@conference {
	title = {A Stochastic Algorithm for Self-Organization of Autonomous Swarms},
	author = {Xi, Wei., Tan, Xiaobo., Baras, John S.},
	year = {2005},
	month = {12/2005},
	abstract = {In earlier work of the authors simulation results indicated the possibility of achieving self-organization of autonomous vehicles through Gibbs sampler-based simulated annealing. However, the dynamic graph structure associated with the network evolution presents challenges in convergence analysis. In this paper a novel algorithm is presented and shown to yield desired global configurations with primarily local interactions. Its convergence speed is provided in terms of the Gibbs potential function. The analytical results are further verified through simulation.},
	address = {Seville, Spain},
	booktitle = {44th IEEE Conference on Decision and Control and the European Control Conference (CDC-ECC {\textquoteright}05)},
	pages = {pp. 765-770}
}
@conference {
	title = {Gibbs Sampler-Based Path Planning for Autonomous Vehicles: Convergence analysis},
	author = {Xi, Wei., Tan, Xiaobo., Baras, John S.},
	year = {2005},
	month = {07/2005},
	abstract = {Simulation has indicated that distributed self-organization of autonomous swarms might be achieved through Gibbs sampler-based simulated annealing. However, the dynamic nature of the underlying graph presents significant challenges in convergence analysis. As a first step toward such analysis, convergence of the algorithm is established in this paper for two special cases: single vehicle with limited sensing/moving range, and multiple vehicles with full sensing/moving range. The impact of Gibbs potential functions on the convergence speed is also investigated, which provides insight into the design of these functions.},
	address = {Prague, Czech Republic},
	booktitle = {IFAC 2005}
}
@conference {
	title = {A Hybrid Scheme for Distributed Control of Autonomous Swarms},
	author = {Xi, Wei., Tan, Xiaobo., Baras, John S.},
	year = {2005},
	month = {06/2005},
	abstract = {In this paper, a hybrid scheme for distributed control of autonomous vehicles is presented by combining the deterministic gradient-flow method and the stochastic method based on the Gibbs sampler. The scheme has the advantages of both methods and can potentially provide fast, distributed maneuvers while avoiding getting trapped at local minima of the potential function. Preliminary analysis is performed for the optimal design of the parameters controlling the switching between the two methods. The performance of the hybrid scheme is further enhanced by the introduction of vehicle memory. Simulation results are provided to confirm the analysis and show the effectiveness of the proposed algorithm.},
	address = {Portland USA},
	booktitle = {American Control Conference},
	pages = {pp. 3486-3491}
}
@article {
	title = {Control of Hysteresis in Smart Actuators with Application to Micro-Positioning},
	author = {Tan, Xiaobo., Baras, John S., Krishnaprasad, P S.},
	year = {2005},
	month = {05/2005},
	abstract = {Hysteresis in smart material actuators makes the effective use of these actuators quite challenging. The Preisach operator has been widely used to model smart material hysteresis. Motivated by positioning applications of smart actuators, this paper addresses the value inversion problem for a class of discretized Preisach operators, i.e., to find an optimal input trajectory given a desired output value. This problem is solved through optimal state transition of a finite state machine (FSM) that corresponds to the discretized Preisach operator. A state-space reduction scheme for the FSM is developed, which significantly saves the memory and the computation time. Experimental results on micro-positioning control of a magnetostrictive actuator are presented to demonstrate the effectiveness of the proposed approach.},
	pages = {pp. 483-492},
	volume = {Volume 54},
	number = {Issue 5},
	journal = {Systems \&amp; Control Letters}
}
@conference {
	title = {Numerical Study on Joint Quantization and Control Under Block-Coding},
	author = {Tan, Xiaobo., Xi, Wei., Baras, John S.},
	year = {2004},
	month = {12/2004},
	abstract = {This paper addresses the joint quantization and control problem for hidden Markov chains with variable-length block-coding. The aim is to understand the impact of communication bandwidth and information delay (due to block-coding) on the control performance. A heuristic algorithm is developed to solve the dynamic programming (DP) equation through the introduction of a metric on the discrete observation space. Numerical results are presented demonstrating the attention division in block-coding and the tradeoffs between control performance and communication bandwidth.},
	address = {Atlantis, Paradise Island, Bahamas},
	booktitle = {43rd IEEE Conference on Decision and Control},
	pages = {pp. 4515-4520}
}
@conference {
