85 research outputs found
Visualization of formal specifications for understanding and debugging an industrial DSL
In this work we report on our proof of concept of a generic approach: visualized formal specification of a Domain Specific Language (DSL) can be used for debugging, understanding, and impact analysis of the DSL programs. In our case study we provide a domain-specific visualization for the Event-B specification of a real-life industrial DSL and perform a user study among DSL engineers to discover opportunities for its application. In this paper, we explain the rationale behind our visualization design, discuss the technical challenges of its realization and how these challenges were solved using the Model Driven Engineering (MDE) techniques. Based on the positive feedback of the user study, we present our vision on how this successful experience can be reused and the approach can be generalized for other DSLs
Rare earth element distribution and mineralization in Sweden: an application of principal component analysis to FOREGS soil geochemistry
This paper presents results of statistical analyses and spatial interpretations of distributions of rare earth elements (REEs) in Sweden using the Forum of European Geological Surveys (FOREGS) geochemical database of topsoil, subsoil and stream sediment compositions. Raster maps depicting spatial distributions of individual REEs were created by interpolation of uni-element data and then principal component (PC) analysis was carried out on the REE data to identify geochemical anomalies associated with bedrock lithology and known mineralizations. The spatial distributions of REEs in Sweden are studied using only the Swedish data subset and the entire European data set. The light rare earth elements (LREEs) La, Ce, Nd and Sm show good correlations among each other but not with Eu. The heavy rare earth elements (HREEs) including Tb, Dy, Ho, Er, Tm, Yb and Lu also show good correlations among each other but not necessarily with the LREE. La, Ce and Nd are the most abundant REEs in all the studied media (topsoils, subsoils and stream sediments), with average median concentrations of 25.3 mg/kg, 53.6 mg/kg and 23.9 mg/kg, respectively. The total explained variances of the first two PCs of each of the REE dataset for topsoils, subsoils, and stream sediments are 95.4%, 95.8% and 95.2%, respectively. Biplots of the first two PCs of each of the REE dataset for topsoils, subsoils, and stream sediments commonly reveal two distinct groupings – HREEs and LREEs – whereas biplots of PC1 versus PC3 of these datasets commonly reveal three distinct groupings – Eu, Ce and other REEs. The main difference between the distribution patterns of LREE and HREE is likely due to enrichment of the LREEs in the Archean bedrock underlying northern Sweden. HREE concentrations in the Archean to Paleoproterozoic metasediments are rather low. Color composites of PC maps produced from the topsoil and subsoil datasets clearly reflect the Archean rocks in northern Sweden and outline the second phase of the Svecokarelian orogen
Provenance of Neoproterozoic sediments in the Särv nappes (Middle Allochthon) of the Scandinavian Caledonides: LA-ICP-MS and SIMS U-Pb dating of detrital zircons
We present U-Pb age data for detrital zircons from dike-intruded Neoproterozoic sedimentary rocks of the Caledonian Middle Allochthon in central Sweden and Norway. Detrital zircons from 11 samples from the Särv, Sætra and upper Leksdal nappes (informally referred to as the Särv nappes) are clustered within ca. 0.9-1.75. Ga, but display a bimodal distribution with major ca. 1.45-1.75. Ga and ca. 0.9-1.2. Ga components. An apparent increase of younger (0.9-1.2. Ga) components to the northwest reflects varying source terranes. Detrital zircons from an additional sample from the lower part of the Leksdal Nappe, of uncertain affiliation to the Särv has a prominent 1.75-1.85. Ga component supporting previous suggestions that this part of the nappe belonged to a more proximal basin. Comparison of the Särv age probability patterns with data from basement windows and basement slices within the Middle Allochthon in central Sweden and Norway supports the derivation of the sediments from the attenuated Baltican continental crust on which they were presumably deposited. Similar comparisons suggest that derivation from the southern segment of the Fennoscandian Shield or from eastern segments of Laurentia is less likely, mostly because they include also older components.We infer that the ca. 200. km wide belt of attenuated Baltican continental crust included northern extensions of Mesoproterozoic to early Neoproterozoic terranes exposed in the southern part of the Fennoscandian Shield and the easternmost part of Laurentia, which at ca. 900. Ma were still adjacent. Pre-1.75. Ga terranes of the Fennoscandian Shield were probably isolated from the Särv distal basin(s) by intra-cratonic basins and uplifted margins associated with early development of this extended continental crust. The significantly older ages in the lower part of the Leksdal Nappe and its inferred more proximal position support this model. The proposed northern extension of Mesoproterozoic-early Neoproterozoic terranes can explain in a simpler way the occurrence of such detritus in many Caledonide-Appalachian allochthons exposed at the margins of the North Atlantic, with no need to infer large displacement along the axis of the Caledonide Orogen or to postulate selective transport of Grenville-age material from the south over large distances. One of our Särv samples located at the Norwegian coast revealed Caledonian reworking at ca. 395. Ma. This age agrees with ages of late-tectonic amphibolite-facies metamorphism and pegmatite intrusion recorded in this part of the Caledonides
REE concentrations in agricultural soil in Sweden and Italy: Comparison of weak MMI (R) extraction with near total extraction data.
