The objective of this thesis is to determine the average probability of bit error of an asynchronous, noncoherent, direct-sequence, code-division multiple-access (CDMA) system using wideband M-ary FSK as bandpass modulation. The immediate analysis and determination of the average probability of bit error is made inherently more difficult because of two random effects. The first disturbance encountered in the analysis is the existence of additive, white, Gaussian noise and multi-user noise. The second disturbance, which is more difficult to analyze, is the effect of multipath fading, which is caused by reflections of the transmitted signal through the propagating medium to the receiver. / Master of Science

Twenty-five gay men, 20 with Acquired Immune Deficiency Syndrome (AIDS) and 5 with either AIDS Related Complex (ARC) or who tested positive for the AIDS virus, were asked in semi-structured interviews whether they felt supported or isolated. Areas covered included society in general, employment, housing, health care, insurance, religion, families of origin, ex-wives, children, friends and lovers. Subjects indicated that fear of AIDS, homophobia, and death anxiety were all present in certain circumstances, but there was no attempt to differentiate between these three possible causes of social isolation in this exploratory study. / Master of Science

Software development cost estimating models were analyzed using an application of the hedonic pricing approach. Several recently proposed software cost estimating tools were surveyed for the purpose of revealing their roots in the hedonic pricing approach. The analysis includes discussion of the hedonic pricing approach, the logic of several software cost models, and analysis of the models' hedonic pricing traits. Hedonic prices are the implicit prices of attributes of I differentiated products as revealed in the market through attribute levels associated with market-clearing prices. Several aspects of the software costing models fit within the hedonic pricing approach. Many of the models base cost estimates on the varying quantities of software product attributes (e.g., complexity of program, schedule requirements, etc.). Similarities and differences of traits among cost models were noted. / Master of Arts

A survey of research in nonlinear optical fibers is given. Important background concepts are introduced and explained. Present and future applications of nonlinear optical fibers arc reviewed. A mathematical model of a nonlinear optical fiber is developed using a coupled-mode theory approach, and methods of solving nonlinear partial differential equations arc discussed. A detailed history of research in the field is given, and recommendations for future research are made. / Master of Science

Scholars in many fields have long studied the patterns of employment and promotions in industries and occupations. However, the area of sport has been largely omitted from studies of this type. This study explored the possibility of an internal labor market for head coaches of the National Football League (NFL). Subjects were those people who were the head coaches of NFL teams for the years 1970 to 1975 and 1980 to 1985. Following theoretical guidelines, the subjects were tested for evidence of industrial, occupational, and/or pure internal labor markets. Statistical treatment of the data utilized chi square tests. The results of this study provided evidence of industrial and occupational internal labor markets, but there was no support for a pure internal labor market. The tests showed an intertwining of the industrial and occupational internal labor markets over the course of the subjects' careers. There also were significant findings in the areas of mentor and position played by the subjects. This study can serve as a foundation for further studies. / Master of Science

Music composed by computers has always been lacking in "musical" qualities: mood, emotional expression and a sense of purposefulness or goal. A musical expert system, called EMOTER, is the first attempt to address these important musical aspects. EMOTER receives as input a list of moods (e.g., happy, lively) and generates melodic passages intended to evoke those moods in an organized, coherent fashion. EMOTER composes the basic units of music called phrases. The program uses the mood-specification from a theory due to Deryck Cooke to derive a few motifs (very primitive melodic material) exemplifying the moods and computes a number of musical attributes to guide its compositional choices. A theory of emotion due to Leonard Meyer further helps plan the phrase. The theory states that an emotional response is stimulated in a listener when expectations about the progression of the music are first established and then inhibited (with the understanding that the expectations will eventually be fulfilled). A melodic passage is composed using the selected motifs, attributes and emotional theory to create a "skeletal" phrase. This is embellished and developed (also using the attributes and theory) to flesh-out the bare melodic material into a passage that embodies the musical characteristics of the mood-specification. Results with EMOTER are excellent. Many musical phrases comparable to music of normal composers are generated from a single mood-specification. More theory is needed, however, before the full complexities of human-composed music are sufficiently captured in code for EMOTER to pass a Turing test in music composition. / Master of Science

