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Journal articles on the topic 'Images assimilation'
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Plu, M. "A variational formulation for translation and assimilation of coherent structures." Nonlinear Processes in Geophysics 20, no. 5 (October 17, 2013): 793–801. http://dx.doi.org/10.5194/npg-20-793-2013.
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Abstract. The assimilation of observations from teledetected images in geophysical models requires one to develop algorithms that would account for the existence of coherent structures. In the context of variational data assimilation, a method is proposed to allow the background to be translated so as to fit structure positions deduced from images. Translation occurs as a first step before assimilating all the observations using a classical assimilation procedure with specific covariances for the translated background. A simple validation is proposed using a dynamical system based on the one-dimensional complex Ginzburg–Landau equation in a regime prone to phase and amplitude errors. Assimilation of observations after background translation leads to better scores and a better representation of extremas than the method without translation.
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Le Dimet, F. X., I. Souopgui, O. Titaud, V. Shutyaev, and M. Y. Hussaini. "Toward the assimilation of images." Nonlinear Processes in Geophysics 22, no. 1 (January 13, 2015): 15–32. http://dx.doi.org/10.5194/npg-22-15-2015.
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Abstract. The equations that govern geophysical fluids (namely atmosphere, ocean and rivers) are well known but their use for prediction requires the knowledge of the initial condition. In many practical cases, this initial condition is poorly known and the use of an imprecise initial guess is not sufficient to perform accurate forecasts because of the high sensitivity of these systems to small perturbations. As every situation is unique, the only additional information that can help to retrieve the initial condition are observations and statistics. The set of methods that combine these sources of heterogeneous information to construct such an initial condition are referred to as data assimilation. More and more images and sequences of images, of increasing resolution, are produced for scientific or technical studies. This is particularly true in the case of geophysical fluids that are permanently observed by remote sensors. However, the structured information contained in images or image sequences is not assimilated as regular observations: images are still (under-)utilized to produce qualitative analysis by experts. This paper deals with the quantitative assimilation of information provided in an image form into a numerical model of a dynamical system. We describe several possibilities for such assimilation and identify associated difficulties. Results from our ongoing research are used to illustrate the methods. The assimilation of image is a very general framework that can be transposed in several scientific domains.
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Le Dimet, F. X., I. Souopgui, O. Titaud, and V. Shutyaev. "Toward the assimilation of images." Nonlinear Processes in Geophysics Discussions 1, no. 2 (August 19, 2014): 1381–430. http://dx.doi.org/10.5194/npgd-1-1381-2014.
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Abstract. The equations that govern geophysical fluids (namely atmosphere, ocean and rivers) are well known but their use for prediction requires the knowledge of the initial condition. In many practical cases, this initial condition is poorly known and the use of an imprecise initial guess is not sufficient to perform accurate forecasts because of the high sensitivity of these systems to small perturbations. As every situation is unique, the only additional information than can help to retrieve the initial condition are observations and statistics. The set of methods that combine these sources of heterogeneous information to construct such an initial condition are referred to as data assimilation. More and more images and sequences of images, of increasing resolution, are produced for scientific or technical studies. This is particularly true in the case of geophysical fluids that are permanently observed by remote sensors. However, the structured information contained in images or image sequences is not assimilated as regular observations: images are still (under)utilized to produce qualitative analysis by experts. This paper deals with the quantitative assimilation of information provided in an image form into a numerical model of a dynamical system. We describe several possibilities for such assimilation and identify associated difficulties. Results from our ongoing research are used to illustrate the methods. The assimilation of image is a very general framework that can be transposed in several scientific domains.
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Li, Ya. "FEMININE ASSIMILATIONS IN TEXT FORMATION OF "THE KUKOTSKY ENIGMA" BY L. ULITSKAYA." Bulletin of Kemerovo State University, no. 2 (August 3, 2018): 199–205. http://dx.doi.org/10.21603/2078-8975-2018-2-199-205.
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The article features comparisons by similarity and functionally equivalent metaphors targeting the heroines of The Kukotsky Enigma by L. Ulitskaya. The author proposes to take into account the differences between logical and figurative comparisons, emphasizing its subjective character and surreal modality. Also, the author suggests that figurative and logical comparisons can be combined in a compound sentence with a comparative subordinate clause. The thematic variety of feminine images of assimilation in the novel correlates with the application of nature-related and anthroponymic comparisons. Zoomorphous type prevails in nature-related comparisons, some of them shaping the associative microfields of the main characters. An attempt is made to explain the writer's conceptual thematic purpose connected with these microfields. The textual connections between comparison and metaphor are considered to be genetically close linguistic phenomena, which are combined by the common concept of "comparative". This makes it possible 1) to maintain the perceptive integrity of thematic associative microfields with comparative dominants involved in the female images; 2) to trace the correlation of tropes with realia in textual formation. A gender approach to the description of assimilative images and the representation of a wide variety of their modes of expression in L. Ulitskaya's novel have allowed the author to reveal the idiostyle features of the female author. It includes frequent forms of assimilation accompanied by explanations and clarifications that reflect, directly or indirectly, the author's attitude (sympathy, irony, or sarcasm) towards her female characters, as well as her conceptual thematic purpose related to the main characters’ fates and that of the family of the famous gynecologist doctor Kukotsky. The article features speech differentiation in the feminine images of assimilation by the author and her characters. The analysis performed has revealed a tendency to female comparative characteristics in L. Ulitskaya’s style.
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Margolis, Eric, and Jeremy Rowe. "Images of assimilation: photographs of Indian schools in Arizona." History of Education 33, no. 2 (March 2004): 199–230. http://dx.doi.org/10.1080/0046760032000151456.
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Chen, Pengfei. "Estimation of Winter Wheat Grain Protein Content Based on Multisource Data Assimilation." Remote Sensing 12, no. 19 (September 30, 2020): 3201. http://dx.doi.org/10.3390/rs12193201.
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Data assimilation is a robust method to predict crop biophysical and biochemical parameters. However, no previous study has attempted to predict grain protein content (GPC) at a regional scale using this method. This study explored the feasibility of designing an assimilation model for wheat GPC estimation using remote sensing, a crop growth model, and a priori knowledge. The data included a field experiment and regional sampling data, and Landsat Operational Land Imager images were employed, with the CERES (Crop Environment REsource Synthesis)-Wheat model used as simulation model. To select an optimal method for data assimilation in GPC prediction, different state variable scenarios and cost function solving algorithm scenarios were compared. Additionally, to determine whether a priori information could improve GPC prediction, the collected leaf area index (LAI) and leaf N content sampling data and the range of GPC in the study region were used to constrain the data assimilation process. Furthermore, the data assimilation method was compared to the use of only the CERES-Wheat model. The results showed that GPC could be predicted by remote sensing observation, a crop growth model, and a priori knowledge at regional scale, where the use of data assimilation improved the GPC prediction compared to using only the CERES-Wheat model.
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Cenci, Luca, Luca Pulvirenti, Giorgio Boni, and Nazzareno Pierdicca. "Defining a Trade-off Between Spatial and Temporal Resolution of a Geosynchronous SAR Mission for Soil Moisture Monitoring." Remote Sensing 10, no. 12 (December 4, 2018): 1950. http://dx.doi.org/10.3390/rs10121950.
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The next generation of synthetic aperture radar (SAR) systems could foresee satellite missions based on a geosynchronous orbit (GEO SAR). These systems are able to provide radar images with an unprecedented combination of spatial (≤1 km) and temporal (≤12 h) resolutions. This paper investigates the GEO SAR potentialities for soil moisture (SM) mapping finalized to hydrological applications, and defines the best compromise, in terms of image spatio-temporal resolution, for SM monitoring. A synthetic soil moisture–data assimilation (SM-DA) experiment was thus set up to evaluate the impact of the hydrological assimilation of different GEO SAR-like SM products, characterized by diverse spatio-temporal resolutions. The experiment was also designed to understand if GEO SAR-like SM maps could provide an added value with respect to SM products retrieved from SAR images acquired from satellites flying on a quasi-polar orbit, like Sentinel-1 (POLAR SAR). Findings showed that GEO SAR systems provide a valuable contribution for hydrological applications, especially if the possibility to generate many sub-daily observations is sacrificed in favor of higher spatial resolution. In the experiment, it was found that the assimilation of two GEO SAR-like observations a day, with a spatial resolution of 100 m, maximized the performances of the hydrological predictions, for both streamflow and SM state forecasts. Such improvements of the model performances were found to be 45% higher than the ones obtained by assimilating POLAR SAR-like SM maps.