	title = {Control of Autonomous Swarms Using Gibbs Sampling},
	author = {Baras, John S., Tan, Xiaobo.},
	year = {2004},
	month = {12/2004},
	abstract = {A distributed control approach is proposed for self-organization of autonomous swarms. The swarm is modeled as a Markov random field (MRF) on a graph where the (mobile) nodes and their communication/sensing links constitute the vertices and the edges of the graph, respectively. The movement of nodes is governed by the Gibbs sampler. The Gibbs potentials, local in nature, are designed to reflect collective goals such as gathering, dispersion, and linear formation. The algorithm can be run completely in parallel, and hence it is robust and scalable. Simulation results are provided to illustrate the proposed method.},
	address = {Atlantis, Paradise Island, Bahamas},
	booktitle = {43rd IEEE Conference on Decision and Control},
	pages = {pp. 4752-4757}
}
@conference {
	title = {Vision-Based Microtribological Characterization of Linear Microball Bearings},
	author = {Tan, Xiaobo., Modafe, Alireza., Hergert, R., Ghalichechian, N., Shapiro, B, Baras, John S., Ghodssi, R.},
	year = {2004},
	month = {10/2004},
	abstract = {Microball bearings can potentially provide robust and low friction support in micromachines such as micromotors and microgenerators. Their microtribological behavior needs to be investigated for design and control of such micromachines. In this paper a vision-based, non-intrusive measurement method is presented for characterization of friction in linear microball bearings. Infrared imaging is used to directly observe the dynamics of microballs and track the motion of bearing components. It is verified that microballs roll most of the time with occasional sliding or bumping resulting from fabrication nonuniformity. The friction-velocity curve demonstrates evident hysteresis. The dependence of frictional behavior on several factors is studied.},
	address = {Long Beach, California},
	booktitle = {ASME/STLE International Joint Tribology Conference (IJTC04)},
	pages = {pp. 1-6}
}
@article {
	title = {Modeling and Control of Hysteresis in Magnetostrictive Actuators},
	author = {Tan, Xiaobo., Baras, John S.},
	year = {2004},
	month = {07/2004},
	abstract = {A novel dynamic model is proposed for the hysteresis in magnetostrictive actuators by coupling a Preisach operator to an ordinary differential equation, and a parameter identification method is described. An efficient inversion algorithm for a class of Preisach operators with piecewise uniform density functions is then introduced, based upon which an inverse control scheme for the dynamic hysteresis model is presented. Finally, the inversion error is quantified and l1 control theory is applied to improve the robustness of inverse compensation. Simulation and experimental results based on a Terfenol-D actuator are provided.},
	pages = {pp. 1469-1480},
	volume = {Volume 40},
	number = {Issue 9},
	journal = {Automatica}
}
@article {
	title = {Adaptive Identification and Control of Hysteresis in Smart Materials},
	author = {Tan, Xiaobo., Baras, John S.},
	year = {2004},
	month = {09/2004},
	abstract = {Hysteresis hinders the effective use of smart materials in sensors and actuators. This paper addresses recursive identification and adaptive inverse control of hysteresis in smart material actuators, where hysteresis is modeled by a Preisach operator with a piecewise uniform density function. Two classes of identification schemes are proposed and compared, one based on the hysteresis output, the other based on the time difference of the output. Conditions for parameter convergence are presented in terms of the input to the Preisach operator. An adaptive inverse control scheme is developed by updating the Preisach operator (and thus its inverse) with the output-based identification method. The asymptotic tracking property of this scheme is established, and for periodic reference trajectories, the parameter convergence behavior is characterized. Practical issues in the implementation of the adaptive identification and inverse control methods are also investigated. Simulation and experimental results based on a magnetostrictive actuator are provided to illustrate the proposed approach.},
	pages = {pp. 827-839},
	volume = {Vol.  50},
	number = {No. 6},
	journal = {IEEE Transactions on Automatic Control.}
}
@conference {
	title = {Adaptive Inverse Control of Hysteresis in Smart Materials},
	author = {Tan, Xiaobo., Baras, John S.},
	year = {2004},
	month = {09/2004},
