A novel outlier recognition method in surveying data is presented based on Shannon information entropy. The probability distribution of surveying data does not need to be known or hypothesized in this method, and it i...A novel outlier recognition method in surveying data is presented based on Shannon information entropy. The probability distribution of surveying data does not need to be known or hypothesized in this method, and it is not only accurate but also convenient to calculate in this method compared with statistical recognition method.展开更多
The objective of this paper is to improve the monitoring speed and precision of fractional vegetation cover (fc). It mainly focuses on fc estimation when fcmax and fcmin are not approximately equal to 100% and 0%, res...The objective of this paper is to improve the monitoring speed and precision of fractional vegetation cover (fc). It mainly focuses on fc estimation when fcmax and fcmin are not approximately equal to 100% and 0%, respectively due to using remote sensing image with medium or low spatial resolution. Meanwhile, we present a new method of fc estimation based on a random set of fc maximum and minimum values from digital camera (DC) survey data and a di- midiate pixel model. The results show that this is a convenient, efficient and accurate method for fc monitoring, with the maximum error -0.172 and correlation coefficient of 0.974 between DC survey data and the estimated value of the remote sensing model. The remaining DC survey data can be used as verification data for the precision of the fc estimation. In general, the estimation of fc based on DC survey data and a remote sensing model is a brand-new development trend and deserves further extensive utilization.展开更多
The Large sky Area Multi-Object Fiber Spectroscopic Telescope（LAMOST） general survey is a spectroscopic survey that will eventually cover approximately half of the celestial sphere and collect 10 million spectra of ...The Large sky Area Multi-Object Fiber Spectroscopic Telescope（LAMOST） general survey is a spectroscopic survey that will eventually cover approximately half of the celestial sphere and collect 10 million spectra of stars, galaxies and QSOs. Objects in both the pilot survey and the first year regular survey are included in the LAMOST DR1. The pilot survey started in October 2011 and ended in June 2012, and the data have been released to the public as the LAMOST Pilot Data Release in August 2012. The regular survey started in September 2012, and completed its first year of operation in June 2013. The LAMOST DR1 includes a total of 1202 plates containing 2 955 336 spectra, of which 1 790 879 spectra have observed signalto-noise ratio（SNR） ≥ 10. All data with SNR ≥ 2 are formally released as LAMOST DR1 under the LAMOST data policy. This data release contains a total of 2 204 696 spectra, of which 1 944 329 are stellar spectra, 12 082 are galaxy spectra and 5017 are quasars. The DR1 not only includes spectra, but also three stellar catalogs with measured parameters： late A,FGK-type stars with high quality spectra（1 061 918 entries）, A-type stars（100 073 entries）, and M-type stars（121 522 entries）. This paper introduces the survey design, the observational and instrumental limitations, data reduction and analysis, and some caveats. A description of the FITS structure of spectral files and parameter catalogs is also provided.展开更多
This paper describes the data release of the LAMOST pilot survey, which includes data reduction, calibration, spectral analysis, data products and data access. The accuracy of the released data and the information abo...This paper describes the data release of the LAMOST pilot survey, which includes data reduction, calibration, spectral analysis, data products and data access. The accuracy of the released data and the information about the FITS headers of spectra are also introduced. The released data set includes 319 000 spectra and a catalog of these objects.展开更多
Hyperspectral remote sensing is now a frontier of the remote sensing technology. Airborne hyperspectral remote sensing data have hundreds of narrow bands to obtain complete and continuous ground-object spectra. Theref...Hyperspectral remote sensing is now a frontier of the remote sensing technology. Airborne hyperspectral remote sensing data have hundreds of narrow bands to obtain complete and continuous ground-object spectra. Therefore, they can be effectively used to identify these grotmd objects which are difficult to discriminate by using wide-band data, and show much promise in geological survey. At the height of 1500 m, have 36 bands in visible to the CASI hyperspectral data near-infrared spectral range, with a spectral resolution of 19 nm and a space resolution of 0.9 m. The SASI data have 101 bands in the shortwave infrared spectral range, with a spectral resolution of 15 nm and a space resolution of 2.25 m. In 2010, China Geological Survey deployed an airborne CASI/SASI hyperspectral measurement project, and selected the Liuyuan and Fangshankou areas in the Beishan metallogenic belt of Gansu Province, and the Nachitai area of East Kunlun metallogenic belt in Qinghai Province to conduct geological survey. The work period of this project was three years.展开更多
Extensive investigation has been performed in location-centric or geocast routing protocols for reliable and efficient dissemination of information in Vehicular Adhoc Networks （VANETs）. Various location-centric rout...Extensive investigation has been performed in location-centric or geocast routing protocols for reliable and efficient dissemination of information in Vehicular Adhoc Networks （VANETs）. Various location-centric routing protocols have been suggested in literature for road safety ITS applications considering urban and highway traffic environment. This paper characterizes vehicular environments based on real traffic data and investigates the evolution of location-centric data dissemination. The current study is carded out with three main objectives： （i） to analyze the impact of dynamic traffic environment on the design of data dissemination techniques, （ii） to characterize location-centric data dissemination in terms of functional and qualitative behavior of protocols, properties, and strengths and weaknesses, and （iii） to find some future research directions in information dissemination based on location. Vehicular traffic environments have been classified into three categories based on physical characteristics such as speed, inter-vehicular distance, neighborhood stability, traffic volume, etc. Real traffic data is considered to analyze on-road traffic environments based on the measurement of physical parameters and weather conditions. Design issues are identified in incorporating physical parameters and weather conditions into data dissemination. Functional and qualitative characteristics of location-centric techniques are explored considering urban and highway environments. Comparative analysis of location-centric techniques is carded out for both urban and highway environments individually based on some unique and common characteristics of the environments. Finally, some future research directions are identified in the area based on the detailed investigation of traffic environments and location-centric data dissemination techniques.展开更多