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Michel, Yann. "Data Assimilation of Tropopause Height Using Dry Intrusion Observations." Monthly Weather Review 138, no. 1 (January 1, 2010): 101–22. http://dx.doi.org/10.1175/2009mwr2912.1.
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Abstract This article investigates the problem of initializing upper-level potential vorticity by using the detection of dry intrusions that can be seen in water vapor images. First, a satellite image processing technique has been developed for the identification and tracking of dry intrusions on geostationary satellite images. This technique can also be applied to images derived from model fields through a radiative transfer model. A linking algorithm automatically compares the trajectories of the dry intrusions in the model and in the satellite images. Differences of brightness temperatures are then converted to differences of tropopause height through a simple linear model, which is based on the correlation found in the background. As the scheme is likely to provide observations of the tropopause height, it also suggests that a space-alignment representation of the errors be used. A simple one-dimensional study provides a depiction of the background error covariance in alignment space, which is compared to the traditional approach of background error covariance in amplitude space. An approximate form of the Ertel potential vorticity operator is then used to incorporate pseudo-observations inside a global four-dimensional variational assimilation scheme. A case study of cyclogenesis highlights the difference between the amplitude–space assimilation of potential vorticity values and the alignment space assimilation of the height of the tropopause.
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Liu, Zhengchun, Zhanjun Xu, Rutian Bi, Chao Wang, Peng He, Yaodong Jing, and Wude Yang. "Estimation of Winter Wheat Yield in Arid and Semiarid Regions Based on Assimilated Multi-Source Sentinel Data and the CERES-Wheat Model." Sensors 21, no. 4 (February 10, 2021): 1247. http://dx.doi.org/10.3390/s21041247.
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The farmland area in arid and semiarid regions accounts for about 40% of the total area of farmland in the world, and it continues to increase. It is critical for global food security to predict the crop yield in arid and semiarid regions. To improve the prediction of crop yields in arid and semiarid regions, we explored data assimilation-crop modeling strategies for estimating the yield of winter wheat under different water stress conditions across different growing areas. We incorporated leaf area index (LAI) and soil moisture derived from multi-source Sentinel data with the CERES-Wheat model using ensemble Kalman filter data assimilation. According to different water stress conditions, different data assimilation strategies were applied to estimate winter wheat yields in arid and semiarid areas. Sentinel data provided LAI and soil moisture data with higher frequency (<14 d) and higher precision, with root mean square errors (RMSE) of 0.9955 m2 m−2 and 0.0305 cm3 cm−3, respectively, for data assimilation-crop modeling. The temporal continuity of the CERES-Wheat model and the spatial continuity of the remote sensing images obtained from the Sentinel data were integrated using the assimilation method. The RMSE of LAI and soil water obtained by the assimilation method were lower than those simulated by the CERES-Wheat model, which were reduced by 0.4458 m2 m−2 and 0.0244 cm3 cm−3, respectively. Assimilation of LAI independently estimated yield with high precision and efficiency in irrigated areas for winter wheat, with RMSE and absolute relative error (ARE) of 427.57 kg ha−1 and 6.07%, respectively. However, in rain-fed areas of winter wheat under water stress, assimilating both LAI and soil moisture achieved the highest accuracy in estimating yield (RMSE = 424.75 kg ha−1, ARE = 9.55%) by modifying the growth and development of the canopy simultaneously and by promoting soil water balance. Sentinel data can provide high temporal and spatial resolution data for deriving LAI and soil moisture in the study area, thereby improving the estimation accuracy of the assimilation model at a regional scale. In the arid and semiarid region of the southeastern Loess Plateau, assimilation of LAI independently can obtain high-precision yield estimation of winter wheat in irrigated area, while it requires assimilating both LAI and soil moisture to achieve high-precision yield estimation in the rain-fed area.
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Zhuo, Wen, Jianxi Huang, Li Li, Xiaodong Zhang, Hongyuan Ma, Xinran Gao, Hai Huang, Baodong Xu, and Xiangming Xiao. "Assimilating Soil Moisture Retrieved from Sentinel-1 and Sentinel-2 Data into WOFOST Model to Improve Winter Wheat Yield Estimation." Remote Sensing 11, no. 13 (July 8, 2019): 1618. http://dx.doi.org/10.3390/rs11131618.
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Crop yield estimation at a regional scale over a long period of time is of great significance to food security. In past decades, the integration of remote sensing observations and crop growth models has been recognized as a promising approach for crop growth monitoring and yield estimation. Optical remote sensing data are susceptible to cloud and rain, while synthetic aperture radar (SAR) can penetrate through clouds and has all-weather capabilities. This allows for more reliable and consistent crop monitoring and yield estimation in terms of radar sensor data. The aim of this study is to improve the accuracy for winter wheat yield estimation by assimilating time series soil moisture images, which are retrieved by a water cloud model using SAR and optical data as input, into the crop model. In this study, SAR images were acquired by C-band SAR sensors boarded on Sentinel-1 satellites and optical images were obtained from a Sentinel-2 multi-spectral instrument (MSI) for Hengshui city of Hebei province in China. Remote sensing data and ground data were all collected during the main growing season of winter wheat. Both the normalized difference vegetation index (NDVI), derived from Sentinel-2, and backscattering coefficients and polarimetric indicators, computed from Sentinel-1, were used in the water cloud model to derive time series soil moisture (SM) images. To improve the prediction of crop yields at the field scale, we incorporated remotely sensed soil moisture into the World Food Studies (WOFOST) model using the Ensemble Kalman Filter (EnKF) algorithm. In general, the trend of soil moisture inversion was consistent with the ground measurements, with the coefficient of determination (R2) equal to 0.45, 0.53, and 0.49, respectively, and RMSE was 9.16%, 7.43%, and 8.53%, respectively, for three observation dates. The winter wheat yield estimation results showed that the assimilation of remotely sensed soil moisture improved the correlation of observed and simulated yields (R2 = 0.35; RMSE =934 kg/ha) compared to the situation without data assimilation (R2 = 0.21; RMSE = 1330 kg/ha). Consequently, the results of this study demonstrated the potential and usefulness of assimilating SM retrieved from both Sentinel-1 C-band SAR and Sentinel-2 MSI optical remote sensing data into WOFOST model for winter wheat yield estimation and could also provide a reference for crop yield estimation with data assimilation for other crop types.
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Zakharyna, Yu Yu. "Archetypes of images of nonlinear architecture: randomness or conscious assimilation." Proceedings of the National Academy of Sciences of Belarus, Humanitarian Series 67, no. 2 (May 6, 2022): 217–24. http://dx.doi.org/10.29235/2524-2369-2022-67-2-217-224.
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For the first time in art history the problem of the appeal of architects of the digital era to the reconstruction of images of objects of the organic world through nonlinear shaping is raised. The aim of the research is to establish the archetypal nature of the images of nonlinear architecture through the essence of the phenomenon of sporadicity and conscious choice. It is revealed on the basis of the author’s artistic and figurative concept, which represents architecture as a symbiosis of phenomenological, procedural (evolutionary) and reproduced existences. The methodological basis is provided by the scientific works of scientists in the field of art and architecture (F. Johnson, A. Vidler, P. Schumacher, I. Dobritsyna, I. Azizyan, E. Lapshina, E. Sokolova, A. Shamruk). Through the prism of retrospection and comparative analysis, the architects aspirations to imitate the objects of the surrounding reality in the forms and structures of structures are revealed. The author substantiates the premeditation and randomness in the modeling of images of nonlinear architecture as a result of synthetic architecture. It is concluded that in appealing to the prototypes of real reality, the architect of the digital age acted as the creator of the beautiful, designed in the image and likeness of nature.
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Annis, Antonio, Fernando Nardi, and Fabio Castelli. "Simultaneous assimilation of water levels from river gauges and satellite flood maps for near-real-time flood mapping." Hydrology and Earth System Sciences 26, no. 4 (February 22, 2022): 1019–41. http://dx.doi.org/10.5194/hess-26-1019-2022.
