Cascade Of Gates Research Articles

Designing of Reversible Functions in Classical and Quantum Domains

First sections of the paper contain some considerations relevant to the reversibility of quantum gates. The Solovay-Kitayev theorem shows that using proper set of quantum gates one can build a quantum version of the nondeterministic Turing machine. On the other hand the Gottesmann-Knill theorem shows the possibility to simulate the quantum machine consisting of only Clifford/Pauli group of gates. This paper presents also an original method of designing the reversible functions. This method is intended for the most popular gate set with three types of gates CNT (Control, NOT and Toffoli). The presented algorithm leads to cascade with minimal number CNT gates. This solution is called optimal reversible circuits. The paper is organized as follows. Section 5 recalls basic concepts of reversible logic. Section 6 contain short description of CNT set of the reversible gates. In Section 7 is presented form of result of designing as the cascade of gates. Section 8 describes the algorithm and section 9 simple example.

ROTOR SPEED OBSERVER OF ASYNCHRONOUS GATE CASCADE

The vector control system of an asynchronous motor, which is closed in terms of the rotor speed, assumes the presence of a sensor on the shaft of the electric machine. However, in practice, often there are problems of regulating the speed of rotation of asynchronous electric drives, in the solution of which the use of mechanical movement coordinate sensors is technically irrational or impossible. In this case, it is necessary to use one of the sensorless vector control algorithms, which involve direct measurement of only electrical quantities. In rotor vector control systems, when the stator is connected to the network at the same time, the need to measure the angle of rotation of the rotor relative to the stator is added, which complicates the structure of the observer.
 For the synthesis of speed observers in asynchronous electric drives, the approach known in control theory is widely used, in which, based on the second Lyapunov method, an adaptation function is formed that provides asymptotic convergence of the adaptive model to the reference one.
 In this paper, the synthesis of the rotor speed observer of an asynchronous gate cascade (AGC) was carried out for its application in a sensorless relay-vector control system. Equations of electromagnetic processes in an asynchronous machine, formulas for coordinate transformations and an identifier for the position angle of the rotor AGC were used as initial mathematical models. The observer synthesis is based on the second Lyapunov method, which allows to determine the structure of the adaptation function, which adjusts the adaptive model in such a way that the difference between the outputs of the adaptive and reference models tends to zero. Thus, the adaptation function, which uses the stator flux vector, ensures the asymptotic stability of the perturbed motion. The proposed speed observer AGC differs from the known observers for stator control in that, along with the speed calculation, the trigonometric functions of the rotor rotation angle are determined, and the structure of the observer includes coordinate transducers that are absent in stator vector control systems, since they do not need to calculate the projections of the voltage vector of one part of the machine onto the orthogonal axes of its other part.

SYNTHESIS OF THE TURNING ANGLE IDENTIFIER ROTOR IN VECTOR CONTROL SYSTEM ASYNCHRONOUS ELECTRIC DRIVE

The paper for a dual-feed machine, new equations of the mathematical model of the identifier of the rotor position angle are obtained, which can be used in the synthesis of vector control systems for asynchronous gate cascade. An analysis of the stability of the developed identifier was carried out, the results of which were used in the synthesis of the identifier structure, which expands the range of its operation modes.

Thioanisole ester based logic gate cascade to control ROS-triggered micellar degradation.

In certain tumor and diseased tissues, reactive oxygen species (ROS), such as H2O2, are produced in higher concentrations than in healthy cells. Drug delivery and release systems that respond selectively to the presence of ROS, while maintaining their stability in “healthy” biological conditions, have great potential as on-site therapeutics. This study presents polymer micelles with 4-(methylthio)phenyl ester functionalities as a ROS-responsive reactivity switch. Oxidation of the thioether moieties triggers ester hydrolysis, exposing a hydrophylic carboxylate and leading to micellar disassembly. At 37 °C, the micelles fall apart on a timescale of days in the presence of 2 mM H2O2 and within hours at higher concentrations of H2O2 (60–600 mM). In the same time frame, the nanocarriers show no hydrolysis in oxidant-free physiological or mildly acidic conditions. This logic gate cascade behavior represents a step forward to realize drug delivery materials capable of selective response to a biomarker input.

