- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Analysis for the Weakly Pareto Optimum in Multiobjective-Based Hyperspectral Band Selection
摘要： Band selection refers to finding the most representative channels from hyperspectral images. Usually, certain objective functions are designed and combined via regularization terms. A possible drawback of these methods is that they can only generate one solution in a single run with a given band number. To overcome this problem, multiobjective (MO)-based methods, which were able to simultaneously obtain a series of subsets with different band numbers, were investigated for band selection. However, because the range of band selection problem is discrete, recently proposed weighted Tchebycheff (WT)-based MO methods may suffer weakly Pareto optimal problem. In this case, the solutions for each band number will be nonunique and no optimal solution exists. Decision makers have to manually select a unique solution for each band number. In this paper, we provide a theoretical analysis about the weakly Pareto optimal problem in band selection, and quantitatively give the boundary conditions. Moreover, we further summarize the suggestions which will help users avoid the weakly Pareto optimal problem. According to these criteria, we develop a new adaptive-penalty-based boundary intersection (APBI) framework to improve the MO algorithm in hyperspectral band selection. APBI mainly includes two advantages: 1) avoiding weakly Pareto optimum and 2) reducing the sensibility of the penalty factor. The theoretical analysis is further validated by contrast experiments. The results demonstrate that the weakly Pareto optimal solutions really exist in WT methods, while APBI can overcome this problem.
关键词： multiobjective (MO) optimization,Band selection,weakly Pareto optimum,hyperspectral imagery (HSI)
更新于2025-09-23 15:22:29
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A Visible Light-Near-Infrared Dual-Band Smart Window with Internal Energy Storage
摘要： The integration of electrochromic smart windows with energy storage is an appealing concept for green building development. Herein, we report a dual-band electrochromic energy storage (DEES) window capable of independent control of visible light (VIS) and near-infrared (NIR, solar heat) transmittance with a high internal charge storage. The key design feature is the use of composition-optimized Ta-doped nano-TiO2 nanocrystals as a multifunctional active material to deliver a high charge-storage capability concurrently with high bistability and long-cycle-life electrochromism in three distinct operating modes: (1) the VIS and NIR transparent "bright" mode; (2) the VIS transparent and NIR opaque "cool" mode; and (3) the completely opaque "dark" mode. The independent control of VIS (sunlight) and NIR (solar heat) modulation was successfully demonstrated in a DEES prototype with a high charge-storage capacity of 466.5 mA hr m?2 at 150 mA m?2 of current density.
关键词： nanocrystals,dual-band electrochromic,smart window,energy storage,Ta-doped TiO2
更新于2025-09-23 15:22:29
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[IEEE 2018 IEEE Asia-Pacific Conference on Antennas and Propagation (APCAP) - Auckland (2018.8.5-2018.8.8)] 2018 IEEE Asia-Pacific Conference on Antennas and Propagation (APCAP) - A Broadband and Wide-angle Band-stop Frequency Selective Surface (FSS) Based on Dual-layered Fractal Square Loops
摘要： In this work, a broadband and wide-angle band-stop FSS based on dual-layered periodic arrays of fractal square loops was proposed and demonstrated. Equivalent circuit model and full-wave electromagnetic simulation were used to analyze this FSS. The sample of designed FSS with optimized structure parameters for center working frequency about 13GHz was fabricated and measured. The experimental results agree well with the simulated ones. Both of them indicated that the FSS has broad stop bands for both TE and TM polarization under incident angles from 0° to 60°. Specifically, the stop bands under incident angle 60° are over 7.35GHz and 5.91GHz for TE and TM polarization, respectively.
