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International Journal of Digital Earth 2016年第2期9卷 113-133页

作者： Min Feng Joseph O.Sexton saurabh channan John R.Townshend Global Land Cover Facility Department of Geographical SciencesUniversity of MarylandCollege ParkMDUSA

The science and management of terrestrial ecosystems require accurate,high-resolution mapping of surface *** produced a global,30-m-resolution inland surface water dataset with an automated algorithm using Landsat-based surface reflectance estimates,multispectral water and vegetation indices,terrain metrics,and prior coarse-resolution water *** dataset identified 3,650,723 km2 of inland water globally–nearly three quarters of which was located in North America(40.65%)and Asia(32.77%),followed by Europe(9.64%),Africa(8.47%),South America(6.91%),and Oceania(1.57%).Boreal forests contained the largest portion of terrestrial surface water(25.03%of the global total),followed by the nominal‘inland water’biome(16.36%),tundra(15.67%),and temperate broadleaf and mixed forests(13.91%).Agreement with respect to the Moderate-resolution Imaging Spectroradiometer water mask and Landsat-based national land-cover datasets was very high,with commission errors<4%and omission errors<14%relative to *** of these were accounted for in the seasonality of water cover,snow and ice,and clouds–effects which were compounded by differences in image acquisition date relative to reference *** Global Land Cover Facility(GLCF)inland surface water dataset is available for open access at the GLCF website(http://***).

关键词： inland water Landsat global high resolution MODIS

Integrating global land cover products for improved forest cover characterization: an application in North America

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International Journal of Digital Earth 2014年第9期7卷 709-724页

作者： Xiao-Peng Song Chengquan Huang Min Feng Joseph O.Sexton saurabh channan John R.Townshend Global Land Cover Facility Department of Geographical SciencesUniversity of MarylandCollege ParkMDUSA

Six widely used coarse-resolution global land cover data-sets–Global Land Cover Characterization(GLCC),Global Land Cover 2000(GLC2000),GlobCover land cover product(GlobCover),MODIS land cover product(MODIS LC),the University of Maryland land cover product(UMD LC),and the MODIS Vegetation Continuous Fields tree cover layer(MODIS VCF)disagree substantially in their estimates of forest *** a regression tree model trained on higher-resolution,Landsat-based data,these multisource multiresolution maps were integrated for an improved characterization of forest cover over North *** using a withheld test sample,the integrated percent forest cover(IPFC)data-set has a root mean square error of 11.75%–substantially better than the 17.37% of GLCC,17.61% of GLC2000,17.96% of GlobCover,15.23% of MODIS LC,19.25%of MODIS VCF,and 15.15%of UMD LC,*** demonstrated for forest,this approach based on integration of multiple products has potential for improved characterization of other land cover types as well.

关键词： land cover forest data fusion regression tree North America

Global, 30-m resolution continuous fields of tree cover: Landsat-based rescaling of MODIS vegetation continuous fields with lidar-based estimates of error

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International Journal of Digital Earth 2013年第5期6卷 427-448页

作者： Joseph O.Sexton Xiao-Peng Song Min Feng Praveen Noojipady Anupam Anand Chengquan Huang Do-Hyung Kim Kathrine M.Collins saurabh channan Charlene DiMiceli John R.Townshend Global Land Cover Facility Department of Geographical SciencesUniversity of MarylandCollege ParkMDUSA Department of Geographical Sciences University of MarylandCollege ParkMDUSA

We developed a global,30-m resolution dataset of percent tree cover by rescaling the 250-m MOderate-resolution Imaging Spectroradiometer(MODIS)Vegetation Continuous Fields(VCF)Tree Cover layer using circa-2000 and 2005 Landsat images,incorporating the MODIS Cropland Layer to improve accuracy in agricultural *** Landsat-based estimates maintained consistency with the MODIS VCF in both epochs(RMSE=8.6%in 2000 and 11.9%in 2005),but showed improved accuracy in agricultural areas and increased discrimination of small forest *** lidar measurements,the Landsat-based estimates exhibited accuracy slightly less than that of the MODIS VCF(RMSE=16.8%for MODIS-based vs.17.4%for Landsat-based estimates),but RMSE of Landsat estimates was 3.3 percentage points lower than that of the MODIS data in an agricultural *** Landsat data retained the saturation artifact of the MODIS VCF at greater than or equal to 80%tree cover but showed greater potential for removal of errors through calibration to lidar,with post-calibration RMSE of 9.4%compared to 13.5%in MODIS *** for free download at the Global Land Cover Facility(GLCF)website(***),the 30-m resolution GLCF tree cover dataset is the highest-resolution multi=temporal depiction of Earth’s tree cover available to the Earth science community.

