Attack on Optical Double Random Phase Encryption Based on the Principle of Ptychographical Imaging

The principle of ptychography is applied in known plain text attack on the double random phase encoding （DRPE） system. We find that with several pairs of plain texts and cipher texts, the model of attack on DRPE can be converted to the model of ptyehographical imaging. Owing to the inherent merits of the ptyehographical imaging, the DRPE system can be breached totally in a fast and nearly perfect way, which is unavailable for currently existing attack methods. Further, since the decryption keys can be seen as an object to be imaged from the perspective of imaging, the ptychographical technique may be a kind of new direction to further analysis of the security of other encryption systems based on double random keys.

GAUSSIAN PRINCIPLE COMPONENTS FOR NONLOCAL MEANS IMAGE DENOISING

NonLocal Means(NLM),taking fully advantage of image redundancy,has been proved to be very effective in noise removal.However,high computational load limits its wide application.Based on Principle Component Analysis(PCA),Principle Neighborhood Dictionary(PND) was proposed to reduce the computational load of NLM.Nevertheless,as the principle components in PND method are computed directly from noisy image neighborhoods,they are prone to be inaccurate due to the presence of noise.In this paper,an improved scheme for image denoising is proposed.This scheme is based on PND and uses preprocessing via Gaussian filter to eliminate the influence of noise.PCA is then used to project those filtered image neighborhood vectors onto a lower-dimensional space.With the preproc-essing process,the principle components computed are more accurate resulting in an improved de-noising performance.A comparison with some NLM based and state-of-art denoising methods shows that the proposed method performs well in terms of Peak Signal to Noise Ratio(PSNR) as well as image visual fidelity.The experimental results demonstrate that our method outperforms existing methods both subjectively and objectively.

Marchenko imaging based on self-adaptive traveltime updating

Marchenko imaging obtains the subsurface reflectors using one-way Green’s functions,which are retrieved by solving the Marchenko equation.This method generates an image that is free of spurious artifacts due to internal multiples.The Marchenko imaging method is a target-oriented technique;thus,it can image a user specified area.In the traditional Marchenko method,an accurate velocity model is critical for estimating direct waves from imaging points to the surface.An error in the velocity model results in the inaccurate estimation of direct waves.In turn,this leads to errors in computation of one-way Green’s functions,which then affects the final Marchenko images.To solve this problem,in this paper,we propose a self-adaptive traveltime updating technique based on the principle of equal traveltime to improve the Marchenko imaging method.The proposed method calculates the time shift of direct waves caused by the error in the velocity model,and corrects the wrong direct wave according to the time shift and reconstructs the correct Green’s functions.The proposed method improves the results of imaging using an inaccurate velocity model.By comparing the results from traditional Marchenko and the new method using synthetic data experiments,we demonstrated that the adaptive traveltime updating Marchenko imaging method could restore the image of geological structures to their true positions.

Pre-image Variational Principle for Subadditive Sequence Functions

In this paper we define the pre-image topological pressure for a sequence of subadditive continuous functions on the compact metric space. And we also give a subadditive pre-image variational principle under a very weak condition.

Preparation of earthquake-triggered landslide inventory maps using remote sensing and GIS technologies:Principles and case studies

Inventory maps of earthquake-triggered landslides can be constructed using several methods,which are often subject to obvious differences due to lack of commonly accepted criteria or principles,To solve this problem,the author describes the principles for preparing inventory maps of earthquake-triggered landslides,focusing on varied methods and their criteria,The principles include the following key points：all landslides should be mapped as long as they can be recognized from images;both the boundary and source area position of landslides should be mapped;spatial distribution pattern of earthquake-triggered landslides should be continuous;complex landslides should be divided into distinct groups;three types of errors such as precision of the location and boundary of landslides,false positive errors,and false negative errors of earthquake-triggered landslide inventories should be controlled and reduced;and inventories of co-seismic landslides should be constructed by the visual interpretation method rather than automatic extraction of satellite images or/and aerial photographs,In addition,selection of remote sensing images and creation of landslides attribute database are also discussed in this paper,Then the author applies these principles to produce inventory maps of four events：the 12 May 2008 Wenchuan,China M_w 7.9,14 April 2010 Yushu,China M_w 6,9,12 January 2010 Haiti M_w7.0,and 2007 Aysen Fjord,Chile M_w 6.2,The results show obvious differences in comparison with previous studies by other researchers,which again attest to the necessity of establishment of unified principles for preparation of inventory maps of earthquake-triggered landslides.

