Reconstructing the landing trajectory of the CE-3 lunar probe by using images from the landing camera

An accurate determination of the landing trajectory of Chang＇e-3 （CE-3） is significant for verifying orbital control strategy, optimizing orbital planning, accu- rately determining the landing site of CE-3 and analyzing the geological background of the landing site. Due to complexities involved in the landing process, there are some differences between the planned trajectory and the actual trajectory of CE-3. The land- ing camera on CE-3 recorded a sequence of the landing process with a frequency of 10 frames per second. These images recorded by the landing camera and high-resolution images of the lunar surface are utilized to calculate the position of the probe, so as to reconstruct its precise trajectory. This paper proposes using the method of trajectory reconstruction by Single Image Space Resection to make a detailed study of the hov- ering stage at a height of 100 m above the lunar surface. Analysis of the data shows that the closer CE-3 came to the lunar surface, the higher the spatial resolution of im- ages that were acquired became, and the more accurately the horizontal and vertical position of CE-3 could be determined. The horizontal and vertical accuracies were 7.09 m and 4.27 m respectively during the hovering stage at a height of 100.02 m. The reconstructed trajectory can reflect the change in CE-3＇s position during the powered descent process. A slight movement in CE-3 during the hovering stage is also clearly demonstrated. These results will provide a basis for analysis of orbit control strategy, and it will be conducive to adjustment and optimization of orbit control strategy in follow-up missions.

Population Spatial Distribution Based on Luojia 1-01 Nighttime Light Image:A Case Study of Beijing

With the continuous development of urbanization in China,the country’s growing population brings great challenges to urban development.By mastering the refined population spatial distribution in administrative units,the quantity and agglomeration of population distribution can be estimated and visualized.It will provide a basis for a more rational urban planning.This paper takes Beijing as the research area and uses a new Luojia1-01 nighttime light image with high resolution,land use type data,Points of Interest(POI)data,and other data to construct the population spatial index system,establishing the index weight based on the principal component analysis.The comprehensive weight value of population distribution in the study area was then used to calculate the street population distribution of Beijing in 2018.Then the population spatial distribution was visualize using GIS technology.After accuracy assessments by comparing the result with the WorldPop data,the accuracy has reached 0.74.The proposed method was validated as a qualified method to generate population spatial maps.By contrast of local areas,Luojia 1-01 data is more suitable for population distribution estimation than the NPP/VIIRS(Net Primary Productivity/Visible infrared Imaging Radiometer)nighttime light data.More geospatial big data and mathematical models can be combined to create more accurate population maps in the future.

BACKGROUND RECTIFICATION AND FEATURE EXTRACTION OF IMAGE IN A SPOT WELD OF AL ALLOY X-RAY DETECTION

A primary study on Processing in X - ray inspection of spot weld for aluminum alloy spot welding,in- cluding for background simulation,acquisition of ideal binary image, and extraction and identifi- cation of defect features was presented.

Example-based super-resolution for single-image analysis from the Chang'e-1 Mission

Due to the low spatial resolution of images taken from the Chang＇e-1 （CE-I） orbiter, the details of the lunar surface are blurred and lost. Considering the limited spatial resolution of image data obtained by a CCD camera on CE-1, an example-based super-resolution （SR） algorithm is employed to obtain high- resolution （HR） images. SR reconstruction is important for the application of image data to increase the resolution of images. In this article, a novel example-based algorithm is proposed to implement SR reconstruction by single-image analysis, and the computational cost is reduced compared to other example-based SR methods. The results show that this method can enhance the resolution of images using SR and recover detailed information about the lunar surface. Thus it can be used for surveying HR terrain and geological features. Moreover, the algorithm is significant for the HR processing of remotely sensed images obtained by other imaging systems.

Eurovet Unveils the New Image of Hong Kong Mode Lingerie 2010 March 30-31, at the Hong Kong Convention and Exhibition Centre

Organized by Eurovet, the world’s leading lingerie and beachwear trade show organizer and supported by Hong

Wavelet Analysis of Space Solar Telescope Images

The scientific satellite SST (Space Solar Telescope) is an important research project strongly supported by the Chinese Academy of Sciences. Every day, SST acquires 50 GB of data (after processing) but only 10GB can be transmitted to the ground because of limited time of satellite passage and limited channel volume. Therefore, the data must be compressed before transmission. Wavelets analysis is a new technique developed over the last 10 years, with great potential of application. We start with a brief introduction to the essential principles of wavelet analysis, and then describe the main idea of embedded zerotree wavelet coding, used for compressing the SST images. The results show that this coding is adequate for the job.

