@conference {
	title = {Semiring Pruning for Information Dissemination in Mobile Ad Hoc Networks},
	author = {Somasundaram, Kiran K., Baras, John S.},
	year = {2009},
	month = {12/2009},
	abstract = {Link state routing mechanisms have shown good convergence behaviour with mobile hosts. Pruning methods such as those used in Optimized Link State Routing (OLSR) have showed good throughput behaviour when compared to traditional link-state approaches which suffered from broadcast storm problems. In this paper, we show that the pruning function is a fundamental component of link-state routing protocols for mobile networks. We also show that this component architecture aids in interpreting both distance vector and link-state approaches under a common framework. We develop a class of pruning methods for many of the most commonly used routing objectives and show that these pruning methods are a special case of the semiring distribution property.},
	address = {Chennai, India},
	booktitle = {Proceedings of the The First International Conference on Networks and Communications(NetCoM-2009)},
	pages = {pp. 319-325}
}
@conference {
	title = {Achieving Symmetric Pareto Nash Equilibria using Biased Replicator Dynamics},
	author = {Somasundaram, Kiran K., Baras, John S.},
	year = {2009},
	month = {12/2009},
	abstract = {Achieving the Nash equilibria for single objective games is known to be a computationally difficult problem. However, there is a special class of equilibria called evolutionary robust equilibria which can be obtained through a special type of evolutionary dynamics called the replicator dynamics. These dynamics has special properties over the simplex, which has been studied in optimization theory to solve several combinatorial problems. In this work, we consider the essentially hard combinatorial optimization problem of computing the equilibria in games with multiple objectives. We extend the notion of replicator dynamics to handle such games. We establish proofs of dynamic stability of this modified replicator dynamics and present their relation to the Pareto Nash equilibria in multiobjective games.},
	address = {Shanghai, China},
	booktitle = {48th IEEE Conference on Decision and Control},
	pages = {pp.7000 - 7005}
}
@conference {
	title = {Context-Dependent Multi-class Classification with Unknown Observation and Class Distributions with Applications to Bioinformatics},
	author = {Baras, A. S., Baras, John S.},
	year = {2009},
	month = {12/2009},
	abstract = {We consider the multi-class classification problem, based on vector observation sequences, where the conditional (given class observations) probability distributions for each class as well as the unconditional probability distribution of the observations are unknown. We develop a novel formulation that combines training with the quality of classification that can be obtained using the learned (via training) models. The parametric models we use are finite mixture models, where the same component densities are used in the model for each class, albeit with different mixture weights. Thus we use a model known as All-Class-One-Network (ACON) model in the neural network literature. We argue why this is a more appropriate model for context-dependent classification, as is common in bioinformatics. We derive rigorously the solution to this joint optimization problem. A key step in our approach is to consider a tight (provably) bound between the average Bayes error (the true minimal classification error) and the average model-based classification error. We rigorously show that the parameter estimates maximize the likelihood of the model-based class posterior probability distributions. We illustrate by application examples in the bioinformatics of cancer.},
	address = {Shanghai, China},
	booktitle = {48th IEEE Conference on Decision and Control},
	pages = {pp. 8523-8530}
}
@conference {
	title = {Efficient and Robust Communication Topologies for Distributed Decision Making in Networked Systems},
	author = {Baras, John S., Hovareshti, Pedram.},
	year = {2009},
	month = {12/2009},
	abstract = {Distributed decision making in networked systems depends critically on the timely availability of critical fresh information. Performance of networked systems, from the perspective of achieving goals and objectives in a timely and efficient manner is constrained by their collaboration and communication structures and their interplay with the networked system{\textquoteright}s dynamics. In most cases achieving the system objectives requires many agent to agent communications. A reasonable measure for system robustness to communication topology change is the number of spanning trees in the graph abstraction of the communication system. We address the problem of network formation with robustness and connectivity constraints. Solutions to this problem have also applications in trust and the relationship of trust to control. We show that the general combinatorial problem can be relaxed to a convex optimization problem. We solve the special case of adding a shortcut to a given structure and provide insights for derivation of heuristics for the general case. We also analyze the small world effect in the context of abrupt increases in the number of spanning trees as a result of adding a few shortcuts to a base lattice in the Watts-Strogatz framework and thereby relate efficient topologies to small world and expander graphs.},
	address = {Shanghai, China},
	booktitle = {48th IEEE Conference on Decision and Control},
	pages = {pp. 3751-3756}
}
@conference {
