Object-oriented remote sensing image classification is becoming more and more popular because it can integrate spatial information from neighboring regions of different shapes and sizes into the ...classification procedure to improve the mapping accuracy. However, object identification itself is difficult and challenging. Superpixels, which are groups of spatially connected similar pixels, have the scale between the pixel level and the object level and can be generated from oversegmentation. In this paper, we establish a new classification framework using a superpixel-based graphical model. Superpixels instead of pixels are applied as the basic unit to the graphical model to capture the contextual information and the spatial dependence between the superpixels. The advantage of this treatment is that it makes the classification less sensitive to noise and segmentation scale. The contribution of this paper is the application of a graphical model to remote sensing image semantic segmentation. It is threefold. 1) Gradient fusion is applied to multispectral images before the watershed segmentation algorithm is used for superpixel generation. 2) A probabilistic fusion method is designed to derive node potential in the superpixel-based graphical model to address the problem of insufficient training samples at the superpixel level. 3) A boundary penalty between the superpixels is introduced in the edge potential evaluation. Experiments on three real data sets were conducted. The results show that the proposed method performs better than the related state-of-the-art methods tested.
A textured urban 3D mesh is an important part of 3D real scene technology. Semantically segmenting an urban 3D mesh is a key task in the photogrammetry and remote sensing field. However, due to the ...irregular structure of a 3D mesh and redundant texture information, it is a challenging issue to obtain high and robust semantic segmentation results for an urban 3D mesh. To address this issue, we propose a semantic urban 3D mesh segmentation network (MeshNet) with sparse prior (SP), named MeshNet-SP. MeshNet-SP consists of a differentiable sparse coding (DSC) subnetwork and a semantic feature extraction (SFE) subnetwork. The DSC subnetwork learns low-intrinsic-dimensional features from raw texture information, which increases the effectiveness and robustness of semantic urban 3D mesh segmentation. The SFE subnetwork produces high-level semantic features from the combination of features containing the geometric features of a mesh and the low-intrinsic-dimensional features of texture information. The proposed method is evaluated on the SUM dataset. The results of ablation experiments demonstrate that the low-intrinsic-dimensional feature is the key to achieving high and robust semantic segmentation results. The comparison results show that the proposed method can achieve competitive accuracies, and the maximum increase can reach 34.5%, 35.4%, and 31.8% in mR, mF1, and mIoU, respectively.
Microglia-mediated neuroinflammation is important in the pathogenesis of neonatal hypoxic-ischemic encephalopathy (HIE). This study aimed to investigate the expression of microRNA-384 (miR-384) in ...HIE newborns and evaluate the clinical and functional role of miR-384 in HIE diagnosis and neuroinflammation. The expression of miR-384 was estimated using quantitative real-time PCR. The levels of proinflammatory cytokines were examined using ELISA. Receiver operating characteristic (ROC) analysis was applied to evaluate the diagnostic performance of miR-384. The oxygen–glucose deprivation (OGD) experiment was adopted to activate primary neonatal microglia. A putative target of miR-384 was analyzed by bioinformatics prediction and a luciferase reporter assay. The expression of miR-384 was decreased in the serum of HIE newborns and OGD-induced activated microglia. Serum miR-384 had relatively high diagnostic accuracy for the screening of HIE cases from healthy newborns and the differentiation between newborns with different HIE severities. The OGD-induced increase in microglial neuroinflammation was significantly attenuated by the overexpression of miR-384, and AKT3, as a downstream target of miR-384, was inhibited by miR-384 in activated microglia. The data of this study demonstrated that decreased serum miR-384 expression may be a novel noninvasive biomarker for the diagnosis and progression of neonatal HIE. miR-384 can inhibit the neuroinflammation in activated microglia, which may be mediated by targeting AKT3.
Automatic registration of unordered point clouds is the prerequisite for urban reconstruction. However, most of the existing technologies still suffer from some limitations. On one hand, most of them ...are sensitive to noise and repetitive structures, which makes them infeasible for the registration of large-scale point clouds. On the other hand, most of them dealing with point clouds with limited overlaps and unpredictable location. All these problems make it difficult for registration technology to obtain qualified results in outdoor point cloud. To overcome these limitations, this paper presents a grid graph-based point cloud registration (GGR) algorithm to align pairwise scans. First, point cloud is divided into a set of 3D grids. We propose a voting strategy to measure the similarity between two grids based on feature descriptor, transforming the superficial correspondence into 3D grid expression. Next, a graph matching is proposed to capture the spatial consistency from putative correspondences, and graph matching hierarchically refines the corresponding grids until obtaining point-to-point correspondences. Comprehensive experiments demonstrated that the proposed algorithm obtains good performance in terms of successful registration rate, rotation error, translation error, and outperformed the state-of-the-art approaches.
Conditional random fields (CRF) have been introduced to remote sensing image classification recently to integrate contextual information into remote sensing classification. It employs the spatial ...property on both pixel's spectral data and labels. However, this leads to a large number of model parameters to train. In this letter, the training efficiency is improved by modifying the conventional CRF model. At the same time, a class boundary constraint is imposed into this framework to avoid over correction. The advantages of the developed method are demonstrated in the experimental results using real remotely sensed data.
