• Retractions onto series-parallel posets

  Dalmau, Víctor; Krokhin, Andrei; Larose, Benoit (Elsevier, 2008)

  The poset retraction problem for a poset P is whether a given poset Q containing P as a subposet admits a retraction onto P, that is, whether there is a homomorphism from Q onto P which fixes every element of P. We study ...
• Majority constraints have bounded pathwidth duality

  Dalmau, Víctor; Krokhin, Andrei (Elsevier, 2008)

  We study certain constraint satisfaction problems which are the problems of deciding whether there exists a homomorphism from a given relational structure to a fixed structure with a majority polymorphism. We show that ...
• Towards a dichotomy theorem for the counting constraint satisfaction problem

  Bulatov, Andrei A.; Dalmau, Víctor (Elsevier, 2007)

  The Counting Constraint Satisfaction Problem (#CSP) can be expressed as follows: given a set of variables, a set of values that can be taken by the variables, and a set of constraints specifying some restrictions on the ...
• Learning intersection-closed classes with signatures

  Bulatov, Andrei; Chen, Hubie; Dalmau, Víctor (Elsevier, 2007)

  Intersection-closed classes of concepts arise naturally in many contexts and have been intensively studied in computational learning theory. In this paper, we study intersection-closed classes that contain the concepts ...
• Planning as heuristic search

  Bonet, Blai; Geffner, Héctor (Elsevier, 2001)

  In the AIPS98 Planning Contest, the hsp planner showed that heuristic search planners can be competitive with state-of-the-art Graphplan and sat planners. Heuristic search planners like hsp transform planning problems into ...
• Phase transitions of PP-complete satisfiability problems

  Bailey, Delbert D.; Dalmau, Víctor; Kolaitis, Phokion G. (Elsevier, 2007)

  The complexity class PP consists of all decision problems solvable by polynomial-time probabilistic Turing machines. It is well known that PP is a highly intractable complexity class and that PP-complete problems are in ...
• CSP duality and trees of bounded pathwidth

  Carvalho, Catarina; Dalmau, Víctor; Krokhin, Andrei (Elsevier, 2010)

  We study non-uniform constraint satisfaction problems definable in monadic Datalog stratified by the use of non-linearity. We show how such problems can be described in terms of homomorphism dualities involving trees of ...
• Technological support for the enactment of collaborative scripted learning activities across multiple spatial locations

  Fuente Valentín, Luis de la; Pérez-Sanagustín, Mar; Hernández-Leo, Davinia; Pardo Sánchez, Abelardo; Blat, Josep; Delgado Kloos, Carlos (Elsevier, 2014)

  Computer Supported Collaborative Blended Learning (CSCBL) scripts are innovative practices that benefit from interactive devices to combine and coordinate activities occurring in different spatial locations. However, the ...
• Sustaining continuous collaborative learning flows in MOOCs: orchestration agent approach

  Amarasinghe, Ishari; Hernández Leo, Davinia; Manathunga, Kalpani; Jonsson, Anders, 1973- (Graz University of Technology. Institut für Informationssysteme und Computer Medien (IICM), 2018)

  Collaborative learning spaces deployed in Massive Open Online Courses (MOOCs) provide productive social learning opportunities. However, sustaining collaboration in these spaces is challenging. This paper provides a ...
• Smartphones or laptops in the collaborative classroom? A study of video-based learning in higher education

  Albó, Laia; Hernández Leo, Davinia; Moreno Oliver, Verónica (Taylor & Francis, 2018)

  This paper explores how the use of smartphones vs. laptops influences students’ engagement, behaviour and experience watching academic videos in a collaborative classroom. Experiments were run in authentic teaching sessions ...
• Fundamentos biológicos en la extracción de regularidades del habla

  Toro Soto, Juan Manuel, 1976- (Konrad Lorenz Fundación Universitaria, 2011)

  Uno de los mayores problemas en el estudio del lenguaje es la comprensión de sus fundamentos biológicos. Una forma de abordar este problema que ha resultado efectiva es la de estudiar hasta qué punto compartimos con otros ...
• On the overlap between bilingual language control and domain-general executive control

  Branzi, Francesca Martina, 1984-; Calabria, Marco; Boscarino, Maria Lucrezia; Costa, Albert (Elsevier, 2016)

  We explored the overlap between bilingual language control (bLC) and domain-general executive control (EC) by focusing on inhibitory control processes. We tested 62 bilinguals in linguistic and non-linguistic switching ...
• Report of the results of an IMS Learning Design Expert Workshop

  Neumann, S.; Klebl, M.; Griffiths Jenkins, David; Hernández Leo, Davinia; de la Fuente Valentín, L.; Hummel, H.; Brouns, F.; Derntl, Michael; Oberhuemer, P. (International Association of Online Engineering, 2010)

  Europe has seen a number of learning design initiatives in the past years. Among them are the Open University UK Learning Design Initiative, JISC’s Design for Learning Programme, as well as the Open University of the ...
• Irreversible electroporation for the treatment of cardiac arrhythmias

  Sugrue, Alan; Maor, Elad; Ivorra Cano, Antoni, 1974-; Vaidya, Vaibhav; Witt, Chance; Kapa, Suraj; Asirvatham, Samuel (Taylor & Francis, 2018)

  Cardiac ablation is an established treatment modality for the management of patients with cardiac arrhythmias. Current approaches to cardiac ablation employ thermal based energy to achieve lesions (damage) within the ...
• Stochastic transitions into silence cause noise correlations in cortical circuits

  Mochol, Gabriela; Hermoso Mendizabal, Ainhoa; Sakata, Shuzo; Harris, Kenneth D.; De la Rocha, Jaime (National Academy of Sciences, 2015)

  The spiking activity of cortical neurons is highly variable. This variability is generally correlated among nearby neurons, an effect commonly interpreted to reflect the coactivation of neurons due to anatomically shared ...
• A Parabolic quasilinear problem for linear growth functionals

  Andreu, Fuensanta; Caselles, Vicente; Mazón, José (European Mathematical Society (EMS), 2002)

  We prove existence and uniqueness of solutions for the Dirichlet problem for quasilinear parabolic equations in divergent form for which the energy functional has linear growth. A typical example of energy functional we ...
• The Total variation flow in RN

  Bellettini, Giovanni; Caselles, Vicente; Novaga, Matteo (Elsevier, 2002)

  In this paper, we study the minimizing total variation flow ut=div(Du/∣Du∣) in N for initial data u0 in Lloc1(N), proving an existence and uniqueness result. Then we characterize all bounded sets Ω of finite perimeter in ...
• Total variation and cheeger sets in Gauss space

  Caselles, Vicente; Miranda, Michele; Novaga, Matteo (Elsevier, 2010)

  The aim of this paper is to study the isoperimetric problem with fixed volume inside convex sets and other related geometric variational problems in the Gauss space, in both the finite and infinite dimensional case. We ...
• Uniqueness of the cheeger set of a convex body

  Alter, François; Caselles, Vicente (Springer, 2009)

  We prove that if C C RN is an open bounded convex set, then there is only one Cheeger set inside C and it is convex. A Cheeger set of C is a set which minimizes the ratio perimeter over volume among all subsets of C.
• Some remarks on uniqueness and regularity of cheeger sets

  Caselles, Vicente; Chambolle, Antonin; Novaga, Matteo (European Mathematical Society (EMS), 2010)

  We show that generically the subsets of RN with finite volume RN have a unique Cheeger set, in the sense that there always exists a nearby set which has a unique Cheeger set. We also prove that Cheeger sets are C1,1, when ...

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