	title = {The Institute for Systems Research: the longest sustained ERC ~ 25 yrs},
	author = {Baras, John S.},
	year = {2009},
	month = {12/2009},
	address = {Bethesda, Maryland},
	booktitle = {NSF ERC Annual Meeting}
}
@conference {
	title = {Trust and Reputation in Networked Systems: Social, Information, Communication, Control},
	author = {Baras, John S.},
	year = {2009},
	month = {11/2009},
	address = {Irvine, CA},
	booktitle = {Networked Systems Seminar},
	organization = {University of California, Irvine}
}
@conference {
	title = {System Architecture and Component Based System Synthesis},
	author = {Baras, John S.},
	year = {2009},
	month = {11/2009},
	address = {Shanghai, China}
}
@conference {
	title = {Collaboration in Networks of Autonomous Agents: Coalitional Games, Constraints and Architectures},
	author = {Baras, John S.},
	year = {2009},
	month = {11/2009},
	address = {New Haven, CT},
	booktitle = {Workshop on Frontiers in Distributed Communication, Sensing and Control},
	organization = {Yale University}
}
@conference {
	title = {Network Cell Routing Model For Control of Throughput and Delay of Air Traffic},
	author = {Nguyen, Alex T., Baras, John S.},
	year = {2009},
	month = {10/2009},
	abstract = {Attempts to manage air traffic by either decreasing delay or increasing flow can have the reverse effect on the other. In the National Airspace System (NAS), flights typically depart at their chosen times, and flow management techniques are implemented in the air in an effort to maximize flow, which could lead to delay for individual aircraft. Other areas of the world allow flights to depart only at predetermined slot times knowing that there is a clear unobstructed path, leading to minimal delays but possibly under utilizing airspace. We propose a new approach in leveraging the highway cell transmission model (CTM) to the airspace in the form of a multi-objective optimization that trades between maximizing throughput and minimizing delay. The model is posed as a multi commodity traffic flow integer program where the constraints are relaxed slightly from the CTM to examine strategies for achieving optimal throughput and delay. In practice, the model is envisioned to initially run offline to determine a preliminary solution to the initial state of the system. Solutions for subsequent changes in actual state can be determined by running the model online for the incremental state change. Stochastic events such as convective weather clearing times or capacities can be included in the model to better see the benefits and impacts of pre-positioning traffic to take advantage of possible future clearing.},
	address = {Orlando, FL},
	booktitle = {28th Digital Avionics Systems Conference (DASC - 2009)},
	pages = {pp. 2.B.2-1 - 2.B.2-6}
}
@conference {
	title = {Modeling and Sensitivity Analysis of Reservation Based USAP Unicast Traffic in MANETs},
	author = {Perumal, Senni., Tabatabaee, Vahid., Baras, John S., Graff, Charles J., Yee, David G.},
	year = {2009},
	month = {10/2009},
	abstract = {In this paper, we develop and evaluate models to estimate and optimize various performance metrics for unicast traffic using the hard scheduling (virtual circuit connection oriented) mode of the reservation-based protocol USAP in mobile ad-hoc wireless networks (MANETs). USAP (Unifying Slot Assignment Protocol) is a dynamic distributed resource allocation protocol for MANETs. We model USAP hard scheduling mode using loss network models along with reduced link capacity that couple physical, MAC and routing layers effects. The key effect of multiuser interference on a link is modeled via reduced link capacity where the effects of transmissions and receptions in the link neighborhood are modeled using USAP reservation rules. We compare our results with simulation and obtain good results using our loss network models but with reduced link capacity distribution obtained by simulation. We also compute the throughput sensitivities with respect to network parameters and use these sensitivities to improve network performance.},
	address = {Boston, Massachusetts},
	booktitle = {MILCOM 2009 "The Challenge of Convergence"},
	pages = {pp.1-7}
}
@conference {
	title = {Component Based Modeling for Cross-layer Analysis of 802.11 MAC and OLSR Routing Protocols in Ad-hoc Networks},
	author = {Baras, John S., Tabatabaee, Vahid., Jain, Kaustubh.},
	year = {2009},
	month = {10/2009},
	abstract = {We present a complete scenario driven component based analytic model of 802.11 MAC and OLSR routing protocols in MANETs. We use this model to provide a systematic approach to study the network performance and cross-layer analysis and design of routing, scheduling, MAC, and PHY layer protocols. The routing protocol is divided into multiple components. Componentization is a standard methodology for analysis and synthesis of complex systems. To provide a component based design methodology, we have to develop a component based model of the wireless network that considers cross-layer dependency of performance. The component based model enables us to study the effect of each component on the overall performance of the wireless network and to design each component separately. For the MAC layer, we use a fixed point loss model of 802.11 protocol that considers effects of hidden nodes and finite retransmission attempts. We have also considered simple models for PHY and scheduling. The main focus of this paper is on the integration of these models to obtain a complete model for wireless networks. In several scenario driven studies, with user-specified topologies and traffic demands, we study the performance metrics - throughput and delay. By analyzing the performances under varying network scenarios, we are able to identify a few sources of performance degradation. We also study the effect of certain design parameters on the network performance. Thus, demonstrating the ability of the model to quickly identify problem components and try alternative design parameters},
