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arXiv 2018年

作者： Xie, Yutong Zhang, Jianpeng Xia, Yong National Engineering Laboratory for Integrated Aero-Space-Ground-Ocean Big Data Application Technology School of Computer Science and Engineering Northwestern Polytechnical University Xi'an710072 China

A multi-level deep ensemble (MLDE) model that can be trained in an 'end to end' manner is proposed for skin lesion classification in dermoscopy images. In this model, four pre-trained ResNet-50 networks are used to characterize the multiscale information of skin lesions and are combined by using an adaptive weighting scheme that can be learned during the error back propagation. The proposed MLDE model achieved an average AUC value of 86.5% on the ISIC-skin 2018 official validation dataset, which is substantially higher than the average AUC values achieved by each of four ResNet-50 networks. Copyright © 2018, The Authors. All rights reserved.

关键词： Image classification

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The design and implementation of intersection points of geometric figures in netpad 13

The design and implementation of intersection points of geom...

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13th International Conference on computer science and Education, ICCSE 2018

作者： Chen, Ruxian Rao, Yonesheng Guan, Hao Wang, Ying School of Computer Science and Education Software Guangzhou University Guangzhou China Guangdong Provincial Engineering and Technology Research Center for Mathematical Education Software Guangzhou China Institute of Computing Science and Technoligy Guangzhou University Guangzhou China Guizhou Provincal Academician Workstation of Educational Big Date Technology and Educational Mathematics Guiyang China University of the Chinese Academy of Sciences Beijing China Chengdu Institute of Computer Application Chinese Academy of Sciences Chengdu China Department of Network Technology South China Institute of Software Engineering Guangzhou China

ISBN: (纸本)9781538654958

It is a very important function of dynamic geometry software to construct intersection points of geometric figures. However, this function isn't perfect in most dynamic geometry software yet. In this paper, we design and implement intersection points of geometric figures in NetPad, an advanced online dynamic mathematics software designed for teaching and learning mathematics in elementary and secondary school. Under the design concepts of convenience, completion and stability, NetPad not only can conveniently construct intersection points of any geometric figures, but also maintain the continuity and stability of intersection points. Through some teaching cases, we demonstrate the simplicity and efficiency of constructing intersection points of geometric figures in NetPad. © 2018 IEEE.

关键词： Geometry

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Characterizing weibo social media posts from wuhan, china during the early stages of the COVID-19 pandemic: Qualitative content analysis

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JMIR Public Health and Surveillance 2020年第4期6卷 e24125页

作者： Xu, Qing Shen, Ziyi Shah, Neal Cuomo, Raphael Cai, Mingxiang Brown, Matthew Li, Jiawei Mackey, Tim Department of Healthcare Research and Policy University of California San Diego - Extension San Diego CA United States Global Health Policy and Data Institute San Diego CA United States S-3 Research LLC San Diego CA United States Masters Program in Computer Science Jacobs School of Engineering University of California San Diego San Diego CA United States Department of Anesthesiology School of Medicine University of California San Diego San Diego CA United States US Embassy National Cancer Institute National Institutes of Health Beijing China Department of Anesthesiology Division of Infectious Diseases and Global Public Health School of Medicine University of California San Diego San Diego CA United States

Background: The COVID-19 pandemic has reached 40 million confirmed cases worldwide. Given its rapid progression, it is important to examine its origins to better understand how people’s knowledge, attitudes, and reactions have evolved over time. One method is to use data mining of social media conversations related to information exposure and self-reported user experiences. Objective: This study aims to characterize the knowledge, attitudes, and behaviors of social media users located at the initial epicenter of the outbreak by analyzing data from the Sina Weibo platform in Chinese. Methods: We used web scraping to collect public Weibo posts from December 31, 2019, to January 20, 2020, from users located in Wuhan City that contained COVID-19–related keywords. We then manually annotated all posts using an inductive content coding approach to identify specific information sources and key themes including news and knowledge about the outbreak, public sentiment, and public reaction to control and response measures. Results: We identified 10,159 COVID-19 posts from 8703 unique Weibo users. Among our three parent classification areas, 67.22% (n=6829) included news and knowledge posts, 69.72% (n=7083) included public sentiment, and 47.87% (n=4863) included public reaction and self-reported behavior. Many of these themes were expressed concurrently in the same Weibo post. Subtopics for news and knowledge posts followed four distinct timelines and evidenced an escalation of the outbreak’s seriousness as more information became available. Public sentiment primarily focused on expressions of anxiety, though some expressions of anger and even positive sentiment were also detected. Public reaction included both protective and elevated health risk behavior. Conclusions: Between the announcement of pneumonia and respiratory illness of unknown origin in late December 2019 and the discovery of human-to-human transmission on January 20, 2020, we observed a high volume of public anxie

