198 results on '"VHR"'
Search Results
52. Object-based classification of urban plant species from very high-resolution satellite imagery.
- Author
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Sicard, Pierre, Coulibaly, Fatimatou, Lameiro, Morgane, Araminiene, Valda, De Marco, Alessandra, Sorrentino, Beatrice, Anav, Alessandro, Manzini, Jacopo, Hoshika, Yasutomo, Moura, Barbara Baesso, and Paoletti, Elena
- Subjects
PLANT classification ,PLANT species ,REMOTE-sensing images ,URBAN plants ,URBAN trees ,SPECIES diversity ,PUBLIC spaces - Abstract
Cities are facing too many challenges. Urban vegetation, in particular trees, are essential as they provide services in terms of air pollution mitigation, freshness, biodiversity, and citizens' well-being. Accurate data on location, species, and structural characteristics are essential for quantifying their benefits. However, the cost of measuring thousands of individual trees through field campaigns can be prohibitive and reliable information on domestic gardens is lacking due to difficulties in acquiring systematic data. The main objective of this study was to investigate the suitability of very-high resolution satellite imagery, e.g., WorldView-2, for detecting, delineating, and classifying the urban plant species in both public and private areas. The characterization of urban vegetation is difficult due to the complexity of the urban environment (buildings, shadows, open courtyards), the diversity of species and the spatial proximity between trees. To overcome these constraints, an object-based classification was developed with the selection of new relevant spectral and texture-based features for each plant species. Four spectral bands (blue, green, yellow, red) and four texture features (i.e., energy, entropy, inverse difference moment, Haralick correlation) were found to be the most efficient attributes for object-based classification from WV-2 images. Then, a classification of plant species, by using a Random Forest classifier, and ground validation were performed. In the two study areas, Aix-en-Provence (France) and Florence (Italy), 22 and 20 dominant plant species, and grassland, were identified and classified with an overall accuracy of 84% and 83%, respectively. The highest classification accuracy was obtained for Pinus spp. and Platanus acerifolia in Aix-en-Provence, and for Celtis australis and Cupressus sempervirens in Florence. The lowest classification accuracy was obtained for Quercus spp. in Aix-en-Provence, and Magnolia grandiflora in Florence. • Full inventory is needed to quantify the benefits provided by urban vegetation • Suitability of very-high resolution satellite imagery to detect plant species in cities. • Object-based classification applied for identifying tree species and grassland. • Most of urban plants (>85%) grow in private areas. • In both cities, 22 and 20 plant species are identified with an accuracy of 84% and 83%. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
53. Estimation of Boreal Forest Attributes from Very High Resolution Pléiades Data.
- Author
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Persson, Henrik J.
- Subjects
- *
TAIGA ecology , *FOREST conservation , *FOREST management , *MULTIPLE use of forest lands , *IMAGE registration - Abstract
In this study, the potential of using very high resolution Pléiades imagery to estimate a number of common forest attributes for 10-m plots in boreal forest was examined, when a high-resolution terrain model was available. The explanatory variables were derived from three processing alternatives. Height metrics were extracted from image matching of the images acquired from different incidence angles. Spectral derivatives were derived by performing principal component analysis of the spectral bands and lastly, second order textural metrics were extracted from a gray-level co-occurrence matrix, computed with an 11 x 11 pixels moving window. The analysis took place at two Swedish test sites, Krycklan and Remningstorp, containing boreal and hemi-boreal forest. The lowest RMSE was estimated with 1.4 m (7.7%) for Lorey's mean height, 1.7 m (10%) for airborne laser scanning height percentile 90, 5.1 m⋅ ha-1 (22%) for basal area, 66 m² ⋅ ha-1 (27%) for stem volume, and 26 tons ⋅ ha-1 (26%) for above-ground biomass, respectively. It was found that the image-matched height metrics were most important in all models, and that the spectral and textural metrics contained similar information. Nevertheless, the best estimations were obtained when all three explanatory sources were used. To conclude, image-matched height metrics should be prioritised over spectral metrics when estimation of forest attributes is concerned. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
54. AUTOMATIC APPROACH TO VHR SATELLITE IMAGE CLASSIFICATION.
- Author
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Kupidura, P., Osińska-Skotak, K., and Pluto-Kossakowska, J.
- Subjects
REMOTE-sensing images ,CLASSIFICATION algorithms ,NORMALIZED difference vegetation index - Abstract
In this paper, we present a proposition of a fully automatic classification of VHR satellite images. Unlike the most widespread approaches: supervised classification, which requires prior defining of class signatures, or unsupervised classification, which must be followed by an interpretation of its results, the proposed method requires no human intervention except for the setting of the initial parameters. The presented approach bases on both spectral and textural analysis of the image and consists of 3 steps. The first step, the analysis of spectral data, relies on NDVI values. Its purpose is to distinguish between basic classes, such as water, vegetation and non-vegetation, which all differ significantly spectrally, thus they can be easily extracted basing on spectral analysis. The second step relies on granulometric maps. These are the product of local granulometric analysis of an image and present information on the texture of each pixel neighbourhood, depending on the texture grain. The purpose of texture analysis is to distinguish between different classes, spectrally similar, but yet of different texture, e.g. bare soil from a built-up area, or low vegetation from a wooded area. Due to the use of granulometric analysis, based on mathematical morphology opening and closing, the results are resistant to the border effect (qualifying borders of objects in an image as spaces of high texture), which affect other methods of texture analysis like GLCM statistics or fractal analysis. Therefore, the effectiveness of the analysis is relatively high. Several indices based on values of different granulometric maps have been developed to simplify the extraction of classes of different texture. The third and final step of the process relies on a vegetation index, based on near infrared and blue bands. Its purpose is to correct partially misclassified pixels. All the indices used in the classification model developed relate to reflectance values, so the preliminary step of recalculation of pixel DNs to reflectance is required. Thanks to this, the proposed approach is in theory universal, and might be applied to different satellite system images of different acquisition dates. The test data consists of 3 Pleiades images captured on different dates. Research allowed to determine optimal indices values. Using the same parameters, we obtained a very good accuracy of extraction of 5 land cover/use classes: water, low vegetation, bare soil, wooded area and built-up area in all the test images (kappa from 87% to 96%). What constitutes important, even significant changes in parameter values, did not cause a significant declination of classification accuracy, which demonstrates how robust the proposed method is. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
55. COMPARISON OF OPEN SOURCE COMPRESSION ALGORITHMS ON VHR REMOTE SENSING IMAGES FOR EFFICIENT STORAGE HIERARCHY.
- Author
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Akoguz, A., Bozkurt, S., Gozutok, A. A., Alp, G., Turan, E. G., Bogaz, M., and Kent, S.
- Subjects
REMOTE sensing ,IMAGE processing - Abstract
High resolution level in satellite imagery came with its fundamental problem as big amount of telemetry data which is to be stored after the downlink operation. Moreover, later the post-processing and image enhancement steps after the image is acquired, the file sizes increase even more and then it gets a lot harder to store and consume much more time to transmit the data from one source to another; hence, it should be taken into account that to save even more space with file compression of the raw and various levels of processed data is a necessity for archiving stations to save more space. Lossless data compression algorithms that will be examined in this study aim to provide compression without any loss of data holding spectral information. Within this objective, well-known open source programs supporting related compression algorithms have been implemented on processed GeoTIFF images of Airbus Defence & Spaces SPOT 6 & 7 satellites having 1.5 m. of GSD, which were acquired and stored by ITU Center for Satellite Communications and Remote Sensing (ITU CSCRS), with the algorithms Lempel-Ziv-Welch (LZW), Lempel-Ziv-Markov chain Algorithm (LZMA & LZMA2), Lempel-Ziv-Oberhumer (LZO), Deflate & Deflate 64, Prediction by Partial Matching (PPMd or PPM2), Burrows-Wheeler Transform (BWT) in order to observe compression performances of these algorithms over sample datasets in terms of how much of the image data can be compressed by ensuring lossless compression. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
56. Characterizing Small-Town Development Using Very High Resolution Imagery within Remote Rural Settings of Mozambique
- Author
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Chen, Dong, Chen, Dong, Loboda, Tatiana V., Silva, Julie A., Tonellato, Maria R., Chen, Dong, Chen, Dong, Loboda, Tatiana V., Silva, Julie A., and Tonellato, Maria R.
- Abstract
While remotely sensed images of various resolutions have been widely used in identifying changes in urban and peri-urban environments, only very high resolution (VHR) imagery is capable of providing the information needed for understanding the changes taking place in remote rural environments, due to the small footprints and low density of man-made structures in these settings. However, limited by data availability, mapping man-made structures and conducting subsequent change detections in remote areas are typically challenging and thus require a certain level of flexibility in algorithm design that takes into account the specific environmental and image conditions. In this study, we mapped all buildings and corrals for two remote villages in Mozambique based on two single-date VHR images that were taken in 2004 and 2012, respectively. Our algorithm takes advantage of the presence of shadows and, through a fusion of both spectra- and object-based analysis techniques, is able to differentiate buildings with metal and thatch roofs with high accuracy (overall accuracy of 86% and 94% for 2004 and 2012, respectively). The comparison of the mapping results between 2004 and 2012 reveals multiple lines of evidence suggesting that both villages, while differing in many aspects, have experienced substantial increases in the economic status. As a case study, our project demonstrates the capability of a coupling of VHR imagery with locally adjusted classification algorithms to infer the economic development of small, remote rural settlements.