	abstract = {Hysteresis hinders the effective use of smart materials in sensors and actuators. This paper addresses recursive identification and adaptive inverse control of hysteresis in smart material actuators, where hysteresis is modeled by a Preisach operator with a piecewise uniform density function. Two classes of identification schemes are proposed and compared, one based on the hysteresis output, the other based on the time-difference of the output. Conditions for parameter convergence are presented in terms of the input to the Preisach operator. An adaptive inverse control scheme is developed by updating the Preisach operator (and thus its inverse) with the output-based identification method. The asymptotic tracking property of this scheme is established, and for periodic reference trajectories, the parameter convergence behavior is characterized. Practical issues in the implementation of the adaptive identification and inverse control methods are also investigated. Simulation and experimental results based on a magnetostrictive actuator are provided to illustrate the proposed approach.},
	address = {Stuttgart, Germany},
	booktitle = {2004 Nonlinear Control Systems (NOLCOS) IFAC Workshop}
}
@conference {
	title = {Recursive Identification of Hysteresis in Smart Materials},
	author = {Tan, Xiaobo., Baras, John S.},
	year = {2004},
	month = {06/2004},
	abstract = {This paper studies recursive identification of hysteresis in smart materials. A Preisach operator with a piece-wise uniform density function is used to model the hysteresis. Persistent excitation conditions for parameter convergence are discussed in terms of the input to the Preisach operator. Two classes of recursive identification schemes are explored, one based on the hysteresis output, the other based on the time difference of the output. Experimental results based on a magnetostrictive actuator are presented.},
	address = {Boston, MA},
	booktitle = {2004 American Control Conference},
	pages = {pp. 3857-3862}
}
@conference {
	title = {A Parallel Virtual Queue Structure for Active Queue Management},
	author = {Jou,  Jia-Shiang., Tan, Xiaobo., Baras, John S.},
	year = {2004},
	month = {03/2004},
	abstract = {Performance of the Adaptive RED scheme is susceptible to bursty web traffic. A parallel queue structure was proposed earlier to address this problem, where real time connections (such as web and UDP) and non-real time connections (such as FTP) are served in two different queues with droptail and Adaptive RED policies, respectively. In this paper a modified Adaptive RED scheme is proposed for the second queue to improve the goodput of non-real time connections. In this scheme the queue length thresholds for the Adaptive RED are dynamically determined by the average droppping probability. Simulation shows that the packet dropping probability of the Adaptive RED queue stays within a desired small region. The stability of the queue length variation under this policy is proved under mild conditions.},
	address = {Princeton, New Jersey},
	booktitle = {Proceedings of 38th Conference on Information Sciences and Systems - CISS 2004,},
	pages = {pp. 1-6}
}
@conference {
	title = {A Parallel Queue Structure for Active Queue Management},
	author = {Jou,  Jia-Shiang., Tan, Xiaobo., Baras, John S.},
	year = {2004},
	month = {03/2004},
	address = {Princeton, NJ},
	booktitle = {Annual Conference on Information Sciences and Systems}
}
@conference {
	title = {Jointly optimal quantization, estimation, and control of hidden Markov chains},
	author = {Baras, John S., Tan, Xiaobo., Xi, Wei.},
	year = {2003},
	month = {12/2003},
	abstract = {It is of interest to understand the tradeoff between the communication resource consumption and the achievable system performance in networked control systems. In this paper we explore a general framework for tradeoff analysis and decision making in such systems by studying joint quantization, estimation, and control of a hidden Markov chain. Dynamic programming is used to find the optimal quantization and control scheme that minimizes a weighted combination of different cost terms including the communication cost, the delay, the estimation error, and the running cost. Simulation and analysis based on example problems show that this approach is able to capture the tradeoffs among competing objectives by adjusting the cost weights.},
	address = {Maui, Hawaii},
	booktitle = {42nd IEEE Conference on Decision and Control},
	pages = {pp. 1098-1103}
}
@conference {
	title = {Decentralized control of autonomous vehicles},
	author = {Baras, John S., Tan, Xiaobo., Hovareshti, Pedram.},
	year = {2003},
	month = {12/2003},
	abstract = {Decentralized control methods are appealing in coordination of multiple vehicles due to their low demand for long-range communication and their robustness to single-point failures. In this paper we explore a decentralized approach to path generation for a group of vehicles in a battlefield scenario. The mission is to maneuver the vehicles to cover a target area while avoiding obstacles and threats during the maneuver. Each vehicle makes its moving decision by minimizing a potential function that encodes information about its neighbours, obstacles, threats and the target. Preliminary analysis of vehicle behaviors is conducted. Simulation has shown that this approach leads to interesting emergent behaviors, and the behaviors can be varied by adjusting the weighting coefficients of different potential function terms.},
