Exposure of mortars to cyclic chloride ingress and carbonation

The presence of chloride ions is one of the primary factors causing the degradation of reinforced concrete structures. An investigation to monitor ingress of chlorides during a 24-week wetting and drying exposure regime to simulate conditions in which multiple-mode transport mechanisms are active was conducted on a variety of binders. Penetration was evaluated using free and total chloride profiles. Acid extraction of chlorides is quantitatively reliable and practical for assessing penetration. X-ray diffraction was used to determine the presence of bound chlorides and carbonation. The ability of the cement blends to resist chloride penetration was, from best to worst, ground granulated blast-furnace slag, microsilica, pulverised-fuel ash, Portland cement. The effect of carbonation on binding capability was observed and the relative quantity of chlorides also showed a correlation with the amount of chlorides bound in the form of Friedel’s salt.

An Analytical Study of Surplus Value using a Value Driven Design Methodology

People are now becoming more environmentally aware and as a consequence of this, industries such as the aviation industry are striving to design more environmentally friendly products. To achieve this, the current design methodologies must be modified to ensure these issues are considered from product conception through to disposal. This paper discusses the environmental problems in relation to the aviation industry and highlights some logic for making the change from the traditional Systems Engineering approach to the recent design paradigm known as Value Driven Design. Preliminary studies have been undertaken to aid in the understanding of this methodology and the existing surplus value objective function. The main results from the work demonstrate that surplus value works well bringing disparate issues such as manufacture and green taxes together to aid decision making. Further, to date studies on surplus value have used simple sensitivity analysis, but deeper consideration shows non-linear interactions between some of the variables and further work will be needed to fully account for complex issues such as environmental impact and taxes.

Family-based association studies of lipid gene polymorphisms in coronary artery disease

Dysfunction of lipid-metabolizing proteins is implicated in the pathogenesis of coronary artery disease. Single nucleotide polymorphisms in genes that encode sterol regulatory binding protein-la, adenosine triphosphate binding cassette-A1, hepatic lipase, lipoprotein lipase, and cholesteryl ester transfer protein were assessed as potential markers of disease susceptibility in a family-based study of 1,012 patients from 386 families. Association between single nucleotide polymorphisms and coronary artery disease was tested by the combined transmission disequilibrium test/sib transmission disequilibrium test and pedigree disequilibrium test. After Bonferroni's correction, the pedigree disequilibrium test demonstrated significant excess transmission (p < 0.0083) to affected patients of the hepatic lipase -514 T allele, which suggests that this may constitute a novel disease-susceptibility locus. (c) 2005 Elsevier Inc. All rights reserved.

Gender Classification via Lips: Static and Dynamic Features

Automatic gender classification has many security and commercial applications. Various modalities have been investigated for gender classification with face-based classification being the most popular. In some real-world scenarios the face may be partially occluded. In these circumstances a classification based on individual parts of the face known as local features must be adopted. We investigate gender classification using lip movements. We show for the first time that important gender specific information can be obtained from the way in which a person moves their lips during speech. Furthermore our study indicates that the lip dynamics during speech provide greater gender discriminative information than simply lip appearance. We also show that the lip dynamics and appearance contain complementary gender information such that a model which captures both traits gives the highest overall classification result. We use Discrete Cosine Transform based features and Gaussian Mixture Modelling to model lip appearance and dynamics and employ the XM2VTS database for our experiments. Our experiments show that a model which captures lip dynamics along with appearance can improve gender classification rates by between 16-21% compared to models of only lip appearance.

A Novel Method to Enable Trade-offs Across the Whole Product Life of an Aircraft Using Value Driven Design

The increasing need to understand complex products and systems with long life spans, presents a significant challenge to designers who increasingly require a broader understanding of the operational aspects of the system. This demands an evolution in current design practice, as designers are often constrained to provide a subsystem solution without full knowledge of the global system operation. Recently there has been a push to consider value centric approaches which should facilitate better or more rapid convergence to design solutions with predictable completion schedules. Value Driven Design is one such approach, in which value is used as the system top level objective function. This provides a broader view of the system and enables all sub-systems and components to be designed with a view to the effect on project value. It also has the capacity to include value expressions for more qualitative aspects, such as environmental impact. However, application of the method to date has been restricted to comparing value in a programme where the lifespan is fixed and known a priori. This paper takes a novel view of value driven design through the surplus value objective function, and shows how it can be used to identify key sensitivities to guide designers in design trade-off decisions. By considering a new time based approach it can be used to identify optimum programme life-span and hence allow trade-offs over the whole product life.

