- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Robust Content-Based Digital Image Watermarking Scheme in Steerable Pyramid Domain
摘要： In the digital world in which we are living, the intellectual property protection becomes a concern especially with the proliferation of files transfer over networks. The ability to access data such as text, images, video, and audio has become quicker and easier for people with little to no knowledge of technology. In this paper, a robust watermarking scheme based on the original image content is proposed and simulated. Steerable pyramid transform is used as an embedding domain to its good spatial-frequency characteristics, and its wide applications in the image/video coding standards. The embedding process aims to insert some information in a digital document to identify its owner later. This process requires the original image to be protected and the watermark image related to the image’s owner. It needs also a threshold value used by Sobel-Feldman operator to extract the original image features. The embedding of the watermark image is performed in high frequency components of the original image. Experimental evaluation demonstrates that the proposed watermarking scheme is able to withstand a variety of attacks and at the same time provide good visual quality of the watermarked image.
关键词： watermarking,geometric attacks,robustness,steerable pyramid transform
更新于2025-09-09 09:28:46
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[IEEE 2018 IEEE 3rd International Conference on Image, Vision and Computing (ICIVC) - Chongqing (2018.6.27-2018.6.29)] 2018 IEEE 3rd International Conference on Image, Vision and Computing (ICIVC) - Angle Quantization Index Modulation Based on Block Compressive Sensing for Robust and Secure Image Watermarking
摘要： A novel angle quantization index modulation watermarking scheme based on block compressive sensing (BCS-AQIM) is proposed to embed robust and secure watermark. In this algorithm, sparse random matrices constructed by chaotic sequence are chosen as the measurement matrix and the measurement vector of host image is obtained by block compressive sensing. In each block, two optimal measurements are chosen to embed the watermark into their angle. Then, the watermarked image is recovered through the algorithm. The measurement matrix and the position of watermarked measurements are used as a key. The performance of BCS-AQIM under AWGN attacks and its security are analyzed and assessed by simulations. Experiment results demonstrate that the proposed method is robust to different types of attacks and outperforms common existing methods in terms of the robustness.
关键词： robustness,angle quantization index modulation,block compressive sensing,security
更新于2025-09-09 09:28:46
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On-Machine Optical Probe Based on Discrete Rotational Symmetric Triangulation
摘要： In the field of modern manufacturing, probes have been playing a more and more crucial role. However, contact probes are unfit for measuring objects with soft surfaces or very tiny cavities and require radius compensation of stylus. In comparison, noncontact probes such as optical probes do not have to consider these problems and are well-performed in measurement. However, existing optical probes (triangulation) may fail to detect objects with rich spatial structures (due to the occlusion effect) and highly reflective curved surfaces (due to existence of highlight spots). Considering the problems, an optical probe based on discrete rotational symmetric triangulation is proposed in this paper. The emitting laser beam of the probe is the rotational axis and the five receiving optical paths (lenses and mirrors) are rotationally symmetrically distributed around the laser axis and are coimaged on a CMOS camera. Results of simulations and experiments show that the new-established prototype is designed with good robustness under various conditions such as different surface characteristics and different inclination degrees. The probe enables conducting real-time on-machine measurement without directional dependency with a resolution of 39 ???? and repeatability accuracy of 0.72 ????.
关键词： robustness,on-machine measurement,optical probe,noncontact measurement,discrete rotational symmetric triangulation
更新于2025-09-04 15:30:14
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Facile spraying fabrication of highly flexible and mechanically robust superhydrophobic F-SiO <sub/>2</sub> @PDMS coatings for self-cleaning and drag-reduction applications
摘要： Superhydrophobic coatings treated as surface functional materials are endowed with great application potential with respect to self-cleaning, drag-reduction, anti-icing, etc. In this study, we fabricated a highly flexible and mechanically robust superhydrophobic F-SiO2@PDMS coating through a facile layer-by-layer strategy. It was demonstrated that PDMS played a crucial role of binder for immobilizing the F-SiO2 nanoparticles and improving their adhesion to substrate materials. Meanwhile, the PDMS layer endowed the superhydrophobic coating with superior mechanical flexibility. Finally, the as-constructed superhydrophobic coating exhibited excellent water-repellency with a high water contact angle of 156.5° and low sliding angle of only 2.0°. Furthermore, the water adhesion strength on the superhydrophobic coating was only 2 mN, indicating its ultralow viscous resistance to dynamic moving water droplets. The superhydrophobic F-SiO2@PDMS coating was independent of the substrates without any limitations, and they exhibited high flexibility and mechanical robustness with the elongation ratio reaching 83.3% under the conditions of high superhydrophobicity. Also, the superhydrophobic coating exhibited strong durability under the severe environments of corrosion and mechanical abrasion. Thus, the as-fabricated highly flexible and mechanically robust superhydrophobic F-SiO2@PDMS coating is considered to be an ideal candidate for applications in the fields of self-cleaning and drag-reduction.
