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After years of development, today's society is a prosperous era of the knowledge economy. Different from the previous period of development by consuming natural resources, people have realized that talents with technology and knowledge have become an important factor in promoting the development of social production. That is to say, the improvement of population quality has not only an impact on its own development but also an important impact on the comprehensive strength and competitiveness of its location. Population quality is the stipulation of the population in terms of quality, also known as population quality. It includes ideological quality, cultural quality, physical quality, and so on. Data fusion is a technology for the comprehensive analysis and processing of information from multiple sources. Therefore, this paper comprehensively considers the influence of ideological and moral quality and population structure. Under the algorithm of fusion data, the impact of population quality on residents' income is explored. This paper uses the analytic hierarchy process to weight each indicator and calculate the comprehensive score. This paper ranks the quality of population and economic development of each province, city, and autonomous region in China according to their high scores. The results of the experiments in this paper indicate a relevant analysis with the income distribution of the nation's residents, and the correlation is −0.9493. There exists a negative relation between the overall quality of Chinese residents and the income gap. [ABSTRACT FROM AUTHOR]

Voltage sag is the most serious power quality problem in the three-phase symmetrical power system. The influence of multiple factors on the voltage sag level and low computational efficiency also pose challenges to the prediction of residual voltage amplitude of voltage sag. This paper proposes a voltage sag amplitude prediction method based on data fusion. First, the multi-dimensional factors that influence voltage sag residual voltage are analyzed. Second, these factors are used as input, and a model for predicting voltage sag residual voltage based on data fusion is constructed. Last, the model is trained and debugged to enable it to predict the voltage sag residual voltage. The accuracy and feasibility of the method are verified by using the actual power grid data from East China. [ABSTRACT FROM AUTHOR]

There are a variety of land cover products generated from remote-sensing images. However, misclassification errors in individual products and inconsistency among them undermine their utilities for research and other applications. While it is worth developing advanced pattern classifiers and utilizing the images of finer spatial, temporal, and/or spectral resolution for increased classification accuracy, it is also sensible to increase map classification accuracy through effective map fusion by exploiting complementarity among multi-source products over a study area. This paper presents a novel fusion method that works by weighting multiple source products based on their map-reference cover type transition probabilities, which are predicted using random forest for individual map pixels. The proposed method was tested and compared with three alternatives: consensus-based weighting, random forest, and locally modified Dempster–Shafer evidential reasoning, in a case study, over Shaanxi province, China. For this case study, three types of land cover products (GlobeLand30, FROM-GLC, and GLC_FCS30) of two nominal years (2010 and 2020) were used as the base maps for fusion. Reference sample data for model training and testing were collected following a robust stratified random sampling design that allows for augmenting reference data flexibly. Accuracy assessments show that overall accuracies (OAs) of fused land cover maps have been improved (1~9% in OAs), with the proposed method outperforming other methods by 2~8% in OAs. The proposed method does not need to have the base products' classification systems harmonized beforehand, thus being robust and highly recommendable for fusing land cover products. [ABSTRACT FROM AUTHOR]

Public-Private-Partnership (PPP) as an efficient mode to provide public services through the government and social capital's cooperation has been in China for more than 30 years. In this paper, we propose an approach to evaluate PPP's advancement in different areas based on the subjective and objective information fusion. At first, we establish an index system from the perspective of the stakeholder. Then, considering that double hierarchy hesitant fuzzy linguistic term set (DHHFLTS) that has two hierarchies of linguistic term sets can describe the subjective linguistic information more accurately, it is applied in the paper to depict the subjective information. By applying the entropy of the DHHFLTS, a programming model is proposed to derive the attribute weight through combining subjective evaluation with objective data. In addition, we develop the double hierarchy hesitant fuzzy linguistic PROMETHEE combining the subjective and objective information (DHHFL-PROMETHEE-S&O) method. At last, we illustrate the index system and the method with the PPP's advancement evaluation problem, and we can find the best choice based on the ranking result. Meanwhile, we also find that the objective information and the subjective information are complementary in the evaluation process. [ABSTRACT FROM AUTHOR]

