Doctoral Recital

List of performers and performances

A psychophysical study of visual texture

Thesis (Ph.D.)--Boston UniversityI. Introduction One of the major historical traditions in psychological research has been the investigation of the ways in which an observer can differentiate or discriminate various sensory events in relation to some objective dimension of the event. Furthermore, the features of sensory events investigated have been abstract properties of the stimulus for which there were already existing physical-measure correlates such as brightness, hue, distance, etc. The nature of sensory events, however, does not necessarily restrict one to investigation of these features. Gibson has recently formulated a theoretical view of visual perception in which the status of these features is secondary. His position asserts that the immediate given of visual experience is surfaces and thus directs concern to the properties of surfaces as sensory events. Although the concept of texture of a surface is a central one in his scheme, there seems to be a complete lack of psychophysical investigation of this notion in the literature. The above considerations led to the formulation of the present problem. Specifically, the relationship between a set of physical measure· operations and a set of observer responses on a class of stimuli denoted as "textured surfaces" was investigated. Texture in this study is defined as the distribution of alternations in light intensity over a surface on which areas of equal intensity occupy small portions of the surface relative to its total extent [TRUNCATED]

Fundamental Theory of Scientific Computer Simulation Review

"How much work is required to trust the results of a scientific computer simulation when human lives are at stake?" For many, this question is purely academic. But for those dealing with high consequence simulations, such as the simulations performed to demonstrate the safety of a nuclear power plant, the question is very pertinent and answering it is the domain of scientific computer simulation review. While simulation review has been performed for many years, it is rarely seen as a field of study in its own right. Consequently, requirements are often developed for a specific simulation and a particular use. If either the simulation or the use changes, new requirements must developed. To help solve this problem, some fundamental theory of scientific computer simulation review is proposed. This fundamental theory included the generation of a basic vocabulary, a formalization of the concept of maturity, the creation of simulation hierarchy, and the development of an assessment framework. A basic vocabulary was generated to define the many common and important concepts used in simulation review. By focusing on review in general, the resulting vocabulary captures many of the ideas important to all simulation reviews and provides a better means of discussing the trustworthiness of their results. The concept of maturity was formalized into Maturity Theory. This theory provides a detailed analysis of maturity, which was used to better understand the tools available in simulation review. The Hierarchy for Scientific Computer Simulations was created to capture the various components of a generic simulation and define the relationships between those components. This Hierarchy provides a methodology which can be used to organize and represent many simulations. The Theoretical/Logical Maturity Assessment Framework for Scientific Computer Simulations was developed using the concepts from Maturity Theory and the Hierarchy. This framework provides a structure which establishes the boundaries of simulation review, highlights many of the assumptions of a simulation which need to be supported if the results of the simulation are to be trusted, and establishes a method for its continually evolution. By contributing this fundamental theory, these advancements better established the field scientific computer simulation review

Documenting informal and customary land rights in Africa Challenges of using participatory means

The adoption of modern Land Administration Systems (LAS) in Sub Saharan Africa is done with the expectation that principles of equity, non-discrimination, efficiency, transparency, productivity and sustainability among others may be achieved to meet societal needs in those countries.  However, a lack of functional systems to document land through the provision of proper documentation particularly in Sub Saharan Africa has led to a high tenure insecurity in local communities, landlessness and a lack of proper investment in the land they hold. This study designed a typology that highlights key challenges of administering informal and customary land in five countries from different regions of Sub Saharan Africa regarded as leaders in land administration. Moreover, it proposes five innovative parameters for addressing the challenges of documenting informal and customary land rights using participatory means, such that governments can establish LAS that best meet the need of local communities