- Published
- 2021
57. Characterizing Small-Town Development Using Very High Resolution Imagery within Remote Rural Settings of Mozambique
- Author
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Tatiana V. Loboda, Julie A. Silva, Maria R. Tonellato, and Dong Chen
- Subjects
Flexibility (engineering) ,Very high resolution ,Small town ,Computer science ,Science ,LCLUC ,Data availability ,Statistical classification ,VHR ,Africa ,Low density ,General Earth and Planetary Sciences ,Algorithm design ,Rural settlement ,Mozambique ,Remote sensing - Abstract
While remotely sensed images of various resolutions have been widely used in identifying changes in urban and peri-urban environments, only very high resolution (VHR) imagery is capable of providing the information needed for understanding the changes taking place in remote rural environments, due to the small footprints and low density of man-made structures in these settings. However, limited by data availability, mapping man-made structures and conducting subsequent change detections in remote areas are typically challenging and thus require a certain level of flexibility in algorithm design that takes into account the specific environmental and image conditions. In this study, we mapped all buildings and corrals for two remote villages in Mozambique based on two single-date VHR images that were taken in 2004 and 2012, respectively. Our algorithm takes advantage of the presence of shadows and, through a fusion of both spectra- and object-based analysis techniques, is able to differentiate buildings with metal and thatch roofs with high accuracy (overall accuracy of 86% and 94% for 2004 and 2012, respectively). The comparison of the mapping results between 2004 and 2012 reveals multiple lines of evidence suggesting that both villages, while differing in many aspects, have experienced substantial increases in the economic status. As a case study, our project demonstrates the capability of a coupling of VHR imagery with locally adjusted classification algorithms to infer the economic development of small, remote rural settlements.
- Published
- 2021
- Full Text
- View/download PDF
58. Engaging ‘the crowd’ in remote sensing to learn about habitat affinity of the Weddell seal in Antarctica
- Author
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Leo Salas, Nadav Nur, Luke Barrington, Sharon Stammerjohn, Michelle A. LaRue, David G. Ainley, Kostas Stamatiou, and Jean Pennycook
- Subjects
Ecology ,very high‐resolution satellite imagery ,lcsh:T ,lcsh:Technology ,Seal (mechanical) ,Geography ,VHR ,Habitat ,Remote sensing (archaeology) ,lcsh:QH540-549.5 ,citizen science ,Citizen science ,Antarctica ,lcsh:Ecology ,Computers in Earth Sciences ,Southern Ocean ,Weddell seal ,Ecology, Evolution, Behavior and Systematics ,Nature and Landscape Conservation ,Remote sensing - Abstract
Satellites Over Seals (SOS), a project initiated in late 2016, is a crowdsourced method to determine factors behind the presence/absence patterns and to ultimately determine the global population of the Weddell seal (Leptonychotes weddellii). An iconic species, the Weddell seal is proposed to be part of the Antarctic Research and Monitoring Program required in the newly designated Ross Sea Region Marine Protected Area. This species is easy to detect via satellite imagery, due to its large size (3–4 m long, 1 m wide) and its dark color contrasting with the Antarctic coastal fast ice, where it aggregates on during breeding season. Using very high‐resolution satellite imagery (VHR; 0.31–0.60 m resolution) and the online platform Tomnod, we used VHR images from November 2010 and 2011 to cover the entirety of available fast ice around Antarctica. Before correcting for time of day or date, we searched for the presence/absence to identify a subset of where abundance estimates should be concentrated. More than 325 000 citizen scientists searched 790 VHR images, covering 268 611 km2 of fast ice, to determine the locations of seals. Algorithms ranked searchers to the degree their votes corresponded with others, a measure of searcher relative quality that we used to filter out unreliable searchers. Seal presence was detected on only 0.55% of available maps (total n = 1 116 058) within fast ice, revealing a sparse, irregular distribution. The rate of false‐negative detections was 1.7%, though false positives were high (67%), highlighting the importance of training for image interpretation to ensure differentiation between seals and landscape features (such as large rocks, ice chunks or depressions/holes in the ice). This approach not only allowed us to assess image resolution and quality, but also training, outreach and the effectiveness of this platform for introducing citizen scientists to the ecology of the Southern Ocean.
- Published
- 2019
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59. Hyperspatial and Multi-Source Water Body Mapping: A Framework to Handle Heterogeneities from Observations and Targets over Large Areas
- Author
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Raphaël d’Andrimont, Catherine Marlier, and Pierre Defourny
- Subjects
water body ,LiDAR ,aerial photograph ,heterogeneity ,pond ,sub-meter ,sub-pixel ,UAV ,hyperspatial ,map ,fusion ,VHR ,Science - Abstract
Recent advances in remote sensing technologies and the cost reduction of surveying, along with the importance of natural resources management, present new opportunities for mapping land cover at a very high resolution over large areas. This paper proposes and applies a framework to update hyperspatial resolution (
- Published
- 2017
- Full Text
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60. Contribution of VHR Coherence, Complex Intensity, and Sigma0 to the Identification of Urban Structures in Hue, Central Vietnam
- Author
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Braun, Andreas and Bachofer, Felix
- Subjects
VHR ,Vietnam ,urban ,coherence - Published
- 2021
61. Damage and geological assessment of the 18 September 2011 Mw 6.9 earthquake in Sikkim, India using very high resolution satellite data.
- Author
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Martha, Tapas R., Babu Govindharaj, K., and Vinod Kumar, K.
- Abstract
Post-disaster very high resolution (VHR) satellite data are potential sources to provide detailed information on damage and geological changes for a large area in a short time. In this paper, we studied landslides triggered by the M w 6.9 earthquake in Sikkim, India which occurred on 18 September 2011 using VHR data from Cartosat-1, GeoEye-1, QuickBird-2 and WorldView-2 satellites. Since the earthquake-affected area is located in mostly inaccessible Himalayan terrain, VHR data from these satellites provided a unique opportunity for quick and synoptic assessment of the damage. Using visual change analysis technique through comparison of pre- and post-earthquake images, we assessed the damage caused by the event. A total of 123 images acquired from eight satellites, covering an area of 4105 km 2 were analysed and 1196 new landslides triggered by the earthquake were mapped. Road blockages and severely affected villages were also identified. Geological assessment of the terrain highlighted linear disposition of landslides along existing fault scarps, suggesting a reactivation of fault. The landslide inventory map prepared from VHR images also showed a good correlation with the earthquake shake map. Results showed that several parts of north Sikkim, particularly Mangan and Chungthang, which are close to the epicentre, were severely affected by the earthquake, and that the event-based landslide inventory map can be used in future earthquake-triggered landslide susceptibility assessment studies. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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- View/download PDF
62. Perspective: Tyrosine phosphatases as novel targets for antiplatelet therapy.
- Author
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Tautz, Lutz, Senis, Yotis A., Oury, Cécile, and Rahmouni, Souad
- Subjects
- *
PROTEIN-tyrosine phosphatase , *PLATELET aggregation inhibitors , *TARGETED drug delivery , *THROMBOSIS , *MYOCARDIAL infarction , *ETIOLOGY of diseases - Abstract
Arterial thrombosis is the primary cause of most cases of myocardial infarction and stroke, the leading causes of death in the developed world. Platelets, highly specialized cells of the circulatory system, are key contributors to thrombotic events. Antiplatelet drugs, which prevent platelets from aggregating, have been very effective in reducing the mortality and morbidity of these conditions. However, approved antiplatelet therapies have adverse side effects, most notably the increased risk of bleeding. Moreover, there remains a considerable incidence of arterial thrombosis in a subset of patients receiving currently available drugs. Thus, there is a pressing medical need for novel antiplatelet agents with a more favorable safety profile and less patient resistance. The discovery of novel antiplatelet targets is the matter of intense ongoing research. Recent findings demonstrate the potential of targeting key signaling molecules, including kinases and phosphatases, to prevent platelet activation and aggregation. Here, we offer perspectives to targeting members of the protein tyrosine phosphatase (PTP) superfamily, a major class of enzymes in signal transduction. We give an overview of previously identified PTPs in platelet signaling, and discuss their potential as antiplatelet drug targets. We also introduce VHR (DUSP3), a PTP that we recently identified as a major player in platelet biology and thrombosis. We review our data on genetic deletion as well as pharmacological inhibition of VHR, providing proof-of-principle for a novel and potentially safer VHR-based antiplatelet therapy. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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63. Thermal analysis of CuMg alloys deformed by equal channel angular pressing
- Author
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Universitat Politècnica de Catalunya. Departament de Ciència i Enginyeria de Materials, Universitat Politècnica de Catalunya. PROCOMAME - Processos de Conformació de Materials Metàl·lics, Cabrera Marrero, José M., Ferrer Cruselles, Núria, Universitat Politècnica de Catalunya. Departament de Ciència i Enginyeria de Materials, Universitat Politècnica de Catalunya. PROCOMAME - Processos de Conformació de Materials Metàl·lics, Cabrera Marrero, José M., and Ferrer Cruselles, Núria
- Abstract
The thermal behavior of two copper alloys, with 0.2 and 0.5 mass % of Mg, was analyzed after severe plastic deformation processing by Equal Channel Angular Pressing (ECAP). Both alloys were forced to be passed through a 90º inner angle ECAP die at room temperature up to 16 passes following route Bc. The thermal stability was analyzed in terms of the recrystallization kinetics by using the Various Heating Rates method, derived from the Johnson–Mehl–Avrami–Kolmogorov equation, after analyzing the Differential Scanning Calorimetry peaks for both alloys at any pass of ECAP. The calculated recrystallization parameters included the activation energies (E (kJ mol-1) ECuMg02¿=¿42.6¿±¿19.8 ECuMg05¿=¿52.7¿±¿13 kJ mol-1) and the kinetic exponent n which took an average value of ˜ 1.75, irrespective of the considered alloy., Postprint (published version)
- Published
- 2020
64. The Role of Emotion in Product, Service and Business Model Design.
- Author
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Straker, Karla and Wrigley, Cara
- Subjects
EMOTIONS ,BUSINESS models - Abstract
Copyright of Journal of Entrepreneurship, Management & Innovation is the property of Wyzsza Szkola Biznesu-National Louis University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2015