关键词： Attitude Behavior China Content analysis COVID-19 Data mining Infodemic Infodemiology Infoveillance Knowledge Social media Weibo

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Li, An, and Morozov Reply:

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Physical Review Letters 2019年第11期123卷 119602-119602页

作者： Guodong Li Qi An Sergey I. Morozov Hubei Key Laboratory of Theory and Application of Advanced Materials Mechanics School of Science Wuhan University of Technology Wuhan 430070 China State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology Wuhan 430070 China Department of Chemical and Materials Engineering University of Nevada Reno Reno Nevada 89557 USA Department of Computer Simulation and Nanotechnology South Ural State University Chelyabinsk 454080 Russia

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An improved Isomap method for manifold learning

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International Journal of Intelligent Computing and Cybernetics 2017年第1期10卷 30-40页

作者： Taiguo Qu Zixing Cai College of Computer Science and Technology Hengyang Normal UniversityHengyangChina Hunan Provincial Key Laboratory of Intelligent Information Processing and Application HengyangChina School of Information Science and Engineering Central South UniversityChangshaChina

Purpose-Isometric feature mapping(Isomap)is a very popular manifold learning method and is widely used in dimensionality reduction and data *** most time-consuming step in Isomap is to compute the shortest paths between all pairs of data points based on a neighbourhood *** classical Isomap(C-Isomap)is very slow,due to the use of Floyd’s algorithm to compute the shortest *** purpose of this paper is to speed up ***/methodology/approach-Through theoretical analysis,it is found that the neighbourhood graph in Isomap is *** this case,the Dijkstra’s algorithm with Fibonacci heap(Fib-Dij)is faster than Floyd’s *** this paper,an improved Isomap method based on Fib-Dij is *** using Fib-Dij to replace Floyd’s algorithm,an improved Isomap method is presented in this ***-Using the S-curve,the Swiss-roll,the Frey face database,the mixed national institute of standards and technology database of handwritten digits and a face image database,the performance of the proposed method is compared with C-Isomap,showing the consistency with C-Isomap and marked improvements in terms of the high *** also demonstrate that Fib-Dij reduces the computation time of the shortest paths from O(N3)to O(N2lgN).Research limitations/implications-Due to the limitations of the computer,the sizes of the data sets in this paper are all smaller than 3,***,researchers are encouraged to test the proposed algorithm on larger data ***/value-The new method based on Fib-Dij can greatly improve the speed of Isomap.

关键词： Dijkstra’s algorithm Fibonacci heap Floyd’s algorithm Isomap Manifold learning Shortest path Paper type Research paper

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Personalized next point-of-interest recommendation via latent behavior patterns inference

arXiv

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arXiv 2018年

作者： He, Jing Li, Xin Liao, Lejian Cheung, William K. Beijing Engineering Research Center of High Volume Language Information Processing and Cloud Computing Application School of Computer Science and Technology Beijing Institute of Technology Beijing10081 China

In this paper, we address the problem of personalized next Point-of-interest (POI) recommendation which has become an important and very challenging task for location-based social networks (LBSNs), but not well studied yet. With the conjecture that, under different contextual scenarios, human exhibits distinct mobility pattern, we attempt here to jointly model the next POI recommendation under the influence of user's latent behavior pattern. We propose to adopt a third-rank tensor to model the successive check-in behaviors. By integrating categorical influence into mobility patterns and aggregating user's spatial preference on a POI, the proposed model deal with the next new POI recommendation problem by nature. By incorporating softmax function to fuse the personalized Markov chain with latent pattern, we furnish a Bayesian Personalized Ranking (BPR) approach and derive the optimization criterion accordingly. Expectation Maximization (EM) is then used to estimate the model parameters. We further develop a personalized model by taking into account personalized mobility patterns under the contextual scenario to improve the recommendation performance. Extensive experiments on two large-scale LBSNs datasets demonstrate the significant improvements of our model over several state-of-the-art methods. Copyright © 2018, The Authors. All rights reserved.

