Computer Circuit Research Articles

Advancing nanoscale computing: Efficient reversible ALU in quantum-dot cellular automata

This paper presents a significant contribution to the field of nanoscale computing by proposing an innovative reversible Arithmetic and Logic Unit (ALU) implemented in Quantum-Dot Cellular Automata (QCA). Reversible logic and QCA technology offer promising alternatives to conventional CMOS technology, addressing the challenges of operating at nanoscale dimensions. The primary objective is to develop a highly efficient ALU capable of performing 26 distinct arithmetic and logical operations. The ALU design is based on a novel reversible full adder-subtractor optimized for minimal quantum cost, which is crucial for energy-efficient quantum computation. The evaluation encompasses various criteria related to reversibility, such as gate count, number of constant inputs, number of garbage outputs, and quantum cost. QCA-specific criteria, including cell count, occupied area, and clock cycles, are also considered. The outcomes of this research contribute to the advancement of cell-efficient nanoscale computing, with implications for quantum computation, emerging technologies, and future integrated circuit design.

A real-time field bus architecture for multi-smart-motor servo system

The multi-motor servo system (MMSS) is an electro-mechanical system widely used in various fields, including electric vehicles, robotics, and industrial machinery. Depending on the application, the number of motors in the system can range from several dozens to tens of thousands, which imposes additional communication demands. Thus, ensuring synchronization and control precision of the system requires addressing the challenge of guaranteeing the performance and reliability of communication among motors in the MMSS. In this paper, we design a smart servo motor (SSM) to upgrade the system to the multi-smart-motor servo system (MSMSS) based on a distributed real-time field bus architecture, namely, Multi-Motor Bus (MMB) architecture. The proposed MMB architecture is lightweight and stable, providing real-time support for Control Area Network connections to a central user computer and inter-integrated circuit connections to SSM units. This MMB architecture facilitates the synchronization of command transmission across SSMs and ensures the consistency of motors in the MSMSS. Additionally, a serial experiments to examine 3 key system performance and reliability characteristics are conducted, including command transmission time, transmission jitters, and rotation consistency. The analysis of these characteristics demonstrates the system’s potential and feasibility to be applicable in industry.

Development of Circuits for Antilogarithmic Converters with Efficient Error–Area–Delay Product Using the Fractional-Bit Compensation Scheme for Digital Signal Processing Applications

Digital signal processing (DSP) has been widely adopted in sensor systems, communication systems, digital image processing, artificial intelligence, and Internet of Things applications. However, these applications require circuits for complex arithmetic computation. The logarithmic number system is a method to reduce the implementation area and transmission delay for arithmetic computation in DSP. In this study, we propose antilogarithmic converters with efficient error–area–delay products (eADPs) based on the fractional-bit compensation scheme. We propose three mathematical approximations—case 1, case 2, and case 3—to approximate the accurate antilogarithmic curve with different DSP requirements. The maximum percentage errors of conversion for case 1, case 2, and case 3 are 1.9089%, 1.7330%, and 1.2063%, respectively. Case 1, case 2, and case 3 can achieve eADP savings of 15.66%, 80.80%, and 84.61% compared with other methods reported in the literature. The proposed eADP-efficient antilogarithmic converters can achieve lower eADP and digitalized circuit implementation. The hardware implementation utilizes Verilog Hardware Description Language and the digital circuits are created via very-large-scale integration by the Taiwan Semiconductor Manufacturing Company with 0.18 µm CMOS technology. This proposed antilogarithmic converter can be efficiently applied in DSP.

