首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   33篇
  免费   7篇
化学工业   8篇
建筑科学   2篇
轻工业   2篇
水利工程   1篇
无线电   6篇
一般工业技术   7篇
冶金工业   4篇
自动化技术   10篇
  2022年   2篇
  2021年   4篇
  2020年   5篇
  2018年   2篇
  2017年   3篇
  2016年   1篇
  2014年   2篇
  2013年   3篇
  2012年   5篇
  2011年   1篇
  2010年   1篇
  2009年   3篇
  2008年   1篇
  2007年   1篇
  2005年   1篇
  2002年   1篇
  1998年   2篇
  1993年   1篇
  1988年   1篇
排序方式: 共有40条查询结果,搜索用时 15 毫秒
1.
We consider the structural change in a class of discrete valued time series, which the conditional distribution belongs to the one‐parameter exponential family. We propose a change point test based on the maximum likelihood estimator of the model's parameter. Under the null hypothesis (of no change), the test statistic converges to a well‐known distribution, allowing the calculation of the critical value of the test. The test statistic diverges to infinity under the alternative, meaning that the test has asymptotic power one. Some simulation results and real data applications are reported to show the effectiveness of the proposed procedure.  相似文献   
2.
The Tol-Pal proteins of Escherichia coli are involved in maintaining outer membrane integrity. Transmembrane domains of TolQ, TolR and TolA interact in the cytoplasmic membrane, while TolB and Pal form a complex near the outer membrane. TolB and the central domain of TolA interact in vitro with the outer membrane porins. In this study, both genetic and biochemical analyses were carried out to analyse the links between TolB, Pal and other components of the cell envelope. It was shown that TolB could be cross-linked in vivo with Pal, OmpA and Lpp, while Pal was associated with TolB and OmpA. The isolation of pal and tolB mutants disrupting some interactions between these proteins represents at first approach to characterizing the residues contributing to the interactions. We propose that TolB and Pal are part of a multiprotein complex that links the peptidoglycan to the outer membrane. The Tol-Pal proteins might form transenvelope complexes that bring the two membranes into close proximity and help some outer membrane components to reach their final destination.  相似文献   
3.
In this paper a coupled mono-inductance transmission line is considered and the envelope modulation is reduced to the generalized 2D-Ginzburg-Landau system (2D-GL system). The case of scalar equation is also considered and we deduce from the obtained 2D-GL system a 2D-cubic Ginzburg-Landau equation (2D-GL equation) containing the derivatives with respect to one spatial variable in the cubic terms. The obtained 2D-GL system and 2D-GL equation admit spatial wave solutions. The modulational instability of these spatial wave solutions is investigated. In the case of the 2D-GL system we have restricted ourselves in the zero wavenumber of the perturbations, and the obtained modulational instability conditions depends only on the system’s coefficients and the wavenumber of the carriers. The modulational instability criterion is established for non zero wavenumber of the perturbation, and depends on both the wavenumber of the perturbation and the carrier. For the 2D-GL system we also study the coherent structures and present some numerical studies.   相似文献   
4.
The latest-generation earth observation instruments on airborne and satellite platforms are currently producing an almost continuous high-dimensional data stream. This exponentially growing data poses a new challenge for real-time image processing and recognition. Making full and effective use of the spectral information and spatial structure information of high-resolution remote sensing image is the key to the processing and recognition of high-resolution remote sensing data. In this paper, the adaptive multipoint moment estimation (AMME) stochastic optimization algorithm is proposed for the first time by using the finite lower-order moments and adding the estimating points. This algorithm not only reduces the probability of local optimum in the learning process, but also improves the convergence rate of the convolutional neural network (Lee Cun et al. in Advances in neural information processing systems, 1990). Second, according to the remote sensing image with characteristics of complex background and small sensitive targets, and by automatic discovery, locating small targets, and giving high weights, we proposed a feature extraction method named weighted pooling to further improve the performance of real-time image recognition. We combine the AMME and weighted pooling with the spatial pyramid representation (Harada et al. in Comput Vis Pattern Recognit 1617–1624, 2011) algorithm to form a new, multiscale, and multilevel real-time image recognition model and name it weighted spatial pyramid networks (WspNet). At the end, we use the MNIST, ImageNet, and natural disasters under remote sensing data sets to test WspNet. Compared with other real-time image recognition models, WspNet achieve a new state of the art in terms of convergence rate and image feature extraction compared with conventional stochastic gradient descent method [like AdaGrad, AdaDelta and Adam (Zeiler in Comput Sci, 2012; Kingma and Ba in Comput Sci, 2014; Duchi et al. in J Mach Learn Res 12(7):2121–2159, 2011] and pooling method [like max-pooling, avg-pooling and stochastic-pooling (Zeiler and Fergus in stochastic-pooling for regularization of deep convolutional neural networks, 2013)].  相似文献   
5.
