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Analysis and Simulink Modeling of the Performance of Dynamic Web Server Using JSP and PHP

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Communications and Network 2018年第4期10卷 196-210页

作者： Fontaine Rafamantanantsoa Paulson Ravomampiandra university of fianarantsoa Fianarantsoa Madagascar

In recent years, web technology carried on growing and at same time, the number of internet users increased significantly in number. Today, a Web server is capable of processing millions of requests per day, but during the peak period may collapse and becomes critical causing unavailability of the services offered by the servers. That is why Web server performance is a topic of great interest to many researchers. In this paper, we evaluate experimentally the impact of JSP and PHP dynamic content technology: JSP and PHP with access to a database of performance data of Apache Web server. Using the “ApacheBench” performance measurement tool, the approach is to compare the performances of four different configurations of a Web server, such as: Apache Web server implementing JSP technology with access to PostgreSQL database, Apache using PHP technology with the PostgreSQL as database, Apache Web server using the JSP technology with access to MySQL database, finally Apache and PHP with DBMS MySQL. At the end of this article, we also present a Simulink model of Web server performance based on the simple M/M/1 queue. During the modeling, the MATLAB software was used.

关键词： Analysis Queue JSP Model Performances Evaluation PHP Web Server Simulink

Mathematical Model and Non-Pharmaceutical Control of the Coronavirus 2019 Disease in Madagascar

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Open Journal of Modelling and Simulation 2021年第3期9卷 259-274页

作者： Angelo Raherinirina Fontaine Rafamatanantsoa Tsilefa Stefana Fandresena Rivo Andry Rakotoarivelo university of fianarantsoa Fianarantsoa Madagascar

For Madagascar, with the uncertainty over vaccines against the novel coronavirus 2019 and its variants, non-pharmaceutical approach is widely used. Our objective is to propose a mathematical control model which will serve as a tool to help decision-makers in the strategy to be implemented to better face the pandemic. By separating asymptomatic cases which are often not reported and symptomatic who are hospitalized after tests;we develop a mathematical model of the propagation of covid-19 in Madagascar, by integrating control strategies. We study the stability of the model by expressing the basic reproduction number using the next-generation matrix. Simulation with different parameters shows the effects of non-pharmaceutical measures on the speed of the disease spread. By integrating a control parameter linked to compliance with barrier measures in the virus propagation equation, we were able to show the impacts of the implementation of social distancing measures on the basic reproduction number. The strict application of social distancing measures and total confinement is unfavorable for economic situation even if they allow the contamination to be reduced quickly. Without any restrictions, the disease spreads at high speed and the peak is reached fairly quickly. In this condition, hospitals are overwhelmed and the death rate increases rapidly. With 50% respect for non-pharmaceutical strategies such as rapid detection and isolation of positive cases a

关键词： Covid-19 Madagascar Epidemic Model Non-Pharmaceutical Control Equilibrium Points Stability Analysis Reproduction Number

Performance Comparison and Simulink Model of Firewall Free BSD and Linux

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Communications and Network 2018年第4期10卷 180-195页

作者： Fontaine Rafamantanantsoa Haja Louis Rabetafika university of fianarantsoa Fianarantsoa Madagascar

In recent years, the number of users connected to the Internet has experienced a phenomenal growth. The security of systems and networks become essential. That is why the performance of Linux firewall and Berkeley Software Distribution (BSD) are of paramount importance in security systems and networks in all businesses. The following evaluates the firewall based tool that we have developed in Python and Scapy, which performs time measurements by serving packets traversing the firewall test. Several results were presented: the speed of the firewall under FreeBSD in terms of service time compared to the speed of the firewall under Linux as the number of rules increases;the speed of the filtering rule of a firewall stateless in terms of service time compared to the filtering rule of an active firewall gradually as the number of rules increases. Then, for care of simplicity, we have presented the queue M/M/1/K to model the performances of firewalls. The resulting model was validated using Simulink and mean squared error. The analytical model and Simulink of the firewalls are presented in the article.

