379 research outputs found

    Observation of implicit complexity by non confluence

    Get PDF
    We propose to consider non confluence with respect to implicit complexity. We come back to some well known classes of first-order functional program, for which we have a characterization of their intentional properties, namely the class of cons-free programs, the class of programs with an interpretation, and the class of programs with a quasi-interpretation together with a termination proof by the product path ordering. They all correspond to PTIME. We prove that adding non confluence to the rules leads to respectively PTIME, NPTIME and PSPACE. Our thesis is that the separation of the classes is actually a witness of the intentional properties of the initial classes of programs

    Follow-up monitoring in a cat with leishmaniosis and coinfections with Hepatozoon felis and ‘Candidatus Mycoplasma haemominutum’

    Get PDF
    Case summary A 6-year-old female neutered domestic shorthair cat from Cyprus was presented with multiple ulcerated skin nodules. Cytology and histopathology of the lesions revealed granulomatous dermatitis with intracytoplasmic organisms, consistent with amastigotes of Leishmania species. Biochemistry identified a mild hyperproteinaemia. Blood extraction and PCR detected Leishmania species, Hepatozoon species and ‘Candidatus Mycoplasma haemominutum’ (CMhm) DNA. Subsequent sequencing identified Hepatozoon felis. Additionally, the rRNA internal transcribed spacer 1 locus of Leishmania infantum was partially sequenced and phylogeny showed it to cluster with species derived from dogs in Italy and Uzbekistan, and a human in France. Allopurinol treatment was administered for 6 months. Clinical signs resolved in the second month of treatment with no deterioration 8 months post-treatment cessation. Quantitative PCR and ELISA were used to monitor L infantum blood DNA and antibody levels. The cat had high L infantum DNA levels pretreatment that gradually declined during treatment but increased 8 months post-treatment cessation. Similarly, ELISA revealed high levels of antibodies pretreatment, which gradually declined during treatment and increased slightly 8 months post-treatment cessation. The cat remained PCR positive for CMhm and Hepatozoon species throughout the study. There was no clinical evidence of relapse 24 months post-treatment. Relevance and novel information To our knowledge, this is the first clinical report of a cat with leishmaniosis with H felis and CMhm coinfections. The high L infantum DNA levels post-treatment cessation might indicate that although the lesions had resolved, prolonged or an alternative treatment could have been considere

    Exploring the role of professional associations in collective learning in London and New York's advertising and law professional service firm clusters.

    Get PDF
    The value of regional economies for collective learning has been reported by numerous scholars. However often work has been criticised for lacking analytical clarity and failing to explore the architectures of collective learning and the role of the knowledge produced in making firms in a cluster economy successful. This paper engages with these problematics and investigates how collective learning is facilitated in the advertising and law professional service firm clusters in London and New York. It explores the role of professional associations and investigates how they mediate a collective learning process in each city. It argues that professional associations seed urban communities of practice that emerge outside of the formal activities of professional associations. In these communities individual with shared interests in advertising and law learn from one-another and are therefore able to adapt and evolve one-another approaches to common industry challenges. The paper suggests this is another form of the variation Marshall highlighted in relation to cluster-based collective learning. The paper also shows how the collective learning process is affected by the presence, absence and strength of an institutional thickness. It is therefore argued that a richer understanding of institutional affects is needed in relation to CL

    Abstract Canonical Inference

    Full text link
    An abstract framework of canonical inference is used to explore how different proof orderings induce different variants of saturation and completeness. Notions like completion, paramodulation, saturation, redundancy elimination, and rewrite-system reduction are connected to proof orderings. Fairness of deductive mechanisms is defined in terms of proof orderings, distinguishing between (ordinary) "fairness," which yields completeness, and "uniform fairness," which yields saturation.Comment: 28 pages, no figures, to appear in ACM Trans. on Computational Logi

    Regular Topologies for Gigabit Wide-Area Networks

    Get PDF
    In general terms, this project aimed at the analysis and design of techniques for very high-speed networking. The formal objectives of the project were to: (1) Identify switch and network technologies for wide-area networks that interconnect a large number of users and can provide individual data paths at gigabit/s rates; (2) Quantitatively evaluate and compare existing and proposed architectures and protocols, identify their strength and growth potentials, and ascertain the compatibility of competing technologies; and (3) Propose new approaches to existing architectures and protocols, and identify opportunities for research to overcome deficiencies and enhance performance. The project was organized into two parts: 1. The design, analysis, and specification of techniques and protocols for very-high-speed network environments. In this part, SRI has focused on several key high-speed networking areas, including Forward Error Control (FEC) for high-speed networks in which data distortion is the result of packet loss, and the distribution of broadband, real-time traffic in multiple user sessions. 2. Congestion Avoidance Testbed Experiment (CATE). This part of the project was done within the framework of the DARTnet experimental T1 national network. The aim of the work was to advance the state of the art in benchmarking DARTnet's performance and traffic control by developing support tools for network experimentation, by designing benchmarks that allow various algorithms to be meaningfully compared, and by investigating new queueing techniques that better satisfy the needs of best-effort and reserved-resource traffic. This document is the final technical report describing the results obtained by SRI under this project. The report consists of three volumes: Volume 1 contains a technical description of the network techniques developed by SRI in the areas of FEC and multicast of real-time traffic. Volume 2 describes the work performed under CATE. Volume 3 contains the source code of all software developed under CATE

