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OPTIMal CONTROL OF AN M/G/1 RETRIal QUEUE WITH VACATIONS

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Journal of Systems Science and Systems Engineering 2008年第4期17卷 487-502页

作者： amar AISSANI University of Science & Technology Houari Boumediene BP 32 El alia Bab-Ez-Zouar 16111Algeria

In this note, we consider an M/G/1 retrial queue with server vacations, when retrial times, service times and vacation times are arbitrary distributed. The distribution of the number of customers in the system in stationary regime is obtained in terms of generating function. Next, we give heavy traffic approximation of such distribution. We show that the system size can be decomposed into two random variables, one of which corresponds to the system size of the ordinary M/G/1 FIFO queue without vacation. Such a stochastic decomposition property is useful for the computation of performance measures of interest. Finally, we solve simple problems of optimal control of vacation and retrial policies.

关键词： Retrial queues vacation optimal control stochastic decomposition ageing distribution heavy traffic

A New Enhanced Arabic Light Stemmer for IR in Medical Documents

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Computers, Materials & Continua 2021年第7期68卷 1255-1269页

作者： Ra’ed M.al-Khatib Taha Zerrouki Mohammed M.Abu Shquier amar Balla Asef al-Khateeb Department of Computer Sciences Yarmouk UniversityIrbid21163Jordan Faculty of Sciences and Applied Sciences Bouira UniversityBouiraAlgeria Faculty of Computer Science and Information Technology Jerash UniversityJordan Ecole Nationale Supérieure d’Informatique(ESI) AlgiersAlgeria Department of Computer Science College of Shari’a and Islamic Studies in Al AhsaaImam Mohammad Ibn Saud Islamic University(IMSIU)Saudi Arabia

This paper introduces a new enhanced Arabic stemming algorithm for solving the information retrieval problem,especially in medical *** proposed algorithm is a light stemming algorithm for extracting stems and roots from the input *** of the main challenges facing the light stemming algorithm is cutting off the input word,to extract the initial *** initiating the light stemmer with strong initial segments,the final extracting stems and roots will be more ***,a new enhanced segmentation based on deploying the Direct Acyclic Graph(DAG)model is *** addition to extracting the powerful initial segments,the main two procedures(i.e.,stems and roots extraction),should be also reinforced with more efficient operators to improve the final *** validate the proposed enhanced stemmer,four data sets are *** achieved stems and roots resulted from our proposed light stemmer are compared with the results obtained from five other well-known Arabic light stemmers using the same data *** evaluation process proved that the proposed enhanced stemmer outperformed other comparative stemmers.

关键词： Machine learning information retrieval systems medical documents stemming algorithms arabic light stemmer natural language processing

Finite element analysis of slope stability by expanding the mobilized principal stress Mohr's circles-Development, encoding and validation

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Journal of Rock Mechanics and Geotechnical Engineering 2022年第4期14卷 1165-1179页

作者： Djillali amar Bouzid Department of Civil Engineering Faculty of TechnologyUniversity of Blida 1Blida09000Algeria

In recent years,finite element analysis is increasingly being proposed in slope stability problems as a competitive method to traditional limit equilibrium methods(LEMs)which are known for their inherent ***,the application of finite element method(FEM)to slope stability as a strength reduction method(SRM)or as finite element limit analysis(FELA)is not always a success for the drawbacks that characterize both *** increase the performance of finite element analysis in this problem,a new approach is proposed in this *** consists in gradually expanding the mobilized stress Mohr’s circles until the soil failure occurs according to a prescribed non-convergence *** present approach called stress deviator increasing method(SDIM)is considered rigorous for three main ***,it preserves the definition of the factor of safety(FOS)as the ratio of soil shear strength to the mobilized shear ***,it maintains the progressive development of shear stress resulting from the increase in the principal stress deviator on the same plane,on which the shear strength takes ***,by introducing the concept of equivalent stress loading,the resulting trial stresses are checked against the violation of the actual yield criterion formed with the real strength parameters rather than those reduced by a trial *** new numerical procedure was encoded in a Fortran computer code called S^(4)DINA and verified by several *** with other numerical methods such as the SRM,gravity increasing method(GIM)or even FELA by assessing both the FOS and contours of equivalent plastic strains showed promising results.

