检索结果-南通市图书馆

Finite difference analysis of an advance core pre-reinforcement system for Toulon's south tube

在线全文

学校读者我要写书评

暂无评论

Journal of Rock Mechanics and Geotechnical Engineering 2016年第5期8卷 703-713页

作者： fethi kitchah sadok benmebarek MN2I2S Laboratory Department of Civil and Hydraulic EngineeringBiskra UniversityBiskra 07000Algeria

The stability of shallow tunnels excavated in full face has been a major challenge to the scientific community for a long time. In recent years, new techniques based on the installation of a pre-reinforcement system ahead of the tunnel face were developed to control the deformations and surface settlements induced by the excavation and to ensure the sustainability of the tunnel in the long term. In this paper, a finite difference numerical simulation was conducted to study the behaviors and effects of two pre-reinforcement systems, i.e. the face bolting and the umbrella arch system installed in a section of southern Toulon tunnel in France. For this purpose, two approaches were taken and compared： a two-dimensional （2D） approach based on the convergence–confinement method, and a three-dimensional （3D） approach taking into account the complete modeling of the tunnel. A 2D numerical back-analysis was performed to identify the geomechanical parameters that offer satisfactory agreement with the measurement results. The limit of this method lies in the exact choice of the stress relaxation ratio λ. To overcome this uncertainty, a 3D model was developed, which permitted to study the influence of different pre-support systems on the reaction of ground mass. Both 2D and 3D numerical approaches have been fitted to measurements recorded in a section of the Toulon tunnel and the very satisfactory correspondence has allowed validating the simulations. The results show that the 3D numerical analysis with a full discretization of the inclusions seems unquestionably the most reliable approach.

关键词： Face bolting Numerical modeling Pre-reinforcement Stress relaxation ratio Umbrella arch

Interaction analysis of back-to-back mechanically stabilized earth walls

在线全文

学校读者我要写书评

暂无评论

Journal of Rock Mechanics and Geotechnical Engineering 2016年第5期8卷 697-702页

作者： sadok benmebarek Samir Attallaoui Nai'ma benmebarek NMISSI Laboratory Biskra UniversityBiskra 07000Algeria

Back-to-back mechanically stabilized earth walls （BBMSEWs） are encountered in bridge approaches, ramp ways, rockfall protection systems, earth dams, levees and noise barriers. However, available design guidelines for BBMSEWs are limited and not applicable to numerical modeling when back-to-back walls interact with each other. The objective of this paper is to investigate, using PLAXIS code, the effects of the reduction in the distance between BBMSEW, the reinforcement length, the quality of backfill material and the connection of reinforcements in the middle, when the back-to-back walls are close. The results indicate that each of the BBMSEWs behaves independently if the width of the embankment between mechanically stabilized earth walls is greater than that of the active zone. This is in good agreement with the result of FHWA design guideline. However, the results show that the FHWA design guideline underestimates the lateral earth pressure when back-to-back walls interact with each other. Moreover, for closer BBMSEWs, FHWA design guideline strongly overestimates the maximum tensile force in the reinforcement. The investigation of the quality of backfill material shows that the minor increase in embankment cohesion can lead to significant reductions in both the lateral earth pressure and the maximum tensile force in geosynthetic. When the distance between the two earth walls is close to zero, the connection of reinforcement between back-to-back walls significantly improves the factor of safety.

