Changes In Speed Research Articles

Study on Multi-Span Tension Coupling Relationship of Gravure Printed Electronic Equipment

To improve the performance of the tension control system in gravure printed electronic equipment, it is necessary to study the tension system model of gravure-printing electronic equipment. This paper focuses on the coupling characteristics of multi-span tension systems. Firstly, based on the single-span tension model, the mathematical model of the printing tension subsystem is established and simplified into a general multi-span tension coupling model. Then, using the relationship between the inputs and outputs of the system, the coupling model is simulated using MATLAB/Simulink and verified through experiments on the gravure printed electronic platform. Finally, the coupling relationship and influence laws among multi-physical quantities of the system are analyzed. The research results show that changes in the input web tension of the multi-span system will affect the steady-state tension values of all subsequent spans. Moreover, the speed change in a roller in the multi-span system will not only affect the steady-state tension value of its own span, but also cause transient tension fluctuations in all subsequent spans. The findings of this paper provide an important theoretical basis for the research of the tension system in gravure printed electronic equipment, contributing to the enhancement of printed electronic product quality.

Physiological and transcriptomic changes of zebrafish (Danio rerio) in response to Isopropylate Triphenyl Phosphate (IPPP) exposure

Isopropylate Triphenyl Phosphate (IPPP), a novel organophosphorus flame retardant, has become a widespread environmental pollutant. However, the toxic effects and mechanisms of IPPP remain unclear. In this study, we evaluated the neurodevelopmental toxicity effects of IPPP on zebrafish embryonic development, neurobehavior, and physiological and transcriptomic changes. The results showed that IPPP induced adverse developments such as low survival rates and hatching rates, decreased body length and eye distance, and also led to increased heart rates and embryonic malformation rates. The developmental defects mainly included typical pericardial edema, eye deformities, and a reduction in the number of newborn neurons. Mitochondrial energy metabolism disorders and apoptosis of cardiomyocytes may be responsible for heart malformation. Behavioral results showed that IPPP caused abnormal changes in swimming speed, total swimming distance and trajectory, and showed a low-dose effect. In addition, the decreased activity of neurotransmitters such as acetylcholinesterase (AchE) and dopamine (DA), and the changes in genes related to the central nervous system (CNS) and metabolism pathway may be the causes of neurodevelopmental toxicity of IPPP. Meanwhile, IPPP induced oxidative stress and apoptosis, and changed the ATPase activity of zebrafish larvae by altering nuclear factor erythroid2-related factor 2 (Nrf2) and mitochondrial signaling pathways, respectively. Transcriptome sequencing results indicated that Cytochrome P450 and drug metabolism, Energy metabolism-related pathways, Glutathione metabolism, Retinoid acid (RA) and REDOX signaling pathways were significantly enriched, and most of the genes in these pathways were up-regulated after IPPP treatment, which may be new targets for IPPP-induced neurodevelopment. In summary, the results of this study provide an important reference for a comprehensive assessment of the toxic effects and health risks of the new pollutant IPPP.

The power control and efficiency optimization strategy of dynamic wireless charging system for multiple electric vehicles

Purpose This study aims to solve the problem that both the speed and the required driving power of electric vehicles (EVs) will change during the dynamic wireless charging (DWC) process, making it difficult to charge EVs with a constant power considering the overall efficiency of DWC system, the numbers of EVs and the power supply capacity. Therefore, this paper proposes the power control and efficiency optimization strategies for multiple EVs. Design/methodology/approach The wireless power charging system for multiple loads with a structure of double-sided LCC compensation topology is established. The expressions of optimal transmission efficiency and optimal equivalent impedance are derived. Taking the Tesla Model 3 as an example, a method to determine the number of EVs allowed by one transmitter coil and the overall charging power is proposed considering EV speed, power supply capacity, safe braking distance and overall efficiency. Then, the power control strategy, which can adapt to the changes of EV speed and the efficiency optimization strategy under different numbers of EVs are proposed. Findings In this paper, a method to determine the numbers of EVs allowed by one transmitter coil and the overall charging power is proposed considering EVs speed, power supply capacity, safe braking distance and overall efficiency. The accuracy of the charging power is good enough and the overall efficiency reaches a maximum of 91.79% when the load resistance changes from 5Ω to 20Ω. Originality/value In this paper, the power control and efficiency optimization strategy of DWC system for multiple EVs are proposed. Specifically, a method of designing the number of EVs and charging power allowed by one transmitter coil considering the factors of EV speed, power supply capacity, safe braking distance and overall efficiency is designed. The overall efficiency of the experiment reaches a maximum of 91.79% after adopting the optimization strategy.