关键词： tree cover continuous fields Landsat MODIS lidar

Assessment of the three factors affecting Myanmar’s forest cover change using Landsat and MODIS vegetation continuous fields data

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International Journal of Digital Earth 2016年第6期9卷 562-585页

作者： Fu-Jiang Liu Chengquan Huang Yong Pang Mengxue Li Dan-Xia Song Xiao-Peng Song saurabh channan Joseph O.Sexton Die Jiang Ping Zhang Yan Guo Yao-Feng Li John R.Townshend Department of Remote Sensing Science and Technology China University of GeosciencesWuhan CityPeople’s Republic of China Department of Geographical Sciences University of MarylandCollege ParkMDUSA Institute of Forest Resource Information Technique Chinese Academy of ForestryBeijingPeople’s Republic of China Department of Computer Science and Technology China University of GeosciencesWuhan CityPeople’s Republic of China

Long-term observation of the earth is essential for studying the factors affecting global environmental *** earth technology can facilitate the monitoring of global environmental change with its ability to process vast amounts of *** this study,we map the forest cover change of Myanmar from 2000 to 2005 using a training data automation procedure and support vector machines *** results show that Myanmar’s forests have declined 0.68%annually over this six-year *** validated our derived change results and found the overall accuracy to be greater than 88%.We also assessed forest loss from protected areas,areas close to roads,and areas subject to fire,which were most likely to lose forested *** results revealed the main reasons for forest losses in some hotspots to be increased agricultural conversion,fire,and the construction of *** information is useful for identifying the driving forces behind forest changes and to support environmental policy development in Myanmar.

关键词： Forest cover change deforestation Landsat protected area roads Myanmar

Global characterization and monitoring of forest cover using Landsat data: opportunities and challenges

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International Journal of Digital Earth 2012年第5期5卷 373-397页

作者： John R.Townshend Jeffrey G.Masek Chengquan Huang Eric.F.Vermote Feng Gao saurabh channan Joseph O.Sexton Min Feng Raghuram Narasimhan Dohyung Kim Kuan Song Danxia Song Xiao-Peng Song Praveen Noojipady Bin Tan Matthew C.Hansen Mengxue Li Robert E.Wolfe Global Land Cover Facility Department of Geographical SciencesUniversity of MarylandCollege ParkMDUSA Goddard Space Flight Center National Aeronautics and Space AdministrationGreenbeltMDUSA Department of Geographical Sciences University of MarylandCollege ParkMDUSA USDA-ARS Hydrology and Remote Sensing Laboratory BeltsvilleMDUSA

The compilation of global Landsat data-sets and the ever-lowering costs of computing now make it feasible to monitor the Earth’s land cover at Landsat resolutions of 30 *** this article,we describe the methods to create global products of forest cover and cover change at Landsat ***,there are many challenges in ensuring the creation of high-quality *** we propose various ways in which the challenges can be *** the challenges are the need for atmospheric correction,incorrect calibration coefficients in some of the data-sets,the different phenologies between compila-tions,the need for terrain correction,the lack of consistent reference data for training and accuracy assessment,and the need for highly automated character-ization and change *** propose and evaluate the creation and use of surface reflectance products,improved selection of scenes to reduce phenological differences,terrain illumination correction,automated training selection,and the use of information extraction procedures robust to errors in training data along with several other *** several stages we use Moderate Resolution Spectro-radiometer data and products to assist our analysis.A global working prototype product of forest cover and forest cover change is included.

