Miracle-dz/UniFAR-FTUs huggingface dataset:
Simulation and analysis of wind speed and direction of unmanned aerial vehicle route in the Beijing-Tianjin-Hebei region based on high resolution model

: With the continuous opening of China's low-altitude airspace, relying on the existing low-altitude flight weather support technology to provide services for low-altitude safe flight is to some extent insufficient, and it is also difficult to forecast wind speed that has the greatest impact on flight. Based on the Weather Research and Forecasting (WRF) model mesoscale numerical model, this study simulated the wind speed and direction in the Beijing - Tianjin - Hebei region from 2015 to 2019, then compared the simulation results with the observation data of the weather stations in order to provide simulation tools for the safety of drones flying on low-altitude routes in the region. The main conclusions are as follows: the WRF model can better simulate the seasonal trend of wind speed, the simulation result in the plain areas is better than in the mountainous areas, and the simulated wind speed in the mountainous areas is higher than the observed data but the error is within an acceptable range (RMSE<1.5 m · s - 1 ). The minimum values of average wind speed and maximum wind speed both appear in the late summer, and the maximum average wind speed appears in spring (4.43 m · s - 1 in the mountainous areas, 4.13 m · s - 1 in the plain areas). The maximum wind speed fluctuates and increases in winter, spring, and early summer, begins to decrease in mid-summer, and decreases to a minimum in late summer and early autumn. Wind speed in the Beijing-Tianjin-Hebei region is decreasing from northwest to southeast, the average wind speed at Potou Station ( - 0.02 m · s - 1 · (5 a) - 1 ) and Tianjin Station ( - 0.02 m · s - 1 · (5 a) - 1 ) showed a downward trend, the wind speed at other stations showed an upward trend, and Tangshan Station has the largest increase rate (0.08 m · s - 1 · (5 a) - 1 ). With regard to the seasonal spatial distribution of wind speed, the average wind speed is mainly on the rise, and the station proportions are 45.45% in spring, 90.91% in summer, 63.63% in autumn, and 81.81% in winter. The prevailing wind in the plain areas is northeast-southwest; the wind direction of Huailai Station in the mountainous area is mainly in WNW direction (18.70%) and W direction (15.01%), while the wind direction of Yuxian Station is mainly in N (16.79%) and NNW (12.03%). Compared with the plain areas, the number of strong winds with wind speed of 8.0 m · s - 1 has increased significantly in the mountainous areas. At a height of 1000 m, the frequency of strong winds in the plain areas increased significantly and the growth rate was higher than in the mountainous areas, which is not conducive to UAV flight, and the probability of occurrence of wind speeds above 17.0 m · s - 1 is also significantly higher than in the mountainous areas.
The performance improvement of conductivity sensor via primary field compensation

In this paper we propose novel magnetic sensor architecture to estimate the conductivity distribution of sample. However, the magnetic field received by the sensor coil would be impaired by primary field (excitation field). For the biologic tissues measurement, the ratio between the primary and secondary components can be up to 10000:1. This could reduce the sensitivity of measurement system substantially. For improving the sensitivity of measurements, the aligning coil and differential technique were applied together to eliminate the component of primary magnetic field which is coupled on the sensor coil. To evaluate the performance of noise on the differential alignment gradiometer, we have compared the noise component of differential alignment coil with other measurement coils. By the aligning coil and differential technique, the component of primary magnetic field could be eliminated largely. So, the proposed contactless conductivity sensor not only can improve the measurement sensitivity but also reduce the undesired interference. This technique can be use to estimate low conductivity material, such as biologic tissue. We hope this technique can applied to the analysis of biologic material further
Slaughter yield, quality of meat from broiler chickens of different origin and age on diet with extruded or meal soybean

ABSTRACT The study aimed to compare meat traits from different ages and origin chickens fed with extruded soybean (ES) instead of soybean meal (SBM). 150 male Ross 308 (R) and 150 male Cobb 500 (C) were used, with 2 replicates (75 birds each). The control groups (1) were fed with SM and experimental groups (2) with ES. After 35 and 42 days of rearing, birds were selected for slaughter (80 in total). The carcass and meat quality were analysed. A lower body and carcass weight was demonstrated in all variants in the experimental groups. The age of the birds affected all the slaughter traits of the chickens, with a benefit for day 42, except for the percentage of leg muscles and carcass remains. The origin of the birds influenced some features, especially fatness in C groups. The effect of the diet varied between age groups and origins, especially in the C group, where lower dressing percentage and muscle weight was shown, but the chemical composition was better for the ES diet. According to the effect of age and origin, feed with ES could be used due to carcass and meat quality results after 42 days, especially for Ross 308.
R&D Investments and Productivity Growth An empirical study of the German manufacturing sector over 45 years

