled flight with all the constraints satisfied even in the presence of initial state uncertainty.
Wu, Huai-Ning; Li, Mao-Mao; Guo, Lei
2015-07-01
This paper studies the finite-horizon optimal guaranteed cost control (GCC) problem for a class of time-varying uncertain nonlinear systems. The aim of this problem is to find a robust state feedback controller such that the closed-loop system has not only a bounded response in a finite duration of time for all admissible uncertainties but also a minimal guaranteed cost. A neural network (NN) based approximate optimal GCC design is developed. Initially, by modifying the cost function to account for the nonlinear perturbation of system, the optimal GCC problem is transformed into a finite-horizon optimal control problem of the nominal system. Subsequently, with the help of the modified cost function together with a parametrized bounding function for all admissible uncertainties, the solution to the optimal GCC problem is given in terms of a parametrized Hamilton-Jacobi-Bellman (PHJB) equation. Then, a NN method is developed to solve offline the PHJB equation approximately and thus obtain the nearly optimal GCC policy. Furthermore, the convergence of approximate PHJB equation and the robust admissibility of nearly optimal GCC policy are also analyzed. Finally, by applying the proposed design method to the entry guidance problem of the Mars lander, the achieved simulation results show the effectiveness of the proposed controller.
Eckmann, B
2008-01-01
At the close of the 1980s, the independent contributions of Yann Brenier, Mike Cullen and John Mather launched a revolution in the venerable field of optimal transport founded by G Monge in the 18th century, which has made breathtaking forays into various other domains of mathematics ever since. The author presents a broad overview of this area.
DEFF Research Database (Denmark)
Bendsøe, Martin P.; Sigmund, Ole
2007-01-01
Taking as a starting point a design case for a compliant mechanism (a force inverter), the fundamental elements of topology optimization are described. The basis for the developments is a FEM format for this design problem and emphasis is given to the parameterization of design as a raster image...
Combinatorial Gene Regulation Using Auto-Regulation
Hermsen, Rutger; Ursem, Bas; ten Wolde, Pieter Rein
2010-01-01
As many as 59% of the transcription factors in Escherichia coli regulate the transcription rate of their own genes. This suggests that auto-regulation has one or more important functions. Here, one possible function is studied. Often the transcription rate of an auto-regulator is also controlled by additional transcription factors. In these cases, the way the expression of the auto-regulator responds to changes in the concentrations of the “input” regulators (the response function) is obviously affected by the auto-regulation. We suggest that, conversely, auto-regulation may be used to optimize this response function. To test this hypothesis, we use an evolutionary algorithm and a chemical–physical model of transcription regulation to design model cis-regulatory constructs with predefined response functions. In these simulations, auto-regulation can evolve if this provides a functional benefit. When selecting for a series of elementary response functions—Boolean logic gates and linear responses—the cis-regulatory regions resulting from the simulations indeed often exploit auto-regulation. Surprisingly, the resulting constructs use auto-activation rather than auto-repression. Several design principles show up repeatedly in the simulation results. They demonstrate how auto-activation can be used to generate sharp, switch-like activation and repression circuits and how linearly decreasing response functions can be obtained. Auto-repression, on the other hand, resulted only when a high response speed or a suppression of intrinsic noise was also selected for. The results suggest that, while auto-repression may primarily be valuable to improve the dynamical properties of regulatory circuits, auto-activation is likely to evolve even when selection acts on the shape of response function only. PMID:20548950
Optimal GENCO bidding strategy
Gao, Feng
Electricity industries worldwide are undergoing a period of profound upheaval. The conventional vertically integrated mechanism is being replaced by a competitive market environment. Generation companies have incentives to apply novel technologies to lower production costs, for example: Combined Cycle units. Economic dispatch with Combined Cycle units becomes a non-convex optimization problem, which is difficult if not impossible to solve by conventional methods. Several techniques are proposed here: Mixed Integer Linear Programming, a hybrid method, as well as Evolutionary Algorithms. Evolutionary Algorithms share a common mechanism, stochastic searching per generation. The stochastic property makes evolutionary algorithms robust and adaptive enough to solve a non-convex optimization problem. This research implements GA, EP, and PS algorithms for economic dispatch with Combined Cycle units, and makes a comparison with classical Mixed Integer Linear Programming. The electricity market equilibrium model not only helps Independent System Operator/Regulator analyze market performance and market power, but also provides Market Participants the ability to build optimal bidding strategies based on Microeconomics analysis. Supply Function Equilibrium (SFE) is attractive compared to traditional models. This research identifies a proper SFE model, which can be applied to a multiple period situation. The equilibrium condition using discrete time optimal control is then developed for fuel resource constraints. Finally, the research discusses the issues of multiple equilibria and mixed strategies, which are caused by the transmission network. Additionally, an advantage of the proposed model for merchant transmission planning is discussed. A market simulator is a valuable training and evaluation tool to assist sellers, buyers, and regulators to understand market performance and make better decisions. A traditional optimization model may not be enough to consider the distributed
Real time production optimization
Energy Technology Data Exchange (ETDEWEB)
Saputelli, Luigi; Otavio, Joao; Araujo, Turiassu; Escorcia, Alvaro [Halliburton, Houston, TX (United States). Landmark Division
2004-07-01
Production optimization encompasses various activities of measuring, analyzing, modeling, prioritizing and implementing actions to enhance productivity of a field. We present a state-of-the-art framework for optimizing production on a continuous basis as new sensor data is acquired in real time. Permanently acquired data is modeled and analyzed in order to create predictive models. A model based control strategy is used to regulate well and field instrumentation. The optimum field operating point, which changes with time, satisfies the maximum economic return. This work is a starting point for further development in automatic, intelligent reservoir technologies which get the most out of the abilities of permanent, instrumented wells and remotely activated downhole completions. The strategy, tested with history-matched data from a compartmentalised giant field, proved to reduce operating costs while increasing oil recovery by 27% in this field. (author)
Real time production optimization
Energy Technology Data Exchange (ETDEWEB)
Saputelli, Luigi; Otavio, Joao; Araujo, Turiassu; Escorcia, Alvaro [Halliburton, Houston, TX (United States). Landmark Division
2004-07-01
Production optimization encompasses various activities of measuring, analyzing, modeling, prioritizing and implementing actions to enhance productivity of a field. We present a state-of-the-art framework for optimizing production on a continuous basis as new sensor data is acquired in real time. Permanently acquired data is modeled and analyzed in order to create predictive models. A model based control strategy is used to regulate well and field instrumentation. The optimum field operating point, which changes with time, satisfies the maximum economic return. This work is a starting point for further development in automatic, intelligent reservoir technologies which get the most out of the abilities of permanent, instrumented wells and remotely activated downhole completions. The strategy, tested with history-matched data from a compartmentalised giant field, proved to reduce operating costs while increasing oil recovery by 27% in this field. (author)
Market, Regulation, Market, Regulation
DEFF Research Database (Denmark)
Frankel, Christian; Galland, Jean-Pierre
2015-01-01
This paper focuses on the European Regulatory system which was settled both for opening the Single Market for products and ensuring the consumers' safety. It claims that the New Approach and Standardization, and the Global Approach to conformity assessment, which suppressed the last technical...... barriers to trade in Europe, realized the free movement of products by organizing progressively several orders of markets and regulation. Based on historical and institutional documents, on technical publications, and on interviews, this article relates how the European Commission and the Member States had...... alternatively recourse to markets and to regulations, at the three main levels of the New Approach Directives implementation. The article focuses also more specifically on the Medical Devices sector, not only because this New Approach sector has long been controversial in Europe, and has recently been concerned...
Market, Regulation, Market, Regulation
DEFF Research Database (Denmark)
Frankel, Christian; Galland, Jean-Pierre
2015-01-01
This paper focuses on the European Regulatory system which was settled both for opening the Single Market for products and ensuring the consumers' safety. It claims that the New Approach and Standardization, and the Global Approach to conformity assessment, which suppressed the last technical...... barriers to trade in Europe, realized the free movement of products by organizing progressively several orders of markets and regulation. Based on historical and institutional documents, on technical publications, and on interviews, this article relates how the European Commission and the Member States had...... alternatively recourse to markets and to regulations, at the three main levels of the New Approach Directives implementation. The article focuses also more specifically on the Medical Devices sector, not only because this New Approach sector has long been controversial in Europe, and has recently been concerned...
Institute of Scientific and Technical Information of China (English)
仲志余; 余启辉
2015-01-01
随着三峡水库及上游干支流控制性水库的逐步投运，长江中下游防洪形势得到极大改善。同时，由于蓄水拦沙，“清水”下泄，江湖关系已经并将继续发生变化，导致两湖水文情势进一步变化，对两湖地区水资源综合利用和水生态环境保护产生深刻影响。分析了洞庭湖江湖关系变化趋势和鄱阳湖枯水变化情势及其影响，结合湖区经济社会发展和生态环境保护对水利的要求，研究了两湖水量优化调控总体思路，提出了优化调控两湖水量的工程措施，为两湖生态经济区和长江经济带建设提供支撑和保障。%With the progressive operation of Three Gorges reservoir and other controlling reservoirs on the mainstream and trib-utaries of Yangtze River, the flood control in the mid-lower Yangtze River is significantly improved. Meanwhile, due to the run-off storage and sediment detention and clear water discharging, the river-lake relation has been changed and will continuously change, which leads to further variation of hydrological regime of Dongting Lake and Poyang Lake and would bring profound im-pact on the comprehensive utilization of water resources and protection of water ecology and environment for the two lake-areas. The variation trend of river-lake relation of Dongting Lake and Yangtze River is analyzed, so are the dry water level variation of Poyang Lake and its impacts. The general thought of optimizing and regulating the water storage of the two lakes are studied and the engineering measures are put forward by consideration of the requirement of social and economical development in the lake re-gion and ecological and environmental protection, so as to support and ensure the construction of ecological-economical region of the lake region and Yangtze River economic belt.
Institute of Scientific and Technical Information of China (English)
李婷; 潘欣; 应铁进
2011-01-01
对KCl溶液、NaCl溶液作为食品相变蓄冷剂的配方进行优化,通过添加人工晶核改善蓄冷剂的过冷性能,并筛选合适的蓄冷载体.结果显示:1％ SiO2和0.1％ CuS能够较好地减少KCl溶液的过冷现象,3％四硼酸钠(Na2B4O7)能较好地改善NaCl溶液的过冷现象,它们都可以用作相变蓄冷剂的人工晶核.SAP(超吸水性树脂)吸水能力随着离子浓度的增加而迅速减小,其对1.99％ NaCl水溶液的吸液率为621.47 g/g,对9.91％ KCl水溶液的吸液率为63.83 g/g.SAP和人工晶核对盐水的热力学性质影响较小,可以作为蓄冷剂的载体和防过冷剂.通过应用研究发现蓄冷剂(9.91％ KCl+SAP+1％ SiO2)可以减缓雪糕和速冻汤圆在室温条件下硬度的降低,保持其较好的外观,维持雪糕的商品价值和食用价值.蓄冷剂在隔热包装中显示出较好的温度调控性能,能在较长一段时间内将包装箱内的温度维持在目标温度.%The formula using phase change materials KC1 solution or NaCl solution as temperature regulators for food storage were optimized. The super cooling phenomenon was alleviated by application of artificial nucleation agents, and proper carrier was selected. The result showed that 1% SiO2 and 0.1% CuS can minimize the super cooling phenomenon in KCL solution, 3% Na2B4O7 can better alleviate the super cooling phenomenon. Both of them can be used as artificial nucleation agents. The water absorbing capacity of Super-absorbent Polymers(SAP) decreased rapidly with the increase of ion concentration. The absorbing rate for 1.99% Nad solution was 621.47 g/g and that for 9.91% KC1 solution was 63.83 g/g. The SAP and artificial nucleation agents had little impact on the thermodynamic characteristics of salt solution and can be used as a carrier of CTESM and protective agent of super-cooling. Further studies showed that the use of Cold Thermal Energy Storage Material (CTESM) (9.91%KCl+SAP+l%SiO2) can slow the rigidity
Aschepkov, Leonid T; Kim, Taekyun; Agarwal, Ravi P
2016-01-01
This book is based on lectures from a one-year course at the Far Eastern Federal University (Vladivostok, Russia) as well as on workshops on optimal control offered to students at various mathematical departments at the university level. The main themes of the theory of linear and nonlinear systems are considered, including the basic problem of establishing the necessary and sufficient conditions of optimal processes. In the first part of the course, the theory of linear control systems is constructed on the basis of the separation theorem and the concept of a reachability set. The authors prove the closure of a reachability set in the class of piecewise continuous controls, and the problems of controllability, observability, identification, performance and terminal control are also considered. The second part of the course is devoted to nonlinear control systems. Using the method of variations and the Lagrange multipliers rule of nonlinear problems, the authors prove the Pontryagin maximum principle for prob...
Trommer, Jochen
2005-01-01
In dieser Dissertation schlage ich eine Synthese (Distributed Optimality, DO) von Optimalitätstheorie und einem derivationellen, morphologischem Asatz, Distributed Morphology (DM; Halle & Marantz, 1993) vor. Durch die Integration von OT in DM wird es möglich, Phänomene, die in DM durch sprachspezifische Regeln oder Merkmale von lexikalischen Einträge erfasst werden, auf die Interaktion von verletzbaren, universellen Constraints zurückzuführen. Andererseits leistet auch DM zwei substantielle B...
Powell, Warren B
2012-01-01
Learn the science of collecting information to make effective decisions Everyday decisions are made without the benefit of accurate information. Optimal Learning develops the needed principles for gathering information to make decisions, especially when collecting information is time-consuming and expensive. Designed for readers with an elementary background in probability and statistics, the book presents effective and practical policies illustrated in a wide range of applications, from energy, homeland security, and transportation to engineering, health, and business. This book covers the
Directory of Open Access Journals (Sweden)
Yaping Hu
2015-01-01
the nonsmooth convex optimization problem. First, by using Moreau-Yosida regularization, we convert the original objective function to a continuously differentiable function; then we use approximate function and gradient values of the Moreau-Yosida regularization to substitute the corresponding exact values in the algorithm. The global convergence is proved under suitable assumptions. Numerical experiments are presented to show the effectiveness of this algorithm.
Parker, R Gary
1988-01-01
This book treats the fundamental issues and algorithmic strategies emerging as the core of the discipline of discrete optimization in a comprehensive and rigorous fashion. Following an introductory chapter on computational complexity, the basic algorithmic results for the two major models of polynomial algorithms are introduced--models using matroids and linear programming. Further chapters treat the major non-polynomial algorithms: branch-and-bound and cutting planes. The text concludes with a chapter on heuristic algorithms.Several appendixes are included which review the fundamental ideas o
Chvátal, V
2011-01-01
This book is a collection of six articles arising from the meeting of the NATO Advanced Study Institute (ASI) "Combinatorial Optimization: Methods and Applications," which was held at the University of Montreal in June 2006. This ASI consisted of seven series of five one-hour lectures and one series of four one-hour lectures. It was attended by some sixty students of graduate or postdoctoral level from fifteen countries worldwide. It includes topics such as: integer and mixed integer programming, facility location, branching on split disjunctions, convexity in combinatorial optimizat
Aircraft Trajectory Optimization Using Parametric Optimization Theory
Valenzuela Romero, Alfonso
2012-01-01
In this thesis, a study of the optimization of aircraft trajectories using parametric optimization theory is presented. To that end, an approach based on the use of predefined trajectory patterns and parametric optimization is proposed. The trajectory pat
Optimal control of sun tracking solar concentrators
Hughes, R. O.
1979-01-01
Application of the modern control theory to derive an optimal sun tracking control for a point focusing solar concentrator is presented. A standard tracking problem converted to regulator problem using a sun rate input achieves an almost zero steady state tracking error with the optimal control formulation. However, these control techniques are costly because optimal type algorithms require large computing systems, thus they will be used mainly as comparison standards for other types of control algorithms and help in their development.
Optimal control of radiator systems; Optimal reglering av radiatorsystem
Energy Technology Data Exchange (ETDEWEB)
Wollerstrand, J.; Ljunggren, P.; Johansson, P.O.
