Increase In Operating Speed Research Articles

IoT-driven optimization of a NxN enhanced pipeline multiplier

As the Internet of Things (IoT) continues to evolve, the demand for efficient hardware solutions is crucial. The paper explores the significance of hardware multiplication in IoT devices and discusses the challenges and opportunities in implementing dedicated hardware accelerators for multiplication operations. It specifically focuses on a highly efficient NxN-bit folded pipeline multiplier designed using advanced 22 nm CMOS technology and a modified hierarchical design approach. This multiplier achieves remarkable performance enhancements by reducing critical path delay through pipelining, resulting in a three-fold increase in operational speed compared to conventional multipliers. Additionally, it consumes only 0.2 mW of power and reduces chip area consumption by over 28 %. The paper emphasizes the importance of minimizing computational latency and power consumption to enable IoT devices to execute complex algorithms with improved speed and resource utilization. It also addresses trade-offs, such as area overhead and design flexibility, associated with hardware multiplication. The insights provided contribute to ongoing efforts to optimize hardware components for IoT applications, fostering the development of more capable and responsive IoT ecosystems. The study presents a rapid and energy-efficient alternative for multiplication in digital hardware, addressing the need for high-performance and energy-efficient devices in the context of the IoT.

Metaheuristic tuned decentralized PID controller based active suspension system for railway vehicle

AbstractA high‐speed railway system is one of the sustainable alternatives to other modes of transportation and may connect the most congested urban cities with minimum carbon emissions. However, the vibration intensity increases as the train's operating speed increases, resulting in deteriorated ride comfort and stability. Hence, this article investigates a 27‐degree‐of‐freedom (DOF) dynamic model of railway vehicles with an improved active suspension system. The decentralized control structure performs the controlling action with five optimized Proportional Integral Derivative (PID) controllers that suppress the vehicle body's vertical, lateral, pitch, roll, and yaw motions. Further, to optimize the PID parameters, three metaheuristic optimization techniques, Genetic algorithm (GA), Grey Wolf Optimization (GWO), and Flower Pollination Algorithm (FPA), are utilized, and their simulated results are compared with the passive system as well as other conventional tuning technique. Moreover, the performance of the proposed control strategy is evaluated in the frequency domain under random track irregularities, and the results are characterized in terms of power spectral densities (PSDs). The simulated results show that among the proposed metaheuristic algorithms, FPA outperforms with a significant reduction in vehicle vibration compared to other tuning methods. The percentage reduction of the vertical, lateral, pitch, rolls, and yaw accelerations is 71.4%, 35.1%, 52.8%, 48.1%, and 38.2%, respectively, ensuring enhanced vehicle ride comfort.

Study on the sound radiation characteristics of polygonal wear wheels of CRH3 high-speed train

Abstract Due to the increase in train operating speed, the phenomenon of collision vibration between wheels and rails becomes more and more obvious, and the degree of wheel wear increases dramatically. As a result, the wheel-rail noise problem has become more and more complex. The wheel polygonal wear is also widespread on the train. For the wheel in the form of polygonal wear of the wheel-rail vertical force, combined with the principle of wheel-rail noise, we conduct an in-depth study. An aerodynamic mutual coupling model for CRH3 high-speed vehicles is proposed. The role of the amplitude of 0.03 mm, i.e., the twentieth-order polygonal abrasion rate on the wheel-rail force is analyzed at the speed class of 200~350 km/h, and the acoustic radiation characteristics of the wheels are investigated at different speed classes. The results show that under different speed classes, when the wheel polygon order is in the twentieth order, the wheel-rail vertical force rises with the increase of speed, and the wheel sound power is also affected by a great change. There is a significant increase in the sound power from the low frequency of 20 Hz to 100 Hz and a peak in the mid-frequency up to 1, 000 Hz. Secondly, when the wheel radiated sound pressure levels at different speed levels, significant changes also occurred, with the sound pressure reaching a maximum of 110 dB at 350 km/h.

