379 research outputs found

    Activities of Samuel Hoare in Russia 1916

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    The article examines the formation and activities of the British intelligence officer S. Hoare in Russia. His memories as a witness of the last days of the Russian Empire are very useful for researchers. Relations with representatives of the Russian liberal opposition allowed S. Hoare to gather important information about the Russian economy. The author concludes that Samuel Hoare significantly influenced Russia’s strengthening of the continental blockade

    RISINGTIDEFALLINGSTAR

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    From the author of Leviathan, or, The Whale, comes a composite portrait of the subtle, beautiful, inspired and demented ways in which we have come to terms with our watery planet.In the third of his watery books, the author goes in pursuit of human and animal stories of the sea. Of people enchanted or driven to despair by the water, accompanied by whales and birds and seals familiar spirits swimming and flying with the author on his meandering odyssey from suburbia into the unknown.Along the way, he encounters drowned poets and eccentric artists, modernist writers and era-defining performers, wild utopians and national heroes famous or infamous, they are all surprisingly, and sometimes fatally, linked to the sea.Out of the storm-clouds of the twenty-first century and our restive time, these stories reach back into the past and forward into the future. This is a shape-shifting world that has never been certain, caught between the natural and unnatural, where the state between human and animal is blurred. Time, space, gender and species become as fluid as the sea.Here humans challenge their landbound lives through art or words or performance or myth, through the animal and the elemental. And here they are forever drawn back to the water, forever lost and found on the infinite sea

    The Characterization Problem for Hoare Logics

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    Research by this author and others has shown that there are natural programming control language control structures which are impossible to describe accurately by means of Hoare axioms

    James Hall’s (1856) Rostroconchs from the Mississippian of Indiana and Illinois

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    Author Institution: Dept of Geology, Bowling Green State University, Bowling Green, OHHall (1856) described without illustrations six species of the rostroconch Conocardium in his study of the fauna of the Salem Limestone in Indiana and the Warsaw Shale in Illinois. The species represent five genera, two of which are new, Leptoconocardium and Kyoconocardium. Other species represent the genera Hippocardia Brown, 1843; Oxyprora Hoare, Mapes, and Yancey, 2002; and Diedrorynchus Hoare and Peck, 2005

    Mechanizing Hoare Style Proof Outlines for Imperative Programs in Agda

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    Formal verification of imperative programs can be carried out on paper by annotating programs to obtain an outline of a proof in the style of Hoare. This process has been mechanized by the introduction of Separation Logic and computer assisted verification tools. However, the tools fail to achieve the readability and convenience of manual paper proof outlines. This is a pity, because getting ideas and proofs across is essential for scientific research. I introduce a mechanization for proof outlines of imperative programs to interactively write human readable outlines in the dependently typed programming language and proof assistant Agda. I achieve this by introducing practical syntax and proof automation to write concise proof outlines for a simple imperative programming language based on λ-calculus. The proposed solution results in proof outlines that combine the readability of paper proof outlines and the precision of mechanization.Implementation in Agda can be found at: https://github.com/Olavhaasie/hoare-proof-outlinesComputer Scienc

    Formal verification of quantum algorithms using quantum hoare logic

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    © The Author(s) 2019. We formalize the theory of quantum Hoare logic (QHL) [TOPLAS 33(6),19], an extension of Hoare logic for reasoning about quantum programs. In particular, we formalize the syntax and semantics of quantum programs in Isabelle/HOL, write down the rules of quantum Hoare logic, and verify the soundness and completeness of the deduction system for partial correctness of quantum programs. As preliminary work, we formalize some necessary mathematical background in linear algebra, and define tensor products of vectors and matrices on quantum variables. As an application, we verify the correctness of Grover’s search algorithm. To our best knowledge, this is the first time a Hoare logic for quantum programs is formalized in an interactive theorem prover, and used to verify the correctness of a nontrivial quantum algorithm

    Approximate Relational Hoare Logic for Continuous Random Samplings

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    AbstractApproximate relational Hoare logic (apRHL) is a logic for formal verification of the differential privacy of databases written in the programming language pWHILE. Strictly speaking, however, this logic deals only with discrete random samplings. In this paper, we define the graded relational lifting of the subprobabilistic variant of Giry monad, which described differential privacy. We extend the logic apRHL with this graded lifting to deal with continuous random samplings. We give a generic method to give proof rules of apRHL for continuous random samplings

    The impact of brain lesion characteristics and the corticospinal tract wiring on mirror movements in unilateral cerebral palsy.

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    Mirror movements (MM) influence bimanual performance in children with unilateral cerebral palsy (uCP). Whilst MM are related to brain lesion characteristics and the corticospinal tract (CST) wiring pattern, the combined impact of these neurological factors remains unknown. Forty-nine children with uCP (mean age 10y6mo) performed a repetitive squeezing task to quantify similarity (MM-similarity) and strength (MM-intensity) of the MM activity. We used MRI data to evaluate lesion type (periventricular white matter, N = 30; cortico-subcortical, N = 19), extent of ipsilesional damage, presence of bilateral lesions, and damage to basal ganglia, thalamus and corpus callosum. The CST wiring was assessed with Transcranial Magnetic Stimulation (17 CSTcontralateral, 16 CSTipsilateral, 16 CSTbilateral). Data was analyzed with regression analyses. In the more-affected hand, MM-similarity and intensity were higher with CSTbilateral/ipsilateral. In the less-affected hand, MM-similarity was higher in children with (1) CSTcontra with CSC lesions, (2) CSTbilat/ipsi with PVL lesions and (3) CSTbilat/ipsi with unilateralized lesions. MM-intensity was higher with larger damage to the corpus callosum and unilateral lesions. A complex combination of neurological factors influences MM characteristics, and the mechanisms differ between hands

    Spain and the Spaniards through the eyes of the Extraordinary British Ambassador Samuel Hoare (1940–1944)

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    Based on the materials of the memoirs of the participants of the events and the business correspondence of the embassy with the British government, the image of the Spanish people in the representations of the British ambassador to Spain – Samuel Hoare, who held the post from 1940 to 1944, is considered. The Spanish Civil War of 1936–1939 led to a crisis in many spheres of society. The author comes to the conclusion that the conflict within the state has led to a deep cultural split in Spanish society

    Relating and Visualising CSP, VCR and Structural Traces

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    As well as being a useful tool for formal reasoning, a trace can provide insight into a concurrent program's behaviour, especially for the purposes of run-time analysis and debugging. Long-running programs tend to produce large traces which can be difficult to comprehend and visualise. We examine the relationship between three types of traces (CSP, VCR and Structural), establish an ordering and describe methods for conversion between the trace types. Structural traces preserve the structure of composition and reveal the repetition of individual processes, and are thus well-suited to visualisation. We introduce the Starving Philosophers to motivate the value of structural traces for reasoning about behaviour not easily predicted from a program's specification. A remaining challenge is to integrate structural traces into a more formal setting, such as the Unifying Theories of Programming – however, structural traces do provide a useful framework for analysing large systems
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