| 1. |
- Corradini, Andrea, et al.
(författare)
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Term graph rewriting and parallel term rewriting
- 2011
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Ingår i: Proceedings of the 6th International Workshop on Computing with Terms and Graphs. - : Open Publishing Association. ; , s. 3-18
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Konferensbidrag (refereegranskat)abstract
- The relationship between Term Graph Rewriting and Term Rewriting is well understood: a single term graph reduction may correspond to several term reductions, due to sharing. It is also known that if term graphs are allowed to contain cycles, then one term graph reduction may correspond to infinitely many term reductions. We stress that this fact can be interpreted in two ways. According to the "sequential interpretation", a term graph reduction corresponds to an infinite sequence of term reductions, as formalized by Kennaway et.al. using strongly converging derivations over the complete metric space of infinite terms. Instead according to the "parallel interpretation" a term graph reduction corresponds to the parallel reduction of an infinite set of redexes in a rational term. We formalize the latter notion by exploiting the complete partial order of infinite and possibly partial terms, and we stress that this interpretation allows to explain the result of reducing circular redexes in several approaches to term graph rewriting.
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| 2. |
- Corradini, Flavio, et al.
(författare)
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Tangramob : An Agent-Based Simulation Framework for Validating Urban Smart Mobility Solutions
- 2020
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Ingår i: Journal of Intelligent Systems. - : WALTER DE GRUYTER GMBH. - 0334-1860 .- 2191-026X. ; 29:1, s. 1188-1201
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Tidskriftsartikel (refereegranskat)abstract
- Estimating the effects of introducing a range of smart mobility solutions within an urban area is a crucial concern in urban planning. The lack of a simulator for the assessment of mobility initiatives forces local public authorities and mobility service providers to base their decisions on guidelines derived from common heuristics and best practices. These approaches can help planners in shaping mobility solutions; however, given the high number of variables to consider, the effects are not guaranteed. Therefore, a solution conceived respecting the available guidelines can result in a failure in a different context. In particular, difficult aspects to consider are the interactions between different mobility services available in a given urban area and the acceptance of a given mobility initiative by the inhabitants of the area. In order to fill this gap, we introduce Tangramob, an agent-based simulation framework capable of assessing the impacts of a smart mobility initiative within an urban area of interest. Tangramob simulates how urban traffic is expected to evolve as citizens start experiencing newly offered traveling solutions. This allows decision makers to evaluate the efficacy of their initiatives, taking into account the current urban system. In this paper, we provide an overview of the simulation framework along with its design. To show the potential of Tangramob, three mobility initiatives are simulated and compared in the same scenario. This demonstrates how it is possible to perform comparative experiments so as to align mobility initiatives to the user goals.
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| 3. |
- Mumme, Steffen, et al.
(författare)
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Wherever I may roam—Human activity alters movements of red deer (Cervus elaphus) and elk (Cervus canadensis) across two continents
- 2023
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Ingår i: Global Change Biology. - Chichester : Wiley-Blackwell Publishing Inc.. - 1354-1013 .- 1365-2486. ; 29:20, s. 5788-5801
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Tidskriftsartikel (refereegranskat)abstract
- Human activity and associated landscape modifications alter the movements of animals with consequences for populations and ecosystems worldwide. Species performing long-distance movements are thought to be particularly sensitive to human impact. Despite the increasing anthropogenic pressure, it remains challenging to understand and predict animals' responses to human activity. Here we address this knowledge gap using 1206 Global Positioning System movement trajectories of 815 individuals from 14 red deer (Cervus elaphus) and 14 elk (Cervus canadensis) populations spanning wide environmental gradients, namely the latitudinal range from the Alps to Scandinavia in Europe, and the Greater Yellowstone Ecosystem in North America. We measured individual-level movements relative to the environmental context, or movement expression, using the standardized metric Intensity of Use, reflecting both the directionality and extent of movements. We expected movement expression to be affected by resource (Normalized Difference Vegetation Index, NDVI) predictability and topography, but those factors to be superseded by human impact. Red deer and elk movement expression varied along a continuum, from highly segmented trajectories over relatively small areas (high intensity of use), to directed transitions through restricted corridors (low intensity of use). Human activity (Human Footprint Index, HFI) was the strongest driver of movement expression, with a steep increase in Intensity of Use as HFI increased, but only until a threshold was reached. After exceeding this level of impact, the Intensity of Use remained unchanged. These results indicate the overall sensitivity of Cervus movement expression to human activity and suggest a limitation of plastic responses under high human pressure, despite the species also occurring in human-dominated landscapes. Our work represents the first comparison of metric-based movement expression across widely distributed populations of a deer genus, contributing to the understanding and prediction of animals' responses to human activity. Global Change Biology© 2023 The Authors. Global Change Biology published by John Wiley & Sons Ltd.
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