Motion coding of image primitives

We introduce an algorithm for matching stationary or moving image primitive lines between adjacent frames of a video sequence. Starting from local measures of proximity and similarity of shape, the algorithm computes the distance between pairs of primitives. It has strategies for dealing with broken lines and various kinds of connections between lines. The output of the algorithm is used to control a motion coding system, where only unmatched threads need be transmitted. The system can function in a simple conditional replenishment mode, or with motion compensation. Experimental results are reported showing an improvement of compression rate of 2:1 between intraframe primitivebased coding and motion-compensated primitive-based coding.     

用光学联合变换方法对手写汉字进行分类识别

用光学联合变换方法，结合ＣＣＤ数据采集系统，对手写汉字进行统计分类识别，通过实验得出了各类别的相关峰值范围，其实验结果良好，有较大的应用前景。     

红外背景中点与近点源目标探测的卷积减法滤波算法

远距离下点与近点源红外目标的有效探测与捕获，很大程度上依赖于对背景杂波的抑制，诸多滤波技术已经提出。本文在简述了主要滤波技术的特点后，提出一种新的卷积减法滤波算法（ＣｏｎｖｏｌｕｔｉｏｎＳｕｂｔｒａｃｔｉｏｎＦｉｌｔｅｒｉｎｇ），数理模型分析与计算机模拟的结果说明：这是一种易于硬件实现，能有效抑制背景杂波的线性技术。     

Controls on the organic carbon content of the lower Cambrian black shale in the southeastern margin of Upper Yangtze

Control of various factors, including mineral components, primary productivity and redox level, on the total organic carbon(TOC) in the lower Cambrian black shale from southeastern margin of Upper Yangtze(Taozichong, Longbizui and Yanbei areas) is discussed in detail in this article. Mineral components in the study strata are dominated by quartz and clay minerals. Quartz in the Niutitang Formation is mainly of biogenic origin, and the content is in positive correlation with TOC, while the content of clay minerals is negatively correlated with TOC. Primary productivity, represented by the content of Mobio(biogenic molybdenum), Babio(biogenic barium) and phosphorus, is positively correlated with TOC. The main alkanes in studied samples are nC_(18–n)C_(25), and odd–even priority values are closed to 1(0.73–1.13), which suggest the organic matter source was marine plankton. Element content ratios of U/Th and Ni/Co and compound ratio Pr/Ph indicate dysoxic–anoxic bottom water, with weak positive relative with TOC. In total, three main points can be drawn to explain the relationship between data and the factors affecting organic accumulation:(1) quartz-rich and clay-mineral-poor deep shelf–slope–basin environment was favorable for living organisms;(2) high productivity provided the material foundation for organic generation;(3) the redox conditions impact slightly on the content of organic matter under high productivity and dysoxic–anoxic condition.     

Numerical analysis of a PbTiO3 ferroelectric thin-filminfrared optical diode

A thin PbTiO₃-n-p⁺ silicon diode has been developed, in which the conductivity increases with the infrared light power. The infrared-sensitive part consists of PbTiO₃ ferroelectric thin film deposited by RF sputtering. The diode has smaller heat capacity compared with other conventional infrared sensors because the tunneling current is allowed through the PbTiO₃ layer so that the PbTiO₃ film thickness can be thinned. Numerical analysis of the operational mechanism, such as the effects of infrared light power on the depletion layer width, n-p⁺ junction voltage, surface depletion region voltage drop, and voltage drop across the thin PbTiO₃ film, are reported in detail. Furthermore, some experimental measurements, such as the effects of infrared light power on current-voltage (I-V) curves and the dielectric constant of PbTiO₃ film, are compared with the theoretical analysis     

