An irgacure 784 doped photopolymers for display holograms recording at 532 nm

This paper presents an investigation on the preparation and characterization of thick photopolymers for display holograms recording at 532 nm. Based on our previous research on fabrication and characterization of the doped photopolymer for volume holographic data storage, we develop a new large size Irgacure 784 doped epoxy resin photopolymer plate for display holograms recording in this research. The material system consists of two sub-systems. The first one is the epoxy resin polymer matrix, which provides a strong material structure so that the optical induced shrinkage during hologram recording can be minimized. The second part consists of photosensitive elements, which are uniformly dispersed in the epoxy resin to provide a mechanism for holograms recording. Material fabrication technique and the characteristics including absorption spectra, dynamic range and recording sensitivity are reported in this paper. Successful recording and reconstruction of a Fresnel hologram of the transmission type in a photopolymer plate of size 20 cm × 30 cm demonstrates the feasibility of display holograms recording in this material.     

一种基于图像的全息图计算方法及其模拟重现

传统的计算机产生全息图方法由于在标量衍射的光场描述中没有统一的数值计算方法从而计算复杂度高,而且重构的3D图像的体积和视场都比较小,离市场化的要求较远.提出一种基于图像(而又不同于体视全息)频谱的计算全息图方法,实现了一种基于图像生成全息图的计算及其计算机显示,模拟实验结果验证了算法的正确性.     

Process Crystallographic Simulation for Biocompatible Piezoelectric Material Design and Generation

From 1880’s discovery of piezoelectricity by French physicists Jacques and Pierre Curie, a huge number of piezoelectric materials have been developed and applied to the industrial equipment and scientific instrument. In the middle of 20th century, most widely used ceramic piezoelectric materials, BaTiO₃ (BTO) in 1944, PbTiO₃ in 1950, and Pb(Zr,Ti)O₃ (PZT) in 1955, were discovered through “hermetic art approach.” It was not CAE driven material discovery. Actually, the experimental trial and error approach is inefficient way for the material discovery. Therefore a new CAE technique to develop a new high performance piezoelectric material under a short lead time is strongly required. It can analyze material characteristics, and design material structure and generation process simultaneously before actual production. This overall CAE technique for new material design and generation, which can be called as “process crystallographic simulation,” is discussed in this state-of-the-art paper, which will be able to establish a new concept of material and process design. Now, we have serious problem with the piezoelectric material. Actually, PZT is most used in the world. However, “lead,” which is a component of PZT-based piezoelectric material, is the toxic material. The usage of lead and toxic materials is prohibited by the waste electrical and electronic equipment (WEEE) and the restriction on hazardous substances (RoHS). Therefore, CAE driven new biocompatible material development is recognized as urgent subject. A goal is to develop an environmentally and biologically compatible piezoelectric material, which can be applied for human healthcare devices, such as Bio-MEMS devices. Until now, we have CAE methodologies to develop a new material, such as the atomic simulation, the continuum mechanics base finite element method, and the crystal process optimization method, but these are not cooperated effectively. An overall and simultaneous computational technique is strongly required. In this review paper, we survey and discuss numerical methodologies, “process crystallographic simulation,” for material and generation process design. Further, an invention of a new biocompatible piezoelectric material, its generation and validation of a newly developed numerical technique, are demonstrated. In this paper, below described subjects are reviewed and discussed.

1. Numerical analysis technique, “process crystallographic simulation,” which consists of a three-scale structure analysis and a generation process analysis.
2. Material and Process design of new biocompatible piezoelectric materials.
3. Generation of MgSiO₃ thin film by using radio-frequency (RF) magnetron sputtering system. Validation of CAE technique.

Consequently, a general concept of CAE driven material discovery technique could be understood through this state-of-the-art paper.     

An Automatic Test-Generation System for Large Digital Circuits

A new test-generation system (FUTURE) for large digital circuits (more than 10K gates) is based on a nine-valued FAN algorithm. Fault simulation adopts a concurrent simulation adopts a concurrent simulation technique. The system consists of four major modules: fault modeling, random pattern generation, algorithmic pattern generation, and fault simulation. The system can be a powerful CAD tool and effectively generate test patterns for large sequential circuits with Scan Path.     