关键词： Slope stability,Finite element analysis Strength reduction method(SRM),Stress point-based factor of safety(FOS),Limit equilibrium method(LEM),Stress deviator Mohr’s circle,Plastic strain

THE LERAy-SCHAUDER CONDITION FOR 1-SET WEAKLy-CONTRACTIVE AND(ws)-COMPACT OPERATORS

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Acta Mathematica Scientia 2014年第2期34卷 263-273页

作者： Afif BEN amar Department of Mathematics Faculty of Sciences

Abstract The main purpose of this article is to prove a collection of new nxea point theorems for （ws）-compact and so-called 1-set weakly contractive operators under Leray- Schauder boundary condition. We also introduce the concept of semi-closed operator at the origin and obtain a series of new fixed point theorems for such class of operators. As consequences, we get new fixed point existence for （ws）-compact （in particular nonexpansive） self mappings unbounded closed convex subset of Banach spaces. The main condition in our results is formulated in terms of axiomatic measures of weak noncompactness. Later on, we give an application to generalized Hammerstein type integral equations.

关键词： Measure of weak noncompactness weakly condensing and weakly nonexpan-sire (ws)-compact operator fixed point theorems semi-closed at the origin

Are environment-related technologies key to unlock the path towards sustainable development:An econometric analysis

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Geoscience Frontiers 2024年第4期15卷 437-448页

作者： amar Rao Satish Kumar School of Management BML Munjal UniversityGurugramHaryanaIndia Indian Institute of Management Nagpur India

The objective of this study is to investigate the correlation between energy intensity and environmentrelated technology in industrialized *** utilizing panel data from 23 countries over a span of 32 years(1990-2021),this research aims to contribute to the comprehension of the role of green innovation in sustainable *** study employs the Stochastic Impacts by Regression on Population,Affluence,and Technology model while controlling for variables including population growth,gross domestic product in purchasing power parity,Information and Communication Technology capital deepening,renewable energy consumption,and green innovation represented by research and development expenditure on environment-related *** results of the analysis,employing panel unit root tests,cross-sectional dependence tests,and a Method of Moments quantile regression,reveal that green innovation has a positive influence on diminishing energy intensity,with a more substantial impact at higher ***,ICT capital deepening is determined to have a positive and noteworthy effect on reducing energy *** findings of this study offer valuable insights for policymakers in their endeavours to accomplish sustainable development goals.

关键词： Technology Sustainable development Energy intensity Quantile regression

THE EFFECT OF SUBSTITUENT ON THE THERMal PROPERTIES OF POLyESTERS CONSISTING OF AROMATIC TyPE SCHIFF BASE MESOGENIC UNITS AND POLyMETHyLENE SPACERS

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Chinese Journal of Polymer Science 1995年第1期13卷 51-58页

作者： amar H.al-Dujaili Iman F.Mustafa Amir T.Atto Department of Chemistry College of Education Ibn Al-Hytham University of Baghdad Baghdad P. O. Box 7358 IraqDepartment of Chemistry College of Education Ibn Al-Hytham University of Baghdad Baghdad P. O. Box 7358 IraqDepartment of Chemistry College of Sciences University of Sadaam Baghdad Iraq

Polyesters consisting of substituted aromatic type Schiff base mesogenic unit andpolymethylene spacers were synthesized and their thermal transitions and liquid crystallineproperties were studied. The liquid crystalline behaviour has been characterized by differentialscanning calorimetry (DSC) and optical polarizing microscopy. Structural broadening bysubstitution of methoxy group in 2, 2' positions of the mesogenic core produce polymers withlower transition temperatures. Polymers synthesized from ortho and meta substituted phenylenediamine did not form a liquid crystal phase.

关键词： Liquid crystal polymer Polyesters Aromatic type schiff base Mesogenic units Spacers

Prognostic value of baseline FDG uptake on PET-CT in esophageal carcinoma

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World Journal of Gastrointestinal Oncology 2014年第5期6卷 139-144页

作者： Omar S al-Taan amar Eltweri David Sharpe Peter M Rodgers Sukhbir S Ubhi David J Bowrey Departments of Surgery University Hospitals of Leicester Departments of Radiology University Hospitals of Leicester