Bayesian inference using stochastic logic: A study of buffering schemes for mitigating autocorrelation

Bayesian inference has become near ubiquitous in the design of algorithms for machine learning and autonomous robotic systems as this method provides a rigorous mathematical framework for the probabilistically handling of data with elements of uncertainty. As conventional computer architectures are inefficient in their implementation of probabilistic approaches to inference, stochastic computation has recently emerged as a viable alternative. Recent research has demonstrated that Bayes' rule can be directly implemented with a Muller C-element using stochastic computing. However, the switching inertia at the output due to the inherent memory effect in the C-element limits the accuracy of this approach. Previous methods for reducing this autocorrelation effect have ranged in complexity from counter-based regeneration to bit-reshuffling with memory buffers. Simplified buffering techniques that function independently of the state of C-element are proposed in this work and the effectiveness of the autocorrelation mitigation is evaluated. In addition, the use of multi-input C-elements are shown to add design flexibility for implementing Bayesian inference. Detailed numerical simulations and analysis of configurations that range from a simple cascade of gates to tree structures with large multi-input C-elements demonstrate the viability and limitations of the proposed simplified buffering approaches. These results are significant for their potential for enabling compact implementations of stochastic Bayesian approaches as control lines and random number generators can be shared across multiple C-elements.

ASYNCHRONOUS GATE CASCADE WITH ORIENTED TO VECTOR CURRENT OF MAGNETIZATION CONTROL SYSTEM

In the paper, closed control system of the asynchronous gate cascade (AGC) in axes of coordinates oriented on the magnetization current vector, which is defined as the geometric sum of stator and rotor vectors, is developed and investigated. The search coordinates axes and the optimal structure of the mathematical model of AGC for achieving the best value of a given quality criterion can not be formalized. Therefore, the definition of the structure of the mathematical model of AGC and the synthesis on its basis of the control system, which ensures the qualitative regulation of the electromagnetic torque, have no unam-biguous solution. The paper describes the main stages of the construction of the AGC control system, which is oriented on the magnetization current vector, provided that the structure and parameters of the automated model AGC as a control object are known. The greatest attention is paid to the identification of the reference vector and the study of the dynamic modes of operation AGC with the proposed system of vector control by the method of mathematical modeling. The identification of the stator and rotor currents, and hence the magnetization current, is technically simpler than identifying the asynchronous machine's magnetic fields. The paper proposes to change the structure of the channel of reactive power and its control system in comparison with the most common control system AGC, which is oriented by the vector of the stator flux linkage. Using the vector control system of AGC with the chosen reference vector and the developed structure allows qualitatively to control the magnetization current module and, consequently, the electromagnetic torque that increases the dynamic characteristics of the AGC in comparison with known control systems and approximates the AGC at the regulatory capabilities to direct current electric drives

Introducing Ratiometric Fluorescence to MnO2 Nanosheet-Based Biosensing: A Simple, Label-Free Ratiometric Fluorescent Sensor Programmed by Cascade Logic Circuit for Ultrasensitive GSH Detection.

Glutathione (GSH) plays crucial roles in various biological functions, the level alterations of which have been linked to varieties of diseases. Herein, we for the first time expanded the application of oxidase-like property of MnO2 nanosheet (MnO2 NS) to fluorescent substrates of peroxidase. Different from previously reported fluorescent quenching phenomena, we found that MnO2 NS could not only largely quench the fluorescence of highly fluorescent Scopoletin (SC) but also surprisingly enhance that of nonfluorescent Amplex Red (AR) via oxidation reaction. If MnO2 NS is premixed with GSH, it will be reduced to Mn2+ and lose the oxidase-like property, accompanied by subsequent increase in SC's fluorescence and decrease in AR's. On the basis of the above mechanism, we construct the first MnO2 NS-based ratiometric fluorescent sensor for ultrasensitive and selective detection of GSH. Notably, this ratiometric sensor is programmed by the cascade logic circuit (an INHIBIT gate cascade with a 1 to 2 decoder). And a linear relationship between ratiometric fluorescent intensities of the two substrates and logarithmic values of GSH's concentrations is obtained. The detection limit of GSH is as low as 6.7 nM, which is much lower than previous ratiometric fluorescent sensors, and the lowest MnO2 NS-based fluorescent GSH sensor reported so far. Furthermore, this sensor is simple, label-free, and low-cost; it also presents excellent applicability in human serum samples.

