A High Bandwidth Power Scalable Sub-Sampling 10-Bit Pipelined ADC With Embedded Sample and Hold

A pipelined ADC architecture for use in sub-sampled systems which is power scalable in relation to its down sampled bandwidth is presented. The ADC uses a technique to eliminate the front-end sample hold, thereby reducing power consumption. The technique allows for a power savings of 20% compared to a previous design. A method to improve the settling behavior of rapid power-on opamps is also presented. Measured results in a 1.8 V 0.18 CMOS process verify the removal of the front-end sample and hold does not cause gross MSB errors for input frequencies higher than 267 MHz. With 50 MS/s, for the SNDR is 51.5 dB, and with 4.55 MS/s for the SNDR is 52.2 dB.     

Cooperative transmission protocol with full diversity and iterative detection

The authors propose a three-node full diversity cooperative protocol, which allows the retransmission of all symbols. By allowing multiple nodes to transmit simultaneously, relaying transmission only consumes limited bandwidth resource. To facilitate the performance analysis of the proposed cooperative protocol, the lower and upper bounds of the outage probability are first developed, and then the high signal-to-noise ratio behaviour is studied. Our analytical results show that the proposed strategy can achieve full diversity. To achieve the performance gain promised by the cooperative diversity, at the relays decode-and-forward strategy is adopted and an iterative soft-interference-cancellation minimum mean-squared error equaliser is developed. The simulation results compare the bit-error-rate performance of the proposed protocol with the non-cooperative scheme and the scheme presented by Azarian et al. (2005).     

Silicene Nanoribbons on an Insulating Thin Film

Silicene, a new 2D material has attracted intense research because of the ubiquitous use of silicon in modern technology. However, producing free-standing silicene has proved to be a huge challenge. Until now, silicene could be synthesized only on metal surfaces where it naturally forms strong interactions with the metal substrate that modify its electronic properties. Here, the authors report the first experimental evidence of silicene nanoribbons on an insulating NaCl thin film. This work represents a major breakthrough, for the study of the intrinsic properties of silicene, and by extension to other 2D materials that have so far only been grown on metal surfaces.     

UNICORE 6 — Recent and Future Advancements

UNICORE is a European Grid Technology with more than 10 years of history. Originating from the Supercomputing domain, the latest version UNICORE 6 has turned into a general-purpose Grid technology that follows established standards and offers a rich set of features to its users. The paper starts with an architectural insight into UNICORE 6, highlighting the workflow features, standards and the different clients. Next, the current state of advancement is presented by describing recent developments. The paper closes with an outlook on future planned developments.     

Average and randomized communication complexity

The communication complexity of a two-variable function f(x,y) is the number of information bits two communicators need to exchange to compute f when, initially, each knows only one of the variables. There are several communication-complexity measures corresponding to whether (1) the worst case or average number of bits is considered, (2) computation errors are allowed and (3) randomization is allowed. Tight bounds are provided for the typical behavior of all bounded-error communication-complexity measures of Boolean functions. In the present work, the authors formally define the deterministic model. They describe randomized protocols and compare them to deterministic ones. They both survey previous work and describe original results     

INSPAD: a system for automatic bond pad inspection

A method of detecting probe mark defects in semiconductor bond pads is presented that uses digitized images of color Polaroid photographs from an optical microscope. INSPAD inspects the bond pads in a magnified IC circuit image taken after the electrical testing stage. These are: probe marks must not extend beyond pad boundaries such that they damage glassivation; scratches on the bond pads must not exceed 50% of the bond pad width; and the probe marks must not exceed 25% of the bond pad area. Three types of commonly used bond pad geometries have been addressed. Morphological filtering is performed on the bond pad, to isolate and identify the major probe mark regions. Inspection of each pad takes approximately 2 to 3 s on an Apollo DN-4000 workstation which makes it suitable for real-time applications     

On the design of Robust‐WDM local area networks

Robust wavelength division multiplexing (Robust‐WDM) is a proposal to realize cost‐effective WDM local area networks (LANs) which can get around the expensive need for laser wavelength stabilization. The type of these networks that relies on an access protocol with aperiodic reservations and lenient‐token‐passing based control channel (the AR/LTP protocol) is promising. We look at the deployment of the AR/LTP analytical model in designing this type of network. The model is used to predict the effect of component and network parameters on the waiting time characteristics of the network. An increase in node operation times (i.e. receiver response time, transmitter select time and reservation period) would result in increasing the average waiting time of a connection request, but the waiting time is more sensitive to the physical span of the network and its size. It is also observed that increasing the inter‐reservation threshold may result in little increase in waiting time up to some limit beyond which delay increases rapidly. Copyright © 2001 John Wiley & Sons, Ltd.     

Analysis of Acceleration Effect in Data Dissemination in Vehicular Networks Using Rateless Codes

Mobility models of nodes have an important role in the evaluation of data dissemination protocols in vehicular ad hoc networks (VANETs). Many recent researches have used the constant velocity mobility models while vehicles have acceleration and their speeds change as they move. Because of the dynamic nature of VANETs, the network changes from a densely connected to the sparsely connected environment in a short time. In sparsely connected networks, it is said that vehicles move in clusters. In this paper, the constant acceleration mobility calculations for the sparsely connected network and its characteristics have been presented. These characteristics are usable for the evaluation of the data dissemination protocols in VANETs. The results show that acceleration affects the number of viewed clusters during the trip and the number of vehicles within a cluster. In fact, acceleration has a significant impact on the network sparsely connection. This matter shows that the appropriate data dissemination protocol should be used to study the acceleration effect which is applicable in sparse networks. The analysis in this research provides the necessary background for better understanding and accurate calculations for the evaluation of data dissemination in VANETs.     

Effects of Plasticizers,Antioxidants and Burning Rate Modifiers on Aging Performance of the HTPB/HMDI Composite Solid Propellant

The effects of plasticizers,antioxidants and burning rate modifiers on the aging performance of the composite solid propellant based on hydroxyl-terminated polybutadiene(HTPB)/hexamethylene diisocyanate(HMDI)were explored by apply-ing an accelerated aging program for 90 day at 70 ℃. The HTPB propellant matrix with the diisooctyl sebacate(DOS)as plasti-cizers and diisooctyl azelate(DOZ), antioxidants as N,N ′-Diphenyl-p-phenylenediamine(AO) and 2,2′-methylenebis(4-methyl-6-tert-butylphenol)(cyanox 2246)and burning rate modifiers as barium ferrite(BF),copper chromites(CC)and fer-ric oxide(FO)were varied. Results show that sample(S1)which based on DOS decreases the stress value and increases the strain value which considered to be an excellent start for aging program. Sample(S3)containing AO presents the higher resis-tance to oxidation showing the better performance that reflects on increasing the shelf life of the composite solid propellant mo-tor. Sample(S5)which based on BF enhances the ballistic performance among over the other tested two samples. The accelerat-ed aging program allowed us to estimate the motor in-service lifetime.     

New CMOS Fully‐Differential Transconductor and Application to a Fully‐Differential Gm‐C Filter

A new CMOS voltage‐controlled fully‐differential transconductor is presented. The basic structure of the proposed transconductor is based on a four‐MOS transistor cell operating in the triode or saturation region. It achieves a high linearity range of ± 1 V at a 1.5 V supply voltage. The proposed transconductor is used to realize a new fully‐differential Gm‐C low‐pass filter with a minimum number of transconductors and grounded capacitors. PSpice simulation results for the transconductor circuit and its filter application indicating the linearity range and verifying the analytical results using 0.35 μm technology are also given.