Many calculation methods have been developed to forecast carbon emissions (CE). These methods can be classified into two categories: time series prediction and variables regression. However, time series prediction cannot fully use all CE‐related information and variables regression can only predict CE by knowing other variables in advance. To solve these problems, KLS is proposed in this paper which is a fusion of Kalman filter (KF), long short‐term memory (LSTM), and support vector machine (SVM). LSTM is used to predict CE as a time series, and 10 of 14 variables are selected by ridge regression (RR) to regress CE by SVM. Finally, KF is used to integrate the results of LSTM and SVM based on their variances. Overall, statistical filtering and deep learning algorithms are used in this paper, which achieved the fusion of time series prediction and variables regression. To confirm the effectiveness of KLS, we trained KLS model by CE from 1965 to 2005 and tested the model by the data from 2006 to 2014. The results showed KLS was more accurate than other four existing methods. Finally, we predicted the CE of China in next decade. [ABSTRACT FROM AUTHOR]

According to the location of sensors, there are two main ways to obtain lightning detection data: satellite-based and ground-based, each have its own advantages and disadvantages, the assessment of data quality is an important issue. In this paper, based on comprehensive analysis of the data from satellite- and ground-based detector (2013-2016), a sensitivity test is designed, and a scientific comparison method is proposed. From multiple dimensions, the differences and similarities between them, the sources of error and the method of correcting are investigated. Through the comparative analysis, we can get more information on spatial and temporal lightning distribution characteristics in China the following conclusions are drawn: 1. satellite- and ground-based lightning detection data over China show good consistency during 2013-2016, and with the development of technology and the improvement of detection stations layout, the proportion of matches go up steadily. Furthermore, limited by geographical factors, the layout of China Lightning Detection Network (CLDN) is uneven, the East is comparatively dense, and West is comparatively sparse, so the matching ratio is not exactly the same. We also noticed that Lightning Imaging Sensor (LIS) cannot continuously monitor the evolution process of lightning, and it's a reason that the proportion of matches are not very high in general. 2. Matching proportion shows obvious time diversity. It presented a single peak in August. Matching proportion among seasons as follows: summer-autumn-spring-winter (from high to low), in particular, it had less variability during winter and spring than summer and autumn, reflecting the characters of strong convective weather in China. 3. Due to the different detection principles, the amount of lightning events that occur at "night" detected by LIS, much more than lightning events that occur in the "day" time. While the situation is completely different for CLDN, there was no significant difference in the amount of lightning that occurs between day and night, and there is still a lot of space for improvement. 4. Sample data revealed that larger radiance LIS signals did not mean a higher matching ratio, this is different from conventional wisdom. It may imply that satellite-based detection and ground-based detection are sensitive to lightning signals with different radiation levels. The work of this paper also provides the basis for the quality evaluation and fusion analysis of the satellite-based vs. ground-based multi-source lightning detection data. [ABSTRACT FROM AUTHOR]

For online video service providers, the accurate prediction of video popularity directly impacts their advertisement revenue, bandwidth provisioning policy and copyright procurement decision. Most of previous approaches only utilize data from a single platform (e.g., view history) for prediction. However, such approaches cannot provide satisfactory prediction accuracy, as video popularity may be affected by many influential features dispersed over multiple platforms. In this paper, we focus on the popularity prediction of online movies and propose a prediction framework called DeepFusion to fuse salient features from multiple platforms so as to boost the accuracy of popularity prediction of online movies. For this purpose, we extract influential factors from Douban, which is a leading movie rating website in China, and Youku, which is one of the largest online video service providers in China. Considering the complexity incurred by numerous parameters, we choose to feed these influential factors into deep neural networks for prediction and thus avoid the limitation of traditional predictive models. Compared with previous approaches, our solution can significantly improve the prediction accuracy over 40%. Moreover, even for movies without any historical views, our approach can also well capture their popular trends and overcome the cold-start problem. [ABSTRACT FROM AUTHOR]

Satellite precipitation products can help improve precipitation estimates where ground-based observations are lacking; however, their relative accuracy and applicability in data-scarce areas remain unclear. Here, we evaluated the accuracy of different satellite precipitation datasets for the Lancang River Basin, Western China, including the Tropical Rainfall Measuring Mission (TRMM) 3B42RT, the Global Precipitation Measurement Integrated Multi-satellitE Retrievals (GPM IMERG), and Fengyun 2G (FY-2G) datasets. The results showed that GPM IMERG and FY-2G are superior to TRMM 3B42RT for meeting local research needs. A subsequent bias correction on these two datasets significantly increased the correlation coefficient and probability of detection of the products and reduced error indices such as the root mean square error and mean absolute error. To further improve data quality, we proposed a novel correction–fusion method based on window sliding data correction and Bayesian data fusion. Specifically, the corrected FY-2G dataset was merged with GPM IMERG Early, Late, and Final Runs. The resulting FY-Early, FY-Late, and FY-Final fusion datasets showed high correlation coefficients, strong detection performances, and few observation errors, thereby effectively extending local precipitation data sources. The results of this study provide a scientific basis for the rational use of satellite precipitation products in data-scarce areas, as well as reliable data support for precipitation forecasting and water resource management in the Lancang River Basin. [ABSTRACT FROM AUTHOR]