Integrative neuromuscular training and detraining in pre-adolescent basketball players

Youth sports participation can promote better physical activity levels and motor competence (MC) in young populations. However, it shows risks of injury and burnout. Integrative neuromuscular training (INT) is presented as a training alternative capable of reducing the incidence of injury and improving MC in young athletes. The aim of this study was to evaluate the effects of 6 weeks of individualized INT as a warm-up in preadolescent basketball players on their acceleration, change of direction (COD), vertical jump (CMJ) and dynamic unipodal balance (SEBT). Subjects (143.37 ± 8.75 cm, 40.66 ± 7.65 kg; 10.08 ± 0.27 years) underwent 20 minutes of INT three days per week during six weeks, where strength, change of direction speed, plyometrics, balance and coordination were trained. Assessments were performed before the intervention (P1), after the intervention (P2), and after 3 weeks of detraining (P3). At P2, significant improvements were obtained in COD test, CMJ, and in the posterolateral direction of the right leg and in the posteromedial direction of the left leg in the SEBT test. At P3, significant improvements were maintained for CMJ and SEBT. An INT warm-up can affect improvements in COD, CMJ and some directions of SEBT in pre-adolescent basketball players.

Adaptive QSMO-Based Sensorless Drive for IPM Motor with NN-Based Transient Position Error Compensation

In commercial electrical equipment, the popular sensorless drive scheme for the interior permanent magnet synchronous motor, based on the quasi-sliding mode observer (QSMO) and phase-locked loop (PLL), still faces challenges such as position errors and limited applicability across a wide speed range. To address these problems, this paper analyzes the frequency domain model of the QSMO. A QSMO-based parameter adaptation method is proposed to adjust the boundary layer and widen the speed operating range, considering the QSMO bandwidth. A QSMO-based phase lag compensation method is proposed to mitigate steady-state position errors, considering the QSMO phase lag. Then, the PLL model is analyzed to select the estimated speed difference for transient position error compensation. Specifically, a transient position error compensator based on a feedback time delay neural network (FB-TDNN) is proposed. Based on the back propagation learning algorithm, the specific structure and optimal parameters of the FB-TDNN are determined during the offline training process. The proposed parameter adaptation method and two position error compensation methods were validated through simulations in simulated wide-speed operation scenarios, including sudden speed changes. Overall, the proposed scheme fully mitigates steady-state position errors, substantially mitigates transient position errors, and exhibits good stability across a wide speed range.

Are the peak accelerations and decelerations registered during the pro-agility test replicated during matches and training sessions?

ABSTRACT Change of direction speed (CODS) tests can provide insights about the acceleration and deceleration abilities of soccer players. We compared peak accelerations and decelerations during matches, training sessions and the pro-agility test. Sixteen (n = 16) players from the men’s Portuguese first division were monitored with global navigation satellite systems during half of one season. Peak efforts were retrieved during matches, training sessions and the pro-agility test. Mean paired differences with effect sizes [95% confidence intervals] compared peak efforts registered during matches, training sessions and the pro-agility test. The pro-agility test peak accelerations were similar to matches (p = 0.81; d = 0.09 [−0.68, 0.88]; unclear effect size), but largely different from training sessions (p < .001; d = 1.30 [0.78, 2.05]); increasingly, peak accelerations differ moderately (p = 0.02; d = 0.95 [0.24, 1.83]) between matches and training sessions. The pro-agility test peak decelerations differ largely from matches (p < .001; d = 3.83 [2.85, 5.43]) and hugely from training sessions (p < .001; d = 5.74 [4.37, 8.05]); additionally, peak decelerations were similar between matches and training sessions (p = 0.26; d = 0.43 [−0.31, 1.25]; unclear effect size). The findings of this study indicate that the pro-agility test can be a good predictor of match peak accelerations. Finally, monitoring training sessions may be a more appropriate strategy to predict peak decelerations during matches.

The Effect of Total Knee Replacement on Dual-Task Gait Performance in Older Adults.

