Due to the limitations of its analog flight control system, the F-14 aircraft exhibited several major flying qualities deficiencies. To correct these deficiencies, the Department of the Navy instigated a program to replace the analog system with digital flight control computers incorporating enhanced control laws. A new control law was designed for the powered approach configuration (landing phase) using classical control techniques, and demonstrated greatly improved flying qualities in piloted simulator testing. To determine if further increases in system performance were realizable, an advanced multivariable control system was designed. Although the multivariable control law design resulted in excellent flying qualities, a significant improvement was not realized over the classically designed system and therefore should not be considered for implementation into the actual flight control software. / Master of Science

The use of plasma-sprayed coatings as surface pretreatments for adhesive bonding has been investigated. Increased pressure by the Environmental Protection Agency and other environmental groups has prompted the search for environmentally safe methods of pretreating metals before bonding. Plasma spraying techniques may offer an appropriate non-chemical-solution method to prepare metal surfaces for adhesive bonding. The technique has the capability of coating an adherend with almost any chemical compound. Plasma spraying techniques allow for optimization of coating characteristics such as thickness, porosity, and uniformity. Both the chemical and the physical properties of an adherend surface coating influence the durability performance in a bonded sample. Polymer and inorganic powders were plasma-sprayed on aluminum and titanium. Polymer powders included an epoxy, a polyester, a bismaleimide/cyanate ester mixture, and a bismaleimide/LARC TPI 1500 mixture. Inorganic powders, Al₂O₃, AIPO₄, MgO, and SiO₂ were sprayed on aluminum adherends, and TiO₂, TiSi₂, MgO, and SiO₂ were sprayed on titanium adherends. Inorganic coatings were sprayed at two different coating thicknesses. Surface analytical techniques, X-ray Photoelectron Spectroscopy (XPS) and Scanning Electron Microscopy/Energy Dispersive X-ray analysis (SEM/EDX), were used for the surface characterization of the plasma-sprayed adherends and failure surfaces. XPS results suggest that the chemical state of an element is sometimes altered during the plasma spraying process. SEM photomicrographs reveal various topographical differences in the sprayed coatings. All polymer powders were smooth with the exception of the bismaleimide/polyimde samples. The inorganic specimens exhibited differences in coating uniformity and surface morphology. The strength and durability of samples where the plasma-sprayed coatings were used as surface pretreatments for adhesive bonding were evaluated by loading the bonded specimens with either a peel or a shear stress and cycling the specimens through an environmental cycle that would simulate use conditions. The durability tests suggest that many of the samples prepared using thin plasma-sprayed coatings had crack growths and failure modes equivalent to reference specimens, phosphoric acid anodized aluminum and Turco 5578 treated titanium. / Master of Science

This study examined how the nursing home search and selection process may vary depending upon the sponsor's gender and relationship to the patient. Based on previous studies on caregiving, I assume that different gender and kin roles are associated with varying self-perceptions as caregivers according to societal expectations. Symbolic interaction ism suggests that these differential caregiving self-perceptions may be reflected in actual searching activities and in perceptions about the search and selection process. The data set for this investigation was taken from the Virginia Nursing Home Search and Selection Survey. Relationship- and gender-based group differences (spouses/adult children/others, females/males, and daughters/sons) in searching activities and perceptions about the search and selection process were assessed among 149 respondents who identified themselves as responsible parties for the process. The results showed that closer kin, females, and daughters did not differ from their counterparts in most cases of searching activities, such as searching time, the number of facilities considered and visited, and the number of facility attributes considered. The only significant differences were found in male-female comparisons regarding the number of facility attributes considered. On the other hand, there were significant group differences across gender and relationship type in the degree of negative feelings about the search and selection process: adult children, females, and daughters were found to have more negative perceptions about their experience than others, males, and sons, respectively. Moreover, daughters were found to be the most negatively affected group during the search experience. The need for an educational campaign or program to reduce family members' negative perceptions about the search and selection process is discussed. / Master of Science

The parallel pattern single fault propagation (PPSFP) method is known to be the most efficient for fault simulation of combinational circuits. Recently, PPSFP has been extended to synchronous sequential circuits [1]. The fault simulator called PARIS is the unique sequential circuit fault simulator based on PPSFP. In this thesis, four new heuristics are proposed to enhance the speed of PARIS. The four heuristics are: 1. Immediate fault dropping after every iteration, 2. Filler bit simulation at the first packet 3. Look-ahead of initial states, and 4. Single bit correction for flip-flop evaluation. The four heuristics have been implemented separately, and the performance of the heuristics were measured. According to our results, the four heuristics improve the speed of most benchmark circuits. The four heuristics are integrated into a fault simulator, which we call VISION. The speed of VISION is, on an average, 1.3 times faster than PARIS for the benchmark circuits. / Master of Science

