Rationale: Laryngopharygeal reflux (LPR) is a controversial area of diagnosis and consequently management. Many patients suffering from voice and swallowing disorders may be suffering from LPR but decreased specificity of diagnosis makes management ineffective and impacts on quality of life as well as leading to overdiagnosis of LPR. Aims: (1) To establish the relationship between the Reflux Symptom Index (RSI) and the Reflux Finding Score (RFS) in participants who have attended the Wits University Donald Gordon Voice and Swallowing clinic. (2) To establish if there is a correlation between the total RFS and RSI scores. (3) To ascertain which test items of the RSI and the RFS are elevated in the participants. (4) To describe trends in RFS and RSI sub scores and (5) to determine if extraneous factors such as age, gender, professional voice use and smoking impact on the subscores of the RFS and RSI and to describe the trends based on these variables Method: A quantitative retrospective chart review of 105 patients who attended the Voice and Swallowing clinic was conducted. Each participant completed a self-rating scale for reflux severity (the RSI) as well as undergoing stroboscopic examination. Stroboscopic results were rated by a multidisciplinary team (2 otolaryngologists, a speech therapist and a voice coach) to ascertain the patient’s Reflux Finding Score (RFS). Inferential and descriptive statistics were employed to achieve the aims. Results: A weak negative significant correlation on totals of the RFS and RSI (r=0,20; p= 0,0395) was established. There were a number of intra-item correlations on the RSI and the RFS. Descriptive statistics revealed that hoarseness, excess mucus and throat clearing were the most frequently rated symptoms on the RSI and erythemia, posterior commisure hyperatrophy and diffuse laryngeal oedema most frequently rated signs on the RFS. Gender was the only variable found to have a significant effect on the total RFS and RSI ratings. Conclusion: There is specificity in the RSI and RFS as diagnostic materials for LPR. However, there may be an incidence of over diagnosis. Factors such as age, smoking, professional voice use and gender must be considered in diagnosis.

In this work we are going to investigate a factorization method that was invented by John Pollard. It makes possible to factorize medium large integers into a product of prime numbers. We will run a C++ program and test how do different parameters affect the results. There will be a connection drawn between the Pollard's rho method, the Birthday paradox and the Floyd's cycle finding algorithm. In results we will find a polynomial function that has the best effectiveness and performance for Pollard's rho method.

The bending of elastic strips and rods is a field of research that continues to offer new possibilities for exploration. This dissertation focuses on two distinct problems within this context. These are the search for the equilibrium shape of thin inextensible elastic strips, such as a M�öbius strip made out of paper, and the optimal shape of tapered columns that are stable against buckling. A theoretical approach based on the principle of virtual work is used to investigate both problems. This produces novel governing non-linear differential equations that describe both equilibrium and form. In order to discover the equilibrium shapes, numerical algorithms are developed that are based on Dynamic Relaxation. There are two ways in which they are used, one as an explicit form-finding tool, and the other as a way of solving differential equations. Results are provided that extend current theoretical models. The numerical schemes produce three-dimensional shapes for strips, going beyond the canonical Möbius strip, and solution shapes for tapered columns made from non-linear elastic materials. With the aid of analytical and numerical tools, finding the form of the M�öbius strip and the tallest possible column are interesting challenges in the search for new shapes that are driven by physical and material rules. These have applicability in structural engineering, architecture, nano-technology and even artistic endeavour.

