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- 摘要
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- 实验方案
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[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - NIEL Dose Analysis on triple and single junction InGaP/GaAs/Ge solar cells irradiated with electrons, protons and neutrons
摘要： Quantitative grading of opals is a challenging task even for skilled opal assessors. Current opal evaluation practices are highly subjective due to the complexities of opal assessment and the limitations of human visual observation. In this paper, we present a novel machine vision system for the automated grading of opals—the gemological digital analyzer (GDA). The grading is based on statistical machine learning with multiple characteristics extracted from opal images. The assessment work-flow includes calibration, opal image capture, image analysis, and opal classification and grading. Experimental results show that the GDA-based grading is more consistent and objective compared with the manual evaluations conducted by the skilled opal assessors.
关键词： feature extraction,image analysis,machine vision,learning systems,Artificial intelligence
更新于2025-09-23 15:21:01
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Vertically aligned 2D/3D Pb-Sn perovskites with enhanced charge extraction and suppressed phase segregation for efficient printable solar cells
摘要： The concept of mixed 2D/3D heterostructures has emerged as an effective method in improving the stability of lead halide perovskite solar cells (PSCs), which is, however, rarely reported in lead-tin (Pb-Sn) mixed perovskite devices. Here, we report a scalable process for depositing mixed 2D/3D Pb-Sn perovskite solar cells that deliver remarkably enhanced efficiency and stability compared to their 3D counterparts. The incorporation of a small amount (3.75%) of an organic cation 2-(4-fluorophenyl)ethyl ammonium iodide (FPEAI) induces the growth of highly orientated Pb-Sn perovskite crystals perpendicularly aligned to the substrate. Moreover, for the first time, phase segregation is observed in pristine 3D Pb-Sn perovskite, which is suppressed due to the presence of the 2D perovskites. Accordingly, a high current density of 28.42 mA cm-2 is obtained due to markedly enhanced spectral response and charge extraction. Eventually, mixed 2D/3D Pb-Sn perovskite devices with a bandgap of 1.33 eV yield efficiencies as high as 17.51% and in parallel exhibit good stability.
关键词： 2D/3D heterostructures,charge extraction,Pb-Sn perovskite,solar cells,phase segregation
更新于2025-09-23 15:21:01
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[IEEE 2020 IEEE International Conference on Power Electronics, Smart Grid and Renewable Energy (PESGRE) - Cochin, India (2020.1.2-2020.1.4)] 2020 IEEE International Conference on Power Electronics, Smart Grid and Renewable Energy (PESGRE2020) - Improved H-bridge Multilevel Inverter for Grid Integration of Photovoltaic Power Conversion System with Power Quality Enhancement
摘要： This paper proposes an improved H-bridge multi-level inverter in the photovoltaic power conversion system (PPCS) system which is connected to the distribution grid. The power quality is improved with the number of levels and balanced active power sharing between the sources has been achieved. The bidirectional power ?ow is achieved. The two-stage SPVS extracts the maximum power from the solar panels through the incremental conductance (IC) algorithm based control of the DC-DC converter. The system is designed with multi-functional objectives such as reactive power support and load harmonic mitigation in addition with the active power penetration to the grid. The system is modelled and simulated in MATLAB/Simulink platform and the laboratory prototype is developed, and test results are produced for result validation.
关键词： Photovoltaic,Cascaded H-bridge,Maximum Power Extraction,power quality
更新于2025-09-23 15:21:01
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[IEEE 2019 Compound Semiconductor Week (CSW) - Nara, Japan (2019.5.19-2019.5.23)] 2019 Compound Semiconductor Week (CSW) - Growth of InGaAs solar cells on InP(001) miscut substrates using solid-source molecular beam epitaxy
摘要： In this paper, we present a new motor imagery classification method in the context of electroencephalography (EEG)-based brain–computer interface (BCI). This method uses a signal-dependent orthogonal transform, referred to as linear prediction singular value decomposition (LP-SVD), for feature extraction. The transform defines the mapping as the left singular vectors of the LP coefficient filter impulse response matrix. Using a logistic tree-based model classifier; the extracted features are classified into one of four motor imagery movements. The proposed approach was first benchmarked against two related state-of-the-art feature extraction approaches, namely, discrete cosine transform (DCT) and adaptive autoregressive (AAR)-based methods. By achieving an accuracy of 67.35%, the LP-SVD approach outperformed the other approaches by large margins (25% compared with DCT and 6 % compared with AAR-based methods). To further improve the discriminatory capability of the extracted features and reduce the computational complexity, we enlarged the extracted feature subset by incorporating two extra features, namely, Q- and the Hotelling’s T 2 statistics of the transformed EEG and introduced a new EEG channel selection method. The performance of the EEG classification based on the expanded feature set and channel selection method was compared with that of a number of the state-of-the-art classification methods previously reported with the BCI IIIa competition data set. Our method came second with an average accuracy of 81.38%.
