The thesis focuses on activity recognition from sensor data, which has spurred a great deal of interest due to its impact on health care and security. Previous work on activity recognition from multivariate time series data has mainly applied supervised learning techniques which require a high degree of annotation effort...
Realistic (ideally photorealistic) real-time rendering has remained an elusive goal in computer graphics. While photorealistic rendering has certainly been achieved at the expense of tremendous computational resources and corresponding rendering times; real-time rendering typically must accept a great number of compromises to achieve adequate performance, such as aliasing artifacts, the...
The study of variational typing originated from the problem of type inference for variational programs, which encode numerous different but related plain programs. In this dissertation, I present a sound and complete type inference algorithm for inferring types of all plain programs encoded in variational programs. The proposed algorithm runs...
A bad software development process leads to wasted effort and inferior products. In order to improve a software process, it must be first understood. In this work I focus on understanding software processes.
The first process we seek to understand is Continuous Integration (CI). CI systems automate the compilation, building,...
In this work, I examine the problem of understanding American football in video. In particular, I present several mid-level computer vision algorithms that each accomplish a different sub-task within a larger system for annotating, interpreting, and analyzing collections of American football video. The analysis of football video is useful in...
In real networks, identifying dense regions is of great importance. For example, in a network that represents academic collaboration, authors within the densest component of the graph tend to be the most prolific. Dense subgraphs often identify communities in social networks. And dense subgraphs can be used to discover regulatory...
In this thesis I present the choice calculus, a formal language for representing variation in software and other structured artifacts. The choice calculus is intended to support variation research in a way similar to the lambda calculus in programming language research. Specifically, it provides a simple formal basis for presenting,...
Software testing is of critical importance for the success of software projects. Current inefficient testing methods often still take up half or more of a software project's budget. Automatic test data generation is the most promising way to lower the software testing cost. Manually creating testing data is expensive and...
Many applications in computer graphics and geometry processing rely on the ability to
locally orient 2D and 3D entities on a surface, or inside a volume, such as the sinusoidal
kernels in Gabor noise, the color and geometry textures in pattern synthesis, and the
finite elements in remeshing. In these...
Most tasks in natural language processing (NLP) try to map structured input (e.g., sentence or word sequence) to some form of structured output (tag sequence, parse tree, semantic graph, translated/paraphrased/compressed sentence), a problem known as “structured prediction”. While various learning algorithms such as the perceptron, maximum entropy, and expectation-maximization have...