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Abstract. Hydro-meteo hazard early warning systems (EWSs) are operating in many regions of the world to mitigate nuisance effects of floods. EWS performances are majorly impacted by the computational burden and complexity affecting flood prediction tools, especially for ungauged catchments that lack adequate river flow gauging stations. Earth observation (EO) systems may integrate the lack of fluvial monitoring systems supporting the setting up of affordable EWSs. But, EO data, constrained by spatial and temporal resolution limitations, are not sufficient alone, especially at medium–small scales. Multiple sources of distributed flood observations need to be used for managing uncertainties of flood models, but this is not a trivial task for EWSs. In this work, a near-real-time flood modelling approach is developed and tested for the simultaneous assimilation of both water level observations and EO-derived flood extents. An integrated physically based flood wave generation and propagation modelling approach, that implements an ensemble Kalman filter, a parsimonious geomorphic rainfall–runoff algorithm (width function instantaneous unit hydrograph, WFIUH) and a quasi-2D hydraulic algorithm, is proposed. An approach for assimilating multiple stage gauge observations is proposed to overcome stability issues related to the updating of the quasi-2D hydraulic model states. Furthermore, a methodology to retrieve distributed observed water depths from satellite images to update 2D hydraulic modelling state variables is implemented. Performances of the proposed approach are tested on a flood event for the Tiber River basin in central Italy. The selected case study shows varying performances depending on whether local and distributed observations are separately or simultaneously assimilated. Results suggest that the injection of multiple data sources into a flexible data assimilation framework constitutes an effective and viable advancement for flood mitigation to tackle EWS uncertainty and numerical stability issues. Specifically, our findings reveal that the simultaneous assimilation of observations from static sensors and satellite images led to an overall improvement of the Nash–Sutcliffe efficiency (NSE) between 5 % and 40 %, the Pearson correlation up to 12 % and bias reduction up to 80 % with respect to the open-loop simulation. Moreover, this combined assimilation allows us to reduce the flood extent uncertainty with respect to the disjoint assimilation simulations for several hours after the satellite image acquisition.
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de Weert, Charles M. M., and Noud A. W. H. van Kruysbergen. "Assimilation: Central and Peripheral Effects." Perception 26, no. 10 (October 1997): 1217–24. http://dx.doi.org/10.1068/p261217.
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Assimilation and contrast have opposite effects: Contrast leads to an increase of perceived differences between neighbouring fields, whereas assimilation leads to a reduction. It is relatively easy to demonstrate these effects, but the precise localisation of these effects in the perceptual system is not yet possible. In an experiment the strength of assimilation effects was modified by adding spatial noise. By varying the localisation in perceived space of the added noise (by presentation of the noise pattern with different binocular disparities) the masking effect of this noise can be influenced. Masking caused by binocularly disparate noise is less than masking caused by binocularly non-disparate noise. It is concluded that the effect at least partly occurs beyond the (binocular) locus of separation in different depth planes. A similar approach, involving moving noise, is also presented. Finally, several demonstrations show that images that are peripherally similar can give rise to differences in the perceived amount of assimilation. These effects further indicate that a central mechanism is involved in assimilation.
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Ma, Zaizhong, Eric S. Maddy, Banglin Zhang, Tong Zhu, and Sid Ahmed Boukabara. "Impact Assessment of Himawari-8 AHI Data Assimilation in NCEP GDAS/GFS with GSI." Journal of Atmospheric and Oceanic Technology 34, no. 4 (April 2017): 797–815. http://dx.doi.org/10.1175/jtech-d-16-0136.1.
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AbstractAs the first of the next-generation geostationary meteorological satellites, Himawari-8 was successfully launched in October 2014 by the Japan Meteorological Agency (JMA) and placed over the western Pacific Ocean domain at 140.7°E. It carries the Advanced Himawari Imager (AHI), which provides full-disk images of Earth at 16 bands in the visible and infrared domains every 10 min. Efforts are currently ongoing at the National Oceanic and Atmospheric Administration (NOAA)/National Environmental Satellite, Data, and Information Service (NESDIS)/Center for Satellite Applications and Research (STAR) to assimilate Himawari-8 AHI radiance measurements into the National Centers for Environmental Prediction (NCEP) Gridpoint Statistical Interpolation analysis system (GSI). All software development within the GSI to allow for assimilation of Himawari-8 AHI radiance has been completed.This study reports on the assessment of AHI preassimilation data quality by comparing observed clear-sky ocean-only radiances to those simulated using collocated ECMWF analysis, as well as describing procedures implemented for quality control. The impact of the AHI data assimilation on the resulting analyses and forecasts is then assessed using the NCEP Global Forecast System (GFS). A preliminary assessment of the assimilation of AHI data from infrared water vapor channels and atmospheric motion vectors (AMVs) on top of the current global observing system shows neutral to marginal positive impact on analysis and forecast skill relative to an assimilation without AHI data. The main positive impact occurs for short- to medium-range forecasts of global upper-tropospheric water vapor. The results demonstrate the feasibility of direct assimilation of AHI radiances and highlight how humidity information can be extracted within the assimilation system.
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Zhou, Gaoxiang, Xiangnan Liu, and Ming Liu. "Assimilating Remote Sensing Phenological Information into the WOFOST Model for Rice Growth Simulation." Remote Sensing 11, no. 3 (January 30, 2019): 268. http://dx.doi.org/10.3390/rs11030268.
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Precise simulation of crop growth is crucial to yield estimation, agricultural field management, and climate change. Although assimilation of crop model and remote sensing data has been applied in crop growth simulation, few studies have considered optimizing the crop model with respect to phenology. In this study, we assimilated phenological information obtained from Moderate Resolution Imaging Spectroradiometer (MODIS) time series data into the World Food Study (WOFOST) model to improve the accuracy of rice growth simulation at the regional scale. The particle swarm optimization (PSO) algorithm was implemented to optimize the initial phenology development stage (IDVS) and transplanting date (TD) in the WOFOST model by minimizing the difference between simulated and observed phenology, including heading and maturity date. Assimilating phenology improved the accuracy of the rice growth simulation, with correlation coefficients (R) equal to 0.793, 0822, and 0.813 at three fieldwork dates. The performance of the proposed strategy is comparable with that of the enhanced vegetation index (EVI) time series assimilation strategy, with less computation time. Additionally, the result confirms that the proposed strategy could be applied with different spatial resolution images and the difference of simulated LAImean is less than 0.35 in three experimental areas. This study offers a novel assimilation strategy with regard to the phenology development process, which is efficient and scalable for crop growth simulation.
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Michel, Yann. "Displacing Potential Vorticity Structures by the Assimilation of Pseudo-Observations." Monthly Weather Review 139, no. 2 (February 1, 2011): 549–65. http://dx.doi.org/10.1175/2010mwr3395.1.
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Abstract Classic formulations of variational data assimilation in amplitude space are not able to directly handle observations that measure the geographical positions of meteorological features like fronts and vortices. These observations can be derived from satellite images, as is already the case for tropical cyclones. Although some advanced data assimilation algorithms have been specifically designed to tackle the problem, a widespread way of dealing with this information is to use so-called bogussing pseudo-observations: user-specified artificial observations are inserted in a traditional data assimilation scheme. At the midlatitudes, there is a relationship between dry intrusions in water vapor images and upper-level potential vorticity structures. Some prior work has also shown that it was possible to automatically identify dry intrusions with tracking algorithms. The difference of positions between model and image dry intrusions could therefore be used as observations of the misplacement of potential vorticity structures. One strategy to achieve the displacement of potential vorticity anomalies is to sample them, and assimilate the values at displaced locations. The uncertainty of these pseudo-observations is left as a tuning parameter to try to make the displacement both effective and robust. A simple one-dimensional assimilation model is used to study the displacement of curves defined by Gaussian humps. The concept is then illustrated in realistic examples from real synoptic systems, where pseudo-observations of potential vorticity are incorporated in a global variational data assimilation scheme. Overall and despite reasonable optimization, the results contain artifacts. This suggests that the use of pseudo-observations to displace identifiable structures is not an effective strategy.
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Pan, Haizhu, Zhongxin Chen, Allard de Wit, and Jianqiang Ren. "Joint Assimilation of Leaf Area Index and Soil Moisture from Sentinel-1 and Sentinel-2 Data into the WOFOST Model for Winter Wheat Yield Estimation." Sensors 19, no. 14 (July 18, 2019): 3161. http://dx.doi.org/10.3390/s19143161.
