@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 = {Modeling and Simulation of Telecommunication Networks for Control and Management},
	author = {Baras, John S.},
	year = {2003},
	month = {12/2003},
	abstract = {In this paper, we describe methodologies for telecommunication networks modeling and simulation that are targeted to be useful as tools in on-line and off-line decision making of the type encountered in network control, management and planning problems. We describe the development, validation and use of self-similar and multifractal models, queuing control and performance evaluation, assessing the incremental utility of various models, hierarchical models based on aggregation, analytic approximation models for various performance metrics, trade-off and sensitivity analysis using a multi-objective optimization framework and automatic differentiation. We also describe four illustrative examples of applying these methodologies to dynamic network control and management problems. The examples involve primarily mobile ad hoc wireless and satellite networks in changing environments.},
	address = {New Orleans, Louisiana},
	booktitle = {35th Winter Simulation Conference: Driving Innovation},
	pages = {pp. 431-440}
}
@conference {
	title = {A Feedback Implosion Suppression Algorithm for Satellite Reliable Multicast},
	author = {Akkor, Gun., Baras, John S., Hadjitheodosiou, Michael.},
	year = {2003},
	month = {12/2003},
	abstract = {In this paper, we propose a knapsack-based feedback suppression algorithm for reliable multicast transport protocols operating over a satellite network. A reliable transport protocol needs to identify the packets which failed to reach a given destination. This is achieved through feedback packets returned to the source. For multicast services, receive feedback has been shown to lead to the feedback implosion problem. Feedback implosion is a well-studied problem and various solutions exist in the literature. However, these solutions mainly focus on wireline terrestrial networks and do not take into account the inherent characteristics of the satellite channel and the architecture of the deployed network. Therefore, we need to revisit the problem and provide a new set of solutions for efficient integration to next-generation satellite systems. In this paper, we introduce a feedback implosion suppression algorithm, which effectively suppresses the amount of feedback relayed through the satellite channel, while ensuring that the critical information is conveyed in a timely fashion. The performance of the algorithm is evaluated through simulations.},
	address = {San Francisco, California},
	booktitle = {IEEE Globecom 2003},
	pages = {pp. 3765-3769}
}
@conference {
	title = {Modeling vulnerabilities of ad hoc routing protocols},
	author = {Yang, Shahan., Baras, John S.},
	year = {2003},
	month = {12/2003},
	abstract = {The purpose of this work is to automate the analysis of ad hoc routing protocols in the presence of attackers. To this end, a formal model fo protocol behavior is developed in which time is modeled by a set of constraints on the time of occurrence of events, enabling the representation of partially ordered timed events and asynchronous communication. Data variables are represented symbolically, capturing a range of distinct executions in each expression. Given a formal description of Ad Hoc On-Demand Distance Vector Routing Algorithm (AODV) and the desired safety property (route stability), an analysis by a naive semi-decision procedure discovers an instance of an attack that leads to a violation of the property.},
	address = {Fairfax, Virginia},
	booktitle = {1st ACM workshop on Security of ad hoc and sensor networks},
	pages = {pp. 12-20.},
	organization = {George Mason University}
}
@conference {
	title = {Probability of Imminent Failure as a Routing Metric in a High-Mobility Wireless Ad Hoc Network},
	author = {Alzate, Marco A., Baras, John S.},
	year = {2003},
	month = {10/2003},
	abstract = {The current duration of a link in a mobile wireless ad hoc network (MANET) has important information to offer with respect to its stability. Unlike location or signal strength methods, life measurements implicitly include the effects of true propagation mechanisms, mobility space geometry, power control mechanisms and other phenomena that are ignored or simplistically modeled in the methods mentioned above. Consequently, the information contained in the current duration of the links can be used to enhance the accuracy of these methods. Furthermore, under high mobility conditions and in the absence of any resources for location and signal strength measurements, this information can also be used alone to obtain new routing metrics to enhance the performance of routing algorithms in a MANET. One such metric is the probability of imminent failure, which can also be used to predict route failures with relatively high accuracy. Here we modify DSR to use this metric, improving the efficiency by reducing the routing overhead.},
	address = {Seoul, Korea},
	booktitle = {8th International Conference on Intelligent Communications (CIC 2003)}
}
@conference {
	title = {Dynamic Adaptation of Access Control Policies},
	author = {Bharadwaj, Vijay G., Baras, John S.},
	year = {2003},
	month = {10/2003},
