基于SIFT和加权信息熵的红外小目标检测

针对红外图像中弱小目标的检测需求,文中提出基于尺度不变特征变换Scale Invariant Feature Transform(SIFT)和加权信息熵的红外小目标检测算法.该方法根据红外小目标的成像特点,采用SIFT特征描述子进行关键点的提取,利用帧间的匹配初步获得了目标的可能位置;进一步使用红外图像加权信息熵得到图像在灰度信息和平均信息量意义下的特征;再针对复杂云背景成像弱小目标实时检测的需要对计算出的特征进行再一次判定进而检测出目标.实验结果表明该方法在天空云背景中处理效果较好,具有良好鲁棒性.     

基于FSVM时域背景预测的红外弱小目标检测

本文提出了一种基于模糊支持向量机(FSVM)时域背景预测的红外弱小目标检测方法.首先针对前几帧图像中对应同一位置像素点的灰度值序列,利用模糊支持向量机进行函数拟合,并据此预测下一帧图像在该位置处像素点的灰度值:然后将原始图像与预测图像相减得到预测残差图像,利用基于二维Tsallis-Havrda-Charvat熵的阈值选取快速算法进行分割,并根据小目标运动的连续性和轨迹的一致性进一步分离噪声和小目标.文中给出了实验结果及分析,并与现有的检测红外小目标的空域和时域背景预测算法进行了比较.结果表明,本文提出的算法具有更高的检测概率,明显优于已有的基于背景预测的红外小目标检测算法.     

一种新的空时域滤波小目标检测方法

为了提高红外图像序列中弱小目标的信噪比和检测概率,同时考虑检测算法实时性,提出了一种新的基于空时域滤波的小目标检测方法.首先,以第一帧图像为参考帧,对各帧图像进行运动补偿;然后,对运动补偿后的各帧图像在空域进行方差加权信息熵滤波,对空域滤波后图像采取双向隔帧差分的时域滤波;最后通过检测差分图像中的"凸包",抑制背景和噪声,检测小目标.文中给出了实验结果与分析,并与其他方法作了比较.实验结果表明,上述方法能大幅度的提高目标的信噪比,检测小目标,且实时性好.     

空中红外小目标并行分割算法

为提高空中红外小目标检测速度,提出了一种基于灰值形态学序列图像膨胀累加、背景估计和自适应阈值分割的并行结构小目标分割算法。该算法对灰值膨胀运算后的相邻三帧图像进行累加以增强小目标能量;将灰值形态学开、闭运算的平均值作为背景估计图像;采用自适应阈值算法从二者相减的差图像中分割出可能目标;其中小目标能量增强和背景估计采用并行处理结构。基于VisualC 6.0编程进行了实验,结果表明,算法对连续三帧768像素×576像素红外视频采集图像的处理时间为3.73s,较常规串行分割算法快一倍以上。     

基于模糊融合的红外弱小目标快速检测算法

提出了一种基于模糊融合的红外弱小目标快速检测新算法。算法以差分图像为基础，根据差分图像的噪声特性引入衡量像素点灰度变化程度的隶属度函数，将经过隶属度函数“模糊化”的数帧差分图像进行模糊“与”操作实现融合，按照规则对融合后的图像进行两次模糊推理，实现了弱小目标的检测。仿真实验结果表明，该算法保留了差分法良好的实时性，克服了确定检测阈值难和“硬”判决带来检测概率低的缺点，能快速有效地检测出低信噪比红外图像序列中的像素个数不小于4的弱小运动目标。     

用高阶累积量投影法检测红外弱小目标

为检测弱小红外运动目标,提出了一种基于高阶累积量投影的检测算法.红外图像序列经背景抑制后,首先计算时域数据的归一化三阶累积量,并将其投影到二维空间,然后在二维空间内对目标轨迹进行统计判决,以实现目标检测.推导出了目标和噪声在二维投影空间中的分布公式.通过与相关算法对比分析,该算法计算量小,检测率随目标信噪比增长较快.利用实际录制的图像序列进行了仿真实验,成功检测到了信噪比不小于2、像面运动速度为2帧/像素的目标,验证了算法的有效性.     

复杂背景下迎头点目标检测算法

针对传统检测跟踪算法无法有效处理迎头点目标的问题,提出了基于红外序列图像相邻两帧间匹配的检测算法.根据迎头点目标的红外序列图像特点,采取点对点标记匹配结果,点对点统计标记次数,阈值门限输出迎头点目标.算法无需假定目标点位置,检测过程不随背景复杂程度和目标点数目变化而变化,尤其解决了高噪声情况下迎头点目标的检测和跟踪问题.算法结构简单、存储量小、运算速度快,根据多次仿真和实拍照片实验,验证了该方法的可行性和有效性.     

一种特征点跟踪的运动目标检测

提出一种基于特征点跟踪的运动目标分割算法。在角点跟踪过程中,8等分匹配点邻域,构造方向子邻域提高匹配精度;提出一种新的聚类准则抽取最优特征子集估计运动参数;结合统计方法消除残差噪声;采用时域滤波滤除孤立区域检测出运动目标。对200帧可见光视频序列和100帧红外图像序列中运动汽车进行检测分割实验,检出率分别达到96%和94%。     

红外弱小目标检测背景抑制算法研究

复杂背景下红外小目标识别一直是红外图像处理的关键技术之一,针对复杂云背景下红外弱小目标的时域和空域特征,考虑到易于硬件实现和实时性要求,提出基于快速统计排序滤波和Robinson Guard滤波并行快速处理算法,对复杂背景进行高信噪比抑制。实验证明,该方法能够有效地提高红外弱小目标图像信噪比和复杂背景下的小目标的检测概率。     

基于改进半因果支持域的镁熔液第一气泡检测

为精准识别镁熔液含氢量检测中镁熔液复杂表面背景下的第一气泡,在基于图像处理的镁熔液第一气泡检测算法的基础上提出了一种基于改进半因果支持域的实时检测算法.该算法首先采用改进半因果支持域模型对4帧原始图像进行估计得到背景预测图像,其次使用原始图像减去背景预测图像得到残差图像;而后利用隔帧差分算法并结合双层流水线算法获取阈值分割后的二值图像;最后对二值图像进行逻辑与运算和形态学开运算,获取真实的第一气泡目标,并在相同实验条件下将该算法对单帧图像的预处理效果、序列图像的检测性能与基于改进背景预测和流水线算法进行比较.仿真结果表明:该算法可达到实时检测的要求,且在单帧图像预处理方面对复杂背景的抑制效果更好,预处理时间减少6.2%,同时在序列图像检测方面,算法的抗干扰能力更强,检测到的目标点更易观察,检测总时间减少17.3%.     

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.……     

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.     

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.     

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.