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It is well known that timely crop growth monitoring and accurate crop yield estimation at a fine scale is of vital importance for agricultural monitoring and crop management. Crop growth models have been widely used for crop growth process description and yield prediction. In particular, the accurate simulation of important state variables, such as leaf area index (LAI) and root zone soil moisture (SM), is of great importance for yield estimation. Data assimilation is a useful tool that combines a crop model and external observations (often derived from remote sensing data) to improve the simulated crop state variables and consequently model outputs like crop total biomass, water use and grain yield. In spite of its effectiveness, applying data assimilation for monitoring crop growth at the regional scale in China remains challenging, due to the lack of high spatiotemporal resolution satellite data that can match the small field sizes which are typical for agriculture in China. With the accessibility of freely available images acquired by Sentinel satellites, it becomes possible to acquire data at high spatiotemporal resolution (10–30 m, 5–6 days), which offers attractive opportunities to characterize crop growth. In this study, we assimilated remotely sensed LAI and SM into the Word Food Studies (WOFOST) model to estimate winter wheat yield using an ensemble Kalman filter (EnKF) algorithm. The LAI was calculated from Sentinel-2 using a lookup table method, and the SM was calculated from Sentinel-1 and Sentinel-2 based on a change detection approach. Through validation with field data, the inverse error was 10% and 35% for LAI and SM, respectively. The open-loop wheat yield estimation, independent assimilations of LAI and SM, and a joint assimilation of LAI + SM were tested and validated using field measurement observation in the city of Hengshui, China, during the 2016–2017 winter wheat growing season. The results indicated that the accuracy of wheat yield simulated by WOFOST was significantly improved after joint assimilation at the field scale. Compared to the open-loop estimation, the yield root mean square error (RMSE) with field observations was decreased by 69 kg/ha for the LAI assimilation, 39 kg/ha for the SM assimilation and 167 kg/ha for the joint LAI + SM assimilation. Yield coefficients of determination (R2) of 0.41, 0.65, 0.50, and 0.76 and mean relative errors (MRE) of 4.87%, 4.32%, 4.45% and 3.17% were obtained for open-loop, LAI assimilation alone, SM assimilation alone and joint LAI + SM assimilation, respectively. The results suggest that LAI was the first-choice variable for crop data assimilation over SM, and when both LAI and SM satellite data are available, the joint data assimilation has a better performance because LAI and SM have interacting effects. Hence, joint assimilation of LAI and SM from Sentinel-1 and Sentinel-2 at a 20 m resolution into the WOFOST provides a robust method to improve crop yield estimations. However, there is still bias between the key soil moisture in the root zone and the Sentinel-1 C band retrieved SM, especially when the vegetation cover is high. By active and passive microwave data fusion, it may be possible to offer a higher accuracy SM for crop yield prediction.
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Kolberg, S., H. Rue, and L. Gottschalk. "A Bayesian spatial assimilation scheme for snow coverage observations in a gridded snow model." Hydrology and Earth System Sciences 10, no. 3 (June 1, 2006): 369–81. http://dx.doi.org/10.5194/hess-10-369-2006.
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Abstract. A method for assimilating remotely sensed snow covered area (SCA) into the snow subroutine of a grid distributed precipitation-runoff model (PRM) is presented. The PRM is assumed to simulate the snow state in each grid cell by a snow depletion curve (SDC), which relates that cell's SCA to its snow cover mass balance. The assimilation is based on Bayes' theorem, which requires a joint prior distribution of the SDC variables in all the grid cells. In this paper we propose a spatial model for this prior distribution, and include similarities and dependencies among the grid cells. Used to represent the PRM simulated snow cover state, our joint prior model regards two elevation gradients and a degree-day factor as global variables, rather than describing their effect separately for each cell. This transformation results in smooth normalised surfaces for the two related mass balance variables, supporting a strong inter-cell dependency in their joint prior model. The global features and spatial interdependency in the prior model cause each SCA observation to provide information for many grid cells. The spatial approach similarly facilitates the utilisation of observed discharge. Assimilation of SCA data using the proposed spatial model is evaluated in a 2400 km2 mountainous region in central Norway (61° N, 9° E), based on two Landsat 7 ETM+ images generalized to 1 km2 resolution. An image acquired on 11 May, a week before the peak flood, removes 78% of the variance in the remaining snow storage. Even an image from 4 May, less than a week after the melt onset, reduces this variance by 53%. These results are largely improved compared to a cell-by-cell independent assimilation routine previously reported. Including observed discharge in the updating information improves the 4 May results, but has weak effect on 11 May. Estimated elevation gradients are shown to be sensitive to informational deficits occurring at high altitude, where snowmelt has not started and the snow coverage is close to unity. Caution is therefore required when using early images.
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Elfering, Achim. "Human Factors in Matching Images to Standards: Assimilation and Time Order Error." International Journal of Occupational Safety and Ergonomics 11, no. 4 (January 2005): 399–407. http://dx.doi.org/10.1080/10803548.2005.11076659.
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Delingette, H., F. Billet, K. C. L. Wong, M. Sermesant, K. Rhode, M. Ginks, C. A. Rinaldi, R. Razavi, and N. Ayache. "Personalization of Cardiac Motion and Contractility From Images Using Variational Data Assimilation." IEEE Transactions on Biomedical Engineering 59, no. 1 (January 2012): 20–24. http://dx.doi.org/10.1109/tbme.2011.2160347.
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Perler, Dominik. "Disembodied Cognition and Assimilation: Thirteenth-Century Debates on an Epistemological Puzzle." Vivarium 57, no. 3-4 (August 15, 2019): 317–40. http://dx.doi.org/10.1163/15685349-12341375.
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AbstractMedieval Aristotelians assumed that we cannot assimilate forms unless our soul abstracts them from sensory images. But what about the disembodied soul that has no senses and hence no sensory images? How can it assimilate forms? This article discusses this problem, focusing on two thirteenth-century models. It first looks at Thomas Aquinas’ model, which invokes divine intervention: the separated soul receives forms directly from God. The article examines the problems this explanatory model poses and then turns to a second model, defended by Matthew of Aquasparta: the separated soul actively apprehends forms that are present to it. It will be argued that this model explains assimilation in terms of appropriation, rather than reception, of forms and thereby radically changes the traditional account of cognition. Finally, the article draws some methodological conclusions, arguing that the focus on the ‘limit case’ of separated souls made theoretical change possible.
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Rios, O., E. Pastor, M. M. Valero, and E. Planas. "Short-term fire front spread prediction using inverse modelling and airborne infrared images." International Journal of Wildland Fire 25, no. 10 (2016): 1033. http://dx.doi.org/10.1071/wf16031.
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A wildfire forecasting tool capable of estimating the fire perimeter position sufficiently in advance of the actual fire arrival will assist firefighting operations and optimise available resources. However, owing to limited knowledge of fire event characteristics (e.g. fuel distribution and characteristics, weather variability) and the short time available to deliver a forecast, most of the current models only provide a rough approximation of the forthcoming fire positions and dynamics. The problem can be tackled by coupling data assimilation and inverse modelling techniques. We present an inverse modelling-based algorithm that uses infrared airborne images to forecast short-term wildfire dynamics with a positive lead time. The algorithm is applied to two real-scale mallee-heath shrubland fire experiments, of 9 and 25 ha, successfully forecasting the fire perimeter shape and position in the short term. Forecast dependency on the assimilation windows is explored to prepare the system to meet real scenario constraints. It is envisaged the system will be applied at larger time and space scales.
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Yatsenko, Sergei A. "ON THE IMAGES OF PEOPLES FROM THE SOGDIAN DIASPORA IN CHINA." RSUH/RGGU Bulletin. "Literary Theory. Linguistics. Cultural Studies" Series, no. 8 (2020): 66–81. http://dx.doi.org/10.28995/2686-7249-2020-8-66-81.
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The reliable identification of Sogdians in the art of China of the early Tang dynasty is the big methodological problem. The difficulty of identification is compound by the fact that many of their images were found during the non-official excavations. The cultural assimilation of the Sogdians, which was going quite quickly, also makes it difficult. The cultural assimilation of the Sogdians, which was going quite quickly, also makes it difficult. This problem studied by the author in recent years on the basis of a comprehensive study of the costume of Sogdians and their neighbors, and their recognized social roles. There is a significant difference in the social status of most of the personages depicted in the art of Sogdia and in the Diaspora. Chinese clay burial figures “mingqi”, produced between 660 and 755 yy. CE, are sometimes portraits of Sogdians, depicted with high accuracy in ethnographic details. However, the meaning of placing them in the graves of Chinese officials is not entirely clear. A list of 15 costume elements that were the peculiar signs of Sogdian cultural identity for the Chinese was revealed. Occasionally, among “mingqi” there are such exotic-looking characters as a Sogdian aristocrat-official or a merchant of expensive wine.
