Determining tendon tension in the finger is essential to understanding forces that may be detrimental to hand function. Direct measurement is not feasible, making biomechanical modelling the best way to estimate these forces. In this study, the intrinsic muscles and extensor mechanism were added to an existing model of the index finger, and as such, it has been named the Intrinsic model. The Intrinsic model of the index finger has 4 degrees of freedom and 7 muscles (with 14 components). Muscle properties and paths for all extrinsic and intrinsic muscles were derived from the literature. Two models were evaluated, the Intrinsic model and the model it was adapted from (identified in this thesis as the Extrinsic-only model). To complement the model, multiple static optimization solution methods were also developed that allowed for EMG-constrained solutions and applied objective functions to promote co-contraction. To test the models and solution methods, 10 participants performed 9 static pressing tasks at 3 force levels, and 5 free motion dynamic tasks at 2 speeds. Kinematics, contact forces, and EMG (from the extrinsic muscles and first dorsal interosseous) were collected. For all solution methods, muscle activity predicted using the Intrinsic model was compared to activity from the model currently available through open-source software (OpenSim). Just by using the Intrinsic model, co-contraction increased by 16% during static palmar pressing tasks. The EMG-constrained solution methods gave a smaller difference between predicted and experimental activity compared to the optimization-only approach (p < 0.03). The model and solution methods developed in this thesis improve co-contraction and tendon tension estimates in the finger. As such, this work contributes to our understanding of the control of the hand and the forces that may be detrimental to hand function. / Thesis / Master of Science (MSc)

No description available.

The quality and reliability of software systems, in terms of their functional correctness, critically relies on the effectiveness of the testing tools and techniques to detect errors in the system before deployment. A lack of testing tools for concurrent programs that systematically control thread scheduling choices has not allowed concurrent software development to keep abreast with hardware trends of multi-core and multi-processor technologies. This motivates a need for the development of systematic testing techniques that detect errors in concurrent programs. The work in this dissertation presents a potentially scalable technique that can be used to detect concurrency errors in production code. The technique is a viable solution for software engineers and testers to detect errors in multi-threaded programs before deployment. We present a guided testing technique that combines static analysis techniques, systematic verification techniques, and heuristics to efficiently detect errors in concurrent programs. An abstraction-refinement technique lies at the heart of the guided test technique. The abstraction-refinement technique uses as input potential errors in the program generated by imprecise, but scalable, static analysis tools. The abstraction further leverages static analyses to generate a set of program locations relevant in verifying the reachability of the potential error. Program execution is guided along these points by ranking both thread and data non-determinism. The set of relevant locations is refined when program execution is unable to make progress. The dissertation also discusses various heuristics for effectively guiding program execution. We implemented the guided test technique to detect errors in Java programs. Guided test successfully detects errors caused by thread schedules and data input values in Java benchmarks and the JDK concurrent libraries for which other state of the art analysis and testing tools for concurrent programs are unable to find an error.

Calculating WCET for schedulability analysis of RTIC applications is today performed with a hybrid approach with both static analysis of code and hardware measurements. A fully static analysis tool would allow for a easier integration into a CI/CD pipeline without the actual hardware. This thesis attempts to compute WCET statically, using symbolic execution engine KLEE to generate all the possible paths of execution for a task and then analyses these paths to approximate the worst-case for each path which would yield a approximate WCET for the analysed program. To analyze a path in a program the low-level intermediary assembly language used by the LLVM optimization infrastructure (called LLVM IR) is compared to the finished assembly language to draw conclusions on how an LLVM IR instruction is processed into assembly. To be able to perform this mapping from LLVM IR to assembly, the symbolic execution engine KLEE has been extended to also log each LLVM IR instruction run in a path. These logs combined with a translation table is how the approximations are calculated. The resulting approximations correlate with the actual cycles when the analysed program is run on actual hardware, which indicates that tool could actually be used to approximate WCET. There are however no guarantees and the tool has not been tested for larger scale programs.