Our world teems with networked devices. Their configuration exerts an ever-expanding influence on our daily lives. Yet correctly configuring systems, networks, and access-control policies is notoriously difficult, even for trained professionals. Automated static analysis techniques provide a way to both verify a configuration's correctness and explore its implications. One such approach is scenario-finding: showing concrete scenarios that illustrate potential (mis-)behavior. Scenarios even have a benefit to users without technical expertise, as concrete examples can both trigger and improve users' intuition about their system. This thesis describes a concerted research effort toward improving scenario-finding tools for configuration analysis. We developed Margrave, a scenario-finding tool with special features designed for security policies and configurations. Margrave is not tied to any one specific policy language; rather, it provides an intermediate input language as expressive as first-order logic. This flexibility allows Margrave to reason about many different types of policy. We show Margrave in action on Cisco IOS, a common language for configuring firewalls, demonstrating that scenario-finding with Margrave is useful for debugging and validating real-world configurations. This thesis also presents a theorem showing that, for a restricted subclass of first-order logic, if a sentence is satisfiable then there must exist a satisfying scenario no larger than a computable bound. For such sentences scenario-finding is complete: one can be certain that no scenarios are missed by the analysis, provided that one checks up to the computed bound. We demonstrate that many common configurations fall into this subclass and give algorithmic tests for both sentence membership and counting. We have implemented both in Margrave. Aluminum is a tool that eliminates superfluous information in scenarios and allows users' goals to guide which scenarios are displayed. We quantitatively show that our methods of scenario-reduction and exploration are effective and quite efficient in practice. Our work on Aluminum is making its way into other scenario-finding tools. Finally, we describe FlowLog, a language for network programming that we created with analysis in mind. We show that FlowLog can express many common network programs, yet demonstrate that automated analysis and bug-finding for FlowLog are both feasible as well as complete.

O Método das Densidades de Força (MDF), proposto primeiramente por Linkwitz (1971) e depois por Scheck (1974), é uma alternativa conveniente para encontrar configurações de redes de cabos e membranas, uma vez que fornece geometrias viáveis com uma única análise linear de equilíbrio. O Método das Densidades de Força Natural (MDFN) é uma extensão do MDF para busca de formas de estruturas de membranas, que preserva a linearidade do método original e supera suas dificuldades em lidar com malhas irregulares. Foi primeiramente sugerido por Pauletti em 2006, baseado no elemento triangular de membrana introduzido por Argyris em 1974. O Método tem sido aplicado com sucesso em vários projetos. O MDFN original requer o uso de malhas compostas exclusivamente por elementos triangulares. Esta dissertação apresenta uma extensão do método para elementos quadrangulares, considerando um elemento composto por quatro subelementos triangulares. Mesmo que a ideia básica seja muito simples, algumas dificuldades surgem do fato de que nesta abordagem, o elemento de quatro nós pode não conter todos os nós em um mesmo plano, especialmente no caso de superfícies anticlásticas, sendo que não existe um campo de tensões bem definido para o interior do elemento. O trabalho compara alguns resultados obtidos com malhas exclusivamente triangulares, como requerido pelo método original, com os resultados obtidos com o elemento quadrangular proposto, discutindo a forma de combinar as tensões dos subelementos triangulares para originar as tensões atuantes no elemento quadrangular. Os modelos obtidos no MDFN são inseridos no programa Ansys, e os resultados são comparados para analisar a viabilidade da solução proposta e dos resultados obtidos por meio desta. / The Force Density Method (FDM), first proposed by Linkwitz(1971) and after by Scheck(1974), is a convenient alternative for finding configurations of cable nets and membranes, since it provides viable geometries in a single linear equilibrium analysis. The Natural Force Density Method (NFDM) is an extension of the FDM to the shape finding of membrane structures, which preserves the linearity of the original method and overcomes the difficulties of the original method to deal with irregular meshes. It was first suggested by Pauletti in 2006, based on a triangular membrane element introduced by Argyris in 1974. The method has been successfully applied to several design cases. The original NFDM required the use of meshes composed exclusively of triangular elements. This text presents an extension of the method to quadrangular elements, considering an equivalent assemblage of flat triangular elements. Even if the basic idea is very simple, some difficulties arise from the fact that in this approach, the quadrangular element can have a non-flat configuration, especially in the anticlastic shape, and there is not a know stress field into the interior of the element. The text compares several results obtained with fully triangulated meshes, as required by the original NFDM, to those obtained with the proposed quadrangular element, discussing the different strategies that have been explored to map stresses from the internal triangular mesh to the four nodes of the element. The models obtained in the NFDM are inserted in software Ansys and the results compared to approve the solution and the results obtained.

