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- 2015
- Xanthomonas oryzae
- multispectral and multimodal microscopy
- spectroscopic imaging
- plant cell diseases
- classification
- rice
- Applied Physics
- University of Sciences, Technique and Technology Bamako
- Institut National Polytechnique Felix Houphou?t-Boigny Yamoussoukro
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[American Society of Agricultural and Biological Engineers 2018 Detroit, Michigan July 29 - August 1, 2018 - ()] 2018 Detroit, Michigan July 29 - August 1, 2018 - <i>Cotton Yield Estimation based on Plant Height From UAV-based Imagery Data </i>
摘要： Accurate estimation of crop yield before harvest, especially in early growth stages, is important for farmers and researchers to optimize field management and evaluate crop performance. However, conventional methods of using ground sensing to estimate crop yield are not efficient. The goal of this research was to evaluate the potential of using a UAV-based remote sensing system with a low-cost RGB camera to estimate yield of cotton within season. The UAV system took images at 50 m above ground level over a cotton field at the growth stage of first flower. Waypoints and flight speed were selected to allow > 70% image overlap in both forward and side directions. Images were processed to develop a geo-referenced orthomosaic image and a digital elevation model (DEM) of the field, which was then used to map plant height by calculating the difference in elevation between the crop canopy and the bare soil surface. Twelve ground control points (calibration objects) with known GPS coordinates and height were deployed in the field and were used as check points for geo-referencing and height calibration. Geo-referenced yield data were registered with the plant height map row-by-row. Correlation analysis between yield and plant height was conducted row-by-row with row registration and without row registration respectively. Pearson correlation coefficients between yield and plant height for all individual rows were in the range of 66% to 96%, higher than those without row registration (54% to 95%). A non-parametric regression used for building a yield estimation model based on image-derived plant height was able to estimate yield with less than 10% error (root mean square error of 360.4 kg ha-1 and mean absolute error of 180.9 kg ha-1). The results indicated that the UAV-based remote sensing system equipped with a low-cost digital camera was able to estimate cotton yield with acceptable errors.
关键词： yield estimation,UAV-based remote sensing,geo-registration,plant height,Cotton
更新于2025-09-23 15:21:01
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Effectiveness of camera traps for quantifying daytime and nighttime visitation by vertebrate pollinators
摘要： Identification of pollen vectors is a fundamental objective of pollination biology. The foraging and social behavior of these pollinators has profound effects on plant mating, making quantification of their behavior critical for understanding the ecological and evolutionary consequences of different pollinators for the plants they visit. However, accurate quantification of visitation may be problematic, especially for shy animals and/or when the temporal and spatial scale of observation desired is large. Sophisticated heat- and movement-triggered motion-sensor cameras (“camera trapping”) provide new, underutilized tools to address these challenges. However, to date, there has been no rigorous evaluation of the sampling considerations needed for using camera trapping in pollination research. We measured the effectiveness of camera trapping for identifying vertebrate visitors and quantifying their visitation rates and foraging behavior on Banksia menziesii (Proteaceae). Multiple still cameras (Reconyx HC 500) and a video camera (Little Acorn LTL5210A) were deployed. From 2,753 recorded visits by vertebrates, we identified five species of nectarivorous honeyeater (Meliphagidae) and the honey possum (Tarsipedidae), with significant variation in the species composition of visitors among inflorescences. Species of floral visitor showed significant variation in their time of peak activity, duration of visits, and numbers of flowers probed per visit. Where multiple cameras were deployed on individual inflorescences, effectiveness of individual still cameras varied from 15% to 86% of all recorded visits. Methodological issues and solutions, and the future uses of camera traps in pollination biology, are discussed. Conclusions and wider implications: Motion-triggered cameras are promising tools for the quantification of vertebrate visitation and some aspects of behavior on flowers. However, researchers need to be mindful of the variation in effectiveness of individual camera traps in detecting animals. Pollinator studies using camera traps are in their infancy, and the full potential of this developing technology is yet to be realized.