	address = {Maui, Hawaii},
	booktitle = {42nd IEEE Conference on Decision and Control},
	pages = {pp. 1532-1537}
}
@conference {
	title = {A robust control framework for smart actuators},
	author = {Tan, Xiaobo., Baras, John S.},
	year = {2003},
	month = {06/2003},
	abstract = {Hysteresis in smart actuators presents a challenge in control of these actuators. A fundamental idea to cope with hysteresis is inverse compensation. But due to the open loop nature of inverse compensation, its performance is susceptible to model uncertainties and to errors introduced by inverse schemes. In this paper, we develop a robust control framework for smart actuators by combining inverse control with the l/sub 1/ robust control theory, where the inversion error is modeled as an exogenous disturbance with a magnitude bound quantifiable in terms of parameter uncertainties and inversion schemes. Through the example of controlling a magnetostrictive actuator, we present a systematic controller design method which guarantees robust stability and robust trajectory tracking while taking actuator saturation into account. Simulation and experimental results are provided.},
	address = {Denver, Colorado},
	booktitle = {2003 American Control Conference},
	pages = {pp. 4645-4650}
}
@conference {
	title = {A dynamic model for magnetostrictive hysteresis},
	author = {Tan, Xiaobo., Baras, John S., Krishnaprasad, P S.},
	year = {2003},
	month = {06/2003},
	abstract = {The rate-dependent hysteresis present in thin magnetostrictive actuators can be captured by a dynamic model, consisting of a Preisach operator coupled to an ordinary differential equation in an unusual way. The model presents interesting problems in analysis and computation due to its special structure. In this paper, we first transform the model into a more amenable form and gain insight into the model by introducing a new hysteretic operator. Then we investigate some system-theoretic properties of the model: stability of equilibria, input-output stability, reachability~and observability. Existence of periodic solutions under periodic forcing is also established. Finally, numerical integration schemes for the model are discussed.},
	address = {Denver, Colorado},
	booktitle = {2003 American Control Conference},
	pages = {pp. 1074-1079}
}
@conference {
	title = {Modeling and control of a magnetostrictive actuator},
	author = {Tan, Xiaobo., Baras, John S.},
	year = {2002},
	month = {12/2002},
	abstract = {The rate-dependent hysteresis existing in magnetostrictive actuators presents a challenge in control of these actuators. In this paper we propose a novel dynamical model for the hysteresis in a thin magnetostrictive actuator. The model features the coupling of the Preisach operator with an ordinary differential equation (ODE). We prove the well-posedness of the model, study the parameter identification methods, and propose an inverse control scheme. The effectiveness of the identification and inverse control schemes is demonstrated through experimental results.},
	address = {Las Vegas, Nevada},
	booktitle = {41st IEEE Conference on Decision and Control},
	pages = {pp. 866-872}
}
@conference {
	title = {Optimal Control of Hysteresis in Smart Actuators: A Viscosity Solution Approach},
	author = {Tan, Xiaobo., Baras, John S.},
	year = {2002},
	month = {03/2002},
	abstract = {Hysteresis in smart materials hinders their wider applicability in actuators. The low dimensional hysteresis models for these materials are hybrid systems with both controlled switching and autonomous switching. In particular, they belong to the class of Duhem hysteresis models and can be formulated as systems with both continuous and switching controls. In this paper, we study the control methodology for smart actuators through the example of controlling a commercially available magnetostrictive actuator. For illustrative purposes, an infinite horizon optimal control problem is considered. We show that the value function satisfies a Hamilton-Jacobi-Bellman equation (HJB) of a hybrid form in the viscosity sense. We further prove uniqueness of the viscosity solution to the (HJB), and provide a numerical scheme to approximate the solution together with a sub-optimal controller synthesis method. Numerical and experimental results based on this approach are presented.},
	address = {Palo Alto, CA},
	booktitle = {5th International Workshop on Hybrid Systems: Computation and Control, Springer Lecture notes in Computer Science(LNCS)},
	pages = {pp.451-464}
}
@conference {
	title = {Computational Micromagnetics for Magnetostrictive Actuators},
	author = {Tan, Xiaobo., Baras, John S., Krishnaprasad, P S.},
