cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
The energetics of relativistic magnetic reconnection: ion-electron repartition and particle distribution hardness
Creators: name: Melzani, Mickaël
name: Walder, Rolf
name: Folini, Doris
name: Winisdoerffer, Christophe
name: Favre, Jean M.
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Plasma Physics (physics.plasm-ph)
subject: Space Physics (physics.space-ph)
subject: FOS: Physical sciences

description: Collisionless magnetic reconnection is a prime candidate to account for flare-like or steady emission, outflow launching, or plasma heating, in a variety of high-energy astrophysical objects, including ones with relativistic ion-electron plasmas. But the fate of the initial magnetic energy in a reconnection event remains poorly known: what is the amount given to kinetic energy, the ion/electron repartition, and the hardness of the particle distributions? We explore these questions with 2D particle-in-cell simulations of ion-electron plasmas. We find that 45 to 75% of the total initial magnetic energy ends up in kinetic energy, this fraction increasing with the inflow magnetization. Depending on the guide field strength, ions get from 30 to 60% of the total kinetic energy. Particles can be separated into two populations that only weakly mix: (i) particles initially in the current sheet, heated by its initial tearing and subsequent contraction of the islands; and (ii) particles from the background plasma that primarily gain energy via the reconnection electric field when passing near the X-point. Particles (ii) tend to form a power-law with an index $p=-d\log n(γ)/d\logγ$, that depends mostly on the inflow Alfvén speed $V_A$ and magnetization $σ_s$ of species $s$, with for electrons $p=5$ to $1.2$ for increasing $σ_e$. The highest particle Lorentz factor, for ions or electrons, increases roughly linearly with time for all the relativistic simulations. This is faster, and the spectra can be harder, than for collisionless shock acceleration. We discuss applications to microquasar and AGN coronae, to extragalactic jets, and to radio lobes. We point out situations where effects such as Compton drag or pair creation are important.
description: 15 pages, submitted to A&A
Genome-wide genotype-serum proteome mapping provides insights into the cross-ancestry differences in cardiometabolic disease susceptibility.
Creators: name: Xu, Fengzhe
name: Yu, Evan Yi-Wen
name: Cai, Xue
name: Yue, Liang
name: Jing, Li-Peng
name: Liang, Xinxiu
name: Fu, Yuanqing
name: Miao, Zelei
name: Yang, Min
name: Shuai, Menglei
name: Gou, Wanglong
name: Xiao, Congmei
name: Xue, Zhangzhi
name: Xie, Yuting
name: Li, Sainan
name: Lu, Sha
name: Shi, Meiqi
name: Wang, Xuhong
name: Hu, Wensheng
name: Langenberg, Claudia
name: Yang, Jian
name: Chen, Yu-Ming
name: Guo, Tiannan
name: Zheng, Ju-Sheng
Publisher: name: Apollo - University of Cambridge Repository
Year: 2023
Subjects: Humans
Proteome
Genome-Wide Association Study
Genotype
Phenotype
Cardiovascular Diseases
Genetic Predisposition to Disease
Polymorphism, Single Nucleotide

description: Identification of protein quantitative trait loci (pQTL) helps understand the underlying mechanisms of diseases and discover promising targets for pharmacological intervention. For most important class of drug targets, genetic evidence needs to be generalizable to diverse populations. Given that the majority of the previous studies were conducted in European ancestry populations, little is known about the protein-associated genetic variants in East Asians. Based on data-independent acquisition mass spectrometry technique, we conduct genome-wide association analyses for 304 unique proteins in 2,958 Han Chinese participants. We identify 195 genetic variant-protein associations. Colocalization and Mendelian randomization analyses highlight 60 gene-protein-phenotype associations, 45 of which (75%) have not been prioritized in Europeans previously. Further cross-ancestry analyses uncover key proteins that contributed to the differences in the obesity-induced diabetes and coronary artery disease susceptibility. These findings provide novel druggable proteins as well as a unique resource for the trans-ancestry evaluation of protein-targeted drug discovery.
Evaluating human decisions during time and actor independent variables
Creators: name: Walker, Charles
Publisher: name: University of Lincoln
Year: 2023
Subjects: I100 - Computer science

