Plane wave shot PSDM and controlled illumination techniques

The Pre-Stack Depth Migration （PSDM） method based on wavefield continuation is the most reliable method for imaging complex structure in the subsurface, although there are large computational costs and poorly adaptive geometry. Plane wave shot migration is another method to perform exact wave equation prestack imaging with high computational efficiency and without the migration aperture problem. Moreover, wavefield energy can be compensated at the target zone by controlled illumination. In this paper, plane wave shot PSDM was implemented by the control of the plane down-going wavefield and selection of number and range of the raypaths in order to optimize the imaging effect. In addition, controlled illumination techniques are applied to enhance the imaging precision of interesting areas at different depths. Numerical calculation indicates that plane wave shot imaging is a rapid and efficient method with less computational cost and easy parallel computation compared to the single-square-root operator imaging for common shot gathers and double- square-root operator imaging for common midpoint gathers.

Reverse-time migration and amplitude correction in the angle-domain based on Poynting vector

We propose a method based on the Poynting vector that combines angle-domain imaging and image amplitude correction to overcome the shortcomings of reverse-time migration that cannot handle different angles during wave propagation. First, the local image matrix （LIM） and local illumination matrix are constructed, and the wavefield propagation directions are decomposed. The angle-domain imaging conditions are established in the local imaging matrix to remove low-wavenumber artifacts. Next, the angle-domain common image gathers are extracted and the dip angle is calculated, and the amplitude-corrected factors in the dip angle domain are calculated. The partial images are corrected by factors corresponding to the different angles and then are superimposed to perform the amplitude correction of the final image. Angle-domain imaging based on the Poynting vector improves the computation efficiency compared with local plane-wave decomposition. Finally, numerical simulations based on the SEG/EAGE velocity model are used to validate the proposed method.

Simulation study on radiative imaging of combustion flame in furnace

Radiative imaging of combustion flame in furnace of power plant plays an increasingly important role in combustion diagnosis. This paper presents a new method for calculating the radiative imaging of three-dimensional (3D) combustion flame based on Monte Carlo method and optical lens imaging. Numerical simulation case was used in this study. Radiative images were calculated and images obtained can not only present the energy distribution on the charge-coupled device (CCD) camera target plane but also reflect the energy distribution condition in the simulation furnace. Finally the relationships between volume ele- ments and energy shares were also discussed.

Clinical study of digital mammography,contrast-enhanced MRI as well as their combination in the diagnosis of breast cancer

Objective： To compare the effectiveness of digital mammography and MRI in the detection and diagnosis of breast cancer and to assess the value of these modalities as well as the combination of the two. Methods： Sixty-seven patients with surgery and pathology proved breast lesion （malignant, n = 32; benign, n = 46） underwent digital mammography and MRI, the pulse sequences included T1WI, T2WI, diffuse weighted imaging （DWI）, and dynamic contrast-enhanced MRI before surgery. Of the results of these two modalities, all lesions were classified into 5 groups according to BI-RADS classification, and the imaging findings were correlated to histopathology. The sensitivity and specificity of each modality as well as the combination of the two were calculated. Results： Of these 78 breasts lesions, The sensitivity was 78.13%% （25/32） for digital mammography and 93.75% （30/32） for MRI （P 〉 0.05）. The specificity was 73.91%% （34/46） and 89.13% （41/46） accordingly （P 〈 0.05）, both of them showed statistical difference. The sensitivity and specificity was 98.63% and 97.16% respectively as these two modalities were used in combination. Conclusion： Digital mammography in combination with MRI is helpful in the diagnosis of breast cancer, the sensitivity and specificity was enhanced when compared to that of single modality.

From a Vernacular Photograph to an Icon： The Spirited Face of Gezi Park Resistance

During spring 2013, an important uprising had broken out and marked a historic period for political activism in Turkish memory. Focusing on the afterlives of photographic portraits produced during this “Occupy Gezi Movement”, the paper considers iconized digital portraitures as a peculiar genre of vernacular photography and focuses on its visual language, and cultural codes as a part of the underground resisting culture in daily life. It explores different contexts in which photographic portraits have been used as a tool of protest and their various kinds of remediation from the Gezi Park Protest onwards. Private portraits as an agent of resistance have been creatively modified, recreated, rematerialized and circulated in distinct ways during and after the protest： from city walls as stencils, stickers, and graffiti （in actual public spaces） to Facebook profile walls as online digital re-mastering （virtual spheres）. This article concentrates on aesthetics of such iconized digital photographic portraitures in contemporary Turkey. It particularly focuses on one of the instances that have labeled the Occupy Gezi Movement： the death of Berkin Elvan, who turned 15 while in a coma who has been struck in the head by a tear gas canister, fired by police, while on his way to buy bread. This case has been a catalyst for further demonstrations against Turkey＇s ruling party and turned Elvan＇s high-spirited face and dark eyebrows, to one of the strong symbols of the resistance. The teenage boy＇s injury during the protests, his birthday while he was in a coma at the hospital, his death, funeral and commemorations have been stress points in which his photographic portrait have been modified and redesigned according to the occasion and circulated widely. The image of the youth symbol of the struggle and the different kinds of cultural work his photograph have performed is the main focus of this research. The digital social afterlives of Elvan＇s iconized imagery as illustrations and drawings; as stencils and graffiti at streets; as posters and framed photographs in political performances carried around in public spaces and commemorative acts; and as digital data circulated in social media both consisting of indexical and iconic dements regarding their photographic features. This transformation of the single analog vernacular photograph of Elvan to various digital versions and continuous re-interpretation and re-materialization is discussed depending on the local history of the occasion and the critical literature on photographic history and theories of photographic vernacularity. This research makes use of data collecting methods that netnographic research methodology uses. The paper focuses on the ways local vernacularity is historically produced and evolved in this particular time of Gezi Park Resistance.

