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21.
El-Sayed Ahmed El-Dahshan Tamer Hosny Abdel-Badeeh M. Salem 《Digital Signal Processing》2010,20(2):433-441
This paper presents a hybrid technique for the classification of the magnetic resonance images (MRI). The proposed hybrid technique consists of three stages, namely, feature extraction, dimensionality reduction, and classification. In the first stage, we have obtained the features related to MRI images using discrete wavelet transformation (DWT). In the second stage, the features of magnetic resonance images have been reduced, using principal component analysis (PCA), to the more essential features. In the classification stage, two classifiers have been developed. The first classifier based on feed forward back-propagation artificial neural network (FP-ANN) and the second classifier is based on k-nearest neighbor (k-NN). The classifiers have been used to classify subjects as normal or abnormal MRI human images. A classification with a success of 97% and 98% has been obtained by FP-ANN and k-NN, respectively. This result shows that the proposed technique is robust and effective compared with other recent work. 相似文献
22.
Mohammad Al Hasan Saeed Salem Mohammed J. Zaki 《Knowledge and Information Systems》2011,28(3):665-685
Clustering algorithms generally accept a parameter k from the user, which determines the number of clusters sought. However, in many application domains, like document categorization,
social network clustering, and frequent pattern summarization, the proper value of k is difficult to guess. An alternative clustering formulation that does not require k is to impose a lower bound on the similarity between an object and its corresponding cluster representative. Such a formulation chooses exactly one representative for
every cluster and minimizes the representative count. It has many additional benefits. For instance, it supports overlapping
clusters in a natural way. Moreover, for every cluster, it selects a representative object, which can be effectively used
in summarization or semi-supervised classification task. In this work, we propose an algorithm, SimClus, for clustering with lower bound on similarity. It achieves a O(log n) approximation bound on the number of clusters, whereas for the best previous algorithm the bound can be as poor as O(n). Experiments on real and synthetic data sets show that our algorithm produces more than 40% fewer representative objects,
yet offers the same or better clustering quality. We also propose a dynamic variant of the algorithm, which can be effectively
used in an on-line setting. 相似文献
23.
The staining of intracellular antigenic sites in postembedded samples is a challenging problem. Deterioration of antigenicity and limited antibody accessibility to the antigen are commonly encountered on account of processing steps. In this study preservation of the antigen was achieved by fixing the tissues with mild fixatives, performing partial dehydration, and embedding in a low crosslinked hydrophilic acrylic resin, LR-White. Permeabilization of cell membranes with Triton X-100 is well documented but can affect some antigen conformations. We tested the effect of Triton X-100 on the ED1 antigen present in the lysosomal membrane of the macrophage in cell culture. The ED1 antigen in the lysosome was resistant to extraction by Triton X-100. Interestingly pretreating the LR-White sections of macrophage pellets with Triton X-100 improved the staining intensity of ED1. The most intense and clear specific fluorescent staining was observed when sections were pretreated with 0.2% Triton X-100 for 2 min. Longer exposure of sections to 0.2% Triton or 2 min exposure to 2% Triton lead to reduced ED1 labeling. SEM observations indicated that the detergent extracted a component from the cells and not the resin and was determined to be lipid. This novel technique could be applied in many research areas where postembedding fluorescent immunolabeling with higher labeling intensity is desired. 相似文献
24.
In this paper, we present the concept of work compatibility as an integrated work design criterion that simultaneously improves human health and safety, productivity, and work quality in manufacturing systems. In this respect, we have modeled work compatibility as a work design parameter that mathematically integrates the energizing (i.e., system resources) and the demand (i.e., system requirements) forces in the work system. A mathematical equation has been derived for the work compatibility matrix. Furthermore, an operating zone has been developed in which there is a region of optimality for the employee to function on practical grounds with a good degree of efficiency and sustainability. An application example is provided to demonstrate the potential of work compatibility to improve productivity and quality along with improvement in worker safety and health. © 2004 Wiley Periodicals, Inc. Hum Factors Man 14: 379–402, 2004. 相似文献
25.
J. Habibian A. Salar Elahi M. K. Salem S. Saviz 《Journal of Inorganic and Organometallic Polymers and Materials》2016,26(5):1061-1065
High confinement mode (H-mode) in tokamaks is characterized by the formation of a transport barrier at the edge of the plasma. The H-mode increases the plasma energy confinement time by around a factor of two compared to the Low confinement mode (L-mode). This result made a great step towards achieving the higher temperatures and pressures needed to create ignition conditions. The Grad–Shafranov Equation describes the magnetic flux distribution of plasma in an axisymmetric system like a tokamak. In this paper, we have calculated the magnetic flux surfaces in IR-T1 tokamak by two methods. An analytical solution of magnetic surfaces approximated by equilibrium calculation of GS equation based on first three (and then four) terms of expansion in flux function. Results of two methods are in good agreement with each other. 相似文献
26.