An Ultra-Energy-Efficient Reversible Quantum-Dot Cellular Automata 8:1 Multiplexer Circuit

Energy efficiency considerations in terms of reduced power dissipation are a significant issue in the design of digital circuits for very large-scale integration (VLSI) systems. Quantum-dot cellular automata (QCA) is an emerging ultralow power dissipation approach, distinct from traditional, complementary metal-oxide semiconductor (CMOS) technology, for building digital computing circuits. Developing fully reversible QCA circuits has the potential to significantly reduce energy dissipation. Multiplexers are fundamental elements in the construction of useful digital circuits. In this paper, a novel, multilayer, fully reversible QCA 8:1 multiplexer circuit with ultralow energy dissipation is introduced. The power dissipation of the proposed multiplexer is simulated using the QCADesigner-E version 2.2 tool, describing the microscopic physical mechanisms underlying the QCA operation. The results show that the proposed reversible QCA 8:1 multiplexer consumes 89% less energy than the most energy-efficient 8:1 multiplexer circuit previously presented in the literature.

Corrosion Behavior of X80 Steel in a Simulated Soil Solution Under Square-Wave Current Interference

The buried pipeline is disturbed by the dynamic direct current (DC) stray current with the subway as the main leakage source, which has the safety risk of accelerating corrosion, resulting in pipeline failure, which not only causes economic losses but also threatens personal safety. Therefore, it is necessary to study the corrosion behavior of pipeline steel under dynamic DC interference. The corrosion behavior of X80 steel under dynamic DC interference were studied by a mass loss test, alternating current impedance, circuit simulation, x-ray diffraction, and a Pourbaix diagram. Combined with the corrosion efficiency and Pourbaix diagram of the Fe-H2O system, the reversible process and reduction process mechanism in the Faraday process are proposed. The reason why the corrosion efficiency slows down in the process of non-Faraday is analyzed by the electric double-layer model of equivalent circuit calculation. In addition, based on the above corrosion process, the corresponding conceptual model of the corrosion mechanism is proposed. The experimental results show that with the asymmetry of positive and negative half-cycle interference duration and the increase of current density, the corrosion efficiency, and current corrosion efficiency of X80 steel decrease, and local corrosion intensifies. The length of the negative half-cycle interference affects the capacitive charge-discharge effect at the metal/solution interface and the reduction reaction process of corrosion products, resulting in corrosion slowing down and corrosion efficiency reduction. This is also an important reason for the reduction of corrosion mass loss observed in the experiment compared with steady-state DC.

Radio Absorbing Material for Next-Generation Wireless Devices

Electrical and computer circuits are particularly susceptible to interference from a wide range of human or natural factors. Interference can occur as noise on communication equipment, flashing over televisions and computer monitors, errors in instrumentation, computer network compatibility problems, and electronic malfunctions. Material absorption and safety serve as a shield to prevent the intrusion of the radio wave from getting through critical components and ensure that electrical circuits perform as planned. Since radio frequency interference can also contribute to damage to infrastructure, proper safety and absorption can greatly increase the service life of electrical and electronic equipment. This paper presents a holistic view of the basic concepts of electromagnetic analysis and developments in radio absorbing materials.

Harnessing DNA computing and nanopore decoding for practical applications: from informatics to microRNA-targeting diagnostics.

DNA computing represents a subfield of molecular computing with the potential to become a significant area of next-generation computation due to the high programmability inherent in the sequence-dependent molecular behaviour of DNA. Recent studies in DNA computing have extended from mathematical informatics to biomedical applications, with a particular focus on diagnostics that exploit the biocompatibility of DNA molecules. The output of DNA computing devices is encoded in nucleic acid molecules, which must then be decoded into human-recognizable signals for practical applications. Nanopore technology, which utilizes an electrical and label-free decoding approach, provides a unique platform to bridge DNA and electronic computing for practical use. In this tutorial review, we summarise the fundamental knowledge, technologies, and methodologies of DNA computing (logic gates, circuits, neural networks, and non-DNA input circuity). We then focus on nanopore-based decoding, and highlight recent advances in medical diagnostics targeting microRNAs as biomarkers. Finally, we conclude with the potential and challenges for the practical implementation of these techniques. We hope that this tutorial will provide a comprehensive insight and enable the general reader to grasp the fundamental principles and diverse applications of DNA computing and nanopore decoding, and will inspire a wide range of scientists to explore and push the boundaries of these technologies.