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Wunenburger, Jean-Jacques. "Extase scopique, sédimentation langagičre et inscription corporelle. Les images dans la civilisation contemporaine." PARADIGMI, no. 3 (November 2009): 71–83. http://dx.doi.org/10.3280/para2009-003006.
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- Linguistic Sedimentation, and Bodily Inscription At present, we are exposed to an excessive offer of images, which raises a problem of assimilation. Subjects are increasingly passive, in ways that can border on pathological conditions. Yet, it is not so much a question of condemning this situation as of finding a way of re-symbolizing images, saving them from mere contemplation and inserting them in a process of contextualisation. Such a process requires an understanding of the role of the body and of the incorporation of images along the lines of Bachelard's intuition of the "resisting" nature of images. This raises the possibility of an education to images suited to the present age.Key words: Alienation, Education, Embodiment, Image, Informatics, Symbolisation.Parole chiave: Alienazione, Educazione, Immagine, Incorporazione, Informatica, Simbolizzazione.
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Sousa, Adriano Marlison Leão de, Maria Isabel Vitorino, Nilza Maria dos Reis Castro, Marcel do Nascimento Botelho, and Paulo Jorge Oliveira Ponte de Souza. "Evapotranspiration from Remote Sensing to Improve the Swat Model in Eastern Amazonia." Floresta e Ambiente 22, no. 4 (August 25, 2015): 456–64. http://dx.doi.org/10.1590/2179-8087.083814.
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ABSTRACT In this study, we estimated the evapotranspiration from orbital images - MODIS (Moderate Resolution Imaging Spectroradiometer) for assimilation in the hydrological modeling of the SWAT (Soil Water Assessment Tools) model. The data used include the period between October 2003 and December 2006 of the sub-basin of the Lajeado River, located in the Tocantins-Araguaia River basin in Tocantins state. Overall, the results of the use of heat flows estimated by remote sensors in the SWAT model can be considered satisfactory. The values of the COE (coefficient of efficiency of Nash-Sutcliffe) ranged from -0.40 to 0.91 in the comparison with the daily flow data and from 0.17 to 0.77 with the monthly flow data, with the assimilation of evapotranspiration from orbital images. These results indicate benefit to the model adjustment due to improvement in the data assimilated of approximately 0.91 in the COE on daily scale and 0.60 in the CEO on monthly scale.
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Yee, Yangli Hector, and Sumanta Pattanaik. "Segmentation and adaptive assimilation for detail-preserving display of high-dynamic range images." Visual Computer 19, no. 7-8 (December 2003): 457–66. http://dx.doi.org/10.1007/s00371-003-0211-5.
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Soares, R. V., H. N. Formentin, C. Maschio, and D. J. Schiozer. "EVALUATING THE IMPACT OF PETROPHYSICAL IMAGES PARAMETERIZATION IN DATA ASSIMILATION FOR UNCERTAINTY REDUCTION." Brazilian Journal of Petroleum and Gas 13, no. 4 (December 20, 2019): 249–63. http://dx.doi.org/10.5419/bjpg2019-0021.
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Aoyama, Tatsuro, Muneyoshi Yasuda, Hitoshi Yamahata, Mikinobu Takeuchi, Masahiro Joko, Kazuhiro Hongo, and Masakazu Takayasu. "Radiographic measurements of C-2 in patients with atlas assimilation." Journal of Neurosurgery: Spine 21, no. 5 (November 2014): 732–35. http://dx.doi.org/10.3171/2014.7.spine131087.
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Object The object of this study was to evaluate the radiographic characteristics of C-2 using multiplanar CT measurements for anchor screw placement in patients with C-1 assimilation (C1A). Insertion of a C-2 pedicle screw in the setting of C1A is relatively difficult and technically demanding, and there has been no report about the optimal sizes of the pedicles and laminae of C-2 for screw placement in C1A. Methods An institutional database was searched for all patients who had undergone cervical CT scanning and cervical spine surgery between April 2006 and December 2012. Two neurosurgeons reviewed the CT scans from 462 patients who met these criteria, looking for C1A and other anomalies of the craniocervical junction such as high-riding vertebral artery (VA), basilar invagination, and VA anomaly. The routine axial images were reloaded on a workstation, and reconstruction CT images were used to measure parameters: the minimum width of bilateral pedicles and laminae and the length of bilateral laminae of the atlas. Results Seven patients with C1A were identified, and 14 sex-matched patients without C1A were randomly selected from the same database as a control group. The mean minimum pedicle width was 5.21 mm in patients with C1A and 7.17 mm in those without. The mean minimum laminae width was 5.29 mm in patients with C1A and 6.53 mm in controls. The mean minimum pedicle and laminae widths were statistically significantly smaller in the patients with C1A (p < 0.05). Conclusions In patients with C1A, the C-2 bony structures are significantly smaller than normal, making C-2 pedicle screw or translaminar screw placement more difficult.
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Upreti, Deepak, Stefano Pignatti, Simone Pascucci, Massimo Tolomio, Wenjiang Huang, and Raffaele Casa. "Bayesian Calibration of the Aquacrop-OS Model for Durum Wheat by Assimilation of Canopy Cover Retrieved from VENµS Satellite Data." Remote Sensing 12, no. 16 (August 18, 2020): 2666. http://dx.doi.org/10.3390/rs12162666.
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Crop growth models play an important role in agriculture management, allowing, for example, the spatialized estimation of crop yield information. However, crop model parameter calibration is a mandatory step for their application. The present work focused on the regional calibration of the Aquacrop-OS model for durum wheat by assimilating high spatial and temporal resolution canopy cover data retrieved from VENµS satellite images. The assimilation procedure was implemented using the Bayesian approach with the recent implementation of the Markov chain Monte Carlo (MCMC)-based Differential Evolution Adaptive Metropolis (DREAM) algorithm DREAM(KZS). The fraction of vegetation cover (fvc) was retrieved from the VENµS satellite images for two years, during the durum wheat growing seasons of 2018 and 2019 in Central Italy. The retrieval was based on a hybrid method using PROSAIL Radiative Transfer Model (RTM) simulations for training a Gaussian Process Regression (GPR) algorithm, combined with Active Learning to reduce the computational cost. The Aquacrop-OS model was calibrated with the fvc data of 2017–2018 for the Maccarese farm in Central Italy and validated with the 2018–2019 data. The retrieval accuracy of the fvc from the VENµS images were the Coefficient of Determination (R2) = 0.76, Root Mean Square Error (RMSE) = 0.09, and Relative Root Mean Square Error (RRMSE) = 11.6%, when compared with the ground-measured fvc. The MCMC results are presented in terms of Gelman–Rubin R statistics and MR statistics, Markov chains, and marginal posterior distribution functions, which are summarized with the mean values for the most sensitive crop parameters of the Aquacrop-OS model subjected to calibration. When validating for the fvc, the R2 of the model for year (2018–2019) ranged from 0.69 to 0.86. The RMSE, Relative Error (RE), Relative Variability (α), and Relative Bias (β) ranged from 0.15 to 0.44, 0.19 to 2.79, 0.84 to 1.45, and 0.91 to 1.95, respectively. The present work shows the importance of the calibration of the Aquacrop-OS (AOS) crop water productivity model for durum wheat by assimilating remote sensing information from VENµS satellite data.
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Larin, S. V., and S. V. Chilbak-ool. "ANIMATED IMAGES AS A MEANS OF DIGITAL TECHNOLOGIES IN TEACHING MATHEMATICS." Bulletin of Krasnoyarsk State Pedagogical University named after V.P. Astafiev 53, no. 3 (October 30, 2020): 54–61. http://dx.doi.org/10.25146/1995-0861-2020-53-3-220.
