期刊文献+
共找到11篇文章
< 1 >
每页显示 20 50 100
An Enhanced Multiview Transformer for Population Density Estimation Using Cellular Mobility Data in Smart City
1
作者 Yu Zhou Bosong Lin +1 位作者 Siqi Hu Dandan Yu 《Computers, Materials & Continua》 SCIE EI 2024年第4期161-182,共22页
This paper addresses the problem of predicting population density leveraging cellular station data.As wireless communication devices are commonly used,cellular station data has become integral for estimating populatio... This paper addresses the problem of predicting population density leveraging cellular station data.As wireless communication devices are commonly used,cellular station data has become integral for estimating population figures and studying their movement,thereby implying significant contributions to urban planning.However,existing research grapples with issues pertinent to preprocessing base station data and the modeling of population prediction.To address this,we propose methodologies for preprocessing cellular station data to eliminate any irregular or redundant data.The preprocessing reveals a distinct cyclical characteristic and high-frequency variation in population shift.Further,we devise a multi-view enhancement model grounded on the Transformer(MVformer),targeting the improvement of the accuracy of extended time-series population predictions.Comparative experiments,conducted on the above-mentioned population dataset using four alternate Transformer-based models,indicate that our proposedMVformer model enhances prediction accuracy by approximately 30%for both univariate and multivariate time-series prediction assignments.The performance of this model in tasks pertaining to population prediction exhibits commendable results. 展开更多
关键词 population density estimation smart city TRANSFORMER multiview learning
下载PDF
Multi-criteria Satisfaction Assessment of the Spatial Distribution of Urban Emergency Shelters Based on High-Precision Population Estimation 被引量:9
2
作者 Jia Yu Jiahong Wen 《International Journal of Disaster Risk Science》 SCIE CSCD 2016年第4期413-429,共17页
This article introduces a framework for the multi-criteria satisfaction assessment of the spatial distribution of urban emergency shelters.A GIS-based analytic hierarchy process approach was utilized to conduct the as... This article introduces a framework for the multi-criteria satisfaction assessment of the spatial distribution of urban emergency shelters.A GIS-based analytic hierarchy process approach was utilized to conduct the assessment based on selected criteria layers for daytime and nighttime scenarios,respectively.The layers were generated from high-precision land use data based on highresolution aerial images and census data.Considering the uncertainty in criteria weighting,a spatial sensitivity analysis was undertaken for deriving more accurate results.The feasibility of the framework was tested on a case study in Jing'an District,Shanghai,China.The assessment results show that both at nighttime and during daytime,even if all potentially available shelters are open,the demand in large areas can only be marginally satisfied or not satisfied,especially in the northern,eastern,and central parts of Jing'an District.The quantitative analysis of the satisfaction conditions of the buildings or land parcels and the affected people,especially children and the elderly,shows a low satisfaction level of shelter services in these areas.The satisfaction assessment of emergency shelters can help government decision makers find low satisfaction areas of sheltering services and support further locationallocation optimization of urban emergency shelters. 展开更多
关键词 population estimation SHANGHAI Spatial distribution Urban emergency shelters
原文传递
Supply-Demand Analysis of Urban Emergency Shelters Based on Spatiotemporal Population Estimation 被引量:3
3
作者 Xiaodong Zhang Jia Yu +3 位作者 Yun Chen Jiahong Wen Jiayan Chen Zhan'e Yin 《International Journal of Disaster Risk Science》 SCIE CSCD 2020年第4期519-537,共19页
Supply–demand analysis is an important part of the planning of urban emergency shelters.Using Pudong New Area,Shanghai,China as an example,this study estimated daytime and nighttime population of the study area based... Supply–demand analysis is an important part of the planning of urban emergency shelters.Using Pudong New Area,Shanghai,China as an example,this study estimated daytime and nighttime population of the study area based on fine-scale land use data,census data,statistical yearbook information,and Tencent user-density big data.An exponential function-based,probability density estimation method was used to analyze the spatial supply of and demand for shelters under an earthquake scenario.The results show that even if all potential available shelters are considered,they still cannot satisfy the demand of the existing population for evacuation and sheltering,especially in the northern region of Pudong,under both the daytime and the nighttime scenarios.The proposed method can reveal the spatiotemporal imbalance between shelter supply and demand.We also conducted a preliminary location selection analysis of shelters based on the supply–demand analysis results.The location selection results demonstrate the advantage of the proposed method.It can be applied to identify the areas where the supply of shelters is seriously inadequate,and provide effective decision support for the planning of urban emergency shelters. 展开更多
