23,868 research outputs found
Supersymmetric quantum mechanics and the Korteweg-de Vries hierarchy
The connection between supersymmetric quantum mechanics and the Korteweg- de
Vries (KdV) equation is discussed, with particular emphasis on the KdV
conservation laws. It is shown that supersymmetric quantum mechanics aids in
the derivation of the conservation laws, and gives some insight into the Miura
transformation that converts the KdV equation into the modified KdV equation.
The construction of the -function by means of supersymmetric quantum
mechanics is discussed.Comment: 16 pages, latex, EFI 93/2
Summary of the electromagnetic compatibility evaluation of the proposed satellite power system
The effects of the proposed solar power satellite (SPS) operations on electronic equipment and systems by fundamental, harmonic, and intermodulation component emissions from the orbital station; and the fundamental, harmonic, and structural intermodulation emissions from the rectenna site were evaluated. The coupling and affects interactions affecting a wide spectrum of electronic equipment are considered. The primary EMC tasking areas are each discussed separately
Laser velocimeter for simultaneous two-dimensional velocity measurements
Laser velocimeter provides simultaneous orthogonal measurements in manner which minimizes many problems attending prior systems, and allows spatial traversing of flowfield in order to obtain velocity profiles. Velocimeter permits rapid interrogation of unsteady flows where area of interest is of the order of one meter in extent and flow does not vary appreciably over time of about one second
Developing site-specific guidelines for orchard soils based on bioaccessibility – Can it be done?
Horticultural land within the periurban fringe of NZ towns and cities increasingly is being developed for residential subdivision. Recent surveys have shown that concentrations of As, Cd, Cu, Pb, and ΣDDT (sum of DDT and its degradation products DDE and DDD) in such soils can exceed criteria protective of human health.¹ Soil ingestion is a key exposure pathway for non-volatile contaminants in soil. Currently in NZ, site-specific risk assessments and the derivation of soil guidelines protective of human health assume that all of the contaminant present in the soil is available for uptake and absorption by the human gastrointestinal tract. This assumption can overestimate health risks and has implications for the remediation of contaminated sites.² In comparison, the bioavailability of contaminants is considered when estimating exposure via dermal absorption and by ingestion of home-grown produce.³ Dermal absorption factors and plant uptake factors are included in the calculations for estimating exposures via these routes
Cellular Multilayer Perceptron for Prediction of Voltages in a Power System
With the increase in renewable energy sources connected to the power grid, better identification tools are needed for power system voltage profile prediction. Current deregulation trends have led to voltages operating close to stability limits which increases the need for quick estimation tools for system security and contingency analysis. This paper presents a Cellular Multilayer Perceptron (CMLP) architecture for fast identification and prediction of bus voltages. the CMLP method is compared with a standard MLP neural network for bus voltage prediction on the 12-bus three-area test power system. CMLPs can represent a direct mapping of any power system simplifying the equations and allowing for easy scalability to large power systems. © 2009 IEEE
Voltage Prediction using a Cellular Network
Better identification tools are needed for power system voltage profile prediction. the power systems of the future will see an increase in both renewable energy sources and load demand increasing the need for quick estimation of bus voltages and line power flows for system security and contingency analysis. a Cellular Simultaneous Recurrent Neural Network (CSRN) to identify and predict bus voltage dynamics is presented in this paper. the benefit of using a cellular structure over traditional neural network architectures is that the network can represent a direct mapping of any power system allowing for easier scalability to large power systems. a comparison with a standard single SRN is provided to show the advantages of this cellular method. Two types of disturbance are evaluated including perturbations on the power system generators and on the least stable loads. the method is also evaluated for a case involving a transmission line outage. ©2010 IEEE
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