关键词： Firewall Ipfw Iptables Python Scapy Simulink Statefull Firewall Stateless Firewall

A Gaussian Multivariate Hidden Markov Model for Breast Tumor Diagnosis

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Applied Mathematics 2021年第8期12卷 679-693页

作者： Angelo Raherinirina Adore Randriamandroso Aimé Richard Hajalalaina Rivo Andry Rakotoarivelo Fontaine Rafamatantantsoa university of fianarantsoa Fianarantsoa Madagascar

The stage of a tumor is sometimes hard to predict, especially early in its development. The size and complexity of its observations are the major problems that lead to false diagnoses. Even experienced doctors can make a mistake in causing terrible consequences for the patient. We propose a mathematical tool for the diagnosis of breast cancer. The aim is to help specialists in making a decision on the likelihood of a patient’s condition knowing the series of observations available. This may increase the patient’s chances of recovery. With a multivariate observational hidden Markov model, we describe the evolution of the disease by taking the geometric properties of the tumor as observable variables. The latent variable corresponds to the type of tumor: malignant or benign. The analysis of the covariance matrix makes it possible to delineate the zones of occurrence for each group belonging to a type of tumors. It is therefore possible to summarize the properties that characterize each of the tumor categories using the parameters of the model. These parameters highlight the differences between the types of tumors.

关键词： Hidden Markov Chain Gaussian Mixture Breast Tumor Malignant and Benign

Modeling the Unsteady Flow of a Newtonian Fluid Originating from the Hole of an Open Cylindrical Reservoir

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Fluid Dynamics & Materials Processing 2022年第6期18卷 1737-1748页

作者： Andrianantenaina Marcelin Hajamalala Ratovonarivo Noarijaona Zeghmati Belkacem Laboratory of Mechanics Energetic and Environment(LMEE) University of FianarantsoaFianarantsoaB.P.1264Madagascar Laboratory of Mathematics and Physics(LA.M.P.S) University of Perpignan Via DomitiaPerpignan66860France

This work deals with the modeling of the unsteady Newtonian fluid flow associated with an open cylindrical *** reservoir presents a hole on the right bottom *** volume variation,heat and mass transfers are *** unsteady governing equations are based on the conservation of mass and momentum.A finite volume technique is used to solve the non-dimensional equations and related boundary *** algebraic system of equations resulting from the discretization process are solved by means of the THOMAS *** pressure-velocity coupling,the SIMPLE algorithm(Semi Implicit Method for Pressure Linked Equations)is *** for laminar flow(Re<1000),including the pressure and velocities profiles as well as the streamlines in the reservoir are ***,the effects of the D/d and H0/D ratios and Reynolds number Re on the fluid flow are *** is shown that the velocities and pressure depend essentially on the reservoir *** validate the model,the present results have been compared with Zhou et al.’s results,Poiseuille’s and Bernoulli’s exact solution.

关键词： Modeling newtonian fluid cylindrical reservoir navier-stokes

Analysis and Evaluation of Performance Related to Java and PHP Security Codes

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Communications and Network 2021年第1期13卷 36-49页

作者： Fontaine Rafamantanantsoa Rabetafika Louis Haja Randrianomenjanahary Lala Ferdinand university of fianarantsoa Fianarantsoa Madagascar

In recent years, Internet exposure of applications continuously engenders new forms threats that can endanger the security of the entire system and raises many performance issues related to code security. The safety of information systems becomes essential. This is why the performance linked to security codes is of importance essential in the security systems of all companies. Indeed, as contribution, to carry out measurements, it appropriates tools that are the JMH tool (Java Microbenchmark Harness) and the PHP Benchmark script tool which include unsecure java and PHP codes and secured against SQL (Structured Query Language) injection, XSS (Cross Site Scripting) i.e., using prepared requests, stored procedures, validation of input from white lists, reinforcement of minimum privilege, when sending requests from the last ones to MySQL databases and Postgresql. We recover the times of response to his requests. From java codes and PHP (Hypertext Preprocessor) secure, we also retrieve the response time for requests to databases MySQL and PostgresqL data. We then obtain the curves and interpretations comparing performance related to security and non-security of codes. The goal is to analyze and evaluate the performance comparing secure Java and PHP code against unsecure java and PHP code using MySQL and Postgresql databases. In Section 1, we presented the performance of the code Java and PHP. The configuration of the experiments and the experimental results are discussed in Sections 2 and 3, respectively. Use of suitable tool which is the JMH tool and the PHP Benchmark script tool, we have developed in Java 1.8 and PHP 7.4 secure and non-secure codes that send the queries to the MySQL or Postgresql database to carry out the measurements which led to the conclusion that the insecure PHP and Java codes are faster in terms of response time compared to the PHP and Java secure codes as the number of tables linked to the query increases because the bl

