Motion estimation in wide band synthetic aperture sonar based on the raw echo data using the method of displaced phase center antenna

Phase errors in synthetic aperture sonar (SAS) imaging must be reduced to less than one eighth of a wavelength so as to avoid image destruction. Most of the phase errors occur as a result of platform motion errors, for example, sway yaw and surge that are the most important error sources. The phase error of a wide band synthetic aperture sonar is modeled and solutions to sway yaw and surge motion estimation based on the raw sonar echo data with a Displaced Phase Center Antenna (DPCA) method are proposed and their implementations are detailed in this paper. It is shown that the sway estimates can be obtained from the correlation lag and phase difference between the returns at coincident phase centers. An estimate of yaw is also possible if such a technique is applied to more than one overlapping phase center positions. Surge estimates can be obtained by identifying pairs of phase centers with a maximum correlation coefficient. The method works only if the platform velocity is low enough such that a number of phase centers from adjacent pings overlap.

Characteristics of Fengyun-4A Satellite Atmospheric Motion Vectors and Their Impacts on Data Assimilation

The high observation efficiency,scanning speed and observation frequency of the Fengyun-4A(FY-4A)satellite indicates the progress of Chinese geostationary meteorological satellites.The characteristics of FY-4A atmospheric motion vectors(AMVs)derived from the high-level water vapor(WV-High)channel,mid-level water vapor(WV-Mid)channel,and infrared(IR)channel of FY-4A are analyzed,and their corresponding observation errors estimated.Then,the impacts of single-channel and multi-channel FY-4A AMVs on RMAPS-ST(the Rapid-refresh Multi-scale Analysis and Prediction System-Short Term)are evaluated based on one-month data assimilation cycling and forecasting experiments.Results show that the observation errors of FY-4A AMVs from the three channels have an explicit vertical structure.Results from the cycling experiments indicate that the assimilation of AMVs from WV-High produces more apparent improvement of the wind in the upper layer,while a more positive effect in the lower layer is achieved by the assimilation of AMVs from IR.Furthermore,the assimilation of AMVs from IR is more skillful for medium and moderate precipitation than from other channels owing to the good quality of data in the lower layer in the AMVs from IR.Assimilation of FY-4A AMVs from the three channels could combine the advantages of assimilation from each individual channel to improve the wind in the upper,middle and lower layers simultaneously.

EXISTENCE TIME FOR SOLUTIONS OFSEMILINEAR DIFFERENT SPEED KLEIN-GORDONSYSTEM WITH WEAK DECAY DATA IN 1D

A -4/3|log |-2 result is obtained for the existence time of solutions of semi- linear different speed Klein-Gordon system in one space dimension for weakly decaying Cauchy data, of size , in certain circumstances of nonlinearity.

Three dimensional passive underwater target motion analysis using correlated data fusion

In this paper a new method of passive underwater TMA (target motion analysis) using data fusion is presented. The findings of this research are based on an understanding that there is a powerful sonar system that consists of many types of sonar but with one own-ship, and that different target parameter measurements can be obtained simultaneously. For the analysis 3 data measurements, passive bearing, elevation and multipath time-delay, are used, which are divided into two groups: a group with estimates of two preliminary target parameter obtained by dealing with each group measurement independently, and a group where correlated estimates are sent to a fusion center where the correlation between two data groups are considered so that the passive underwater TMA is realized. Simulation results show that curves of parameter estimation errors obtained by using the data fusion have fast convergence and the estimation accuracy is noticeably improved. The TMA algorithm presented is verified and is of practical significance because it is easy to be realized in one ship.

ZTE Communications Special Issue on Motion and Emotion Sensing Driven by Big Data

Motion and emotions are two critical features of human presence and activities. Recent developments in the field of indoor motion and emotion sensing have revealed their potentials in enhancing our living experiences through applications like public safety and smart health. However, existing solutions still face several critical downsides such as the availability (specialized hardware), reliability (illumination and line-of-sight constraints) and privacy issues (being watched). To this end, this special issue seeks original articles describing development, relevant trends, challenges,and current practices in the field of applying Artificial Intelligence to address various issues of motion and emotion sensing brought by the“Big data”. Position papers, technology overviews, and case studies are also welcome.

