New basal Odonatoptera (Insecta) from the lower Carboniferous (Serpukhovian) of Argentina

Nuevos Odonatoptera basales del Serpukhoviano superior (325-324 Ma) son descriptos de la localidad Guandacol 1, Quebrada de las Libélulas, Formación Guandacol, provincia de La Rioja, centro oeste de la Argentina. Otras dos especies conocidas del Serpukhoviano, Eugeropteron lunatum Riek, 1983 y Geropteron arcuatum Riek, 1983, de Cuestita de La Herradura, Formación Malanzán, provincia de La Rioja, son discutidas. Varios taxones de orden superior nuevos son nominados para incluir estas especies, resultando en una nueva clasificación: 1 Superorden Odonatoptera, 1.1 Eugeroptera ord. nov., 1.1.1 Eugeropteridae, 1.1.1.1 Eugeropteron, 1.1.1.1.1 Eugeropteron lunatum, 1.1.1.1.2 Tupacsala niunamenos gen. nov. et sp. nov., 1.2 Palaeodonatoptera taxon nov., 1.2.1 Kukaloptera ord. nov., 1.2.1.1 Kirchneralidae fam. nov., 1.2.1.1.1 Kirchnerala treintamil gen. nov. et sp. nov., 1.2.2 Plesiodonatoptera taxon nov., 1.2.2.1 Argentinoptera ord. nov., 1.2.2.1.1 Argentinalidae fam. nov., 1.2.2.1.1.1 Argentinala cristinae gen. nov. et sp. nov., 1.2.2.2 Apodonatoptera taxon nov., 1.2.2.2.1 Orden Geroptera, 1.2.2.2.1.1 Geropteridae fam. nov., 1.2.2.2.1.1.1 Geropteron, 1.2.2.2.1.1.1.1 Geropteron arcuatum, 1.2.2.2.2 Neodonatoptera.Three new basal species of Odonatoptera from the upper Serpukhovian (325-324 Ma) of Guandacol 1 locality, Quebrada de las Libélulas, Guandacol Formation, La Rioja province, central West Argentina, are described. Two known species also from the Serpukhovian, Eugeropteron lunatum Riek, 1983 and Geropteron arcuatum Riek, 1983, from Cuestita de La Herradura, Malanzán Formation, La Rioja province, are discussed. Several higher taxa are nominated to include these species, resulting in a new classification: 1 Superorder Odonatoptera, 1.1 Eugeroptera ord. nov., 1.1.1 Eugeropteridae, 1.1.1.1 Eugeropteron, 1.1.1.1.1 Eugeropteron lunatum, 1.1.1.1.2 Tupacsala niunamenos gen. nov. et sp. nov., 1.2 Palaeodonatoptera taxon nov., 1.2.1 Kukaloptera ord. nov., 1.2.1.1 Kirchneralidae fam. nov., 1.2.1.1.1 Kirchnerala treintamil gen. nov. et sp. nov., 1.2.2 Plesiodonatoptera taxon nov., 1.2.2.1 Argentinoptera ord. nov., 1.2.2.1.1 Argentinalidae fam. nov., 1.2.2.1.1.1 Argentinala cristinae gen. nov. et sp. nov., 1.2.2.2 Apodonatoptera taxon nov., 1.2.2.2.1 Order Geroptera, 1.2.2.2.1.1 Geropteridae fam. nov., 1.2.2.2.1.1.1 Geropteron, 1.2.2.2.1.1.1.1 Geropteron arcuatum, 1.2.2.2.2 Neodonatoptera.Fil: Petrulevicius, Julian Fernando. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Gutierrez, Pedro Raul. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentin

The \mu-Calculus Alternation Hierarchy Collapses over Structures with Restricted Connectivity

It is known that the alternation hierarchy of least and greatest fixpoint operators in the mu-calculus is strict. However, the strictness of the alternation hierarchy does not necessarily carry over when considering restricted classes of structures. A prominent instance is the class of infinite words over which the alternation-free fragment is already as expressive as the full mu-calculus. Our current understanding of when and why the mu-calculus alternation hierarchy is not strict is limited. This paper makes progress in answering these questions by showing that the alternation hierarchy of the mu-calculus collapses to the alternation-free fragment over some classes of structures, including infinite nested words and finite graphs with feedback vertex sets of a bounded size. Common to these classes is that the connectivity between the components in a structure from such a class is restricted in the sense that the removal of certain vertices from the structure's graph decomposes it into graphs in which all paths are of finite length. Our collapse results are obtained in an automata-theoretic setting. They subsume, generalize, and strengthen several prior results on the expressivity of the mu-calculus over restricted classes of structures.Comment: In Proceedings GandALF 2012, arXiv:1210.202

