Speed Operation Research Articles

Integrated segmented IQ-modulator for orthogonal sampling and multi-level high-bandwidth signal generation.

Photonic-assisted signal processing of high-bandwidth signals emerges as a solution for challenges encountered in electronic-based processing. Here we present a concept for a compact, photonic-assisted digital-to-analog converter (DAC) and optical IQ-modulator in one single integrated device based on two innovative concepts: a segmented Mach-Zehnder modulator and orthogonal sampling. For electrically driving the modulator, only a single radio frequency oscillator and no pulse source or electrical DAC are required. The presented and simulated proof-of-concept device with six segments can generate a multi-level and high-bandwidth signal from low-bandwidth electronic drivers; e.g., we show the generation of a 120 Gbps data rate, 16-quadrature amplitude modulation (16-QAM, 30 Gbaud) signal solely based on low-bandwidth (5 GHz) non-return-to-zero (NRZ) signals. Integrated on a silicon photonic platform, the device provides fixable speed and bandwidth operations, positioning it as a viable solution for diverse communication systems.

Co‐excitation control of a four‐degree‐of‐freedom magnetic bearing switched reluctance motor based on mathematical models

AbstractIn traditional magnetic bearing motors, the magnetic bearing and the motor are usually driven and controlled separately, resulting in higher controller costs and limiting further expansion of their applications. The author presents a four‐degree‐of‐freedom (4DOF) magnetic bearing switched reluctance motor (MBSRM), consisting of two 8‐pole active radial magnetic bearings (RMBs) and two two‐phase 4/2‐pole switched reluctance motors (SRMs), driven simultaneously by a set of asymmetrical power converters together. Firstly, the structure, winding configuration and co‐excitation working principles of the 4DOF‐MBSRM system are described in detail. Then the radial force formula for an 8‐pole RMB and the torque mathematical model for a 4/2‐pole SRM are briefly derived based on equivalent magnetic circuits, respectively. Furthermore, a co‐excitation control strategy for the 4DOF MBSRM is developed wherein an instantaneous radial force is used to control its rotor shaft levitation, an instantaneous torque is employed for rotational control at low and medium speeds, and an average torque is used for high speed operation. Finally, the good performance of the co‐excitation control for the proposed 4DOF‐MBSRM is proved by simulation analysis.

Manipulation of high-frequency spin waves in ferromagnetic thin films via magnetic torques induced by ultrafast demagnetization

Spin-based technologies demand the effective excitation and control of high-frequency spin waves in order to increase the operational speed of magnonic logic circuits. An available option for the high-frequency spin wave is the perpendicular standing spin waves (PSSWs) in ferromagnetic thin films. However, the practical utilization of a PSSW is still challenging due to a few unsolved critical issues such as its relatively low amplitude and simultaneous excitation of other PSSW modes. Here, efficient excitation and control of a first-order PSSW mode are demonstrated in Ni80Fe20 thin films using a double-laser-pulse scheme. Based upon our experimental and theoretical investigations, it is found that the precession amplitudes of the Kittel and PSSW modes show strong dependence on equivalent torques (i.e., the averaged torques during fast relaxation process after the second pulse excitation) applied to these two modes. Thus, selective excitation and amplification of the first-order PSSW mode can be realized by manipulating the equivalent torque, i.e., introducing a second laser pulse with an appropriate arrival time and laser fluence. Moreover, the spectral tuning of this single PSSW mode can be achieved by proportionately adjusting the laser fluence of two pump pulses. These findings may pave the way for the realization and construction of future high-performance spintronic devices.

Control Unit of a Three-Ports Hybrid Converter of a Microgrid Based on Ternary Logic Circuits

This paper, provides the design and simulation of the control modes of three different power sources that are commonly used in hybrid systems especially when combining the sources of photovoltaic (PV), electric vehicles (EV) and Energy storage system (ESS). The control scenarios discuss the different combinations of sources and loads based on ternary logic system (0,1,2) that has many advantages over the classical binary logic system (0,1). To prove that, first, the ternary logic gates must be verified and simulated as MOSFET by Matlab / Simulink then a ternary logic control (TLCU) will be designed. TLCU can select the right direction of power flow from the energy source to the load based on the ternary truth table that shows the relationship between the inputs (ternary states of sources and loads) and each output that has only two states (ON or Off). At the end of the paper, the circuit of a ternary logic control circuit that can optimize the number of used elements of MOSFET is designed and tested. Comparing to binary, it is expected not only to optimize the number of MOSFET but also to accelerate the speed of operation.

