1,720,964 research outputs found
Signals and Systems
No full textThis book has been published for the bachelor students of the Electrical and Computer Engineering. The chapters are as follows: 1) Introduction to signals and systems, 2) Convolution and analysis of LTI systems, 3) Fourier series for periodic signals, 4) Fourier transforms, 5) Laplace transform, and 6) Z transform
Stability analysis of nonlinear hybrid delayed systems described by impulsive fuzzy differential equations
No full textIn this paper we introduce some stability criteria of nonlinear hybrid systems with time delay described by impulsive hybrid fuzzy system of differential equations. Firstly, a comparison principle for fuzzy differential system based on a notion of upper quasi-monotone nondecreasing is presented. Here, for stability analysis of fuzzy dynamical systems, vector Lyapunov-like functions are defined. Then, by using these functions together with the new comparison theorem, we will get results for some concepts of stability (eventual stability, asymptotic stability, strong stability and uniform stability) for impulsive hybrid fuzzy delay differential systems. Furthermore, theorems for practical stability in terms of two measures are introduced and are proved. Finally, an illustrating example for stability checking of a differential system with fuzziness and time delay is given. Then, by introducing an applied example in Pharmacokinetics, we bridge theoretical concepts to the application of research in real worl
Stability analysis of impulsive fuzzy differential equations with finite delayed state
No full textIn this paper we introduce some stability criteria for impulsive fuzzy system of differential equations with finite delay in states. Firstly, a new comparison principle for fuzzy differential system compared to crisp ordinary differential equation, based on a notion of upper quasi-monotone nondecreasing, in N dimentional state space is presented. Furthermore, in order to analyze the stability of fuzzy dynamical systems, vector Lyapunov like functions are defined. Then, by using these vector Lyapunov-like functions together with the new comparison theorem which is presented before, we will get results for some concepts of stability (eventual stability, asymptotic stability, strong stability, uniform stability and their combinations) for impulsive fuzzy delayed system of differential equations. Moreover, some theorems for practical stability in terms of two measures are introduced and are proved. Finally, an illustrating example for stability checking of a system of differential equations with fuzziness and time delay in states is given
Multi-Layer Network Sliced Distributed Learning for Satellite IoT
No full textDistributed Learning (DL) is a promising suite of techniques enabling progressive Internet of Things (IoT) systems with built-in intelligence. A diverse range of DL methods with specific performance, characteristics, and requirements are available for IoT users. However, implementing multiple DL techniques to serve various user groups and applications in traditional IoT settings can be difficult due to their specific needs and resource constraints. In light of emerging network paradigms with highly distributed computing and communication resources, such as joint terrestrial/non-terrestrial networks, it is essential to leverage available resources while simultaneously implementing various DL methods. Network Slicing (NS) can be highly beneficial in this regard, as it enables the implementation of heterogeneous services over a shared network infrastructure in a virtualized environment. In this study, we introduce NS, then propose a framework that enables DL-as-a-Service (DLaaS) over a distributed IoT platform using a multi-layer hierarchical structure using satellites at the highest level. This framework allows for the proactive deployment of distributed IoT systems and facilitates the management of heterogeneous services with varying requirements. Then, we explore the advantages and challenges of the proposed hierarchical structure, along with some solutions to address those issues, such as split learning (SL) and differential privacy (DP)
In-Space Computation Offloading for Multi-Layer LEO Constellations
No full textNon-terrestrial Networks (NTN) will play a key role in enabling a fully
connected, digitized, and intelligent society through their integration
into traditional terrestrial communication networks in the upcoming 6G
world. The space-based Orbital Edge Computing (OEC) has already shown some
promising results in terms of boosting the capacity, coverage, security,
and resilience of communication systems. Among others, Low Earth Orbit
(LEO) satellite constellations can be beneficial in terms of reduced
communication distances and easy and flexible deployments. With integrated
OEC facilities into NTN platforms, a new era of space computing has begun.
It has several benefits in terms of serving space/ground users through
satellite computation, communication, and storage resources. However, with
size limitations, each LEO satellite node can have a limited amount of
resources. This restricts the number of services provided by the satellites
and the users served. Therefore a proper user-satellite assignment is
needed. Additionally, with a boost in communication technologies, different
terrestrial and NTN layers can form multi-tier computing facilities with
higher capacity and coverage. We aim to solve the network selection problem
over multi-service multi-tier edge computing facilities provided by
multiple LEO constellations and cloud computing facilities. A Hierarchical
Reinforcement Learning (HRL) based solution is proposed for optimizing the
multi-level network selection decisions to minimize the task processing
latency. The simulation results show improvements in terms of latency
performance and service reliability, considering user/system constraint
satisfaction
Electrical engineering master's entrance examination (Electromagnetics chapters)
No full textThis book has been written for the Bachlor graduates who wants to sit the Electrical engineering master's entrance examination. It includes chapters on Electromagnetis, Mathematics, Signals and Systems, Power Systems, Control Systems, Electrical Circuits and Electronics
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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