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Communications in Theoretical Physics 2023年第6期75卷 39-50页

作者： H I abdel-Gawad Mathematics Department Faculty of Science Cairo University GizaEgypt

The wave-operator nonlinear Schrödinger equation was introduced in the ***,nonlocal space-time reverse complex field equations were also recently *** in this area were focused on employing the inverse scattering method and Darboux ***,we present an approach to find the solutions of the wave-operator nonlinear Schrödinger equation with space and time reverse(W-O-NLSE-STR).It is based on implementing the unified method together with introducing a conventional formulation of the ***,a field and a reverse field may be ***,for deriving the solutions of W-O-NLSE-STR,it is evident to distinguish two cases(when the field and its reverse are interactive or not-interactive).In the non-interactive and interactive cases,exact and approximate solutions are *** both cases,the solutions are evaluated numerically and they are displayed *** is observed that the field exhibits solitons propagating essentially(or mainly)on the negative space variable,while those of the reverse field propagate on the other side(or vice versa).These results are completely novel,and we think that it is an essential behavior that characterizes a complex field system with *** the other hand,they may exhibit right and left cable patterns(or vice versa).It is found that the solutions of the field and its reverse exhibit self-phase modulation by solitary *** the interactive case,the pulses of the field and its reverse propagate in the whole *** analysis of modulation stability shows that,when the field is stable,its reverse is unstable or both are *** holds whenever the polarization of the medium is selfdefocusing.

关键词： wave-operator nonlinear Schrödinger equation space-time reverse unified method

A ROUGH SET APPROACH TO FEATURE SELECTION BASED ON SCATTER SEARCH METAHEURISTIC

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Journal of Systems Science & Complexity 2014年第1期27卷 157-168页

作者： WANG Jue ZHANG Qi abdel-RAHMAN Hedar abdel-MONEM M Ibrahim Center for Forecasting Science Academy of Mathematics and System Science Chinese Academy of ScienceBeijing 100190 China. Department of Computer Science Faculty of Computers and Information Assiut University Assiut 71516Egypt.

Rough set theory is an effective method to feature selection, which has recently fascinated many researchers. The essence of rough set approach to feature selection is to find a subset of the original features. It is, however, an NP-hard problem finding a minimal subset of the features, and it is necessary to investigate effective and efficient heuristic algorithms. This paper presents a novel rough set approach to feature selection based on scatter search metaheuristic. The proposed method, called scatter search rough set attribute reduction （SSAR）, is illustrated by 13 well known datasets from UCI machine learning repository. The proposed heuristic strategy is compared with typical attribute reduction methods including genetic algorithm, ant colony, simulated annealing, and Tabu search. Computational results demonstrate that our algorithm can provide efficient solution to find a minimal subset of the features and show promising and competitive performance on the considered datasets.

关键词： Attribute reduction computational intelligence metaheuristics rough set scatter search.

Finite element modeling assumptions impact on seismic response demands of MRF-buildings

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Earthquake Engineering and Engineering Vibration 2018年第4期17卷 821-834页

作者： Shehata E abdel Raheem Ahmed K abdel Zaher Ahmed MA Taha Civil Engineering Department Engineering College Taibah University Civil Engineering Department Faculty of Engineering Assiut University

Recent seismic events have raised concerns over the safety and vulnerability of reinforced concrete moment resisting frame ＂RC-MRF＂ buildings. The seismic response of such buildings is greatly dependent on the computational tools used and the inherent assumptions in the modelling process. Thus, it is essential to investigate the sensitivity of the response demands to the corresponding modelling assumption. Many parameters and assumptions are justified to generate effective structural finite element（FE） models of buildings to simulate lateral behaviour and evaluate seismic design demands. As such, the present study focuses on the development of reliable FE models with various levels of refinement. The effects of the FE modelling assumptions on the seismic response demands on the design of buildings are investigated. the predictive ability of a FE model is tied to the accuracy of numerical analysis; a numerical analysis is performed for a series of symmetric buildings in active seismic zones. The results of the seismic response demands are presented in a comparative format to confirm drift and strength limits requirements. A proposed model is formulated based on a simplified modeling approach, where the most refined model is used to calibrate the simplified model.