АНАЛИЗ ЭНЕРГОНАСЫЩЕННОСТИ РЫНКА СЕЛЬСКОХОЗЯЙСТВЕННЫХ ТРАКТОРОВ РОССИЙСКОЙ ФЕДЕРАЦИИ

The modern level of technical development makes it possible to produce high-power agricultural tractors and at the same time reduce the specific weight of the unit. Most of the US and European markets are represented by tractors up to the 2nd traction class, while in Russia there is a steady increase in the use of tractors of traction class over 2. It is known that an increase in the power of machine-tractor units leads to an increase in nominal operating speeds, as well as fuel and lubricants costs. There is also a decrease in the total mass of machine-tractor units, which, while increasing power, reduces the efficiency of using the unit when performing agrotechnological operations. Underloading of a high-power and low-weight unit leads to incomplete and irrational use of the life of machine-tractor units laid down by the manufacturer. (Research purpose) The research purpose is determining the share of high-power equipment in the markets of the Russian Federation. (Materials and methods) Studied the market of machine-tractor units in the Russian Federation on the basis of well-known works and information on technical data provided in open sources by manufacturers. (Results and discussion) We obtained diagrams describing the percentage of world and domestic agricultural tractor manufacturers in the Russian markets, their price range, the share of countries producing tractors of different traction classes, the number of high-power equipment for various traction classes. Based on the analysis of technical characteristics, we have compiled a summary table of the energy saturation of machine-tractor units in the Russian market. The specific power of each tractor model under study was calculated. The specific power of tractors within each traction class was brought. (Conclusions) It was shown that the results obtained indicate a high specific power of the tractor market in the Russian Federation.

Comparative study on seed metering units for wet-direct seeding of rice

In sowing operation, seed metering units plays a crucial role in achieving the optimal plant spacing, uniform crop emergence, crop yield, resource efficiency, and overall farm profitability. This research was conducted to access performance of four metering mechanisms (drum type, fluted roller type, inclined plate type-I, and inclined plate type-II) with three distinct paddy varieties (IR-64, JR-206, and Kranti) and at three levels of operating speed (1, 1.5 and 2 km/h). A test rig was developed for conducting the lab experiments to measure the seed rate and mechanical damage for all four metering units. Across all types of metering units and seed varieties, a trend was observed where the seed rate tends to decrease as the operating speed increases and mechanical damage to seeds increases with increase in operating speed. For drum type, fluted roller type, inclined plate type-I, inclined plate type-II metering unit seed rate varies from 21.67 to 27.91 kg/ha, 47.44 to 55.98 kg/ha, 26.5 to 30.09 kg/ha, and 28.98 to 33.23 Kg/ha whereas, seed damage ranged from 1.1 to 2.1%, 8.89 to 12.8 %,0.09 to 0.17 %, and 2.21 to 3.54 %, respectively. Among the metering units, the inclined plate type-I emerges as the preferred choice, showcasing minimal mechanical damage alongside optimum seed rate. These findings have important implications in selecting metering unit for wet-direct seeding method of rice cultivation, with the potential to enhance rice production and productivity.

QPWS Feature Selection and CAE Fusion of Visible/Near-Infrared Spectroscopy Data for the Identification of Salix psammophila Origin

Salix psammophila, classified under the Salicaceae family, is a deciduous, densely branched, and erect shrub. As a leading pioneer tree species in windbreak and sand stabilization, it has played a crucial role in combating desertification in northwestern China. However, different genetic sources of Salix psammophila exhibit significant variations in their effectiveness for windbreak and sand stabilization. Therefore, it is essential to establish a rapid and reliable method for identifying different Salix psammophila varieties. Visible and near-infrared (Vis-NIR) spectroscopy is currently a reliable non-destructive solution for origin traceability. This study introduced a novel feature selection strategy, called qualitative percentile weighted sampling (QPWS), based on the principle of the long tail effect for Vis-NIR spectroscopy. The core idea of QPWS combines weighted sampling and percentage wavelength selection to identify key wavelengths. By employing a multi-threaded parallel execution of multiple QPWS instances, we aimed to search for the optimal feature bands to address the instability issues that can arise during the feature selection process. To address the problem of reduced prediction performance in one-dimensional convolutional neural network (1D-CNN) models after feature selection, we have introduced convolutional autoencoders (CAEs) to reduce the dimensions of wavelengths that are discarded during feature selection. Subsequently, these reduced dimensions are fused with the selected wavelengths, thereby enhancing the model’s performance. With our completed model, we selected outstanding models for model fusion and established a decision system for Salix psammophila. It is worth noting that all 1D-CNN models in this study were developed using Bayesian optimization methods. In comparison with principal component analysis (PCA) and full spectrum methods, QPWS exhibits superior predictive performance in the field of machine learning. In the realm of deep learning, the fusion of data combining QPWS with CAE demonstrated even greater potential with an improvement of average accuracy of approximately 2.13% when compared to QPWS alone and a 228% increase in operational speed compared to a model with full spectra. These results indicated that the combination of CAE with QPWS can be an effective tool for identifying the origin of Salix psammophila.

