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.

Automatic Visual Leakage Detection and Localization from Pipelines in Chemical Process Plants Using Machine Vision Techniques

Liquid leakage from pipelines is a critical issue in large-scale process plants.Damage in pipelines affects the normal operation of the plant and increases maintenance costs.Furthermore,it causes unsafe and hazardous situations for operators.Therefore,the detection and localization of leakages is a crucial task for maintenance and condition monitoring.Recently,the use of infrared(IR)cameras was found to be a promising approach for leakage detection in large-scale plants.IR cameras can capture leaking liquid if it has a higher(or lower)temperature than its surroundings.In this paper,a method based on IR video data and machine vision techniques is proposed to detect and localize liquid leakages in a chemical process plant.Since the proposed method is a vision-based method and does not consider the physical properties of the leaking liquid,it is applicable for any type of liquid leakage(i.e.,water,oil,etc.).In this method,subsequent frames are subtracted and divided into blocks.Then,principle component analysis is performed in each block to extract features from the blocks.All subtracted frames within the blocks are individually transferred to feature vectors,which are used as a basis for classifying the blocks.The k-nearest neighbor algorithm is used to classify the blocks as normal(without leakage)or anomalous(with leakage).Finally,the positions of the leakages are determined in each anomalous block.In order to evaluate the approach,two datasets with two different formats,consisting of video footage of a laboratory demonstrator plant captured by an IR camera,are considered.The results show that the proposed method is a promising approach to detect and localize leakages from pipelines using IR videos.The proposed method has high accuracy and a reasonable detection time for leakage detection.The possibility of extending the proposed method to a real industrial plant and the limitations of this method are discussed at the end.

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.

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.

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.

基于小波模极大值和Neyman-Pearson准则阈值的图像去噪

首先给出了2维噪声的小波变换特性,分析图像小波变换模的极大值与小波分解级数j和李氏指数之间的关系,指出如何确定和保护图像的边缘;接着阐述了基于软、硬阈值的图像正交小波变换去噪法,然后提出一种基于Neym an-Pearson准则的小波阈值的确定,从而又提出了一种基于小波模极大值和Neym an-Pearson准则阈值的图像去噪方法,解决了图像去噪和保护图像边缘这个“两难”问题。针对期望图像叠加了不规则噪声的假设,对几种去噪方法做了定性比较,并给出了去噪性能的定量分析,仿真结果表明,此方法能提高去噪后图像的信噪比,使评价原图像与去噪后的图像近似程度的方差和相对熵为最小,同时能很好地保留原始图像的边缘信息。

矩不变调整的二维Shannon熵图像分割及其快速实现

为了克服二维Shannon熵阈值法的缺陷,提出了一种使用矩不变法来调整二维直方图斜分Shannon熵的阈值分割方法。首先将二维直方图斜分原理运用到两种Shannon熵阈值法中,然后利用矩不变法从两种熵阈值法获取的阈值中选择最佳阈值,并提出二维直方图斜分Shannon熵阈值法的一般递推算法,最后将二维直方图分布特性与这种算法有机结合得到新型快速的递推算法。实验结果表明,提出的方法不仅分割效果优于当前的二维直方图斜分的最大熵阈值法,而且运行速度更快,约快4倍。

基于Radon逆变换的CT系统参数标定及成像分析

针对计算机断层成像(CT)系统安装时存在误差,导致机械系统无法实现精确扫描而影响成像质量的问题,提出基于Radon逆变换的CT系统参数标定及成像分析.使用CT图像重建、微分方程及改良的遗传算法等理论,建立正弦投影图、定点吸收率、精度及稳定性分析等模型.模拟结果表明,所建模型可有效测得未知介质的几何形状及定点吸收率,提高CT系统扫描轨迹的精度.基于质心法改进模板,可提高CT系统标定精度和稳定性,具有较好的可行性和实用性.

