31 research outputs found

    Formal specification of multi-agent systems by using EUSMs

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    The behavior of e-commerce agents can be defined at different levels of abstraction. A formalism allowing to define them in terms of their economic activities, Utility State Machines, has been proposed. Due to its high level of abstraction, this formalism focuses on describing the economic goals rather on how they are achieved. Though this approach is suitable to specify the objectives of e-commerce agents, as well as to construct formal analysis methodologies, this framework is not suitable to define the strategic behavior of agents. In this paper we develop a new formalism to explicitly define the strategic behavior of agents in a modular way. In particular, we reinterpret the role of utility functions, already used in USMs in a more restrictive manner, so that they define strategic preferences and activities of agents. We apply the formalism to define the agents in a benchmark e-commerce agent environment, the Supply Chain Management Game. Since the strategic behavior of agents is located in a specific part of the formalism, different strategies can be easily considered, which enhances the reusability of the proposed specification

    Heart failure in COVID-19: the multicentre, multinational PCHF-COVICAV registry.

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    AIMS: We assessed the outcome of hospitalized coronavirus disease 2019 (COVID-19) patients with heart failure (HF) compared with patients with other cardiovascular disease and/or risk factors (arterial hypertension, diabetes, or dyslipidaemia). We further wanted to determine the incidence of HF events and its consequences in these patient populations. METHODS AND RESULTS: International retrospective Postgraduate Course in Heart Failure registry for patients hospitalized with COVID-19 and CArdioVascular disease and/or risk factors (arterial hypertension, diabetes, or dyslipidaemia) was performed in 28 centres from 15 countries (PCHF-COVICAV). The primary endpoint was in-hospital mortality. Of 1974 patients hospitalized with COVID-19, 1282 had cardiovascular disease and/or risk factors (median age: 72 [interquartile range: 62-81] years, 58% male), with HF being present in 256 [20%] patients. Overall in-hospital mortality was 25% (n = 323/1282 deaths). In-hospital mortality was higher in patients with a history of HF (36%, n = 92) compared with non-HF patients (23%, n = 231, odds ratio [OR] 1.93 [95% confidence interval: 1.44-2.59], P < 0.001). After adjusting, HF remained associated with in-hospital mortality (OR 1.45 [95% confidence interval: 1.01-2.06], P = 0.041). Importantly, 186 of 1282 [15%] patients had an acute HF event during hospitalization (76 [40%] with de novo HF), which was associated with higher in-hospital mortality (89 [48%] vs. 220 [23%]) than in patients without HF event (OR 3.10 [2.24-4.29], P < 0.001). CONCLUSIONS: Hospitalized COVID-19 patients with HF are at increased risk for in-hospital death. In-hospital worsening of HF or acute HF de novo are common and associated with a further increase in in-hospital mortality

    Agent Models for Concurrent Software Systems

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    Decomposed replay using hiding and reduction

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    In the area of process mining, decomposed replay has been proposed to be able to deal with nets and logs containing many different activities. The main assumption behind this decomposition is that replaying many subnets and sublogs containing only some activities is faster then replaying a single net and log containing many activities. Although for many nets and logs this assumption does hold, there are also nets and logs for which it does not hold. This paper shows an example net and log for which the decomposed replay may take way more time, and provides an explanation why this is the case. Next, to mitigate this problem, this paper proposes an alternative decomposed replay, and shows that this alternative decomposed replay is faster than the monolithic replay even for the problematic cases as identified earlier.owever, the alternative decomposed replay is often slower than the original decomposed approach. An advantage of the alternative decomposed approach over the original approach is that its cost estimates are typically better

    Grade/CPN : semi-automatic support for teaching Petri nets by checking many Petri nets against one specification

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    Grading dozens of Petri net models manually is a tedious and error-prone task. In this paper, we present Grade/CPN, a tool supporting the grading of Colored Petri nets modeled in CPN Tools. The tool is extensible, conÂżgurable, and can check static and dynamic properties. It automatically handles tedious tasks like checking that good modeling practise is adhered to, and supports tasks that are diÂżcult to automatize, such as checking model legibility. We propose and support the Britney Temporal Logic which can be used to guide the simulator and to check temporal properties. We provide our experiences with using the tool in a course with 100 participants

    Access/CPN 2.0 : a high-level interface to coloured Petri net models

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    This paper introduces Access/CPN 2.0, which extends Access/ CPN with high-level primitives for interacting with coloured Petri net (CPN) models in Java programs. The primitives allow Java programs to monitor and interact with places and transitions during execution, and embed entire programs as subpages of CPN models or embed CPN models as parts of programs. This facilitates building environments for systematic testing of program components using a CPN models. We illustrate the use of Access/CPN 2.0 in the context of business processes by embedding a workflow system into a CPN model
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