Human communication has become increasingly reliant on systems made and managed by large technology companies like Google, Apple, Twitter, and Meta (formerly Facebook). These systems offer people many benefits, but they also present new challenges for society. In recent years, researchers, lawmakers, and journalists have suggested that large technology companies...
This research looks at the robotic shape formation problem, which is one of the fundamental problems in robotic swarm systems. Here, the task is to move a group of robots to form a user-specified shape. In this dissertation, the task of shape formation is divided to four problems: (i) using...
In recent years, machine learning on graphs (or networks) has gone from a niche topic with only a few active researchers worldwide, to a heavily invested field with novel use cases for dealing with relationships and/or interactions within complex systems in the natural and social sciences. Traditionally, choosing the right...
Existing nonlinear optimization methods have proven reliable over the past few decades for a wide range of applications but have critically relied on accurate function and gradient evaluations. Modern nonlinear optimization problems arising from machine learning and scientific computing applications are increasingly complex and large scale, which make accurate evaluations...
The world is awash in data and much of artificial intelligence focuses on learning models of the underlying structure in this data or the mechanisms governing its evolution. Both neural and symbolic models have weaknesses that make these models sub-optimal from a use perspective. Much of this data is in...
X-ray imaging at nano and micro-scale is of great importance for the material science and defense industry. Large penetration depth and low wavelength of x-rays offer an important potential to image objects at high resolution and in a non-invasive process. While the ever-growing community is pursuing novel applications and looking...
This dissertation introduces several novel computational imaging techniques that capture and analyze the 3D surface shapes and internal layered materials. The research proposes user-friendly and non-invasive imaging systems, constructed using only commercial off-the-shelf (COTS) components, which provide accurate measurement of 3D information that was previously inaccessible. The dissertation focuses on...
Language models are the foundation of many natural language tasks such as machine translation, speech recognition, and dialogue systems. Modeling the probability distributions of text accurately helps capture the structures of language and extract valuable information contained in various corpora. In recent years, many advanced models have achieved state-of-the-art performance...
Many volunteer communities rely on technological systems to help their members connect, collaborate and learn the norms of how to participate in the organization. This dissertation presents research that examines technological interventions designed to support participation in three different volunteer-run communities, all of which have porous boundaries, and allow volunteers...
Visual Question Answering (VQA) increasingly attracts industry and academia attention. It requires the model to provide a natural language answer by an image and a related natural language question. Meanwhile, it relates to multidisciplinary research such as natural language understanding, visual information retrieval, and multimodal reasoning. As a multimodality task,...
Our experience of the physical world is mediated by our senses, but while most people have five senses, interactions with computer systems are largely limited to the visual sense. When working with nonvisual artifacts, like sound, on computers, such artifacts are typically transformed, or re-encoded, into something visual. Determining how...
Three-dimensional (3D) imaging has been widely used in academic research and industrial applications. Compared to 2D representations, 3D imaging can yield more information about geometric structures of an object such as small surface variations that are difficult to perceive otherwise. 3D image contents provide additional information that is complementary to...
We live in an increasingly computational world; one that, in the near term, may require everyone to be computationally literate. Computer science (CS) education has greatly increased its reach in the last two decades with an increasing number of students having access to formal computer science classroom experiences in the...
The study and design of machines that are able to analyze the auditory scene and organize sound into parts that are perceptually meaningful to humans is referred to as machine hearing. Such machines are expected to distinguish between different sound categories (e.g., speech, music, background noise), focus on a sound...
Imagine sitting in a room listening to some friends play a song. Perhaps one friend is playing guitar, another playing bass, and a third is playing drums. The musical content in this scene is extraordinarily complex, yet it contains many types of structure that is easy for us to comprehend....
In the late 2000’s, scientific studies in cultural heritage saw a great advancement in macro X-ray fluorescence (XRF) imaging of paintings. These images are used to generate elemental distribution maps, which aid in identifying chemical elements and paint pig- ments as well as their locations throughout the layers of the...
Location-aware technologies, such as personal navigation applications, location-based AR games, and artificial intelligence systems that learn from data about places, increasingly mediate our understanding of and interactions with the world. However, a number of risks associated with location-aware technologies have emerged, jeopardizing the welfare of its users. This dissertation seeks...
Due to their widespread applicability, graphs and networks appear in various contexts. The increasing scale of graphs encountered in the real-world requires the developmentof efficient algorithms that run reasonably fast and produce close to optimal solutions.
The main focus of this thesis is the development of fast graph algorithms for...
Social media and online forums provide spaces where people can gather beyond restrictions of geographic proximity. For some individuals with mental illness, these spaces are vital; providing outlets and communities where a multitude of experiences are accepted and understood, rather than judged against normative, often ableist standards. For nearly three...
Surface appearance represents the sense impression of the surface. In visual art, the artists try to use the appearance of their artworks to express their mental state and philosophy. Researchers in the cultural heritage community has been trying to use different analysis approaches to interpret artworks. In Computer Graphics and...