Articles — Two-column

devoir 1 ere annee niveu lycee

In this document we focus on modifying the Linux Kernel through memory and scheduler parameters. The main objective is to study the performance of a computer during the execution of AIO-Stress Benchmark. It was necessary to run the test several times since three of the parameter mentioned in this project were modified 5 times. After completing the test, the results were displayed on graphs, showing that all the variables have a noticeable influence on the performance of the computer.

The density of solid water, unlike most molecules, is less than that of its liquid form. Its precise value is of use in many applications. Freezing a spherical droplet of water and analyzing the changed shape from a sphere to a sphere with a slight peak in order to find the density of ice. We find the density of ice to be at 0.90 ± 1.66 · 106 g/mL. The precision of our measurement was limited by uncertainty in the angle measurements of the peak of the droplet.

In this paper we will study an algorithm designed by Madgwick which is commonly used to determine the orientation of a quadcopter. The algorithm uses a group of accelerometers, gyroscopes and magnetometers integrated in what is called an IMU as input. Some differences have been found between the results obtained by the original paper and the implementation done by the author. Therefore, a thorough study has been made, finding a miscalculation in the equations. The results show a relative average error in the orientation of 1,44 ppm.

Distributed system is a collection of independent systems which can communicate with each other by transferring massages. There are some major issues in distributed systems but we focus in this paper on fault tolerance. It is the system’s ability to work in the condition when there occur any type of some fault in the system, like failure in communication, hardware or resources. It is a very important issue in distributed system, in this paper we present a survey of different types of fault tolerance techniques and their comparison.

Breu resum sobre l'amor al món medieval. Basat en apunts de l'assignatura de la UB.

Web security issues remain a major challenge with numerous security concerns, Distributed Denial of Service Attack (DDos) leads among these. It was evolved from DOS and its main purpose is to consume large amount of server resources so that the server cannot provide service to normal users. Attackers usually gain access to large number of computers by exploiting the vulnerabilities to set up attack armies (i.e., Botnets). This paper will review and analyse different existing DDoS detecting techniques against different parameters, and propose a new hybrid architecture for the defence mechanism of DDoS attack.

Precision viticulture is a specialization of precision agriculture techniques applied to viticulture. Precision agriculture is the use of information system technologies applied to agricultural production. Some of the applicable technologies are; Wireless Sensor Networks (WSN), Global Positioning Systems (GPS), spectroscopy analysis of Near-Infrared (NIR), Geographic Information Systems (GIS). These systems provide means of observation, evaluation and control of agricultural activities. The farmers demand assistant systems to perform actions for saving time and avoiding risks. There are studies of maps crops and mesh-sampling techniques to predict the harvest volume in a vineyard with a certain varieties of grapes. The prediction is based on a previous study of crops over a period of three to four years. Along these three or four years a large volume of samples is taken to study several parameters. In this application area is where the wireless sensor networks technologies would have high incidence. In this context we intend to analyse, at first place, the specific characteristics of the operational environment of a vineyard. Second, we will analyse the most appropriate architecture for a sensor network in this environment. Application of wireless sensor networks technology can take many forms depending of environment, and implementation objectives. In this paper we discuss about the best procedure for deployment and the optimal topology of a wireless sensor network for viticulture.

his project is part of the FlowNet initiative. FlowNet aims at providing Internet freedom and free flow information through socially informed, censor resistant online social networks. My contribution for FLowNet is in devel- oping an Android application, SecurePost. The requirement for SecurePost is two-fold. First, the system should facilitate secure, anonymous, group communication within a closed group of trusted members. Second, the general public on the Internet viewing this content, should be able to verify that the content was generated only by the said closed group of trusted members. The system consists of an Android client application, a proxy server and a browser-plugin. The OSNs supported by this system are Twitter and Facebook.