Personalities Within Sports Teams

Personality traits among athletes is a highly researched topic. A primary area of research focuses on studying personality traits in individuals who classify themselves as athletes versus non-athletes and this research shows significant differences between these two groups. Research also shows personality differences between female and male athletes and how these personality differences help each gender cope with injuries in athletics. In addition, research has been completed to support the notion that athletes who participate in different sports contain distinguishing personality traits. These findings parallel the idea that people in different occupations contain different personality traits. Though personality traits amongst athletes and occupations are highly researched topics, there is one area where not much research has been completed. I am interested in researching personality differences between athletes who participate in the same sport but compete in different events. For example, I am interested in observing if athletes who compete in distance events contain personality traits different from athletes who participate in sprint or specialty events. This is an important topic to study because athletes may be attracted to certain sports not based off of physical ability, but on certain personality traits they possess that may make them a good fit for that sport/event. This is analogous to individuals choosing a certain occupation because their personality traits make them a good match for that job. A survey, composed of several personality questionnaires, was distributed to men and women on a track and field team and women on a swimming and diving team. The study did not show any significant results when comparing personality traits amongst athletes in different events but results were significant when correlating personality traits amongst all athletes

A singular controllability problem with vanishing viscosity

The aim of this paper is to answer the question: Do the controls of a vanishing viscosity approximation of the one dimensional linear wave equation converge to a control of the conservative limit equation? Our viscous term contains the fractional power of the Dirichlet Laplace operator and it is multiplied by a small parameter devoted to tend to zero. Our analysis, based on moment problems and biorthogonal sequences, enables us to evaluate the magnitude of the controls needed for each eigenmode and to show their uniform boundedness with respect to the vanishing parameter

Uniform controllability for the beam equation with vanishing structural damping

summary:This paper is devoted to studying the effects of a vanishing structural damping on the controllability properties of the one dimensional linear beam equation. The vanishing term depends on a small parameter $\varepsilon \in (0,1)$. We study the boundary controllability properties of this perturbed equation and the behavior of its boundary controls $v_{\varepsilon }$ as $\varepsilon$ goes to zero. It is shown that for any time $T$ sufficiently large but independent of $\varepsilon$ and for each initial data in a suitable space there exists a uniformly bounded family of controls $(v_\varepsilon )_\varepsilon$ in $L^2(0, T)$ acting on the extremity $x = \pi$. Any weak limit of this family is a control for the beam equation. This analysis is based on Fourier expansion and explicit construction and evaluation of biorthogonal sequences. This method allows us to measure the magnitude of the control needed for each eigenfrequency and to show their uniform boundedness when the structural damping tends to zero

Automatically Identifying Soundness and Completeness Errors in Program Analysis Tools

Program analysis tools (such as static analyzers, SMT solvers, and program verifiers) are extremely important for ensuring the correctness of a large variety of software systems. Very often, these tools are assumed to be sound (i.e., do not miss errors) and complete (i.e., have a low rate of false positives), otherwise their results are not reliable. However, these assumptions do not always hold in practice. Even if their theoretical designs have been proven correct, the actual implementations can still contain issues. We thus propose through this dissertation systematic techniques for automatically identifying soundness and completeness errors in the implementations of program analysis tools. Other types of bugs, such as performance or convergence issues, can be also detected as by-products. Our first contribution is a novel combination of automatic test case generation approaches for identifying soundness, precision, and termination issues in the implementations of numerical abstract domains, the main components of static analyzers based on abstract interpretation. We show that our technique effectively detects errors in widely-used libraries for numerical analyses, outperforming dynamic symbolic execution and grey-box fuzzing. Our work applies also to abstract domains that rely on machine learning to improve the performance of the analysis. Our second contribution is an automated approach for synthesizing SMT formulas that are satisfiable or unsatisfiable by construction. Together with the known ground truth, these are used to test the implementations of SMT solvers. We generate satisfiable formulas together with models, and unsatisfiable formulas together with unsat cores; being incrementally complex, they facilitate debugging and faster error localization. We evaluated our work on three widely-used SMT solvers, Z3-seq, Z3str3, and CVC4 and on the automata-based solver MT-ABC. Our experimental results show that our approach effectively detects soundness, performance, completeness, and precision problems. It is applicable also to MAX-SMT solvers. Our third contribution is an automated technique that allows the developers to detect completeness issues in SMT-based program verifiers and soundness errors in their axiomatizations. Moreover, our approach helps them devise better triggering strategies for all future runs of their tool with E-matching. We developed a novel algorithm for synthesizing the triggering terms necessary to complete unsatisfiability proofs using E-matching.We evaluated our work on benchmarks with known triggering issues from four program verifiers. Our experiments show that it successfully synthesized the missing triggering terms in the majority of the cases, and can significantly reduce the human effort in localizing and fixing the errors

