This paper is a review of problems and challenges in the Internet of things (IoT) security. The management of key pre-distribution is a cryptographic challenge in every kind of application where security is worried. In recent years there are many papers have proposed different schemes for security. We classify in this paper the existing solutions of key pre-distribution schemes, in order to categorize them, we draw a taxonomy and describe the key pre-distribution coming from combinatorial design and we give examples for that.

Maximum Power Point Tracking (MPPT) method frequently used in photovoltaic systems to maximize photovoltaic power generation Generator (PVG). The principle of these technologies is making PVG reach the maximum power point (MPP), depending on environmental factors such as solar irradiance and ambient temperature, ensure the best power transfer between PVG and load. In this article, we present the implementation of a MPPT command using the Arduino nano. The proposed MPPT command is based on Perturbation and Observation Algorithm (P&O). The PV system is simulated and studied using ISIS Proteus software. Results show that the algorithm shows good results in time response and oscillations.

The studies presented in this paper focus on the recovery of vibrational energy using a piezoelectric beam. The device implemented in this work is quite far from industrial realities, but it has the advantage of being easily reproducible and inexpensive. In a first step we will design a circuit for mechanical Energy Harvesting. In practice these systems recover the little energy from ambient vibrations in order to power low consumption electrical systems (typically from a few ?W to mW). After comparison with a basic recovery system (diode bridge) examined both experimentally and by simulation, the model is used on a more efficient recovery system. This study focuses on non-linear circuit topologies, and the improvement of the recovered power compared to the standard technique (STD) To charge a datalogger. The simulation results of this system evaluate an improvement of 325% compared to the standard system.

Battery modeling is one of the most important functions in a battery management system for different applications such as electrical vehicles, This article focuses on state of the art of lithium-ion battery modeling by exploring different existing modeling methods, such as Electrochemical models, Analytical models and the equivalent electrical circuit. First, the characteristics of the lithium-ion battery for different applications are reviewed ,we chose to study this type of battery because it offers satisfactory characteristics compared to other battery types, then the different modeling methods have been explored, finaly a conclusion with suggestion of other modeling type such as fractional order model have been proposed to improve efficiency and precision of battery management system.

We consider the Weinstein type operator ??;d on Rd. We build transmutation operators R? which turn out to be transmutation operator between ??;d and the Laplacian ?d. Using this transmutation operators and its dual tR?, we develop a new commutative harmonic analysis on Rd corresponding to the operator ??;d.

The purpose of this paper is to study the Quaternion Fourier transforms of functions that satisfy Lipschitz conditions of certain orders. Thus we study the Quaternion Fourier transforms of Lipschitz function in the functions space Lr(R2; H), where H a quaternion algebra which will be specified in due course. Our investigation into the problem was motivated by a theorem proved by Titchmarsh [[29], Theorem 85] for Lipschitz functions on the real line. we will give also some results on calculation of the K-functional which have number of applications of interpolation theory. In particular some recent problems in image processing and singular integral operators require the computation of suitable K-functionals. In this paper we will give some results concerning the equivalence of a K-functional and the modulus of smoothness constructed by the Steklov function.

This paper falls under the problems of the diagnosis of Discrete Event System (DES) such as coil winding machine. Among the various techniques used for the on-line diagnosis, we are interested in the chronicle recognition and fault tree. The Chronicle can be defined as temporal patterns that represent system possible evolutions of an observed system. Starting from the model of the system to be diagnosed, the proposed method based on the P-time Petri net allows to generate the chronicles necessary to the diagnosis. Finally, to demonstrate the effectiveness and accuracy of the monitoring approach, an application to a coil winding unit is outlined.

With modern technologies, most devices such as electric vehicles are powered by lithium batteries. This kind of battery is advantageous to other types of batteries, such as higher energy density, reliability, etc. to work effectively, it is necessary to handle them using a battery management system BMS, which guarantees their safety and optimizes their performances in normal conditions. One of the things that a BMS must do is to estimate the state of charge SOC of the battery because it is the most critical indicator of battery state. This task is very challenging because the lithium-ion battery is a highly time-invariant, nonlinear, and complex electrochemical system. In this paper, we present a cell model that can be used in the state of the charge estimation process. This model is based on an electrical approach where we build an electrical circuit that has the same behavior as the real cell, this approach is called the Equivalent circuit model ECM. using a set of laboratory data, we will determine the model parameters using multiple techniques. Those parameters will be used in process of estimating the state of charge and other internal parameters.

A great deal of research has in recent years been carried out on harvesting energy using smart systems. Harvesting energy from the ambient environment has become an emerging technology for many applications, ranging from portable electric devices to renewable energy. This article constitutes a synthesis of work carried out within the framework of a study on systems for energy harvesting. The objective of the project was to design an intelligent retarder system. The advantage of the energy recovery system is that it transforms the kinetic energy produced by the passage of vehicles on the retarder to electric energy using a mechanism. The powers involved in this context can go up to 46 kW/h.