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.

REQUIRED VIOLA REPERTOIRE FOR THE PRIMROSE COMPETITION AND THE TERTIS COMPETITION

William Primrose (1903-1982) and Lionel Tertis (1876-1975) made the viola a grand instrument for public performances of solo and chamber music throughout their long and active lives characterized by a common passion for the viola. I, too, have been deeply inspired by their passion for the viola. I chose, therefore, for my doctoral performance project to feature works for viola from the required repertoire of the William Primrose and Lionel Tertis competitions of 2001 and 2003, respectively. For purposes of the performances, I divided selections from the combined repertoire for the William Primrose and Lionel Tertis competitions into three recitals. The first recital included Sonata, Opus 120, No.2 in E-flat Major (1894) by Johannes Brahms; Sonata, Opus 147 (1975) by Dmitri Shostakovich; and Sonata (1919) by Rebecca Clarke. These pieces represent standard components of the general repertoire for both the Primrose and Tertis competitions. The second recital was comprised of two works dedicated by their composers to Primrose: Lachrymae, Opus 48 (1950) by Benjamin Britten; and Concerto (1945) by Bela Bartok. The third recital included three pieces dedicated by their composers to Tertis: Sonata (1922) by Arnold Bax; Sonata in C Minor (1905) by York Bowen; and Sonata (1952) by Arthur Bliss. The goal of my preparation for these recitals was to emphasize a variety of techniques and, also, the unique timbre of the viola. For example, the works I selected emphasized high-position technique, which was not much used before the nineteenth century, and featured the lowest string (the C-string), which provides a beautifully somber and austere sonority characteristic of the viola. For these reasons, the selected works provided not only attractive and interesting pieces to study and perform but were also of educational merit.

A GOLDEN AGE: FRENCH AND SPANISH CELLO MUSIC FROM SAINT-SAENS TO CASSADO

Motivated by both the delicacy of French music, such as La Mer by Claude Debussy, and the exotic atmosphere of Spanish music, such as Zigeunerweisen by Pablo Sarasate, I decided to investigate the characteristics of French and Spanish cello music from Camille Saint-Saens to Gaspar Cassad6. French cello music flourished from the end ofthel9th to the middle of the 20th century because of the innovation of many unprecedented techniques and experimentation with a variety of sonorities. The Spanish were heavily influenced by the French due to the geographical connection. Cello virtuosi like Auguste Tolbecque, August Franchomme, Pierre Fournier, and Paul Tortelier inspired composers of their day, creating a "golden age" of cello music. This dissertation consisted of three recitals in Gildenhom Recital Hall. The first recital was held on May lOth, 2007 at 5:30pm with pianist David Ballena. The second recital was held on October 14th, 2007 at 2pm with collaborators Minna Han, piano and Jenny Wu, violin. The third recital was held on March 301 2008 at 5:30 with pianist Naoko Takao. Here is the program of the recitals: The first recital: Gabriel Faure(1856-1924): Sonate pour Violoncello et Piano Op.109(1917) Gaspar Cassad6 (1897-1966): Suite per Violoncello Solo (1926) Claude Debussy (1862-1918): Sonate pour Violoncelle et Piano (1915) The second recital: Manuel de Falla (1876-1946): Melodia (1897), Romanza (1898) Camille Saint-Saens (1835-1921): Concerto for Cello and Orchestra No.1 in A minor Op.33 (1873) Maurice Ravel (1875-1973): Sonata for Violin and Cello (1920-22) The third recital: Pablo Casals (1876-1973): Song of the Birds (1925) Edouard Lalo (1823-1892): Concerto for Cello and Orchestra in D Minor (1877) Franscis Poulenc (1899-1963): Sonata for Cello and Piano Op.l43(1940-48)