778 research outputs found
Financing problems of small and micro enterprises under digital Inclusive Finance
small and micro enterprises are the main body of Inclusive Finance and the main direction of its development. âDiffi cult
and expensive fi nancingâ has hindered the development of small and micro enterprises. Inclusive Finance is a fi nancial service that takes
into account the common interests of banks and banks and can better meet the financing needs of small and micro enterprises. Taking
Inclusive Finance as the breakthrough point, this paper focuses on the challenges faced by small and micro enterprises, such as the imperfect
regulatory system, the turmoil of private fi nance, and the diffi culties in the development of the guarantee industry. Under the background of
digital Inclusive Finance, the author puts forward solutions to the fi nancing problems of small and micro enterprises, so as to promote the
healthy development of small and micro enterprises
An ASIFT-based local registration method for satellite imagery
Imagery registration is a fundamental step, which greatly affects later processes in image mosaic, multi-spectral image fusion, digital surface modelling, etc., where the final solution needs blending of pixel information from more than one images. It is highly desired to find a way to identify registration regions among input stereo image pairs with high accuracy, particularly in remote sensing applications in which ground control points (GCPs) are not always available, such as in selecting a landing zone on an outer space planet. In this paper, a framework for localization in image registration is developed. It strengthened the local registration accuracy from two aspects: less reprojection error and better feature point distribution. Affine scale-invariant feature transform (ASIFT) was used for acquiring feature points and correspondences on the input images. Then, a homography matrix was estimated as the transformation model by an improved random sample consensus (IM-RANSAC) algorithm. In order to identify a registration region with a better spatial distribution of feature points, the Euclidean distance between the feature points is applied (named the S criterion). Finally, the parameters of the homography matrix were optimized by the LevenbergâMarquardt (LM) algorithm with selective feature points from the chosen registration region. In the experiment section, the ChangâE-2 satellite remote sensing imagery was used for evaluating the performance of the proposed method. The experiment result demonstrates that the proposed method can automatically locate a specific region with high registration accuracy between input images by achieving lower root mean square error (RMSE) and better distribution of feature points
Phonon dynamic behaviors induced by amorphous interlayer at heterointerfaces
Interface impedes heat flow in heterostructures and the interfacial thermal
resistance (ITR) has become a critical issue for thermal dissipation in
electronic devices. To explore the mechanism leading to the ITR, in this work,
the dynamic behaviors of phonons passing through the GaN/AlN interface with an
amorphous interlayer is investigated by using phonon wave packet simulation. It
is found the amorphous interlayer significantly impedes phonon transport across
the interface, and leads to remarkable phonon mode conversions, such as
LATA, TALA, and LATO conversion.
However, due to mode conversion and inelastic scattering, we found a portion of
high-frequency TA phonons, which are higher than the cut-off frequency and
cannot transmit across the ideal sharp interface, can partially transmit across
the amorphous interlayer, which introduces additional thermal transport
channels through the interface and has positive effect on interfacial thermal
conductance. According to phonon transmission coefficient, it is found the ITR
increases with increasing of amorphous interlayer thickness L. The phonon
transmission coefficient exhibits an obvious oscillation behavior, which is
attributed to the multiple phonon scattering in the amorphous interlayer, and
the oscillation period is further revealed to be consistent with the
theoretical prediction by the two-beam interference equation. In addition,
obvious phonon frequency shifts and phonon energy localization phenomena were
observed in the amorphous interlayer. Finally, to improve phonon transmission,
the interface morphology was further optimized via the annealing reconstruction
technique, which results in re-crystallization of the amorphous interlayer and
the decrease of ITR by ~21% as L=2 nm
Regulation of B cell fate by chronic activity of the IgE B cell receptor.