	address = {Boston, Massachusetts},
	booktitle = {MILCOM 2009 \&quot;The Challenge of Convergence\&quot;},
	pages = {pp. 1-7}
}
@conference {
	title = {Securing the Communication of Medical Information Using Local Biometric Authentication and Commercial Wireless Links},
	author = {Ivanov, Vladimir I., Yu, Paul L., Baras, John S.},
	year = {2009},
	month = {10/2009},
	abstract = {Medical information is extremely sensitive in nature  a compromise, such as eavesdropping or tampering by a malicious third party, may result in identity theft, incorrect diagnosis and treatment, and even death. Therefore, it is important to secure the transfer of the medical information from its source, i.e., the patient, to the system that collects and records it or its technology adoption will face a strong resistance from the users. We consider the scenario where a patient has a portable, wireless medical device that transfers the medical information to a remote server. We decompose this problem into two sub-problems and propose security solutions to each of them: (a) to secure the link between the patient and the portable device, and (b) to secure the link between the portable device and the network. Thus, we push the limits of the network security to the cutting edge: authenticating the user using their biometric information, authenticating the device to the network at the physical layer, and strengthening the security of the wireless link with a key exchange mechanism. The proposed authentication methods can be used for recording the readings of medical data in a central database and for accessing medical records.},
	address = {Kalmar, Sweden},
	booktitle = {International Symposium on Health Information Management Research (ISHIMR 2009)},
	pages = {pp.119-127}
}
@conference {
	title = {Network Cell Air Traffic Routing Model For Control of Throughput and Delay},
	author = {Nguyen, Alex T., Baras, John S.},
	year = {2009},
	month = {10/2009},
	abstract = {Attempts to manage air traffic by either decreasing delay or increasing flow can have the reverse effect on the other. In the National Airspace System (NAS), flights typically depart at their chosen times, and flow management techniques are implemented in the air in an effort to maximize flow, which could lead to delay for individual aircraft. Other areas of the world allow flights to depart only at predetermined slot times knowing that there is a clear unobstructed path, leading to minimal delays but possibly underutilizing airspace. We propose a new approach in leveraging the highway cell transmission model (CTM) to the airspace in the form of a multi-objective optimization that trades between maximizing throughput and minimizing delay. The model is posed as a multicommodity traffic flow integer program where the constraints are relaxed slightly from the CTM to examine strategies for achieving optimal throughput and delay. In practice, the model is envisioned to initially run offline to determine a preliminary solution to the initial state of the system. Solutions for subsequent changes in actual state can be determined by running the model online for the incremental state change. Stochastic events such as convective weather clearing times or capacities can be included in the model to better see the benefits and impacts of pre-positioning traffic to take advantage of possible future clearing.},
	address = {San Diego, CA},
	booktitle = {INFORMS 2009},
	pages = {2.B.2-1 - 2.B.2-6}
}
@conference {
	title = {Dynamic Self-Organization and Clustering in Distributed Networked Systems for Performance Improvement},
	author = {Baras, John S., Hovareshti, Pedram., Perumal, Senni.},
	year = {2009},
	month = {09/2009},
	abstract = {We consider two closely related dynamic self-organization problems in networked control systems. Both are forms of the~dynamic clustering of nodes. The structure of networked control systems is often abstracted using graph theory. In this abstraction, the nodes of the graph represent the agents and the edges between them represent the relation(s) or the possibility of communication between the corresponding agents. The topology of the communication network supporting a networked control system has critical consequences for its performance. The first problem we address is the development of a distributed self-organization algorithm, resulting into a dynamic two level hierarchy of leader and regular agents, which substantially improves the convergence speed of distributed algorithms utilized by the networked control system. For the second problem, we consider the collaborative control of a group of autonomous mobile agents (e.g. vehicles, robots) supported by a mobile wireless network, consisting of many grounds and a few aerial nodes. The agents collaborate to achieve a common goal or objective, like to move in a particular area and cover it, while avoiding obstacles and collisions. Building upon our earlier work on deterministic, randomized and hybrid distributed coordination algorithms we consider the communication needs of the agents, and in particular, the connectivity of their communication network as they move. We develop distributed algorithms that automatically select some agents and move them appropriately so as to maintain a~certain degree of desired connectivity among the moving agents. We characterize the trade-off between the gain from maintaining a certain degree of connectivity vs. the combined cost of communications and the associated dynamic re-positioning of agents. We also describe classes of efficient communication topologies and in particular their similarity to dynamic small-world topologies and extensions.},