关键词： feature extraction,linear prediction,Brain-computer interface,orthogonal transform,channel selection
更新于2025-09-23 15:21:01
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[IEEE 2019 8th International Conference on Renewable Energy Research and Applications (ICRERA) - Brasov, Romania (2019.11.3-2019.11.6)] 2019 8th International Conference on Renewable Energy Research and Applications (ICRERA) - Estimation of Photovoltaic Panel Parameters by a Numerical Heuristic Searching Algorithm
摘要： This work uses the Nelder-Mead approach, which is a direct search optimization method, to obtain the accurate photovoltaic parameters by minimizing a predetermined objective function of five variables. This paper presents some new modifications made to the Nelder-Mead algorithm which allow a better convergence of the method. A comparison study has conducted between this proposed technique and a classical Nelder-Mead algorithm towards the additive noise of the current along with a sensitivity analysis towards the resolution of ADC.
关键词： parameter extraction,Photovoltaic panel,Nelder-Mead algorithm
更新于2025-09-23 15:21:01
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[IEEE 2018 IEEE 8th International Conference Nanomaterials: Application & Properties (NAP) - Zatoka, Ukraine (2018.9.9-2018.9.14)] 2018 IEEE 8th International Conference Nanomaterials: Application & Properties (NAP) - Study of Self-assembled 2D Ag Nanostructures Intercalated into In <sub/>4</sub> Se <sub/>3</sub> Layered Semiconductor Crystal
摘要： This paper presents an advanced depth intra-coding approach for 3D video coding based on the High Efficiency Video Coding (HEVC) standard and the multiview video plus depth (MVD) representation. This paper is motivated by the fact that depth signals have specific characteristics that differ from those of natural signals, i.e., camera-view video. Our approach replaces conventional intra-picture coding for the depth component, targeting a consistent and efficient support of 3D video applications that utilize depth maps or polygon meshes or both, with a high depth coding efficiency in terms of minimal artifacts in rendered views and meshes with a minimal number of triangles for a given bit rate. For this purpose, we introduce intra-picture prediction modes based on geometric primitives along with a residual coding method in the spatial domain, substituting conventional intra-prediction modes and transform coding, respectively. The results show that our solution achieves the same quality of rendered or synthesized views with about the same bit rate as MVD coding with the 3D video extension of HEVC (3D-HEVC) for high-quality depth maps and with about 8% less overall bit rate as with 3D-HEVC without the combination of related depth tools. At the same time, the combination of 3D video with 3D computer graphics content is substantially simplified, as the geometry-based depth intra signals can be represented as a surface mesh with about 85% less triangles, generated directly in the decoding process as an alternative decoder output.
关键词： 3D video coding,High Efficiency Video Coding (HEVC),multiview video plus depth (MVD),depth intra coding,wedgelets,mesh extraction,inter component prediction,3D video extension of HEVC (3D-HEVC)
更新于2025-09-23 15:21:01
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Stretchable Hole Extraction Layer for Improved Stability in Perovskite Solar Cells
摘要： Flexibility and stretchability of solar cells are crucial factors for enhancing their real-life application for wearable devices. Although poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) has been conventionally employed as a hole extraction layer (HEL) in flexible organic or perovskite solar cells, the inherent stretchability of PEDOT:PSS has yet to be convinced. Here, we report a highly stretchable and mechanically stable PEDOT:PSS-based thin film and its application on flexible perovskite solar cells. We synthesized a chemically linked copolymer, P(SS-co-TFPMA), consisting of PSS and tetrafluoropropylmethacrylate (TFPMA), followed by graft-copolymerization with poly(ethylene glycol) methyl ether methacrylate (PEGMA) to form a P(SS-co-TFPMA)-g-PEGMA dopant for the PEDOT HEL. The PEDOT:P(SS-co-TFPMA)-g-PEGMA (PEDOT:PTP) copolymer solution has excellent homogeneity and high phase stability and its developed HEL film exhibits outstanding stretching capability. After stretching of 300%, PEDOT:PTP films sustain conductivity of over 80% of its original conductivity whereas the conventional PEDOT:PSS films completely lose their conductivity after the strain of 300 %. In addition, the PEDOT:PTP incorporated flexible perovskite solar cells exhibited improved mechanical stability compared with the unassisted cells, retaining 92% of the initial power conversion efficiency after 1500 bending cycles at a 7 mm radius.
