Search results for "NETWORK"
showing 10 items of 7718 documents
Invariant aspects in M-commerce environments
2005
Mobile phones and other small and powerful portable devices have revolutionized personal communication and affected the lifestyles of the people in the industrialized world. Following credible estimates, in a few years there will over two - billions of such portable devices in use. An emerging trend is the electronic commerce performed using mobile terminals over wireless networks, often called mobile commerce or M-commerce. Mobile commerce environments are characterized by high complexity, including myriads of technical and organizational aspects. This property makes it difficult to distinguish the more fundamental issues, structures, and concepts in mobile commerce from the hype. To captu…
Measurement of the single-top-quark production cross section at CDF.
2008
We report a measurement of the single top quark production cross section in 2.2 ~fb-1 of p-pbar collision data collected by the Collider Detector at Fermilab at sqrt{s}=1.96 TeV. Candidate events are classified as signal-like by three parallel analyses which use likelihood, matrix element, and neural network discriminants. These results are combined in order to improve the sensitivity. We observe a signal consistent with the standard model prediction, but inconsistent with the background-only model by 3.7 standard deviations with a median expected sensitivity of 4.9 standard deviations. We measure a cross section of 2.2 +0.7 -0.6(stat+sys) pb, extract the CKM matrix element value |V_{tb}|=0…
Self-powered IoT Device based on Energy Harvesting for Remote Applications
2018
In this paper, we present the design and prototype implementation of self-powered Internet of Things (IoT) device based on energy harvesting from a small solar panel of size 63mm x 63mm and 0.36W for remote applications. These IoT devices can be deployed in remote places within the range of a gateway. A complete proof of concept IoT device based on ambient energy harvesting is designed, prototyped and tested with super capacitors and Lithium cells in star topology. Based on the measurements, the IoT device can potentially last for one year with 55 seconds transmission interval with the fully charged 120mAh coin cell battery. On the other hand, a fully charged single 5F supercapacitor lasts …
A Network Formation Game Approach to Study BitTorrent Tit-for-Tat
2007
The Tit-for-Tat strategy implemented in BitTorrent (BT) clients is generally considered robust to selfish behaviours. The authors of [1] support this belief studying how Tit-for-Tat can affect selfish peers who are able to set their upload bandwidth. They show that there is a "good" Nash Equilibrium at which each peer uploads at the maximum rate. In this paper we consider a different game where BT clients can change the number of connections to open in order to improve their performance. We study this game using the analytical framework of network formation games [2]. In particular we characterize the set of pairwise stable networks the peers can form and how the peers can dynamically reach…
Nonlinear Complex PCA for spatio-temporal analysis of global soil moisture
2020
Soil moisture (SM) is a key state variable of the hydrological cycle, needed to monitor the effects of a changing climate on natural resources. Soil moisture is highly variable in space and time, presenting seasonalities, anomalies and long-term trends, but also, and important nonlinear behaviours. Here, we introduce a novel fast and nonlinear complex PCA method to analyze the spatio-temporal patterns of the Earth's surface SM. We use global SM estimates acquired during the period 2010-2017 by ESA's SMOS mission. Our approach unveils both time and space modes, trends and periodicities unlike standard PCA decompositions. Results show the distribution of the total SM variance among its differ…
Importance of the Window Function Choice for the Predictive Modelling of Memristors
2021
Window functions are widely employed in memristor models to restrict the changes of the internal state variables to specified intervals. Here, we show that the actual choice of window function is of significant importance for the predictive modelling of memristors. Using a recently formulated theory of memristor attractors, we demonstrate that whether stable fixed points exist depends on the type of window function used in the model. Our main findings are formulated in terms of two memristor attractor theorems, which apply to broad classes of memristor models. As an example of our findings, we predict the existence of stable fixed points in Biolek window function memristors and their absenc…
Using neural networks to obtain indirect information about the state variables in an alcoholic fermentation process
2020
This work provides a manual design space exploration regarding the structure, type, and inputs of a multilayer neural network (NN) to obtain indirect information about the state variables in the alcoholic fermentation process. The main benefit of our application is to help experts reduce the time needed for making the relevant measurements and to increase the lifecycles of sensors in bioreactors. The novelty of this research is the flexibility of the developed application, the use of a great number of variables, and the comparative presentation of the results obtained with different NNs (feedback vs. feed-forward) and different learning algorithms (Back-Propagation vs. Levenberg&ndash
Descriptor-type Kalman Filter and TLS EXIN Speed Estimate for Sensorless Control of a Linear Induction Motor.
2014
This paper proposes a speed observer for linear induction motors (LIMs), which is composed of two parts: 1) a linear Kalman filter (KF) for the online estimation of the inductor currents and induced part flux linkage components; and 2) a speed estimator based on the total least squares (TLS) EXIN neuron. The TLS estimator receives as inputs the state variables, estimated by the KF, and provides as output the LIM linear speed, which is fed back to the KF and the control system. The KF is based on the classic space-vector model of the rotating induction machine. The end effects of the LIMs have been considered an uncertainty treated by the KF. The TLS EXIN neuron has been used to compute, in …
Handbook of Memristor Networks
2019
Inversion of matrix pencils for generalized systems
1993
Abstract This paper clarifies the nature of the Leverrier-Faddeev algorithm for generalized and state-space systems. It presents useful diagrams for recursive computation of the coefficients of the characteristic polynomial and the coefficient matrices of the adjoint matrix for various matrix pencils. A simplified case covers recursive equations and diagrams for inversion of the second-order matrix pencil (Es2 + A1s + A0) where E may be singular. The appendix provides two examples of mechanical and heat exchange systems which can be described by the generalized models.