A Direct Translation from XPath to Nondeterministic Automata

Abstract. Since navigational aspects of XPath correspond to first-order definability, it has been proposed to use the analogy with the very successful technique of translating LTL into automata, and produce efficient translations of XPath queries into automata on unranked trees. These translations can then be used for a variety of reasoning tasks such as XPath consistency, or optimization, under XML schema constraints. In the verification scenarios, translations into both nondeterministic and alternating automata are used. But while a direct translation from XPath into alternating automata is known, only an indirect translation into nondeterministic automata- going via intermediate logics- exists. A direct translation is desirable as most XML specifications have particularly nice translations into nondeterministic automata and it is natural to use such automata to reason about XPath and schemas. The goal of the paper is to produce such a direct translation of XPath into nondeterministic automata.

On discrete functional inequalities for some finite volume schemes

We prove several discrete Gagliardo-Nirenberg-Sobolev and Poincar\'e-Sobolev inequalities for some approximations with arbitrary boundary values on finite volume meshes. The keypoint of our approach is to use the continuous embedding of the space $BV(\Omega)$ into $L^{N/(N-1)}(\Omega)$ for a Lipschitz domain $\Omega \subset \mathbb{R}^{N}$, with $N \geq 2$. Finally, we give several applications to discrete duality finite volume (DDFV) schemes which are used for the approximation of nonlinear and non isotropic elliptic and parabolic problems

Multilayer chromium based coatings grown by atmospheric pressure direct liquid injection CVD

There is a great interest for multilayer hard coatings because they exhibit enhanced properties resulting from their nanostructuration. Such coatings are frequently constituted of carbide and nitride and are generally deposited under very low pressure by plasma and PVD processes. These vacuum techniques enable the growth of heterostructures with nanometric thick individual layers and sharp interfaces, which are two requirements for advanced performances. However, both to develop more economical processes and with the goal of continuous deposition applications, the CVD processes operating under atmospheric pressure are particularly attractive. In this paper we show that the combination of pulsed direct liquid injection and the use of metalorganic precursor (DLI-MOCVD) is a promising route for the growth of nanostructured multilayer coatings under atmospheric pressure. Chromium metal as well as chromium carbide and nitrides monolithic coatings have been deposited at 773 K by this process using liquid solution of bis(benzene) chromium as Cr molecular precursor. Then, CrCx/CrN nanostructured multilayer coatings with a bilayer period as low as 50 nm have been grown. Structural characterizations and preliminary mechanical properties of these metallurgical coatings are discussed

Asymptotic behavior of a finite volume scheme for the transient drift-diffusion model

International audienceIn this paper, we propose a finite volume discretization for multidimensional nonlinear drift-diffusion system. Such a system arises in semi-conductors modeling and is composed of two parabolic equations and an elliptic one. We prove that the numerical solution converges to a steady state when time goes to infinity. Several numerical tests show the efficiency of the method

The morphology and exine ornamentation of fresh pollen from four dipterocarp species in Sabah

Peer reviewedPublisher PD

Engagement With a Custom-Made Online System Designed to Support Undergraduate Work Placement

This paper describes an online system that was custom-made to allow BSc Optometry undergraduates to submit work electronically, while off-campus on work placement. One of the main aims of the system was to allow internal (college) supervisors to provide students with timely, formative feedback on work submitted. The system was piloted in academic year 2013-14 and an intrinsic case study was carried out to examine the engagement of the students, the external placement supervisors and the internal supervisors with the system. Engagement was gauged by examining all subjects’ interaction with the system and by asking them to complete a post placement questionnaire. The results showed a high level of engagement from both the students and external supervisors but a lower level of engagement from the internal supervisors, in particular with regard to the provision of formative feedback. Possible reasons for the different levels of engagement are discussed and changes to be made to the system for academic year 2014-15 (based on the findings of the case study) are outlined

Run-Based Semantics for RPQs

The formalism of RPQs (regular path queries) is an important building block of most query languages for graph databases. RPQs are generally evaluated under homomorphism semantics; in particular only the endpoints of the matched walks are returned. Practical applications often need the full matched walks to compute aggregate values. In those cases, homomorphism semantics are not suitable since the number of matched walks can be infinite. Hence, graph-database engines adapt the semantics of RPQs, often neglecting theoretical red flags. For instance, the popular query language Cypher uses trail semantics, which ensures the result to be finite at the cost of making computational problems intractable. We propose a new kind of semantics for RPQs, including in particular simple-run and binding-trail semantics, as a candidate to reconcile theoretical considerations with practical aspirations. Both ensure the output to be finite in a way that is compatible with homomorphism semantics: projection on endpoints coincides with homomorphism semantics. Hence, testing the emptiness of result is tractable, and known methods readily apply. Moreover, simple-run and binding-trail semantics support bag semantics, and enumeration of the bag of results is tractableComment: 35 page

Increasing Obesity in Treated Female HIV Patients from Sub-Saharan Africa: Potential Causes and Possible Targets for Intervention.

Objectives: To investigate changing nutritional demographics of treated HIV-1-infected patients and explore causes of obesity, particularly in women of African origin. Methods: We prospectively reviewed nutritional demographics of clinic attenders at an urban European HIV clinic during four one-month periods at three-yearly intervals (2001, 2004, 2007, and 2010) and in two consecutive whole-year reviews (2010-2011 and 2011-2012). Risk-factors for obesity were assessed by multiple linear regression. A sub-study of 50 HIV-positive African female patients investigated body-size/shape perception using numerical, verbal, and pictorial cues. Results: We found a dramatic rise in the prevalence of obesity (BMI > 30 kg/m(2)), from 8.5 (2001) to 28% (2011-2012) for all clinic attenders, of whom 86% were on antiretroviral treatment. Women of African origin were most affected, 49% being obese, with a further 32% overweight (BMI 25-30 kg/m(2)) in 2012. Clinical factors strongly associated with obesity included female gender, black African ethnicity, non-smoking, age, and CD4 count (all P < 0.001); greater duration of cART did not predict obesity. Individual weight-time trends mostly showed slow long-term progressive weight gain. Investigating body-weight perception, we found that weight and adiposity were underestimated by obese subjects, who showed a greater disparity between perceived and actual adiposity (P < 0.001). Obese subjects targeted more obese target "ideal" body shapes (P < 0.01), but were less satisfied with their body shape overall (P = 0.02). Conclusion: Seropositive African women on antiretroviral treatment are at heightened risk of obesity. Although multifactorial, body-weight perception represents a potential target for intervention