	address = {Montecello, Illinois},
	booktitle = {Forty-Seventh Annual Allerton Conference on Communication, Control, and Computing (Allerton Conference 2009)},
	pages = {pp. 968-975},
	organization = {University of Illinois at Urbana-Champaign}
}
@conference {
	title = {Probabilistic Non-Repudiation for Source Authentication with TESLA Certificates in Hybrid Satellite/Wireless and Performance Analysis of the Authentication Protocol},
	author = {Roy-Chowdhury, Ayan., Baras, John S.},
	year = {2009},
	month = {09/2009},
	abstract = {In this work, we describe a novel non-repudiation mechanism for an authentication protocol based on the extended TESLA certificate construct. With the non-repudiation mechanism, the authentication protocol is ideally suited for source authentication of low-powered nodes that participate in group communication in hybrid satellite/wireless networks. Security is a necessary parameter in hybrid wireless networks (consisting of groups of terrestrial wireless nodes interconnected by a satellite overlay) if the communication between a pair of nodes, or amongst a group of nodes, is to be protected from unauthorized The focus of our research work is on user authentication and message integrity protocols, which are required to enable communications and ensure that messages between communicating nodes are correctly delivered. This is a non-trivial problem in group communication, where authentication has been traditionally done using asymmetric cryptographic techniques such as public key certificates and digital signatures. However, such asymmetric techniques can be very expensive in terms of processing power and node energy for wireless nodes in hybrid networks. As a solution to this problem, we have proposed a new class of lightweight, symmetric key certificates called extended TESLA certificates, and we have designed an energy-efficient source authentication protocol for group communication that utilizes the infrastructure present in hybrid satellite networks. In our authentication protocol based on the extended TESLA certificate, we propose to add non-repudiation by taking advantage of the satellite infrastructure and the proposed mechanism of key disclosure by proxy. This is a major improvement over previous authentication algorithms based on TESLA, which does not provide for non-repudiation due to the symmetric nature of the underlying cryptographic primitive, Message Authentication Codes. In this paper, we describe the mechanism by which non-repudiation is achieved in our authentication protocol. The non-repudiation is probabilistic in nature, and we analyze the tradeoff between the degree of non-repudiation and the overhead due to the additional information necessary for non-repudiation. Furthermore, through simulations, we compare the performance between the basic authentication protocol and authentication with non-repudiation, and also compare the latter to public key-based schemes.},
	address = {Sardinia, Italy},
	booktitle = {The Ka and Broadband Communications Conference Navigation and Earth Observation Conference 2009 (KaConf2009)},
	pages = {pp.1-8},
	organization = {Cagliari}
}
@conference {
	title = {Rate-Control System with Heterogeneous Time-varying Delays in Broadband Satellite Networks},
	author = {Zeng, Hui., Hadjitheodosiou, Michael., Baras, John S.},
	year = {2009},
	month = {09/2009},
	abstract = {In a broadband satellite communications network, the propagation delays are not only significant, but also variable among users due to their different geographical locations and the problem becomes more severe with increasing data rates. We consider rate control algorithms with user feedback in the form of single bits and formulate analytic fluid flow models composed of first-order delay differential equations. Both single-flow and multi-flow system models are analyzed, with special attention paid to the Mitra-Seery algorithm. The stationary solutions are investigated first. For the fluctuating solutions, their dynamic behavior is analyzed, in terms of amplitude, transient behavior, fairness, and adaptability, etc., analytically and numerically. Especially the effects of heterogeneous time-varying delays are investigated. It is shown that with proper parameter design the system can achieve stabling behavior with close to pointwise proportional fairness among flows.},
	address = {Sardinia, Italy},
	booktitle = {The Ka and Broadband Communications Conference Navigation and Earth Observation Conference 2009 (KaConf2009)},
	pages = {pp. 1-8},
	organization = {Cagliari}
}
@conference {
	title = {Coalition Formation and Trust in Collaborative Control},
	author = {Baras, John S., Jiang, Tao., Hovareshti, Pedram.},
	year = {2009},
	month = {08/2009},