Data Wipe-Off Technique for Tracking Weak GPS Signals

In this paper,the data wipe-off(DWO)algorithm is incorporated into the vector tracking loop of the Global Positioning System(GPS)receiver for improving signal tracking performance.The navigation data,which contains information that is necessary to perform navigation computations,are binary phase-shift keying(BPSK)modulated onto the GPS carrier phase with the bit duration of 20 ms(i.e.,50 bits per second).To continuously track the satellite’s signal in weak signal environment,the DWO algorithm on the basis of pre-detection method is adopted to detect data bit sign reversal every 20 ms.Tracking accuracy of a weak GPS signal is decreased by possible data bit sign reversal every 20 ms to the predetection integration time(PIT)or integration interval.To achieve better tracking performance in weak signal environment,the coherent integration interval can be extended.However,increase of the integration interval lead to decrease of the tracking accuracy by possible data bit sign reversal every 20 ms to the integration interval.When the integration interval of the correlator is extended over 20 ms in low C/No levels,the navigation DWO algorithm can be employed to avoid energy loss due to bit transitions.The method presented in this paper has an advantage to continuously estimate the navigation data bit and achieve improved tracking performance.Evaluation of the tracking performance based on the various integration intervals for the vector tracking loop of a GPS receiver will be presented.

基于多Leap Motion传感器的机械手手势控制系统

为了实现对工业机械手的手势控制,并针对单个Leap Motion传感器在使用时因手指或者手掌遮挡而导致识别率降低的缺点,提出了基于多Leap Motion传感器,用于人手数据采集的新型控制系统。该系统采用基于主成分分析法的数据融合技术对该多传感器数据进行数据融合以得到人手姿态完整的信息,再将该融合数据送入SVM多分类器进行手势姿态识别。实验结果表明该系统能准确地检测人手完整信息,避免了使用单个Leap Motion传感器因视觉干扰或者不可避免的遮挡导致手势姿态数据不准确的问题,提高了手势识别率,可以准确、有效地实现对机械手进行控制。

基于Motion-JPEG2000的远程图像传输技术研究

对于远程无线视频图像传输,由于数据量大、通讯带宽窄等原因常常导致传输速度慢,难以满足实际工程需要。为解决这一问题,论文提出了基于Motion-JPEG2000序列图像压缩技术的远程无线高速图像传输系统设计方案,在C/S模式下实现MJ2K文件传输,采用基于内存池的循环链表作为数据缓存实现解码图像接收与存储,并给出了系统在实验环境中的实验数据和结果分析。

基于卷积神经网络的Leap Motion运动数据优化网络

为提高Leap Motion设备的采集精准度,解决自遮挡、采样频率不稳定等设备固有问题,首先,设计了使用Leap Motion和动作捕捉设备的手部多模态同步运动采集方案,采集了日常动作数据集;其次,提出了基于卷积神经网络(convolutional neural network,CNN)的Leap Motion手部运动数据优化方法,使用日常动作数据集训练Leap Motion数据到动作捕捉数据的映射网络;最后,提出手指平面约束,确保网络输出数据保持稳定的手部骨骼结构.通过15名志愿者采集了6类动作共967550帧的同步运动数据集,进行了手指平面约束有效性、动作一致性实验,并与双向循环自编码器(bidirectional recurrent autoencoder,BRA)、双向编解码器(encoder-bidirectional-decoder,EBD)方法进行了精度对比.结果表明,文中方法支持使用Leap Motion获取固定采样频率且近似动捕设备精度的手部运动数据,效果较BRA和EBD更加稳定平滑.将文中方法应用于康复游戏中,明显减少了交互动作识别的错误次数.

