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Geo-Spatial Information science 2019年第4期22卷 251-264,I0003页

作者： Yunzhe Liu Alex Singleton Daniel Arribas-Bel geographic data science lab Department of Geography and PlanningUniversity of LiverpoolLiverpoolUK

A geodemographic classification aims to describe the most salient characteristics of a small area zonal ***,such representations are influenced by the methodological choices made during their *** particular debate are the choice and specification of input variables,with the objective of identifying inputs that add value but also aim for model *** this context,our paper introduces a principal component analysis(PCA)-based automated variable selection methodology that has the objective of identifying candidate inputs to a geodemographic classification from a collection of *** proposed methodology is exemplified in the context of variables from the UK 2011 Census,and its output compared to the Office for National Statistics 2011 Output Area Classification(2011 OAC).Through the implementation of the proposed methodology,the quality of the cluster assignment was improved relative to 2011 OAC,manifested by a lower total withincluster sum of square *** the UK,more than 70.2%of the Output Areas(OAs)occupied by the newly created classification(***-OAC)outperform the 2011 OAC,with particularly strong performance within Scotland and Wales.

关键词： Geodemographics variable selection UK census spatial data mining principal component analysis

MARIE:One-Stage Object Detection Mechanism for Real-Time Identifying of Firearms

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Computer Modeling in Engineering & sciences 2025年第1期142卷 279-298页

作者： Diana Abi-Nader Hassan Harb Ali Jaber Ali Mansour Christophe Osswald Nour Mostafa Chamseddine Zaki Computer science Department Faculty of SciencesLebanese UniversityBeirut146404Lebanon College of Engineering and Technology American University of the Middle EastEgaila54200Kuwait lab-STICC CNRS UMR 6285ENSTA-BretagneBrest29200France

Security and safety remain paramount concerns for both governments and individuals *** today’s context,the frequency of crimes and terrorist attacks is alarmingly increasing,becoming increasingly intolerable to ***,there is a pressing need for swift identification of potential threats to preemptively alert law enforcement and security forces,thereby preventing potential attacks or violent *** advancements in big data analytics and deep learning have significantly enhanced the capabilities of computer vision in object detection,particularly in identifying *** paper introduces a novel automatic firearm detection surveillance system,utilizing a one-stage detection approach named MARIE(Mechanism for Realtime Identification of Firearms).MARIE incorporates the Single Shot Multibox Detector(SSD)model,which has been specifically optimized to balance the speed-accuracy trade-off critical in firearm detection *** SSD model was further refined by integrating MobileNetV2 and InceptionV2 architectures for superior feature extraction *** experimental results demonstrate that this modified SSD configuration provides highly satisfactory performance,surpassing existing methods trained on the same dataset in terms of the critical speedaccuracy *** these innovations,MARIE sets a new standard in surveillance technology,offering a robust solution to enhance public safety effectively.

关键词： Firearm and gun detection single shot multi-box detector deep learning one-stage detector MobileNet inception convolutional neural network

Spatial and Temporal Distributions and Sources of Anthropogenic NMVOCs in the Atmosphere of China:A Review

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Advances in Atmospheric sciences 2021年第7期38卷 1085-1100页

作者： Fanglin WANG Wei DU Shaojun LV Zhijian DING Gehui WANG Key lab of geographic Information science of the Ministry of Education School of Geographic SciencesEast China Normal UniversityShanghai 200241China Institute of Eco-Chongming Shanghai 200062China

As the key precursors of O_(3),anthropogenic non-methane volatile organic compounds(NMVOCs)have been studied *** paper performed a meta-analysis on the spatial and temporal variations of NMVOCs,their roles in photochemical reactions,and their sources in China,based on published *** results showed that both nonmethane hydrocarbons(NMHCs)and oxygenated VOCs(OVOCs)in China have higher mixing ratios in the eastern developed cities compared to those in the central and western *** are the most abundant NMHCs species in all reported sites while formaldehyde is the most abundant among the *** have the highest mixing ratios in summer and the lowest in winter,which is opposite to *** all NMVOCs,the top eight species account for 50%−70%of the total ozone formation potential(OFP)with different compositions and contributions in different *** devolved regions,OFP-NMHCs are the highest in winter while OFP-OVOCs are the highest in *** on positive matrix factorization(PMF)analysis,vehicle exhaust,industrial emissions,and solvent usage in China are the main sources for ***,the emission trend analysis showed that solvent usage and industrial emissions will exceed vehicle exhaust and become the two major sources of NMVOCs in near *** on the meta-analysis conducted in this work,we believe that the spatio-temporal variations and oxidation mechanisms of atmospheric OVOCs,as well as generating a higher spatial resolution of emission inventories of NMVOCs represent an area for future studies on NMVOCs in China.