Data from the 2013 Canadian Tobacco, Alcohol and Drugs Survey, and two other surveys are used to determine the effects of cannabis use on self-reported physical and mental health. Daily or almost daily marijuana use i...Data from the 2013 Canadian Tobacco, Alcohol and Drugs Survey, and two other surveys are used to determine the effects of cannabis use on self-reported physical and mental health. Daily or almost daily marijuana use is shown to be detrimental to both measures of health for some age groups but not all. The age group specific effects depend on gender. Males and females respond differently to cannabis use. The health costs of regularly using cannabis are significant but they are much smaller than those associated with tobacco use. These costs are attributed to both the presence of delta9-tetrahydrocannabinol and the fact that smoking cannabis is itself a health hazard because of the toxic properties of the smoke ingested. Cannabis use is costlier to regular smokers and age of first use below the age of 15 or 20 and being a former user leads to reduced physical and mental capacities which are permanent. These results strongly suggest that the legalization of marijuana be accompanied by educational programs, counseling services, and a delivery system, which minimizes juvenile and young adult usage.展开更多
In the formation process of megacities,urban population is constantly gathering from other cities to large and medium-sized cities,and from the periphery of the city to the center of the city,inducing traffic congesti...In the formation process of megacities,urban population is constantly gathering from other cities to large and medium-sized cities,and from the periphery of the city to the center of the city,inducing traffic congestion,overload of main center,reduction of space efficiency,and other major urban diseases.Multi-center urban spatial structure is an effective way to solve the above negative externalities.It is helpful to evaluate the efficiency of the existing industrial distribution structure in the cities and make a reasonable estimate of the future enterprise growth by clarifying the interactive relationship between the development process of a city and the change of the employment center.Based on survey data of Shenzhen "Four Up-scale Enterprises" in 2017,threshold method is used to identify the existing employment centers of Shenzhen,and describe the characteristics of each employment center.Combining calculation of industry location entropy,below conclusions are obtained:①the double main centers (Futian-Luohu center and Nanshan center) in Shenzhen are obvious,and the weak multi-center has initially formed;②the development of the industry is relatively balanced in Futian-Luohu center,and Nanshan center has absolute advantage in information technology industry;③the employment centers outside the original special economic zone are mainly manufacturing industries,showing a highly specialized trend of industries,and cultivation of service industries is insufficient.展开更多
The Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST, also called the Guo Shou Jing Telescope) is a special reflecting Schmidt telescope. LAMOST’s special design allows both a large aperture (effecti...The Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST, also called the Guo Shou Jing Telescope) is a special reflecting Schmidt telescope. LAMOST’s special design allows both a large aperture (effective aperture of 3.6 m–4.9 m) and a wide field of view (FOV) (5°). It has an innovative active reflecting Schmidt configuration which continuously changes the mirror’s surface that adjusts during the observation process and combines thin deformable mirror active optics with segmented active optics. Its primary mirror (6.67m×6.05 m) and active Schmidt mirror (5.74m×4.40 m) are both segmented, and composed of 37 and 24 hexagonal sub-mirrors respectively. By using a parallel controllable fiber positioning technique, the focal surface of 1.75 m in diameter can accommodate 4000 optical fibers. Also, LAMOST has 16 spectrographs with 32 CCD cameras. LAMOST will be the telescope with the highest rate of spectral acquisition. As a national large scientific project, the LAMOST project was formally proposed in 1996, and approved by the Chinese government in 1997. The construction started in 2001, was completed in 2008 and passed the official acceptance in June 2009. The LAMOST pilot survey was started in October 2011 and the spectroscopic survey will launch in September 2012. Up to now, LAMOST has released more than 480 000 spectra of objects. LAMOST will make an important contribution to the study of the large-scale structure of the Universe, structure and evolution of the Galaxy, and cross-identification of multiwaveband properties in celestial objects.展开更多
New methods are presented for processing and interpretation of shallow marine differential magnetic data, including constructing maps of offshore total magnetic anomalies with an extremely high reso- lution of up to 1...New methods are presented for processing and interpretation of shallow marine differential magnetic data, including constructing maps of offshore total magnetic anomalies with an extremely high reso- lution of up to 1-2 nT, mapping weak anomalies of 5-10 nT caused by mineralization effects at the contacts of hydrocarbons with host rocks, estimating depths to upper and lower boundaries of anom- alous magnetic sources, and estimating thickness of magnetic layers and boundaries of tectonic blocks. Horizontal dimensions of tectonic blocks in the so-called ＂seismic gap＂ region in the central Kuril Arc vary from 10 to 100 km, with typical dimensions of 25-30 km. The area of the ＂seismic gap＂ is a zone of intense tectonic activity and recent volcanism. Deep sources causing magnetic anomalies in the area are similar to the ＂magnetic belt＂ near Hokkaido. In the southern and central parts of Barents Sea, tectonic blocks with widths of 30-100 kin, and upper and lower boundaries of magnetic layers ranging from depths of 10 to 5 km and 18 to 30 km are calculated. Models of the magnetic layer underlying the Mezen Basin in an inland part of the White Sea-Barents Sea paleorift indicate depths to the lower boundary of the layer of 12-30 km. Weak local magnetic anomalies of 2-5 nT in the northern and central Caspian Sea were identified using the new methods, and drilling confirms that the anomalies are related to concentrations of hydrocarbon. Two layers causing magnetic anomalies are identified in the northern Caspian Sea from magnetic anomaly spectra. The upper layer lies immediately beneath the sea bottom and the lower layer occurs at depths between 30-40 m and 150-200 m.展开更多
The Large Sky Area Multi-Object Fiber Spectroscopic Telescope （LAMOST） published its first data release （DR1） in 2013, which is currently the largest dataset of stellar spectra in the world. We combine the PASTEL ...The Large Sky Area Multi-Object Fiber Spectroscopic Telescope （LAMOST） published its first data release （DR1） in 2013, which is currently the largest dataset of stellar spectra in the world. We combine the PASTEL catalog and SIMBAD radial velocities as a testing standard to validate stellar parameters （effec- tive temperature Tefr, surface gravity log g, metallicity [Fe/H] and radial velocity Vr） derived from DR1. Through cross-identification of the DR1 catalogs and the PASTEL catalog, we obtain a preliminary sample of 422 stars. After removal of stellar param- eter measurements from problematic spectra and applying effective temperature con- straints to the sample, we compare the stellar parameters from DR1 with those from PASTEL and SIMBAD to demonstrate that the DR1 results are reliable in restricted ranges of Tefr. We derive standard deviations of 110 K, 0.19 dex and 0.11 dex for Tell, log 9 and [Fe/H] respectively when Teff〈 8000 K, and 4.91 km s-1 for Vr when Teff 〈 10 000 K. Systematic errors are negligible except for those of Vr. In addition, metallicities in DR1 are systematically higher than those in PASTEL, in the range of PASTEL [Fe/H] 〈 -1.5.展开更多
