Towards semantic software engineering environments

Software tools processing partially common set of data should share an understanding of what these data mean. Since ontologies have been used to express formally a shared understanding of information, we argue that they are a way towards Semantic SEEs. In this paper we discuss an ontology-based approach to tool integration and present ODE, an ontology-based SEE

A Tabu Search Heuristic Procedure in Markov Chain Bootstrapping

Markov chain theory is proving to be a powerful approach to bootstrap nite states processes, especially where time dependence is non linear. In this work we extend such approach to bootstrap discrete time continuous-valued processes. To this purpose we solve a minimization problem to partition the state space of a continuous-valued process into a nite number of intervals or unions of intervals (i.e. its states) and identify the time lags which provide \memory" to the process. A distance is used as objective function to stimulate the clustering of the states having similar transition probabilities. The problem of the exploding number of alternative partitions in the solution space (which grows with the number of states and the order of the Markov chain) is addressed through a Tabu Search algorithm. The method is applied to bootstrap the series of the German and Spanish electricity prices. The analysis of the results conrms the good consistency properties of the method we propose

Electron transport through electrically induced nanoconstrictions in HfSiON gate stacks

A microscopic picture for the progressive leakage current growth in electrically stressed HfxSi1−xON/SiON gate stacks in metal-oxide-semiconductor transistors based on the physics of mesoscopic conductors is proposed. The breakdown spot is modeled as a nanoconstriction connecting two electron reservoirs. We show that after eliminating the tunnelingcurrent component that flows through the nondamaged device area, the postbreakdown conductance exhibits levels of the order of the quantum unit 2e2/h, where e is the electron charge and h the Planck's constant, as is expected for atomic-sized contacts. Similarities and differences with previous studied systems are discussed

Remarks on 2+1 Self-dual Chern-Simons Gravity

We study 2+1 Chern-Simons gravity at the classical action level. In particular we rederive the linear combinations of the ``standard'' and ``exotic'' Einstein actions, from the (anti) self-duality of the ``internal'' Lorentzian indices. The relation to a genuine four-dimensional (anti)self-dual topological theory greatly facilitates the analysis and its relation to hyperbolic three-dimensional geometry. Finally a non-abelian vector field ``dual'' action is also obtained.Comment: 16+1 pages, LaTeX file, no figures, clarifications and comments added, typos corrected and one reference adde

Relevant states and memory in Markov chain bootstrapping and simulation

Markov chain theory is proving to be a powerful approach to bootstrap and simulate highly nonlinear time series. In this work, we provide a method to estimate the memory of a Markov chain (i.e. its order) and to identify its relevant states. In particular, the choice of memory lags and the aggregation of irrelevant states are obtained by looking for regularities in the transition probabilities. Our approach is based on an optimization model. More specifically, we consider two competing objectives that a researcher will in general pursue when dealing with bootstrapping and simulation: preserving the “structural” similarity between the original and the resampled series, and assuring a controlled diversification of the latter. A discussion based on information theory is developed to define the desirable properties for such optimal criteria. Two numerical tests are developed to verify the effectiveness of the proposed method

The Strategic Exploitation of Limited Information and Opportunity in Networked Markets

This paper studies the effect of constraining interactions within a market. A model is analysed in which boundedly rational agents trade with and gather information from their neighbours within a trade network. It is demonstrated that a trader’s ability to profit and to identify the equilibrium price is positively correlated with its degree of connectivity within the market. Where traders differ in their number of potential trading partners, well-connected traders are found to benefit from aggressive trading behaviour.Where information propagation is constrained by the topology of the trade network, connectedness affects the nature of the strategies employed

Physical activity to improve cognition in older adults: can physical activity programs enriched with cognitive challenges enhance the effects? A systematic review and meta-analysis

: EPHPP quality rating scores (DOCX 38 kb

Approximating Markov Chains for Bootstrapping and Simulation

In this work we develop a bootstrap method based on the theory of Markov chains. The method moves from the two competing objectives that a researcher pursues when performing a bootstrap procedure: (i) to preserve the structural similarity -in statistical sense- between the original and the bootstrapped sample; (ii) to assure a diversification of the latter with respect to the former. The original sample is assumed to be driven by a Markov chain. The approach we follow is to implement an optimization problem to estimate the memory of a Markov chain (i.e. its order) and to identify its relevant states. The basic ingredients of the model are the transition probabilities, whose distance is measured through a suitably defined functional. We apply the method to the series of electricity prices in Spain. A comparison with the Variable Length Markov Chain bootstrap, which is a well established bootstrap method, shows the superiority of our proposal in reproducing the dependence among data

Sensitization to inhalant and food allergens in Brazilian atopic children by in vitro total and specific IgE assay: Allergy Project - PROAL

