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- 2019
- Photovoltaic Array
- MPPT
- Matching Efficiency
- modified incremental conductance
- Partially Shaded
- Blocking Diode
- Electrical Engineering and Automation
- Institut Teknologi Sepuluh Nopember- ITS
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A Facile Film-Nanoctahedron Assembly Route to Plasmonic Metamaterial Absorbers at Visible Frequencies
摘要： Plasmonic metamaterial absorbers (MAs) with broadband and near-perfect absorption properties in the visible region were successfully fabricated via a facile film-colloidal nanoparticle (NP) assembly method. In this approach, colloidal octahedral Au NPs were employed as the surface meta-atoms of MAs, while the nanoscale-thick SiO2 and Al films were used as the dielectric spacer and reflector respectively. It is worth noting that the Au nanoctahedron were randomly assembled onto the Al-SiO2 films, and no effort was made to precisely control their spatial arrangements. The optical characterization showed that the as-prepared MAs exhibited broadband high absorption (average absorptivity above 85%) within the whole visible spectrum for a broad range of incident angles (0°–60°). In particular, two polarization-independent near-perfect absorption peaks (absorptance above 99%) were recorded near 540 nm and 727 nm respectively. Moreover, the absorption properties of the MAs can be effectively controlled and tailored by varying the geometry (the thickness of the dielectric spacer and the surface coverages of the Au nanoctahedron). Electromagnetic simulations further demonstrated that enhanced Mie resonances and strong plasmonic coupling effects were critical for the designed MAs. This work here may provide an efficient and alternative route for the design of scalable visible light absorbers for applications such as solar cells, photothermalvoltaics, and biochemical sensors.
关键词： metamaterial absorbers,broadband and near-perfect absorption,aperiodic nanostructures,optical impedance matching,self-assembly
更新于2025-10-22 19:40:53
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Stereo-Matching Network for Structured Light
摘要： Recently, deep learning has been widely applied in binocular stereo matching for depth acquisition, which has led to an immense increase of accuracy. However, little attention has been paid to the structured light ?eld. In this letter, a network for structured light is proposed to extract effective matching features for depth acquisition. The proposed network promotes the Siamese network by considering receptive ?elds of different scales and assigning proper weights to the corresponding features, which is achieved by combining pyramid-pooling structure with the squeeze-and-excitation network into the Siamese network for feature extraction and weight calculations, respectively. For network training and testing, a structured-light dataset with amended ground truths is generated by projecting a random pattern into the existing binocular stereo dataset. Experiments demonstrate that the proposed network is capable of real-time depth acquisition, and it provides superior depth maps using structured light.
关键词： SLNet,stereo matching,Structured light,siamese network
更新于2025-09-23 15:23:52
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Resonance Tunneling Phenomena in Two-Dimensional Multilayer van der Waals Crystalline Systems
摘要： Works, mostly experimental, concerning the most interesting features of application of the resonant tunneling spectroscopy to a new type of heterosystems, van der Waals heterostructures, have been briefly reviewed. These heterostructures appeared after the recent discovery of two-dimensional crystals, which are a new class of materials beginning with graphene. The role of the angular matching of crystal lattices of conducting graphene electrodes of van der Waals systems in carrier tunneling between them has been analyzed together with the closely related problems of satisfaction of conservation laws in tunneling transitions. Manifestations of multiparticle correlation interactions between carriers in van der Waals systems such as Wigner crystallization of electrons in a two-dimensional electron gas in a magnetic field and Bose condensation of excitons in parallel two-dimensional electron gases have been briefly discussed.
关键词： angular matching,momentum conservation,resonant tunneling spectroscopy,graphene,two-dimensional crystals,Wigner crystallization,van der Waals heterostructures,Bose condensation
更新于2025-09-23 15:23:52
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[IEEE 2018 19th International Conference of Young Specialists on Micro/Nanotechnologies and Electron Devices (EDM) - Erlagol (Altai Republic), Russia (2018.6.29-2018.7.3)] 2018 19th International Conference of Young Specialists on Micro/Nanotechnologies and Electron Devices (EDM) - The System of Frequency Matching of the Ultrasonic Generators with the Radiators in “Bulava” Apparatuses
摘要： The article is devoted to the problem concerned with the determination of resonance frequency of the ultrasonic vibrating systems (the radiators) intended for the operation as a part of the ultrasonic technological apparatuses of “Bulava” type.