Breve memoria acerca del origen conservación y límites del Obispado de Astorga

Copia digital. Valladolid : Junta de Castilla y León. Consejería de Cultura y Turismo, 2010-201

Parallelization of a Six Degree of Freedom Entry Vehicle Trajectory Simulation Using OpenMP and OpenACC

The art and science of writing parallelized software, using methods such as Open Multi-Processing (OpenMP) and Open Accelerators (OpenACC), is dominated by computer scientists. Engineers and non-computer scientists looking to apply these techniques to their project applications face a steep learning curve, especially when looking to adapt their original single threaded software to run multi-threaded on graphics processing units (GPUs). There are significant changes in mindset that must occur; such as how to manage memory, the organization of instructions, and the use of if statements (also known as branching). The purpose of this work is twofold: 1) to demonstrate the applicability of parallelized coding methodologies, OpenMP and OpenACC, to tasks outside of the typical large scale matrix mathematics; and 2) to discuss, from an engineers perspective, the lessons learned from parallelizing software using these computer science techniques. This work applies OpenMP, on both multi-core central processing units (CPUs) and Intel Xeon Phi 7210, and OpenACC on GPUs. These parallelization techniques are used to tackle the simulation of thousands of entry vehicle trajectories through the integration of six degree of freedom (DoF) equations of motion (EoM). The forces and moments acting on the entry vehicle, and used by the EoM, are estimated using multiple models of varying levels of complexity. Several benchmark comparisons are made on the execution of six DoF trajectory simulation: single thread Intel Xeon E5-2670 CPU, multi-thread CPU using OpenMP, multi-thread Xeon Phi 7210 using OpenMP, and multi-thread NVIDIA Tesla K40 GPU using OpenACC. These benchmarks are run on the Pleiades Supercomputer Cluster at the National Aeronautics and Space Administration (NASA) Ames Research Center (ARC), and a Xeon Phi 7210 node at NASA Langley Research Center (LaRC)

On fixpoint logics and equivalences for processes with restricted nondeterminism

In concurrency, processes can be studied using a partial order or an interleaving semantics. In partial order semantics, at least four different kinds of behaviour can be recognized: concurrency, causality, conflict and confusion. In interleaving semantics, only conflicts can be observed. All these features can be characterized in logical terms, and various logics have been defined for this purpose. For instance, Hennessy–Milner logic is a modal language that captures strong bisimilarity, the standard bisimulation equivalence for processes with interleaving semantics. However, when considering processes with partial order semantics, stronger equivalences are used and more discriminating logics are needed. In the present article, we study conditions to ease the definition of such logics and equivalences for processes with partial order semantics. More specifically, we study the impact that nondeterminism can have on some fixpoint modal logics and bisimulation equivalences for concurrent and multi-agent systems, when it is systematically restricted within the four kinds of behaviours mentioned above. Our results show that when the concurrency and confusion relations are taken to be deterministic, then the main equivalence for causal behaviour can be completely captured (even in logical and game-theoretic terms) by a simpler, weaker, more local bisimulation relation. We also provide key examples of the kinds of processes that can be modelled using deterministic confusion to illustrate the expressive power of the general framework defined here

On the determinacy of concurrent games on event structures with infinite winning sets

We consider nondeterministic concurrent games played on event structures and study their determinacy problem—the existence of winning strategies. It is known that when the winning conditions of the games are characterised by a collection of finite winning sets/plays, a restriction (called race-freedom) on the boards where the games are played guarantees determinacy. However the games may no longer be determined when the winning sets are infinite. This paper provides a study of concurrent games and nondeterministic winning strategies by analysing conditions that ensure determinacy when infinitely many events are played, that is, when the winning sets are infinite. The main result is a determinacy theorem for a class of games with a bounded concurrency property and infinite winning sets shown to be finitely decidable