- Full Text
- View/download PDF
65. Terrasar next generation - Mission capabilities.
- Author
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Janoth, Jurgen, Gantert, Steffen, Schrage, Thomas, and Kaptein, Alexander
- Abstract
The TerraSAR-X Next Generation (TerraSAR-X NG) mission is intended to take the TerraSAR-X data and service continuity well beyond 2025 taking benefit of a 9.5 years satellite lifetime [1]. The Space Segment, initially a single spacecraft, will be launched into the TerraSAR-X reference orbit while first generation TerraSAR-X systems will still be operational. The TerraSAR-X NG Mission will benefit from an advanced SAR sensor technology allowing a spatial resolution down to 0.25 meter depending on allowable chirp bandwidth in the future. Besides advanced Very High Resolution Modes TerraSAR-X NG will provide heritage modes enabling TerraSAR-X data continuity and improved wide swath modes to support large area applications. In addition the TerraSAR-X NG Mission will feature full polarimetry and improved near real time capabilities. The TerraSAR-X NG Mission and potential extensions will be subject to a partnership model, “WorldSAR”, in which partners can participate through co-investment, subscription, and ownership of additional satellites operated in constellation. [ABSTRACT FROM PUBLISHER]
- Published
- 2013
- Full Text
- View/download PDF
66. Land Use Classification of VHR Images for Mapping Small-Sized Abandoned Citrus Plots by Using Spectral and Textural Information
- Author
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Javier Estornell, Sergio Morell-Monzó, and María-Teresa Sebastiá-Frasquet
- Subjects
random forests ,Citrus ,Land abandonment ,010504 meteorology & atmospheric sciences ,Image classification ,Science ,0211 other engineering and technologies ,Decision tree ,02 engineering and technology ,01 natural sciences ,land abandonment ,land use ,agriculture ,citrus ,gray level co-occurrence matrix ,VHR ,image classification ,semantic segmentation ,remote sensing ,Normalized Difference Vegetation Index ,Gray level co-occurrence matrix ,Agricultural land ,Statistics ,TECNOLOGIA DEL MEDIO AMBIENTE ,021101 geological & geomatics engineering ,0105 earth and related environmental sciences ,Mathematics ,Pixel ,Contextual image classification ,Land use ,Contrast (statistics) ,Agriculture ,Random forests ,Remote sensing ,Semantic segmentation ,Random forest ,INGENIERIA CARTOGRAFICA, GEODESIA Y FOTOGRAMETRIA ,General Earth and Planetary Sciences - Abstract
[EN] Agricultural land abandonment is an increasing problem in Europe. The Comunitat Valenciana Region (Spain) is one of the most important citrus producers in Europe suffering this problem. This region characterizes by small sized citrus plots and high spatial fragmentation which makes necessary to use Very High-Resolution images to detect abandoned plots. In this paper spectral and Gray Level Co-Occurrence Matrix (GLCM)-based textural information derived from the Normalized Difference Vegetation Index (NDVI) are used to map abandoned citrus plots in Oliva municipality (eastern Spain). The proposed methodology is based on three general steps: (a) extraction of spectral and textural features from the image, (b) pixel-based classification of the image using the Random Forest algorithm, and (c) assignment of a single value per plot by majority voting. The best results were obtained when extracting the texture features with a 9 x 9 window size and the Random Forest model showed convergence around 100 decision trees. Cross-validation of the model showed an overall accuracy of the pixel-based classification of 87% and an overall accuracy of the plot-based classification of 95%. All the variables used are statistically significant for the classification, however the most important were contrast, dissimilarity, NIR band (720 nm), and blue band (620 nm). According to our results, 31% of the plots classified as citrus in Oliva by current methodology are abandoned. This is very important to avoid overestimating crop yield calculations by public administrations. The model was applied successfully outside the main study area (Oliva municipality); with a slightly lower accuracy (92%). This research provides a new approach to map small agricultural plots, especially to detect land abandonment in woody evergreen crops that have been little studied until now., This research was funded by regional government of Spain, Generalitat Valenciana, within the framework of the research project AICO/2020/246 and the APC was also funded by the research project AICO/2020/246.
- Published
- 2021
67. UAV PHOTOGRAMMETRY AND VHR SATELLITE IMAGERY FOR EMERGENCY MAPPING. THE OCTOBER 2020 FLOOD IN LIMONE PIEMONTE (ITALY)
- Author
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Andrea Maria Lingua, L. Teppati Losè, F. Giulio Tonolo, and Filiberto Chiabrando
- Subjects
UAVs, Direct Georeferencing, Emergency Mapping, VHR, Satellite, SfM ,Technology ,Data processing ,Flood myth ,Satellite system ,UAVs ,Engineering (General). Civil engineering (General) ,TA1501-1820 ,Photogrammetry ,Emergency Mapping ,VHR ,GNSS applications ,Satellite ,Direct Georeferencing ,SfM ,Environmental science ,Applied optics. Photonics ,Satellite imagery ,TA1-2040 ,Scale (map) ,Remote sensing - Abstract
Heavy rain between the 2nd and 3rd of October 2020 severely affected the area of Limone Piemonte, Piemonte Region (Italy). The consequence of those two days of rain was a flood that, starting from the hamlet of Limonetto severely damaged the areas close to the riverbed of the Vermegnana river and the related hydrographyc network. A synergistic multi-sensor and multi-scale approach for documenting the affected areas using VHR satellite images and UAVs (Uncrewed Aerial Vehicles) is presented. The pro and cons in terms of level of detail and processing strategies are reviewed with a focus on the workflows adopted for processing large UAV datasets. A thorough analysis of the 3D positional accuracy achievable with different georeferentation strategies for UAVs data processing is carried out, confirming that if an RTK (Reale Time Kinematic)-enabled GNSS (Global Navigation Satellite System) receiver is available on the UAV platform and proper acquisition guidelines are followed, the use of GCPs (Ground Control Points) is not impacting significantly on the overall positional accuracy. Satellite data processing is also presented, confirming the suitability for large scale mapping.
- Published
- 2021
68. TerraSAR-X2 - Mission overview.
- Author
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Janoth, Juergen, Gantert, Steffen, Koppe, Wolfgang, Kaptein, Alexander, and Fischer, Christian
- Abstract
The TerraSAR-X2 Mission is intended to insure the TerraSAR-X service continuity from 2016 onwards and to provide new very high resolution products with improved performance parameters to the user community. The TerraSAR-X2 Mission will benefit from an advanced SAR sensor technology allowing a spatial resolution down to 0.25 meter depending on selected and allowable chirp bandwidth in the future. Besides the advanced Very High Resolution Modes the TerraSAR-X2 satellite will provide heritage modes that allow direct continuity of TerraSAR-X data and improved wide swath modes to support large area applications. In addition the TerraSAR-X2 Mission will feature full polarimetry and improved near real time capabilities. The TerraSAR-X2 Mission and potential extensions will be subject to a partnership model, “WorldSAR”, in which partners can participate through co-investment, subscription, and up to ownership of additional satellites operated in constellation. Service continuity through TerraSAR-X2 is intended to be ensured from 2016 until 2025, taking benefit of a 9.5 years satellite lifetime. [ABSTRACT FROM PUBLISHER]
- Published
- 2012
- Full Text
- View/download PDF
69. Estimation of Boreal Forest Attributes from Very High Resolution Pléiades Data
- Author
-
Henrik J. Persson
- Subjects
canopy ,image matching ,forestry ,Pléiades ,biomass ,VHR ,Science - Abstract
In this study, the potential of using very high resolution Pléiades imagery to estimate a number of common forest attributes for 10-m plots in boreal forest was examined, when a high-resolution terrain model was available. The explanatory variables were derived from three processing alternatives. Height metrics were extracted from image matching of the images acquired from different incidence angles. Spectral derivatives were derived by performing principal component analysis of the spectral bands and lastly, second order textural metrics were extracted from a gray-level co-occurrence matrix, computed with an 11 × 11 pixels moving window. The analysis took place at two Swedish test sites, Krycklan and Remningstorp, containing boreal and hemi-boreal forest. The lowest RMSE was estimated with 1.4 m (7.7%) for Lorey’s mean height, 1.7 m (10%) for airborne laser scanning height percentile 90, 5.1 m2·ha−1 (22%) for basal area, 66 m3·ha−1 (27%) for stem volume, and 26 tons·ha−1 (26%) for above-ground biomass, respectively. It was found that the image-matched height metrics were most important in all models, and that the spectral and textural metrics contained similar information. Nevertheless, the best estimations were obtained when all three explanatory sources were used. To conclude, image-matched height metrics should be prioritised over spectral metrics when estimation of forest attributes is concerned.
- Published
- 2016
- Full Text
- View/download PDF
70. A Comparison of Mangrove Canopy Height Using Multiple Independent Measurements from Land, Air, and Space
- Author
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David Lagomasino, Temilola Fatoyinbo, SeungKuk Lee, Emanuelle Feliciano, Carl Trettin, and Marc Simard
- Subjects
canopy height ,DSM ,biomass ,Africa ,H100 ,blue carbon ,TDX ,VHR ,MRV ,Science - Abstract
Canopy height is one of the strongest predictors of biomass and carbon in forested ecosystems. Additionally, mangrove ecosystems represent one of the most concentrated carbon reservoirs that are rapidly degrading as a result of deforestation, development, and hydrologic manipulation. Therefore, the accuracy of Canopy Height Models (CHM) over mangrove forest can provide crucial information for monitoring and verification protocols. We compared four CHMs derived from independent remotely sensed imagery and identified potential errors and bias between measurement types. CHMs were derived from three spaceborne datasets; Very-High Resolution (VHR) stereophotogrammetry, TerraSAR-X add-on for Digital Elevation Measurement, and Shuttle Radar Topography Mission (TanDEM-X), and lidar data which was acquired from an airborne platform. Each dataset exhibited different error characteristics that were related to spatial resolution, sensitivities of the sensors, and reference frames. Canopies over 10 m were accurately predicted by all CHMs while the distributions of canopy height were best predicted by the VHR CHM. Depending on the guidelines and strategies needed for monitoring and verification activities, coarse resolution CHMs could be used to track canopy height at regional and global scales with finer resolution imagery used to validate and monitor critical areas undergoing rapid changes.