description: The Trolley Problem, a well known thought experiment comparing decisions duringlife or death circumstances, was applied by the Moral Machine. This gained 40million decisions from millions of participants. Whilst accepted and praised for itssuccess, investigation is available of participants position in the environment and theeffect of time-pressure on the decisions made.To answer this, a web study was conducted to gain a quantitative understanding ofparticipants likelihood to make life or death decisions under the effect of the independent variables via generalised estimating equation. The effects of which provedto be non-significant across both independent variables. Time-pressure showed self-sacrifice to be twice as likely when under time-pressure (B = 0.512, p = 0.012). Thiseffect was studied via a quantitative and qualitative virtual reality study, understanding whether the significance is repeatable. The results indicate the opposite,showing regardless of the independent variable, participants are likely to sacrificethemselves. The explanation of the prior studies findings being concluded as 5�lse positive in regards to significance.The implications of both studies provide validation into the Moral Machine’s results, showing the independent variables not chosen by the Moral Machine had littlesignificance on participants decisions. This provides understanding around the development of a Trolley Problem algorithm in autonomous vehicles and the effectsthat would occur in the world. The research also provides a recommendation thatresearch is required to understand the time taken to make a decision during bothtime and non-time pressure decisions. This would be to see if non-time pressure isbeing treated as such.
Control and Stabilization of the Benjamin-Ono equation in $L^2(\mathbb T)$
Creators: name: Laurent, Camille
name: Linares, Felipe
name: Rosier, Lionel
Publisher: name: arXiv
Year: 2014
Subjects: subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics

description: We prove the control and stabilization of the Benjamin-Ono equation in $L^2(\T)$, the lowest regularity where the initial value problem is well-posed. This problem was already initiated in \cite{LinaresRosierBO} where a stronger stabilization term was used (that makes the equation of parabolic type in the control zone). Here we employ a more natural stabilization term related to the $L^2$ norm. Moreover, by proving a theorem of controllability in $L^2$, we manage to prove the global controllability in large time. Our analysis relies strongly on the bilinear estimates proved in \cite{MolinetPilodBO} and some new extension of these estimates established here.
Best Days of Our Lives: Community Reminiscence
Creators: name: Newall, Helen
Publisher: name: Edge Hill University
Year: 2020
Subjects: subject: 190402 Creative Writing (incl. Playwriting)
subject: FOS: Arts (arts, history of arts, performing arts, music)
subject: 190404 Drama, Theatre and Performance Studies

description: Best Days of our Lives was a highly ambitious and successful spectacle which celebrated the lives of past and present pupils who have grown up and gone to school in Blacon, Chester. Commissioned by Dave Williams, Head Teacher of Dee Point Primary and Chair of The Collaborative Educational Group, Blacon, the piece was inspired by the stories of many people of all ages who were interviewed, and the archives held in each school. The book and lyrics were written by Helen Newall with music composed by Matt Baker, and was directed by Matt Baker, with choreography by led by Julia Williams, Homegrown Dance Theatre.
 The piece involved over 300 children from all 6 schools in Blacon; a community chorus of 60 people; a band of 6 musicians; and 3 professional actors, Francis Tucker, Rachael Rae and Judy Jones.
 Digital Scenography for the production was created by Andy Davies and DeeVideo and featured many people from Blacon as well as arial shots of the neighbourhood. Best Days of Our Lives enjoyed three sell out shows in Chester Cathedral.
An HI study of NGC 3521 - a galaxy with a slow-rotating halo
Creators: name: Elson, Edward
Publisher: name: arXiv
Year: 2013
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: A study is presented of HI line observations of the nearby spiral galaxy NGC 3521 observed with the VLA as part of The HI Nearby Galaxy Survey. Clearly evident in the HI data cube is the presence of an anomalous HI component that is both diffuse and slow-rotating. The data cube is dynamically decomposed into regular and anomalous HI components. A mass of M_HI=1.5 x 10^9 Msun is estimated for the anomalous HI - 20 per cent of the total HI mass. Standard HI data products and rotation curves are produced for each dynamical component. In terms of circular rotation speed, the anomalous HI is found to lag the regular HI by ~25 - 125 km/s. Three-dimensional models are generated and used to determine the possible location of the anomalous HI. The results strongly suggest it to be distributed in a thick disc with a scale-height of a few kpc (~3.5 kpc). It is concluded that the anomalous HI in NGC 3521 constitutes a slow-rotating halo gas component, consistent with similar findings for other nearby galaxies. A study of the radial distribution of the anomalous HI shows it to be spatially coincident with the inner regions of the stellar disc where the star formation rate is highest. It is most likely a galactic fountain that has deposited gas from the disc of the galaxy into the halo.
description: MNRAS, in press. 14 pages, 13 figures
A variant proof of Con(b
Creators: name: Brendle, Jörg
name: Brooke-Taylor, Andrew D.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Logic (math.LO)
subject: FOS: Mathematics
subject: 03E17