The satellite Fengyun 3C(FY3C) launched in 2013 and carried a global navigation satellite system (GNSS) occultation sounder, which is the first BDS/GPS compatible radio occultation sounder in the world and records both GPS and BDS measurements. It provides an opportunity for investigating the precision realtime orbit determination based on space‐borne GPS/BDS measurements. In order to realize the real‐time orbit determination based on space‐borne GPS/BDS measurements with decimeter‐level accuracy, this paper carries out in‐depth research in the following aspects. Firstly, the real‐time orbit determination mathematical model based on the space‐borne GPS/BDS carrier phase observations is introduced. Then the properties of the errors in the signal’s propagation path that originates from GPS/BDS broadcast ephemeris are analyzed, and the signal‐in ‐propagation path error(SIPPE) statistics of different kinds of GPS/BDS satellites are also presented. Based on the analysis, a pseudo‐ambiguity is modeled as a stochastic process and estimated in the real‐time orbit determmination(RTOD) filter to absorb the SIPPE error, and then the decimeter‐ level accuracy can be realized. The space‐borne GPS/BDS data from China’ s FY3C satellite are em ‐ ployed for the simulative RTOD test using the SATODS software. Results have demonstrated that the position and velocity accuracy of 30 cm and 0.3 mm/s, respectively, are achieved when using GPS/BDS carrierphase data and broadcast ephemeris. Although the accuracy of BDS broadcast ephemeris is obviously worse than that of GPS, orbit results of the GPS/BDS fusion solution with reasonable stochastic models for pseudo‐ambiguities will be slightly superior to that using single GPS data. For example, when the FY3C satellite flew over Asia/Pacific region where more BDS satellites can be tracked, the orbit accuracy can be improved by 10% with the GPS/BDS fusion solution. [ABSTRACT FROM AUTHOR]

Urban expressways, as the backbone of a city's transportation network, are critical for reducing traffic congestion and improving transportation efficiency of the whole network. The estimation of traffic states and emissions for urban expressways supports traveler information provision and system-wide traffic management. This paper aims to modify the extended generalized Treiber-Helbing filter (EGTF) to fuse GPS data (probe vehicles) and traditional traffic data (loop detectors), so as to enhance more accurate estimations of traffic states and emissions on urban expressways. The speed field is first reconstructed based on heterogeneous data, and then travel time and emissions are estimated using a virtual trajectory method and the VT-Micro model, respectively. The algorithm is applied to a real-world case study for an urban expressway in Beijing, China. After the parameter tuning, the proposed algorithm is compared with existing algorithms from the literature. Numerical results show that data fusion using the proposed algorithm could make better use of heterogeneous data and increase the accuracy of travel time and emissions estimations. [ABSTRACT FROM AUTHOR]

The local climate zone (LCZ) scheme is of great value for urban heat island (UHI) effect studies by providing a standard classification framework to describe the local physical structure at a global scale. In recent years, with the rapid development of satellite imaging techniques, both multi-spectral (MS) and synthetic aperture radar (SAR) data have been widely used in LCZ classification tasks. However, the fusion of MS and SAR data still faces the challenges of the different imaging mechanisms and the feature heterogeneity. In this study, to fully exploit and utilize the features of SAR and MS data, a data-grouping method was firstly proposed to divide multi-source data into several band groups according to the spectral characteristics of different bands. Then, a novel network architecture, namely Multi-source data Fusion Network for Local Climate Zone (MsF-LCZ-Net), was introduced to achieve high-precision LCZ classification, which contains a multi-branch CNN for multi-modal feature extraction and fusion, followed by a classifier for LCZ prediction. In the proposed multi-branch structure, a split–fusion-aggregate strategy was adopted to capture multi-level information and enhance the feature representation. In addition, a self channel attention (SCA) block was introduced to establish long-range spatial and inter-channel dependencies, which made the network pay more attention to informative features. Experiments were conducted on the So2Sat LCZ42 dataset, and the results show the superiority of our proposed method when compared with state-of-the-art methods. Moreover, the LCZ maps of three main cities in China were generated and analyzed to demonstrate the effectiveness of our proposed method. [ABSTRACT FROM AUTHOR]