Proposal for a Reasonable Model of the Visual System： Principles of Clinical Neurosociology

This paper maintains that when photons enter the pupil and reach the Inner Limiting Membrane （ILM）, they are reflected onto a point or centroid of the vitreous body, which could be the lens, to be transmitted by the Muiller cells to the Retinal Pigment Epithelium （RPE） hexagonal cells, where an almost complete image is formed in each of them, overlapping with the adjacent images, to be carried subsequently by each of the ganglion cell axons to a place where the single image we are aware of is formed. This process calls for a high degree of control and coordination, which must be effected by the horizontal, amacrine, and interplexiform cells, gap junctions and the feedback provided from the V1 area to the Lateral Geniculate Nucleus （LGN）. But, as the ILM covers the optic disc but not the fovea, the latter must produce the blind spot and the rays reflected radially from the centroid must have the same centre as the Muller cells in order to be able to channel them to the RPE cells.

Design of Quasi-Optical Lens Antenna for W-Band Short Range Passive Millimeter-Wave Imaging

A quasi-optical dielectric lens used for W-band focal plane array passive imaging has been developed. The imaging system requires the lens to form beam spot with 3 dB width less than 35 mm at distance of 3500 mm. The powerful optical design software ZEMAX was utilized to design the contours of the lens, and numerical method based on ray tracing and Huygens’ Principle was processed to verify the design result. Measurement result shows that the 3 dB width of the beam spot formed by the lens is 34 mm at distance of 3460 mm, and the beam pattern on imaging plane are equally arranged and the intensity decreases only 0.55 dB while the object lateral deviation increases to 300 mm.

Design Principles of External Lighting for Architectural Objects

Nowadays, lighting design is the modern attractive field of professional activity. Although its theoretical and methodological bases are in the initial stage of formulation. Though there are standards for regulating illumination quantitatively, the science has never created a bridge to transfer illumination quantity into illumination quality. How to keep a day image of architectural object without imitating natural lighting？ How unrecognizably to change the image, to make it extraordinary and catchy？ This paper offers a solution in the form of external illumination designing principles. This paper proposes two conceptual ways of creating artificial lighting of buildings and constructions that pursue different goals： the principle of ＂tectonic＂ illumination and the principle of ＂decorative＂ illumination. These principles were developed based on the analysis of the state of the art experience of lighting architectural objects and author＇s empirical study. The latter contained measuring luminosity with luminance meter, processing the data, statistical survey （180 respondents） and lighting modeling in the laboratory of Moscow Architectural Institute.

GLOBAL MEASURE ON IMAGE CONTENT

This paper investigated approaches to supporting effective and efficient retrieval of image based on principle component analysis. First, it extracted the image content, texture and color. Gabor wavelet transforms were used to extract texture feature of the image and the average color was used to extract the color features. The principle component of the feature vector of image can be constructed. Content based image retrieval was performed by comparing the feature vector of the query image with the projection feature vector of the image database on the principle component space of the query image. By this technique, it can reduce the dimensionality of feature vector, which in turn reduce the searching time.

Super-resolution amplification of bitmap images based on 3D modeling theory

As a general format of the image,bitmap(BMP)image has wide applications,and consequently it is an important part of image processing.By segmenting the bitmap and combining the three-dimesional(3D)model of the discrete algorithm with the scanning line compensation algorithm,a mathematical model is built.According to the topological relations between several control points on the model surface,the surface of the model is discretized,and a planar triangle sequence is used to describe 3D objects.Finally,the bitmap is enlarged by combining the borrowing compensation based on 3D modeling principle of discrete algorithm with the scanning line compensation algorithm of binary lattice image,thus getting a relatively clear enlarged BMP image.