关键词： Back-to-back walls Numerical analysis Geosynthetic Factor of safety Lateral earth pressure Maximum tensile force Reinforcement

Intelligent Solution System for Cloud Security Based on Equity Distribution:Model and Algorithms

在线全文

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2024年第1期78卷 1461-1479页

作者： Sarah Mustafa Eljack Mahdi Jemmali Mohsen Denden Mutasim Al Sadig Abdullah M.Algashami sadok Turki Department of Computer Science and Information College of Science at ZulfiMajmaah UniversityAl-Majmaah11952Saudi Arabia Department of Computer Science College of Computing and InformaticsUniversity of SharjahSharjahUnited Arab Emirates Higher Institute of Computer Science and Mathematics University of MonastirMonastir5000Tunisia Mars Laboratory University of SousseSousseTunisia Department of Logistic and Maintenance UFR MIM at MetzUniversity of LorraineMetzFrance Department of Computer and Information Technologies College of Telecommunicationand Information Riyadh CTITechnical and Vocational Training Corporation TVTCRiyadh12464Saudi Arabia Department of Computer Science Higher Institute of Applied Sciences of SousseSousse UniversitySousse4000Tunisia

In the cloud environment,ensuring a high level of data security is in high *** planning storage optimization is part of the whole security process in the cloud *** enables data security by avoiding the risk of data loss and data *** development of data flow scheduling approaches in the cloud environment taking security parameters into account is *** our work,we propose a data scheduling model for the cloud *** is made up of three parts that together help dispatch user data flow to the appropriate *** first component is the Collector Agent whichmust periodically collect information on the state of the network *** second one is the monitoring agent which must then analyze,classify,and make a decision on the state of the link and finally transmit this information to the *** third one is the scheduler who must consider previous information to transfer user data,including fair distribution and reliable *** should be noted that each part of the proposedmodel requires the development of its *** this article,we are interested in the development of data transfer algorithms,including fairness distribution with the consideration of a stable link *** algorithms are based on the grouping of transmitted files and the iterative *** proposed algorithms showthe performances to obtain an approximate solution to the studied problem which is an NP-hard(Non-Polynomial solution)*** experimental results show that the best algorithm is the half-grouped minimum excluding(HME),with a percentage of 91.3%,an average deviation of 0.042,and an execution time of 0.001 s.

关键词： Cyber-security cloud computing cloud security algorithms heuristics

Data generative machine learning model for the assessment of outdoor thermal and wind comfort in a northern urban environment

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Architectural Research 2023年第3期12卷 541-555页

作者： Nasim Eslamirad Francesco De Luca Kimmo Sakari Lylykangas sadok Ben Yahia FinEst Centre for Smart Cities Tallinn University of TechnologyTallinn 10319Estonia Department of Civil Engineering andArchitecture TallinnUniversity ofTechnologyTallinn 10319Estonia Department of Software Science Tallinn University of TechnologyTallinn 10319Estonia

Predicting comfort levels in cities is challenging due to the many metric *** overcome these challenges,much research is being done in the computing community to develop methods capable of generating outdoor comfort *** Learning(ML)provides many opportunities to discover patterns in large datasets such as urban *** paper proposes a data-driven approach to build a predictive and data-generative model to assess outdoor thermal *** model benefits from the results of a study,which analyses Computational Fluid Dynamics(CFD)urban simulation to determine the thermal and wind comfort in Tallinn,*** ML model was built based on classification,and it uses an opaque ML *** results were evaluated by applying different metrics and show us that the approach allows the implementation of a data-generative ML model to generate reliable data on outdoor comfort that can be used by urban stakeholders,planners,and researchers.

关键词： Urban climate Outdoor thermal and wind comfort Predictive model Data generative model Machine learning approach

Prevalence of intestinal parasite infections among patients in local public hospitals of Hail,Northwestern Saudi Arabia

在线全文

学校读者我要写书评

暂无评论

Asian Pacific Journal of Tropical Medicine 2016年第1期9卷 41-45页

作者： Omar Hassen Amer Ibraheem M Ashankyty Najoua Al sadok Haouas Department of Clinical Laboratory Science College of Applied Medical SciencesUniversity of Hail Departement de Biologie Clinique B Laboratoire de Parasitologie-Mycologie Medicate et Moleculaire(LR12ES08)Faculte de PharmacieUniversite de Monastir

