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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Abstract satisfaction

Haller, Leopold Carl Robert January 2013 (has links)
This dissertation shows that satisfiability procedures are abstract interpreters. This insight provides a unified view of program analysis and satisfiability solving and enables technology transfer between the two fields. The framework underlying these developments provides systematic recipes that show how intuition from satisfiability solvers can be lifted to program analyzers, how approximation techniques from program analyzers can be integrated into satisfiability procedures and how program analyzers and satisfiability solvers can be combined. Based on this work, we have developed new tools for checking program correctness and for solving satisfiability of quantifier-free first-order formulas. These tools outperform existing approaches. We introduce abstract satisfaction, an algebraic framework for applying abstract interpre- tation to obtain sound, but potentially incomplete satisfiability procedures. The framework allows the operation of satisfiability procedures to be understood in terms of fixed point computations involving deduction and abduction transformers on lattices. It also enables satisfiability solving and program correctness to be viewed as the same algebraic problem. Using abstract satisfaction, we show that a number of satisfiability procedures can be understood as abstract interpreters, including Boolean constraint propagation, the dpll and cdcl algorithms, St ̊almarck’s procedure, the dpll(t) framework and solvers based on congruence closure and the Bellman-Ford algorithm. Our work leads to a novel understand- ing of satisfiability architectures as refinement procedures for abstract analyses and allows us to relate these procedures to independent developments in program analysis. We use this perspective to develop Abstract Conflict-Driven Clause Learning (acdcl), a rigorous, lattice-based generalization of cdcl, the central algorithm of modern satisfiability research. The acdcl framework provides a solution to the open problem of lifting cdcl to new prob- lem domains and can be instantiated over many lattices that occur in practice. We provide soundness and completeness arguments for acdcl that apply to all such instantiations. We evaluate the effectiveness of acdcl by investigating two practical instantiations: fp-acdcl, a satisfiability procedure for the first-order theory of floating point arithmetic, and cdfpl, an interval-based program analyzer that uses cdcl-style learning to improve the precision of a program analysis. fp-acdcl is faster than competing approaches in 80% of our benchmarks and it is faster by more than an order of magnitude in 60% of the benchmarks. Out of 33 safe programs, cdfpl proves 16 more programs correct than a mature interval analysis tool and can conclusively determine the presence of errors in 24 unsafe benchmarks. Compared to bounded model checking, cdfpl is on average at least 260 times faster on our benchmark set.
2

Interpreting Industrial Arts in the School-Community

Ford, Hilary Blanton 08 1900 (has links)
The purpose of this study is threefold: (1) to review the literature concerning school interpretation programs and the industrial arts phase of the public relations program based upon research studies, opinions and recommendations of leaders in education and industrial arts education; (2) to gather data concerning current practices used in the industrial arts departments during the year 1953-1954; and (3) to analyze the data in order to determine whether the current practice of industrial arts interpretation coincide with the interpretation program recommended by leaders in the field of education.

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