Specializing pedestrian maps to address the needs of people using wheelchairs: a case study in community-sustainable information systems

Gemstone Team FASTR (Finding Alternative Specialized Travel Routes)

Tying it Together: Education-Focused Community Change Initiatives

Policymakers make many demands of our schools to produce academic success. At the same time, community organizations, government agencies, faith-based institutions, and other groups often are providing support to students and their families, especially those from high-poverty backgrounds, that are meant to impact education but are often insufficient, uncoordinated, or redundant. In many cases, these institutions lack access to schools and school leaders. What’s missing from the dominant education reform discourse is a coordinated education-focused approach that mobilizes community assets to effectively improve academic and developmental outcomes for students. This study explores how education-focused comprehensive community change initiatives (CCIs) that utilize a partnership approach are organized and sustained. In this study, I examine three research questions: 1. Why and how do school system-level community change initiative (CCI) partnerships form? 2. What are the organizational, financial, and political structures that support sustainable CCIs? What, in particular, are their connections to the school systems they seek to impact? 3. What are the leadership functions and structures found within CCIs? How are leadership functions distributed across schools and agencies within communities? To answer these questions, I used a cross-case study approach that employed a secondary data analysis of data that were collected as part of a larger research study sponsored by a national organization. The original study design included site visits and extended interviews with educators, community leaders and practitioners about community school initiatives, one type of CCI. This study demonstrates that characteristics of sustained education-focused CCIs include leaders that are critical to starting the CCIs and are willing to collaborate across institutions, a focus on community problems, building on previous efforts, strategies to improve service delivery, a focus on education and schools in particular, organizational arrangements that create shared leadership and ownership for the CCI, an intermediary to support the initial vision and collaborative leadership groups, diversified funding approaches, and political support. These findings add to the literature about the growing number of education-focused CCIs. The study’s primary recommendation—that institutions need to work across boundaries in order to sustain CCIs organizationally, financially, and politically—can help policymakers as they develop new collaborative approaches to achieving educational goals.

Sparse Signal Representation in Digital and Biological Systems

Theories of sparse signal representation, wherein a signal is decomposed as the sum of a small number of constituent elements, play increasing roles in both mathematical signal processing and neuroscience. This happens despite the differences between signal models in the two domains. After reviewing preliminary material on sparse signal models, I use work on compressed sensing for the electron tomography of biological structures as a target for exploring the efficacy of sparse signal reconstruction in a challenging application domain. My research in this area addresses a topic of keen interest to the biological microscopy community, and has resulted in the development of tomographic reconstruction software which is competitive with the state of the art in its field. Moving from the linear signal domain into the nonlinear dynamics of neural encoding, I explain the sparse coding hypothesis in neuroscience and its relationship with olfaction in locusts. I implement a numerical ODE model of the activity of neural populations responsible for sparse odor coding in locusts as part of a project involving offset spiking in the Kenyon cells. I also explain the validation procedures we have devised to help assess the model's similarity to the biology. The thesis concludes with the development of a new, simplified model of locust olfactory network activity, which seeks with some success to explain statistical properties of the sparse coding processes carried out in the network.

Dielectric studies of Liquid Crystal Nanocomposites and Nanomaterial systems.

Liquid crystals (LCs) have revolutionized the display and communication technologies. Doping of LCs with inorganic nanoparticles such as carbon nanotubes, gold nanoparticles and ferroelectric nanoparticles have garnered the interest of research community as they aid in improving the electro-optic performance. In this thesis, we examine a hybrid nanocomposite comprising of 5CB liquid crystal and block copolymer functionalized barium titanate ferroelectric nanoparticles. This hybrid system exhibits a giant soft-memory effect. Here, spontaneous polarization of ferroelectric nanoparticles couples synergistically with the radially aligned BCP chains to create nanoscopic domains that can be rotated electromechanically and locked in space even after the removal of the applied electric field. The resulting non-volatile memory is several times larger than the non-functionalized sample and provides an insight into the role of non-covalent polymer functionalization. We also present the latest results from the dielectric and spectroscopic study of field assisted alignment of gold nanorods.