2007-07-01
This report presents results from a study aiming to considerably improve the development towards minimizing the primary return temperature from a district heating (DH) substation by optimizing the control algorithm for the space heating system. The investigation of this research field started about 20 years ago in Sweden when low flow operation of space heating systems was introduced. Following a couple of years of partly confused discussions, the method was accepted by many, but was rejected by others. Our thesis is that further improvement of cooling of DH water is possible when advanced, but robust, control algorithms are used for the space heating system. A space heating system is traditionally designed for a specific constant circulation flow combined with a suitable control curve for the space heating supply temperature as a function of the outdoor temperature. Optimal choice of the control curve varies from case to case and is an issue both we and others have dealt with in previous work. A large step was to derive theoretical control curves for optimal control of the space heating system, with an analysis of how temperature and circulation flow varies with heat load. The estimated gain varies strongly depending on the conditions, however, with realistic conditions it can be as much as 5 deg C decreased DH return temperature on yearly average. To be able to work properly under varying physical circumstances, a control algorithm must be able to combine variation of space heating supply temperature and circulation flow as a function of the heat load. By regulating the rotation speed of the circulation pump this can be achieved. Such regulation can be adjusted for each and every building by regulating a few parameters in a regulator. The results from this work are, that important theoretical knowledge has been completed, to show results systematically and to find support from practical experiments. A hands-on description of the method for optimizing DH water
Energy Technology Data Exchange (ETDEWEB)
Dall' Anese, Emiliano
2016-08-01
Past works that focused on addressing power-quality and reliability concerns related to renewable energy resources (RESs) operating with business-as-usual practices have looked at the design of Volt/VAr and Volt/Watt strategies to regulate real or reactive powers based on local voltage measurements, so that terminal voltages are within acceptable levels. These control strategies have the potential of operating at the same time scale of distribution-system dynamics, and can therefore mitigate disturbances precipitated fast time-varying loads and ambient conditions; however, they do not necessarily guarantee system-level optimality, and stability claims are mainly based on empirical evidences. On a different time scale, centralized and distributed optimal power flow (OPF) algorithms have been proposed to compute optimal steady-state inverter setpoints, so that power losses and voltage deviations are minimized and economic benefits to end-users providing ancillary services are maximized. However, traditional OPF schemes may offer decision making capabilities that do not match the dynamics of distribution systems. Particularly, during the time required to collect data from all the nodes of the network (e.g., loads), solve the OPF, and subsequently dispatch setpoints, the underlying load, ambient, and network conditions may have already changed; in this case, the DER output powers would be consistently regulated around outdated setpoints, leading to suboptimal system operation and violation of relevant electrical limits. The present work focuses on the synthesis of distributed RES-inverter controllers that leverage the opportunities for fast feedback offered by power-electronics interfaced RESs. The overarching objective is to bridge the temporal gap between long-term system optimization and real-time control, to enable seamless RES integration in large scale with stability and efficiency guarantees, while congruently pursuing system-level optimization objectives. The
Liu, Wei; Huang, Jie
2017-01-11
This paper studies the cooperative global robust output regulation problem for a class of heterogeneous second-order nonlinear uncertain multiagent systems with jointly connected switching networks. The main contributions consist of the following three aspects. First, we generalize the result of the adaptive distributed observer from undirected jointly connected switching networks to directed jointly connected switching networks. Second, by performing a new coordinate and input transformation, we convert our problem into the cooperative global robust stabilization problem of a more complex augmented system via the distributed internal model principle. Third, we solve the stabilization problem by a distributed state feedback control law. Our result is illustrated by the leader-following consensus problem for a group of Van der Pol oscillators.
Directory of Open Access Journals (Sweden)
Öje Danell
1999-04-01
Full Text Available Optimal Production in Reindeer Husbandry.There are three ways to optimize the reindeer herd: 1 Adjusting the reindeer number to pasture resources. 2 Keeping as many productive animals in the herd as possible through slaughter. 3 Increasing the herd quality through selection.Renhjorden bör optimeras så att den fungerar som en "skördeapparat" for bete och lämnar största möjliga bidrag till försörjningen för dem som lever av renskötsel. Det finns minst tre sätt att optimera renhjorden, nämligen (1 anpassning av djurantalet till betesresurserna så att djurens kondition och därmed produktiviteten kan bibehållas på hög nivå, (2 utforma renhjordens struktur med hjalp av slaktuttaget så att den innehåller så stor andel produktiva djur som möjligt, och (3 förbättra djurmaterialets produktionsmässiga kvalitet genom urval baserat på registrerad produktion. Betesanpassningen är den mest grundläggande åtgärden och ger den snabbaste effekten. Även hjordstrukturering är en åtgärd som ger relativt snabb effekt och som dessutom kan beslutas och utforas av den enskilde djuraägaren utan att störa den kollektiva renskötseln. Urval är en åtgärd som ger effekt först på längre sikt och därför kräver en konsekvent insats under en längre tid.
Trajectory Optimization: OTIS 4
Riehl, John P.; Sjauw, Waldy K.; Falck, Robert D.; Paris, Stephen W.
2010-01-01
The latest release of the Optimal Trajectories by Implicit Simulation (OTIS4) allows users to simulate and optimize aerospace vehicle trajectories. With OTIS4, one can seamlessly generate optimal trajectories and parametric vehicle designs simultaneously. New features also allow OTIS4 to solve non-aerospace continuous time optimal control problems. The inputs and outputs of OTIS4 have been updated extensively from previous versions. Inputs now make use of objectoriented constructs, including one called a metastring. Metastrings use a greatly improved calculator and common nomenclature to reduce the user s workload. They allow for more flexibility in specifying vehicle physical models, boundary conditions, and path constraints. The OTIS4 calculator supports common mathematical functions, Boolean operations, and conditional statements. This allows users to define their own variables for use as outputs, constraints, or objective functions. The user-defined outputs can directly interface with other programs, such as spreadsheets, plotting packages, and visualization programs. Internally, OTIS4 has more explicit and implicit integration procedures, including high-order collocation methods, the pseudo-spectral method, and several variations of multiple shooting. Users may switch easily between the various methods. Several unique numerical techniques such as automated variable scaling and implicit integration grid refinement, support the integration methods. OTIS4 is also significantly more user friendly than previous versions. The installation process is nearly identical on various platforms, including Microsoft Windows, Apple OS X, and Linux operating systems. Cross-platform scripts also help make the execution of OTIS and post-processing of data easier. OTIS4 is supplied free by NASA and is subject to ITAR (International Traffic in Arms Regulations) restrictions. Users must have a Fortran compiler, and a Python interpreter is highly recommended.
[SIAM conference on optimization
Energy Technology Data Exchange (ETDEWEB)
1992-05-10
Abstracts are presented of 63 papers on the following topics: large-scale optimization, interior-point methods, algorithms for optimization, problems in control, network optimization methods, and parallel algorithms for optimization problems.
DEFF Research Database (Denmark)
Abildtrup, Jens; Jensen, Frank
2014-01-01
This paper examines a tax/subsidy on hunters based on game population. The tax/subsidy is the difference between actual and optimal population multiplied by an individual, variable tax rate. The tax rate is, among other things, based on the difference between the marginal value of the game...... population to the hunter and the regulator and differences in user costs of the population. The paper shows that the population tax/subsidy secures a first-best optimum....
Fuzzy Constrained Predictive Optimal Control of High Speed Train with Actuator Dynamics
Directory of Open Access Journals (Sweden)
Xi Wang
2016-01-01
Full Text Available We investigate the problem of fuzzy constrained predictive optimal control of high speed train considering the effect of actuator dynamics. The dynamics feature of the high speed train is modeled as a cascade of cars connected by flexible couplers, and the formulation is mathematically transformed into a Takagi-Sugeno (T-S fuzzy model. The goal of this study is to design a state feedback control law at each decision step to enhance safety, comfort, and energy efficiency of high speed train subject to safety constraints on the control input. Based on Lyapunov stability theory, the problem of optimizing an upper bound on the cruise control cost function subject to input constraints is reduced to a convex optimization problem involving linear matrix inequalities (LMIs. Furthermore, we analyze the influences of second-order actuator dynamics on the fuzzy constrained predictive controller, which shows risk of potentially deteriorating the overall system. Employing backstepping method, an actuator compensator is proposed to accommodate for the influence of the actuator dynamics. The experimental results show that with the proposed approach high speed train can track the desired speed, the relative coupler displacement between the neighbouring cars is stable at the equilibrium state, and the influence of actuator dynamics is reduced, which demonstrate the validity and effectiveness of the proposed approaches.
Wang, Gang; Chen, Changzheng; Yu, Shenbo
2016-09-01
In this paper, the static output-feedback control problem of active suspension systems with information structure constraints is investigated. In order to simultaneously improve the ride comfort and stability, a half car model is used. Other constraints such as suspension deflection, actuator saturation, and controller constrained information are also considered. A novel static output-feedback design method based on the variable substitution is employed in the controller design. A single-step linear matrix inequality (LMI) optimization problem is solved to derive the initial feasible solution with a sparsity constraint. The initial infeasibility issue of the static output-feedback is resolved by using state-feedback information. Specifically, an optimization algorithm is proposed to search for less conservative results based on the feasible controller gain matrix. Finally, the validity of the designed controller for different road profiles is illustrated through numerical examples. The simulation results indicate that the optimized static output-feedback controller can achieve better suspension performances when compared with the feasible static output-feedback controller.
Optimal control linear quadratic methods
Anderson, Brian D O
2007-01-01
This augmented edition of a respected text teaches the reader how to use linear quadratic Gaussian methods effectively for the design of control systems. It explores linear optimal control theory from an engineering viewpoint, with step-by-step explanations that show clearly how to make practical use of the material.The three-part treatment begins with the basic theory of the linear regulator/tracker for time-invariant and time-varying systems. The Hamilton-Jacobi equation is introduced using the Principle of Optimality, and the infinite-time problem is considered. The second part outlines the
Optimal census by quorum sensing
Taillefumier, Thibaud
Bacteria regulate their gene expression in response to changes in local cell density in a process called quorum sensing. To synchronize their gene-expression programs, these bacteria need to glean as much information as possible about local density. Our study is the first to physically model the flow of information in a quorum-sensing microbial community, wherein the internal regulator of the individual's response tracks the external cell density via an endogenously generated shared signal. Combining information theory and Lagrangian optimization, we find that quorum-sensing systems can improve their information capabilities by tuning circuit feedbacks. At the population level, external feedback adjusts the dynamic range of the shared input to individuals' detection channels. At the individual level, internal feedback adjusts the regulator's response time to dynamically balance output noise reduction and signal tracking ability. Our analysis suggests that achieving information benefit via feedback requires dedicated systems to control gene expression noise, such as sRNA-based regulation.
需求不确定时电力最优价格上限管制分析%Optimal Price Cap Regulation under Demand Uncertainty in Electricity Market
Institute of Scientific and Technical Information of China (English)
邹建平; 张信; 王恩琦; 李娜; 曾鸣
2012-01-01
In order to study the optimal price cap under demand uncertainty in electricity market, the demand fluctuation is simulated by the geometric Brownian motion equation and a continuous time model with stochastic demand is established to analyze generators' optimal investment strategy in terms of real option theory. The results show that the optimal price cap under demand uncertainty is still investment marginal price in competitive market;the optimal cap price depends on the demand fluctuation and risk rate.%采用随机需求下的连续时间模型,基于实物期权理论,运用几何布朗运动方程模拟了需求波动,分析了发电方最优投资策略,探讨了在需求不确定条件下电力价格最优上限管制问题.结果表明,需求不确定条件下最优价格上限依然为竞争性条件下的投资边际价格,最优上限价格取决于需求波动和风险率.
Optimal Control of Reservoir Discharge Quality through Selective Withdrawal.
1982-02-01
this report is to present a procedure for the solution of the dynamic-optimal reservoir regulation problem . -- TTARGET a0 • o T MELEASII JAN STATIC...output state as a function of the input state and the associated decisions; that is, y = g(x,d) The dynamic-optimal reservoir regulation problem can be
Cao, Ning; Zhang, Huaguang; Luo, Yanhong; Feng, Dezhi
2012-09-01
In this article, a novel iteration algorithm named two-stage approximate dynamic programming (TSADP) is proposed to seek the solution of nonlinear switched optimal control problem. At each iteration of TSADP, a multivariate optimal control problem is transformed to be a certain number of univariate optimal control problems. It is shown that the value function at each iteration can be characterised pointwisely by a set of smooth functions recursively obtained from TSADP, and the associated control policy, continuous control and switching control law included, is explicitly provided in a state-feedback form. Moreover, the convergence and optimality of TSADP is strictly proven. To implement this algorithm efficiently, neural networks, critic and action networks, are utilised to approximate the value function and continuous control law, respectively. Thus, the value function is expressed by the weights of critic networks pointwise. Besides, redundant weights are ruled out at each iteration to simplify the exponentially increasing computation burden. Finally, a simulation example is provided to demonstrate its effectiveness.
Multiple Satellite Trajectory Optimization
2004-12-01
SOLVING OPTIMAL CONTROL PROBLEMS ........................................5...OPTIMIZATION A. SOLVING OPTIMAL CONTROL PROBLEMS The driving principle used to solve optimal control problems was first formalized by the Soviet...methods and processes of solving optimal control problems , this section will demonstrate how the formulations work as expected. Once coded, the
Antenna optimization using Particle Swarm Optimization algorithm
Directory of Open Access Journals (Sweden)
Golubović Ružica M.
2006-01-01
Full Text Available We present the results for two different antenna optimization problems that are found using the Particle Swarm Optimization (PSO algorithm. The first problem is finding the maximal forward gain of a Yagi antenna. The second problem is finding the optimal feeding of a broadside antenna array. The optimization problems have 6 and 20 optimization variables, respectively. The preferred values of the parameters of the PSO algorithm are found for presented problems. The results show that the preferred parameters of PSO are somewhat different for optimization problems with different number of dimensions of the optimization space. The results that are found using the PSO algorithm are compared with the results that are found using other optimization algorithms, in order to estimate the efficiency of the PSO.
State estimation and optimal long period clinical treatment of HIV seropositive patients
Directory of Open Access Journals (Sweden)
Juliana M. Grégio
2009-03-01
Full Text Available Optimal control theory provides a very interesting quantitative method that can be used to assist the decision making process in several areas of application, such as engineering, biology, economics and sociology. The main idea is to determine the values of the manipulated variables, such as drug doses, so that some cost function is minimized, subject to physical constraints. In this work, the cost function reflects the number of CD4+T cells, viral particles and the drug doses. It is worth noticing that high drug doses are related to more intense side-effects, apart from the impact on the actual cost of the treatment. In a previous paper by the authors, the LQR - Linear Quadratic Regulator approach was proposed for the computation of long period maintenance doses for the drugs, which turns out to be of state feedback form. However, it is not practical to determine all the components of the state vector, due to the fact that infected and uninfected CD4+T cells are not microscopically distinguishable. In order to overcome this difficulty, this work proposes the use of Extended Kalman Filter to estimate the state, even though, because of the nonlinear nature of the involved state equations, the separation principle may not be valid. Extensive simulations were then carried out to investigate numerically if the control strategy consisting of the feedback of estimated states yielded satisfactory clinical results.A teoria de controle ótimo apresenta um método quantitativo muito interessante que pode ajudar no processo de tomada de decisão em algumas áreas de aplicação, tais como engenharia, biologia, economia e sociologia. A principal idéia é determinar os valores das variáveis controladas, tais como doses de medicamentos, onde alguma função-custo é minimizada, sujeito às restrições físicas. Neste trabalho, a função-custo reflete o número de células CD4+T, partículas virais e doses de medicamentos. É fato que altas dosagens de
Institute of Scientific and Technical Information of China (English)
无
2006-01-01
Legislation to determine brain death is viewed as essential in controlling the organ transplant industry Organ transplant represents a very sensitive and complicated issue. Experts say the temporary administrative regulations recently promulgated by the Central Government are an important step, but relevant laws and regulations must follow. Among these, the
Optimization modeling with spreadsheets
Baker, Kenneth R
2015-01-01
An accessible introduction to optimization analysis using spreadsheets Updated and revised, Optimization Modeling with Spreadsheets, Third Edition emphasizes model building skills in optimization analysis. By emphasizing both spreadsheet modeling and optimization tools in the freely available Microsoft® Office Excel® Solver, the book illustrates how to find solutions to real-world optimization problems without needing additional specialized software. The Third Edition includes many practical applications of optimization models as well as a systematic framework that il
New numerical methods for open-loop and feedback solutions to dynamic optimization problems
Ghosh, Pradipto
is that the resulting control law has an algebraic closed-form structure. The proposed method uses an optimal spatial statistical predictor called universal kriging to construct the surrogate model of a feedback controller, which is capable of quickly predicting an optimal control estimate based on current state (and time) information. With universal kriging, an approximation to the optimal feedback map is computed by conceptualizing a set of state-control samples from pre-computed extremals to be a particular realization of a jointly Gaussian spatial process. Feedback policies are computed for a variety of example dynamic optimization problems in order to evaluate the effectiveness of this methodology. This feedback synthesis approach is found to combine good numerical accuracy with low computational overhead, making it a suitable candidate for real-time applications. Particle swarm and universal kriging are combined for a capstone example, a near optimal, near-admissible, full-state feedback control law is computed and tested for the heat-load-limited atmospheric-turn guidance of an aeroassisted transfer vehicle. The performance of this explicit guidance scheme is found to be very promising; initial errors in atmospheric entry due to simulated thruster misfirings are found to be accurately corrected while closely respecting the algebraic state-inequality constraint.