description: We present a variation of the proof in the first author's "Mob families and mad families" of Con(b
description: 10 pages. To appear in the proceedings of the RIMS set theory workshop 2013
Ubiquity of Linear Resistivity at Intermediate Temperature in Bad Metals
Creators: name: Boyd, G. R.
name: Zlatic', V.
name: Freericks, J. K.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Bad metals display transport behavior that differs from what is commonly seen in ordinary metals. One of the most significant differences is a resistivity that is linear in temperature and rises to well above the Ioffe-Regel limit (where the mean-free path is equal to the lattice spacing). Using an exact Kubo formula, we show that a linear resistivity naturally occurs for many systems when they are in an incoherent intermediate-temperature state. We verify the analytic arguments with numerical calculations for a simplified version of the Hubbard model which is solved with dynamical mean-field theory. Similar features have also been seen in Hubbard models, where they can begin at even lower temperatures due to the formation of resilient quasiparticles.
description: (5 pages, 3 figures)
Plasmon-phonon coupling in large-area graphene dot and antidot arrays
Creators: name: Zhu, Xiaolong
name: Wang, Weihua
name: Yan, Wei
name: Larsen, Martin B.
name: Bøggild, Peter
name: Pedersen, Thomas Garm
name: Xiao, Sanshui
name: Zi, Jian
name: Mortensen, N. Asger
Publisher: name: arXiv
Year: 2013
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: Nanostructured graphene on SiO2 substrates pave the way for enhanced light-matter interactions and explorations of strong plasmon-phonon hybridization in the mid-infrared regime. Unprecedented large-area graphene nanodot and antidot optical arrays are fabricated by nanosphere lithography, with structural control down to the sub-100 nanometer regime. The interaction between graphene plasmon modes and the substrate phonons is experimentally demonstrated and structural control is used to map out the hybridization of plasmons and phonons, showing coupling energies of the order 20 meV. Our findings are further supported by theoretical calculations and numerical simulations.
description: 7 pages including 6 figures. Supporting information is available upon request to authors
Groups and Lie rings with a Frobenius group of automorphisms
Creators: name: Iusa, Valentina
Publisher: name: University of Lincoln
Year: 2023
Subjects: G100 - Mathematics