The South Galactic Cap u-band Sky Survey （SCUSS） was established in 2009 in order to provide a photometric input catalog for target selection of the Large Sky Area Multi-Object Fiber Spectroscopic Telescope （LAMOST...The South Galactic Cap u-band Sky Survey （SCUSS） was established in 2009 in order to provide a photometric input catalog for target selection of the Large Sky Area Multi-Object Fiber Spectroscopic Telescope （LAMOST） project. SCUSS is an international cooperative project between National Astronomical Observatories, Chinese Academy of Sciences, and Steward Observatory at the University of Arizona, using the 90 inch （2.3 m） Bok telescope on Kitt Peak. The telescope is equipped with a prime focus camera that is composed of a mosaic of four 4096 × 4096 CCDs and has a field of view of about 1 deg2. From 2009 to 2013, SCUSS performed a sky survey of an approximately 5000 deg2 field of the South Galactic Cap in u band, including the Galactic anticenter area and the SDSS-IV extended imaging area. The limiting magnitude of SCUSS is deeper than 23 mag （at a signal-to-noise ratio of 5）. In this paper, we briefly describe the goals of this project, method of observations and data reduction, and we also introduce current and potential scientific activities related to the SCUSS project.展开更多
In this paper, we construct a model in which the impact of pollution on health is exerted through both direct and indirect channels. The indirect channel is captured by a production func-tion in which the principal he...In this paper, we construct a model in which the impact of pollution on health is exerted through both direct and indirect channels. The indirect channel is captured by a production func-tion in which the principal health-improving factor, income growth, can be realized only in the cost of pollution increase. This model is then tested by the aggregated chronicle disease data in over 78 Chinese counties. Our results show, after attaining the threshold of 8 μg/m2, continuous increase in industrial SO2 emission density will lead the ratio of population suffering chronicle diseases, among which respiratory diseases occupy a significant proportion, to rise. However, owing to technological progress in pollution control activities, the needed SO2 emission to produce one unit of GDP diminishes with time. Therefore, the negative effect from pollution augmentation on public health seems to be recompensed more and more by the positive effect of economic growth.展开更多
Abstract We present astrometric calibration of the Xuyi Schmidt Telescope Photometric Survey of the Galactic Anti-center （XSTPS-GAC）. XSTPS-GAC is the photometric part of the Digital Sky Survey of the Galactic Anti-...Abstract We present astrometric calibration of the Xuyi Schmidt Telescope Photometric Survey of the Galactic Anti-center （XSTPS-GAC）. XSTPS-GAC is the photometric part of the Digital Sky Survey of the Galactic Anti-center （DSS-GAC）, which is a photometric and spectroscopic sky survey, in combination with LAMOST. In order to select an astrometric reference catalog, we made comparisons between the four widely used astrometric catalogs, GSC2.3, USNO-B1.0, UCAC3 and PPMXL. PPMXL shows relatively small systematic errors in positions and more homogeneous proper motion distributions toward the Galactic Anti-center （GAC）, and was selected as the reference catalog. Based on the high quality and bright reference stars that were picked out from PPMXL, we performed a 4th-order polynomial fitting in image units, to construct the transformation relation between coordinates used by XSTPS-GAC and standard coordinates, and to simultaneously correct the image distortions in the CCD. Then we applied the derived relation to all sources to obtain their mean celestial coordinates based on the Intemational Celestial Reference System. For bright point sources with r 〈 17.0 mag, the accuracy of astrometric calibration could reach about 80 mas for each of the g, r, i bands, with systematic errors being less than 10 mas. But for the faint sources at the brightness limit of the survey, which was r - 19.0 mag, the accuracy can still reach 200 mas. After combining all observations, the final weighted average coordinates could reach an accuracy of less than 70 mas for bright stars. For faint stars, the rms residuals of weighted coordinates decrease to -110 mas. The final combined XSTPS-GAC coordinates show a good consistency with the Sloan Digital Sky Survey.展开更多
In this work, we provide 2189 photometrically- and kinematically-selected candidate members of 24 star clusters from the LAMOST DR2 catalog. We perform two-step membership identification： selection along the stellar ...In this work, we provide 2189 photometrically- and kinematically-selected candidate members of 24 star clusters from the LAMOST DR2 catalog. We perform two-step membership identification： selection along the stellar track in the colormagnitude diagram, i.e., photometric identification, and selection from the distribution of radial velocities, i.e. the kinematic identification. We find that the radial velocities from the LAMOST data are very helpful in the membership identification. The mean probability of membership is 40% for the sample selected with radial velocity. With these 24 star clusters, we investigate the performance of the radial velocity and metallicity estimated with the LAMOST pipeline. We find that the systematic offsets in radial velocity and metallicity are 0.85 ± 1.26 km s-1and-0.08 ± 0.04 dex, with dispersions of 5.47＋1.16-0.71 km s-1and 0.13＋0.04-0.02 dex, respectively. Finally, we propose that the photometrically-selected candidate members of the clusters covered by the LAMOST footprint should be assigned higher priority so that more candidate stars can be observed.展开更多
The goal of this study was to map rainfed and irrigated rice-fallow cropland areas across South Asia,using MODIS 250 m time-series data and identify where the farming system may be intensified by the inclusion of a sh...The goal of this study was to map rainfed and irrigated rice-fallow cropland areas across South Asia,using MODIS 250 m time-series data and identify where the farming system may be intensified by the inclusion of a short-season crop during the fallow period.Rice-fallow cropland areas are those areas where rice is grown during the kharif growing season(June–October),followed by a fallow during the rabi season(November–February).These cropland areas are not suitable for growing rabi-season rice due to their high water needs,but are suitable for a short-season(≤3 months),low water-consuming grain legumes such as chickpea(Cicer arietinum L.),black gram,green gram,and lentils.Intensification(double-cropping)in this manner can improve smallholder farmer’s incomes and soil health via rich nitrogen-fixation legume crops as well as address food security challenges of ballooning populations without having to expand croplands.Several grain legumes,primarily chickpea,are increasingly grown across Asia as a source of income for smallholder farmers and at the same time providing rich and cheap source of protein that can improve the nutritional quality of diets in the region.The suitability of rainfed and irrigated rice-fallow croplands for grain legume cultivation across South Asia were defined by these identifiers:(a)rice crop is grown during the primary(kharif)crop growing season or during the north-west monsoon season(June–October);(b)same croplands are left fallow during the second(rabi)season or during the south-east monsoon season(November–February);and(c)ability to support low water-consuming,short-growing season(≤3 months)grain legumes(chickpea,black gram,green gram,and lentils)during rabi season.Existing irrigated or rainfed crops such as rice or wheat that were grown during kharif were not considered suitable for growing during the rabi season,because the moisture/water demand of these crops is too high.The study established cropland classes based on the every 16-day 250 m normalized difference vegetation index(NDVI)time series for one year(June 2010–May 2011)of Moderate Resolution Imaging Spectroradiometer(MODIS)data,using spectral matching techniques(SMTs),and extensive field knowledge.Map accuracy was evaluated based on independent ground survey data as well as compared with available sub-national level statistics.The producers’and users’accuracies of the cropland fallow classes were between 75%and 82%.The overall accuracy and the kappa coefficient estimated for rice classes were 82%and 0.79,respectively.The analysis estimated approximately 22.3 Mha of suitable rice-fallow areas in South Asia,with 88.3%in India,0.5%in Pakistan,1.1%in Sri Lanka,8.7%in Bangladesh,1.4%in Nepal,and 0.02%in Bhutan.Decision-makers can target these areas for sustainable intensification of short-duration grain legumes.展开更多