关键词： RC-MRF buildings design codes provisions seismic design finite element modeling modeling assumptions response demands

Evaluation of the 8th AJCC staging system for pathologically versus clinically staged pancreatic adenocarcinoma: A time to revisit a dogma?

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Hepatobiliary & Pancreatic Diseases International 2018年第1期17卷 64-69页

作者： Omar abdel-Rahman Clinical Oncology Department Faculty of Medicine Ain Shams University

Background: The 8 th edition of the American Joint Committee on Cancer(AJCC) staging system for pancreatic exocrine adenocarcinoma has been released. The current study seeks to assess the 7 th and 8 th editions among patients registered within the surveillance, epidemiology and end results(SEER) ***: SEER database(2010–2013) has been accessed through SEER*Stat program and AJCC 8 th edition stages were reconstructed utilizing the collaborative stage descriptions. Kaplan–Meier analysis of overall survival and pancreatic cancer-specific survival analyses(according to both 7 th and 8 th editions and according to whether pathological or clinical staging were conducted) has been performed. Multivariate analysis of factors affecting pancreatic cancer-specific survival was also conducted through a Cox proportional hazard ***: A total of 18 948 patients with pancreatic adenocarcinoma were identified in the period from 2010–2013. Pancreatic cancer-specific survival among pathologically staged patients and according to the 8 th edition showed significant differences for all pair wise comparisons among different stages(P < 0.0001) except for the comparison between stage IA and stage IB(P = 0.307) and the comparison between stage IB and stage IIA(P = 0.116). Moreover, P value for stage IA vs IIA was 0.014; while pancreatic cancer-specific survival according to the 7 th edition among pathologically staged patients showed significant differences for all pair wise comparisons among different stages(P < 0.0001) except for the comparison between IA and IB(P = 0.072), the comparison between stage IIA and stage IIB(P = 0.065), the comparison between stage IIA and stage Ⅲ(P = 0.059) and the comparison between IIB and Ⅲ(P = 0.595).Among clinically staged patients(i.e. those who did not undergo initial radical surgery), the prognostic performance of both 7 th and 8 th stages for both overall survival and pancreatic cancer-specific survival was ***: Th

关键词： Pancreatic cancer AJCC SEER Prognosis

Upgrading of Industrial Wastewater Treatment Units at Automobile Industry

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Biomedical and Environmental Sciences 2000年第3期13卷 219-224页

作者： abdel Wahaab R Water Pollution Research Department National Research CenterCairoEgypt

Industrial wastewater is one of the major sources of water pollution in *** principal hazard to public health caused by industrial wastes is pollution with toxic materials,which may enter a municipal water supply or may be harmful to people using the stream for recreatinal *** wastes can damage aquatic life,sewer fabric and interfere with the operation of treatment ***,persistent untreated pollutats passing through these systems may contaminate receving water bodies and incresae the cost and environmental risks of sludge treatment and disposal.

关键词： Upgrading of Industrial Wastewater Treatment Units at Automobile Industry

An application of a simple computer program for neutron activation analysis

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Journal of Environmental Sciences 2001年第1期13卷 22-24页

作者： N.abdel Basset Nuclear Physics Laboratory Ain Shams UniversityFaculty of Girs-HeliopolisCairoEgypt

A simple computer program is designed for estimation of elemental concentration values in complex samples by neutron activation analysis technique. The program is applied for an Egyptian cement sample which irradiated at the Egyptian Research Reactor 1(ET RR 1). The data obtained is compared with the reported values. The time consumed for such calculations has a remarkable reduction in comparison with the routine work.