We prove that no disjoint union of any number of copies of even dimensional complex projective space can bound a smooth oriented compact manifold with boundary. We prove this by defining and computing certain algebraic invariants for smooth oriented manifolds. A non-diffeomorphic relationship is established between boundary manifolds and complex projective space by contrasting invariants computed for these spaces. / Master of Science

This thesis is a search for a position about architecture. The position which I have been exploring is found in the simplicity of the forms, geometry and conditions in the architecture of the Shakers and the Ticino architects in Switzerland. The formal simplicity of this architecture allows for a clarity in the relationship between light, construction and space. This position 1s investigated through the design of four contiguous houses which are one point “..in the slow unfolding of form.”. This project looks at autonomous architecture and its generation as the manipulation of simple geometries. Inherent in the idea of architectural autonomy is the notion of architecture as an object of pure form. As formal objects, these houses explore the ability of architecture to be generated from within. However, realizing that form and geometry alone do not necessarily equal architecture, these houses find architecture within the complex relationships between geometry, light, space and construction. / Master of Architecture

The architectural design process is a cycle of analysis and synthesis which ultimately yields a built structure that responds not only to functional needs but also provides revelations about the world in which we live. Architecture presents a dialogue at different levels and scales, allowing for many interpretations as well as revealing basic truths. / Master of Architecture

"The problem of the contemporary language of Greek architecture still remains ‘unsolved’ and any debate about the contemporary ‘Greek styles’ is a debate about the ideology and culture of today." Christofellis, Alexander, Function and Strategies of Architectural Composition The primary motivating force that led to the realization of this project, was a continuous need I felt to "reconnect" with the physical and spiritual reality of Greece, for this is the place I shall return to and attempt to understand and taste the next step of my life. Throughout the past six years of my studies within the realm of architecture, Greece was standing like a shadow away from the "center of the picture"; mostly referred to as a "historic place" or "the land of Acropolis", it was treated as "a country of the past." My perception of Greece is that of a place which is still very much alive and evolving and my desire was to find a way to communicate these intense feelings. This is the reason I chose to work on a project that takes place in the shadow of the rock of the Acropolis, the symbol of both past and future Greece. The difficulties and dangers of using such a site, became apparent during my visit and subsequent analysis of the context of the area. This thesis has become a stepping stone in my understanding of the architecture of Greece, its forms, its materials, its images, its sunlight...As one can understand, such a project was the "excuse" for something bigger than just the completion of a degree. It signified the acceptance of a new responsibility in terms of understanding and acknowledging the physical and social complexities of the specific region of Greece. I urge the reader to see this thesis not as having an end within itself but rather as an initiative towards the refinement of my perception and the formalization of my position on architecture and architectural thought. Its primary intent was to enable me to explore the fundamental issues and concerns derived from the life, attitudes, climate, context, materials and topography within Old Athens, in the specific region known as Plaka. Therefore, the whole process is just part of a personal search which will continue as I return to Greece and try to evaluate the assumptions, thoughts, criticisms and approach that I assumed. / Master of Architecture

The following project is an enclosed ice skating facility located in Fairfax County, Virginia. The Ice Rink will be constructed to support and encourage all phases of skating activity including figure skating, hockey, and year ‘round recreational skating. Because there is only one other enclosed ice skating rink within a 60 mile radius and the demand for ice time at that rink is nearing capacity, the need for another facility is great. During the winter months, there is a diminished number of activities, especially for children. There, the creation of an ice rink becomes not only a catalyst for exercise and enjoyment, but it also provides relaxation and a place to gather and socialize. Fairfax County has already proposed locating a facility in Lake Fairfax Park. The project’s inclusion on the site requires a large number of parking spaces to accommodate ice rink patrons as well as support the existing buildings, future park construction, and other activities that will occur at Lake Fairfax Park. The project is intended to accommodate functions other than those involving ice skating. Included are a large number of offices that will provide space for the Park Authority management. A section of the building, near the main entrance, will act as a visitor’s center and provide information on all park activities and events. Overall, the project will support a variety of recreational activities and events and promote greater interest in Lake Fairfax Park and the surrounding area. / Master of Architecture

This thesis is about the process of discovery. It is a search for an ordered architecture that is faithful to the generating ideas that formed it. It is the creation of an architecture that captures the spirit of the place where it lives. The form of architecture is the manifestation of an idea that satisfies and expresses a need. The purpose of architecture is to inspire and fulfill the spirit. But the true essence of architecture lies beyond appearance. It is an internal quality revealed by what it is, what it represents, and what it contributes to mankind. It is essential to reach beyond merely satisfying the functional requirements of a building to create meaningful architecture. Architecture is born from an idea and success is measured by how well that idea is portrayed. Ideas can be expressed in an infinite number of ways and studying the guiding principles proven throughout history can help to govern and direct a design as it progresses. True architecture results from an uncompromising position about certain ideas and the resulting work reveals the dedication to those ideas. / Master of Architecture