	abstract = {We describe an architecture and algorithms for deriving an access control policy by composing access control requirements specified at multiple levels in a command hierarchy. Our method can detect conflicts in requirements, and find a policy that maximally satisfies the requirements, by satisfying higher priority requirements at the expense of lower priority ones. It also allows for easy verification of the final policy by an administrator. The architecture allows quick adaptation of policies to changing situations, by providing for delegation of authority while ensuring that high priority requirements will always be satisfied.},
	address = {Boston, Massachusetts},
	booktitle = {MILCOM 2003},
	pages = {pp. 761-766}
}
@conference {
	title = {Clustering for transmission range control and connectivity assurance for self configured ad hoc networks},
	author = {Manousakis, Kyriakos., Baras, John S.},
	year = {2003},
	month = {10/2003},
	abstract = {Ad hoc networks have been the new networking technology trend because of their promising characteristics. These characteristics fit better the requirements of today{\textquoteright}s army and the needs of today{\textquoteright}s commercial world. Most of the applications that have been referred in the bibliography assume devices that are of finite power. The latter is true because of the existing technology (web-enabled cell phones, PDAs, laptops, PPCs). The goal for ad hoc networks is to accommodate lightweight, battery-powered portable devices. Because of the finite power limitation, we have to design efficient ways to use the existing power. A first step towards efficient utilization of power is to eliminate its unnecessary usage wherever possible. For a networking device, significant part of power is consumed for communications and more specifically for transmissions. In this work we focus on eliminating the transmission power consumed into the network subject to the network{\textquoteright}s connectivity. The assurance of network connectivity is essential in this problem since the usage of limited transmission power from the nodes may result in a partitioned network. We provide solutions to the efficient usage of transmission power by clustering the nodes based on their proximity and ensuring the intracluster and intercluster connectivity of the network. The algorithms presented in this paper achieve their objective as the collected results from their simulation show.},
	address = {Boston, MA},
	booktitle = {Military Communications Conference, MILCOM 2003},
	pages = {pp. 1043-1047}
}
@conference {
	title = {Key Distribution Protocols for Secure Multicast Communication Survivable in MANETs},
	author = {Striki, Maria., Baras, John S.},
	year = {2003},
	month = {10/2003},
	abstract = {In this paper, we develop a secure, robust and scalable key management scheme for multicast communications in Mobile Ad Hoc Networks (MANETs). Most key distribution protocols of today are primarily designed for wire-line networks. Frequent node failures, network partitions, inefficient computational and communication capabilities of wireless nodes, network delay, bad quality of signal etc, are some of the reasons why they fail to work properly in MANETs. We classify existing and newly developed protocols in two families, contributory and non-contributory. We evaluate them and compare their performance. We focus on studying and developing key distribution techniques that achieve scalability and high performance within our framework without sacrificing the security level of the network. We also describe a hierarchical two-level hybrid key management scheme that utilizes some of the above protocols in the appropriate combinations to further reduce the storage, communication and computation costs of nodes.},
	address = {Boston, Massachusetts},
	booktitle = {MILCOM 2003},
	pages = {pp. 1-6}
}
@conference {
	title = {Data Dependent Keying for Wireless Networks},
	author = {Karir, Manish., Baras, John S.},
	year = {2003},
	month = {10/2003},
	abstract = {The failure of the 802.11 WEP security specifications to provide any reasonable level of security has come under sharp criticism recently. In this paper we propose a novel scheme for providing security in both a base station based, as well as an ad hoc network environment. Our proposed scheme uses data exchanged between communicating peers to evolve per-packet keys. In addition to the concept of data dependent keying (DDK), we include other well-known security primitives such as SHA-1 based HMAC and RC4 encryption to provide a complete security solution for wireless networks. We argue that our scheme provides an adequate security/overhead tradeoff, and can be easily implemented on current hardware platforms. In addition, the low overhead characteristic as well as the use of symmetric cryptographic functions makes the scheme an attractive option for sensor networks, where energy efficiency is a primary objective.},
	address = {Orlando, Florida},
	booktitle = {58th Vehicular Technology Conference},
	pages = {pp. 2098-2102}
}
@conference {
	title = {Near-optimal Policies for Broadcasting Files with Unequal Sizes},
	author = {Raissi-Dekhordi, Majid., Baras, John S.},
	year = {2003},
	month = {10/2003},
