658 research outputs found

    On bounded query machines

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    AbstractSimple proofs are given for each of the following results: (a) P = Pspace if and only if, for every set A, P(A) = Pquery(A) (Selman et al., 1983): (b) NP = Pspace if and only if, for every set A, NP(A) = NPquery(S) (Book, 1981); (c) PH = Pspace if and only if, for every set A, PH(A) = PQH(A) (Book and Wrathall, 1981); (c) PH = Pspace if and only if, for every set set S, PH(S) = PQH(S) = Pspace(S) (BalcĂĄzar et al., 1986; Long and Selman, 1986)

    Hardness of Sparse Sets and Minimal Circuit Size Problem

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    We develop a polynomial method on finite fields to amplify the hardness of spare sets in nondeterministic time complexity classes on a randomized streaming model. One of our results shows that if there exists a 2no(1)2^{n^{o(1)}}-sparse set in NTIME(2no(1))NTIME(2^{n^{o(1)}}) that does not have any randomized streaming algorithm with no(1)n^{o(1)} updating time, and no(1)n^{o(1)} space, then NEXP=ÌžBPPNEXP\not=BPP, where a f(n)f(n)-sparse set is a language that has at most f(n)f(n) strings of length nn. We also show that if MCSP is ZPPZPP-hard under polynomial time truth-table reductions, then EXP=ÌžZPPEXP\not=ZPP

    "Boring formal methods" or "Sherlock Holmes deduction methods"?

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    This paper provides an overview of common challenges in teaching of logic and formal methods to Computer Science and IT students. We discuss our experiences from the course IN3050: Applied Logic in Engineering, introduced as a "logic for everybody" elective course at at TU Munich, Germany, to engage pupils studying Computer Science, IT and engineering subjects on Bachelor and Master levels. Our goal was to overcome the bias that logic and formal methods are not only very complicated but also very boring to study and to apply. In this paper, we present the core structure of the course, provide examples of exercises and evaluate the course based on the students' surveys.Comment: Preprint. Accepted to the Software Technologies: Applications and Foundations (STAF 2016). Final version published by Springer International Publishing AG. arXiv admin note: substantial text overlap with arXiv:1602.0517

    P-Selectivity, Immunity, and the Power of One Bit

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    We prove that P-sel, the class of all P-selective sets, is EXP-immune, but is not EXP/1-immune. That is, we prove that some infinite P-selective set has no infinite EXP-time subset, but we also prove that every infinite P-selective set has some infinite subset in EXP/1. Informally put, the immunity of P-sel is so fragile that it is pierced by a single bit of information. The above claims follow from broader results that we obtain about the immunity of the P-selective sets. In particular, we prove that for every recursive function f, P-sel is DTIME(f)-immune. Yet we also prove that P-sel is not \Pi_2^p/1-immune

    Irradiation study of a fully monolithic HV-CMOS pixel sensor design in AMS 180 nm

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    High-Voltage Monolithic Active Pixel Sensors (HV-MAPS) based on the 180 nm HV-CMOS process have been proposed to realize thin, fast and highly integrated pixel sensors. The MuPix7 prototype, fabricated in the commercial AMS H18 process, features a fully integrated on-chip readout, i.e. hit-digitization, zero suppression and data serialization. It is the first fully monolithic HV-CMOS pixel sensor that has been tested for the use in high irradiation environments like HL-LHC. We present results from laboratory and test beam measurements of MuPix7 prototypes irradiated with neutrons (up to 5.0⋅1015 neq/cm25.0\cdot10^{15}{\,\rm{n}_{\rm{eq}}/cm^2}) and protons (up to 7.8⋅1015 protons/cm27.8\cdot 10^{15} \,\rm{protons}/cm^2) and compare the performance with non-irradiated sensors. Efficiencies well above 90 % at noise rates below 200 Hz per pixel are measured. A time resolution better than 22 ns is measured for all tested settings and sensors, even at the highest irradiation fluences. The data transmission at 1.25 Gbit/s and the on-chip PLL remain fully functional

    Design and Development of Personal GeoServices for Universities

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    Personal GeoServices are emerging as an interaction paradigm linking users to information rich environments like a university campus or to Big Data sources like the Internet of Things by delivering spatially intelligent web-services. OpenStreetMap (OSM) constitutes a valuable source of spatial base-data that can be extracted, integrated, and utilised with such heterogeneous data sources for free. In this paper, we present a Personal GeoServices application built on OSM spatial data and university-specific business data for staff, faculty, and students. While generic products such as Google Maps and Google Earth enable basic forms of spatial exploration, the domain of a university campus presents specific business information needs, such as “What classes are scheduled in that room over there?” and “How can I get to Prof. Murray’s office from here?” Within the framework of the StratAG project (www.StratAG.ie), an eCampus Demonstrator was developed for the National University of Ireland Maynooth (NUIM) to assist university users in exploring and analysing their surroundings within a detailed data environment. This work describes this system in detail, discussing the usage of OSM vector data, and providing insights for developers of spatial information systems for personalised visual exploration of an area

    The dose makes the poison: have “field realistic” rates of exposure of bees to neonicotinoid insecticides been overestimated in laboratory studies?

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    Recent laboratory based studies have demonstrated adverse sub-lethal effects of neonicotinoid insecticides on honey bees and bumble bees, and these studies have been influential in leading to a European Union moratorium on the use of three neonicotinoids, clothianidin, imidacloprid, and thiamethoxam on “bee attractive” crops. Yet so far, these same effects have not been observed in field studies. Here we review the three key dosage factors (concentration, duration and choice) relevant to field conditions, and conclude that these have probably been over estimated in many laboratory based studies

    The MuPix Telescope: A Thin, high Rate Tracking Telescope

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    The MuPix Telescope is a particle tracking telescope, optimized for tracking low momentum particles and high rates. It is based on the novel High-Voltage Monolithic Active Pixel Sensors (HV-MAPS), designed for the Mu3e tracking detector. The telescope represents a first application of the HV-MAPS technology and also serves as test bed of the Mu3e readout chain. The telescope consists of up to eight layers of the newest prototypes, the MuPix7 sensors, which send data self-triggered via fast serial links to FPGAs, where the data is time-ordered and sent to the PC. A particle hit rate of 1 MHz per layer could be processed. Online tracking is performed with a subset of the incoming data. The general concept of the telescope, chip architecture, readout concept and online reconstruction are described. The performance of the sensor and of the telescope during test beam measurements are presented.Comment: Proceedings TWEPP 2016, 8 pages, 7 figure

    Nominal Unification of Higher Order Expressions with Recursive Let

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    A sound and complete algorithm for nominal unification of higher-order expressions with a recursive let is described, and shown to run in non-deterministic polynomial time. We also explore specializations like nominal letrec-matching for plain expressions and for DAGs and determine the complexity of corresponding unification problems.Comment: Pre-proceedings paper presented at the 26th International Symposium on Logic-Based Program Synthesis and Transformation (LOPSTR 2016), Edinburgh, Scotland UK, 6-8 September 2016 (arXiv:1608.02534
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