	abstract = {We consider the collaboration of autonomous agents as a coalitional game subject to constraints, like communication, trust or reputation. We analyze the tradeoff between the benefits of collaboration and these constraints (or costs of collaboration) via dynamic, iterative stochastic games. The agents can observe locally the actions of other agents in their neighborhood and decide whether to collaborate or not in a distributed asynchronous manner. Trust values are taken into consideration when agents act and collaborate. Specifically they affect the selection of agents to collaborate with. We consider only problems where the information used for either estimating reputations or deciding on strategies is mostly local; i.e. from the neighbors of each agent. We show that randomized algorithms emerge as the agents try to reach the maximum payoff. We also investigate the topology of the formed network by studying the second largest eigenvalue of the corresponding graph, and describe its effects on control performance.},
	address = {Budapest, Hungary},
	booktitle = {European Control Conference 2009 (ECC {\textquoteright}09)},
	pages = {pp.1197-1202}
}
@conference {
	title = {Event Triggered Distributed Collaborative Control},
	author = {Baras, John S., Hovareshti, Pedram., Perumal, Senni.},
	year = {2009},
	month = {08/2009},
	abstract = {We consider the collaborative control of a group of autonomous mobile agents (e.g. vehicles, robots). The agents collaborate to achieve a common goal or objective, like to move in a particular area and cover it, while avoiding obstacles and collisions. Building upon our earlier work on deterministic, randomized and hybrid distributed coordination algorithms we consider the communication needs of the agents, and in particular, the connectivity of their communication network as they move. We develop algorithms that automatically sense the possibility or inset of loss of connectivity among the agents. We also consider the automatic detection of path disconnection when more than one paths need to be maintained between pairs of agents. Using local probing schemes we formulate such problems as event-triggered control problems. We develop distributed algorithms that automatically select some agents and move them appropriately so as to maintain a~certain degree of desired connectivity among the moving agents. We characterize the trade-off between the gain from maintaining a certain degree of connectivity vs the combined cost of communications and the associated dynamic re-positioning of agents. The results illustrate the efficiency achieved by the~event-triggered control in such problems. We also describe the resulting communication topologies and in particular their similarity to dynamic small-world topologies.},
	address = {Budapest, Hungary},
	booktitle = {European Control Conference 2009 (ECC {\textquoteright}09)},
	pages = {pp.3797-3802}
}
@conference {
	title = {Forward Looking Panel Discussion},
	author = {Baras, John S.},
	year = {2009},
	month = {07/2009},
	address = {Denver, Colorado},
	booktitle = {2009 SIAM Conference on Control and its Applications}
}
@conference {
	title = {Efficient Connectivity Topologies for Networked Control Systems},
	author = {Baras, John S.},
	year = {2009},
	month = {07/2009},
	abstract = {This paper presents a perceptually optimized joint source/channel coding scheme for video transmission over satellite broadcast channel. We express the end-to-end expected distortion in terms of the source coder distortion and the channel distortion. Perceptual distortion model just-noticeable-distortion (JND) is applied to improve the subjective quality of compressed video. 3-D wavelet video codec that is jointly optimized with channel codec can remove spatial and temporal redundancy and provide the scalability of video quality for broadcast channel. In order to conceal the errors under bad channel conditions and prevent the error propagation of arithmetic decoding, slicing method and a channel coding scenario that combines RCPC, Reed-Solomon codes and CRC are proposed. Two perceptual distortion indices based on JND are discussed. These two indices are combined in our joint source/channel coding scenario to achieve minimal bandwidth consumption subject to acceptable visual quality under normal and bad channel conditions. Computer simulation is conducted at difference signal-to-noise ratios (SNR). Our system uses offset QPSK (OQPSK) modulation scheme to combat the nonlinear effect of satellite channels. Acknowledgment: Research supported by the Communications and Networks Consortium sponsored by the U. S. Army Research Laboratory under the Collaborative Technology Alliance Program, Cooperative Agreement DAAD19-01-2-0011, and by the ARO MAASCOM MURI, grant W911NF-08-1-0238.},
	address = {Denver, Colorado},
	booktitle = {SIAM Conference on Control \& Its Applications (CT09)}
}
@conference {
	title = {Performance Improvements in Distributed Estimation and Fusion Induced by a Trusted Core},
	author = {Somasundaram, Kiran K., Baras, John S.},
	year = {2009},
	month = {07/2009},
	abstract = {We consider distributed state estimation and fusion in autonomic ad-hoc sensor networks when some nodes are untrusted, corrupted or malicious. We provide rigorous graph models to capture both trust and network functionality relations. We propose a novel hierarchical scheme, inspired from socio-cognitive dynamics in economics and sociology, that utilizes a trusted core. We provide a component-based architecture to show the interplay between the trust and estimation schemes. As an explanatory example we consider the problem of distributed Kalman filtering. We show that trust-based schemes, implemented by a trusted core, result in significant improvement in the state estimation procedure. We also find that the interplay between estimation and trust updates quickly isolates malicious nodes and helps the observation limited nodes (corrupted sensor nodes).},
	address = {Seattle, WA},