关键词： Applications Attacks XSS Security Java PHP Performances

Analysis and Neural Networks Modeling of Web Server Performances Using MySQL and PostgreSQL

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Communications and Network 2018年第4期10卷 142-151页

作者： Fontaine Rafamantanantsoa Maherindefo Laha university of fianarantsoa Fianarantsoa Madagascar

The purpose of this study is to analyze and then model, using neural network models, the performance of the Web server in order to improve them. In our experiments, the parameters taken into account are the number of instances of clients simultaneously requesting the same Web page that contains the same SQL queries, the number of tables queried by the SQL, the number of records to be displayed on the requested Web pages, and the type of used database server. This work demonstrates the influences of these parameters on the results of Web server performance analyzes. For the MySQL database server, it has been observed that the mean response time of the Web server tends to become increasingly slow as the number of client connection occurrences as well as the number of records to display increases. For the PostgreSQL database server, the mean response time of the Web server does not change much, although there is an increase in the number of clients and/or size of information to be displayed on Web pages. Although it has been observed that the mean response time of the Web server is generally a little faster for the MySQL database server, it has been noted that this mean response time of the Web server is more stable for PostgreSQL database server.

关键词： Web Server Performances Neural Network Database Server MySQL PostgreSQL Apache Mean Response Time Apache Benchmark SNNS

Python Server Page Performance Analysis and Modeling

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Communications and Network 2024年第1期16卷 1-30页

作者： Razafindraibe Marolahy Alix Randrianomenjanahary Lala Ferdinand Rafamantanantsoa Fontaine Mahatody Thomas F. Angelo Raherinirina university of fianarantsoa Fianarantsoa Madagascar

Today, in the field of computer networks, new services have been developed on the Internet or intranets, including the mail server, database management, sounds, videos and the web server itself Apache. The number of solutions for this server is therefore growing continuously, these services are becoming more and more complex and expensive, without being able to fulfill the needs of the users. The absence of benchmarks for websites with dynamic content is the major obstacle to research in this area. These users place high demands on the speed of access to information on the Internet. This is why the performance of the web server is critically important. Several factors influence performance, such as server execution speed, network saturation on the internet or intranet, increased response time, and throughputs. By measuring these factors, we propose a performance evaluation strategy for servers that allows us to determine the actual performance of different servers in terms of user satisfaction. Furthermore, we identified performance characteristics such as throughput, resource utilization, and response time of a system through measurement and modeling by simulation. Finally, we present a simple queue model of an Apache web server, which reasonably represents the behavior of a saturated web server using the Simulink model in Matlab (Matrix Laboratory) and also incorporates sporadic incoming traffic. We obtain server performance metrics such as average response time and throughput through simulations. Compared to other models, our model is conceptually straightforward. The model has been validated through measurements and simulations during the tests that we conducted.

关键词： Performance Analysis Queue Performance Model Web Server Internet World Wide Web Web Server Performance

Pedagogical Alignment of Large Language Models (LLM) for Personalized Learning: A Survey, Trends and Challenges

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Journal of Intelligent Learning Systems and Applications 2024年第4期16卷 448-480页

作者： Mahefa Abel Razafinirina William Germain Dimbisoa Thomas Mahatody School of Computer Science University of Fianarantsoa Fianarantsoa Madagascar

This survey paper investigates how personalized learning offered by Large Language Models (LLMs) could transform educational experiences. We explore Knowledge Editing Techniques (KME), which guarantee that LLMs maintain current knowledge and are essential for providing accurate and up-to-date information. The datasets analyzed in this article are intended to evaluate LLM performance on educational tasks, such as error correction and question answering. We acknowledge the limitations of LLMs while highlighting their fundamental educational capabilities in writing, math, programming, and reasoning. We also explore two promising system architectures: a Mixture-of-Experts (MoE) framework and a unified LLM approach, for LLM-based education. The MoE approach makes use of specialized LLMs under the direction of a central controller for various subjects. We also discuss the use of LLMs for individualized feedback and their possibility in content creation, including the creation of videos, quizzes, and plans. In our final section, we discuss the difficulties and potential solutions for incorporating LLMs into educational systems, highlighting the importance of factual accuracy, reducing bias, and fostering critical thinking abilities. The purpose of this survey is to show the promise of LLMs as well as the issues that still need to be resolved in order to facilitate their responsible and successful integration into the educational ecosystem.

关键词： Chain of Thought Education IA LLM Machine Learning NLP Personalized Learning Prompt Optimization Video Generation