Distances between composition operators

The norm distance between two composition operators is calculated in select cases

Transition Systems for Model Generators - A Unifying Approach

A fundamental task for propositional logic is to compute models of propositional formulas. Programs developed for this task are called satisfiability solvers. We show that transition systems introduced by Nieuwenhuis, Oliveras, and Tinelli to model and analyze satisfiability solvers can be adapted for solvers developed for two other propositional formalisms: logic programming under the answer-set semantics, and the logic PC(ID). We show that in each case the task of computing models can be seen as "satisfiability modulo answer-set programming," where the goal is to find a model of a theory that also is an answer set of a certain program. The unifying perspective we develop shows, in particular, that solvers CLASP and MINISATID are closely related despite being developed for different formalisms, one for answer-set programming and the latter for the logic PC(ID).Comment: 30 pages; Accepted for presentation at ICLP 2011 and for publication in Theory and Practice of Logic Programming; contains the appendix with proof

Representing First-Order Causal Theories by Logic Programs

Nonmonotonic causal logic, introduced by Norman McCain and Hudson Turner, became a basis for the semantics of several expressive action languages. McCain's embedding of definite propositional causal theories into logic programming paved the way to the use of answer set solvers for answering queries about actions described in such languages. In this paper we extend this embedding to nondefinite theories and to first-order causal logic.Comment: 29 pages. To appear in Theory and Practice of Logic Programming (TPLP); Theory and Practice of Logic Programming, May, 201

Measurement of the cross-section and charge asymmetry of WW bosons produced in proton-proton collisions at s=8\sqrt{s}=8 TeV with the ATLAS detector

This paper presents measurements of the $W^+ \rightarrow \mu^+\nu$ and $W^- \rightarrow \mu^-\nu$ cross-sections and the associated charge asymmetry as a function of the absolute pseudorapidity of the decay muon. The data were collected in proton--proton collisions at a centre-of-mass energy of 8 TeV with the ATLAS experiment at the LHC and correspond to a total integrated luminosity of 20.2~\mbox{fb^{-1}}. The precision of the cross-section measurements varies between 0.8% to 1.5% as a function of the pseudorapidity, excluding the 1.9% uncertainty on the integrated luminosity. The charge asymmetry is measured with an uncertainty between 0.002 and 0.003. The results are compared with predictions based on next-to-next-to-leading-order calculations with various parton distribution functions and have the sensitivity to discriminate between them.Comment: 38 pages in total, author list starting page 22, 5 figures, 4 tables, submitted to EPJC. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2017-13

Inverse Scattering and Stability Estimates for The Biharmonic Operator

We study an inverse scattering problem of a perturbed biharmonic operator. we show that the high-frequency asymptotic of scattering amplitude of the biharmonic operator uniquely determine the curl A and {V -1/2 nablaA}. We also study the near-field scattering problem and show that the high-frequency asymptotic expansion up to a certain error in terms of frequency lambda recovers the same two above quantities with no additional information about A and V. We also prove stability estimates for curl A and {V -1/2 nablaA}

A posteriori error estimation and adaptivity in stochastic Galerkin FEM for parametric elliptic PDEs: beyond the affine case

We consider a linear elliptic partial differential equation (PDE) with a generic uniformly bounded parametric coefficient. The solution to this PDE problem is approximated in the framework of stochastic Galerkin finite element methods. We perform a posteriori error analysis of Galerkin approximations and derive a reliable and efficient estimate for the energy error in these approximations. Practical versions of this error estimate are discussed and tested numerically for a model problem with non-affine parametric representation of the coefficient. Furthermore, we use the error reduction indicators derived from spatial and parametric error estimators to guide an adaptive solution algorithm for the given parametric PDE problem. The performance of the adaptive algorithm is tested numerically for model problems with two different non-affine parametric representations of the coefficient.Comment: 32 pages, 4 figures, 6 table

Enhancing security incident response follow-up efforts with lightweight agile retrospectives