    Variant-Based Decidable Satisfiability in Initial Algebras with Predicates

    Get PDF
    [EN] Decision procedures can be either theory-specific, e.g., Presburger arithmetic, or theory-generic, applying to an infinite number of user-definable theories. Variant satisfiability is a theory-generic procedure for quantifier-free satisfiability in the initial algebra of an order-sorted equational theory (¿,E¿B) under two conditions: (i) E¿B has the finite variant property and B has a finitary unification algorithm; and (ii) (¿,E¿B) protects a constructor subtheory (¿,E¿¿B¿) that is OS-compact. These conditions apply to many user-definable theories, but have a main limitation: they apply well to data structures, but often do not hold for user-definable predicates on such data structures. We present a theory-generic satisfiability decision procedure, and a prototype implementation, extending variant-based satisfiability to initial algebras with user-definable predicates under fairly general conditions.Partially supported by NSF Grant CNS 14-09416, NRL under contract number N00173-17-1-G002, the EU (FEDER), Spanish MINECO project TIN2015-69175- C4-1-R and GV project PROMETEOII/2015/013. Ra´ul Guti´errez was also supported by INCIBE program “Ayudas para la excelencia de los equipos de investigaci´on avanzada en ciberseguridad”.Gutiérrez Gil, R.; Meseguer, J. (2018). Variant-Based Decidable Satisfiability in Initial Algebras with Predicates. Lecture Notes in Computer Science. 10855:306-322. https://doi.org/10.1007/978-3-319-94460-9_18S30632210855Armando, A., Bonacina, M.P., Ranise, S., Schulz, S.: New results on rewrite-based satisfiability procedures. TOCL 10(1), 4 (2009)Armando, A., Ranise, S., Rusinowitch, M.: A rewriting approach to satisfiability procedures. I&C 183(2), 140–164 (2003)Barrett, C., Shikanian, I., Tinelli, C.: An abstract decision procedure for satisfiability in the theory of inductive data types. JSAT 3, 21–46 (2007)Bouchard, C., Gero, K.A., Lynch, C., Narendran, P.: On forward closure and the finite variant property. In: Fontaine, P., Ringeissen, C., Schmidt, R.A. (eds.) FroCoS 2013. LNCS (LNAI), vol. 8152, pp. 327–342. Springer, Heidelberg (2013). https://doi.org/10.1007/978-3-642-40885-4_23Bradley, A.R., Manna, Z.: The Calculus of Computation - Decision Procedures with Applications to Verification. Springer, Heidelberg (2007). https://doi.org/10.1007/978-3-540-74113-8Cholewa, A., Meseguer, J., Escobar, S.: Variants of variants and the finite variant property. Technical report, CS Dept. University of Illinois at Urbana-Champaign (2014). http://hdl.handle.net/2142/47117Ciobaca., S.: Verification of composition of security protocols with applications to electronic voting. Ph.D. thesis, ENS Cachan (2011)Comon, H.: Complete axiomatizations of some quotient term algebras. TCS 118(2), 167–191 (1993)Comon-Lundh, H., Delaune, S.: The finite variant property: how to get rid of some algebraic properties. In: Giesl, J. (ed.) RTA 2005. LNCS, vol. 3467, pp. 294–307. Springer, Heidelberg (2005). https://doi.org/10.1007/978-3-540-32033-3_22Dershowitz, N., Jouannaud, J.P.: Rewrite systems. In: Handbook of Theoretical Computer Science, North-Holland, vol. B, pp. 243–320 (1990)Dovier, A., Piazza, C., Rossi, G.: A uniform approach to constraint-solving for lists, multisets, compact lists, and sets. TOCL 9(3), 15 (2008)Dross, C., Conchon, S., Kanig, J., Paskevich, A.: Adding decision procedures to SMT solvers using axioms with triggers. JAR 56(4), 387–457 (2016)Escobar, S., Sasse, R., Meseguer, J.: Folding variant narrowing and optimal variant termination. JALP 81, 898–928 (2012)Goguen, J.A., Meseguer, J.: Models and equality for logical programming. In: Ehrig, H., Kowalski, R., Levi, G., Montanari, U. (eds.) TAPSOFT 1987. LNCS, vol. 250, pp. 1–22. Springer, Heidelberg (1987). https://doi.org/10.1007/BFb0014969Goguen, J., Meseguer, J.: Order-sorted algebra I: equational deduction for multiple inheritance, overloading, exceptions and partial operations. TCS 105, 217–273 (1992)Gutiérrez, R., Meseguer, J.: Variant satisfiability in initial algebras with predicates. Technical report, CS Department, University of Illinois at Urbana-Champaign (2018). http://hdl.handle.net/2142/99039Jouannaud, J.P., Kirchner, H.: Completion of a set of rules modulo a set of equations. SICOMP 15, 1155–1194 (1986)Kroening, D., Strichman, O.: Decision Procedures - An algorithmic point of view. Texts in TCS. An EATCS Series. Springer, Heidelberg (2008). https://doi.org/10.1007/978-3-540-74105-3Lynch, C., Morawska, B.: Automatic decidability. In: Proceedings of LICS 2002, p. 7. IEEE Computer Society (2002)Lynch, C., Tran, D.-K.: Automatic decidability and combinability revisited. In: Pfenning, F. (ed.) CADE 2007. LNCS (LNAI), vol. 4603, pp. 328–344. Springer, Heidelberg (2007). https://doi.org/10.1007/978-3-540-73595-3_22Meseguer, J.: Variant-based satisfiability in initial algebras. SCP 154, 3–41 (2018)Meseguer, J.: Strict coherence of conditional rewriting modulo axioms. TCS 672, 1–35 (2017)Meseguer, J., Goguen, J.: Initiality, induction and computability. In: Algebraic Methods in Semantics, Cambridge, pp. 459–541 (1985)Meseguer, J., Goguen, J.: Order-sorted algebra solves the constructor-selector, multiple representation and coercion problems. I&C 103(1), 114–158 (1993)Nelson, G., Oppen, D.C.: Simplification by cooperating decision procedures. TOPLAS 1(2), 245–257 (1979)Shostak, R.E.: Deciding combinations of theories. J. ACM 31(1), 1–12 (1984)Skeirik, S., Meseguer, J.: Metalevel algorithms for variant satisfiability. In: Lucanu, D. (ed.) WRLA 2016. LNCS, vol. 9942, pp. 167–184. Springer, Cham (2016). https://doi.org/10.1007/978-3-319-44802-2_10Stump, A., Barrett, C.W., Dill, D.L., Levitt, J.R.: A decision procedure for an extensional theory of arrays. In: Proceedings of LICS 2001, pp. 29–37. IEEE (2001)Tushkanova, E., Giorgetti, A., Ringeissen, C., Kouchnarenko, O.: A rule-based system for automatic decidability and combinability. SCP 99, 3–23 (2015