The Projection of China’s National Image in President Xi Jinping’s Speeches

In the 21st century, soft power has become an important element to evaluate a nation’s comprehensive strength. Meanwhile, as an indispensable part of soft power, national image receives more and more attention on the political stage. Since Chinese President Xi Jinping’s speeches have unique features and greatly reflect positive national images of China, many scholars start to analyze them from diversified perspectives. Based on Du Bois’ theory of “the Stance Triangle” and the Indexicality Principle, taking President Xi Jinping’s speech at the opening ceremony of the Belt and Road Forum for International Cooperation for example, this paper expounds how President Xi achieves the evaluation, position, and alignment between the subject and object by means of overt labeling, implicature and presupposition, covert evaluation statement, and ideology-laden linguistic structure, in order to establish China’s national image. Through the analysis, the author intends to figure out how national leaders use various persuasive methods to achieve their political purpose. And the author hopes this thesis can provide a new perspective for further analysis on national leaders’ speeches.

机器视觉技术在大坝表面变形监测中的适用性研究

针对大坝表面变形自动化监测中GNSS系统垂直位移监测精度低、费用昂贵和静力水准仪布设难度大、维修成本高等问题,利用机器视觉技术对大坝表面变形进行监测。室内试验结果表明,相机与标靶距离在100 m范围内,机器视觉的测量精度可达到亚毫米级,且水平和垂直变形位移精度相近。由误差分析可知,标靶与相机的距离与测量精度有明显的相关性,而环境因素是影响远距离监测精度的重要因素,并利用大坝视准线原理优化了机器视觉监测系统。最后以浙江省大力塘水库为试点,对大坝表面变形进行实时监测,结果表明,机器视觉技术完全可满足实际工程需求,且优化后的机器视觉测量技术可明显提高监测数据的精度和稳定性。

文化基因视域下区域农产品品牌视觉形象设计

随着国家对乡村振兴事业的进一步扶持,区域农产品品牌化已成为必然趋势。针对现阶段区域农产品品牌视觉形象良莠不齐、同质化严重的现状,探索文化基因视域下区域农产品品牌视觉形象的设计原则与设计策略,旨在通过地域文化赋能品牌的方式打造差异化定位,为其创意设计及其延展提供源源不断的设计动力;层次分析法的介入可以通过为创意设计提供量化依据,来克服传统方案在择优过程中的绝对主观性,从而减少品牌的试错成本。

基于上下文提取与注意力融合的遮挡服装图像分割

针对遮挡服装图像分割准确率低的问题,提出一种融合上下文提取与注意力机制的遮挡服装图像实例分割方法。以Mask R-CNN为基础网络,首先采用上下文提取模块优化ResNet的输出特征,通过融合不同速率的多路径特征从多个感受野中捕获图像的上下文信息,强化遮挡服装特征表示的识别及提取能力;然后引入通道注意力机制与空间注意力机制的残差连接,自适应地专注于捕捉遮挡服装图像的空间和通道维度上的语义相互依赖关系,降低上下文提取模块在处理特征图时因冗余的上下文关系扩大造成误定位与误识别的概率;最后,采用目标检测损失函数CIoU计算原理作为非极大值抑制的评判标准,关注预测框和真实框的重叠与非重叠区域,最大程度地选择遮挡服装的最优目标框,使预测框更加贴近真实框。结果表明,与其它方法相比,改进方法显著改善了不同遮挡程度服装图像的误分割现象,能提取出更精确的服装实例,其对遮挡服装图像的平均分割精度比原模型提升了4.4%。

电阻抗断层成像技术(EIT)的数学建模与其他应用场景

电阻抗断层成像(EIT)技术在医学成像和隐身技术等领域有着广泛的应用前景,本文首先对EIT的成像原理及其优缺点进行了论述;然后,对EIT在隐身技术和作为机械通气检测新技术的临床应用方面进行了介绍;最后,介绍了EIT的数学建模,尤其详细介绍了四种电极模型.EIT数学模型带来了偏微分方程的正问题、反问题、硬件系统设计以及图像去噪问题,成为这一技术的核心的“卡脖子”部分.