DEFF Research Database (Denmark)
Abildtrup, Jens; Jensen, Frank
of the individual harvest. However, information about the individual harvest may be costly to obtain. Thus, we may have to look for alternatives to the existing system. This paper proposes a population tax/subsidy as an alternative which is the difference between the actual and optimal population multiplied...... by an individual, variable tax rate. The variable tax rate is, among other things, based on the difference in marginal value of the population between the hunter and the regulator. The paper shows that the population tax/subsidy secures a first-best optimum. Thus, the population tax is a good alternative...
Applications of combinatorial optimization
Paschos, Vangelis Th
2013-01-01
Combinatorial optimization is a multidisciplinary scientific area, lying in the interface of three major scientific domains: mathematics, theoretical computer science and management. The three volumes of the Combinatorial Optimization series aims to cover a wide range of topics in this area. These topics also deal with fundamental notions and approaches as with several classical applications of combinatorial optimization. "Applications of Combinatorial Optimization" is presenting a certain number among the most common and well-known applications of Combinatorial Optimization.
New Hoopoe Heuristic Optimization
El-Dosuky, Mohammed; EL-Bassiouny, Ahmed; Hamza, Taher; Rashad, Magdy
2012-01-01
Most optimization problems in real life applications are often highly nonlinear. Local optimization algorithms do not give the desired performance. So, only global optimization algorithms should be used to obtain optimal solutions. This paper introduces a new nature-inspired metaheuristic optimization algorithm, called Hoopoe Heuristic (HH). In this paper, we will study HH and validate it against some test functions. Investigations show that it is very promising and could be seen as an optimi...
Plant nutrient transporter regulation in arbuscular mycorrhizas
DEFF Research Database (Denmark)
Burleigh, Stephen; Bechmann, I.E.
2002-01-01
This review discusses the role arbuscular mycorrhizal fungi play in the regulation of plant nutrient transporter genes. Many plant nutrient transporter genes appear to be transcriptionally regulated by a feed-back mechanism that reduces their expression when the plant reaches an optimal level...
APPLYING CLASSICAL FOREST REGULATION METHODS TO SMALLHOLDINGS WITH COOPERATIVE CONSTRAINTS
Directory of Open Access Journals (Sweden)
Rafael Rode
2016-06-01
Full Text Available This study aims to assess the cooperative regulation process of forestry producers in comparison to the traditional individual regulation of properties. Twenty (20 forest properties are studied as examples of the development of three forest regulation scenarios: 1 individual regulation, 2 group regulation, and 3 cooperative regulation. The Net Present Value (NPV of each of the scenarios is optimized according to mathematical programming models and compared to a baseline scenario without forest regulation. According to the proposed cooperative regulation, properties had a proportion factor for annual net revenue distribution calculated from results of the baseline scenario. By comparing the NPV maximization results from scenarios 1 and 3 with the non-regulation scenario, the cost for individual regulation is on average 25%, while being only 11% for cooperative regulation, that is, a 14% reduction in property regulation costs. Additionally, cooperative regulation had the advantage of dividing properties into fewer areas when compared to individual regulation.
Energy Technology Data Exchange (ETDEWEB)
Gray, P. [ed.
1997-02-01
The author reviews the question of regulation for naturally occuring radioactive material (NORM), and the factors that have made this a more prominent concern today. Past practices have been very relaxed, and have often involved very poor records, the involvment of contractors, and the disposition of contaminated equipment back into commercial service. The rationale behind the establishment of regulations is to provide worker protection, to exempt low risk materials, to aid in scrap recycling, to provide direction for remediation and to examine disposal options. The author reviews existing regulations at federal and state levels, impending legislation, and touches on the issue of site remediation and potential liabilities affecting the release of sites contaminated by NORM.
Selection, optimization, and compensation strategies : Interactive effects on daily work engagement
Zacher, Hannes; Chan, Felicia; Bakker, Arnold B.; Demerouti, Evangelia
2015-01-01
The theory of selective optimization with compensation (SOC) proposes that the "orchestrated" use of three distinct action regulation strategies (selection, optimization, and compensation) leads to positive employee outcomes. Previous research examined overall scores and additive models (i.e., main
Wei, Xile; Lu, Meili; Wang, Jiang; Tsang, K. M.; Deng, Bin; Che, Yanqiu
2010-05-01
We consider the assumption of existence of the general nonlinear internal model that is introduced in the design of robust output regulators for a class of minimum-phase nonlinear systems with rth degree (r ≥ 2). The robust output regulation problem can be converted into a robust stabilisation problem of an augmented system consisting of the given plant and a high-gain nonlinear internal model, perfectly reproducing the bounded including not only periodic but also nonperiodic exogenous signal from a nonlinear system, which satisfies some general immersion assumption. The state feedback controller is designed to guarantee the asymptotic convergence of system errors to zero manifold. Furthermore, the proposed scheme makes use of output feedback dynamic controller that only processes information from the regulated output error by using high-gain observer to robustly estimate the derivatives of the regulated output error. The stabilisation analysis of the resulting closed-loop systems leads to regional as well as semi-global robust output regulation achieved for some appointed initial condition in the state space, for all possible values of the uncertain parameter vector and the exogenous signal, ranging over an arbitrary compact set.
Mechanical Design Optimization Using Advanced Optimization Techniques
Rao, R Venkata
2012-01-01
Mechanical design includes an optimization process in which designers always consider objectives such as strength, deflection, weight, wear, corrosion, etc. depending on the requirements. However, design optimization for a complete mechanical assembly leads to a complicated objective function with a large number of design variables. It is a good practice to apply optimization techniques for individual components or intermediate assemblies than a complete assembly. Analytical or numerical methods for calculating the extreme values of a function may perform well in many practical cases, but may fail in more complex design situations. In real design problems, the number of design parameters can be very large and their influence on the value to be optimized (the goal function) can be very complicated, having nonlinear character. In these complex cases, advanced optimization algorithms offer solutions to the problems, because they find a solution near to the global optimum within reasonable time and computational ...
Benchmarking optimization solvers for structural topology optimization
DEFF Research Database (Denmark)
Rojas Labanda, Susana; Stolpe, Mathias
2015-01-01
The purpose of this article is to benchmark different optimization solvers when applied to various finite element based structural topology optimization problems. An extensive and representative library of minimum compliance, minimum volume, and mechanism design problem instances for different...... sizes is developed for this benchmarking. The problems are based on a material interpolation scheme combined with a density filter. Different optimization solvers including Optimality Criteria (OC), the Method of Moving Asymptotes (MMA) and its globally convergent version GCMMA, the interior point...... profiles conclude that general solvers are as efficient and reliable as classical structural topology optimization solvers. Moreover, the use of the exact Hessians in SAND formulations, generally produce designs with better objective function values. However, with the benchmarked implementations solving...
Microgenetic optimization algorithm for optimal wavefront shaping
Anderson, Benjamin R; Gunawidjaja, Ray; Eilers, Hergen
2015-01-01
One of the main limitations of utilizing optimal wavefront shaping in imaging and authentication applications is the slow speed of the optimization algorithms currently being used. To address this problem we develop a micro-genetic optimization algorithm ($\\mu$GA) for optimal wavefront shaping. We test the abilities of the $\\mu$GA and make comparisons to previous algorithms (iterative and simple-genetic) by using each algorithm to optimize transmission through an opaque medium. From our experiments we find that the $\\mu$GA is faster than both the iterative and simple-genetic algorithms and that both genetic algorithms are more resistant to noise and sample decoherence than the iterative algorithm.
Particle Swarm Optimization Toolbox
Grant, Michael J.
2010-01-01
The Particle Swarm Optimization Toolbox is a library of evolutionary optimization tools developed in the MATLAB environment. The algorithms contained in the library include a genetic algorithm (GA), a single-objective particle swarm optimizer (SOPSO), and a multi-objective particle swarm optimizer (MOPSO). Development focused on both the SOPSO and MOPSO. A GA was included mainly for comparison purposes, and the particle swarm optimizers appeared to perform better for a wide variety of optimization problems. All algorithms are capable of performing unconstrained and constrained optimization. The particle swarm optimizers are capable of performing single and multi-objective optimization. The SOPSO and MOPSO algorithms are based on swarming theory and bird-flocking patterns to search the trade space for the optimal solution or optimal trade in competing objectives. The MOPSO generates Pareto fronts for objectives that are in competition. A GA, based on Darwin evolutionary theory, is also included in the library. The GA consists of individuals that form a population in the design space. The population mates to form offspring at new locations in the design space. These offspring contain traits from both of the parents. The algorithm is based on this combination of traits from parents to hopefully provide an improved solution than either of the original parents. As the algorithm progresses, individuals that hold these optimal traits will emerge as the optimal solutions. Due to the generic design of all optimization algorithms, each algorithm interfaces with a user-supplied objective function. This function serves as a "black-box" to the optimizers in which the only purpose of this function is to evaluate solutions provided by the optimizers. Hence, the user-supplied function can be numerical simulations, analytical functions, etc., since the specific detail of this function is of no concern to the optimizer. These algorithms were originally developed to support entry
Optimization of composite laminates
Gurdal, Zafer; Haftka, Raphael T.
Design of composite structures can be viewed as a multi-faceted task, one which requires integration of issues related to composite mechanics, structural analysis, optimization, and manufacturing. The major coverage of the paper is on the issue of optimization, with special emphasis on the use of optimization for designing with discrete and integer valued variables required for the stacking-sequence optimization. Different techniques that can be used for stacking sequence optimization are introduced, and different aspects of their application are demonstrated for laminate buckling optimization.
Optimal Heating Strategies for a Convection Oven
Stigter, J.D.; Scheerlinck, N.; Nicolai, B.M.; Impe, van J.F.
2001-01-01
In this study classical control theory is applied to a heat conduction model with convective boundary conditions. Optimal heating strategies are obtained through solution of an associated algebraic Riccati equation for a finite horizon linear quadratic regulator (LQR). The large dimensional system
Energy Technology Data Exchange (ETDEWEB)
Barkhausen, J.; Schoenfelder. D.; Stoeblen, F. [Universitaetsklinikum Essen (Germany). Zentralinstitut fuer Roentgendiagnostik; Nagel, H.D.; Mueller, R.D. [Philips Medizin Systeme, Hamburg (Germany)
1999-11-01
Aim of study: Evaluation of radiation exposure and image quality during fluoroscopy using a new vascular X-ray system. Material and methods: The measurements were made on an Integris V 3000 X-ray system with MRC tube and SpectraBeam technology (Philips Medical Systems, Hamburg). Entrance dose rates were measured with phantoms for the three fluoroscopy levels (1-3) which differed with regard to beam filtering and image intensiver entrance exposure rate. We evaluated 132 diagnostic and interventional angiographic studies. The angiographic investigators were asked to start with level 1 and to change to the next fluoroscopy level only in the case of insufficient image quality. Results: Entrance dose rate is reduced by approx. 74% at fluoroscopy level 1 and by approx. 46% at level 2 relative to level 3 which is comparable to angiographic X-ray systems without MRC tube and SpectraBeam technology. Because level 1 ensured a sufficient image quality in 92% of the diagnostic and 60% of the interventional angiographic procedures a change to higher fluoroscopy levels was not necessary. Conclusion: Reduction of the intensifier exposure rate and the optimization of beam filtering enabled us to reduce the radiation exposure considerably. The procedure was well accepted by the angiographic investigators due to the diagnostically sufficient image quality of the fluoroscopy level 1. (orig.) [German] Zielsetzung: Untersuchung der Strahlenexposition und der Abbildungsqualitaet bei der Durchleuchtung an einem Angiographiearbeitsplatz. Material und Methoden: Die Messungen wurden am Angiographiearbeitsplatz Integris V 3000 mit MRC-Roehre und SpectraBeam-Technologie (Philips Medizin Systeme, Hamburg) durchgefuehrt. An Phantomen wurde die Patienten-Eintrittsdosisleistung der drei zur Verfuegung stehenden Durchleuchtungsstufen (1-3) gemessen, die sich durch die Kennlinien, die Filterung und die Bildverstaerker-Eintrittsdosisleistung unterscheiden. Bei den bisher ausgewerteten 132
Institute of Scientific and Technical Information of China (English)
武新宇; 程春田; 申建建; 唐红兵
2012-01-01
With the development of the scale of power grids and hydropower systems in China, the problem of peak load regulation for multiple power grid will be more and more prominent. On the background of hydropower system of China Southern Grid （CSG）, a peak load regulation model for multiple power grid with large scale hydropower systems is proposed. Aggregated function and multi-objective fuzzy optimization model are adopted to establish a fungible objective. A successive associated search method is proposed to address the problem of many time coupling constraints. Practice operation study shows that the method yield practicable results, and is feasible to peak load regulation problems for multi power grid.%随着我国电网和水电规模的扩大,水电系统多电网调峰的问题越来越突出。以南方电网的水电系统为背景,构建了跨流域巨型水电站群多电网调峰优化调度模型。结合凝聚函数法和多目标模糊优选法建立替代优化目标,提出逐次逼近的关联搜索算法来满足求解过程中大量的时间耦合型约束。实际运行过程表明,本文提出的模型和求解方法能够得到高效的、满足实际工程中需求的应用结果,是一种切实可行的水电多电网调峰优化调度方法。
Oil Reservoir Production Optimization using Optimal Control
DEFF Research Database (Denmark)
Völcker, Carsten; Jørgensen, John Bagterp; Stenby, Erling Halfdan
2011-01-01
Practical oil reservoir management involves solution of large-scale constrained optimal control problems. In this paper we present a numerical method for solution of large-scale constrained optimal control problems. The method is a single-shooting method that computes the gradients using the adjo......Practical oil reservoir management involves solution of large-scale constrained optimal control problems. In this paper we present a numerical method for solution of large-scale constrained optimal control problems. The method is a single-shooting method that computes the gradients using...... the adjoint method. We use an Explicit Singly Diagonally Implicit Runge-Kutta (ESDIRK) method for the integration and a quasi-Newton Sequential Quadratic Programming (SQP) algorithm for the constrained optimization. We use this algorithm in a numerical case study to optimize the production of oil from an oil...... reservoir using water ooding and smart well technology. Compared to the uncontrolled case, the optimal operation increases the Net Present Value of the oil field by 10%....
Neuro-optimal control of helicopter UAVs
Nodland, David; Ghosh, Arpita; Zargarzadeh, H.; Jagannathan, S.
2011-05-01
Helicopter UAVs can be extensively used for military missions as well as in civil operations, ranging from multirole combat support and search and rescue, to border surveillance and forest fire monitoring. Helicopter UAVs are underactuated nonlinear mechanical systems with correspondingly challenging controller designs. This paper presents an optimal controller design for the regulation and vertical tracking of an underactuated helicopter using an adaptive critic neural network framework. The online approximator-based controller learns the infinite-horizon continuous-time Hamilton-Jacobi-Bellman (HJB) equation and then calculates the corresponding optimal control input that minimizes the HJB equation forward-in-time. In the proposed technique, optimal regulation and vertical tracking is accomplished by a single neural network (NN) with a second NN necessary for the virtual controller. Both of the NNs are tuned online using novel weight update laws. Simulation results are included to demonstrate the effectiveness of the proposed control design in hovering applications.
Optimization with PDE constraints
Pinnau, Rene
2008-01-01
Presents an introduction of pde constrained optimization. This book provides a precise functional analytic treatment via optimality conditions and a non-smooth algorithmical framework. It also presents structure-exploiting discrete concepts and large scale, practically relevant applications.
