图像复制中GCR与UCR适用性的研究

设计了用于图像复制的色标图原稿,对该原稿分别进行GCR与UCR分色后进行输出。分析了不同分色方式下图像密度、色彩饱和度及中性灰的复制特点,比较了不同类型黑版对于阶调层次、色彩及灰平衡的适用性。结果表明:GCR更适合处理暗调图像,有助于改善图像灰平衡,但会损失色彩密度及饱和度;UCR有利于色彩密度和色度的良好再现,但会损失图像的反差和灰平衡效应。     

基于改进K均值聚类的图像修复方法

目的 解决特定工艺条件下灰平衡数据的再现问题。方法 通过在一定工艺条件下,获得青、品、黄、黑等4色阶调复制曲线,并拟合曲线方程,根据方程求取同一密度(理论密度)条件下青、品和黄色的网点面积率,据所得青、品、黄网点面积率设计样本色,检测其色度和密度值(实际密度)。结果 经验证,样本色色度值趋近于0,即证明样本色块趋于中性灰。建立了理论密度值与实际密度值之间的数学模型,再通过该模型和阶调复制曲线方程,获得了该工艺条件下灰平衡数据参数。结论 该方法可以准确获得特定条件下的灰平衡数据参数,为特定工艺条件下灰平衡数据的数字化建模提供了理论依据。     

关于灰平衡数据的计算

灰平衡数据是彩色图像复制中色彩变化的依据,文中应用灰平衡方程作为理论基础,通过测量四色各级网点密度,求取灰平衡数据,并利用n值进行修正网点面积,再利用打样来检验所得数据的可行性,以保证图像色彩得到正确还原.     

网点形状对图像复制质量影响的实验研究

网点形状是影响印刷图像复制质量的因素之一,在一定的实验条件下,将标准彩色图像数据N1~N8作为测试图像,进行了圆形、椭圆形、方形、方圆形网点的输出。对图像的阶调层次、清晰度、色彩、灰平衡等进行了主观评价,统计并分析了评价结果。实验表明:圆形网点在高调层次、清晰度、色彩方面的复制效果最好;椭圆形及方圆形网点在中暗调层次复制方面表现最好。     

多色分色模型中中性灰的调控

利用颜色分区理论将多色色空间进行分区,在各分区内设计色块确定 K 与 CMY 的等效关系,结合灰成分替代率,确定了多色分色模型中中性灰调控的方法。 实验证明,分色时不考虑灰平衡会影响最终颜色复制的效果,分色模型中灰平衡方法的确定是非常必要的。     

基于视觉灰平衡的灰成分替代

提出了视觉灰平衡的概念和模型,并应用于分色过程中的灰成分替代。首先,以视觉中性灰色的色度值为标准,使用查找表的方法获取了视觉灰平衡数据,然后基于中性灰密度,建立了K 与CMY 替代方程,最后设置4 种不同的替代率,对CMY 色块进行灰成分替代。实验结果表明,当替代率设置为0. 4 时,计算出与未取代的灰色之间的色差最小,并且扩大了中亮调的色域范围。     

基于加权遗传算法的旋转机械不平衡振动溯源定位方法研究

针对高端旋转机械多平面多转速下的不平衡振动定位问题,提出一种基于加权遗传算法的转子不平衡溯源定位方法,并开发了一套不平衡溯源计算软件。该方法在遗传算法的基础上进行改进,增加了针对各测点各转速下振动的赋权过程,并分别在某双跨转子有限元模型以及某模拟发电机实验台上,通过将该方法与最小二乘法和遗传算法进行对比,进一步验证该改进方法的不平衡量溯源效果。仿真结果表明,该技术针对高权重测点处的溯源精度高于其余两种算法。在模拟发电机转子实验台上,应用该技术开展多平面多转速不平衡溯源定位实验。实验结果表明,基于加权遗传算法的溯源结果进行平衡后,高权重测点振幅降幅超过80%,降幅较其余两种算法有明显提升。综合仿真与实验结果,该方法较最小二乘法与遗传算法更有针对性及目的性。     

色彩管理中灰平衡数据控制

目的针对Photoshop色彩管理中数码样张与印刷样张存在较大的色差问题,提出了修正ICC Profile文件的方法。方法以灰色为研究对象,利用数码打样机分别输出了GMG和Photoshop色彩管理流程下的数码样张,分析比较了2种流程下数码样张的色差特性,并利用ProfileEditor软件对印刷ICC Profile文件进行灰平衡数据的调整与修正。结果在Photoshop色彩管理流程中使用调整后的ICC Profile文件,使仿铜版纸的数码样张中性灰的平均色差由原来的8.0863降低到4.2284,仿特种纸的数码样张中性灰的平均色差由原来的10.1063降低到5.5908。结论优化ICC Profile文件中的灰平衡参数,能够使数码样张与印刷样张获得更小的色差,提高了颜色再现的准确性。     

白墨底基结合热干性油墨的中性灰平衡研究

对包装行业印铁制罐中白墨底基结合热干性油墨的中性灰平衡进行了研究.以金属四色油墨印刷于马口铁为例,讨论了白墨底基结合热干性油墨获得中性灰平衡的全过程,设计制作测试样张,应用视觉比较和密度测量的方法获得灰平衡数据,最终找出符合人眼视觉的中性灰平衡.     

基于多项式回归的七色分色方法

利用多项式回归法进行分色建模,结合灰平衡及兼色设置,获得了最终的分色结果,然后设计实验,从分色误差、分色精度方面进行了评价。 结果表明,该分色方法取得的分色效果较好,可以更加准确地进行颜色复制。     

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.     

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.     

From Industry 4.0 to Research 4.0. Development of High Performance Fibers in the Light of Digitization

We associate a variety of innovations with the term ＂Industry 4.0＂. The pioneer of many 4.0 modifications forms the basisfor the trend towards the integrated di...     

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.……     

Roman iron and steel: A review

ABSTRACT

The production of ferrous metal increased during the Roman Late Republican period, Principate and Empire. The direct bloomery process was used to extract the metal from its ores using slag-tapping and slag-pit furnaces. The fuel was charcoal and an air blast was introduced by bellows-operated tuyères. Iron formed as a bloom, often as a spongy mass of metal, which contained impurities from the smelting process, including unreacted ore, fuel, slag and fragments from the furnace walls, while the metal was often inhomogeneous with varied carbon contents. Blooms were either smithed directly into bars or ingots or they were broken up, which also allowed the removal of gross impurities and a selection of pieces with similar properties to be made. These could then be forge-welded together and formed into characteristically shaped ingots. Making steel in the furnace seems to have been achieved: it depended on the ore and the furnace and conditions within it. Surface carburization was also carried out. Iron and steel were used extensively in construction and for tools and weapons. Fire welding was often used to add pieces of steel to make the edges of tools and weapons, which could be heat-treated by quenching to harden them.     

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.     

Thixotropy of Systems with Shear Thinning and Plastic Flow Behavior

The definition of the thixotropy is a decrease in viscosity with time in shear and a subsequent recovery of viscosity after the shear deformation is removed.We ...