关键词： frequency control system,generator,resonance matching,Ultrasound
更新于2025-09-23 15:23:52
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Generating a hyperspectral digital surface model using a hyperspectral 2D frame camera
摘要： Miniaturised 2D frame format hyperspectral camera technology that is suitable for small unmanned aerial vehicles (UAVs) has entered the market, making the generation of hyperspectral digital surface models (HDSMs) feasible. HDSMs offer a rigorous approach to capturing the target spectral and 3D geometric data. The main objective of this investigation was to study and develop techniques for the generation of HDSMs in forest areas using novel hyperspectral 2D frame camera technologies. An approach based on object-space image matching was developed, adapting the traditional vertical line locus (VLL) method for HDSM generation; this was then named the hyperspectral VLL (HVLL) approach. Additionally, image classification was introduced into the processing chain in order to adapt the matching parameters, based on different classes. We also proposed a method for extracting the spectral and viewing angle information of the points. An empirical study was carried out using UAV datasets from tropical and boreal forests using 2D format hyperspectral cameras, based on tuneable Fabry-Pérot interferometer (FPI) technology. Quality assessment was performed using DSMs based on state-of-the-art commercial software and airborne laser scanning (ALS). The results showed that the proposed technique generated a high-quality HDSM in both tested environments. The HDSM had higher deviations over the continuous canopy cover than the digital surface models (DSMs) generated using commercial software. The method using image classification information outperformed the commercial approach with respect to the ability to measure ground points in shadowed areas and in canopy gaps. The proposed method is of great interest in supporting automated interpretations of novel multi- and hyperspectral imaging technologies, especially when applied complex objects, such as forests.
关键词： Forest,Hyperspectral 2D frame camera,Image matching,Hyperspectral digital surface model
更新于2025-09-23 15:23:52
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Comparison of block-based stereo and semi-global algorithm and effects of pre-processing and imaging parameters on tree disparity map
摘要： One method of creating a 3D model of a tree is stereo vision technique. Tree geometric characteristics have been used to predict yield, fertilizer application in citrus crops, water consumption or biomass. So, a disparity map and 3D model of the tree can be useful. There are different algorithms to match the stereo pair for calculating disparity maps. Many parameters affect the disparity map, such as the lighting that affects camera and imaging parameters, the calibration that needed to rectify the image, etc. In this study, the block-based stereo and semi-global algorithms with 5 implementations were compared to calculate tree disparity maps. Also, the effects of ISO speed, exposure time, metering mode (imaging parameters) and image un-distortion and rectification (pre-processing) were investigated. The results showed that the semi-global algorithm was better than the block-based stereo algorithm. Windows size affected on disparity maps and best results obtained when this parameter was set to default. Maximum disparity value limits search space. Best results obtained in real value. For smaller value than real value, disparity map was not calculated outside that maximum disparity. Therefore, disparities or pixels missed. It observed that image rectifying, ISO speed, exposure time and metering mode were affected on disparity map. When pictures did not rectify, disparity map calculated but with some errors. Camera parameters were affected on light intensity of pictures. Best disparity map obtained in conditions that ISO speed and exposure time had fewer value and metering mode was set to pattern mode and these parameters were similar for both left and right images.
关键词： ISO speed,Exposure time,Rectify,Disparity map,Semi-global matching,Tree
更新于2025-09-23 15:23:52
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Pressure dependence of high order harmonic generation in nitrogen molecular gas and atmospheric air
摘要： The effect of the variation of the gas pressure on the high harmonic generation (HHG) from nitrogen molecular gas (N2) and atmospheric air with ultrashort intense laser pulses is measured. The optimum pressure in the interaction region of a gas jet for maximizing the HHG yield is determined for both gases. Enhancement of the HHG output and its extension to higher harmonic orders are observed around the optimum pressure value of 0.33 bar. Theoretical calculations based on one-dimensional models explain this effect and provide reasonable agreement with experimental results.