关键词： wide-angle,fractal Square Loop,broadband,band-stop frequency selective surface,dual-layered
更新于2025-09-23 15:22:29
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[IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - A Car-Borne SAR System for Interferometric Measurements: Development Status and System Enhancements
摘要： Terrestrial radar systems are used operationally for area-wide measurement and monitoring of surface displacements on steep slopes, as prevalent in mountainous areas or also in open pit mines. One limitation of these terrestrial systems is the decreasing cross-range resolution with increasing distance of observation due to the limited antenna size of the real aperture radar or the limited synthetic aperture of the quasi-stationary SAR systems. Recently, we have conducted a first experiment using a car-borne SAR system at Ku-band, demonstrating the time-domain back-projection (TDBP) focusing capability for the FMCW case and single-pass interferometric capability of our experimental Ku-band car-borne SAR system. The cross-range spatial resolution provided by such a car-based SAR system is potentially independent from the distance of observation, given that an adequate sensor trajectory can be built. In this paper, we give (1) an overview of the updated system hardware (radar setup and high-precision combined INS/GNSS positioning and attitude determination), and (2) present SAR imagery obtained with the updated prototype Ku-band car-borne SAR system.
关键词： azimuth focusing,Ku-band,SAR imaging,ground-based SAR system,car-borne SAR,parallelization,SAR interferometry,GPU,CUDA,interferometry,CARSAR,Synthetic aperture radar (SAR)
更新于2025-09-23 15:22:29
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[IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Accounting for Static and Dynamic Open Water in the Modeling of SMAP Brightness Temperatures Over Peatlands
摘要： Hydrological change in peatlands due to anthropogenic disturbance and global warming can release enormous amounts of greenhouse gas emissions. Passive microwave satellite observations are an opportunity to globally monitor these changes. Abundant static and dynamic open water surfaces in peatlands strongly affect observed brightness temperatures (Tb). Here, we account for these contributions in radiative transfer modeling using NASA's Goddard Earth Observing System Model version 5 (GEOS-5) static open water mask and, for the dynamic open water fraction, the simulated inundated area using a version of the GEOS-5 Catchment land surface model that has been modified for peatland areas (PEAT-CLSM). Modeled Tb is compared against two years of SMAP L-band Tb. Preliminary results indicate: (i) a bias reduction when including the static open water fraction in a simple RTM mixing model, and (ii) significantly improved correlation between modeled and observed Tb when using land surface output from PEAT-CLSM instead of the operational CLSM.
关键词： organic soil,radiative transfer model,soil moisture,L-band,passive microwave
更新于2025-09-23 15:22:29
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Highly-transparent, UV-B protective Al-Zn-O films with potential application in greenhouse screen systems
摘要： Extremely thin, Al-Zn-O composite films (21±6 nm) are deposited on fused silica substrates under various percentages of oxygen in the oxygen/argon gas mixture (3, 4.5, 6, and 7.5 %). The films are prepared by a cylindrical DC magnetron sputtering system, utilizing a single compound target. The effects of the oxygen percentage on the compositional, morphological, and optical properties of the films are investigated by energy-dispersive X-ray spectroscopy, scanning electron microscopy, UV-Visible spectrophotometry, and atomic force microscopy. The chemical composition of the films is Al1 Z1+X O with 0.2<X<1. The average visible transmittance of 93.6% with a high level of uniformity is obtained when the sputtering deposition performs under the oxygen percentage of 6%. It is found that the optical band gap of the films can be tailored towards higher energy by increasing oxygen percentage; however, the adjustable range is not so significant. The results offer cost-efficient films with high, uniform transmittance in the visible region and with an ability to attenuate more than 10% of incident UV-B radiation (280-315 nm). This type of films can potentially be included in greenhouse screen systems to effectively protect the plants from the elevated UV-B radiation without altering natural conditions.
