experiment

摘要： In the real-time scheduling theory,schedulability and synchronization analyses are used to evaluate scheduling algorithms and real-time locking protocols,respectively,and the empirical synthesis experiment is one of the major methods to compare the performance of such analyses.However,since many sophisticated techniques have been adopted to improve the analytical accuracy,the implementation of such analyses and experiments is often time-consuming.This paper proposes a schedulability experiment toolkit for multiprocessor real-time systems(SET-MRTS),which provides a framework with infrastructures to implement the schedulability and synchronization analyses and the deployment of empirical synthesis experiments.Besides,with well-designed peripheral components for the input and output,experiments can be conducted easily and flexibly on SET-MRTS.This demonstration further proves the effectiveness of SET-MRTS in both functionality and availability.

摘要： Aiming at the position and attitude tracking of coaxial rotor aircraft(CRA),this paper proposes a combinatorial control method of sliding mode control(SMC)coupled with proportional-integralderivative control(PIDC).Considering the complete description of flight dynamics,aerodynamics and airflow interference,the dynamical model of CRA is established.The dynamical model is simplified according to the actual flight,then the simplified dynamical model is divided into two subsystems:a fully-actuated subsystem and an under-actuated subsystem.The controller of the fully-actuated subsystem consists of a SMC controller coupled with a rate bounded PIDC controller,while the controller of the under-actuated subsystem is composed of a SMC controller.The sliding manifold is defined by combining the position and velocity tracking errors of the state variables for each subsystem.Lyapunov stability theory is used to verify the stability of the sliding mode controller,which ensures that all state trajectories of the system can reach and stay on the sliding mode surface,the uncertainty and external interference of the model are compensated.Simulation and experiment compared with the conventional PIDC are carried out,the results demonstrate the effectiveness and the robustness of the proposed control method of this paper.

摘要： Purpose:Goal Setting Theory(GST)created by Edwin Locke and Gary Latham has proven to be an incredibly versatile theory.Its widespread utilization has proven it to be a valuable theory to further explore and understand.The purpose of this paper is to examine current approaches to and practices of GST.Methodology:This systematic literature review is based on 12 recent articles using GST and examining their collective findings.The articles were a mix of theory description,quantitative experiments,empirical experiments,and literature review.Findings:Most of the reviewed literature agreed that further and more defined research would be greatly beneficial for future applications of this theory.Given the broad nature of this theory,a more defined approach would likely prove useful for future utilization.Value:Exploring the multitude of ways this theory has already been applied gives an understanding of shortcomings as well as successes.Reviewing the current available literature allows GST to be utilized in a more precise way in the future.

摘要： The rust⁃proof ability relate to the reliability of bolt connection,and the painting is the most simple and effective rust⁃proof method in industry.Because of lacking general standard,there are different coating thicknesses painted on the surface of workpieces,which influences the loose life of connecting bolt.For the longer loose life,Three kinds of applied coatings(primer coating,primer+top⁃coat coating,primer+intermediate⁃coat+top⁃coat coating)in industry are tested in the experiment,and the best coating is found.All the conclusions gotten by analyzing the testing phenomenon of every coating shown in experiment,have profound meaning for practical industry application.

摘要： Piezoelectric(PZ)energy has been paid attention to as conventional renewable energy sources including solar,wind,and geothermal power.To address the dilemma of climatic conditions affecting the energy harvesting using Lead Zirconate Titanate(PZT)in pavement,wafer-boxes were used with embedded PZT sensors,since wafer-boxes have the ability to be embedded in the pavement where sensors are protected from any kind of physical damage.This research project was designed to identify which shaped wafer-box produced the most electric voltage and power.Various forms of wafer-box were developed to identify if there was any potential difference in voltage generation due to the structural shapes of the box.Seven different shapes of prototype wafer-boxes were designed utilizing both a 3D printer and 3D Computer Aided Design(CAD).These wafer-boxes were coupled with embedded PZT sensors which were tested in asphalt pavement analyzer(APA)machine under certain load to produce electric voltage.Collected voltage data from the APA wheel load test(WLT)were analyzed using various statistical methods.The statistical analyses results indicated that out of the seven different shaped wafer-boxes,the right-angled triangular shaped box produced the highest average voltage values where’s square shaped wafer-box produced the lowest amount of voltage.Structural properties of a wafer-box in terms of section modulus,area moment of inertia,extreme points,and radius of gyration were also analyzed,and a regression analysis was conducted to identify the reasons of different amounts of voltage produced.These voltage values could be used to calculate the power using power formulas showing relationship between power and voltage values.The outcome helped to identify which shape is most effective to power generation under certain circumstances.The regression analysis results indicated that out of four properties the section modulus is the most influential structural property affecting voltage production.