Utilizing immutability is considered to have many desired benefits when it comes to software development and reasoning about programs. It is also one of the core principles of functional programming, and many programming languages have support for specifying immutability. Developers can by specifying immutability write code that, for example, prevent program state from being unintentionally mutated. The Scala programming language is a functional and object-oriented language where developers can specify immutability with reassignable and non-reassignable variables. The type system in Scala has no built-in support for developers to express the fact that a type is immutable, immutability is instead by convention and considered best practice. However, knowledge about the immutability usage and how prevalent it is in real-world Scala code are until this point non-existent.            This project presents an immutability analysis and evaluation of six small-to-large open source projects written in Scala providing empirical data on immutability usage. The analysis investigates the immutability property of templates, where a template refers to one of Scala's different class types, on three distinct properties: shallow, conditionally deep and deep immutability, where deep is the strongest immutability property. The analysis works as a plug-in for the Scala compiler that statically analyzes the source code of projects. We report immutability statistics for each evaluated project, including three widely used projects, Scala's standard library, Akka's actor framework and ScalaTest. Explanations to why stronger immutability properties do not hold are also provided. The analysis show that the majority of templates for each project satisfied an immutability property and were not classified as mutable. Because each analyzed project had templates that were assumed to be mutable, as they were unreachable by our analysis, there could potentially be more templates that satisfy an immutability property. Inheritance is shown to be an important factor when it comes to a template's immutability and mutability was found to be lower for the template types case class and singleton object. This can be seen as intended by the designers of Scala, indicating that these type of class abstractions help programmers utilize immutability. Our results show that immutability is frequently used in Scala and the high degree of immutability usage could be due to the functional nature of the language. / Att använda immuterbar (oföränderlig) data anses ha många önskvärda fördelar när det kommer till utveckling av program och att kunna resonera om dess funktionalitet. Immuterbar data är också en viktig princip inom funktionell programmering och många språk har idag stöd för att ange immuterbarhet. Utvecklare kan i kod ange ifall data ska vara immuterbar för att till exempel förhindra ett programtillstånd från att oavsiktligt förändras. Programmeringsspråket Scala är ett funktionellt och objektorienterat språk där utvecklare kan ange immuterbarhet med två typer av variabler, en som är tilldelningsbar och en som är icke-tilldelningsbar. Typsystemet i Scala har inget inbyggt stöd för utvecklare att uttrycka det faktum att en typ är immuterbar, att använda immuterbarhet är i stället konvention och anses vara den bästa metoden. Men uppgifter om hur immuterbarhet egentligen används i riktiga Scala projekt har fram tills nu inte varit tillgängligt. Detta projekt presenterar en immuterbarhetsanalys och en utvärdering av sex små till stora projekt med öppen källkod skrivna i programmeringsspråket Scala. Analysen undersöker immuterbarhetsegenskaper hos Scalas olika typer av klasser med avseende på tre olika egenskaper: ytlig, villkorligt djup och djup immuterbar, där djup är den starkaste immuterbarhetsegenskapen. Analysen fungerar som ett tillägg för Scalas kompilator och utfärdar en statisk analys av källkoden för ett projekt. Statistik om immuterbarhet för varje projekt redovisas och utvärderas, bland annat tre välkända och populära kodbaser, Scalas standard bibliotek, Akka’s actor ramverk och ScalaTest. Förklaringar till varför klasser inte uppfyller en immuterbarhetsegenskap visas också. Analysen visar att majoriteten av alla klasser i projekten har en immuterbarhetsegenskap och var inte klassificerade som muterbara. Eftersom varje projekt hade klasser som antogs vara muterbara för att dessa inte var nåbara för våran analys så kan det potentiellt finnas fler klasser som har en immuterbarhetsegenskap. Vad en klass ärver visar sig vara en viktig faktor när det kommer till vilken typ av immuterbarhetsegenskap den har. Muterbarhet visade sig vara lägre för klasser som är av typen case class and singleton object vilket kan anses vara avsett av Scalas skapare, då dessa klass abstraktioner hjälper programmerare att använda immuterbarhet. Resultaten visar att immuterbarhet används flitigt i Scala och den höga användningsgraden kan vara på grund av att det är ett funktionellt språk.

Particulate composites are widely used in many aerospace and military applications as energetic materials, armor materials or coatings and their behavior under dynamic loads have gained increasing significance. The addition of modifiers such as alumina nanoparticles generally facilitates the improvement of the mechanical strength to density ratio due to high specific area and particle rigidity. This allows for sufficient particlematrix bonding and therefore improved stiffness and load transfer in the composite. Photo-luminescent α-alumina nanoparticles when embedded in an epoxy matrix allow for the added benefit of in situ measurements at low strain rates to provide stress-sensitive information using the particle piezospectroscopic (PS) property. To investigate the low strain rate behavior, cylindrical specimens of alumina-epoxy composites with varying volume fractions of alumina were fabricated using a casting process to ensure minimal surface finishing and reduced manufacturing time. The results illustrate the capability of alumina nanoparticles to act as diagnostic sensors to measure the stress-induced shifts of the spectral R-line peaks resulting from low compressive strain rates. The range of PS coefficients measured, -3.15 to -5.37 cm−1/GP a for R1 and -2.62 to -5.39 cm−1/GP a for R2, correlate well with static test results of similar volume fractions. Results reveal a general trend of increasing sensitivity of the PS coefficients with increasing strain rate when compared to similar materials under static conditions. In contrast to static results, at a given strain rate, the PS coefficients show varying degrees of sensitivity for each iii volume fraction. This information can be used to determine the time-dependent microscale stresses the nanoparticles sustain during composite loading. Additionally, this work facilitates failure prediction by monitoring upshifts in the PS information. Calibration of the in situ diagnostic stress sensing capabilities of varying volume fractions of alumina nanocomposites under quasi-static strain rates in this work sets the precedent for future studies at high strain rates.