关键词： Femtosecond laser,Conversion efficiency,High-order harmonic generation (HHG),Phase matching,XUV radiation,Pressure optimization
更新于2025-09-23 15:23:52
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[IEEE 2018 19th International Conference on Electronic Packaging Technology (ICEPT) - Shanghai (2018.8.8-2018.8.11)] 2018 19th International Conference on Electronic Packaging Technology (ICEPT) - Polymorphic impedance matching technique for MEMS phase shifter
摘要： The amplitude and phase consistency control level is an important factor affecting the performance of phased array antenna. MEMS phase shifter has important application potential in phased array antenna, but the current MEMS phase shifter device has poor amplitude and phase consistency, making it difficult to integrate directly in phased array antenna system. In this paper, a novel multi-states matching technology for MEMS phase shifter is proposed to overcome the above-mentioned difficulty. To control amplitude fluctuation and phase shift error of phase shifter in the using process, we proposed a general network design method focusing on the given polymorphic S parameter matrix of MEMS phase shifter based on the theory of microwave network. The key of the method is as following: with the help of the mature microwave network synthesis method and the particle swarm optimization algorithm combined by matching circuit parameter optimization, obtain actual S parameter matrixes of two polymorphic matching networks for the corresponding MEMS phase shifter, so as to enhance the amplitude and phase consistency integrated application. The simulation results verify the feasibility of the method, and so that we form a technical way to improve the consistency of amplitude and phase of MEMS phase shifter system through polymorphic matching network, which has important theoretical and practical value.
关键词： multi-states,MEMS phase shifter,matching technology
更新于2025-09-23 15:23:52
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[IEEE 2018 International Conference on Machine Learning and Cybernetics (ICMLC) - Chengdu (2018.7.15-2018.7.18)] 2018 International Conference on Machine Learning and Cybernetics (ICMLC) - Solar Image Matching Based on Improved Freak Algorithm
摘要： FREAK algorithm has the defects of not having scale invariance and single feature point matching strategy, being prone to unsatisfactory results. Based on AKAZE and RANSAC algorithm, an improved FREAK algorithm is proposed, named AKAZE-FREAK. The image pyramid was constructed by using the nonlinear diffusion filter and the numerical solution was obtained by fast display diffusion (FED) to obtain the image point coordinates with sub-pixel precision. Then the feature points were described by the FREAK descriptors to distribute directions for the feature points. Finally, based on the initial matching of the hamming distance to the eigen vector, RANSAC is used to eliminate the error matching point. In this paper, this algorithm is applied to the recognition of repeated shooting solar images. After the improved algorithm is compared with the SIFT-FREAK, SURF-FREAK and FREAK algorithms, it shows an improvement in the image feature point matching accuracy with good robustness on the scale difference, illumination difference and rotation difference of the image. It also improves the accuracy of the judgement of the late repeat.
关键词： Feature point matching,Improvement,AKAZE,FREAK
更新于2025-09-23 15:23:52
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GENERATION OF COMPLEX SOURCE POINT EXPANSIONS FROM RADIATION INTEGRALS (Invited Paper)
摘要： This paper discusses methods for expanding fields radiated by arbitrary sources enclosed by a certain minimum sphere in terms of Complex Source Point (CSP) beams. Two different approaches are reviewed; the first one is based on a spectral radiation integral, where the Fourier-spectrum is obtained by far field matching. The second approach consists of two steps: first, the equivalence principle is applied to a sphere enclosing the real sources, and a continuous equivalent electric current distribution is obtained in terms of spherical waves; then, the continuous current is extended to complex space and its SW components are properly filtered and sampled to generate the discrete set of CSPs. In both cases, the final result is a compact finite series representation with a number of terms that matches the degrees of freedom of arbitrary radiated fields; it is particularly efficient when the fields are highly directional and the observation domain is limited to a given angular sector. The fact that the CSPs rigorously respect Maxwell's equations ensures the validity of the expansion from near to far zone and allows one to incorporate the CSP representation in a generalized admittance matrix formalism for the analysis of complex problems.
关键词： CSP beams,field expansion,degrees of freedom,generalized admittance matrix,spectral matching,radiation integrals,Complex Source Point,spherical waves
更新于2025-09-23 15:23:52