A Comparison of Presentation Methods for Reading on Mobile Phones

A study compares two methods of reading text-based content on mobile phones: traditional scroll-based reading and Rapid Serial Visual Presentation, which displays words rapidly in a sequence. University students used a prototype called Feedo to test both methods, and their reading comprehension, efficiency, and preference ratings were measured. The results show that efficiency increases with fast RSVP, comprehension is equal, and preference rating is lower than with self-paced scroll.     

Lactoferrin and lysozyme in milk during acute mastitis and their inhibitory effect in Delvotest P

Microbiological methods for detection of antibiotic residues in milk give no explanations regarding the identity of the inhibitory substance(s). Natural antibacterial substances, present at higher concentrations in mastitic milk and in colostrum, occasionally cause false positive results in antibiotic assays. In an earlier investigation, lysozyme and lactoferrin were shown to inhibit the growth of Bacillus stearothermophilus var. calidolactis spores, used as test organism in Delvotest P. To study the effect of high lysozyme and lactoferrin concentrations in milk on the Delvotest P, cows were subjected to acute experimental mastitis by infusion of Salmonella typhimurium SH 4809 endotoxin. Milk samples were collected up to 11 h postinfusion. Concentrations of lactoferrin and lysozyme, somatic cell count, and effect on Delvotest P were determined. A positive reaction in the Delvotest correlated well with an increase in lactoferrin and lysozyme concentrations. The nature of the inhibitory effect is briefly discussed.     

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.     

Behavioral Modeling and Simulation of Mixed-Signal System-on-a-Chip using SystemC

We describe an efficient software framework for rapid behavioral modeling and simulation of mixed-signalSystem-on-a-Chip (SoC). The framework is based on the SystemC C++ class libraries and has beenproven to be a very effective tool for exploring different system-level architectures in the early stages of thedesign process. We also present the results of three case studies where we have used the framework: a 10-bit, 60Mega-sample/s pipelined ADC, 14-bit, 100 Mega-sample/s pipelined ADC with background calibration, and aCMOS camera-on-a-chip.     

Vapor Phase Growth of Functional Pentacene Films at Atmospheric Pressure

Compared to traditional vacuum evaporation techniques for small organic molecules, organic vapor phase deposition (OVPD) possesses a extra processing parameter: the pressure of process gas P_ch. Here, the influence of large P_ch variations (from 0.1 mbar to atmospheric pressure) on pentacene thin film growth is explored. OVPD operation at higher P_ch is characterized by lower carrier gas velocities and lower organic diffusivities. These result in an invariance of the material utilization efficiency over the entire pressure span and in an advantageous equilibrium evaporation regime in the source. An increase in P_ch yields rough pentacene layers. Classical nucleation theory is applied to demonstrate how the pressure rise triggers homogeneous nucleation in the gas phase, causing the observed roughening. The use of lower deposition rates, higher dilution flow rates, and higher substrate temperatures result in the suppression of gas phase nucleation and the growth of smooth pentacene films at atmospheric pressure. Using these optimized conditions, state‐of‐the‐art pentacene thin film transistors with saturation mobilities above 0.9 cm²/Vs are reproducibly fabricated. p‐Type circuits are also made and a 19‐stage ring oscillator with a stage delay of 51 μs at a supply voltage of 15 V is demonstrated.     

Distributed cross-layer coordination of congestion control and resource allocation in S-TDMA wireless networks

We consider the problem of joint congestion control and resource allocation in spatial-TDMA wireless networks. The design problem is posed as a utility maximization problem subject to link rate constraints which involve both transmission scheduling and power allocation. Starting from the performance limitations of a centralized optimization based on global network information, we proceed systematically in our development of two distributed and transparent protocols that rely on local information only. In the process, we introduce a novel decomposition method for convex optimization, establish its convergence for the utility maximization problem, and demonstrate how it suggests a distributed solution based on TCP/AQM and incremental updates of the transmission schedule. We develop a two-step procedure for finding the schedule updates and suggest two schemes for distributed link scheduling and power control under realistic interference models. Although the final protocols are suboptimal, we isolate and quantify the performance losses incurred by each simplification and demonstrate strong performance in examples.

Effect of Copper on the Carrier Lifetime in Black Silicon

Black silicon is produced by laser annealing of a-Si:H films. During annealing, silicon microstructures are formed on the surface. We use time-resolved terahertz spectroscopy to study the photoconductivity dynamics in black silicon. We find that when a copper film is deposited on top of the a-Si:H layer prior to laser annealing, the carrier lifetime of black silicon is significantly reduced.     

A New Design Concept for High-Performance Fading Channel Simulators Using Set Partitioning

In this paper, we introduce a new technique for the design of high-performance Rayleigh fading channel simulators. The proposed design method uses set partitioning – a technique, which plays a key role in the design of trellis-coded modulation schemes. We show how set partitioning can be used to design multiple uncorrelated fading waveforms enabling the simulation of Rayleigh fading channels. For the important case of isotropic scattering, we show that the sample average of the generated waveforms results in a deterministic process, the autocorrelation function (ACF) of which tends to the zeroth-order Bessel function of the first kind as the number of sample functions increases. The proposed procedure is completely deterministic. The comparison with a stochastic procedure using Monte Carlo techniques will be made. A study of the performance shows clearly that the new technique using set partitioning outperforms by far existing Monte Carlo methods.     

Low‐loss TCP/IP header compression for wireless networks

Wireless is becoming a popular way to connect mobile computers to the Internet and other networks. The bandwidth of wireless links will probably always be limited due to properties of the physical medium and regulatory limits on the use of frequencies for radio communication. Therefore, it is necessary for network protocols to utilize the available bandwidth efficiently. Headers of IP packets are growing and the bandwidth required for transmitting headers is increasing. With the coming of IPv6 the address size increases from 4 to 16 bytes and the basic IP header increases from 20 to 40 bytes. Moreover, most mobility schemes tunnel packets addressed to mobile hosts by adding an extra IP header or extra routing information, typically increasing the size of TCP/IPv4 headers to 60 bytes and TCP/IPv6 headers to 100 bytes. In this paper, we provide new header compression schemes for UDP/IP and TCP/IP protocols. We show how to reduce the size of UDP/IP headers by an order of magnitude, down to four to five bytes. Our method works over simplex links, lossy links, multi‐access links, and supports multicast communication. We also show how to generalize the most commonly used method for header compression for TCP/IPv4, developed by Jacobson, to IPv6 and multiple IP headers. The resulting scheme unfortunately reduces TCP throughput over lossy links due to unfavorable interaction with TCP's congestion control mechanisms. However, by adding two simple mechanisms the potential gain from header compression can be realized over lossy wireless networks as well as point‐to‐point modem links. This revised version was published online in June 2006 with corrections to the Cover Date.     

Optimum processing of qpsk signals for site diversity

For satellite communications systems which use frequencies above 10 GHz, rain and clouds attenuate signals severely, leading to an increase in bit error rate (BER) in digital links. This may be coped with by using two or more receivers on the ground, spaced far enough apart to avoid simultaneous rain outages. In this paper, a BER-minimizing decision processor is derived for two receivers and QPSK modulation. In particular, it is applied to a linear attenuating transmission channel adding independent white Gaussian noise. It is found that gains of nearly 3 dB compared to a switched system are possible in down-link limited cases.