A Multicore Tool for Constraint Solving

*** To appear in IJCAI 2015 proceedings *** In Constraint Programming (CP), a portfolio solver uses a variety of different solvers for solving a given Constraint Satisfaction / Optimization Problem. In this paper we introduce sunny-cp2: the first parallel CP portfolio solver that enables a dynamic, cooperative, and simultaneous execution of its solvers in a multicore setting. It incorporates state-of-the-art solvers, providing also a usable and configurable framework. Empirical results are very promising. sunny-cp2 can even outperform the performance of the oracle solver which always selects the best solver of the portfolio for a given problem

Solving XCSP problems by using Gecode

Gecode is one of the most efficient libraries that can be used for constraint solving. However, using it requires dealing with C++ programming details. On the other hand several formats for representing constraint networks have been proposed. Among them, XCSP has been proposed as a format based on XML which allows us to represent constraints defined either extensionally or intensionally, permits global constraints and has been the standard format of the international competition of constraint satisfaction problems solvers. In this paper we present a plug-in for solving problems specified in XCSP by exploiting the Gecode solver. This is done by dynamically translating constraints into Gecode library calls, thus avoiding the need to interact with C++.Comment: 5 pages, http://ceur-ws.org/Vol-810 CILC 201

SUNNY-CP and the MiniZinc Challenge

In Constraint Programming (CP) a portfolio solver combines a variety of different constraint solvers for solving a given problem. This fairly recent approach enables to significantly boost the performance of single solvers, especially when multicore architectures are exploited. In this work we give a brief overview of the portfolio solver sunny-cp, and we discuss its performance in the MiniZinc Challenge---the annual international competition for CP solvers---where it won two gold medals in 2015 and 2016. Under consideration in Theory and Practice of Logic Programming (TPLP)Comment: Under consideration in Theory and Practice of Logic Programming (TPLP

Wormlike reverse micelles in lecithin/bile salt/water mixtures in oil

Knowing the ability of water and bile salts to promote the reverse wormlike micelle growth in lecithin/water or lecithin/bile salt mixtures in oil, this work was aimed at elucidating the association properties of the three solutes lecithin, water and the bile salt (BS) sodium deoxycholate in cyclohexane. By systematically changing the fraction of the two additives (i.e.: water and BS) we could identify a region at low additive/lecithin molar ratios where stable wormlike micelle dispersions were formed. Small angle X-ray scattering and oscillatory rheology measurements demonstrated that the ability of bile salt and water to transform the originally spherical lecithin reverse micelles into wormlike micelles and thereby impart to the sample viscoelastic properties is preserved in the three-solute mixture. The results suggest that reverse micelle including both bile salt and water are formed in this system. Reasonably the two primers interact with the same region of the lecithin headgroups and are complementary in altering the packing parameter of the amphiphile to values suitable for the formation of cylindrical aggregates

Dynamic Choreographies - Safe Runtime Updates of Distributed Applications

Programming distributed applications free from communication deadlocks and races is complex. Preserving these properties when applications are updated at runtime is even harder. We present DIOC, a language for programming distributed applications that are free from deadlocks and races by construction. A DIOC program describes a whole distributed application as a unique entity (choreography). DIOC allows the programmer to specify which parts of the application can be updated. At runtime, these parts may be replaced by new DIOC fragments from outside the application. DIOC programs are compiled, generating code for each site, in a lower-level language called DPOC. We formalise both DIOC and DPOC semantics as labelled transition systems and prove the correctness of the compilation as a trace equivalence result. As corollaries, DPOC applications are free from communication deadlocks and races, even in presence of runtime updates.Comment: Technical Repor

Dynamic Choreographies: Theory And Implementation

Programming distributed applications free from communication deadlocks and race conditions is complex. Preserving these properties when applications are updated at runtime is even harder. We present a choreographic approach for programming updatable, distributed applications. We define a choreography language, called Dynamic Interaction-Oriented Choreography (AIOC), that allows the programmer to specify, from a global viewpoint, which parts of the application can be updated. At runtime, these parts may be replaced by new AIOC fragments from outside the application. AIOC programs are compiled, generating code for each participant in a process-level language called Dynamic Process-Oriented Choreographies (APOC). We prove that APOC distributed applications generated from AIOC specifications are deadlock free and race free and that these properties hold also after any runtime update. We instantiate the theoretical model above into a programming framework called Adaptable Interaction-Oriented Choreographies in Jolie (AIOCJ) that comprises an integrated development environment, a compiler from an extension of AIOCs to distributed Jolie programs, and a runtime environment to support their execution.Comment: arXiv admin note: text overlap with arXiv:1407.097

