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排序方式: 共有558条查询结果,搜索用时 46 毫秒
91.
Fatma M. El-Ghamry Walid El-Shafai Mahmouad I. Abdalla Ghada M. El-Banby Abeer D. Algarni Moawad I. Dessouky Adel S. Elfishawy Fathi E. Abd El-Samie Naglaa F. Soliman 《计算机、材料和连续体(英文)》2022,71(3):4457-4487
Recently, ground-penetrating radar (GPR) has been extended as a well-known area to investigate the subsurface objects. However, its output has a low resolution, and it needs more processing for more interpretation. This paper presents two algorithms for landmine detection from GPR images. The first algorithm depends on a multi-scale technique. A Gaussian kernel with a particular scale is convolved with the image, and after that, two gradients are estimated; horizontal and vertical gradients. Then, histogram and cumulative histogram are estimated for the overall gradient image. The bin values on the cumulative histogram are used for discrimination between images with and without landmines. Moreover, a neural classifier is used to classify images with cumulative histograms as feature vectors. The second algorithm is based on scale-space analysis with the number of speeded-up robust feature (SURF) points as the key parameter for classification. In addition, this paper presents a framework for size reduction of GPR images based on decimation for efficient storage. The further classification steps can be performed on images after interpolation. The sensitivity of classification accuracy to the interpolation process is studied in detail. 相似文献
92.
Mohamed B. Elamien Soliman A. Mahmoud 《Analog Integrated Circuits and Signal Processing》2018,97(2):225-241
This paper proposes a novel highly linear digitally programmable fully differential operational transconductance amplifier (DPOTA) circuit. Two versions of the proposed DPOTA structure are designed. The first version is optimized for high-frequency operation with current division networks designated to 3-bit control code words. On the other hand, the second version is optimized for low-frequency operation with 4-bit control code words. The third-order harmonic distortion (HD3) of the first DPOTA version remains below ? 66 dB up to 0.4 V differential input voltage at 10 MHz frequency. The second DPOTA version achieved HD3 of ? 70 dB with an amplitude of 20 mVp–p and at 100 Hz frequency. The proposed circuits are designed and simulated in 90 nm CMOS model, BSIM4 (level 54) under a balanced 1.2 V supply voltage. 相似文献
93.
Ahmed Soltan Ahmed G. Radwan Ahmed M. Soliman 《International Journal of Circuit Theory and Applications》2016,44(1):85-97
This paper introduces for the first time the generalized concept of the mutual inductance in the fractional‐order domain where the symmetrical and unsymmetrical behaviors of the fractional‐order mutual inductance are studied. To use the fractional mutual inductance in circuit design and simulation, an equivalent circuit is presented with its different conditions of operation. Also, simulations for the impedance matrix parameters of the fractional mutual inductance equivalent circuit using Advanced Design System and MATLAB are illustrated. The Advanced Design System and MATLAB simulations of the double‐tuned filter based on the fractional mutual inductance are discussed. A great matching between the numerical analysis and the circuit simulation appears, which confirms the reliability of the concept of the fractional mutual inductance. Also, the analysis of the impedance matching using the fractional‐order mutual inductance is introduced. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
94.
Samah M S El‐Shafei Sally S Sakr Nagwa H I Abou‐Soliman 《International Journal of Dairy Technology》2020,73(1):126-133
This study investigated the impact of supplementing goats' milk with quinoa extracts, in the range of 5, 10 and 15 g/100 g on the milk fermentation. The properties of yoghurt produced from this milk, which include viscosity, microstructure and sensory acceptability, were assessed. The supplementation of goats' milk with quinoa extracts, particularly permeate extract, reduced the fermentation time and enhanced the viability of lactic acid bacteria. Supplementation of yoghurt with increased levels of quinoa extracts increased the apparent viscosity and changed the yoghurt protein matrix. Panellists highly accepted the yoghurt that contained quinoa permeate extract. 相似文献
95.
In this paper, the effect of the testing technique in the method of moments (MoM) solution for multiconductor transmission lines is investigated. Two important testing techniques, namely, Galerkin and razor‐blade testing, are used and compared. The problem is formulated using the mixed potential integral equation. The analysis shows that the solution of the longitudinal modal current near the edge of the conductor is significantly affected by the testing scheme in the MoM kernel. For the selected expansion functions, razor‐blade testing gives more reasonable modal current distribution than Galerkin testing. © 2000 John Wiley & Sons, Inc. Int J RF and Microwave CAE 10: 132–138, 2000. 相似文献
96.
