排序方式: 共有36条查询结果,搜索用时 140 毫秒
31.
Amin Malekmohammadi Mohammed Hayder Al-Mansoori Ahmad Fauzi Abas 《Optics Communications》2010,283(16):3145-3148
We modeled and analyzed a method to improve receiver sensitivity of the Absolute Polar Duty Cycle Division Multiplexing (AP-DCDM) transmission system by using Dual-Drive Mach-Zehnder-Modulator (DD-MZM). It is found that by optimizing the bias voltage in DD-MZM, the sensitivity of the AP-DCDM can be improved. The optimizations lead towards the larger eye opening. As opposed to the previous work, in terms of receiver sensitivity and dispersion tolerance, similar performance for all channels was achieved. In comparison to the previously reported AP-DCDM system, this work resulted in almost 3.6 dB improvement of the receiver sensitivity, came together with acceptable chromatic dispersion tolerance. 相似文献
32.
A stochastic geometrical modeling technique is used to reconstruct a laboratory scale Fontainebleau sandstone with a sidelength of 1.5 cm. The model reconstruction is based on crystallite properties and diagenetic parameters determined from two-dimensional images. The three-dimensional pore scale microstructure of the sandstone is represented by a list of quartz crystallites defined geometrically and placed in the continuum. This allows generation of synthetic μ-CT images of the rock model at arbitrary resolutions. Quantitative microstructure comparison based on Minkowski functionals, two-point correlation function and local porosity theory indicates that this modeling technique can provide more realistic and accurate models of sandstones than many existing techniques used currently. Synthetic μ-CT images at different resolutions from a laboratory scale model of Fontainebleau sandstone are made available to the scientific community for resolution dependent petrophysical analysis. 相似文献
33.
Aida Esmaeilian-Marnani Ahmad Fauzi Abas Mohd Adzir Mahdi Khairulmizam Samsudin 《Optical Review》2012,19(2):71-77
Propagation of temporal 50 femtosecond pulse and pulse stream, which is realized by substituting each input pulse with reduced-order
overlapping soliton pair, is investigated through short standard single-mode fiber. For the pulse stream the initial inter-pulse
delay is selected to be 227 fs and the pulses are to be perturbed to avoid collision with the neighboring pulses. This method
reduces the pulse time delay and properly retains the amplitude despite tradeoff between these two. This is a significant
improvement in the low power femtosecond pulse and pulse stream propagation. 相似文献
34.
In this paper, we present non-identical unsupervised clustering techniques for the segmentation of CT brain images. Prior
to segmentation, we enhance the visualization of the original image. Generally, for the presence of abnormal regions in the
brain images, we partition them into 3 segments, which are the abnormal regions itself, the cerebrospinal fluid (CSF) and
the brain matter. However, for the absence of abnormal regions in the brain images, the final segmented regions will consist
of CSF and brain matter only. Therefore, our system is divided into two stages of clustering. The initial clustering technique
is for the detection of the abnormal regions. The later clustering technique is for the segmentation of the CSF and brain
matter. The system has been tested with a number of real CT head images and has achieved satisfactory results. 相似文献
35.
Saravana Kumar Jaganathan Mohan Prasath Mani Praseetha Prabhakaran Eko Supriyanto Ahmad Fauzi Ismail 《International Journal of Polymer Analysis and Characterization》2019,24(5):457-474
Scaffolds used in skin tissue engineering must mimic the native function of the extracellular matrix (ECM) and facilitate the fibroblast cell response for new tissue growth. In this study, a novel dressing scaffold based on polyurethane (PU) with sesame oil, honey, and propolis was fabricated by electrospinning. Scanning electron microscopy (SEM) images showed that the diameter of the electrospun scaffolds decreased by blending sesame oil (784?±?125.46?nm) and sesame oil/honey/propolis (576?±?133.72?nm) into the PU matrix (890?±?116.911?nm). Fourier infrared (FT-IR) and thermogravimetric (TGA) analysis demonstrated the formation of hydrogen bonds and interaction between PU and sesame oil, honey, and propolis. Contact-angle measurement indicated reduced wettability of PU/sesame oil scaffold (114?±?1.732) and improved wettability (54.33?±?1.528) in the PU/sesame oil/honey/propolis scaffold. Further, tensile tests and atomic force microscopy (AFM) analysis indicated that the fabricated composite membrane exhibited enhanced mechanical strength and reduced surface roughness compared to the pristine PU. The developed composite displayed less toxicity to the red blood cells (RBC’s) compared to the pristine PU. Cytotoxicity assay showed enhanced cell viability of HDF in electrospun scaffolds than pristine PU after 72?h culture. These enhanced properties of the developed scaffolds suggest the potential of utilizing them in skin tissue engineering. 相似文献
36.
M. Zaini Jamaludin M. Khazani Abdullah Fairuz Abdullah A. Fauzi Abas M. Adzir Mahdi Faidz Rahman 《Optics & Laser Technology》2008,40(2):270-272
A new double-pass erbium-doped fiber amplifier (DP-EDFA) using chirped fiber Bragg grating (CFBG) is reported here showing a gain of 53.4 dB and noise figure (NF) of 5.36 dB. The proposed amplifier at the same time provides dispersion compensation through the use of CFBG. 相似文献