关键词： Al-Zn-O film,cylindrical DC magnetron sputtering,band gap tailoring,effective UV-B protection of plants
更新于2025-09-23 15:22:29
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[IEEE 2018 IEEE Asia-Pacific Conference on Antennas and Propagation (APCAP) - Auckland (2018.8.5-2018.8.8)] 2018 IEEE Asia-Pacific Conference on Antennas and Propagation (APCAP) - Design of Band-notched UWB Rectangular Dielectric Resonator Antenna
摘要： A rectangular dielectric resonator antenna fed by microstrip line at non-central symmetric position with partial ground plane is presented. The proposed dielectric resonator with given dimensions is easy to excite multiple modes and generate the broadband of 7.09GHz, ranging from 3.89 to 10.98GHz. Due to the introduction of parasitic metal ring, band-notched property can be achieved. When the total length comes to the half a guide wavelength, the notched band at corresponding frequency is generated. Simulations confirm the validation of the design principle. The compact size of the band-notched DRA is 25mm×28mm with 4.037mm thickness.
关键词： rectangular dielectric resonator,UWB,dielectric resonator antenna,band-notched
更新于2025-09-23 15:22:29
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[IEEE 2018 International Conference on Microwave and Millimeter Wave Technology (ICMMT) - Chengdu, China (2018.5.7-2018.5.11)] 2018 International Conference on Microwave and Millimeter Wave Technology (ICMMT) - Modeling and Verification of Ku-Band Tracking Radar System
摘要： Taking a certain type of Ku-band fire-control radar tracking system as example, the monopulse tracking radar standard library and simulation system are investigated and developed based on Simulink. Under the condition of true input value of flying target, the effectiveness and reliability of signal generator, clutter, Moving Target Indication (MTI), Moving Target Detection (MTD) and tracking module are verified. The actual measured data and simulation data are compared, the error is less than 1.5%. The operational frequency of the radar is 15 GHz and the bandwidth is 2 GHz.
关键词： system modeling,Simulink,Ku-band Radar
更新于2025-09-23 15:22:29
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First-principles study of the surface reparation of ultrathin InSe with Se-atom vacancies by thiol chemistry
摘要： Utilizing first-principles calculations, the surface reparation of monolayer InSe with Se-atom vacancies by thiol chemistry was studied. The geometrical structures and electronic properties of monolayer InSe with Se-atom vacancies were evaluated before and after reparation by S atoms, benchmarked against defect-free case. The parameters of bond lengths, band gaps and carrier mobilities can be recovered to the standard of pristinely defect-free structure. Moreover, the interaction of S atom with complete part of monolayer InSe was also investigated. S atom cannot adsorb on the surface without Se-atom vacancies, while it can substitute Se atom or insert into the interior of monolayer InSe. And the insertion was able to induce a decrease by one order of magnitude. It was demonstrated that thiol chemistry was an effective method to repair Se-atom vacancies and maintain its oxidation resistance, while the insertion of S atom into the interior of monolayer InSe should be avoided.
关键词： Indium selenides,Carrier mobility,Se-atom vacancies,Band gap,First-principles
更新于2025-09-23 15:22:29
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[Institution of Engineering and Technology 12th European Conference on Antennas and Propagation (EuCAP 2018) - London, UK (9-13 April 2018)] 12th European Conference on Antennas and Propagation (EuCAP 2018) - Remote Vital Sign Recognition through Machine Learning augmented UWB
摘要： This paper describes an experimental demonstration of machine learning (ML) techniques supplementing radar to distinguish and detect vital signs of users in a domestic environment. This work augments an intelligent location awareness system previously proposed by the authors. That research employed Ultra-Wide Band (UWB) radar complemented by supervised machine learning techniques to remotely identify a person’s room location via ?oor plan training and time stamp correlations. Here, the remote breathing and heartbeat signals are analyzed through Short Term Fourier Transformation (STFT) to determine the Micro-Doppler signature of those vital signs in different room locations. Then, Multi-Class Support Vector Machine (MC-SVM) is implemented to train the system to intelligently distinguish between vital signs during different activities. Statistical analysis of the experimental results supports the proposed algorithm. This work could be used to further understand, for example, how active older people are by engaging in typical domestic activities.
关键词： Short Term Fourier Transform (STFT),Breathing,Ultra-Wide Band (UWB),Multi-Class Support Vector Machine (MC-SVM),Heartbeat,Indoor Positioning System (IPS)
更新于2025-09-23 15:22:29