Rare Earth Element (REE) concentrations in agricultural soil obtained from the Mobile Metal Ion (MMI (R)) weak extraction technique are compared with soil total concentrations (sodium peroxide fusion followed by acid dissolution) for 118 and 174 agricultural soil samples from Italy and Sweden, respectively. Spatial distribution maps and statistics for both analytical techniques are compared between the two national datasets. In spite of similarity of REE concentration in two countries, the median values of REE is higher than Italy but extreme concentration of REE in Italy is due to young volcanic activities. Extractability of REEs is significantly higher in Swedish soils than in Italian soils. Heavy Rare Earth Element (HREE) in Sweden show higher concentrations compared to Italy in MMI (R) extraction data where correlate with REE mineralisation. Principal Component Analysis (PCA) is used to elucidate correlations and anomalies in the REE distribution. Results show that there is a clear correlation between REE anomalies and natural factors such as lithology of the underlying bedrock, the presence of mineralisations, pH of soils, climate and precipitation. According to the PCA results, anomalous behaviour of Eu, Ce, Tb and Gd can be explained by the dominant mineralogy of the parent material and the variable affinity of REEs to bind to clay minerals and clay-size particles
REE contents in soils and sediments from the GEMAS and FOREGS data-bases: comparison between different geological contexts in Italy and Sweden
Comparazione di distribuzione di Terre Rare in suoli e sedimenti di Italia e Svezia da campioni di progetti FOREGS e GEMA
Assessment of a formal requirements modeling approach on a transportation system
International audienceThis paper describes a case study of the SysML/KAOS method for a road transportation system for the City of Montreal (VdM), the second-largest city in Canada. The transportation system was developed from unstructured requirements represented in textual and schematic documents. Therefore, the VdM wanted to investigate new ways of organising and analysing the requirements of traffic projects, in order to increase the level of confidence in their safety, usability and reusability. This paper describes the formal specification, verification and validation of system requirements and provides an appraisal of the SysML/KAOS requirements engineering method on an industrial-scale case study. SysML/KAOS is designed within the ANR FORMOSE project to bridge the gap between stakeholder needs and the formal specification of system functionalities and domain constraints. The method has proven useful to deal with the seven refinement levels, twelve components (human, hardware, software and cyber-physical) and a hundred functional and non-functional goals that constitute the specification of the road transportation system, mainly focused on the safe movement of vehicles on road. It especially facilitated their validation with VdM stakeholders who had never dealt with formal methods and requirements engineering. Animation tools (ProB and B-Motion Studio) were also used to validate the formal specification with VdM stakeholders. This paper also reports improvements identified to enhance the expressiveness of SysML/KAOS goal modeling languages during validation sessions with VdM stakeholders. This includes the introduction of a non-functional goal refinement strategy based on logical formulas and of an obstacle modeling language
Gemas: issues from the comparison of aqua regia and X-ray fluorescence results
Contenuti riportati in: Geophysical Research Abstracts, Vol. 16, EGU201
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