2-D distributed pose estimation of multi-agent systems using bearing measurements

This article studies distributed pose(orientation and position)estimation of leader–follower multi-agent systems over𝜅-layer graphs in 2-D plane.Only the leaders have access to their orientations and positions,while the followers can measure the relative bearings or(angular and linear)velocities in their unknown local coordinate frames.For the orientation estimation,the local relative bearings are used to obtain the relative orientations among the agents,based on which a distributed orientation estimation algorithm is proposed for each follower to estimate its orientation.For the position estimation,the local relative bearings are used to obtain the position constraints among the agents,and a distributed position estimation algorithm is proposed for each follower to estimate its position by solving its position constraints.Both the orientation and position estimation errors converge to zero asymptotically.A simulation example is given to verify the theoretical results.

SOLVING THE VELOCITY PARAMETER OF THE 2-D WAVE INVERSE PROBLEMS WITH THE INTEGRATION-CHARACTERISTIC METHOD

For the 2-D wave inverse problems introduced from geophysical exploration, in this paper, the author presents integration-characteristic method to solve the velocity parameter, and then applies it to common shotpoint model data, in noise-free case. The accuracy is quite good.

A TWO-DIMENSIONAL LAGRANGIAN TECHNIQUE FOR FLOW FIELD MEASUREMENT UNDER HIGH DYNAMIC PRESSURE

In this paper,a two-dimensional(2-D)Lagrangian technique for flow field measurement under high dynamic pressure is presented,which includes a set of experimental device and 2-D Lagrange composite manganin-constantan ring gages.With this kind of gage,the histories of pressure and radial displacement can be measured simultaneously at different Lagrange positions in an axisymmetric shock loading flow field. The technique has some advantages over the 1-D one,such as,simplified loading device,continuously adjust- able output pressure,no restriction on sample length and the availability for the study of lateral rarefaction in shock propogation.As a preliminary application,the processes of 2-D shock initiation and attenuation in compacted TNT are measured.

2-D crustal structure of Changbaishan-Tianchi volcanic region determined by seismic traveltime inversion

2-D velocity structure and tectonics of the crust and upper mantle is revealed by inversion of seismic refraction and wide-angle reflection traveltimes acquired along the profile L1 in the Changbaishan-Tianchi volcanic region. It is used in this study that seismic traveltime inversion for simultaneous determination of 2-D velocity and interface structure of the crust and upper mantle. The result shows that, under Changbaishan-Tianchi crater, there exists a low-velocity body in the shape of an inverted triangle, and the crustal reflecting boundaries and Moho all become lower by a varying margin of 2-6 km, forming a crustal root which is assumed to be the Changbaishan-Tianchi volcanic system. Finally, we make a comparison between our 2-D velocity model and the result from the studies by using trial-and-error forward modeling with SEIS83.

Cosmetic Lifting Effect of a Formula Combining Tetrahydroxypropyl Ethylenediamine, Ononis Spinosa and Glycerin as Shown by a New 2-D Imaging Method

Facial sagging is a major aging change that affects the overall shape of the face. Sagging can negatively impact self-perception and consequently quality of life. In order to fight against this aging sign, we developed a combination of three active ingredients: Tetrahydroxypropyl Ethylenediamine (THPE), Ononis Spinosa extract and Glycerin. In a clinical study, we assessed the efficacy of this association on facial sagging and wrinkles, with a special focus on immediate and lasting effects. Thirty-nine women applied the tested product daily during an eight-week treatment period. Clinical grading by experts and a new, easy to operate, 2-D imaging method were performed at different time points. The 2-D imaging method measured the upper eyelid lifting effect. The results showed an immediate and significant improvement in sagging and wrinkle parameters;these benefits were still observed seven hours after the first application. Results also showed a significant long-term improvement. The lifting effect calculated from the 2-D pictures was 1.08 mm immediately after application;the same method showed a 1.80 mm lifting effect following the eight-week treatment period. These results suggest that a skin care product combining THPE, Ononis Spinosa and Glycerin properties may be used to reduce sagging as well as wrinkles with both immediate and long term benefits.

Three-dimensional finite-time cooperative guidance for multiple missiles without radial velocity measurements

In order to simultaneously attack a target with impact angle constraint in threedimensional(3-D) space, a novel distributed cooperative guidance law for multiple missiles under directed communication topologies is proposed without radial velocity measurements. First, based on missiles-target 3-D relative motion equations, the multiple missiles cooperative guidance model with impact angle constraint is constructed. Then, in Line-of-Sight(LOS) direction, based on multiagent system cooperative control theory, one guidance law with directed topologies is designed with strict proof, which can guarantee finite time consensus of multiple missiles' impact times. Next, in elevation direction and azimuth direction of LOS, based on homogeneous system stability theory and integral sliding mode control theory, two guidance laws are proposed respectively with strict proof, which can guarantee LOS angles converge to desired values and LOS angular rates converge to zero in finite time. Finally, the effectiveness of the designed cooperative guidance law is demonstrated through simulation results.

