A new approach to secure economic power dispatch

This article presents a new nonlinear convex network flow programming model and algorithm for solving the on-line economic power dispatch with N and N−1 security. Based on the load flow equations, a new nonlinear convex network flow model for secure economic power dispatch is set up and then transformed into a quadratic programming model, in which the search direction in the space of the flow variables is to be solved. The concept of maximum basis in a network flow graph was introduced so that the constrained quadratic programming model was changed into an unconstrained quadratic programming model which was then solved by the reduced gradient method. The proposed model and its algorithm were examined numerically with an IEEE 30-bus test system on an ALPHA 400 Model 610 machine. Satisfactory results were obtaine

Human Auditory cortical processing of changes in interaural correlation

Sensitivity to the similarity of the acoustic waveforms at the two ears, and specifically to changes in similarity, is crucial to auditory scene analysis and extraction of objects from background. Here, we use the high temporal resolution of magnetoencephalography to investigate the dynamics of cortical processing of changes in interaural correlation, a measure of interaural similarity, and compare them with behavior. Stimuli are interaurally correlated or uncorrelated wideband noise, immediately followed by the same noise with intermediate degrees of interaural correlation. Behaviorally, listeners' sensitivity to changes in interaural correlation is asymmetrical. Listeners are faster and better at detecting transitions from correlated noise than transitions from uncorrelated noise. The cortical response to the change in correlation is characterized by an activation sequence starting from ∼50 ms after change. The strength of this response parallels behavioral performance: auditory cortical mechanisms are much less sensitive to transitions from uncorrelated noise than from correlated noise. In each case, sensitivity increases with interaural correlation difference. Brain responses to transitions from uncorrelated noise lag those from correlated noise by ∼80 ms, which may be the neural correlate of the observed behavioral response time differences. Importantly, we demonstrate differences in location and time course of neural processing: transitions from correlated noise are processed by a distinct neural population, and with greater speed, than transitions from uncorrelated noise

Does consumer sentiment accurately forecast UK household consumption? Are there any comparisons to be made with the US?

This paper investigates how well survey data depicting consumer sentiment forecasts household’s consumption behavior for the UK. We consider whether consumer sentiment is able to predict the growth of household’s consumption, in addition to the growth of labor income. The empirical analysis finds that Consumer Confidence Indices (CCI) does predict the household’s consumption of durable goods. We also draw comparisons with recent analysis for the US. In addition, we analyze whether both the UK and US CCI are accurate and useful predictors of household’s consumption growth using directional analysis. We find that the UK confidence indicators predict better the US

Processing asymmetry of transitions between order and disorder in human auditory cortex

Purpose: To develop an algorithm to resolve intrinsic problems with dose calculations using pencil beams when particles involved in each beam are overreaching a lateral density interface or when they are detouring in a laterally heterogeneous medium. Method and Materials: A finding on a Gaussian distribution, such that it can be approximately decomposed into multiple narrower, shifted, and scaled ones, was applied to dynamic splitting of pencil beams implemented in a dose calculation algorithm for proton and ion beams. The method was tested in an experiment with a range-compensated carbon-ion beam. Its effectiveness and efficiency were evaluated for carbon-ion and proton beams in a heterogeneous phantom model. Results: The splitting dose calculation reproduced the detour effect observed in the experiment, which amounted to about 10% at a maximum or as large as the lateral particle-disequilibrium effect. The proton-beam dose generally showed large scattering effects including the overreach and detour effects. The overall computational times were 9 s and 45 s for non-splitting and splitting carbon-ion beams and 15 s and 66 s for non-splitting and splitting proton beams. Conclusions: The beam-splitting method was developed and verified to resolve the intrinsic size limitation of the Gaussian pencil-beam model in dose calculation algorithms. The computational speed slowed down by factor of 5, which would be tolerable for dose accuracy improvement at a maximum of 10%, in our test case.AAPM Annual Meeting 200

Design and analysis of a new permanent magnet brushless DC machine

A new permanent magnet (PM) brushless dc machine with a unique feature of flux regulation is presented. The machine offers the merits of high density, high efficiency, high starting torque and wide constant power speed range.published_or_final_versio

A permanent-magnet double-stator integratedstarter-generator for hybrid electric vehicles

This paper presents a new permanent magnet double-stator integrated-starter-generator (ISG) for hybrid electric vehicles (HEVs). Compared with conventional PM electric machines, it has the advantage that currents of both the inner and outer stators produce electromagnetic torque and two air-gaps can deliver the output torque, thus improving the torque density and providing a high starting torque for cold cranking. Because of the nature of doublestator windings, the machine can flexibly change their connections, hence providing a constant output voltage over a wide speed range for battery charging. By using time-stepping finite element method (TS-FEM), the steady-state and dynamic performance of the machine is analyzed. Hence, due to the high starting torque and good controllability, this proposed ISG is desirable for HEVs application. A three-phase 22-pole 2 kW prototype is designed and built for experimentation verification. © 2008 IEEE.published_or_final_versio

Application of linear magnetic gears for pseudo-direct-drive oceanic wave energy harvesting

Session AZ: Magnetic Machine (Poster Session): AZ-07This paper proposes a linear permanent magnet (PM) machine for direct-drive wave energy harvesting by using a linear magnetic gear. The proposed machine consists of a linear magnetic gear cascaded with a linear PM generator in which the high-speed mover of the linear magnetic gear and the translator of the PM generator artfully shares with the same shaft. In short, the slow reciprocating wave motion is directly captured by the low-speed mover of the gear, and then amplified in speed via the gear to actuate the generator, hence producing higher output voltage. By using finite element analysis, the steady and dynamic performances are analyzed, which confirms that the proposed machine can offer higher power density and higher efficiency than its counterpart. © 2011 IEEE.published_or_final_versionThe IEEE International Magnetic Conference (INTERMAG2011), Taipei, Taiwan, 25-29 April 2011. In IEEE Transactions on Magnetics, 2011, v. 47 n. 10, p. 2624-262

Mutual funds' ownership and firm performance: Evidence from China

Mutual funds have emerged and rapidly developed since 2000 in China. This study tests empirically the impact of mutual funds' ownership on firm performance in China, using a large sample for the period of 2001-2005. We find that equity ownership by mutual funds has a positive effect on firm performance. The result is robust to several measures of firm performance and various estimations. Our finding supports recent regulatory efforts in China to promote mutual funds as a corporate governance mechanism and suggests that pooling diffuse minority interests of individual shareholders who are prone to free-rider problems via mutual funds is beneficial. © 2007 Elsevier B.V. All rights reserved.preprin