National Aeronautics and Space Administration — An optimal alarm system is simply an optimal level-crossing predictor that can be designed to elicit the fewest false alarms for a fixed detection probability. It...
Boost变换器的非线性最优控制系统%Nonlinear optimal control system for Boost converter
Institute of Scientific and Technical Information of China (English)
钟建伟; 杨永超
2011-01-01
The nonlinear affine model of Boost converter is built based on its state space average model, which applies the nonlinear optimal control strategy based on differential geometry. The nonlinear state feedback functions of Boost converter are deduced,its exact linearization model with state feedback is obtained,and its controller is designed to enhance the dynamic and static performances of the system for realizing the stable system operation when the working point varies greatly. The simulative results of Matlab/Simulink show that the Boost converter operates stably at the objective working point,immune from supply voltage change and load mutation.%在Boost变换器状态空间平均模型的基础上,利用基于微分几何的非线性最优控制策略,建立了非线性仿射模型,且推导出了非线性状态反馈表达式,得到了Boost变换器状态反馈精确线性化模型,并对其控制器进行了设计,实现了系统在工作点大范围内变化时的稳定运行,有效提高了系统的动、静态性能.Matlab/Simulink仿真结果表明,系统能稳定运行在目标工作点,对电源电压的变化和负载突变具有较强的鲁棒性.
Directory of Open Access Journals (Sweden)
Deepak Goyal
2013-07-01
Full Text Available This paper addresses the malicious node detection and path optimization problem for wireless sensor networks. Malicious node detection in neighborhood is a needed because that node may cause incorrect decisions or energy depletion. In this paper APSO (combination of Artificial bee colony and particular swarm optimization is used to choose an optimized path. Through this improved version we will overcome the disadvantage of local optimal which comes when we use PSO approach.
Optimization techniques in statistics
Rustagi, Jagdish S
1994-01-01
Statistics help guide us to optimal decisions under uncertainty. A large variety of statistical problems are essentially solutions to optimization problems. The mathematical techniques of optimization are fundamentalto statistical theory and practice. In this book, Jagdish Rustagi provides full-spectrum coverage of these methods, ranging from classical optimization and Lagrange multipliers, to numerical techniques using gradients or direct search, to linear, nonlinear, and dynamic programming using the Kuhn-Tucker conditions or the Pontryagin maximal principle. Variational methods and optimiza
Pseudolinear functions and optimization
Mishra, Shashi Kant
2015-01-01
Pseudolinear Functions and Optimization is the first book to focus exclusively on pseudolinear functions, a class of generalized convex functions. It discusses the properties, characterizations, and applications of pseudolinear functions in nonlinear optimization problems.The book describes the characterizations of solution sets of various optimization problems. It examines multiobjective pseudolinear, multiobjective fractional pseudolinear, static minmax pseudolinear, and static minmax fractional pseudolinear optimization problems and their results. The authors extend these results to locally
Optimization algorithms and applications
Arora, Rajesh Kumar
2015-01-01
Choose the Correct Solution Method for Your Optimization ProblemOptimization: Algorithms and Applications presents a variety of solution techniques for optimization problems, emphasizing concepts rather than rigorous mathematical details and proofs. The book covers both gradient and stochastic methods as solution techniques for unconstrained and constrained optimization problems. It discusses the conjugate gradient method, Broyden-Fletcher-Goldfarb-Shanno algorithm, Powell method, penalty function, augmented Lagrange multiplier method, sequential quadratic programming, method of feasible direc
Optimal obstacle control problem
Institute of Scientific and Technical Information of China (English)
ZHU Li; LI Xiu-hua; GUO Xing-ming
2008-01-01
In the paper we discuss some properties of the state operators of the optimal obstacle control problem for elliptic variational inequality. Existence, uniqueness and regularity of the optimal control problem are established. In addition, the approximation of the optimal obstacle problem is also studied.
Schaft, A.J. van der
1987-01-01
It is argued that the existence of symmetries may simplify, as in classical mechanics, the solution of optimal control problems. A procedure for obtaining symmetries for the optimal Hamiltonian resulting from the Maximum Principle is given; this avoids the actual calculation of the optimal
[Sleep: regulation and phenomenology].
Vecchierini, M-F
2013-12-01
This article describes the two-process model of sleep regulation. The 24-hour sleep-wake cycle is regulated by a homeostatic process and an endogenous, 2 oscillators, circadian process, under the influence of external synchronisers. These two processes are partially independent but influence each other, as shown in the two-sleep-process auto-regulation model. A reciprocal inhibition model of two interconnected neuronal groups, "SP on" and "SP off", explains the regular recurrence of paradoxical sleep. Sleep studies have primarily depended on observation of the subject and have determined the optimal conditions for sleep (position, external conditions, sleep duration and need) and have studied the consequences of sleep deprivation or modifications of sleep schedules. Then, electrophysiological recordings permitted the classification of sleep stages according to the observed EEG patterns. The course of a night's sleep is reported on a "hypnogram". The adult subject falls asleep in non-REM sleep (N1), then sleep deepens progressively to stages N2 and N3 with the appearance of spindles and slow waves (N2). Slow waves become more numerous in stage N3. Every 90minutes REM sleep recurs, with muscle atonia and rapid eye movements. These adult sleep patterns develop progressively during the 2 first years of life as total sleep duration decreases, with the reduction of diurnal sleep and of REM sleep. Around 2 to 4 months, spindles and K complexes appear on the EEG, with the differentiation of light and deep sleep with, however, a predominance of slow wave sleep.
Implementing the optimal provision of ecosystem services.
Polasky, Stephen; Lewis, David J; Plantinga, Andrew J; Nelson, Erik
2014-04-29
Many ecosystem services are public goods whose provision depends on the spatial pattern of land use. The pattern of land use is often determined by the decisions of multiple private landowners. Increasing the provision of ecosystem services, though beneficial for society as a whole, may be costly to private landowners. A regulator interested in providing incentives to landowners for increased provision of ecosystem services often lacks complete information on landowners' costs. The combination of spatially dependent benefits and asymmetric cost information means that the optimal provision of ecosystem services cannot be achieved using standard regulatory or payment for ecosystem services approaches. Here we show that an auction that sets payments between landowners and the regulator for the increased value of ecosystem services with conservation provides incentives for landowners to truthfully reveal cost information, and allows the regulator to implement the optimal provision of ecosystem services, even in the case with spatially dependent benefits and asymmetric information.
Optimization and optimal control in automotive systems
Kolmanovsky, Ilya; Steinbuch, Maarten; Re, Luigi
2014-01-01
This book demonstrates the use of the optimization techniques that are becoming essential to meet the increasing stringency and variety of requirements for automotive systems. It shows the reader how to move away from earlier approaches, based on some degree of heuristics, to the use of more and more common systematic methods. Even systematic methods can be developed and applied in a large number of forms so the text collects contributions from across the theory, methods and real-world automotive applications of optimization. Greater fuel economy, significant reductions in permissible emissions, new drivability requirements and the generally increasing complexity of automotive systems are among the criteria that the contributing authors set themselves to meet. In many cases multiple and often conflicting requirements give rise to multi-objective constrained optimization problems which are also considered. Some of these problems fall into the domain of the traditional multi-disciplinary optimization applie...
Optimal Load Dispatch Using Ant Lion Optimization
Directory of Open Access Journals (Sweden)
Menakshi Mahendru Nischal
2015-08-01
Full Text Available This paper presents Ant lion optimization (ALO technique to solve optimal load dispatch problem. Ant lion optimization (ALO is a novel nature inspired algorithm. The ALO algorithm mimics the hunting mechanism of ant lions in nature. Five main steps of hunting prey such as the random walk of ants, building traps, entrapment of ants in traps, catching preys, and re-building traps are implemented. Optimal load dispatch (OLD is a method of determining the most efficient, low-cost and reliable operation of a power system by dispatching available electricity generation resources to supply load on the system. The primary objective of OLD is to minimize total cost of generation while honoring operational constraints of available generation resources. The proposed technique is implemented on 3, 6 & 20 unit test system for solving the OLD. Numerical results shows that the proposed method has good convergence property and better in quality of solution than other algorithms reported in recent literature.
Particle Swarm Optimization Based Reactive Power Optimization
Sujin, P R; Linda, M Mary
2010-01-01
Reactive power plays an important role in supporting the real power transfer by maintaining voltage stability and system reliability. It is a critical element for a transmission operator to ensure the reliability of an electric system while minimizing the cost associated with it. The traditional objectives of reactive power dispatch are focused on the technical side of reactive support such as minimization of transmission losses. Reactive power cost compensation to a generator is based on the incurred cost of its reactive power contribution less the cost of its obligation to support the active power delivery. In this paper an efficient Particle Swarm Optimization (PSO) based reactive power optimization approach is presented. The optimal reactive power dispatch problem is a nonlinear optimization problem with several constraints. The objective of the proposed PSO is to minimize the total support cost from generators and reactive compensators. It is achieved by maintaining the whole system power loss as minimum...
Non-fragile robust optimal guaranteed cost control of uncertain 2-D discrete state-delayed systems
Tandon, Akshata; Dhawan, Amit
2016-10-01
This paper is concerned with the problem of non-fragile robust optimal guaranteed cost control for a class of uncertain two-dimensional (2-D) discrete state-delayed systems described by the general model with norm-bounded uncertainties. Our attention is focused on the design of non-fragile state feedback controllers such that the resulting closed-loop system is asymptotically stable and the closed-loop cost function value is not more than a specified upper bound for all admissible parameter uncertainties and controller gain variations. A sufficient condition for the existence of such controllers is established under the linear matrix inequality framework. Moreover, a convex optimisation problem is proposed to select a non-fragile robust optimal guaranteed cost controller stabilising the 2-D discrete state-delayed system as well as achieving the least guaranteed cost for the resulting closed-loop system. The proposed method is compared with the previously reported criterion. Finally, illustrative examples are given to show the potential of the proposed technique.
Modelling and optimization of computer network traffic controllers
Directory of Open Access Journals (Sweden)
N. U. Ahmed
2005-01-01
operation of the controller and evaluate the benefits of using a genetic algorithm approach to speed up the optimization process. Our results show that the use of the genetic algorithm proves particularly useful in reducing the computation time required to optimize the operation of a system consisting of multiple token-bucket-regulated sources.
Optimal Environmental Standards under Asymmetric Information and Imperfect Enforcement
Arguedas, C.
2005-01-01
We study optimal policies composed of pollution standards, probabilities of inspection and fines dependant on the degree of noncompliance with the standards, in a context where regulated firms own private information.In contrast with previous literature, we show that optimal policies, being either p
Cost-optimal levels for energy performance requirements
DEFF Research Database (Denmark)
Thomsen, Kirsten Engelund; Aggerholm, Søren; Kluttig-Erhorn, Heike
2011-01-01
The CA conducted a study on experiences and challenges for setting cost optimal levels for energy performance requirements. The results were used as input by the EU Commission in their work of establishing the Regulation on a comparative methodology framework for calculating cost optimal levels o...
Concepts of combinatorial optimization
Paschos, Vangelis Th
2014-01-01
Combinatorial optimization is a multidisciplinary scientific area, lying in the interface of three major scientific domains: mathematics, theoretical computer science and management. The three volumes of the Combinatorial Optimization series aim to cover a wide range of topics in this area. These topics also deal with fundamental notions and approaches as with several classical applications of combinatorial optimization.Concepts of Combinatorial Optimization, is divided into three parts:- On the complexity of combinatorial optimization problems, presenting basics about worst-case and randomi
Introduction to Continuous Optimization
DEFF Research Database (Denmark)
Andreasson, Niclas; Evgrafov, Anton; Patriksson, Michael
optimal solutions for continuous optimization models. The main part of the mathematical material therefore concerns the analysis and linear algebra that underlie the workings of convexity and duality, and necessary/sufficient local/global optimality conditions for continuous optimization problems. Natural...... algorithms are then developed from these optimality conditions, and their most important convergence characteristics are analyzed. The book answers many more questions of the form “Why?” and “Why not?” than “How?”. We use only elementary mathematics in the development of the book, yet are rigorous throughout...
Optimization theory with applications
Pierre, Donald A
1987-01-01
Optimization principles are of undisputed importance in modern design and system operation. They can be used for many purposes: optimal design of systems, optimal operation of systems, determination of performance limitations of systems, or simply the solution of sets of equations. While most books on optimization are limited to essentially one approach, this volume offers a broad spectrum of approaches, with emphasis on basic techniques from both classical and modern work.After an introductory chapter introducing those system concepts that prevail throughout optimization problems of all typ
ON THE OPTIMAL CONTROL COMPUTATION OF LINEAR SYSTEMS
Directory of Open Access Journals (Sweden)
H. Tjahjana
2012-05-01
Full Text Available In this paper, we consider a numerical method for designing optimal controlon Linear Quadratic Regulator (LQR problem. In the optimal control design process through Pontryagin Maximum Principle (PMP, we obtain a system of diferential equations in state and costate variables. This system lacks of initial condition on the adjoint variables, and this situation creates classic dificulty for solving optimal control problems.This paper proposes a constructive method to approximate the initial condition of the adjoint system.
Multidisciplinary optimization of a butterfly valve.
Song, Xue Guan; Wang, Lin; Baek, Seok Heum; Park, Young Chul
2009-07-01
A butterfly valve is a type of flow control device, typically used to regulate fluid flow. This paper proposes a new process to meet desired needs in valve design that is characterized by the complex configuration. First, the need is identified according to the valve user/company, and then the problem is defined with a characteristic function. Second, the initial model of valve is made, and then the initial analysis including fluid and/or structural analysis is carried out to predict the fluid and/or structural performance of the valve. Third, the optimization in the form of mathematical functions, which considers single or multiple objective and/or discipline, is handled. This part includes the design of computer experiment, approximation technique, topology optimization and sizing optimization. Finally, the validation experiment is conducted based on the optimum result to verify the accuracy of the optimization. An example is provided to confirm the availability of the process proposed here.
Venter, Gerhard; Sobieszczanski-Sobieski Jaroslaw
2002-01-01
The purpose of this paper is to show how the search algorithm known as particle swarm optimization performs. Here, particle swarm optimization is applied to structural design problems, but the method has a much wider range of possible applications. The paper's new contributions are improvements to the particle swarm optimization algorithm and conclusions and recommendations as to the utility of the algorithm, Results of numerical experiments for both continuous and discrete applications are presented in the paper. The results indicate that the particle swarm optimization algorithm does locate the constrained minimum design in continuous applications with very good precision, albeit at a much higher computational cost than that of a typical gradient based optimizer. However, the true potential of particle swarm optimization is primarily in applications with discrete and/or discontinuous functions and variables. Additionally, particle swarm optimization has the potential of efficient computation with very large numbers of concurrently operating processors.
Integrated controls design optimization
Lou, Xinsheng; Neuschaefer, Carl H.
2015-09-01
A control system (207) for optimizing a chemical looping process of a power plant includes an optimizer (420), an income algorithm (230) and a cost algorithm (225) and a chemical looping process models. The process models are used to predict the process outputs from process input variables. Some of the process in puts and output variables are related to the income of the plant; and some others are related to the cost of the plant operations. The income algorithm (230) provides an income input to the optimizer (420) based on a plurality of input parameters (215) of the power plant. The cost algorithm (225) provides a cost input to the optimizer (420) based on a plurality of output parameters (220) of the power plant. The optimizer (420) determines an optimized operating parameter solution based on at least one of the income input and the cost input, and supplies the optimized operating parameter solution to the power plant.
Evolutionary constrained optimization
Deb, Kalyanmoy
2015-01-01
This book makes available a self-contained collection of modern research addressing the general constrained optimization problems using evolutionary algorithms. Broadly the topics covered include constraint handling for single and multi-objective optimizations; penalty function based methodology; multi-objective based methodology; new constraint handling mechanism; hybrid methodology; scaling issues in constrained optimization; design of scalable test problems; parameter adaptation in constrained optimization; handling of integer, discrete and mix variables in addition to continuous variables; application of constraint handling techniques to real-world problems; and constrained optimization in dynamic environment. There is also a separate chapter on hybrid optimization, which is gaining lots of popularity nowadays due to its capability of bridging the gap between evolutionary and classical optimization. The material in the book is useful to researchers, novice, and experts alike. The book will also be useful...