This paper studies a novel and practical distributed flexible assembly permutation flowshop scheduling problem with makespan criterion, which has attracted wide attention due to important ...applications in modern manufacturing. The problem integrates two machine environments of distributed production and flexible assembly, which can process and assemble the jobs into customized products. We first present a mixed integer linear programming model to characterize the problem essence and to solve small-size problems. Due to the NP-hard, we further propose an efficient memetic algorithm, which consists of a global exploration optimizer designed based on improved social spider optimization and two local exploitation optimizers designed based on meta-Lamarckian learning and simplex search, respectively. To implement the algorithm, a problem-specific encoding scheme is presented. Algorithmic parameters are calibrated by a design of experiments, and a comprehensive computational campaign is conducted to evaluate the performance of the mathematical model and algorithms. Statistical results show that their problem-solving abilities are effective, and especially the proposed memetic algorithm outperforms the existing algorithms significantly.
This paper first focuses on the study of the relationship between the urban heat island (UHI) and the selected physical variables (percentage of urban surface covers, Normalized Difference Vegetation ...Index (NDVI)) and social variables (population density (PDEN)), and then concentrates on the study of the relationship between UHI and the landscape spatial geometric patterns. The researched results discover that urban Land Surface Temperature (LST) is not only impacted by land cover composition, i.e. land use/cover, which is expressed in this paper as the PURB (commerce/industry/transportation), but also its spatial geometric configuration, i.e. various landscape geometric pattern metrics, which in this paper are expressed by compositional percentage of landscape area (PLAND), configurational edge density (ED), patch density (PD), landscape shape index (LSI), clumpiness index (CI), and Shannon's diversity index (SHDI). The results show that the proportion of vegetation coverage out of a tract impacts its contribution to an entire UHI in Washington District of Columbia (DC), in particular, interspersing vegetation within a tract is capable of making a stronger mitigation effect to UHI than its concentrated form. Thus, a scatter spatial arrangement and distribution of vegetation is proposed to mitigate UHI effect.
Conventional rational polynomial coefficients (RPC)-based orthorectification methods are unable to satisfy the demands of timely responses to terrorist attacks and disaster rescue. To accelerate the ...orthorectification processing speed, we propose an on-board orthorectification method, i.e., a field-programmable gate array (FPGA)-based fixed-point (FP)-RPC orthorectification method. The proposed RPC algorithm is first modified using fixed-point arithmetic. Then, the FP-RPC algorithm is implemented using an FPGA chip. The proposed method is divided into three main modules: a reading parameters module, a coordinate transformation module, and an interpolation module. Two datasets are applied to validate the processing speed and accuracy that are achievable. Compared to the RPC method implemented using Matlab on a personal computer, the throughputs from the proposed method and the Matlab-based RPC method are 675.67 Mpixels/s and 61,070.24 pixels/s, respectively. This means that the proposed method is approximately 11,000 times faster than the Matlab-based RPC method to process the same satellite images. Moreover, the root-mean-square errors (RMSEs) of the row coordinate (Δ
), column coordinate (Δ
), and the distance Δ
are 0.35 pixels, 0.30 pixels, and 0.46 pixels, respectively, for the first study area; and, for the second study area, they are 0.27 pixels, 0.36 pixels, and 0.44 pixels, respectively, which satisfies the correction accuracy requirements in practice.
To evaluate the wave energy conditions along the coastal waters of Beibu Gulf, China, the SWAN (Simulated WAve Nearshore) model is used to estimate the wave field using 20 years of wind field data. ...The results show that (1) the wave field conditions are promising, for example, in the coastal waters off Guangxi, where the annually averaged significant wave height and peak wave period are approximately 0.45 m and 3.0 s, respectively, and especially along the coast of Hainan Island, where the annually averaged significant wave height and peak wave period are approximately 0.60 m and 3.7 s, respectively; (2) The major direction of wave energy is west or southwest of Guangxi and northeast or northeast by north of Hainan Island; and (3) The wave energy conditions show clear seasonal variations. The maximum storages are approximately 4.48 × 103 kWh/m off Guangxi and approximately 8.02 × 103 kWh/m off Hainan Island. In addition, the wave energy is more stable in the coastal waters off Guangxi than off Hainan Island. Finally, Weizhou Island and the southern coast of Hainan Island are suggested as potential wave power sites.
•Wave fields covering 20 years are estimated by SWAN in Beibu Gulf, China.•Wave energy along the coastal waters are assessed.•Weizhou Island and southern of Hainan Island are suitable for wave power generation.
The active components of ginseng, such as ginsenosides and polysaccharides, have high therapeutic value in treating cancer, decreasing obesity, and enhancing immunity. However, simple primary ginseng ...treatment cannot maximize this medicinal potential. Therefore, in this study,
was co-fermented with multi-enzyme-coupling probiotics to obtain a fermentation broth with higher levels of ginsenosides, polysaccharides, and probiotics. When compared to other treatment methods for cyclophosphamide-induced immunosuppression in mice, the results reveal that the
fermentation broth treated with multi-enzyme-coupling probiotics could significantly improve the immune function of immunosuppressive mice and restore intestinal flora stability. Overall, this processing method will provide a novel strategy for promoting the application of ginseng and the relief of immunosuppression.
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