基于动态参数的Tikhonov方法在电容成像图像重建中的应用

该文针对电容成像(ECT)图像重建问题的病态性,采用Tikhonov正则化方法进行图像重建,并选用三种方法动态选择正则化参数。仿真结果表明对某些流型分布,用文中所述方法得到的重建结果优于目前普遍使用的线性反投影(LBP)算法。该方法为提高ECT图像重建质量提供了新的途径。

基于RADON逆变换对CT系统参数标定及成像分析

针对CT系统参数标定及成像,运用了Radon逆变换、微分方程及改良的遗传算法等理论,构建了正弦图求解距离及角度、基于遗传算法的旋转中心位置及基于衰减原理的定点吸收率、精读及稳定性分析等模型,综合运用了MATLAB、EXCEL及C++等软件编程求解,得出了CT系统旋转中心位置、探测器单元之间的距离及入射角度、未知介质几何形状和吸收率等物理信息等结论.最后设计新模板,给出改进CT系统标定精度和稳定性的相关可行方案.

Revolution能谱CT技术原理与临床应用

从探测器、驱动系统及CT球管和高压发生器3个方面介绍了Revolution能谱CT在结构上的创新,从冠状动脉运动追踪冻结成像、多模型迭代重建算法、无限制心脏成像、物质分离与定量分析4个方面分析了Revolution能谱CT的技术原理,阐述了Revolution能谱CT在肝癌、胆囊结石、肾脏结石诊断,冠状动脉造影,去金属伪影方面的临床应用。指出了Revolution能谱CT将是鉴别病灶的性质、肿瘤是否同源性,无机物成分鉴别,多物质定量定性分析的一种新方法,能更好地应对CT在临床应用中的技术性挑战。

Analytical Study on Wave Diffraction from a Vertical Circular Cylinder in Front of Orthogonal Vertical Walls

In this paper, the principle of mirror image is used to transform the problem of wave diffraction from a circular cylinder in front of orthogonal vertical walls into the problem of diffraction of four symmetric incident waves from four symmetrically arranged circular cylinders, and then the eigenfunction expansion of velocity potential and Grafs addition theorem are used to give the analytical solution to the wave diffraction problem. The relation of the total wave force on cylinder to the distance between the cylinder and orthogonal vertical walls and the incidence angle of wave is also studied by numerical computation.

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.

Fine upper crustal structure of Jiashi strong earthquake swarm region in Xinjiang in-ferred from high resolution seismic refraction profile data

The data obtained from a high resolution seismic refraction profile, which was carded out in Jiashi, Xinjiang, strong earthquake swarm area, were processed with both finite difference inversion and Hagedoorn refractor wavefront imaging technique and the fine upper crustal structure was determined. The results show that the upper crustal structure is relatively well-distributed in laterally and obviously by layers vertically.From surface to 11.0 km depth, there are about four layers. The P wave velocity of top two layers range from 1.65 to 4.5 km/s and their bottom boundaries, the buried depths of which are 0.4, 2.96-3.0 km respectively, are almost horizontal; The third layer is comparatively complicated and its P wave velocity presents inhomogeneous in both laterally and vertically. The bottom boundary of third layer is crystalline basement and shows a little uplift, which seemly suggest that the upper crust had been resisted while the hard Tarim block inserting into Tianshan Mountain; The forth layer is relatively even and its P wave velocity is about 6.3 km/s. There are a lateral velocity variation at the depth of about 4.0 km, and suggest that it has something to do with the hidden Meigaiti fault and Meigaiti-Xiasuhong fault but there are no the structure features about these faults stretching to the surface and passing through the crystalline basement. The seismogenic tectonic of Jiashi strong earthquake swarm at least lies in middle or lower crust beneath 11.0 km depth.

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.

Migration of Magnetotelluric Data in Two——Dimensional Model

Since the wave equation of magnetoteiluric (MT)field is similar to the one of seismic , the migration techniques used in seismic can be applied to MT data . In this paper we make use of the principle of reflector mapping (i. e. U/D imaging principle ) to image MT data . That is, the MT wavefield observed on the surface of the earth can be resolved into upgoing and downgoing waves , the waves are extrapolated downward by the phase - shift method or the phase - shift plus interpolation (PSPI )method . Conductivity interfaces of the medium could be found by using the time coincidence of the upgoing and downgoing waves . Theoretical calculations show that the migration technique of MT data presented here is very effective . It can not only enhance the lateral resolution of MT data , but also obtain the visual image of subsurface interfaces . As compared with the conventional 2 - D inversion , this procedure is more simple in calculation and can be easily put into practice on a personal computer and is able to obtain the MT depth section , which is similar to seismic section .

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.

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.

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.

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.