Combined Model-Free Data-Interpretation Methodologies for Damage Detection during Continuous Monitoring of Structures

Despite the recent advances in sensor technologies and data-acquisition systems, interpreting measurement data for structural monitoring remains a challenge. Furthermore, because of the complexity of the structures, materials used, and uncertain environments, behavioral models are difficult to build accurately. This paper presents novel model-free data-interpretation methodologies that combine moving principal component analysis (MPCA) with each of four regression-analysis methodsrobust regression analysis (RRA), multiple linear analysis (MLR), support vector regression (SVR), and random forest (RF)for damage detection during continuous monitoring of structures. The principal goal is to exploit the advantages of both MPCA and regression-analysis methods. The applicability of these combined methods is evaluated and compared with individual applications of MPCA, RRA, MLR, SVR, and RF through four case studies. Result showed that the combined methods outperformed noncombined methods in terms of damage detectability and time to detection. (C) 2013 American Society of Civil Engineers

Managing Decision Tasks and Events in Time-Aware Business Process Models

Time-aware business process models capture processes where temporal properties and constraints have to be suitably managed to achieve proper completion. Temporal aspects also constrain how decisions are made in processes: while some constraints hold only along certain paths, decision outcomes may be restricted to satisfy temporal constraints. In this paper, we present time-aware BPMN processes and discuss how to: (i) add temporal features to process elements, by considering also the impact of events on temporal constraint management; (ii) characterize decisions based on when they are made and used within a process; (iii) specify and use two novel kinds of decisions based on how their outcomes are managed; (iv) deal with intertwined temporal and decision aspects of time-aware BPMN processes to ensure proper execution

Organic carbon content and carbon isotope variations across the Permo-Triassic boundary in the Gartnerkofel-1 borehole, Carnic Alps, Austria

The Gartnerkofel borehole is one of the most thoroughly studied and described Permo-Triassic sections in the world. Detailed bulk organic carbon isotope studies show a negative base shift from − 24‰ to − 28‰ in the Latest Permian which latter value persists into the Earliest Triassic after which it decreases slightly to − 26‰. Two strongly negative peaks of > − 38‰ in the Latest Permian and a lesser peak of − 31‰ in the Early Triassic are too negative to be due to a greater proportion of more negative organic matter and must be due to very negative methane effects. The overall change to more negative values across the Bulla/Tesero boundary fits the relative rise in sea level for this transition based on the facies changes. A positive shift in organic carbon isotope values at the Late Permian Event Horizon may be due to an increase in land-derived organic detritus at this level—a feature shown by all Tethyan Permo-Triassic boundary sections though these other sections do not have the same values. Carbonate carbon isotope trends are similar in all sections dropping by 2–3 units across the Permo-Triassic boundary. Gartnerkofel carbonate oxygen values are surprisingly, considering the ubiquitous dolomitization, compatible with values elsewhere and indicate reasonable tropical temperatures of 60 °C in the Latest Permian sabkhas to 20–40 °C in the overlying marine transition beds. Increased land-derived input at the Late Permian Event Horizon may be due to offshore transport by tsunamis whose deposits have been recognized in India at this level

Sedimentary and bio-chronostratigraphical aspects of the P/T boundary in the eastern Southern Alps.

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Adaptive strategies of Lower Jurassic and Eocene multivincular bivalves

The adaptive strategies of three multivincular bivalves are described: two Liassic species of the Lithiotis Facies (Lithioperna scutata and Mytiloperna sp.) and an Eocene species (Pachyperna laverdana). These taxa are characterized by a high intraspecific variability and unusual shell form which are typical features of the secondary soft-bottom dwellers. P. laverdana shows a high ontogenetic variability with behavioural changes from pleurothetic, byssally attached, hard-bottom dweller to edgewise, soft-bottom recliner. Mytiloperna sp. shows a very high morphological and behavioural variability in the adult shells; its adaptive strategy ranges from an epifaunal, edgewise recliner to semi-infaunal mud sticker. The behaviour of L. scutata ranges from pleurothetic recliner to semi-infaunal mud sticker. P. laverdana probably inhabited higher energy environments with a minor spatial competition with respect to the Liassic species. A less static stability of Mytiloperna sp. with respect to the Eocene species has been proposed. Thus its bottom stabilization could also be guaranteed by other factors (e.g. dense package of the host bivalve community, semi-infaunal behaviour, anchorage with beaks). L. scutata has a shell with the lowest hydrodynamic stability. All three taxa have inner shell layers made up of an irregular simple prismatic microstructure. It becomes massive and fibrous in P. layerdana and Mytiloperna sp., where it mainly carried out a static function in the heavyweight strategy. The mechanical, environmental and taxonomical significance of the morphology and microstructure are discussed

The early macrofaunas of the Werfen Formation and the Permian-Triassic boundary in the Dolomites (Southern Alps, Italy)

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