In recent years, significant progress has been made in the development of the Rapidly-exploring Random Trees (RRT) algorithm, a probabilistic sampling-based search approach. This algorithm effectively addresses comple...
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Optimal torque(OT)control is a widely used method for maximum power point tracking(MPPT)due to its *** order to overcome the adverse impacts of turbulent wind speed variations on MPPT,in several methods,modification f...
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Optimal torque(OT)control is a widely used method for maximum power point tracking(MPPT)due to its *** order to overcome the adverse impacts of turbulent wind speed variations on MPPT,in several methods,modification factors have been proposed to dynamically modify the ideal power curve for OT ***,this paper finds that the update cycles used in existing methods to adjust power curve modification factors are very long and hence these factors are difficult to be updated in a timely manner along with the wind speed *** thereby may deteriorate the effectiveness of wind energy ***,an optimal decreased torque gain(DTG)control method is proposed in this *** on the persistence method,an offline mapping from the wind speed and rotor speed to optimal modification factors is established via optimal control *** power curve can be periodically modified online through the mapping *** this method,the update cycles for these power curve modification factors are shortened from tens of minutes to *** simulations and experiments show that the proposed method is more efficient than others in terms of energy extraction under varying wind speeds,especially for turbulent wind cases.
Automated test generation tools enable test automation and further alleviate the low efficiency caused by writing hand-crafted test ***,existing automated tools are not mature enough to be widely used by software test...
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Automated test generation tools enable test automation and further alleviate the low efficiency caused by writing hand-crafted test ***,existing automated tools are not mature enough to be widely used by software testing *** paper conducts an empirical study on the state-of-the-art automated tools for Java,i.e.,EvoSuite,Randoop,JDoop,JTeXpert,T3,and *** design a test workflow to facilitate the process,which can automatically run tools for test generation,collect data,and evaluate various ***,we conduct empirical analysis on these six tools and their related techniques from different aspects,i.e.,code coverage,mutation score,test suite size,readability,and real fault detection *** discuss about the benefits and drawbacks of hybrid techniques based on experimental ***,we introduce our experience in setting up and executing these tools,and summarize their usability and ***,we give some insights into automated tools in terms of test suite readability improvement,meaningful assertion generation,test suite reduction for random testing tools,and symbolic execution integration.
High piezoelectric properties and low strain hysteresis(H)are both equally necessary for practical applications in precisely controlled piezoelectric devices and *** most of previous reports,where enhanced piezoelectr...
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High piezoelectric properties and low strain hysteresis(H)are both equally necessary for practical applications in precisely controlled piezoelectric devices and *** most of previous reports,where enhanced piezoelectric performance is typically accompanied by large hysteresis in lead-/lead-free-based ceramics,in this work,we report a reconstructed relaxor ferroelectric composition in 0.68Pb(Mg_(1/3)Nb_(2/3))O3-0.32PbTiO_(3)(0.68PMN-0.32PT)ceramics through the introduction of(Bi_(0.5)Na_(0.5))ZrO(BNZ)to simultaneously achieve low strain hysteresis(~7.68%),superior piezoelectricity(~1040 pC·N^(-l)),and an electric field induced strain of 0.175%.Our work not only paves the way to simultaneously large piezoelectricity and negligible strain hysteresis in ceramic systems,but also lays the foundation for the further development of novel functional materials.
This research combines the NAO robot platform to develop three single scene modes (visual line-following navigation, object location and grabbing, and moving object tracking and obstacle avoidance), and finally throug...
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This research combines the NAO robot platform to develop three single scene modes (visual line-following navigation, object location and grabbing, and moving object tracking and obstacle avoidance), and finally through the frame based expert system to form a knowledge base of each mode, and uses the inference engine to achieve multi-mode fusion. In the development of visual line-following navigation, the proposed fast path extraction processing method can not only accurately extract the path information in the case of noisy interference, but also improve the running speed to ensure the real-time performance of the robot. A slope compensation PID controller is proposed to control the parameters of the robot during walking, which ensures low error and high stability when the robot follows the navigation line. In the development of object positioning and grabbing, a monocular localization algorithm is proposed using the characteristics of QR code, then the kinematics of the robot arm is modeled. Finally, the end effector of the robot is moved to the specified position according to the three-dimensional coordinates of the QR code to grasp the target object. In the development of moving object tracking and obstacle avoidance, the NaoMark marker is used to simplify the characteristics of the moving target, and the parameters of the robot walking are controlled according to the central position of the marker in the image. In order to avoid the collision of the robot with the obstacle during the movement, the obstacle avoidance is realized by combining the ultrasonic sensor measurement and the artificial potential field algorithm. Finally, the implementation methods of each part of the above three modes are formed into a knowledge base in the form of a framework based expert system, and the knowledge is combined by the inference engine to realize the fusion of multiple modes to complete tasks that require multiple modes. This research has presented an original solution, as
Current motion detection and evaluation technologies face challenges such as limited scalability, imprecise feedback, and lack of personalized guidance. To address these challenges, this research integrated efficient ...
