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An adaptive Mealy machine model for monitoring crop status

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Journal of Integrative Agriculture 2017年第2期16卷 252-265页

作者： Berk Ustundag Agricultural and Environmental Informatics Application & Research Center/Faculty of informatics and Computer Engineering Istanbul Technical University Istanbul 34469 Turkey

Variation in phenological stage is the major nonlinearity in monitoring, modeling and various estimations of agricultural systems. Indices are used as a common means of evaluating agricultural monitoring data from remote sensing and terrestrial observation systems, and many of these indices have linear characteristics. The analysis of and relationships between indices are dependent on the type of plant, but they are also highly variable with respect to its phenologicat stage. For this reason, variations in the phenologica! stage affect the performance of spatiotemporal crop status monitoring. We hereby propose an adaptive event-triggered model for monitoring crop status based on remote sensing data and terrestrial observations. In the proposed model, the estimation of phenological stage is a part of predicting crop status, and spatially distributed remote sensing parameters and temporal terrestrial monitoring data are used together as inputs in a state space system model. The temporal data are segmented with respect to the phenological stage-oriented timing of the spatial data, so instead of a generalized discrete state space model, we used logical states combined with analog inputs and adaptive trigger functions, as in the case of a Mealy machine model. This provides the necessary nonlinearity for the state transi- tions. The results showed that observation parameters have considerably greater significance in crop status monitoring with respect to conventional agricultural data fusion techniques.

关键词： plant phenology monitoring yield prediction finite automata Mealy machine remote sensing

Global precision analysis of carrier phase relative positioning in BeiDou navigation satellite system and United States global positioning system

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Science China Earth Sciences 2019年第4期62卷 733-749页

作者： Letao ZHOU Dingfa HUANG Wei FENG Wu CHEN Xi ZHANG Li YAN Department of Surveying and Geo-informatics Faculty of Geosciences and Environmental EngineeringSouthWest JiaoTong University Department of Land Surveying and Geo-informatics Hong Kong Polytechnic University

In this paper, we derived a high-efficiency formula for calculating the precision of carrier phase relative positioning,analyzed the various factors that affect the positioning accuracy using the carrier phase, and proposed the concept of using a frequency dilution of precision to describe the quantitative effect of different frequency combinations on the positioning precision. To this end, we computed and plotted the global spatial distribution map of the relative positioning dilution of precision for single-day solution, half-hour solution, and single-epoch solution of the global positioning system(GPS), regional Beidou navigation satellite system(BDS2), future global Beidou navigation satellite system(BDS3), and their fusion systems.Using processing software with autonomous intellectual property rights(GCN and VENUS/ARSNet), we solved the measurement data and examined the positioning precision of the single-day solution and single-epoch solution of GPS and BDS2.The analysis demonstrated that the B1/B2 frequency positioning precision of BDS2 was better than that of L1/L2 frequency positioning of GPS, but the positioning precision of the BDS2 is worse than that of GPS over most of the service region of the BDS2. Further, the positioning precision of BDS3 is better than that of GPS in the Asia-Pacific region, while it is the opposite in other regions. Based on these conclusions, we put forth some optimization recommendations regarding the signal frequency of the navigation system and GPS measurement standards to serve as references for optimizing the system performance and formulating standards.

关键词： BeiDou navigation satellite system Relative positioning Dilution of precision Frequency dilution of precision Spatial-temporal availability

Fabrication of bimetallic Ag/Fe immobilized on modified biochar for removal of carbon tetrachloride

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Journal of environmental Sciences 2017年第4期29卷 346-357页

作者： Hongwei Wu Qiyan Feng School of environmental Science and Spatial informatics China University of Mining and Technology Department of Chemistry Zaozhuang University

As an effective conventional absorbent, biochar exhibited limited adsorption ability toward small hydrophobic molecules. To enhance the adsorption capacity, a novel adsorbent was prepared by immobilizing nanoscale zero-valent iron onto modified biochar（MB） and then the elemental silver was attached to the surface of iron（Ag/Fe/MB）. It＇s noted that spherical Ag/Fe nanoparticles with diameter of 51 nm were highly dispersed on the surface of MB. As the typical hydrophobic contaminant, carbon tetrachloride was selected for examining the removal efficiency of the adsorbent. The removal efficiencies of carbon tetrachloride by original biochar（OB）, Ag/Fe, Ag/Fe/OB and Ag/Fe/MB were fully investigated. It＇s found that Ag/Fe/MB showed higher carbon tetrachloride removal efficiency, which is about 5.5 times higher than that of the OB sample due to utilizing the merits of high adsorption and reduction. Thermodynamic parameters revealed that the removal of carbon tetrachloride by Ag/Fe/MB was a spontaneous and exothermic process, which was affected by solution p H, initial carbon tetrachloride concentration and temperature. The novel Ag/Fe/MB composites provided a promising material for carbon tetrachloride removal from effluent.