关键词： F-SiO2@PDMS,drag-reduction,mechanical robustness,superhydrophobic coatings,self-cleaning
更新于2025-09-04 15:30:14
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[IEEE 2018 13th European Microwave Integrated Circuits Conference (EuMIC) - Madrid, Spain (2018.9.23-2018.9.25)] 2018 13th European Microwave Integrated Circuits Conference (EuMIC) - Robust X-band GaN LNA with Integrated Active Limiter
摘要： In this paper, design and measurement of X-Band monolithic microwave integrated circuit (MMIC) low noise amplifiers (LNA) using a commercial 0.25 um microstrip GaN-on-SiC high electron mobility transistor (HEMT) technology are reported. Using a novel active limiting approach in measurements, lower than 1.75 dB noise figure (NF) and higher than 16 W CW input power survivability is obtained from a single chip. To the best of authors’ knowledge, said LNA has the highest input power handling performance for the given noise figure level although transistors are not optimized for low-noise operation and input matching network is realized to compromise between noise figure and input return loss which is better than 10 dB. Results are promising for single chip GaN frontend transceiver architecture realization.
关键词： X-Band,MMIC,active limiter,LNA,survivability,robustness,GaN
更新于2025-09-04 15:30:14
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Robust fusion algorithm based on RBF neural network with TS fuzzy model and its application to infrared flame detection problem
摘要： A robust fusion algorithm based on Radial Basis Function (RBF) neural network with Takagi-Sugeno (TS) fuzzy model is proposed in view of the data loss, data distortion or signal saturation which is usually occurred in the process of infrared flame detecting with multiple sensors. To initialize the model, the traditional K-means clustering algorithm is used to obtain the number of the fuzzy rules and the center of the membership function. Compared with the traditional RBF neural network with TS fuzzy model, the output of the node in the proposed model is constructed taking into account the membership degree of the feature components in each item of the output polynomial of the hidden layer nodes in consequent fuzzy network. A new weighted activation degree (WAD) is defined to calculate the firing strength (i.e., fuzzy rule applicability) of the fuzzy node instead of the commonly used Mahalanobis distance. The feature representation coefficients used in the above WAD fully consider the variant representation degree of different features in different fuzzy clusters, thus the developed method can deal with the abnormal outputs of the fuzzy rules caused by the variation of the feature components of the raw data obtained from the complex industrial environments. The robustness of the proposed approach is validated with experimental data obtained from a developed triple-channel infrared flame detector and the experiment results show that the convergence rate, accuracy and generalization ability of the proposed method are improved compared with the traditional RBF neural network with TS fuzzy model in [1] and the GA-BP (Genetic Algorithm-Back Propagation) model in [2]. In particular, the required number of the hidden layer nodes in the proposed approach is the least among the aforementioned methods.
关键词： robustness,feature representation coefficient,Infrared flame detector,TS fuzzy model,RBF neural network
更新于2025-09-04 15:30:14
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[IEEE 2018 IEEE 6th Workshop on Wide Bandgap Power Devices and Applications (WiPDA) - Atlanta, GA, USA (2018.10.31-2018.11.2)] 2018 IEEE 6th Workshop on Wide Bandgap Power Devices and Applications (WiPDA) - New Short Circuit Failure Mechanism for 1.2kV 4H-SiC MOSFETs and JBSFETs
摘要： The short circuit (SC-SOA) capability of power devices is crucial for power systems. In this paper, 1.2 kV SiC MOSFETs and JBSFETs are characterized, and their SC-SOA behavior was tested and analyzed. Due to the lower saturated drain current, the JBSFETs were found to have superior SC-SOA compared with MOSFETs despite the integrated Schottky contact. A new short circuit failure mechanism related to melting of the top Al metallization is proposed based up on non-isothermal TCAD numerical simulations supported with SEM measurements of failed die using Energy Dispersive X-ray Spectroscopy (EDS) analysis.
关键词： JBSFET,Robustness,MOSFET,Reliability,Silicon Carbide,4H-SiC,Failure Mechanism,Short Circuit,Ruggedness
更新于2025-09-04 15:30:14