Objective:To evaluate the prevalence of intestinal parasites among patients in Hail,Northwestern Saudi ***:Stool samples were collected from 130 patients(69females and 61 males) in Hail General *** sample was examined by direct wet mount microscopic examination using both normal saline and Lugol's iodine preparation and concentration techniques using salt and formol-ether *** stained smears were performed for intestinal coccidian using modified Ziehl-Neelsen ***:The overall prevalence of intestinal parasitic infection was 45.38%(59 cases).Forty-four(33.84%)were found to be infected with one or more intestinal protozoa.5(3.84%) were infected with helminthes and 10(7.69%) had mixed infection with both helminthes and *** most common intestinal helminth detected was Ancyloxtoma duvdenale(n=5.3.84%),followed by Ascaris *** *** Trichuris trichiura(n=2 for each species,1.5%).For intestinal protozoa,the coccidian Cryptosporidium parvum(n=25,19.23%) was the most common followed by Entamoeba histolytica/dispur(n=21,16.15%),Giurdia lamblia(n=15,11.54%),Entamoeba coli(n=5.3.85%) and Blastocysts hominis(n=3,2.30%).The prevalence of intestinal parasitic infections in females was significantly higher than in males(P<0.05).Conclusions:This is the first study highlighting that intestinal parasites are still an important public health problem in Northwestern Saudi Arabia Therefore,health education would be the best way to prevent from intestinal parasite infections which are mainly food borne diseases.

关键词： Prevalence Intestinal parasites Hail KSA

Relationship between gravitational flap structures in the backlimb of anticlinal breakthrough Fault-Propagation Folds:case study of the Southern-Central Tunisian Atlas

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Mountain Science 2023年第12期20卷 3525-3541页

作者： Soulef AMAMRIA Hassen BENSALEM Hassan TAIB Mohamed sadok BENSALEM Riheb HADJI Younes HAMED Faculty of Sciences Gabès Erriadh City Gabès University of GabèsErriadh city 6072Tunisia Higher Institute of Water Sciences and Techniques of Gabès University of GabèsErriadh city 6072Tunisia Faculty of Earth Sciences and Architecture Larbi Ben M’hidi UniversityOum El Bouaghi 4000Algeria Institute of Architecture and Earth Sciences Setif 1UniversitySetif city 19000Algeria Faculty of Sciences of Gafsa University of GafsaSidi Ahmed zarroug 2100Tunisia

The development of orogenic belts structures in the Southern-Central Tunisian Atlas is influenced by the evolution of tectonic activities during different phases,which are also closely linked to the formation of gravitational collapse *** typical example is that of the northern flank of the Jebel Orbata particularly the Ben Zannouch *** is an asymmetrical anticline interpreted by the model of“Fault Propagation Folds”.The development of the Ben Zannouch structures is resulted from landslides,scree falls and inverted layers plunging to the *** direction of resulted gravitational structure is parallel to the main thrust direction of the Bou Omrane *** thrust activity of Bou Omrane fault is associated to the important paleo-slope facing south and plastic lithology(incompetent marl layers)of outcropped series,facilitates the development of the Ben Zannouch Flap *** definition of gravitational collapse structures for the first time in Tunisia particularly in the northern flank of the Jebel Orbata is controlled by many principal structural conditions:fragmentation of the landslide surfaces,rheology and *** regional factors can be distinguished in the Southern-Central Tunisian Atlas as the seismic activity of the pre-existing Gafsa fault reactivated during compressive phases and the weather conditions during the postglacial period.