In the remote sensing survey of the country land, cost and accuracy are a pair of conflicts, for which spatial sampling is a preferable solution with the aim of an optimal balance between economic input and accuracy o...In the remote sensing survey of the country land, cost and accuracy are a pair of conflicts, for which spatial sampling is a preferable solution with the aim of an optimal balance between economic input and accuracy of results, or in other words, acquirement of higher ac-curacy at less cost. Counter to drawbacks of previous application models, e.g. lack of compre-hensive and quantitative-comparison, the optimal decision-making model of spatial sampling is proposed. This model first acquires the possible accuracy-cost diagrams of multiple schemes through initial spatial exploration, then regresses them and standardizes them into a unified ref-erence frame, and finally produces the relatively optimal sampling scheme by using the discrete decision-making function (built by this paper) and comparing them in combination with the dia-grams. According to the test result in the survey of the arable land using remotely sensed data, the Sandwich model, while applied in the survey of the thin-feature and cultivated land areas with aerial photos, can better realize the goal of the best balance between investment and accuracy. With this case and other cases, it is shown that the optimal decision-making model of spatial sampling is a good choice in the survey of the farm areas using remote sensing, with its distin-guished benefit of higher precision at less cost or vice versa. In order to extensively apply the model in the surveys of natural resources, including arable farm areas, this paper proposes the prototype of development using the component technology, that could considerably improve the analysis efficiency by insetting program components within the software environment of GIS and RS.展开更多
Business survey,which starts from the microeconomic level,is a widely used short-term forecasting tool in practice.In this study,the authors examine whether foreign trade survey data collected by China’s Ministry of ...Business survey,which starts from the microeconomic level,is a widely used short-term forecasting tool in practice.In this study,the authors examine whether foreign trade survey data collected by China’s Ministry of Commerce would provide reliable forecasts of China’s foreign trade.The research procedure is designed from three perspectives including forecast information test,turning point forecast,and out-of-sample value forecast.First,Granger causality test detects whether survey data lead exports and imports.Second,business cycle analysis,a non-model based method,is performed.The authors construct composite indexes with business survey data to forecast turning points of foreign trade.Third,model-based numerical forecasting methods,including the Autoregressive Integrated Moving Average Model with Exogenous Variables(ARIMAX)and the artificial neural networks(ANNs)models are estimated.Empirical results show that survey data granger cause imports and exports,the leading composite index provides signal for changes of trade cycles,and quantitative models including survey data generate more accurate forecasts than benchmark models.It is concluded that trade survey data has excellent predictive capabilities for imports and exports,which can offer some priorities for government policy-making and enterprise decision making.展开更多
Cadastral surveying plays an important role in defining legal boundaries of land and property.The current practice for recording cadastral survey data mainly relies on 2D digital or analog documents.This practice is e...Cadastral surveying plays an important role in defining legal boundaries of land and property.The current practice for recording cadastral survey data mainly relies on 2D digital or analog documents.This practice is efficient for simple land parcels but can be challenged in complex building developments.To address the issues stemmed from 2D methods of representing cadastral survey data,3D spatial information models can be considered as a viable solution for managing cadastral survey data.Building Information Modeling(BIM)enables colsslaborative 3D management of the design,construction,and operation of buildings.There have been extensive studies conducted to investigate the connectivity between BIM and 3D cadaster.Most of these studies focus on managing legal information,such as ownership boundaries and attributes,in BIM-based environments.However,there is limited investigation on how survey-ing measurements can be mapped into BIM.In this study,the proposed method for integrating the cadastral survey data into the BIM environment includes identifying cadastral survey requirements,using BIM entities relevant to cadastral survey data,enrichment of a BIM proto-type,and evaluation of the prototype.The major contribution of this study is to demonstrate the storage of cadastral survey data such as survey marks and traverse lines in the BIM environment.Therefore,this research contributes to the further enrichment of BIM with incorporating data elements related to cadastral surveying practices.It is confirmed that current BIM-based tools provide restricted capabilities for explicit management and visualiza-tion of cadastral survey data.This limitation can be addressed in the future enhancements of BIM in terms of supporting important elements for cadastral survey data.展开更多
In July of 1987, the Sampling Survey of Children's Situation was conducted in 9 provincesautonomous regions of China. A stratified two--stage cluster sampling plan was designed for thesurvey. The paper presents th...In July of 1987, the Sampling Survey of Children's Situation was conducted in 9 provincesautonomous regions of China. A stratified two--stage cluster sampling plan was designed for thesurvey. The paper presents the methods of stratification, selecting n=2 PSU's (cities/counties) withunequal probabilities without replacement in each stratum and selecting residents/village committeein each sampled city/county. All formulae of estimating population characteristics (especiallypopulation totals and the ratios of two totals), and estimating variances of those estimators aregiven. Finally, we analyse the precision of the survey preliminarily from the result of dataprocessing.展开更多
文摘A novel outlier recognition method in surveying data is presented based on Shannon information entropy. The probability distribution of surveying data does not need to be known or hypothesized in this method, and it is not only accurate but also convenient to calculate in this method compared with statistical recognition method.
