The constraints make a process nonlinear even for a linear system in process control. A robust model predictive control (MPC) algorithm for the linear systems with disturbance by explicitly considering the constraints...
详细信息
ISBN:
(纸本)9781424421138
The constraints make a process nonlinear even for a linear system in process control. A robust model predictive control (MPC) algorithm for the linear systems with disturbance by explicitly considering the constraints is proposed in this paper. By introducing an auxiliary system to the uncertain MPC system, the robust H-2 problem is converted to an LQ problem. Then the constraint can be exploited explicitly. Based on polynomial matrix description of the plant, the robust MPC algorithm is formulated as an optimization problem of a semi-definite programming. The utility of the proposed algorithm is demonstrated through a numerical example.
One classic problem in air traffic management (ATM) has been the problem of detection and resolution of conflicts between aircraft. Traditionally, a conflict between two aircraft is detected whenever the two protectiv...
详细信息
ISBN:
(纸本)9783540891963
One classic problem in air traffic management (ATM) has been the problem of detection and resolution of conflicts between aircraft. Traditionally, a conflict between two aircraft is detected whenever the two protective cylinders surrounding the aircraft intersect. In Trajectory-based Air Traffic Management, a baseline for the next generation of air traffic management system, we suggest that these protective cylinders be deformable volumes induced by variations in weather information such as wind speed and directions subjected to uncertainties of future states of trajectory controls. Using contact constraints oil deforming parametric surfaces of these protective volumes, a constrained minimization algorithm is proposed to compute collision between two deformable bodies, and a differential optimization scheme is proposed to resolve detected conflicts. Given the covariance matrix representing the state of aircraft trajectory and its control and objective functions, we consider the problem of maximizing the variance explained by a particular linear combination of the input variables where the coefficients in this combination are required to be non-negative, and the number of non-zero coefficients is constrained (e.g. state of trajectory and estimated time of arrival over one change point). Using convex relaxation and re-weighted l(1) technique, we reduce the problem to solving some semi-definite programming ones, and reinforce the non-negative principal components that satisfy the sparsity constraints. Numerical results show that the method presented in this paper is efficient and reliable in practice. Since the proposed method can be applied to a wide range of dynamic modeling problems such as collision avoidance in dynamic autonomous robots environments, dynamic interactions with 4D computer animation scenes, financial asset trading, or autonomous intelligent vehicles, we also attempt to keep all descriptions as general as possible.
We consider an ad hoc network consisting of d source-destination pairs and R relaying nodes. Each source wishes to transmit its data to its corresponding destination through the relay network. Each relay in the networ...
详细信息
ISBN:
(纸本)9781424414833
We consider an ad hoc network consisting of d source-destination pairs and R relaying nodes. Each source wishes to transmit its data to its corresponding destination through the relay network. Each relay in the network transmits a properly scaled version of its received signal thereby cooperating with other relays to deliver each source's data to the corresponding destination. Assuming a minimal cooperation among the relaying nodes, we design a distributed beamformer such that the total relay transmit power dissipated by all relays is minimized while, at the same time, the quality of services at all destinations are guaranteed to be above certain pre-defined thresholds. We show that using a semi-definite relaxation approach, the power minimization problem can be turned into a semi-definite programming (SDP) optimization, and therefore, it can be solved efficiently using interior point methods. Our results show that the distributed relay multiplexing is possible and may be beneficial depending on the channel conditions.
In this paper, we develop an improved approach to the worst-case robust adaptive beamforming for general-rank signal models by means of taking into account the positive semi-definite constraint for the mismatched sign...
详细信息
ISBN:
(纸本)9781424414833
In this paper, we develop an improved approach to the worst-case robust adaptive beamforming for general-rank signal models by means of taking into account the positive semi-definite constraint for the mismatched signal covariance matrix. The resulting robust adaptive beamforming problem is solved in an iterative way using semi-definite programming (SDP) at each iteration. Simulation results show that the proposed technique achieves a substantially improved performance as compared to the current robust adaptive beamforming techniques developed for the general-rank signal environments.
This paper considers the linear transceiver optimization problem for multi-carrier multiple-input multiple-output (MIMO) channels with per-antenna power constraints. Because in practical implementations each antenna i...