- Published
- 2016
- Full Text
- View/download PDF
71. Método para la ortorrectificación de imágenes satelitales monoscópicas de muy alta resolución espacial empleando algoritmos evolutivos
- Author
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Ramírez Gutiérrez, Miguel Angel, Upegui Cardona, Erika Sofía, Leon Sanchez, Camilo Alexander, GEFEM: Grupo de Estudio en temas de la Física, de la Estadística y la Matemática, Upegui Cardona, Erika Sofia, and León Sanchez, Camilo Alexander
- Subjects
Cartography ,Algoritmos ,Ortorrectificación ,380 - Comercio , comunicaciones, transporte ,004 - Procesamiento de datos Ciencia de los computadores [000 - Ciencias de la computación, información y obras generales] ,Tratamiento de imágenes ,PSO ,OLS ,satellite imagery ,algorithms ,Orthorectification ,Alta resolución ,image processing ,Imágenes satelitales ,VHR ,RFM ,High resolution ,Satellite images ,Cartografía ,Imágenes por satélites - Abstract
ilustraciones, fotografías, gráficas, tablas La ortorrectificación de imágenes satelitales monoscópicas de muy alta resolución (VHR, por sus siglas en inglés) espacial es un proceso fundamental para asegurar la interoperabilidad de la información espacial obtenida a partir de ellas y más si se desea generar cartografía básica. Por lo anterior, estudios previos han utilizado distintos tipos de insumos entre los que se destacan múltiples fuentes de puntos de control y modelos digitales de elevación (DEM) de todo tipo, además de probar distintos métodos de optimización. Este trabajo de investigación tiene como objetivo usar de manera conjunta y evaluar la utilización de algoritmo evolutivo Particle Swarm Optimization (PSO, por sus siglas en inglés), puntos estereoscópicos provenientes de bloques fotogramétricos y DEM de distintas fuentes, para la obtención de productos cartográficos de escala 1:10.000 comparando sus resultados con lo obtenido por mínimos cuadrados ordinarios (OLS, por sus siglas en inglés) que ofrece las soluciones comerciales más utilizadas en el mercado. La metodología se compone de tres etapas. La primera corresponde al procedimiento de evaluación de DEM disponibles, generación de bloques fotogramétricos y puntos estereoscópicos junto al aseguramiento de la calidad de estos productos desde un enfoque fotogramétrico. La segunda etapa fue realizada la ortorrectificación de las imágenes monoscópicas VHR utilizando los módulos especializados de las soluciones comerciales (OLS) más utilizadas seleccionando el grado del apropiado del modelo de disposición espacial Rational Functional Model (RFM, por sus siglas en inglés) con su correspondiente evaluación. La tercera y última etapa corresponde a los procesos necesarios para la estimación y selección de los coeficientes del modelo de disposición espacial RFM usando PSO y el método Feature Condition Analysis junto a todo el flujo necesario para la generación de la ortoimagen final junto a una validación de los supuestos estadísticos sobre los residuales. Como resultado de los experimentos con OLS se observa que el uso de los puntos estereoscópicos es adecuado, pero el DEM influencia significativamente la exactitud posicional del producto final, a pesar de no ser adecuados para la escala objetivo. Además, cada algoritmo posee su propio procesamiento traducido en el resultado final y diferente modelo seleccionado, razón de la diferencia en los resultados, por lo que es necesario profundizar con mayor rigor en estos experimentos si se desea estudiar otros tipos de métodos de optimización. Mientras que con el uso del algoritmo PSO se observó mejora en promedio en un 3% la exactitud posicional de la ortoimagen sin embargo su utilización requiere de elevados recursos computacionales y además este tipo de método de optimización no se encuentra disponible aún en software especializado siendo difícil su implementación en masa de procesos productivos cartográficos. (Texto tomado de la fuente). The orthorectification of very high resolution (VHR) monoscopic spatial satellite images is a fundamental process to ensure the interoperability of the spatial information obtained from them. Therefore, previous studies have used different types of inputs, among which multiple sources of control points and digital elevation models (DEM) of all kinds stand out, in addition to testing different optimization methods. This research work aims to jointly use and evaluate the use of the evolutionary algorithm Particle Swarm Optimization (PSO), stereoscopic points from photogrammetric blocks and DEM from different sources, to obtain cartographic products of scale 1:10.000 comparing its results with that obtained by Ordinary Least Squares (OLS) that offers the most used commercial solutions. The methodology is made up of three stages. The first stage corresponds to the available DEM evaluation procedure, generation of photogrammetric blocks and stereoscopic points, together with the quality assurance of these products from a photogrammetric approach. The second stage was performed the orthorectification of the monoscopic VHR images using the specialized modules of the most used commercial solutions (OLS), selecting the degree of the appropriate spatial arrangement model Rational Functional Model (RFM) with its corresponding evaluation. The third and last stage corresponds to the processes necessary for the estimation and selection of the coefficients of the RFM spatial arrangement model using PSO and the Feature Condition Analysis method together with all the necessary flow for the generation of the final orthoimage together to a validation of the statistical assumptions about the residuals. As a result of the OLS experiments, it is observed that the use of stereoscopic points is adequate, but the DEM significantly influences the positional accuracy of the final product, despite not being suitable for the target scale. In addition, each algorithm has its own processing translated into the final result and a different selected model, which is the reason for the difference in the results, so it is necessary to delve more rigorously into these experiments if you want to study other types of optimization methods. While with the use of the PSO algorithm, an average 3 \% improvement in the positional accuracy of the orthoimage was observed; however, its use requires high computational resources and, furthermore, this type of optimization method is not yet available in specialized software. difficult its mass implementation of cartographic production processes. Incluye anexos Maestría Magíster en Geomática Tecnologías geoespaciales Ciencias Agronómicas
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- 2020
72. Fusion Approach for Remotely-Sensed Mapping of Agriculture (FARMA): A Scalable Open Source Method for Land Cover Monitoring Using Data Fusion
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Mark L. Carroll, Jessica L. McCarty, Peter Bunting, Christopher S.R. Neigh, and Nathan Thomas
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Synthetic aperture radar ,fusion ,010504 meteorology & atmospheric sciences ,Computer science ,Science ,Big data ,0211 other engineering and technologies ,02 engineering and technology ,Land cover ,01 natural sciences ,law.invention ,VHR ,law ,Radar ,agriculture ,021101 geological & geomatics engineering ,0105 earth and related environmental sciences ,Remote sensing ,object-oriented ,business.industry ,time-series ,computer.file_format ,Sensor fusion ,radar ,rice ,backscatter ,GEOBIA ,food security ,Scalability ,General Earth and Planetary Sciences ,Raster graphics ,Scale (map) ,business ,computer - Abstract
The increasing availability of very-high resolution (VHR
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- 2020
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73. Very high resolution environmental predictors in species distribution models: Moving beyond topography?
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Pradervand, Jean-Nicolas, Dubuis, Anne, Pellissier, Loïc, Guisan, Antoine, and Randin, Christophe
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SPECIES distribution , *REMOTE sensing , *DISPERSAL (Ecology) , *BIODIVERSITY , *DIGITAL elevation models , *MANAGEMENT - Abstract
Recent advances in remote sensing technologies have facilitated the generation of very high resolution (VHR) environmental data. Exploratory studies suggested that, if used in species distribution models (SDMs), these data should enable modelling species’ micro-habitats and allow improving predictions for fine-scale biodiversity management. In the present study, we tested the influence, in SDMs, of predictors derived from a VHR digital elevation model (DEM) by comparing the predictive power of models for 239 plant species and their assemblages fitted at six different resolutions in the Swiss Alps. We also tested whether changes of the model quality for a species is related to its functional and ecological characteristics. Refining the resolution only contributed to slight improvement of the models for more than half of the examined species, with the best results obtained at 5 m, but no significant improvement was observed, on average, across all species. Contrary to our expectations, we could not consistently correlate the changes in model performance with species characteristics such as vegetation height. Temperature, the most important variable in the SDMs across the different resolutions, did not contribute any substantial improvement. Our results suggest that improving resolution of topographic data only is not sufficient to improve SDM predictions – and therefore local management – compared to previously used resolutions (here 25 and 100 m). More effort should be dedicated now to conduct finer-scale in-situ environmental measurements (e.g. for temperature, moisture, snow) to obtain improved environmental measurements for fine-scale species mapping and management. [ABSTRACT FROM AUTHOR]
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- 2014
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74. Natural products with protein tyrosine phosphatase inhibitory activity.
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Carr, Gavin, Berrue, Fabrice, Klaiklay, Saranyoo, Pelletier, Isabelle, Landry, Melissa, and Kerr, Russell G.