基金Projects NCET-04-0484 supported by the New-Century Outstanding Young Scientist Program from the Ministry of Education and D0605046040191-101Beijing Science and Technology Program
文摘The objective of this paper is to improve the monitoring speed and precision of fractional vegetation cover (fc). It mainly focuses on fc estimation when fcmax and fcmin are not approximately equal to 100% and 0%, respectively due to using remote sensing image with medium or low spatial resolution. Meanwhile, we present a new method of fc estimation based on a random set of fc maximum and minimum values from digital camera (DC) survey data and a di- midiate pixel model. The results show that this is a convenient, efficient and accurate method for fc monitoring, with the maximum error -0.172 and correlation coefficient of 0.974 between DC survey data and the estimated value of the remote sensing model. The remaining DC survey data can be used as verification data for the precision of the fc estimation. In general, the estimation of fc based on DC survey data and a remote sensing model is a brand-new development trend and deserves further extensive utilization.
基金funded by the National Basic Research Program of China (973 Program, 2014CB845700)the National Natural Science Foundation of China (Grant Nos. 11390371)Funding for the project has been provided by the National Development and Reform Commission
文摘The Large sky Area Multi-Object Fiber Spectroscopic Telescope（LAMOST） general survey is a spectroscopic survey that will eventually cover approximately half of the celestial sphere and collect 10 million spectra of stars, galaxies and QSOs. Objects in both the pilot survey and the first year regular survey are included in the LAMOST DR1. The pilot survey started in October 2011 and ended in June 2012, and the data have been released to the public as the LAMOST Pilot Data Release in August 2012. The regular survey started in September 2012, and completed its first year of operation in June 2013. The LAMOST DR1 includes a total of 1202 plates containing 2 955 336 spectra, of which 1 790 879 spectra have observed signalto-noise ratio（SNR） ≥ 10. All data with SNR ≥ 2 are formally released as LAMOST DR1 under the LAMOST data policy. This data release contains a total of 2 204 696 spectra, of which 1 944 329 are stellar spectra, 12 082 are galaxy spectra and 5017 are quasars. The DR1 not only includes spectra, but also three stellar catalogs with measured parameters： late A,FGK-type stars with high quality spectra（1 061 918 entries）, A-type stars（100 073 entries）, and M-type stars（121 522 entries）. This paper introduces the survey design, the observational and instrumental limitations, data reduction and analysis, and some caveats. A description of the FITS structure of spectral files and parameter catalogs is also provided.
文摘This paper describes the data release of the LAMOST pilot survey, which includes data reduction, calibration, spectral analysis, data products and data access. The accuracy of the released data and the information about the FITS headers of spectra are also introduced. The released data set includes 319 000 spectra and a catalog of these objects.
基金funded by China Geological Survey (grant no.1212011120899)the Department of Geology & Mining, China National Nuclear Corporation (grant no.201498)
文摘Hyperspectral remote sensing is now a frontier of the remote sensing technology. Airborne hyperspectral remote sensing data have hundreds of narrow bands to obtain complete and continuous ground-object spectra. Therefore, they can be effectively used to identify these grotmd objects which are difficult to discriminate by using wide-band data, and show much promise in geological survey. At the height of 1500 m, have 36 bands in visible to the CASI hyperspectral data near-infrared spectral range, with a spectral resolution of 19 nm and a space resolution of 0.9 m. The SASI data have 101 bands in the shortwave infrared spectral range, with a spectral resolution of 15 nm and a space resolution of 2.25 m. In 2010, China Geological Survey deployed an airborne CASI/SASI hyperspectral measurement project, and selected the Liuyuan and Fangshankou areas in the Beishan metallogenic belt of Gansu Province, and the Nachitai area of East Kunlun metallogenic belt in Qinghai Province to conduct geological survey. The work period of this project was three years.
文摘Extensive investigation has been performed in location-centric or geocast routing protocols for reliable and efficient dissemination of information in Vehicular Adhoc Networks （VANETs）. Various location-centric routing protocols have been suggested in literature for road safety ITS applications considering urban and highway traffic environment. This paper characterizes vehicular environments based on real traffic data and investigates the evolution of location-centric data dissemination. The current study is carded out with three main objectives： （i） to analyze the impact of dynamic traffic environment on the design of data dissemination techniques, （ii） to characterize location-centric data dissemination in terms of functional and qualitative behavior of protocols, properties, and strengths and weaknesses, and （iii） to find some future research directions in information dissemination based on location. Vehicular traffic environments have been classified into three categories based on physical characteristics such as speed, inter-vehicular distance, neighborhood stability, traffic volume, etc. Real traffic data is considered to analyze on-road traffic environments based on the measurement of physical parameters and weather conditions. Design issues are identified in incorporating physical parameters and weather conditions into data dissemination. Functional and qualitative characteristics of location-centric techniques are explored considering urban and highway environments. Comparative analysis of location-centric techniques is carded out for both urban and highway environments individually based on some unique and common characteristics of the environments. Finally, some future research directions are identified in the area based on the detailed investigation of traffic environments and location-centric data dissemination techniques.
文摘Data from the 2013 Canadian Tobacco, Alcohol and Drugs Survey, and two other surveys are used to determine the effects of cannabis use on self-reported physical and mental health. Daily or almost daily marijuana use is shown to be detrimental to both measures of health for some age groups but not all. The age group specific effects depend on gender. Males and females respond differently to cannabis use. The health costs of regularly using cannabis are significant but they are much smaller than those associated with tobacco use. These costs are attributed to both the presence of delta9-tetrahydrocannabinol and the fact that smoking cannabis is itself a health hazard because of the toxic properties of the smoke ingested. Cannabis use is costlier to regular smokers and age of first use below the age of 15 or 20 and being a former user leads to reduced physical and mental capacities which are permanent. These results strongly suggest that the legalization of marijuana be accompanied by educational programs, counseling services, and a delivery system, which minimizes juvenile and young adult usage.
