基于局部特征组合的目标跟踪算法

为了克服目前大多数观测模型在小样本空间中鲁棒性不高的弱点,文中在粒子滤波框架下提出基于局部特征组合的粒子滤波视频跟踪算法。局部特征能更有效描述目标模板细节信息,可降低特征匹配中目标形变、光照变化和部分遮挡的影响。该方法借鉴混合高斯模型思想,采用多模式描述有效局部观测信息,这种融合策略更加准确可靠,能够较好地通过最新观测减轻了粒子退化现象,从而提高目标跟踪效率。小样本空间一定程度上降低了粒子数量和计算代价。实验结果表明该算法相比单一特征或一般多特征融合跟踪算法具有优越性,并能实现复杂场景下的目标跟踪。     

基于在线特征选择的粒子滤波跟踪算法

在复杂场景下,传统的粒子滤波跟踪算法较难定位目标.针对此问题,提出了一种基于在线特征选择的粒子滤波跟踪算法.该算法首先在线、自适应地通过Fisher判别准则,从16个不同的颜色特征空间中选择最能区分目标及其邻近背景的1个最佳特征空间,然后在这个最佳特征空间中用基于统计直方图的粒子滤波算法跟踪目标.试验结果表明,该算法鲁棒性和准确性较好,在光照变化.目标自身发生形变和遮挡情况下能够准确地对目标进行跟踪.     

一种基于运动检测的粒子滤波跟踪方法

针对传统粒子滤波的建议分布没有利用到当前观测信息的不足,本文提出了一种基于运动检测以改进建议分布的粒子滤波跟踪方法.该方法利用系统的状态转移密度分布,结合目标当前时刻的运动信息共同决定目标的先验分布.首先从一阶自回归的状态转移模型中生成部分粒子,然后采用单高斯背景建模进行局部运动检测,在检测到的运动区域中采样其余粒子,由此得到粒子的先验分布.用该方法分别对动态背景和存在完全遮挡情况下的运动目标进行跟踪,实验结果表明该方法有较高的跟踪精度和较强的稳定性.     

基于视觉显著性的灰色粒子滤波跟踪方法

针对传统的粒子滤波算法在目标运动状态突然改变时(如突然加速、减速或者转弯等)容易发生目标丢失的问题,提出了一种基于视觉显著性的灰色粒子滤波跟踪算法。该算法根据灰度预测模型来预测产生建议分布,实现对粒子的繁殖和传播,同时根据调节因子的优化计算,对灰度预测模型的待定系数进行自适应调节,并通过局部显著性检测对低相似度粒子进行快速筛除提高跟踪精度和计算效率。实验结果表明,该跟踪算法能够有效提升粒子滤波的目标跟踪能力。     

一种基于粒子滤波的特征融合跟踪算法

针对单纯的基于颜色的跟踪方法在复杂背景下会导致跟踪失败的问题,本文提出一种基于粒子滤波的特征融合跟踪算法。颜色直方图是对目标的全局描述,而方向梯度直方图包含了一定的结构信息,二者可以互为补充,因此本文算法同时用颜色直方图和方向梯度直方图来描述目标,在粒子滤波框架下将目标颜色和梯度信息有机结合,并自适应更新。实验表明,本文算法不仅提高了跟踪精度,而且具有较强的鲁棒性。     

改进的粒子滤波目标跟踪算法

针对环境迁移、目标被遮挡或姿态变化较大时传统粒子滤波算法的鲁棒性不强的问题,提出一种改进的粒子滤波目标跟踪算法。建立目标模型时,将目标的HSV颜色特征和Uniform LBP纹理特征进行加权融合;粒子重采样过程中,采用加权随机采样方法,将粒子权值作为重采样的影响因子而非决定因子,以提升粒子多样性,降低粒子衰退对目标跟踪的影响;目标被干扰时,采用卡尔曼滤波对目标位置进行偏移校正,以获取目标正确位置;最后采用模板更新策略对目标模板进行实时更新。实验结果表明：相较于传统粒子滤波算法和CMT算法,本文算法对复杂环境中目标被遮挡和姿态变化的情况下都具有较好的鲁棒性。     

多特征融合的非线性目标跟踪算法

为克服视频目标跟踪中仅利用单一特征易导致的跟踪失败,提出了一种基于多特征融合的非线性目标跟踪算法。通过灰度直方图来表征目标的总体分布,利用边缘特征来提取目标的高频细节,将两者融合于粒子滤波的概率模型框架中。并提出一种基于半峰宽和贡献度的特征可信度计算方法,动态调节粒子数目,使可信度高的特征拥有较多的粒子。最后,进行了目标跟踪仿真实验,结果表明,该算法具有较强的抗局部遮挡能力,与单特征跟踪算法相比,平均跟踪误差减小了0．5个像素。     

一类基于信息融合的粒子滤波跟踪算法

本文提出了一种基于图像多特征信息融合的粒子滤波跟踪算法.该算法利用颜色柱状图描述运动目标颜色分布信息,帧间差的梯度图像描述目标运动信息,并在柱状图框架下给出了运动目标颜色和运动似然模型,保证了颜色和运动似然模型在尺度上的统一.由于图像多特征提供了运动目标多方面的测量信息,从而提高了算法的可靠性.试验表明该算法在使用相同粒子数目的情况下较采用单一颜色特征的粒子滤波跟踪算法效果好.     