面向大范围手势捕捉的Leap Motion数据结构体优化

无标记人手和虚拟环境交互是实现沉浸式虚拟装配的关键,多Leap Motion数据融合是扩展捕捉范围的有效途径。然而,多Leap Motion系统的数据量冗杂,增加了基于局域网传输的网络负荷,使得手势反应迟滞,影响了沉浸感和装配效率。建立了Leap Motion数据结构体优化模型,获得了各类数据的权重,提出了优化方案,优化后数据量降低了36%,针对5个Leap Motion系统进行测试。结果表明:优化后系统的数据传输速度和融合效果得到大幅提升,满足了多Leap Motion实时手工装配的需求。

Prediction of efficient outputs based on GM(1,N) model and weak DEA efficiency

This paper expresses the efficient outputs of decisionmaking unit（DMU） as the sum of ＂average outputs＂ forecasted by a GM（1,N） model and ＂increased outputs＂ which reflect the difficulty to realize efficient outputs.The increased outputs are solved by linear programming using data envelopment analysis efficiency theories,wherein a new sample is introduced whose inputs are equal to the budget in the issue No.n ＋ 1 and outputs are forecasted by the GM（1,N） model.The shortcoming in the existing methods that the forecasted efficient outputs may be less than the possible actual outputs according to developing trends of input-output rate in the periods of pre-n is overcome.The new prediction method provides decision-makers with more decisionmaking information,and the initial conditions are easy to be given.

Parameter inversion and location determination of evolutionary weak layer for open-pit mine slope

In light of the complex and dynamic mechanical properties of evolving weak strata in open-pit mines,and the consequent difficulty of determining their mechanical parameters,this study uses the ultimate balance theory,along with the back analysis method combined with monitoring data on field displacement,to carry out parameter inversion using the FLAC3D numerical simulation software.The edge slope of a working pit of the Weijiamao open-pit mine was used as research object to this end.As the results obtained by the constitutive model were consistent with the field monitoring data,the evolving weak strata in the slope and the position of the landslide in the mine could be obtained.The landslide was directed northeast.The mechanism of the edge slope of the working pit was identified as unloading shear failure,and the feasibility of the method of parameter inversion was verified.The internal friction angle φand cohesion C of evolving weak strata in the slope of the open-pit mine were also obtained,where this compensated for the deficiency of laboratory tests and enabled the transformation from qualitative to quantitative analysis.This can provide a reliable basis for the safe operation of open-pit mines.

Spin-Spin Interactions in Gauge Theory of Gravity, Violation of Weak Equivalence Principle and New Classical Test of General Relativity

For a long time, it has been generally believed that spin-spin interactions can only exist in a theory where Lorentz symmetry is gauged, and a theory with spin-spin interactions is not perturbatively renormalizable. But this is not true. By studying the motion of a spinning particle in gravitational field, it is found that there exist spin-spin interactions in gauge theory of gravity. Its mechanism is that a spinning particle will generate gravitomagnetic field in space-time, and this gravitomagnetic field will interact with the spin of another particle, which will cause spin-spin interactions. So, spin-spin interactions are transmitted by gravitational field. The form of spin-spin interactions in post Newtonian approximations is deduced. This result can also be deduced from the Papapetrou equation. This kind of interaction will not affect the renormalizability of the theory. The spin-spin interactions will violate the weak equivalence principle, and the violation effects are detectable. An experiment is proposed to detect the effects of the violation of the weak equivalence principle.

基于Motion-JPEG2000的远程图像传输技术

对于远程无线视频图像传输,由于数据量大、通讯带宽窄等原因常常导致传输速度慢,难以满足实际工程需要.为解决这一问题,提出了基于Motion-JPEG2000序列图像压缩技术的远程无线高速图像传输系统设计方案,在C/S模式下实现MJ2K文件传输,采用基于内存池的循环链表作为数据缓存实现解码图像接收与存储,并给出了系统在实验环境中的实验数据和结果分析.