	abstract = {Information broadcasting is an effective method to deliver popular information pages to a large number of users in wireless and satellite networks. In a previous work, we used a dynamic optimization approach to address the problem of broadcast scheduling for a pull system with equal file sizes. In this paper, we address that problem in a more general setting where the file sizes are not equal and have geometric size distributions with possibly different means. The dynamic optimization approach allows us to find a near-optimal scheduling policy, which we use as a benchmark to evaluate a number of other heuristic policies. Also, we modify the resulting policy and apply it to the case with fixed (unequal) file sizes and compare the results with some other well known, as well as new, heuristic policies. Finally, we introduce a low-complexity heuristic policy to be used for practical implementations. The results show that the performance of the new policy is very close to that of the original policy.},
	address = {Monticello, Illinois},
	booktitle = {41st Annual Allerton 2003 Conference},
	pages = {pp. 279-288}
}
@conference {
	title = {Multi-Agent Stochastic Control: Models Inspired from Quantum Physics},
	author = {Baras, John S.},
	year = {2003},
	month = {08/2003},
	abstract = {In this paper, we consider multi-agent stochastic optimization and control problems, with partial information. The agent can operate in a distributed and asynchronous fashion. We investigate new problems that arise out of the interaction between observations and control actions by the agent. We show that new non-classical and non-commutative probability models are needed in order to properly formulate such problems. The models we develop here are inspired by models developed for dynamical physics problems. We establish a series of fundamental results for the trade-off between information and control patterns in distributed stochastic control, detection and estimation.},
	address = {Saint Petersburg, Russia},
	booktitle = {2003 International Conference on Physics and Control},
	pages = {pp. 747-758}
}
@conference {
	title = {Correctness Proof for a Dynamic Adaptive Routing Algorithm for Mobile Ad-hoc Networks},
	author = {Yang, Shahan., Baras, John S.},
	year = {2003},
	month = {07/2003},
	abstract = {Dynamic and adaptive routing algorithms are the {\textquotedblleft}brains{\textquotedblright} of mobile ad-hoc networks (MANETs), in that they govern the self-organization of these networks. MANETs are infrastructureless {\textquotedblleft}intelligent{\textquotedblright} networks, which are becoming increasingly popular and have wide applicability. In this paper, we view dynamic adaptive routing algorithms for MANETs as hybrid systems (partly based on logic and partly based on numerics). In this paper, we introduce formal models for the analysis and verification of one such routing algorithm, the Temporally Oriented Routing Algorithm (TORA) under certain assumptions. More specifically we give a rigorous mathematical proof of correctness and convergence of TORA. Other formal methods, their limitations~and future research challenges are also discussed.},
	address = {Lake Baikal, Russia},
	booktitle = {IFAC Workshop \&ndash; Modeling and Analysis of Logic Controlled Dynamic Systems},
	pages = {pp. 1-10}
}
@conference {
	title = {An Implementation Study of Multicast Extensions of AODV},
	author = {Dharmaraju, Dinesh., Karir, Manish., Baras, John S., Das, Subir.},
	year = {2003},
	month = {07/2003},
	abstract = {In this paper we describe our experience of implementing multicast extensions of AODV (MAODV). Using insight gained from our implementation we propose some enhancements to MAODV that enhance its stability and its performance. We propose the use of a tree optimization scheme based on Group Hello messages, a scheme for merging group partitions, as well as a method to add reliability to the multicast tree formation and maintenance, via the use of an acknowledgement for MACT messages. Our implementation is based on the kernel AODV implementation from NIST. We describe details regarding our implementation that can provide valuable insight to future implementers of ad hoc routing protocols, and in particular, people attempting to implement multicast routing protocols. We also provide a brief description of some basic validation experiments that we used to verify the functionality and the various features of our implementation.},
	address = {Montreal, Canada},
	booktitle = {SPECTS 2003 Conference}
}
@conference {
	title = {Performance evaluation of run-to-run control methods in semiconductor processes},
	author = {Zhang, Chang., Deng, Hao., Baras, John S.},
	year = {2003},
	month = {06/2003},
	abstract = {Run-to-run (RtR) control plays an important role in semiconductor manufacturing processes. In this paper, RtR control methods are classified and evaluated. The set-valued RtR controllers with ellipsoid approximation are compared with two typical RtR controllers: the exponentially weighted moving average (EWMA) controller and the optimizing adaptive quality controller (OAQC) by simulations according to the following criteria: a good RtR controller should be able to compensate for various disturbances, such as small drifts, step disturbances and model errors; moreover, it should be able to deal with bounds, cost requirement and multiple targets that are often encountered in semiconductor processes. Based on our simulation results, suggestions on selection of a proper RtR controller for a semiconductor process are given as conclusions.},