Variability in HfO2-based memristors described with a new bidimensional statistical technique.

A new statistical analysis is presented to assess cycle-to-cycle variability in resistive memories. This method employs two-dimensional (2D) distributions of parameters to analyse both set and reset voltages and currents, coupled with a 2D coefficient of variation (CV). This 2D methodology significantly enhances the analysis, providing a more thorough and comprehensive understanding of the data compared to conventional one-dimensional methods. Resistive switching (RS) data from two different technologies based on hafnium oxide are used in the variability study. The 2D CV allows a more compact assessment of technology suitability for applications such as non-volatile memories, neuromorphic computing and random number generation circuits.

An Optimized Structure for Data Alignment Logic in Parallel CRC Computing Circuits

An Optimized Structure for Data Alignment Logic in Parallel CRC Computing Circuits

Design and Application of Programmable Analog Computing Circuit for Kalman Filter Algorithm Based on Memristive Array

Design and Application of Programmable Analog Computing Circuit for Kalman Filter Algorithm Based on Memristive Array

Refined design of a DNA logic gate for implementing a DNA-based three-level circuit.

DNA computing circuits are favored by researchers because of their high density, high parallelism, and biocompatibility. However, compared with electronic circuits, current DNA circuits have significant errors in understanding the OFF state and logic "0". Nowadays, DNA circuits only have two input states: logic "0" and logic "1", where logic "0" also means the OFF state. Corresponding to an electronic circuit, it is more like an on-off switch than a logic circuit. To correct this conceptual confusion, we propose a three-level circuit. The circuit divides the input signal into three cases: "none", logic "0" and logic "1". In subsequent experiments, 34 input combinations of the primary AND gate, OR gate as well as secondary AND-OR and OR-AND cascade circuits were successfully implemented to perform the operation, which distinguished the OFF state and logic "0" correctly. Based on this, we successfully implemented a more complex voting operation with only 12 strands. We believe that our redefinition of the OFF state and logic "0" will promote tremendous developments in DNA computing circuits.

Preliminary Design of Electric Part of Thermoelectric Unit in a Power Plant

With the rapid development of society, people’s awareness of environmental protection continues to strengthen, countries also pay more and more attention to environmental protection, whether from the national policy or from the green development of enterprises in the future, the improvement of power plant operation efficiency is imperative. Among them, improving the operation efficiency of thermal power plants is the top priority, and it is also an important link of national economic transformation. The design of electrical part is an important part of improving the operation efficiency of thermal power plants. 2x300MW thermal power plant is designed, including the power plant electrical main wiring design, plant power design, the main circuit of the power plant short-circuit calculation, and it choose the electrical stability and thermal stability of the better electrical equipment. The short circuit calculation of the main circuit of the power plant is carried out and preliminary planning of the secondary circuit scheme is made. A power plant with higher operating efficiency is designed. While improving the operation and economic efficiency of the power plant, it also ensures the reliability, stability and economy of the power plant.

Automatic feedthrough cancellation methods for MEMS gyroscopes

The feedthrough effect can significantly affect the performance of MEMS gyroscopes and even lead to device failure. In order to address the inevitable problem of feedthrough capacitance caused by microfabrication process and circuit structure, two automatic feedthrough cancellation solutions are proposed based on the analysis of the feedthrough effect. Firstly, an equivalent feedthrough model is established for MEMS gyroscopes. Then, through theoretical derivation and model simulation, various influences of feedthrough effect are analysed, and the critical value of feedthrough capacitance is calculated to achieve better compensation effects. For feedthrough capacitance greater than the critical value, a feedthrough cancellation method utilizing AD5231 digital potentiometer for generating an inverse signal is designed. For the situation of feedthrough capacitance less than the critical value, a feedthrough cancellation method based on pure digital circuit calculation is proposed. The experimental results show that the method of utilizing digital potentiometer effectively reduces the feedthrough level from −17.46 dB to −32.75 dB, and the method of utilizing pure digital circuit calculation compensates the feedthrough signal of 100.04 mV to almost zero (2.44 mV) within the range of ADC sampling accuracy. These two methods can accurately and quickly suppress feedthrough signal to improve the detection performance of MEMS gyroscopes, and are expected to meet the needs of future mass production. In addition, they can be widely applied to various MEMS devices that require feedthrough cancellation.

