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Analyzing Capacitor-Based Reconfigurable Antennas Using Graph Models, Chaouki Abdallah, J. Costantine, Christos G. Christodoulou, S.E. Barbin Nov 2009

Analyzing Capacitor-Based Reconfigurable Antennas Using Graph Models, Chaouki Abdallah, J. Costantine, Christos G. Christodoulou, S.E. Barbin

Electrical & Computer Engineering Faculty Publications

This paper discusses reconfigurable antennas using variable capacitors or varactors to achieve reconfiguration. We propose graph models as tools to understand reconfigurable antenna topologies and their configurations. Guidelines are set to model this type of reconfigurable antennas using graphs and examples are studied to investigate their optimal performance.


A Control Theory Approach On The Design Of A Marx Generator Network, Chaouki Abdallah, L. Zaccarian, S. Galeani, M. Francaviglia, E. Schamiloglu, C.J. Buchenauer Jun 2009

A Control Theory Approach On The Design Of A Marx Generator Network, Chaouki Abdallah, L. Zaccarian, S. Galeani, M. Francaviglia, E. Schamiloglu, C.J. Buchenauer

Electrical & Computer Engineering Faculty Publications

A Marx generator is a well-known type of electrical circuit first described by Erwin Otto Marx in 1924. It has been utilized in numerous applications in pulsed power with resistive or capacitive loads. To-date the vast majority of research on Marx generators designed to drive capacitive loads relied on experimentation and circuit-level modeling to guide their designs. In this paper we describe how the problem of designing a Marx generator to drive a capacitive load is reduced to that of choosing a diagonal gain matrix F that places the eigenvalues of the closed-loop matrix A+BF at specific locations. Here A …


Identifier-Based Discovery Mechanism Design In Large-Scale Networks, Chaouki T. Abdallah, Joud Khoury Jun 2009

Identifier-Based Discovery Mechanism Design In Large-Scale Networks, Chaouki T. Abdallah, Joud Khoury

Electrical & Computer Engineering Faculty Publications

This paper introduces identifier-based discovery mechanisms in large-scale networks and presents a taxonomy of discovery schemes and proposals based on their business model. The paper poses several questions that are becoming increasingly important as we proceed to design the inter-network of the future. We first define and motivate a multi-level discovery problem that accounts for discovery service differentiation and we present an architecture that provides differentiated services. We then proceed to present an economic framework that accounts for the cost of discovery and for the players' valuations and to discuss the inherent challenges.


H? Filtering Of Networked Systems With Time-Varying Sampling Rates, Chaouki T. Abdallah, Renato A. Borges, Ricardo C.L.F. Oliveira, Pedro L.D. Peres Jun 2009

H? Filtering Of Networked Systems With Time-Varying Sampling Rates, Chaouki T. Abdallah, Renato A. Borges, Ricardo C.L.F. Oliveira, Pedro L.D. Peres

Electrical & Computer Engineering Faculty Publications

In this paper, the problem of robust filter design for networked systems with time-varying sampling rate is investigated. The design conditions are obtained by using the Lyapunov theory and the Finsler's Lemma. A robust filter, that minimizes an upper bound to the Hinfin performance of the estimation error, is obtained as the solution of an optimization problem. A path-dependent Lyapunov function is used in order to obtain less conservative design conditions. Robust filters based on affine parameter-dependent Lyapunov functions can be obtained as a particular case of the proposed method. Numerical examples illustrate the results.


Modeling Multi-Agent Systems With Hybrid Interacting Dynamics, Chaouki T. Abdallah, Jorge Piovesan, Herbert Tanner Jun 2009

Modeling Multi-Agent Systems With Hybrid Interacting Dynamics, Chaouki T. Abdallah, Jorge Piovesan, Herbert Tanner

Electrical & Computer Engineering Faculty Publications

We present a new framework for describing multi-agent systems with hybrid interacting dynamics, where the interaction between agents occurs at both the continuous and discrete levels. We define multi-agent systems as Interconnected Hybrid Systems, recast fundamental hybrid concepts such as hybrid execution and reachability in this new interconnected hybrid systems framework, and prove a necessary and sufficient condition for the existence and uniqueness of the interconnected hybrid executions, extending previous work on hybrid systems. We provide conditions on each agent's hybrid model that guarantee the multi-agent system's existence and uniqueness property. Finally, we provide an example that shows how to …


2009 Index Ieee Antennas And Wireless Propagation Letters Vol. 8, Chaouki T. Abdallah Jan 2009

2009 Index Ieee Antennas And Wireless Propagation Letters Vol. 8, Chaouki T. Abdallah

Electrical & Computer Engineering Faculty Publications

This index covers all technical items - papers, correspondence, reviews, etc. - that appeared in this periodical during the year, and items from previous years that were commented upon or corrected in this year. Departments and other items may also be covered if they have been judged to have archival value. The Author Index contains the primary entry for each item, listed under the first author's name. The primary entry includes the coauthors' names, the title of the paper or other item, and its location, specified by the publication abbreviation, year, month, and inclusive pagination. The Subject Index contains entries …


Optimization And Complexity Reduction Of Switch-Reconfigured Antennas Using Graph Models, Chaouki T. Abdallah, Joseph Costantine, Christos G. Christodoulou, Silvio E. Barbin Jan 2009

Optimization And Complexity Reduction Of Switch-Reconfigured Antennas Using Graph Models, Chaouki T. Abdallah, Joseph Costantine, Christos G. Christodoulou, Silvio E. Barbin

Electrical & Computer Engineering Faculty Publications

This letter addresses the optimization and complexity reduction of switch-reconfigured antennas. A new optimization technique based on graph models is investigated. This technique is used to minimize the redundancy in a reconfigurable antenna structure and reduce its complexity. A graph modeling rule for switch-reconfigured antennas is proposed, and examples are presented.


Innovation And Us Engineering School Ranking, Andres C. Salazar Jan 2009

Innovation And Us Engineering School Ranking, Andres C. Salazar

Electrical & Computer Engineering Faculty Publications

An association between the national ranking of a graduate school in engineering and innovation is investigated by product moment analysis and Spearman correlation coefficients. This paper combines school statistical data used in the national ranking with data normally associated with innovation, e.g., the college’s number of patents, licenses and startups, to determine if there is some correlation between these factors and if so, to what extent there is a relationship. We determine the product moment and Spearman correlation coefficients between the ranking data and the innovation data from the top twenty five engineering schools in a recent USNWR ranking (2006). …


Seven Deadly Factors Associated With Technology Company Failure, Andres C. Salazar Jan 2009

Seven Deadly Factors Associated With Technology Company Failure, Andres C. Salazar

Electrical & Computer Engineering Faculty Publications

Seven factors associated with technology company failure (or death) are described along with features that distinguish each factor. A company is commonly defined to have failed when it passes through a stage of insolvency and then an asset sale or a merger. It is well known that several critical factors can lead to a successful launch of a company – market timing, management experience, product differentiation, product quality, financing, sales execution, team compatibility, etc. High tech companies deal with additional risks at launch such as commercialization difficulties, team formation and technology lifespan. Little research has been done on identifying major …