Research Projects

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The following only represents a small sample of research projects I have worked on. Please ask me if you have any questions about these or any other projects.

Rover: A Context-Aware Architecture and Platform

University of Maryland, College Park - Maryland Information and Network Dynamics Laboratory
Led by Professor Ashok K. Agrawala and Dr. Christian B. Almazan. Applications Developed by Countless Talented People, with Special Thanks to Vinay Gangadhar, Thomas Krug, Saurabh Kulkarni, and Ankur Oberoi. Thanks to all participants at the 2008, 2009, and 2010 Maryland Day Events.

Dissertation Defense, Technical Video of Rover Applications (MyeVyu and V911): [wmv (43mb)]

The main topic of my doctoral dissertation, Rover aims to be a context-aware framework which manages entity context effectively on a Rover server. Entities can be the Rover server itself, any variety of client devices, and services (including databases) connected to a Rover server. At its core, a Rover server (written using Python and Twisted) effectively receives messages, retrieves information from a variety of services, and can push information to any entity connected to it. Rover servers have been tested in multiple environments (Linux and Windows) over multiple communication mechanisms (WiFi and WiMAX). Entities connect via any number of interfaces (including TCP, TLS, RPC, HTTP, and HTTPS) and must be authenticated with a Rover server and the server has a pluggable authentication scheme.

Entities can communicate with each other through the messaging calls, either directly or broadcasting messages based on context (such as sending a message to everyone whose context indicates they are in a particular building). Any number of services can be provided to entities, including external web services. Rover stores active context as provided by entities. All calls to the Rover server are actively recorded into a database, including requests and responses to external servers.

An important aspect of my work has also focused on defining entity spaces called a Rover ecosystem. Related entities should communicate with each other and nothing more. For instance, in a campus environment, Users (such as students) communicate with each other. If we consider an emergency scenario, Rover can be used to communicate with public safety personnel. A Dispatcher can pickup requests for assistance from Users in a Campus Rover ecosystem and forward them to First Responders in an Emergency Personnel Rover ecosystem, thereby separating the two. In this case, the Dispatcher acts as an intermediary to manage the flow of information between the two Rover ecosystems, but this process can be automated. This separation allows a clean separation of domains and aids in preparing any security considerations which must be put in place.

Rover has been used as the basis of two applications: MyeVyu and V911. Both of these applications received a fair amount of press and we actively collaborate with other university departments and efforts. These two applications have been described below.


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MyeVyu: Improving the Quality of Life in Campus Environments

Collaborating with the Office of Information Technology and the Mobility Initiative.

MyeVyu has been developed with one goal in mind: enhancing the quality-of-life of individuals and groups who use it. This application uses context provided by users to enhance services which have been integrated into a particular Rover server. These services include real-time transit information, dining services, and localized weather information, all available on the web and on mobile devices. Some of the applications we have developed are illustrated on the picture to the left.


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V911: Next-Generation 9-1-1

Collaborating with the Department of Public Safety.

As it stands today, 9-1-1 response mechanisms do not take into account the rise of connectivity and technology people carry around with them today. Although the Apple iPhone revolutionized the way people connect to the Internet in 2007, 9-1-1 public safety answering points and first responders do not utilize mobile devices to their fullest. Recently, I witnessed a tragic 9-1-1 medical call dialed from an Apple iPhone in which the context (location) and capabilities (audio and video) did not transmit to the appropriate individuals and groups.

Our efforts transmit all of the possible context a mobile device provides (such as GPS location or WiFi signal strength information) and starts an audio/video stream to a dispatcher, which in turn queries databases which may contain relevant information regarding the emergency call, such as the person's information.

Recently, as part of Project WiLD, we have consumed and produced location for multiple standards. These standards include HTTP Enabled Location Delivery (HELD, as implemented by Raytheon/BBN Technologies) and Location in SIP/IP Core (LOCSIP, as implemented by Telcordia Technologies). Although HELD and LOCSIP have completely different paradigms, by using Rover we demonstrated how they can interoperate with each other through one or more Rover ecosystems.


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Horus: Location Determination through Analyzing Signal Strength

University of Maryland, College Park - Maryland Information and Network Dynamics Laboratory
With Professor Ashok K. Agrawala, Dr. Moustafa Youssef (his Ph.D. dissertation), Dr. Chuck Rieger, and Matthew Mah.

One of the two actively developed indoor and outdoor location determination technologies developed at the MIND Lab (the other called PinPoint, based on time-of-flight measurements), Horus uses signal strength sensor information gathered from wireless devices. Horus uses two phases: an offline phase in which signal strengths are collected at various points on a map and then an online phase in which collected signal strength is actively fed to an algorithm, based on Bayesian probability and the signal strengths collected in the offline phase, which computes the location of a wireless device. The picture illustrates the offline phase with blue dots and the estimated location during the online phase with a purple dot.

I developed signal strength collection nodes which collect signal strength pushed to a program on the local machine, socket, or web server. Initially, we used laptop computers running Windows XP with wireless PC cards with Orinoco chipsets, but have moved towards collecting signal strengths from internal wireless cards, to mobile devices (such as the Nokia N810 running maemo), and to embedded computers (such as the Rabbit MiniCore microprocessor). As wireless chipsets and the software interfaces which access them can give signal strengths with varying statistical characterstics, other researchers have been involved in seeing how each individiual chipset and access mechanism may be able to map to each other. I have been focused on evaluating different chipsets and seeing how accurate each individual chipset performs using the Horus algorithm.

I have also ported the original dissertation code from C++ to C#.NET. This enables Horus to be used in standalone applications and in a web server environment (using a Microsoft Internet Information Services server with ASP.NET). Prior to this, I prototyped the Horus algorithms with Python.


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Distributed Coalitions (DisCo)

New York University - Parallel and Distributed Systems Group
Efforts led by Dr. Vijay Karamcheti and Dr. Eric Freudenthal.

I assisted in the development of a toolkit, written in Java, used in the Distributed Coalitions (DisCo) project. The project as a whole included tools which expressed access rights (Distributed Role-Based Access Control, dRBAC), a modular and secure communication stack (Switchboard), locality-aware service discovery, and component deployment using the three other tools to machines which may lose privileges in an instant. For instance, if a person has been compromised, the system needs to reflect this. This influenced general thinking in the future in which my thesis which focused on a broad area using context to influence decisions that go beyond just security.

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Christian B. Almazan
Centennial, CO
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