Total knee replacement (TKR) is a common solution for patients with advanced knee osteoarthritis (OA). Still, fall rates remain relatively high after surgery. TKR may alter pain and knee function, balance control, and proprioception. However, given the role of complex (dual-task) walking in fall prediction for older adults, it is unknown how TKR alters the attentional demand of walking in older adults. The goal of this study was to examine the effect of TKR on dual-task walking among older adults. Participants were evaluated 1month before surgery and 4.5months after surgery. Participants walked along an instrumented 7-meter path for 1minute with and without a cognitive task (serial-3 subtraction). Pain and knee function, knee proprioception, dynamic balance, and balance confidence, as well as dual-task costs (DTC) were compared before and after the surgery and factors associated with change in gait DTCs were assessed. Thirty-eight participants completed the study (age 72.6years, SD = 4.9; 11 men). A significant decrease in pain was found following TKR, with no change in balance, balance confidence, or proprioception. There were no differences in gait DTCs before and after the surgery. However, change in dynamic balance, specifically reactive postural control and dynamic gait, predicted changes in gait speed and stride time DTCs. The absence of an effect of TKR on gait DTCs can potentially underlie increased fall risk after TKR. Results from this study emphasize the significance of balance as a measure and focal point for rehabilitation after TKR. This study contributes to our understanding of the attentional cost of walking in people before and after TKR, as well as to factors associated with it. Results from this work can assist formulation of rehabilitation programs for people with knee OA.

Commercial Adaptive Cruise control (ACC) and capacity drop at freeway bottlenecks

Vehicle automation has already become commercially available. Today’s mainstream vehicles are equipped with Adaptive Cruise Control (ACC) to automate longitudinal car-following. However, ACC’s limited detection range and delayed reaction hinder the vehicle’s ability to respond promptly to speed changes, and ACC could amplify minor disturbance into severe stop-and-go waves and form queues at bottlenecks. Consequently, the discharge flow could be lower than the maximum flow observed in absence of queues or congested conditions, also known as capacity drop. Microscopic simulation of freeway bottlenecks consisting of a single lane with reduced speed zone, multilane with an on-ramp merge, and multilane with an off-ramp diverge demonstrates that ACC vehicles lead to capacity drop at freeway bottlenecks. For the single lane reduced speed zone, the extent of capacity drop for ACC could be either less or more severe than that of human driven vehicles. However, the multilane freeway on-ramp and off-ramp bottlenecks are more susceptible to capacity drop than human driven vehicles, due to ACC significantly amplifying disturbances caused by lane changes, merging, and diverging.

Managing Green and Sustainable Technologies: Climate-Informed Corrosion Prediction for Steel Structures

The unpredictability of atmospheric circumstances is one of the major elements that contribute to the capability to anticipate the corrosion growth in metal structures over time accurately. Climate shifts can potentially modify the long-term attributes of these factors throughout the operational life of metal structures, both those currently in existence and those newly developed. The impact of climate irregularity on the probabilistic nature of atmospheric variables, which significantly impact corrosion situations, can add intricacy to corrosion predictions in these constructions. This project presents an incorporated framework to quantify the impact of climate alteration on the corrosion rates of steel structures in Jordan. It considers the changes in environmental conditions, specifically temperature, relative humidity, and wind speed, and their impacts on atmospheric corrosion. Global Climate Models are employed to assess the long-term effects of climate transformation on these environmental circumstances. An analytical model for anticipating corrosion rate is integrated with climate transformation models to predict modifications in the corrosion rates of steel parts relative to historical situations. This project also examines the impact of climate transformation on the fluctuations of these climatic parameters and offers a contrast between historical data and projected conditions across the country. The findings indicate a significant increase in corrosion rates across Jordan, which calls for localized green building codes and standards to ensure that future infrastructure is sustainable and capable of withstanding the new climatic norms. This approach addresses the immediate challenges posed by climate change and contributes to the broader goals of sustainable urban development and managing green technology adoption in Jordan. Doi: 10.28991/CEJ-2024-010-08-016 Full Text: PDF

Frailty in Medicare Advantage Beneficiaries and Traditional Medicare Beneficiaries

