INVESTIGATION OF FLIGHT DYNAMICS OF THRUST VECTORING AIRCRAFT USING EXTENDED CONTINUATION METHODS

This paper presents the flight dynamical behavior of the thrust vectoring aircraft with extended bifurcation and continuation methods. In contrast to the standard bifurcation and continuation methods, the extended methods are capable of calculating the continuation curves of the equilibrium points for the particular type of trimming flight. Therefore, these methods can not only give the performance measures of aircraft, but also determine the stability of trimming points. In this paper, the methods are used to verify the effectiveness of the thrust vectoring control law, to define the flight envelope boundary, to analyze the stability and controllability of trimming flight, and to predict the departures of the instable flight. The result shows that the extended methods provide more flight dynamic information and are useful in preliminary design of the thrust vectoring aircraft.

Jet Vectoring Control Using a Novel Synthetic Jet Actuator

A primary air jet vectoring control system with a novel synthetic jet actuator （SJA） is presented and simulated numerically. The results show that, in comparison with an existing traditional synthetic jet actuator, which is able to perform the duty of either ＂push＂ or ＂pull＂, one novel synthetic jet actuator can fulfill both ＂push＂ and ＂pull＂ functions to vector the primary jet by shifting a slide block inside it. Therefore, because the new actuator possesses greater efficiency, it has potentiality to replace the existing one in various appli- cations, such as thrust vectoring and the reduction of thermal signature. Moreover, as the novel actuator can fulfill those functions that the existing one can not, it may well be expected to popularize it into more flow control systems.

浅析基于Vectoring技术的宽带提速

随着中国电信"宽带中国光网城市"工程的大规模推进,接入网的宽带提速呈现出白花齐放的局面",光进铜退"、"光铜协作"等各种模式应运而生,基于VDSL2的Vectoring技术在很大程度上消除FEXT对VDSL2性能的影响,实现相同距离下速率的提升,或相同速率的更广覆盖,为宽带提速提供了又一高效的途径。

EFFECTS OF VECTORING JET ON AERODYNAMIC CHARACTERISTICS OF AIRCRAFT

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Physical factors of primary jet vectoring control using synthetic jet actuators

A primary jet vectoring using synthetic jet actuators with different exit configurations was investigated, and the main physical factors influencing jet vectoring were analyzed and summarized. The physical factors of the pressure difference, the location and area of the lower pressure region, the component of the synthetic jet momentum and the entrainment ratio of the synthetic jet flow to primary jet flow directly control the vectoring force and the vectoring angle. Three characteristic parameters of the synthetic jet contribute to the pressure difference and the area of the lower pressure region Both the extension step and slope angle of the actuator exit have functions of regulating the location of the lower pressure region, the area of the lower pressure region, and the entrainment ratio of the synthetic jet flow to primary jet flow. The slope angle of the actuator exit has additional functions of regulating the component of the synthetic jet momentum. Based upon analyzing the physical factors of jet vectoring control with synthetic jets, the source variables of the physical factors were established. A preparatory control model of jet vectoring using synthetic jet actuator was presented, and it has the benefit of explaining the efficiency of jet vectoring using synthetic jet actuator with source variables at different values, and it indicates the optimal actuator is taking full advantage of the regulating function.

G.fast及vectoring技术的应用

随着互联网的高速发展,人们对于接入互联网速率的要求越来越高,尽管4G移动接入备受关注,但是快速、稳定的固定网络仍然是商业和住宅用户的基本需求。近些年光纤技术的飞速发展对固定网络的接入影响很大,但是光纤接入的入户困难和成本很高的问题,使得接入网最后一公里接入技术成为一个难题,FTTdp+G.fast接入技术方案可以有效解决这个难题。

Classification and Analysis of Electric-Powered Lateral Torque-Vectoring Differentials with Six Elements

The principle of improving the torque amplification factor of E-TVDs with six elements is illustrated in this paper.A velocity diagram is used to study speed and torque relationships.The results reveal that the torque amplification factor is the linear combination of the ratio of the differentials of the four elements and the ratio of planetary gear units,and its maximum value is easily more than 10.The E-TVDs with six elements are classified into three types,and there are six different configurations for each type.The torque amplification factor and the speed of interconnection between two planetary gear units are employed to evaluate the different characteristics of each E-TVD with six elements.The feasible configurations of a differential with four elements are also presented by the analysis of velocity level and planarity.This paper helps to further the understanding of the complex interconnection of the planetary gear units in E-TVDs with six elements and the differences of their characteristics.

