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Use of non-destructive test methods on Irish hardwood standing trees and small-diameter round timber for prediction of mechanical properties / Daniel F. Llana in Annals of Forest Science [en ligne], vol 77 n° 3 (September 2020)  

Public [article]  inAnnals of Forest Science [en ligne] > vol 77 n° 3 (September 2020) Titre : Use of non-destructive test methods on Irish hardwood standing trees and small-diameter round timber for prediction of mechanical properties Type de document : Article/Communication Auteurs : Daniel F. Llana, Auteur ; Ian Short, Auteur ; Annette M. Harte, Auteur Année de publication : 2020 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes descripteurs IGN] acer pseudoplatanus [Termes descripteurs IGN] acoustique [Termes descripteurs IGN] Betula pendula [Termes descripteurs IGN] betula pubescens [Termes descripteurs IGN] bois sur pied [Termes descripteurs IGN] densité du bois [Termes descripteurs IGN] diamètre des arbres [Termes descripteurs IGN] éclaircie (sylviculture) [Termes descripteurs IGN] élagage (sylviculture) [Termes descripteurs IGN] élasticité [Termes descripteurs IGN] feuillu [Termes descripteurs IGN] fraxinus (genre) [Termes descripteurs IGN] fraxinus excelsior [Termes descripteurs IGN] Irlande [Termes descripteurs IGN] modèle de simulation [Termes descripteurs IGN] résonance [Termes descripteurs IGN] vent [Vedettes matières IGN] Sylviculture Résumé : (auteur) Key message: Mechanical properties of small-diameter round timber from hardwood thinnings of common alder ( Alnus glutinosa (L.) Gaertn.), European ash ( Fraxinus excelsior L.), European birch ( Betula pendula Roth. and Betula pubescens Ehrh.), and sycamore ( Acer pseudoplatanus L.) can be evaluated by non-destructive testing on either standing trees or green logs without wood density determination. Velocity differences between acoustic and resonance methods are influenced by tree species and age. Tree diameter improves the estimation of bending strength but not of stiffness. Context: There is a need for a reliable, fast, and inexpensive evaluation method to better sort hardwood thinnings according to mechanical properties for use in potential added-value applications. Aims: The estimation by non-destructive testing of mechanical properties of round small-diameter timber of four hardwood species (common alder, European ash, European birch, and sycamore). Methods: Acoustic velocity was measured in 38 standing trees and resonance velocity was recorded in green logs from these trees. The logs were then dried and tested in bending. Estimation models to predict mechanical properties from non-destructive testing measurements were developed. Results: Large differences between velocities from acoustic and resonance techniques were found. Models based on both non-destructive testing velocities together with a species factor are well correlated with bending modulus of elasticity while models including tree diameter are moderately well correlated with bending strength. Inclusion of density in the models does not improve the estimation. Conclusion: Models based on acoustic measurements on standing trees or resonance on green logs together with tree species and diameter provide reliable estimates of mechanical properties of round timber from hardwood thinnings. This methodology can be easily used for pre-sorting material in the forest. Numéro de notice : A2020-403 Thématique : FORET Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s13595-020-00957-x date de publication en ligne : 17/06/2020 En ligne : https://doi.org/10.1007/s13595-020-00957-x Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=95453 [article]

Constrained and network multi-receiver single-epoch RTK positioning / Mieczysław Bakula in Survey review, vol 52 n° 373 (July 2020)  

Public [article]  inSurvey review > vol 52 n° 373 (July 2020) . - pp 289 - 298 Titre : Constrained and network multi-receiver single-epoch RTK positioning Type de document : Article/Communication Auteurs : Mieczysław Bakula, Auteur Année de publication : 2020 Article en page(s) : pp 289 - 298 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Navigation et positionnement [Termes descripteurs IGN] compensation par moindres carrés [Termes descripteurs IGN] EUPOS [Termes descripteurs IGN] instrumentation Trimble [Termes descripteurs IGN] modèle mathématique [Termes descripteurs IGN] positionnement cinématique en temps réel [Termes descripteurs IGN] récepteur GNSS [Termes descripteurs IGN] station de référence Résumé : (auteur) This work presents the concept of RTK positioning based on two or three rover GNSS receivers from two or three different reference stations. Additionally, detailed mathematical models of constrained least squares adjustments of RTK positioning based on two or three different RTK/GNSS receivers are presented. The models were tested on real RTK data using three rover Trimble RTK receivers and three reference stations of the ASG-EUPOS system. Practical calculations obtained from the adjustments showed improved accuracy over traditional RTK positioning when reference GNSS stations were located far away (about 30 km from the mobile RTK receivers). The maximum average absolute error for horizontal and vertical coordinates in constrained RTK positioning was over two times lower than in the single baseline RTK positioning, and reached 0.021 and 0.046 m, respectively. Since the concept of constrained and redundant, single-epoch RTK adjustment can be used for static or kinematic applications in real-time positioning, it can also be widely used in geoscience surveying and remote sensing. Numéro de notice : A2020-376 Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/00396265.2018.1547532 date de publication en ligne : 28/11/2018 En ligne : https://doi.org/10.1080/00396265.2018.1547532 Format de la ressource électronique : url article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=95352 [article]