The latest progress of thermal neutron tomography at SPRR-300 reactor

Thermal neutron radiography is a useful complementary tool of the other non-destructive testing methods for the hydrogenous materials and heavy metal subassembly.By the use of MC method program and the thermal neutron digital radiography facility at SPRR-300 reactor,the simulation and experimental study of the thermal neutron tomography has been developed.Its method and result has been introduced and analyzed.

The Effect of Verbal Anchoring on the Processing of Advertising Pictorial Metaphors

Although investigating metaphors in advertising is gaining in popularity, there are still certain unresolved arguments, such as the interaction between elements of different modalities. This study,composed of three behavioral experiments, aims to identify how verbal anchoring(literal anchoring, metaphor anchoring and unrelated anchoring) influences the processing of pictorial metaphors in advertising, by observing the cognitive and affective indicators, advertising comprehension and advertising likeability. The results showed 1) that metaphors in pictorial modality were recognized more quickly than those in verbal modality, 2) that verbal anchoring facilitated participants ’ comprehending and appreciating of pictorial metaphors and 3) that literally-anchored metaphors with a moderate level of novelty yielded the most favorable cognitive responses. The study not only enriches the existing theoretical framework of multimodal metaphors in advertising, but also proposes an optimal match between pictorial metaphors and verbal elements, for advertisers and manufacturers to design effective multimodal advertisements.

Neutron imaging at Peking University

Neutron imaging techniques were investigated at Peking University based on a 4.5 MV Van de Graaff accelerator.The thermal neutron radiography,fast neutron radiography and fast neutron resonance radiography were tested.The low neutron flux limits the image quality.A new radio frequency quadrupole (RFQ) accelerator based on neutron source with a yield of 1 012 n/s is being set up.

The review and prospect of neutron radiography in China

Neutron radiography is one of radiography non-destructive testing.It is a valuable complementary of X and γ rays radiography.The present status and history of neutron radiography in China was described briefly,facilities of neutron radiography and their development were introduced in this paper.

Computer-aided Visual Assessment of the Grade of Clothing Fit

The paper first introduces and analyzes the merits and demerits of some traditional methods of evaluating the grade of clothing fit. Then a computer-aided evaluating method is put forward. In this process two groups are needed. The control group is made up of people who wear maillot while the experimental group consists of those who wear target clothes to be evaluated. People in these two groups are taken photos respectively from front, back and lateral sides. The photos are input computer and receive a series of image processing using Open CV which provides the open source library function including image preprocessing, edge detection and image segmentation, etc. Finally, taking the clothing ease into account, the processed data is used for region matching and evaluating the grade of clothing fit.

Image Based Rendering under Varying Illumination

A new approach for photorealistic rendering of a class of objects at arbitrary illumination is presented. The approach of the authors relies entirely on image based rendering techniques. A scheme is utilized for re-illumination of objects based on linear combination of low dimensional image representations. The minimum rendering condition of technique of the authors is three sample images under varying illumination of a reference object and a single input image of an interested object. Important properties of this approach are its simplicity, robustness and speediness. Experimental results validate the proposed rendering approach.

HL-2A Tokamak Gas Puff Imaging

Gas puff imaging （GPI） is one of the important diagnostics for the （ITPAC international tokamak physics activity ） and entering the ITPA IDD （ international diagnostics database ） . GPI is related to many investigations, for example, edge radiations, etc.

AN LBP-BASED MULTI-SCALE ILLUMINATION PREPROCESSING METHOD FOR FACE RECOGNITION

It is one of the major challenges for face recognition to minimize the disadvantage of il- lumination variations of face images in different scenarios. Local Binary Pattern (LBP) has been proved to be successful for face recognition. However, it is still very rare to take LBP as an illumination preprocessing approach. In this paper, we propose a new LBP-based multi-scale illumination pre- processing method. This method mainly includes three aspects: threshold adjustment, multi-scale addition and symmetry restoration/neighborhood replacement. Our experiment results show that the proposed method performs better than the existing LBP-based methods at the point of illumination preprocessing. Moreover, compared with some face image preprocessing methods, such as histogram equalization, Gamma transformation, Retinex, and simplified LBP operator, our method can effectively improve the robustness for face recognition against illumination variation, and achieve higher recog- nition rate.

