927 research outputs found
High-strain rate compressive behavior of CFRP confined concrete: Large diameter SHPB tests
No full textThe behavior of a material under high-strain rate compression can be different from quasi-static one and can be determined by using the so-called Split-Hopkinson Pressure Bar (SHPB). The aim of this study is to investigate the high-strain rate compressive behavior of Carbon Fiber Reinforced Polymer (CFRP) confined concrete in comparison with unconfined concrete. A total of 112 specimens with a diameter of 150 mm were tested under quasi-static (with a length to diameter ratio of 0.5 and 2) and under high-strain rate axial compression (with a length to diameter ratio of 0.5) using a universal testing machine and a SHPB with a large diameter of 155 mm, respectively. The specimens were characterized by two different strength classes, namely C30 and C60, and by a different number of CFRP layers ranging from 0 (plain cylinder) to 3. Tests were executed up to a strain rate of 100 s(-1). The measurements were validated by checking the consistency of the large diameter SHPB and by comparing the results of plain concrete with the data available in the literature. The results indicate that the strength of CFRP confined concrete is not significantly sensitive to strain rate effects. (C) 2018 Elsevier Ltd. All rights reserved
A security analysis of automated Chinese turing tests
No full textText-based Captchas have been widely used to deter misuse of services on the Internet. However, many designs have been broken. It is intellectually interesting and practically relevant to look for alternative designs, which are currently a topic of active research. We motivate the study of Chinese Captchas as an interesting alternative design - counterintuitively, it is possible to design Chinese Captchas that are universally usable, even to those who have never studied Chinese language. More importantly, we ask a fundamental question: is the segmentation-resistance principle established for Roman-character based Captchas applicable to Chinese based designs? With deep learning techniques, we offer the first evidence that computers do recognize individual Chinese characters well, regardless of distortion levels. This suggests that many real-world Chinese schemes are insecure, in contrast to common beliefs. Our result offers an essential guideline to the design of secure Chinese Captchas, and it is also applicable to Captchas using other large-alphabet languages such as Japanese
Guan yu gong ren he gong si jin rong de yan jiu
No full textShen, Beibei.Thesis Ph.D. Chinese University of Hong Kong 2015.Includes bibliographical references.Abstracts also in Chinese.Title from PDF title page (viewed on 02, November, 2016).Shen, Beibei
Hourly operation strategy of a CCHP system with GSHP and thermal energy storage (TES) under variable loads: a case study
No full textAbstract not availableWei Liu, Guanyi Chen, Beibei Yan, Zhihua Zhou, Haowei Du, Jian Zu
Supplemental Material - Identification of heterogeneous subsets of aortic interleukin-17A-expressing CD4<sup>+</sup> T cells in atherosclerotic mice
No full textSupplemental Material for Identification of heterogeneous subsets of aortic interleukin-17A-expressing CD4+ T cells in atherosclerotic mice by Guizhen Lin, Lei Zhang, Zheng Yan, Wei Jiang, Beibei Wu, Dongsheng Li and Xiaofang Xiong in International Journal of Immunopathology and Pharmacology</p
The Construction of Orange Drought Warning Model—A case study of Beibei Orangery in Chongqing City
No full textOn the basis of expounding the status quo of China’s orange drought warning model research, according to the real-time monitoring data of Beibei Orangery in Chongqing City from June to August in 2010, by using factor analysis and principal component regression, we construct the drought warning model of Beibei Orangery in Chongqing City, and we conduct test and correction on drought warning model by using MAPE principle of assessment and prediction accuracy and the real-time monitoring data of September. The results show that as for the prediction of orange drought, the model has strong credibility. If we conduct continuous dynamic monitoring on the relevant indices regarding orange drought by virtue of this model, and pay attention to the analysis of variation trend of prediction value, then it will be more practical; the warning effect, to some extent, further indicates that using factor analysis and principal component analysis method to conduct drought warning is rational; as the prediction model is static and linear, so we should perfect model to promote the accuracy and practicality of model
The Construction of Orange Drought Warning Model—A case study of Beibei Orangery in Chongqing City
No full textOn the basis of expounding the status quo of China’s orange drought warning model research, according to the real-time monitoring data of Beibei Orangery in Chongqing City from June to August in 2010, by using factor analysis and principal component regression, we construct the drought warning model of Beibei Orangery in Chongqing City, and we conduct test and correction on drought warning model by using MAPE principle of assessment and prediction accuracy and the real-time monitoring data of September. The results show that as for the prediction of orange drought, the model has strong credibility. If we conduct continuous dynamic monitoring on the relevant indices regarding orange drought by virtue of this model, and pay attention to the analysis of variation trend of prediction value, then it will be more practical; the warning effect, to some extent, further indicates that using factor analysis and principal component analysis method to conduct drought warning is rational; as the prediction model is static and linear, so we should perfect model to promote the accuracy and practicality of model.Orange, Drought warning, Chongqing City, Principal component analysis method, factor analysis method, China, Agribusiness,
Strengthening public health services to achieve universal health coverage in China.
No full textBetter integration of public health and medical services and greater focus on quality of services are needed to make further progress on health outcomes, say Beibei Yuan and colleague
Enhancing clustering blog documents by utilizing author/reader comments
No full textBlogs are a new form of internet phenomenon and a vast everincreasing information resource. Mining blog files for information is a very new research direction in data mining. We propose to include the title, body, and comments of the blog pages in clustering datasets from blog documents. In particular, we argue that the author/reader comments of the blog pages may have more discriminating effect in clustering blog documents. We constructed a word-page matrix by downloading blog pages from a well-known website and experimented a k-means clustering algorithm with different weights assigned to the title, body, and comment parts. Our experimental results show that assigning a larger weight value to the blog comments helps the k-means algorithm produce better clustering solutions. The experimental results confirm our hypothesis that the author/reader comments of the blog files are very useful in discriminating blog files
Coercivity and thermal stability improvement in sintered Nd-Fe-B permanent magnets by intergranular addition of Dy-Mn alloy
No full textTo increase coercivity and thermal stability of sintered Nd-Fe-B magnets for high temperature applications, Dy88Mn12 (wt%) alloy powders were intergranular added into (Pr0.25Nd0.75)(30).6Cu0.15FebalB1 (wt%) starting magnet. The magnetic properties, microstructure and thermal stability of the sintered magnets with different amounts of DyooMn12 were investigated. By adding a small amount of Dy88Mn12, the coercivity was significantly increased from 12.56 kOe to 17.49 kOe. Microstructure analysis showed that a optimized microstructure, i.e. continuous, uniform grain boundary phase was achieved with Dy88Mn12 alloy addition, and Dy was enriched in the outer region of the Nd(2)Fei(4)B matrix grains during the sintering process, which favored to substitute for Nd in matrix grains to form the (Nd,Dy)(2)Fei(4)B core-shell phase. The greatly increased magnetocrystalline anisotropy of the core-shell phase and the improved decoupling by the continuous grain boundary phase accounted for the coercivity enhancement. Furthermore, by adding 0-4 wt% Dy88Mn12, the reversible temperature coefficients of remanence (a) and coercivity (/3) of the magnet were improved from 0.115%/Qc to 0.107%/Qc and 0.744%PC to 0.696%/degrees C in the range of 20-100 degrees C, respectively. In addition, the irreversible flux loss of magnetic flow (h,) decreased sharply as DyooMn12 addition. The temperature-dependent magnetic properties results indicated that with intergranular addition of DyooMn12 alloy, the thermal stability of the magnets was effectively improved. (C) 2016 Elsevier B.V. All rights reserved
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