	booktitle = {12th International Conference on Information Fusion (Fusion 2009)},
	pages = {pp. 1942-1949}
}
@conference {
	title = {Dynamic Distributed Control over Semirings and Applications},
	author = {Baras, John S.},
	year = {2009},
	month = {07/2009},
	abstract = {We demonstrate that many constrained dynamic control problems involving hybrid systems are control problems for dynamical systems over partially ordered semirings. Applications include biological-social-communication networks, collaborative robotics, consensus, flocking, trust, swarms. We next show that when time is discrete and inputs, outputs and states take values in finite sets, these problems are equivalent to constrained shortest path problems. We then develop algorithms, mostly distributed ones, for solving these dynamic constrained shortest path problems over semirings.},
	address = {Denver, Colorado},
	booktitle = {SIAM Conference on Control and its Applications (CT09)}
}
@conference {
	title = {A Composite Trust Model and its Application to Collaborative Distributed Information Fusion},
	author = {Matei, Ion., Baras, John S., Jiang, Tao.},
	year = {2009},
	month = {07/2009},
	abstract = {We consider distributed state estimation of~linear dynamic systems, observed by various sensors, as a problem in information fusion. We introduce a novel model of trust, using weights on the graph links and nodes that represent the sensor network. These weights can represent several interpretations of trustworthiness in sensor networks. We describe three algorithms that integrate distributed Kalman filtering with these trust weights. We consider two interpretations of these trust weights as information accuracy and reliability. We show that by appropriate use of these weights the distributed estimation algorithm avoids using information from untrusted sensors. Simulation experiments further demonstrate the behavior of these algorithms.},
	address = {Seattle, WA},
	booktitle = {12th International Conference on Information Fusion (Fusion 2009)},
	pages = {pp. 1950-1957}
}
@conference {
	title = {Evolutionary Dynamics of Collaborative Environments with Heterogenous Agents},
	author = {Somasundaram, Kiran K., Baras, John S.},
	year = {2009},
	month = {06/2009},
	abstract = {The seminal work of Maynard Prince and Price in 1973 laid the foundations in establishing the concepts of evolutionarily stable game strategies. It attempts to select strategies which are robust to evolutionary selection pressures. We observe that most of the literature as evolved is concentrated on single objective games. In this work, we extend the notion of evolutionary stability to games with vector payoff functions. We illustrate by examples that this notion of Multicriteria evolutionary stability models a much larger class of interactions in social, economic and biological problems. Particular applications of interest are in autonomic wireless sensor networks and autonomic networked control systems. We present a multi-population replicator dynamics, which models the evolution of agent actions in a network with varying levels of selfishness. We observe this model clearly demarks the regions of co-operation among these selfish agents. We provide analytical results on the dynamic stability of the replication. This clearly characterizes the aforementioned demarcations.},
	address = {Thessaloniki, Greece},
	booktitle = {17th Mediterranean Conference on Control \&amp; Automation (MED 09)},
	pages = {pp 121-125}
}
@conference {
	title = {Performance-aware Security of Unicast Communication in Hybrid Satellite Networks},
	author = {Roy-Chowdhury, Ayan., Baras, John S.},
	year = {2009},
	month = {06/2009},
	abstract = {In this work, we address the performance problems that arise when unicast security protocols IPSEC and SSL are applied for securing the end-to-end communication in hybrid satellite networks. Satellite networks use TCP and HTTP performance-enhancing proxy servers to overcome the adverse
effect of the large delay-bandwidth product of the satellite channel. However, the proxy servers cannot function when IPSEC and SSL are used for secure unicast communication in hybrid satellite networks. We, therefore, propose the use of the Layered IPSEC (LES) protocol as an alternative to IPSEC for networklayer security. We describe a modification to the Internet Key Exchange protocol if dynamic key establishment is needed for
Layered IPSEC. For application-level security of web browsing with acceptable end-to-end delay, we propose the Dual-mode SSL protocol (DSSL) to be used instead of SSL. We describe how LES and DSSL protocols achieve the desired end-to-end communication security while allowing the TCP and HTTP proxy servers to function correctly. Through simulation studies, we quantify the improvement in performance that is achieved using
our proposed protocols, compared to traditional IPSEC and SSL.},
	address = {Dresden, Germany},
	booktitle = {IEEE ICC 2009 Communication and Information Systems Security Symposium},
	pages = {pp.1-6}
}
@conference {
	title = {Component Based Performance Modeling of Wireless Routing Protocols},
	author = {Baras, John S., Tabatabaee, Vahid., Purkayastha, Punyaslok., Somasundaram, Kiran K.},
	year = {2009},
	month = {06/2009},
