Volume 18, 1999, No. 1


On yager's theory of bags and fuzzy bags

K. Chakrabarty, R. Biswas, S. Nanda

Abstract. In the present paper, the bag structure viewed by Yager is studied. Complementation of bags and fuzzy bags is done, Cartesian product of bags is defined and some propositions are proved.

 

A unified approach to FAST computation of discrete sinusoidal transforms II: DFT and DWT transforms

V. Britaňák

Abstract. Discrete Fourier transforms (DFT), discrete Hartley transform (DHT), and various types of discrete W transform (DWT) are also members of discrete sinusoidal transform family. A unified approach to the fast computation of the DFT and DWT transforms for real data sequences is presented. It takes advantage of the regular universal DCT-II/DST-II/DST-III computational structure in existing real sparse matrix factorizations leading to simple, numerically stable, in  place and efficient algorithms for any N = 2m, m > 0. The computational complexity of all algorithms both in the sense of the number of arithmetic operations and structural simplicity is better or identical compared with the best known algorithms. The proposed generalized signal flow graphs are regular and confirm the importance of the universal DC-/II/DST-II (DCT/III/DST-III) computational structure for its implementation on one VLSI chip.

 

Distributed tree processing devices

Z. Fülöp

Abstract. Distributed tree processing devices, like regular tree grammars, top-down tree automata and transducers, and bottom-up tree automata and transducers are considered. The concept of distribution lies in that the set of rewriting rules are distributed among n sets, called components. The components work on deriving a sentential form such that they cooperate with each other concerning cooperation strategies. We develop a technical toolkit for studying distributed tree processing devices. We mainly consider the strategy which means that a component should work on a sentential form as far as it can. We show that in general the above distributed tree processing devices with cooperation strategy are more powerful than the ordinary ones with respect to generating capacity.

 

an event structure model for dataflow computing

I.B. Virbitskaite

Abstract. The intention of the paper is to provide "true" concurrency semantics to dynamic dataflow computing. To this end, we study the behaviour of coloured dataflow networks comparatively, incorporating such concepts as firing sequences,  data dependence graphs, partial orders and event structures. The coincidence of the above semantic notions up to an isomorphism  is established.  In particular, the classes of well-formed coloured dataflow networks and prime event structures are examined.

 

multiple-output multilevel logic circuits synthesis technique using multiplexers

M. Kolesár

Abstract. In this paper a new efficient synthesis technique for multiple-output multilevel combinational logic circuits is described.  For an implementation of logic circuits the use of universal logic modules - multiplexers - is assumed.  The decomposition of collection m functions of n variables and the reduction  of canonical multiplexer trees are made by means of the table of residue functions.  The resulting circuits are well suited for FPGA's implementations.  The synthesis technique presented has been implemented in TURBO C++ on PC under MS-DOS. The computer program creates such a tree structure, which contains a minimum number of logic levels and multiplexers.


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