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PROTEIN-tyrosine phosphatase , *NATURAL products , *PHOSPHORYLATION , *BIOLOGICAL assay , *SPONGES (Invertebrates) - Abstract
Abstract: Protein tyrosine phosphatases (PTPs) play an essential role in maintaining the proper tyrosine phosphorylation state of proteins. Abnormal tyrosine phosphorylation has been implicated in diseases as diverse as type 2 diabetes, cancer, immune disorders and neurological disorders, and thus inhibitors of PTPs have been investigated as potential treatments of these diseases. Natural products are widely regarded to be privileged structures in drug discovery efforts, and are therefore a good starting point for the development of PTP inhibitors. Here we describe reported natural product PTP inhibitors as well as methods to screen for natural product PTP inhibitors using bioassay-guided fractionation. These methods are illustrated using the example of a family of bromotyrosine-derived PTP inhibitors isolated from two marine sponges. We also identify potential pitfalls and false-positives, in particular compounds that are oxidizing agents that react irreversibly with the PTP. [Copyright &y& Elsevier]
- Published
- 2014
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75. Validation of global urban density products with very high resolution imagery
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Blersch, Mario
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validation ,density ,VHR ,Remote sensing ,urban - Published
- 2020
76. Errors related to the automatized satellite-based change detection of boreal forests in Finland
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Laura Sirro, Timo P. Pitkänen, Lauri Häme, Markus Törmä, Annika Kangas, and Tuomas Häme
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010504 meteorology & atmospheric sciences ,Cloud cover ,detection ,0211 other engineering and technologies ,clouds ,02 engineering and technology ,visuaalinen arviointi ,01 natural sciences ,remote sensing ,image quality ,mapping ,pilvipeite ,Finland ,trade-off ,tunnistus ,Global and Planetary Change ,evaluation ,Forest management ,Taiga ,trees ,metsät ,classification ,material ,satellite-based ,satellite-based detection ,mallintaminen ,Growing season ,boreaaliset metsät ,pilvet ,Management, Monitoring, Policy and Law ,change detections ,automaatio ,VHR ,reaaliaikainen työkalu ,errors ,change categories ,forests ,growing season ,materiaali ,modeling ,puut ,15. Life on land ,Workflow ,kasvukausi ,Satellite ,Sentinel-2 ,satellite images ,hallinta ,Image quality ,Computer science ,muutoskategoriat ,mapping frequency ,cloud cover ,monitorointi ,virheiden arviointi ,broadleaved trees ,kartoitus ,satellites ,real-time tool ,evaluation of forest characteristics ,muutosten tunnistaminen ,boreal forests ,tunnistaminen ,automatized workflow ,ennustaminen ,visual evaluation ,muutosten seuranta ,VHR images ,kuvanlaatu ,Change monitoring ,metsien ominaisuudet ,virheet ,management ,Change detection ,automatic change detection modelling chain ,validation data ,tarkkuuden arviointi ,reaaliaikaisuus ,error evaluation ,unchanged ,Computers in Earth Sciences ,kartoitusfrekvenssi ,Earth & Environmental Sciences ,automation ,021101 geological & geomatics engineering ,0105 earth and related environmental sciences ,Earth-Surface Processes ,Remote sensing ,prediction ,forest characteristics ,metsän hoito ,monitoring ,thinned ,luokittelu ,satelliitit ,Accuracy assessment ,clear-cut ,kaukokartoitus ,arviointi - Abstract
Highlights • Forest changes were automatically modelled from multitemporal Sentinel-2 images. • Errors were evaluated based on visually interpreted VHR images. • Extraction of clear-cuts was accurate whereas thinnings had more variation. • Image quality and translucent clouds had most significant effect on errors. • Results were regarded applicable for operational change monitoring. The majority of the boreal forests in Finland are regularly thinned or clear-cut, and these actions are regulated by the Forest Act. To generate a near-real time tool for monitoring management actions, an automatic change detection modelling chain was developed using Sentinel-2 satellite images. In this paper, we focus mainly on the error evaluation of this automatized workflow to understand and mitigate incorrect change detections. Validation material related to clear-cut, thinned and unchanged areas was collected by visual evaluation of VHR images, which provided a feasible and relatively accurate way of evaluating forest characteristics without a need for prohibitively expensive fieldwork. This validation data was then compared to model predictions classified in similar change categories. The results indicate that clear-cuts can be distinguished very reliably, but thinned stands exhibit more variation. For thinned stands, coverage of broadleaved trees and detections from certain single dates were found to correlate with the success of the modelling results. In our understanding, this relates mainly to image quality regarding haziness and translucent clouds. However, if the growing season is short and cloudiness frequent, there is a clear trade-off between the availability of good-quality images and their preferred annual span. Gaining optimal results therefore depends both on the targeted change types, and the requirements of the mapping frequency.
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- 2020
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77. Thermal analysis of CuMg alloys deformed by equal channel angular pressing
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Nuria Ferrer, Pablo Rodriguez-Calvillo, José-María Cabrera, Universitat Politècnica de Catalunya. Departament de Ciència i Enginyeria de Materials, and Universitat Politècnica de Catalunya. PROCOMAME - Processos de Conformació de Materials Metàl·lics
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Materials science ,Alloy ,chemistry.chemical_element ,Anàlisi tèrmica ,02 engineering and technology ,engineering.material ,Enginyeria dels materials [Àrees temàtiques de la UPC] ,01 natural sciences ,DSC ,Differential scanning calorimetry ,VHR ,Thermal stability ,Thermal analysis ,Physical and Theoretical Chemistry ,Composite material ,Pressing ,ECAP ,Recrystallization (metallurgy) ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Copper ,010406 physical chemistry ,0104 chemical sciences ,chemistry ,engineering ,Severe plastic deformation ,CuMg alloy ,0210 nano-technology ,Aliatges -- Metal·lúrgia - Abstract
The thermal behavior of two copper alloys, with 0.2 and 0.5 mass % of Mg, was analyzed after severe plastic deformation processing by Equal Channel Angular Pressing (ECAP). Both alloys were forced to be passed through a 90o inner angle ECAP die at room temperature up to 16 passes following route Bc. The thermal stability was analyzed in terms of the recrystallization kinetics by using the Various Heating Rates method, derived from the Johnson–Mehl–Avrami–Kolmogorov equation, after analyzing the Differential Scanning Calorimetry peaks for both alloys at any pass of ECAP. The calculated recrystallization parameters included the activation energies (E (kJ mol−1) ECuMg02 = 42.6 ± 19.8 ECuMg05 = 52.7 ± 13 kJ mol−1) and the kinetic exponent n which took an average value of ≈ 1.75, irrespective of the considered alloy.
- Published
- 2020
78. Improved Mapping of Tropical Forests With Optical and SAR Imagery, Part I: Forest Cover and Accuracy Assessment Using Multi-Resolution Data.
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Hame, Tuomas, Kilpi, Jorma, Ahola, Heikki A., Rauste, Yrjö, Antropov, Oleg, Rautiainen, Miina, Sirro, Laura, and Bounpone, Sengthong
- Abstract
This paper describes an improved concept for the mapping of tropical forest classes with ALOS AVNIR and ALOS PALSAR data. The improvement comes from a combination of a sample of very high resolution (VHR) satellite images with medium resolution wall-to-wall mapping in a statistical sampling framework. The approach developed makes it possible to obtain reliable information on mapping accuracy over the whole area of interest. [ABSTRACT FROM PUBLISHER]
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- 2013
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79. Protein Tyrosine Phosphatase Biochemical Inhibition Assays.
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Baranowski MR, Wu J, Han YN, Lambert LJ, Cosford NDP, and Tautz L
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Disturbance of the dynamic balance between protein tyrosine phosphorylation and dephosphorylation, modulated by protein tyrosine kinases (PTKs) and protein tyrosine phosphatases (PTPs), is known to be crucial for the development of many human diseases. The discovery of agents that restore this balance has been the subject of many drug research efforts, most of which have focused on tyrosine kinase inhibitors (TKIs), resulting in the development of more than 50 FDA-approved TKIs during the past two decades. More recently, accumulating evidence has suggested that members of the PTP superfamily are also promising drug targets, and efforts to discover tyrosine phosphatase inhibitors (TPIs) have increased dramatically. Here, we provide protocols for determining the potency of TPIs in vitro. We focus on the use of fluorescence-based substrates, which exhibit a dramatic increase in fluorescence emission when dephosphorylated by the PTP, and thus allow setting up highly sensitive and miniaturized phosphatase activity assays using 384-well or 1536-well microplates and a continuous (kinetic) assay format. The protocols cover PTP specific activity assays, Michaelis-Menten kinetics, dose-response inhibition assays, and dose-response data analysis for determining IC
50 values. Potential pitfalls are also discussed. While advanced instrumentation is utilized for compound spotting and liquid dispensing, all the assays can be adapted to existing equipment in most laboratories. Assays are described for selected PTP drug targets, including SHP2 ( PTPN11 ), PTP1B ( PTPN1 ), STEP ( PTPN5 ), and VHR ( DUSP3 ). However, all protocols are applicable to members of the PTP enzyme family in general. Graphical abstract., Competing Interests: Competing interests The authors declare that they have no conflicts of interest with the contents of this article., (Copyright © 2022 The Authors; exclusive licensee Bio-protocol LLC.)- Published
- 2022
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80. Object-Based Image Analysis Applied to Low Altitude Aerial Imagery for Potato Plant Trait Retrieval and Pathogen Detection
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Siebring, Jasper, Valente, João, Domingues Franceschini, Marston Heracles, Kamp, Jan, Kooistra, Lammert, Siebring, Jasper, Valente, João, Domingues Franceschini, Marston Heracles, Kamp, Jan, and Kooistra, Lammert
- Abstract
There is a growing demand in both food quality and quantity, but as of now, one-third of all food produced for human consumption is lost due to pests and other pathogens accounting for roughly 40% of pre-harvest loss in potatoes. Pathogens in potato plants, like the Erwinia bacteria and the PVYNTN virus for example, exhibit symptoms of varying severity that are not easily captured by pixel-based classes (as these ignore shape, texture, and context in general). The aim of this research is to develop an object-based image analysis (OBIA) method for trait retrieval of individual potato plants that maximizes information output from Unmanned Aerial Vehicle (UAV) RGB very high resolution (VHR) imagery and its derivatives, to be used for disease detection of the Solanum tuberosum. The approach proposed can be split in two steps: (1) object-based mapping of potato plants using an optimized implementation of large scale mean-shift segmentation (LSMSS), and (2) classification of disease using a random forest (RF) model for a set of morphological traits computed from their associative objects. The approach was proven viable as the associative RF model detected presence of Erwinia and PVY pathogens with a maximum F1 score of 0.75 and an average Matthews Correlation Coefficient (MCC) score of 0.47. It also shows that low-altitude imagery acquired with a commercial UAV is a viable off-the-shelf tool for precision farming, and potato pathogen detection.