Introducing semantic information into motion graph

To improve motion graph based motion synthesis,semantic control was introduced.Hybrid motion features including both numerical and user-defined semantic relational features were extracted to encode the characteristic aspects contained in the character's poses of the given motion sequences.Motion templates were then automatically derived from the training motions for capturing the spatio-temporal characteristics of an entire given class of semantically related motions.The data streams of motion documents were automatically annotated with semantic motion class labels by matching their respective motion class templates.Finally,the semantic control was introduced into motion graph based human motion synthesis.Experiments of motion synthesis demonstrate the effectiveness of the approach which enables users higher level of semantically intuitive control and high quality in human motion synthesis from motion capture database.

FIRST ORDER QUASILINEAR EQUATIONS IN SEVERAL INDEPENDENT VARIABLES WITH SINGULAR INITIAL DATA L^p（P＜∞）

We study the existence problem for the equations of first order quasilinearequations in several inpendent variables with singular initial data Lp(P<∞). We the convergence of the Lp(P<∞) bounded approximating sequences generatedby the method of vanishing viscosity. The uniqueness of the generalized solutions whichcan be obtained by the method of vanishing viscosity is also obtained.

Motion information analysis system based on acceleration signals

A motion information analysis system based on the acceleration data is proposed in this paper,consisting of filtering,feature extraction and classification.The Kalman filter is adopted to eliminate the noise.With the time-domain and frequency-domain analysis,acceleration features like the amplitude,the period and the acceleration region values are obtained.Furthermore,the accuracy of the motion classification is improved by using the k-nearest neighbor （KNN） algorithm.

Weak Dissipative Structure for Compressible Navier-Stokes Equations

This paper concerns the Cauchy problem for compressible Navier-Stokes equations.The weak dissipative structure is explored and a new proof for the classical solutions are shown to exist globally in time if the initial data is sufficiently small.

The Study on the Strong Ground Motion Attenuation Relationship in the Pishan Area,Xinjiang Uygur Autonomous Region

Small earthquake data from the Pishan MS6.5 aftershocks is collected by the Xinjiang Regional Digital Seismic Observation Network.Five parameters of the focal region are obtained by micro genetic inversion:stress dropΔσof 75.95 bars,quality factor parameters Q0of 186.33 andηof 0.26,geometric attenuation parameters R1of 72.18km and R2of 139.70km.We calculate the Fourier spectrum and combine it with the random phase spectrum to get the ground motion time history,and build the strong motion acceleration attenuation relationship.The strong ground motion acceleration attenuation of the Pishan area is thus obtained.Because of the insufficiency of strong ground motion records,we added the records from the Wuqia MS6.9 earthquake on October 5,2008,the Akto MS6.2 earthquake on October 6,2008,and the Lop MS6.0 earthquake on March 9,2012 to the data.The comparison of the calculation results and the empirical attenuation relationships with strong ground motion records reveal that the strong motion data of Pishan and Lop earthquakes is higher than the empirical attenuation relationships.The Wuqia MS6.9 earthquake strong motion data is consistent with Yu Yanxiangs(2013)short axis result,and lower than the present result.

A Smart Multi-Sensor Approach to Monitoring Weak People in Indoor Environments

This paper deals with a novel system to assist weak people while exploring indoor environments. The proposed architecture is aimed to monitor the position and inertial behavior of users as well as environmental status (e.g. temperature, humidity, gases leakage, or smoke). The system is based on a Wireless Sensor Network and smart paradigms which extract relevant information from data collected through the multi-sensor architecture. The data collected are then processed to build awareness of User-Environment Interaction and User-Environment Contextualization. This knowledge is used to build information that is useful to the user for safe and efficient exploitation of the environment and to the supervisor for a suitable assessment and management of hazard situations. The paper mainly focuses on the multi-sensor system architecture and smart paradigms used to implement the User-Environment Contextualization feature.