Interactive Topology Optimization
DEFF Research Database (Denmark)
Nobel-Jørgensen, Morten
software where the users are assumed to be well-educated both in the finite element method and topology optimization. This dissertation describes how various topology optimization methods have been used for creating cross-platform applications with high performance. The user interface design is based......Interactivity is the continuous interaction between the user and the application to solve a task. Topology optimization is the optimization of structures in order to improve stiffness or other objectives. The goal of the thesis is to explore how topology optimization can be used in applications...... in an interactive and intuitive way. By creating such applications with an intuitive and simple user interface we allow non-engineers like designers and architects to easily experiment with boundary conditions, design domains and other optimization settings. This is in contrast to commercial topology optimization...
The flood control and regulation of Three Gorges Project
Institute of Scientific and Technical Information of China (English)
Cai Qihua
2011-01-01
The important role of Three Gorges Project （TGP） in the flood management of the Yangtze River Basin is summarized. The Optimal Regulation Schemes of the Three Gorge Reservoir is briefly described. The flood regulation effect of TGP is analyzed. Typical issues related to reservoir operation for flood regulation are discussed and suggestions are put forward for the future work.
To regulate or not to regulate?
Energy Technology Data Exchange (ETDEWEB)
Mason, G.; Wrixon, A. [IAEA, Vienna (Austria)
2006-07-01
Full text of publication follows: In Hamlet famous soliloquy to be or not to be, he wrestles with the perennial human problem of choosing the right course of action in difficult circumstances. In recent years, we have witnessed a cast of thousands playing out a long-running scene that seems to echo Hamlet dilemma on a rather more prosaic level. When is it necessary to apply regulations to the control of exposure to ionizing radiation and when is regulatory control not warranted? This seemingly straightforward question has brought out the philosopher, ethician, lawyer, pragmatist, orator in simple radiation protection folk and has led to passionate debate on numerous occasions. This paper attempts an answer based on a review of recent developments. For deciding when to apply regulatory controls, several concepts have evolved over time, including exemption of practices and sources, exclusion of exposures and clearance of materials. These have different origins, purposes and characteristics. Exemption and clearance have often been associated with triviality of risk, while exclusion has been related to un-amenability of control. For each concept, criteria have been developed to assist the regulator in reaching a decision, but there has much disputation over numerical values. This paper briefly reviews and analyses recent developments and attempts to clarify the problem from first principles. The conclusion is that the underlying issue in each case is to determine when regulatory controls become unwarranted: that is, when the societal resources expended in applying them and complying with them would be disproportionate to any benefit they might bring. This is a natural extension of the principle of optimization of protection to the regulatory control of protection, in the context of exposure to radiation at very low levels. It also reflects common expectations of good governance: wise management of finite societal resources and avoidance of unwarranted controls on
Kontoleontos, E.; Weissenberger, S.
2016-11-01
In order to be able to predict the maximum Annual Energy Production (AEP) for tidal power plants, an advanced AEP optimization procedure is required for solving the optimization problem which consists of a high number of design variables and constraints. This efficient AEP optimization procedure requires an advanced optimization tool (EASY software) and an AEP calculation tool that can simulate all different operating modes of the units (bidirectional turbine, pump and sluicing mode). The EASY optimization software is a metamodel-assisted Evolutionary Algorithm (MAEA) that can be used in both single- and multi-objective optimization problems. The AEP calculation tool, developed by ANDRITZ HYDRO, in combination with EASY is used to maximize the tidal annual energy produced by optimizing the plant operation throughout the year. For the Swansea Bay Tidal Power Plant project, the AEP optimization along with the hydraulic design optimization and the model testing was used to evaluate all different hydraulic and operating concepts and define the optimal concept that led to a significant increase of the AEP value. This new concept of a triple regulated “bi-directional bulb pump turbine” for Swansea Bay Tidal Power Plant (16 units, nominal power above 320 MW) along with its AEP optimization scheme will be presented in detail in the paper. Furthermore, the use of an online AEP optimization during operation of the power plant, that will provide the optimal operating points to the control system, will be also presented.
On Validating Boolean Optimizers
Morgado, Antonio
2011-01-01
Boolean optimization finds a wide range of application domains, that motivated a number of different organizations of Boolean optimizers since the mid 90s. Some of the most successful approaches are based on iterative calls to an NP oracle, using either linear search, binary search or the identification of unsatisfiable sub-formulas. The increasing use of Boolean optimizers in practical settings raises the question of confidence in computed results. For example, the issue of confidence is paramount in safety critical settings. One way of increasing the confidence of the results computed by Boolean optimizers is to develop techniques for validating the results. Recent work studied the validation of Boolean optimizers based on branch-and-bound search. This paper complements existing work, and develops methods for validating Boolean optimizers that are based on iterative calls to an NP oracle. This entails implementing solutions for validating both satisfiable and unsatisfiable answers from the NP oracle. The wo...
Workshop on Computational Optimization
2015-01-01
Our everyday life is unthinkable without optimization. We try to minimize our effort and to maximize the achieved profit. Many real world and industrial problems arising in engineering, economics, medicine and other domains can be formulated as optimization tasks. This volume is a comprehensive collection of extended contributions from the Workshop on Computational Optimization 2013. It presents recent advances in computational optimization. The volume includes important real life problems like parameter settings for controlling processes in bioreactor, resource constrained project scheduling, problems arising in transport services, error correcting codes, optimal system performance and energy consumption and so on. It shows how to develop algorithms for them based on new metaheuristic methods like evolutionary computation, ant colony optimization, constrain programming and others.
Homotopy optimization methods for global optimization.
Energy Technology Data Exchange (ETDEWEB)
Dunlavy, Daniel M.; O' Leary, Dianne P. (University of Maryland, College Park, MD)
2005-12-01
We define a new method for global optimization, the Homotopy Optimization Method (HOM). This method differs from previous homotopy and continuation methods in that its aim is to find a minimizer for each of a set of values of the homotopy parameter, rather than to follow a path of minimizers. We define a second method, called HOPE, by allowing HOM to follow an ensemble of points obtained by perturbation of previous ones. We relate this new method to standard methods such as simulated annealing and show under what circumstances it is superior. We present results of extensive numerical experiments demonstrating performance of HOM and HOPE.
Optimization and approximation
Pedregal, Pablo
2017-01-01
This book provides a basic, initial resource, introducing science and engineering students to the field of optimization. It covers three main areas: mathematical programming, calculus of variations and optimal control, highlighting the ideas and concepts and offering insights into the importance of optimality conditions in each area. It also systematically presents affordable approximation methods. Exercises at various levels have been included to support the learning process.
Topology optimized microbioreactors
DEFF Research Database (Denmark)
Schäpper, Daniel; Lencastre Fernandes, Rita; Eliasson Lantz, Anna
2011-01-01
. Topology optimization is then used to change the spatial distribution of cells in the reactor in order to optimize for maximal product flow out of the reactor. This distribution accounts for potentially negative effects of, for example, by-product inhibition. We show that the theoretical improvement...... in productivity is at least fivefold compared with the homogeneous reactor. The improvements obtained by applying topology optimization are largest where either nutrition is scarce or inhibition effects are pronounced....
Topics in Nonconvex Optimization
Mishra, Shashi Kant
2011-01-01
Nonconvex Optimization is a multi-disciplinary research field that deals with the characterization and computation of local/global minima/maxima of nonlinear, nonconvex, nonsmooth, discrete and continuous functions. Nonconvex optimization problems are frequently encountered in modeling real world systems for a very broad range of applications including engineering, mathematical economics, management science, financial engineering, and social science. This contributed volume consists of selected contributions from the Advanced Training Programme on Nonconvex Optimization and Its Applications he
POSTDOC : THE HUMAN OPTIMIZATION
Satish Gajawada
2013-01-01
This paper is dedicated to everyone who is interested in the Artificial Intelligence. John Henry Holland proposed Genetic Algorithm in the early 1970s. Ant Colony Optimization was proposed by Marco Dorigo in 1992. Particle Swarm Optimization was introduced by Kennedy and Eberhart in 1995. Storn and Price introduced Differential Evolution in 1996. K.M. Passino introduced Bacterial Foraging Optimization Algorithm in 2002. In 2003, X.L. Li proposed Artificial Fish Swarm Algorithm....
Optimization : insights and applications
Brinkhuis, Jan
2005-01-01
This self-contained textbook is an informal introduction to optimization through the use of numerous illustrations and applications. The focus is on analytically solving optimization problems with a finite number of continuous variables. In addition, the authors provide introductions to classical and modern numerical methods of optimization and to dynamic optimization. The book's overarching point is that most problems may be solved by the direct application of the theorems of Fermat, Lagrange, and Weierstrass. The authors show how the intuition for each of the theoretical results can be s
Integer and combinatorial optimization
Nemhauser, George L
1999-01-01
Rave reviews for INTEGER AND COMBINATORIAL OPTIMIZATION ""This book provides an excellent introduction and survey of traditional fields of combinatorial optimization . . . It is indeed one of the best and most complete texts on combinatorial optimization . . . available. [And] with more than 700 entries, [it] has quite an exhaustive reference list.""-Optima ""A unifying approach to optimization problems is to formulate them like linear programming problems, while restricting some or all of the variables to the integers. This book is an encyclopedic resource for such f
Sequential stochastic optimization
Cairoli, Renzo
1996-01-01
Sequential Stochastic Optimization provides mathematicians and applied researchers with a well-developed framework in which stochastic optimization problems can be formulated and solved. Offering much material that is either new or has never before appeared in book form, it lucidly presents a unified theory of optimal stopping and optimal sequential control of stochastic processes. This book has been carefully organized so that little prior knowledge of the subject is assumed; its only prerequisites are a standard graduate course in probability theory and some familiarity with discrete-paramet
Optimization under Uncertainty
Lopez, Rafael H.
2016-01-06
The goal of this poster is to present the main approaches to optimization of engineering systems in the presence of uncertainties. We begin by giving an insight about robust optimization. Next, we detail how to deal with probabilistic constraints in optimization, the so called the reliability based design. Subsequently, we present the risk optimization approach, which includes the expected costs of failure in the objective function. After that the basic description of each approach is given, the projects developed by CORE are presented. Finally, the main current topic of research of CORE is described.
Control and optimization system
Xinsheng, Lou
2013-02-12
A system for optimizing a power plant includes a chemical loop having an input for receiving an input parameter (270) and an output for outputting an output parameter (280), a control system operably connected to the chemical loop and having a multiple controller part (230) comprising a model-free controller. The control system receives the output parameter (280), optimizes the input parameter (270) based on the received output parameter (280), and outputs an optimized input parameter (270) to the input of the chemical loop to control a process of the chemical loop in an optimized manner.
MULTIDISCIPLINARY ROBUST OPTIMIZATION DESIGN
Institute of Scientific and Technical Information of China (English)
Chen Jianjiang; Xiao Renbin; Zhong Yifang; Dou Gang
2005-01-01
Because uncertainty factors inevitably exist under multidisciplinary design environment, a hierarchical multidisciplinary robust optimization design based on response surface is proposed. The method constructs optimization model of subsystem level and system level to coordinate the coupling among subsystems, and also the response surface based on the artificial neural network is introduced to provide information for system level optimization tool to maintain the independence of subsystems,i.e. to realize multidisciplinary parallel design. The application case of electrical packaging demonstrates that reasonable robust optimum solution can be yielded and it is a potential and efficient multidisciplinary robust optimization approach.
Graben, Peter beim; Fröhlich, Flavio
2015-01-01
We optimally estimate the recurrence structure of a multivariate time series by Markov chains obtained from recurrence grammars. The goodness of fit is assessed with a utility function derived from the stochastic Markov transition matrix. It assumes a local maximum for the distance threshold of the optimal recurrence grammar. We validate our approach by means of the nonlinear Lorenz system and its linearized stochastic surrogates. Finally we apply our optimization procedure to the segmentation of neurophysiological time series obtained from anesthetized animals. We propose the number of optimal recurrence domains as a statistic for classifying an animals' state of consciousness.
OPTIMAL DELAUNAY TRIANGULATIONS
Institute of Scientific and Technical Information of China (English)
Long Chen; Jin-chao Xu
2004-01-01
The Delaunay triangulation, in both classic and more generalized sense, is studied in this paper for minimizing the linear interpolation error (measure in Lp-norm) for a given function. The classic Delaunay triangulation can then be characterized as an optimal triangulation that minimizes the interpolation error for the isotropic function ‖x‖2 among all the triangulations with a given set of vertices. For a more general function, a functiondependent Delaunay triangulation is then defined to be an optimal triangulation that minimizes the interpolation error for this .function and its construction can be obtained by a simple lifting and projection procedure.The optimal Delaunay triangulation is the one that minimizes the interpolation error among all triangulations with the same number of vertices, i.e. the distribution of vertices are optimized in order to minimize the interpolation error. Such a function-dependent optimal Delaunay triangulation is proved to exist for any given convex continuous function.On an optimal Delaunay triangulation associated with f, it is proved that ▽f at the interior vertices can be exactly recovered by the function values on its neighboring vertices.Since the optimal Delaunay triangulation is difficult to obtain in practice, the concept of nearly optimal triangulation is introduced and two sufficient conditions are presented for a triangulation to be nearly optimal.
Deterministic Global Optimization
Scholz, Daniel
2012-01-01
This monograph deals with a general class of solution approaches in deterministic global optimization, namely the geometric branch-and-bound methods which are popular algorithms, for instance, in Lipschitzian optimization, d.c. programming, and interval analysis.It also introduces a new concept for the rate of convergence and analyzes several bounding operations reported in the literature, from the theoretical as well as from the empirical point of view. Furthermore, extensions of the prototype algorithm for multicriteria global optimization problems as well as mixed combinatorial optimization
Stochastic optimization methods
Marti, Kurt
2008-01-01
Optimization problems arising in practice involve random model parameters. This book features many illustrations, several examples, and applications to concrete problems from engineering and operations research.
Institute of Scientific and Technical Information of China (English)
刘奕涛; 钟凯雄
2016-01-01
“好教师”是教师成长新的方向。高校应从文化管理视角剖析“好教师”成长环境的文化维度，通过建构教师学习共同体，完善现代大学制度文化建设，催生人际信任的教师行为文化，打造教育性、人文性、特色性和整体性相融的物质文化环境等文化管理策略，对“好教师”成长环境进行持续的调控和优化，为其成长提供充溢文化动力的生态环境。%Becoming "good teacher" is a new direction of teachers growing and development .Universities should base on the perspective of cultural management to analyze the cultural dimensions of "good teachers" growing environment, concentrate on constructing teachers' learning community, improve modern university institutional culture construction, encourage the growth of teachers’ interpersonal trust behavior culture, create an educational, humanism and characteristic material culture environment. These are the strategies of cultural management to continuously regulate and optimize the "good teachers" growing environment, which provide the cultural ecological environment for their growth.
Optimal Regulation within Spatial Constraints. An Application to Flexible Structures.
1980-08-01
oT 0 IM EDC -8. -1 -7 -5 -q -3 - -I 03 FAEQ ( HZJ -LOO 10 Figure C-15. Power spectral density plot of output 5, example 1. TEST , -5 -5 S-6 -7 -8,o -7...en r- -4H ~ I I U) 00 0 (I I I N o 00 00 LA Lm vej 00N n e 0 wA( E(7 uH DD ’DH 2200 N- N N -4 -4 - N N -4 4 4 4 14 0 n0 0 0- N ( N 4 tD (n~ - ODmD 0 r
Optimality Principles in the Regulation of Metabolic Networks
Directory of Open Access Journals (Sweden)
Jan Berkhout
2012-08-01
Full Text Available One of the challenging tasks in systems biology is to understand how molecular networks give rise to emergent functionality and whether universal design principles apply to molecular networks. To achieve this, the biophysical, evolutionary and physiological constraints that act on those networks need to be identified in addition to the characterisation of the molecular components and interactions. Then, the cellular “task” of the network—its function—should be identified. A network contributes to organismal fitness through its function. The premise is that the same functions are often implemented in different organisms by the same type of network; hence, the concept of design principles. In biology, due to the strong forces of selective pressure and natural selection, network functions can often be understood as the outcome of fitness optimisation. The hypothesis of fitness optimisation to understand the design of a network has proven to be a powerful strategy. Here, we outline the use of several optimisation principles applied to biological networks, with an emphasis on metabolic regulatory networks. We discuss the different objective functions and constraints that are considered and the kind of understanding that they provide.
