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It is posited that the process of measuring the various parameters that characterize a signal is equivalent to a fitting problem in mathematics. The equation being fit is a model based on the “physics” of the signal. The Fourier transform or rms calculations in a phasor measurement unit (PMU) furnish the values of the coefficients. Regardless of exactly how the measurement is made, a metric we define...
We consider the problem of efficiently learning mixtures of a large number of spherical Gaussians, when the components of the mixture are well separated. In the most basic form of this problem, we are given samples from a uniform mixture of k standard spherical Gaussians with means mu_1,...,mu_k in R^d, and the goal is to estimate the means up to accuracy δ using poly(k,d, 1/δ)...
Electrical energy generation is evolving from centralized towards distributed energy resources (DER) like wind and solar power plants. In such power systems, new challenges arise for the design of voltage source converter (VSC) control strategies. In the last few years synchronverters have gained interest from the research community due to their capability of emulating synchronous machines (SMs) and...
Successful implementation of Model-based Systems Engineering(MBSE) obviously needs a model supporting efficient communication among engineers of various domains. The system modeling language standard, SysML is designed to create MBSE supporting models. However, SysML itself is not practical enough to be used for real-world engineering projects. As SysML is designed for generic systems and requires...
The vision is considered the most important sense in humans, the visual field may be affected by various diseases or conditions that can even be congenital, resulting in a high percentage of people with visual problems, low vision to blindness. In the majority of cases can be corrected with conventional methods, however, if a suitable control could be prevented and up to early detection of various...
This article presents the simulation and harmonic analysis of a charging station model developed in “Modeling and protection of electric vehicle charging station”, which was adapted with the electrical parameters of the distribution system of Cuenca city, with The purpose of quantifying the amount of harmonics that this type of stations can produce in the network. The simulation resulted, that the...
A design gauge pressure of an eco-friendly gas insulated switchgear (GIS) with an application of vacuum interrupters (VIs) ranges from 0.1 to 0.3MPa. Therefore, a high differential pressure is imposed on bellows of the VIs, which increases the fatigue failure risk of the bellows after cycles of operations. Although, there are some empirical equations recommended by the Chinese National Standard GB/T...
In this paper we present a new method for creating polynomial solvers for problems where a (possibly infinite) subset of the solutions are undesirable or uninteresting. These solutions typically arise from simplifications made during modeling, but can also come from degeneracies which are inherent to the geometry of the original problem. The proposed approach extends the standard action matrix method...
In August 2017 under the auspices of the International Union of Physiological Sciences (IUPS), we will launch a new journal: Physiome. The goal of Physiome is to promote, encourage, and support the wide-spread adoption of technologies and workflows that generally improve the ability of scientists to discover existing computational models which are relevant to their work, reproduce the predictions...
Automatic grading systems, such as WebWork, are becoming much more widely used as they relieve the instructor from needing to grade student work, provide students with automatic feedback, and can allow for immediate resubmission. They have also been shown to improve the effectiveness of teaching and learning. In this paper, we apply Item Response Theory (IRT) to a large WebWork Calculus homework dataset...
To support evidence-based science and technology policy, it is important to provide information systematically through platforms such as a decision support system. This study suggests an integrated classification system for categorizing information as a way to provide it systematically. The integrated classification system was developed by analysis of relationship among keywords of R&D classification...
We propose a new algorithm for portfolio optimization based on statistical arbitrage, that uses a multi-criteria decision making approach to obtain the most preferred assets. A preference flow graph of financial assets is constructed at each time step, with the aid of statistical arbitrage algorithm that describes preferences among the assets. Then, the individual preferences for each asset are obtained...
Exploration and exploitation are two strategies used to search the problem space in Evolutionary Algorithms (EAs). To significantly increase the performance of these optimization techniques in terms of the solution optimality is to strike the right balance between exploration and exploitation. Firefly is one of the most favored EAs. In this study, we introduce an entire fuzzy system to tune dynamically...
The paper presents the validation of the implementation made by the user of the standard wall function for the standard k-ε turbulence model against the built-in standard wall function for the standard k-ε turbulence mode, in numerical computation software (ANSYS Fluent). A comparison was made between the results of two flow simulations: the first case consisted in using the built-in standard wall...
The accuracy and productivity of measurement performed with the help of coordinate measuring machines depend not only on their technical characteristics but also on the strategy used to select the number, location of the points and the sequence of their circumvention on the surface. The article proposes a new strategy for the determination of the number and location of control points on surfaces based...
We consider the economic and mathematical model of forming unified information Internet space for scientific and educational resources by integration of scientific and educational resources in certain “cloud”, based on the needs of consumers, the possibility of required generation in information sources and the availability of nodes (providers) in the network to organize the process of receiving,...
European countries start rising the standards regarding the energy performance of buildings by adopting the European Commission's directives with the purpose of driving change in the building sector and promoting a low carbon economy. The energy performance of buildings and the related costs with energy can be reduced from the design phase, by choosing high quality and energy performant materials...
The computer modeling system of industrial extruders with adjustable configuration has been developed allowing solving control tasks of multi-assortment polymeric film quality under change-over of production lines on new assignments and under product manufacture. The system includes module for extruder mark choice, module for extruder configuration design, module for calculation of geometrical parameters...
An inverse boundary value problem is considered for a non-linear parabolic equation. Two-sided estimates are obtained for the norms of non-linear operator values in terms of the norms of values of the corresponding linear operator. As a consequence, two-sided estimates are established for the modulus of continuity of a nonlinear inverse problem in terms of the modulus of continuity of the corresponding...
This paper proposes optimal background modeling scheme for the cluttered scenes. The background initialization is the first step in the process of segmenting out moving information. Concrete background model ensures the proper segmentation of moving information from the scene. Each pixel is modeled as mixture of Gaussian. Using decision criteria, background/foreground pixels are differentiated. During...
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