    The economic geography of the meso-global spaces: integrating multinationals and clusters at the local-global level

    Full text link
    This is an author's accepted manuscript of an article published in: “European Planning Studies"; Volume 21, Issue 7, 2013; copyright Taylor & Francis; available online at: http://dx.doi.org/10.1080/09654313.2013.733853[EN] The local global phenomenon literature is fragmented between the fields of international business and economic geography (EG). In the case of the latter, the literature, produced within the global production networks (GPNs) and global value chain frameworks, does not address the central role of firms, especially multinationals which co-locate and connect territories along GPNs. This paper develops a cross-field conceptual integration in order to enrich the EG perspective, using qualitative research methodology to test the framework. The results have important implications for scholars and policymakers.We are very thankful to the “Ministry of Economics” funding ECO2010:17318 and “Generalitat Valenciana” for its support in visiting the London School of Economics and Political Science (BEST 2011 grants)Hervás Oliver, JL.; Boix Domenech, R. (2012). The economic geography of the meso-global spaces: integrating multinationals and clusters at the local-global level. European Planning Studies. 21(7):1064-1080. https://doi.org/10.1080/09654313.2013.733853S1064108021

    The embedding of transnational entrepreneurs in diaspora networks:Leveraging the assets of foreignness

    Get PDF
    In this paper we examine how foreign actors capitalize on their ethnic identity to gain skills and capabilities that enable them to operate in a new and strange environment. We explore the mechanisms by which Bulgarian entrepreneurs in London use their ethnic identity to develop competitive advantage and business contacts. We find that the entrepreneurs studied gain access to a diaspora network, which enables them to develop essential business capabilities and integrate knowledge from both home and host country environments. The diaspora community possesses a collective asset (transactive memory) that allows its members to remove competition from the interfirm level to the network level (i.e., diaspora networks vs. networks of native businesspeople). Additionally, the cultural identity and networks to which community members have access provide bridging capabilities that allow diaspora businesspeople to make links to host country business partners and thus embed themselves in the host country environment. Thus, this paper adds to the growing body of work showing how foreignness can serve as an asset in addition to its better-known role as a liability

    A Constructor-Based Reachability Logic for Rewrite Theories

    Get PDF
    Reachability logic has been applied to K rewrite-rule-based language definitions as a language-generic logic of programs. It has been proved successful in verifying a wide range of sophisticated programs in conventional languages. Here we study how reachability logic can be made not just language-generic, but rewrite-theory-generic to make it available not just for conventional program verification, but also to verify rewriting-logic-based programs and distributed system designs. A theory-generic reachability logic is presented and proved sound for a wide class of rewrite theories. Particular attention is given to increasing the logic's automation by means of constructor-based semantic unification, matching, and satisfiability procedures. The relationships to Hoare logic and LTL are discussed, new methods for proving invariants of possibly never terminating distributed systems are developed, and experiments with a prototype implementation illustrating the new methods are presented.Partially supported by NSF Grants CNS 13-19109 and CNS 14-09416, and AFOSR Contract FA8750-11-2-0084.Ope
    corecore