Implementation of High-Speed Compact Level-Up Shifter for Nano-Scale Applications

The objective of this study is to present a level shifter architecture that utilizes a pair of inverters and a Wilson current mirror to reduce power consumption while improving voltage shifting capabilities. We introduce novel components such as super-cut-off pull-down and stacked pull-up networks to effectively minimize leakage power. Our design leverages multi-threshold CMOS (MTCMOS) technology, incorporating sleep transistors to boost operational speed, decrease power consumption, and reduce the physical footprint. The proposed circuit is engineered to step up voltage levels, ranging from a mere 0.4 V to a substantial 1.2 V. Through extensive optimization of performance parameters, including power efficiency, delay, and area utilization, we have tailored this design to cater specifically to the demands of nano-scale applications. Key results from our research reveal that the average active power consumption for “level-up” shifts is impressively low at 48.5 nW, with an average latency of a mere 1.58 ns for 1 MHz transmission frequencies. Post-layout modeling demonstrates that our suggested design occupies a compact area of just 9.97 µm2. These findings were meticulously modeled using Cadence Virtuoso with 45 nm processes. Furthermore, our research highlights the substantial advancements achieved when compared to previous methods. The proposed design boasts a threefold increase in operational speed and delivers significant savings in both area and power consumption. These outcomes have far-reaching implications for emerging technologies and applications in the field.

A spinwave Ising machine

Time-multiplexed Coherent Ising Machines (CIMs) have demonstrated promising results in rapidly solving large-scale combinatorial problems. However, CIMs remain relatively large and power-demanding. Here, we demonstrate a spinwave-based Ising machine (SWIM) that due to the low spinwave group velocity allows for sufficient miniaturization and reduced power consumption. The SWIM is implemented using a 10-mm-long 5-μm-thick Yttrium Iron Garnet film with off-the-shelf microwave components and can support an 8-spin MAX-CUT problem and solve it in less than 4 μs consuming only 7 μJ. As the SWIM minimizes its energy, we observe that the spin states can demonstrate both uniform and domain-propagation-like switching. The developed SWIM has the potential for substantial further miniaturization with reduction of power consumption, scalability in the number of supported spins, increase of operational speed, and may become a versatile platform for commercially feasible high-performance solvers of combinatorial optimization problems.

MPSoC design and implementation using microblaze soft core processor architecture for faster execution of arithmetic application

The research paper presents the design methodology with novel task distribution technique on multi-processor system on chip (MPSoC) for speeding up the execution of arithmetic application. Utilisation of multiple soft core processors on field programmable gate array (FPGA) reduces the overload of adding external hardware to a system. Parallel processing of soft core processor with proposed task distribution technique makes any application to execute at faster rate. This task distribution based speed enhancement technique for arithmetic application is very feasible and appealing to the modern applications like neural networks, fuzzy logic, algorithms of machine learning etc. Experimentation on such architecture with arithmetic application shows significant increase in speed of operation with respect to conventional design. This is implemented using Microblaze soft core processor architecture on Xilinx Virtex 5 FPGA board.

High Speed Permanent Magnet Assisted Synchronous Reluctance Machines – Part II: Performance Boundaries

The insertion of permanent magnets (PMs) within the rotor slots of Synchronous Reluctance Machines (SyRM) is the most common design strategy used to increase significantly their performance. In this paper it is shown how a permanent magnet assisted synchronous reluctance machine (PMaSyRM) can be optimized to satisfy all the electromagnetic and structural constraints arising as the maximum operating speed increases. This is done considering a variety PMs material. This work, the second of two companion papers, briefly recalls the novel systematic design approach proposed in Part I, and then describes the characteristics of the optimal machines achieved considering a maximum speed ranging from 1 to 140 krpm with and without the assistance of ferrite and neodymium based PMs. The reasons behind the performance deterioration as the speed increases are all investigated along with the geometrical variations of the optimal designs. The selection of the design solution to be manufactured is justified as well as the final structural and electromagnetic refinement stages leading to the prototype. All the reported considerations are experimentally validated testing an 8.5 kW at 80 krpm PMaSyRM, comparing the measured and expected performance in terms of torque and internal power factor.