Path length correction for improving leaf area index measurements over sloping terrains: A deep analysis through computer simulation / Gaofei Yin in IEEE Transactions on geoscience and remote sensing, vol 58 n° 7 (July 2020)  

Public [article]  inIEEE Transactions on geoscience and remote sensing > vol 58 n° 7 (July 2020) . - pp 4573 - 4589 Titre : Path length correction for improving leaf area index measurements over sloping terrains: A deep analysis through computer simulation Type de document : Article/Communication Auteurs : Gaofei Yin, Auteur ; Biao Cao, Auteur ; Jing Li, Auteur ; et al., Auteur Année de publication : 2020 Article en page(s) : pp 4573 - 4589 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection [Termes descripteurs IGN] canopée [Termes descripteurs IGN] couvert végétal [Termes descripteurs IGN] densité du feuillage [Termes descripteurs IGN] incertitude de mesurage [Termes descripteurs IGN] indice foliaire [Termes descripteurs IGN] longueur de trajet [Termes descripteurs IGN] modèle de simulation [Termes descripteurs IGN] path length correction [Termes descripteurs IGN] pente [Termes descripteurs IGN] topographie Résumé : (auteur) The in situ measurement of the leaf area index (LAI) from gap fraction is often affected by terrain slope. Path length correction (PLC) is commonly used to mitigate the topographic effect on the LAI measurements. However, the terrain-induced uncertainty and the accuracy improvement of the PLC for LAI measurements have not been systematically analyzed, hindering the establishment of an appropriate protocol for LAI measurements over mountainous regions. In this article, the above knowledge gap was filled using a computer simulation framework, which enables the estimated LAI before and after PLC to be benchmarked against the known and precise model truth. The simulation was achieved by using CANOPIX software and a dedicatedly designed ray-tracing method for continuous and discrete canopies, respectively. Simulations show that the slope distorts the angular pattern of the gap fraction, i.e., increasing the gap fraction in the down-slope direction and reducing it in the up-slope direction. The horizontally equivalent hemispheric gap fraction from the PLC can reconstruct the azimuthally symmetric angular pattern of the real horizontal surface. The azimuthally averaged gap fraction for sloping terrain can both be underestimated or overestimated depending on the LAI and can be successfully corrected through PLC. The topography-induced uncertainty in LAI measurements is found to be ~14.3% and >20% for continuous and discrete canopies, respectively. This uncertainty can be, respectively, reduced to ~1.8% and Numéro de notice : A2020-379 Thématique : FORET/IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2019.2963366 date de publication en ligne : 30/01/2020 En ligne : https://doi.org/10.1109/TGRS.2019.2963366 Format de la ressource électronique : url article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=95372 [article]

Predictive land value modelling in Guatemala City using a geostatistical approach and Space Syntax / Jose Morales in International journal of geographical information science IJGIS, vol 34 n° 7 (July 2020)  

Public [article]  inInternational journal of geographical information science IJGIS > vol 34 n° 7 (July 2020) . - pp 1451 - 1474 Titre : Predictive land value modelling in Guatemala City using a geostatistical approach and Space Syntax Type de document : Article/Communication Auteurs : Jose Morales, Auteur ; Alfred Stein, Auteur ; Johannes Flacke, Auteur ; Jaap Zevenbergen, Auteur Année de publication : 2020 Article en page(s) : pp 1451 - 1474 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Analyse spatiale [Termes descripteurs IGN] analyse de la valeur [Termes descripteurs IGN] analyse syntaxique [Termes descripteurs IGN] cartographie statistique [Termes descripteurs IGN] estimation quantitative [Termes descripteurs IGN] évaluation foncière [Termes descripteurs IGN] géostatistique [Termes descripteurs IGN] Guatemala [Termes descripteurs IGN] krigeage [Termes descripteurs IGN] méthode du maximum de vraisemblance (estimation) [Termes descripteurs IGN] modèle conceptuel de données localisées [Termes descripteurs IGN] modèle de simulation [Termes descripteurs IGN] régression [Termes descripteurs IGN] système d'information foncière Résumé : (auteur) Spatial information of land values is fundamental for planners and policy makers. Individual appraisals are costly, explaining the need for predictive modelling. Recent work has investigated using Space Syntax to analyse urban access and explain land values. However, the spatial dependence of urban land markets has not been addressed in such studies. Further, the selection of meaningful variables is commonly conducted under non-spatialized modelling conditions. The objective of this paper is to construct a land value map using a geostatistical approach using Space Syntax and a spatialized variable selection. The methodology is applied in Guatemala City. We used an existing dataset of residential land value appraisals and accessibility metrics. Regression-kriging was used to conduct variable selection and derive a model for spatial prediction. The prediction accuracy is compared with a multivariate regression. The results show that a spatialized variable selection yields a more parsimonious model with higher prediction accuracy. New insights were found on how Space Syntax explains land value variability when also modelling the spatial dependence. Space Syntax can contribute with relevant spatialized information for predictive land value modelling purposes. Finally, the spatial modelling framework facilitates the production of spatial information of land values that is relevant for planning practice. Numéro de notice : A2020-306 Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/13658816.2020.1725014 date de publication en ligne : 11/02/2020 En ligne : https://doi.org/10.1080/13658816.2020.1725014 Format de la ressource électronique : url article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=95148 [article]

