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Diversifying Top-κRoutes with spatial Constraints

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Journal of Computer Science & Technology 2019年第4期34卷 818-838页

作者： Hong-Fei Xu Yu Gu Jian-Zhong Qi Jia-Yuan He Ge Yu College of Computer Science and Engineering Northeastern UniversityShenyang 110169China Department of Computing and Information Systems The University of MelbourneMelbourneVIC 3010Australia

Trip recommendation has become increasingly popular with the rapid growth of check-in data in location-based social *** existing studies focused only on the popularity of *** this paper,we consider further the usability of trip recommendation results through spatial *** thereby formulate a new type of queries named spatial diversified top-κroutes(SDκR)*** type of queries finds k trip routes with the highest popularity,each of which starts at a given starting point,consumes travel time within a given time budget,and passes through points of interest(POIs)of given *** two trip routes returned are diversified to a certain degree defined by the spatial distance between the two *** show that the SDkR problem is *** propose two precise algorithms to solve the *** first algorithm starts with identifying all candidate routes that satisfy the query constraints,and then searches for theκ-route combination with the highest *** second algorithm identifies the candidate routes and builds up the optimalκ-route combination progressively at the same ***,we propose an approximate algorithm to obtain even higher query efficiency with precision *** demonstrate the effectiveness and efficiency of the proposed algorithms on real *** experimental results show that our algorithms find popular routes with diversified POI *** approximate algorithm saves up to 90%of query time compared with the baseline algorithms.

关键词： trip recommendation spatial diversity route search check-in data

Growth-induced Stacking Faults of ZnO Nanorods Probed by spatial Resolved Cathodoluminescence

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Chinese Physics Letters 2012年第7期29卷 261-264页

作者： XIE Yong JIE Wan-Qi WANG Tao WIEDENMANN Michael NEUSCHL Benjamin MADEL Manfred WANG Ya-Bin FENEBERG Martin THONKE Klaus State Key Laboratory of Solidification Processing School of Materials Science and EngineeringNorthwestern Polytechnical UniversityXi’an 710072 Institut fur Quantenmaterie/Gruppe Halbleiterphysik Universitat Ulm89069 UlmGermany Institut fur Experimentelle Physik Otto-von-Guericke-Universitat Magdeburg39106 MagdeburgGermany

Low density ZnO nanorods are grown by modified chemical vapor deposition on silicon substrates using gold as a *** use high resolution photoiuminescence spectroscopy to gain the optical properties of these nanorods in large *** as-grown samples show sharp near-band-gap luminescence with a full width at half maximum of bound exciton peaks at about 300μeV,and the ratio of ultraviolet/yellow luminescence larger than *** spatial and spectral resolved scanning electron microscope-cathodoluminescence is performed to excite the ZnO nanorods in single rods or different positions of single rods with the vapour-solid grovth *** bottom of the nanorod has a 3.31-eV luminescence,which indicates that basal plane stacking faults are related to the defects that are created at the first stage of growth due to the misfit between ZnO and Si.

关键词： vapour spatial ultraviolet

Big spatial data for urban and environmental sustainability

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Geo-spatial Information Science 2020年第2期23卷 125-140页

作者： Bo Huang Jionghua Wang Department of Geography and Resource Management The Chinese University of Hong KongHong KongChina

Eighty percent of big data are associated with spatial information,and thus are Big spatial Data(BSD).BSD provides new and great opportunities to rework problems in urban and environmental sustainability with advanced BSD *** fully leverage the advantages of BSD,it is integrated with conventional data(*** sensing images)and improved methods are *** paper introduces four case studies:(1)Detection of polycentric urban structures;(2)Evaluation of urban vibrancy;(3)Estimation of population exposure to PM2.5;and(4)Urban land-use classification via deep *** results provide evidence that integrated methods can harness the advantages of both traditional data and ***,they can also improve the effectiveness of big data ***,this study makes three key recommendations for the development of BSD with regards to data fusion,data and predicting analytics,and theoretical modeling.

关键词： Big spatial data analytics review spatial modeling data fusion

spatial distribution and accumulation of heavy metals in tidal flat sediments of Shanghai coastal zone

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Science China Chemistry 2001年第S1期44卷 197-208页

作者：陈振楼刘培芳许世远柳林余佳俞立中 E China Normal Univ State Key Lab Estuarine & Coastal Sediment Dynam Shanghai 200062 Peoples R China

Surface and core sediments from the high, middle and low tidal flats of Shanghai coastal zone were analyzed for heavy metal (e.g. Cu, Pb, Zn, Cr, Cd, Fe, Mn) concentrations. Besides Cd, the concentrations of Cu, Zn, Cr and Pb are 2-5 times higher than their background values and show serious pollution trend due to the direct discharge of industrial and municipal sewage along the Shanghai tidal flat, as well as the wet and dry depositions of industrial dusts. It seems that heavy metals prefer to accumulate and be enriched in the sediments near large sewage outlets, high flats, and the subsurface layer at the depth of 10-30 cm. Several main factors, which include the direct sewage discharge along the tidal flat, tidal hydrodynamic action, large engineering activity, early diagenesis and windstorm tide, are considered to be responsible for influencing spatial distribution patterns of heavy metals in the Shanghai tidal flat.

关键词： Shanghai coastal zone tidal flat sediments heavy metals spatial distribution spatial accumulation.