	abstract = {We propose a component-based methodology for modelling and design of wireless routing protocols. Componentization is a standard methodology for analysis and synthesis of complex systems, or software. The feasibility of the component based design relies heavily on the compositionality property (i.e. system-level properties can be computed from properties of components). To provide a component based design methodology and to test compositionality for routing protocols, we have to develop a component-based model of the wireless network. We present the main components of the routing protocol that should be modelled and focus on three main components: neighborhood discovery, selector of topology information to disseminate, and the path selection components. For each component, we identify the inputs, outputs, and a generic methodology for modelling. Throughout the paper, we use the Optimized Link State Routing (OLSR) protocol as a case study to demonstrate the effectiveness of our approach. Using the neighborhood discovery component, we present our design methodology and design a modified enhanced version of this component, and compare its performance to the original OLSR design.},
	address = {Dresden, Germany},
	booktitle = {IEEE ICC 2009 Ad Hoc and Sensor Networking Symposium},
	pages = {pp.1-6}
}
@conference {
	title = {Consensus Problems with Directed Markovian Communication Patterns},
	author = {Matei, Ion., Martins, Nuno C., Baras, John S.},
	year = {2009},
	month = {06/2009},
	abstract = {This paper is a continuation of our previous work and discusses the consensus problem for a network of dynamic agents with directed information flows and random switching topologies. The switching is determined by a Markov chain, each topology corresponding to a state of the Markov chain. We show that in order to achieve consensus almost surely and from any initial state, each union of graphs from the sets of graphs corresponding to the closed positive recurrent sets of states of the Markov chain must have a spanning tree. The analysis relies on tools from matrix theory, Markovian jump linear systems theory and random process theory. The distinctive feature of this work is addressing the consensus problem with {\textquotedblleft}Markovian switching{\textquotedblright} topologies.},
	address = {St. Louis, Missouri},
	booktitle = {2009 American Automatic Control Conference},
	pages = {pp.1298-1303}
}
@conference {
	title = {Swarms, Coalitional Games, Trust, and Network Topologies},
	author = {Baras, John S.},
	year = {2009},
	month = {06/2009},
	address = {Block Island, Rhode Island},
	booktitle = {3rd Workshop on Swarming in Natural and Engineering Systems}
}
@conference {
	title = {Trust and Reputation in Communication, Social and Biological Autonomic Networks},
	author = {Baras, John S.},
	year = {2009},
	month = {06/2009},
	address = {Volos, Greece},
	booktitle = {2009 Information Theory Workshop}
}
@conference {
	title = {Effects of Network Structure on the Performance of Networked Systems},
	author = {Baras, John S.},
	year = {2009},
	month = {05/2009},
	address = {Santa Barbara, CA},
	booktitle = {Control Frontiers Workshop, in honor of Professor Petar Kokotovic},
	organization = {University of California Santa Barbara}
}
@conference {
	title = {Future of Multi-hopping: from Theory to Practice},
	author = {Baras, John S.},
	year = {2009},
	month = {05/2009},
	address = {New Orleans, Louisiana},
	booktitle = {Tenth ACM International Symposium on Mobile Ad Hoc Networking and Computing (Mobilhoc09)}
}
@conference {
	title = {Coalition Formation through Learning in Autonomic Networks},
	author = {Jiang, Tao., Baras, John S.},
	year = {2009},
	month = {05/2009},
	abstract = {Autonomic networks rely on the cooperation of participating nodes for almost all their functions. However, due to resource constraints, nodes are generally selfish and try to maximize their own benefit when participating in the network. Therefore, it is important to study mechanisms, which can be used as incentives for cooperation inside the network. In this paper, the interactions among nodes are modeled as games. A node joins a coalition if it decides to cooperate with at least one node in the coalition. The dynamics of coalition formation proceed via nodes that interact strategically and adapt their behavior to the observed behavior of others. We present conditions that the coalition formed is stable in terms of Nash stability and the core of the coalitional game.},
	address = {Istanbul, Turkey},
	booktitle = {International Conference on Game Theory for Networks (GameNets09)},
	pages = {pp.10-16}
}
@conference {
	title = {Performance Comparison of Two Sequential Change Detection Algorithms on Detection of In-band Wormholes},
	author = {Zheng, Shanshan., Jiang, Tao., Baras, John S.},
	year = {2009},
	month = {03/2009},
	abstract = {This paper compares the performance of parametric and non-parametric sequential change detection algorithms for detecting in-band wormholes in wireless ad hoc networks. The algorithms considered are the non-parametric cumulative sum (NP-CUSUM) and the repeated sequential probability ratio test (R-SPRT). Theoretical performance of the two is compared using metrics that take into account the algorithms{\textquoteright} repeated nature, and the advantage of the parametric method is illustrated. On the other hand, connections between the parametric and non-parametric methods are made in the proposed worst-case adversary model, where the non-parametric method is shown to be more robust to attack strategy changes. Experimental evaluation of wormhole detection schemes based on the two algorithms is presented. This work has implications for both the theoretical understanding and practical design of wormhole detection schemes based on parametric and nonparametric change detection algorithms.},
	address = {Baltimore, MD},
	booktitle = {Conference on Information Sciences and Systems (CISS 2009)},