A growing proportion of the population is enrolling in Medicare Advantage (MA), which typically offers additional benefits compared with traditional Medicare (TM). To determine whether frailty and frailty trajectories differ between MA enrollees and TM enrollees. This retrospective cohort study used data from the National Health and Aging Trends Study (2015-2016). Analyses were conducted from August 2023 to March 2024. Participants were community-dwelling Medicare beneficiaries aged 65 years and older. Enrollment in MA vs TM. Frailty was calculated by a frailty index (FI) (range, 0-1, with higher values indicating greater frailty) and the Fried Frailty Phenotype (FFP) score (range, 0-5, with higher values indicating greater frailty). Physical performance, including Short Physical Performance Battery (SPPB) score (range, 0-12, with higher values indicating better performance), and gait speed (meters per second) were measured. The primary outcome was the difference in FI and FFP scores from the 2015 baseline assessment to the 2016 follow-up assessment. Secondary outcomes include the 1-year changes in SPPB and gait speed. The final cohort consisted of 7063 participants (2775 [23.1%] aged >80 years; 4040 [54.7%] female), representing a sample of the 38.8 million beneficiaries. There were 2583 (35.0%) MA enrollees (13.6 million) and 4480 (65.0%) TM enrollees (25.2 million). At baseline, the FI score was similar between MA and TM enrollees (mean [SD], 0.22 [0.15] vs 0.21 [0.14]), although MA enrollees had worse phenotypic frailty (496 participants [15.2%] vs 811 participants [13.7%] considered frail by FFP score), SPPB scores (mean [SD], 6.91 [3.34] vs 7.21 [3.27]), and gait speed (0.79 [0.24] m/s vs 0.82 [0.23] m/s) than TM enrollees. One year later, there were no differences between MA and TM enrollees in the 1-year change in FI score (mean [SD], 0.016 [0.071] vs 0.014 [0.066]; adjusted mean difference, 0.001 [95% CI, -0.004 to 0.005]), FFP score (mean [SD], 0.017 [1.004] vs 0.007 [0.958]; adjusted mean difference, -0.009 [95% CI, -0.067 to 0.049]), SPPB score (mean [SD], -0.144 [2.064] vs -0.211 [1.968]; adjusted mean difference, 0.068 [95% CI, -0.076 to 0.212]), and gait speed (mean [SD], -0.0160 [0.148] m/s vs -0.007 [0.148] m/s; adjusted mean difference, -0.010 m/s [95% CI, -0.067 to 0.049 m/s]). In this cohort study of Medicare beneficiaries from 2015, MA enrollees experienced similar declines in frailty over 1 year compared with TM enrollees. Future work should examine whether the specific types of services covered by health insurance can impact frailty and health trajectories for older adults.

Thermal characterization of cylindrical roller bearings based on thermal-structural coupling approach

High-speed running bearings generate a large amount of heat, which has a significant impact on the accuracy of machine tool feeding system. In this paper, by applying the bearing proposed statics and local heat source method, considering the combined surface contact thermal resistance and lubricant viscous temperature characteristics of the influence of the thermal network method to determine the main thermal characteristics of the shaft system parameters, the establishment of the transient thermal equilibrium equations, in the iterative process of the shaft system temperature field and deformation of the coupling; through the solution, the bearing temperature field and the transient change of the thermal parameters of the characteristics of the bearing, analyze the working conditions and structural parameters of the bearing transient thermal characteristics curve; using the finite element method coupled field simulation and test bed test, to verify the theoretical model is reasonable. The influence of working conditions and structural parameters on the transient thermal characteristic curve of the bearing is analyzed. The reasonableness of the theoretical model is verified by using the finite element method coupled field simulation and test bench test. After in-depth analysis: no matter the initial clearance or the change of rotational speed and load, it will lead to the change of thermal equilibrium temperature of the bearings, and will produce heat-induced load. Therefore, by choosing the appropriate clearance, improving the viscosity of lubricant, and enhancing the air convection, the heat generation and thermal deformation can be effectively reduced, which provides an important method to support the optimization of the bearing structure and the design of thermal balance.