Regulation for Optimal Liquid Products during Biomass Pyrolysis: A Review
Wang, F.; Hu, L. J.; Zheng, Y. W.; Huang, Y. B.; Yang, X. Q.; Liu, C.; Kang, J.; Zheng, Z. F.
2016-08-01
The liquid product obtained from biomass pyrolysis is very valuable that it could be used for extraction of chemicals as well as for liquid fuel. The desire goal is to obtain the most bio-oil with desired higher heating value (HHV), high physicochemical stability. The yields and chemical composition of products from biomass pyrolysis are closely related to the feedstock, pyrolysis parameters and catalysts. Current researches mainly concentrated on the co-pyrolysis of different biomass and introduce of novel catalysts as well as the combined effect of catalysts and pyrolysis parameters. This review starts with the chemical composition of biomass and the fundamental parameters and focuses on the influence of catalysts on bio-oil. What is more, the pyrolysis facilities at commercial scales were also involved. The classic researches and the current literature about the yield and composition of products (mainly liquid products) are summarized.
Nonlinear Non-convex Optimization of Hydraulic Networks
DEFF Research Database (Denmark)
Tahavori, Maryamsadat; Kallesøe, Carsten; Leth, John-Josef
2013-01-01
Pressure management in water supply systems is an effective way to reduce the leakage in a system. In this paper, the pressure management and the reduction of power consumption of a water supply system is formulated as an optimization problem. The problem is to minimize the power consumption...... in pumps and also to regulate the pressure at the end-user valves to a desired value. The optimization problem which is solved is a nonlinear and non-convex optimization. The barrier method is used to solve this problem. The modeling framework and the optimization technique which are used are general...
DEFF Research Database (Denmark)
Dalgaard, Carl-Johan Lars; Strulik, Holger
2010-01-01
This study introduces physiological aging into a simple model of optimal intertemporal consumption. In this endeavor we draw on the natural science literature on aging. According to the purposed theory, the speed of the aging process and the time of death are endogenously determined by optimal...
Energy Technology Data Exchange (ETDEWEB)
Costa, Geraldo R.M. da [Sao Paulo Univ., Sao Carlos, SP (Brazil). Escola de Engenharia
1994-12-31
This paper discusses, partially, the advantages and the disadvantages of the optimal power flow. It shows some of the difficulties of implementation and proposes solutions. An analysis is made comparing the power flow, BIGPOWER/CESP, and the optimal power flow, FPO/SEL, developed by the author, when applied to the CEPEL-ELETRONORTE and CESP systems. (author) 8 refs., 5 tabs.
Overall bolt stress optimization
DEFF Research Database (Denmark)
Pedersen, Niels Leergaard
2013-01-01
The state of stress in bolts and nuts with International Organization for Standardization metric thread design is examined and optimized. The assumed failure mode is fatigue, so the applied preload and the load amplitude together with the stress concentrations define the connection strength....... Maximum stress in the bolt is found at the fillet under the head, at the thread start, or at the thread root. To minimize the stress concentration, shape optimization is applied. Nut shape optimization also has a positive effect on the maximum stress. The optimization results show that designing a nut......, which results in a more evenly distribution of load along the engaged thread, has a limited influence on the maximum stress due to the stress concentration at the first thread root. To further reduce the maximum stress, the transition from bolt shank to the thread must be optimized. Stress reduction...
Optimized manufacturable porous materials
DEFF Research Database (Denmark)
Andreassen, Erik; Andreasen, Casper Schousboe; Jensen, Jakob Søndergaard
Topology optimization has been used to design two-dimensional material structures with specific elastic properties, but optimized designs of three-dimensional material structures are more scarsely seen. Partly because it requires more computational power, and partly because it is a major challenge...... to include manufacturing constraints in the optimization. This work focuses on incorporating the manufacturability into the optimization procedure, allowing the resulting material structure to be manufactured directly using rapid manufacturing techniques, such as selective laser melting/sintering (SLM....../S). The available manufacturing methods are best suited for porous materials (one constituent and void), but the optimization procedure can easily include more constituents. The elasticity tensor is found from one unit cell using the homogenization method together with a standard finite element (FE) discretization...
Workshop on Computational Optimization
2016-01-01
This volume is a comprehensive collection of extended contributions from the Workshop on Computational Optimization 2014, held at Warsaw, Poland, September 7-10, 2014. The book presents recent advances in computational optimization. The volume includes important real problems like parameter settings for controlling processes in bioreactor and other processes, resource constrained project scheduling, infection distribution, molecule distance geometry, quantum computing, real-time management and optimal control, bin packing, medical image processing, localization the abrupt atmospheric contamination source and so on. It shows how to develop algorithms for them based on new metaheuristic methods like evolutionary computation, ant colony optimization, constrain programming and others. This research demonstrates how some real-world problems arising in engineering, economics, medicine and other domains can be formulated as optimization tasks.
Directory of Open Access Journals (Sweden)
Ben Niu
2012-01-01
Full Text Available This paper investigates the behaviors at different developmental stages in Escherichia coli (E. coli lifecycle and developing a new biologically inspired optimization algorithm named bacterial colony optimization (BCO. BCO is based on a lifecycle model that simulates some typical behaviors of E. coli bacteria during their whole lifecycle, including chemotaxis, communication, elimination, reproduction, and migration. A newly created chemotaxis strategy combined with communication mechanism is developed to simplify the bacterial optimization, which is spread over the whole optimization process. However, the other behaviors such as elimination, reproduction, and migration are implemented only when the given conditions are satisfied. Two types of interactive communication schemas: individuals exchange schema and group exchange schema are designed to improve the optimization efficiency. In the simulation studies, a set of 12 benchmark functions belonging to three classes (unimodal, multimodal, and rotated problems are performed, and the performances of the proposed algorithms are compared with five recent evolutionary algorithms to demonstrate the superiority of BCO.
Hybrid Batch Bayesian Optimization
Azimi, Javad; Fern, Xiaoli
2012-01-01
Bayesian Optimization aims at optimizing an unknown non-convex/concave function that is costly to evaluate. We are interested in application scenarios where concurrent function evaluations are possible. Under such a setting, BO could choose to either sequentially evaluate the function, one input at a time and wait for the output of the function before making the next selection, or evaluate the function at a batch of multiple inputs at once. These two different settings are commonly referred to as the sequential and batch settings of Bayesian Optimization. In general, the sequential setting leads to better optimization performance as each function evaluation is selected with more information, whereas the batch setting has an advantage in terms of the total experimental time (the number of iterations). In this work, our goal is to combine the strength of both settings. Specifically, we systematically analyze Bayesian optimization using Gaussian process as the posterior estimator and provide a hybrid algorithm t...
Colonius, Fritz
1988-01-01
This research monograph deals with optimal periodic control problems for systems governed by ordinary and functional differential equations of retarded type. Particular attention is given to the problem of local properness, i.e. whether system performance can be improved by introducing periodic motions. Using either Ekeland's Variational Principle or optimization theory in Banach spaces, necessary optimality conditions are proved. In particular, complete proofs of second-order conditions are included and the result is used for various versions of the optimal periodic control problem. Furthermore a scenario for local properness (related to Hopf bifurcation) is drawn up, giving hints as to where to look for optimal periodic solutions. The book provides mathematically rigorous proofs for results which are potentially of importance in chemical engineering and aerospace engineering.
Cortez, Paulo
2014-01-01
The goal of this book is to gather in a single document the most relevant concepts related to modern optimization methods, showing how such concepts and methods can be addressed using the open source, multi-platform R tool. Modern optimization methods, also known as metaheuristics, are particularly useful for solving complex problems for which no specialized optimization algorithm has been developed. These methods often yield high quality solutions with a more reasonable use of computational resources (e.g. memory and processing effort). Examples of popular modern methods discussed in this book are: simulated annealing; tabu search; genetic algorithms; differential evolution; and particle swarm optimization. This book is suitable for undergraduate and graduate students in Computer Science, Information Technology, and related areas, as well as data analysts interested in exploring modern optimization methods using R.
SAGD optimization under uncertainty
Energy Technology Data Exchange (ETDEWEB)
Gossuin, J.; Naccache, P. [Schlumberger SIS, Abingdon (United Kingdom); Bailley, W.; Couet, B. [Schlumberger-Doll Research, Cambridge, MA, (United States)
2011-07-01
In the heavy oil industry, the steam assisted gravity drainage process is often used to enhance oil recovery but this is a costly method and ways to make it more efficient are needed. Multiple methods have been developed to optimize the SAGD process but none of them explicitly considered uncertainty. This paper presents an optimization method in the presence of reservoir uncertainty. This process was tested on an SAGD model where three equi-probable geological models are possible. Preparatory steps were first performed to identify key variables and the optimization model was then proposed. The method was shown to be successful in handling a significant number of uncertainties, optimizing the SAGD process and preventing premature steam channels that can choke production. The optimization method presented herein was successfully applied to an SAGD process and was shown to provide better strategies than sensitivity analysis while handling more complex problems.
Optimal screening for genetic diseases.
Nævdal, Eric
2014-12-01
Screening for genetic diseases is performed in many regions and/or ethnic groups where there is a high prevalence of possibly malign genes. The propagation of such genes can be considered a dynamic externality. Given that many of these diseases are untreatable and give rise to truly tragic outcomes, they are a source of societal concern, and the screening process should perhaps be regulated. This paper incorporates a standard model of genetic propagation into an economic model of dynamic management to derive cost benefit rules for optimal screening. The highly non-linear nature of genetic dynamics gives rise to perhaps surprising results that include discontinuous controls and threshold effects. One insight is that any screening program that is in place for any amount of time should screen all individuals in a target population. The incorporation of genetic models may prove to be useful to several emerging fields in economics such as genoeconomics, neuroeconomics and paleoeconomics.
Institute of Scientific and Technical Information of China (English)
ZHANG DE-TAO
2009-01-01
In this paper, we use the solutions of forward-backward stochastic differential equations to get the optimal control for backward stochastic linear quadratic optimal control problem. And we also give the linear feedback regulator for the optimal control problem by using the solutions of a group of Riccati equations.
Global Optimization using Interval Analysis: Interval Optimization for Aerospace Applications
Van Kampen, E.
2010-01-01
Optimization is an important element in aerospace related research. It is encountered for example in trajectory optimization problems, such as: satellite formation flying, spacecraft re-entry optimization and airport approach and departure optimization; in control optimization, for example in adapti
Modeling, Optimization & Control of Hydraulic Networks
DEFF Research Database (Denmark)
Tahavori, Maryamsadat
2014-01-01
to check if the network is controllable. Afterward the pressure control problem in water supply systems is formulated as an optimal control problem. The goal is to minimize the power consumption in pumps and also to regulate the pressure drop at the end-users to a desired value. The formulated optimal...... in water network is pressure management. By reducing the pressure in the water network, the leakage can be reduced significantly. Also it reduces the amount of energy consumption in water networks. The primary purpose of this work is to develop control algorithms for pressure control in water supply...... systems. To have better understanding of water leakage, to control pressure and leakage effectively and for optimal design of water supply system, suitable modeling is an important prerequisite. Therefore a model with the main objective of pressure control and consequently leakage reduction is presented...
Judo Biomechanical Optimization
Sacripanti, Attilio
2016-01-01
In this paper, for the first time, there is comprehensively tackling the problem of biomechanical optimization of a sport of situation such as judo. Starting from the optimization of more simple sports, optimization of this kind of complex sports is grounded on a general physics tool such as the analysis of variation. The objective function is divided for static and dynamic situation of Athletes couple, and it is proposed also a sort of dynamic programming problem Strategic Optimization. A dynamic programming problem is an optimization problem in which decisions have to be taken sequentially over several time periods linked in some fashion. A strategy for a dynamic programming problem is just a contingency plan, a plan that specifies what is to be done at each stage as a function of all that has transpired up to that point. It is possible to demonstrate, under some conditions, that a Markovian optimal strategy is an optimal strategy for the dynamic programming problem under examination. At last we try to appr...
Eberhard, Andrew; Ralph, Daniel; Glover, Barney M
1999-01-01
Although the monograph Progress in Optimization I: Contributions from Aus tralasia grew from the idea of publishing a proceedings of the Fourth Optimiza tion Day, held in July 1997 at the Royal Melbourne Institute of Technology, the focus soon changed to a refereed volume in optimization. The intention is to publish a similar book annually, following each Optimization Day. The idea of having an annual Optimization Day was conceived by Barney Glover; the first of these Optimization Days was held in 1994 at the University of Ballarat. Barney hoped that such a yearly event would bring together the many, but widely dispersed, researchers in Australia who were publishing in optimization and related areas such as control. The first Optimization Day event was followed by similar conferences at The University of New South Wales (1995), The University of Melbourne (1996), the Royal Melbourne Institute of Technology (1997), and The University of Western Australia (1998). The 1999 conference will return to Ballarat ...
Optimization and Control of Cyber-Physical Vehicle Systems
Directory of Open Access Journals (Sweden)
Justin M. Bradley
2015-09-01
Full Text Available A cyber-physical system (CPS is composed of tightly-integrated computation, communication and physical elements. Medical devices, buildings, mobile devices, robots, transportation and energy systems can benefit from CPS co-design and optimization techniques. Cyber-physical vehicle systems (CPVSs are rapidly advancing due to progress in real-time computing, control and artificial intelligence. Multidisciplinary or multi-objective design optimization maximizes CPS efficiency, capability and safety, while online regulation enables the vehicle to be responsive to disturbances, modeling errors and uncertainties. CPVS optimization occurs at design-time and at run-time. This paper surveys the run-time cooperative optimization or co-optimization of cyber and physical systems, which have historically been considered separately. A run-time CPVS is also cooperatively regulated or co-regulated when cyber and physical resources are utilized in a manner that is responsive to both cyber and physical system requirements. This paper surveys research that considers both cyber and physical resources in co-optimization and co-regulation schemes with applications to mobile robotic and vehicle systems. Time-varying sampling patterns, sensor scheduling, anytime control, feedback scheduling, task and motion planning and resource sharing are examined.
Optimization and Control of Cyber-Physical Vehicle Systems
Bradley, Justin M.; Atkins, Ella M.
2015-01-01
A cyber-physical system (CPS) is composed of tightly-integrated computation, communication and physical elements. Medical devices, buildings, mobile devices, robots, transportation and energy systems can benefit from CPS co-design and optimization techniques. Cyber-physical vehicle systems (CPVSs) are rapidly advancing due to progress in real-time computing, control and artificial intelligence. Multidisciplinary or multi-objective design optimization maximizes CPS efficiency, capability and safety, while online regulation enables the vehicle to be responsive to disturbances, modeling errors and uncertainties. CPVS optimization occurs at design-time and at run-time. This paper surveys the run-time cooperative optimization or co-optimization of cyber and physical systems, which have historically been considered separately. A run-time CPVS is also cooperatively regulated or co-regulated when cyber and physical resources are utilized in a manner that is responsive to both cyber and physical system requirements. This paper surveys research that considers both cyber and physical resources in co-optimization and co-regulation schemes with applications to mobile robotic and vehicle systems. Time-varying sampling patterns, sensor scheduling, anytime control, feedback scheduling, task and motion planning and resource sharing are examined. PMID:26378541
Optimization and Control of Cyber-Physical Vehicle Systems.
Bradley, Justin M; Atkins, Ella M
2015-09-11
A cyber-physical system (CPS) is composed of tightly-integrated computation, communication and physical elements. Medical devices, buildings, mobile devices, robots, transportation and energy systems can benefit from CPS co-design and optimization techniques. Cyber-physical vehicle systems (CPVSs) are rapidly advancing due to progress in real-time computing, control and artificial intelligence. Multidisciplinary or multi-objective design optimization maximizes CPS efficiency, capability and safety, while online regulation enables the vehicle to be responsive to disturbances, modeling errors and uncertainties. CPVS optimization occurs at design-time and at run-time. This paper surveys the run-time cooperative optimization or co-optimization of cyber and physical systems, which have historically been considered separately. A run-time CPVS is also cooperatively regulated or co-regulated when cyber and physical resources are utilized in a manner that is responsive to both cyber and physical system requirements. This paper surveys research that considers both cyber and physical resources in co-optimization and co-regulation schemes with applications to mobile robotic and vehicle systems. Time-varying sampling patterns, sensor scheduling, anytime control, feedback scheduling, task and motion planning and resource sharing are examined.