关键词： NMVOCs spatial-temporal distribution photochemical activity source analysis

Effect of NOx and RH on the secondary organic aerosol formation from toluene photooxidation

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Journal of Environmental sciences 2022年第4期34卷 1-9页

作者： Shijie Liu Xiaodi Liu Yiqian Wang Si Zhang Can Wu Wei Du Gehui Wang Key lab of geographic Information science of the Ministry of Education School of Geographic SciencesEast China Normal UniversityShanghai 210062China Institute of Eco-Chongming 3663 North Zhongshan RoadShanghai 200062China

The secondary organic aerosol(SOA)formation mechanism and physicochemical properties can highly be influenced by relative humidity(RH)and NOx *** this study,we performed a laboratory investigation of the SOA formation from toluene/OH photooxidation system in the presence or absence of NOx in dry and wet *** chemical composition of toluene-derived SOA was measured using Aerodyne high-resolution timeof-flight aerosol mass spectrometer(HR-ToF-AMS).It was found that the mass concentration of toluene decreased with increasing RH and NOx ***,the change of SOA chemistry composition(f_(44),O/C)with increased RH was not consistent in the condition with or without *** light absorption and mass absorption coefficient(MAC)of the toluene-derived SOA only increased with RH in the presence of *** contrast,MAC is invariant with RH in the absence of ***-ToF-AMS results showed that,in the presence of NOx,the increased nitro-aromatic compounds and N/C ratio concurrently caused the increase of SOA light absorption and O/C in wet conditions,*** relative intensity of CHON and CHOxN family to the total nitrogen-containing organic compounds(NOCs)increased with the increasing RH,and be the major components of NOCs in wet *** work revealed a synergy effect of NOx and RH on SOA formation from toluene photooxidation.

关键词： Toluene Photooxidation Relative humidity NOx Optical property

Federated learning-outcome prediction with multi-layer privacy protection

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Frontiers of Computer science 2024年第6期18卷 186604页

作者： ZHANG Yupei LI Yuxin WANG Yifei WEI Shuangshuang XU Yunan SHANG Xuequn School of Computer science Northwestern Polytechnical University MIIT lab of Big data Storage and Management

Learning-outcome prediction (LOP) is a long-standing and critical problem in educational routes. Many studies have contributed to developing effective models while often suffering from data shortage and low generalization to various institutions due to the privacy-protection issue. To this end, this study proposes a distributed grade prediction model, dubbed FecMap, by exploiting the federated learning (FL) framework that preserves the private data of local clients and communicates with others through a global generalized model. FecMap considers local subspace learning (LSL), which explicitly learns the local features against the global features, and multi-layer privacy protection (MPP), which hierarchically protects the private features, including model-shareable features and not-allowably shared features, to achieve client-specific classifiers of high performance on LOP per institution. FecMap is then achieved in an iteration manner with all datasets distributed on clients by training a local neural network composed of a global part, a local part, and a classification head in clients and averaging the global parts from clients on the server. To evaluate the FecMap model, we collected three higher-educational datasets of student academic records from engineering majors. Experiment results manifest that FecMap benefits from the proposed LSL and MPP and achieves steady performance on the task of LOP, compared with the state-of-the-art models. This study makes a fresh attempt at the use of federated learning in the learning-analytical task, potentially paving the way to facilitating personalized education with privacy protection.

关键词： federated learning local subspace learning hierarchical privacy protection learning outcome prediction privacy-protected representation learning

Extending attributes page:a scheme for enhancing the reliability of storage system metadata

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Journal of Zhejiang University-science A(Applied Physics & Engineering) 2009年第8期10卷 1106-1113页

作者： Juan WANG Dan FENG Fang WANG Cheng-tao LU MOE Key lab of data Storage System Huazhong University of Science and Technology Wuhan 430074 China

In an object-based storage system,a novel scheme named EAP(extending attributes page) is presented to enhance the metadata reliability of the system by adding the user object file information attributes page for each user object and storing the file-related attributes of each user object in object-based storage *** EAP scheme requires no additional hardware equipments compared to a general method which uses backup metadata servers to improve the metadata *** a Markov chain,this paper compares the metadata reliability of the system using the EAP scheme with that using only metadata servers to offer the file metadata *** results demonstrate that the EAP scheme can dramatically enhance the reliability of storage system metadata.