Code clones are duplicate fragments of code that perform the same task. As software code bases increase in size, the number of code clones also tends to increase. These code clones, possibly created through copy-and-paste methods or unintentional duplication of effort, increase maintenance cost over the lifespan of the software. Code clone detection tools exist to identify clones where a human search would prove unfeasible, however the quality of the clones found may vary. I demonstrate that the performance of such tools can be improved by normalizing the source code before usage. I developed Normalizer, a tool to transform C source code to normalized source code where the code is written as consistently as possible. By maintaining the code's function while enforcing a strict format, the variability of the programmer's style will be taken out. Thus, code clones may be easier to detect by tools regardless of how it was written. Reordering statements, removing useless code, and renaming identifiers are used to achieve normalized code. Normalizer was used to show that more clones can be found in Introduction to Computer Networks assignments by normalizing the source code versus the original source code using a small variety of code clone detection tools.

The main objective of this investigation is to examine how various material properties, governed by code specification, affect the seismic response of a twelve- story reinforced concrete building. This study incorporates the pushover and response history analysis to examine how varying steel yield strength (Fy), 28 day nominal compressive concrete strength (f’c), modes, and ground motions may affect the base shear capacity and displacements of a reinforced concrete structure. Different steel and concrete strengths were found to have minimal impact on the initial stiffness of the structure. However, during the post-yielding phase, higher steel and concrete compressive strengths resulted in larger base shear capacities of up to 22%. The base shear capacity geometric median increased as f’c or Fy increased, and the base shear capacity dispersion measure decreased as f’c or Fy increased. Higher mode results were neglected in this study due to non-convergent pushover analyses results. According to the response history analysis, larger yield and concrete compressive strengths result in lower roof displacement. The difference in roof displacement was less than 12% throughout. This displays the robustness of both analysis methods because material properties have insignificant impact on seismic response. Therefore, acceptable yield and compressive strengths governed by seismic code will result in acceptable building performance.

<p> A general formulation of the analysis of plane coupled shear walls is presented. The "continuous method" of analysis of coupled shear walls is reformulated in terms of deflection variables. The assumption that midpoints of the connecting beams are points of contraflexure is relaxed so that the resulting theory is applicable to the general case where the lateral loading on the piers can be arbitrarily distributed. The governing equation of the structural system under static loading with the appropriate boundary conditions are given. The effect of asymmetry of the structure is discussed. As an application of the derived theory, the problem of shear walls subjected to differential foundation settlement and rotation is studied. Solutions to deflections and internal stresses, under such conditions, are given. Evaluation of the internal stresses was performed on a practical shear wall structure and the results analysed. Through the use of deflection variables, the formulation is extended into the regime of dynamics. The governing equation of motion with appropriate boundary conditions are given. The free vibration of coupled shear walls is studied and design curves for the fundamental natural frequency are presented. The use of substitutive symmetric systems and its effects on the fundamental frequency of asymmetric systems are examined. Theoretical natural frequencies were verified by dynamic testing on two models to show that the proposed theory is sufficiently accurate to provide information for dynamic analysis in seismic design. / Thesis / Master of Engineering (ME)

<p> The electron density approach in conjunction with the Hellmann-Feynman theorem is used for a systematic analysis of binding characteristics of the two isoelectronic molecular series: N₂, CO, BF, and LiF, BeO. Electron density distributions, forces and field gradients corresponding to static properties of electron densities, have been calculated from Hartree-Fock wavefunctions (obtained from the work of other authors) for these molecules. Correlation of these static properties with binding characteristics are presented. Covalent and ionic characteristics are made evident by an analysis of the density distributions, density difference maps obtained by subtracting atomic from molecular distributions, and the forces exerted on nuclei by these distributions. A discussion of the field gradients, as related to quadrupole polarizations of the electron densities, is presented and the relevance of these polarizations to the interpretation of nuclear quadrupole coupling constants is indicated. </p> <p> Dynamic properties, as reflected by the magnitude of force constants, are analyzed in terms of functionals of the one-electron density. Force constant expressions are derived from the Hellmann-Feynman theorem. Any relation of force constants to field gradients is shown to be not unique as a result of cancellation of static and dynamic electron contributions to the total force constant. The total electronic contribution is shown to arise from a relaxation of density after a displacement of a certain nucleus. Relaxation of density with respect to one nucleus but which remains localized on some other nucleus in a molecule is shown to be equivalent to a field gradient. Thus, such density is separated from other density and its contribution to the force constant is treated as a field gradient. All contributions are computed from polynomial fits of the corresponding forces calculated at a number of internuclear distances. Relaxation density maps for the remaining atomic and overlap densities centered on a specific nucleus are presented. These maps are calculated as the difference between densities of the extended and equilibrium configurations of a molecule. The relaxation densities are correlated to the magnitude of the corresponding electronic force constant components. Thus, for the first time, there is demonstrated the concrete relation between covalent and ionic characteristics of electron densities in molecules and their dynamic properties which result in the magnitude of force constants. </p> / Thesis / Doctor of Philosophy (PhD)