	pages = {pp.270-275}
}
@conference {
	title = {Constrained Coalitional Games and Network Science},
	author = {Baras, John S.},
	year = {2009},
	month = {03/2009},
	address = {Stockholm, Sweden},
	organization = {Department of Electrical Engineering, Royal Institute of Technology (KTH)}
}
@conference {
	title = {Cooperative Multi-agent Systems and {\textquotedblleft}Magical{\textquotedblright} Graphs},
	author = {Baras, John S.},
	year = {2009},
	month = {03/2009},
	address = {Ann Arbor, MI},
	booktitle = {Electrical and Computer Engineering Control Seminar},
	organization = {University of Michigan, Ann Arbor}
}
@conference {
	title = {Trust and Reputation in Communication, Social and Other Networks},
	author = {Baras, John S.},
	year = {2009},
	month = {03/2009},
	address = {Washington DC},
	organization = {Mathe matics Department, Howard University}
}
@conference {
	title = {New Algorithm for the Design of Topology Aware Hypercube in Multi-hop Ad hoc Networks},
	author = {Striki, Maria., Manousakis, Kyriakos., Baras, John S.},
	year = {2009},
	month = {03/2009},
	abstract = {Securing group communications in resource constrained, infrastructure-less environments such as Mobile Ad Hoc Networks (MANETs) has become one of the most challenging research directions in the areas of wireless network security. MANETs are emerging as the desired environment for an increasing number of commercial and military applications, addressing also an increasing number of users. Security, on the other hand, is becoming an indispensable requirement of our modern life for all these applications. The inherent limitations of such dynamic and resource-constraint networks impose major difficulties in establishing a suitable secure group communications framework. This is even more so for the operation of Key Agreement (KA), under which all parties contribute equally to the group key. The logical design of efficient KA protocols has been the main focus of the related research to-date. Such a consideration, however, gives only a partial account on the actual performance of a KA protocol in a multi-hop network. This is because protocols have been evaluated only in terms of the group key related messaging in isolation from the underlying network functions that interact with the logical scheme and support its correct execution (i.e. routing). In recent work, we contributed towards efficiently extending a number of Diffie-Hellman (DH)-based group KA protocols in wireless multi-hop ad-hoc networks. Towards this end, we introduced a number of new algorithms to efficiently estimate the combined routing {\textendash} communication costs. We then improved these protocols with the addition of a new communication schedule subject to the underlying routing. Indeed, the resulting protocols were significantly more efficient in some or all of the metrics of interest, as our analytical and simulation results indicated. In this work, we contribute towards the latter, by extending an existing KA scheme that was left out in our previous work: Hypercube. Through our analysis and simulations, we demonstrate the superiority of the new, {\textquotedblleft}enriched{\textquotedblright} Hypercube that takes into account the underlying routing via the application of a topologically aware communications schedule.},
	address = {Gosier Guadeloupe, France},
	booktitle = {8th International Conference on Networks ICN 2009},
	pages = {pp.236-244}
}
@conference {
	title = {The Role of Trust in Collaborative and Adversarial Behavior in Networks of Autonomous Agents},
	author = {Baras, John S.},
	year = {2009},
	month = {03/2009},
	address = {Arlington, VA},
	booktitle = {AFOSR Workshop on Adversarial and Stochastic Elements in Autonomous Systems}
}
@conference {
	title = {Autonomic Networked Information and Control Systems: The Critical Effects of Connectivity Architectures},
	author = {Baras, John S.},
	year = {2009},
	month = {02/2009},
	abstract = {We develop a unifying analytical and optimization framework for networks of autonomous agents. The fundamental view is that agents in such a network are dynamic entities that collaborate because via collaboration they can accomplish objectives and goals much better than working alone, or even accomplish objectives that they cannot achieve alone at all. Yet the benefits derived from such collaboration require some costs (or expenditures), for example due to communications. Or in equivalent terms, the collaboration is subject to constraints (static and dynamic). Understanding and quantifying this tradeoff between the benefits vs the costs of collaboration, leads to new methods that can be used to analyze, design and control/operate networks of agents. An important, yet not emphasized to-date, aspect of collaboration is the role of topologies and connectivities linking the agents. This is the main topic of this paper. We demonstrate that connectivities related to small world graphs and expander graphs offer dramatic advantages with respect to many problems that need to be solved in a distributed manner in collaborative information and control systems. These topologies are efficient from the perspective of costs yet lead to fast convergence of distributed algorithms from the benefits perspective. We show how they can be self-generated in response to cost-benefit tradeoffs. We illustrate by simple examples from communication, social and biological networks.},
	address = {San Diego, CA},
	booktitle = {2009 Workshop on Information Theory and Applications (ITA09)},
	organization = {University of California San Diego}
}
