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Using TanDEM-X Pursuit Monostatic Observations with a Large Perpendicular Baseline to Extract Glacial Topography
摘要： Space-based Interferometric Synthetic Aperture Radar (InSAR) applications have been widely used to monitor the cryosphere over past decades. Owing to temporal decorrelation, interferometric coherence often severely degrades on fast moving glaciers. TanDEM-X observations can overcome the temporal decorrelation because of their simultaneous measurements by two satellite constellations. In this study, we used the TanDEM-X pursuit monostatic mode with large baseline formation following a scientific phase timeline to develop highly precise topographic elevation models of the Petermann Glacier of Northwest Greenland. The large baseline provided the advantage of extracting topographic information over low relief areas, such as the surface of a glacier. As expected, coherent interferometric phases (>0.8) were well maintained over the glaciers, despite their fast movement, due to the nearly simultaneous TanDEM-X measurements. The height ambiguity, which was defined as the altitude difference corresponding to a 2π phase change of the flattened interferogram, of the dataset was 10.63 m, which was favorable for extracting topography in a low relief region. We validated the TanDEM-X derived glacial topography by comparing it to the SAR/Interferometric radar altimeter observations acquired by CryoSat-2 and the IceBridge Airborne Topographic Mapper laser altimeter measurements. Both observations showed very good correlation within a few meters of the offsets (?12.5~ ?3.1 m), with respect to the derived glacial topography. Routine TanDEM-X observations will be very useful to better understand the dynamics of glacial movements and topographic change.
关键词： digital elevation model,radar interferometry,petermann glacier,TanDEM-X science phase,TanDEM-X,ambiguity height
更新于2025-09-09 09:28:46
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Estimation of state of charge of lithium-ion battery based on photovoltaic generation energy storage system
摘要： The fast and accurate estimation of state of charge (SOC) of lithium-ion battery is one of the key technologies of battery management system. In view of this nonlinear dynamic system of lithium battery, through the test and analysis of lithium-ion battery hysteresis characteristics, the second-order RC hysteresis model is established, and the cubature Kalman filter algorithm is used to estimate the battery state of charge in this report. The experiment results show that the battery model can essentially predict the dynamic hysteresis voltage behavior of the lithium-ion battery and cubature Kalman Filtering algorithm can maintain high accuracy in the estimation process.
关键词： cubature Kalman filter,Lithium-ion battery,state of charge,hysteresis model
更新于2025-09-09 09:28:46
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Estimation of Pine Forest Height and Underlying DEM Using Multi-Baseline P-Band PolInSAR Data
摘要： On the basis of the Gaussian vertical backscatter (GVB) model, this paper proposes a new method for extracting pine forest height and forest underlying digital elevation model (FUDEM) from multi-baseline (MB) P-band polarimetric-interferometric radar (PolInSAR) data. Considering the linear ground-to-volume relationship, the GVB is linked to the interferometric coherences of different polarizations. Subsequently, an inversion algorithm, weighted complex least squares adjustment (WCLSA), is formulated, including the mathematical model, the stochastic model and the parameter estimation method. The WCLSA method can take full advantage of the redundant observations, adjust the contributions of different observations and avoid null ground-to-volume ratio (GVR) assumption. The simulated experiment demonstrates that the WCLSA method is feasible to estimate the pure ground and volume scattering contributions. Finally, the WCLSA method is applied to E-SAR P-band data acquired over Krycklan Catchment covered with mixed pine forest. It is shown that the FUDEM highly agrees with those derived by LiDAR, with a root mean square error (RMSE) of 3.45 m, improved by 23.0% in comparison to the three-stage method. The difference between the extracted forest height and LiDAR forest height is assessed with a RMSE of 1.45 m, improved by 37.5% and 26.0%, respectively, for model and inversion aspects in comparison to three-stage inversion based on random volume over ground (RVoG) model.
