Search results for "asynchronous"

Coordination in a multi-cell multi-antenna multi-user W-CDMA system: a beamforming approach

2008

The problem of designing joint power control and optimal beamforming (JPCOB) algorithms for the downlink of a coordinated multi-cell WCDMA system is considered throughout this paper. In this case, the JPCOB design is formulated as the problem of minimizing the total transmitted power in the coordinated multi-cell system, subject to a certain quality of service requirement for each user. In this paper, the performance of two JPCOB algorithms based on different beamforming approaches is compared over the coordinated multi-cell system. The first one, obtains local beamformers by means of the well-known virtual uplink-downlink duality. In contrast, the second algorithm implements multi-base bea…

Perceived Support in E-Collaborative Learning: An Exploratory Study Which Make Use of Synchronous and Asynchronous Online-Teaching Approaches

2012

This study compares four different learning environments for e-collaborative learning in two European countries related to the dimension of student's mutual support. The theoretical baseline is Vygotsky's zone of proximal development (ZOPD) and the socio-genetic approach of Piaget. The analyzed data are based on questionnaires collected over the time period of an entire semester including four different courses at the master's level. These courses applied different e-collaborative approaches including a variety of tools for supporting communication. It is assumed that these courses including communication tools e.g. virtual face-to-face meetings enhance the chances for better communication,…

Research of Complex Forms in Cellular Automata by Evolutionary Algorithms

2004

This paper presents an evolutionary approach for the search for new complex cellular automata. Two evolutionary algorithms are used: the first one discovers rules supporting gliders and periodic patterns, and the second one discovers glider guns in cellular automata. An automaton allowing us to simulate AND and NOT gates is discovered. The results are a step toward the general simulation of Boolean circuits by this automaton and show that the evolutionary approach is a promising technic for searching for cellular automata that support universal computation.

Asynchronous Runtime Verification of Business Processes: Proof of Concept

2020

Promoting multilingual communicative competence through multimodal academic learning situations

2016

This paper presents information on the factors affecting the development of multilingual and multicultural communicative competence in interactive multimodal learning environments in an academic context. The interdisciplinary course in multilingual interaction offered at the University of Jyväskylä aims to enhance students’ competence in multilingual and multicultural academic communication by promoting the use of their entire linguistic repertoire in various learning situations. Throughout the course, we observed the students’ engagement in multilingual and multicultural activities. These observations suggest that simultaneous use of multiple languages in synchronous and asynchronous learn…

Asynchronous sensor fusion of GPS, IMU and CAN-based odometry for heavy-duty vehicles

2021

[EN] In heavy-duty vehicles, multiple signals are available to estimate the vehicle's kinematics, such as Inertial Measurement Unit (IMU), Global Positioning System (GPS) and linear and angular speed readings from wheel tachometers on the internal Controller Area Network (CAN). These signals have different noise variance, bandwidth and sampling rate (being the latter, possibly, irregular). In this paper we present a non-linear sensor fusion algorithm allowing asynchronous sampling and non-causal smoothing. It is applied to achieve accuracy improvements when incorporating odometry measurements from CAN bus to standard GPS+IMU kinematic estimation, as well as the robustness against missing da…

Feedback linearization control of wind turbine equipped with doubly fed induction generator

2017

This paper focuses on several control techniques of a wind turbine of rated power of about 1 MW. In particular, a wind generator equipped with an asynchronous doubly-fed induction machine has been considered and its dynamic model in MATLAB/SIMULINK environment has been implemented. Starting from this model the feedback linearization control has been derived, and several simulations have been carried out, with the aim of compare its dynamic performances with the classical field oriented control, and with the V/f control. The results allow us to conclude that a DFIG controlled by a feedback linearization technique ensures better dynamic performance.

Speech Intelligibility Analysis and Approximation to Room Parameters through the Internet of Things

2021

In recent years, Wireless Acoustic Sensor Networks (WASN) have been widely applied to different acoustic fields in outdoor and indoor environments. Most of these applications are oriented to locate or identify sources and measure specific features of the environment involved. In this paper, we study the application of a WASN for room acoustic measurements. To evaluate the acoustic characteristics, a set of Raspberry Pi 3 (RPi) has been used. One is used to play different acoustic signals and four are used to record at different points in the room simultaneously. The signals are sent wirelessly to a computer connected to a server, where using MATLAB we calculate both the impulse response (IR…

Fault detection for continuous-time switched systems under asynchronous switching

2013

In this chapter, the problem of FD for continuous-time switched systems under asynchronous switching is investigated. The designed FD filter is assumed to be asynchronous with the original systems. Attention is focused on designing a FD filter such that the estimation error between the residual and the fault is minimized in the sense of H ∞ norm. By employing piecewise Lyapunov function and ADT techniques, a sufficient condition for the existence of such a filter is exploited in terms of certain LMIs. Finally, an example is provided to illustrate the effectiveness of the proposed approach.

An asynchronous covert channel using spam

2012

AbstractCurrent Internet e-mail facilities are built onto the foundation of standard rules and protocols, which usually allow a considerable amount of “freedom” to their designers. Each of these standards has been defined based on a number of vendor specific implementations, in order to provide common inter-working procedures for cross-vendor communication. Thus, a lot of optional and redundant information is being exchanged during e-mail sessions, which is available to implement versatile covert channel mechanisms.This work exploits this possibility by presenting a simple but effective steganographic scheme that can be used to deploy robust secret communication through spam e-mails. This s…