基于结构重参数化的太阳斑点图像弱监督去模糊方法

针对云南天文台拍摄的模糊太阳斑点图像使用有监督学习模型进行重建时容易产生伪像、训练时间长、重建结果过分依赖参考图像等问题,提出一种基于结构重参数化与多分支模块相结合的弱监督去模糊方法重建太阳斑点图。首先,结合单尺度与多尺度网络设计去模糊模型,在模型中构造多分支模块提取不同尺度的特征,增强细节信息,减少伪像生成;其次,对每个分支结构进行重参数化,使得结构参数的重用贯穿整个特征提取过程,节省计算时间;之后,将去模糊模型分别嵌入退化学习与逆退化学习的弱监督训练中,先对模糊图像进行等级划分,利用退化模型分别学习不同等级的退化,构成对应等级的配对数据集,再使用去模糊模型对数据集进行逆退化,实现太阳斑点图的重建。实验结果表明,该方法与现有深度学习去模糊方法相比,模型训练效率更高,对参考图像的依赖较小,能够满足太阳斑点图像高分辨率重建要求。     

Comparative analysis of optical arrangements intended for recording of holograms with optically encoded and concealed images

In the paper we analyze some optical arrangements intended for recording of holograms with optical encoding of the image. In the first section on the basis of the Opto-electronic systems theory we are considering the processes of hologram recording and reconstruction with optically encoded images for Fourier and Fresnel hologram recording schemes with encoding mask in reference and subject branches. In the second section the detailed analysis of these schemes with encoding mask consisting of a set of secondary point sources placed in reference branch is made. The results of influence of optical elements installing inaccuracy in the arrangement of image retrieval on a quality of this image are obtained. The hologram recording arrangement for the further studies on the base of the analysis is chosen. In the third section we estimate a signal to noise ratio in the image plane for the arrangements selected. Analysis of multiplexing holograms using possibility with image optical encoding is made. The article is published in the original.     

计算全息图的球面重现

该文研究重现于球面的计算全息图(CGH)的生成和重现。当用平面波照射傅里叶全息图时,所重现的图像一般显示在平面上。该文利用坐标变换方法实现显示于球面的二维图像的计算全息图的生成,并由所生成全息图得到原始图像,从而实现整个全息记录和重现过程的计算机模拟。二维图像重现于球面实际上产生了三维显示,因此该文所提到的方法在从计算全息图重现三维图像方面起到了重要的作用。     

基于POVRAY的三维全景图像的计算机生成方法

三维全景图像技术（Integral Imaging,简称II）是一种采用微透镜阵列进行记录和显示的三维图像技术。该技术目前正成为最有希望实现下一代三维电视的方法,吸引着国际上三维技术领域的重多关注。本文提出了一种新的基于三维图形软件POVRAY的快速生成II图像的相机模型构造方法,详细阐述了该相机模型的实现算法,并采用该相机对虚拟的三维场景进行记录。实验结果表明,使用该相机模型能在保证图像质量的情况下,最大程度满足实时性要求。     

Data-driven modeling and simulation framework for material handling systems in coal mines

In coal mining industry, discrete-event simulation has been widely used to support decisions in material handling system (MHS) to achieve premiums on revenues. However, the conventional simulation modeling approach requires extensive expertise of simulation during the modeling phase and lacks flexibility when the MHS structure changes. In this paper, a data-driven modeling and simulation framework is developed for MHS of coal mines to automatically generate a discrete-event simulation model based on current MHS structural and operational data. To this end, a formal information model based on Unified Modeling Language (UML) is first developed to provide MHS structural information for simulation model generation, production information for simulation execution, and output requirement information for defining simulation outputs. Then, Petri net-based model generation procedures are designed and used to automatically generate a simulation model in Arena® based on the simulation inputs conforming to the constructed information model. The proposed framework is demonstrated for one of the largest open-pit coal mines in the USA, and it has been demonstrated that the framework can be used to effectively generate the simulation models that precisely represent MHS of coal mines, and then be used to support various decisions in coal mining such as equipment scheduling.     

