Efficient Low Dissipative High Order Schemes for Multiscale MHD Flows, II: Minimization of ∇·B Numerical Error

An adaptive numerical dissipation control in a class of high order filter methods for compressible MHD equations is systematically discussed. The filter schemes consist of a divergence-free preserving high order spatial base scheme with a filter approach which can be divergence-free preserving depending on the type of filter operator being used, the method of applying the filter step, and the type of flow problem to be considered. Some of these filter variants provide a natural and efficient way for the minimization of the divergence of the magnetic field (∇·B) numerical error in the sense that commonly used divergence cleaning is not required. Numerical experiments presented emphasize the performance of the ∇·B numerical error. Many levels of grid refinement and detailed comparison of the filter methods with several commonly used compressible MHD shock-capturing schemes will be illustratedA condensed version appears in the Proceedings of the International Conference on High Performance Scientific Computing, March 10-14, 2003, Hanoi, Vietnam. This is a revised version of a longer internal report, Feb. 19, 2004. The longer internal report was published as a RIACS Technical Report TR03.10, July 2003, NASA Ames Research Center     

液压多功能小件落物打捞器的研制与应用

由于侧钻井、水平井特殊井身结构限制，常规的小件落物打捞器打捞成功率低。为此经过认真分析和现场实践，将常规机械操作的一把抓改成液压操作，常规强磁打捞器的圆柱形平面磁铁改成具有伸缩性的磁针，同时结合套铣筒，研制出一种液压多功能小件落物打捞器，克服了侧钻井、水平井井身结构的限制，大大提高了一次打捞成功率，现场应用效果明显。     

飞行目标3维姿态测量的新方法

针对传统光测方法通常用于测量目标的点运动轨迹,而难以获得目标的3维姿态参数的情况,提出用数字图像处理手段,对目标图像建立特征点,结合特定的算法,得出目标的俯仰角、偏航角、滚动角、漂移量等3维参数,从而获取更多的目标姿态参数的新方法。     

四川南桠河一期工程姚河坝水电斜井开挖施工技术浅论

以姚河坝水电站引水隧洞50°倾角、长度为194.734m的斜井开挖为实例,从施工测量、开挖方法、通风防尘、临时支护斜井及安全施工等方面探讨长洞身、大倾角斜井在无爬罐条件下的人工开挖方法.     

基于TMS320VC54X的实时卫星信号跟踪系统

介绍了一种在移动载体上实现卫星信号实时跟踪的系统设计方案，该方法以TMS320VC54X为核心信号处理芯片，利用姿态敏感元件稳定运动中的卫星接收天线，以使其始终对准所要跟踪的同步卫星，文章给出了这种方法的硬件原理和主要的软件设计思路。     

Learning-based dynamic coupling of discrete and continuous trackers

We present a data-driven dynamic coupling between discrete and continuous methods for tracking objects of high dofs, which overcomes the limitations of previous techniques. In our approach, two trackers work in parallel, and the coupling between them is based on the tracking error. We use a model-based continuous method to achieve accurate results and, in cases of failure, we re-initialize the model using our discrete tracker. This method maintains the accuracy of a more tightly coupled system, while increasing its efficiency. At any given frame, our discrete tracker uses the current and several previous frames to search into a database for the best matching solution. For improved robustness, object configuration sequences, rather than single configurations, are stored in the database. We apply our framework to the problem of 3D hand tracking from image sequences and the discrimination between fingerspelling and continuous signs in American Sign Language.     

基于HMM方法的动态手势轨迹训练性能研究

基于HMM(Hidden Markov Model,隐形马尔可夫模型)对动态手势轨迹的训练是手势识别的关键技术之一。本文对HMM的模型训练采用Baum.Welch算法,并分别从迭代次数,样本个数选取,以及模型初值选取等方面对动态手势轨迹的训练性能进行了研究。实验结果表明HMM方法对具有时空特性的动态手势轨迹识别是非常有效的。     

From children's hands to adults' ears: Gesture's role in the learning process.

Children can express thoughts in gesture that they do not express in speech--they produce gesture-speech mismatches. Moreover, children who produce mismatches on a given task are particularly ready to learn that task. Gesture, then, is a tool that researchers can use to predict who will profit from instruction. But is gesture also useful to adults who must decide how to instruct a particular child? We asked 8 adults to instruct 38 third- and fourth-grade children individually in a math problem. We found that the adults offered more variable instruction to children who produced mismatches than to children who produced no mismatches--more different types of instructional strategies and more instructions that contained two different strategies, one in speech and the other in gesture. The children thus appeared to be shaping their own learning environments just by moving their hands. Gesture not only reflects a child's understanding but can play a role in eliciting input that could shape that understanding. As such, it may be part of the mechanism of cognitive change. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

误读与纠正

分析材料试验机度盘偏转角度小 (准确度低 )、试样打滑、定义 (上屈服强度 -下屈服强度 -屈服强度 )模糊、不同应力速率等导致误读 ,并针对误读原因提出纠正方法。     

Real-time accurate hand path tracking and joint trajectory planning for industrial robots (I)

Previously, researchers raised the accuracy for a robot’s hand to track a specified path in Cartesian space mainly through increasing the number of knots on the path and the number of the path’s segments, which results in the heavier online computational burden for the robot controller. Aiming at overcoming this drawback, the authors propose a new kind of real-time accurate hand path tracking and joint trajectory planning method. Through selecting some extra knots on the specified hand path by a certain rule and introducing a sinusoidal function to the joint displacement equation of each segment, this method can greatly raise the path tracking accuracy of robot’s hand and does not change the number of the path’s segments. It also does not increase markedly the computational burden of robot controller. The result of simulation indicates that this method is very effective, and has important value in increasing the application of industrial robots. Foundation item: Foundation of the Robotics Laboratory, Chinese Academy of Sciences (No. RL200002) Biography of the first author: TAN Guan-zheng, Dr., professor, born in Oct. 1962, majoring in artificial intelligence, robotics and automation.