关键词 Big data China population estimation Probability density estimation Supply-demand analysis Urban emergency shelters
原文传递
A new approach on seismic mortality estimations based on average population density 被引量:2
4
作者 Xiaoxin Zhu Baiqing Sun Zhanyong Jin 《Earthquake Science》 CSCD 2016年第6期337-344,共8页
This study examines a new methodology to predict the final seismic mortality from earthquakes in China. Most studies established the association between mortality estimation and seismic intensity without considering t... This study examines a new methodology to predict the final seismic mortality from earthquakes in China. Most studies established the association between mortality estimation and seismic intensity without considering the population density. In China, however, the data are not always available, especially when it comes to the very urgent relief situation in the disaster. And the popu- lation density varies greatly from region to region. This motivates the development of empirical models that use historical death data to provide the path to analyze the death tolls for earthquakes. The present paper employs the average population density to predict the final death tolls in earthquakes using a case-based reasoning model from realistic perspective. To validate the forecasting results, historical data from 18 large-scale earthquakes occurred in China are used to estimate the seismic morality of each case. And a typical earthquake case occurred in the northwest of Sichuan Province is employed to demonstrate the estimation of final death toll. The strength of this paper is that it provides scientific methods with overall forecast errors lower than 20 %, and opens the door for conducting final death forecasts with a qualitative and quantitative approach. Limitations and future research are also analyzed and discussed in the conclusion. 展开更多
关键词 Emergency management . Earthquake . Finalmortality estimation . Average population density . China
下载PDF
Earthquake loss estimation by using Gross Domestic Product and population data 被引量:2
5
作者 陈棋福 陈禺页 陈凌 《Acta Seismologica Sinica(English Edition)》 CSCD 1997年第6期95-104,共10页
In the traditional method of earthquake loss estimation, all the social wealthes are classified according to their structural type and occupational use. Inventory data is collected and the total loss is estimated from... In the traditional method of earthquake loss estimation, all the social wealthes are classified according to their structural type and occupational use. Inventory data is collected and the total loss is estimated from each facility class separately. For many regions of the world, however, the vast amount of data required by this method is difficult or impossible to obtain. The traditional method is also unable to estimate quickly the loss from an unexpected disaster earthquake. It is difficult to give the necessary risk information to help the government to rescue and relief the earthquake disaster. This paper proposes a simple estimation method of earthquake loss based on macroscopic economical index of Gross Domestic Product (GDP) and population distribution data. A preliminary nonlinear relation among hazard loss, seismic intensity and social wealth was developed by means of some earthquake disaster records during 1980~1995. This method was applied to analyze several assumed earthquakes. The preliminary analysis results show that the new method is effective and reasonable for quick assessment of earthquake loss. 展开更多
关键词 earthquake disaster loss estimation assumed earthquake Gross Domestic Product population
下载PDF
Global population estimate and conservation gap analysis for the Nordmann's Greenshank(Tringa guttifer)
6
作者 Ranxing Cao Waner Liang +8 位作者 Jia Guo Hongyan Yang Lili Sun Qing Chen Tao Yu Sicheng Ren Cai Lu Guangchun Lei Yifei Jia 《Avian Research》 SCIE CSCD 2023年第2期250-256,共7页
