Topology-aware Quality-of-Service Support in Highly Integrated Chip Multiprocessors

Current design complexity trends, poor wire scalability, and power limitations argue in favor of highly modular onchip systems. Today’s state-of-the-art CMPs already feature up to a hundred discrete cores. With increasing levels of integration, CMPs with hundreds of cores, cache tiles, and specialized accelerators are anticipated in the near future. Meanwhile, server consolidation and cloud computing paradigms have emerged as profit vehicles for exploiting abundant resources of chip-multiprocessors. As multiple, potentially malevolent, users begin to share virtualized resources of a single chip, CMP-level quality-of-service (QOS) support becomes necessary to provide performance isolation, service guarantees, and security. This work takes a topology-aware approach to on-chip QOS. We propose to segregate shared resources, such as memory controllers and accelerators, into dedicated islands (shared regions) of the chip with full hardware QOS support. We rely on a richly connected Multidrop Express Channel (MECS) topology to connect individual nodes to shared regions, foregoing QOS support in much of the substrate and eliminating its respective overheads. We evaluate several topologies for the QOSenabled shared regions, focusing on the interaction between network-on-chip (NOC) and QOS metrics. We explore a new topology called Destination Partitioned Subnets (DPS), which uses a light-weight dedicated network for each destination node. On synthetic workloads, DPS nearly matches or outperforms other topologies with comparable bisection bandwidth in terms of performance, area overhead, energyefficiency, fairness, and preemption resilience.

Low-Energy Proton Testing Methodology

Use of low-energy protons and high-energy light ions is becoming necessary to investigate current-generation SEU thresholds. Systematic errors can dominate measurements made with low-energy protons. Range and energy straggling contribute to systematic error. Low-energy proton testing is not a step-and-repeat process. Low-energy protons and high-energy light ions can be used to measure SEU cross section of single sensitive features; important for simulation

Evaluation of sesamum gum as an excipient in matrix tablets

In developing countries modern medicines are often beyond the affordability of the majority of the population. This is due to the reliance on expensive imported raw materials despite the abundance of natural resources which could provide an equivalent or even an improved function. The aim of this study was to investigate the potential of sesamum gum (SG) extracted from the leaves of Sesamum radiatum (readily cultivated in sub-Saharan Africa) as a matrix former. Directly compressed matrix tablets were prepared from the extract and compared with similar matrices of HPMC (K4M) using theophylline as a model water soluble drug. The compaction, swelling, erosion and drug release from the matrices were studied in deionized water, 0.1 N HCl (pH 1.2) and phosphate buffer (pH 6.8) using USP apparatus II. The data from the swelling, erosion and drug release studies were also fitted into the respective mathematical models. Results showed that the matrices underwent a combination of swelling and erosion, with the swelling action being controlled by the rate of hydration in the medium. SG also controlled the release of theophylline similar to the HPMC and therefore may have use as an alternative excipient in regions where Sesamum radiatum can be easily cultivated

Predictors of retinochoroiditis in children with congenital toxoplasmosis : European, prospective cohort study

OBJECTIVE. By school age, 20% of children infected with congenital toxoplasmosis will have > 1 retinochoroidal lesion. We determined which children are most at risk and whether prenatal treatment reduces the risk of retinochoroiditis to help clinicians decide about treatment and follow-up. PATIENTS AND METHODS. We prospectively studied a cohort of children with congenital toxoplasmosis identified by prenatal or neonatal screening in 6 European countries. We determined the effects of prenatal treatment and prognostic markers soon after birth on the age at first detection of retinochoroiditis. RESULTS. Of 281 children with congenital toxoplasmosis, 50 developed ocular disease, and 17 had recurrent retinochoroiditis during a median follow-up of 4.1 years. Prenatal treatment had no significant effect on the age at first or subsequent lesions. Delayed start of postnatal treatment did not increase retinochoroiditis, but the analysis lacked power. Older gestational age at maternal seroconversion was weakly associated with a reduced risk of retinochoroiditis. The presence of nonocular clinical manifestations of congenital toxoplasmosis at birth strongly predicted retinochoroiditis. For 92% (230 of 249) of children with no retinochoroiditis detected before 4 months of age, the probability of retinochoroiditis by 4 years was low, whether clinical manifestations were present or not 8.0%. CONCLUSIONS. Prenatal treatment did not significantly reduce the risk of retinochoroiditis in this European cohort. If children have no retinochoroiditis in early infancy, the low risk of subsequent ocular disease may not justify postnatal treatment and repeated ophthalmic assessments during childhood. Controlled trials are needed to address the lack of evidence for the effectiveness of postnatal treatment

High resolution measurement and modelling of magnetic domain structures in epitaxial FePd (001) L1(0) films with perpendicular magnetisation

Magnetic domain structures in two 50 nm thick chemically- ordered FePd (001) epitaxial films with different perpendicular anisotropies have been studied using Lorentz microscopy. Domain and domain wall structures vary significantly according to the magnitude of the anisotropy. For lower anisotropy films, a stripe domain structure with a period of approximate to 100 nm is formed in which there is a near-continuous variation in orientation of the magnetisation vector. By contrast, in the film with higher anisotropy, a maze-like domain structure is supported. The magnetisation within domains is perpendicular to the film plane and adjacent domains are separated by narrow walls, less than 20 nm wide. Micromagnetic modelling is generally in good quantitative agreement with experimental observations and provides additional information on the domain wall structure

High resolution measurement and modelling of magnetic domain structures in epitaxial FePd (001) L10 films with perpendicular magnetization

Magnetic domain structures in two 50 nm thick chemically-ordered FePd (001) epitaxial films with different perpendicular anisotropies have been studied using Lorentz microscopy. Domain and domain wall structures vary significantly according to the magnitude of the anisotropy. For lower anisotropy films, a stripe domain structure with a period of ≈100 nm is formed in which there is a near-continuous variation in orientation of the magnetization vector. By contrast, in the film with higher anisotropy, a maze-like domain structure is supported. The magnetization within domains is perpendicular to the film plane and adjacent domains are separated by narrow walls, less than 20 nm wide. Micromagnetic modelling is generally in good quantitative agreement with experimental observations and provides additional information on the domain wall structure