The effect of covering structure in pantograph sinking platform on the aerodynamics of high- speed train

ABSTRACT The aerodynamic drag of pantograph system hinders the increase of train operating speed, which can be reduced by the covering structure proposed in this study. Exploring the drag reduction mechanism of covering structure is critical. An IDDES method based on the SST κ–ω turbulence model was utilized to study the effect of covering structure on aerodynamic performance of high-speed train. The results show that the covering structure reduces the overall drag by 5.6% for 3-car train-set since the impingement of incoming flow on the surface of sinking platform is alleviated. The aerodynamic drag of the middle car is significantly reduced while that of the tail car increases due to higher pressure on the train joint surface caused by the covering plates. The turbulence of the flow field surrounding sinking platform is suppressed by weakening the flow separations from cavity edge. Vortical structure changes occur to the vortices shed from the leading edge of cavity because the front covering plate delays the process of flow separation, further leading to the alteration of dominant frequencies for folded pantograph. The covering structure will decrease the oscillation of lift force by 24.74% and 37.14% for lifted and folded pantograph.

Effect of assessment methods on the determination of the critical wind speeds of high-speed trains

Abstract Critical wind speed can play an important guiding role in developing an initial train operation schedule and knowledge of it may prevent safety risks for a train. Hence, the efficient and accurate calculation of the critical wind speeds of trains is critical. This study addresses this topic and focuses on the influence of different methods on the calculation of the critical wind speed. The result reveals that the five-mass and three-mass methods can both be used to determine the critical wind speed of a train more quickly with acceptable accuracy, but these two methods overestimate the crosswind safety risk of the train. With the increase of the train's operating speed, the nonlinearity of the vehicle system is further enhanced. In particular, the influence of the rolling motion between the car body and the bogie is more prominent, and the results of the five-mass method and the multi-body simulation method tend to be the closest. Last but not least, the damping parameters and inertial forces ignored by the quasi-static method will effectively reduce the wind forces transmitted to the track, resulting in a smaller overturning coefficient and higher critical wind speed.

Digital Sliding Mode Based Model-Free PWM Current Control of Switched Reluctance Machines

This article presents a digital sliding mode based robust model-free pulsewidth mode current control method for switched reluctance machine (SRM) drives. The model-free nature of the proposed controller allows complete elimination of the phase inductance or flux-linkage identification process. From the controller point of view, this exclusion yields excellent computational efficiency and low memory usage. In the proposed control method, the model information required to achieve a consistent closed-loop dynamic response is treated as an extended state and it is estimated online via unit time-step delayed approximation. The effect of this delay becomes significant as the operating speed increases. The estimation accuracy of the extended state is also affected by the noise in the current measurement. The effect of these factors on the control performance is compensated by using an auxiliary control action derived from a Lyapunov energy function analysis in the discrete-time domain. The resultant controller achieves accurate tracking of the reference phase current profile at fixed switching frequency modulation. It demonstrates a robust tracking performance throughout the controllable operating range of the SRM drive amid low signal-to-noise ratio.

Enhanced Electromagnetic Shielding and Thermal Conductive Properties of Polyolefin Composites with a Ti3C2Tx MXene/Graphene Framework Connected by a Hydrogen-Bonded Interface.

The rapid increase of operation speed, transmission efficiency, and power density of miniaturized devices leads to a rising demand for electromagnetic interference (EMI) shielding and thermal management materials in the semiconductor industry. Therefore, it is essential to improve both the EMI shielding and thermal conductive properties of commonly used polyolefin components (such as polyethylene (PE)) in electronic systems. Currently, melt compounding is the most common method to fabricate polyolefin composites, but the difficulty of filler dispersion and high resistance at the filler/filler or filler/matrix interface limits their properties. Here, a fold fabrication strategy was proposed to prepare PE composites by incorporation of a well-aligned, seamless graphene framework premodified with MXene nanosheets into the matrix. We demonstrate that the physical properties of the composites can be further improved at the same filler loading by nanoscale interface engineering: the formation of hydrogen bonds at the graphene/MXene interface and the development of a seamlessly interconnected graphene framework. The obtained PE composites exhibit an EMI shielding property of ∼61.0 dB and a thermal conductivity of 9.26 W m-1 K-1 at a low filler content (∼3 wt %, including ∼0.4 wt % MXene). Moreover, other thermoplastic composites with the same results can also be produced based on our method. Our study provides an idea toward rational design of the filler interface to prepare high-performance polymer composites for use in microelectronics and microsystems.