Angle compensation of the reference beam in a retrieving process of the holographic data storage system

Holographic data storage system is one of a strong candidate of the next generation high capacity data storage system with a high storage density and a fast data transfer rate. The holographic data storage system uses two beams in a recording process and only a reference beam is used for retrieving stored data. With the angle multiplexing when the angle of the reference beam is deviated from its correct point, the diffraction efficiency of the corresponding data page is reduced and SNR is decreased. Therefore it is necessary to compensate the angle of the reference beam to reconstruct a good data page. To compensate the angle error, the angle of the reference beam is changed precisely within a specific range and stopped at the angle with the highest diffraction efficiency. By this method, in a retrieving process if there is a difference between the real angle of the reference beam and its correct angle, the error can be compensated and the best data page can be obtained.     

Walking Pattern Generation for a Biped Walking Robot Using Convolution Sum

This paper describes a novel walking pattern generation method for a biped humanoid robot using a convolution sum. For a biped walking model, a single mass inverted pendulum model is generally used and the zero moment point (ZMP) equation is described by a decoupled linear differential equation. As a walking pattern generation method for the robot model, a novel method using a convolution sum is proposed in this paper. From the viewpoint of the linear system response, walking pattern generation can be regarded as a convolution of an arbitrary reference ZMP and the walking pattern for an impulse reference ZMP. For the calculation of convolution, the walking pattern for an impulse reference ZMP is first derived from the analytic walking pattern for a step reference ZMP. The convolution sum is then derived in two recursive forms, which can be applied online and offline, respectively. The proposed algorithm requires low computation power, since the walking pattern equation is composed of a recursive form. As the algorithm is expressed in analytic form, it is not necessary to solve optimization problems or calculate the fast Fourier transform, contrary to previous approaches. A computer simulation of walking demonstrates that the proposed algorithm yields excellent accuracy compared to the preview control method — one of the most highly regarded walking pattern generation methods. In addition, the application on the multi-point mass model is shown with the computer simulation.     

菲涅耳全息图的CCD记录及重现

为了更好地进行菲涅耳全息图的CCD记录及重现,设计了一种CCD同轴全息图的重构算法,该方法首先用CCD代替传统干版直接记录菲涅耳同轴全息图,并以位图形式存储到计算机中;然后利用数值计算代替光学衍射过程来再现物体的像;最后通过实验验证了该算法及数字全息图的不可撕毁性。     

Numerical investigation of zoomable holographic projection without a zoom lens

Holographic projection is for laser displays and has the merits of being aberration free, producing high‐contrast images, having the ability of color reconstruction with one spatial light modulator, and so on. In this paper, we propose a zoomable holographic projection without using a zoom lens and verify the proposed method by using numerical simulation. Although such a system can be readily realized to use the features of holography, which is capable of recording a large image exceeding the hologram size, the required calculation is very time consuming. For acceleration, we used shifted Fresnel diffraction for setting different sampling rates on a hologram and projected image. The proposed method can project any zoom‐in and zoom‐out image between zeroth‐order and first‐order lights, and the processing time and required memory for the zoom are constant.     

Synthesis of Holograms fROM Computer-Generated Output

It has long been accepted that construction of holograms by computer simulation of Maxwell's equations of wave propagation is extremely difficult and expensive. A noteworthy and considerably less expensive departure from computer hologram generation in the strict sense is the binary Fourier hologram1 1< technique, but it still leaves much to be desired. These and other problems have, for most practical purposes, forced computer holography into the category of a novelty and an educational exercise.2     

一种基于激光散斑去相关技术的三维重建方法

为了解决测量范围有限和摄像机标定复杂的问题,本文在传统的数字散斑相关计量方法基础上,提出一种基于数字散斑去相关测量的三维重建方法。首先通过激光照射散射体的不同面元发生干涉,在物体表面叠加形成散斑图像;其次利用不同空间距离处参考散斑图像的去相关特性来估计物体的位置;最后通过三角测量原理求出物体散斑图像和参考图像局部偏移量来确定物体的三维图。仿真实验结果表明,该系统能够在误差允许范围内得到基本完整的物体深度图像,并且与物体自身特性无关,具有良好的鲁棒性。     