文摘In the formation process of megacities,urban population is constantly gathering from other cities to large and medium-sized cities,and from the periphery of the city to the center of the city,inducing traffic congestion,overload of main center,reduction of space efficiency,and other major urban diseases.Multi-center urban spatial structure is an effective way to solve the above negative externalities.It is helpful to evaluate the efficiency of the existing industrial distribution structure in the cities and make a reasonable estimate of the future enterprise growth by clarifying the interactive relationship between the development process of a city and the change of the employment center.Based on survey data of Shenzhen "Four Up-scale Enterprises" in 2017,threshold method is used to identify the existing employment centers of Shenzhen,and describe the characteristics of each employment center.Combining calculation of industry location entropy,below conclusions are obtained:①the double main centers (Futian-Luohu center and Nanshan center) in Shenzhen are obvious,and the weak multi-center has initially formed;②the development of the industry is relatively balanced in Futian-Luohu center,and Nanshan center has absolute advantage in information technology industry;③the employment centers outside the original special economic zone are mainly manufacturing industries,showing a highly specialized trend of industries,and cultivation of service industries is insufficient.
文摘The Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST, also called the Guo Shou Jing Telescope) is a special reflecting Schmidt telescope. LAMOST’s special design allows both a large aperture (effective aperture of 3.6 m–4.9 m) and a wide field of view (FOV) (5°). It has an innovative active reflecting Schmidt configuration which continuously changes the mirror’s surface that adjusts during the observation process and combines thin deformable mirror active optics with segmented active optics. Its primary mirror (6.67m×6.05 m) and active Schmidt mirror (5.74m×4.40 m) are both segmented, and composed of 37 and 24 hexagonal sub-mirrors respectively. By using a parallel controllable fiber positioning technique, the focal surface of 1.75 m in diameter can accommodate 4000 optical fibers. Also, LAMOST has 16 spectrographs with 32 CCD cameras. LAMOST will be the telescope with the highest rate of spectral acquisition. As a national large scientific project, the LAMOST project was formally proposed in 1996, and approved by the Chinese government in 1997. The construction started in 2001, was completed in 2008 and passed the official acceptance in June 2009. The LAMOST pilot survey was started in October 2011 and the spectroscopic survey will launch in September 2012. Up to now, LAMOST has released more than 480 000 spectra of objects. LAMOST will make an important contribution to the study of the large-scale structure of the Universe, structure and evolution of the Galaxy, and cross-identification of multiwaveband properties in celestial objects.
基金supported by the Russian Fund of Fundamental Research(Grant No.11-05-00280)
文摘New methods are presented for processing and interpretation of shallow marine differential magnetic data, including constructing maps of offshore total magnetic anomalies with an extremely high reso- lution of up to 1-2 nT, mapping weak anomalies of 5-10 nT caused by mineralization effects at the contacts of hydrocarbons with host rocks, estimating depths to upper and lower boundaries of anom- alous magnetic sources, and estimating thickness of magnetic layers and boundaries of tectonic blocks. Horizontal dimensions of tectonic blocks in the so-called ＂seismic gap＂ region in the central Kuril Arc vary from 10 to 100 km, with typical dimensions of 25-30 km. The area of the ＂seismic gap＂ is a zone of intense tectonic activity and recent volcanism. Deep sources causing magnetic anomalies in the area are similar to the ＂magnetic belt＂ near Hokkaido. In the southern and central parts of Barents Sea, tectonic blocks with widths of 30-100 kin, and upper and lower boundaries of magnetic layers ranging from depths of 10 to 5 km and 18 to 30 km are calculated. Models of the magnetic layer underlying the Mezen Basin in an inland part of the White Sea-Barents Sea paleorift indicate depths to the lower boundary of the layer of 12-30 km. Weak local magnetic anomalies of 2-5 nT in the northern and central Caspian Sea were identified using the new methods, and drilling confirms that the anomalies are related to concentrations of hydrocarbon. Two layers causing magnetic anomalies are identified in the northern Caspian Sea from magnetic anomaly spectra. The upper layer lies immediately beneath the sea bottom and the lower layer occurs at depths between 30-40 m and 150-200 m.
基金supported by the National Key Basic Research Program of China (NKBRP) 2014CB845700supported by National Natural Science Foundation of China (Grant Nos.11473001 and 11233004)
文摘The Large Sky Area Multi-Object Fiber Spectroscopic Telescope （LAMOST） published its first data release （DR1） in 2013, which is currently the largest dataset of stellar spectra in the world. We combine the PASTEL catalog and SIMBAD radial velocities as a testing standard to validate stellar parameters （effec- tive temperature Tefr, surface gravity log g, metallicity [Fe/H] and radial velocity Vr） derived from DR1. Through cross-identification of the DR1 catalogs and the PASTEL catalog, we obtain a preliminary sample of 422 stars. After removal of stellar param- eter measurements from problematic spectra and applying effective temperature con- straints to the sample, we compare the stellar parameters from DR1 with those from PASTEL and SIMBAD to demonstrate that the DR1 results are reliable in restricted ranges of Tefr. We derive standard deviations of 110 K, 0.19 dex and 0.11 dex for Tell, log 9 and [Fe/H] respectively when Teff〈 8000 K, and 4.91 km s-1 for Vr when Teff 〈 10 000 K. Systematic errors are negligible except for those of Vr. In addition, metallicities in DR1 are systematically higher than those in PASTEL, in the range of PASTEL [Fe/H] 〈 -1.5.