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- 2019
81. Quantitative Analysis of Second Order Statistical Class Feature for VHR Remote Sensed Imagery.
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Zhou, Guoqiong, Chen, Jianming, Wu, Guangmin, Lv, Peng, and Chu, Hequn
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REMOTE-sensing images ,MATHEMATICAL statistics ,QUANTITATIVE research ,PATTERN recognition systems ,COMPUTER vision ,OPTICAL resolution - Abstract
Abstract: The progresses of statistical texture analysis have been playing a more and more important roles in remote sensing mapping, pattern recognition and computer vision. The achievements and research approaches have found important applications in many fields, including industry inspection, remote sensed data analysis and mapping, medical imaging, textile defect detection, video image analysis, food grading, and natural texture recognition and retrieval, object recognition, etc.[1] This paper starts with the principles and algorithms of second order statistics. Based on the theoretical analysis, we selected 5 typical texture class samples from Quick Bird RGB fused data with 0.61m resolution. We used GLCMs to quantitatively calculate texture features, which parameter values are suitable for the specific texture classifications. GLCMs of 5 typical texture class samples from the data set were calculated. Six statistical features for every class sample in four orientations and 1 pixel of pair-wise distance were obtained, including: energy, entropy, contrast, homogeneity, correlation, and dissimilarity respectively. The average values in four directions were computed and compared. The results show that dissimilarity and entropy have biggest value differences among six samples. They are the most important features for classification or recognition of class samples. The statistics of dissimilarity, entropy, homogeneity, contrast have been demonstrated a decrease in classification ability. But the average contrast can discriminate the complex building sample from other textures in spite of small differences with others. The results of the research supplied important references for the quantitative interpretation of VHR Quick Bird imagery in the applications of land cover/use classification and mapping. [Copyright &y& Elsevier]
- Published
- 2011
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82. Object-based Image Analysis of VHR Imagery by Combining Spectrum and Texture.
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Liu, Yue, Chen, Jianming, Wu, Guangmin, and Chu, Hequn
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IMAGE analysis ,OBJECT-oriented methods (Computer science) ,SATELLITE image maps ,REMOTE-sensing images ,SPECTRUM analysis ,THREE-dimensional imaging ,COMPUTER graphics - Abstract
Abstract: In this paper, we proposed a contextual and Object-based Image Analysis (OBIA) classification approach through the experiment, which was using Cognition Network Language (CNL) of commercial software eCognition Developer. Combination of spectrum and texture explored the rich information contents in the Very High-spatial Resolution (VHR) satellite imagery. Meanwhile, contextual relation was adopted in the experiment to improve the classification accuracy. In the research, a few land cover characteristics (contrast, entropy, etc.) were studied for the local land covers. By the experiment, six different classes were extracted: building, road, forest, water, farmland and bare soil. 94.05% classification overall accuracy and 0.92 Kappa coefficient were achieved by the approach for the complex land covers. Data set was five bands QuickBird imagery located nearby Kunming Dianchi Lake (KDL), which is a very important highland lake in China, also in the world. The results may be used in lake protection, environment protection, land planning and land use management, and government decision making around KDL. [Copyright &y& Elsevier]
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- 2011
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83. Using active learning to adapt remote sensing image classifiers
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Tuia, D., Pasolli, E., and Emery, W.J.
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ACTIVE learning , *REMOTE-sensing images , *CLASSIFICATION , *LAND use , *ANALYSIS of covariance , *IMAGE analysis , *REMOTE sensing , *STATISTICAL sampling - Abstract
Abstract: The validity of training samples collected in field campaigns is crucial for the success of land use classification models. However, such samples often suffer from a sample selection bias and do not represent the variability of spectra that can be encountered in the entire image. Therefore, to maximize classification performance, one must perform adaptation of the first model to the new data distribution. In this paper, we propose to perform adaptation by sampling new training examples in unknown areas of the image. Our goal is to select these pixels in an intelligent fashion that minimizes their number and maximizes their information content. Two strategies based on uncertainty and clustering of the data space are considered to perform active selection. Experiments on urban and agricultural images show the great potential of the proposed strategy to perform model adaptation. [Copyright &y& Elsevier]
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- 2011
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84. Solvent Substitution: An Analysis of Comprehensive Hazard Screening Indices.
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Debia, M., Bégin, D., and Gérin, M.
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HAZARDOUS substances , *INDUSTRIAL hygiene , *RESEARCH funding , *SOLVENTS , *STATISTICS , *DATA analysis , *ENVIRONMENTAL exposure , *DATA analysis software - Abstract
The air index (ψiair) of the PARIS II software (Environmental Protection Agency), the Indiana Relative Chemical Hazard Score (IRCHS), and the Final Hazard Score (FHS) used in the P2OASys system (Toxics Use Reduction Institute) are comprehensive hazard screening indices that can be used in solvent substitution. The objective of this study was to evaluate these indices using a list of 67 commonly used or recommended solvents. The indices ψiair, IRCHS and FHS were calculated considering 9, 13, and 33 parameters, respectively, that summarized health and safety hazards, and environmental impacts. Correlation and sensitivity analyses were performed. The vapor hazard ratio (VHR) was used as a reference point. Two good correlations were found: (1) between VHR and ψiair (ρ = 0.84), (2) and between IRCHS and FHS (ρ = 0.81). Values of sensitivity ratios above 0.2 were found with ψiair (4 of 9 parameters) and IRCHS (3 of 13 parameters), but not with FHS. Overall, the three indices exhibited important differences in the way they integrate key substitution factors, such as volatility, occupational exposure limit, skin exposure, flammability, carcinogenicity, photochemical oxidation potential, atmospheric global effects, and environmental terrestrial and aquatic effects. These differences can result in different choices of alternatives between indices, including the VHR. IRCHS and FHS are the most comprehensive indices but are very tedious and complex to use and lack sensitivity to several solvent-specific parameters. The index ψiair is simpler to calculate but does not cover some parameters important to solvents. There is presently no suitably comprehensive tool available for the substitution of solvents. A two-tier approach for the selection of solvents is recommended to avoid errors that could be made using only a global index or the consideration of the simple VHR. As a first tier, one would eliminate solvent candidates having crucial impacts. As a second tier, other parameters would be considered, with emphasis on the VHR. [ABSTRACT FROM AUTHOR]
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- 2011
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85. Quantitative property-property relationships for computing Occupational Exposure Limits and Vapour Hazard Ratios of organic solvents.
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Debia, M. and Krishnan, K.
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QSAR models , *THRESHOLD limit values (Industrial toxicology) , *ORGANIC solvents , *OLIVE oil , *PREDICTION models , *TOXICOLOGICAL chemistry , *PARTITION coefficient (Chemistry) - Abstract
Vapour Hazard Ratio (VHR) is used in solvent substitution to select the best replacement option regarding overexposure potential of solvents. However, VHR calculations are limited by the availability of Occupational Exposure Limits (OELs). The overall objective of this study was to develop quantitative property-property relationship (QPPR) approaches for computing OELs, in view of supporting the derivation of VHRs for solvents without OELs. QPPRs were developed for estimating OELs using a database of 88 solvents which have health-based Time-Weighted Average (TWA) OELs published by the American Conference of Governmental Industrial Hygienists (ACGIH). Three surrogates of biotic lipid : air partition coefficients [n-octanol : air (Koa), olive oil : air (Koila) and fat : air (Kfa)] were selected for evaluating the descriptive/predictive relationship with OELs for solvents with local modes of action. For solvents with systemic modes of action, the prediction of OEL needs to consider quantitative differences in toxicokinetics (i.e. kinetic variability factor, KVF) and toxicological potency (i.e. effective internal concentration, EIC). The n-octanol : water (Kow), the oil : water (Koilw) and the fat : water (Kfw) partition coefficients were selected for evaluating the relationship with EICs. For local modes of action, Koa is the most accurate predictor of OELs [OEL (ppm) = [image omitted]; n = 21, r2 = 0.71, PRESS/SSY = 0.36, F = 45.5 with p < 0.001] and the mean (±SD) (range) of the recommended to predicted OELs was 1.04 ± 0.61 (0.2-2.5). For systemic modes of action, KVFs and EICs vary in a range from 0.73 to 41.4 µmol L-1 and 1.20-848 µmol L-1, respectively. Kow is an accurate predictor of calculated EICs [EIC (µmol L-1) = [image omitted]; n = 27, r2 = 0.88, PRESS/SSY = 0.12, F = 181 with p < 0.001] and 50% of the predicted OEL values were within a factor of two of the recommended TWA OELs. Overall, 61% and 87% of the predicted VHRs were within a factor of two and five, respectively, of the calculated VHRs. The QPPR models developed in this study represent potentially useful tools for estimating provisional OELs for solvents lacking such guideline values. These provisional OELs are developed only to support initial estimations of VHR for dealing with the challenge of solvent substitution where relative values rather than absolute values of OEL and vapour pressure guide the hygienist in making pragmatic decisions for managing occupational health hazards. [ABSTRACT FROM AUTHOR]
- Published
- 2010
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86. Geo-spatial information and technologies in support of EU crisis management.
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Al-Khudhairy, DelilahH.A.