关键词： Bimetallic Ag/Fe nanoparticles Modified biochar Carbon tetrachloride

Downscaling Landsat-8 land surface temperature maps in diverse urban landscapes using multivariate adaptive regression splines and very high resolution auxiliary data

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International Journal of Digital Earth 2020年第8期13卷 899-914页

作者： Joanna Zawadzka Ron Corstanje Jim Harris Ian Truckell Centre for environmental and Agricultural informatics School of WaterEnergy and EnvironmentCranfield UniversityBedfordshireUK

We propose a method for spatial downscaling of Landsat 8-derived LST maps from 100(30 m)resolution down to 2–4 m with the use of the Multiple Adaptive Regression Splines(MARS)models coupled with very high resolution auxiliary data derived from hyperspectral aerial imagery and large-scale topographic maps.We applied the method to four Landsat 8 scenes,two collected in summer and two in winter,for three British towns collectively representing a variety of urban form.We used several spectral indices as well as fractional coverage of water and paved surfaces as LST predictors,and applied a novel method for the correction of temporal mismatch between spectral indices derived from aerial and satellite imagery captured at different dates,allowing for the application of the downscaling method for multiple dates without the need for repeating the aerial survey.Our results suggest that the method performed well for the summer dates,achieving RMSE of 1.40–1.83 K prior to and 0.76–1.21 K after correction for residuals.We conclude that the MARS models,by addressing the non-linear relationship of LST at coarse and fine spatial resolutions,can be successfully applied to produce high resolution LST maps suitable for studies of urban thermal environment at local scales.

关键词： Land surface temperature downscaling urban multivariate adaptive regression splines remote sensing

Land deformation monitoring in mining area with PPP-AR

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International Journal of Mining Science and Technology 2014年第2期24卷 207-212页

作者： Hu Hong Gao Jingxiang Yao Yifei School of environmental Science & Spatial informatics China University of Mining & TechnologyJiangsu Key Laboratory of Resources and Environmental Information Engineering

The mining area deformation monitoring theory and method using precise point positioning(PPP) ambiguity resolution(AR) were studied, and an ambiguity fixing model with satellite and receiver combination phase delay(CPD) was proposed for zero-differenced PPP ambiguity fixing and its corresponding formula derivation was given. The data processing results for 1 h at six IGS stations in China show that93% of ambiguities can be fixed within 10 min and all ambiguities can be fixed within 15 min. After ambiguity fixing, the positioning accuracy is improved by more than 85% in the E and N directions, with absolute positioning accuracy reaching millimeter level, and it was improved by 70% in the U direction,reaching centimeter level; the proposed zero-differenced ambiguity fixing model can effectively improve the convergence rate and positioning accuracy in PPP. Data monitoring continuously conducted for half a year at four CORS stations of Shanxi China Coal Pingshuo Group validated the feasibility of using PPP in mining area deformation monitoring.

关键词：变形监测矿区土地精密单点定位定位精度 PPP 相位延迟数据处理 IGS站

A deep learning approach for spatial error correction of numerical seasonal weather prediction simulation data

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Big Earth Data 2023年第2期7卷 231-250页

作者： Stelios Karozis Iraklis A.Klampanos Athanasios Sfetsos Diamando Vlachogiannis environmental Research Laboratory(EREL) INRaSTESNational Centre for Scientific Research“Demokritos”AthensGreece Institute of informatics and Telecommunications National Centre for Scientific Research“Demokritos”AthensGreece

Numerical Weather Prediction(NWP)simulations produce meteorological data in various spatial and temporal scales,depending on the application requirements.In the current study,a deep learning approach,based on convolutional autoencoders,is explored to effectively correct the error of the NWP simulation.An undercomplete convolutional autoencoder(CAE)is applied as part of the dynamic error correction of NWP data.This work is an attempt to improve the seasonal forecast(3-6 months ahead)data accuracy for Greece using a global reanalysis dataset(that incorporates observations,satellite imaging,etc.)of higher spatial resolution.More specifically,the publically available Meteo France Seasonal(Copernicus platform)and the National Centers for environmental Prediction(NCEP)Final Analysis(FNL)(NOAA)datasets are utilized.In addition,external information is used as evidence transfer,concerning the time conditions(month,day,and season)and the simulation characteristics(initialization of simulation).It is found that convolutional autoencoders help to improve the resolution of the seasonal data and successfully reduce the error of the NWP data for 6-months ahead forecasting.Interestingly,the month evidence yields the best agreement indicating a seasonal dependence of the performance.