基于多角度偏振信息反演海洋上空卷云云顶高度

采用偏振辐射信息反演云顶高度时,为了减小由云层及地表偏振辐射特性变化带来的反演结果不确定度,使用490 nm和865 nm通道多角度偏振信息反演卷云云顶高度.理论分析大气顶偏振特征,给出490 nm与865 nm通道偏振特性差异,说明使用此两通道偏振反射率差反演云顶高度的可行性.假设卷云为一般种类混合模型(General Habit Mixture,GHM),使用倍加累加矢量辐射传输模型计算和分析大气顶490 nm和865 nm通道偏振反射率差对卷云有效粒子半径、光学厚度和云顶压强的敏感性.分析表明,当卷云光学厚度大于3时,偏振反射率差对有效粒子半径和光学厚度的变化不敏感,对云顶压强变化敏感.根据敏感性分析结果选择适当的参数构建偏振反射率差查找表,使用查找表方法反演POLDER3数据的卷云云顶高度,并与POLDER3产品和MODIS产品进行比较.结果表明,与POLDER3的官方算法相比,使用偏振反射率差查找表方法有更宽的散射角适用范围,反演结果与MODIS产品有更好的一致性.     

Benzobisthiazole as Weak Donor for Improved Photovoltaic Performance: Microwave Conductivity Technique Assisted Molecular Engineering

New donor–acceptor‐type copolymers comprised of benzobisthiazole (BBTz) as a weak donor rather than acceptor are proposed. This approach can simultaneously lead to deepening the HOMO and LUMO of the polymers with moderate energy offset against fullerene derivatives in bulk heterojunction organic photovoltaics. As a proof‐of‐concept, BBTz‐based random copolymers conjugated with typical electron acceptors: thienopyrroledione (TPD) and benzothiadiazole (BT) based on density functional theory calculations are synthesized. Laser‐flash and Xe‐flash time‐resolved microwave conductivity (TRMC) evaluations of polymer:[6,6]‐phenyl C₆₁ butyric acid methyl ester (PCBM) blends are conducted to screen the feasibility of the copolymers, leading to optimization of processing conditions for photovoltaic device application. According to the TMRC results, alternating BBTz‐BT copolymers are designed, exhibiting extended photoabsorption up to ca. 750 nm, deep HOMO (–5.5 to –5.7 eV), good miscibility with PCBM, and inherent crystalline nature. Moreover, the maximized PCE of 3.8%, the top‐class among BBTz‐based polymers reported so far, is realized in an inverted cell using TiO_x and MoO_x as the buffer layers. This study opens up opportunities to create low‐bandgap polymers with deep HOMO, and shows how the device‐less TRMC evaluation is of help for decision‐making on judicious molecular design.     

频率/波数谱法用于分析鱼雷壳体样品

本文利用快速傅里叶变换和最大熵谱法计算频率 /波数谱 ,对鱼雷壳体的受激响应特性进行了频率 /波数谱分析 ,得到了振动波在鱼雷壳体中传播的波数、波速、波型和波的传播方向 ,并进行了讨论     

A unified method for evaluating the error-correction radius ofreliability-based soft-decision algorithms for linear block codes

This paper presents a unified method for evaluating the error-correction radii of many reliability-based soft-decision decoding algorithms for binary linear block codes. Based on this unified method, these decoding algorithms as well as their potential improvements can be compared directly. The error-correction radius for each of these decoding algorithms is determined by finding the closest point on the boundary of the decision region of the soft-decision decoder to the transmitted signal sequence. It is shown that this problem can be formulated as a constrained optimization problem. Although no general closed-form expression is possible, a simple algorithm that always converges to the optimum solution of this optimization problem is presented. Based on these results, the error-correction radii of some well-known reliability-based soft-decision decoding algorithms are revisited and compared     

Some block- and trellis-coded modulations for the Rayleigh fadingchannel

The error performance of a modulation code over a channel depends on several distance parameters and the path multiplicity of the code. For the AWGN channel, the error performance of a modulation code depends mainly on its minimum squared Euclidean distance and path multiplicity. For the Rayleigh fading channel, however, the error performance of a modulation code depends strongly on its minimum symbol distance, minimum product distance, and path multiplicity. It depends on the minimum squared Euclidean distance in a lesser degree. This paper is concerned with the construction of block and trellis MPSK modulation codes for the Rayleigh fading channel. In each construction, the distance parameters are chosen to achieve good error performance with reduced decoding complexity