基于数字图像相关原理的埋头弹程序燃烧特性试验研究

为分析埋头弹的装药程序燃烧特性和上膛挤进运动特性,对埋头弹两级点火发射过程进行试验研究。设计并建立程序燃烧特性试验系统,采用高速摄像系统获得各组弹丸的运动图像序列。基于数字图像相关原理,对各组图像序列进行定性和定量分析,对回收的弹带刻槽形貌分析测量,获得一级点火的弹丸运动特性,两级点火的程序燃烧特性以及弹带刻槽形貌特性。研究结果表明:速燃点火药的质量直接影响一级点火弹丸上膛性能,质量增加时弹丸上膛时间显著缩短,上膛速度大幅提高;可燃导向筒过早的破碎会导致上膛速度大幅增加,使弹带刻槽形貌非常恶劣,不能可靠密封弹后火药燃气和可靠导转弹丸运动,影响内弹道性能和弹丸的膛内运动姿态;需要对速燃点火药与可燃导向筒进行合理的匹配设计,保证可燃导向筒的破碎时机处于可控范围,从而实现理想的两级点火和程序燃烧设计目标。

具有积分边界条件的耦合φ-Hilfer分数阶微分系统解的存在性

为了拓展分数阶微分方程系统的相关理论,研究了一类具有积分边界条件的耦合φ-Hilfer分数阶微分系统。首先,将具有积分边界条件的耦合φ-Hilfer分数阶微分系统转化为积分系统;其次,定义合适的Banach乘积空间和范数,构造合适的积分算子,分别运用压缩映像原理和Kransnoselskii不动点定理得出耦合φ-Hilfer分数阶微分系统在积分边界条件下解的存在性结果;最后,通过列举实例说明所得结论的正确性。研究表明,积分边界条件下的耦合φ-Hilfer分数阶微分系统的解具有存在性。研究结论丰富了耦合分数阶微分系统理论可解性的相关理论,可为深入研究分数阶微分方程提供一定的理论参考。

文本图像生成技术在视觉传达设计中的应用

文本图像生成技术可以通过输入自然语言文本进行图像生成操作,输出图像精度高、样本量丰富且生成内容与文本一致性强,在视觉传达设计中有巨大应用潜力。该文在分析视觉传达设计图像生成需求基础上,解析文本生成图像的技术原理,探索文本生成图像技术在视觉传达设计中的应用路径,研究成果可以辅助设计师提高工作效率,激发创意灵感,为视觉传达设计视觉创作提供实践技术参考。

基于红外热像的建筑结构裂缝监测技术及其应用

在城市建设飞速发展的今天,建筑结构的安全性问题备受社会关注。其中,裂缝问题作为潜在的安全隐患,传统的人工巡检方法存在效率低、容易遗漏微小裂缝等弊端,若不及时处理,可能危及结构安全。红外热像技术通过无损、实时监测手段,弥补传统巡检的不足,能够及时准确地探测裂缝,有效提高建筑结构的整体安全性。该文详细阐述采用红外热像技术的方法及监测过程,通过实际应用案例展示该技术在不同场景下的有效性和实用性。

基于光学干涉原理的温度传感研究(特邀)

提出一种基于光学干涉原理的温度传感器。通过在参考光路中引入单模光纤产生高斯光束;在测量光路中引入光纤光栅结构,使入射光通过光纤光栅、准直器产生平行的高斯光束,经螺旋相位板产生带有轨道角动量的拉盖尔-高斯光束,两束光将在合束器上发生干涉,产生螺旋式干涉图像。在测量光路中引入光纤光栅结构,主要是利用光纤光栅的光延迟特性。当环境温度变化时,光在光纤光栅中的传播产生相位延迟,导致测量光路和参考光路之间相位差发生变化,使螺旋干涉图像发生旋转。通过高分辨率相机实时检测干涉图像的变化,并对干涉图像进行图像处理,准确提取干涉图像的变化信息。通过上述方法,使传感器的温度灵敏度达到4.08°/℃,这将在温度传感领域具有重要的应用价值。