Investigation of Key Parameters for 3-D Dredging Plume Model Validation

Dredging plume dispersion studies, use dredging plume models to predict the fate of sediment plumes resulting from dredging activities and dredge spoil disposal. The model results are applied as input to environmental impact assessment of the proposed dredging, particularly those associated with suspended sediments and sedimentation. Model validation and performance are still not resolved because of the difficulty of site measurements and the understanding of the parameters used in the model. This paper presents a 3-D dredging plume model based on the MIKE3 software package to investigate parameters which affect the model performances. As a result of lack of site data for the public domain uses, the model scenarios are designed artificially for sensitive runs to identify the key parameters affecting plume behaviours. The factors include dredging spill rates using different dredging methods, equipment and sediment settling velocities. The influence of wave and wind effects combined with tidal forces on the sediment re-suspended rates and the advection/dispersion scales are also assessed.

基于超声造影剂谐波图像的流场测量技术

本文研究了基于超声造影剂的血流运动场估计与显示技术，通过在血液中注入超声造影剂作为示踪粒子，对造影谐波图像进行时域相关处理，可得到成像部位的二维流场分布图。相对于常规Ｄｏｐｐｌｅｒ方法中用Ｄｏｐｐｌｅｒ回波信号的频偏计算流速值，该技术可直接从超声图像提取与夹角无关的流速矢量信息。本文通过流动模型验证该方法，浸入超声水槽中的乳胶管中流动着血液替代品，沿水流方向进行超声成像，对实验所得的造影后的Ｂ超图像以及谐波图像，用一种节省计算量的多尺度相关算法进行处理，并相互比较。结果显示，谐波图像相对Ｂ超基波图像具有更高的信杂比，从根本上解决了基波图像低信噪比对时域相关测量精度的限制，可以得到与夹角无关的二维血流场分布图，该方法是医学和有关工业领域中超声流场测量的一种有效的方法。

旋转式一孔测压管及其应用1）

由圆柱三孔型二元复合测压管的测速原理出发，提出用一孔测压管通过旋转实现平面气流速度大小与方向的自动测量，建立了相应的测试系统．通过大量实验，研究了该系统的性能．在多种回流和旋流流场测量中进行了应用．结果表明该系统测量原理正确，重复性好。

A Statistical Method for Analysis of Technical Data of a Badminton Match Based on 2-D Seriate Images

The use of computer vision technology to collect and analyze statistics during badminton matches or training sessions can be expected to provide valuable information to help coaches to determine which tactics should be used by a player in a given game or to improve the player＇s tactical training. A method based on 2-D seriate images by which statistical data of a badminton match can be obtained is presented. Image capture and analysis were performed synchronously using a multithreading technique. The regions of movement in the images were detected using a temporal difference method, and the trajectories of the movement regions were analyzed using sedate images. The shuttlecock trajectory was extracted from all detected trajectories using various characteristic parameters. The stroke type was determined by comparing the shuttlecock trajectory data with a set of stroke definition data. The algorithm was tested at a training center, and the results were compared with baseline data obtained by expert visual inspection using four video samples, which included approximately 10 000 frames. The shuttlecock trajectory and stroke type were detected correctly in almost 100% of the analyzed video sequences. The average speed of the automated analysis was approximately 40 frames/s, indicating that the method can be used for real-time analysis during a badminton match. The system is convenient for use by a sports coach.

基于二维速度测量的简易火控装置

基于二维速度测量的简易火控装置由火控计算机、轴角编码器、倾斜角传感器、激光测距机、键盘、目标锁定按钮、显示屏等组成。该装置可测出瞄准线转动的任意角度,能随时停止测角进行射击。由两次测距的目标径向运动信息,实现目标二维运动速度测量,改善射击精度。装置计算模型包括射角、方向角提前量的解算及其倾斜修正。

严格血糖控制对糖尿病周围神经病变的影响

目的对比常规与强化血糖控制对糖尿病周围神经功能的影响。方法筛选临床没有明显神经病变的2型糖尿病患者123例,收集一般临床资料并进行相关生化检查,随机分组后给予强化(HbA1c<7%)治疗(强化组)或常规降糖(HbA1c在8%左右)治疗(对照组),随访2年,随访中定期检测血糖、随访前后测定神经传导速度(NCV)和定量感觉测定(QST)。结果无论是强化治疗还是常规治疗,大部分运动神经NCV有所增加,感觉神经的有所减退,两组治疗前后差值比较显示强化组NCV较常规组增加明显,这些差异只有部分神经的NCV有统计学意义(P<0.05)。两组前后的热感觉、冷感觉和振动觉均改善,其差异有统计学意义(P<0.05),两组治疗前后QST差值比较显示,强化组热感觉及热痛觉较对照组降低明显(P<0.05)。两组数据病变患病率前后均没有显著差异。结论糖尿病患者降低血糖治疗对神经功能均能带来益处,强化降糖对神经功能的改善获益可能更多。