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CRISIS management , *REMOTE sensing in earth sciences , *GEOGRAPHIC information systems , *INTERNET , *DECISION making - Abstract
This paper discusses the challenges in operational crisis management and describes the role of information and geo-spatial technologies in meeting those challenges. The paper discusses two main sources of data, Web and very high resolution (VHR) earth observation sensors, in terms of relevance to crisis management and techniques for information extraction and analysis. Although research in information text extraction and analysis is more advanced than in information image extraction and analysis, further research is required in both these fields to take advantage of the increasing complexity but richness of open source and VHR satellite data. The paper also discusses the use of Web, GIS and Digital Earth technologies in facilitating collaborative work, decision-making and information sharing in crisis management. Despite exciting and relevant advances in information sources, information extraction and analysis methods, and collaborative crisis technologies, the main challenge remains to convince stakeholders in operational crisis management that the adoption of these technologies will lead to enhanced and effective crisis management. [ABSTRACT FROM AUTHOR]
- Published
- 2010
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- View/download PDF
87. Earthquake-Damaged Buildings Detection in Very High-Resolution Remote Sensing Images Based on Object Context and Boundary Enhanced Loss
- Author
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Xing Qiu, Hai Huan, Xiaohui Chen, Shuai Wang, Chao Wang, Yan Zhang, and Wei He
- Subjects
Spatial contextual awareness ,Pixel ,object context ,Computer science ,Science ,convolutional neural network ,Boundary (topology) ,Object (computer science) ,Convolutional neural network ,earthquake-damaged buildings ,boundary ,VHR ,remote sensing images ,Feature (computer vision) ,Benchmark (computing) ,General Earth and Planetary Sciences ,Representation (mathematics) ,Remote sensing - Abstract
Fully convolutional networks (FCN) such as UNet and DeepLabv3+ are highly competitive when being applied in the detection of earthquake-damaged buildings in very high-resolution (VHR) remote sensing images. However, existing methods show some drawbacks, including incomplete extraction of different sizes of buildings and inaccurate boundary prediction. It is attributed to a deficiency in the global context-aware and inaccurate correlation mining in the spatial context as well as failure to consider the relative positional relationship between pixels and boundaries. Hence, a detection method for earthquake-damaged buildings based on the object contextual representations (OCR) and boundary enhanced loss (BE loss) was proposed. At first, the OCR module was separately embedded into high-level feature extractions of the two networks DeepLabv3+ and UNet in order to enhance the feature representation; in addition, a novel loss function, that is, BE loss, was designed according to the distance between the pixels and boundaries to force the networks to pay more attention to the learning of the boundary pixels. Finally, two improved networks (including OB-DeepLabv3+ and OB-UNet) were established according to the two strategies. To verify the performance of the proposed method, two benchmark datasets (including YSH and HTI) for detecting earthquake-damaged buildings were constructed according to the post-earthquake images in China and Haiti in 2010, respectively. The experimental results show that both the embedment of the OCR module and application of BE loss contribute to significantly increasing the detection accuracy of earthquake-damaged buildings and the two proposed networks are feasible and effective.
- Published
- 2021
- Full Text
- View/download PDF
88. The Study on DC Resistibility of Positive and Negative Dielectric Anisotropy Liquid Crystal in AH-IPS Mode.
- Author
-
Yoon, Sang-Soon, Ahn, So-Hyeong, Choi, Woo-Young, Lee, Joun-Ho, Kim, Hyoung-Sik, Jun, Myung-Chul, and Kang, In-Byoung
- Subjects
ANISOTROPY ,LIQUID crystals ,TRANSMITTANCE (Physics) - Abstract
Negative dielectric liquid crystal (nLC) represents lower resistibility than positive dielectric liquid crystal in spite of its higher transmittance in AH-IPS mode. Based on the analysis between transmittance under DC signal and resistivity of LC, DC resistibility is increased by the new nLC with high VHR and thus flickering phenomenon could be improved. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
89. Identifying damage caused by the 2008 Wenchuan earthquake from VHR remote sensing data.
- Author
-
Ehrlich, D., Guo, H.D., Molch, K., Ma, J.W., and Pesaresi, M.
- Subjects
- *
REMOTE-sensing images , *SPACE surveillance , *ARTIFICIAL satellites , *INFORMATION resources management , *EMERGENCY management - Abstract
The paper discusses the potential of very high resolution (VHR) satellite imagery for post-earthquake damage assessment in comparison with the role of aerial photographs. Post-disaster optical and radar satellite data are assessed for their ability to resolve collapsed buildings, destroyed transportation infrastructure, and specific land cover changes. Optical VHR imagery has shown to be effective in quantifying building stock and for assessing damage at the building level. High-resolution synthetic aperture radar (SAR) imagery requires further research to identify optimum information extraction procedures for rapid assessment of affected buildings. Based on current technical and operational capabilities increasing efforts should be devoted to the generation of spatial datasets for disaster preparedness. [ABSTRACT FROM AUTHOR]
- Published
- 2009
- Full Text
- View/download PDF
90. A Review of Landcover Classification with Very-High Resolution Remotely Sensed Optical Images—Analysis Unit, Model Scalability and Transferability.
- Author
-
Qin, Rongjun and Liu, Tao
- Subjects
- *
OPTICAL images , *REMOTE sensing , *DEEP learning , *SCALABILITY , *IMAGE analysis , *CLASSIFICATION , *CONCEPT mapping - Abstract
As an important application in remote sensing, landcover classification remains one of the most challenging tasks in very-high-resolution (VHR) image analysis. As the rapidly increasing number of Deep Learning (DL) based landcover methods and training strategies are claimed to be the state-of-the-art, the already fragmented technical landscape of landcover mapping methods has been further complicated. Although there exists a plethora of literature review work attempting to guide researchers in making an informed choice of landcover mapping methods, the articles either focus on the review of applications in a specific area or revolve around general deep learning models, which lack a systematic view of the ever advancing landcover mapping methods. In addition, issues related to training samples and model transferability have become more critical than ever in an era dominated by data-driven approaches, but these issues were addressed to a lesser extent in previous review articles regarding remote sensing classification. Therefore, in this paper, we present a systematic overview of existing methods by starting from learning methods and varying basic analysis units for landcover mapping tasks, to challenges and solutions on three aspects of scalability and transferability with a remote sensing classification focus including (1) sparsity and imbalance of data; (2) domain gaps across different geographical regions; and (3) multi-source and multi-view fusion. We discuss in detail each of these categorical methods and draw concluding remarks in these developments and recommend potential directions for the continued endeavor. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
91. High intracellular Zn2+ ions modulate the VHR, ZAP-70 and ERK activities of LNCaP prostate cancer cells.
- Author
-
Wong, Pooi-Fong and Abubakar, Sazaly
- Abstract
Malignant prostate tissues have markedly reduced zinc (Zn
2+ ) contents in comparison to non-malignant tissues. In this study, we restored a high intracellular Zn2+ level to LNCaP prostate cancer cells by culturing the cells in a growth medium supplemented with a supraphysiological concentration of Zn2+ (10 μg/ml) over 5 weeks. The intracellular Zn2+ level increased in the Zn2+ -treated cells, and there was a marked increase in the presence of zincosomes, a Zn2+ -specific intracellular organelle. The proliferation rate of the Zn2+ -treated cells was markedly reduced. There was also a significant increase (36.6% ± 6.4%) in the total tyrosine phosphorylated proteins. Vaccinia H1-related (VHR) phosphatase, zeta chain-associated protein-70 (ZAP-70) kinase and phosphorylated extracellular signal-regulated protein kinase 1 and 2 (p-ERK 1 and 2) were also present in higher abundance. Treatment with TPEN, which chelates Zn2+ , reduced the abundance of VHR phosphatase and ZAP-70 kinase, but increased the abundance of p-ERK 1. However, the TPEN treatment restored the Zn2+ -treated LNCaP cell proliferation to a rate comparable to that of the non Zn2+ -treated cells. These results highlight the importance of a high intracellular Zn2+ content and the VHR/ZAP-70-associated pathways in the modulation of LNCaP prostate cancer cell growth. [ABSTRACT FROM AUTHOR]- Published
- 2008
- Full Text
- View/download PDF
92. Functional Significance of Conserved Glycine 127 in a Human Dual-Specificity Protein Tyrosine Phosphatase.
- Author
-
Zeng, W.-Y., Wang, Y.-H., Zhang, Y.-C., Yang, W.-L., and Shi, Y.-Y.
- Subjects
- *
GLYCINE , *ACETIC acid , *AMINO acid neurotransmitters , *TYROSINE , *GENETIC mutation , *VIRUS diseases in cattle , *BIOCHEMISTRY - Abstract
Using site-directed mutagenesis and steady-state kinetic measurements, the functional role of the conserved glycine 127 in a human vaccinia H1-related phosphatase (VHR) was investigated. The mutations of Gly127 to Ala and Pro resulted in a significant decrease in kcat/Km, and increase in Ki for arsenate, indicating that flexibility at the Gly127 site has a large effect on substrate binding and catalytic activity. No substantial decrease in kcat/Km and increase in Ki values were observed for G127 deletion mutant. This showed the conformational flexibility of the PTP loop also affected the enzymatic activity of VHR. Our data suggest that the flexibility of the PTP loop in VHR is probably controlled by Gly127, and that even subtle changes in the loop flexibility may interfere with substrate binding and enzymatic reaction. [ABSTRACT FROM AUTHOR]
- Published
- 2003
- Full Text
- View/download PDF
93. Separation of Cdc25 dual specificity phosphatase inhibition and DNA cleaving activities in a focused library of analogs of the antitumor antibiotic Dnacin
- Author
-
Wipf, Peter, Hopkins, Corey R., Phillips, Eleanor O., and Lazo, John S.
- Subjects
- *
PHOSPHATASES , *PROTEIN-tyrosine phosphatase - Abstract
Biological evaluation of 96 analogs and synthetic intermediates of the naphthyridinomycin-type antitumor antibiotic Dnacin led to the identification of several low-micromolar inhibitors of dual specificity phosphatases, specifically Cdc25A1, Cdc25B2, and VHR, as well as the tyrosine phosphatase PTP1B. While the parent Dnacins are potent DNA cleavage agents, most of the analog structures, even those that retained significant phosphatase inhibitory activities, did not lead to plasmid DNA cleavage. Thus, the DNA-targeting and the phosphatase-inhibitory activities of Dnacins can be assigned to different pharmacophores. [Copyright &y& Elsevier]
- Published
- 2002
- Full Text
- View/download PDF
94. Earthquake-Damaged Buildings Detection in Very High-Resolution Remote Sensing Images Based on Object Context and Boundary Enhanced Loss.