IgE can trigger potent allergic responses, yet the mechanisms regulating IgE production are poorly understood. Here we reveal that IgE+ B cells are constrained by chronic activity of the IgE B cell receptor (BCR). In the absence of cognate antigen, the IgE BCR promoted terminal differentiation of B cells into plasma cells (PCs) under cell culture conditions mimicking T cell help. This antigen-independent PC differentiation involved multiple IgE domains and Syk, CD19, BLNK, Btk, and IRF4. Disruption of BCR signaling in mice led to consistently exaggerated IgE+ germinal center (GC) B cell but variably increased PC responses. We were unable to confirm reports that the IgE BCR directly promoted intrinsic apoptosis. Instead, IgE+ GC B cells exhibited poor antigen presentation and prolonged cell cycles, suggesting reduced competition for T cell help. We propose that chronic BCR activity and access to T cell help play critical roles in regulating IgE responses
Summer moisture changes in the Lake Qinghai area on the northeastern Tibetan Plateau recorded from a meadow section over the past 8400 yrs
Holocene climatic and environmental changes on the northeastern Tibetan Plateau (TP) have been widely discussed based on the climatic records from sedimentary cores. However, differences in the reconstructed climatic history from various studies in this region still exist, probably due to influence of climatic proxies from multiple factors and the chronological uncertainties in lacustrine sediments. Here we present records of terrestrial plant delta C-13, soil color and total organic carbon content over the past 8400 years from a well-dated meadow section on the northeastern TP. The terrestrial plant delta C-13 value serves as a good summer precipitation/moisture indicator in the studied region. Soil color property and TOC content are also able to disentangle the moisture evolution history. All the data show much wet climates at 8400-7400 cal yr BP, dry climates at 7400-6000 cal yr BP and then wet conditions with fluctuation at 6000-3200 cal yr BP. Late Holocene moisture appears to be comparable with moist conditions from 6000 to 3200 cal yr BP. By further comparing the climatic variations in the Lake Qinghai area with records of the reconstructed summer temperature and the Asian Monsoon precipitation, we believe that the pattern of moisture/precipitation evolution in the Lake Qinghai area was not completely consistent with regions around Lake Qinghai, probably due to complicated interaction between the East Asian Summer Monsoon and the Indian Summer Monsoon
Panoramic mosaics from ChangâE-3 PCAM images at Point A
This paper presents a unique approach for panoramic mosaics based on Moon surface images from the ChangâE-3 (CE-3) mission, with consideration of the exposure time and external illumination changes in CE-3 Panoramic Camera (PCAM) imaging. The engineering implementation involves algorithms of image feature points extraction by using Speed-Up Robust Features (SURF), and a newly defined measure is used to obtain the corresponding points in feature matching. Then, the transformation matrix is calculated and optimized between adjacent images by the LevenbergâMarquardt algorithm. Finally, an image is reconstructed by using a fade-in-fade-out method based on linear interpolation to achieve a seamless mosaic. The developed algorithm has been tested with CE-3 PCAM images at Point A (one of the rover sites where the rover is separated from the lander). This approach has produced accurate mosaics from CE-3 PCAM images, as is indicated by the value of the Peak Signal to Noise Ratio (PSNR), which is greater than 31 dB between the overlapped region of the images before and after fusion
Recommended from our members
Evaluation of positioning error-induced pixel shifts on satellite linear push-broom imagery
Georeferencing is one of the major tasks of satellite-borne remote sensing. Compared to traditional indirect methods, direct georeferencing through a Global Positioning System/inertial navigation system requires fewer and simpler steps to obtain exterior orientation parameters of remotely sensed images. However, the pixel shift caused by geographic positioning error, which is generally derived from boresight angle as well as terrain topography variation, can have a great impact on the precision of georeferencing. The distribution of pixel shifts introduced by the positioning error on a satellite linear push-broom image is quantitatively analyzed. We use the variation of the object space coordinate to simulate different kinds of positioning errors and terrain topography. Then a total differential method was applied to establish a rigorous sensor model in order to mathematically obtain the relationship between pixel shift and positioning error. Finally, two simulation experiments are conducted using the imaging parameters of Changâ E-1 satellite to evaluate two different kinds of positioning errors. The experimental results have shown that with the experimental parameters, the maximum pixel shift could reach 1.74 pixels. The proposed approach can be extended to a generic application for imaging error modeling in remote sensing with terrain variation
- âŚ