Nordmann's Greenshank(Tringa guttifer)is a globally endangered species that has received little research attention.It is threatened by rapid habitat loss,an incomplete network of protected sites,and lack of long-t... Nordmann's Greenshank(Tringa guttifer)is a globally endangered species that has received little research attention.It is threatened by rapid habitat loss,an incomplete network of protected sites,and lack of long-term data on population dynamics.Citizen science data can be combined with survey data to support population estimation and conservation gap analysis.From 2020 to 2021,Nordmann's Greenshank was surveyed in Tiaozini,Xiaoyangkou,and Dongling on the southern coast of Jiangsu Province,China,and the global population of the species was re-evaluated using the data obtained.We integrated citizen science data from eBird and the China Bird Report from 2000 to 2020 with the survey results to identify important habitats harboring over 1%of its total population,and compared this data with existing protected areas to identify gaps in its global conservation.Our survey found that Tiaozini supported at least 1194 individuals.Consequently,its global population was reestimated to be 1500-2000.Moreover,45 important habitats were identified based on citizen data and survey results.Although 44.4%and 50.0%of the priority sites in the world and China,respectively,are located outside protected areas,the Conservation Effectiveness Index(C)is 68.4%and 71.1%,respectively,showing that the current coverage of protected areas for this part of its range is reasonable.This study presents the most complete and recent population data to date.Tiaozini is the most important migration stopover site for Nordmann's Greenshanks.The species is under threat in terms of breeding,wintering,and stopover sites.Therefore,we suggest improving monitoring,establishing new protected sites to complete the habitat protection network,and improving the effectiveness of existing habitat protection strategies,including further developing high tide roosting sites. 展开更多
关键词 Citizen science Conservation gaps Nordmann's Greenshank population estimate
下载PDF
Investigation on the Relationship between Population Density and Satellite Image Features——a Deep Learning Based Approach 被引量:1
7
作者 Junxiang ZHANG Peiran LI +1 位作者 Haoran ZHANG Xuan SONG 《Journal of Geodesy and Geoinformation Science》 2022年第4期50-58,共9页
Timely and accurate population statistic data plays an important role in many fields.To illustrate the demographic characteristics,population density is a crucial factor in evaluating population data.With a dynamic re... Timely and accurate population statistic data plays an important role in many fields.To illustrate the demographic characteristics,population density is a crucial factor in evaluating population data.With a dynamic regional migration in population,it is a challenging job to evaluate population density without a census-based survey.We present the approach to classify satellite images in different magnitudes in population density and execute the comparative experiment to discuss the factors that influence the identification to the images with the deep learning approach.In this paper,we use satellite imagery and community population density data.With convolutional neural networks,we evaluated the performance of CNN on population estimation with satellite images,found the features that are important in population estimation,and then perform the sensitive analysis. 展开更多
关键词 population estimation satellite imagery convolutional neural network
下载PDF
A revised species population estimate for the Bar-headed Goose(Anser indicus) 被引量:4
8
作者 Dongping Liu Guogang Zhang +3 位作者 Fengshan Li Tian Ma Jun Lu Fawen Qian 《Chinese Birds》 CSCD 2017年第1期57-62,共6页
Background: The Bar-headed Goose(Anser indicus) is a species that relies heavily on the plateau wetlands of Asia and whose population was thought to be declining. Over the past decade, south-central Tibet, one of the ... Background: The Bar-headed Goose(Anser indicus) is a species that relies heavily on the plateau wetlands of Asia and whose population was thought to be declining. Over the past decade, south-central Tibet, one of the most important wintering grounds, supported large numbers of Bar-headed Geese, but the population had not been regularly monitored in this area.Methods: We surveyed wintering Bar-headed Geese along the Yarlung Zangbo, Lhasa and Nyang Qu rivers, the three major river valleys and their tributaries in south-central Tibet in January 2014 and recorded their location, flock size and habitat utilization. Based on these data and the latest wintering counts elsewhere, we revised the population estimate for this species.Results: We recorded more than 67,000 Bar-headed Geese in south-central Tibet during January 2014. By geographic area, the geese were most abundant in the Lhasa River valley(38.5%) and the Nyang Qu River valley(31.0%), and by administrative division in Lhunzhub(27.2%) and Shigatse(26.7%). Bar-headed Geese were most often observed feeding in winter wheat fields and ploughed fields, resting on pastureland and marshes. The approximate number of 67,000 geese recorded in Tibet is more than four times the estimate of 1993 for the same region and exceeds the most recent world population estimate of 52,000–60,000. Based on our work in Tibet and the latest wintering counts available from other areas, we revised the estimated population size of this species to 97,000–118,000.Conclusions: Our result reveals a remarkable increase in the number of Bar-headed Geese wintering in south-central Tibet. This population increase most likely stems from a proliferation of cropland and especially winter wheat fields in south-central Tibet. This habitat improvement may also cause short-stopping of the Bar-headed Goose and thus reduce mortality of the geese that would otherwise undertake a somewhat daunting trans-Himalayan migration. 展开更多