	year = {2000},
	month = {05/2000},
	abstract = {Computational micromagnetics plays an important role in design and control of magnetostrictive actuators. A systematic approach to calculate magnetic dynamics and magnetostriction is presented. A method is developed to solve the coupled Landau-Lifshitz-Gilbert equation for dynamics of magnetization and the 1-D elastic motion equation. A hierarchical algorithm using multipole approximation speeds up the evaluation of the demagnetizing eld, reducing computational cost from O(N2) to O(NlogN). A hybrid 3D-1D scheme is adopted to compute the magnetostriction. Numerical results include domain wall dynamics, hysteresis, magnetostriction, and applications to control of actuators.},
	address = {Philadelphia, Pennsylvania},
	booktitle = {3rd SIAM Conference on Mathematical aspects of Materials Science}
}
@conference {
	title = {Fast Evaluation of Demagetizing Field in Three Dimensional Micromagnetics Using Multipole Approximation},
	author = {Tan, Xiaobo., Baras, John S., Krishnaprasad, P S.},
	year = {2000},
	month = {03/2000},
	abstract = {Computational micromagnetics in three dimensions is of increasing interest with the development of magnetostrictive sensors and actuators. In solving the Landau-Lifshitz-Gilbert (LLG) equation, the governing equation of magnetic dynamics for ferromagnetic materials, we need to evaluate the effective field. The effective field consists of several terms, among which the demagnetizing field is of long-range nature. Evaluating the demagnetizing field directly requires work of O(N2) for a grid of N cells and thus it is the bottleneck in computational micromagnetics. A fast hierarchical algorithm using multipole approximation is developed to evaluate the demagnetizing field. We first construct a mesh hierarchy and divide the grid into boxes of different levels. The lowest level box is the whole grid while the highest level boxes are just cells. The approximate field contribution from the cells contained in a box is characterized by the box attributes, which are obtained via multipole approximation. The algorithm computes field contributions from remote cells using attributes of appropriate boxes containing those cells, and it computes contributions from adjacent cells directly. Numerical results have shown that the algorithm requires work of O(NlogN) and at the same time it achieves high accuracy. It makes micromagnetic simulation in three dimensions feasible},
	address = {Newport Beach, CA},
	booktitle = {7th SPIE International Symposium on Smart Structures and Materials},
	pages = {pp. 195-201}
}
@conference {
	title = {Computational Micromagnetics for Magnetostrictive Actuators},
	author = {Tan, Xiaobo., Baras, John S., Krishnaprasad, P S.},
	year = {2000},
	month = {03/2000},
	abstract = {Computational micromagnetics plays an important role in design and control of magnetostrictive actuators. A systematic approach to calculate magnetic dynamics and magnetostriction is presented. A method is developed to solve the coupled Landau-Lifshitz-Gilbert equation for dynamics of magnetization and the 1-D elastic motionequation.},
	address = {Newport Beach, CA},
	booktitle = {7th SPIE International Symposium on Smart Structures and Materials},
	pages = {pp. 162-173}
}
@article {
	title = {Decentrailzed Coordination of Autonomous Swarms Using Parallel Gibbs Sampling},
	author = {Tan, Xiaobo., Xi, Wei., Baras, John S.},
	year = {2010},
	month = {12/2010},
	abstract = {In this paper, we present analysis of a discrete-time, decentralized, stochastic coordination algorithm for a group of mobile nodes, called an autonomous swarm, on a finite spatial lattice. All nodes take their moves by sampling in parallel their locally perceived Gibbs distributions corresponding to a pairwise, nearest-neighbor potential. The algorithm has no explicit requirements on the connectedness of the underlying information graph, which varies with the swarm configuration. It is established that, with an appropriate annealing schedule, the algorithm results in swarm configurations converging to the (global) minimizers of a modified potential energy function. The extent of discrepancy between the modified and original potential energy functions is determined by the maximum node travel between time steps, and when such distance is small, the ultimate swarm configurations are close to the global minimizers of the original potential energy. Simulation results are further presented to illustrate the capability of the sampling algorithm in approximate global optimization for swarms.},
	pages = {pp. 2068-2076},
	volume = {Volume 46},
	number = {Issue 12},
	journal = {Automatica}
}
@article {
	title = {Gibbs Sampler-Based Self-Organization of Autonomous Swarms},
	author = {Xi, Wei., Tan, Xiaobo., Baras, John S.},
	year = {2006},
	month = {07/2006},