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Narrow bandgap non-fullerene acceptors(NFAs)are relevant as key materials components for the fabrication of near-infrared(NIR)organic solar cells(OSCs)and organic photodiodes(OPDs)thanks to their complementary absorpt...
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Narrow bandgap non-fullerene acceptors(NFAs)are relevant as key materials components for the fabrication of near-infrared(NIR)organic solar cells(OSCs)and organic photodiodes(OPDs)thanks to their complementary absorption,tunable energy levels,and enhanced ***,high-performance NIR photodetectors are still scarce due to the absence of narrow bandgap ***,an asymmetric A-D-π-A type NFA,named ABTPV-S,with a broad optical absorption approaching 1,000 nm is designed and synthesized through integrating alkylthio side chains and a vinyleneπ-*** optimal inverted OPD device exhibits an excellent performance with a photoresponsivity of 0.39 AW-1,a noise current of 2.25×10^(-14)A Hz^(-0.5),a specific detectivity(D*)of 3.43×10^(12)Jones at 840 nm,and linear dynamic range(LDR)of 140 d *** addition,the rise and fall times for ABTPV-S-based OPDs also reach 1.07 and 0.71μs,***-S-based OPDs exhibit a high D*over 1012Jones at 950 nm,which is a competitive result for the self-powered photodiode-type NIR *** findings highlight the outstanding potential of asymmetric A-D-π-A type NIR NFAs for high-performance OPDs competing with their silicon counterparts.
Accurate prediction of the state-of-charge(SOC)of battery energy storage system(BESS)is critical for its safety and lifespan in electric *** overcome the imbalance of existing methods between multi-scale feature fusio...
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Accurate prediction of the state-of-charge(SOC)of battery energy storage system(BESS)is critical for its safety and lifespan in electric *** overcome the imbalance of existing methods between multi-scale feature fusion and global feature extraction,this paper introduces a novel multi-scale fusion(MSF)model based on gated recurrent unit(GRU),which is specifically designed for complex multi-step SOC prediction in practical *** correlation analysis is first employed to identify SOC-related *** parameters are then input into a multi-layer GRU for point-wise feature ***,the parameters undergo patching before entering a dual-stage multi-layer GRU,thus enabling the model to capture nuanced information across varying time ***,by means of adaptive weight fusion and a fully connected network,multi-step SOC predictions are *** extensive validation over multiple days,it is illustrated that the proposed model achieves an absolute error of less than 1.5%in real-time SOC prediction.
Multi-objective optimization(MOO)for the microwave metamaterial absorber(MMA)normally adopts evolutionary algo-rithms,and these optimization algorithms require many objec-tive function *** remedy this issue,a surrogat...
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Multi-objective optimization(MOO)for the microwave metamaterial absorber(MMA)normally adopts evolutionary algo-rithms,and these optimization algorithms require many objec-tive function *** remedy this issue,a surrogate-based MOO algorithm is proposed in this paper where Kriging models are employed to approximate objective *** efficient sampling strategy is presented to sequentially capture promising samples in the design region for exact ***,new sample points are generated by the MOO on surro-gate ***,new samples are captured by exploiting each objective ***,a weighted sum of the improvement of hypervolume(IHV)and the distance to sampled points is calculated to select the new *** with two well-known MOO algorithms,the proposed algorithm is vali-dated by benchmark *** addition,two broadband MMAs are applied to verify the feasibility and efficiency of the proposed algorithm.
Nowadays, the proliferation of open Internet of Things (IoT) devices has made IoT systems increasingly vulnerable to cyber attacks. It is of great practical significance to solve the security issues of IoT systems. Dr...
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