Implementation Of Logic Gates Research Articles

Analysis of the properties of soft morphological filtering using threshold decomposition

We present the properties of soft morphological operations and the new definitions of binary soft morphological operations. It is shown that soft morphological filtering an arbitrary signal is equivalent to decomposing the signal into binary signals, filtering each binary signal with a binary soft morphological filter, and then reversing the decomposition. This equivalence allows problems in the analysis and the implementation of soft morphological operations in real time by using only logic gates for binary signals instead of sorting the numbers. The architectures of logic-gate implementation of soft morphological operations are also presented. Furthermore, unlike standard morphological filters, the soft morphological closing and opening are in general not idempotent. We develop the conditions and properties for a new class of idempotent soft morphological filters. >

Computational functions in biochemical reaction networks

In prior work we demonstrated the implementation of logic gates, sequential computers (universal Turing machines), and parallel computers by means of the kinetics of chemical reaction mechanisms. In the present article we develop this subject further by first investigating the computational properties of several enzymatic (single and multiple) reaction mechanisms: we show their steady states are analogous to either Boolean or fuzzy logic gates. Nearly perfect digital function is obtained only in the regime in which the enzymes are saturated with their substrates. With these enzymatic gates, we construct combinational chemical networks that execute a given truth-table. The dynamic range of a network's output is strongly affected by "input/output matching" conditions among the internal gate elements. We find a simple mechanism, similar to the interconversion of fructose-6-phosphate between its two bisphosphate forms (fructose-1,6-bisphosphate and fructose-2,6-bisphosphate), that functions analogously to an AND gate. When the simple model is supplanted with one in which the enzyme rate laws are derived from experimental data, the steady state of the mechanism functions as an asymmetric fuzzy aggregation operator with properties akin to a fuzzy AND gate. The qualitative behavior of the mechanism does not change when situated within a large model of glycolysis/gluconeogenesis and the TCA cycle. The mechanism, in this case, switches the pathway's mode from glycolysis to gluconeogenesis in response to chemical signals of low blood glucose (cAMP) and abundant fuel for the TCA cycle (acetyl coenzyme A).

Logic gate implementation for gray-scale morphology

In this paper, we show that the direct logic gate implementation of gray-scale morphology can be modified using threshold decomposition principle. The resulting new architecture has the advantage that the number of logic levels is not sensitive to structuring element size increases, yet it requires much less number of logic gates than a previously reported architecture having the same advantage.

Pass-transistor logic design

Logic functions implemented using CMOS transmission gates provide a moderate improvement in area and speed over logic gate implementations. Several techniques for the implementation of pass transistor logic are presented. These techniques use only nMOS transistors in the pass network. The output logic level is restored using additional circuitry. The proposed designs require less silicon area, less power dissipation, and operate at higher speeds compared with the conventional CMOS pass-transistor networks. The speed of operation depends mainly on the circuitry used to restore the output signal of the pass network. The different techniques are compared with respect to the layout area and operating speed.

Optical parallel logic gates using inexpensive liquid-crystal televisions

The optical implementation of parallel logic gates using inexpensive liquid-crystal televisions (LCTV's) is demonstrated, and basic experimental results are presented. While it is certainly unreasonable to expect general-purpose optical computers to be built from LCTV's, demonstration-level systems can be built, from which a great deal may be learned.

Optical Computing Based On Interference Fringe Shifting

Novel optical computing techniques based on shifting operations of an optical interference fringe are described. Architectures of optical processing systems in both the bulk and the guided-wave approach are discussed. The dividing of the shifted output fringe allows the parallel implementation of multiple logic gates. The multiple-output scheme is controllable in number and sort via a photorefractive effect. Representative examples of applications to an optical half-adder, binary multiplication, and vector-matrix arithmetic are given.