摄像测量学简介与展望

摄像测量学是摄影测量学、计算机视觉、光学测量、数字图像处理分析等学科交叉融合形成的新兴交叉学科,集各学科的优势。在对各种运动、变化过程参数进行测量方面,摄像测量方法具有精度高、自动化、非接触、动态测量、实时测量、易于实施等特点。近十几年来,摄像测量学在国际上发展迅速,国内目前还未见到对摄像测量学的释著述。本文从学科内涵、历史、基本原理、应用、优势和发展前景等方面对摄像测量学进行了简介和展望。     

基于光流技术的运动目标检测和跟踪方法研究

光流技术作为一种重要的二维运动估计技术,在运动目标检测和跟踪中有着重要的作用.为了更好地将光流技术运用到实时的运动目标检测和跟踪系统中,针对微分光流信息量丰富但计算量大、特征光流计算量小但信息量不足的现状,提出了一种基于最优估计的点匹配技术和光流均匀采样策略的光流场计算方法,并通过对灰度化后的光流场进行自适应阈值分割、形态学滤波等处理,实现了实时的运动目标检测和跟踪.通过对图像序列取700个样本点的仿真实验表明,该方法帧间处理时间基本小于100ms,同时基本解决了信息量和计算量的矛盾.     

基于广义能量法的曲面光顺

提出了同时考虑曲面几何及物理等多项光顺准则的基于广义能量法的曲面整体光顺思路，建立了包含曲面截线族粗光顺、曲面粗光顺两个步骤的曲面光顺方法，论述了曲面精光顺中广义能量表达式和约束条件的建立，实践证明，这种方法对于提高曲面的整体光顺性能具有良好的效果。     

Hard Decision Directed Frequency Tracking for OFDM on Frequency Selective Channel

This paper presents a decision directed frequency tracking scheme to improve the spectrum efficiency of Orthogonal Frequency Division Modulation (OFDM) transmission for frequency selective channels.OFDM divides a broadband channel into parallel narrowband subchannels with different channel characteristics.The subcarriers with lower attenuation are selected to do the decision directed based frequency tracking.A phase error detection method is needed to keep the hard decision working stable during tracking.The algorithm ensures that the carrier frequency offset could be solved from the detected phase error.The Mean Square Error (MSE) estimate and the loop bandwidth are also presented.Simulations illustrate that this scheme has better MSE and bit error rate performance than the traditional scheme.Furthermore,the pilots are saved in this scheme,which lead to improved spectrum efficiency.     

Asymptotic Mandelbrot Law for Some Evolving Networks

Complex networks are now the focus of many branches of research. Particularly, the scale-free property of some networks is of great interest, due to their importance and pervasiveness. Recent studies have shown that in some complex networks, e.g., transportation networks and social collaboration networks, the degree distribution follows the so-called "shifted power law" （or Mandelbrot law） P （ k ） ∝ （ k + c ）-γ. This study analyzes some evolving networks that grow with linear preferential attachments. Recent results for the quotient Gamma function are used to prove the asymptotic Mandelbrot law for the degree distribution in certain conditions. The best fit values for the scaling exponent, γ , and the shifting coefficient, c , can be directly calculated using Bernoulli polynomial functions. The study proves that the degree distribution of some complex networks follows an asymptotic Mandelbrot law with linear preferential attachment depicted by P k ∝ ( k +（b+a+1）/2^-b-a.     

流化床煤燃烧N_2O，SO_x及NO_x的消减

在一台循环流化床实验台上，研究了石灰石脱硫过程中Ｎ_２Ｏ／ＳＯ_ｘ／ＮＯ_ｘ浓度的变化，并在空床上进行了再燃烧法脱除Ｎ２Ｏ的实验，结果表明，石灰石脱硫会使ＮＯｘ少量增加，再燃烧法可以在不增加ＮＯｘ的同时使Ｎ_２Ｏ大大降低；再燃燃料的挥发分含量越高，Ｎ２Ｏ的消减率越高；气体停留时间越长，Ｎ２Ｏ的分解率越高；低氧量对再燃烧法消减Ｎ２Ｏ有利     

On the Small SNR Processing Ability of IR Point Target Detection

: Three-dimensional (3-D) matched filtering has been suggested as a powerful processing technique for detecting weak, moving IR point target immersed in a noisy Held. Based on the theory of the 3-D matched filtering and the optimal linear processing, the optimal point target detector is being analyzed in this paper. The performance of the detector is introduced in detail. The results provide a standard reference to evaluate the performance of any other point target detection algorithms.     

客车车外加速噪声测试方法探讨

本文通过对现行汽车车外噪声相关法规的分析,提出客车车外加速噪声测试方法的问题,并探讨其解决方法。     

Solar magnetic field:The key to understanding the Sun

The Sun is our star, which gives us light, heat and life. The Sun is also the nearest star, detailed observations of which provide us a unique chance to test our understandings of fundamental physics. So far we have understood why the Sun gives out that much heat, how old it is, what its internal structure is, and so on. With these understandings we have already been able to study other stars, galaxies and even the universe with certain successes.     

从国家自然科学基金看我国各省市基础研究竞争力

国家自然科学基金是我国支持基础研究的主要渠道之一,被科研人员公认为国内最规范、最公正、最能反映研究者竞争能力的研究基金.获得国家自然科学基金资助的竞争能力可以比较直观地反映出地区基础研究的水平和竞争力.基于对国家自然科学基金立项信息的深入计算分析,本文构建了基于国家自然科学基金竞争能力的基础研究综合竞争力指数,并结合其他相关统计指标,利用动态图表对我国大陆31个省市的基础研究竞争力进行了系统的动态交互式的可视化对比分析.研究结果表明:我国基础研究力量的地理分布非常不均匀,各省市间的竞争力差异巨大,但总体正朝着积极向好的方向发展.