- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Non-uniform distribution of sulfur vapor and its influence on Cu2ZnSnS4 thin film solar cells
摘要： Deep neural network with recurrent structure was proposed in the recent years and has been applied to time series forecasting. Many optimization algorithms are developed under the assumption of invariant and stationary data distributions, which is invalid for the non-stationary data. A novel optimization algorithm for modeling non-stationary time series is proposed in this paper. A moving window and exponential decay weights are used in this algorithm to eliminate the effects of the history gradients. The regret bound of the new algorithm is analyzed to ensure the convergency of the calculation. Simulations are done on short-term power load data sets, which are typically non-stationary. The results are superior to the existing optimization algorithms.
关键词： Recursive neural network,ADAptive Moment estimation,Time series forecast,Non-stationary data,Optimization method
更新于2025-09-11 14:15:04
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Resistive Switching and Charge Transport in Laser-Fabricated Graphene Oxide Memristors: A Time Series and Quantum Point Contact Modeling Approach
摘要： This work investigates the sources of resistive switching (RS) in recently reported laser-fabricated graphene oxide memristors by means of two numerical analysis tools linked to the Time Series Statistical Analysis and the use of the Quantum Point Contact Conduction model. The application of both numerical procedures points to the existence of a filament connecting the electrodes that may be interrupted at a precise point within the conductive path, resulting in resistive switching phenomena. These results support the existing model attributing the memristance of laser-fabricated graphene oxide memristors to the modification of a conductive path stoichiometry inside the graphene oxide.
关键词： graphene oxide,memristor,autocovariance,RRAM,variability,laser,time series modeling
更新于2025-09-11 14:15:04
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[IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia, Spain (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Innovative Exploitation of Long, Dense and Coherent Insar Sentinel-L Time Series forland Survey and Classification
摘要： During the last three years the European Space Agency (ESA) Sentinel-1 (S1) mission, gathered large collections of Synthetic Aperture Radar (SAR) data over the Earth’s surface. A wide variety of SAR applications have benefited from the use of large stacks of S1 products. Surface displacement monitoring, land cover mapping, crop monitoring or flood detection are successful examples that are being increasingly employed by both public administrations and/or private companies in order to improve the productivity of processes (mining or oil & gas sector) and to provide a rapid response in front of disaster risk management (earthquakes, floods, etc.). The features of S1 sensor, i.e, short revisiting time, wide area processing, high slant-range resolution, improved radiometric accuracy or the availability to work with dual polarimetric data, benefits the reliability of all these applications. In this paper the benefits of multi-temporal SAR applications based on DARES TECHNOLOGY experience using S1 sensor is presented over three classic SAR applications.
关键词： SAR,coherence,InSAR,time series,vegetation,classification,land-cover,Sentinel-1,mapping
更新于2025-09-10 09:29:36
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[IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia, Spain (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Soil Moisture Estimation by Linear Regression from Smap Polarimetric Radar Data with Aquarius Derived Coefficients
摘要： Algorithms for soil moisture estimation from radars conventionally use substantial amounts of ancillary data to parametrize complex electromagnetic models. In contrast, we describe radar data of a vegetated scene as a linear function of soil moisture. This eliminates the dependence on ancillary data while providing reasonable global soil moisture estimates. We derive two polarization dependent coefficients of a linear model on the basis of spatial and temporal similarity at a global scale from nearly 4 years of L-band Aquarius radar and radiometer derived soil moisture data. These global coefficients are then used to derive soil moisture from 2.5 months of L-band SMAP radar data. The resulting soil moisture estimates are evaluated with the SMAP Level 2 radiometer-only soil moisture product.
关键词： Soil moisture,synthetic aperture radar (SAR),time series,polarimetric radar
更新于2025-09-10 09:29:36
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[IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia, Spain (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Surface Deformation Mapping of Italy Through the P-Sbas Dinsar Processing of Sentinel-L Data in a Cloud Computing Environment
摘要： In this work we implement a completely automatic interferometric processing chain, based on the well-known advanced DInSAR algorithm referred to as Parallel Small BAseline Subset (P-SBAS), for the generation of Sentinel-1 (S-1) Interferometric Wide Swath (IWS) deformation mean velocity maps and time-series of very wide areas, implemented within the Amazon Web Services (AWS) Elastic Cloud Compute environment. Our processing chain consists of the initial data query to the S-1 archive that we created on the AWS S3 storage, then the data transfer to the AWS computing nodes, the data processing and, finally, the transfer of the obtained interferometric results back to the original S3 storage. In order to demonstrate the capability of the implemented Cloud-based processing chain to deal with massive amount of data, we focus our analysis on the whole Italian territory by processing all the available data acquired both from ascending and descending orbits within the October 2014 – March 2017 time interval. As final result we combine the retrieved LOS displacements in order to compute the mean velocity maps and time-series of the vertical and East-West surface deformation components.