Security incidents detected by organizations are escalating in both scale and complexity. As a result, security incident response has become a critical mechanism for organizations in an effort to minimize the damage from security incidents. The final phase within many security incident response approaches is the feedback/follow-up phase. It is within this phase that an organization is expected to use information collected during an investigation in order to learn from an incident, improve its security incident response process and positively impact the wider security environment. However, recent research and security incident reports argue that organizations find it difficult to learn from incidents. A contributing factor to this learning deficiency is that industry focused security incident response approaches, typically, provide very little practical information about tools or techniques that can be used to extract lessons learned from an investigation. As a result, organizations focus on improving technical security controls and not examining or reassessing the effectiveness or efficiency of internal policies and procedures. An additional hindrance, to encouraging improvement assessments, is the absence of tools and/or techniques that organizations can implement to evaluate the impact of implemented enhancements in the wider organization. Hence, this research investigates the integration of lightweight agile retrospectives and meta-retrospectives, in a security incident response process, to enhance feedback and/or follow-up efforts. The research contribution of this paper is twofold. First, it presents an approach based on lightweight retrospectives as a means of enhancing security incident response follow-up efforts. Second, it presents an empirical evaluation of this lightweight approach in a Fortune 500 Financial organization's security incident response team

Predicting Outcomes in Investment Treaty Arbitration

Crafting appropriate dispute settlement processes is challenging for any conflict-management system, particularly for politically sensitive international economic law disputes. As the United States negotiates investment treaties with Asian and European countries, the terms of dispute settlement have become contentious. There is a vigorous debate about whether investment treaty arbitration (ITA) is an appropriate dispute settlement mechanism. While some sing the praises of ITA, others offer a spirited critique. Some critics claim that ITA is biased against states, while others suggest ITA is predictable but unfair due to factors like arbitrator identity or venue. Using data from 159 final cases derived from 272 publicly available ITA awards, this Article examines outcomes of ITA cases to explore those concerns. Key descriptive findings demonstrate that states reliably won a greater proportion of cases than investors; and for the subset of cases investors won, the mean award was US$45.6 million with mean investor success rate of 35%. State success rates were roughly similar to respondent-favorable or state-favorable results in whistleblowing, qui tam, and medical-malpractice litigation in U.S. courts. The Article then explores whether ITA outcomes varied depending upon investor identity, state identity, the presence of repeat-player counsel, arbitrator-related, or venue variables. Models using case-based variables always predicted outcomes whereas arbitrator-venue models did not. The results provide initial evidence that the most critical variables for predicting outcomes involved some form of investor identity and the experience of parties’ lawyers. For investor identity, the most robust predictor was whether investors were human beings, with cases brought by people exhibiting greater success than corporations; and when at least one named investor or corporate parent was ranked in the Financial Times 500, investors sometimes secured more favorable outcomes. Following Marc Galanter’s scholarship demonstrating that repeat-player lawyers are critical to litigation outcomes, attorney experience also affected ITA outcomes. Investors with experienced counsel were more likely to obtain a damage award against a state, whereas states retaining experienced counsel were only reliably associated with decreased levels of relative investor success. Although there was variation in outcomes, ultimately, the data did not support a conclusion that ITA was completely unpredictable; rather, the results called into question some critiques of ITA and did not prove that ITA is a wholly unacceptable form of dispute settlement. Instead, the results suggest the vital debate about ITA’s future would be well served by focusing on evidence-based insights and reliance on data rather than nonreplicable intuition

Review of The Slow Professor: Challenging the Culture of Speed in the Academy

Rory J. Conces reviews The Slow Professor: Challenging the Culture of Speed in the Academy. Maggie Berg and Barbara K. Seeber, with a new Foreword by Stefan Collini. Toronto: University of Toronto Press, 2017, ISBN: 978-1-4875-2185-1.

Review: 'Queer Activism in India: A Story in the Anthropology of Ethics' by Naisargi N. Dave.

The queer movement in India has been adept at documenting itself. A succession of anthologies compiled by leading voices from within the movement has made available to a wider reading public the lives and longings of many of its diverse participants (Sukthankar 1999; Bhattacharyya and Bose 2005; Narrain and Bhan 2006; Narrain and Gupta 2011). Naisargi Dave’s book on queer activism in India offers something new and valuable. A book-length account of the queer political landscape with a focus on lesbian activism, this study is distinctive both for its longer temporal view and for the productively ambivalent positionality of its author. Based in Toronto where she teaches anthropology, Dave presents herself in her writing as both insider and outsider, as both participant in the groups and movements she writes about and critical observer of their everyday activity; sometimes she is neither, inhabiting the liminal position of the diasporic Indian. “Insiders” will read with amusement of her self-avowedly clumsy discovery that “lesbian sexual encounters were there to be had, often in the most unexpected of places” (50), but will also be enlightened by this nuanced cultural history of their own subjectivities. “Outsiders” will find in this book a model of an intimate ethnography by someone who does not pretend to belong