Inhibition of Notch 1 signaling in the subacute stage after stroke promotes striatal astrocyte-derived neurogenesis

Inhibition of Notch1 signaling has been shown to promote astrocyte-derived neurogenesis after stroke.To investigate the regulatory role of Notch1 signaling in this process,in this study,we used a rat model of stroke based on middle cerebral artery occlusion and assessed the behavior of reactive astrocytes post-stroke.We used theγ-secretase inhibitor N-[N-(3,5-diuorophenacetyl)-1-alanyl]-S-phenylglycine t-butylester(DAPT)to block Notch1 signaling at 1,4,and 7 days after injury.Our results showed that only administration of DAPT at 4 days after stroke promoted astrocyte-derived neurogenesis,as manifested by recovery of white matter fiber bundle integrity on magnetic resonance imaging,which is consistent with recovery of neurologic function.These findings suggest that inhibition of Notch1 signaling at the subacute stage post-stroke mediates neural repair by promoting astrocyte-derived neurogenesis.

A super-high angular resolution principle for coded-mask X-ray imaging beyond the diffraction limit of a single pinhole

High angular resolution X-ray imaging is always useful in astrophysics and solar physics. In principle, it can be performed by using coded-mask imaging with a very long mask-detector distance. Previously, the diffraction-interference effect was thought to degrade coded-mask imaging performance dramatically at the low energy end with its very long mask-detector distance. The diffraction-interference effect is described with numerical calculations, and the diffraction-interference cross correlation reconstruction method （DICC） is developed in order to overcome the imaging performance degradation. Based on the DICC, a super-high angular resolution principle （SHARP） for coded-mask X-ray imaging is proposed. The feasibility of coded mask imaging beyond the diffraction limit of a single pinhole is demonstrated with simulations. With the specification that the mask element size is 50 × 50 μm^2 and the mask-detector distance is 50 m, the achieved angular resolution is 0.32arcsec above about 10keV and 0.36arcsec at 1.24keV （λ = 1 nm）, where diffraction cannot be neglected. The on-axis source location accuracy is better than 0.02 arcsec. Potential applications for solar observations and wide-field X-ray monitors are also briefly discussed.

An image compression method for space multispectral time delay and integration charge coupled device camera

Multispectral time delay and integration charge coupled device （TDICCD） image compression requires a low- complexity encoder because it is usually completed on board where the energy and memory are limited. The Consultative Committee for Space Data Systems （CCSDS） has proposed an image data compression （CCSDS-IDC） algorithm which is so far most widely implemented in hardware. However, it cannot reduce spectral redundancy in mukispectral images. In this paper, we propose a low-complexity improved CCSDS-IDC （ICCSDS-IDC）-based distributed source coding （DSC） scheme for multispectral TDICCD image consisting of a few bands. Our scheme is based on an ICCSDS-IDC approach that uses a bit plane extractor to parse the differences in the original image and its wavelet transformed coefficient. The output of bit plane extractor will be encoded by a first order entropy coder. Low-density parity-check-based Slepian-Wolf （SW） coder is adopted to implement the DSC strategy. Experimental results on space multispectral TDICCD images show that the proposed scheme significantly outperforms the CCSDS-IDC-based coder in each band.

The Influence of Culture and Biographical Variables on the Brand Image of Google and Baidu: An Exploratory Study in Guangzhou,China

The study found significant correlations between the culture dimensions of Confucian work dynamism,humanheartedness and moral discipline and the brand image dimensions of online search engines.It was also found that several significant relationships exist between the biographical variables of age and education and the brand image dimensions,and that culture and biographical variables have a linear relationship with brand image.The findings highlight that culture and biographical information can influence Chinese consumer perceptions of an international or local brand.Organizations thus need to align their brands with the culture and biographical profile of their target markets.

Colorimetric Sensor Arrays System Based on FPGA for Image Recognition

A FPGA-based image recognition system is designed for eolorimetric sensor array in order to recognize a wide range of volatile organic compounds. The gas molecule is detected by the responsive sensor array and the responsive image is obtained. The image is decomposed to RGB color components using CMOS image sensor. An embedded image recognition archi- tecture based on Xilinx Spartan-3 FPGA is designed to implement the algorithms of image recognition. The algorithm of color coherence vector is discussed in detail compared with the algorithm of color histograms, and experimental results demonstrate that both of the two algorithms could be analyzed effectively to represent different volatile organic compounds according to their different responsive images in this system.

