Home Page

Where can you find me ?

In order of preferred method of contact I can be found:

In person :276 Levine/GRW building"We knew so little then.
Skype :aribeiro_de_montevideoI know even less now"
Cell :612 889 9217 
email :aribeiro@seas.upenn.edu 
mail:Dept. of Electrical & Systems Engineering 
 University of Pennsylvania 
 Room 203 Moore Building 
 200 South 33rd Street 
 Philadelphia, PA 19104 

Who Am I ?

I am an Assistant Professor with the Department of Electrical and Systems Engineering at the University of Pennsylvania (Penn). I was born in Montevideo, Uruguay in 1975 where I lived until 2003. I received a B.Sc. degree in Electrical Engineering from the “Universidad de la Republica” in 1998 and worked for Bellsouth’s cellular operation in Uruguay for five years. I moved to Minneapolis, Minnesota on 2003 to study at the University of Minnesota (UoM). I received M. Sc. and Ph. D. degrees from the UoM on 2005 and 2007 and spent 1 year in a postdoctoral position. I started at Penn in 2008. I received the 2012 S. Reid Warren, Jr. Award presented by Penn's undergraduate student body for outstanding teaching, the NSF CAREER award in 2010, and student paper awards at ICASSP 2005 and ICASSP 2006. I am also a Fulbright Scholar.

My research is in the application of Signal Processing to Network and Wireless Communications theory. I am interested in any problem that involves a network and/or wireless communication links. If you want a description more detailed than this one you can look at my Research page and the work I do with Ph. D. students described later in this page.

More detailed information is available in my CV. A good snapshot of my work is my Google Scholar profile.

What's in here ?

This page is for my teaching and research at Penn. If you are looking for something specific, my list of journal papers is here, my list of conference papers here and my M. Sc. and Ph.D. theses here. You can also find brief high level descriptions of my research projects.

At the graduate level, I teach a class on Wireless Networking.

In the personal section there are a few materials describing Uruguay's history, culture and place in the world. I once made a steel reproduction of a constructivist painting, a story I always like telling. My children are learning to write wikis. Their first attempts are here. Links to various web resources can be found here.

Ph.D. Students

I use most of my time to work with Ph. D. students without whose help my research projects would move at a much lower pace than they do. I currently advise 6 students all of which are very smart and most of the time hardworking. This is who they are and what they do (names are listed here in order of appearance, I love them all the same):

  • Yichuan Hu. Yichuan started at Penn in Fall 2009 after getting his M. Sc. degree from the University of Delaware. The goal of Yichuan's Ph. D. is to develop theory and algorithms for wireless networks when channel state information (CSI) is imperfect. What makes this problem interesting is not that CSI is imperfect but that is different at different nodes. Nodes know their local channels well, have some information about the channels of their neighbors and a rough idea of how the rest of the network looks like. We want to determine an optimal allocation of resources in this setting that takes into account the fact that different terminals have different beliefs on the network state and are bound to select conflicting actions.
  • Felicia Jakubiec. Felicia got her M. Sc. from Georgia Tech and started working on her Ph. D. at Penn in Spring 2011. Felicia works in advancing the theory of distributed statistical signal processing. It has become common in many contexts that acquisition of information about events of interest happens in a distributed network. The problem that arises here is how to aggregate this distributed information into distributed estimates that incorporate information acquired elsewhere in the network. Of the many problems that are of interest in this context Felicia focuses on the estimation of dynamic processes.
  • Ceyhun Eksin. Ceyhun began his Ph. D. studies in Fall 2009 and has been working with me since Fall 2011. He holds a degree from Istanbul Technical University. Ceyhun's Ph. D. work is on models of optimal behavior in social, biological, and technological networks. The problem here involves a network of agents that observe actions of neighboring peers and respond optimally to those observations. Over time, the repetition of actions that are optimal in a local sense leads to the emergence of some global behavior. Ceyhun's work is on characterizing these emergent global behaviors depending on the type of local interactions.
  • Santiago Segarra. Santiago holds a degree from Instituto Tecnologico de Buenos Aires. He spent a semester at Penn as an undergraduate and started work towards his Ph. D. in Fall 2011. The intent of Santiago's Ph. D. is to devise ways of modeling networks more appropriate than the graph models in current use. To take a motivating example consider the idea that the human social network has a diameter smaller than 6. If you look at the evidence supporting this claim you'll see that the conclusions depend on what is meant by a connection between two individuals. You are certainly connected to your close friends and certainly not connected to people you've never seen. In between, however, the decision is not clear cut. Are you connected to your next door neighbor? And to the coffee shop cashier that you see everyday but whose name you can't remember? Santiago's work in this area is based on the idea that different connectivity resolutions give rise to different networks, that all resolutions are important, and that all resolutions shall be reported. His intent is then to define a network as a family of graphs indexed by a connectivity parameter. Whereas in a graph the goal is to study numbers that summarize its properties, the objective in Santiago's work is to study corresponding functions of the connectivity parameter that summarize properties of the graph family.
  • James Stephan. Jim has a double degree in Computer Science and Electrical Engineering as well as a M. Sc. degree all from Johns Hopkins. He worked at Northrop Grumman for four years before starting his Ph. D. at Penn in Fall 2011. Jim's work is on communication between mobile robots in an autonomous team. It is common to conceive of teams of robots that cooperate to accomplish some task. A prerequisite for collaboration is that the robots should be able to communicate with each other. This is easier said than done because the teams are to be deployed in challenging electromagnetic propagation environments. The purpose of Jim's work is to develop protocols to provide seamless connectivity as robots move to accomplish their assigned tasks.
  • Aryan Mokhtari. Aryan is a graduate of Sharif University of Technology and started at Penn in Spring 2012. A lot of the work that I do relies on stochastic approximation algorithms to determine optimal operating points in wireless systems. This algorithms are stochastic versions of gradient descent and as such exhibit slow convergence rates. Aryan is focusing in the development of faster convergence alternatives to stochastic approximation.