Designing spintronic devices in two-dimensional γ-graphyne: from ultrafast spin dynamics to logic applications

Abstract The integration of two-dimensional (2D) materials into spintronics represents a frontier in the development of novel computational devices. In this work, by utilizing ab initio many-body theory, we investigate the spin dynamics within the Co-doped γ-graphyne structure, with a particular emphasis on the role of cobalt atoms as magnetic centers. The result reveals that each cobalt atom on the γ-graphyne hosts states with enough spin-density localization to facilitate both local spin flips and global spin transfers. The spin-dynamic processes in our study are characterized by ultrafast time scales and high fidelities, demonstrating efficient spin control in the system. Building upon these spin dynamics processes, we theoretically construct a spin-based Reset-Set (RS) latch, thus demonstrating the feasibility of sophisticated logic operations in our system. Such spin-based devices exhibit the advantages of nano-spintronics over conventional-electronic approaches, offering lower energy consumption, faster operational speeds, and greater potential for miniaturization. The results highlight the efficacy of γ-graphyne nanoflakes doped with cobalt atoms as spin-information processing units, signifying a pivotal advancement in the incorporation of graphyne-based materials into sophisticated spintronic devices. This research paves the way for their application in areas such as data storage, quantum computing, and the development of complex logic-processing architectures.

Optimization of Power Tiller Operated Pneumatic Planter under Laboratory Conditions for Enhancing Cotton Planting Efficiency

Aim: The study aimed to optimize the operational parameters viz. orifice diameter, suction pressure and forward speed of operation of a power tiller operated pneumatic planter specifically for cotton crops in laboratory condition, focusing on improving planting operation. Study Design: A Central Composite Rotatable Design (CCRD) was employed to optimize the operational parameters. Place and Duration of Study: The study was conducted in a Soil test bin (sand bed test) in the Tillage and Traction Laboratory in the year 2023 to evaluate the effect of various operational parameters on seed uniformity. Methodology: Based on the study of engineering properties of cotton seed, the size of the orifice on the seed drum was determined. The effect of operational parameters was examined by evaluating mean seed spacing, precision in spacing (coefficient of variation), miss index, multiple index, and quality of feed index. Results: The study found that for achieving singulation of seeds, optimal parameters included a metering drum with an orifice size of 3 mm, a suction pressure of 2.78 kPa, and a forward speed of 1.36 km/h. Corresponding actual values of miss index, multiple index, quality feed index, and precision index were found 7.6±2.5, 6.8±1.6, 82.4±2.5 and 4.1±1.2 against predicted values of 4.40, 4.56, 90.1, and 3.90, respectively. Conclusion: The findings suggest that optimizing operational parameters such as orifice size, suction pressure, and forward speed can significantly improve the performance of power tiller operated pneumatic planters for cotton seed planting. These results contribute to enhancing planting accuracy and efficiency in cotton sown areas.

Evaluation of Field Performance and Energy Consumption of a Medium-sized Combine Harvester for Harvesting Glutinous Rice in Malaysia

A medium-sized combine harvester has been recently deployed to harvest newly introduced high-value glutinous rice in Malaysia. Thus, efficient utilisation of combine harvesters during harvest is essential to minimise operating costs and grain loss. This study evaluated a medium-sized combine harvester’s performance and energy consumption for harvesting glutinous rice. The experiment was carried out on a one-hectare paddy field with three sub-plots using a central composite design (CCD). A time-motion study was conducted during the harvesting operation to determine the combine harvester’s performance parameters, which included field operating speed (FS), field efficiency (FE), theoretical field capacity (TFC), effective field capacity (EFC), grain throughput capacity (GTC), fuel consumption (FC) and field machine index (MI). The energy expended during the operation, which included machinery energy (ME), fuel energy (FCE), human energy (HE), and total energy (TE) input, were also computed. The average FS, FE, TFC, EFC, FC, and MI values were 2.42 km/h, 59.78%, 0.56 ha/h, 0.33 ha/h, 14.89 l/ha, and 0.30, respectively. The mean values of ME, FCE, HE, and TE were 305.35, 711.69, 3.62, and 1020.66 MJ/ha, respectively. The combine harvester achieved an average grain throughput capacity (GTC) of 1796.91 kg/h, demonstrating its effectiveness in handling glutinous rice harvesting. The average time distribution for the harvesting operation, such as effective harvesting time, turning/reversing time, and unloading time, was 1.85 h/ha, 0.38 h/ha, and 1.05 h/ha, respectively. Based on the results, it is concluded that the medium-sized combine harvester is technically and economically suitable for harvesting glutinous rice.