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Statement of the problem. Universal digitalization of economy and public relations is a reality of today, and a school teacher is faced with the task of forming a personality ready to reveal his/her creative potential in the digital economy. The problem is to outline the ways of digitalization of teaching mathematics that meets the needs of society, and contribute to the understanding and assimilation of mathematical knowledge based on digital educational resources using the animation capabilities of computer environments. The purpose of the article is to present animated images in the GeoGebra environment as new means of digital technologies for teaching mathematics. Research methodology. Analysis of scientific, educational and methodological literature, synthesis of the authors’ work experience at school and university in approbation of elements of the mathematics teaching system using animated images. Research results. Specific types of animated images are presented and the expediency of their use as effective means of digital technologies for teaching mathematics in the lessons of arithmetic, algebra, trigonometry and the beginnings of mathematical analysis is substantiated. Conclusion. The use of new technology with the use of animated images in mathematics lessons at school increases the level of understanding and assimilation of mathematical knowledge by providing clarity of mathematical concepts and statements. In addition, animated images are used to eliminate computational difficulties, to generate tasks of the same type, and to organize self-testing of students’ knowledge. The creation of digital educational content using the animation capabilities of computer environments increases the technological equipment of a modern mathematics teacher, which will allow him/her to achieve better educational results.
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Wang, J., and AE Douglas. "Nitrogen recycling or nitrogen conservation in an alga-invertebrate symbiosis?" Journal of Experimental Biology 201, no. 16 (August 15, 1998): 2445–53. http://dx.doi.org/10.1242/jeb.201.16.2445.
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When corals and allied animals are deprived of their symbiotic algae, the ammonium content in their tissues rises. This is commonly interpreted as evidence for nitrogen recycling (i.e. algal assimilation of animal waste ammonium into amino acids that are released back to the animal), but it can also be explained as nitrogen conservation by the animal (i.e. reduced net ammonium production in response to the receipt of algal photosynthetic carbon). This study discriminated between these interpretations in two ways. First, the increased ammonium concentration in the sea anemone Aiptasia pulchella, caused by darkness or depletion of the alga Symbiodinium, was partially or completely reversed by supplementing the medium with organic carbon compounds (e.g. <IMG src="/images/symbols/&agr ;.gif" WIDTH="9" HEIGHT="12" ALIGN= "BOTTOM" NATURALSIZEFLAG="3">-ketoglutarate). Second, the activity of the ammonium-assimilating enzyme glutamine synthetase and the concentration of protein amino acids in the free amino acid pool of the animal, which were depressed by darkness and algal depletion, were restored by exogenous carbon compounds. It is concluded that organic carbon, whether derived from algal photosynthate or exogenously, promotes the animal's capacity for ammonium assimilation and reduces ammonium production from amino acid degradation. These processes contribute to nitrogen conservation in the animal, but they confound the interpretation of various studies on nitrogen recycling by symbiotic algae.
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Lafrance, Bruno, Xavier Lenot, Caroline Ruffel, Patrick Cao, and Thierry Rabaute. "Outils de prétraitements des images optiques Kalideos." Revue Française de Photogrammétrie et de Télédétection, no. 197 (April 21, 2014): 10–16. http://dx.doi.org/10.52638/rfpt.2012.78.
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La communauté scientifique a besoin de disposer de séries temporelles d'observations récurrentes, couvrant des sites d'intérêt pour le suivi de l'évolution des surfaces terrestres (études agronomiques par assimilation de données, suivi de traits de côte, glissements de terrain, surveillance des volcans, cartographie littorale, etc.). L'analyse de ces séries temporelles demande à avoir des images superposables entre elles qui renseignent sur la réflectance des sites (grandeur physique indépendante du capteur).Dans l'objectif de rendre accessibles de telles données physiques et de garantir une homogénéité des traitements de séries temporelles d'images, le CNES a mis en place le programme Kalideos. Dans ce cadre, CS SI a développé et opère les chaines de traitement des images.Cet article présente les traitements appliqués aux images optiques des bases Kalideos (capteurs Spot et Formosat). Ces traitements permettent de convertir les produits de niveau 1A en ortho-images, donnant la réflectance mesurée au sommet de l'atmosphère et celle estimée au niveau de la surface après correction des effets atmosphériques.
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Nonaka, Takako, Morimasa Matsuda, and Tomohiro Hase. "Modulation Transfer Function Model of Assimilation Phenomenon on Monochrome Images Based on Visual Characteristics." IEEJ Transactions on Electronics, Information and Systems 126, no. 3 (2006): 327–32. http://dx.doi.org/10.1541/ieejeiss.126.327.
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KOROTAEV, G., E. HUOT, F. LEDIMET, I. HERLIN, S. STANICHNY, D. SOLOVYEV, and L. WU. "Retrieving ocean surface current by 4-D variational assimilation of sea surface temperature images." Remote Sensing of Environment 112, no. 4 (April 15, 2008): 1464–75. http://dx.doi.org/10.1016/j.rse.2007.04.020.
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Sun, Xiaofang. "Resuming Gynocratic Principles: Cultural Reterritorialization of Native Traditions in Linda Hogan’s Fiction." English Language and Literature Studies 11, no. 4 (September 27, 2021): 36. http://dx.doi.org/10.5539/ells.v11n4p36.
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Native Americans’ cultural system has been utterly undermined in the early colonial conquest and the later neo-colonial expansion. Cultural annihilation is primarily caused by the forced cultural assimilation, especially by the white government’s practice of eradicating native traditions and beliefs. To rebuild the native culture system, Native American writer Linda Hogan attempts to employ the pre-colonial gynocratic principles in her literary creation, thus reterritorializing their cultural identity among the modern natives. This paper reveals how Hogan effectively resumes the ancient gynocratic principles by portraying a series of typical female images in the woman-centered native community, with an aim to fight against cultural assimilation guided by the white male-dominated western metaphysical epistemology.
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Kolberg, S., H. Rue, and L. Gottschalk. "A Bayesian spatial assimilation scheme for snow coverage observations in a gridded snow model." Hydrology and Earth System Sciences Discussions 2, no. 4 (July 25, 2005): 1185–219. http://dx.doi.org/10.5194/hessd-2-1185-2005.
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Abstract. A spatial probability distribution of the variables in a parametric snow depletion curve (SDC) is tailored to the assimilation of satellite snow cover data into a gridded hydrological model. The assimilation is based on Bayes' theorem, in which the proposed distribution represents the a priori information about the SDC variables. From the prior gridded maps of snow storage and accumulated melt depth, the elevation gradients and the degree-day factor are separated out, creating elevation-normalised surfaces of snow storage and degree-day sum. Because the small-scale variability linked to elevation is removed, these surfaces can be described by prior distribution models with a strong spatial dependency structure. This reduction of spatial uniqueness in the prior distribution greatly increases the informational value of the remotely sensed snow coverage data. The assimilation is evaluated in a 2400 km2 mountainous region in central Norway (61° N, 9° E), based on two Landsat 7 ETM+ images evaluated at 1 km2 scale. An image acquired on 11 May, a week before the peak flood, removes 78% of the variance in the remaining snow storage. Even an image from 4 May, less than a week after the melt onset, reduces this variance by 53%. Including observed discharge in the updating information improves the 4 May results, but has weak effect on 11 May. Estimated elevation gradients are shown to be sensitive to informational deficits occurring at high altitude, where snowmelt has not yet started. Caution is therefore required when using early images.
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Sbii, Siham, Mimoun Zazoui, and Noureddine Semane. "Dynamical contribution of mean potential vorticity pseudo-observations derived from MetOp/GOME2 ozone data into short-range weather forecast during high precipitation events." International Journal of Basic and Applied Sciences 4, no. 2 (April 28, 2015): 206. http://dx.doi.org/10.14419/ijbas.v4i2.4435.
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<p>Satellites are uniquely capable of providing uniform data coverage globally. Motivated by such capability, this study builds on a previously described methodology that generates numerical weather prediction initial conditions from satellite total column ozone data. The methodology is based on two principal steps. Firstly, the studied linear regression between vertical (100hPa-500hPa) Mean Potential Vorticity (MPV) and MetOp/GOME2 total ozone data (O3) generates MPV pseudo-observations. Secondly, the 3D variational (3D-Var) assimilation method is designed to take into account MPV pseudo-observations in addition to conventional observations.</p><p>After a successful assimilation of MPV pseudo-observations using a 3D-Var approach within the Moroccan version of the ALADIN limited-area model, the present study aims to assess the dynamical behavior of the short-range forecast at upper levels during heavy precipitation events (HPEs). It is found that MPV assimilation offers the possibility to internally monitor the model upper-level dynamics in addition to the use of Water Vapor Satellite images.</p>
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Howe, Catherine Q., and Dale Purves. "Size Contrast and Assimilation Explained by the Statistics of Natural Scene Geometry." Journal of Cognitive Neuroscience 16, no. 1 (January 2004): 90–102. http://dx.doi.org/10.1162/089892904322755584.
