On-Line Instruction-checking in Pipelined Microprocessors

Microprocessors performances have increased by more than five orders of magnitude in the last three decades. As technology scales down, these components become inherently unreliable posing major design and test challenges. This paper proposes an instruction-checking architecture to detect erroneous instruction executions caused by both permanent and transient errors in the internal logic of a microprocessor. Monitoring the correct activation sequence of a set of predefined microprocessor control/status signals allow distinguishing between correctly and not correctly executed instruction

Chiral transition of fundamental and adjoint quarks

The chiral symmetry breaking transition of quarks in the fundamental and adjoint representation is studied in a model where the gap equation contains two contributions, one containing a confining propagator and another corresponding to the exchange of one-dressed dynamically massive gluons. When quarks are in the fundamental representation the confinement effect dominates the chiral symmetry breaking while the gluon exchange is suppressed due to the dynamical gluon mass effect in the propagator and coupling constant. In this case the chiral and deconfinement transition temperatures are approximately the same. For quarks in the adjoint representation, due to the larger Casimir eigenvalue, the gluon exchange is operative and the chiral transition happens at a larger temperature than the deconfinement one.Comment: 12 pages, 1 figure, improved discussio

QCD chiral symmetry restoration with a large number of quarks in a model with a confining propagator and dynamically massive gluons

Considering a QCD chiral symmetry breaking model where the gap equation contains an effective confining propagator and a dressed gluon propagator with a dynamically generated mass, we verify that the chiral symmetry is restored for a large number of quarks $n_{f}\approx 7-13$. We discuss the uncertainty in the results, that is related to the determination of the string tension ($K_{F}$), appearing in the confining propagator, and the effective gluon mass ($m_{g}$) at large $n_{f}$.Comment: 5 pages, 6 figure

A genetic algorithm-assisted semi-adaptive MMSE multi-user detection for MC-CDMA mobile communication systems

In this work, a novel Minimum-Mean Squared-Error (MMSE) multi-user detector is proposed for MC-CDMA transmission systems working over mobile radio channels characterized by time-varying multipath fading. The proposed MUD algorithm is based on a Genetic Algorithm (GA)-assisted per-carrier MMSE criterion. The GA block works in two successive steps: a training-aided step aimed at computing the optimal receiver weights using a very short training sequence, and a decision-directed step aimed at dynamically updating the weights vector during a channel coherence period. Numerical results evidenced BER performances almost coincident with ones yielded by ideal MMSE-MUD based on the perfect knowledge of channel impulse response. The proposed GA-assisted MMSE-MUD clearly outperforms state-of-the-art adaptive MMSE receivers based on deterministic gradient algorithms, especially for high number of transmitting users

Relating a gluon mass scale to an infrared fixed point in pure gauge QCD

We show that in pure gauge QCD (or any pure non-Abelian gauge theory) the condition for the existence of a global minimum of energy with a gluon (gauge boson) mass scale also implies the existence of a fixed point of the $\beta$ function. We argue that the frozen value of the coupling constant found in some solutions of the Schwinger-Dyson equations of QCD can be related to this fixed point. We also discuss how the inclusion of fermions modifies this property.Comment: 4 pages, Revtex - Added some clarifying comments and new reference

Evidence for pseudogap and phase-coherence gap separation by Andreev reflection experiments in Au/La_{2-x}Sr_{x}CuO_4 point-contact junctions

We present new Au/La_{2-x}Sr_{x}CuO_{4} (LSCO) point-contact conductance measures as a function of voltage and temperature in samples with 0.08 <= x <= 0.2. Andreev reflection features disappear at about the bulk Tc, giving no evidence of gap for T > Tc. The fit of the normalized conductance at any T < Tc supports a (s + d)-wave symmetry of the gap, whose dominant low-T s component follows the Tc(x) curve in contrast with recent angle-resolved photoemission spectroscopy and quasiparticle tunneling data. These results prove the separation between pseudogap and phase-coherence superconducting gap in LSCO at x <= 0.2.Comment: 4 pages, 4 eps figures, 1 table (RevTeX). Labels added to Fig. 1; Fig. 3 resized; references added; short discussion about ballistic contact regime adde

Electroless plating of NiP and Cu on polylactic acid and polyethylene terephthalate glycol-modified for 3D printed flexible substrates

Electroless nickel and copper metallization of 3Dprinted polymers like polylactic acid and polyethylene terephthalate glycol modified is presented. The plating process is tested on suitable samples, which reproduce the characteristic morphologies used in 3D printing of objects. An alkaline etching is used for both polymers in order to modify the surface properties and to enhance the adhesion and uniformity of the metallic coating. In the case of polylactic acid, a plasma treatment is applied as well to further improve adhesion of the metallic coating. For the activation of the surface, a tin free process involving an immersion in a palladium solution and subsequent reduction to form metallic nuclei is employed. Electrolytes are formulated and selected to operate in temperature ranges comparable with the glass transition temperatures of the polymers. Adherent and uniform layers of NiP (3-4% P wt) and Cu can be easily obtained for esthetic and functional applications, also on flexible substrates

Critical coupling for chiral symmetry breaking in QCD motivated models

We determine the critical coupling constant above which dynamical chiral symmetry breaking occurs in a class of QCD motivated models where the gluon propagator has an enhanced infrared behavior. Using methods of bifurcation theory we find that the critical value of the coupling constant is always smaller than the one obtained for QCD

Expression of aldehyde dehydrogenase family 1, member A3 in glycogen trophoblast cells of the murine placenta

Introduction: Retinoic acid (RA) signaling is a well known regulator of trophoblast differentiation and placental development, and maternal decidual cells are recognized as the source of much of this RA. We explored possible trophoblast-derived sources of RA by examining the expression of RA synthesis enzymes in the developing mouse placenta, as well as addressed potential sites of RA action by examining the ontogeny of gene expression for other RA metabolizing and receptor genes. Furthermore, we investigated the effects of endogenous RA production on trophoblast differentiation