关键词： camera trapping,honeyeaters,pollination,plant mating,vertebrates,pollination syndrome,remote sensing,honey possum,Banksia
更新于2025-09-23 15:21:01
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Which active optical sensor vegetation index is best for nitrogen assessment in irrigated cotton?
摘要： Use of active optical sensors (AOS) in nitrogen (N) management of row crops continues to grow. Since the first studies in the mid-1990s, several commercial AOS are now available. Typically, canopy reflectance in red and near infrared (NIR) bands are used to calculate the normalized difference vegetation index (NDVI). More recently, commercially available AOS include a third, red-edge band that allows the calculation of additional vegetation indices (VIs). We present two studies of five site-years of N management studies in Maricopa, AZ on a Casa Grande sandy loam with cotton (Gossypium hirsutum L.). The 2014-2015 study was conducted under an overhead sprinkler irrigation system (OSI), and the 2016-2018 study was in subsurface drip irrigation (SDI). The study objective was to compare the ability of 12 different VIs to detect N deficiency among N treatments from shortly after emergence to mid-bloom. In the OSI study, which showed delayed, small N treatment effects, NDRE and the chlorophyll index using amber (CIRE) detected N deficiency in zero-N and in reduced N-reflectance-based plots 7-23 days before other VIs did. With SDI, the choice of VI was less critical as several VIs could distinguish N deficiency in zero-N and in reflectance plots. The commonly used NDVI red (NDVIR) only detected N deficiency in reflectance plots in one of five site-years. In conclusion, we recommend the use of AOS with NIR and red-edge bands and the calculation of NDRE or CIRE to guide AOS-based in-season N management of irrigated cotton.
关键词： N fertilizer management,proximal sensing,lint yields,plant biomass,plant N
更新于2025-09-23 15:19:57
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Laser spectroscopy steered <sup>13</sup> Ca??labelling of plant material in a walka??in growth chamber
摘要： Carbon‐13 (13C)‐labelled plant material forms the basis for experiments elucidating carbon dynamics and greenhouse gas emissions. Quantitative field‐scale tracing is only possible if plants are labelled homogeneously in large quantities. By using a laser spectrometer to automatically steer the isotopic ratio in the chamber, it is possible to obtain large amounts of homogeneously labelled plant material. Methods: Ninety‐six maize plants were labelled for 25 days until tassel formation in a 15 m3 walk‐in growth chamber with a continuous air δ13C‐CO2 value of 400‰. A Los Gatos Research laser absorption spectrometer controlled the ambient δ13C‐CO2 value in the chamber through steering of the mass flow controllers with 13C‐enriched and natural abundance CO2 gas. Results: Laser absorption spectroscopy steering kept the δ13C value of chamber air between 368 and 426‰. The resulting 1 kg dry matter of 13C‐labelled shoots showed an average δ13C value of 384‰ and accuracy of 8‰ (half width of the 95% confidence interval). Only the oldest leaves showed larger heterogeneity. The growth chamber eliminated variability between plants. The δ13C value of the stabile material did not differ significantly from that of bulk material. Conclusions: Laser spectroscopy controlled 13C labelling of plants in a walk‐in growth chamber successfully kept the isotopic ratio of the CO2 in the chamber air constant. Therefore, large quantities of material were labelled homogeneously at the inter‐ and intra‐plant level, thus establishing a method to provide high‐quality input for quantitative isotopic tracer studies.