基于感知模式纹理的人脸识别

稀疏表示分类法和局部二值模式是目前广泛运用的人脸表示方法.虽然稀疏表示分类法通过重构算法能很好的稀疏表示人脸,但在人脸的局部特征表示上不够理想.局部二值模式是基于局部纹理特征表示人脸,其提取的局部纹理简单、不连续、不光滑,造成纹理损失严重.提出局部纹理特征的感知模式纹理的概念,克服了稀疏表示分类法在局部特征表现不佳的缺点,同时又比局部二值模式纹理光滑、鲁棒.利用感知模式纹理特征在Yale和ORL数据库取得了较好的识别效果.

The role of radiocarpal injection arthrography and magnetic resonance imaging in the diagnosis of triangular fibrocartilage complex injuries

Objective:: To investigate the radiocarpal joint injection arthrography and magnetic resonance imaging for diagnosis of the triangular fibrocartilage complex (TFCC) injuries. Methods: Thirteen cases whose main complaints were ulnar wrist pain were given radiocarpal joint arthrography and eight of them were also given magnetic resonance imaging for evaluating the integrity of the triangular fibrocartilage complex. Results: Ten of thirteen cases presented the leakage of contrast medium to distal radioulnar joint from the radiocarpal joint, in whom, 8 were demonstrated triangular fibrocartilage tear on magnetic resonance imaging, and 3 located at radial side, 2 at central, 3 at ulnar side. One of three cases which were demonstrated without the leakage of contrast medium in arthrography were displayed with marked TFCC tear on magnetic resonance imaging. Conclusions: The wrist arthrography can provide a definite diagnosis for triangular fibrocartilage disruption with higher sensitivity. magnetic resonance imaging not only demonstrates the site of triangular fibrocartilage disruption as the same value as wrist arthrography, but also displays the other related bony and soft tissues changes.

Automatic texture exemplar extraction based on global and local textureness measures

Texture synthesis is widely used for modeling the appearance of virtual objects. However, traditional texture synthesis techniques eInphasize creation of optimal target textures, and pay insufficient attention to choice of suitable input texture exemplars. Currently, of taining texture exemplars from natural images is a labor intensive task for the artists, requiring careful photography and significant post- processing. In this paper, we present an automatic texture exemplar extraction method based on global and local textureness measures. To improve the efficiency of dominant texture identification, we first perform Poisson disk sampling to randomly and uniformly erop patches from a natural image. For global textureness assessment, we use a GIST descriptor to distinguish textured t）atches from non-textured patches, in conjunction with SVM prediction. To identify real texture, exemplars consisting solely of the dominant texture, we further measure the local textureness of a patch by extracting and matching the local structure （using t）inary Gabor pattern （BGP）） and dominant color features （using color histograms） between a patch and its sub-regions. Finally, we obtain optimal texture exemplars by scoring and ranking extracted patches using these global and local textureness measures We evaluate our method on a variety of images with different kinds of textures. A convincing visual comparison with textures mauually selected by an artist and a statistical study demonstrate its effectiveness.

Accurate mirror-based camera pose estimation with explicit geometric meanings

An accurate closed form solution is proposed to estimate camera pose by several mirrored reference object images acquired via a planar mirror under different unknown poses. Compared with state-of-the-art methods, our method is more accurate when there are more than three images and has explicit geometric meanings. This method also properly handles cases in which some of the mirror poses are parallel. The central idea is to minimize an error metric based on all reflections of rotation, which enables the camera rotation to be estimated directly by SVD of sum of mirrored camera rotations. After that, the camera translation is computed by solving a large system of linear equations to minimize object space collinearity error. Both synthesized data and real data experiments show the advantages of our approach.

Etching Process of Back-Illuminated ZnO Ultraviolet Focal Plane Array Imagers

Etching process of back-illuminated ZnO ultraviolet focal plane array imagers was investigated. The etching result of 128 × 128 array ,in which the area of unit ceil was 25μm × 25μm, was studied. The profile angle was approximately 80°. There was a linear relationship between the etching depth and the etching time. The dependence of etching rate on NH4Cl solution concentration was also studied. The photoresponsivity of the array＇s unit cells was measured. The UV-to- visible rejection ratio was around 60 ： 1.

Experimental study of unsteady supersonic flow interacting with porous cavity and jets or rods

In this study,an experiment was performed to clarify the flow field,in which the jets were normally injected into a main supersonic flow surrounded by a porous cavity,and this report figures out interaction between starting shock wave and porous cavity.In the experiment,a porous cavity is attached to a main duct and jets and rods are inserted to the main duct on the porous cavity.To reveal this flow field,the thermal tuft probe was adopted to experimentally investigate the flow in the cavity.In the experiments,the effect of the porous cavity with jets or rods on the flow field is studied by means of visualization of schlieren method with a high speed camera and measurement of cavity flow with thermal tuft probe.As a results,frequency analysis of output of the thermal tuft probe revealed that some clear dominant frequencies were confirmed when the starting shock wave existed around the porous cavity in all cases of jets and rods arrangements.Moreover,visualization of schlieren method with a high speed camera clarified that a starting shock wave had the same dominant frequencies as that of the flow fluctuation in the cavity only around the cavity.