Ghost Images in Schmidt CCD Photometry

The wide field of the Schmidt telescope implies a greater chance of the field containing bright objects, and the presence of a corrector lens produces a certain type of ghost images. We summarize and confirm the features of such ghost images in Schmidt CCD photometry. The ghost images could be star-like under special observational conditions. The zenith distance of the telescope, among other factors, is found to correlate with different patterns of the ghost images. Some relevant issues are discussed and possible applications of our results are suggested.

Value of CA19-9, CA125 and CEA combined magnetic resonance imaging in the diagnosis of pancreatic cancer

Objective:To study the value of CA19-9, CA125 and CEA combined magnetic resonance imaging (MRI) in the diagnosis of pancreatic cancer, and to provide a reference for clinical diagnosis and treatment.Methods:A total of 110 cases of pancreatic cancer admitted to our hospital from November 2015 to November 2017 were selected as the observation group, and another 80 normal pancreas organizers who participated in the physical examination in the same period were selected as the control group. The change of magnetic resonance scanning parameters and serum CA19-9, CA125 and CEA detection were compared between the two groups of subjects at the same time, contrast scan and serum magnetic resonance detection of CA19-9, CA125 and CEA positive rate, and to evaluate the four alone and in combination with the diagnosis of pancreatic cancer specificity, sensitivity, negative predictive value and positive predictive value.Results:The T1WI of the observation group was low or slightly low signal, T2WI was slightly high signal, and the tumor of fat suppression sequence was low signal, which was in line with the typical characteristics of pancreatic cancer. The serum levels of CA19-9, CA125 and CEA in the observation group were significantly higher than those in the control group, and the difference was statistically significant. Compared with the two groups, the positive rates of MRI and serum CA19-9, CA125 and CEA in the observation group were higher than those in the control group, and the difference was statistically significant. The sensitivity and accuracy of MRI scan combined with three serological markers were higher than those of single detection. The specificity was between four.Conclusion: CA19-9, CA125 and CEA combined magnetic resonance imaging (MRI) have good sensitivity and accuracy in diagnosis of pancreatic cancer, but their specificity is common, which should be used for reference.

基于小波-Contourlet变换与Cycle Spinning相结合的SAR图像去噪

由于合成孔径雷达(SAR)在农业、林业、水文、地矿、海洋、测绘等领域广泛应用,SAR图像质量和视觉效果提升成为了各国学者研究的热点问题。SAR图像的主要噪声源——相干斑噪声的抑制和去除显得越来越重要。本文通过分析了SAR图像的噪声成因以及其噪声模型。基于SAR图像的特性,本文结合小波变换和Contourlet变换各自的优点,提出了一种基于小波-轮廓波变换与图像循环平移结合的SAR图像去噪算法。本文所提出的算法不仅可以显著去除相干斑噪声,提高图像的信噪比,而且还具有平移不变性,可明显改善图像的视觉效果。实验结果表明:与单独使用小波变换去噪相比,本文算法的信噪比提高2分贝;与单独使用Contourlet变换去噪相比,本文的算法去噪后的图像更平滑,抑制了人造纹理产生,视觉效果得到了明显的改善。

影像导航在有骨性解剖变异的慢性鼻-鼻窦炎手术中的应用

目的评价分析影像导航系统在有骨性解剖变异的慢性鼻-鼻窦炎鼻内镜手术中的作用。方法对影像导航系统辅助下行鼻内镜手术的慢性鼻-鼻窦炎患者216例进行回顾分析,根据有无骨性解剖变异分成两组。对导航系统的精确性、术中使用影像导航的次数、术前准备时间、总的手术时间、术中术后的并发症及术后疗效等进行统计学分析。结果有骨性解剖变异组(186例)比无骨性解剖变异组(30例)在术中影像导航使用次数上更多(P<0.05);不同骨性解剖变异组间使用影像导航次数进行比较,差异亦有统计学意义(P<0.05),存在多种解剖变异者使用导航次数最多。两组影像导航系统的精确性、术前准备时间、总的手术时间、术中术后的严重并发症及术后疗效进行比较,差异无统计学意义(P>0.05)。结论解剖变异不同,术中导航使用的次数不同,解剖变异越复杂,越能体现影像导航系统在鼻内镜手术中的作用。