Ahmed M. Soliman Ramy A. Saad 《International Journal of Circuit Theory and Applications》2010,38(8):787-795
The voltage mirror–current mirror (VM–CM) pair is shown to be a universal active element. It provides two alternative realizations for the nullor. The VM–CM pair is also capable of realizing the op amp and all the four types of the current conveyors namely CCII?, CCII+, ICCII? and ICCII+ as special cases. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
97.
M. Feteha Sh. Ebrahim M. Soliman W. Ramdan M. Raoof 《Journal of Materials Science: Materials in Electronics》2012,23(11):1938-1943
In the present work, mercaptopropionic acid (MPA) capped CdTe and CdHgTe quantum dots (QDs) are synthesized using a method based on the bottom up approach in aqueous medium. The CdTe QDs were prepared with a two different ratios of Cd:Te (3:1 and 4:1). It was noticed that there was a minimum concentration of MPA for each Cd:Te ratio. The resulting QDs were characterized using optical absorption spectroscopy, energy dispersion X-ray (EDX) and high resolution transmission electron microscopy (HRTEM). It was found that the EDXs of CdTe and CdHgTe QDs showed that the stiochiometric ratios of CdTe obtained with Cd:Te ratio of 3:1 is 50:50 and for CdHgTe is 40:26:34 for 100?% of Hg. The band gap of CdHgTe QDs varies slightly with composition from 2.21?eV for a pure CdTe to 1.4?eV for a CdHgTe with 100?% of Hg. The HRTEM image showed a good dispersed nano-crystalline structure for the CdTe QDs with average size of 3–4?nm. The existence of the lattice planes on the HRTEM images of the QD indicated that the CdTe QDs are highly crystalline. In addition, the CdHgTe QDs size is 12?nm for 100?% of Hg. 相似文献
98.
Soliman AR Helmy S 《Hemodialysis international. International Symposium on Home Hemodialysis》2010,14(4):523-525
Neurological and psychiatric symptoms are common presentations, but are often ignored in fresh salted gray Mullet fish intoxication. We report 2 patients with chronic renal failure at a predialyzed stage who developed refractory status epilepticus after ingestion of putrid salted gray Mullet. We warn consultant neurologists that fresh salted gray Mullet fish intoxication must be considered when patients with chronic kidney disease present with seizures or other unexplained neurological or psychiatric symptoms. 相似文献
99.
The objective of this study is to examine the transient single-phase thermal behavior of micro-channel heat sinks during startup and over a short-duration power surge, and to investigate the effects of property and geometry parameters on this behavior. The transient analysis required the solution of three-dimensional conjugate heat transfer in the heat sink. These solutions were obtained numerically using the finite control-volume method and the numerical accuracy of the results was carefully assessed. Accuracy of the numerical model was validated by comparisons with available experimental data. The behavior of heat sinks with different values for the fin width, channel width, material thickness between the top of the channels and top of the heat sink, and different sink materials was examined during startup from a uniform initial temperature with a uniform input heat flux, followed by a short-duration power surge from the steady-state condition. It is concluded that increasing the fin width or channel width increases the steady-state and maximum transient temperatures in the solid, and that increasing the material thickness between the heat-sink channels and the chip or using a material with larger density and specific heat increases the transient period and lowers the maximum transient temperature in the solid during the power surge. 相似文献
100.
M. Eid M. B. El-Arnaouty M. Salah El-Sayed Soliman El-Sayed A. Hegazy 《Journal of Polymer Research》2012,19(3):9835
A series of PVA/PVP based hydrogels at different compositions were prepared by gamma irradiation. The gel fraction degree
of swelling were investigated. Highly stable and uniformly distributed silver nanoparticles have been obtained onto hydrogel
networks. The morphology and structure of (PVA/PVP) hydrogel and dispersion of the silver nanoparticles in the polymeric matrix
were examined by scanning electron microscopy (SEM) and infrared spectroscopy (FT-IR), respectively. The formation of silver
nanoparticles has been confirmed by ultraviolet visible (UV–vis) spectroscopy. A strong characteristic absorption peak was
found to be around 420 nm for the silver nanoparticles in the hydrogel nanocomposite. The X-ray diffraction pattern confirmed
the formation of silver nanoparticles with average particle size of 12 nm. The diameter distribution of silver nanoparticles
was determined by dynamic light scattering DLS. Transmission electron microscope (TEM) showed almost spherical and uniform
distribution of silver nanoparticles through the hydrogel network and the mean size of silver nanoparticles ranging is 23 nm.
The good swelling properties and antibacterial of PVA/PVP-Ag hydrogel suggest that it can be a good candidate as wound dressing. 相似文献