A novel nanosheet reconfigurable field effect transistor with dual-doped source/drain

—In this paper, a reconfigurable field-effect transistor (RFET) with dual-doped nanosheet architecture and triple independent gates is proposed and studied with the numerical simulations. The proposed RFET can behave as either an n/p-type MOSFET or an n/p-type tunneling-FET (TFET) according to different program biases. A comprehensive study is carried out on the device mechanism and the influence of key device parameters. Various metrics, such as the on-state current (ION), off-state current (IOFF), ION/IOFF, threshold voltage (VT) and sub-threshold swing (SS), are used to evaluate the proposed RFET. This RFET combining the advantages of the conventional MOSFETs (High ION and operation speed) and the new emerging TFETs (Low IOFF, sub-threshold swing and power dissipation) could make the circuit design more flexible and high efficiency, and improve the circuit performance.

HIGHER PERFORMANCE ENHANCEMENT OF DIRECT TORQUE CONTROL BY USING ARTIFICIAL NEURAL NETWORKS FOR DOUBLY FED INDUCTION MOTOR

Recently Direct Torque Control is widely appreciated compared to other conventional control methods due to its numerous advantages, notably its speed and precision. However, despite its qualities, it often encounters torque ripples that limit its operational effectiveness. These variations can be attributed to the use of hysteresis comparators, leading to variable frequency operation and undesirable speed overshoots. To address these challenges and enhance overall motor control, this article introduces a new approach based on neural networks. Direct Torque Control method is specifically designed for Doubly Fed Induction Motors and utilizes an Artificial Neural Network. Unlike conventional methods, this approach eliminates the need for speed controllers, commutation tables, and hysteresis comparators, thus providing a more integrated and efficient solution. Simulations conducted in the Matlab/Simulink environment have demonstrated the significant advantages of this approach with a higher performance enhancement. Not only were torque ripples reduced, but speed overshoot was completely eliminated. Furthermore, significant reductions in Total Harmonic Distortion values of stator and rotor currents were achieved, indicating an overall improvement in system performance.

Particle-level insights into the powder flow behavior of the Fette 1200i tablet press feed frame using the discrete element method (DEM)

This study employs the DEM to simulate powder flow in the Fette-1200i tablet press three-chambered feed-frame system under varying operating conditions. It examines the influence of operational speeds on parameters like residence time, particle travel distance, shear work, paddle torque, tablet weight, and API concentration. Utilizing continuous spatial surface maps, the research comprehensively analyzes powder flow behavior. Results indicate that particle residence time increases with paddle speed but decreases with turret speed. Similar trends are observed for particle travel distance and shear work. Larger particle residence time can lead to overlubrication. The torque of the paddles is related to the volume of material in each chamber, with the distributing chamber having the largest volume. Tablet weight rises with paddle speed but drops with turret speed. The smallest particle (API) tends to collect near the paddle hub due to limited centrifugal force and on the chamber floor due to percolation. However, the tablet's API content eventually stabilizes at the target concentration.

Multi‐objective hierarchical optimisation design and experimental verification of an alterable‐magnetic‐circuit variable‐flux memory machine

AbstractRare‐earth permanent magnet synchronous machines face challenges in manipulating their magnetic fields, which hinders the ability to extend the operation speed range. Moreover, this inflexibility leads to reduced efficiency in high‐speed scenarios when the machine is under flux‐weakening control and increases the risk of the magnets becoming demagnetised. The authors propose an alterable‐magnetic‐circuit variable‐flux memory machine (AMC‐VFMM) and a multi‐objective hierarchical optimisation method is conducted to optimise the machine. Firstly, the topology and alterable‐magnetic‐circuit principle of the proposed AMC‐VFMM are introduced. Then, optimisation objectives including torque production capability, flux regulation capability, and resisting unintentional demagnetisation capability are defined, and the hierarchical optimisation approach is established by stratifying the optimisation objectives and variables through the sensitivity analysis. Finite element analysis indicates that electromagnetic performances of the optimised design scheme are significantly enhanced. The bench test of the prototype demonstrates the superiority of the proposed AMC‐VFMM and validates the effectiveness of the optimisation design method.