Motivated by recent statistics that show significant growth in labor productivity, this paper seeks to analyze the relationship between domestic RD recent rates of return on R&D are estimated to have reached an all-time low spanning the last 45 years. Current yields of R&D are only one third compared to the sixties. In conclusion, though the productivity slowdown of the seventies seems to have been overcome, this is not attributed to R&D investments.
An Enhanced Approach for Load Behavior and Battery Residual Capacity Prediction Using Markov Chain and Monte Carlo Method

The demands for energy storage systems and energy management systems are increasing with the development of modern electric vehicles. The battery management technology is the basis and key to ensure vehicle safety and prolong the battery life of electrified vehicles. One of the technical bottlenecks in battery management technology is the state estimation of the power batteries. Because the behavior of the lithium-ion battery is highly nonlinear, and the internal states and model parameters are susceptible to temperature, noise, and other factors, the battery states are difficult to be observed accurately. In the past decades, many battery state estimation strategies have been developed. However, dynamic systems in the real world, whether linear or nonlinear, usually exhibit behavior that leads to excessive outliers. This article attempts to discuss the coestimation method for state-of-charge and remaining discharge time. First, a temperature-compensated model is presented based on the equivalent-circuit model. Then, the Bayesian estimation method is employed for the coestimation of state-of-charge and remaining discharge time. Moreover, the Markov chain prediction model is presented for the load profiles. Experimental studies showed that the proposed methods have accurate and robust state-of-charge estimates under dynamic driving cycles with mean absolute error less than 2%.
Algoritmo Multirecombinativo para la Planificación Dinámica del Mantenimiento de Locaciones Petroleras

The development of a computer tool named PAE (Scheduling based on an Evolutionary Algorithm) that improves the dynamic schedules of the maintenance of oil fields, is presented. This tool uses a multirecombinative evolutionary algorithm generator of multiple solutions to this problem. The results were compared with information of historical schedules facilitated by the company. The obtained results have been satisfactory concluding that the use of this tool improves the total timing of the original schedule and dynamic re-scheduling is allowed keeping the same quality level in the results. Finally, the benefit of this should be observed from two points of view: the decrease of the maintenance cost and the reduction of the probability of falling or contingencies in the production.
DETERMINATION OF FRACTURE TOUGHNESS OF CONCRETE AND ROCK USING UNNOTCHED SPECIMENS

It presents a theoretical model and its associated analytical expression for determining the fracture toughness of concrete and rock using unnotched specimens. The important influence of the size of concrete aggregates and rock particles is fully considered in the proposed model, and only the peak load of small-scale unnotched specimens of concrete or rock is required. Size-independent fracture toughness can be directly determined. Furthermore, a series of fracture tests on the rock specimens with different notch lengths is conducted. Experimental results show that the fracture toughness of unnotched rock specimens obtained using the proposed model is consistent with that determined from the prefabricated specimens with a notch of 1 mm length. The fracture toughness of unnotched specimens is also consistent with that of the notched specimens based on the regression analysis method. The test results of the unnotched and notched rock and concrete specimens from other studies are further analyzed using the proposed model. The rationality and applicability of the proposed model and associated method are also verified. It provides new insights into the determination of the size-independent fracture toughness of concrete and rock by using small-scale unnotched specimens in a laboratory.
Use of hydrophone sensors to characterize two-phase systems in bubble columns

Two-phase systems are very common in chemical process indurrrics and biotechnology. Undecsnndiog of the physicochemical changes in such systems is esscntid for prop design and operation of equipmenn carrying such systems. Various types of sensors have bcen used CO characteke two-phase systems in bubble columns. In this work, acoustic measurements employing hydrophone sensor were used to charanetire al-water system in three different sizes bubble columns. The advantage of acoustics is that unlike 0th- techniques, direct conma with the pcaccss under inveatiption is not requiicd so intrusion was kept to minimum. Global gas holdups were inferred from acou~tic spcctnvn created by bubbler fomadon and compared well to conventional methods.
A comprehensive review of the development of adaptive cruise control systems

It has been 15 years since the first generation of adaptive cruise control (ACC)-equipped vehicles was available on the market and 7 years since the ISO standard for the first generation of ACC systems was produced. Since the next generation of ACC systems and more advanced driver-assistant systems are at the verge of complete introduction and deployment, it is necessary to summarise the development and research achievements of the first generation of ACC systems in order to provide more useful experiential guidance for the new deployment. From multidimensional perspectives, this paper looks into the related development and research achievements to objectively and comprehensively introduce an ACC system to researchers, automakers, governments and consumers. It attempts to simply explain what an ACC system is and how it operates from a systematic perspective. Then, it clearly draws a broad historical picture of ACC development by splitting the entire history into three different phases. Finally, the most significant research findings-related ACC systems have been reviewed and summarised from the human, traffic and social perspectives respectively.
Transfer of biological principles into the construction of quadruped walking machines