Comparing and Contrasting the Impacts of Macro-Level Factors on Crash Duration and Frequency.

Road traffic crashes cause social, economic, physical and emotional losses. They also reduce operating speed and road capacity and increase delays, unreliability, and productivity losses. Previous crash duration research has concentrated on individual crashes, with the contributing elements extracted directly from the incident description and records. As a result, the explanatory variables were more regional, and the effects of broader macro-level factors were not investigated. This is in contrast to crash frequency studies, which normally collect explanatory factors at a macro-level. This study explores the impact of various factors and the consistency of their effects on vehicle crash duration and frequency at a macro-level. Along with the demographic, vehicle utilisation, environmental, and responder variables, street network features such as connectedness, density, and hierarchy were added as covariates. The dataset contains over 95,000 vehicle crash records over 4.5 years in Greater Sydney, Australia. Following a dimension reduction of independent variables, a hazard-based model was estimated for crash duration, and a Negative Binomial model was estimated for frequency. Unobserved heterogeneity was accounted for by latent class models for both duration and frequency. Income, driver experience and exposure are considered to have both positive and negative impacts on duration. Crash duration is shorter in regions with a dense road network, but crash frequency is higher. Highly connected networks, on the other hand, are associated with longer length but lower frequency.

Effect of dynamic load and cooling path on the frost characteristics of saturated lean clay

With the traffic load increase in heavy-haul railways, the subgrade's frost heave damage should be emphasized in colder seasons for operational safety. The effects of dynamic vehicle load (mean value and frequency), step cooling path, and dry density on filler's frost characteristics are not explored in existing heavy-haul lines. This study performed L9(43) orthogonal tests for saturated lean clay filler. The test results were analyzed using the analysis of variance method and the grey incidence (GI) model. The external water supply caused a shallower frozen depth, more segregated ice, and a frost heave ratio exceeding 4.0% under a dynamic load. The dry density, associated with the migrating water's permeability, had the highest significance on the open system's frost heave. As the phase change of water depends on the negative temperature, the step cooling path had the highest impact on the frost heave ratio and frozen depth in the closed system. The significance of dynamic load on the frost heave ratio was slight, so an increase in axle load and operating speed had little impact on the lean clay's frost heave characteristics. Compared with other factors, the water supply conditions had the most significant impact on the test results. This study clarifies the significance of the four factors on the filler's frost characteristics in heavy-haul railways, which serves as an essential guide to frost damage management.

Field Capacity and Efficiency of a Turmeric Rhizome Planter in Response to Machine Speeds and Some Selected Crop Parameters

This study present variation in field capacity and efficiency of a turmeric rhizome planter in response to the machine speed and some selected turmeric parameters (dimension); turmeric rhizome length and diameter. This was done with a view to ascertaining the best condition under which the planter could perform optimally. The land area covered in a specific duration by the planter depends largely on the field capacity. The turmeric rhizome planter consists of trapezoidal hopper, grooved cylindrical metering devise, ground wheels made of mild steel, chain/sprocket drive system, three linkage point and frame. The experiment was randomized in a factorial design of three levels of rhizome lengths of 30, 45 and 60 mm, diameter of 25, 30 and 35 mm and operational speeds of 8, 10, and 12 kmh-1. The result of the study shows that increase in planter operational speed resulted in an increase in field capacity and efficiency of the planter, and had a significant effect on them. The turmeric rhizome lengths and diameter were found to have insignificant effects on the field capacity and efficiency of the planter.

