- 标题
- 摘要
- 关键词
- 实验方案
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Analysis of Dendrite Images Formed by Electrochemical Migration in a Semiconductor Sensor
摘要： Dendrites were observed in the failure of semiconductor sensor devices. EDX analysis showed that the dendrites grown from bare sensor dice consisted of tin metal. The tin dendrites exhibited massive and dense branches. Dendrites grown from mechanically decapped parts consisted of silver. The silver dendrites exhibited delicate, lace-like structure. Binary and grey scale images of dendrites were analyzed for fractal dimension number and branch density. The tin dendrites had a higher, statistically significant branch density number than silver, due to tin’s more intricate branching pattern. Fractal numbers can be used to differentiate between tin and silver dendrites, even in the absence of EDX analysis equipment.
关键词： dendrites,fractal characteristics
更新于2025-09-10 09:29:36
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[IEEE 2018 IEEE 17th International Conference on Mathematical Methods in Electromagnetic Theory (MMET) - Kiev (2018.7.2-2018.7.5)] 2018 IEEE 17th International Conference on Mathematical Methods in Electromagnetic Theory (MMET) - Modeling of Electromagnetic Wave Scattering and Propagation in the Presence of a Pre-Fractal PEC Strip Grating
摘要： Classes of one-dimensional self-similar fractals with variable Hausdorff–Besicovitch dimension are presented. They can be used in the pre-fractal modelling in electromagnetic and acoustic wave theory: wave scattering by pre-fractal gratings and wave propagation in pre-fractal systems of microstrip lines.
关键词： self-similar fractals,wave scattering,wave propagation,pre-fractal modelling,fractal dimension
更新于2025-09-09 09:28:46
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Wide band fractal-based perfect energy absorber and power harvester
摘要： In this article, a novel wide band polarization and incident angle independent meta-material absorber (MA) and energy harvesting applications which operates at C (4GHz-8 GHz) and X (8GHz-12 GHz) is proposed. The unit-cell of the proposed structure based on fractal circle loop. Four lumped resistors are mounted the structure to obtain a broad band absorption characteristics. Resistors increase the absorption characteristic of proposed MA significantly at mentioned frequency ranges. In addition, under favor of the resistors proposed MA can convert absorbed energy from incident wave to appearing power.
关键词： metamaterial,wide band absorber,energy harvesting,fractal metamaterial absorber
更新于2025-09-09 09:28:46
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Effective detection by fusing visible and infrared images of targets for Unmanned Surface Vehicles
摘要： The research progress for Unmanned Surface Vehicle (USV) is of great significance to human off-shore operations. Target detection is the foundation for USV applications. Ocean wave, frog, and illumination are the most important factors that affect exactness of target detection through visible and infrared images. This paper proposes an algorithm for weighted averaging fusion of visible/infrared images. Firstly, the visible light/infrared devices are required to collect the target surrounding information, perform feature analysis, and complete the anti-fog and de-noising preprocessing. These operations aim at improving the accuracy of image segmentation. Secondly, feature extractions of the visible and infrared target images are performed, respectively, and the recognition of the target image is further completed. Finally, image fusion is performed by weighted averaging of the targets detected by visible light and infrared images. The fusion uses a matching matrix to represent the similarity of the two images. When the two images are very similar, the image is fused by weighting pixels, which effectively improves the accuracy of the detection. Lots of simulations were conducted on MATLAB 2015a with a personal computer, and the results verified the success rate of target detection and recognition.
关键词： fusion,Multi-scale fractal,target detection,visible image,infrared image
更新于2025-09-09 09:28:46
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Fractal simulation of thin film nucleation growth process using a diffusion-limited aggregation model
摘要： In order to study the initial nucleation and growth process of the films, a two-dimensional (2D) DLA model was established, and fractal dimension was calculated by sandbox method. Compared with the experimental results, the model can well characterize the morphology of nucleation and growth in the initial stage of film growth. In addition to the number of particles and deposition probability involved in other studies, the size of substrate and the location of central particles are also considered in this work. The growth morphology, fractal dimension and the number of simulated steps are presented in this paper.
关键词： thin film,Diffusion-limited aggregation,2D DLA,nucleation growth,fractal dimension
更新于2025-09-09 09:28:46
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CIRCULAR POLARIZATION FRACTAL SLOT BY JERUSALEM CROSS SLOT FOR WIRELESS APPLICATIONS
摘要： In this letter, a new model of antenna with Jerusalem crosses (JC) as fractal slots for circular polarization applications is designed. The proposed slot antenna has a fractal cross formation with four Jerusalem crosses (JC) to achieve wide bandwidth and a compact size as well as circular polarization. A T-shaped feed line is implemented in the proposed antenna for improving the bandwidth while the interaction of the feed line with cross-shaped slots makes circular polarization. The proposed antenna shows bi-directional pattern and bandwidth at 2.42–3.0 GHz with VSWR < 2, which can be used in Wi-Fi and Bluetooth applications with a gain of 3.5 dBi. The proposed fractal antenna size is 40 × 40 mm, and it is designed and fabricated on an FR-4 low-cost substrate with thickness of 1.6 mm. It is simulated by HFSS full wave software. In addition, the experimental results are presented and compared with the simulation for VSWR, radiation pattern and axial ratio.