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The term “size contrast and assimilation” refers to a large class of geometrical illusions in which the apparent sizes of identical visual targets in various contexts are different. Here we have examined whether these intriguing discrepancies between physical and perceived size can be explained by a visual process in which percepts are determined by the probability distribution of the possible real-world sources of retinal stimuli. To test this idea, we acquired a range image database of natural scenes that specified the location of every image point in 3-D space. By sampling the possible physical sources of various size contrast or assimilation stimuli in the database, we determined the probability distributions of the size of the target in the images generated by these sources. For each of the various stimuli tested, these probability distributions of target size in different contexts accurately predicted the perceptual effects reported in psychophysical studies. We conclude that size contrast and assimilation effects are a further manifestation of a fundamentally probabilistic process of visual perception.
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Yucel, Ismail, W. James Shuttleworth, X. Gao, and S. Sorooshian. "Short-Term Performance of MM5 with Cloud-Cover Assimilation from Satellite Observations." Monthly Weather Review 131, no. 8 (August 1, 2003): 1797–810. http://dx.doi.org/10.1175//2565.1.
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Abstract This study investigates the extent to which assimilating high-resolution remotely sensed cloud cover into the fifth-generation Pennsylvania State University–National Center for Atmospheric Research (PSU–NCAR) Mesoscale Model (MM5) provides an improved regional diagnosis of downward shortwave surface radiation fluxes and precipitation and enhances the model's ability to make short-range prediction. The high-resolution (4 km × 4 km) clear- and cloudy-sky radiances derived using a cloud-screening algorithm from visible band Geostationary Operational Environmental Satellite (GOES) data were used in the University of Maryland Global Energy and Water Cycle Experiment's Surface Radiation Budget (UMD GEWEX/SRB) model to infer the vertically integrated cloud mass via cloud optical thickness. Three-dimensional cloud fields were created that took their horizontal distribution from the satellite image but derived their vertical distribution, in part, from the fields simulated by MM5 during the time step immediately prior to assimilation and, in part, from the observed cloud-top height derived from the infrared band of GOES. Linear interpolation was used to derive 1-min cloud images between 15-min GOES samples, and the resulting images were ingested every minute. Comparisons were made between modeled and observed data taken from the Arizona Meteorological Network (AZMET) in southern Arizona for model runs with and without cloud ingestion. Cloud ingestion substantially improved the ability of the MM5 model to capture temporal and spatial variations in surface fields associated with cloud cover. Experiments in which the model was operated in forecast mode suggest that cloud ingestion gave some limited enhancement in MM5 short-term prediction ability for up to 3 h. However, an analysis suggests that, in order to get additional forecasting capability, it will be necessary to modify the atmospheric dynamics and thermodynamics in the model to be consistent with the ingested cloud fields.
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Lei, Guo, and He Li. "An Interpretation of Ecological Images in William Yeats’ Poems from the Perspective of New Historicism." Saudi Journal of Humanities and Social Sciences 7, no. 3 (March 6, 2022): 79–82. http://dx.doi.org/10.36348/sjhss.2022.v07i03.001.
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There are many descriptions of the environment in William Yeats’ poems. From the perspective of new historicism, this paper analyzes the ecological images of poetry from two aspects: the historicity of the text and the textuality of history. Ecological images are those depicting nature and cities. Among them, birds, roses, and Innisfree are the classic ones. Through these images, William Yeats concerns the relationship between the ecology and people. The historicity of the text presents the historical reality of Ireland and Irish life experience. Then, based on the function of literary texts which work as an ecological reality, the thesis explores the assimilation and arrogance of humans in constructing Irish life experience. The textuality of history focuses on fiction and historic reality. Through the images, Irish ecology enters the public. Moreover, William Yeats applies defamiliarization and intertextuality to contrasting the authoritative history and offering a fresh history.
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Dyrkheeva, G. A. "SEMANTIC GESTALT OF THE KERNEL OF LANGUAGE CONSCIOUSNESS OF BURYAT-BILINGUALS." Voprosy Kognitivnoy Lingvistiki, no. 3 (2020): 125–31. http://dx.doi.org/10.20916/1812-3228-2020-3-125-131.
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The article is devoted to the experience of the comparative analysis of language consciousness content of the Buryat-bilinguals on the example of a semantic Gestalt of basic fields of people, home, life presented in the Buryat and Russian languages. The main aim of the research is identification of ethnocultural specifics and transformation of language consciousness of modern Buryat-bilinguals, knowing Russian and the Buryat language. The analysis is carried out on the basis of the associative dictionary made by the author of the article. The results of the experiment show that semantic zones of both Gestalts in many respects are identical, consisting of five-eight zones of the same name, however their content and hierarchy of arrangement reveal essential differences in images of consciousness of the Buryat-bilinguals - the carriers of two languages. It was confirmed that for the Buryats in their native language a basic valuable dominant is the family. The main differences in the content of knowledge in different languages in many respects are defined by system and structural features of language and a discrepancy of semantic fields. Buryats’ active assimilating Russian led both to assimilation of new lexicon, and to assimilation of the corresponding lexical stereotypes. It is undoubted that foreign-language influence promotes changes in lexical structure and communicative standards of the Buryat language, it transforms its system of culture and valuable. The received results may be used in social-, psycholinguistic researches, linguistics of language contacts.
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Lydon, Jane. "Photography and Critical Heritage." Public Historian 41, no. 1 (February 1, 2019): 18–33. http://dx.doi.org/10.1525/tph.2019.41.1.18.
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Historical photographs of Australian Aboriginal people were amassed during the colonial period for a range of purposes, yet rarely to further an Indigenous agenda. Today, however, such images have been recontextualized, used to reconstruct family history, document culture, and express connections to place. They have become a significant heritage resource for relatives and descendants. Images stand in for relatives lost through processes of official assimilation—or as this sad history is now known in Australia, the Stolen Generations. This article explores the potential healing power of the photos in addressing loss and dislocation, and emerging tools for supporting this process through reviewing the Returning Photos project outcomes.
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Hasegawa, T., and R. Iiyama. "Difference in Perceived Colour between Painted Chips and CRT Images." Perception 26, no. 1_suppl (August 1997): 171. http://dx.doi.org/10.1068/v970339.
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The inducing effect of blue in colour assimilation on a CRT screen is so strong that pale blue apparently veils the stimulus pattern (Miyamoto and Hasegawa, 1996 Perception25 Supplement, 105). A similar tendency can be observed on painted paper, but this effect is not so marked. This led us to try colour matching between coloured papers and colours reproduced on a CRT screen. In both conditions the shapes (square) and the sizes (35 cm × 35 cm) were the same. They were displayed in the centre of a 155 cm × 155 cm gray (Munsell value 5, 22 cd cm−2) square with 10 cm wide white fringe (74 cd cm−2). The task was to adjust the colour on the CRT screen to match the coloured chip which was inside an illuminated box at a viewing distance of 180 cm in a dark room. Twenty-four colours were tested. Matched blues and other blue hues were slightly more saturated than object colours, but differences in chromaticity coordinates ( u‘ v’) were not statistically significant. This result is opposite to the prediction because it suggests a less bluish impression in the film-colour mode. By contrast, luminance in matched blues was lower than that of the object. This means that the brightness effect increased. An additional experiment in which the stimulus size was larger and the illuminating condition was changed to a light room produced the following results: (i) no meaningful difference in chromaticity coordinates could be seen; and (ii) the luminance of matched colours increased with size and in the lighter viewing condition. These facts show that the bluish colours on the CRT screen do not change their perceived chromaticity or spread spatially. The only difference was the subjective brightness increase in the condition when the room was dark. The strong effect of the blues in assimilation on the screen, therefore, does not depend on the colour identification process itself, but on the combined effect of luminosity and visual frequency response.
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ANDRADE JUNIOR, ADERSON SOARES DE, EDSON ALVES BASTOS, CARLOS ANTONIO FERREIRA DE SOUSA, RAPHAEL AUGUSTO DAS CHAGAS NOQUELI CASARI, and BRAZ HENRIQUE NUNES RODRIGUES. "WATER STATUS EVALUATION OF MAIZE CULTIVARS USING AERIAL IMAGES." Revista Caatinga 34, no. 2 (June 2021): 432–42. http://dx.doi.org/10.1590/1983-21252021v34n219rc.