Cicada(Tibicen linnei) steers by force vectoring

To change flight direction, flying animals modulate aerodynamic force either relative to their bodies to generate torque about the center of mass, or relative to the flight path to produce centripetal force that curves the trajectory. In employing the latter, the direction of aerodynamic force remains fixed in the body flame and rotations of the body redirect the force. While both aforementioned techniques are essential for flight, it is critical to investigate how an animal balances the two to achieve aerial locomotion. Here, we measured wing and body kinematics of cicada （Tibicen linnei） in flee flight, including flight periods of both little and substantial body reorientations. It is found that cicadas employ a common force vectoring technique to execute all these flights. We show that the direction of the half-stroke averaged aerodynamic force relative to the body is independent of the body orientation, varying in a range of merely 20 deg. Despite directional limitation of the aerodynamic force, pitch and roll torque are generated by altering wing angle of attack and its mean position relative to the center of mass. This results in body rotations which redirect the wing force in the global flame and consequently change the flight traiectorv.

Lantiq宣布可实现全系统级噪声消除的VDSL2 Vectoring芯片

领特科技公司（Lantiq）近日宣布：该公司已首次实现其VINAX IVE1000，一款实现系统级串扰抵消的芯片的商用发货。一般线卡级的Vectoring虽然符合G．vector标准，但只有实现系统级的Vectoring，如Lanticl全新的Vectoring Engine芯片所提供的功能，才能够达到两倍以上的数据传输速率和覆盖距离，以满足运营商的下一代网络需求。

可实现全系统级噪声消除的VDSL2Vectoring芯片

一般线卡级的Vectoring虽然符合G．vector标准，但只有实现系统级的Vectoring，如Lantiq全新的VectoringEngille芯片所提供的功能，才能够达到丽倍以上的数据传输速率和覆盖距离，以满足运营商的下一代网络需求。

Lantiq发布可实现全系统级噪声消除的VDSL2 Vectoring芯片

2012年1月，宽带接入和家庭网络技术供应商领特科技公司（Lantiq）首次实现其VINAXTMIVE1000，一款实现系统级串扰抵消的（System Level Vectoring Engine）芯片的商用发货。一般线卡级的Vectoring虽然符合G．vector标准。但只有实现系统级的Vectoring。如Lantiq全新的Vectoring Engine芯片所提供的功能。才能够达到两倍以上的数据传输速率和覆盖距离。以满足运营商的下一代网络需求。

Numerical investigation of dynamic characteristics of dual throat nozzle and bypass dual throat nozzle in thrust vectoring starting process

The Bypass Dual Throat Nozzle(BDTN)is a novel fluidic Thrust Vectoring(TV)nozzle,it switches to TV state by opening the valve in the bypass.To greatly manipulate the BDTN,the dynamic characteristics in the TV starting process should be analyzed.This paper conducts numerical simulations to grasp the variation processes of performances and the flow field evolution of BDTN and Dual Throat Nozzle(DTN).The dynamic responses of TV starting in typical DTN models are investigated at first.Then,the TV starting processes of BDTN in different Nozzle Pressure Ratio(NPR)conditions are simulated,and the valve opening durations(T)are also considered.Before the expected TV direction is achieved in the DTN,the jet is deflected to the opposite direction at the beginning of the dynamic process,which is called the reverse TV phenomenon.However,this phenomenon disappears in the BDTN.The larger injection width of DTN intensifies unsteady oscillations,and the reverse TV phenomenon is strengthened.In the BDTN,T determines the delay degree of performance variations compared to the static results,which is called hysteresis effect.At NPR=10,the hysteresis affects the final stable performance of BDTN.This study analyses the dynamic characteristics in DTN and BDTN,laying a foundation for further design of nozzles and control strategies.