	address = {Istanbul, Turkey},
	booktitle = {2003 IEEE Conference on Control Applications},
	pages = {pp. 841-848}
}
@conference {
	title = {Jitter analysis of CBR streams in multimedia networks},
	author = {Jou,  Jia-Shiang., Baras, John S.},
	year = {2003},
	month = {06/2003},
	abstract = {The performance of real-time applications such as video and voice streams relies on packet delay jitter. Large delay jitter causes buffer overflow or underflow at the receiver end and the user encounters interrupt. The delay jitter is mainly due to the perturbation of background traffic in the bottleneck router. Fulton and Li (1998) provide an analytical approximation for the first-order and second-order statistics of delay jitter. However, their analysis is based on a Markovian model of the background traffic, which is not quite suitable for Internet traffic and requires lots of computational effort. We propose an efficient method to predict the jitter variance of a CBR (constant-bit-rate) connection based on the wavelet model of the background traffic. The wavelet analysis extracts the statistical properties of background traffic and the analysis result can be used to predict an upper bound for the jitter variance of the CBR connection.},
	address = {Istanbul, Turkey},
	booktitle = {2003 IEEE Conference on Control Applications},
	pages = {pp. 1339-1344}
}
@conference {
	title = {A New Adaptive Aggregation Algorithm for Infinite Horizon Dynamic Programming},
	author = {Zhang, Chang., Baras, John S.},
	year = {2003},
	month = {06/2003},
	abstract = {Dynamic programming suffers the {\textquotedblleft}curse of dimensionality{\textquotedblright} when it is employed for complex control systems. State aggregation is used to solve the problem and accelerate computation by looking for a sub-optimal policy. In this paper, a new method, which converges much faster than conventional aggregated value iteration based on TD(0), is proposed for computing the value functions of the aggregated system. Preliminary results show that the new method increases the speed of convergence impressively. Aggregation introduces errors inevitably. An adaptive aggregation scheme employing the new computation method is also proposed to reduce the aggregation errors.},
	address = {Rhodes, Greece},
	booktitle = {11th Mediterranean Conference on Control and Automation (MED\&rsquo;03)},
	pages = {pp. 1-6}
}
@conference {
	title = {Markov Processes with State-Dependent Failure Rates and Application to RED and TCP Window Dynamics},
	author = {Misra, Archan., Ott, Teunis., Baras, John S.},
	year = {2003},
	month = {06/2003},
	abstract = {This paper presents a mathematical technique for computing the stationary distribution of Markov processes that evolve deterministically between arbitrarily distributed {\textquoteleft}failure events{\textquoteright}. The key innovation in this paper is the use of a state-dependent time rescaling technique, such that the re-scaled process can be described by a Poisson-interrupted stochastic differential equation. This technique is first applied to compute the stationary window distribution of a TCP flow performing idealized classical congestion avoidance under variable, but state-dependent, packet loss, and subsequently, to study the distribution of a TCP flow performing generalized congestion avoidance. We show how the stochastic differential equation can be solved by a rapidly convergent numerical technique to obtain the stationary distribution in the re-scaled (subjective) time, and present the re-scalings needed to eventually obtain the distribution of the original Markov process. We demonstrate how this analysis can be used to compute the window distribution of a TCP flow interacting with a RED, ERD or ECN queue, with or without minimally assured throughput guarantees.},
	address = {Rhodes, Greece},
	booktitle = {11th Mediterranean Conference on Control and Automation (MED\&rsquo;03)}
}
@conference {
	title = {Towards automated negotiation of access control policies},
	author = {Baras, John S., Bharadwaj, Vijay G.},
	year = {2003},
	month = {06/2003},
	abstract = {We examine the problem of negotiating access control policies between autonomous domains. Our objective is to develop software agents that can automatically negotiate access control policies between autonomous domains with minimal human guidance. In this paper, we show a mathematical framework that is capable of expressing many such negotiation problems~and illustrate its application to some practical scenarios.},
	address = {Lake Como, Italy},
	booktitle = {4th International Workshop on Policies for Distributed Systems and Networks},
	pages = {pp. 111-119}
}
@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 = {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 = {Routing and Security Problems in Networking: A Systems and Control Perspective},
	author = {Baras, John S.},
	year = {2003},
	month = {05/2003},
	address = {Seattle, WA},
	organization = {University of Washington}
}
@conference {
	title = {Engineering and Information Technology},
	author = {Baras, John S.},
	year = {2003},
	month = {05/2003},
	address = {College Park, MD},
	booktitle = {Charles and Helen White Symposium},
	organization = {University of Maryland}
}
@conference {
	title = {Dynamic Adaptive Routing in MANETs},