Optimal Strategy in Basketball
Skinner, Brian
2015-01-01
This book chapter reviews some of the major principles associated with optimal strategy in basketball. In particular, we consider the principles of allocative efficiency (optimal allocation of shots between offensive options), dynamic efficiency (optimal shot selection in the face of pressure from the shot clock), and the risk/reward tradeoff (strategic manipulation of outcome variance). For each principle, we provide a simple example of a strategic problem and show how it can be described analytically. We then review general analytical results and provide an overview of existing statistical studies. A number of open challenges in basketball analysis are highlighted.
Jędrzejowicz, Piotr; Kacprzyk, Janusz
2013-01-01
This volume presents a collection of original research works by leading specialists focusing on novel and promising approaches in which the multi-agent system paradigm is used to support, enhance or replace traditional approaches to solving difficult optimization problems. The editors have invited several well-known specialists to present their solutions, tools, and models falling under the common denominator of the agent-based optimization. The book consists of eight chapters covering examples of application of the multi-agent paradigm and respective customized tools to solve difficult optimization problems arising in different areas such as machine learning, scheduling, transportation and, more generally, distributed and cooperative problem solving.
Pardalos, Panos
2001-01-01
Optimization problems are widespread in the mathematical modeling of real world systems and their applications arise in all branches of science, applied science and engineering. The goal of the Encyclopedia of Optimization is to introduce the reader to a complete set of topics in order to show the spectrum of recent research activities and the richness of ideas in the development of theories, algorithms and the applications of optimization. It is directed to a diverse audience of students, scientists, engineers, decision makers and problem solvers in academia, business, industry, and government.
Optimal control computer programs
Kuo, F.
1992-01-01
The solution of the optimal control problem, even with low order dynamical systems, can usually strain the analytical ability of most engineers. The understanding of this subject matter, therefore, would be greatly enhanced if a software package existed that could simulate simple generic problems. Surprisingly, despite a great abundance of commercially available control software, few, if any, address the part of optimal control in its most generic form. The purpose of this paper is, therefore, to present a simple computer program that will perform simulations of optimal control problems that arise from the first necessary condition and the Pontryagin's maximum principle.
Contingency contractor optimization.
Energy Technology Data Exchange (ETDEWEB)
Gearhart, Jared Lee; Adair, Kristin Lynn; Jones, Katherine A.; Bandlow, Alisa; Durfee, Justin David.; Jones, Dean A.; Martin, Nathaniel; Detry, Richard Joseph; Nanco, Alan Stewart; Nozick, Linda Karen
2013-10-01
The goal of Phase 3 the OSD ATL Contingency Contractor Optimization (CCO) project is to create an engineering prototype of a tool for the contingency contractor element of total force planning during the Support for Strategic Analysis (SSA). An optimization model was developed to determine the optimal mix of military, Department of Defense (DoD) civilians, and contractors that accomplishes a set of user defined mission requirements at the lowest possible cost while honoring resource limitations and manpower use rules. An additional feature allows the model to understand the variability of the Total Force Mix when there is uncertainty in mission requirements.
Contingency contractor optimization.
Energy Technology Data Exchange (ETDEWEB)
Gearhart, Jared Lee; Adair, Kristin Lynn; Jones, Katherine A.; Bandlow, Alisa; Detry, Richard Joseph; Durfee, Justin David.; Jones, Dean A.; Martin, Nathaniel; Nanco, Alan Stewart; Nozick, Linda Karen
2013-06-01
The goal of Phase 3 the OSD ATL Contingency Contractor Optimization (CCO) project is to create an engineering prototype of a tool for the contingency contractor element of total force planning during the Support for Strategic Analysis (SSA). An optimization model was developed to determine the optimal mix of military, Department of Defense (DoD) civilians, and contractors that accomplishes a set of user defined mission requirements at the lowest possible cost while honoring resource limitations and manpower use rules. An additional feature allows the model to understand the variability of the Total Force Mix when there is uncertainty in mission requirements.
Optimization of photonic crystal cavities
DEFF Research Database (Denmark)
Wang, Fengwen; Sigmund, Ole
2017-01-01
We present optimization of photonic crystal cavities. The optimization problem is formulated to maximize the Purcell factor of a photonic crystal cavity. Both topology optimization and air-hole-based shape optimization are utilized for the design process. Numerical results demonstrate...... that the Purcell factor of the photonic crystal cavity can be significantly improved through optimization....
Particle swarm optimization based optimal bidding strategy in an ...
African Journals Online (AJOL)
user
Particle swarm optimization based optimal bidding strategy in an open ... relaxation-based approach for strategic bidding in England-Wales pool type electricity market has ... presents the mathematical formulation of optimal bidding problem.
On Alternative Optimal Solutions to Linear Fractional Optimization Problems
Institute of Scientific and Technical Information of China (English)
ShengjiaXue
2004-01-01
The structure of the optimal solution set is derived for linear fractional optimization problems with the representation theorem of polyhedral sets．And the computational procedure in determining all optimal solutions is also given．
Robust and optimal attitude control of spacecraft with disturbances
Park, Yonmook
2015-05-01
In this paper, a robust and optimal attitude control design that uses the Euler angles and angular velocities feedback is presented for regulation of spacecraft with disturbances. In the control design, it is assumed that the disturbance signal has the information of the system state. In addition, it is assumed that the disturbance signal tries to maximise the same performance index that the control input tries to minimise. After proposing a robust attitude control law that can stabilise the complete attitude motion of spacecraft with disturbances, the optimal attitude control problem of spacecraft is formulated as the optimal game-theoretic problem. Then it is shown that the proposed robust attitude control law is the optimal solution of the optimal game-theoretic problem. The stability of the closed-loop system for the proposed robust and optimal control law is proven by the LaSalle invariance principle. The theoretical results presented in this paper are illustrated by a numerical example.
Optimal control of stochastic difference Volterra equations an introduction
Shaikhet, Leonid
2015-01-01
This book showcases a subclass of hereditary systems, that is, systems with behaviour depending not only on their current state but also on their past history; it is an introduction to the mathematical theory of optimal control for stochastic difference Volterra equations of neutral type. As such, it will be of much interest to researchers interested in modelling processes in physics, mechanics, automatic regulation, economics and finance, biology, sociology and medicine for all of which such equations are very popular tools. The text deals with problems of optimal control such as meeting given performance criteria, and stabilization, extending them to neutral stochastic difference Volterra equations. In particular, it contrasts the difference analogues of solutions to optimal control and optimal estimation problems for stochastic integral Volterra equations with optimal solutions for corresponding problems in stochastic difference Volterra equations. Optimal Control of Stochastic Difference Volterra Equation...
Towards spatially differentiated regulation of nitrogen
DEFF Research Database (Denmark)
Lajer Højberg, Anker; Refsgaard, Jens Christian; Jørgensen, Lisbeth Flindt
of drains and hydro-biogeochemical conditions in associated riparian lowlands. Hence, a shift of paradigm in regulation practice is needed, whit a cost-effective regulation accounting for this variability and differentiate the regulations/restrictions between resilient and vulnerable areas. However...... on control monitoring of nitrate outputs from agriculture utilising local scale data and knowledge. TReNDS supports a two-tiered approach, where areas subject to further abatement are identified by national screening approaches supported by detailed local studies for the design of optimal measures taking...... advantage of local data and knowledge....
Dynamic stochastic optimization
Ermoliev, Yuri; Pflug, Georg
2004-01-01
Uncertainties and changes are pervasive characteristics of modern systems involving interactions between humans, economics, nature and technology. These systems are often too complex to allow for precise evaluations and, as a result, the lack of proper management (control) may create significant risks. In order to develop robust strategies we need approaches which explic itly deal with uncertainties, risks and changing conditions. One rather general approach is to characterize (explicitly or implicitly) uncertainties by objec tive or subjective probabilities (measures of confidence or belief). This leads us to stochastic optimization problems which can rarely be solved by using the standard deterministic optimization and optimal control methods. In the stochastic optimization the accent is on problems with a large number of deci sion and random variables, and consequently the focus ofattention is directed to efficient solution procedures rather than to (analytical) closed-form solu tions. Objective an...
Accelerated Parallel Texture Optimization
Institute of Scientific and Technical Information of China (English)
Hao-Da Huang; Xin Tong; Wen-Cheng Wang
2007-01-01
Texture optimization is a texture synthesis method that can efficiently reproduce various features of exemplar textures. However, its slow synthesis speed limits its usage in many interactive or real time applications. In this paper, we propose a parallel texture optimization algorithm to run on GPUs. In our algorithm, k-coherence search and principle component analysis (PCA) are used for hardware acceleration, and two acceleration techniques are further developed to speed up our GPU-based texture optimization. With a reasonable precomputation cost, the online synthesis speed of our algorithm is 4000+ times faster than that of the original texture optimization algorithm and thus our algorithm is capable of interactive applications. The advantages of the new scheme are demonstrated by applying it to interactive editing of flow-guided synthesis.
Topology optimized microbioreactors.
Schäpper, Daniel; Lencastre Fernandes, Rita; Lantz, Anna Eliasson; Okkels, Fridolin; Bruus, Henrik; Gernaey, Krist V
2011-04-01
This article presents the fusion of two hitherto unrelated fields--microbioreactors and topology optimization. The basis for this study is a rectangular microbioreactor with homogeneously distributed immobilized brewers yeast cells (Saccharomyces cerevisiae) that produce a recombinant protein. Topology optimization is then used to change the spatial distribution of cells in the reactor in order to optimize for maximal product flow out of the reactor. This distribution accounts for potentially negative effects of, for example, by-product inhibition. We show that the theoretical improvement in productivity is at least fivefold compared with the homogeneous reactor. The improvements obtained by applying topology optimization are largest where either nutrition is scarce or inhibition effects are pronounced.
Linearly constrained minimax optimization
DEFF Research Database (Denmark)
Madsen, Kaj; Schjær-Jacobsen, Hans
1978-01-01
We present an algorithm for nonlinear minimax optimization subject to linear equality and inequality constraints which requires first order partial derivatives. The algorithm is based on successive linear approximations to the functions defining the problem. The resulting linear subproblems...
Cooperative Bacterial Foraging Optimization
Directory of Open Access Journals (Sweden)
Hanning Chen
2009-01-01
Full Text Available Bacterial Foraging Optimization (BFO is a novel optimization algorithm based on the social foraging behavior of E. coli bacteria. This paper presents a variation on the original BFO algorithm, namely, the Cooperative Bacterial Foraging Optimization (CBFO, which significantly improve the original BFO in solving complex optimization problems. This significant improvement is achieved by applying two cooperative approaches to the original BFO, namely, the serial heterogeneous cooperation on the implicit space decomposition level and the serial heterogeneous cooperation on the hybrid space decomposition level. The experiments compare the performance of two CBFO variants with the original BFO, the standard PSO and a real-coded GA on four widely used benchmark functions. The new method shows a marked improvement in performance over the original BFO and appears to be comparable with the PSO and GA.
Handbook of simulation optimization
Fu, Michael C
2014-01-01
The Handbook of Simulation Optimization presents an overview of the state of the art of simulation optimization, providing a survey of the most well-established approaches for optimizing stochastic simulation models and a sampling of recent research advances in theory and methodology. Leading contributors cover such topics as discrete optimization via simulation, ranking and selection, efficient simulation budget allocation, random search methods, response surface methodology, stochastic gradient estimation, stochastic approximation, sample average approximation, stochastic constraints, variance reduction techniques, model-based stochastic search methods and Markov decision processes. This single volume should serve as a reference for those already in the field and as a means for those new to the field for understanding and applying the main approaches. The intended audience includes researchers, practitioners and graduate students in the business/engineering fields of operations research, management science,...
Group Leaders Optimization Algorithm
Daskin, Anmer
2010-01-01
Complexity of global optimization algorithms makes implementation of the algorithms difficult and leads the algorithms to require more computer resources for the optimization process. The ability to explore the whole solution space without increasing the complexity of algorithms has a great importance to not only get reliable results but so also make the implementation of these algorithms more convenient for higher dimensional and complex-real world problems in science and engineering. In this paper, we present a new global optimization algorithm in which the influence of the leaders in social groups is used as an inspiration for the evolutionary technique that is designed into a group architecture similar to the architecture of Cooperative Coevolutionary Algorithms. Therefore, we present the implementation method and the experimental results for the single and multidimensional optimization test problems and a scientific real world problem, the energies and the geometric structures of Lennard-Jones clusters.
Stochastic optimization methods
Marti, Kurt
2005-01-01
Optimization problems arising in practice involve random parameters. For the computation of robust optimal solutions, i.e., optimal solutions being insensitive with respect to random parameter variations, deterministic substitute problems are needed. Based on the distribution of the random data, and using decision theoretical concepts, optimization problems under stochastic uncertainty are converted into deterministic substitute problems. Due to the occurring probabilities and expectations, approximative solution techniques must be applied. Deterministic and stochastic approximation methods and their analytical properties are provided: Taylor expansion, regression and response surface methods, probability inequalities, First Order Reliability Methods, convex approximation/deterministic descent directions/efficient points, stochastic approximation methods, differentiation of probability and mean value functions. Convergence results of the resulting iterative solution procedures are given.
Bolt Thread Stress Optimization
DEFF Research Database (Denmark)
Pedersen, Niels Leergaard
2012-01-01
Designs of threaded fasteners are controlled by different standards, and the number of different thread definitions is large. The most commonly used thread is probably the metric ISO thread, and this design is therefore used in this paper. Thread root design controls the stress concentration factor...... of threads and therefore indirectly the bolt fatigue life. The root shape is circular, and from shape optimization for minimum stress concentration it is well known that the circular shape is seldom optimal. An axisymmetric Finite Element (FE) formulation is used to analyze the bolted connection, and a study...... is performed to establish the need for contact modeling with regard to finding the correct stress concentration factor. Optimization is performed with a simple parameterization with two design variables. Stress reduction of up to 9% is found in the optimization process, and some similarities are found...
Bolt Thread Stress Optimization
DEFF Research Database (Denmark)
Pedersen, Niels Leergaard
2012-01-01
Designs of threaded fasteners are controlled by different standards, and the number of different thread definitions is large. The most commonly used thread is probably the metric ISO thread, and this design is therefore used in this paper. Thread root design controls the stress concentration factor...... of threads and therefore indirectly the bolt fatigue life. The root shape is circular, and from shape optimization for minimum stress concentration it is well known that the circular shape is seldom optimal. An axisymmetric Finite Element (FE) formulation is used to analyze the bolted connection, and a study...... is performed to establish the need for contact modeling with regard to finding the correct stress concentration factor. Optimization is performed with a simple parameterization with two design variables. Stress reduction of up to 9% is found in the optimization process, and some similarities are found...
Sinha, B K; Pal, Manisha; Das, P
2014-01-01
The book dwells mainly on the optimality aspects of mixture designs. As mixture models are a special case of regression models, a general discussion on regression designs has been presented, which includes topics like continuous designs, de la Garza phenomenon, Loewner order domination, Equivalence theorems for different optimality criteria and standard optimality results for single variable polynomial regression and multivariate linear and quadratic regression models. This is followed by a review of the available literature on estimation of parameters in mixture models. Based on recent research findings, the volume also introduces optimal mixture designs for estimation of optimum mixing proportions in different mixture models, which include Scheffé’s quadratic model, Darroch-Waller model, log- contrast model, mixture-amount models, random coefficient models and multi-response model. Robust mixture designs and mixture designs in blocks have been also reviewed. Moreover, some applications of mixture desig...
DEFF Research Database (Denmark)
Pedersen, Niels Leergaard
2013-01-01
The state of stress in bolts and nuts with ISO metric thread design is examined and optimized. The assumed failure mode is fatigue so the applied preload and the load amplitude together with the stress concentrations define the connection strength. Maximum stress in the bolt is found at, the fillet...... under the head, at the thread start or at the thread root. To minimize the stress concentration shape optimization is applied....
Polynomial Datapaths Optimization
Parta, Hojat
2014-01-01
The research presented focuses on optimization of polynomials using algebraic manipulations at the high level and digital arithmetic techniques at the implementation level. Previous methods lacked any algebraic understanding of the polynomials or only exposed limited potential. We have treated the polynomial optimization problem in abstract algebra allowing us algebraic freedom to transform polynomials. Unlike previous attempts where only a set of limited benchmarks have been used, we have fo...