OBJECTIVE: To determine the frequency of sensitization to inhalant and food allergens in children seen at Brazilian allergy services. PATIENTS AND METHODS: Total and specific IgE serum levels to inhalant and food allergens (RAST, UniCAP® - Pharmacia) were measured in 457 children accompanied in pediatric allergy services and in 62 control children age matched. RAST equal or higher than class 1 was considered as positive (R+). RESULTS: Frequency of R+ was significantly higher among atopics (361/457, 79%) when compared to controls (16/62, 25.8%). There were no differences according to gender. The frequency of R+ to all allergens evaluated were higher among atopics when compared to controls. Significantly higher total IgE serum levels were observed among the atopics with R+ in comparison to those with R-. The frequency of R+ to main inhalant allergens were: D. pteronyssinus = 66.7% x 14.5% (p < 0.05), D. farinae = 64.5% x 17.8% (p < 0.05), B. tropicalis = 55.2% x 19.4% (p < 0.05), cockroach = 32.8% x 9.7% (p < 0.05), and cat = 12% x 8.1%. In relation to food allergens we observed: fish = 29.5% x 11.3% (p < 0.05), egg = 24.4% x 4.8% (p < 0.05), cow's milk = 23.1% x 3.2% (p < 0.05), wheat = 20% x 8.1% (p < 0.05), peanuts = 14% x 4.8% (p < 0.05), soy = 11.8% x 4.8% (p < 0.05), and corn = 10.6% x 4.8% (p < 0.05). With respect of age, food allergen sensitization predominates in young children whereas the inverse occurs with inhalant allergens. CONCLUSIONS: There was a predominant frequency of sensitization to inhalant allergens, mainly house dust mites in the evaluated patients. Food allergens were also responsible for a significant proportion of sensitization, mainly in infants.OBJETIVO: Determinar a freqüência de sensibilização a alérgenos inalantes e alimentares em crianças atendidas em serviços brasileiros de alergia. PACIENTES E MÉTODOS: IgE sérica total e específica (RAST) a alérgenos inalantes e alimentares (UniCAP® - Pharmacia) foram determinados em 457 crianças acompanhadas em serviços de alergia pediátrica e em um grupo de controles (n = 62). Resultados classe igual ou maior que 1 foram considerados positivos (R+). RESULTADOS: A freqüência de R+ foi significantemente maior entre os atópicos (361/457, 79%) quando comparados aos controles (16/62, 25,8%). Não houve diferenças quanto ao sexo. A prevalência de R+ entre os atópicos foi significantemente maior para todos os alérgenos avaliados. Os níveis séricos de IgE total foram significantemente mais elevados entre os atópicos com R+ quando comparados aos com R-. Comparando-se atópicos e controles, a freqüência de R+ para os principais alérgenos inalantes foi como segue: D. pteronyssinus = 66,7 versus 14,5% (p < 0,05), D. farinae = 64,5 versus 17,8% (p < 0,05), B. tropicalis = 55,2 versus 19,4% (p < 0,05), barata = 32,8 versus 9,7% (p < 0,05) e gato = 12 versus 8,1%. Com os alimentos, observou-se: peixe = 29,5 versus 11,3% (p < 0,05), ovo = 24,4 versus 4,8% (p < 0,05), leite de vaca = 23,1 versus 3,2% (p < 0,05), trigo = 20 versus 8,1% (p < 0,05), amendoim = 14 versus 4,8% (p < 0,05), soja = 11,8 versus 4,8% (p < 0,05) e milho = 10,6 versus 4,8% (p < 0,05). Segundo a idade, os R+ aos alimentares predominaram entre as crianças mais jovens, e o inverso ocorreu com os inalantes. CONCLUSÕES: Nesta população, predominou a sensibilização aos aeroalérgenos, sobretudo aos ácaros domiciliares, e os alimentos foram importantes em crianças mais jovens.Universidade Federal de São Paulo (UNIFESP) Departamento de Pediatria Disciplina de Alergia e Imunologia Clínica e ReumatologiaUniversidade Federal de São Paulo (UNIFESP)Grupo PROALUNIFESP, Depto. de Pediatria Disciplina de Alergia e Imunologia Clínica e ReumatologiaUNIFESPSciEL

A Computational Approach to Sequential Decision Optimization in Energy Storage and Trading

Due to recent technical progress, battery energy storages are becoming a viable option in the power sector. Their optimal operational management focuses on load shift and shaving of price spikes. However, this requires optimally responding to electricity demand, intermittent generation, and volatile electricity prices. More importantly, such optimization must take into account the so-called deep discharge costs, which have a significant impact on battery lifespan. We present a solution to a class of stochastic optimal control problems associated with these applications. Our numerical techniques are based on efficient algorithms which deliver a guaranteed accurac