关键词： Landsat land cover forest cover change global mapping global monitoring

An experimental study on optimizing parameters for sand consolidation with organic-inorganic silicate solutions

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Petroleum 2024年第3期10卷 483-493页

作者： saurabh Mishra Geetanjali Chauhan Keka Ojha Department of Energy Science and Technology Centre for Advanced StudiesLucknowIndia Department of Petroleum Engineering and Earth Sciences Indian Institute of Petroleum and EnergyVisakhapatnamIndia Department of Petroleum Engineering Indian Institute of Technology(ISM)DhanbadIndia

Sand production along with the oil/gas detrimentally affects the oil production rate,downhole&subsurface *** equipment and various chemicals like epoxy resin,furan resin,phenolic resin,*** used in the industry to reduce or eliminate this *** the present study,a blend of organic and inorganic silicates are used to consolidate loose sand in the presence and absence of crude oil using a core flooding *** effects of chemical concentration,pH,curing temperature and time,and the presence of residual oil on the consolidation treatment results such as compressive strength and permeability retention,were investigated and ***-IR and FE-SEM characterization techniques were employed to investigate the interaction between the chemical molecules and the sand *** current binding agent exhibited a viscosity of less than 6 cP at room temperature,which facilitates efficient pumping of binding agent into the desired formation through the well *** developed mixture demonstrated consolidation properties across all pH ***,during the experimental investigation,the curing time and temperature was carefully optimized at 12 h and 423.15K,respectively to achieve the highest compressive strength of 2021 psi while achieving the permeability retention of 64%.The current chemical system exhibited improved consolidation capacity and can be effectively utilized for sand consolidation treatment in high-temperature formations.

关键词： Chemical sand consolidation Rheology Compressive strength Permeability retention Silicate system Curing

EPASAD:ellipsoid decision boundary based Process-Aware Stealthy Attack Detector

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Cybersecurity 2024年第3期7卷 32-48页

作者： Vikas Maurya Rachit Agarwal saurabh Kumar Sandeep Shukla Department of Computer Science and Engineering Indian Institute of Technology KanpurkanpurIndia Merkle Science BangaloreIndia

Due to the importance of Critical Infrastructure(Cl)in a nation's economy,they have been lucrative targets for cyber *** critical infrastructures are usually Cyber-Physical Systems such as power grids,water,and sewage treatment facilities,oil and gas pipelines,*** recent times,these systems have suffered from cyber attacks numer-ous *** have been developing cyber security solutions for Cls to avoid lasting *** to standard frameworks,cyber security based on identification,protection,detection,response,and recovery are at the core of these *** of an ongoing attack that escapes standard protection such as firewall,anti-virus,and host/network intrusion detection has gained importance as such attacks eventually affect the physical dynamics of the ***,anomaly detection in physical dynamics proves an effective means to implement *** is one example of anomaly detection in the sensor/actuator data,representing such systems physical *** present EPASAD,which improves the detection technique used in PASAD to detect these micro-stealthy attacks,as our experiments show that PASAD's spherical boundary-based detection fails to *** method EPASAD overcomes this by using Ellipsoid boundaries,thereby tightening the boundaries in various dimen-sions,whereas a spherical boundary treats all dimensions *** validate EPASAD using the dataset produced by the TE-process simulator and the C-town *** results show that EPASAD improves PASAD's average recall by 5.8%and 9.5%for the two datasets,respectively.

关键词： Intrusion detection system Critical infrastructure security Industrial control system Machine learning

A hybrid machine learning approach based study of production forecasting and factors influencing the multiphase flow through surface chokes

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Petroleum 2024年第2期10卷 354-371页

作者： Waquar Kaleem saurabh Tewari Mrigya Fogat Dmitriy A.Martyushev Department of Industrial and Manufacturing Engineering The Pennsylvania State UniversityUniversity ParkPA16802United States Department of Data Sciences Gyan Ganga Institute of Technology and SciencesJabalpur482002India Department of Petroleum and Geo-Engineering Rajiv Gandhi Institute of Petroleum Technology JaisBahadurpur229304India Department of Oil and Gas Technologies Perm National Research Polytechnic UniversityPerm614990Russia