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ABSTRACT The objective of this study was to evaluate the water status of maize cultivars through thermal and vegetation indexes generated from multispectral aerial images obtained from an unmanned aerial vehicle (UAV), and correlate them with physiological indicators and soil water contents. The application of three water regimes based on the reference evapotranspiration (ETo) (30%, 90%, and 150% ETo) was evaluated for two maize cultivars (AG-1051 and BRS-Caatingueiro). An UAV was used to acquire thermal and multispectral images. The indexes evaluated were CWSI, CI-G, CI-RE, CIV, NDVI and OSAVI, which were correlated with gas exchange and soil moisture measures. The CWSI present correlation with physiological indicators (stomatal conductance, transpiration, and net CO2 assimilation rate) that can be used to evaluate water status of maize plants. The multispectral vegetation indexes NDVI and OSAVI can replace the CWSI thermal index in water status evaluations for maize plants.
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Du, Mei, Yijun Hou, Po Hu, and Kai Wang. "Effects of Typhoon Paths on Storm Surge and Coastal Inundation in the Pearl River Estuary, China." Remote Sensing 12, no. 11 (June 8, 2020): 1851. http://dx.doi.org/10.3390/rs12111851.
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A coastal inundation simulation system was developed for the coast of the Pearl River estuary (PRE), which consists of an assimilation typhoon model and the coupled ADCIRC (Advanced Circulation) + SWAN (Simulating Waves Nearshore) model. The assimilation typhoon model consists of the Holland model and the analysis products of satellite images. This is the first time an assimilation typhoon model has been implemented and tested for coastal inundation via case studies. The simulation results of the system agree well with the real measurements. Three observed typhoon paths (Hope, Nida, and Hato) were chosen to be the studied paths based on their positions relative to the PRE, China. By comparing the results of experiments with different forcing fields, we determined that the storm surge and the coastal inundation were mainly induced by wind forcing. By simulating coastal inundation for different typhoon center speeds, the Hato3 path most easily causes coastal inundation in the PRE. Moreover, the moving speed of the typhoon’s center significantly affects the coastal inundation in the PRE. The inundation becomes very serious as the movement of the typhoon center was slow down. This study provides a new reference for future predictions of coastal inundations.
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Shulman, Igor, Richard W. Gould, Sergey Frolov, Sean McCarthy, Brad Penta, Stephanie Anderson, and Peter Sakalaukus. "Bio-Optical Data Assimilation With Observational Error Covariance Derived From an Ensemble of Satellite Images." Journal of Geophysical Research: Oceans 123, no. 3 (March 2018): 1801–13. http://dx.doi.org/10.1002/2017jc013171.
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Baba, Mohamed, Simon Gascoin, and Lahoucine Hanich. "Assimilation of Sentinel-2 Data into a Snowpack Model in the High Atlas of Morocco." Remote Sensing 10, no. 12 (December 7, 2018): 1982. http://dx.doi.org/10.3390/rs10121982.
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The snow melt from the High Atlas is a critical water resource in Morocco. In spite of its importance, monitoring the spatio-temporal evolution of key snow cover properties like the snow water equivalent remains challenging due to the lack of in situ measurements at high elevation. Since 2015, the Sentinel-2 mission provides high spatial resolution images with a 5 day revisit time, which offers new opportunities to characterize snow cover distribution in mountain regions. Here we present a new data assimilation scheme to estimate the state of the snowpack without in situ data. The model was forced using MERRA-2 data and a particle filter was developed to dynamically reduce the biases in temperature and precipitation using Sentinel-2 observations of the snow cover area. The assimilation scheme was implemented using SnowModel, a distributed energy-balance snowpack model and tested in a pilot catchment in the High Atlas. The study period covers 2015-2016 snow season which corresponds to the first operational year of Sentinel-2A, therefore the full revisit capacity was not yet achieved. Yet, we show that the data assimilation led to a better agreement with independent observations of the snow height at an automatic weather station and the snow cover extent from MODIS. The performance of the data assimilation scheme should benefit from the continuous improvements of MERRA-2 reanalysis and the full revisit capacity of Sentinel-2.
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Panasenko, N. D., and N. S. Motuz. "Detection of water surface natural objects based on the satellite sensing data." Journal of Physics: Conference Series 2131, no. 3 (December 1, 2021): 032053. http://dx.doi.org/10.1088/1742-6596/2131/3/032053.
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Abstract The article shows an application of satellite sensing data method in geoenvironmental monitoring of water surface. It is expected to apply combination of LBP and neural network approaches for detection and identification objects of natural and anthropogenic origin. The applying of satellite images, the implementation and operation of the filtration method and satellite sensing data assimilation in real or near-real time are considered to detect the blooming areas and their coordinates. The research demonstrates the need and possibility to apply neural approach and the theory of deep learning for solving the tasks. The results of computer experiments are presented basing on the images from satellites Resurs-P, WorldView and Landsat over the Azov sea area.
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Koshimura, Shunichi. "Establishing the Advanced Disaster Reduction Management System by Fusion of Real-Time Disaster Simulation and Big Data Assimilation." Journal of Disaster Research 11, no. 2 (March 1, 2016): 164–74. http://dx.doi.org/10.20965/jdr.2016.p0164.
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A project titled “Establishing the advanced disaster reduction management system by fusion of real-time disaster simulation and big data assimilation,” was launched as Core Research for Evolutional Science and Technology (CREST) by the Japan Science and Technology Agency (JST). Intended to save as many lives as possible in future national crises involving earthquake and tsunami disasters, the project works on a disaster mitigation system of the big data era, based on cooperation of large-scale, high-resolution, real-time numerical simulations and assimilation of real-time observation data. The world’s most advanced specialists in disaster simulation, disaster management, mathematical science, and information science work together to create the world’s first analysis platform for real-time simulation and big data that effectively processes, analyzes, and assimilates data obtained through various observations. Based on quantitative data, the platform designs proactive measures and supports disaster operations immediately after disaster occurrence. The project was launched in 2014 and is working on the following issues at present.Sophistication and fusion of simulations and damage prediction models using observational big data: Development of a real-time simulation core system that predicts the time evolution of disaster effect by assimilating of location information, fire information, and building collapse information which are obtained from mobile terminals, satellite images, aerial images, and other new observation data in addition to sensing data obtained by the undersea high-density seismic observation network.Latent structure analysis and major disaster scenario creation based on a huge amount of simulation results: Development of an analysis and extraction method for the latent structure of a huge amount of disaster scenarios generated by simulation, and creation of severe scenarios with minimum “unexpectedness” by controlling disaster scenario explosion (an explosive increase in the number of predicted scenarios).Establishment of an earthquake and tsunami disaster mitigation big data analysis platform: Development of an earthquake and tsunami disaster mitigation big data analysis platform that realizes analyses of a huge number of disaster scenarios and increases in speed of data assimilation, and clarifies the requirements for operation of the platform as a disaster mitigation system.The project was launched in 2014 as a 5-year project. It consists of element technology development and system fusion, feasibility study as a next-generation disaster mitigation system (validation with/without introduction of the developed real-time simulation and big data analysis platform) in the affected areas of the Great East Japan Earthquake, and test operations in affected areas of the Tokyo metropolitan earthquake and the Nankai Trough earthquake.
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Otsuka, Shigenori, Shunji Kotsuki, and Takemasa Miyoshi. "Nowcasting with Data Assimilation: A Case of Global Satellite Mapping of Precipitation." Weather and Forecasting 31, no. 5 (August 22, 2016): 1409–16. http://dx.doi.org/10.1175/waf-d-16-0039.1.
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Abstract Space–time extrapolation is a key technique in precipitation nowcasting. Motions of patterns are estimated using two or more consecutive images, and the patterns are extrapolated in space and time to obtain their future patterns. Applying space–time extrapolation to satellite-based global precipitation data will provide valuable information for regions where ground-based precipitation nowcasts are not available. However, this technique is sensitive to the accuracy of the motion vectors, and over the past few decades, previous studies have investigated methods for obtaining reliable motion vectors such as variational techniques. In this paper, an alternative approach applying data assimilation to precipitation nowcasting is proposed. A prototype extrapolation system is implemented with the local ensemble transform Kalman filter and is tested with the Japan Aerospace Exploration Agency’s Global Satellite Mapping of Precipitation (GSMaP) product. Data assimilation successfully improved the global precipitation nowcasting with the real-case GSMaP data.