200 research outputs found
Linear dependence of bivariate Minimal Support and Locally Refined B-splines over LR-meshes
The focus on locally refined spline spaces has grown rapidly in recent years
due to the need in Isogeoemtric analysis (IgA) of spline spaces with local
adaptivity: a property not offered by the strict regular structure of tensor
product B-spline spaces. However, this flexibility sometimes results in
collections of B-splines spanning the space that are not linearly independent.
In this paper we address the minimal number of B-splines that can form a linear
dependence relation for Minimal Support B-splines (MS B-splines) and for
Locally Refinable B-splines (LR B-splines) on LR-meshes. We show that the
minimal number is six for MS B-splines, and eight for LR B-splines. The risk of
linear dependency is consequently significantly higher for MS B-splines than
for LR B-splines. Further results are established to help detecting collections
of B-splines that are linearly independent
Verification of Agent-Based Artifact Systems
Artifact systems are a novel paradigm for specifying and implementing
business processes described in terms of interacting modules called artifacts.
Artifacts consist of data and lifecycles, accounting respectively for the
relational structure of the artifacts' states and their possible evolutions
over time. In this paper we put forward artifact-centric multi-agent systems, a
novel formalisation of artifact systems in the context of multi-agent systems
operating on them. Differently from the usual process-based models of services,
the semantics we give explicitly accounts for the data structures on which
artifact systems are defined. We study the model checking problem for
artifact-centric multi-agent systems against specifications written in a
quantified version of temporal-epistemic logic expressing the knowledge of the
agents in the exchange. We begin by noting that the problem is undecidable in
general. We then identify two noteworthy restrictions, one syntactical and one
semantical, that enable us to find bisimilar finite abstractions and therefore
reduce the model checking problem to the instance on finite models. Under these
assumptions we show that the model checking problem for these systems is
EXPSPACE-complete. We then introduce artifact-centric programs, compact and
declarative representations of the programs governing both the artifact system
and the agents. We show that, while these in principle generate infinite-state
systems, under natural conditions their verification problem can be solved on
finite abstractions that can be effectively computed from the programs. Finally
we exemplify the theoretical results of the paper through a mainstream
procurement scenario from the artifact systems literature
A tool for compiling Declarative Process Mining problems in ASP
We present a tool for compiling three problems from the Process Mining community into Answer Set Programming: Log Generation, Conformance Checking, and Query Checking. For each problem, two versions are addressed, one considering only the control-flow perspective and the other considering also the data perspective. The tool can support companies in analyzing their business processes; it is highly flexible and general, and can be easily modified to address other problems from Declarative Process Mining
Adaptive refinement with locally linearly independent LR B-splines: Theory and applications
In this paper we describe an adaptive refinement strategy for LR B-splines.
The presented strategy ensures, at each iteration, local linear independence of
the obtained set of LR B-splines. This property is then exploited in two
applications: the construction of efficient quasi-interpolation schemes and the
numerical solution of elliptic problems using the isogeometric Galerkin method.Comment: 23 pages, 14 figure
Process mining meets model learning: Discovering deterministic finite state automata from event logs for business process analysis
Within the process mining field, Deterministic Finite State Automata (DFAs) are largely employed as foundation mechanisms to perform formal reasoning tasks over the information contained in the event logs, such as conformance checking, compliance monitoring and cross-organization process analysis, just to name a few. To support the above use cases, in this paper, we investigate how to leverage Model Learning (ML) algorithms for the automated discovery of DFAs from event logs. DFAs can be used as a fundamental building block to support not only the development of process analysis techniques, but also the implementation of instruments to support other phases of the Business Process Management (BPM) lifecycle such as business process design and enactment. The quality of the discovered DFAs is assessed wrt customized definitions of fitness, precision, generalization, and a standard notion of DFA simplicity. Finally, we use these metrics to benchmark ML algorithms against real-life and synthetically generated datasets, with the aim of studying their performance and investigate their suitability to be used for the development of BPM tools
Francisco Patricio, De reyno y de la institucion del que ha de reynar y de como deue auerse con los subditos y ellos con el : donde se traen notables exemplos è historias y dichos agudos y peregrinos ...
Copia digital. Valladolid : Junta de Castilla y LeĂłn. ConsejerĂa de Cultura y Turismo, 2009-2010Sign.: [calderĂłn]4, A4, B-Z8, 2A-2Z8, 3A-3F8, 3G4Port. con esc. xil
A severe case of hemobilia and biliary fistula following an open urgent cholecystectomy
<p>Abstract</p> <p>Background</p> <p>Cholecystectomy has been the treatment of choice for symptomatic gallstones, but remains the greatest source of post-operative biliary injuries. Laparoscopic approach has been recently preferred because of short hospitalisation and low morbidity but has an higher incidence of biliary leakages and bile duct injuries than open one due to a technical error or misinterpretation of the anatomy. Even open cholecystectomy presents a small number of complications especially if it was performed in urgency. Hemobilia is one of the most common cause of upper gastrointestinal bleeding from the biliary ducts into the gastrointestinal tract due to trauma, advent of invasive procedures such as percutaneous liver biopsy, transhepatic cholangiography, and biliary drainage.</p> <p>Methods</p> <p>We report here a case of massive hemobilia in a 60-year-old man who underwent an urgent open cholecystectomy and a subsequent placement of a transhepatic biliary drainage.</p> <p>Conclusion</p> <p>The management of these complications enclose endoscopic, percutaneous and surgical therapies. After a diagnosis of biliary fistula, it's most important to assess the adequacy of bile drainage to determine a controlled fistula and to avoid bile collection and peritonitis. Transarterial embolization is the first line of intervention to stop hemobilia while surgical intervention should be considered if embolization fails or is contraindicated.</p
Italian Guidelines in diagnosis and treatment of alopecia areata
Alopecia areata (AA) is an organ-specific autoimmune disorder that targets anagen phase hair follicles. The course is unpredictable and current available treatments have variable efficacy. Nowadays, there is relatively little evidence on treatment of AA from well-designed clinical trials. Moreover, none of the treatments or devices commonly used to treat AA are specifically approved by the Food and Drug Administration. The Italian Study Group for Cutaneous Annexial Disease of the Italian Society of dermatology proposes these Italian guidelines for diagnosis and treatment of Alopecia Areata deeming useful for the daily management of the disease. This article summarizes evidence-based treatment associated with expert-based recommendations
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