Intelligent optimization prediction of screw conveyor speed for earth pressure balance shield machine based on complete ensemble empirical mode decomposition of adaptive noise and deep learning

The excavation stratum of the earth pressure balance (EPB) shield machine is complex and changeable. For ensuring the excavated interface stabilization, the rotational speed of screw conveyor must be precisely controlled to maintain the balance of earth pressure in sealed cabin and to avoid accidents such as ground collapse or upliftment. A data-driven intelligent optimal model is presented by the paper, which organically integrates the complete ensemble empirical mode decomposition of adaptive noise (CEEMDAN), sparrow search algorithm (SSA) and long short-term memory (LSTM) network to achieve accurate prediction of screw conveyor rotation speed. Firstly, Pearson correlation analysis method is used to analyze the historical data of shield tunneling, and the tunneling parameters strongly related to the change of screw conveyor rotation speed are obtained as model input. Secondly, the CEEMDAN is used to decompose the obtained parameter data set into several modal components, and then the denoised data is reorganized to capture the changing characteristics of the original data and reduce the complexity of the data. Then, the parameters such as the learning rate of the LSTM network are optimized by using the strong global search ability of SSA to enhance the prediction precision further in the model. Finally, based on decomposed and reorganized data, SSA-LSTM is used to establish a rotation speed intelligent prediction model realize precise controlling of screw conveyor rotation speed. The simulation experiment is carried out by using the construction data of a section of Beijing Metro Line 10, and the results of three evaluation indexes of the model are given: Mean Absolute Error (MAE) is 0.02878, Mean Absolute Percentage Error (MAPE) is 0.00882 and R2 is 0.99909, which shows that the model has good prediction performance. The control effect of the method on the earth pressure balance of the sealed cabin is tested, and the maximum error value is 0.25%, which verifies the engineering applicability of the method.

Effects of Shoulder Corrective Training Program on Pitching Loads and Sonographic Morphology in Elbow Joint in Youth Baseball Players.

Chen, P-T, Lin, Y-C, Chang, H-Y, Chiu, C-H, Chen, C-Y, Chen, P, and Lin, Y-H. Effects of shoulder corrective training program on pitching loads and sonographic morphology in elbow joint in youth baseball players. J Strength Cond Res 38(8): e440-e447, 2024-We assessed the effects of a 12-week shoulder corrective training program for shoulder flexibility and strengthening on pitching loads and sonographic morphology of the elbow joints in youth baseball players. Seventeen subjects were recruited and underwent evaluations before and after the training program. We found that following training, subjects demonstrated significantly increased ranges of shoulder internal rotation (38.9 ± 12.9° vs. 69.2 ± 10.8°, p < 0.001), external rotation (91.2 ± 14.6° vs. 107.3 ± 9.5°, p = 0.004), and horizontal adduction (21.5 ± 8.0° vs. 32.7 ± 7.3°, p = 0.002); improved strength in the shoulder internal rotators (8.7 ± 1.6 kg vs. 9.8 ± 2.1 kg, p = 0.04), external rotators (6.5 ± 1.9 kg vs. 7.5 ± 2.8 kg, p = 0.04), middle trapezius (12.7 ± 2.1 kg vs. 14.3 ± 2.4 kg, p = 0.04), and middle deltoid muscles (10.8 ± 3.3 kg vs. 14.8 ± 3.2 kg, p = 0.001); and decreased thickness of the ulnar collateral ligament (6.1 ± 0.6 mm vs. 4.8 ± 0.7 mm, p = 0.002). Although there was no substantial change in elbow torque and arm speed, significantly increased ball speed (51.2 ± 4.6 mph vs. 54.1 ± 4.5 mph, p < 0.001) and decreased arm slot (63.8 ± 11.9° vs. 53.0 ± 12.7°, p = 0.02) were observed. We suggest that adequate corrective training should be performed regularly to minimize or mitigate adverse soft tissue changes at the elbow in youth baseball players. Balanced shoulder strength and flexibility may decrease medial elbow stress during pitching. Future studies should consider the kinetic and kinematic effects of other corrective training programs on the shoulder or elbow joint during pitching.

Speech emotion recognition method based on time-aware bidirectional multi-scale network

Abstract In response to the difficulty of traditional speech emotion recognition models in capturing long-distance dependencies in speech signals and the impact of changes in speaker pronunciation speed and pause time, this paper proposes a new time emotion modeling method called Time Perceived Bidirectional Multi-scale Network (TIM-Net), which is used to learn Multi-scale contextual emotion expression in different time scales. TIM-Net starts by acquiring temporal emotional representations using time-aware blocks. Subsequently, information from different time points is combined to enhance contextual understanding of emotional expression. Finally, it consolidates various Timescale features to better accommodate emotional fluctuations. The experiment shows that the network can focus useful information on features, and the WAR and UAR of TIM-Net are significantly better than other models on RAVDESS, EMO-DB, and EMOVO datasets.

