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Representing reality in computer graphics requires simulating the appearance of real-world materials. Bidirectional Reflectance Distribution Functions (BRDFs) are commonly used to perform this task, as they represent the appearance of a material through the quotient between the reflected radiance and the incoming irradiance at this point. Acquiring the BRDF of a real material is an expensive task...
The droop control technology, which can achieve an autonomous power sharing among distributed resources interface converters, provides the advantages of enhanced system reliability and reduced complexity. However, the reactive power sharing accuracy of the conventional Q — V droop method can be degraded due to its dependence on the line impedances. The Q — V droop control method was proposed to reduce...
In this paper, a model based signal processing method is proposed to diagnose two faults under different load condition for permanent magnet synchronous machines. This method captures the spectrum of stator current in a compact representation. Then, its dimensionality is reduced using the discriminant analysis. Finally a support vector machine automatically classifies the health state of the system...
A quasi-optimal regulator design problem is solved for nonlinear control objects described in the state-space by nonlinear matrix ordinary differential equations with quadratically-cubic nonlinearities, where polynomial terms are constructed using the Kronecker matrix product. A.A. Krasovskiy's generalized work criterion is used as the cost functional. The Lyapunov function is determined by the integration...
We show variants of spectral sparsification routines can preserve the totalspanning tree counts of graphs, which by Kirchhoffs matrix-tree theorem, isequivalent to determinant of a graph Laplacian minor, or equivalently, of any SDDM matrix. Our analyses utilizes this combinatorial connection to bridge between statisticalleverage scores / effective resistances and the analysis of random graphsby [Janson,...
In order to scientifically and effectively allocate university education resources and improve the efficiency of educational resources, we need to evaluate the efficiency of university education. Delphi, AHP and DEA organically combine to establish a combination of university efficiency evaluation model. The model can not only reflect the preferences of decision makers, but also objectively evaluate...
Air traffic and on-board data access services are expected to have tremendous growth, possibly even exponentially in the near future. In order to meet these challenges, Orthogonal Frequency Division Multiplexing (OFDM) can be deployed to enable the increased usage of broadband services on-board. The Doppler effect is one of the major issues in implementing OFDM modulation in aeronautical satellite...
To improve the spectrum efficiency in wireless communication systems, multiple-input multiple-output (MIMO) technology uses multiple antennas and allows several users to share the same spectrum and antennas by using precoding technique. In the leakage-based precoding technique, generalized eigenvalue decomposition (GEVD) must generate many precoding matrices for all users in the base station to avoid...
Recently Ntogramatzidis et al [1] gave a design method for a linear time-invariant state feedback controller to monotonically track a constant step reference at any desired rate of convergence for any initial condition. In this paper we describe a new public-domain MATLAB® toolbox to implement this control scheme. The toolbox enables interested users to implement the controller design methods of [1]...
We study streaming principal component analysis (PCA), that is to find, in O(dk) space, the top k eigenvectors of a d× d hidden matrix \bold \Sigma with online vectors drawn from covariance matrix \bold \Sigma.We provide global convergence for Ojas algorithm which is popularly used in practice but lacks theoretical understanding for k≈1. We also provide a modified variant \mathsf{Oja}^{++}...
The visual and automatic classification of vehicles plays an important role in the Transport Area. Besides of security issues, the monitoring of the type of traffic in streets and highways, as well the traffic dynamics over time, allows the optimization of use and of resources related to such public infrastructure. In this work we propose a novel method, called 2D-DBM, for robust and efficient automatic...
VSCs connected to the grid through LCL filters are common in the integration of renewable energies into electrical systems. Therefore, in this paper small signal stability of the current loop of this configuration is performed. The analysis includes the getting of a state-space representation of the system, the calculation of their eigenvalues and the sensitivity analysis to the variation of some...
Gesture recognition is an important research area in video analysis and computer vision. Gesture recognition systems include several advantages, such as the interaction with machines without needing additional external devices. Moreover, gesture recognition involves many challenges, as the distribution of a specific gesture largely varies depending on viewpoints due to its multiple joint structures...
Three-dimensional model of the interested region on the surface of an object provides an important information for a variety of industrial robot applications including welding, deburring, reverse engineering, etc. In this paper, we present a method that enables to determine 3D surface points of the objects by using a single camera and a rotary stage. The method utilizes a stereo vision triangulation...
There is an increasing need to model large networks of inverter-based distributed generation due to the limits of existing simulation tools. A deliberate enforcement of intra-feeder coherency between adjacent droop-controlled inverters is a worthwhile objective, as phase angle coherency will allow for a deliberate partitioning of fast and slow dynamics within the network. This partitioning, in turn,...
Cooperative containment problem is presented in this paper for discrete-time multi-agent systems with different dynamics subject to structural uncertainties. The topologies of the agents could be assumed that one leader contains a directed path to all the follower agents. The paper obtains some novel and challenging results on cooperative containment control problem of discrete-time multi-agent systems:...
This paper considers the distributed output consensus problem of heterogeneous linear multi-agent networks with event-triggered communications. To handle the heterogeneity existing in the network, we first design adaptive event-based dynamic compensators for the agents. Distributed output feedback protocols, consisting of the dynamic compensators and the distributed state observers, the local controllers,...
In this note, under time varying undirected graph, we discuss fixed-time consensus of multi-agent systems and present one framework for constructing effective distributed protocols, which is continuous and distributed state feedbacks. Based on the theory of fixed-time stability, and we prove that if the sum of time intervals is larger than a given time, and the bounded of initial states is known,...
The Buck converter exhibits interesting nonlinear phenomena which many studies have addressed, and the resonant parametric perturbation is effective to control these nonlinear phenomena. We investigate the control mechanism by using the monodromy matrix derived from the Filippov's method when the perturbation has an appropriate phase shift and the duty ratio is not changed. We find that only one term...
This paper studies chaotic behavior in cancer dynamics when a treatment procedure is introduced. Recently introduced virotherapy is considered for the cancer treatment. Chaotic behaviors are investigated by using the Lyapunov Exponent for a set of parameters. The chaotic behavior is studied by using the mathematical model of the cancer dynamics involving the virotherapy. Through simulations and the...
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