In the wide range of possible biological and technical solutions for legged terrestrial locomotion, quadrupeds represent a compromise between lightweight construction, dynamic stability, and usage of self-stabilizing effects and minimization of neural control. Several biomechanical features indicate that mammals form interesting and preferable paradigms for the construction of walking machines, even if their morphology and locomotory functions in some issues seem to be more complicated than that of the phylogenetically older amphibians and reptiles.
A Fast and Generalized Space Vector Modulation Scheme for Multilevel Inverters

This paper presents a fast and generalized space vector pulse width modulation (SVPWM) scheme for any multilevel inverter. The SVPWM scheme generates all the available switching states and switching sequences based on two simple and general mappings, and calculates the duty cycles simply as if for a two-level SVPWM, thus independent of the level number of the inverter. Because the switching states, duty cycles, and switching sequences are all obtained by simple calculation in the proposed SVPWM scheme, no lookup table is needed and the scheme is computationally fast. The generalized method of generating the switching states (first mapping), calculating the duty cycles, and determining the switching sequence (second mapping) is described in this paper. The scheme is suitable for any reference vector with any modulation index, and can be conveniently extended to meet specific requirements, such as symmetric switching sequences. Compared with prior methods, the SVPWM scheme proposed in this paper provides two more degrees of freedom, i.e., the adjustable switching sequences and duty cycles, thus offering significant flexibility for optimizing the performance of multilevel inverters. The influence of redundant switching sequences in the output phase voltage of inverters is demonstrated for a nine-level inverter. This paper also thoroughly compares the proposed SVPWM scheme with prior methods. Both simulation and experimental results are given.
Effect of finite ground-plane widths on quasistatic parameters of asymmetrical coplanar waveguides

CAD-oriented closed-form expressions are presented for calculating the quasistatic TEM parameters of asymmetrical coplanar waveguides (ACPWs) with finite ground planes. The effect of the ground-plane width on the quasistatic parameters has been investigated by using the formulas derived by the conformal mapping techniques. Comparisons have also been made between the present results and the results available in the literature for both the conventional coplanar waveguide (CPW) and ACPW. The results are in good agreement with the results derived by the conformal mapping technique and the spectral-domain method. It has been shown that the present expressions can also be used for calculating the quasistatic parameters of both symmetric and asymmetric CPWs with finite and infinite ground planes.
On Developing a Runtime Environment for Heterogeneous Distributed Computing

This paper presents the design and implementation of a distributed runtime environment to support the deployment and execution of distributed actor-based applications on connected heterogeneous computing machines. The distributed runtime environment consists of connected runtime environments, which support the execution of individual application components (actors) and managing their communication. The programmability benefits of our runtime environment are evaluated by developing a computational-intensive application across three connected heterogeneous devices. Finally, we evaluated the performance of the developed prototype experimentally using different metrics.
Compact and broadband microstrip-to-waveguide transition using antisymmetric tapered probes

A compact and broadband microstrip-to-waveguide transition using antisymmetric tapered probes is proposed. The proposed transition has 47.4% fractional bandwidth for which the return loss is larger than 15%dB, covering the whole frequency range 8-13 GHz. As compared with the microstrip-to-waveguide transition using the tapered CPS probe, the 15%dB fractional bandwidth is increased from 35 to 47.4% along with 44.8% reduction in the transition size. To verify the simulation result, a back-to-back transition has been fabricated and measured, and the measurement result shows good agreement with the simulation result.
High Temperature Hydrocarbon Sensing with Pt-Thin Ga2O3-SiC Diodes

Silicon carbide based metal-oxide-semiconductor (MOS) devices are attractive for gas sensing in harsh, high temperature environments. We present a hydrocarbon gas sensor based on a Pt–thin Ga2O3–SiC device. This sensor has been employed as a Schottky diode, and is capable of operating at temperatures around 600°C. Exposure to propene (C3H6) gas results in shift towards lower voltages in the current-voltage (I-V) characteristic curve, as well as a change in series resistance of the diode. The Ga2O3 thin films were prepared by the sol-gel process and deposited onto the SiC by spin coating. The Pt layer was deposited on the top of the Ga2O3, forming the Schottky contact. It also serves to dehydrogenate the hydrocarbons. The sensors responses were stable and repeatable towards propene at operating temperatures between 300 and 600°C. In this paper the effect of biasing is investigated by analyzing the output voltage of the diodes when biased at different constant currents.
Converter with 77-dB Dynamic Range

The design of a low-voltage and low-power analog-to-digital (A/D) converter is presented. A third-order single-loop modulator topology is implemented with the differential modified switched op-amp technique. The modulator topology has been transformed as to accommodate half-delay integrators. Dedicated low-voltage circuit building blocks, such as a class AB operational transconductance amplifier, a common- mode feedback amplifier, and a comparator are treated, as well as low-voltage design techniques. The influence of very low supply voltage on power consumption is discussed. Measurement results of the 900-mV A/D converter show a 77-dB dynamic range in a 16-kHz bandwidth and a 62-dB peak signal-to-noise ratio for a 40- W power consumption.
Broadband printed ring-slot array with circular polarisation