Knockout of Hsp70 genes significantly affects locomotion speed and gene expression in leg skeletal muscles of Drosophila melanogaster.

The functions of the heat shock protein 70 (Hsp70) genes were studied using a line of Drosophila melanogaster with a knockout of 6 of these genes out of 13. Namely, the effect of knockout of Hsp70 genes on negative geotaxis climbing (locomotor) speed and the ability to adapt to climbing training (0.5-1.5 h/day, 7 days/wk, 19 days) were examined. Seven- and 23-day-old Hsp70- flies demonstrated a comparable reduction (twofold) in locomotor speed and widespread changes in leg skeletal muscle transcriptome (RNA sequencing) compared with w1118 flies. To identify the functions of genes related to decreased locomotor speed, the overlapped differentially expressed genes at both time points were analyzed: the upregulated genes encoded extracellular proteins, regulators of drug metabolism, and the antioxidant response, whereas downregulated genes encoded regulators of carbohydrate metabolism and transmembrane proteins. In addition, in Hsp70- flies, activation of transcription factors related to disruption of the fibril structure and heat shock response (Hsf) was predicted, using the position weight matrix approach. In control flies, adaptation to chronic exercise training was associated mainly with gene response to a single exercise bout, whereas the predicted transcription factors were related to stress/immune (Hsf, NF-κB, etc.) and early gene response. In contrast, Hsp70- flies demonstrated no adaptation to training as well as a significantly impaired gene response to a single exercise bout. In conclusion, the knockout of Hsp70 genes not only reduced physical performance but also disrupted adaptation to chronic physical training, which is associated with changes in the leg skeletal muscle transcriptome and impaired gene response to a single exercise bout.NEW & NOTEWORTHY Knockout of six heat shock protein 70 (Hsp70) genes in Drosophila melanogaster reduced locomotion (climbing) speed that is associated with genotype-specific differences in leg skeletal muscle gene expression. Disrupted adaptation of Hsp70- flies to chronic exercise training is associated with impaired gene response to a single exercise bout.

Design of intelligent cruise control system using fuzzy-PID control on autonomous electric vehicles prototypes

Electric vehicles provide a solution for using alternative fuels, namely, electricity. Electric vehicles are used for short distances and intercity travel over long distances, increasing the risk of accidents. Cruise Control is a technology embedded in vehicles to maintain stable speeds; this system will automatically adjust the vehicle's speed when motion changes cause changes in vehicle speed. This study aims to apply lidar sensors to detect distance in the Intelligent Cruise Control (ICC) system using the Fuzzy-PID control method. Testing results were obtained at safe distance inputs of 5, 6, and 7 meters with various object distances. All the tests were carried out; the response systems were obtained with an average settling time of 5 seconds and an average overshoot of 1.53%. Therefore, the proposed Fuzzy-PID method works well for controlling Intelligent Cruise Control systems in autonomous electric vehicle prototypes.

LCC-based approach for design and requirement specification for railway track system

AbstractLife cycle cost (LCC) analysis is an important tool for effective infrastructure management. It is an essential decision support methodology for selection, design, development, construction, maintenance and renewal of railway infrastructure system. Effective implementation of LCC analysis will assure cost-effective operation of railways from both investment and life-cycle perspectives. A major setback in the successful implementation of LCC analysis by infrastructure managers is the availability of relevant, reliable, and structured data. Different cost estimation methods and prediction models have been developed to deal with this challenge. However, there is a need to include condition degradation models as an integral part of LCC model to account for possible changes in the model variables. This article presents an approach for integrating degradation models with LCC model to study the impact of change in design speed on key decision criteria such as track possession time, service life of track system, and LCC. The methodology is applied to an ongoing railway investment project in Sweden to investigate and quantify the impact of design speed change from 250 to 320 km/h. The results of the studied degradation models show that the intended change in speed corresponds to correction factor values between 0.79 and 0.96. Using this correction factor to compensate for changes in design speed, the service life of ballasted track system is estimated to decrease by an average of 15%. Further, the expected value of LCC for the route under consideration will increase by 30%. The outcome of this study will be used to support the design and requirement specification of railway track system for the project under consideration.