	author = {Baras, John S., Mehta, Harsh.},
	year = {2003},
	month = {04/2003},
	abstract = {Mobile ad hoc networks are infrastructure-less networks consisting of wireless, possibly mobile nodes that are organized in peer-to-peer and autonomous fashion. The highly dynamic topology, limited bandwidth availability and energy constraints make the routing problem a challenging one. The Swarm Intelligence paradigm has recently been used in solving the routing problem in static computer networks with encouraging results. These algorithms have been proven to be robust and resilient to topology changes. In this paper, we present performance results on a new routing algorithm for MANETs based on the swarm intelligence paradigm. We present simulation results that measure the performance of our algorithm with respect to the characteristics of a MANET, the varying parameters of the algorithm itself as well as performance comparison with other well-known MANET routing protocols.},
	address = {College Park, Maryland},
	booktitle = {Collaborative Technology Alliances (CTA) Communications \&amp; Networks (C\&amp;N) Alliance- 2003 Annual Symposium},
	pages = {pp. 367-371},
	organization = {University of Maryland Conference Center}
}
@conference {
	title = {Performance Evaluation and Traffic Analysis for Routing Protocols in a Real MANET},
	author = {Chen, Huigang., Jou,  Jia-Shiang., Dharmaraju, Dinesh., Papageorgiou, George., Baras, John S.},
	year = {2003},
	month = {04/2003},
	abstract = {Mobile Ad-hoc NETworks (MANETs) are characterized by bandwidth constrained links, multiple hops, varying link qualities and highly dynamic topologies. In this paper, we evaluate the performance and analyze the traffic of a mobile ad-hoc network in a realistic setting. Using simulation, we provide results of performance evaluation in terms of various metrics. We study performance with scenarios of different propagation matrices, different traffic mixes, and different routing protocols (DSDV, DSR, AODV). The results show that in most cases, the performance is sensitive to the routing protocol, path loss, and traffic characteristics. This provides rationale and insight for choosing the right protocols to provide quality of service in terms of different metrics in different environments. Also, we find that in a MANET, we obtain long-range dependency traffic regardless of source file size distribution. This discovery will help in providing methodology to tackle the network dimensioning problem in ad hoc networks.},
	address = {College Park, Maryland},
	booktitle = {Collaborative Technology Alliances (CTA) Communications \&amp; Networks (C\&amp;N) Alliance - 2003 Annual Symposium},
	pages = {pp.147-151},
	organization = {University of Maryland Conference Center}
}
@conference {
	title = {Dynamic Clustering for Transmission Range Control in Ad Hoc Networks},
	author = {Manousakis, Kyriakos., Baras, John S.},
	year = {2003},
	month = {04/2003},
	abstract = {Ad hoc networks have being given a lot of attention in recent years. The problems associated with this kind of networks are many and difficult to solve because of their dynamic nature {\textendash} networks with non-static topology and non-static infrastructure. A large number of the issues under investigation are related with the finite power of the mobile devices. In terms of the communication tasks that those devices perform, the transmission power that is utilized plays a very important role to the long-term survivability of the network. The issue of transmission power affects the connectivity of the network, in a way that when the utilized transmission power is small then the network may be partitioned. In this work the latter has equivalent importance with the case where the assignment of excessive transmission power, resulting in a very dense net of communication links. When we use large transmission power then the long-term survivability and connectivity of the network is jeopardized because the nodes use their finite power inefficiently. Our task is to adjust the transmission power to the level where both the connectivity of the network is ensured and the transmitted power is minimized among all participating devices.},
	address = {College Park, Maryland},
	booktitle = {Collaborative Technology Alliances (CTA) Communications \&amp; Networks (C\&amp;N) Alliance - 2003 Annual Symposium},
	organization = {University of Maryland Conference Center}
}
@conference {
	title = {Distributed Trust Establishment in MANETs{\textquoteright} Swarm Intelligence},
	author = {Eschenauer, Laurent., Baras, John S., Gligor, Virgil D.},
	year = {2003},
	month = {04/2003},
	abstract = {We present some properties of trust establishment in mobile, ad-hoc networks and illustrate how they differ from those of trust establishment in the Internet. We present a framework for trust establishment in mobile ad-hoc networks and argue that peer-to-peer networks are especially suitable to solve the problems of generation, distribution, and discovery of trust evidence in mobile ad-hoc networks. We develop a new scheme based on swarm intelligence and demonstrate its advantages over the peer to peer scheme. We evaluate our approach through simulation with NS-2.},
	address = {College Park, Maryland},
	booktitle = {Collaborative Technology Alliances (CTA) Communications \&amp; Networks (C\&amp;N) Alliance - 2003 Annual Symposium},