Improved privacy-preserving PCA using optimized homomorphic matrix multiplication

Principal Component Analysis (PCA) is a pivotal technique widely utilized in the realms of machine learning and data analysis. It aims to reduce the dimensionality of a dataset while minimizing the loss of information. In recent years, there have been endeavors to utilize homomorphic encryption in privacy-preserving PCA algorithms for secure cloud computing. These approaches commonly employ a PCA routine known as PowerMethod, which takes the covariance matrix as input and generates an approximate eigenvector corresponding to the primary component of the dataset. However, their performance is constrained by the absence of an efficient homomorphic covariance matrix computation circuit and an accurate homomorphic vector normalization strategy in the PowerMethod algorithm. In this study, we propose a novel approach to privacy-preserving PCA that addresses these limitations, resulting in superior efficiency, accuracy, and scalability compared to previous approaches.We attain such efficiency and precision through the following contributions: (i) We implement space and speed optimization techniques for a homomorphic matrix multiplication method, specifically tailored for parallel computing scenarios. (ii) Leveraging the benefits of this optimized matrix multiplication, we devise an efficient homomorphic circuit for computing the covariance matrix homomorphically. (iii) Utilizing the covariance matrix, we develop a novel and efficient homomorphic circuit for the PowerMethod that incorporates a universal homomorphic vector normalization strategy to enhance both its accuracy and practicality.Our privacy-preserving PCA scheme, implemented using our innovative homomorphic PowerMethod circuit, surpasses the state-of-the-art approach with an average speedup of 1.9 times on datasets with size 200×256. Notably, our scheme demonstrates an even more remarkable estimated speedup of 25 times when applied to larger datasets of size 60000×256, along with an R2 accuracy improvement of up to 0.285, showcasing efficiency and accuracy that has not been reported by previous approaches.

Analysis and Simulation Test of Electromagnetic Disturbance Mode Conversion in Secondary Circuit of Substation

Under ideal conditions, the electromagnetic interference experienced by the secondary circuit is manifested as a common mode. However, due to circuit imbalance, common mode disturbance is converted into differential mode disturbance, thereby presenting a danger to the normal functioning of secondary equipment. The investigation measured the distribution ratio of common mode voltages and differential mode voltages at the ports of secondary equipment during switching operations. A computational circuit model of the secondary circuit was established by using multi-conductor transmission line theory. The mechanisms and influencing factors of transformation from common mode to differential mode were analyzed, and a simulation test was carried out in a substation to explore the conversion law under impedance imbalance. The results showed that the differential mode voltage of the secondary equipment port was greater than the common mode voltage when the circuit breaker was in operation. Common-differential mode conversion in the secondary loop was predominantly caused by an imbalance in circuit structure and extraneous parameters. Differential mode disturbance generated by switch field side imbalance had a greater impact than that generated by protection chamber side imbalance. As the degree of imbalance increased, the differential mode voltage also increased.

Power-Impact-Harmonic Characteristics Analysis and Modeling of Diversified Power Loads in Urban Power Grid

Different load models of the same load have different effects on power flow calculation, short circuit calculation, voltage stability, and frequency stability after power system accidents. In this paper, some power load components in urban power grids are modeled by analyzing and fitting the measured power curve of load components, and they are divided into the power model, impact model, and harmonic model according to their characteristics. The power model includes the power models of some household appliances, industrial motors, and arc furnaces. The impact model includes the time series fitting model and probability fitting model. According to the measured power curve of load components, the load model established in this paper can avoid some risks of power calculation caused by the absence of a detailed load model.