A novel design of a printed ring-slot antenna with circular polarisation (CP) is first proposed. The CP radiation of the slot antenna is achieved by a series microstrip-line feed configuration. Using the single CP slot antenna as an array element, the 1×2 and 2×2 slot arrays are constructed and measured. To obtain wider CP bandwidth, phase sequential rotation technique is applied to the feed network of these printed slot arrays. The experimental results show that the 2×2 slot array antenna is capable of 15% bandwidth for an axial ratio of less than 3 dB.
Estimation of typical squirrel-cage induction motor parameters for dynamic performance simulation

Whenever the transient behaviour of a squirrel-cage induction motor is studied, double-cage model parameters are necessary. These parameters are usually hard to obtain. An estimation of typical double-cage induction parameters with regression-based equations that depend on mechanical power and line voltage is proposed. The starting current and torque, maximum torque, full-load slip and efficiency, calculated with the estimated typical parameters, are compared with the data of 608 low-voltage induction motors obtained from different manufacturers. The features of different power induction motors are well approximated with the proposed equations.
Parental Report of Preschoolers’ Jewish Day School Engagement and Adjustment During the Covid-19 Shutdown

ABSTRACT The COVID-19 forced shutdown of Jewish preschools (Spring, 2020) presented an unprecedented challenge for schools, preschoolers, and their families. During the preschool years, children are vulnerable to trauma, potentially affecting later adjustment. Relationships between school offerings, preschoolers’ school engagement and psychosocial outcomes were explored. Teacher immediacy behaviors were associated with preschoolers’ engagement in online learning but not with psychosocial outcomes. There were correlations between students’ willingness to engage and actual participation in online education and psychosocial adjustment. This study highlights the role that teachers and schools may play in keeping students connected and engaged in school during times of crisis.
Dual half bridge series resonant inverter for induction heating appliance with two loads

A novel dual half bridge series resonant inverter (DHB-SRI) for an induction heating appliance with two loads is proposed to improve the power utilisation capability by virtue of high-speed load changes. The circuit can remove acoustic noise caused by the difference between the operating frequencies of adjacent loads, and enables independent full power range control of two induction heating elements.
Sensitivity analysis of the maximum likelihood direction-finding algorithm

A first-order analysis is performed of the sensitivity of the maximum likelihood (ML) direction-finding algorithm to system errors which cause differences between the array manifold used by the algorithm and the true array manifold. The effect of such errors on the directions-of-arrival (DOA) estimates is investigated. The ability of the ML algorithm to resolve two closely spaced sources in the presence of phase and gain errors in the array elements or in the receivers, or errors in the element locations, is analyzed. A formula for computing the failure threshold of the algorithm as a function of source separation and other system parameters is derived and tested by simulation. The analysis assumes that the exact covariance matrix of array element outputs is known. >
Performances analysis of a piezo-pump

Piezo-pumps, in the last decade, have received extensive attention because of their potential applications in biomedical devices, biological and chemical analysis, micro-electronics cooling and space exploration. In this paper an analytical model is developed to analysis the parameters effect on the pump flow. The micro-pump driven by piezostack (PZT alloy multilayer) as actuator is studied as function size and working middle. This one is compared with SCMCP pump actuated by PZT alloy as piezomembrane. The flow change as a function frequency, the chamber diameter and control voltage are analyzed. The simulation results obtained with two different liquids (water and blood) as working middle are discussed and compared with experimental results. The results are satisfactory.
Creating Appropriate Trust for Autonomous Vehicle Systems: A Framework for HMI Design

While autonomous vehicle technology progresses, potentially leading to a safer and more efficient traffic environment, many challenges remain within the area of human factors, such as user trust for Autonomous Driving (AD) vehicle systems. The aim of this paper is to investigate how an appropriate level of user trust for AD vehicle systems can be created via human-machine interaction (HMI). A guiding framework for implementing trust-related factors into the HMI interface is presented. This trust-based framework incorporates usage phases, AD events, trust-affecting factors, and levels explaining each event from a trust perspective. Based on the research findings, the authors recommend that HMI designers and autonomous vehicle manufacturers take a more holistic perspective on trust rather than focusing on single, “isolated” events, for example understanding that trust formation is a dynamic process that starts long before a user’s first contact with the system, and continues long thereafter. Furthermore, factors affecting trust change, both during user interactions with the system and over time; thus HMI concepts need to be able to adapt. Future work should be dedicated to understanding how trust-related factors interact, as well as validating and testing the trust-based framework.