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Indicator-Kriging-Integrated Evidence Theory for Unsupervised Change Detection in Remotely Sensed Imagery
摘要： This study proposes a novel approach based on indicator kriging and Dempster–Shafer (DS) theory for unsupervised change detection (CD) in remote sensing images (DSK). Indicator kriging is integrated to the standard DS theory. A feature set with four difference images (DIs) providing complementary change information is initially generated. Subsequently, the mass functions for each DI are determined automatically using fuzzy logic, the four pieces of DI evidence are combined by DS theory, and a preliminary CD map is achieved. The preliminary CD map is then divided into three parts adaptively—weakly con?icting part of no change, weakly con?icting part of change, and strongly con?icting part—by calculating the evidence con?ict degree for each pixel. Finally, the pixels in the weakly con?icting parts, which have little or no con?ict, are labeled as the current class, and the pixels in the strongly con?icting part that contains misclassi?ed pixels are reclassi?ed based on indicator kriging. DSK combines the advantages of different DI features and solves the con?icting situations to a large extent. The main contributions of this study include the following: 1) introducing indicator kriging into CD to manage con?ict information during DS fusion and 2) presenting a scheme for producing DI set with complementary change information, developing a novel DSK fusion model for information fusion, and de?ning the proposed CD framework. Experimental results verify that the proposed DSK is robust and effective for CD.
关键词： unsupervised change detection (CD),remote sensing,Con?ict management,indicator kriging,Dempster–Shafer (DS) theory
更新于2025-09-23 15:22:29
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Use of DEMs Derived from TLS and HRSI Data for Landslide Feature Recognition
摘要： This paper addresses the problems arising from the use of data acquired with two different remote sensing techniques—high-resolution satellite imagery (HRSI) and terrestrial laser scanning (TLS)—for the extraction of digital elevation models (DEMs) used in the geomorphological analysis and recognition of landslides, taking into account the uncertainties associated with DEM production. In order to obtain a georeferenced and edited point cloud, the two data sets require quite different processes, which are more complex for satellite images than for TLS data. The differences between the two processes are highlighted. The point clouds are interpolated on a DEM with a 1 m grid size using kriging. Starting from these DEMs, a number of contour, slope, and aspect maps are extracted, together with their associated uncertainty maps. Comparative analysis of selected landslide features drawn from the two data sources allows recognition and classification of hierarchical and multiscale landslide components. Taking into account the uncertainty related to the map enables areas to be located for which one data source was able to give more reliable results than another. Our case study is located in Southern Italy, in an area known for active landslides.
关键词： kriging,Geo-Eye-1,TLS,morphometric feature,HRSI,uncertainty,DEM
更新于2025-09-23 15:22:29
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Multi-fidelity EM simulations and constrained surrogate modelling for low-cost multi-objective design optimisation of antennas
摘要： In this study, a technique for low-cost multi-objective design optimisation of antenna structures has been proposed. The proposed approach is an enhancement of a recently reported surrogate-assisted technique exploiting variable-fidelity electromagnetic (EM) simulations and auxiliary kriging interpolation surrogate, the latter utilised to produce the initial approximation of the Pareto set. A bottleneck of the procedure for higher-dimensional design spaces is a large number of training data samples necessary to construct the surrogate. Here, the authors propose a procedure that allows us to confine the model domain to the subset spanned by the reference points, including the extreme Pareto-optimal designs obtained by optimising the individual objectives as well as an additional design that determines the Pareto front curvature. Setting up the surrogate in the constrained domain leads to a dramatic reduction of the required number of data samples, which results in lowering the overall cost of the optimisation process. Furthermore, the model domain confinement is generic, i.e. applicable for any number of design goals considered. The proposed technique is demonstrated using an ultra-wideband monopole antenna optimised with respect to three objectives. Significant reduction of the design cost is obtained as compared to the reference surrogate-assisted algorithm.
关键词： Pareto set,antenna structures,variable-fidelity EM simulations,kriging interpolation surrogate,multi-objective design optimisation,ultra-wideband monopole antenna
更新于2025-09-23 15:21:21
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[IEEE 2019 IEEE 8th International Conference on Advanced Optoelectronics and Lasers (CAOL) - Sozopol, Bulgaria (2019.9.6-2019.9.8)] 2019 IEEE 8th International Conference on Advanced Optoelectronics and Lasers (CAOL) - Metrological assessment of the indirect method of measuring the concentration of oxygen in the air
摘要： Greenhouse Gases Observing Satellite (GOSAT), which measures column-averaged carbon dioxide dry air mole fractions (Xco2) from space, provides new data sources to improve our understanding of carbon cycle. The available GOSAT data, however, have many gaps and are irregularly positioned, which make it difficult to directly interpret their scientific significance without further data analysis. Spatio-temporal geostatistical prediction approach can be used to fill the gaps for global and regional Xco2 mapping. It is important to choose a suitable spatio-temporal variogram model since modeling spatio-temporal correlation structure using variogram model is a critical step in the geostatistical prediction. In this study, three different flexible spatio-temporal variogram models, including the product-sum model, Cressie–Huang model, and Gneiting model, are used to model the spatio-temporal correlation structure of Xco2 over China, using the Atmospheric CO2 Observations from Space retrievals of the GOSAT (ACOS-GOSAT) Xco2 (v3.3) data products. The three models are compared and evaluated using the weighted mean square errors (WMSE) indicating the fitness between the empirical variogram surface and the theoretical variogram model, cross-validation for quantifying prediction accuracies, and the performance of the three models when used to fill the spatial gaps and generate Xco2 maps in 3-day temporal interval. The results indicate that 1) the model fitness of the commonly used product-sum model is slightly better than Cressie–Huang model and Gneiting model as indicated from WMSE, and 2) all the three models present similar summary statistics in cross-validation, all with a significantly high correlation coefficient of 0.92, and about 83% of prediction error within 2 ppm and about 53% within 1 ppm, and (3) differences between the mapping results using the three models are generally less than 0.1 ppm, and no significant differences can be identified. As a conclusion from the above results, all the three variogram models can precisely catch the empirical characteristics of the spatio-temporal correlation structure of Xco2 over China, and the precision and effectiveness of predicting and mapping Xco2 using the three models are almost the same.