Comprehensive and Comparative Analysis of QCA-based Circuit Designs for Next-generation Computation

For the past several decades, VLSI design has been focused on lowering the size, power, and delay. As of now, this miniaturization does not seems to be a possible way to address the demands of consumers. Quantum Dot Cellular Automata (QCA) technology is a promising technique that is able to provide low-power high-speed circuits at nano-scale. Much work has been done in this area where the researchers have proposed a variety of combinational and sequential logic circuits for future computation. This article presents a concrete review of design approaches, logic circuits, clocking schemes, implementation tools, and possible fabrication methodologies presented so far in QCA technology. A critical comparative analysis is provided on the basis of reported performance parameters in the domain. The aim of this article is to collect all necessary information into a single source, highlight the research challenges to be taken in the near future, and enlighten the path for upcoming researchers in the area.

Explicit Linear Model of Bus Impedance With Unknown Branch Status

This letter presents an accurate and explicit linear model of bus impedance for a power network with unknown branch status. Firstly, an equivalent network of the power network is constructed, and the relationship between bus voltage and bus impedance is established. Then, the linear expression of bus impedance with unknown branch status is built. This model can be easily included as constraints in various optimization problems with network topology adjustment involving short circuit calculation.

Hysteresis Resonance and Multi-Pinched Hysteresis Loops in Cu/Cu:ZnO/Cu Resistive Switching Devices

At present, great attention is being devoted towards resistive switching devices owing to lower switching voltage (<3 V), higher tolerance (> 10∧6 cycles), higher scalability (< 10 nm), multi-bit operations, and higher information storage time (10 years) compared to the existing broadly employed transistor technology. This was all possible owing to the accidental discovery of memristance by Hewlett Packard (HP) labs in 2008. In the past few decades, discoveries of such unique electronic properties have led to tremendous technological advancements. Consequently, it is very important to continually seek newer electronic characteristics. In this work, copper (Cu)-doped zinc oxide (ZnO) thin film was synthesized on Cu electrodes to form a Cu/Cu: ZnO/Cu resistive switching device. Function generator and oscilloscope were employed to obtain the electronic characteristics of the device instead of conventional techniques, which resulted in a 96.17% improvement in total equipment expenses. Most importantly, the proposed device exhibited hysteresis resonance and multi-pinched hysteresis; such phenomena have never been reported to date. These characteristics are extremely essential towards futuristic electronics for the development of computational circuits with meliorated performance, electronic systems with improved controllability, memory cells with higher data storage, and in-memory-based processing capabilities.

Quasi-Static Modelling of a Full-Channel Effective Magnetorheological Damper with Trapezoidal Magnetic Rings.

Magnetorheological damper (MRD) has been successfully applied to vehicle suspension systems as an intelligent core component. Most conventional MRDs have closed rectangle-shaped magnetic circuits, resulting in a short effective working length and negligible damping force. To address the above issues, a novel full-channel effective MRD with trapezoidal magnetic rings (FEMRD_TMR) is proposed. The trapezoidal magnetic ring can shunt the magnetic circuit, distributing it evenly along the damping channel and increasing the effective working length. Additionally, which has the same variation trend as the magnetic flux through it, makes the magnetic induction intensity distribution more uniform to reduce the magnetic saturation problem. Theoretically analyzing the damping characteristics of the FEMRD_TMR, a quasi-static model is developed to forecast the output damping force. The structural design of MRD is challenging since conventional quasi-static models rely on the yield stress of magnetorheological fluid (MRF) to reflect the rheological property, which cannot be directly observed and is challenging to calculate. The Takagi-Sugeno (T-S) fuzzy neural network and a unique magnetic circuit computation are offered as a novel quasi-static modeling approach to address the issue. The MRF's yield stress is linearized into magnetic induction intensity functions by the T-S fuzzy neural network and then converted into the MRD's structural size by the special magnetic circuit calculation. Therefore, the proposed quasi-static model can directly reflect the relationship between the damping force and structure size, simplifying MRD's structure design. The novel quasi-static model is shown to be more straightforward and understandable than the conventional Bingham quasi-static model and to have approximately accurate damping force prediction when compared to experimental data.