关键词： wireless applications,Wi-Fi,Circular polarization,Jerusalem cross slot,fractal slot,Bluetooth
更新于2025-09-09 09:28:46
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GENERATION, APPLICATION AND ANALYSIS OF A NOVEL FAMILY OF M-SEGMENT QUADRATIC FRACTAL CURVES TO ANTENNAS
摘要： A novel family of fractal curves is proposed which provides the designer a systematic way of miniaturizing the microwave components with the freedom of choosing among form factor, design complexity and achieved miniaturization. The proposed fractal curve is characterized by two integer values m and n. The m value determines the form factor of the fractal while n value governs the iteration number. The equations governing the geometry of fractals are also presented. The proposed fractal is characterized for miniaturization by designing a printed monopole antenna for various values of m and n. The results from the full wave simulations and experiments are analysed and explained. The effect of fractal on reducing the resonant frequency is quantified by an equation based on its physical interpretation. Based on this analysis, saturation point for miniaturization is established. The curves being symmetric around a straight line, distortionless radiation patterns are seen.
关键词： fractal curves,microwave components,resonant frequency,monopole antenna,miniaturization
更新于2025-09-09 09:28:46
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Freshwater Fish Habitat Complexity Mapping Using Above and Underwater Structure-From-Motion Photogrammetry
摘要： Substrate complexity is strongly related to biodiversity in aquatic habitats. We illustrate a novel framework, based on Structure-from-Motion photogrammetry (SfM) and Multi-View Stereo (MVS) photogrammetry, to quantify habitat complexity in freshwater ecosystems from Unmanned Aerial Vehicle (UAV) and underwater photography. We analysed sites in the Xingu river basin, Brazil, to reconstruct the 3D structure of the substrate and identify and map habitat classes important for maintaining fish assemblage biodiversity. From the digital models we calculated habitat complexity metrics including rugosity, slope and 3D fractal dimension. The UAV based SfM-MVS products were generated at a ground sampling distance (GSD) of 1.20–2.38 cm while the underwater photography produced a GSD of 1 mm. Our results show how these products provide spatially explicit complexity metrics, which are more comprehensive than conventional arbitrary cross sections. Shallow neural network classification of SfM-MVS products of substrate exposed in the dry season resulted in high accuracies across classes. UAV and underwater SfM-MVS is robust for quantifying freshwater habitat classes and complexity and should be chosen whenever possible over conventional methods (e.g., chain-and-tape) because of the repeatability, scalability and multi-dimensional nature of the products. The SfM-MVS products can be used to identify high priority freshwater sectors for conservation, species occurrences and diversity studies to provide a broader indication for overall fish species diversity and provide repeatability for monitoring change over time.
关键词： Xingu river,Brazil,neural network,river,UAV,rugosity,fractal dimension,underwater
更新于2025-09-09 09:28:46
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Multiband FSS with Fractal Characteristic Based on Jerusalem Cross Geometry
摘要： This paper proposes a new Frequency Selective Surface (FSS) with modifications on the Jerusalem Cross (JC) geometry to provide a multiband response. Fractal levels are created by introducing concentric self-similar JC copies in the original unit cell. This modification results in new dipoles at the structure which allows for the appearance of new bands proportional to these diploles’ lengths, while maintaining total unit cell size. Three fractal levels of the JC FSS are studied in this paper, and third level presents five resonant frequencies which are f1=1.78 GHz, f2=6.42 GHz, f3=8.69 GHz, f4=10.94 GHz and f5=12.98 GHz. Simulation results for the insertion loss (S21), surface current distribution and measurement results are presented.
关键词： Jerusalem Cross,Frequency Selective Surface,Fractal,Multiband Response
更新于2025-09-09 09:28:46
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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) - Fractal Antenna of MIMO System WLAN
摘要： The design of fractal antenna covering two-bands of WLAN-MIMO system is presented. To achieve compact size and dual frequency operation the Minkowski fractal island were used. The design and numerical simulations were done by means of HFSS software. The antenna operates at 2.443 and 5.261 GHz WLAN-bands. The overall dimension of the antenna is 23×23 mm2. Antenna was fabricated on microwave laminate FR4-epoxy. The numerical and experimental results agree favorable.
关键词： frequency tuning,design,Minkowski fractal island,MIMO system,fractal antenna,WLAN
更新于2025-09-04 15:30:14