关键词： Southern-Central Tunisian Atlas Gravitational collapses structures Paleo-slope Gafsa fault

Optimization of Manufacturing Supply Chain with Stochastic Demand and Planned Delivery Time

在线全文

学校读者我要写书评

暂无评论

Journal of Traffic and Transportation Engineering 2017年第1期5卷 32-43页

作者： sadok Turki Nidhal Rezg LGIPM Universite de Lorraine Ile du Saulcy 57045 Metz Cedex France

In this paper, a manufacturing supply chain system composed by a single-product machine, a buffer and a stochastic demand is considered. A stochastic fluid model is adopted to describe the system and to take into account stochastic delivery times. The objective of this paper is to evaluate the optimal buffer level used in hedging point policy taken into account planned delivery times, machine failures and random demands. This optimal buffer allows minimizing the sum of inventory, transportation, lost sales and late delivery costs. Infinitesimal perturbation analysis method is used for optimizing the proposed system. Using the stochastic fluid model, the trajectories of buffer level are studied and the infinitesimal perturbation analysis estimators are evaluated. These estimators are shown to be unbiased and then they are implanted in an optimization algorithm, which determines the optimal buffer level in the presence of planned delivery time. Also in this work, we discuss the advantage of the use of the infinitesimal perturbation analysis method comparing to classical simulation methods.

关键词： Manufacturing supply chain stochastic fluid model infinitesimal perturbation analysis planned delivery time.

Gripper Design for Radio Base Station Autonomous Maintenance System

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Automation and computing 2021年第4期18卷 645-653页

作者： Gabriel Reis Marrone Dantas Daniel Bezerra Gibson Nunes Pedro Dreyer Carolina Ledebour Judith Kelner Djamel sadok Ricardo Souza Silvia Lins Maria Marquezini Networking and Telecommunications Research Group Informatics CenterFederal University of PernambucoRecife 50730-120Brazil Ericsson Research Indaiatuba 13337-300Brazil

For an autonomous system to perform maintenance tasks in a networking device or a radio base station(RBS), it has to deal with a series of technological challenges ranging from identifying hardware-related problems to manipulating connectors. This paper describes the development of a robot maintenance system dedicated to detect and resolve faulty links caused by unplugged or poorly connected cables. Although the maintenance system relies on four subsystems, we significantly focus on our low-cost and efficient custom gripper solution developed to handle RJ45 Ethernet connectors. To examine our gripper, we conducted three experiments. First, a qualitative questionnaire was submitted to 30 users in the case of the teleoperated scenario of the gripper attached to a robotic arm. Similarly, we also tested the automatic operation mode. The results showed that our system is reliable and delivers a highly efficient maintenance tool in both teleoperated and autonomous operation modes. The practical experiment containing the removal or unplugging of connectors demonstrated our gripper′s ability to adequately handle these, whereas the feedback from the questionnaire pointed to a positive user experience. The automatic test assessed the gripper′s robustness against the continuous operation.

关键词： Robotic gripper maintenance system gripper design 3D print product development

Assessment Approach of <i>Melicertus kerathurus</i>Stock along the North-Eastern Tunisian Coast Using a Surplus Production Model Incorporating Temperature Parameter

在线全文

学校读者我要写书评

暂无评论

American Journal of Climate Change 2015年第5期4卷 417-430页

作者： Héla Jaziri Widien Khoufi sadok Ben Meriem National Institute of Sciences and Technologies of the Sea (INSTM) Port La Goulette Tunisia

In frame of fisheries management, a stock assessment using surplus production models incorporating environmental parameters was dealt with one of the most important commercially crustacean fisheries resources along the Tunisian coast, the Melicertus kerathurus stock. The analysis was carried out for a period of 17 years with a database including fishing efforts, catches, catch per unit effort (CPUE) and sea surface temperature (SST). CLIMPROD is the software used to select the appropriate model and fit to the fishery and environmental data. Overall, SST was positively correlated to the yield and abundance index (CPUE) explaining 47% and 57% of their variability respectively, nevertheless. The incorporation of the SST in global model demonstrated that the SST influenced both the catchability and the abundance of this species separately. In fact the impact of SST leads to consider a production model impacted on the one hand by a linear relationship between the CPUE and the fishing effort, and on the other hand by also a linear relationship between the CPUE and the SST for both catchability or abundance of the species. The interpretation of global model with environmental parameters is changed with the incorporation of climate parameter.

关键词： Melicertus kerathurus SST Abundance Catchability Assessment