基金SCUSS project is funded by the Main Direction Program of Knowledge Innovation of Chinese Academy of Sciences(No.KJCX2-EWT06)supported by the National Natural Science Foundation of China(NSFC+2 种基金Nos.11433005,11373035,11203034,11203031,11303038 and 11303043)the National Basic Research Program of China(973 Program,Nos.2014CB845704,2014CB845702 and 2013CB834902)the joint fund of Astronomy of the National Natural Science Foundation of China and the Chinese Academy of Science(Grant U1231113)
文摘The South Galactic Cap u-band Sky Survey （SCUSS） was established in 2009 in order to provide a photometric input catalog for target selection of the Large Sky Area Multi-Object Fiber Spectroscopic Telescope （LAMOST） project. SCUSS is an international cooperative project between National Astronomical Observatories, Chinese Academy of Sciences, and Steward Observatory at the University of Arizona, using the 90 inch （2.3 m） Bok telescope on Kitt Peak. The telescope is equipped with a prime focus camera that is composed of a mosaic of four 4096 × 4096 CCDs and has a field of view of about 1 deg2. From 2009 to 2013, SCUSS performed a sky survey of an approximately 5000 deg2 field of the South Galactic Cap in u band, including the Galactic anticenter area and the SDSS-IV extended imaging area. The limiting magnitude of SCUSS is deeper than 23 mag （at a signal-to-noise ratio of 5）. In this paper, we briefly describe the goals of this project, method of observations and data reduction, and we also introduce current and potential scientific activities related to the SCUSS project.
文摘In this paper, we construct a model in which the impact of pollution on health is exerted through both direct and indirect channels. The indirect channel is captured by a production func-tion in which the principal health-improving factor, income growth, can be realized only in the cost of pollution increase. This model is then tested by the aggregated chronicle disease data in over 78 Chinese counties. Our results show, after attaining the threshold of 8 μg/m2, continuous increase in industrial SO2 emission density will lead the ratio of population suffering chronicle diseases, among which respiratory diseases occupy a significant proportion, to rise. However, owing to technological progress in pollution control activities, the needed SO2 emission to produce one unit of GDP diminishes with time. Therefore, the negative effect from pollution augmentation on public health seems to be recompensed more and more by the positive effect of economic growth.
基金Supported by the National Natural Science Foundation of China
文摘Abstract We present astrometric calibration of the Xuyi Schmidt Telescope Photometric Survey of the Galactic Anti-center （XSTPS-GAC）. XSTPS-GAC is the photometric part of the Digital Sky Survey of the Galactic Anti-center （DSS-GAC）, which is a photometric and spectroscopic sky survey, in combination with LAMOST. In order to select an astrometric reference catalog, we made comparisons between the four widely used astrometric catalogs, GSC2.3, USNO-B1.0, UCAC3 and PPMXL. PPMXL shows relatively small systematic errors in positions and more homogeneous proper motion distributions toward the Galactic Anti-center （GAC）, and was selected as the reference catalog. Based on the high quality and bright reference stars that were picked out from PPMXL, we performed a 4th-order polynomial fitting in image units, to construct the transformation relation between coordinates used by XSTPS-GAC and standard coordinates, and to simultaneously correct the image distortions in the CCD. Then we applied the derived relation to all sources to obtain their mean celestial coordinates based on the Intemational Celestial Reference System. For bright point sources with r 〈 17.0 mag, the accuracy of astrometric calibration could reach about 80 mas for each of the g, r, i bands, with systematic errors being less than 10 mas. But for the faint sources at the brightness limit of the survey, which was r - 19.0 mag, the accuracy can still reach 200 mas. After combining all observations, the final weighted average coordinates could reach an accuracy of less than 70 mas for bright stars. For faint stars, the rms residuals of weighted coordinates decrease to -110 mas. The final combined XSTPS-GAC coordinates show a good consistency with the Sloan Digital Sky Survey.
基金supported by the Strategic Priority Research Program "The Emergence of Cosmological Structures" of the Chinese Academy of Sciences (Grant No. XDB09000000)the National Key Basic Research Program of China (2014CB845700)+3 种基金CL acknowledges the National Natural Science Foundation of China (NSFC, Grant Nos. 11373032, 11333003 and U1231119)XYC acknowledges the NSFC (Grant No. 11403036)the Youth Innovation Promotion Association of Chinese Academy of Sciences (Grant No. Y429012001)two Young Researcher Grants from National Astronomical Observatories, Chinese Academy of Sciences
文摘In this work, we provide 2189 photometrically- and kinematically-selected candidate members of 24 star clusters from the LAMOST DR2 catalog. We perform two-step membership identification： selection along the stellar track in the colormagnitude diagram, i.e., photometric identification, and selection from the distribution of radial velocities, i.e. the kinematic identification. We find that the radial velocities from the LAMOST data are very helpful in the membership identification. The mean probability of membership is 40% for the sample selected with radial velocity. With these 24 star clusters, we investigate the performance of the radial velocity and metallicity estimated with the LAMOST pipeline. We find that the systematic offsets in radial velocity and metallicity are 0.85 ± 1.26 km s-1and-0.08 ± 0.04 dex, with dispersions of 5.47＋1.16-0.71 km s-1and 0.13＋0.04-0.02 dex, respectively. Finally, we propose that the photometrically-selected candidate members of the clusters covered by the LAMOST footprint should be assigned higher priority so that more candidate stars can be observed.
基金supported by two CGIAR Research Programs:Dryland Cereals,Grain legumes and WLE.The research was also supported by the global food security support analysis data at 30 m project(GFSAD30http://geography.wr.usgs.gov/science/croplands/https://croplands.org/)funded by the NASA MEaSUREs[grant number:NNH13AV82I](Making Earth System Data Records for Use in Research Environments)funding obtained through NASA ROSES solicitation as well as by the Land Change Science(LCS),Land Remote Sensing(LRS),and Climate Land Use Change Mission Area Programs of the U.S.Geological Survey(USGS).