关键词： digital terrain model,complex least squares,P-band polarimetric-interferometric radar (PolInSAR),forest vertical structure
更新于2025-09-09 09:28:46
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Temperature Measurement Method for Blast Furnace Molten Iron Based on Infrared Thermography and Temperature Reduction Model
摘要： The temperature measurement of blast furnace (BF) molten iron is a mandatory requirement in the ironmaking process, and the molten iron temperature is signi?cant in estimating the molten iron quality and control blast furnace condition. However, it is not easy to realize real-time measurement of molten iron temperature because of the harsh environment in the blast furnace casthouse and the high-temperature characteristics of molten iron. To achieve continuous detection of the molten iron temperature of the blast furnace, this paper proposes a temperature measurement method based on infrared thermography and a temperature reduction model. Firstly, an infrared thermal imager is applied to capture the infrared thermal image of the molten iron ?ow after the skimmer. Then, based on the temperature distribution of the molten iron ?ow region, a temperature mapping model is established to measure the molten iron temperature after the skimmer. Finally, a temperature reduction model is developed to describe the relationship between the molten iron temperature at the taphole and skimmer, and the molten iron temperature at the taphole is calculated according to the temperature reduction model and the molten iron temperature after the skimmer. Industrial experiment results illustrate that the proposed method can achieve simultaneous measurement of molten iron temperature at the skimmer and taphole and provide reliable temperature data for regulating the blast furnace.
关键词： skimmer,taphole,blast furnace,temperature reduction model,molten iron temperature,infrared thermography
更新于2025-09-09 09:28:46
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Estrategia Metaheurística para Redes ópticas sin Conversión de Longitud de Onda con Tráfico Dinámico (WDM)
摘要： This research shows the performance comparison between different heuristics such as genetic algorithms, simulated annealing, Tabu Search, Snake-One and a new metaheuristic called Snake-Two. Earlier were obtained low blocking probability but with a tendency to increase network utilization. The new Snake-Two strategy can prove that the behavior of the blocking probability decreases at low network usage. These results are compared with a conventional algorithm that was used to visualize the improvement of each indicator. The indicators used for comparison, are the blocking probability and the network utilization and a new indicator called Heuristic Algorithm Rate. This strategy proposes using the congested links, allowing increasing the traffic in some areas, and reducing it in other areas. The results are promising to achieve lower blocking probability but the tendency of increasing the use of the network resources continues.
关键词： active contour model,simulated annealing,genetics algorithm,snakes methods
更新于2025-09-09 09:28:46
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Diagnosis of undesired scenarios in hydrogen production by photo-fermentation
摘要： This study presents the use of a machine learning method from the artificial intelligence area, such as the support vector machines, applied to the construction of data-based classification models for diagnosing undesired scenarios in the hydrogen production process by photo-fermentation, which was carried out by an immobilized photo-bacteria consortium. The diagnosis models were constructed with data obtained from simulations run with a mechanistic model of the process and assessed on both modelled and experimental batches. The results revealed a 100% diagnosis performance in those batches where light intensity was below and above an optimum operation range. Nevertheless, 55% diagnosis performance was obtained in modelled batches where pH was away from its optimum operation range, showing that diagnosis model predictions during the first observations of those batches were classified as normal operation and revealing diagnosis delay in pH oscillations. In general, results demonstrate the reliability of classification models to be used in future applications such as the on-line process monitoring to detect and diagnose undesired operating conditions and take corrective actions on time to maintain high hydrogen productivities.
关键词： hydrogen production,photo-fermentation process,mechanistic model,undesired scenarios,diagnosis models,supervised learning methods
更新于2025-09-09 09:28:46
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Effective Medium Model of Periodic Nanolayered Transparent Shields
摘要： An innovative effective medium model based on the transfer matrix method is proposed for the simulation of 1D-periodic subwavelength metal–dielectric laminated structures excited by TM- or TE-polarized plane wave with oblique incidence angles. The homogeneous medium of each period is characterized by TM or TE complex effective permeability and conductivity. The resulting effective single layer (ESL), having the same total thickness of the multilayer laminate, is represented by a transfer matrix given by the product of the transmission matrices of the periods composing the structure. Notice that this model allows the homogenization of n-layer periods, while the effective medium approximation method is formulated for only two-layer periods. The ESL is used to compute the transmission and reflection coefficients and the shielding effectiveness of 1D-periodic nanolayered transparent coatings made by alternating layers of silver, zinc oxide, or titanium dioxide films, in the frequency range from 100 MHz up to 10 THz. The propagating wave performances of the ESL are compared with the ones given by the rigorous multilayer model. Finally, two different screens made of transparent coatings over glass are proposed and analyzed.