Machine learning-assisted efficient design of Cu-based shape memory alloy with specific phase transition temperature

The martensitic transformation temperature is the basis for the application of shape memory alloys(SMAs),and the ability to quickly and accurately predict the transformation temperature of SMAs has very important practical significance.In this work,machine learning(ML)methods were utilized to accelerate the search for shape memory alloys with targeted properties(phase transition temperature).A group of component data was selected to design shape memory alloys using reverse design method from numerous unexplored data.Component modeling and feature modeling were used to predict the phase transition temperature of the shape memory alloys.The experimental results of the shape memory alloys were obtained to verify the effectiveness of the support vector regression(SVR)model.The results show that the machine learning model can obtain target materials more efficiently and pertinently,and realize the accurate and rapid design of shape memory alloys with specific target phase transition temperature.On this basis,the relationship between phase transition temperature and material descriptors is analyzed,and it is proved that the key factors affecting the phase transition temperature of shape memory alloys are based on the strength of the bond energy between atoms.This work provides new ideas for the controllable design and performance optimization of Cu-based shape memory alloys.

Passive vectoring of entomopathogenic fungus Beauveria bassiana among the wax moth Galleria mellonella larvae by the ectoparasitoid Habrobracon hebetor females

Females of the ectoparasitoid Habrobracon hebetor attack and envenomate numerous host individuals during oviposition. The vectoring of the entomopathogenic fungus Beauveria bassiana during the adhesion stage by ectoparasitoid females among the wax moth larvae Galleria mellonella was explored under laboratory conditions. Vectoring occurred both from infected parasitoids to wax moth larvae and from infected to healthy wax moth larvae by parasitoids. The efficacy of vectoring in both cases was dose dependent. Parasitoid females were unable to recognize infected larvae in a labyrinth test. In addition, the presence of H. hebetor females significantly （1.5-13 fold） increased the mycoses level in clusters of G. mellonella, with 40% of the larvae infected with ftmgal conidia. Envenomation by H. hebetor increased conidia germination on the cuticles of the wax moth larvae by 4.4 fold. An enhanced germination rate （2 fold） was registered in the n- hexane epicuticular extract of envenomated larvae compared to that of healthy larvae. Both envenomation and mycoses enhanced the phenoloxidase （PO） activity in the integument of G. mellonella and, in contrast, decreased the encapsulation rate in hemolymphs. We hypothesize that changes in the integument property and inhibition of cellular immunity provide the highest infection efficacy of entomopathogenic fungi with H. hebetor.

Simulation investigation of tractive energy conservation for a cornering rear-wheel-independent-drive electric vehicle through torque vectoring

Although electric vehicle fully exhibits its comparative merits of energy conservation and environmental friendliness, further improvement of its traction energy efficiency lacks comprehensive investigations in the past. In this paper, the effect of the torque vectoring on traction energy conservation during cornering for a rear-wheel-independent-drive electric vehicle is investigated.Firstly, turning resistance coefficient and energy conservation mechanism of torque vectoring are derived from the single track dynamic model. Next, an optimal torque vectoring control strategy based on genetic algorithm is proposed, with the consideration of the influence of the operation-point change of the in-wheel motors, to find out the best torque vectoring ratio offline. Finally,various simulation tests are conducted to validate the energy conservation effect after Simulink modelling. The results verify that though the optimization of the operating region of the motors is the main part for tractive energy conservation, the contribution of torque vectoring itself can reach up to 1.7% in some typical cases.

DeepSVDNet:A Deep Learning-Based Approach for Detecting and Classifying Vision-Threatening Diabetic Retinopathy in Retinal Fundus Images

Artificial Intelligence(AI)is being increasingly used for diagnosing Vision-Threatening Diabetic Retinopathy(VTDR),which is a leading cause of visual impairment and blindness worldwide.However,previous automated VTDR detection methods have mainly relied on manual feature extraction and classification,leading to errors.This paper proposes a novel VTDR detection and classification model that combines different models through majority voting.Our proposed methodology involves preprocessing,data augmentation,feature extraction,and classification stages.We use a hybrid convolutional neural network-singular value decomposition(CNN-SVD)model for feature extraction and selection and an improved SVM-RBF with a Decision Tree(DT)and K-Nearest Neighbor(KNN)for classification.We tested our model on the IDRiD dataset and achieved an accuracy of 98.06%,a sensitivity of 83.67%,and a specificity of 100%for DR detection and evaluation tests,respectively.Our proposed approach outperforms baseline techniques and provides a more robust and accurate method for VTDR detection.