Surface chokes are widely utilized equipment installed on wellheads to control hydrocarbon flow *** correlations have been suggested to model the multiphase flow of oil and gas via surface ***,substantial errors have been reported in empirical fitting models and correlations to estimate hydrocarbon flow because of the reservoir's heterogeneity,anisotropism,variance in reservoir fluid characteristics at diverse subsurface depths,which introduces complexity in production ***,the estimation of daily oil and gas production rates is still challenging for the petroleum ***,hybrid data-driven techniques have been reported to be effective for estimation problems in various aspects of the petroleum *** paper investigates hybrid ensemble data-driven approaches to forecast multiphase flow rates through the surface choke(*** generalization and voting architectures),followed by an assessment of the impact of input production control ***,machine learning models are also trained and tested individually on the production data of hydrocarbon wells located in North *** engineering has been properly applied to select the most suitable contributing control variables for daily production rate *** study provides a chronological explanation of the data analytics required for the interpretation of production *** test results reveal the estimation performance of the stacked generalization architecture has outperformed other significant paradigms considered for production forecasting.

关键词： Machine learning Tree-based methods Stacking ensemble Multiphase flow Data analytics Wellhead choke variables

Barriers and drivers for sustainable public transportation in Indian context

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Green Energy and Intelligent Transportation 2024年第1期3卷 32-45页

作者： Gopi R Dev Vrat Pathak saurabh Pratap Lakshay Department of Mechanical Engineering Indian Institute of TechnologyVaranasiIndia

Rising negative externalities,including greenhouse gas emissions,climate change,and environmental pollution,shows the need for sustainable and environmentally friendly modes of *** zero-emission,environmentally friendly electric buses in public transportation systems can be an effective solution for both developing and developed countries,including *** the Indian government is making numerous efforts to promote electric buses in commercial and public transportation systems,it faces several formidable *** research objective is to analyze and evaluate the primary factors influencing the adoption and usage of electric buses in the Indian public transportation system,within the limited available resources.A survey questionnaire is prepared with several perceptual subjects for the key perceived *** empirical analysis using Structural Equation Modeling(SEM)is then performed to identify the critical *** result of this study demonstrates that the infrastructural barriers substantially impact the adoption and utilization of electric ***,the study provides critical insights and managerial implications for decision-makers.

关键词： Electric bus adoption Public transportation system Barriers Structural equation modelling Exploratory factor analysis Confirmatory factor analysis

Role of endoscopic ultrasound-guided biliary drainage for palliation of malignant biliary obstruction

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World Journal of Gastrointestinal Surgery 2024年第8期16卷 2369-2373页

作者： Sahib Singh saurabh Chandan Antonio Facciorusso Department of Internal Medicine Sinai HospitalBaltimoreMD 21215United States Center for Interventional Endoscopy(CIE) Advent HealthOrlandoFL 32803United States Gastroenterology Unit Department of Medical and Surgical SciencesUniversity of FoggiaFoggia 71122Italy

Endoscopic ultrasound-guided biliary drainage(EUS-BD)directs bile flow into the digestive tract and has been mostly used in patients with malignant biliary obstruction(MBO)where endoscopic retrograde cholangiopancreatography-guided biliary drainage was unsuccessful or was not *** apposing metal stents(LAMS)are deployed during EUS-BD,with the newer electrocautery-enhanced LAMS reducing procedure time and complication rates due to the inbuilt cautery at the catheter ***-BD with electrocautery-enhanced LAMS has high technical and clinical success rates for palliation of MBO,with bleeding,cholangitis,and stent occlusion being the most common adverse *** studies have even suggested comparable efficacy between EUS-BD and endosc-opic retrograde cholangiopancreatography as the primary approach for distal *** this editorial,we commented on the article by Peng et al published in the recent issue of the World Journal of Gastrointestinal Surgery in 2024.

关键词： Endoscopic ultrasound Endoscopic ultrasound guided biliary drainage Cancer Pancreas Bile duct Endoscopy