关键词： 1D-periodic multilayer (ML) coating,Effective homogeneous model,terahertz (THz) shielding effectiveness
更新于2025-09-09 09:28:46
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A MINIATURIZED BANDPASS FREQUENCY SELECTIVE SURFACE WITH HIGH SELECTIVITY BASE ON SLOT COUPLING
摘要： A Ku-band bandpass frequency selective surface (FSS) with high selectivity and miniaturization is proposed in this paper. We use two metallic strips and one slot to design the frequency selective surface structure which contains both electrical and magnetic couplings. A metallic via is introduced in the FSS element for miniaturization. With the via inserted at the end of the metallic strip, the FSS unit size is reduced to half compared to that without via inserted. To investigate the operating principle of the slot-coupled FSS, an equivalent-circuit model is given and analysed using the odd- and even-mode method. The constructed out-of-phase signal path causes two transmission zeros (TZs) near the skirts of the narrow pass band, thereby enhancing the selectivity. A prototype of the proposed FSS operating at 16 GHz is fabricated and measured. The measured results agree well with the full-wave and circuit simulation results, thus verifying the FSS design.
关键词： slot coupling,Ku-band,bandpass frequency selective surface,metallic via,high selectivity,equivalent-circuit model,transmission zeros,miniaturization
更新于2025-09-09 09:28:46
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MUTUAL COUPLING REDUCTION BETWEEN PRINTED DUAL-FREQUENCY ANTENNA ARRAYS
摘要： A new defected ground structure (DGS) is designed to reduce the mutual coupling of a dual-frequency printed monopole array. The designed dual-frequency DGS consists of two concentric split ring slots. Each split ring slot produces band rejection characteristics at one resonant frequency of the antennas. An e?ective equivalent circuit model of the DGS section is proposed with the circuit parameters successfully extracted. Good agreement exists among the circuit simulation, EM simulation and experimental results. With the inclusion of the DGS, the measured mutual coupling of the dual-band array has been e?ectively reduced by 10 dB and 20 dB at two resonant frequencies, respectively.
关键词： dual-frequency printed monopole array,equivalent circuit model,defected ground structure (DGS),mutual coupling reduction
更新于2025-09-09 09:28:46
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Application of Kinetic Flux Vector Splitting Scheme for Solving Viscous Quantum Hydrodynamical Model of Semiconductor Devices
摘要： In this article, one-dimensional viscous quantum hydro dynamical model of semiconductor devices is numerically investigated. The model treats the propagation of electrons in a semiconductor device as the flow of a charged compressible fluid. It plays an important role in predicting the behaviour of electron flow in semiconductor devices. The nonlinear viscous quantum hydrodynamic models contain Euler-type equations for density and current, viscous and quantum correction terms, and a Poisson equation for electrostatic potential. Due to high nonlinearity of model equations, numerical solution techniques are applied to obtain their solutions.. The proposed numerical scheme is a splitting scheme based on the kinetic flux-vector splitting (KFVS) method for the hyperbolic step, and a semi-implicit Runge-Kutta method for the relaxation step. The KFVS method is based on the direct splitting of macroscopic flux functions of the system on the cell interfaces. The second order accuracy of the scheme is achieved by using MUSCL-type initial reconstruction and Runge-Kutta time stepping method. Several case studies are considered. For validation, the results of current scheme are compared with those obtained from the splitting scheme based on the NT central scheme. The effects of various parameters such as device length, viscosities, different doping and voltage are analyzed. The accuracy, efficiency and simplicity of the proposed KFVS scheme validates its generic applicability to the given model equation.
关键词： Semiconductor devices,Kinetic flux vector,Viscous quantum hydro dynamical model
更新于2025-09-09 09:28:46