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101.
102.
M. Sh. El-Gayar A. E.-M. Ahmed G. A. Gohar A. H. Hegazi H. M. Ibrahim A. M. Aly 《Petroleum Science and Technology》2013,31(14):1434-1444
Abstract Vacuum distillates of an Egyptian crude oil were subjected to solvent extraction process applying N-methyl-2-pyrrolidone (NMP) and furfural as dearomatization solvents. The study shows that the extraction solvent together with the temperature and solvent-to-oil ratio have a significant effect on the yield and quality of produced lubricating oils. The optimum temperature for extracting light waxy distillates with NMP is 55°C at the solvent-to-feed ratio 2:1. These conditions are appropriate to remove the major portion of aromatics from the raffinate. The apparent activation energy (Ea), enthalpy (ΔH*), entropy (ΔS*), and free energy of activation (ΔG*) were calculated for the solvent dearomatization process. 相似文献
103.
Theoretical bounds for the bit error rate for SAC OCDMA balanced detectors with multiple photodiodes
Alhassan Ahmed M. Badruddin Nasreen Saad N. M. Aljunid S. A. 《Photonic Network Communications》2020,40(1):49-57
Photonic Network Communications - In this paper, we derive the theoretical lower and upper bounds for bit error rate (BER) for spectral amplitude coding OCDMA balanced detector (BD) employing... 相似文献
104.
High-gain observers have been used in non-linear control to estimate derivatives of the output. In this paper, we study discrete-time implementation of high-gain observers and their use as numerical differentiators, in noise-free as well as noisy measurements. We show that discretization using the bilinear transformation method gives better results than other discretization methods. We also show that many of the available numerical differentiators are special cases of the bilinear discrete-time equivalents of full-order or reduced-order high-gain observers. 相似文献
105.
Tariq Mahmood Syed Imran Jami Zubair Ahmed Shaikh Muhammad Hussain Mughal 《Computer Standards & Interfaces》2013,35(1):6-29
In this paper, we implement a provenance-aware system for documenting publications, called PADS. It employs a three-layered provenance hierarchy, which can output diverse types of provenance data related to the research life cycle. From this, we generate different profiles for research ventures, reviewers, and authors. PADS employs the standard Open Provenance Model (OPM) specification for capturing provenance data, and stores this data as ontological instances. We show that data is retrieved without any apparent delay in the execution time of the queries. We also demonstrate how this data can be used to make useful recommendations to the organizers, in order to manage upcoming research ventures. 相似文献
106.
The surface tension of silver-copper binary liquid alloys is calculated, in the frame work of Eyring theory. The calculations were made for different compositions (mole fraction, xCu = 0, 0.2, 0.4, 0.6, 0.8 and 1), in the temperature range 1100-1800 K. The surface tension decreases with temperature increase, at a fixed copper fraction xCu, and increases with increasing copper content. The calculated results are appropriately compared with existing literature data. 相似文献
107.
108.
Staples Julie K.; Abdel Atti Jamil Ahmed; Gordon James S. 《Canadian Metallurgical Quarterly》2011,18(3):246
A mind-body skills group program was evaluated to determine its effects on symptoms of posttraumatic stress disorder (PTSD) and depression, and on hopelessness in children and adolescents in Gaza. The 10-session mind-body skills groups included meditation, guided imagery, breathing techniques, autogenic training, biofeedback, genograms, and self-expression through words, drawings, and movement. Data were analyzed from 129 children and adolescents meeting criteria for PTSD. Significant improvements in PTSD and depression symptoms and a significant decrease in a sense of hopelessness were observed immediately following participation in the program. At 7-month follow-up, the improvements in the total PTSD and depression scores were largely maintained and the decreased sense of hopelessness was fully maintained despite ongoing violent conflict and economic hardship. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献
109.
High utility pattern (HUP) mining is one of the most important research issues in data mining. Although HUP mining extracts important knowledge from databases, it requires long calculations and multiple database scans. Therefore, HUP mining is often unsuitable for real-time data processing schemes such as data streams. Furthermore, many HUPs may be unimportant due to the poor correlations among the items inside of them. Hence,the fast discovery of fewer but more important HUPs would be very useful in many practical domains. In this paper, we propose a novel framework to introduce a very useful measure, called frequency affinity, among the items in a HUP and the concept of interesting HUP with a strong frequency affinity for the fast discovery of more applicable knowledge. Moreover, we propose a new tree structure, utility tree based on frequency affinity (UTFA), and a novel algorithm, high utility interesting pattern mining (HUIPM), for single-pass mining of HUIPs from a database. Our approach mines fewer but more valuable HUPs, significantly reduces the overall runtime of existing HUP mining algorithms and is applicable to real-time data processing. Extensive performance analyses show that the proposed HUIPM algorithm is very efficient and scalable for interesting HUP mining with a strong frequency affinity. 相似文献
110.
Imtnan-Ul-Haque Qazi Author Vitae Olivier Alata Author Vitae Author Vitae Ahmed Moussa Author Vitae Author Vitae 《Pattern recognition》2011,44(1):16-31
This article presents a comparison of different color spaces including RGB, IHLS and L?a*b* for color texture characterization. This comparison is based on the fusion of the independent spatial structure and color feature cues. In IHLS and L*a*b*, two channel complex color images are created from the luminance and the chrominance values. For such images, two dimensional complex multichannel linear prediction models are used to perform parametric power spectrum estimation and the structure feature cues are computed from this estimated power spectrum. Quantitative comparison of auto spectra of luminance and combined chrominance channels for different color spaces is done. This comparison is based on the degree of decorrelation between luminance and chrominance information provided by different color space transformations. Three dimensional histograms are used as color feature cues. Then, to classify color textures, Kullback-Leibler divergence based symmetric distance measures are calculated for pure color, luminance structure and chrominance structure feature cues. Individual as well as combined effect of information from all feature cues on classification results is then compared for different color spaces and different color texture data sets. The proposed color texture classification method performs better than the state of the art methods in certain cases. The L*a*b* color space gives us a better characterization of the chrominance spatial structure as well as the overall spatial structure for all of the chosen data sets. Experimental results on pixel classification of color textures are also presented and discussed. 相似文献