关键词： spatio-temporal kriging,spatio-temporal variogram models,carbon dioxide,mapping,ACOS-GOSAT
更新于2025-09-16 10:30:52
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Robust Optimization of Nanoslit Array Sensor Based on Extraordinary Optical Transmission
摘要： A robust optimization approach for plasmonic periodic array sensor based on extraordinary optical transmission is proposed using Kriging surrogate models to reduce the effects of uncertainty in various manufacturing processes while maintaining sensor performance. For systematic design with reasonable computation cost, the author adopt the universal Kriging models whose regression function is a polynomial. The gradient index and the multiobjective genetic algorithm are chosen as a robustness measure and a global optimization tool, respectively. The figure of merit and the gradient index are set as two objective functions, and the design variables are the slit width and height, respectively. The optical properties of interest are investigated using the finite-element method. The numerical optimization results show the proposed scheme to be powerful and efficient in designing nanoslity array sensors based on extraordinary optical transmission with fabrication uncertainty.
关键词： gradient index,robust optimization,Plasmonics,surface plasmon polariton,multiobjective optimization,Kriging model
更新于2025-09-09 09:28:46
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KRIGING-PARETO FRONT APPROACH FOR THE MULTI-OBJECTIVE EXPLORATION OF METAMATERIAL TOPOLOGIES
摘要： Metamaterials provide the opportunity for designers to create customisable artificial materials by independently tailoring the electric and magnetic response of sub-wavelength geometric structures to electromagnetic energy. Due to the increased complexity of these geometric structures, exacerbated by the increased interest in generating inhomogeneous and anisotropic metamaterials, direct optimisation of these designs using conventional approaches often becomes impractical and limited. In order to alleviate this issue, we propose an alternative optimisation approach which exploits the Kriging methodology in conjunction with an adaptive sampling plan to simultaneously optimise multiple conflicting objectives. Results show the effectiveness of the outlined algorithm in calculating a uniform spread of optimal trade-off designs, balancing the real and imaginary components of the refractive index over a wide range of values.
关键词： Kriging,Metamaterials,Refractive Index,Multi-Objective Optimisation,Pareto front
更新于2025-09-09 09:28:46
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GIST-PM-Asia v1: development of a numerical system to improve particulate matter forecasts in South Korea using geostationary satellite-retrieved aerosol optical data over Northeast Asia
摘要： To improve short-term particulate matter (PM) forecasts in South Korea, the initial distribution of PM composition, particularly over the upwind regions, is primarily important. To prepare the initial PM composition, the aerosol optical depth (AOD) data retrieved from a geostationary equatorial orbit (GEO) satellite sensor, GOCI (Geostationary Ocean Color Imager) which covers a part of Northeast Asia (113–146? E; 25–47? N), were used. Although GOCI can provide a higher number of AOD data in a semicontinuous manner than low Earth orbit (LEO) satellite sensors, it still has a serious limitation in that the AOD data are not available at cloud pixels and over high-re?ectance areas, such as desert and snow-covered regions. To overcome this limitation, a spatiotemporal-kriging (STK) method was used to better prepare the initial AOD distributions that were converted into the PM composition over Northeast Asia. One of the largest advantages in using the STK method in this study is that more observed AOD data can be used to prepare the best initial AOD ?elds compared with other methods that use single frame of observation data around the time of initialization. It is demonstrated in this study that the short-term PM forecast system developed with the application of the STK method can greatly improve PM10 predictions in the Seoul metropolitan area (SMA) when evaluated with ground-based observations. For example, errors and biases of PM10 predictions decreased by ～ 60 and ～ 70%, respectively, during the ?rst 6 h of short-term PM forecasting, compared with those without the initial PM composition. In addition, the in?uences of several factors on the performances of the short-term PM forecast were explored in this study. The in?uences of the choices of the control variables on the PM chemical composition were also investigated with the composition data measured via PILS-IC (particle-into-liquid sampler coupled with ion chromatography) and low air-volume sample instruments at a site near Seoul. To improve the overall performances of the short-term PM forecast system, several future research directions were also discussed and suggested.
关键词： particulate matter,short-term forecast,geostationary satellite,spatiotemporal-kriging,aerosol optical depth
更新于2025-09-04 15:30:14