- Author
-
Wang, Chao, Qiu, Xing, Huan, Hai, Wang, Shuai, Zhang, Yan, Chen, Xiaohui, and He, Wei
- Subjects
- *
REMOTE sensing , *HAITI Earthquake, Haiti, 2010 , *EFFECT of earthquakes on buildings , *FEATURE extraction , *CONVOLUTIONAL neural networks - Abstract
Fully convolutional networks (FCN) such as UNet and DeepLabv3+ are highly competitive when being applied in the detection of earthquake-damaged buildings in very high-resolution (VHR) remote sensing images. However, existing methods show some drawbacks, including incomplete extraction of different sizes of buildings and inaccurate boundary prediction. It is attributed to a deficiency in the global context-aware and inaccurate correlation mining in the spatial context as well as failure to consider the relative positional relationship between pixels and boundaries. Hence, a detection method for earthquake-damaged buildings based on the object contextual representations (OCR) and boundary enhanced loss (BE loss) was proposed. At first, the OCR module was separately embedded into high-level feature extractions of the two networks DeepLabv3+ and UNet in order to enhance the feature representation; in addition, a novel loss function, that is, BE loss, was designed according to the distance between the pixels and boundaries to force the networks to pay more attention to the learning of the boundary pixels. Finally, two improved networks (including OB-DeepLabv3+ and OB-UNet) were established according to the two strategies. To verify the performance of the proposed method, two benchmark datasets (including YSH and HTI) for detecting earthquake-damaged buildings were constructed according to the post-earthquake images in China and Haiti in 2010, respectively. The experimental results show that both the embedment of the OCR module and application of BE loss contribute to significantly increasing the detection accuracy of earthquake-damaged buildings and the two proposed networks are feasible and effective. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
95. Remote Sensing Analysis Framework for Maritime Surveillance Application
- Author
-
Schwarz, Egbert, Voinov, Sergey, Frauenberger, Olaf, Krause, Detmar, and Tings, Björn
- Subjects
VHR ,Near-Real Time processing ,Oil detection ,Ship detection ,Synthetic Aperture Radar - Published
- 2018
96. The Role of Emotion in Product, Service and Business Model Design
- Author
-
Cara Wrigley and Karla Straker
- Subjects
Service (business) ,innowacje biznesowe ,Knowledge management ,business.industry ,Service design ,business innovation ,Context (language use) ,emotional design ,Product-service system ,Business model ,projektowanie emocjonalne ,Product planning ,tworzenie usług ,projektowanie modelu biznesowego ,Empirical research ,VHR ,Management of Technology and Innovation ,Tourism, Leisure and Hospitality Management ,business model design ,Business ,Product (category theory) ,service design ,Business and International Management ,visceral hedonic rhetoric - Abstract
Designers have become aware of the importance of creating strong emotional experiences intertwined with new tangible products for the past decade, however an increased interest from firms has emerged in developing new service and business models as complimentary forms of emotion-driven innovation. This interdisciplinary study draws from the psychological sciences – theory of emotion – and the management sciences – business model literature to introduce this new innovation agenda. The term visceral hedonic rhetoric (VHR) is defined as the properties of a product, (and in this paper service and business model extensions) that persuasively induce the pursuit of pleasure at an instinctual level of cognition. This research paper lays the foundation for VHR beyond a product setting, presenting the results from an empirical study where organizations explored the possibilities for VHR in the context of their business. The results found that firms currently believe VHR is perceived in either their product and/or services they provide. Implications suggest shifting perspective surrounding the use of VHR across a firm’s business model design in order to influence the outcomes of their product and/or service design, resulting in an overall stronger emotional connection with the customer. Projektanci stają się świadomi znaczenia tworzenia silnych doznań emocjonalnych powiązanych z nowymi produktami materialnymi w ostatnim dziesięcioleciu. Jednak, również ze strony firm, pojawiło się zwiększone zainteresowanie w opracowywaniu nowych usług i modeli biznesowych, jako uzupełniających innowacyjnych form opartych na emocjach. To interdyscyplinarne badanie czerpie z nauk psychologicznych – teorii emocji – i nauk o zarządzaniu – literatury modelu biznesowego do wprowadzenia nowego programu innowacyjnego. Termin VHR – retoryka dogłębnego hedonizmu jest zdefiniowany jako właściwości produktu (w tej pracy rozszerzenie usług i modelu biznesu), który przekonująco skłania do dążenia do przyjemności na instynktownym poziomie poznania. Ta praca stanowi podstawę dla VHR poza domyślnym środowiskiem produktu, prezentując wyniki badań empirycznych, które organizacje przeprowadziły badając możliwości zastosowania VHR w kontekście ich działalności. Stwierdzono, że firmy obecnie wierzą, że VHR jest postrzegane albo w ich produkcie i/ lub w usługach, które świadczą. W konsekwencji, sugeruje to przeniesienie perspektywy wokół korzystania z VHR w konstrukcji modelu biznesowego danej firmy, w celu wpływania na wyniki swoich produktów i / lub projektowania usług, co prowadzi do ogólnego silniejszego związku emocjonalnego z klientem.
- Published
- 2015
- Full Text
- View/download PDF
97. Land Use Classification of VHR Images for Mapping Small-Sized Abandoned Citrus Plots by Using Spectral and Textural Information.
- Author
-
Morell-Monzó, Sergio, Sebastiá-Frasquet, María-Teresa, Estornell, Javier, and Qureshi, Salman
- Subjects
- *
ZONING , *NORMALIZED difference vegetation index , *RANDOM forest algorithms , *CITRUS , *PLURALITY voting , *DECISION trees - Abstract
Agricultural land abandonment is an increasing problem in Europe. The Comunitat Valenciana Region (Spain) is one of the most important citrus producers in Europe suffering this problem. This region characterizes by small sized citrus plots and high spatial fragmentation which makes necessary to use Very High-Resolution images to detect abandoned plots. In this paper spectral and Gray Level Co-Occurrence Matrix (GLCM)-based textural information derived from the Normalized Difference Vegetation Index (NDVI) are used to map abandoned citrus plots in Oliva municipality (eastern Spain). The proposed methodology is based on three general steps: (a) extraction of spectral and textural features from the image, (b) pixel-based classification of the image using the Random Forest algorithm, and (c) assignment of a single value per plot by majority voting. The best results were obtained when extracting the texture features with a 9 × 9 window size and the Random Forest model showed convergence around 100 decision trees. Cross-validation of the model showed an overall accuracy of the pixel-based classification of 87% and an overall accuracy of the plot-based classification of 95%. All the variables used are statistically significant for the classification, however the most important were contrast, dissimilarity, NIR band (720 nm), and blue band (620 nm). According to our results, 31% of the plots classified as citrus in Oliva by current methodology are abandoned. This is very important to avoid overestimating crop yield calculations by public administrations. The model was applied successfully outside the main study area (Oliva municipality); with a slightly lower accuracy (92%). This research provides a new approach to map small agricultural plots, especially to detect land abandonment in woody evergreen crops that have been little studied until now. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
98. Hyperspatial and Multi-SourceWater Body Mapping : A Framework to Handle Heterogeneities from Observations and Targets over Large Areas
- Author
-
UCL - SST/ELI/ELIE - Environmental Sciences, d'Andrimont, Raphaël, Marlier, Catherine, Defourny, Pierre, UCL - SST/ELI/ELIE - Environmental Sciences, d'Andrimont, Raphaël, Marlier, Catherine, and Defourny, Pierre
- Abstract
Recent advances in remote sensing technologies and the cost reduction of surveying, along with the importance of natural resources management, present new opportunities for mapping land cover at a very high resolution over large areas. This paper proposes and applies a framework to update hyperspatial resolution (<1 m) land thematic mapping over large areas by handling multi-source and heterogeneous data. This framework deals with heterogeneity both from observation and the targeted features. First, observation diversity comes from the different platform and sensor types (25-cm passive optical and 1-m LiDAR) as well as the different instruments (three cameras and two LiDARs) used in heterogeneous observation conditions (date, time, and sun angle). Second, the local heterogeneity of the targeted features results from their within-type diversity and neighborhood effects. This framework is applied to surface water bodies in the southern part of Belgium (17,000 km2). This makes it possible to handle both observation and landscape contextual heterogeneity by mapping observation conditions, stratifying spatially and applying ad hoc classification procedures. The proposed framework detects 83% of the water bodies—if swimming pools are not taken into account—and more than 98% of those water bodies greater than 100 m2, with an edge accuracy below 1 m over large areas.
- Published
- 2017
99. Monitoring von Kulturerbestätten mittels sehr hoch auflösender Satellitenaufnahmen
- Author
-
Plank, Simon
- Subjects
Monitoring ,VHR ,Kulturerbestätte - Published
- 2017
100. An Automatic Shadow Detection Method for VHR Remote Sensing Orthoimagery
- Author
-
Zhenling Ma, Li Yan, Qiangqiang Yuan, and Qiongjie Wang
- Subjects
Shadow mask ,Brightness ,010504 meteorology & atmospheric sciences ,Computer science ,Science ,0211 other engineering and technologies ,ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION ,skeleton operation ,02 engineering and technology ,01 natural sciences ,GeneralLiterature_MISCELLANEOUS ,DSM ,Data acquisition ,VHR ,Shadow ,geometrical method ,Computer vision ,matting ,021101 geological & geomatics engineering ,0105 earth and related environmental sciences ,Remote sensing ,ComputingMethodologies_COMPUTERGRAPHICS ,shadow detection ,business.industry ,Orthophoto ,Photogrammetry ,General Earth and Planetary Sciences ,Artificial intelligence ,Geometric modeling ,business - Abstract
The application potential of very high resolution (VHR) remote sensing imagery has been boosted by recent developments in the data acquisition and processing ability of aerial photogrammetry. However, shadows in images contribute to problems such as incomplete spectral information, lower intensity brightness, and fuzzy boundaries, which seriously affect the efficiency of the image interpretation. In this paper, to address these issues, a simple and automatic method of shadow detection is presented. The proposed method combines the advantages of the property-based and geometric-based methods to automatically detect the shadowed areas in VHR imagery. A geometric model of the scene and the solar position are used to delineate the shadowed and non-shadowed areas in the VHR image. A matting method is then applied to the image to refine the shadow mask. Different types of shadowed aerial orthoimages were used to verify the effectiveness of the proposed shadow detection method, and the results were compared with the results obtained by two state-of-the-art methods. The overall accuracy of the proposed method on the three tests was around 90%, confirming the effectiveness and robustness of the new method for detecting fine shadows, without any human input. The proposed method also performs better in detecting shadows in areas with water than the other two methods.
- Published
- 2017
- Full Text
- View/download PDF
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