Search results for "Generator"
showing 10 items of 426 documents
A Visualizable Test Problem Generator for Many-Objective Optimization
2022
Visualizing the search behavior of a series of points or populations in their native domain is critical in understanding biases and attractors in an optimization process. Distancebased many-objective optimization test problems have been developed to facilitate visualization of search behavior in a two-dimensional design space with arbitrarily many objective functions. Previous works have proposed a few commonly seen problem characteristics into this problem framework, such as the definition of disconnected Pareto sets and dominance resistant regions of the design space. The authors’ previous work has advanced this research further by providing a problem generator to automatically create use…
Contractions yielding new supersymmetric extensions of the poincaré algebra
1991
Two new Poincare superalgebras are analysed. They are obtained by the Wigner-Inonu contraction from two real forms of the superalgebra OSp(2;4;C) - one describing the N = 2 anti-de-Sitter superalgebra with a non-compact internal symmetry SO(1, 1) and the other corresponding to the de-Sitter superalgebra with internal symmetry SO(2). Both are 19-dimensional self-conjugate extensions of the Konopel'chenko superalgebra. They contain 10 Poincare generators and one generator of internal symmetry in addition to 8 odd generators half of which, however, do not commute with translations.
Real time estimation of photovoltaic modules characteristics and its application to maximum power point operation
2007
In this paper, an approximate curve fitting method for photovoltaic modules is presented. The operation is based on solving a simple solar cell electrical model by a microcontroller in real time. Only four voltage and current coordinates are needed to obtain the solar module parameters and set its operation at maximum power in any conditions of illumination and temperature. Despite its simplicity, this method is suitable for low cost real time applications, as control loop reference generator in photovoltaic maximum power point circuits. The theory that supports the estimator together with simulations and experimental results are presented.
Modeling of mobility and groups in inter-vehicular MANET-based networks
2007
This paper evaluates the behavior of mobile ad hoc networks when group mobility is involved. We concentrate on group mobility because road vehicles tend to form groups or fleets whose behavior depends on the behavior of the close-by vehicles. We propose four different group mobility models and present a mobility pattern generator, called grcmob that we designed to be used with the ns-2 simulator. We evaluate the performance of vehicular ad hoc networks under a wide number of scenarios using both TCP and UDP data traffic. We show that the number of groups is more important than the number of nodes and that the impact of area size is almost negligible. We also reveal that the mixture of inter…
A Bond Graph Approach to Modeling and Simulation of Nonlinear Wind Turbine System
2013
This chapter addresses the problem of bond graph methodology as a graphical approach for modeling of wind turbine generating systems. The purpose of this chapter is to show some of the benefits of the bond graph approach in contributing a model for wind turbine systems. We will present a nonlinear model of a wind turbine generating system, containing pitch, drive train, tower motion and generator. All which will be modeled by means of bond graph. We will especially focus on the drive train, and show the difference between modeling with a classical mechanical method and by using bond graph. The model consists of realistic parameters, but we are not trying to validate a specific wind turbine …
How a Fish’s Brain May Move a Fish’s Body
1990
The brainstem of the electric fish Eigenmannia virescens contains a small number of neural networks projecting directly onto the motoneuron pools of the spinal cord such that each segment is reached by at least one neuron of all the networks. Quantitative data of movement patterns, recorded from freely moving animals as well as elicited by electrical stimulation of the single networks, suggest that each network contains a full program for a particular movement, e. g. bending of the body axis to one side. By virtue of the structural relationship the programs are executable with a small number of segments. Mixing of small pieces of programs along the body axis allows for a far larger variety …
On the designing of densely dispersion-managed optical fiber systems for ultrafast optical communication
2003
We present some theoretical and experimental results which suggest the possibility of constructing a non-empirical methodology of designing optical transmission systems with ultra high bit-rate per channel. Theoretically, we present an average dispersion decreasing densely dispersion-managed (A4dm) fiber system, which exhibits many advantages over the densely dispersion-managed fiber system, such as the possibility of transmitting chirp-free Gaussian pulses at 160 Gbit/s per channel over transoceanic distances, with a reduced energy and minimal intra-channel interaction. Experimentally we present generation of a 160-GHz picosecond pulse train at 1550 nm using multiple four-wave mixing tempo…
Past, present and future of 68Ge/68Ga generators.
2013
(68)Ga represents one of the very early radionuclides applied to positron emission tomography (PET) imaging at a time when even the wording PET itself was not established. Today it faces a renaissance in terms of new (68)Ge/(68)Ga radionuclide generators, sophisticated (68)Ga radiopharmaceuticals, and state-of-the-art clincial diagnoses via positron emission tomography/computed tomography (PET/CT). Thanks to the pioneering achievement of radiochemists in Obninsk, Russia, a new type of (68)Ge/(68)Ga generators became commercially available in the first years of the 21st century. Generator eluates based on hydrochloric acid provided "cationic" (68)Ga instead of "inert" (68)Ga-complexes, openi…
An Efficient NURBS Path Generator for a Open Source CNC
2014
In this paper a NURBS path generator (on the plane XY) is proposed to be developed for those CNC machine tools and robot which are Open Source or Opening Architecture. The goal is to use simple and efficient techniques to manufacture geometries which are very complex, whose main feature is the presence of free-form surfaces and contours. To reach this goal, the NURBS path generator has been optimized in order to enable the user to select among three different options to generate the tool path, using a specific parameter. The three options are respectively called “NURBS interpolation with constant increments of u parameter” (NICU), “NURBS interpolation with constant displacement increments b…
Growth mechanisms and related thermoelectric properties of innovative hybrid networks fabricated by direct deposition of Bi2Se3 and Sb2Te3 on multiwa…
2020
Abstract Flexible thermoelectric generators are an emerging trend in the field of waste heat conversion, as well as wearable and autonomous devices. However, the energy conversion efficiency of the state-of-the-art flexible thermoelectric devices is too low for their wide application and commercialization. In this work, n- and p-type multiwalled carbon nanotube (MWCNT)-thermoelectric material hybrid networks that may become a promising building block for the fabrication of flexible thermoelectric devices are presented. The hybrid networks were fabricated by direct deposition of thermoelectric material (Bi2Se3, Sb2Te3) on the MWCNT networks using physical vapor deposition technique. Growth m…