In this paper, a minimization of Haar wavelet series for simplification of circuits and Haar based decision diagrams representing discrete multiple-valued functions is proposed. The minimization is performed by permut...
详细信息
In this paper, a minimization of Haar wavelet series for simplification of circuits and Haar based decision diagrams representing discrete multiple-valued functions is proposed. The minimization is performed by permutation of indices of generalized Haar functions. Experimental results show that this method provides reasonable reduction in the number of non-zero coefficients. The Haar series reduced this way can be useful in the circuit synthesis for realization of multiple-valued functions. The same algorithm can be also used to reduce the number of paths in decision diagrams related to the Haar wavelet transforms. In many cases, this reduction provides smaller size of such decision diagrams. (c) 2005 Elsevier Ltd. All rights reserved.
This paper is devoted to the reduction of decision diagram (DD) representations of discrete functions by using the non-Abelian groups and Fourier DDs on these groups. The number of levels in a DD can be reduced throug...
详细信息
This paper is devoted to the reduction of decision diagram (DD) representations of discrete functions by using the non-Abelian groups and Fourier DDs on these groups. The number of levels in a DD can be reduced through decomposition of the domain group of the represented function into large subgroups. That approach however increases the number of nodes per levels which may decrease the global reduction possibilities in the DD. At the same time, the nodes with a considerable number of outgoing edges an required. In applications, the complexity, thus the prise, of a node is proportional to the number of outgoing edges. From an inspection of optimization methods fur DDs representations, it follows that a solution of this problem can hardly be found with DDs on Abelian groups. Therefore. we are proposing the use of Fourier DDs on finite non-Abelian groups. In that way, the matrix-valued decision diagrams are introduced, since in Fourier DDs on non-Abelian groups some of constant nodes are matrices. Three DDs permit two-steps optimization. First we determine the optimal structure of the corresponding decision tree by the reduction of which a DD is derived. The optimization is done with respect to the combination of the number of nodes and levels we may require depending on the application intended. Then, we do the optimization of the representations of matrix-valued constant nodes by ordinary DDs of smaller size. In that way, the complex-valued and integer-valued Fourier DDs are derived depending on the chosen group representations for these applications where the matrix-valued Fourier DDs may not be allowed. With thus derived Fourier DDs, the reduction of both number of levels and non-terminal nodes map be achieved. Efficiency of representations with the Fourier DDs on non-Abelian groups is illustrated by the example of DDs representations of n-bit multipliers.
The unequal meshsteps are unavoidable in general for scientific and engineering computations especially in large Scale computations. The analysis of difference schemes with nonuniform meshes is very rare even by use o...
详细信息
The unequal meshsteps are unavoidable in general for scientific and engineering computations especially in large Scale computations. The analysis of difference schemes with nonuniform meshes is very rare even by use of fully heuristic methods. For the purpose of the systematic and theoretical study of the finite difference method with nonuniform meshes for the problems of partial differential equations, the general interpolation formulas for the spaces of discrete functions of one index with unequal meshsteps are established in the present work. These formulas give the connected relationships among the norms of various types, such as' the sum of powers of discrete values, the discrete maximum modulo, the discrete Holder and Lipschitz coefficients.
With the application of Hammer integral formulas of a continuous function on a triangular element, the numerical integral formulas of some discrete functions on the element are derived by means of decomposition and re...
详细信息
With the application of Hammer integral formulas of a continuous function on a triangular element, the numerical integral formulas of some discrete functions on the element are derived by means of decomposition and recombination of base functions. Hammer integral formulas are the special examples of those of the paper.
The total and local unateness of discrete and of switching functions are studied from a theoretical point of view. One shows that the local unateness leads to the concept of hazard-free transition for a discrete funct...
详细信息
The total and local unateness of discrete and of switching functions are studied from a theoretical point of view. One shows that the local unateness leads to the concept of hazard-free transition for a discrete function. Unate covers for discrete functions are defined: they are either the smallest unate functions larger than a discrete function, or the largest unate functions smaller than a discrete function. These concepts play a key role in hazard-free design of multiple-valued networks. Three-level types of multiple-valued networks using MIN and MAX gates are presented. These networks improve, from a hazard point of view the well known two-level networks presented by Eichel-berger in the frame of switching theory.
This paper presents a technique for direct truth table implementation of residue-based functions by an encoding scheme that employs programmable array logic (PAL) technology. The scheme models the basic associative me...
详细信息
This paper presents a technique for direct truth table implementation of residue-based functions by an encoding scheme that employs programmable array logic (PAL) technology. The scheme models the basic associative memory operation, i.e., the detection of matchings between input patterns and prestored information in the PAL"s. The complexity of this model is related to the amount of stored logic, i.e., the P-terms in the logic arrays. A linear programming approach is proposed for the encoding of the residue set with the objective of minimizing the complexity of addition and multiplication, modulo M, simultaneously. It is shown that the addition is more complex than the multiplication modulo M, with both (two-operand) operations being upper bounded by O(M2). Results produced using the optimal encoding compare favorably to corresponding results regarding the usual binary representation of residues. Practical constraints are also considered such as limitations on the number of pins, the number of P-terms, and the chip area, with the latter shown to be more efficiently utilized in the PAL scheme than in a ROM-or PLA-based implementation. The encoding technique is also applicable to the functions of discrete logic, in general.
The aim of this paper is to propose quasiconvexity concepts for discrete single variable functions and state some related optimality conditions. Four classes of discrete quasiconvex single variable functions are intro...
详细信息
The aim of this paper is to propose quasiconvexity concepts for discrete single variable functions and state some related optimality conditions. Four classes of discrete quasiconvex single variable functions are introduced, compared and characterized. Two different algorithm procedures for determining a minimum are provided.
In this paper we examine the relationship between multiple-valued bent functions and Vilenkin-Chrestenson spectral invariant operations and Vilenkin-Chrestenson decision diagrams. In binary domain bent functions are a...
详细信息
In this paper we examine the relationship between multiple-valued bent functions and Vilenkin-Chrestenson spectral invariant operations and Vilenkin-Chrestenson decision diagrams. In binary domain bent functions are a class of discrete functions with a highest degree of nonlinearity and form an essential part of cryptographic systems. Multiple-valued bent functions are an extension of bent functions to higher order finite fields. These functions are defined in terms of properties of their Vilenkin-Chrestenson spectra. We demonstrate that the application of spectral invariant operations to a given multiple-valued bent function does not alter the structure of the corresponding Vilenkin-Chrestenson decision diagrams. We exploit this property to efficiently represent whole sets of multiple-valued bent functions using a single Vilenkin-Chrestenson decision diagram. Furthermore, we present a decision diagram based method of construction of multiple-valued bent functions of arbitrary size.
This paper proposes some operations on maximally asymmetric functions. The proposed operations are unary, and produce another function from a maximally asymmetric function. Since the proposed operations can keep the a...
详细信息
ISBN:
(纸本)9798350343090;9798350343083
This paper proposes some operations on maximally asymmetric functions. The proposed operations are unary, and produce another function from a maximally asymmetric function. Since the proposed operations can keep the asymmetry of functions, the produced function is maximally asymmetric as well if the original function is maximally asymmetric. Based on the operations, we can divide the set of maximally asymmetric functions into equivalence classes that have functions able to be produced from the same original function (a representative) by those operations. By using the operations and some representatives of the equivalence classes, we can efficiently generate many benchmarks of maximally asymmetric functions without generating functions from scratch. This paper also shows that the number of the equivalence classes for some examples is very small. This means that most of the benchmarks can be generated by applying only the operations.
暂无评论