Tree-code simulations of proton acceleration from laser-irradiated wire targets

Recent experiments using Terawatt lasers to accelerate protons deposited on thin wire targets are modeled with a new type of gridless plasma simulation code. In contrast to conventional mesh-based methods, this technique offers a unique capability in emulating the complex geometry and open-ended boundary conditions characteristic of contemporary experimental conditions. Comparisons of ion acceleration are made between the tree code and standard particle-in-cell simulations for a typical collisionless

Tree-Based Adaptive Spatial Detection for Adaptive Modulated MIMO Systems

Adaptive Multiple-Input Multiple-Output (MIMO) systems achieve a much higher information rate than conventional fixed schemes due to their ability to adapt their configurations according to the wireless communications environment. However, current adaptive MIMO detection schemes exhibit either low performance (and hence low spectral efficiency) or huge computational
complexity. In particular, whilst deterministic Sphere Decoder (SD) detection schemes are well established for static MIMO systems, exhibiting deterministic parallel structure, low computational complexity and quasi-ML detection performance, there are no corresponding adaptive schemes. This paper solves
this problem, describing a hybrid tree based adaptive modulation detection scheme. Fixed Complexity Sphere Decoding (FSD) and Real-Values FSD (RFSD) are modified and combined into a hybrid scheme exploited at low and medium SNR to provide the highest possible information rate with quasi-ML Bit Error
Rate (BER) performance, while Reduced Complexity RFSD, BChase and Decision Feedback (DFE) schemes are exploited in the high SNR regions. This algorithm provides the facility to balance the detection complexity with BER performance with compatible information rate in dynamic, adaptive MIMO communications
environments.

VQ tree search system based on bit level systolic arrays

A bit-level systolic array system for performing a binary tree vector quantization (VQ) codebook search is described. This is based on a highly regular VLSI building block circuit. The system in question exhibits a very high data rate suitable for a range of real-time applications. A technique is described which reduces the storage requirements of such a system by 50%, with a corresponding decrease in hardware complexity.

A bit-level systolic architecture for implementing a VQ tree search

A bit-level systolic array system for performing a binary tree Vector Quantization codebook search is described. This consists of a linear chain of regular VLSI building blocks and exhibits data rates suitable for a wide range of real-time applications. A technique is described which reduces the computation required at each node in the binary tree to that of a single inner product operation. This method applies to all the common distortion measures (including the Euclidean distance, the Weighted Euclidean distance and the Itakura-Saito distortion measure) and significantly reduces the hardware required to implement the tree search system. © 1990 Kluwer Academic Publishers.

Tea tree oil (5%) body wash versus standard care (Johnson's Baby Softwash) to prevent colonization with methicillin-resistant Staphylococcus aureus in critically ill adults::a randomized controlled trial

OBJECTIVES: To determine whether the daily use of 5% tea tree oil (TTO) body wash (Novabac 5% Skin Wash) compared with standard care [Johnson's Baby Softwash (JBS)] had a lower incidence of methicillin-resistant Staphylococcus aureus (MRSA) colonization.

PATIENTS: The study setting was two intensive care units (ICUs; mixed medical, surgical and trauma) in Northern Ireland between October 2007 and July 2009. The study population comprised 391 patients who were randomized to JBS or TTO body wash.

METHODS: This was a Phase 2/3, prospective, open-label, randomized, controlled trial. Trial registration: ISRCTN65190967. The primary outcome was new MRSA colonization during ICU stay. Secondary outcomes included the incidence of MRSA bacteraemia and maximum increase in sequential organ failure assessment score.

RESULTS: A total of 445 patients were randomized to the study. After randomization, 54 patients were withdrawn; 30 because of a positive MRSA screen at study entry, 11 due to lack of consent, 11 were inappropriately randomized and 2 had adverse reactions. Thirty-nine (10%) patients developed new MRSA colonization (JBS n?=?22, 11.2%; TTO body wash n?=?17, 8.7%). The difference in percentage colonized (2.5%, 95% CI -?8.95 to 3.94; P?=?0.50) was not significant. The mean maximum increase in sequential organ failure assessment score was not significant (JBS 1.44, SD 1.92; TTO body wash 1.28, SD 1.79; P?=?0.85) and no study patients developed MRSA bacteraemia.

CONCLUSIONS: Compared with JBS, TTO body wash cannot be recommended as an effective means of reducing MRSA colonization.

Perceptual investigation of image placement with Ambisonics for non-centred listeners

Ambisonics is a scalable spatial audio technique that attempts to present a sound scene to listeners over as large an area as possi- ble. A localisation experiment was carried out to investigate the performance of a first and third order system at three listening positions - one in the centre and two off-centre. The test used a reverse target-pointer adjustment method to determine the error, both signed and absolute, for each combination of listening posi- tion and system. The signed error was used to indicate the direc- tion and magnitude of the shifts in panning angle introduced for the off-centre listening positions. The absolute error was used as a measure of the performance of the listening position and systems combinations for a comparison of their overall performance. A comparison was made between the degree of image shifting be- tween the two systems and the robustness of their off-centre per- formance.

Taiwanese Learners’ Motivation and Attitude Towards Completing an Online Distance Education Course During a One Year Industrial Placement

This mixed methods study investigated language learning motivation in an one-year e-learning course for technological university students to bridge the geographical divide between students on industrial placements when studying graded readers using an e-learning course to improve their English competence and to pass the General English Proficiency Test. Data was collected through questionnaires and course feedback. The results of this study extend Gardner’s socio-educational model in an e-learning environment by adding the new category, Computer Attitudes, which was proven to be highly correlated with Motivation. Although the low proficiency English students had good computer skills, their habits of using the computer for entertainment and their lack of the skill of “technological communication efficacy” caused increased anxiety when using computers and thus provided them with a lower computer confidence over time. Consequently, it is recommended that sound e-learning training should be provided to all of the students prior to embarking on an e-leaning course so that these learners can benefit from online language learning in the future.