Towards Proactive Context-aware Computing and Systems

A primary goal of context-aware systems is delivering the right information at the right place and right time to users in order to enable them to make effective decisions and improve their quality of life. There are three key requirements for achieving this goal: determining what information is relevant, personalizing it based on the users’ context (location, preferences, behavioral history etc.), and delivering it to them in a timely manner without an explicit request from them. These requirements create a paradigm that we term as “Proactive Context-aware Computing”. Most of the existing context-aware systems fulfill only a subset of these requirements. Many of these systems focus only on personalization of the requested information based on users’ current context. Moreover, they are often designed for specific domains. In addition, most of the existing systems are reactive - the users request for some information and the system delivers it to them. These systems are not proactive i.e. they cannot anticipate users’ intent and behavior and act proactively without an explicit request from them. In order to overcome these limitations, we need to conduct a deeper analysis and enhance our understanding of context-aware systems that are generic, universal, proactive and applicable to a wide variety of domains. To support this dissertation, we explore several directions. Clearly the most significant sources of information about users today are smartphones. A large amount of users’ context can be acquired through them and they can be used as an effective means to deliver information to users. In addition, social media such as Facebook, Flickr and Foursquare provide a rich and powerful platform to mine users’ interests, preferences and behavioral history. We employ the ubiquity of smartphones and the wealth of information available from social media to address the challenge of building proactive context-aware systems. We have implemented and evaluated a few approaches, including some as part of the Rover framework, to achieve the paradigm of Proactive Context-aware Computing. Rover is a context-aware research platform which has been evolving for the last 6 years. Since location is one of the most important context for users, we have developed ‘Locus’, an indoor localization, tracking and navigation system for multi-story buildings. Other important dimensions of users’ context include the activities that they are engaged in. To this end, we have developed ‘SenseMe’, a system that leverages the smartphone and its multiple sensors in order to perform multidimensional context and activity recognition for users. As part of the ‘SenseMe’ project, we also conducted an exploratory study of privacy, trust, risks and other concerns of users with smart phone based personal sensing systems and applications. To determine what information would be relevant to users’ situations, we have developed ‘TellMe’ - a system that employs a new, flexible and scalable approach based on Natural Language Processing techniques to perform bootstrapped discovery and ranking of relevant information in context-aware systems. In order to personalize the relevant information, we have also developed an algorithm and system for mining a broad range of users’ preferences from their social network profiles and activities. For recommending new information to the users based on their past behavior and context history (such as visited locations, activities and time), we have developed a recommender system and approach for performing multi-dimensional collaborative recommendations using tensor factorization. For timely delivery of personalized and relevant information, it is essential to anticipate and predict users’ behavior. To this end, we have developed a unified infrastructure, within the Rover framework, and implemented several novel approaches and algorithms that employ various contextual features and state of the art machine learning techniques for building diverse behavioral models of users. Examples of generated models include classifying users’ semantic places and mobility states, predicting their availability for accepting calls on smartphones and inferring their device charging behavior. Finally, to enable proactivity in context-aware systems, we have also developed a planning framework based on HTN planning. Together, these works provide a major push in the direction of proactive context-aware computing.

SELECTED AMERICAN VIOLIN WORKS AND THEIR EUROPEAN CONTEXT

For my dissertation, I did a study and performance of American violin works by Charles Ives, Aaron Copland, Leonard Bernstein, and John Corigliano, along with contemporaneous European works by Paul Hindemith, Bela Bartok, Igor Stravinsky, Sergei Prokofiev, and Francis Poulenc. The selected American violin works display the development of a distinctively American style and cover a significant formative period (1914-1963) of American classical music. I intend that the European works form a backdrop for setting in relief any distinctly American qualities possessed by the American works. This is because they cover a similar time period and have significant stylistic affinities and shared influences. My topic stems from a question, "What defines the American Sound?" I attempted to find the answer by looking at the time when American composers consciously searched for their identities, and declared their music to be distinctly American. I found that those distinctive qualities stemmed from three sources: folk music, jazz and hymns. Ives and Copland can be viewed as American in content for their inclusion of such elements, while Bernstein and Corigliano can also be considered as "ideologically American" for their adventurous and eclectic spirit. The simplicity derived from singing a hymn or crooning a popular song; the freedom inspired by jazz; the optimism of accepting all possibilities-these elements inform the common spirit that I found in the music of these four American composers. FIRST RECITAL Sonatafor Violin Solo Op.3112 (1924), Paul Hindemith (1895-1963) Suite Italiennefor Violin and Piano (1932), Igor Stravinsky (1882-1971) Sonatafor Violin and Piano (1963), John Corigliano (b.1938) SECOND RECITAL Second Sonatafor Violin and Piano (1914-17), Charles Ives (1874-1954) First Rhapsody for Violin and Piano (1928), Bela Bart6k (1881-1971) Violin Sonata No.1 infminor (1938-46), Sergei Prokofiev (1891-1953) THIRD RECITAL Nocturne for Violin and Piano (1926), Aaron Copland (1900-1990)Sonata for Violin and Piano, Op. 119 (1942-3, rev.1949), Francis Poulenc (1899-1963)Serenade (after Plato's "Symposium'') (1954) by Leonard Bernstein (1918-1990) The pianists were Sun Ha Yoon (Bart6k) and Grace Eunae Cho (all other repertoire).