Transactions Letters - Outage Capacity and Optimal Power Allocation for Multiple Time-Scale Parallel Fading Channels

In this paper, we address the optimal power allocation problem for minimizing capacity outage probability in multiple time-scale parallel fading channels. Extending ideas from the work of Dey and Evans (2005), we derive the optimal power allocation scheme for parallel fading channels with fast Rayleigh fading, as a function of the slow fading gains. Numerical results are presented to demonstrate the outage performance of this scheme for lognormal slow fading on two parallel channels.     

Ultra-Thin Si<Subscript>1−<Emphasis Type="Italic">x</Emphasis></Subscript>Ge<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript> Dislocation Blocking Layers for Ge/Strained Si CMOS Devices

We demonstrate ultra-thin (<150 nm) Si_1−x Ge _x dislocation blocking layers on Si substrates used for the fabrication of tensile-strained Si N channel metal oxide semiconductor (NMOS) and Ge P channel metal oxide semiconductor (PMOS) devices. These layers were grown using ultra high vacuum chemical vapor deposition (UHVCVD). The Ge mole fraction was varied in rapid, but distinct steps during the epitaxial layer growth. This results in several Si_1−x Ge _x interfaces in the epitaxially grown material with significant strain fields at these interfaces. The strain fields enable a dislocation blocking mechanism at the Si_1−x Ge _x interfaces on which we were able to deposit very smooth, atomically flat, tensile-strained Si and relaxed Ge layers for the fabrication of high mobility N and P channel metal oxide semiconductor (MOS) devices, respectively. Both N and P channel metal oxide semiconductor field effect transister (MOSFETs) were successfully fabricated using high-k dielectric and metal gates on these layers, demonstrating that this technique of using ultra-thin dislocation blocking layers might be ideal for incorporating high mobility channel materials in a conventional CMOS process.     

Ultrasonic velocity of binary systems at elevated pressures

Various empirical theories of ultrasonic velocity have been applied to three binary liquid mixtures, under pressures up to 200 MPa and their validity have been tested. A pressure dependent study of ultrasonic velocities has been made at 303.15 K. The agreement between theory and experiment is found to be quite satisfactory.     

Cooperativity in multiple unusual weak bonds

This review covers two aspects concerning cooperativity in multiple weak bonds: a summary of literature results and a theoretical study of a complete series of model complexes. All the 15 combination of five weak bonds were explored: hydrogen bonds, hydric bonds, dihydrogen bonds, halogen bonds and ion–π interactions. Since in several cases there were no examples reported, a systematic exploration has been carried out on simple models at the MP2/aug-cc-pVTZ level. The results thus obtained have been analyzed using the atoms in molecules methodology.     

Estimation of parameters of a model of a complex repairable system

This paper deals with estimation of parameters of a model of a complex repairable system with 3ne unit on operation and the remaining (N − 1) units as inactive standbys and having a repair facility. Various operating characteristics, namely, reliability, availability, mean time to failure of the system, s-expected numbers of repairs in (0, t], s-expected numbers of failures of the system in (0, t] are estimated under two censoring schemes namely, the type-I censoring and type-II censoring schemes.     

Complexity reduction in fixed-lag smoothing for hidden Markovmodels

We investigate approximate smoothing schemes for a class of hidden Markov models (HMMs), namely, HMMs with underlying Markov chains that are nearly completely decomposable. The objective is to obtain substantial computational savings. Our algorithm can not only be used to obtain aggregate smoothed estimates but can be used also to obtain systematically approximate full-order smoothed estimates with computational savings and rigorous performance guarantees, unlike many of the aggregation methods proposed earlier     

Optimal power control over multiple time-scale fading channels with service outage constraints

This paper considers the power-control problem for a fading channel in an information-theoretic framework. We derive power-control schemes to optimize ergodic capacity, outage capacity, and capacity with a service outage constraint. The novelty in the paper lies in the use of a two-time-scale fading process and its implications for the channel-state information available at the transmitter.     

Theory of Weak Modified Electron Acoustic Double Layers and Solitary Waves in Presence of Negative Ions

We have studied the analytic solutions for modified electron acoustic double layers and solitary waves in a four component plasma system viz. two electrons and two ions, one positive and the other negative. It has been shown that DL solution does not exist when the temperatures of the free and the trapped particles are considered to be same for all the free species. On the other hand, DL solutions are found to exist when the effects of the reflected electrons (hot) are considered. The velocity and thickness of the DL have been valculated.