机动目标跟踪的自适应相互作用多模型算法

 针对目标跟踪中的目标机动问题提出了一种“基于自适应相互作用多模型”的算法。使用不同的几个子模型来描述目标的运动状态,各个模型有自己的随目标估计状态和当前测量值变化的模型概率,并且各模型之间能通过马尔可夫链的控制自动平滑切换。仿真实验表明了该算法能很好地适应目标的机动,即使采用两个子模型来描述目标的运动,跟踪精度也比较好。     

Discrete filters for large eddy simulation

This paper summarizes several results relative to discrete filters for subgrid‐scale (SGS) models based on a multi‐level filtering procedure. First, a theoretical study of discrete filters in physical space is performed. The analysis is done in the uniform one‐dimensional case, and is then extended to the general multi‐dimensional case for arbitrary structured and unstructured meshes. Some equivalence classes for the discrete filters are defined, based either on a differential approximation or the associated transfer function. Methods for the definition of discrete filters are proposed in the general case, including the approximation of continuous convolution filters. Second, the sensitivity of several SGS models with respect to the test filter is investigated. The selected models are: the dynamic Smagorinsky model, the mixed scale model (MSM), the selective MSM and the Liu–Meneveau–Katz (LMK) similarity model. Improved versions, which explicitly account for the spectral width of the test filter of the MSM and the LMK similarity model are proposed. The analysis, which reveals a significant influence of the test filter, is done through a priori testing on a 128³ field issued from the large eddy simulation (LES) of freely decaying homogeneous isotropic turbulence. Copyright © 1999 John Wiley & Sons, Ltd.     

Unravelling the Photoprotection Properties of Garden Cress Sprout Extract

Plants, as with humans, require photoprotection against the potentially damaging effects of overexposure to ultraviolet (UV) radiation. Previously, sinapoyl malate (SM) was identified as the photoprotective agent in thale cress. Here, we seek to identify the photoprotective agent in a similar plant, garden cress, which is currently used in the skincare product Detoxophane nc. To achieve this, we explore the photodynamics of both the garden cress sprout extract and Detoxophane nc with femtosecond transient electronic absorption spectroscopy. With the assistance of liquid chromatography-mass spectrometry, we determine that the main UV-absorbing compound in garden cress sprout extract is SM. Importantly, our studies reveal that the photoprotection properties of the SM in the garden cress sprout extract present in Detoxophane nc are not compromised by the formulation environment. The result suggests that Detoxophane nc containing the garden cress sprout extract may offer additional photoprotection to the end user in the form of a UV filter booster.     

FST方法分析二维Rayleigh-Bénard湍流热对流系统的能量输运

本文应用空间滤波方法：FST(Filter-space technique)方法,研究二维Rayleigh-Bénard(RB)湍流热对流系统中湍动能、热能和拟涡能的能量输运．研究中Rayleigh数(Ra)选取为1x10^8、1x10^9和1x10^10,Prandtl数(Pr)固定为4.38．我们展示了的结果表明,在二维RB系统中,三个Ra数下全场的平均湍动能和平均拟涡能在不同滤波尺度下的能量输运与Kraichnan在1967年预测的二维湍流中的级串理论有所偏差,而中心区域的能量都是向小尺度输运的．结果还揭示了瞬时能量输运的一些局部特性,包括它们在小尺度上不对称的分布．     

多道预测反褶积

就多维最小平方预测准测,推导了一种分块Toeplitzt矩阵方程组求解的递推公式,并对人工模型进行了实验,实验结果表明采用多道处理反褶积优于单道结果。文中还给出了多道最小相位的定义,并给出了在一步预测下多维反褶积算子确定性稳定的结论。     

显微镜中的可变式假彩色编码

将可变式空间滤波器应用到显微镜中,不仅能实时地从显微镜视场里观察到无色标本的彩色图象,还能根据需要突出图象中某些特征.     

模式滤波器在色谱信号除噪中的应用

提出一种模式滤波器方法,用于解决色谱信号中宽带噪声的除噪问题。模式滤波器的应用原理是基于色谱信号与宽带噪声之间的形态差异。工作过程：先采用模式匹配方法识别宽带噪声,再识别各种噪声的起始点与终止点,最后采用线性插值方法重构含噪声的色谱信号。方法具有实现简单、运算速度快、去除噪声能力强等特点。由实际采集的色谱信号经除噪处理后所得的结果表明：模式滤波器比一般滤波器具有更好的除噪效果。     

用于微全分析系统的数字化微流控芯片的研究

研制出一种基于介质上电润湿(electrowetting-on-d ielectric,EWOD)机制的可编程数字化微流控芯片。它采用“三明治”结构:受控离散液滴被夹在两极板之间;下极板以硅为衬底,掺杂多晶硅作为芯片微电极阵列,其上涂覆有Teflon(AF1600薄膜的S iO2作为疏水性介质层;上极板是涂覆有Teflon(AF1600疏水薄膜的透明电极。通过分析数字化微流控系统的基本操作(离散液滴的传输、拆分及混合)的物理机理和模拟优化,在35 V低驱动电压下实现了约0.35μL和0.45μL去离子水离散液滴的传输和合并,并在70 V驱动电压下实现了0.8μL液滴的拆分等操作。     

扩展Kalman滤波器同时测定苯酚和邻氯苯酚

提出了苯酚和邻氯苯酚混合体系非线性吸光度表示式。即非线性吸光度由两组分各自对吸光度的贡献、由于混合而导致的两组分各自贡献的改变以及交互作用项三部分构成。依据该式,利用非线性Kalman滤波紫外分光光度法同时测量了苯酚和邻氯苯酚混合体系。在250～290 nm 区间测量了32组浓度各自在1～15 mg·L-1范围的苯酚和邻氯苯酚标准混合溶液紫外吸收光谱图。利用偏最小二乘法,将其制作成扩展Kalman滤波标准工作系数矩阵。通过对非线性吸光度关系式Taylor级数展开进行线性化处理,得到其向量函数的Jacobi矩阵,从而完成了非线性Kalman滤波器的设置。回收实验显示出,扩展Kalman滤波同时测量苯酚和邻氯酚双组分体系是准确、稳定的。