文摘The goal of this study was to map rainfed and irrigated rice-fallow cropland areas across South Asia,using MODIS 250 m time-series data and identify where the farming system may be intensified by the inclusion of a short-season crop during the fallow period.Rice-fallow cropland areas are those areas where rice is grown during the kharif growing season(June–October),followed by a fallow during the rabi season(November–February).These cropland areas are not suitable for growing rabi-season rice due to their high water needs,but are suitable for a short-season(≤3 months),low water-consuming grain legumes such as chickpea(Cicer arietinum L.),black gram,green gram,and lentils.Intensification(double-cropping)in this manner can improve smallholder farmer’s incomes and soil health via rich nitrogen-fixation legume crops as well as address food security challenges of ballooning populations without having to expand croplands.Several grain legumes,primarily chickpea,are increasingly grown across Asia as a source of income for smallholder farmers and at the same time providing rich and cheap source of protein that can improve the nutritional quality of diets in the region.The suitability of rainfed and irrigated rice-fallow croplands for grain legume cultivation across South Asia were defined by these identifiers:(a)rice crop is grown during the primary(kharif)crop growing season or during the north-west monsoon season(June–October);(b)same croplands are left fallow during the second(rabi)season or during the south-east monsoon season(November–February);and(c)ability to support low water-consuming,short-growing season(≤3 months)grain legumes(chickpea,black gram,green gram,and lentils)during rabi season.Existing irrigated or rainfed crops such as rice or wheat that were grown during kharif were not considered suitable for growing during the rabi season,because the moisture/water demand of these crops is too high.The study established cropland classes based on the every 16-day 250 m normalized difference vegetation index(NDVI)time series for one year(June 2010–May 2011)of Moderate Resolution Imaging Spectroradiometer(MODIS)data,using spectral matching techniques(SMTs),and extensive field knowledge.Map accuracy was evaluated based on independent ground survey data as well as compared with available sub-national level statistics.The producers’and users’accuracies of the cropland fallow classes were between 75%and 82%.The overall accuracy and the kappa coefficient estimated for rice classes were 82%and 0.79,respectively.The analysis estimated approximately 22.3 Mha of suitable rice-fallow areas in South Asia,with 88.3%in India,0.5%in Pakistan,1.1%in Sri Lanka,8.7%in Bangladesh,1.4%in Nepal,and 0.02%in Bhutan.Decision-makers can target these areas for sustainable intensification of short-duration grain legumes.
基金the National Key Fundamental Research Development Planning Project(Grant No.KZCX1-Y-02)the High-tech Research and Development(863)Programme of the Ministry of Science and Technology(Grant No.2002AA135230)+1 种基金the Projects of the Chinese Academy of Sciences(Grant Nos.KZ951-A1-302,KZ951-A1-203, KJ951-B1-703) the National Natural Science Foundation of China(Grant Nos.49871064 , 69896250).
文摘In the remote sensing survey of the country land, cost and accuracy are a pair of conflicts, for which spatial sampling is a preferable solution with the aim of an optimal balance between economic input and accuracy of results, or in other words, acquirement of higher ac-curacy at less cost. Counter to drawbacks of previous application models, e.g. lack of compre-hensive and quantitative-comparison, the optimal decision-making model of spatial sampling is proposed. This model first acquires the possible accuracy-cost diagrams of multiple schemes through initial spatial exploration, then regresses them and standardizes them into a unified ref-erence frame, and finally produces the relatively optimal sampling scheme by using the discrete decision-making function (built by this paper) and comparing them in combination with the dia-grams. According to the test result in the survey of the arable land using remotely sensed data, the Sandwich model, while applied in the survey of the thin-feature and cultivated land areas with aerial photos, can better realize the goal of the best balance between investment and accuracy. With this case and other cases, it is shown that the optimal decision-making model of spatial sampling is a good choice in the survey of the farm areas using remote sensing, with its distin-guished benefit of higher precision at less cost or vice versa. In order to extensively apply the model in the surveys of natural resources, including arable farm areas, this paper proposes the prototype of development using the component technology, that could considerably improve the analysis efficiency by insetting program components within the software environment of GIS and RS.
基金partially supported by the National Natural Science Foundation of China under Grant Nos.71422015,71988101the National Center for Mathematics and Interdisciplinary Sciences,Chinese Academy of Sciences。
文摘Business survey,which starts from the microeconomic level,is a widely used short-term forecasting tool in practice.In this study,the authors examine whether foreign trade survey data collected by China’s Ministry of Commerce would provide reliable forecasts of China’s foreign trade.The research procedure is designed from three perspectives including forecast information test,turning point forecast,and out-of-sample value forecast.First,Granger causality test detects whether survey data lead exports and imports.Second,business cycle analysis,a non-model based method,is performed.The authors construct composite indexes with business survey data to forecast turning points of foreign trade.Third,model-based numerical forecasting methods,including the Autoregressive Integrated Moving Average Model with Exogenous Variables(ARIMAX)and the artificial neural networks(ANNs)models are estimated.Empirical results show that survey data granger cause imports and exports,the leading composite index provides signal for changes of trade cycles,and quantitative models including survey data generate more accurate forecasts than benchmark models.It is concluded that trade survey data has excellent predictive capabilities for imports and exports,which can offer some priorities for government policy-making and enterprise decision making.
基金This work is supported by the Australian Research Council[grant number LP160100292].
文摘Cadastral surveying plays an important role in defining legal boundaries of land and property.The current practice for recording cadastral survey data mainly relies on 2D digital or analog documents.This practice is efficient for simple land parcels but can be challenged in complex building developments.To address the issues stemmed from 2D methods of representing cadastral survey data,3D spatial information models can be considered as a viable solution for managing cadastral survey data.Building Information Modeling(BIM)enables colsslaborative 3D management of the design,construction,and operation of buildings.There have been extensive studies conducted to investigate the connectivity between BIM and 3D cadaster.Most of these studies focus on managing legal information,such as ownership boundaries and attributes,in BIM-based environments.However,there is limited investigation on how survey-ing measurements can be mapped into BIM.In this study,the proposed method for integrating the cadastral survey data into the BIM environment includes identifying cadastral survey requirements,using BIM entities relevant to cadastral survey data,enrichment of a BIM proto-type,and evaluation of the prototype.The major contribution of this study is to demonstrate the storage of cadastral survey data such as survey marks and traverse lines in the BIM environment.Therefore,this research contributes to the further enrichment of BIM with incorporating data elements related to cadastral surveying practices.It is confirmed that current BIM-based tools provide restricted capabilities for explicit management and visualiza-tion of cadastral survey data.This limitation can be addressed in the future enhancements of BIM in terms of supporting important elements for cadastral survey data.
基金Supported partially by the National Funds of Natural Sciences, 7860013
文摘In July of 1987, the Sampling Survey of Children's Situation was conducted in 9 provincesautonomous regions of China. A stratified two--stage cluster sampling plan was designed for thesurvey. The paper presents the methods of stratification, selecting n=2 PSU's (cities/counties) withunequal probabilities without replacement in each stratum and selecting residents/village committeein each sampled city/county. All formulae of estimating population characteristics (especiallypopulation totals and the ratios of two totals), and estimating variances of those estimators aregiven. Finally, we analyse the precision of the survey preliminarily from the result of dataprocessing.