新型无损检测技术在番茄品质检测中的研究与应用进展

番茄是我国种植面积最广的蔬菜之一,受到广大消费者的青睐。近年来,随着人们对健康饮食需求的逐步提升,番茄的品质愈发受到关注。番茄形状较为规则,但不同品种间的大小、果型、颜色差异较大,蕴含的营养成分种类繁多、化学结构复杂,导致其品质检测存在一定难度。传统番茄品质检测方法大多存在主观性强、破坏性强、耗时费力的缺点,难以满足大规模品质检测的需求。近年来,随着各类无损检测技术的发展,机器学习、多光谱技术、电子鼻/电子舌等新型检测方法也已逐步应用于番茄品质的快速、无损检测中。本文在传统番茄品质检测技术的基础上,重点总结了基于图像识别的人工智能、电子鼻技术和光谱技术在番茄无损检测方面的发展与应用,为番茄品质检测的研究与发展提供参考。

牛肉品质无损检测技术研究进展

牛肉营养物质丰富,是受消费者青睐的肉类之一。牛肉品质的优劣影响市场价格、消费者的购买意愿与满意度,因此牛肉品质的检测工作十分重要。目前传统的牛肉品质检测方法存在耗时、样品损坏以及操作复杂等问题。近年来,无损检测技术凭借其快速、高效、无损、绿色无污染的优势被广泛应用于牛肉品质检测。本文对无损检测技术在牛肉的品质分析(感官品质、营养品质和其他品质)进展进行了总结,系统阐述了近红外光谱、拉曼光谱、高光谱成像、电子舌和电子鼻等无损检测技术的原理,详细论述了近5年内无损检测技术在牛肉品质分析的进展,提出了无损检测技术在牛肉品质分析中存在的问题,并对未来的应用前景进行了展望,以期为牛肉品质无损检测技术的研究与应用提供参考。

薄层层析-图像分析定量热凝胶β-1,3-葡寡糖

单向两次薄层层析展开可以显著提高对热凝胶β-1,3-葡寡糖的分析效果,以Silica gel60 F254硅胶板为固定相,V(乙酸)∶V(乙酸乙酯)∶V(水)=2∶2.4∶1.4为展开剂,展距20 cm时,单向两次展开可以较好地分离聚合度为2~13的热凝胶β-1,3-葡寡糖。此外还建立了Image J软件图像分析定量热凝胶β-1,3-葡寡糖的方法,在不同糖质量浓度范围(0.02~0.1、0.1~0.8、0.8~5.0 g/L)内寡糖显色斑点的灰度积分响应值与糖浓度分别有着很好的线性关系(R2>0.99)。该方法的灵敏度高达0.02 g/L,相对标准偏差为1%~5%,稳定性很好。与HPLC等方法相比具有操作简便、分析快速、不需专门仪器和特定寡糖标准品等优点。

Optical fiber positioning based on four-quadrant detector with Gaussian fitting method

With the development of large-scale spectral surveys, fiber positioning technology has been developing rapidly. Because of the performance advantages of a four-quadrant（4Q） detector, a fiber positioning and real-time monitoring system based on the 4Q detector is proposed. The detection accuracy of this system is directly determined by the precision of the center of the spot. A Gaussian fitting algorithm based on the 4Q detector is studied and applied in the fiber positioning process to improve the calculated accuracy of the spot center. The relationship between the center position of the incident spot and the detector output signal is deduced. An experimental platform is built to complete the simulated experiment. Then we use the Gaussian fitting method to process experimental data, compare the fitting value with the theoretical one and calculate the corresponding error.

Numerical simulation of flow separation over a backward-facing step with high Reynolds number

Large eddy simulation (LES) explicitly calculates the large-scale vortex field and parameterizes the small-scale vortices.In this study,LES and κ-ε models were developed for a specific geometrical configuration of backward-facing step (BFS).The simulation results were validated with particle image velocimetry (PIV) measurements and direct numerical simulation (DNS).This LES simulation was carried out with a Reynolds number of 9000 in a pressurized water tunnel with an expansion ratio of 2.00.The results indicate that the LES model can reveal largescale vortex motion although with a larger grid-cell size.However,the LES model tends to overestimate the top wall separation and the Reynolds stress components for the BFS flow simulation without a sufficiently fine grid.Overall,LES is a potential tool for simulating separated flow controlled by large-scale vortices.