The variability of electromagnetic parameters of induction motors with deep-bar cage or solid rotors is represented, with a satisfactory approximation, by the machine secondary multi-loop equivalent circuit with const...
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The variability of electromagnetic parameters of induction motors with deep-bar cage or solid rotors is represented, with a satisfactory approximation, by the machine secondary multi-loop equivalent circuit with constant lumped parameters. An estimation procedure of electromagnetic parameters of such an equivalent circuit is presented in the paper. The procedure is carried out using the measured frequency characteristic determined on the basis of instantaneous values of investigated induction motor electromechanical quantities. The study has been subjected to an induction motor with a solid rotor manufactured from the magnetic material, i.e. a machine characterized by a significant skin effect occurring in rotor solid conductive elements.
The problem of elimination of impulsive disturbances (such as clicks, pops, ticks, crackles, and record scratches) from archive audio recordings is considered and solved using autoregressive modeling. Three classical ...
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ISBN:
(纸本)9788361402282
The problem of elimination of impulsive disturbances (such as clicks, pops, ticks, crackles, and record scratches) from archive audio recordings is considered and solved using autoregressive modeling. Three classical noise pulse detection schemes are examined and compared: the approach based on open-loop multi-step-ahead signal prediction, the approach based on decision-feedback signal prediction, and the double threshold approach, based on analysis of residual errors. It is shown that the accuracy of the classical schemes can be significantly improved by means of combining the results of forward time and backward time signal processing.
As the importance of the Internet has increased rapidly to new heights especially with wide adoption of web services and advent of cloud computing, the amount of sheer information that can be obtained from this global...
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As the importance of the Internet has increased rapidly to new heights especially with wide adoption of web services and advent of cloud computing, the amount of sheer information that can be obtained from this global information service center leads to major challenges concerning finding relevant information for a casual user or a group of users. On the other hand, even after finding useful documents, it is hard to keep track of them as the amount of useful findings (bookmarks) increases. Also, one has to manually bookmark each time a page is even remotely interesting in order to make it easier to return to that page. In this paper we formulate a new approach to tackling these issues through a model that takes into account not just a single user's experience and intentions, but those of an entire group of users as well. We propose an application in the shape of a browser plugin/extension powered by a dedicated and highly responsive web server that can help the user keep track of his web experience in a highly organized and easy to navigate fashion while also enabling the user to share some of that experience. The clustering of the data is done with a customized algorithm that allows overlapping while showing improved speed and readability.
The large scale emergence of cloud platforms induce the tendency to virtualize application workloads that traditionally ran on physical machines. At the same time, cloud providers advertise unlimited resources availab...
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The large scale emergence of cloud platforms induce the tendency to virtualize application workloads that traditionally ran on physical machines. At the same time, cloud providers advertise unlimited resources available to the customers at any time for a fixed price. These factors create the opportunity for customers to easily scale up and down the infrastructure depending on the real time requirements, reducing the overall costs for providing the service. Cloud platforms today provide a threshold trigger mechanism that can trigger provisioning or de-provisioning of additional resources. This paper argues that the threshold approach is not enough for some real life application scaling requirements and introduces a predictive mechanism that allows accurate and proactive provisioning of workloads. The prediction algorithm is based on the observation that for some applications a usage pattern exists, and this usage pattern is repetitive. This paper presents the usage pattern identified in a large scale travel booking application and the execution of the algorithm on this data. The algorithm tested using IBM CloudBurst 2.1 deployment using a benchmark application and results are discussed.
The Lyapunov, Bohl and Perron exponents belong to the most important numerical characteristics of dynamical systems used in control theory Properties of the first two characteristics are well described in the literatu...
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Public data can be considered large and important sources of data that can be used for different purposes. In this paper we present a method for collecting and analyzing data within urban settlements. For more focused...
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Power factor correction converters are used in many applications as AC-DC power supplies aiming at maintaining a near unity power factor. Systems of this type are known to exhibit nonlinear phenomena such as sub-harmo...
Power factor correction converters are used in many applications as AC-DC power supplies aiming at maintaining a near unity power factor. Systems of this type are known to exhibit nonlinear phenomena such as sub-harmonic oscillations and chaotic regimes that cannot be described by traditional averaged models. In this paper, we derive a time varying discretetime map modeling the behavior of a power factor correction AC-DC boost converter. This map is derived in closed-form and is able to faithfully reproduce the system behavior under realistic conditions. In the chaotic regime the map exhibits a sequence of bifurcation similar to a bandcount doubling cascade on the low frequency. However, the observed scenario appears in some sense incomplete, with some gaps in the bifurcation diagram, whose appearance to our knowledge has never been reported before. We show that these gaps are caused by high frequency oscillations.
The paper is dealing with an analysis of behavior of biologic tissue in interaction with a pulsed magnetic field (a magnetic field commonly used within investigations and treatments, but which can also occur by accide...
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The paper is dealing with an analysis of behavior of biologic tissue in interaction with a pulsed magnetic field (a magnetic field commonly used within investigations and treatments, but which can also occur by accident in electric equipments requiring continuous alteration of running energy parameters). In this interaction, the essential feature pointed out in the paper is that of a major influence of extracellular environment of biologic tissue. The analysis is being performed within the theory of electric circuits by using the electric model of cell membrane. As far the extracellular environment is concerned, it was modelled both as conductive and semiconductive environment to visualize the importance of its characteristics on membrane cell polarization and depolarization phenomena. The analysis has been performed using PSIM software environment by reducing the biologic tissue to the size of two cells and the extracellular environment between them, for this purpose.
This paper presents a model for integrating an advanced process control library in a cloud-based environment. The aim is to lower the development times, to reduce maintenance effort and decrease the complexity of proc...
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This paper presents a model for integrating an advanced process control library in a cloud-based environment. The aim is to lower the development times, to reduce maintenance effort and decrease the complexity of process control applications by adopting a modular approach consisting of generic, reusable control strategies following an IEC 61499 representation. The solution uses open cloud technologies based on Heroku for the deployment in a public cloud structure and Docker for increased portability of the designed solution. The conceptual architecture of the system is presented, as well as the details of the execution module.
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