Constraining Spin-One Color-Octet Resonances Using CDF and ATLAS Data

In this paper, we study the production of spin-one color-octet resonances (colorons) at hadron colliders in a model independent way. We use dijets data measured by CDF (at \sqrt{s}=1.96 TeV and L=1.13$1/pb) and ATLAS (at \sqrt{s}=7$ TeV and L=315 1/nb) collaborations at the Tevatron and the LHC respetively to impose limits on the coupling of colorons to fermions. We show that CDF data still produce the more stringent limits on the coloron coupling constant.Comment: Version accepted for publication in EPJC. Two paragraphs expanded and new references adde

Array signal processing in cochlear implants with regularized inversion

The goal of this work is to explore alternative approaches to the cochlear implant array processing work recently published by Honert and Kelsall [Journal of the Acoustical Society of America, Vol. 121, No. 6, pp. 3703-3716, 2007]. They demonstrated the possibility of phased array excitation of cochlear implant electrodes in order to achieve focused intracochlear excitation. This memorandum outlines an extension of this work by means of more advanced matrix inversion techniques. These techniques allow one to solve for the electrode array impedance matrix; invert the matrix; and influence the inverse solution in desirable ways

The control of rocket fairing interior noise with a networked embedded system

Numerous investigations have been conducted with the purpose of attenuating the acoustic environment within rocket payload fairings. These, to date, theoretical and experimental laboratory studies have demonstrated a great deal of success. However, practical applications to this, and other large-scale noise control problems, have been limited in their success. These limitations are due to nonscalable control systems, weight constraints and complexity. This work seeks to address these limitations by investigating the use of an array of networked embedded processors to control the interior acoustics of a rocket fairing. This networked embedded system consists of numerous computationally elements, paired with appropriate sensors and actuators, that communicate with each other over a wired or wireless network. The goal of the network is to minimize the interior acoustic level while expending a minimum amount of energy. Results from the simulation of such control system will demonstrate the effectiveness of such an approach. These results will also be compared with those obtained by traditional, centralized control architectures

Decentralized control of structural acoustic radiation

Although the application of active control to vibrations has been investigated from many years, the extension of this technology to large-scale systems has been thwarted, in part, by an overwhelming need for computational effort, data transmission and electrical power. This need has been overwhelming in the sense that the potential applications are unable to bear the power, weight and complex communications requirement of large-scale centralized control systems. Recent developments in MEMS devices and networked embedded devices have changed the focus of such applications from centralized control architectures to decentralized ones. A decentralized control system is one that consists of many autonomous, or semi-autonomous, localized controllers called nodes, acting on a single plant, in order to achieve a global control objective. Each of these nodes has the following capabilities and assets: 1) a relatively limited computational capability including limited memory, 2) oversight of a suite of sensors and actuators and 3) a communications link (either wired or wireless) with neighboring or regional nodes. The objective of a decentralized controller is the same as for a centralized control system: to maintain some desirable global system behavior in the presences of disturbances. However, decentralized controllers do so with each node possessing only a limited amount of information on the global systems response. Exactly what information each node has access to, and how that information is used, is the topic of this investigation

The scaling of acoustic streaming for application in micro-fluidic devices

Recent interest in MEMS devices in general, and in microfluidic devices specifically, has spurred a great deal of research into the behavior of fluids in very small-scale devices. Many novel techniques have been proposed for the propulsion of fluids in small-scale devices including peristaltic and electrokinetic. More recently, investigations have considered the use of acoustic streaming, that is, the imposition of steady fluid momentum via nonlinear acoustic effects. The purpose of this talk is to give an overview of the physics of acoustic streaming, to discuss the various physical phenomena which generate the effect, and to highlight the favorable scaling issues of acoustic streaming that make it a viable alternative in microfluidic devices