An architecture of a high-speed digital hologram generator based on FPGA

In this paper, a hardware architecture to generate a computer-generated hologram (CGH) in a real-time is proposed and implemented in FPGAs. The algorithm that generates digital hologram is reinterpreted and rearranged for higher operation speed. In order to optimize the hardware architecture and performance, the precision is analyzed using fixed-point simulation. The bit-width inside the hardware is obtained by numerical and visual precision analysis. The structure of the basic calculational unit (CGH Cell), an arrangement of these cells (CGH Kernel) to calculate a row of a hologram, and a processor (CGH Processor) with the kernels to perform the modified CGH algorithm are proposed.The proposed processor was implemented with Xilinx XC2VP70 FPGAs. A 1408 × 1050 sized hologram for a 3D object consisting of 10,000 light sources can be generated in 0.0093 [s] at the operating frequency of 285 MHz. Our architecture showed 37.32% and 87.32% higher speed than the best previous work when 1408 cells and 5632 cells are used, respectively.     

分数傅里叶变换合成计算全息与数字重现

传统的计算全息图大多采用菲涅耳衍射积分得到,但菲涅耳衍射积分在描述整个衍射光场中,没有一个统一的采样方法对积分进行数值计算,从而给计算带来不便。为了更好地研究计算全息图问题,文章引入了分数傅里叶变换,通过利用分数傅里叶变换的一种快速数值模拟算法,提出了一种基于分数傅里叶变换的合成空间三维物体全息图的新方法,并用计算机模拟了合成的全息图及其数字重构的结果。实验结果表明:由于分数阶的引入,得到一种处理光场衍射问题的统一算法,因此用分数傅里叶变换来处理光场衍射问题是十分理想的。     

一个新的MOS模拟单元电路版图的STACK生成方法

提出了一种新的MOS模拟单元电路的STACK版图自动生成方法。该方法将电路网表映射为扩散图,基于扩散图进行电路划分、模板匹配和对称查找。提出的对称查找算法适用于非全对称电路的最大匹配对称结构查找。文中改进了Atallah欧拉路径生成算法,通过增加哑元条保证欧拉路 径的生成。对生成的STACK,采用分布式寄生电容模型计算各个节点的寄生电容,并计算STACK的面积和形状,以确保其能够满足设计要求。     

Rough sets in hybrid methods for pattern recognition

The article shows how rough sets can be applied to improve the classification ability of a hybrid pattern recognition system. The system presented here consists of a feature extractor based on a computer‐generated hologram (CGH) playing the role of a ring‐wedge detector. Features extracted by it are shift, rotation, and scale invariant. Although they can be optimized, no method has been proposed in the literature. This article presents an original method of optimizing the feature extraction abilities of a CGH. The method uses rough set theory (RST) to measure the amount of essential information contained in the feature vector. This measure is used to define an objective function in the optimization process. Since RST‐based factors are not differentiable, we use a nongradient approach for a search in the space of possible solutions. Finally, RST is used to determine decision rules for the classification of feature vectors. The alternative method of classification based on neural networks is also discussed. The whole method is illustrated by a system recognizing the class of speckle pattern images indicating the class of distortion of optical fibers. © 2001 John Wiley & Sons, Inc.     

Comprehensive static characterization of vertical electrostaticallyactuated polysilicon beams

This article unifies two parameter-extraction methods to generate a consistent simulation model calibrated to multi-user microelectromechanical systems processes (MUMPS). The simulation model is calibrated to optical (buckling amplitude) and electrical (pull-in voltage) measurements concurrently, not independently, thus increasing confidence in the extracted parameters. A simulation-based model consisting of geometrical and material property information precludes the need for ad hoc parametric adjustments and simplifying assumptions. The calibration steps consist of identifying relevant simulation model parameters, designing suitable test structures, measuring geometry, then extracting parameters using detailed, yet fast electromechanical simulations, and finally extrapolating the behavior of an actual complex device. This article targets electrostatically actuated beams fabricated in the Poly1 layer, although the model parameters can be used to simulate other devices