Capítols de llibre
http://hdl.handle.net/2117/3097
Mon, 30 Nov 2020 08:29:39 GMT2020-11-30T08:29:39ZDecomposed process discovery and conformance checking
http://hdl.handle.net/2117/178875
Decomposed process discovery and conformance checking
Carmona Vargas, Josep
Decomposed process discovery and decomposed conformance checking are the corresponding variants of the two monolithic fundamental problems in process mining (van der Aalst 2011): automated process discovery, which considers the problem of discovering a process model from an event log (Leemans 2009), and conformance checking, which addresses the problem of analyzing the adequacy of a process model with respect to observed behavior (Munoz-Gama 2009), respectively.
The term decomposed in the two definitions is mainly describing the way the two problems are tackled operationally, to face their computational complexity by splitting the initial problem into smaller problems, that can be solved individually and often more efficiently.
Fri, 28 Feb 2020 11:16:44 GMThttp://hdl.handle.net/2117/1788752020-02-28T11:16:44ZCarmona Vargas, JosepDecomposed process discovery and decomposed conformance checking are the corresponding variants of the two monolithic fundamental problems in process mining (van der Aalst 2011): automated process discovery, which considers the problem of discovering a process model from an event log (Leemans 2009), and conformance checking, which addresses the problem of analyzing the adequacy of a process model with respect to observed behavior (Munoz-Gama 2009), respectively.
The term decomposed in the two definitions is mainly describing the way the two problems are tackled operationally, to face their computational complexity by splitting the initial problem into smaller problems, that can be solved individually and often more efficiently.Petri net analysis using boolean manipulation
http://hdl.handle.net/2117/134309
Petri net analysis using boolean manipulation
Pastor Llorens, Enric; Roig Mansilla, Oriol; Cortadella, Jordi; Badia Sala, Rosa Maria
This paper presents a novel analysis approach for bounded Petri nets. The net behavior is modeled by boolean functions, thus reducing reasoning about Petri nets to boolean calculation. The state explosion problem is managed by using Binary Decision Diagrams (BDDs), which are capable to represent large sets of markings in small data structures. The ability of Petri nets to model systems, the flexibility and generality of boolean algebras, and the efficient implementation of BDDs, provide a general environment to handle a large variety of problems. Examples are presented that show how all the reachable states (1018) of a Petri net can be efficiently calculated and represented with a small BDD (103 nodes). Properties requiring an exhaustive analysis of the state space can be verified in polynomial time in the size of the BDD.
Wed, 12 Jun 2019 09:58:35 GMThttp://hdl.handle.net/2117/1343092019-06-12T09:58:35ZPastor Llorens, EnricRoig Mansilla, OriolCortadella, JordiBadia Sala, Rosa MariaThis paper presents a novel analysis approach for bounded Petri nets. The net behavior is modeled by boolean functions, thus reducing reasoning about Petri nets to boolean calculation. The state explosion problem is managed by using Binary Decision Diagrams (BDDs), which are capable to represent large sets of markings in small data structures. The ability of Petri nets to model systems, the flexibility and generality of boolean algebras, and the efficient implementation of BDDs, provide a general environment to handle a large variety of problems. Examples are presented that show how all the reachable states (1018) of a Petri net can be efficiently calculated and represented with a small BDD (103 nodes). Properties requiring an exhaustive analysis of the state space can be verified in polynomial time in the size of the BDD.A compositional method for the synthesis of asynchronous communication mechanisms
http://hdl.handle.net/2117/133432
A compositional method for the synthesis of asynchronous communication mechanisms
Costa Gorgônio, Kyller; Cortadella, Jordi; Xia, Fei
Asynchronous data communication mechanisms (ACMs) have been extensively studied as data connectors between independently timed concurrent processes. In previous work, an automatic ACM synthesis method based on the generation of the reachability graph and the theory of regions was proposed. In this paper, we propose a new synthesis method based on the composition of Petri net modules, avoiding the exploration of the reachability graph. The behavior of ACMs is formally defined and correctness properties are specified in CTL. Model checking is used to verify the correctness of the Petri net models. The algorithms to generate the Petri net models are presented. Finally, a method to automatically generate C++ source code from the Petri net model is described.