Modern satellite and aerial imagery outcomes exhibit increasingly complex types of ground objects with continuous developments and changes in land resources. Single remote-sensing modality is not sufficient for the accurate and satisfactory extraction and classification of ground objects. Hyperspectral imaging has been widely used in the classification of ground objects because of its high resolution, multiple bands, and abundant spatial and spectral information. Moreover, the airborne light detection and ranging (LiDAR) point-cloud data contains unique high-precision three-dimensional (3D) spatial information, which can enrich ground object classifiers with height features that hyperspectral images do not have. Therefore, the fusion of hyperspectral image data with airborne LiDAR point-cloud data is an effective approach for ground object classification. In this paper, the effectiveness of such a fusion scheme is investigated and confirmed on an observation area in the middle parts of the Heihe River in China. By combining the characteristics of hyperspectral compact airborne spectrographic imager (CASI) data and airborne LiDAR data, we extracted a variety of features for data fusion and ground object classification. Firstly, we used the minimum noise fraction transform to reduce the dimensionality of hyperspectral CASI images. Then, spatio-spectral and textural features of these images were extracted based on the normalized vegetation index and the gray-level co-occurrence matrices. Further, canopy height features were extracted from airborne LiDAR data. Finally, a hierarchical fusion scheme was applied to the hyperspectral CASI and airborne LiDAR features, and the fused features were used to train a residual network for high-accuracy ground object classification. The experimental results showed that the overall classification accuracy was based on the proposed hierarchical-fusion multiscale dilated residual network (M-DRN), which reached an accuracy of 97.89%. This result was found to be 10.13% and 5.68% higher than those of the convolutional neural network (CNN) and the dilated residual network (DRN), respectively. Spatio-spectral and textural features of hyperspectral CASI images can complement the canopy height features of airborne LiDAR data. These complementary features can provide richer and more accurate information than individual features for ground object classification and can thus outperform features based on a single remote-sensing modality. [ABSTRACT FROM AUTHOR]

The China GaoFen-5 (GF-5) satellite sensor, which was launched in 2018, collects hyperspectral data with 330 spectral bands, a 30 m spatial resolution, and 60 km swath width. Its competitive advantages compared to other on-orbit or planned sensors are its number of bands, spectral resolution, and swath width. Unfortunately, its applications may be undermined by its relatively low spatial resolution. Therefore, the data fusion of GF-5 with high spatial resolution multispectral data is required to further enhance its spatial resolution while preserving its spectral fidelity. This paper conducted a comprehensive evaluation study of fusing GF-5 hyperspectral data with three typical multispectral data sources (i.e., GF-1, GF-2 and Sentinel-2A (S2A)), based on quantitative metrics, classification accuracy, and computational efficiency. Datasets on three study areas of China were utilized to design numerous experiments, and the performances of nine state-of-the-art fusion methods were compared. Experimental results show that LANARAS (this method was proposed by lanaras et al.), Adaptive Gram–Schmidt (GSA), and modulation transfer function (MTF)-generalized Laplacian pyramid (GLP) methods are more suitable for fusing GF-5 with GF-1 data, MTF-GLP and GSA methods are recommended for fusing GF-5 with GF-2 data, and GSA and smoothing filtered-based intensity modulation (SFIM) can be used to fuse GF-5 with S2A data. [ABSTRACT FROM AUTHOR]

Well-estimated air pollutant concentration fields are critically important to compensate for observations that are only sparsely available, especially over non-urban areas. Previous data fusion methods generally used statistical models to relate observations of target variables to proxy data and supporting variables at known stations. In this study, we developed a new data fusion paradigm by designing a deep-learning model framework and workflow to learn multivariable spatial correlations from chemical transport model (CTM) simulations, before using it to estimate PM 2.5 reanalysis fields from station observations. The model was composed of two modules as an explainable PointConv operation to pre-process isolated observations and a regression grid-to-grid network to build correlations among multiple variables. The model was trained with only CTM simulations and supporting geographical covariates. The trained model was evaluated in two aspects of (1) reproducing raw PM 2.5 CTM simulations and (2) generating reanalysis and fused PM 2.5 fields. First, the model was able to reproduce the CTM simulations well on a full domain from sampled CTM data items at sparse locations with an average R2=0.94 and RMSE = 4.85 µgm-3. Second, the fused PM 2.5 fields estimated from observations achieved a good performance with R2=0.77 (RMSE = 14.29 µgm-3) and R2=0.84 (RMSE = 12.96 µgm-3) respectively evaluated at the stringent city level and station level. The generated reanalysis PM 2.5 fields have complete spatial coverage within the modeling domain. One significant benefit of the fusion framework is that the model training does not rely on observations, which can be used to predict PM 2.5 fields in newly set up observation networks such as those using portable sensors. Meanwhile, in the prediction procedure, only station observations are used along with supporting covariates. The fusion model has high computing efficiency (< 1 s d -1) due to acceleration using a graphical processing unit (GPU). As an alternative to generate chemical reanalysis fields, the method can be readily implemented in near-real time and be universally applied for other simulated variables with measurements available. [ABSTRACT FROM AUTHOR]