Decidability properties for fragments of CHR

We study the decidability of termination for two CHR dialects which, similarly to the Datalog like languages, are defined by using a signature which does not allow function symbols (of arity >0). Both languages allow the use of the = built-in in the body of rules, thus are built on a host language that supports unification. However each imposes one further restriction. The first CHR dialect allows only range-restricted rules, that is, it does not allow the use of variables in the body or in the guard of a rule if they do not appear in the head. We show that the existence of an infinite computation is decidable for this dialect. The second dialect instead limits the number of atoms in the head of rules to one. We prove that in this case, the existence of a terminating computation is decidable. These results show that both dialects are strictly less expressive than Turing Machines. It is worth noting that the language (without function symbols) without these restrictions is as expressive as Turing Machines

Structural and dynamical modeling of WINGS clusters. I. The distribution of cluster galaxies of different morphological classes within regular and irregular clusters

[Abridged] We use the WINGS database to select a sample of 67 nearby galaxy clusters with at least 30 spectroscopic members each. 53 of these clusters do not show evidence of substructures in phase-space, while 14 do. We estimate the virial radii and circular velocities of the 67 clusters by a variety of proxies (velocity dispersion, X-ray temperature, and richness) and use these estimates to build stack samples from these 53 and 14 clusters ('Reg' and 'Irr' stacks, respectively). We determine the number-density and velocity-dispersion profiles (VDPs) of E, S0, and Sp+Irr (S) galaxies in the Reg and Irr samples, separately, and fit models to these profiles. The number density profiles of E, S0, and S galaxies are adequately described by either a NFW or a cored King model, both for the Reg and Irr samples, with a slight preference for the NFW model. The spatial distribution concentration increases from the S to the S0 and to the E populations, both in the Reg and the Irr stacks, reflecting the well-known morphology-radius relation. Reg clusters have a more concentrated spatial distribution of E and S0 galaxies than Irr clusters, while the spatial distributions of S galaxies in Reg and Irr clusters are similar. We propose a new phenomenological model that provides acceptable fits to the VDP of all our galaxy samples. The VDPs become steeper and with a higher normalization from E to S0 to S galaxies. The S0 VDP is close to that of E galaxies in Reg clusters, and intermediate between those of E and S galaxies in Irr clusters. Our results suggest that S galaxies are a recently accreted cluster population, that take less than 3 Gyr to evolve into S0 galaxies after accretion, and in doing so modify their phase-space distribution, approaching that of cluster ellipticals. While in Reg clusters this evolutionary process is mostly completed, it is still ongoing in Irr clusters.Comment: A&A, in press - 11 pages, 9 figures, 4 table

Genetic traceability of cinta senese pig (Sus scrofa domesticus L.): a study of the meat and processed products by microsatellite markers

Traceability based on DNA analysis is attracting increasing interest due to the crisis of confidence that consumers show towards the products of animal origin. The present work discusses a genetic traceability system of meat and processed products from an historical Tuscan native pig breed, the Cinta Senese. The study is based on a panel of 8 ISAG (International Society for Animal Genetics) DNA microsatellite markers usage done both on pigs and derived products. The SSRs panel allowed us to obtain a unique fingerprint of the individuals to be used as a tracer “downstream” in the processed products. The molecular method used proved that the hams, analyzed just before commercialization, were obtained from Cinta Senese pigs and that the analyzed meat products derived from the Cinta Senese were produced at least with 95% of Cinta Senese meat. In perspective, the molecular testing could be introduced as a voluntarily adopted method for proving intrinsic quality of many regional food products

Automatic Deployment of Services in the Cloud with Aeolus Blender

International audienceWe present Aeolus Blender (Blender in the following), a software product for the automatic deployment and configuration of complex service-based, distributed software systems in the " cloud ". By relying on a configuration optimiser and a deployment planner, Blender fully automates the deployment of real-life applications on OpenStack cloud deployments , by exploiting a knowledge base of software services provided by the Mandriva Armonic tool suite. The final deployment is guaranteed to satisfy not only user requirements and relevant software dependencies , but also to be optimal with respect to the number of used virtual machines