120 research outputs found
Solving a binary puzzle
A Binary puzzle is a Sudoku-like puzzle with values in each cell taken from the set (Formula presented.). Let (Formula presented.) be an even integer, a solved binary puzzle is an (Formula presented.) binary array that satisfies the following conditions: (1) no three consecutive ones and no three consecutive zeros in each row and each column; (2) the number of ones and zeros must be equal in each row and in each column; (3) there can be no repeated row and no repeated column. This paper proposes three approaches to solve the puzzle. The first method is based on a complete backtrack-based search algorithm. The idea is to propagate and fill an unsolved binary puzzle according to the three constraints, followed by a random guess if the puzzle remains unsolved. The second method of solving a binary puzzle is by representing it as an instance of a Boolean satisfiability problem which allows the solution for a binary puzzle to be obtained using SAT solvers. The third approach is based on expressing a binary puzzle as a system of polynomial equations over the binary field (Formula presented.). The set of solutions for the equation system implies the solutions for the binary puzzle and it is obtained by computing a Gröbner basis of the ideal generated by the polynomials. We experimentally compare the three approaches with binary puzzles of various sizes and different numbers of empty cells using a computer algebra system
Constraint-Driven Fault Diagnosis
Constraint-Driven Fault Diagnosis (CDD) is based on the concept of constraint suspension [6], which was proposed as an approach to fault detection and diagnosis. In this chapter, its capabilities are demonstrated by describing how it might be applied to hardware systems. With this idea, a model-based fault diagnosis problem may be considered as a Constraint Satisfaction Problem (CSP) in order to detect any unexpected behavior and Constraint Satisfaction Optimization Problem (COP) constraint optimization problem in order to identify the reason for any unexpected behavior because the parsimony principle is taken into accountMinisterio de Ciencia y Tecnología TIN2015-63502-C3-2-
Digital Collections of Examples in Mathematical Sciences
Some aspects of Computer Algebra (notably Computation Group Theory and
Computational Number Theory) have some good databases of examples, typically of
the form "all the X up to size n". But most of the others, especially on the
polynomial side, are lacking such, despite the utility they have demonstrated
in the related fields of SAT and SMT solving. We claim that the field would be
enhanced by such community-maintained databases, rather than each author
hand-selecting a few, which are often too large or error-prone to print, and
therefore difficult for subsequent authors to reproduce.Comment: Presented at 8th European Congress of Mathematician
Highly Automated Formal Verification of Arithmetic Circuits
This dissertation investigates the problems of two distinctive formal verification techniques for verifying large scale multiplier circuits and proposes two approaches to overcome some of these problems. The first technique is equivalence checking based on recurrence relations, while the second one is the symbolic computation technique which is based on the theory of Gröbner bases. This investigation demonstrates that approaches based on symbolic computation have better scalability and more robustness than state-of-the-art equivalence checking techniques for verification of arithmetic circuits. According to this conclusion, the thesis leverages the symbolic computation technique to verify floating-point designs. It proposes a new algebraic equivalence checking, in contrast to classical combinational equivalence checking, the proposed technique is capable of checking the equivalence of two circuits which have different architectures of arithmetic units as well as control logic parts, e.g., floating-point multipliers
Satisfiability Modulo Finite Fields
We study satisfiability modulo the theory of finite fields and
give a decision procedure for this theory. We implement our procedure
for prime fields inside the cvc5 SMT solver. Using this theory, we con-
struct SMT queries that encode translation validation for various zero
knowledge proof compilers applied to Boolean computations. We evalu-
ate our procedure on these benchmarks. Our experiments show that our
implementation is superior to previous approaches (which encode field
arithmetic using integers or bit-vectors)
ADAM: Analysis of Discrete Models of Biological Systems Using Computer Algebra
Abstract Background
Many biological systems are modeled qualitatively with discrete models, such as probabilistic Boolean networks, logical models, Petri nets, and agent-based models, to gain a better understanding of them. The computational complexity to analyze the complete dynamics of these models grows exponentially in the number of variables, which impedes working with complex models. There exist software tools to analyze discrete models, but they either lack the algorithmic functionality to analyze complex models deterministically or they are inaccessible to many users as they require understanding the underlying algorithm and implementation, do not have a graphical user interface, or are hard to install. Efficient analysis methods that are accessible to modelers and easy to use are needed. Results
We propose a method for efficiently identifying attractors and introduce the web-based tool Analysis of Dynamic Algebraic Models (ADAM), which provides this and other analysis methods for discrete models. ADAM converts several discrete model types automatically into polynomial dynamical systems and analyzes their dynamics using tools from computer algebra. Specifically, we propose a method to identify attractors of a discrete model that is equivalent to solving a system of polynomial equations, a long-studied problem in computer algebra. Based on extensive experimentation with both discrete models arising in systems biology and randomly generated networks, we found that the algebraic algorithms presented in this manuscript are fast for systems with the structure maintained by most biological systems, namely sparseness and robustness. For a large set of published complex discrete models, ADAM identified the attractors in less than one second. Conclusions
Discrete modeling techniques are a useful tool for analyzing complex biological systems and there is a need in the biological community for accessible efficient analysis tools. ADAM provides analysis methods based on mathematical algorithms as a web-based tool for several different input formats, and it makes analysis of complex models accessible to a larger community, as it is platform independent as a web-service and does not require understanding of the underlying mathematics
Evaluation of the strength and performance of a new hashing algorithm based on a block cipher
The article evaluates the reliability of the new HBC-256 hashing algorithm. To study the cryptographic properties, the algorithm was implemented in software using Python and C programming languages. Also, for the algebraic analysis of the HBC-256 algorithm, a system of Boolean equations was built for one round using the Transalg tool. The program code that implements the hashing algorithm was converted into a software program for generating equations. As a result, one round of the compression function was described as conjunctive normal form (CNF) using 82,533 equations and 16,609 variables. To search for a collision, the satisfiability (SAT) problem solver Lingeling was used, including a version with the possibility of parallel computing. It is shown that each new round doubles the number of equations and variables, and the time to find the solution will grow exponentially. Therefore, it is not possible to find solutions for the full HBC256 hash function
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