Field Capacity and Efficiency of a Turmeric Rhizome Planter in Response to Machine Speeds and Some Selected Crop Parameters

This study present variation in field capacity and efficiency of a turmeric rhizome planter in response to the machine speed and some selected turmeric parameters (dimension); turmeric rhizome length and diameter. This was done with a view to ascertaining the best condition under which the planter could perform optimally. The land area covered in a specific duration by the planter depends largely on the field capacity. The turmeric rhizome planter consists of trapezoidal hopper, grooved cylindrical metering devise, ground wheels made of mild steel, chain/sprocket drive system, three linkage point and frame. The experiment was randomized in a factorial design of three levels of rhizome lengths of 30, 45 and 60 mm, diameter of 25, 30 and 35 mm and operational speeds of 8, 10, and 12 kmh-1. The result of the study shows that increase in planter operational speed resulted in an increase in field capacity and efficiency of the planter, and had a significant effect on them. The turmeric rhizome lengths and diameter were found to have insignificant effects on the field capacity and efficiency of the planter.

Interactive Influence Analysis of Tunnel Lateral Clearance on Driving Behavior Using Expressway Field Data

Changes in lateral clearance are prone to drastic changes in the driving environment at the entrance and exit of the tunnel, which can cause a driver to become psychologically stressed and deviate from the center of a lane, thus creating a greater security risk. However, most of the existing regulations and studies only focus on the horizontal and vertical alignment of the tunnel entrances and exits, and there are few studies on the influence of lateral clearance on driving behavior. This study hired 15 random subjects to conduct real vehicle tests in eight tunnels on expressways with 3 design speeds by using a CAN-OBD analyzer and steering wheel angle meter. First, in five lateral clearance variation schemes, different speed characteristic indicators and steering wheel angles were selected as the indicators of driving behavior. Second, the interactive influence of the design speed, lateral clearance, operating speed, steering wheel angle, and other indicators were analyzed. Finally, paired t-test analysis and Wilcoxon and Friedman nonparametric tests were used to compare the differences in various indicators among different lateral clearance schemes. The results showed that when the left lateral clearance is 1.5 meters, the operating speed is increased by 3.9%, while the standard deviation of speed is small, and the driving performance is higher. When the right lateral clearance is 1.75 and 2.00 meters, the operating speed is not much different. However, the latter’s speed standard deviation is smaller. By contrast, when the right lateral clearance is up to 2.25 m, the operating speed increases by 3.7%. However, the speed standard deviation also increases. Different lateral clearances have little effect on the steering wheel angle. The operating speed on the right side is higher and more stable when the design speed is 100 km/h. This study provides scientific suggestions for the setting of the lateral clearance of the tunnels.

КОМЕРЦІЙНІ РИЗИКИ В СИСТЕМІ МОРСЬКИХ ПЕРЕВЕЗЕНЬ НА ПРИКЛАДІ КОНТЕЙНЕРОВОЗУ «EVER GIVEN»

Every year there is an intensive increase in tonnage and operational speed of vessels in the competition to improve the quality of transport and logistics services. Ship management needs to work in difficult, sometimes extreme conditions. It is necessary to comply with the commercial conditions of charters and not to violate the terms of delivery, to ensure the proper quality of cargo on board the vessel, as well as to comply with the conditions of safety of navigation in difficult weather conditions. All this affects the quality of cargo transportation.Purpose. The purpose of this article is to systematize various aspects of the commercial operation of a vessel, identify possible commercial risks of sea transportation, as well as factors influencing them.Methods. To solve the problem, the following methods were used: the method of theoretical generalization, the method of analysis and synthesis, the method of systematization, the method of deduction.Results. It has been determined that the anticipation of commercial risks of sea transportation will allow to develop mechanisms for their timely overcoming and reduce the commercial costs of all interested parties in the carriage of goods by sea. The main reasons for thegeneral accident of the container ship Ever Given in the Suez Canal are considered and analyzed and the consequences that it caused for the stakeholders of transportation and international maritime shipping in general are identified.Originality. Potential commercial risks of sea transportation have been identified using the example of the accident with the container ship «Ever Given». It is proposed to develop alternative options for a prompt solution to such problems in the future.Output. The blockage of the Suez Canal by the container ship Ever Given will have long-term repercussions, but such incidents could be deliberately provoked, affecting global and local trade in a targeted manner. There is a need to improve the safety of navigation by optimizing pilotage, especially during sandstorms and other situations where visibility is difficult.Keywords: commercial operation of a vessel, risks, sea transport, seaport, navigation safety