Search Results

Considering link vibrations, the main limitation affecting flexible manipulators, this article seeks to make a contribution by presenting an enhanced two degree of freedom vibration controller. This controller uses a filtered right inverse controller in the feedforward and strain feedback controller in the feedback path. The Filtered inverse controller damps transient vibrations while preserving joint…

Due to their efficient flight control systems and their camera of high quality modern drones can fly precisely and take aerial photos of high resolution. Although these multi-rotor devices are not able to fly long distances yet, they are very efficient instruments for taking aerial photographs of their proximate environment. As they are able to…

Proportional navigation (PN) is a widely-used guidance law for missiletarget engagement. The goal of the missile intercept problem is to reduce the closest distance between the missile and target by diminishing the line-of-sight rate (LOS rate). In general, PN guidance law necessitates information of the LOS rate and missile velocity. The closing velocity (relative approaching…

Identity and Access Management (IAM) and Single Sign on (SSO) are two security concepts that are related to each other. IAM governs the user access in an organization whereas SSO facilitates the user by authenticating to one centralized application and not having to re-authenticate when trying to access other applications. This paper addresses the different…

Nowadays, many companies and organizations use various encryption techniques to secure their private data before send it through the unsecure network. However, many attackers try to store private data by using various attacks. Most of the organizations use password based encryption algorithm (PBE) to protect their private data. However, the existing PBE methods are vulnerable…

Finding similarity of textual data is very important task in natural language processing. In this article we present approach to finding similarity of words, paragraphs, sentences and documents. Semantic similarity is one of the central tasks in many applications, including text summarization, Intelligent Tutoring Systems (ITS) etc. In ITS sentence similarity is used to compare…

Doubly fed asynchronous machines have an outstanding property: they can be operated up to twice rated speed delivering full rated torque. This paper presents, for the first time in the literature, a control system for multiphase asynchronous machines fed by Voltage Source Inverters (VSIs) both in stator and rotor that incorporates the harmonic torques. The…

Moderate exercise has been implemented in spaceflight programs to prevent muscle and joint damage under extreme circumstances such as microgravity. Although the physical effects of exercise have been investigated experimentally, advanced modeling and simulation techniques are powerful tools that could provide insight into the physical limitations, optimal conditions, and mechanisms that might lead to muscle…

The objective of this paper is to investigate three different approaches of modeling, design and discrete-time implementation of PI closed-loop control strategies in SIMULINK simulation environment, applied to a centrifugal chiller system. Centrifugal chillers are widely used in large building HVAC systems. The system consists of an evaporator, a condenser, a centrifugal compressor and an…

Patient generated data, or personal clinical data, is considered an important aspect in improving patient outcomes. However, personal clinical data is difficult to collect and manage due to its distributed nature. For example, they can be located in multiple places such as doctors’ offices, radiology centers, hospitals, or some clinics. Another factor that can make…

Examples of analytical calculations of the system characteristics of the hardware and time complexity of the correlation system based on a certain number of microphones and the corresponding number of interrelations are presented. The structural solutions of the hardware special processor implementation of such class of multichannel devices for recognition and identification of types and…

In this paper, we discuss the solvability of the nonlinear parabolic systems associated to the nonlinear parabolic equation: \(\frac{\partial b_{i}(x,u_{i})}{\partial t} -div(a(x,t,u_{i},\nabla u_{i}))- \phi_{i}(x,t,u_{i})) +f_{i}(x,u_{1},u_{2})=0\) where the function  \(b_{i}(x,u_{i})\) verifies some regularity conditions, the term \(\Big(a(x,t,u_{i},\nabla u_{i})\Big)\) is a generalized Leray-Lions operator and \(\phi_{i}\) is a Caratheodory function assumed to be  Continuous on \(u_i\) and satisfy only a…

In this work, we will prove the existence of bounded solutions for the nonlinear elliptic equations \(- div(a(x,u,\nabla u)) = g(x,u,\nabla u) -divf,\) in the setting of the weighted Sobolev space \(W^{1,p}(\Omega,w)\) where \(a\), \(g\) are Caratheodory functions which satisfy some conditions and \(f\) satisfies suitable summability assumption.