Research and Simulation Analysis of Fuzzy Intelligent Control System Algorithm for a Servo Precision Press

With the rapid development of the manufacturing industry toward intelligence and flexibility, traditional mechanical presses are unable to meet the increased stamping requirements due to the difficulties in achieving variable speed control and changing slide motion trajectories. Servo presses, driven directly by servo motors, can realize the flexible control of press movement and have become the trend in the industry for future development. The independent research and development of servo press control systems has become a popular topic and challenge in the domestic press industry. This paper proposes a new type of press transmission mechanism suitable for high-precision stamping, analyzes the working principle of its transmission mechanism, and provides a detailed analysis and discussion on the main research methods of fuzzy intelligent control for servo presses, including fuzzy model and basic control algorithms, fuzzy modeling and control of nonlinear systems, fuzzy predictive control, and stability analysis of fuzzy control systems. Based on the principle of the control scheme, a closed-loop control system block diagram and mathematical model for servo high-precision presses are established. Taking the physical prototype parameters of the STSZG1-250 as an example, the control system is dynamically simulated and verified using Simulink modules. Finally, their role and effects in intelligent control, and prospects for the development of fuzzy intelligent control, are discussed.

An enhanced proportional resonance controller design for the PMSM based electric vehicle drive system

Permanent magnet synchronous machine (PMSM) has proven to be a more economical traction drive system for electric vehicle (EV) applications owing to increased efficiency and high-power density. However, the drive system requires more efficient control schemes to deliver better dynamic performance irrespective of dynamic changes in the motor speed, machine parameters and disturbances. Hence, to tackle the dynamic changes, to enhance the wider operating speed, to achieve precise speed tracking capability, and improved efficiency, a novel control algorithm for the PMSM based EV is proposed in this paper. The control algorithm is implemented by adopting the merits of conventional proportional resonance (PR) and proportional integral (PI) controller. The proposed control strategy is designed with an outer PI speed regulator and the inner enhanced PR (EPR) current regulator. The uniqueness of the proposed EPR controller is that the controller is designed to damp the torsional mode oscillation owing to dynamic changes such as speed and torque regulation evading the additional control loop. The effectiveness of the control scheme is tested in MATLAB Simulink and hardware-in-loop (HIL) real time simulator RT5700. To validate the effectiveness of the proposed control scheme the results are compared with the conventional control schemes. The results presented show that the proposed control technique successfully enhances the static and dynamic performance, and resilience of the EV system. Also, the proposed scheme significantly reduces the flux ripples, torque ripples, current jitter, peak overshoot, undershoot compared to the conventional current controllers.

Investigation on effects of water-shale interaction on acoustic characteristics of organic-rich shale in Ordos Basin, China

The water-shale interaction affect the shale structure, leading to wellbore instability and increasing drilling costs. The extent of structural changes within the shale can be determined non-destructively by analyzing its acoustic characteristics. Experiments were conducted to investigate the acoustic properties of shale from the Yanchang Formation in the Ordos Basin before and after exposure to brines of varying types, soaking times, and salinities. The study investigated the effects of brine type, soaking time, and salinity on shale’s acoustic properties, including changes in acoustic wave propagation speed, P/S wave velocity ratio, and both time-domain and frequency-domain amplitudes. The results indicate that although the type of brine has a limited impact on the water-shale interaction, KCl exhibits a significant inhibitory effect. However, the soaking time and the brine salinity have a significant impact on the acoustic properties of shale. As the soaking time increases, the decrease in wave velocity increases, the P/S wave velocity ratio increases, and the decrease in time-domain amplitude increases. The amplitude of the main frequency in the frequency domain signal also decreases with the increase of reaction time, which is consistent with the analysis results of the time domain signal. As the salinity of brine increases, the decrease in wave velocity decreases, the P/S wave velocity ratio decreases, and the decrease in time-domain amplitude decreases. The amplitude of the main frequency in the frequency domain signal also decreases with the increase of brine salinity, which is consistent with the analysis results of the time domain signal. This work establishes the relationship between water-shale interaction and acoustic characteristics, which can quantitatively evaluate the degree of interaction between water and shale without damaging shale. Furthermore, this research provides new insights and guidance for predicting drilling collapse cycles and optimizing drilling fluid compositions.