320 research outputs found

    Research on Site Coverage Distribution of Beijing Based on Geographic Information System

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    Site coverage is an important index to learn spatial development pattern of the city. In this paper, with the help of spatial analysis functions of GIS, buffer and sector analysis are imposed in pursuit of finding possible spatial distribution rules of Beijing taken flagpole in Tian’anmen square as center. The results of sector analysis indicate that the building densities in such superior geographical condition areas as southeast and south are higher. Building densities of northern and western areas are low because of their bad terrain. The results of buffer analysis indicate the density of city center is the highest and have a negative relation with the augment of distance. That is to say, the average building density of center areas (buffer 1, 2 and 3, about 7.5km away) is about 26%. The average building density of transition region of city and countryside (buffer 10~20, about 25~50km away from center) is about 9%. The average building density of exurbs (after buffer 20~50km away from center) can't reach to 3%

    Learning Compact Recurrent Neural Networks with Block-Term Tensor Decomposition

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    Recurrent Neural Networks (RNNs) are powerful sequence modeling tools. However, when dealing with high dimensional inputs, the training of RNNs becomes computational expensive due to the large number of model parameters. This hinders RNNs from solving many important computer vision tasks, such as Action Recognition in Videos and Image Captioning. To overcome this problem, we propose a compact and flexible structure, namely Block-Term tensor decomposition, which greatly reduces the parameters of RNNs and improves their training efficiency. Compared with alternative low-rank approximations, such as tensor-train RNN (TT-RNN), our method, Block-Term RNN (BT-RNN), is not only more concise (when using the same rank), but also able to attain a better approximation to the original RNNs with much fewer parameters. On three challenging tasks, including Action Recognition in Videos, Image Captioning and Image Generation, BT-RNN outperforms TT-RNN and the standard RNN in terms of both prediction accuracy and convergence rate. Specifically, BT-LSTM utilizes 17,388 times fewer parameters than the standard LSTM to achieve an accuracy improvement over 15.6\% in the Action Recognition task on the UCF11 dataset.Comment: CVPR201

    Scanning tunneling microscopy and spectroscopy of nanoscale twisted bilayer graphene

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    Nanoscale twisted bilayer graphene (TBG) is quite instable and will change its structure to Bernal (or AB-stacking) bilayer with a much lower energy. Therefore, the lack of nanoscale TBG makes its electronic properties not accessible in experiment up to now. In this work, a special confined TBG is obtained in the overlaid area of two continuous misoriented graphene sheets. The width of the confined region of the TBG changes gradually from about 22 nm to 0 nm. By using scanning tunnelling microscopy, we studied carefully the structure and the electronic properties of the nanoscale TBG. Our results indicate that the low-energy electronic properties, including twist-induced van Hove singularities (VHSs) and spatial modulation of local density-of-state, are strongly affected by the translational symmetry breaking of the nanoscale TBG. Whereas, the electronic properties above the energy of the VHSs are almost not influenced by the quantum confinement even when the width of the TBG is reduced to only a single moire spot.Comment: 4 Figure

    In Vivo Evaluation of the Nitroimidazole-Based Thioflavin-T Derivatives as Cerebral Ischemia Markers

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    Timely imaging and accurate interpretation of cerebral ischemia are required to identify patients who might benefit from more aggressive therapy, and nuclear medicine offers a noninvasive method for demonstrating cerebral ischemia. Three nitroimidazole-based thioflavin-T derivatives, N-[4-(benzothiazol-2-yl)phenyl]-3-(4-nitroimidazole-1-yl) propanamide (4NPBTA), N-[4-(benzothiazol-2-yl)phenyl]-3-(4-nitroimidazole-1-yl)-N-methylpropanamide (4NPBTA-1), and N-[4-(benzothiazol-2-yl)phenyl]-3-(2-nitroimidazole-1-yl) propanamide (2NPBTA), were radioiodinated and evaluated as possible cerebral ischemia markers. In normal mice, these compounds showed good permeation of the intact blood-brain barrier (BBB), high initial brain uptake, and rapid washout. In gerbil stroke models that had been subjected to right common carotid artery ligation to produce cerebral ischemia, [131I]2NPBTA, uptake in the right cerebral hemisphere decreased more slowly than that of the left, and the right/left hemisphere uptake ratios increased with time. Also, the right/left hemisphere uptake ratios correlated positively with the severity of the stroke. The results showed that [131I]2NPBTA had a specific location in the cerebral ischemic tissue. This represented a first step in finding new drugs and might provide a possible cerebral ischemic marker

    Evaluation of Community Health Education Workshops among Chinese Older Adults in Chicago: A Community-Based Participatory Research Approach

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    Background: Health education is one of the proven ways to improve knowledge and change health attitudes and behaviors. This study is intended to assess the effectiveness of five health workshops in a Chinese community, focusing on depression, elder abuse, nutrition, breast cancer and stroke. Methods: A community-based participatory research approach was implemented to plan and organize the workshops. A total of 236 Chinese community-dwelling older adults participated in different health workshops. Quantitative questionnaires on knowledge, risk factors and outcomes of each health topic were distributed before and after the workshop. Pre and post workshop comparison analyses were conducted to examine the effectiveness of the workshops on knowledge and learning. Results: Overall, the health workshops have significantly improved participants’ understanding throughout the five health themes (P<0.05). Whereas Chinese older adults have limited knowledge on depression, nutrition and stroke, their health knowledge regarding depression and elder abuse were significantly improved after attending the workshops. In addition, health education workshops increased older adults’ understanding of the risk factors and consequences of depression, elder abuse and breast cancer. Conclusion: This study sheds light on the importance of promoting health education, and the complexity and challenges of designing health education for community dwelling Chinese older adults. Significant implications for researchers, community service providers, health service workers and policy makers are discussed
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