一种应用于超小型无人机的新型定高传感器

使用美国ICSENSOR公司的压阻硅式绝压传感器，对静压进行测量，并设计出适合超小型无人机使用的新型定高传感器，这种定高传感器具有灵敏度高，重量轻，单电源供电，板式结构。可靠性高，重复性好的特点，填补了应用于超小型无人机的定高传感器产品的空白。     

Almost instant time inference for hybrid partially dynamic Bayesian networks

A Bayesian network (BN) is a compact representation for probabilistic models and inference. They have been used successfully for many military and civilian applications. It is well known that, in general, the inference algorithms to compute the exact a posterior probability of a target node given observed evidence are either computationally infeasible for dense networks or impossible for general hybrid networks. In those cases, one either computes the approximate results using stochastic simulation methods or approximates the model using discretization or a Gaussian mixture model before applying an exact inference algorithm. This paper combines the concept of simulation and model approximation to propose an efficient algorithm for those cases. The main contribution here is a unified treatment of arbitrary (nonlinear non-Gaussian) hybrid (discrete and continuous) BN inference having both computation and accuracy scalability. The key idea is to precompile the high-dimensional hybrid distribution using a hypercube representation and apply it for both static and dynamic BN inference. Since the inference process essentially becomes a combination of table look-up and some simple operations, the method is shown to be extremely efficient. It can also he scaled to achieve any desirable accuracy given sufficient preprocessing time and memory for the cases where exact inference is not possible     

Performance evaluation for MAP state estimate fusion

This paper presents a quantitative performance evaluation method for the maximum a posteriori (MAP) state estimate fusion algorithm. Under ideal conditions where data association is assumed to be perfect, it has been shown that the MAP or best linear unbiased estimate (BLUE) fusion formula provides the best linear minimum mean squared estimate (LMMSE) given local estimates under the linear Gaussian assumption for a static system. However, for a dynamic system where fusion is recursively performed by the fusion center on local estimates generated from local measurements, it is not obvious how the MAP algorithm will perform. In the past, several performance evaluation methods have been proposed for various fusion algorithms, including simple convex combination, cross-covariance combination, information matrix, and MAP fusion. However, not much has been done to quantify the steady state behavior of these fusion methods for a dynamic system. The goal of this work is to present analytical fusion performance results for MAP state estimate fusion without extensive Monte Carlo simulations, using an approach developed for steady state performance evaluation for track fusion. Two different communication strategies are considered: fusion with and without feedback to the sensors. Analytic curves for the steady state performance of the fusion algorithm for various communication patterns are presented under different operating conditions.     

1/spl phi/ 3W grid-connection PV power inverter with partial active power filter

This paper presents a single-phase three-wire (1/spl phi/ 3W) grid-connection photovoltaic (PV) power inverter with a of partial active power filter (PAPF) feature, which can not only deal with PV power but filter current harmonics and improve power factor. Once the processed power exceeds the switch ratings, the inverter can reduce its output reactive power and harmonic power, while still supplying the maximum real power generated by the PV arrays. In the derivation of control laws, a limit circle is defined to confine the output power of the inverter. To determine the power that the inverter can process, the instantaneous reactive power of a 1/spl phi/ 3W system is defined and used to calculate reactive power, which can avoid complex detections of phase angle and magnitude of the fundamental component of a nonlinear load current. Simulation results and experimental measurements have verified the proposed algorithm and the feasibility of the inverter.     

关于平面空穴流动的截断误差减小方法(英文)

提出了一种新的截断误差减小方法。该方法是利用在粗网格 ( 2 h)上估算截断误差进而减小在原始网格( h)上的误差的迭代过程 ,最终目的是利用粗网格得出更精确的结果以及发展一种新的粗网格直接数值模拟方法     

基于软件工程基本原理的电子商务网站建设

针对电子商务网站建设过程中存在的问题，从软件工程基本原理出发，分析结合软件生存周期瀑布模型提出电子商务网站的建设过程，对克服当前主要不足有一定的帮助作用。     

开放式飞行任务规划方法

本文给出了一种基于分布式黑板结构的开放式飞行任务规划方法，简要叙述了飞行器飞行任务规划的概念和其独特要求，并对飞行任务规划的数据预处理、知识表达、规划方法作了深入的探讨。最后介绍了分布式黑板的结构和运行方式。     

空间相机中与大口径透镜有关的结构设计分析

某空间相机镜头在光学设计时，因透过率、吸收率等原因，为了满足光学系统要求，经过各方面平衡后，其中有一片透镜比正常径厚比设计的偏薄些。在镜头总体结构设计时，单独对该镜片及与之相配的结构件进行了有限元分析和实验检测，发现不同的结构形式对镜片面形影响不同。为了解决这一问题，在实验中进行了探讨，以保证整个相机系统满足空间相机的实用要求。     

三维热化学非平衡流动非结构网格DSMC方法及其应用

研究了过渡流域三维热化学非平衡流动DSMC方法实现的过程.以四面体非结构网格为基本单元,提出一种新型的高效搜索算法,该算法不仅可以快速跟踪模拟分子在网格之间的迁移,而且可以准确判别分子与物面是否相互作用,避免了原有算法中分子表面反射的非确定论判据.设计了适合三维DSMC方法的动态局部时间步长技术,节约了计算时间.将碰撞距离的思想引入到非结构网格上来,有效地消除了网格尺度小于三分之一平均自由程的限制.利用Foaran90的动态分配内存技术编制了适用于任意外形的通用计算程序.最后对全尺寸航天飞机高超声速绕流进行了数值试验,计算结果验证了该算法的可行性及高效性.     

KuaFu Mission

The KuaFu mission-Space Storms, Aurora and Space Weather Explorer-is an "L1+Polar" triple satellite project composed of three spacecraft: KuaFu-A will be located at L1 and have instruments to observe solar EUV and FUV emissions, and white-light Coronal Mass Ejections (CMEs), and to measure radio waves, the local plasma and magnetic field,and high-energy particles. KuaFuB1 and KuaFu- B2 will bein polar orbits chosen to facilitate continuous 24 hours a day observation of the north polar Aurora Oval. The KuaFu mission is designed to observe the complete chain of disturbances from the solar atmosphere to geospace, including solar flares, CMEs, interplanetary clouds, shock waves, and their geo-effects, such as magnetospheric sub-storms and magnetic storms, and auroral activities. The mission may start at the next solar maximum (launch in about 2012), and with an initial mission lifetime of two to three years. KuaFu data will be used for the scientific study of space weather phenomena, and will be used for space weather monitoring and forecast purposes. The overall mission design, instrument complement, and incorporation of recent technologies will target new fundamental science, advance our understanding of the physical processes underlying space weather, and raise the standard of end-to-end monitoring of the Sun-Earth system.