Game theory and the frequency selective interference channel

As discussed in this paper, the frequency selective interference channel is important, both from a practical as from an information theoretic point of view. We show that it has many intriguing aspects from a game theoretic point of view as well, and that various levels of interference admit different types of game theoretic techniques.     

Design and Evaluation of Adiabatic Arithmetic Units

Adiabatic design is an attractive approach to reducingenergy consumption in VLSI circuits after exhausting the potentialof conventional energy-saving techniques. Despite the plethoraof adiabatic logic architectures that have been proposed in recentyears, several practical considerations in the design of nontrivialadiabatic circuits remain largely unexplored. Moreover, it isstill unclear whether adiabatic circuits of significant sizeand complexity can achieve substantial savings in energy dissipationover corresponding conventional designs. We recently designedseveral low-power arithmetic units using a dual-rail adiabaticlogic design style. We also designed static CMOS versions ofthese units and compared their energy dissipation with theircorresponding adiabatic designs. In this paper we describe ourimplementations, discuss architecture and logic-level issuesrelated to our adiabatic designs, and present the findings ofour empirical comparison. Our results suggest that adiabaticlogic can be used for the implementation of relatively complexVLSI circuits that dissipate significantly less energy than theircorresponding CMOS designs.     

FASTA barcodes: a simple method for the identification of yeast ORF deletions

A consortium of yeast geneticists have created -6000 individual ORF deletions, representing > 96% of the currently verified or predicted ORFs in S. cerevisiae. Importantly, molecular barcodes (each a unique 20 bp sequence termed either Uptag or Downtag) were used as identifiers for every ORF deletion. Microarray analyses of pooled yeast deletions has been used to identify thousands of genes involved in general fitness, haploinsufficiency, drug resistance and DNA damage repair. However, application of this powerful technology requires considerable expense, expertise and specialized equipment. While standard PCR techniques and specifically designed PCR primers can be used to confirm that a given ORF is in fact deleted, this procedure cannot be used to identify unknown deletions. In theory, every ORF deletion could be determined by barcode sequencing. However, neither a consolidated barcode database nor a reliable search engine is currently available for this purpose. To address this need, we have adapted a FASTA sequence program that utilizes the unique barcode database to allow users to identify individual ORF deletions, based upon simple sequencing reactions of PCR amplifications of either Uptag or Downtag barcodes. In silico and practical testing of this application reveals that it is an inexpensive, reliable and reproducible method for rapidly identifying unknown deletions. This approach allows laboratories to conduct small- or large-scale genetic screens with pooled yeast deletion strains and identify or verify any ORF deletion without the need for microarray technology.     

Radiation Heat Transfer and Vapor Shielding in a Two-Dimensional Model of an Electrothermal Plasma Source

Electrothermal (ET) plasma discharges are emerging as valuable mechanisms for pellet injection in magnetic confinement fusion reactors. They have been shown to be capable of achieving the required pellet velocities and pellet launch frequencies required for edge localized mode control. Another advantage of ET plasma discharges is their ability to simulate fusion disruption events by depositing large heat fluxes on exposed materials. A deeper understanding of the heat transfer processes occurring in ET plasma discharges will aid in this particular application. ET plasma discharges involve the passage of high currents (order of tens of kA) along the axis of a narrow, cylindrical channel. As the current passes through the channel, radiant heat is transferred from the plasma core to the capillary wall. Ablated particles eventually fill the plasma channel and the partially ionized plasma is ejected. It is well known that the ablated material separating the plasma core from the ablating surface can act as a vapor shield and limit the radiation heat flux reaching the ablating surface. In this work, the results from a two-dimensional simulation model for ET plasma discharges are presented. The simulation of the plasma in a two-dimensional domain combined with the diffusion approximation for radiation heat transfer is shown to successfully simulate the effects of the vapor shield layer that develops inside these devices.     

Wire Melt Electrospinning of Thin Polymeric Fibers via Strong Electrostatic Field Gradients

Here, a novel melt electrospinning method to produce few‐micron and nanometer thick fibers is presented, in which a polymer‐coated wire with a sharp tip is used as the polymer source. The polymer coating is melted via Joule heating of the source wire and extracted toward the target via electrostatic forces. The high viscosity and low charge density of polymer melts lower their stretchability in melt. The method relies on confining the Taylor cone and reducing initial jet diameter via concentrated electrostatic fields as a means to reduce the diameter of fibers. As a result, the initial jet diameter and the final fiber diameter are reduced by an order of magnitude of three to ten times, respectively, using wire melt electrospinning compared to syringe‐ and edge‐based electrospinning. The fiber diameter melt electrospun via this novel method is 1.0 ± 0.9 µm, considerably thinner than conventional melt electrospinning techniques. The generation of thin fibers are explained in terms of the electrostatic field around the wire tip, as obtained from finite element analysis (FEA), which controls the size and shape of the melt electrospun jet.     

Direction-of-arrival estimation for constant modulus signals

In many cases where direction finding is of interest, the signals impinging on an antenna array are known to be phase modulated and, hence, to have a constant modulus (CM). This is a strong property; by itself, it is already sufficient for source separation and can be used to construct improved direction finding algorithms. We first derive the relevant Cramer-Rao bounds (CRBs) for arbitrary array configurations and specialize to uniform linear arrays. We then propose a simple suboptimal direction estimation algorithm in which the signals are separated using the CM property followed by direction finding on the decoupled signals. Compared with the ESPRIT algorithm and the CRB for arbitrary signals, the algorithm shows good results     

Microwave nondestructive sensing of moisture content in shelled peanuts independent of bulk density and with temperature compensation

Dielectric methods for rapid and nondestructive sensing of moisture content in shelled peanuts from free-space measurement of attenuation and phase shift, and their corresponding dielectric properties at temperatures ranging from 1 to 38 °C and frequencies ranging from 8 to 14 GHz, are presented. These methods provide moisture content independent of bulk density and compensated for temperature effects. Results of moisture prediction with three density-independent calibration functions (ψ₁, ψ₂, and ψ₃) are compared. For each function, the moisture calibration equation with temperature compensation is given along with corresponding standard errors of performance (SEP). For all three calibration functions, the SEP was less than 1% moisture content. Also, the frequency behavior of each of these calibration functions was examined in the frequency range between 8 and 14 GHz. Among the three density-independent calibration functions, calibration function ψ₃ showed the least variation with frequency.