关键词： Metadata server Metadata reliability Markov model Extending attributes page (EAP)

Theory and methodology of research on cloud security

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science China(Information sciences) 2016年第5期59卷 15-17页

作者： Hai JIN Weiqi DAI Deqing ZOU Services Computing Technology and System lab Big Data Technology and System Lab Cluster and Grid Computing Lab School of Computer Science and Technology Huazhong University of Science and Technology

Cloud computing is a model for enabling ubiquitous,convenient,on-demand access to a shared pool of configurable computing *** to Gartner’s survey,cloud computing has been at the head of a list of the top ten IT strategic technologies for some *** computing is currently undergoing vigorous development and promotion by many leading Chinese and foreign enterprises,and it has become the basis for a new

关键词： TPM Theory and methodology of research on cloud security

Towards dataflow based graph processing

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science China(Information sciences) 2017年第12期60卷 274-276页

作者： Hai JIN Pengcheng YAO Xiaofei LIAO Service Computing Technology and System lab Cluster and Grid Computing Lab Big Data Technology and System Lab School of Computer Science and Technology Huazhong University of Science and Technology

Modern graph processing is widely used for solving a vast variety of real-world problems,e.g.,web sites ranking[1]and community detection[2].To better adapt and express the procedure of graph iteration,a wide spectrum... 详细信息

关键词： ILP cycle Towards dataflow based graph processing

Variations in Optical Scattering and Backscattering by Organic and Inorganic Particulates in Chinese Lakes of Taihu, Chaohu and Dianchi

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Chinese geographical science 2015年第1期25卷 26-38页

作者： LYU Heng WANG Qiao WU Chuanqing ZHU Li LI Yunmei HUANG Jiazhu Key laboratory of Virtual geographic Environment Ministry of Education College of Geographic Science Nanjing Normal University Satellite Environment Application Center Ministry of Environmental Protection

This study presents an investigation of the scattering and backscattering properties of the particulates in three Chinese inland lakes(the Taihu Lake, the Chaohu Lake and the Dianchi Lake) based on in situ measurements taken at 119 sites. We modeled the particulate scattering spectra using a wavelength-dependent power-law function, finding that the power-law exponents in the Taihu Lake and the Chaohu Lake differ from those in the Dianchi Lake but are similar to the values in the U.S. coastal waters. In contrast to the open ocean, the backscattering properties in the three lakes can not be determined only from chlorophyll-a concentration. The backscattering ratio spectra exhibit a wavelength dependence feature in all three lakes, generally decreasing with the increasing wavelength. Analysis results of the correlations between the backscattering ratio and the individual water quality parameters clearly show that there are distinctive relations among the three lakes, attributed primarily to different compositions of optically active materials in the three lakes. Analysis of the mass-specific scattering and backscattering coefficients shows that the coefficients at wavelength 532 nm in the Taihu Lake and Chaohu Lake are similar, but they are apparently different from those in the Dianchi Lake. Lastly, Model I multiple linear regressions were adopted to partition the mass-specific cross-sections for scattering and backscattering into organic and inorganic cross-sections to further interpret the scattering and backscattering properties. The relative contribution of organic and inorganic particulates to scattering and backscattering is clearly different among the three lakes. The scattering and backscattering properties of the particulates in the three inland lakes vary significantly based on our collected data. The results indicated that the existing semi-analytical water quality retrieval models of the Taihu Lake can not be applied perfectly to the Chaohu Lake and the Di

关键词： scattering/backscattering coefficient backscattering ratio mass-specific cross-section organic/inorganic particulates Chinese inland lakes

Snapshot boosting: a fast ensemble framework for deep neural networks

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science China(Information sciences) 2020年第1期63卷 77-88页

作者： Wentao ZHANG Jiawei JIANG Yingxia SHAO Bin CUI Center for data science Peking University National Engineering laboratory for Big data Analysis and Applications Department of Computer science Beijing Key lab of Intelligent Telecommunications Software and Multimedia School of Computer ScienceBeijing University of Posts and Telecommunications Key lab of High Confidence Software Technologies Department of Computer SciencePeking University

Boosting has been proven to be effective in improving the generalization of machine learning models in many fields. It is capable of getting high-diversity base learners and getting an accurate ensemble model by combining a sufficient number of weak learners. However, it is rarely used in deep learning due to the high training budget of the neural network. Another method named snapshot ensemble can significantly reduce the training budget, but it is hard to balance the tradeoff between training costs and diversity. Inspired by the ideas of snapshot ensemble and boosting, we propose a method named snapshot boosting. A series of operations are performed to get many base models with high diversity and accuracy, such as the use of the validation set, the boosting-based training framework, and the effective ensemble strategy. Last, we evaluate our method on the computer vision(CV) and the natural language processing(NLP) tasks, and the results show that snapshot boosting can get a more balanced trade-off between training expenses and ensemble accuracy than other well-known ensemble methods.

关键词： ensemble learning deep learning boosting neural network snapshot ensemble