关键词： neutron activation analysis cement sample Egypt

Self-phase modulation via similariton solutions of the perturbed NLSE Modulation instability and induced self-steepening

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Communications in Theoretical Physics 2022年第8期74卷 41-50页

作者： H I abdel-Gawad Department of Mathematics Faculty of Science Cairo University Egypt

The perturbed nonlinear Schrodinger equation(PNLSE)describes the pulse propagation in optical fibers,which results from the interaction of the higher-order dispersion effect,self-steepening(SS)and self-phase modulation(SPM).The challenge between these aforementioned phenomena may lead to a dominant one among *** is worth noticing that the study of modulation instability(MI)leads to the inspection of dominant phenomena(DPh).Indeed,the MI triggers when the coefficient of DPh exceeds a critical value and it may occur that the interaction leads to wave *** PNLSE is currently studied in the literature,mainly on finding traveling wave ***,we are concerned with analyzing the similarity solutions of the *** exact solutions are obtained via introducing similarity transformations and by using the extended unified *** solutions are evaluated numerically and they are shown *** is observed that the intensity of the pulses exhibits self steepening which progresses to shock soliton in ultrashort time(or near t=0).Also,it is found that the real part of the solution exhibits self-phase modulation in *** study of(MI)determines the critical value for the coefficients of SS,SPM,or high dispersivity to occur.

关键词： Perturbed NLSE steepening self–phase modulation extended unified method

The effect of atomic spontaneous decay on the dynamics of the negativity of the Wigner function of radiation

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Chinese Physics B 2011年第9期20卷 44-48页

作者： abdel-Baset A.Mohamed Faculty of Science Assiut UniversityAssiutEgypt

The exact solution of the master equation for the case of a high-Q cavity with atomic decay is found. We use the negativity of the Wigner function （WF） as an indicator of nonclassicality. It is found that the negative values of the field WF are very sensitive to any change in the damping parameter. The atomic spontaneous decay leads to the simultaneous disappearance of both entanglement and nonclassicality of quantum states. Moreover, the purity of the field states is completely lost.

关键词： non-classicality entanglement atomic decay

Seismic response of skewed RC box-girder bridges

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Earthquake Engineering and Engineering Vibration 2008年第4期7卷 415-426页

作者： Ahmed abdel-Mohti Gokhan Pekcan Civil and Environmental Engineering Department University of Nevada Reno

It is critical to ensure the functionality of highway bridges after earthquakes to provide access to important facilities. Since the 1971 San Fernando earthquake, there has been a better understanding of the seismic performance of bridges. Nonetheless, there are no detailed guidelines addressing the performance of skewed highway bridges. Several parameters affect the response of skewed highway bridges under both service and seismic loads which makes their behavior complex. Therefore, there is a need for more research to study the effect of skew angle and other related factors on the performance of highway bridges. This paper examines the seismic performance of a three-span continuous concrete box girder bridge with skew angles from 0 to 60 degrees, analytically. Finite element （FE） and simplified beam-stick （BS） models of the bridge were developed using SAP2000. Different types of analysis were considered on both models such as： nonlinear static pushover, and linear and nonlinear time history analyses. A comparison was conducted between FE and BS, different skew angles, abutment support conditions, and time history and pushover analysis. It is shown that the BS model has the capability to capture the coupling due to skew and the significant modes for moderate skew angles. Boundary conditions and pushover load profile are determined to have a major effect on pushover analysis. Pushover analysis may be used to predict the maximum deformation and hinge formation adequately.

关键词： skew bridge seismic response pushover analysis time history analysis modeling

A poroelastic numerical model for simulation of hydraulic fracture propagation:Application to Upper Safa formation-Western Desert-Egypt

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Petroleum Research 2020年第1期5卷 39-51页

作者： Reda abdel Azim Petroleum Engineering Department American University of KurdistanDohoukIraq

The hydraulic fracturing in tight sand formations has a significant importance in improving its production *** this study,a poroelastic numerical model is presented in order to study the reservoirs and rock mechanical properties that affect the propagation of the hydraulic *** poroelastic model simulate fully coupled fluid flow,pressures and stress changes by using finite element *** results show that the formation permeability and fracture toughness are key parameters in the design of hydraulic fracture treatment.A case study applied in Upper Safa formation in a well-located western desert *** formation is very tight with permeability of 0.1md and the objective here is to optimize the design procedures for hydraulic fracture *** results show that the formation needs to be pumped for about 5min to produce hydraulic fracture length of 182 *** addition,the total pumping time(30 min)is vital to produce the desired total fracture length of 1000 ft.

关键词： Fracture propagation Finite element Upper Safa formation Poroelastic Leak off model