	pages = {pp. 125-129},
	organization = {University of Maryland Conference Center}
}
@conference {
	title = {Efficient Source Authentication for Multicasting in MANETs},
	author = {Baras, John S., Ramachandran, Prabha.},
	year = {2003},
	month = {04/2003},
	abstract = {In this paper, we investigate a popular source authentication scheme, TESLA (Timed Efficient Stream Loss-tolerant Authentication) for multicast communication in mobile ad hoc networks. We evaluate the performance of a source authentication scheme inspired from TESLA and mu-TESLA based on simulations. Time synchronization is a crucial assumption made by these schemes. We describe effective means to achieve time synchronization in MANETs and conclude that overlay networks, whether they are UAVs or satellites are essential for high efficiency and performance. Since such overlay networks are typical in hierarchical wireless mobile networks, the proposed schemes are very appropriate for these scenarios. We claim that having an overlay network will help in routing and key distribution, in addition to time synchronization.},
	address = {College Park, Maryland},
	booktitle = {Collaborative Technology Alliances (CTA) Communications \&amp; Networks (C\&amp;N) Alliance - 2003Annual Symposium},
	organization = {University of Maryland Conference Center}
}
@conference {
	title = {Efficient Scalable Key Agreement Protocols for Secure Multicast Communication in MANETs},
	author = {Striki, Maria., Baras, John S.},
	year = {2003},
	month = {04/2003},
	abstract = {In this paper protocols for group key distribution are compared and evaluated from the point of view of Mobile Ad Hoc Networks (MANETs). A MANET is a collection of wireless mobile nodes, communicating among themselves over possibly multihop paths, without the help of any infrastructure such as base stations or access points. So the need to render those networks as autonomous and secure as possible, since no central authorization can be assumed at all times, becomes emergent. Key management is the service that ensures the security of communication among nodes, and the capability of their cooperation as a secure group. It consists of three important services: key generation, user authentication and key distribution. In this work we assume that the participating users have already been authenticated with some mechanism, and we are focused only on studying and comparing protocols for group key establishment in MANETs. We distinguish the protocols in two families, the contributory and noncontributory and we evaluate them from the point of view of MANETs.},
	address = {College Park, Maryland},
	booktitle = {Collaborative Technology Alliances (CTA) Communications \&amp; Networks (C\&amp;N) Alliance - 2003 Annual Symposium},
	organization = {University of Maryland Conference Center}
}
@conference {
	title = {A framework for automated negotiation of access control policies},
	author = {Bharadwaj, Vijay G., Baras, John S.},
	year = {2003},
	month = {04/2003},
	abstract = {Our research examines the problem of negotiating access control policies between autonomous domains. Our objective is to develop software agents that can automatically negotiate access control policies between autonomous domains with minimal human guidance. In this paper we describe a mathematical framework that is capable of expressing many such negotiation problems, and illustrate its application to some practical scenarios.},
	address = {Washington DC},
	booktitle = {DARPA Information Survivability Conference and Exposition}
}
@conference {
	title = {Integrated security services for dynamic coalitions},
	author = {Khurana, Himanshu., Serban Gavrila, Bobba, Rakeshbabu., Koleva, Radostina. , Sonalker, Anuja., Dinu, Emilian., Gligor, Virgil D., Baras, John S.},
	year = {2003},
	month = {04/2003},
	abstract = {Coalitions are collaborative networks of autonomous domains where resource sharing is achieved by the distribution of access permissions to coalition members based on negotiated resource-sharing agreements. The focus of our research is on dynamic coalitions, namely, coalitions where member domains may leave or new domains may join during the life of the coalition. We have developed a set of tools that integrate security services for dynamic coalitions, namely, services for (1) private and shared resource management, (2) identity and attribute certificate management, (3) secure group communication, and (4) joint administration for enforcing joint-action policies on shared critical resources. In this paper we give an overview of the architecture and implementation of our tools.},
	address = {Washington DC},
	booktitle = {2003 DARPA Information Survivability Conference and Exposition},
	pages = {pp. 38-40}
}
@conference {
	title = {Using Broadband Satellite Systems to Support Aeronautical Communication},
	author = {Shang, Yadong., Hadjitheodosiou, Michael., Baras, John S.},
	year = {2003},
	month = {04/2003},
	abstract = {In this paper we discuss the possibility of using a broadband satellite-based system to support aeronautical communications. First, we investigate the applications and service requirements for current and future aeronautical communications. Then the communication system and network architecture are outlined and some of the system components are discussed in detail, including the satellite transmission channel, the airplane on-board network, and various aspects of aeronautical terminals. Finally we present a simulation analysis of the system with the focus on meeting the Quality of Service requirements for identified service categories.},