This article is devoted to study the existence of solutions for the strongly nonlinear \(p(x)\)-elliptic problem: \(- \Delta_{p(x)} (u) + \alpha_0 |u|^{p(x)-2}u = d(x)\frac{|\nabla u|^{p(x)}}{|u|^{p(x)}+1} + f- div g(x) \quad \text{in } \Omega, \) \(u \in W_0^{1,p(x)}(\Omega), \) Where \(\Omega\) is an open set of \(\mathbb{R}^N\), possibly of infinite measure, we will also give some…

In this paper, we present a novel secure cryptosystem for direct encryption of color images, based on an iterative mixing spread over three rounds of the R, G and B color channels and three enhanced chaotic maps. Each round includes an affine transformation that uses three invertible matrices of order 2 _ 2; whose parameters…

With the abundance of Internet and electronic devices bullying has moved its place from schools and backyards into cyberspace; to be now known as Cyberbullying. Cyberbullying is affecting a lot of children around the world, especially Arab countries. Thus concerns from cyberbullying are rising. A lot of research is ongoing with the purpose of diminishing…

In remote measurements on large-sized objects main focus is on measuring deformations of bridge surfaces and determination of the dynamic amplification factor in particular. The proposed method estimates deflections of entire lower surface of a bridge due to placement of secondary radiators on this surface. Antenna array directivity pattern (ADP) is distorted during deflection of…

In this paper, we prove the existence of a solution of the strongly nonlinear degenerate \(p(x)\)-elliptic equation of type: \(\mathcal{(P)}\left\{\begin{array}{rl} - div\; a(x,u,\nabla u) +g(x,u,\nabla u)& = f \quad in \;\Omega, \\ u = 0 \quad on \quad \partial\Omega, \end{array}\right.\) where \(\Omega\) is a bounded open subset of \( I\!\!R^{N}, N\geq 2, a\) is a…

The discovery of semantic information from complex signals is a task concerned with connecting humans’ perceptions and/or intentions with the signals content. In the case of audio signals, complex perceptions are appraised in a listener’s mind, that trigger affective responses that may be relevant for well-being and survival. In this paper we are interested in…

Cognitive Radio (CR) encompasses a number of technologies which enable adaptive self-programing of systems at different levels to provide more effective use of the increasingly congested radio spectrum. CRs have potential to use spectrum allocated to TV services, which is not used by the primary user (TV), without causing disruptive interference to licensed users by…

Radiation hardened devices are mostly extremely expensive. The continuously downscaling of microelectronic structures and the unavoidable presence of particle radiation on ground and in space leads to unwanted failures in electronic devices. Furthermore it is expected that in the next few years around 8000 new satellites will be launched around the world. Due to the…

Energy efficiency is a salient design consideration for stabilization mechanisms when assembled on a battery-powered vehicle. In this paper we study the implementation of a two-axis gimbal with passive revolute joints for motion isolation of an inertially stabilized platform (ISP) mounted on a host vehicle. The objective is for the ISP to maintain a steady…

Command and control (C2) systems direct operators to make accurate decisions in the stressful atmosphere of the battlefield at the earliest. There are powerful tools that fuse various instant piece of information and brings summary of those in front of operators. Threat evaluation is one of the important fusion method that provides these assistance to…

In this paper we propose our genetic algorithm for solving the SAT problem. We introduce various crossover and mutation techniques and then make a comparative analysis between them in order to find out which techniques are the best suited for solving a SAT instance. Before the genetic algorithm is applied to an instance it is…

At present in Mexico, the renewable energy has become more important due to the great dependence of the country for fossil fuels. Within the several applications of renewable energy, there are the geothermal applications for the air conditioning of spaces. This technology employs heat pumps that interexchange heat with the ground. This technology is relatively…