关键词： walk‐in growth chamber,plant material,laser spectroscopy,13C‐labelling,isotopic tracer studies
更新于2025-09-23 15:19:57
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High performance red/deep-red emitting phosphors for white LEDs
摘要： Highly efficient oxide based red line emitters are still bottleneck for the smart white LEDs. In the present investigation, sequences of narrow band red emitting phosphors were synthesized through the conventional solid-state technique. The X-ray diffraction studies reveals that the synthesized phosphors were crystallized in the trigonal phase with space group I41/a (88). Under 395 nm excitation, NaSrGd(MoO4)3:Eu3+ phosphors shown sharp red emission around at 616 nm because of the 5D0→7F2 transition (ED transition). Moreover, the internal quantum efficiency (IQE) was found to be 82 %, and the thermal stability study showed that the NaSrGd0.5Eu0.5(MoO4)3 phosphor retains the emission intensity around 71.5% at 423K of its initial room temperature. The red LEDs were designed for the NaSrGd0.5Eu0.5(MoO4)3 red phosphors with the NUV LED chip. White LED also been fabricated by conjugating the blue LED with yellow dye + red phosphor and the LED shown CCT (6823 K), CRI (74%), CIE (0.306, 0.331). The Sm3+ and Eu3+ co-doped deep red phosphor were synthesized and studied for the plant growth. The LED emission of Sm3+ and Eu3+ co-doped phosphor is completely covers the absorption spectrum of Phytochrome Pr. All of these consequences revealed that the synthesized phosphor could be the efficient red emitting phosphor for warm white LEDs and plant growth filed research.
关键词： Eu3+ red phosphor,Quantum Yield,White LED,Plant growth,Molybdate
更新于2025-09-23 15:19:57
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Structure identification and strongly enhanced luminescence of Sr9Y2(WO6)4: Mn4+ phosphors by co-doping Mg2+ ions for plant growth LEDs
摘要： In this paper, we reported a novel far-red emitting phosphor Sr9Y2(WO6)4: Mn4+ and alkaline earth metal Mg2+ ion co-doped phosphor Sr9Y2(WO6)4: Mn4+, Mg2+. Systematical studies on its crystal structure and luminescence properties are carried out. X-ray powder diffraction confirmed that the pure phase Sr9Y2(WO6)4: Mn4+ and Sr9Y2(WO6)4: Mn4+, Mg2+ phosphors show a single phase. Upon 350 nm excitation, the phosphors could emit far-red emission in the range of 600–800 nm, peaking at 680 nm (14,706 cm?1) due to the 2Eg→4A2g transition, with broad spectra overlap with the absorption band of phytochrome PFR. The optimal doping concentration, concentration quenching mechanism, as well as the content and temperature dependent decay times of Sr9Y2(WO6)4: Mn4+ and the related mechanisms are deeply studied. Ultimately, a far-red light emitting diode lamp is fabricated by exciting a far red phosphor Sr9Y2(WO6)4: 0.0025Mn4+, 0.01Mg2+ using a 365 nm n-UV illuminating LED chip. Our studies have shown that Sr9Y2(WO6)4: Mn4+, Mg2+ phosphors have potential application in controlling or adjusting plant growth in plant-lighting.
关键词： Sr9Y2(WO6)4: Mn4+,Plant growth,Phosphors,Far-red emitting,Mg2+
更新于2025-09-23 15:19:57
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Geometric Characterization of Vines from 3D Point Clouds Obtained with Laser Scanner Systems
摘要： The 3D digital characterization of vegetation is a growing practice in the agronomy sector. Precision agriculture is sustained, among other methods, by variables that remote sensing techniques can digitize. At present, laser scanners make it possible to digitize three-dimensional crop geometry in the form of point clouds. In this work, we developed several methods for calculating the volume of vine wood, with the ?nal intention of using these values as indicators of vegetative vigor on a thematic map. For this, we used a static terrestrial laser scanner (TLS), a mobile scanning system (MMS), and six algorithms that were implemented and adapted to the data captured and to the proposed objective. The results show that, with TLS equipment and the algorithm called convex hull cluster, the volumes of a vine trunk can be obtained with a relative error lower than 7%. Although the accuracy and detail of the cloud obtained with TLS are very high, the cost per unit for the scanned area limits the application of this system for large areas. In contrast to the inoperability of the TLS in large areas of terrain, the MMS and the algorithm based on the L1-medial skeleton and the modelling of cylinders of a certain height and diameter have solved the estimation of volumes with a relative error better than 3%. To conclude, the vigor map elaborated represents the estimated volume of each vine by this method.