	address = {Yokohama, Japan},
	booktitle = {23rd AIAA International Communications Satellite Systems Conference and Exhibit (ICSSC)},
	pages = {pp. 1-9}
}
@conference {
	title = {Statistical modeling and performance analysis of multi-scale traffic},
	author = {Liu, Nelson X., Baras, John S.},
	year = {2003},
	month = {03/2003},
	abstract = {In this paper we propose a new statistical model for multi-scale traffic, and present an exact queueing analysis for the model. The model is based on the central moments and the marginal distributions of the cumulative traffic loads in different time scales. Only the first two moments are needed to characterize the traffic process, which greatly simplifies the representation and estimation. The queueing analysis uses a very general approach and can evaluate not only the steady state performance but also the transient queuing behavior. The analysis reveals that there exist two classes of packet losses, the absolute loss and the opportunistic loss, both of which can be examined exactly with the method. Based on the statistical model and the queueing analysis method, a compound model is constructed for the practical multiscale traffic, and its performance is evaluated from various aspects. This work provides a good basis for practical application of the multiscale traffic characterizations in network dimensioning and resource management.},
	address = {San Francisco, CA},
	booktitle = {22nd Annual Joint Conference of the IEEE Computer and Communications Societies, INFOCOM 2003},
	pages = {pp. 1837-1847}
}
@conference {
	title = {The Experimentation and Modeling of {\textquotedblleft}Satellite-Friendly{\textquotedblright} HTTP},
	author = {Bhalekar, Aniruddha., Baras, John S.},
	year = {2003},
	month = {03/2003},
	abstract = {The demand for Internet access has been characterized by an exponential growth. The introduction of high-speed satellite communication systems providing direct-to-home Internet services is a response to this increasing demand. However, such systems suffer from high delay-bandwidth product and high bit-error-rate which causes degradation in the performance of HTTP, which is a request-response type, application-layer protocol over TCP. In this paper we investigate HTTP/1.0, HTTP/1.1 and analyze different mechanisms to reduce the user-perceived delay and improve the performance of Internet delivery over satellite links. The paper also suggests other mechanisms, such as multiple parallel connections and a delta encoding implementation to overcome the above-mentioned problem. We show that there is a marked improvement in Internet browsability and user-perceived delay, using these methods.},
	address = {Baltimore, Maryland},
	booktitle = {37th Conference on Information Sciences and Systems (CISS)},
	organization = {John Hopkins University}
}
@conference {
	title = {Finite Automata Models for Anomaly Detection},
	author = {V. R. Ramezani, Yang, Shahan., Baras, John S.},
	year = {2003},
	month = {03/2003},
	abstract = {A fundamental problem in Intrusion detection is the fusion of dependent information sequences.In this paper ,we consider the fusion of two such sequences ,namely the sequence of system calls and the value of the instruction pointer.We introduce FAAD, a finite automation representation defined for the product alphabet of the two sequences where dependencies are implicitly taken into account by a matching procedure.},
	address = {Baltimore, Maryland},
	booktitle = {37th Conference on Information Sciences and Systems (CISS)},
	organization = {Johns Hopkins University}
}
@conference {
	title = {Detection and Classification of Network Intrusions Using Hidden Markov Models},
	author = {Radosavac, Svetlana., Baras, John S.},
	year = {2003},
	month = {03/2003},
	abstract = {This paper demonstrates that it is possible to model attacks with a low number of states and classify them using Hidden Markov Models with very low False Alarm rate and very few False Negatives. We also show that the models developed can be used for both detection and classification. We put emphasis on detection and classification of network intrusions and attacks using Hidden Markov Models and training on anomalous sequences. We test several algorithms, apply different rules for classification and evaluate the relative performance of these. Several of the attack examples presented exploit buffer overflow vulnerabilities, due to availability of data for such attacks. We emphasize that the purpose of our algorithms is not only the detection and classification of buffer overflows; they are designed for detecting and classifying a broad range of attacks.},
	address = {Baltimore, Maryland},
	booktitle = {37th Conference on Information Sciences and Systems (CISS)},
	organization = {Johns Hopkins University}
}
@conference {
	title = {Fault-tolerance and efficiency considerations for key distribution ~protocols in MANETs},
	author = {Striki, Maria., Baras, John S.},
	year = {2003},
	month = {03/2003},