详细信息
ISBN:
(纸本)9781424429400
This paper considers the linear transceiver optimization problem for multi-carrier multiple-input multiple-output (MIMO) channels with per-antenna power constraints. Because in practical implementations each antenna is limited individually by its equipped power amplifier, this paper adopts the more realistic per-antenna power constraints, in contrast to the conventional sum-power constraint on the transmitter antennas. Assuming perfect channel knowledge both at the transmitter and the receiver, the optimization problem can be transformed into a semi-definite program (SDP), which can be solved by convex optimization tools. Furthermore, several objective functions of the MIMO system,, including average bit error rate, can also be optimized by the introduction of the majorization theory.
Support Vector Machines (SVMs) have been dominant learning techniques for almost ten years, and mostly applied to supervised learning problems. Recently nice results are obtained by two-class unsupervised and semi-sup...
详细信息
ISBN:
(纸本)9780769534978
Support Vector Machines (SVMs) have been dominant learning techniques for almost ten years, and mostly applied to supervised learning problems. Recently nice results are obtained by two-class unsupervised and semi-supervised classification algorithms where the optimization problems based on Bounded C-SVMs, Bounded nu-SVMs and Lagrangian SVMs respectively are relaxed to semi-definite programming (SDP). These support vector methods implicitly assume, that training data in the optimization problems are known exactly. But in practice, the training data are usually subjected to measurement noise. Zhao et al proposed robust version to unsupervised and semi-supervised classification problems based on Bounded C-SVMs, which need to find the dual problem twice. In this paper we propose unsupervised classification algorithm based on primal problem of standard SVMs with perturbations, which directly relaxes it with label variables to a semi-definite programming;Numerical results confirm the robustness of the proposed method.
We use semidefiniteprogramming to prove that any constraint satisfaction problem in two variables over any domain allows an efficient approximation algorithm that does better than picking a random assignment. Specifi...
详细信息
We use semidefiniteprogramming to prove that any constraint satisfaction problem in two variables over any domain allows an efficient approximation algorithm that does better than picking a random assignment. Specifically we consider the case when each variable can take values in [d] and that each constraint rejects t out of the d(2) possible input pairs. Then, for some universal constant c, we can, in probabilistic polynomial time, find an assignment whose objective value is, in expectation, within a factor 1 - t/d(2) + ct/d(4) log d of optimal, improving on the trivial bound of 1 - t/d(2).
We analyze a class of quantum operations based on a geometrical representation of d-level quantum system (or qudit for short). A sufficient and necessary condition of complete positivity, expressed in terms of the qua...
详细信息
We analyze a class of quantum operations based on a geometrical representation of d-level quantum system (or qudit for short). A sufficient and necessary condition of complete positivity, expressed in terms of the quantum Fourier transform, is found for this class of operations. A more general class of operations on qudits is also considered and its completely positive condition is reduced to the well-known seriti-definiteprogramming problem. (C) 2004 Elsevier B.V. All rights reserved.
semi-definite programs are convex optimization problems arising in a wide variety of applications and the extension of linear programming. Most methods for linear programming have been generalized to semi-definite pro...
详细信息
semi-definite programs are convex optimization problems arising in a wide variety of applications and the extension of linear programming. Most methods for linear programming have been generalized to semi-definite programs. This paper discusses the discretization method in semi-definite programming. The convergence and the convergent rate of error between the optimal value of the semi-definite programming problems and the optimal value of the discretized problems are obtained. An approximately optimal division is given under certain assumptions. With the significance of the convergence property, the duality result in semi-definite programs is proved in a simple way which is different from the other common proofs. (C) 2004 Elsevier Ltd. All rights reserved.
Using the convex semidefiniteprogramming method and superoperator formalism we obtain the finite quantum tomography of some mixed quantum states such as: truncated coherent states tomography, phase tomography and coh...
详细信息
Using the convex semidefiniteprogramming method and superoperator formalism we obtain the finite quantum tomography of some mixed quantum states such as: truncated coherent states tomography, phase tomography and coherent spin state tomography, qudit tomography, N-qubit tomography, where that obtained results are in agreement with those of References (Buzek et al., Chaos, Solitons and Fractals 10 (1999) 981;Schack and Caves, Separable states of N quantum bits. In: Proceedings of the X. International Symposium on Theoretical Electrical Engineering, 73. W. Mathis and T. Schindler, eds. Otto-von-Guericke University of Magdeburg, Germany (1999);Pegg and Barnett Physical Review A 39 (1989) 1665;Barnett and Pegg Journal of Modern Optics 36 (1989) 7;St. Weigert Acta Physica Slov. 4 (1999) 613).
暂无评论