67 research outputs found
Simultaneous Spectral-Spatial Feature Selection and Extraction for Hyperspectral Images
In hyperspectral remote sensing data mining, it is important to take into
account of both spectral and spatial information, such as the spectral
signature, texture feature and morphological property, to improve the
performances, e.g., the image classification accuracy. In a feature
representation point of view, a nature approach to handle this situation is to
concatenate the spectral and spatial features into a single but high
dimensional vector and then apply a certain dimension reduction technique
directly on that concatenated vector before feed it into the subsequent
classifier. However, multiple features from various domains definitely have
different physical meanings and statistical properties, and thus such
concatenation hasn't efficiently explore the complementary properties among
different features, which should benefit for boost the feature
discriminability. Furthermore, it is also difficult to interpret the
transformed results of the concatenated vector. Consequently, finding a
physically meaningful consensus low dimensional feature representation of
original multiple features is still a challenging task. In order to address the
these issues, we propose a novel feature learning framework, i.e., the
simultaneous spectral-spatial feature selection and extraction algorithm, for
hyperspectral images spectral-spatial feature representation and
classification. Specifically, the proposed method learns a latent low
dimensional subspace by projecting the spectral-spatial feature into a common
feature space, where the complementary information has been effectively
exploited, and simultaneously, only the most significant original features have
been transformed. Encouraging experimental results on three public available
hyperspectral remote sensing datasets confirm that our proposed method is
effective and efficient
Optimization under Uncertainty Tool for Modeling Porous Lithium-Ion Batteries
The motivation of this tool is to optimize the performance of battery based on energy output. During the manufacturing process, several parameters such as cathode thickness, the volume concentration of cathode and radius of negative active materials are subject to uncertainty. To optimize battery performance, it is significant to quantify those uncertainties through electrochemical multiscale computer simulation. Hence, this tool will focus on the optimization of the performance of lithium-ion battery under different currents. This tool will consist of a module on visualized generator of uncertainty input, an electrochemical system simulator, a visualization of output optimization module. First, the uncertainty input generator provides the option for selecting one of several statistical models for the input parameter distributions. The method of moment matching and Gauss-Hermite quadrature formula are used to simulate distribution. Simulations are performed using an existing electrochemical system simulator that in turn uses the data obtained from the uncertainty input generator to simulate energy and power, which can be considered as a black-box function. The simulation results are quantified graphically through error bar plots that visualize the impact of the uncertainties. For the optimization part, the variation and optimization of power and energy densities as a function of current density of the battery electrode are presented using GPy package and the result are obtained and plotted under uncertain input parameters. Bayesian optimization will be utilized to determine the global optimization through the black-box function. Additional work may be needed to include more of the uncertain variables in this framework
Bidirectional Correlation-Driven Inter-Frame Interaction Transformer for Referring Video Object Segmentation
Referring video object segmentation (RVOS) aims to segment the target object
in a video sequence described by a language expression. Typical multimodal
Transformer based RVOS approaches process video sequence in a frame-independent
manner to reduce the high computational cost, which however restricts the
performance due to the lack of inter-frame interaction for temporal coherence
modeling and spatio-temporal representation learning of the referred object.
Besides, the absence of sufficient cross-modal interactions results in weak
correlation between the visual and linguistic features, which increases the
difficulty of decoding the target information and limits the performance of the
model. In this paper, we propose a bidirectional correlation-driven inter-frame
interaction Transformer, dubbed BIFIT, to address these issues in RVOS.
Specifically, we design a lightweight and plug-and-play inter-frame interaction
module in the Transformer decoder to efficiently learn the spatio-temporal
features of the referred object, so as to decode the object information in the
video sequence more precisely and generate more accurate segmentation results.
Moreover, a bidirectional vision-language interaction module is implemented
before the multimodal Transformer to enhance the correlation between the visual
and linguistic features, thus facilitating the language queries to decode more
precise object information from visual features and ultimately improving the
segmentation performance. Extensive experimental results on four benchmarks
validate the superiority of our BIFIT over state-of-the-art methods and the
effectiveness of our proposed modules
MSDH: matched subspace detector with heterogeneous noise
The matched subspace detector (MSD) is a classical subspace-based method for hyperspectral subpixel target detection. However, the model assumes that noise has the same variance over different bands, which is usually unrealistic in practice. In this letter, we relax the equal variance assumption and propose a matched subspace detector with heterogeneous noise (MSDH). In essence, the noise variances are different for different bands and they can be estimated by using iteratively reweighted least squares methods. Experiments on two benchmark real hyperspectral datasets demonstrate the superiority of MSDH over MSD for subpixel target detection
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