An integrated approach for detection and prediction of greening situation in a typical desert area in China and its human and climatic factors analysis / Lei Zhou in ISPRS International journal of geo-information, vol 9 n° 6 (June 2020)  

Public [article]  inISPRS International journal of geo-information > vol 9 n° 6 (June 2020) . - 24 p. Titre : An integrated approach for detection and prediction of greening situation in a typical desert area in China and its human and climatic factors analysis Type de document : Article/Communication Auteurs : Lei Zhou, Auteur ; Siyu Wang, Auteur ; Mingyi Du, Auteur ; et al., Auteur Année de publication : 2020 Article en page(s) : 24 p. Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection [Termes descripteurs IGN] bassin hydrographique [Termes descripteurs IGN] changement climatique [Termes descripteurs IGN] changement d'utilisation du sol [Termes descripteurs IGN] Chine [Termes descripteurs IGN] couvert végétal [Termes descripteurs IGN] désert [Termes descripteurs IGN] détection de changement [Termes descripteurs IGN] données lidar [Termes descripteurs IGN] image Landsat [Termes descripteurs IGN] image MODIS [Termes descripteurs IGN] modèle de simulation [Termes descripteurs IGN] Normalized Difference Vegetation Index [Termes descripteurs IGN] série temporelle [Termes descripteurs IGN] surface cultivée Résumé : (auteur) The combined study of vegetation coverage (VC) and land use change provides important scientific guidance for the restoration and protection of arid regions. Taking Hongjian Nur (HJN) Lake in the desert region as a case study, the VC of this area was calculated using a normalized difference vegetation index (NDVI), which is based on a mixed pixel decomposition method. A grey forecasting model (GM) (1, 1) was used to predict future VC. The driving factors of VC and land use change were analyzed. The results indicate that the average VC of the whole watershed showed a gradual increase from 0.29 to 0.49 during 2000–2017. The prediction results of the GM VC showed that the greening trend is projected to continue until 2027. The area of farmland in the watershed increased significantly and its area was mainly converted from unused land, grassland, and forest. The reason for increased VC may be that the combination of the exploitation of unused land and climate change, which is contrary to the country’s sustainable development goals (SDG; goal 15). Therefore, the particularities of the local ecological environment in China’s desert area needs to be considered in the development of ecological engineering projects. Numéro de notice : A2020-311 Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.3390/ijgi9060364 date de publication en ligne : 02/06/2020 En ligne : https://doi.org/10.3390/ijgi9060364 Format de la ressource électronique : url article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=95163 [article]

A method for urban population density prediction at 30m resolution / Krishnachandran Balakrishnan in Cartography and Geographic Information Science, vol 47 n° 3 (May 2020)  

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A review of assessment methods for cellular automata models of land-use change and urban growth / Xiaohua Tong in International journal of geographical information science IJGIS, vol 34 n° 5 (May 2020)  

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Performance of Galileo precise time and frequency transfer models using quad-frequency carrier phase observations / Pengfei Zhang in GPS solutions, vol 24 n° 2 (April 2020)  

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Predictive mapping with small field sample data using semi‐supervised machine learning / Fei Du in Transactions in GIS, Vol 24 n° 2 (April 2020)  

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Spatiotemporal variation of NDVI in the vegetation growing season in the source region of the yellow river, China / Mingyue Wang in ISPRS International journal of geo-information, vol 9 n° 4 (April 2020)  

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Comparison of spatial modelling approaches to simulate urban growth: a case study on Udaipur city, India / Biswajit Mondal in Geocarto international, vol 35 n° 4 ([15/03/2020])  

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Radar Vegetation Index for assessing cotton crop condition using RISAT-1 data / Dipanwita Haldar in Geocarto international, vol 35 n° 4 ([15/03/2020])  

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Bayesian inversion of convolved hidden Markov models with applications in reservoir prediction / Torstein Fjeldstad in IEEE Transactions on geoscience and remote sensing, vol 58 n° 3 (March 2020)  

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A comprehensive framework for studying diffusion patterns of imported dengue with individual-based movement data / Haiyan Tao in International journal of geographical information science IJGIS, vol 34 n° 3 (March 2020)  

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A sequential Monte Carlo framework for noise filtering in InSAR time series / Mehdi Khaki in IEEE Transactions on geoscience and remote sensing, vol 58 n° 3 (March 2020)  

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