Distributed virtual simulation experimental software for high-power electric traction system of 600 km/h high-speed maglev train

The operational speed of high-speed maglev trains has reached a groundbreaking 600 km/h, facilitating faster intercity transportation. However, the design and verification of corresponding high-power electric traction systems face significant challenges. To address these issues, this study develops a distributed virtual simulation experimental software for the high-power electric traction system of a 600 km/h high-speed maglev train. The software first establishes virtual digital models for the high-speed maglev train, the high-speed maglev guideways, and the high-power electric traction converters to simulate the high-speed maglev line operation scenarios. Next, it constructs a client–server simulation software architecture, designs a human–machine interaction platform and an electric traction mathematical module, and devises an information exchange method to enable real-time tracking and display for the operating conditions of high-power electric traction systems. Lastly, by integrating electric traction control strategies, fault analysis and optimization design modules, the software effectively designs and verifies the optimal electric traction systems of high-speed maglev trains, and promptly identifies the potential faults in long stator linear synchronous motors and high-power electric traction converters within the electric traction systems. Engineering applications demonstrate that the software can significantly enhance the design and virtual simulation efficiency for the high-power electric traction systems of high-speed maglev trains, thus meeting critical engineering application needs.

Constrained Predictive Controllers for High-Performance Sensorless IPMSM Drive Systems With Full-Range Speed Operations

Constrained Predictive Controllers for High-Performance Sensorless IPMSM Drive Systems With Full-Range Speed Operations

Development and Optimization of Cassava (Manihot Esculenta) Peeling Machine

The conventional cassava peeling methods are inefficient, time-consuming, and labor-intensive This study aimed to create an enhanced cassava peeling machine with minimal flesh loss. The machine design includes components like a hopper, shafts, bearings, an electric motor, and a v belt connected to a pulley that drives the brush-equipped shaft. This locally sourced and fabricated machine, designed for 50kg of cassava tubers, was tested at operational speeds of 380, 420, and 460 rpm and retention times of 4, 6, and 8 minutes, optimizing the effects of machine speeds and peeling times on peeling efficiency using I-optimal Response Surface Experimental Design with a mean separation at P<0.05. Results pertaining to tuber properties, such as angle of repose, peel thickness, moisture content, peel penetration force, bulk density, and coefficient of friction, were utilized in the machine's design. The machine achieved maximum peeling efficiency of 74% at a speed of 380m/s when operated for 6 minutes. At this optimal efficiency, the machine reached an optimal throughput capacity of 171.4kg/h, with a 21% flesh loss, a peeling weight proportion of 25.8%, and minimal tuber damage (3.3%). The desirability, which signifies the extent to which these optimal values align with the optimization goal, was 0.83 (83%). In essence, this machine significantly advances cassava peeling mechanization.

Data Structure and Management Protocol to Enhance Name Resolving in Named Data Networking

Named Data Networking (NDN) is a future Internet architecture that requires an Inter-Domain Routing (IDR) to route its traffic globally. Address resolution is a vital component of any IDR system that relies on a Domain Name System (DNS) resolver to translate domain names into their IP addresses in TCP/IP networks. This paper presents a novel two-element solution to enhance name-to-delivery location resolution in NDN networks, consisting of (1) a mapping table data structure and a searching mechanism and (2) a management protocol to automatically populate and modify the mapping table. The proposed solution is implemented and tested on the Peer Name Provider Server (PNPS) mapping table, and its performance is compared with two other algorithms: component and character tries. The findings show a notable enhancement in the operational speed of the mapping table when utilizing the proposed data structure. For instance, the insertion process is 37 times faster compared to previous algorithms.

Optimization of Parameters of Adaptive Spray System for Agricultural Sprayer

Introduction. When growing tall-growth crops (cereal crops in late the phases of development, corn, sunflower, etc.), there are used boom sprayers equipped with twin-fluid spray cones with fixed angles of inclination to the vertical of the spray cones. The working fluid is applied with such sprays are more intensively on the front side of the plant leaves while the intensity of covering the plants from the back side with the working fluid decreases. The development of the spray system will allow improving the quality of crop treatment with boom sprayers. Aim of the Study. The aim of the research is to determine experimentally the algorithm for changing the angles of inclination of a twin-fluid spray cone that provides the same intensity of applying working liquid to the leaves of high-growth plants. Materials and Methods. The research was carried out on a test bench by applying colored water to the front and rear sides of a tall-growth plant model moving at a specified speed. The experiment was carried out according to the method of optimal planning. The difference between the content of droplets on the front and rear sides of the tall-growth plant model was taken as an optimization parameter. Variable factors were the spray cone inclination angles and the operating speed of the sprayer. Results. The algorithm for changing the optimum values of the spray cone inclination angles depending on the sprayer speed was determined based on the equality of the first derivative of the optimization to zero parameter by the value of these angles. Discussion and Conclusion. According to the algorithm, when the sprayer operating speed increases from 1.2 to 3.2 m/s, the optimal angle of inclination to the front spray cone vertical changes linearly from 25 to 21 degrees, and the rear one ‒ from 46.7 to 57 degrees. This algorithm will allow justifying the technical specifications to develop a processor for automatic control of the spray cone inclination angles cones when the sprayer is operating.