Fri, 24 May 2019 09:28:17 GMThttp://hdl.handle.net/2117/1334322019-05-24T09:28:17ZCosta Gorgônio, KyllerCortadella, JordiXia, FeiAsynchronous data communication mechanisms (ACMs) have been extensively studied as data connectors between independently timed concurrent processes. In previous work, an automatic ACM synthesis method based on the generation of the reachability graph and the theory of regions was proposed. In this paper, we propose a new synthesis method based on the composition of Petri net modules, avoiding the exploration of the reachability graph. The behavior of ACMs is formally defined and correctness properties are specified in CTL. Model checking is used to verify the correctness of the Petri net models. The algorithms to generate the Petri net models are presented. Finally, a method to automatically generate C++ source code from the Petri net model is described.Nature inspired meta-heuristics for grid scheduling: single and multi-objective optimization approaches
http://hdl.handle.net/2117/128951
Nature inspired meta-heuristics for grid scheduling: single and multi-objective optimization approaches
Abraham, Ajith; Liu, Hongbo; Grosan, Crina; Xhafa Xhafa, Fatos
In this chapter, we review a few important concepts from Grid computing related to scheduling problems and their resolution using heuristic and meta-heuristic approaches. Scheduling problems are at the heart of any Grid-like computational system. Different types of scheduling based on different criteria, such as static vs. dynamic environment, multi-objectivity, adaptivity, etc., are identified. Then, heuristics and meta-heuristics methods for scheduling in Grids are presented. The chapter reveals the complexity of the scheduling problem in Computational Grids when compared to scheduling in classical parallel and distributed systems and shows the usefulness of heuristics and meta-heuristics approaches for the design of efficient Grid schedulers.
Tue, 12 Feb 2019 12:33:02 GMThttp://hdl.handle.net/2117/1289512019-02-12T12:33:02ZAbraham, AjithLiu, HongboGrosan, CrinaXhafa Xhafa, FatosIn this chapter, we review a few important concepts from Grid computing related to scheduling problems and their resolution using heuristic and meta-heuristic approaches. Scheduling problems are at the heart of any Grid-like computational system. Different types of scheduling based on different criteria, such as static vs. dynamic environment, multi-objectivity, adaptivity, etc., are identified. Then, heuristics and meta-heuristics methods for scheduling in Grids are presented. The chapter reveals the complexity of the scheduling problem in Computational Grids when compared to scheduling in classical parallel and distributed systems and shows the usefulness of heuristics and meta-heuristics approaches for the design of efficient Grid schedulers.Parallel algorithms for two processors precedence constraint scheduling
http://hdl.handle.net/2117/104935
Parallel algorithms for two processors precedence constraint scheduling
Serna Iglesias, María José
The final publication is available at link.springer.com
Fri, 26 May 2017 14:27:35 GMThttp://hdl.handle.net/2117/1049352017-05-26T14:27:35ZSerna Iglesias, María JoséRandomized parallel approximations to max flow
http://hdl.handle.net/2117/104934
Randomized parallel approximations to max flow
Serna Iglesias, María José
The final publication is available at link.springer.com
Fri, 26 May 2017 14:21:33 GMThttp://hdl.handle.net/2117/1049342017-05-26T14:21:33ZSerna Iglesias, María JoséContinuous assessment in the evolution of a CS1 course: The pass rate/workload ratio
http://hdl.handle.net/2117/83244
Continuous assessment in the evolution of a CS1 course: The pass rate/workload ratio
Blesa Aguilera, Maria Josep; Duch Brown, Amalia; Gabarró Vallès, Joaquim; Petit Silvestre, Jordi; Serna Iglesias, María José
The first programming course (Programming-1, CS1) in the Informatics Engineering Degree of the Facultat d'Informàtica de Barcelona was completely redesigned in 2006 in order to reinforce the learn-by-
doing methodology. Along the following eight years several pedagogical measures - mostly related with continous assessment - were introduced with the aim of increasing the pass rate of the course without lowering its high quality standards. This paper analyzes to what extent the added workload on faculty entailed by these measures affects the pass rate. We use a classical marginal cost-benefit approach - from Economics - to compare these two values along time. This process allows us to relate the evolution of the pass rate of students with the workload of the faculty through a productivity curve, as well as to assess the impact of each pedagogical measure. We conclude that, for this course, continuous assessment is expensive. In fact, abstracting from short term oscillations, the slope of the productivity curve is close to zero.
Mon, 22 Feb 2016 14:50:53 GMThttp://hdl.handle.net/2117/832442016-02-22T14:50:53ZBlesa Aguilera, Maria JosepDuch Brown, AmaliaGabarró Vallès, JoaquimPetit Silvestre, JordiSerna Iglesias, María JoséThe first programming course (Programming-1, CS1) in the Informatics Engineering Degree of the Facultat d'Informàtica de Barcelona was completely redesigned in 2006 in order to reinforce the learn-by-
doing methodology. Along the following eight years several pedagogical measures - mostly related with continous assessment - were introduced with the aim of increasing the pass rate of the course without lowering its high quality standards. This paper analyzes to what extent the added workload on faculty entailed by these measures affects the pass rate. We use a classical marginal cost-benefit approach - from Economics - to compare these two values along time. This process allows us to relate the evolution of the pass rate of students with the workload of the faculty through a productivity curve, as well as to assess the impact of each pedagogical measure. We conclude that, for this course, continuous assessment is expensive. In fact, abstracting from short term oscillations, the slope of the productivity curve is close to zero.