Abstract: At present, underground urban metro construction accidents in China are rising with the rapid growth of urbanization and infrastructure investment. Real-time safety and risk management during urban metro construction has become extremely important but is very difficult, time-consuming and unreliable due to the lack of information and experienced managers. This paper presents the development and application of a web-based system for safety risk early warning in urban metro construction. A hybrid data fusion model based on multisource information (monitoring measurements, calculated predictions, and visual inspections) is employed to imitate human experts to give safety risk assessment and early warnings automatically. In addition, it has significantly improved information collection, sharing and communication by establishing a collaborative platform instead of traditional manual management. The system has been successfully applied to several metro construction projects and has perfected the safety management performance in the cities of Wuhan, Shenyang, Zhengzhou and Kunming in China. [Copyright &y& Elsevier]

Increasing the area of planted forests is rather important for compensation the loss of natural forests and slowing down the global warming. Forest growing stem volume (GSV) is a key indicator for monitoring and evaluating the quality of planted forest. To improve the accuracy of planted forest GSV located in south China, four L-band ALOS PALSAR-2 quad-polarimetric synthetic aperture radar (SAR) images were acquired from June to September with short intervals. Polarimetric characteristics (un-fused and fused) derived by the Yamaguchi decomposition from time series SAR images with different intervals were considered as independent variables for the GSV estimation. Then, the general linear model (GLM) obeyed the exponential distribution were proposed to retrieve the stand-level GSV in plantation. The results show that the un-fused power of double bounce scatters and four fused variables derived from single SAR image is highly sensitive to the GSV, and these polarimeric characteristics derived from the time series images more significantly contribute to improved estimation of GSV. Moreover, compared with the estimated GSV using the semi-exponential model, the employed GLM model with less limitations and simple algorithm has a higher saturation level (nearly to 300 m3/ha) and higher sensitivity to high forest GSV values than the semi-exponential model. Furthermore, by reducing the external disturbance with the help of time average, the accuracy of estimated GSV is improved using fused polarimeric characteristics, and the estimation accuracy of forest GSV was improved as the images increase. Using the fused polarimetric characteristics (Dbl×Vol/Odd) and the GLM, the minimum RRMSE was reduced from 33.87% from single SAR image to 24.42% from the time series SAR images. It is implied that the GLM is more suitable for polarimetric characteristics derived from the time series SAR images and has more potential to improve the planted forest GSV. [ABSTRACT FROM AUTHOR]

The methods for accurately fusing medium- and high-spatial-resolution satellite reflectance are vital for monitoring vegetation biomass, agricultural irrigation, ecological processes and climate change. However, the currently existing fusion methods cannot accurately capture the temporal variation in reflectance for heterogeneous landscapes. In this study, we proposed a new method, the spatial and temporal reflectance fusion method based on the unmixing theory and a fuzzy C-clustering model (FCMSTRFM), to generate Landsat-like time-series surface reflectance. Unlike other data fusion models, the FCMSTRFM improved the similarity of pixels grouped together by combining land cover maps and time-series data cluster algorithms to define endmembers. The proposed method was tested over a 2000 km2 study area in Heilongjiang Provence, China, in 2017 and 2018 using ten images. The results show that the accuracy of the FCMSTRFM is better than that of the popular enhanced spatial and temporal adaptive reflectance fusion model (ESTARFM) (correlation coefficient (R): 0.8413 vs. 0.7589; root mean square error (RMSE): 0.0267 vs. 0.0401) and the spatial-temporal data fusion approach (STDFA) (R: 0.8413 vs. 0.7666; RMSE: 0.0267 vs. 0.0307). Importantly, the FCMSTRFM was able to maintain the details of temporal variations in complicated landscapes. The proposed method provides an alternative method to monitor the dynamics of land surface variables over complicated heterogeneous regions. [ABSTRACT FROM AUTHOR]