description: Suppose that a Frobenius group F H, with kernel F and complement H, actsby automorphisms on a ?finite group G. Work of E. Khukhro, N. Makarenkoand P. Shumyatsky showed that many properties of G are influenced by thecorresponding properties of the centraliser of H in G, and possibly by theorder of H as well. In particular, they proved that if F is cyclic actingfixed-point-freely and the centraliser of H is nilpotent of class c, then thenilpotency class of G can be bounded from above by a function of c and theorder of H.In this thesis we prove that the dependence of the bound on the order ofthe Frobenius complement is essential, by constructing an explicit example.We also discuss a generalisation of the quoted result of Khukhro, Makarenkoand Shumyatsky to the case of abelian non-cyclic kernels.These results are obtained by application of different Lie ring methods.In the former case, the desired family of groups is constructed by using theLazard correspondence. The latter result relies on properties of Lie ringsadmitting a grading over an abelian group with few non-trivial componentsand many commuting components.The final chapter can be read independently of the rest of the thesis. Infact it presents our contribution to a different and independent problem, thatis the classification of certain Lie algebras of maximal class.
Cavity-enhanced room-temperature magnetometry using absorption by nitrogen-vacancy centers in diamond
Creators: name: Jensen, K.
name: Leefer, N.
name: Jarmola, A.
name: Dumeige, Y.
name: Acosta, V. M.
name: Kehayias, P.
name: Patton, B.
name: Budker, D.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We demonstrate a cavity-enhanced room-temperature magnetic field sensor based on nitrogen-vacancy centers in diamond. Magnetic resonance is detected using absorption of light resonant with the 1042 nm spin-singlet transition. The diamond is placed in an external optical cavity to enhance the absorption, and significant absorption is observed even at room temperature. We demonstrate a magnetic field sensitivity of 2.5 nT/sqrt(Hz), and project a photon shot-noise-limited sensitivity of 70 pT/sqrt(Hz) for a few mW of infrared light, and a quantum projection-noise-limited sensitivity of 250 fT/sqrt(Hz) for the sensing volume of 90 um x 90 um 200 um.
description: main text 5 pages, supplementary material 3 pages
Active biopolymer networks generate scale-free but euclidean clusters
Creators: name: Sheinman, M.
name: Sharma, A.
name: Alvarado, J.
name: Koenderink, G. H.
name: MacKintosh, F. C.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Biological Physics (physics.bio-ph)
subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: We report analytical and numerical modelling of active elastic networks, motivated by experiments on crosslinked actin networks contracted by myosin motors. Within a broad range of parameters, the motor-driven collapse of active elastic networks leads to a critical state. We show that this state is qualitatively different from that of the random percolation model. Intriguingly, it possesses both euclidean and scale-free structure with Fisher exponent smaller than $2$. Remarkably, an indistinguishable Fisher exponent and the same euclidean structure is obtained at the critical point of the random percolation model after absorbing all enclaves into their surrounding clusters. We propose that in the experiment the enclaves are absorbed due to steric interactions of network elements. We model the network collapse, taking into account the steric interactions. The model shows how the system robustly drives itself towards the critical point of the random percolation model with absorbed enclaves, in agreement with the experiment.
description: 6 pages, 7 figures
Full susceptibility tensor for localized spin models with S=1, 3/2, 2, 5/2 and with rhombic anisotropy
Creators: name: Pelka, R.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Other Condensed Matter (cond-mat.other)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: A general discussion of the simulation procedure of the full susceptibility tensor and isothermal magnetization pseudovector for compounds comprising weakly-interacting magnetic centers is presented. A single-crystal-sample as well as a powder-sample case are considered. The procedure is used to obtain explicit expressions for the full susceptibility tensor for spins S=1, 3/2, 2, and 5/2 for non-vanishing rhombic local anisotropy and any form of spectroscopic tensor.
description: 26 pages, 6 figures
Single-Photon Storing in Coupled Non-Markovian Atom-Cavity System
Creators: name: Shen, H. Z.
name: Qin, M.
name: Yi, X. X.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Taking the non-Markovian effect into account, we study how to store a single photon of arbitrary temporal shape in a single atom coupled to an optical cavity. Our model applies to Raman transitions in three-level atoms with one branch of the transition controlled by a driving pulse, and the other coupled to the cavity. For any couplings of input field to the optical cavity and detunings of the atom from the driving pulse and cavity, we extend the input-output relation from Markovian dynamics to non-Markovian one. For most possible photon shapes, we derive an analytic expression for the driving pulse in order to completely map the input photon into the atom. We find that, the amplitude of the driving pulse depends only on the detuning of the atom from the frequency of the cavity, i.e., the detuning of the atom to the driving pulse has no effect on the strength of the driving pulse.
description: 11 pages, 8 figures
Innovatív módszerek a reaktorfizika oktatásában: a GRE@T-PIONEeR Horizont 2020 projekt bemutatása
Creators: name: Szieberth, Máté
name: Demazière, Christophe
Publisher: name: Zenodo
Year: 2022
Subjects: education
innovative teaching
pedagogy
nuclear reactor
physics
Euratom
nuclear education
Horizon 2020

