393 research outputs found
Fully automatic worst-case execution time analysis for MATLAB/Simulink models
“This material is presented to ensure timely dissemination of scholarly and technical work. Copyright and all rights therein are retained by authors or by other copyright holders. All persons copying this information are expected to adhere to the terms and constraints invoked by each author's copyright. In most cases, these works may not be reposted without the explicit permission of the copyright holder." “Copyright IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.”In today's technical world (e.g., in the automotive industry), more and more purely mechanical components get replaced by electro-mechanical ones. Thus the size and complexity of embedded systems steadily increases. To cope with this development, comfortable software engineering tools are being developed that allow a more functionality-oriented development of applications. The paper demonstrates how worst-case execution time (WCET) analysis is integrated into such a high-level application design and simulation tool MATLAB/Simulink-thus providing a higher-level interface to WCET analysis. The MATLAB/Simulink extensions compute and display worst-case timing data for all blocks of a MATLAB/Simulink simulation, which gives the developer of an application valuable feedback about the correct timing of the application being developed. The solution facilitates a fully-automated WCET analysis, i.e., in contrast to existing approaches the programmer does not have to provide path information
Modelling disaster risk behaviour on the household level
Disaster risk is a combination of natural hazard, exposure, and vulnerability. While the natural hazard can be seen as exogenously given on the household level, exposure and vulnerability are highly heterogeneous. A collection of empirical studies (see references) has investigated the impact of household characteristics (such as education, awareness, access to prevention measures, and time preference) on exposure and vulnerability to natural disasters. However, a theoretical model being able to replicate these findings is still missing in the literature. We propose such a dynamic household model, which consequently allows for better predictions and estimations regarding the impacts and the effectiveness of various community wide policy measures aiming to decrease disaster risk
Test-retest reliability of stride time variability while dual tasking in healthy and demented adults with frontotemporal degeneration
Although test-retest reliability of mean values of spatio-temporal gait parameters has been assessed for reliability while walking alone (i.e., single tasking), little is known about the test-retest reliability of stride time variability (STV) while performing an attention demanding-task (i.e., dual tasking). The objective of this study was to examine immediate test-retest reliability of STV while single and dual tasking in cognitively healthy older individuals (CHI) and in demented patients with frontotemporal degeneration (FTD)
Tradeoffs in Model Performance and Effort for Long-Term Phosphorus Leaching Based on In Situ Field Data
Phosphorus and N are critical nutrients for agriculture but are also responsible for surface water enrichment that leads to toxic algal growth. Although P loading to surface waters has traditionally been thought to occur primarily in surface runoff, contributions from subsurface transport can also be significant. The primary objectives of this research were to evaluate several methods of representing macropore flow and transport in a finite element model using plot-scale infiltration and leaching data and to compare several models of various levels of complexity to simulate long-term P leaching. To determine flow and transport parameters, single- and dual-porosity models in HYDRUS-2D were calibrated with infiltration, Cl−, and P data from a 22-h plot-scale leaching experiment on a silt loam mantle with gravel subsoil. Both homogeneous and heterogeneous gravel profiles were simulated. The dual-porosity model with heterogeneous hydraulic conductivity best matched experimental data, with physical nonequilibrium (dual porosity) being more important than two-dimensional (2D) heterogeneity. Long-term (9 yr) P leaching to the water table (3 m below the soil surface) at the field site was simulated with both one-dimensional (1D) and 2D models using the calibrated parameters. There was little difference between analogous 1D and 2D models, suggesting that HYDRUS-1D may be sufficient to model long-term P leaching. Overall, the most important elements for accurately simulating P leaching in this silt loam and gravel soil profile were found to be (i) field-measured hydraulic conductivity of the limiting soil layer, (ii) calibrated dispersivity, and (iii) dual-porosity, in some circumstances
Should I stay or should I go: Modelling disaster risk behaviour using a dynamic household level approach
In the last decades, many parts of the world faced an increase in the number of extreme weather events and worsening climate conditions endangering the livelihood of households in developing countries that rely on their local environment. While various empirical studies have identified key factors of exposure and vulnerability to disaster risk, we still lack a conceptual understanding of how these forces interact and how they impact household decision making. To gain insight into these mechanisms we set up a dynamic household model where households face environmental hazards. To respond to the risk, households can either relocate to a safer area or undertake preventive measures. Both actions require material and immaterial resources, which constrain the household's decision. Households are assumed to be heterogeneous with respect to key empirically identified factors for individual disaster risk: education, income, risk awareness, time preference and their access to preventive measures. This paper provides analytical insights into the short-run decision making of households derived from the theoretical framework as well as an extensive numerical investigation. To parameterize and calibrate the model we use data from Thailand and Vietnam. The roles of household characteristics on the short-term decision-making and long-run outcomes of households' well-being and disaster risk is discussed. We conclude the paper with an extensive evaluation of different policy interventions including housing and prevention cost subsidies as well as income transfers with respect to their heterogeneous effects on different sub-populations
Pharmacological Inhibition of polysialyltransferase ST8SiaII Modulates Tumour Cell Migration
YesPolysialic acid (polySia), an α-2,8-glycosidically linked polymer of sialic acid, is a developmentally regulated posttranslational
modification predominantly found on NCAM (neuronal cell adhesion molecule). Whilst high levels are expressed during development, peripheral adult organs do not express polySia-NCAM. However, tumours of neural crest-origin re-express polySia-NCAM: its occurrence correlates with aggressive and invasive disease and poor clinical prognosis in different cancer types, notably including small cell lung cancer (SCLC), pancreatic cancer and neuroblastoma. In neuronal development, polySia-NCAM biosynthesis is catalysed by two polysialyltransferases, ST8SiaII and ST8SiaIV, but it is ST8SiaII that is the prominent enzyme in tumours. The aim of this study was to determine the effect of ST8SiaII inhibition by a small molecule on tumour cell migration, utilising cytidine monophosphate (CMP) as a tool compound. Using immunoblotting we showed that CMP reduced ST8iaII-mediated polysialylation of NCAM. Utilizing a novel HPLC-based assay to quantify polysialylation of a fluorescent acceptor (DMB-DP3), we demonstrated that CMP is a competitive inhibitor of ST8SiaII (Ki = 10 μM). Importantly, we have shown that CMP causes a concentration-dependent reduction in tumour cell-surface polySia expression, with an absence of toxicity. When ST8SiaII-expressing tumour cells (SH-SY5Y and C6-STX) were evaluated in 2D cell migration assays, ST8SiaII inhibition led to significant reductions in migration, while CMP had no effect on cells not expressing ST8SiaII (DLD-1 and C6-WT). The study demonstrates for the first time that a polysialyltransferase inhibitor can modulate migration in ST8SiaII-expressing tumour cells. We conclude that ST8SiaII can be considered a druggable target with the potential for interfering with a critical mechanism in tumour cell dissemination in metastatic cancers.Yorkshire Cancer Research; EPSRC; Association for International Cancer Research; Jordanian Government PhD scholarshi
Shape sensitivities for an inverse problem in magnetic induction tomography based on the eddy current model
Comparação das incidências de tumores cutâneos malignos em pacientes submetidos à cirurgia ambulatorial no PACS nos períodos de 1998-1999 e 2000-2001
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Prevalência das patologias mais frequentes diagnosticadas por anatomopatológicos entre junho de 2000 e de 2001 em procedimentos realizados num posto de atendimento primário de Porto Alegre
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