Collision-detection is a critical task for off-line robot path planning. A general robot path verification simulation system, GRPVSS, applicable for all industrial robots with open-looped links, is created to verify the intended robot path. The manipulator and obstacles are modeled by convex polyhedra to reduce the computation burden required by the collision detection algorithm. As a kinematic simulator, GRPVSS employs motion-time profiles or ideal trapezoid profiles which describe the position-vs-time relation of an individual joint, to generate the robot working trajectory. This approach makes the to-be-verified working path closer to the real one. Both point-to-point(PTP) and continuous path(CP) operations can be simulated by GRPVSS. Collision detection is conducted by performing geometric interference detection between the static configurations of the expanded moving robot and the static obstacles at each simulation step. Inn this case, the resolution of a simulation is critical to path verification. Simulations with low resolution take the risk of undetected collisions, while simulations with high resolution consume too much computing time. GRPVSS computes and employs the lowest resolution level that yields 100% path verification for the specified tolerances of manipulator dimensions. The tolerance value is specified by the user but should not be specified smaller than the positioning accuracy of the simulated industrial robot. The links of the manipulator are expanded by the amount of tolerance. GRPVSS is a graphic simulator. A systematic control supervisor is constructed for the simulator to request input and to proceed all functions interactively with users. The robot motion of a simulated path is animated on a 3-D graphical screen. A11 collision configurations and related information of the simulated path are stored in a file and shown on the screen. The graphical display works on graPHIGS, one of the 3-D graphical software packages published by IBM. / Master of Science

Wide-bore, fused-silica capillary columns can be an excellent replacement for packed columns in many cases. They can provide higher surface inertness and thermal stability, as well as higher efficiency or speed of analysis. Wide-bore, open-tubular (WBOT) columns with thick films have higher sample capacities than conventional narrow-bore capillary columns and can be used in unmodified packed-column gas chromatographs. The majority of gas chromatographic analyses are still performed using packed columns. Many chromatographers associate open-tubular columns exclusively with split injection, often perceived as less repeatable or quantitative. Also, many packed-column methods use application-specific stationary phases which are not readily available on capillary columns. WBOT columns with standard phases can often be substituted due to higher available efficiencies. While several studies have been published on qualitative differences, there is little comparative quantitative data available on O.53â mm I.D. and packed columns. / Master of Science

E_h-pH diagrams were constructed from mass-balanced, computer calculations for the copper-sulfur-water system involving different Cu/S ratios that pertain to chalcocite, djurleite, anilite and covellite. Calculations were completed for cases where oxidation of the sulfur proceeded to i) elemental sulfur, ii) thiosulfate, iii) sulfate and iv) destabilized sulfate. Stability regions for each copper sulfide were shown to be dependent on both the Cu/S ratio in the system and the sulfur oxidation state. E_h-pH diagrams were also constructed for chalcocite oxidation to metastable copper sulfides, both with and without xanthate. Stability regions for copper xanthates were also shown to be dependent on the sulfur oxidation state. As oxidation proceeded from elemental sulfur to sulfate, the copper xanthate stability region extended to lower potentials, directly dependent on the sulfide ion concentration. IGP experiments at pH 1.1 suggested that chalcocite oxidation produced metastable nonstoichiometric copper sulfides while cyclic voltammetry indicated they formed at pH 1.1, 4.6, 6.8 and 9.2. XPS implied that copper sulfides may be solid solutions of chalcocite with variable amounts of copper disulfide: CU₂S·xCUS₂. The presence of djurleite in the chalcocite samples was confirmed by X-ray diffraction and may be responsible for the reduction reaction which occurred just prior to the reduction of chalcocite to metallic copper. Reinterpreting cyclic voltammograms from a previous study indicated chalcocite reacted with xanthate to form cuprous xanthate and a nonstoichiometric copper sulfide near 0 mV. Chemisorbed xanthate formed at -295 mV which correlated well with the lower flotation edge determined in this and other studies. The standard free energy of the chemisorbed xanthate was determined to be -13.08 kcal/mole. / Master of Science

This study considers an infinite orthotropic plate on a frictionless elastic foundation subjected to a transverse point load. We are concerned with the stress distribution in the vicinity of the load application. Based on the assumption of a uniform stress distribution under the load, a Fourier Transform technique is utilized to formulate and solve the problem in the transform domain. The inverse transformation is carried out numerically, via the Gaussian Quadrature scheme, to obtain the real response. Symmetry of the transform response due to the material orthotropy has been used to reduce the effort involved in performing the integration. Results indicated a similar symmetric behavior for the real stress distribution, and satisfied the boundary conditions of the problem. The transverse equilibrium is also verified by summing up the reaction forces exerted by the foundation. / M.S.