The Influence Of Component Alignment On The Life Of Total Knee Prostheses

An arthritic knee affects the patient’s life by causing pain and limiting movement. If the cartilage and the bone surfaces are severely affected, the natural joint is replaced with an artificial joint. The procedure is called total knee arthroplasty (TKA). Lately, the numbers of implanted total knee prostheses grow steadily. An important factor in TKA is the perfect alignment of the total knee prosthesis (TKP) components. Component misalignment can lead to the prosthesis loss by producing wear particles. The paper proposes a study on mechanical behaviors of a TKP based on numerical analysis, using ANSYS software. The numerical analysis is based on both the normal and the changed angle of the components alignment

Automatically Testing String Solvers

SMT solvers are at the basis of many applications, such as program verification, program synthesis, and test case generation. For all these applications to provide reliable results, SMT solvers must answer queries correctly. However, since they are complex, highly-optimized software systems, ensuring their correctness is challenging. In particular, state-of-the-art testing techniques do not reliably detect when an SMT solver is unsound. In this paper, we present an automatic approach for generating test cases that reveal soundness errors in the implementations of string solvers, as well as potential completeness and performance issues. We synthesize input formulas that are satisfiable or unsatisfiable by construction and use this ground truth as test oracle. We automatically apply satisfiability-preserving transformations to generate increasingly-complex formulas, which allows us to detect many errors with simple inputs and, thus, facilitates debugging. The experimental evaluation shows that our technique effectively reveals bugs in the implementation of widely-used SMT solvers and applies also to other types of solvers, such as model-counting constraint solvers. We focus on strings here, but our approach carries over to other theories and their combinations

Automatically testing string solvers

SMT solvers are at the basis of many applications, such as program verification, program synthesis, and test case generation. For all these applications to provide reliable results, SMT solvers must answer queries correctly. However, since they are complex, highly-optimized software systems, ensuring their correctness is challenging. In particular, state-of-the-art testing techniques do not reliably detect when an SMT solver is unsound. In this paper, we present an automatic approach for generating test cases that reveal soundness errors in the implementations of string solvers, as well as potential completeness and performance issues. We synthesize input formulas that are satisfiable or unsatisfiable by construction and use this ground truth as test oracle. We automatically apply satisfiability-preserving transformations to generate increasingly-complex formulas, which allows us to detect many errors with simple inputs and, thus, facilitates debugging. The experimental evaluation shows that our technique effectively reveals bugs in the implementation of widely-used SMT solvers and applies also to other types of solvers, such as automata-based solvers. We focus on strings here, but our approach carries over to other theories and their combinations. © 2020 Association for Computing Machinery

A Numerical Method for the Controls of the Heat Equation

This work is devoted to analyze a numerical scheme for the approximation of the linear heat equation’s controls. It is known that, due to the regularizing effect, the efficient computation of the null controls for parabolic type equations is a difficult problem. A possible cure for the bad numerical behavior of the approximating controls consists of adding a singular perturbation depending on a small parameter ε which transforms the heat equation into a wave equation. A space discretization of step h leads us to a system of ordinary differential equations. The aim of this paper is to show that there exists a sequence of exact controls of the corresponding perturbed semi-discrete systems which converges to a control of the original heat equation when both h (the mesh size) and ε (the perturbation parameter) tend to zero