2,441 research outputs found

    Becoming war: towards a martial empiricism

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    Under the banner of martial empiricism, we advance a distinctive set of theoretical and methodological commitments for the study of war. Previous efforts to wrestle with this most recalcitrant of phenomena have sought to ground research upon primary definitions or foundational ontologies of war. By contrast, we propose to embrace war’s incessant becoming, making its creativity, mutability, and polyvalence central to our enquiry. Leaving behind the interminable quest for its essence, we embrace war as mystery. We draw on a tradition of radical empiricism to devise a conceptual and contextual mode of enquiry that can follow the processes and operations of war wherever they lead us. Moving beyond the instrumental appropriations of strategic thought and the normative strictures typical of critical approaches, martial empiricism calls for an unbounded investigation into the emergent and generative character of war. Framing the accompanying special issue, we outline three domains around which to orient future research: mobilization, design, and encounter. Martial empiricism is no idle exercise in philosophical speculation. It is the promise of a research agenda apposite to the task of fully contending with the momentous possibilities and dangers of war in our time

    Fixed-parameter tractability of multicut parameterized by the size of the cutset

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    Given an undirected graph GG, a collection {(s1,t1),...,(sk,tk)}\{(s_1,t_1),..., (s_k,t_k)\} of pairs of vertices, and an integer pp, the Edge Multicut problem ask if there is a set SS of at most pp edges such that the removal of SS disconnects every sis_i from the corresponding tit_i. Vertex Multicut is the analogous problem where SS is a set of at most pp vertices. Our main result is that both problems can be solved in time 2O(p3)...nO(1)2^{O(p^3)}... n^{O(1)}, i.e., fixed-parameter tractable parameterized by the size pp of the cutset in the solution. By contrast, it is unlikely that an algorithm with running time of the form f(p)...nO(1)f(p)... n^{O(1)} exists for the directed version of the problem, as we show it to be W[1]-hard parameterized by the size of the cutset

    Asymptotic Behavior of Inflated Lattice Polygons

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    We study the inflated phase of two dimensional lattice polygons with fixed perimeter NN and variable area, associating a weight exp[pAJb]\exp[pA - Jb ] to a polygon with area AA and bb bends. For convex and column-convex polygons, we show that /Amax=1K(J)/p~2+O(ρp~)/A_{max} = 1 - K(J)/\tilde{p}^2 + \mathcal{O}(\rho^{-\tilde{p}}), where p~=pN1\tilde{p}=pN \gg 1, and ρ<1\rho<1. The constant K(J)K(J) is found to be the same for both types of polygons. We argue that self-avoiding polygons should exhibit the same asymptotic behavior. For self-avoiding polygons, our predictions are in good agreement with exact enumeration data for J=0 and Monte Carlo simulations for J0J \neq 0. We also study polygons where self-intersections are allowed, verifying numerically that the asymptotic behavior described above continues to hold.Comment: 7 page

    Characteristics of patients receiving allergy vaccination: to which extent do socio-economic factors play a role?

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    Background: Little is known about characteristics of patients receiving allergen-specific immunotherapy. Identifying obstacles to appropriate treatment according to guidelines may facilitate the development of strategies aiming at improved treatment of patients with allergic respiratory diseases. The objective of this study was to investigate differences in disease severity, demographic and socioeconomic status between allergic rhinitis patients receiving allergen-specific immunotherapy and allergic rhinitis patients not receiving allergen-specific immunotherapy. Methods: A total of 366 patients were studied of whom 210 were going to receive subcutaneously administrated immunotherapy (SIT) against grass pollen and/or house dust mite allergy. The severity of rhino-conjunctivitis (hay fever) and/or asthma was classified according to international guidelines. The questionnaires included an EQ-5D visual analogue scale instrument and some socio-economic questions. Results: Severity of disease, young age, high level of education as well as greater perceived impairment of health-related quality of life due to allergic symptoms were significantly associated with use of SIT. Somewhat unexpectedly, household income was not associated with use of SIT. Conclusion: Use of SIT was associated with both disease severity measures and educational level, but not income level. These results suggest social inequality as reflected by lower use of SIT among patients with lower educational level may represent an obstacle to treatment with SIT

    Exact enumeration of Hamiltonian circuits, walks, and chains in two and three dimensions