A multiagent network for peer norm enforcement

In a multiagent system where norms are used to regulate the actions agents ought to execute, some agents may decide not to abide by the norms if this can benefit them. Norm enforcement mechanisms are designed to counteract these benefits and thus the motives for not abiding by the norms. In this work we propose a distributed mechanism through which agents in the multiagent system that do not abide by the norms can be ostracised by their peers. An ostracised agent cannot interact anymore and looses all benefits from future interactions. We describe a model for multiagent systems structured as networks of agents, and a behavioural model for the agents in such systems. Furthermore, we provide analytical results which show that there exists an upper bound to the number of potential norm violations when all the agents exhibit certain behaviours. We also provide experimental results showing that both stricter enforcement behaviours and larger percentage of agents exhibiting these behaviours reduce the number of norm violations, and that the network topology influences the number of norm violations. These experiments have been executed under varying scenarios with different values for the number of agents, percentage of enforcers, percentage of violators, network topology, and agent behaviours. Finally, we give examples of applications where the enforcement techniques we provide could be used.

Characterization of Inter-Body Interference in Context Aware Body Area Networking (CABAN)

The characterization and understanding of body to body communication channels is a pivotal step in the development of emerging wireless applications such as ad-hoc personnel localisation and context aware body area networks (CABAN). The latter is a recent innovation where the inherent mobility of body area networks can be used to improve the coexistence of multiple co-located BAN users. Rather than simply accepting reductions in communication performance, sensed changes in inter-network co-channel interference levels may facilitate intelligent inter-networking; for example merging or splitting with other BANs that remain in the same domain. This paper investigates the inter-body interference using controlled measurements of the full mesh interconnectivity between two ambulatory BANs operating in the same environment at 2.45 GHz. Each of the twelve network nodes reported received signal strength to allow for the creation of carrier to interference ratio time series with an overall entire mesh sampling period of 54 ms. The results indicate that even with two mobile networks, it is possible to identify the onset of co-channel interference as the BAN users move towards each other and, similarly, the transition to more favourable physical layer channel conditions as they move apart. © 2011 IEEE.

A Comparison of Programming Models for Multiprocessors with Explicitly Managed Memory Hierarchies

On multiprocessors with explicitly managed memory hierarchies (EMM), software has the responsibility of moving data in and out of fast local memories. This task can be complex and error-prone even for expert programmers. Before we can allow compilers to handle the complexity for us, we must identify the abstractions that are general enough to allow us to write applications with reasonable effort, yet speci?c enough to exploit the vast on-chip memory bandwidth of EMM multi-processors. To this end, we compare two programming models against hand-tuned codes on the STI Cell, paying attention to programmability and performance. The ?rst programming model, Sequoia, abstracts the memory hierarchy as private address spaces, each corresponding to a parallel task. The second, Cellgen, is a new framework which provides OpenMP-like semantics and the abstraction of a shared address spaces divided into private and shared data. We compare three applications programmed using these models against their hand-optimized counterparts in terms of abstractions, programming complexity, and performance.

Evaluation of quality of life and priorities of patients with glaucoma

PURPOSE: To investigate the quality of life and priorities of patients with glaucoma.

METHODS: Patients diagnosed with glaucoma and no other ocular comorbidity were consecutively recruited. Clinical information was collected. Participants were asked to complete three questionnaires: EuroQuol (EQ-5D), time tradeoff (TTO), and choice-based conjoint analysis. The latter used five-attribute outcomes: (1) reading and seeing detail, (2) peripheral vision, (3) darkness and glare, (4) household chores, and (5) outdoor mobility. Visual field loss was estimated by using binocular integrated visual fields (IVFs).

RESULTS: Of 84 patients invited to participate, 72 were enrolled in the study. The conjoint utilities showed that the two main priorities were "reading and seeing detail" and "outdoor mobility." This rank order was stable across all segmentations of the data by demographic or visual state. However, the relative emphasis of these priorities changed with increasing visual field loss, with concerns for central vision increasing, whereas those for outdoor mobility decreased. Two subgroups of patients with differing priorities on the two main attributes were identified. Only 17% of patients (those with poorer visual acuity) were prepared to consider TTO. A principal component analysis revealed relatively independent components (i.e., low correlations) between the three different methodologies for assessing quality of life.

CONCLUSIONS: Assessments of quality of life using different methodologies have been shown to produce different outcomes with low intercorrelations between them. Only a minority of patients were prepared to trade time for a return to normal vision. Conjoint analysis showed two subgroups with different priorities. Severity of glaucoma influenced the relative importance of priorities.