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An electrocardiogram analysis package is developed in this thesis. A parabolic smoothing with pre-set threshold for attenuating effects on high frequency components is applied. The GF and operational transforms are studied and examined for their constraints, applications and flexibility. These transforms are modified and adapted for recognition of QRS onset and offset in the Frank Orthogonal Lead System. An algorithm, based on a set of pre-set criteria and thresholds, is developed. Various clinical parameters, vectors and files for analysis. such as segment or wave intervals, magnitude, areas etc. are generated together with data two-dimensional and three-dimensional graphic In addition. a general purpose graphic package is supplied to create the vector displays for ECG analysis. The algorithm has been tested on three hundred cardiac cycles taken from ten patients with both normal and abnormal ECG characteristics. / Master of Science

Dimensionless hydrographs and equations for the time of equilibrium were developed for sections of nonuniform width. In order to determine the dimensionless hydrographs the equations of momentum and continuity were solved implicitly. This method was chosen because it is unconditionally stable independent of the time and distance increment. Using Manning's Equation for the frictional slope, a time increment of one-twelfth of the time of equilibrium, and boundary conditions of upstream depth and velocity equal to zero the dimensionless hydrograph for uniform sections matched that of the kinematic wave to nearly 60 percent of the equilibrium discharge. It also corresponded well with Morgali's results and Izzard's measured hydrograph. When the model was applied to sections of nonuniform width it was found only the end ratio, defined as the downstream width over the upstream width, affected the shape of the dimensionless hydrograph and the time of equilibrium. Equations were developed to find the time of equilibrium for ranges of end ratios. Corrections to find the hydrographs for sections of nonuniform width were determined to be applied to the kinematic wave discharge equation. For storms of duration less than the time of equilibrium the recession limb coincides with the recession limb from total equilibrium some time T after the rain ends. The time T was found to be independent of the end ratio and only affected by the discharge when the storm ended. / Master of Science

In light of the evidence presented, the modified model has been shown to be valid. However, as with any other validation using test cases, the results cannot be considered a truly formal or general proof of its correctness. However they provide grounds for future work attempting to apply the model, which leads to a series of proposals for future endeavours. Rauscher [1] intended that modelling processors be made an integral part of optimizers in translator systems dynamically microprogrammable machines. This is slightly more difficult to achieve automatically with the modified model than with the original one, since DO blocks and termination code must be recognized by the processor, however it is still very feasible. This shows that one useful investigation would be to search for other easily recognizable structures which may be used to reduce the range of transition probabilities generated for the model, thus further improving its accuracy. The modelling process takes a good deal of computing time, so that decreasing the number of sample probability sets generated could tremendously increase the efficiency of the model processor itself with respect to execution time of the optimizer. Further statistical tests should be devised to determine the number of samples necessary for an accurate result. Finally, the model at a stage where techniques should be developed for using it in applications such as optimization by dynamic microprogramming (1], data flow analysis for debugging [21J, and storage allocation in operating systems using paging. For all of these applications, knowledge of the relative frequency of code blocks is not enough, other information must be attached to the states of the model before it may applied to the problem. When dealing with the optimization of execution me, the execution time of the code in each block is needed. For data flow analysis and storage allocation purposes, a table of the variables used in each block and their attributes is necessary. All of this makes the author feel that there is still much work to be done with this Markov Model of Program Behaviour. / Master of Science

This thesis describes a process of how NASA maintained the NASTRAN (NASA Structural Analysis) computer program. Chapter one addresses my theoretical concern and suggests to learn from both critical theorists and social constructivists. Chapters Two and Three tell the story of NASA and NASTRAN, a computer program developed by NASA for solving problems of airframes and space structures. The story of NASA and NASTRAN demonstrates a structural imbalance between social groups of NASTRAN and results in the revision of NASTRAN in favor of aerospace users. Chapter Four recounts Feynman's concerns regarding the conflicts between managerial and engineering expertise. I discuss these issues in light of the story of NASA and NASTRAN. / Master of Science

Construction of braced excavations in major urban areas has increased over the last few decades. It is a major concern of the designer to limit ground movement around an excavation in order to prevent damage to adjacent structures, utilities and roads. Existing design methods can accurately predict ground and wall movement of a braced excavation, but the calculations become complex when multiple construction stages are considered, or if different design schemes are compared. This thesis presents an interactive personal computer program (called MOVEX) to facilitate braced excavation design. Using input variables for wall stiffness, strut stiffness, and strut spacing, MOVEX includes four design options that allow the designer to adjust the variables in order to develop the optimal bracing design. Details of the design theory, input and output data, and a user's guide are included in this thesis. In addition, the settlement of sand due to pile driving was investigated. A predictive method is presented that relates sand densification to the ground acceleration caused by pile driving. / 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

In recent years, many mathematical models have been developed to be used as mechanisms for carrying out stream and estuary investigations. In 1971, W.R. Schofield and R.G. Krutchkoff completed work on a stochastic model in an attempt to accurately describe the behavior of an estuary. Through the use of a high-speed computer this one-dimensional model predicts the concentrations of twelve interacting components, subdivided into five biological and seven chemical factors. This is a valuable tool, but from a practical viewpoint, the model is difficult to apply without a fairly strong background in computer science. It is the aim of the present study to simplify the use of the SchofieldKrutchkoff estuary model so that it can be readily accessible to the appropriate personnel, irrespective of their previous exposure to computer programming. Dependent upon the particular estuary studied, it was necessary to make internal program adjustments with respect to boundary conditions, applicable rate constants, tidal lag, and maximum tidal velocity rates. These constants have been replaced by variables for the user to define as input data to the main program segment. The options to choose one of several expressions for the oxygen reaeration rate K₂, whether to weight this equation with wind velocity, vary the volumetric freshwater flow rate with position and request plotted output for each day modeled have also been added. / Master of Science

Functional programming systems provide a number of features which facilitate program verification. Such verification may be observed to rest directly upon the theoretical foundations of computing and simultaneously to exhibit a close relation to the programs being verified. In order to demonstrate these aspects of functional systems, two functions, MIN and SORT, are defined on a parameterized type consisting of sequences to elements from some ordered type. Theorems showing that MIN and SORT terminate and return the correct values are stated and proved. Similar results are derived for a function to perform a binary search on an ordered sequence. Finally, conditions similar to Dijkstra’s weakest preconditions are given which allow the simultaneous synthesis and verification of certain programs from program specifications. A function to find the greatest common division of two integers is derived and verified. / M.S.

With the increasing need for large columnless structures in today's society, glued-laminated Triax domes are being designed and built. Even though many have already been constructed, no methods have been established to accurately determine the ultimate load capacity or the factor of safety. Several ABAQUS finite element analyses have been conducted at Virginia Polytechnic Institute and State University to determine these values (Davalos, 1989). The work in this area has been slowed due to the absence of a preprocessor for the creation of the input data file. The use of a preprocessor could greatly accelerate the analysis process and prove to be more efficient. The primary objective of this thesis is to present a clear detailed procedure for the creation of the input data file using the Integrated Design Engineering Analysis Software package (I-DEAS) version 4.1. In addition to meeting this objective, several other topics concerning I-DEAS modeling guidelines and post processing features are discussed. The results oT a linear finite element analysis is also presented. The use of a preprocessor is essential for the creation of the triax input data fiIe. I-DEAS can not only meet this challenge, but can provide assistance in all facets of finite element modeling. / Master of Science