摘要： A numerical triangulation and transformation into the time domain of a Kirchhoff approximation(KA)method is proposed for the modeling of bistatic scattering from an underwater non-penetrable target.The time domain solution in this approximation can be split up into two parts:the solution of reflected field,contributing around the specular direction,and the solution of shadow radiation,contributing around the forward direction.An average solution in the time domain satisfying the reciprocity principle is presented.The solution is expressed in terms of non-singular functions.The proposed method is validated against a normal mode method for bistatic scattering from a rigid sphere.Moreover,the reflected and shadow highlights on the surface of the sphere are shown to verify the integration surface of the reflected field and shadow radiation.It is also tested against a finite element method and an experiment involving a scaled Benchmark Target Strength Simulation Submarine model.The time-angle bistatic spectra for the model are evaluated by the direct and transformed average solutions of KA,and the former accelerates its speed of calculation.The results are good,and show that this method can be used to predict the bistatic scattered field of a non-penetrable target.

摘要： Transportation of heavy oil by the so-called water-ring technique is a very promising method by which pressure drop and pollution can be significantly reduced.Dedicated experiments have been carried out by changing the phase’s density,viscosity,velocity and interfacial tension to systematically analyze the characteristics of the water ring.On the basis of such experimental data,a mathematical model for pressure drop prediction has been introduced.This research shows that as long as the density of oil and water remains the same,a concentric water ring can effectively be formed.In such conditions,the oil-water viscosity difference has little effect on the shape of water ring,and it only affects the pressure drop.The greater the viscosity of heavy oil,the smaller the pressure drop of the oil-water ring transportation system.The influence of phases’interfacial tension on the characteristics and pressure drop of the heavy oil-water ring can be considered negligible.The pressure drop prediction model introduced on the basis of the Buckingham’s principle provides values in good agreement(95%)with the experimental data.

摘要： X oilfield is located in the Western Bohai Sea. During the water injection development process, the oil well productivity continued to decline. The effect of water injection and oil increase is poor. This time, by analyzing the sensitivity of the reservoir, the damage mode of the reservoir is analyzed, the reasons for the poor water injection effect are obtained, because of strong water sensitivity, medium to strong stress sensitivity, and the corresponding measures and suggestions are put forward, such as greater than 4500 mg/l of the salinity of injected water, timely supplement formation energy. Provide basis for the development of similar oil fields.

摘要： Companies differ in their motivation to corporate social responsibility(CSR)practices,with some compa­nies taking a genuine,altruistic approach and others preferring an opportunistic approach(and attempting to mimic the former).If consumers can distinguish them,they will eventually reward the altruistic(being willing to pay more)and penalize the opportunistic ones.This paper performs an experimental study to assess whether differences in consumers’willingness to pay are statistically significant for different classifications of CSR activities:(i)proactive or reactive,(ii)environment,employees,or social,(iii)involving more or less expensive products,(iv)being performed by firms facing competition or not.Results show that consumers are willing to reward CSR initiatives that follow a reactive approach;consumers’decisions are more moderate when rewarding initiatives associated with more expensive products;the rewards provided depend on the CSR dimension;a relationship between market structure and consumers’reaction to CSR was not found.

摘要： 1 Scientists at the University of Florida (UF)have grown plants in soil that came from the Moon.The plants didn’t grow as well as those grown in dirt from Earth, but the experiment marks an important step towards growing plants on the Moon.