关键词 Bar-headed Goose Species population estimate TIBET Wintering ground
下载PDF
An Non-parametrical Approach to Estimate Location Parameters under Simple Order
9
作者 孙旭 《Northeastern Mathematical Journal》 CSCD 2005年第2期175-180,共6页
This paper deals with estimating parameters under simple order when samples come from location models. Based on the idea of Hodges and Lehmann estimator (H-L estimator), a new approach to estimate parameters is propos... This paper deals with estimating parameters under simple order when samples come from location models. Based on the idea of Hodges and Lehmann estimator (H-L estimator), a new approach to estimate parameters is proposed, which is difference with the classical L1 isotonic regression and L2 isotonic regression. An algorithm to compute estimators is given. Simulations by the Monte-Carlo method is applied to compare the likelihood functions with respect to L1 estimators and weighted isotonic H-L estimators. 展开更多
关键词 H-L estimator simple partial the ith population isotonic H-L estimator weighted isotonic H-L estimator
下载PDF
THE ESTIMATION OF THE PREVALENCE OF HEAR-ING-IMPAIRMENT FOR THE NOISE-EXPOSED POPULATION IN CHINA BASED ON ISO/DIS 1999.2
10
作者 ZHANG Jiazhi(Beijing Municipal Research Institute of Labour Protection)ZHANG Ruwei(institute of Acoustics , Academia Sinica) 《Chinese Journal of Acoustics》 1989年第4期366-372,共7页
Based on the noise survey in China ,the formula (H=H+N-HN/120 ) of ISO/DIS 1999.2 (' Acoustics - Determination of Occupational noise exposure and estimation of noise induced hearing impairment ' , 1985) was ap... Based on the noise survey in China ,the formula (H=H+N-HN/120 ) of ISO/DIS 1999.2 (' Acoustics - Determination of Occupational noise exposure and estimation of noise induced hearing impairment ' , 1985) was applied to the calculation of the hearing threshold level associated with age and noise (HTLAN) of the noise - impaired people . According to the Gausscian distribution , when the noise - exposure level LEX8h was 85 ,90 ,95, 100 dB and the hearing threshold frequency is from 0.5k to 6kHz , the HTLAN of noise - exposed people withdifferent duration of exposure and its relation values to the hearing threshold frequency associated with age (HTLA) were obtained . The ISO /DIS 1999.2 has been proved to be applicable in China . 展开更多
关键词 ISO THE estimation OF THE PREVALENCE OF HEAR-ING-IMPAIRMENT FOR THE NOISE-EXPOSED population IN CHINA BASED ON ISO/DIS 1999.2 DIS
原文传递
A new pattern-based method for identifying recent HIV-1 infections from the viral env sequence 被引量:1
11
作者 YANG Jing XIA XiaYu +6 位作者 HE Xiang YANG SenLin RUAN YuHua ZHAO QuanBi WANG ZhiXin SHAO YiMing PAN XianMing 《Science China(Life Sciences)》 SCIE CAS 2012年第4期328-335,共8页
The long asymptomatic stage of HIV infection poses a great challenge in identifying recent HIV infections. This is a bottleneck for monitoring HIV epidemic trends and evaluating the effectiveness of national AIDS cont... The long asymptomatic stage of HIV infection poses a great challenge in identifying recent HIV infections. This is a bottleneck for monitoring HIV epidemic trends and evaluating the effectiveness of national AIDS control programs. Several serological methods were used to address this issue with some success. Because of high false-positive rates in patients with advanced infection or in ART treatment, UNAIDS still hesitates to recommend their use in routine surveillance. We developed a new pattern-based method for measuring intra-patient viral genetic diversity for determination of recent infections and estimation of population incidence. This method is verified by using several datasets (424 subtype B and 77 CRF07_BC samples) with clearly identified HIV-1 infection times. Pattern-based diversities of recent infections are significantly lower than that of chronic ones. With larger window periods varying from 200 to 350 days, a higher accuracy (90% 95%) not affected by advanced disease nor ART treatment could be obtained. The pattern-based genetic method is supplementary to the existing serology-based assays, both of which could be suitable for use in low and high epidemic regions, respectively. 展开更多
关键词 determination of HIV recent infections estimation of population incidence viral genetic diversity pattern-based distance
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部