基于降维变换的低复杂度双基地EMVS-MIMO雷达高分辨多维参数估计

针对当前算法在实现双基地电磁矢量传感器多输入多输出(electromagnetic vector sensors multiple input multiple output,EMVS-MIMO)雷达的多维参数估计时计算代价较高的问题,通过利用降维变换技术来实现低复杂度的角度参数和极化参数求解。针对阵列接收数据维度较大问题,通过设计相应的波束空间变换矩阵来实现对阵列接收数据的降维处理。针对算法本身的较高计算复杂度问题,采用低计算复杂度的平行因子分解算法。所提算法能够精确地实现对发射因子矩阵和接收因子矩阵的求解。同时,通过新的旋转不变关系构建新的估计信号参数,可以实现对发射/接收俯仰角的求解。进一步,发射/接收方位角、发射/接收极化角和发射/接收极化相位差的估计可以通过发射/接收空间响应矩阵的重构来实现。仿真实验结果表明,所提算法在降低计算复杂度的同时能够保持优越的多维参数估计性能。

Structural Topology and Dynamic Response Analysis of an Electric Torque Vectoring Drive-Axle for Electric Vehicles

In-wheel motor-drive electric vehicles have the advantage of independently controllable wheel torque and the disadvantages of unsprung mass rise and power restriction.To address the disadvantages,a centralized layout electric torque vectoring drive-axle system(E-TVDS)with dual motors is proposed,which can realize arbitrary distribution of driving torque between the left and right wheels.First,the speed and torque distribution principle of E-TVDS based on velocity diagram are analyzed,and a virtual prototype of the whole vehicle with basic gear ratio relation model of the E-TVDS is built for simulation to verify the theoretical results and the basic effect of E-TVDS on the steering performance of the vehicle.Second,the charac-teristics of 36 types of the novel E-TVDS topology structure are compared and analyzed,and the optimal structure scheme is selected.Third,the accurate multiple degrees of freedom dynamic model for the optimal structure is established by using the bond graph method,and its dynamic response characteristics are analyzed.The results show that the vehicle equipped with the proposed E-TVDS can distribute the driving torque with the almost identical amount but opposite sign between the left and right wheels in any direction,and varying amount according to different chassis dynamics control requirements,and the torque response performance is great with little delay and overshoot.The function and dynamic response of the proposed E-TVDS show that it has potential application value for various performance improvements of electric vehicles.

A HEVC Video Steganalysis Method Using the Optimality of Motion Vector Prediction

Among steganalysis techniques,detection against MV(motion vector)domain-based video steganography in the HEVC(High Efficiency Video Coding)standard remains a challenging issue.For the purpose of improving the detection performance,this paper proposes a steganalysis method that can perfectly detectMV-based steganography in HEVC.Firstly,we define the local optimality of MVP(Motion Vector Prediction)based on the technology of AMVP(Advanced Motion Vector Prediction).Secondly,we analyze that in HEVC video,message embedding either usingMVP index orMVD(Motion Vector Difference)may destroy the above optimality of MVP.And then,we define the optimal rate of MVP as a steganalysis feature.Finally,we conduct steganalysis detection experiments on two general datasets for three popular steganographymethods and compare the performance with four state-ofthe-art steganalysis methods.The experimental results demonstrate the effectiveness of the proposed feature set.Furthermore,our method stands out for its practical applicability,requiring no model training and exhibiting low computational complexity,making it a viable solution for real-world scenarios.

A semantic vector map-based approach for aircraft positioning in GNSS/GPS denied large-scale environment

Accurate positioning is one of the essential requirements for numerous applications of remote sensing data,especially in the event of a noisy or unreliable satellite signal.Toward this end,we present a novel framework for aircraft geo-localization in a large range that only requires a downward-facing monocular camera,an altimeter,a compass,and an open-source Vector Map(VMAP).The algorithm combines the matching and particle filter methods.Shape vector and correlation between two building contour vectors are defined,and a coarse-to-fine building vector matching(CFBVM)method is proposed in the matching stage,for which the original matching results are described by the Gaussian mixture model(GMM).Subsequently,an improved resampling strategy is designed to reduce computing expenses with a huge number of initial particles,and a credibility indicator is designed to avoid location mistakes in the particle filter stage.An experimental evaluation of the approach based on flight data is provided.On a flight at a height of 0.2 km over a flight distance of 2 km,the aircraft is geo-localized in a reference map of 11,025 km~2using 0.09 km~2aerial images without any prior information.The absolute localization error is less than 10 m.