关键词： Maximum principle

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Cross-domain labeled LDA for cross-domain text classification

arXiv

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arXiv 2018年

作者： Jing, Baoyu Lu, Chenwei Wang, Deqing Zhuang, Fuzhen Niu, Cheng School of Computer Science Carnegie Mellon University PittsburghPA United States School of Computer Science and Engineering Beihang University Beijing China Institute of Computing Technology CAS Beijing China University of Chinese Academy of Science Beijing China Pattern Recognition Center WeChat Search Application Department Tencent China

Cross-domain text classification aims at building a classifier for a target domain which leverages data from both source and target domain. One promising idea is to minimize the feature distribution differences of the two domains. Most existing studies explicitly minimize such differences by an exact alignment mechanism (aligning features by one-to-one feature alignment, projection matrix etc.). Such exact alignment, however, will restrict models' learning ability and will further impair models' performance on classification tasks when the semantic distributions of different domains are very different. To address this problem, we propose a novel group alignment which aligns the semantics at group level. In addition, to help the model learn better semantic groups and semantics within these groups, we also propose a partial supervision for model's learning in source domain. To this end, we embed the group alignment and a partial supervision into a cross-domain topic model, and propose a Cross-Domain Labeled LDA (CDL-LDA). On the standard 20Newsgroup and Reuters dataset, extensive quantitative (classification, perplexity etc.) and qualitative (topic detection) experiments are conducted to show the effectiveness of the proposed group alignment and partial supervision. Copyright © 2018, The Authors. All rights reserved.

关键词： Semantics

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Corrigendum to “Terrestrial and groundwater storage characteristics and their quantification in the Chitral (Pakistan) and Kabul (Afghanistan) river basins using GRACE/GRACE-FO satellite data”

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Groundwater for Sustainable Development 2023年 23卷

作者： Aqil Tariq Shoaib Ali Iqra Basit Ahsan Jamil Nizom Farmonov Behnam Khorrami Muhammad Mohsin Khan Samira Sadri Muhammad Yousuf Jat Baloch Fakhrul Islam Muhammad Bilawal Junaid Wesam Atef Hatamleh Ubaid-ur-Rehman Janjua Department of Wildlife Fisheries and Aquaculture College of Forest Resources Mississippi State University 775 Stone Boulevard 39762-9690 MS USA State Key Laboratory of Information Engineering in Surveying Mapping and Remote Sensing Wuhan University Wuhan 430079 China School of Water Conservancy & Civil Engineering Northeast Agricultural University Harbin Heilongjiang 150030 China Department of Irrigation and Drainage Faculty of Agricultural Engineering and Technology University of Agriculture Faisalabad Faisalabad 38000 Pakistan Remote Sensing GIS and Climate Research Lab (National Center of GIS and Space Application) Centre for Remote Sensing University of the Punjab Lahore 54590 Pakistan Department of Plant and Environmental Sciences New Mexico State University 3170S Espina Street Las Cruces NM 88003 USA Department of Geoinformatics Physical and Environmental Geography University of Szeged Egyetem utca 2 Szeged 6722 Hungary Department of GIS The Graduate School of Applied and Natural Sciences Dokuz Eylul University 35220 Izmir Turkey Department of Agricultural Engineering Muhammad Nawaz Shareef University of Agriculture Multan Multan Pakistan Department of Water Resources Engineering Shahid Chamran University of Ahvaz Ahvaz *** Iran College of New Energy and Environment Jilin University Changchun 130021 China Department of Geology Khushal Khan Khattak University Karak Pakistan Department of Plant Production College of Food and Agriculture King Saud University Riyadh Saudi Arabia Department of Computer Science College of Computer and Information Sciences King Saud University P.O. Box 51178 Riyadh 11543 Saudi Arabia Department of Geography and Geospatial Sciences Geospatial Sciences Center of Excellence South Dakota State University Brookings South Dakota USA

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A W-band Antenna with Dual Circular Polarization for mmWave Wireless Communications

A W-band Antenna with Dual Circular Polarization for mmWave ...