关键词： vine size,mobile mapping,plant vigor,terrestrial laser scanning,precision agriculture,Vitis vinifera
更新于2025-09-23 15:19:57
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[IEEE 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Huangshan, China (2019.8.5-2019.8.8)] 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Experimental Assessment of Photonic Integrated Switches Based Optical Data Center Networks with Virtual Network Slice Services
摘要： The superconducting stellarator Wendelstein 7-X is currently being commissioned. First plasmas are expected for the second half of 2015. W7-X is designed to overcome the main drawbacks of the stellarator concept and simultaneously demonstrate its intrinsic advantages relative to the tokamak—i.e., steady-state operation without the requirement of current drive or stability control. An elaborate optimization procedure was used to avoid excessive neoclassical transport losses at high plasma temperature, while simultaneously achieving satisfactory equilibrium and stability properties at high β in combination with a viable divertor concept. In addition, fast-ion con?nement must be consistent with the requirements of alpha-heating in a power plant. Plasma operation of Wendelstein 7-X follows a staged approach following the successive completion of the in-vessel components. The main objective of Wendelstein 7-X is the demonstration of steady-state plasma at fusion relevant plasma parameters. Wendelstein 7-X will address major questions for the extrapolation of the concept to a power plant. These include divertor operation at high densities, plasma fueling at high central temperatures, avoiding impurity accumulation, and an assessment of the effect of neoclassical optimization on turbulent transport and fast-ion con?nement. A power plant concept based on an extrapolation from Wendelstein 7-X, the helical advanced stellarator, has been developed.
关键词： Fusion power plant,steady-state magnetic con?nement,stellarator
更新于2025-09-23 15:19:57
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A Computer Vision Line-Tracking Algorithm for Automatic UAV Photovoltaic Plants Monitoring Applications
摘要： In this paper, the authors propose an UAV-based automatic inspection method for photovoltaic plants analyzing and testing a vision-based guidance method developed to this purpose. The maintenance of PV plants represents a key aspect for the pro?tability in energy production and autonomous inspection of such systems is a promising technology especially for large utility-scale plants where manned techniques have signi?cant limitations in terms of time, cost and performance. In this light, an ad hoc ?ight control solution is investigated to exploit available UAV sensor data to enhance ?ight monitoring capability and correct GNSS position errors with respect to ?nal target needs. The proposed algorithm has been tested in a simulated environment with a software-in-the loop (SITL) approach to show its effectiveness and ?nal comparison with state of the art solutions.
关键词： PV plant monitoring,Unmanned Aerial Vehicles,image processing,?y-by-sensor,computer vision,automatic ?ight
更新于2025-09-23 15:19:57
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A non-linear auto-regressive exogenous method to forecast the photovoltaic power output
摘要： This paper deal about the prediction of SunModule SW 175 monocrystalline photovoltaic (PV) module power output installed in Belbis, Egypt. The proposes prediction model forecast one month using a non-linear auto-regressive exogenous method, based in neural network times series and Levenberg-Marquardt training algorithm. NARX neural network are powerful to solve several problems and popular in nonlinear control applications. The NARX model is choosing for rapid training and convergence speed and strong representativeness and is characterized by favourable dynamics and resistance to interference. Besides, the exactitude of NARX method has examined as a function of training data sets, error de?nitions relying on experimental data of a PV framework. The predicted power acquired by the NARX method gives a high correlativity with the experimental data and comparatively low errors. The forecast of output power obtained with the NARX method are compared with neural network and experimentally measured data. The obtained result is very accurate in R2 coe?cient 99.47% and MSE = 20.5753% compared to NARX-Bayesian R2 = 99.47 and RMSE = 21.71%. Generally, the execution and exactness of the results are exceedingly relying upon the climate condition, and the R2 took a low value if the user data in series analysis are not very accurate.
关键词： Power output,Times Series Analysis,Forecasting method,Photovoltaic plant,NARX
更新于2025-09-23 15:19:57