Label-free fluorescent enzymatic assay of citrate synthase by CoA–Au(I) co-ordination polymer and its application in a multi-enzyme logic gate cascade

Citrate synthase (CS) is one of the key metabolic enzymes in the Krebs tricarboxylic acid (TCA) cycle. It regulates energy generation in mitochondrial respiration by catalysing the reaction between oxaloacetic acid (OAA) and acetyl coenzyme A (Ac-CoA) to generate citrate and coenzyme A (CoA). CS has been shown to be a biomarker of neurological diseases and various kinds of cancers. Here, a label-free fluorescent assay has been developed for homogeneously detecting CS and its inhibitor based on the in situ generation of CoA–Au(I) co-ordination polymer (CP) and the fluorescence signal-on by SYBR Green II-stained CoA–Au(I) CP. Because of the unique property of the CoA–Au(I) CP, this CS activity assay method could achieve excellent selectivity and sensitivity, with a linear range from 0.0033 U/μL to 0.264 U/μL and a limit of detection to be 0.00165 U/μL. Meanwhile, this assay method has advantages of being facile and cost effective with quick detection. Moreover, based on this method, a biomimetic logic system was established by rationally exploiting the cascade enzymatic interactions in TCA cycle for chemical information processing. In the TCA cycle-derived logic system, an AND–AND–AND-cascaded gate was rigorously operated step by step in one pot, and is outputted by a label-free fluorescent signal with visualized readout.

Considering nearest neighbor constraints of quantum circuits at the reversible circuit level

Since many underlying quantum algorithms include a Boolean component, synthesis of the respective circuits is often conducted by a two-stage procedure: First, a reversible circuit realizing the Boolean component is generated. Afterwards, this circuit is mapped into a respective quantum gate cascade. In addition, recent physical accomplishments have led to further issues to be considered, e.g. nearest neighbor constraints. However, due to the lack of proper metrics, these constraints usually have been addressed at the quantum circuit level only. In this paper, we present an approach that allows the consideration of nearest neighbor constraints already at the reversible circuit level. For this purpose, a recently introduced gate library is assumed for which a proper metric is proposed. By means of an optimization approach, the applicability of the proposed scheme is illustrated.

Fault detection test set for testable realizations of logic functions with ESOP expressions

The circuit testable realization and its fault detection for logic functions with ESOP (EXOR-Sum-Of-Products) expressions are studied. First of all, for the testable realization by using XOR gate cascade, a test set with 2n + m + 1 vectors for the detections of AND bridging faults and a test set with 2n + m vectors for the detections of OR bridging faults are presented. Secondly, for the testable realization by using XOR gate tree, a test set with 2n + m vectors for the detections of AND bridging faults and a test set with 3n + m + 1 vectors for the detections of OR bridging faults are presented. Finally, a single fault test set with n + 5 vectors for the XOR gate tree realization is presented. Where n is the number of input variables and m is the number of product terms in a logic function.

A 4.2-ps logic gate using new Pb-alloy Josephson IC technology

A high-speed logic gate is attained using new Pb-alloy Josephson IC technology. Three design and fabrication techniques are developed for small I j scattering. They are a gate pattern design rule using junctions with identical geometrical construction, a double-layer resist stencil technique, and RF oxidation in CO 2 plasma. A high-gain direct-coupled Josephson logic (HDCL) gate cascade chain is experimentally fabricated using a new 2-µm process developed from this technology. At a high current density of 10 kA/cm2, high quality junctions are obtained with a small I j scattering of &sigma = 6.8 percent. A very fast switching speed of 4.2 ps/gate is achieved.