MuAlloy : an automated mutation system for alloy

textMutation is a powerful technique that researchers have studied for several decades in the context of imperative code. For example, mutation testing is commonly considered a '"gold standard"' for test suite quality. Mutation in the context of declarative languages is a less studied problem. This thesis introduces a foundation for mutation-driven analyses for Alloy, a first-order, declarative language based on relations. Specifically, we introduce a family of mutation operators for Alloy models and define algorithms for applying the operators on different parts of the models. We embody these operators and algorithms in our prototype tool MuAlloy that provides a GUI-based front-end for customizing the application of mutation operators. To demonstrate the potential of our approach, we illustrate the use of MuAlloy in two application scenarios: (1) mutation testing for Alloy (in the spirit of traditional mutation testing for imperative languages); and (2) program repair for Alloy using mutation.Electrical and Computer Engineerin

Robot-Based Research on Three-Layer Oriented Flakeboards

A small jointed-arm motion type robot system was introduced for wood mat formation to study the relationship between wood mat structure and panel properties. Four types of structures of three-layer oriented flakeboards with different face to core ratios and core orientations were formed using the robot as a tool. The panels were then hot-pressed and tested for horizontal density distribution (HDD) by X-ray machine, bending modulus of elasticity (MOE), internal bond (IB) and thickness swelling (TS). The results showed that the programmed robot formed panels with well-defined and reproducible structures. Linked with the existing panel simulation program, X-ray data, and real properties, the panel structure with face to core ratio of 15:70:15 and random core has been considered the most suitable panel pattern for additional research based on its superior performance and lower variation of properties

Quadratic RSM Models of Processing Parameters for Three-Layer Oriented Flakeboards

Response surface method with central composite design was used to establish quadratic regression models and surface maps to relate panel properties, including static bending modulus of elasticity, modulus of rupture, internal bond strength, and thickness swelling with flake slenderness ratio, flake orientation, and panel density. A robot mat formation system was used to form the panels with predefined processing parameters. Results indicated that nonlinear models capable of including interactions were required to relate flake slenderness ratio, flake orientation, and panel density to panel properties. An optimization model was developed to obtain the best panel performance with respect to the three factors. The optimized combination of the three factors within the experimental range is: 133 for flake slenderness ratio, 8° for surface flake orientation, and 0.62g/cm3 for board density

Digital projection photochemical etching for gray-scale semiconductor applications

In the contemporary semiconductor industry, with the ever-growing demand for smaller, denser, and newer device features, various industrial and academic research groups across the world are looking beyond the conventional planar lithography and fabrication methods for semiconductor materials. The rapidly evolving domain of 3-dimensional and gray-scale semiconductor device fabrication paves the way for a wide range of revolutionary techniques, innovative applications, and promising products. This thesis presents digital projection photochemical etching, a novel and dynamic semiconductor fabrication technique that achieves a 3-dimensional structure in a single etch step. This technique utilizes a commercial digital projector to focus a substantially de-magnified image beam pattern onto the semiconductor sample, where the projected image itself is used to catalyze and define the etching. The discussion begins with a thorough introduction and literature review to cover the fundamental mechanisms behind the technique of photochemical etching. This is followed by an in-depth explanation of the methodology of experimental design and setup configuration. Subsequently, the thesis comprehensively describes the fabrication of various novel structures and devices using digital projection photochemical etching, demonstrating this technique’s resolution, dynamics, and ability to integrate with higher-resolution lithography methods while preserving the unique gray-scale feature control

Automated synthesis and debugging of declarative models in alloy

In theory, formal specifications offer numerous benefits in developing more reliable software. In practice however, the use of specifications is rather limited, and practitioners often consider them more trouble than they are worth. Indeed, manually writing detailed specifications using notations that have unfamiliar syntax and semantics can be a daunting task -- even for experienced programmers. We introduce a new automated approach for synthesis of desired specifications and debugging of faulty specifications using given examples that capture the essence of desired properties and serve as test cases. Our focus is specifications written in the declarative language Alloy -- a first-order logic based on relations with transitive closure, and its SAT-based analysis engine. Our key insight is that a test-driven foundation enables modern approaches to synthesis and debugging of imperative code to serve as a basis for developing novel analogous techniques for declarative specifications. For synthesis, we build on equivalence in relational algebra and introduce techniques for generating candidate Alloy expressions. We also introduce a technique to complete a partial Alloy model with holes using constraint solving. For locating faults in buggy specifications, we build on mutation-based fault localization and introduce techniques for locating likely faulty nodes in the abstract syntax tree of the faulty specification. Moreover, we integrate our expression generation and fault localization techniques to introduce a technique for automated specification repair. We experimentally evaluate our techniques using several Alloy models as subjects, including those with real faults. The results show that our techniques are effective at synthesis and debugging of the subjects. We believe our techniques provide an important step towards increasing the role of formal specifications in developing more reliable software and realizing their promise.Electrical and Computer Engineerin