	abstract = {In this paper we address the Fault-Tolerance and Efficiency of key distribution protocols for group communications in Mobile AdHoc Networks. Most key distribution protocols that exist today are primarily designed for wireline networks. These protocols either fail to work as intended or cannot work at all when they are applied to the demanding environment of MANETs. The main reasons for this are: frequent node failures, network partitions and merges, inefficient computational and communication capabilities of certain wireless nodes, network delay, bad quality of signal etc. We determine the framework under which protocols can efficiently work in MANETs, design new protocols or modify existing ones, so that they can be robust, scalable and applicable in this environment. We classify these protocols in two families: contributory and non-contributory. We evaluate them from the point of view of MANETs and compare their performance.},
	address = {Baltimore, Maryland},
	booktitle = {37th Conference on Information Sciences and Systems(CISS)},
	organization = {Johns Hopkins University}
}
@conference {
	title = {A Probabilistic Emergent Routing Algorithm (PERA) for Mobile Ad Hoc Networks},
	author = {Baras, John S., Mehta, Harsh.},
	year = {2003},
	month = {03/2003},
	abstract = {Mobile ad hoc networks are infrastructure-less networks consisting of wireless, possibly mobile nodes which are organized in peer-to-peer and autonomous fashion. The highly dynamic topology, limited bandwidth availability and energy constraints make the routing problem a challenging one. In this paper we take a novel approach to the routing problem in MANETs by using swarm intelligence-inspired algorithms. The proposed algorithm uses Ant-like agents to discover and maintain paths in a MANET with dynamic topology. We present simulation results that measure the performance of our algorithm with respect to the characteristics of a MANET, the varying parameters of the algorithm itself as well as performance comparison with other well-known routing protocols.},
	address = {Sophia-Antipolis, France},
	booktitle = {WiOpt \&rsquo;03: Modeling and Optimization in Mobile, AdHoc and Wireless Networks}
}
@conference {
	title = {TORA, Verification, Proofs and Model Checking},
	author = {Yang, Shahan., Baras, John S.},
	year = {2003},
	month = {03/2003},
	address = {Sophia-Antipolis, France},
	booktitle = {WiOpt \&rsquo;03: Modeling and Optimization in Mobile, AdHoc and Wireless Networks}
}
@conference {
	title = {On the performance limits of data-aided synchronization},
	author = {Jiang, Yimin., Sun, Feng-Wen., Baras, John S.},
	year = {2003},
	month = {01/2003},
	abstract = {This paper addresses data-aided (DA) synchronization, in which the reference parameter acquisition is aided by a training sequence known to the receiver. The Cramer-Rao lower bound (CRB) for the DA timing and/or carrier phase recovery is presented. For DA parameter estimation, the CRB typically varies with the training sequence. This indicates that different training sequences offer fundamentally different performance. In the literature, the widely cited closed-form CRB for timing and carrier phase recovery was derived under the assumption that the training sequence is independent and identically distributed (i.i.d.) and sufficiently long. We derive a closed-form CRB for timing and carrier phase recovery with respect to an arbitrary training sequence and pulse shaping function for the over and under sampling cases. It turns out that the CRB is a weighted summation of the aperiodic correlation of the training sequence and the weighting factor is determined by the pulse shaping filter. Therefore, this paper reveals the fundamental link between a training sequence and its corresponding performance limit.},
	booktitle = {IEEE Transactions on Information Theory},
	pages = {191 - 203}
}
@conference {
	title = {On the convergence of the inverses of Toeplitz matrices and its applications},
	author = {Sun, Feng-Wen., Jiang, Yimin., Baras, John S.},
	year = {2003},
	month = {01/2003},
	abstract = {Many issues in signal processing involve the inverses of Toeplitz matrices. One widely used technique is to replace Toeplitz matrices with their associated circulant matrices, based on the well-known fact that Toeplitz matrices asymptotically converge to their associated circulant matrices in the weak sense. This often leads to considerable simplification. However, it is well known that such a weak convergence cannot be strengthened into strong convergence. It is this fact that severely limits the usefulness of the close relation between Toeplitz matrices and circulant matrices. Observing that communication receiver design often needs to seek optimality in regard to a data sequence transmitted within finite duration, we define the finite-term strong convergence regarding two families of matrices. We present a condition under which the inverses of a Toeplitz matrix converges in the strong sense to a circulant matrix for finite-term quadratic forms. This builds a critical link in the application of the convergence theorems for the inverses of Toeplitz matrices since the weak convergence generally finds its usefulness in issues associated with minimum mean squared error and the finite-term strong convergence is useful in issues associated with the maximum-likelihood or maximum a posteriori principles.},
	booktitle = {IEEE Transactions on Information Theory},
	pages = {180 - 190}
}