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    We present an algorithm for enumerating exactly the number of Hamiltonian chains on regular lattices in low dimensions. By definition, these are sets of k disjoint paths whose union visits each lattice vertex exactly once. The well-known Hamiltonian circuits and walks appear as the special cases k=0 and k=1 respectively. In two dimensions, we enumerate chains on L x L square lattices up to L=12, walks up to L=17, and circuits up to L=20. Some results for three dimensions are also given. Using our data we extract several quantities of physical interest

    On finitely ambiguous B\"uchi automata

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    Unambiguous B\"uchi automata, i.e. B\"uchi automata allowing only one accepting run per word, are a useful restriction of B\"uchi automata that is well-suited for probabilistic model-checking. In this paper we propose a more permissive variant, namely finitely ambiguous B\"uchi automata, a generalisation where each word has at most kk accepting runs, for some fixed kk. We adapt existing notions and results concerning finite and bounded ambiguity of finite automata to the setting of ω\omega-languages and present a translation from arbitrary nondeterministic B\"uchi automata with nn states to finitely ambiguous automata with at most 3n3^n states and at most nn accepting runs per word

    Scaling of the atmosphere of self-avoiding walks

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    The number of free sites next to the end of a self-avoiding walk is known as the atmosphere. The average atmosphere can be related to the number of configurations. Here we study the distribution of atmospheres as a function of length and how the number of walks of fixed atmosphere scale. Certain bounds on these numbers can be proved. We use Monte Carlo estimates to verify our conjectures. Of particular interest are walks that have zero atmosphere, which are known as trapped. We demonstrate that these walks scale in the same way as the full set of self-avoiding walks, barring an overall constant factor

    Fostering the exchange of real-life data across different countries to answer primary care research questions: a protocol for an UNLOCK study from the IPCRG

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    [Excerpt] This protocol describes a study that will explore the lessons of UNLOCK (Uncovering and Noting Long-term COPD and asthma to enhance Knowledge) over the past 5 years of sharing real-life primary care data from different countries to answer research questions on the diagnosis and management of chronic respiratory diseases. UNLOCK is an international collaboration between primary care researchers and practitioners to coordinate and share data sets of relevant diagnostic and follow-up variables for chronic obstructive pulmonary disease (COPD) and asthma management in primary care. It was set up by members of the International Primary Care Respiratory Group (IPCRG) in response to the identified research need for research in primary care, which recruits patients representative of primary care populations, evaluates interventions realistically delivered within primary care and draws conclusions that will be meaningful to professionals working within primary care.1,2 [...]The IPCRG provided funding for this research project as an UNLOCK Group study for which the funding was obtained through an unrestricted grant by Novartis AG, Basel, Switzerland. Novartis has no role in study design, data collection and analysis, decision to publish or preparation of the manuscript.info:eu-repo/semantics/publishedVersio

    Self-avoiding walks crossing a square

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    We study a restricted class of self-avoiding walks (SAW) which start at the origin (0, 0), end at (L,L)(L, L), and are entirely contained in the square [0,L]×[0,L][0, L] \times [0, L] on the square lattice Z2{\mathbb Z}^2. The number of distinct walks is known to grow as λL2+o(L2)\lambda^{L^2+o(L^2)}. We estimate λ=1.744550±0.000005\lambda = 1.744550 \pm 0.000005 as well as obtaining strict upper and lower bounds, 1.628<λ<1.782.1.628 < \lambda < 1.782. We give exact results for the number of SAW of length 2L+2K2L + 2K for K=0,1,2K = 0, 1, 2 and asymptotic results for K=o(L1/3)K = o(L^{1/3}). We also consider the model in which a weight or {\em fugacity} xx is associated with each step of the walk. This gives rise to a canonical model of a phase transition. For x<1/μx < 1/\mu the average length of a SAW grows as LL, while for x>1/μx > 1/\mu it grows as L2L^2. Here μ\mu is the growth constant of unconstrained SAW in Z2{\mathbb Z}^2. For x=1/μx = 1/\mu we provide numerical evidence, but no proof, that the average walk length grows as L4/3L^{4/3}. We also consider Hamiltonian walks under the same restriction. They are known to grow as τL2+o(L2)\tau^{L^2+o(L^2)} on the same L×LL \times L lattice. We give precise estimates for τ\tau as well as upper and lower bounds, and prove that τ<λ.\tau < \lambda.Comment: 27 pages, 9 figures. Paper updated and reorganised following refereein
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