AIM: To evaluate the influence of baseline maximum standardized uptake value(SUVmax) on survival in a cohort of patients, undergoing positron emission tomography-computed tomography(PET-CT) scan for esophageal carcinoma. METHODS: The pre-treatment SUVmax numeric reading was determined in patients with confirmed esophageal or junctional cancer having PET-CT scan during the time period 1st January 2007 until 31 st July 2012. A minimum follow up of 12 mo was required. Patients were subdivided into quartiles according to SUVmax value and the influence of SUVmax on survival was assessed using univariate and multivariate analysis. The following pre-treatment factors were investigated: patient characteristics, tumor characteristics and planned treatment. RESULTS: The study population was 271 patients(191male) with esophageal or junctional carcinoma. The median age was 65 years(range 40-85) and histologic subtype was adenocarcinoma in 197 patients and squamous carcinoma in 74 patients. The treatment intent was radical in 182 and palliative in 89 patients. SUVmax was linked to histologic subtype(P = 0.008), tumor site(P = 0.01) and Union for International Cancer Control(UICC) stage(P alysis, prognosis was significantly associated with SUVmax(P = 0.001), T-stage(P alysis, only T-stage and UICC stage remained significant. CONCLUSION: Pretreatment SUVmax was not a useful marker in isolation for determining prognosis of patients with esophageal carcinoma.

关键词： Esophageal neoplasms Fluorodeoxyglucose F18 Positron emission tomography Positron emission tomography-computed tomography Prognosis

Prediction of the final size for COVID-19 epidemic using machine learning:A case study of Egypt

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Infectious Disease Modelling 2020年第1期5卷 622-634页

作者： Lamiaa A.amar Ashraf A.Taha Marwa y.Mohamed Networks and Distributed Systems Department Informatics Research InstituteCity of Scientific Research and Technological ApplicationsSRTA-CITYEgypt Multimedia and Computer Graphics Department Informatics Research InstituteCity of Scientific Research and Technological ApplicationsSRTA-CITYEgypt Department of Mathematics and Computer Science Faculty of ScienceAlexandria UniversityEgypt

COVID-19 is spreading within the sort of an enormous epidemic for the *** epidemic infects a lot of individuals in *** World Health Organization states that COVID-19 could be spread from one person to another at a very fast speed through contact and respiratory *** these days,Egypt and all countries worldwide should rise to an effective step to investigate this disease and eliminate the effects of this *** this paper displayed,the real database of COVID-19 for Egypt has been analysed from February 15,2020,to June 15,2020,and predicted with the number of patients that will be infected with COVID-19,and estimated the epidemic final *** regression analysis models have been applied for data analysis of COVID-19 of *** this study,we’ve been applied seven regression analysis-based models that are exponential polynomial,quadratic,thirddegree,fourth-degree,fifth-degree,sixth-degree,and logit growth respectively for the COVID-19 ***,the exponential,fourth-degree,fifth-degree,and sixth-degree polynomial regression models are excellent models specially fourth-degree model that will help the government preparing their procedures for one *** addition,we have applied the well-known logit growth regression model and we obtained the following epidemiological insights:Firstly,the epidemic peak could possibly reach at 22-June 2020 and final time of epidemic at 8-September ***,the final total size for cases 1.6676Et05 *** action from government of interevent over a relatively long interval is necessary to minimize the final epidemic size.

关键词： COVID-19 Regression analysis model Epidemic model

Nonlinear ion-acoustic solitary waves in an electron-positron-ion plasma with relativistic positron beam

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Chinese Physics B 2018年第10期27卷 471-476页

作者： Ridip Sarma amar P Misra Nirab C Adhikary Department of Mathematics University of Science and TechnologyTechno CityKhanaparaBaridua9th MileRi-BhoiMeghalayaIndia Department of Mathematics Siksha BhavanaVisva-Bharati University Physical Sciences Division Institute of Advanced Study in Science and TechnologyVigyan PathPaschim BoragaonGarchukGuwahati-781035AssamIndia

The propagation characteristics of nonlinear ion–acoustic（IA） solitary waves（SWs） are studied in thermal electron–positron–ion plasma considering the effect of relativistic positron beam. Starting from a set of fluid equations and using the reductive perturbation technique, we derive a Korteweg–de Vries（KdV） equation which governs the evolution of weakly nonlinear IA SWs in relativistic beam driven plasmas. The properties of the IA soliton are studied, and it is shown that the presence of relativistic positron beam significantly modifies the characteristics of IA solitons.

关键词： electron-positron-ion plasma relativistic effect ion-acoustic wave homogeneous balance method