关键词： PEDOT:PTP,Stretchable,PEDOT:PSS,Hole extraction layer,Flexible,poly(ethylene glycol)methylacrylate
更新于2025-09-23 15:21:01
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Universal Elaboration of Al-Doped TiO <sub/>2</sub> as an Electron Extraction Layer in Inorganic-Organic Hybrid Perovskite and Organic Solar Cells
摘要： Fabricating an electron extraction layer (EEL) with a metal doping transition metal oxide (TMO) in inorganic–organic hybrid perovskite solar cells (PeSCs) and organic solar cells (OSCs) is a simple and efficient process for enhancing photovoltaic properties. Here, the universal benefits and common factors that influence both PeSCs and OSCs as a result of changes in Al-doped TiO2 properties are investigated. These common factors are identified in two separate mechanisms. The first involves surface smoothing of TiO2 films, which affects the formation of a high crystalline active layer and reduces recombination between the electron extraction and active layers. The second involves bandgap widening of TiO2, which reduces the activation energy and enhances the quenching efficiency of devices. These factors are demonstrated in various measurements. The results will help in understanding the fundamental benefits of Al-doped TiO2 in solution-processed thin-film solar cells.
关键词： perovskite solar cells,electron extraction layer,organic solar cells,Al-doped TiO2
更新于2025-09-23 15:21:01
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Fault detection of photovoltaic array based on Grubbs criterion and local outlier factor
摘要： Quantitative grading of opals is a challenging task even for skilled opal assessors. Current opal evaluation practices are highly subjective due to the complexities of opal assessment and the limitations of human visual observation. In this paper, we present a novel machine vision system for the automated grading of opals—the gemological digital analyzer (GDA). The grading is based on statistical machine learning with multiple characteristics extracted from opal images. The assessment workflow includes calibration, opal image capture, image analysis, and opal classification and grading. Experimental results show that the GDA-based grading is more consistent and objective compared with the manual evaluations conducted by the skilled opal assessors.
关键词： feature extraction,image analysis,machine vision,learning systems,Artificial intelligence
更新于2025-09-23 15:21:01
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Understanding Temperature-Dependent Charge Extraction and Trapping in Perovskite Solar Cells
摘要： Understanding the factors that limit the performance of perovskite solar cells (PSCs) can be enriched by detailed temperature (T)-dependent studies. Based on p-i-n type PSCs with prototype methylammonium lead triiodide (MAPbI3) perovskite absorbers, T-dependent photovoltaic properties are explored and negative T-coefficients for the three device parameters (VOC, JSC, and FF) are observed within a wide low T-range, leading to a maximum power conversion efficiency (PCE) of 21.4% with an impressive fill factor (FF) approaching 82% at 220 K. These T-behaviors are explained by the enhanced interfacial charge transfer, reduced charge trapping with suppressed nonradiative recombination and narrowed optical bandgap at lower T. By comparing the T-dependent device behaviors based on MAPbI3 devices containing a PASP passivation layer, enhanced PCE at room temperature is observed but different tendencies showing attenuating T-dependencies of JSC and FF, which eventually leads to nearly T-invariable PCEs. These results indicate that charge extraction with the utilized all-organic charge transporting layers is not a limiting factor for low-T device operation, meanwhile the trap passivation layer of choice can play a role in the T-dependent photovoltaic properties and thus needs to be considered for PSCs operating in a temperature-variable environment.
关键词： temperature dependence,charge trapping,recombination,charge extraction,passivation layer
更新于2025-09-23 15:21:01