关键词： Seasonal weather prediction neural networks convolutional autoencoder evidence transfer

Global kinematics of tectonic plates and subduction zones since the late Paleozoic Era

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Geoscience Frontiers 2019年第3期10卷 989-1013页

作者： Alexander Young Nicolas Flament Kayla Maloney Simon Williams Kara Matthews Sabin Zahirovic R.Dietmar Müller School of Earth and environmental Sciences University of Wollongong EarthByte Group School of Geosciences The University of Sydney Sydney informatics Hub The University of Sydney

Detailed global plate motion models that provide a continuous description of plate boundaries through time are an effective tool for exploring processes both at and below the Earth's surface. A new generation of numerical models of mantle dynamics pre-and post-Pangea timeframes requires global kinematic descriptions with full plate reconstructions extending into the Paleozoic(410 Ma). Current plate models that cover Paleozoic times are characterised by large plate speeds and trench migration rates because they assume that lowermost mantle structures are rigid and fixed through time. When used as a surface boundary constraint in geodynamic models, these plate reconstructions do not accurately reproduce the present-day structure of the lowermost mantle. Building upon previous work, we present a global plate motion model with continuously closing plate boundaries ranging from the early Devonian at 410 Ma to present day.We analyse the model in terms of surface kinematics and predicted lower mantle structure. The magnitude of global plate speeds has been greatly reduced in our reconstruction by modifying the evolution of the synthetic Panthalassa oceanic plates, implementing a Paleozoic reference frame independent of any geodynamic assumptions, and implementing revised models for the Paleozoic evolution of North and South China and the closure of the Rheic Ocean. Paleozoic(410-250 Ma) RMS plate speeds are on average ～8 cm/yr, which is comparable to Mesozoic-Cenozoic rates of ～6 cm/yr on average.Paleozoic global median values of trench migration trend from higher speeds(～2.5 cm/yr) in the late Devonian to rates closer to 0 cm/yr at the end of the Permian(～250 Ma), and during the Mesozoic-Cenozoic(250-0 Ma) generally cluster tightly around ～1.1 cm/yr. Plate motions are best constrained over the past 130 Myr and calculations of global trench convergence rates over this period indicate median rates range between 3.2 cm/yr and 12.4 cm/yr with a present day median rate estimated at～5 cm/yr. For Paleozoic times(410-251 Ma) o

关键词： Tectonic reconstruction Paleozoic Plate velocities Subduction zone kinematics Lower mantle structure South China

The resilience of pollination interactions: importance of temporal phases

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Journal of Plant Ecology 2019年第1期12卷 157-162页

作者： Edy Fantinato Silvia Del Vecchio Carlo Gaetan Gabriella Buffa Department of environmental Sciences Informatics and StatisticsCa’Foscari University of VeniceVia Torino 15530172 VeniceItaly

Aims The loss of species that engage in close ecological interactions,such as pollination,has been shown to lead to secondary extinctions,ultimately threatening the overall ecosystem stability and function-ing.Pollination studies are currently flourishing at all possible levels of interaction organization(i.e.,species,guild,group and network),and different methodological protocols aimed to define the resil-ience of pollination interactions have been proposed.However,the temporal dimension of the resilience of pollination interactions has been often overlooked.In the light of these considerations,we addressed the following questions:does a temporal approach help to reveal critical moments during the flowering season,when polli-nation interactions are less resilient to perturbations?Do pollination interactions evaluated at species,guild,group and network level show different patterns when assessed through time?Methods We monitored contacts between plant and pollinator species in dry grassland communities every 15 days during the overall community flowering season(12 surveys).For each survey,we built a quantita-tive plant-pollinator interaction matrix and we calculated two sets of metrics characterizing,respectively,the diversity and the distribution of interactions across hierarchical levels.To describe the diversity of interactions,we calculated partner diversity(PD)at the species level,vulnerability/generality(V/G)at the guild level,and interaction diver-sity and evenness at the network level.The distribution of interactions was characterized by calculating selectiveness at the species and the network level,and modularity at the group level.We assessed the temporal variation of PD,V/G at the level of plants and pollinators,and species selectiveness,by means of Linear Mixed Models(LMMs).To investigate the temporal variation of indexes calculated at group and network level,we applied simple linear and quadratic regres-sions after checking for temporal autocorrelation in residuals.Important Findings When taking into

关键词： asymmetry complementarity ecosystems’resilience redundancy species-rich ecosystems

environmental Information Systems:Paving the Path for Digitally Facilitated Water Management(Water 4.0)

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Engineering 2019年第5期5卷 828-832页

作者： Olaf Kolditz Karsten Rink Erik Nixdorf Thomas Fischer Lars Bilke Dmitri Naumov Zhenliang Liao Tianxiang Yue Department of Environmental Informatics Helmholtz Center for Environmental Research(UFZ)Leipzig 04318Germany Applied environmental Systems Analysis Technische Universitat DresdenDresden 01069Germany UN Environment–Tongji Institute of Environment for Sustainable Development&College of environmental Science and Engineering Tongji UniversityShanghai 200092China Department for Ecological and Environmental Informatics Institute of Geographical Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 1000101China Sino-German Research Center for environmental Information Science(RCEIS) Leipzig 04318Germany

1.Introduction The availability of reliable information describing our natural and anthropogenic environment—and its changes in particular—is crucial for understanding the complexity of structures and processes within environmental systems.Modern remote sensing and monitoring methods provide an increasing amount of environmental data that can be used for a variety of management purposes[1,2].

关键词： systems. complexity availability