Guided randomness in optimization
Clerc, Maurice
2015-01-01
The performance of an algorithm used depends on the GNA. This book focuses on the comparison of optimizers, it defines a stress-outcome approach which can be derived all the classic criteria (median, average, etc.) and other more sophisticated. Source-codes used for the examples are also presented, this allows a reflection on the ""superfluous chance,"" succinctly explaining why and how the stochastic aspect of optimization could be avoided in some cases.
Optimal Responsible Investment
DEFF Research Database (Denmark)
Jessen, Pernille
The paper studies retail Socially Responsible Investment and portfolio allocation. It extends conventional portfolio theory by allowing for a personal value based investment decision. When preferences for responsibility enter the framework for mean-variance analysis, it yields an optimal...... responsible investment model. An example of index investing illustrates the theory. Results show that it is crucial for the responsible investor to consider portfolio risk, expected return, and responsibility simultaneously in order to obtain an optimal portfolio. The model enables responsible investors...
Optimal exploration target zones
CSIR Research Space (South Africa)
Debba, Pravesh
2008-09-01
Full Text Available Debba, Carranza, Stein, van der Meer Introduction to Remote Sensing Background and Objective of the study Methodology Results Optimal Exploration Target Zones Pravesh Debba1, Emmanual M.J. Carranza2, Alfred Stein2, Freek D. van der Meer2 1... Debba, Carranza, Stein, van der Meer Introduction to Remote Sensing Background and Objective of the study Methodology Results Outline 1 Introduction to Remote Sensing 2 Background and Objective of the study 3 Methodology 4 Results Optimal...
DEFF Research Database (Denmark)
Pedersen, Niels Leergaard
2013-01-01
The state of stress in bolts and nuts with ISO metric thread design is examined and optimized. The assumed failure mode is fatigue so the applied preload and the load amplitude together with the stress concentrations define the connection strength. Maximum stress in the bolt is found at, the fillet...... under the head, at the thread start or at the thread root. To minimize the stress concentration shape optimization is applied....
Coşkun, Filiz; Sayalı, Zeynep Ceyda; Gürbüz, Emine; Balcı, Fuat
2015-01-01
Optimal Time Discrimination Journal: Quarterly Journal of Experimental Psychology Manuscript ID: QJE-STD 14-039.R1 Manuscript Type: Standard Article Date Submitted by the Author: n/a Complete List of Authors: Çoskun, Filiz; Koç University, Psychology Sayalı Ungerer, Zeynep; Koç University, Psychology Gürbüz, Emine; Koç University, Psychology Balcı, Fuat; Koç University, Psychology Keywords: Decision making, Interval Timing, Optimality, Response Times, Temporal ...
Teaching as Regulation and Dealing with Complexity
Boshuizen, H. P. A.
2016-01-01
At an abstract level, teaching a class can be perceived as one big regulation problem. For an optimal result, teachers must continuously (re)align their goals and sub-goals, and need to get timely and valid information on how they are doing in reaching these goals. This discussion describes the specific difficulties due to the time characteristics…
Regularizing portfolio optimization
Still, Susanne; Kondor, Imre
2010-07-01
The optimization of large portfolios displays an inherent instability due to estimation error. This poses a fundamental problem, because solutions that are not stable under sample fluctuations may look optimal for a given sample, but are, in effect, very far from optimal with respect to the average risk. In this paper, we approach the problem from the point of view of statistical learning theory. The occurrence of the instability is intimately related to over-fitting, which can be avoided using known regularization methods. We show how regularized portfolio optimization with the expected shortfall as a risk measure is related to support vector regression. The budget constraint dictates a modification. We present the resulting optimization problem and discuss the solution. The L2 norm of the weight vector is used as a regularizer, which corresponds to a diversification 'pressure'. This means that diversification, besides counteracting downward fluctuations in some assets by upward fluctuations in others, is also crucial because it improves the stability of the solution. The approach we provide here allows for the simultaneous treatment of optimization and diversification in one framework that enables the investor to trade off between the two, depending on the size of the available dataset.
Mees, Alistair; Fisher, Mike; Jennings, Les
2000-01-01
'Optimization Day' (OD) has been a series of annual mini-conferences in Australia since 1994. The purpose of this series of events is to gather researchers in optimization and its related areas from Australia and their collaborators, in order to exchange new developments of optimization theories, methods and their applications. The first four OD mini-conferences were held in The Uni versity of Ballarat (1994), The University of New South Wales (1995), The University of Melbourne (1996) and Royal Melbourne Institute of Technology (1997), respectively. They were all on the eastern coast of Australia. The fifth mini-conference Optimization Days was held at the Centre for Ap plied Dynamics and Optimization (CADO), Department of Mathematics and Statistics, The University of Western Australia, Perth, from 29 to 30 June 1998. This is the first time the OD mini-conference has been held at the west ern coast of Australia. This fifth OD preceded the International Conference on Optimization: Techniques and Applica...
Adaptive Bacterial Foraging Optimization
Directory of Open Access Journals (Sweden)
Hanning Chen
2011-01-01
Full Text Available Bacterial Foraging Optimization (BFO is a recently developed nature-inspired optimization algorithm, which is based on the foraging behavior of E. coli bacteria. Up to now, BFO has been applied successfully to some engineering problems due to its simplicity and ease of implementation. However, BFO possesses a poor convergence behavior over complex optimization problems as compared to other nature-inspired optimization techniques. This paper first analyzes how the run-length unit parameter of BFO controls the exploration of the whole search space and the exploitation of the promising areas. Then it presents a variation on the original BFO, called the adaptive bacterial foraging optimization (ABFO, employing the adaptive foraging strategies to improve the performance of the original BFO. This improvement is achieved by enabling the bacterial foraging algorithm to adjust the run-length unit parameter dynamically during algorithm execution in order to balance the exploration/exploitation tradeoff. The experiments compare the performance of two versions of ABFO with the original BFO, the standard particle swarm optimization (PSO and a real-coded genetic algorithm (GA on four widely-used benchmark functions. The proposed ABFO shows a marked improvement in performance over the original BFO and appears to be comparable with the PSO and GA.
Wecker, Dave; Hastings, Matthew B.; Troyer, Matthias
2016-08-01
We study a variant of the quantum approximate optimization algorithm [E. Farhi, J. Goldstone, and S. Gutmann, arXiv:1411.4028] with a slightly different parametrization and a different objective: rather than looking for a state which approximately solves an optimization problem, our goal is to find a quantum algorithm that, given an instance of the maximum 2-satisfiability problem (MAX-2-SAT), will produce a state with high overlap with the optimal state. Using a machine learning approach, we chose a "training set" of instances and optimized the parameters to produce a large overlap for the training set. We then tested these optimized parameters on a larger instance set. As a training set, we used a subset of the hard instances studied by Crosson, Farhi, C. Y.-Y. Lin, H.-H. Lin, and P. Shor (CFLLS) (arXiv:1401.7320). When tested, on the full set, the parameters that we find produce a significantly larger overlap than the optimized annealing times of CFLLS. Testing on other random instances from 20 to 28 bits continues to show improvement over annealing, with the improvement being most notable on the hardest instances. Further tests on instances of MAX-3-SAT also showed improvement on the hardest instances. This algorithm may be a possible application for near-term quantum computers with limited coherence times.
On Symmetries in Optimal Control
van der Schaft, A. J.
1986-01-01
We discuss the use of symmetries in solving optimal control problems. In particular a procedure for obtaining symmetries is given which can be performed before the actual calculation of the optimal control and optimal Hamiltonian.
Handbook of optimization in telecommunications
Pardalos, Panos M
2008-01-01
Covers the field of optimization in telecommunications, and the optimization developments that are frequently applied to telecommunications. This book aims to provide a reference tool for scientists and engineers in telecommunications who depend upon optimization.
On Symmetries in Optimal Control
Schaft, A.J. van der
1986-01-01
We discuss the use of symmetries in solving optimal control problems. In particular a procedure for obtaining symmetries is given which can be performed before the actual calculation of the optimal control and optimal Hamiltonian.
Optimal control of a CSTR process
Directory of Open Access Journals (Sweden)
A. Soukkou
2008-12-01
Full Text Available Designing an effective criterion and learning algorithm for find the best structure is a major problem in the control design process. In this paper, the fuzzy optimal control methodology is applied to the design of the feedback loops of an Exothermic Continuous Stirred Tank Reactor system. The objective of design process is to find an optimal structure/gains of the Robust and Optimal Takagi Sugeno Fuzzy Controller (ROFLC. The control signal thus obtained will minimize a performance index, which is a function of the tracking/regulating errors, the quantity of the energy of the control signal applied to the system, and the number of fuzzy rules. The genetic learning is proposed for constructing the ROFLC. The chromosome genes are arranged into two parts, the binary-coded part contains the control genes and the real-coded part contains the genes parameters representing the fuzzy knowledge base. The effectiveness of this chromosome formulation enables the fuzzy sets and rules to be optimally reduced. The performances of the ROFLC are compared to these found by the traditional PD controller with Genetic Optimization (PD_GO. Simulations demonstrate that the proposed ROFLC and PD_GO has successfully met the design specifications.
Shale gas development: a smart regulation framework.
Konschnik, Katherine E; Boling, Mark K
2014-01-01
Advances in directional drilling and hydraulic fracturing have sparked a natural gas boom from shale formations in the United States. Regulators face a rapidly changing industry comprised of hundreds of players, operating tens of thousands of wells across 30 states. They are often challenged to respond by budget cuts, a brain drain to industry, regulations designed for conventional gas developments, insufficient information, and deeply polarized debates about hydraulic fracturing and its regulation. As a result, shale gas governance remains a halting patchwork of rules, undermining opportunities to effectively characterize and mitigate development risk. The situation is dynamic, with research and incremental regulatory advances underway. Into this mix, we offer the CO/RE framework--characterization of risk, optimization of mitigation strategies, regulation, and enforcement--to design tailored governance strategies. We then apply CO/RE to three types of shale gas risks, to illustrate its potential utility to regulators.
Optimal component sizing in a two-reservoir passive energy harvesting system
Munsing, E.; Cowell, M.; Moura, S.; Wright, P.
2016-11-01
We utilize particle swarm optimization to reduce the size of the energy management components in an energy harvesting system, allowing us to eliminate the need for voltage regulators or DC-DC converters without affecting system performance. Prior literature on optimal power management in microelectronics [1, 2] has relied on engineering estimates or exhaustive parameter searches to optimize system design. No prior literature has considered the optimal design of a device with only passive components [3]. By using particle swarm optimization, we demonstrate a 55% reduction in device size relative to conventional engineering calculations of an optimal device design.
Optimization of Heat Exchangers
Energy Technology Data Exchange (ETDEWEB)
Ivan Catton
2010-10-01
The objective of this research is to develop tools to design and optimize heat exchangers (HE) and compact heat exchangers (CHE) for intermediate loop heat transport systems found in the very high temperature reator (VHTR) and other Generation IV designs by addressing heat transfer surface augmentation and conjugate modeling. To optimize heat exchanger, a fast running model must be created that will allow for multiple designs to be compared quickly. To model a heat exchanger, volume averaging theory, VAT, is used. VAT allows for the conservation of mass, momentum and energy to be solved for point by point in a 3 dimensional computer model of a heat exchanger. The end product of this project is a computer code that can predict an optimal configuration for a heat exchanger given only a few constraints (input fluids, size, cost, etc.). As VAT computer code can be used to model characteristics )pumping power, temperatures, and cost) of heat exchangers more quickly than traditional CFD or experiment, optimization of every geometric parameter simultaneously can be made. Using design of experiment, DOE and genetric algorithms, GE, to optimize the results of the computer code will improve heat exchanger disign.
Optimization of Metronidazole Emulgel
Directory of Open Access Journals (Sweden)
Monica Rao
2013-01-01
Full Text Available The purpose of the present study was to develop and optimize the emulgel system for MTZ (Metronidazole, a poorly water soluble drug. The pseudoternary phase diagrams were developed for various microemulsion formulations composed of Capmul 908 P, Acconon MC8-2, and propylene glycol. The emulgel was optimized using a three-factor, two-level factorial design, the independent variables selected were Capmul 908 P, and surfactant mixture (Acconon MC8-2 and gelling agent, and the dependent variables (responses were a cumulative amount of drug permeated across the dialysis membrane in 24 h ( and spreadability (. Mathematical equations and response surface plots were used to relate the dependent and independent variables. The regression equations were generated for responses and . The statistical validity of the polynomials was established, and optimized formulation factors were selected. Validation of the optimization study with 3 confirmatory runs indicated a high degree of prognostic ability of response surface methodology. Emulgel system of MTZ was developed and optimized using 23 factorial design and could provide an effective treatment against topical infections.
Optimized Kernel Entropy Components.
Izquierdo-Verdiguier, Emma; Laparra, Valero; Jenssen, Robert; Gomez-Chova, Luis; Camps-Valls, Gustau
2016-02-25
This brief addresses two main issues of the standard kernel entropy component analysis (KECA) algorithm: the optimization of the kernel decomposition and the optimization of the Gaussian kernel parameter. KECA roughly reduces to a sorting of the importance of kernel eigenvectors by entropy instead of variance, as in the kernel principal components analysis. In this brief, we propose an extension of the KECA method, named optimized KECA (OKECA), that directly extracts the optimal features retaining most of the data entropy by means of compacting the information in very few features (often in just one or two). The proposed method produces features which have higher expressive power. In particular, it is based on the independent component analysis framework, and introduces an extra rotation to the eigen decomposition, which is optimized via gradient-ascent search. This maximum entropy preservation suggests that OKECA features are more efficient than KECA features for density estimation. In addition, a critical issue in both the methods is the selection of the kernel parameter, since it critically affects the resulting performance. Here, we analyze the most common kernel length-scale selection criteria. The results of both the methods are illustrated in different synthetic and real problems. Results show that OKECA returns projections with more expressive power than KECA, the most successful rule for estimating the kernel parameter is based on maximum likelihood, and OKECA is more robust to the selection of the length-scale parameter in kernel density estimation.
Moon Landing Trajectory Optimization
Directory of Open Access Journals (Sweden)
Ibrahim Mustafa MEHEDI
2016-03-01
Full Text Available Trajectory optimization is a crucial process during the planning phase of a spacecraft landing mission. Once a trajectory is determined, guidance algorithms are created to guide the vehicle along the given trajectory. Because fuel mass is a major driver of the total vehicle mass, and thus mission cost, the objective of most guidance algorithms is to minimize the required fuel consumption. Most of the existing algorithms are termed as “near-optimal” regarding fuel expenditure. The question arises as to how close to optimal are these guidance algorithms. To answer this question, numerical trajectory optimization techniques are often required. With the emergence of improved processing power and the application of new methods, more direct approaches may be employed to achieve high accuracy without the associated difficulties in computation or pre-existing knowledge of the solution. An example of such an approach is DIDO optimization. This technique is applied in the current research to find these minimum fuel optimal trajectories.
Directory of Open Access Journals (Sweden)
Oren Bar-Gill
2016-03-01
Full Text Available Objective to consider the conception of reverse delegation when the government acts a principal and an individual ndash an agent from the point of view of behavioral PrincipalAgent Theory. Methods statistical method sociological polling. Results In diverse areas ndash from retirement savings to consumer credit to prescription drug use to fuel economy and energy efficiency rules to tobacco consumption to food and beverage consumption ndash government makes decisions for us or endeavors to help us make better decisions thus serving as our agent. From the point of view of PrincipalAgent Theory and behavioral PrincipalAgent Theory a great deal of modern regulation can be helpfully evaluated as a hypothetical delegation. Shifting from personal decisions to public goods problems the authors view the idea of reverse delegation with the government as principal and the individuals as agents. They show that the essence of delegation changes depending on the context. The article describes conditions under which various approaches will make sense. Scientific novelty the paper is devoted to the foreign experience of regulation through delegation by the example of a country with developed market economy the USA. It shows the prospects of such approach in solving both the public and the private tasks. Application of PrincipalAgent Theory and behavioral PrincipalAgent Theory is viewed to distinguish between such types of hypothetical delegation as information default rules incentives precommitments mandates and prohibitions. The article considers the benefits and costs of delegation and circumstances in which one or another approach makes sense. Practical significance PrincipalAgent Theory is widely used in economics and political science and can serve as a convenient tool to consider the optimal scale and essence of the assistance rendered to us by the government as our agent. The paper is of interest for the Russian legal science as the institution of