1,447 research outputs found
Towards Communication-Efficient Quantum Oblivious Key Distribution
Oblivious Transfer, a fundamental problem in the field of secure multi-party
computation is defined as follows: A database DB of N bits held by Bob is
queried by a user Alice who is interested in the bit DB_b in such a way that
(1) Alice learns DB_b and only DB_b and (2) Bob does not learn anything about
Alice's choice b. While solutions to this problem in the classical domain rely
largely on unproven computational complexity theoretic assumptions, it is also
known that perfect solutions that guarantee both database and user privacy are
impossible in the quantum domain. Jakobi et al. [Phys. Rev. A, 83(2), 022301,
Feb 2011] proposed a protocol for Oblivious Transfer using well known QKD
techniques to establish an Oblivious Key to solve this problem. Their solution
provided a good degree of database and user privacy (using physical principles
like impossibility of perfectly distinguishing non-orthogonal quantum states
and the impossibility of superluminal communication) while being loss-resistant
and implementable with commercial QKD devices (due to the use of SARG04).
However, their Quantum Oblivious Key Distribution (QOKD) protocol requires a
communication complexity of O(N log N). Since modern databases can be extremely
large, it is important to reduce this communication as much as possible. In
this paper, we first suggest a modification of their protocol wherein the
number of qubits that need to be exchanged is reduced to O(N). A subsequent
generalization reduces the quantum communication complexity even further in
such a way that only a few hundred qubits are needed to be transferred even for
very large databases.Comment: 7 page
Orbital-selective Mott Transitions in a Doped Two-band Hubbard Model
We extend previous studies on orbital-selective Mott transitions in the
paramagnetic state of the half-filled degenerate two-band Hubbard model to the
general doped case, using a high-precision quantum Monte Carlo dynamical
mean-field theory solver. For sufficiently strong interactions,
orbital-selective Mott transitions as a function of total band filling are
clearly visible in the band-specific fillings, quasiparticle weights, double
occupancies, and spectra. The results are contrasted with those of single-band
models for similar correlation strengths.Comment: 12 pages, 12 figure
Characterizing Creative Thinking and Creative Achievements in Relation to Symptoms of Attention-Deficit/Hyperactivity Disorder and Autism Spectrum Disorder
The Magic Number Problem for Subregular Language Families
We investigate the magic number problem, that is, the question whether there
exists a minimal n-state nondeterministic finite automaton (NFA) whose
equivalent minimal deterministic finite automaton (DFA) has alpha states, for
all n and alpha satisfying n less or equal to alpha less or equal to exp(2,n).
A number alpha not satisfying this condition is called a magic number (for n).
It was shown in [11] that no magic numbers exist for general regular languages,
while in [5] trivial and non-trivial magic numbers for unary regular languages
were identified. We obtain similar results for automata accepting subregular
languages like, for example, combinational languages, star-free, prefix-,
suffix-, and infix-closed languages, and prefix-, suffix-, and infix-free
languages, showing that there are only trivial magic numbers, when they exist.
For finite languages we obtain some partial results showing that certain
numbers are non-magic.Comment: In Proceedings DCFS 2010, arXiv:1008.127
First laser ions at the CERN-MEDICIS facility
The CERN-MEDICIS facility aims to produce emerging medical radionuclides for the theranostics approach in nuclear medicine with mass separation of ion beams. To enhance the radioisotope yield and purity of collected samples, the resonance ionization laser ion source MELISSA was constructed, and provided the first laser ions at the facility in 2019. Several operational tests were accomplished to investigate its performance in preparation for the upcoming production of terbium radioisotopes, which are of particular interest for medical applications. © 2020, The Author(s).KU LeuvenHorizon 2020: 642889 MEDICIS-PROMED05P12UMCIA, 05P15UMCIAOpen Access funding provided by Projekt DEAL. We would like to acknowledge the help and assistance from the whole MEDICIS collaboration; from CERN-ISOLDE Technical and Physical groups. This research project has been supported by a Marie Skłodowska-Curie Innovative Training Network Fellowship of the European Commission’s Horizon 2020 Programme under contract number 642889 MEDICIS-PROMED; by the German Federal Ministry of Education and Research under the consecutive projects 05P12UMCIA and 05P15UMCIA; by the Research Foundation Flanders FWO (Belgium) and by a KU Leuven START grant
Genome variations: Effects on the robustness of neuroevolved control for swarm robotics systems
Manual design of self-organized behavioral control for swarms of robots is a complex task. Neuroevolution has proved a viable alternative given its capacity to automatically synthesize controllers. In this paper, we introduce the concept of Genome Variations (GV) in the neuroevolution of behavioral control for robotic swarms. In an evolutionary setup with GV, a slight mutation is applied to the evolving neural network parameters before they are copied to the robots in a swarm. The genome variation is individual to each robot, thereby generating a slightly heterogeneous swarm. GV represents a novel approach to the evolution of robust behaviors, expected to generate more stable and robust individual controllers, and bene t swarm behaviors that can deal with small heterogeneities in the behavior of other members in the swarm. We conduct experiments using an aggregation task, and compare the evolved solutions to solutions evolved under ideal, noise-free conditions, and to solutions evolved with traditional sensor noise.info:eu-repo/semantics/acceptedVersio
Simulating Kilobots within ARGoS: models and experimental validation
The Kilobot is a popular platform for swarm robotics research
due to its low cost and ease of manufacturing. Despite this, the effort to
bootstrap the design of new behaviours and the time necessary to develop
and debug new behaviours is considerable. To make this process less
burdensome, high-performing and flexible simulation tools are important.
In this paper, we present a plugin for the ARGoS simulator designed
to simplify and accelerate experimentation with Kilobots. First, the plugin
supports cross-compiling against the real robot platform, removing
the need to translate algorithms across different languages. Second, it is
highly configurable to match the real robot behaviour. Third, it is fast
and allows running simulations with several hundreds of Kilobots in a
fraction of real time. We present the design choices that drove our work
and report on experiments with physical robots performed to validate
simulated behaviours
Measurement of the cross-section and charge asymmetry of bosons produced in proton-proton collisions at TeV with the ATLAS detector
This paper presents measurements of the and 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
Search for chargino-neutralino production with mass splittings near the electroweak scale in three-lepton final states in √s=13 TeV pp collisions with the ATLAS detector
A search for supersymmetry through the pair production of electroweakinos with mass splittings near the electroweak scale and decaying via on-shell W and Z bosons is presented for a three-lepton final state. The analyzed proton-proton collision data taken at a center-of-mass energy of √s=13 TeV were collected between 2015 and 2018 by the ATLAS experiment at the Large Hadron Collider, corresponding to an integrated luminosity of 139 fb−1. A search, emulating the recursive jigsaw reconstruction technique with easily reproducible laboratory-frame variables, is performed. The two excesses observed in the 2015–2016 data recursive jigsaw analysis in the low-mass three-lepton phase space are reproduced. Results with the full data set are in agreement with the Standard Model expectations. They are interpreted to set exclusion limits at the 95% confidence level on simplified models of chargino-neutralino pair production for masses up to 345 GeV
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