Investigation on the spatial distribution characteristics of behind-armor debris formed by the perforation of EFP through steel target

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Defence Technology（防务技术） 2020年第1期16卷 119-135页

作者： Xin Wang Jianwei Jiang Shengjie Sun Jianbing Men Shuyou Wang State Key Laboratory of Explosion Science and Technology Beijing Institution of TechnologyChina

The behind-armor debris(BAD) formed by the perforation of an EFP is the main damage factor for the secondary destruction to the behind-armor *** at investigating the BAD caused by EFP,flash X-ray radiography combined with an experimental witness plate test method was used,and the FEM-SPH adaptive conversion algorithm in LS-DYNA software was erployed to model the perforation *** simulation results of the debris cloud shape and number of debris were in good agreement with the flash X-ray radiographs and perforated holes on the witness plate,*** numerical simulations of EFP's penetration under various impact conditions were *** results show that,an ellipsoidal debris cloud,with the major-to-minor axis radio(a/b)smaller than that caused by shaped charge jets,was formed behind the *** the increase of target thickness(h) and decrease of impact velocity(v_0) and obliquity(θ),the value of a/b *** number of debris ejected from target is significantly higher than that from *** on the statistical analysis of the spatial distribution of the BAD,An engineering calculation model was established considering the influence of h,v_0 and θ.The model can with reasonable accuracy predict the quantity and velocity distribution characteristics of BAD formed by EFP.

关键词： Behind-armor debris EFP FEM-SPH adaptive conversion algorithm spatial distribution

Temporal Correlation-Based spatial Filtering of Rician Noise for Functional MRIs

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Chinese Physics Letters 2012年第1期29卷 287-290页

作者： Amir.A.Khaliq I.M.Qureshi Jawad.A.Shah Department of Electronic Engineering International Islamic UniversityIslamabadPakistan Air University ISSSIslamabadPakistan

A novel correlation-based filter is presented for de-noising functional magnetic resonance imaging (fMRI) *** correlation-based exponential weights are defined for spatial smoothing of the data,with bias reduction using estimated noise *** proposed scheme is tested on simulated and real fMRI ***,the results are compared with conventional *** method is found to be effectively suppressing the Rician noise in fMRI data,while improving the SNR.

关键词： weights smoothing spatial

Cooperation of a Dissatisfied Adaptive Prisoner's Dilemma in spatial Structures

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Chinese Physics Letters 2013年第10期30卷 233-236页

作者： ZHANG Wen LI Yao-Sheng DU Peng XU Chen Department of Mechanical and Electrical Engineering Suzhou Institute of Industrial TechnologySuzhou 215104 School of Physical Science and Technology Soochow UniversitySuzhou 215006

We study the cooperative behavior of a dissatisfied adaptive prisoner's dilemma via a pair updating *** compare two kinds of relationship among the competing agents,one is the well-mixed population and the other is the two-dimensional square *** is found that the cooperation emerges in both the cases and the frequency of cooperation is enhanced in the square *** it is impossible for the cooperators to have a higher average payoff than that of the defectors in the well-mixed case,the cooperators in the spatial square lattice could have higher average payoffs in certain regions of the game *** theoretically analyze the well-mixed case exactly and the square lattice by pair *** theoretic results are in agreement with the simulation data.

关键词： spatial operators lemma

Temporal and spatial rupture process of the great Kunlun Mountain Pass earthquake of November 14,2001 from the GDSN long period waveform data

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Science China Earth Sciences 2005年第1期48卷 112-122页

作者： XU Lisheng CHEN Yuntai Institute of Geophysics China Seismological Bureau Beijing 100081 China Institute of Geophysics China Seismological Bureau Beijing 100081 China

The temporal and spatial rupture process of the 14 November 2001 Kunlun Mountain Pass earthquake (KMPE) is obtained by inverting the high signal-to-noise-ratio P-waveform data of vertical components of 20 stations with epicentral distances less than 90°, which are of Global Digital Seismogragh Network (GDSN). The inverted results indicate that the KMPE consists of 3 sub-events. The rupture of the first sub-event initiated at the instrumental epicenter (35.97°N,90.59°E) and then propagated both westwards and eastwards, extending 140 km westwards at the speed of 4.0 km/s and 80 km eastwards at the speed of 2.2 km/s, which appeared to be an asymmetrical bilateral rupture dominantly from east to west. This sub-event formed a 220-km-long fault. Fifty-two seconds after initiation of the first sub-event, at which time the first sub-event was not over but in its healing phase, the rupture of the second sub-event initiated 220 km west of the epicenter and propagated both westwards and eastwards, extending 50 km westwards at the speed of 2.2 km/s and 70 km eastwards at the speed of 5.8 km/s, which appeared to be an asymmetrical bilateral rupture dominantly from west to east. The secondsub-event formed a 120-km-long fault. The second sub-event fused with the first sub-event 140km west to the epicenter right 12 s after its initiation. Fifty-six seconds after initiation of the first sub-event, at which time the first sub-event was getting close to the end of its healing phase, the rupture of the third sub-event initiated 220 km east of the epicenter and propagated both westwards and eastwards, extending 140 km westwards at the speed of 4.0 km/s and 130 km eastwards at the speed of 3.7 km/s, which appeared to be nearly an bilateral rupture. This sub-event formed a 270-km-long fault. The third sub-event fused with the first sub-event 80 km east of the epicenter right 36 s after its initiation. Afterwards, the source process of the KMPE was dominated by the slip after fusion of the

关键词： long-period waveform data, temporal and spatial rupture process, rupture fusion.

spatial PATTERNING OF SPRUCE BUDWORM IN CIRCULAR REGION

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Science China Mathematics 1991年第6期34卷 676-688页

作者：郭本瑜 Shanghai University of Science and Technology Shanghai 201800PRC

The spatial patterning of spruce budworm in a circular region is discussed. In particu-lar, the model with the interaction between the budworm and its predator is studied. Thepossibility of controlling outbreak states... 详细信息

关键词： spatial patterning of budworm predator circular region.