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UK, Europe, China Millimeter Waves and THz Technology Workshop (UCMMT)

作者： Chao Shu Shaoqing Hu Yuan Yao Xiaodong Chen School of Electronic Engineering and Computer Science Queen Mary University of London London UK BUPT-QMUL EM Theory & Application International Research Lab School of Electronic Engineering Beijing University of Posts and Telecommunications Beijing China

ISBN: (数字)9781538674970

ISBN: (纸本)9781538674987

This paper presents our study on a dual circular polarization feed horn for reflector antennas operating in W-Band. It mainly consists of a stepped septum polarizer, a circular horn and dual ports for LHCP and RHCP feeding respectively. Apart from the high gain that can be achieved when it is used together with parabolic reflector as a primary feed, it has the capability of transmitting and receiving two orthogonal circular polarized signal to achieve Polarization-Division Multiplexing (PDM) or a Full-Duplex in mmWave wireless communication systems. The simulation results show that the proposed feed horn can achieve 21% relative bandwidth from 85 GHz to 105 GHz with AR 11 15 dB for both LHCP and RHCP. Radiation pattern with good rotational symmetry over the whole working bandwidth is also obtained in order to achieve high aperture efficiency when the feed horn works with a parabolic reflector.

关键词： Bandwidth Polarization Horn antennas Reflector antennas Antenna feeds Gain

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Comparative studies of optoelectrical properties of prominent PV materials: Halide Perovskite, CdTe, and GaAs

arXiv

引用

arXiv 2019年

作者： Zhang, Fan Castaneda, Jose F. Chen, Shangshang Wu, Wuqiang DiNezza, Michael J. Lassise, Maxwell Nie, Wanyi Mohite, Aditya Liu, Yucheng Liu, Shengzhong Friedman, Daniel Liu, Henan Chen, Qiong Zhang, Yong-Hang Huang, Jinsong Zhang, Yong Department of Electrical and Computer Engineering University of North Carolina at Charlotte CharlotteNC28223 United States Department of Applied Physical Sciences University of North Carolina at Chapel Hill Chapel HillNC27599 United States School of Electrical Computer and Energy Engineering Arizona State University TempeAZ85287 United States Materials Physics and Application Division Los Alamos National Laboratory Los AlamosNM87545 United States Department of Chemical and Biomolecular Engineering Department of Material Science and Nanoengineering Rice University HoustonTX77005 United States Key Laboratory of Applied Surface and Colloid Chemistry National Ministry of Education Institute for Advanced Energy Materials School of Materials Science and Engineering Shaanxi Normal University Xi'an710062 China National Renewable Energy Laboratory GoldenCO80401 United States

We compare three representative high performance PV materials: halide perovskite MAPbI3, CdTe, and GaAs, in terms of photoluminescence (PL) efficiency, PL lineshape, carrier diffusion, and surface recombination, over multiple orders of photo-excitation density. An analytic model is used to describe the excitation density dependence of PL intensity and extract the internal PL efficiency and multiple pertinent recombination parameters. A PL imaging technique is used to obtain carrier diffusion length without using a PL quencher, thus, free of unintended influence beyond pure diffusion. Our results show that perovskite samples tend to exhibit lower Shockley-Read-Hall (SRH) recombination rate in both bulk and surface, thus higher PL efficiency than the inorganic counterparts, particularly under low excitation density, even with no or preliminary surface passivation. PL lineshape and diffusion analysis indicate that there is considerable structural disordering in the perovskite materials, and thus photo-generated carriers are not in global thermal equilibrium, which in turn suppresses the nonradiative recombination. This study suggests that relatively low point-defect density, less detrimental surface recombination, and moderate structural disordering contribute to the high PV efficiency in the perovskite. This comparative photovoltaics study provides more insights into the fundamental material science and the search for optimal device designs by learning from different technologies. Copyright © 2019, The Authors. All rights reserved.

关键词： Perovskite

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