关键词： P-SBAS,Sentinel-1,Cloud Computing,DInSAR,deformation time-series
更新于2025-09-10 09:29:36
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[IEEE 2018 40th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC) - Honolulu, HI, USA (2018.7.18-2018.7.21)] 2018 40th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC) - Reconstructed Dynamics of the Imaging Photoplethysmogram
摘要： Human photoplethysmogram (PPG) is one of the signals widely applied for health monitoring. Development of the new techniques made possible evolution of traditional contact PPG which was measured at red and near-infrared light (NIR) to the contactless, imaging PPG (iPPG) that can be recorded at various light wavelengths, including ambient visible light. However, despite the numerous advantages of iPPG its applications demonstrated so far are quite limited. The NIR PPG was previously found to be useful for various applications in the area of physiological and mental health monitoring by utilizing advanced methods of nonlinear time-series analysis applied on its reconstructed dynamics. The main purpose of this study is to demonstrate data-driven approach with time-delay-reconstructed attractor obtained from the iPPG. The results of this study demonstrated that the iPPG dynamics can be reconstructed with fine data resolution, and its time-delay-reconstructed trajectory is almost deterministic, though contains noise. The obtained results might be useful for further applied studies on the iPPG.
关键词： imaging PPG,iPPG,health monitoring,PPG,nonlinear time-series analysis,photoplethysmogram,NTSA
更新于2025-09-10 09:29:36
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[IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia, Spain (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - A New Automatic Selection of Optimum Interferometric Image Pairs in time Series Sar Interferometry
摘要： Aiming at the problem of wrong selection and missed selection of interferometric image pairs by spatial-temporal small baseline combination method in time series SAR interferometry, this paper proposes an automatic method for selecting the optimum interferometric image pairs based on the coherence of interferograms. By quantitatively evaluating the coherence of point targets in a small feature region like urban area, this method can generate high-quality interferograms with high coherence from all possible interferometric combinations.
关键词： feature region,automatic selection,time series InSAR,interferometric image pairs
更新于2025-09-10 09:29:36
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Electric field dependence of dc conductivity in As2Te3 (in) thin films
摘要： The time evolutions of transient current data for As2Te3(In) thin films were measured at different electric fields for the dc voltages of 0.001 V, 0.002 V, 0.005 V, 0.01 V, 0.1 V, 0.5 V and 1 V at room temperature (296 K). Transient current was analyzed by means of time series analysis in order to identify different conduction regimes. The maximal Lyapunov exponents for the transient currents were calculated. Positive maximal Lyapunov exponents reflected electric field dependence with positive Lyapunov exponents. Existence of a positive Lyapunov exponent means sensitive dependence on initial conditions and As2Te3(In) is known to have memory effects hence different initial conditions for each dc current measurement. Detrended Fluctuation Analysis was utilized to characterize the behavior of dc current time series which is invariant to initial conditions. Detrended Fluctuation Analysis identified three different conduction regimes with multiple conduction mechanisms.
关键词： Weak chaotic systems,Conduction mechanisms,Time Series Analysis,Detrended Fluctuation Analysis,Scaling exponent
更新于2025-09-10 09:29:36
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[IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia, Spain (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - High Frame-Rate Based Moving Point Target Detection
摘要： This paper presents an approach for the detection of moving point targets on high frame-rate image sequences in situations when the spatial signal of the target is swamped by noise. A high frame-rate based moving point target detection framework is proposed, in which a target detector is used for analyzing the time domain evolution of image sequences for distinguishing between background and target, and a statistic based target detection model is used for target detection. The method is evaluated using both simulated and real-world high frame-rate data and we provide a comparison to other widely used point target detection approaches. Our experimental results demonstrate that the proposed framework can be used for robust moving point target detection in very low SNR.
关键词： Moving point target detection,high frame-rate,target detector,framework,time series
更新于2025-09-10 09:29:36
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[IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia, Spain (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - BFAST Explorer: An Effective Tool for Time Series Analysis
摘要： The use of remote sensing images has been broadly employed over the past decades in order to detect and investigate temporal changes on the Earth surface. This is one of the main goals of the widely used Breaks For Additive Season and Trend (BFAST) method. In this paper, we introduce the BFAST Explorer, an effective open-source tool for time series analysis based on BFAST, which is ready to be used at a personal web page. We present its functional and architectural design, as well as a common usage scenario. Moreover, this tool was well received by the target community, notably by its recently integration into a private cloud computing platform.
关键词： structural breaks,remote sensing,BFAST,decomposition,time series
更新于2025-09-09 09:28:46