Geoffrey I. Webb Janice R. Boughton Fei Zheng Kai Ming Ting Houssam Salem 《Machine Learning》2012,86(2):233-272
Averaged n-Dependence Estimators (AnDE) is an approach to probabilistic classification learning that learns by extrapolation from marginal to full-multivariate
probability distributions. It utilizes a single parameter that transforms the approach between a low-variance high-bias learner
(Naive Bayes) and a high-variance low-bias learner with Bayes optimal asymptotic error. It extends the underlying strategy
of Averaged One-Dependence Estimators (AODE), which relaxes the Naive Bayes independence assumption while retaining many of
Naive Bayes’ desirable computational and theoretical properties. AnDE further relaxes the independence assumption by generalizing AODE to higher-levels of dependence. Extensive experimental
evaluation shows that the bias-variance trade-off for Averaged 2-Dependence Estimators results in strong predictive accuracy
over a wide range of data sets. It has training time linear with respect to the number of examples, learns in a single pass
through the training data, supports incremental learning, handles directly missing values, and is robust in the face of noise.
Beyond the practical utility of its lower-dimensional variants, AnDE is of interest in that it demonstrates that it is possible to create low-bias high-variance generative learners and suggests
strategies for developing even more powerful classifiers. 相似文献
27.
Ghayth Rigane Mohamed Bouaziz Nidhal Baccar Samira Abidi Sami Sayadi Ridha Ben Salem 《Journal of food science》2012,77(10):C1077-C1083
Abstract: A very simple method is proposed to produce hydroxytyrosol, a commercially unavailable compound with well‐known biological properties which justify a potential commercial application. The 2‐phase Chemlali olive pomace is selected as substrate for chemical treatment. Different conditions of chemical treatment, including concentration of acid and alkaline solutions, time and temperature, were assayed. A high amount of hydroxytyrosol (1360 mg/kg of fresh 2‐phase olive pomace) was obtained using water bath after treatment at 80 °C for 90 min with 1 M of H3PO4. However, treatment of 2‐phase Chemlali olive pomace using autoclave apparatus could produce a large amount of hydroxytyrosol (1993.60 and 1515.88 mg/kg of fresh alperujo, 1 M acid and basic catalyst, respectively). By taking into consideration practical and economic aspects, acid‐catalyzed treatment was more effective using autoclave conditions, whereas the alkali catalyzed conditions were not very suitable. This study could provide useful information for industry to produce the potentially bioactive compound. Practical Application: The 2‐phase Chemlali olive pomace is selected as substrate for chemical treatment. Treatment of “alperujo” using water bath or autoclave apparatus was carried out. A high amount of hydroxytyrosol was obtained using autoclave apparatus. 相似文献
28.
Kilicaslan M. Fatih Altaib Salaheddin Salem Vurdu Can Doğan 《Metals and Materials International》2019,25(6):1457-1466
Metals and Materials International - In this project the morphology and microstructure of both conventional cast and melt spun of Al–20Si–9Fe–1.2Nb and... 相似文献
29.
Ben Ammar Nour Elhouda Essid Rym Saied Taieb en Murat Elkahoui Salem Hamzaoui Ahmed Hichem 《Polymer Bulletin》2020,77(3):1343-1357
Polymer Bulletin - The aim of this study was to elaborate a suitable hydrogel to be used as drug carrier for antileishmanial treatment. Therefore, a PVP hydrogel was synthesized using gamma... 相似文献
30.
Joydev Dinda Lakshmikanta Maity Chen-Shiang Lee Wen-Shu Hwang Salem S. Al-Deyab 《Journal of Inorganic and Organometallic Polymers and Materials》2016,26(5):1037-1042
Starting from tripodal ligand tris-(methyl-imidazole) amine (1) the colourless complex tris-(methyl-imidazole)aminesilver(I)perchlorate (2) has been synthesized, characterized by IR, UV/Vis and 1HNMR spectroscopic studies and finally solid state structure has been established by single crystal X-ray diffraction studies. A single crystal X-ray structure determination revealed the formation of coordination polymer. The crystal structure possesses weak d10–d10 ‘argentophilic’ interactions with Ag–Ag separation (3.348 Å). The weak luminance at 375 nm may be this Ag–Ag weak interaction. The molecule possesses weak H-bonding with C2 and C4H of imidazole with oxygen of ClO4. 相似文献