	abstract = {In this paper a novel, Gibbs sampler-based algorithm is proposed for coordination of autonomous swarms. The swarm is modeled as a Markov random field (MRF) on a graph with a time-varying neighborhood system determined by local interaction links. The Gibbs potential is designed to reflect global objectives and constraints. It is established that with primarily local sensing/communications, the swarm configuration converges to the global minimizer(s) of the potential function. The impact of the Gibbs potential on the convergence speed is investigated. Finally, a hybrid algorithm is developed to improve the efficiency of the stochastic scheme by integrating the Gibbs sampler-based method with the deterministic gradient-flow method. Simulation results are presented to illustrate the proposed approach and verify the analyses.},
	pages = {pp.  1107-1119},
	volume = {Vol. 42},
	number = {Issue 7},
	journal = {Automatica}
}
@techreport {
	title = {Decentralized Control of Autonomous Vehicles},
	author = {Tan, Xiaobo., Hovareshti, Pedram.},
	year = {2003},
	month = {01/2003},
	abstract = {Decentralized control methods are appealing in coordination ofmultiple vehicles due to their low demand for long-range communication and their robustness to single-point failures. An important approach in decentralized multi-vehicle control involves artificial potentials or digital pheromones. In this paper we explore a decentralized approach to path generation for a group of combat vehicles in a battlefield scenario. The mission is to maneuver the vehicles to cover a target area. The vehicles are required to maintain good overall area coverage, and avoid obstacles and threats during the maneuvering. The gradient descent method is used, where each vehicle makes its moving decision by minimizing a potential function that encodes information about its neighbours, obstacles, threats and the target. We conduct analysis of vehicle behaviors by studying the vector field induced by the potential function. Simulation has shown that this approach leads to interesting emergent behaviors, and the behaviors can be varied by adjusting the weighting coefficientsof different potential function terms.},
	number = {Number: CSHCN TR 2003-8}
}
@techreport {
	title = {A Parallel Virtual Queue Structure for Active Queue Management},
	author = {Jou,  Jia-Shiang., Tan, Xiaobo.},
	year = {2003},
	month = {01/2003},
	abstract = {The performance of the Adaptive RED scheme is susceptible to bursty web traffic. In this paper a parallel virtual queue structure is proposed for active queue management at the bottleneck router. Real time connections such as web and UDP, and non-real time connections such as FTP are served in two different virtual queues with drop-tail and Adaptive RED policies, respectively. Both queues share the same physical buffer memory. Simulation shows that file delivery for the web traffic is greatly improved due to shorter packet delay and lower packet loss rate, and that the queue length variation for the FTP traffic is small. To improve the goodput of the non-real time connections, a modified Adaptive RED scheme with dynamic queue length thresholds is also proposed. This scheme is able to keep the packet dropping probability within a desired small region. Stability of the queue length under this scheme is studied through analysis and numerical computation.},
	number = {Number: CSHCN TR 2003-18}
}
@techreport {
	title = {Jointly Optimal Quantization, Estimation, and Control of Hidden Markov Chains},
	author = {Tan, Xiaobo., Xi, Wei.},
	year = {2003},
	month = {01/2003},
	abstract = {It is of interest to understand the tradeoff between the communication resource comsumption and the achievable system performance in networked control systems. In this paper we explore a general framework for trade-off analysis and decision making in such systems by studying joint quantization,estimation, and control of a hidden Markov chain. We first formulate the joint quantization and estimation problem, where vector quantization with variable-block length is considered. Dynamic programming (DP) is used to find the optimal quantization scheme that minimizes a weighted combination of the estimation error, the communication cost, and the delay due to block coding. The DP equation issolved numerically and simulation shows that this approach is able to capture the tradeoffs among competing objectives by adjusting the cost weights. We then study the joint quantization and control problem. An example problem is solved analytically, which provides interesting insight into the approach. In both the joint quantization/estimation problem and the joint quantization/control problem, we show that the separation principle holds. The approaches to solving these two problemsshare the same spirit, and can be combined and extended to accomodate more objectives.},
	number = {Number: CSHCN TR 2003-9}
}