多特征融合的非线性目标跟踪算法

为克服视频目标跟踪中仅利用单一特征易导致的跟踪失败,提出了一种基于多特征融合的非线性目标跟踪算法.通过灰度直方图来表征目标的总体分布,利用边缘特征来提取目标的高频细节,将两者融合于粒子滤波的概率模型框架中.并提出一种基于半峰宽和贡献度的特征可信度计算方法,动态调节粒子数目,使可信度高的特征拥有较多的粒子.最后,进行了目标跟踪仿真实验,结果表明,该算法具有较强的抗局部遮挡能力,与单特征跟踪算法相比,平均跟踪误差减小了0.5个像素.     

结合颜色和结构信息的粒子滤波跟踪算法

单纯依靠颜色信息往往使得目标跟踪不稳定.为了在复杂背景和光照变化等干扰情况下,能够准确地跟踪到感兴趣的目标,本文提出了将颜色和结构信息相结合的方法.该方法在基于颜色直方图的粒子滤波跟踪框架中,利用目标的灰度图像建立结构模型,通过结构相似性质量因子衡量目标在两帧图像之间的相似性.实验表明,该算法在使用相同粒子数目的情况下较传统的基于颜色直方图的粒子滤波跟踪算法鲁棒性更高,可以用于特定场合可疑目标的跟踪.     

Insertion of triangulated surfaces into a meccano tetrahedral discretization by means of mesh refinement and optimization procedures

In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method.     

The Research of Anti-Wear Properties of Organomolybdenum Compounds in the Engine Oils

A four-ball tester was used to evaluate the anti-wear performance of three kinds of organomolybdemun compounds in the engine oils, i. e., molybdenum dialkyldithiophosphate (MoDDP), molybdenum dialkyldithiocarbamate ( MoDTC), and sulphur and phosphorus freeorganomolybdeum (Molybdate). The results indicate that a low concentration of MoDDP doesn' t improve the anti-wear properties of the commercial engine oils, but a high concentration of MoDDP can obviously improve the anti-wear properties and the load-carrying capacity of the engine oils. MoDTC doesn' t improve the antiwear properties of the engine oils, but worsens the anti-wear properties of the oils. Signifi can timprove ment of frictional and wear characteristics is obtained with Molybdate added in the commercial engine oils and the formulated oils.     

Certification Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

Flow calorimeter for enthalpy increment measurements on condensed gases

A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa.     

Refrigerators Enter a New Era of Health Preservation Frestech initiates the establishment of China's first standard for household sterilization refrigerators

On November 30, 2007, the China Association for Standardization (CAS) held a press conference at Beijing Diaoyutai State Guest House. Leaders from the China Household Electric Appliance Research Institute, the China Household Electric Appliance Association, and the China Consumers' Association attended and made speeches.……     

A study of centrifugal cast high boron high speed steel

In the present study a high‐boron high speed steel (HSS) roll material was designed. Many expensive alloy elements have been substituted by cheap boron alloy, and high‐boron high speed steel roll has been manufactured by centrifugal casting method. The microstructures, mechanical properties and wear resistance of centrifugal casting high‐boron high speed steel roll have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), and X‐ray diffraction (XRD) analysis, hardness test, impact test and wear test. The results indicated that the solidification microstructures of high‐boron high speed steel roll consisted of M₂(B,C), (W,Mo)₂(B,C), M₃(B,C), M₂₃(B,C)₆ type borocarbides and martensite, a small amount of retained austenite. Borocarbides were continuously distributed over the grain boundary. After quenching from 1050 °C, local broken network appeared in partial borocarbides, and fine secondary borocarbide precipitated from the matrix. After tempering from 525 °C, the amount of precipitated borocarbide increased significantly. After heat treatment, the hardness of high‐boron high speed steel roll excelled 60 HRC, and its impact toughness excelled 8.0 J/cm². The single groove steel rolling amount of high‐boron high speed steel rolls increases by 500% than that of bainite cast iron roll, when the rolls are used in K₁ mill housing of bar mill.     

Optimum-Simulation von Ernteprozessen

Zusammenfassung Bei der Gestaltung von Ernteprozessen — beispielsweise des Prozesses Mähdrusch, Körnertransport und -abnahme — als transportverbundene Fließarbeitsverfahren mit mindestens zwei verschiedenen Arbeitsmitteln gibt es einen großen Optimierungsspielraum. Solche Prozesse sind mehrstufige Bedienungsprozesse mit gemischter Anordnung der Bedienungseinrichtungen. Außerdem besitzen sie stark ausgeprägte räumliche Aspekte. Es wird vor allem gezeigt, welche Merkmale solcher Prozesse in Simulationsmodellen abgebildet sein müssen, welche Zielgrößen in Abhängigkeit von welchen Einflußgrößen unter Berücksichtigung welcher Prozeßbedingungen ermittelt werden sollten und wie der Bewertungsprozeß zur Ermittlung der gewünschten Informationen gestaltet werden muß.     

Certification Becomes Important for the I Quality; and Safety Supervision of the Chinese Liquor Sector

The end of 2007, over 200 unit products of more than 80 Chinese firms have passed the quality grade certification for liquor products. These products involve distilled spirits, beer, wine, yellow wine, fruit syrup wine and others, and cover over 80% of the national top-branded liquor products.……     

Deposition and Coating Properties on CVD Tungsten

Surface characterization and microstructure studies are performed on chemical vapor deposited (CVD) tungsten coating. There is about 2 μm thickness diffusion layer of tungsten in the molybdenum substrate. The thermal shock test shows tungsten coating has good adhesion with molybdenum substrate, but the elements of oxygen and carbon in the tungsten coating have the bad affection to the adhesion. The result of high-temperature diffusion experiment is the diffusion rate from molybdenum substrate to tungsten coating is faster.