In recent years, Satisfiability Modulo Theories (SMT) solvers have emerged as powerful tools in many formal methods applications, including verification, automated theorem proving, planning and software synthesis. The expressive power of SMT allows problems from many disciplines to be handled in a single unified approach. While SMT solvers are highly effective at handling certain classes of problems due to highly tuned implementations of efficient ground decision procedures, their ability is often limited when reasoning about universally quantified first-order formulas. Since generally this class of problems is undecidable, most SMT solvers use heuristic techniques for answering unsatisfiable when quantified formulas are present. On the other hand, when the problem is satisfiable, solvers using these techniques will either run indefinitely, or give up after some predetermined amount of effort. In a majority of formal methods applications, it is critical that the SMT solver be able to determine when such a formula is satisfiable, especially when it can return some representation of a model for the formula. This dissertation introduces new techniques for finding models for SMT formulas containing quantified first-order formulas. We will focus our attention on finding finite models, that is, models whose domain elements can be represented as a finite set. We give a procedure that is both finite model complete and refutationally complete for a fragment of first-order logic that occurs commonly in practice.

The study challenges current literature, which views the notion of problem-finding as the initial identification of a problem to be solved. The concept of problem-finding in this study is that problem-finding continues throughout the problem-solving process and is not distinct from it. This thesis aims to develop a better understanding of problem-finding by examining high school students using problem-finding to solve industrial design problems. The study seeks to find out what types of problem-finding exist and what roles they play in solving design problems. To explore problem-finding, this study uses a Think Aloud methodology to examine the thinking of three high school industrial design students and one high school industrial design teacher solving an authentic industrial design problem. Protocol data was gathered from the subjects and then transcribed, segmented and analysed in three ways, each of which became progressively more specific: Firstly, a macroscopic examination which identified problem-finding episodes occurring throughout the design process; secondly, a microscopic examination which identified four categories of problem-finding; and lastly, a microscopic examination which looked at the role played by the different problem-finding categories in solving design problems. The findings of this study are fourfold. Firstly, problem-finding was found to be used throughout the entire design process. Secondly, there were four categories of problemfinding. Thirdly, each category played an important role predominantly through interaction with other categories. Lastly, the more experienced a person was, the more able they were to use problem-finding effectively to solve design problems. Many current practices use trial and error methods to solve design problems. The importance of this study is that through a better understanding of problem-finding, designers may be able to use metacognitive strategies more efficiently in the process. Similarly, in educational practice, high school design students may be able to learn to think about the methods they use to solve design problems, and this may result in more creative designs.

Stanford Goldman. / "December 15, 1947." "Presented at the National Electronics Conference, Chicago, Illinois, November, 1947." / Includes bibliographical references. / Army Signal Corps Contract No. W-36-039 sc-32037.

Pen-based interfaces utilize sketch recognition so users can create and interact with complex, graphical systems via drawn input. In order for people to freely draw within these systems, users' drawing styles should not be constrained. The low-level techniques involved with sketch recognition must then be perfected, because poor low-level accuracy can impair a user's interaction experience. Corner finding, also known as stroke segmentation, is one of the first steps to free-form sketch recognition. Corner finding breaks a drawn stroke into a set of primitive symbols such as lines, arcs, and circles, so that the original stoke data can be transformed into a more machine-friendly format. By working with sketched primitives, drawn objects can then be described in a visual language, noting what primitive shapes have been drawn and the shapes? geometric relationships to each other. We present three new corner finding techniques that improve segmentation accuracy. Our first technique, MergeCF, is a multi-primitive segmenter that splits drawn strokes into primitive lines and arcs. MergeCF eliminates extraneous primitives by merging them with their neighboring segments. Our second technique, ShortStraw, works with polyline-only data. Polyline segments are important since many domains use simple polyline symbols formed with squares, triangles, and arrows. Our ShortStraw algorithm is simple to implement, yet more powerful than previous polyline work in the corner finding literature. Lastly, we demonstrate how a combination technique can be used to pull the best corner finding results from multiple segmentation algorithms. This combination segmenter utilizes the best corners found from other segmentation techniques, eliminating many false negatives (missed primitive segmentations) from the final, low-level results. We will present the implementation and results from our new segmentation techniques, showing how they perform better than related work in the corner finding field. We will also discuss limitations of each technique, how we have sought to overcome those limitations, and where we believe the sketch recognition subfield of corner finding is headed.

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