국내외 인공지능 반도체에 대한 연구 동향

Recently, large-scale artificial intelligence (AI) such as ChatGPT have been developed, and as AI is used across various industrial fields, attention is focused on AI chips (semiconductors). AI chips refer to chips designed for calculations for AI algorithms, and many companies at domestic and abroad, such as NVIDIA, Tesla, and ETRI, are developing AI chips. In this paper, we survey research trends on nine types of AI chips. Currently, many attempts have been made to improve the computational performance of most AI chips, and semiconductors for specific purposes are also being designed. In order to compare various AI semiconductors, each chip is analyzed in terms of operation unit, speed, power, and energy efficiency. We introduce currently existing optimization methodologies for AI computation. Based on this, future research directions for AI semiconductors are presented in this paper.

Fast-speed and low-power-consumption optical phased array based on lithium niobate waveguides

Abstract Fast scanning speed and low-power consumption are becoming progressively more and more important in realizing high-performance chiplet optical phased arrays (OPAs). Here, we successfully demonstrated integrated OPAs with multiple waveguides channels based on thin-film lithium niobate-on-insulator (LNOI) platform. Specifically, two lithium niobate (LN) OPA chips have been implemented with 32 and 48 channels LN waveguides, respectively, enabled by electro-optic modulations, which showcases the low power consumption (1.11 nJ/π) and fast operation speed (14.4 ns), showing obvious advantage of the LNOI platform over others. As results, we experimentally achieved a beam steering with a 62.2° × 8.8° field of view (FOV) and a beam divergence of 2.4° × 1.2° for 32 channels, and a FOV of 40° × 8.8° and a beam divergence of 0.33° × 1.8° for 48 channels. This work also demonstrates the feasibility of LNOI platform in scalable OPA chips.

Experimental Investigation of Mode-Frequency Scattering at Fan Stages

Abstract For the development of low-noise fan designs the sound generation must be reduced at the source, but also sound transmission effects through the rotor can be exploited to reduce the noise emitted to the far-field. Rotor shielding has been identified as a means of noise abatement, where rotor counter-rotating modes are blocked by the rotor and transmit poorly to the inlet. An effect that is rarely considered in this context is mode-frequency scattering at the rotor, which can circumvent the blockage effect by shifting the sound energy in frequency and mode order, typically to a rotor co-rotating mode order that transmits efficiently to the inlet. An experimental investigation is presented, where the transmission, reflection and scattering of individually generated modes through a fan stage is measured by means of a loudspeaker array and microphone arrays, upstream and downstream. The highly resolved measured data comprise the variation of mode order, frequency, rotor speed and aerodynamic operating conditions. In this study the focus is on mode-frequency scattering, for which results are presented for high and low rotor speed.

A Configurable CRYSTALS-Kyber Hardware Implementation with Side-Channel Protection

In this work, we present a configurable and side channel resistant implementation of the post-quantum key-exchange algorithm CRYSTALS-Kyber . The implemented design can be configured for different performance and area requirements leading to different trade-offs for different applications. A low area implementation can be achieved in 5,269 LUTs and 2,422 FFs, whereas a high performance implementation required 7,151 LUTs and 3,730 FFs. Due to a deeply pipelined architecture, a high operating speed of more than 250 MHz could be achieved on 28nm Xilinx FPGAs. The side channel resistance is implemented using a carefully chosen set of novel and known techniques such as Fault Detection Hashes, Instruction Randomization, FSM Protection and so on. resulting in a low overhead of less than 5% while being highly configurable. To the best of our knowledge, this work presents the first side-channel and fault attack protected configurable accelerator for CRYSTALS-Kyber . Using TVLA (test vector leakage assessment), we validate the implemented protection techniques and demonstrate that the design does not leak information even after 200 K traces. Furthermore, one of the configuration choices results in the smallest hardware implementation of CRYSTALS-Kyber known in the literature.