CD38 is a transmembrane glycoprotein expressed by T-cells. It has been reported that patients with systemic lupus erythematosus (SLE) showed increased CD38+CD25+ T-cells correlating with immune activation and clinical signs. Contrariwise, CD38 deficiency in murine models has shown enhanced autoimmunity development. Recent studies have suggested that CD38+ regulatory T-cells are more suppressive than CD38 regulatory T-cells. Thus, we have suggested that CD38 overexpression in SLE patients could play a role in regulating immune activation cells instead of enhancing it. This study found a correlation between CD38 with FoxP3 expression and immunosuppressive molecules (CD69, IL-10, CTLA-4, and PD-1) in T-cells from lupus-prone mice (B6.MRL-Faslpr/J). Additionally, B6.MRL-Faslpr/J mice showed a decreased proportion of CD38+ Treg cells regarding wild-type mice (WT). Furthermore, Regulatory T-Cells (Treg cells) from CD38-/- mice showed impairment in expressing immunosuppressive molecules and proliferation after stimulation through the T-cell receptor (TCR). Finally, we demonstrated an increased ratio of IFN-γ/IL-10 secretion in CD38-/- splenocytes stimulated with anti-CD3 compared with the WT. Altogether, our data suggest that CD38 represents an element in maintaining activated and proliferative Treg cells. Consequently, CD38 could have a crucial role in immune tolerance, preventing SLE development through Treg cells.  相似文献   
6.
The recent development in autonomous driving involves high-level computer vision and detailed road scene understanding.Today,most autonomous vehicles employ expensive high quality sensor-set such as light detection and ranging(LIDAR)and HD maps with high level annotations.In this paper,we propose a scalable and affordable data collection and annotation framework image-to-map annotation proximity(I2MAP),for affordance learning in autonomous driving applications.We provide a new driving dataset using our proposed framework for driving scene affordance learning by calibrating the data samples with available tags from online database such as open street map(OSM).Our benchmark consists of 40000 images with more than40 affordance labels under various day time and weather even with very challenging heavy snow.We implemented sample advanced driver-assistance systems(ADAS)functions by training our data with neural networks(NN)and cross-validate the results on benchmarks like KITTI and BDD100K,which indicate the effectiveness of our framework and training models.  相似文献   
7.
8.
A one-year study of the proliferation of mosquito in a Pistia stratiotes-based waste stabilization ponds in Cameroon revealed that Mansonia and Culex were the main breeding genera with about 55% and 42% of the total imagoes respectively. Though the ponds represent a favorable breeding ground for mosquitoes, only 0.02% of captured imagoes was Anopheles gambiae, suggesting that this wastewater treatment plant does not significantly contribute to the development of the malaria vector in the area. Gambusia sp. introduced to control mosquito population in the ponds acclimatized relatively well in most of the ponds (B3-B7) and their feeding rate without any diet ranged from 15.0 to 50.2 larvae/day for a single fish.  相似文献   
9.
Several problems modeled by dynamic programming have been solved using a coarse-grain multicomputer parallel model (CGM for short). These problems use either polyadic dynamic programming or monadic non-serial dynamic programming. In this paper, we address the general case: we propose a parallel algorithm in the CGM model with p processors for the Optimal String Parenthesizing Problem or Minimum Cost Parenthesizing Problem, which is a typical polyadic non-serial dynamic programming problem. The algorithm we obtain requires ?(2p)1/2? communication rounds and, at most, O(n 3/p) time-steps on p processors. This new CGM algorithm performs better than the previously most efficient solution, which uses p communication rounds.  相似文献   
10.
A new technique for the synthesis of large sheets (>10 cm2) of multi-layered graphene is presented. The condensation onto a heated surface (≈650 °C) of fumes from the thermal decomposition of asphalt in a ceramic crucible produces carbon films with a metallic sheen. Heating was done by a Fisher burner (natural gas/air) flame and the crucible was covered but exposed to laboratory atmosphere. These films were determined to be multi-layered graphene by scanning electron microscopy, atomic force microscopy, X-ray photoelectron spectroscopy (XPS), Raman and infrared spectroscopy and X-ray diffraction. XPS indicates that the films are primarily sp2 hybridized carbon with small amounts of sp3 C–H and C–O or C–N functionalities. Based on the D band shift (1593 cm−1) and the ratio of D band to G band (1354 cm−1) of 0.93, the Raman spectrum also indicates that the material is sp2 C with some nanocrystalline features. The infrared spectrum exhibits A1U (868 cm−1) and E1U (1599 cm−1) stretching of the intralayer bonds of graphene. This form of chemical vapor deposition may be a scalable to give much larger surface areas. Furthermore, the process does not require metal substrates. Deposition onto silica nanosprings and diatomites is demonstrated.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号