description: Overview of the GRE@T-PIONEeR project, courses and methodologies presented at the XIX. Nuclear Technology Symposium of the Hungarian Nuclear Society
Juicy Game Design: Exploring the Impact of Juiciness on the Player Experience
Creators: name: Hicks, Kieran
Publisher: name: University of Lincoln
Year: 2023
Subjects: G900 - Others in mathematical sciences

description: Visual embellishments (VEs) are design elements that support information alreadyconveyed by other means. In games, a similar concept is known as juiciness, andrefers to the provision of superfluous feedback in situations where a single playeraction triggers multiple non-functional reactions. Elements that could be consideredVEs are commonly found in games as a way of improving the feedback loop of thegame. While feedback elements have been previously investigated, juiciness remainsrelatively undefined and is underexplored.In this thesis, this issue is addressed through the creation of an empirically groundeddefinition of juiciness, and an empirical exploration of how the concept affects playerexperience. First, this project presents a literature review of existing research inthis area, exploring the undying motivation through interaction design principles.It then presents a framework for juicy design built from a survey of game designersperspectives. This framework is then applied through several user studies that explore the impact of juiciness on player experience. The first user study explores theeffects of VEs with 40 participants comparing the effects of visual embellishments intwo research games created, the Frogger-clone Cuber, and the FPS game DungeonDescent. The second study explores the effects of juiciness through the commerciallyavailable game Quake 3 Arena with 32 participants. Building from this, two furtheruser studies are presented, exploring the effects of VEs in-the-wild through the deployment of the game Cuber, and through a within-subjects study of juiciness andgamification with 36 participants using an existing research simulation from the lifesciences as research tool.This thesis defines juiciness as coherent design of game mechanics and visuals, whileproviding confirmatory, explicit and ambient feedback. The results of the empiricalwork carried out within this thesis show that the effects of juiciness are nuanced, andcan vary depending on both the implementation and context of the juiciness. Thiswork reveals that juiciness has the potential to target intrinsic motivation factorsand increase the visual appeal of a game. Lastly the overall findings of the thesisare summarised, followed by a discussion of the wider implications of juiciness, andits relevance for game development.
LDPC coded transmissions over the Gaussian broadcast channel with confidential messages
Creators: name: Baldi, Marco
name: Maturo, Nicola
name: Ricciutelli, Giacomo
name: Chiaraluce, Franco
Publisher: name: arXiv
Year: 2014
Subjects: subject: Information Theory (cs.IT)
subject: Cryptography and Security (cs.CR)
subject: FOS: Computer and information sciences

description: We design and assess some practical low-density parity-check (LDPC) coded transmission schemes for the Gaussian broadcast channel with confidential messages (BCC). This channel model is different from the classical wiretap channel model as the unauthorized receiver (Eve) must be able to decode some part of the information. Hence, the reliability and security targets are different from those of the wiretap channel. In order to design and assess practical coding schemes, we use the error rate as a metric of the performance achieved by the authorized receiver (Bob) and the unauthorized receiver (Eve). We study the system feasibility, and show that two different levels of protection against noise are required on the public and the secret messages. This can be achieved in two ways: i) by using LDPC codes with unequal error protection (UEP) of the transmitted information bits or ii) by using two classical non-UEP LDPC codes with different rates. We compare these two approaches and show that, for the considered examples, the solution exploiting UEP LDPC codes is more efficient than that using non-UEP LDPC codes.
description: 5 pages, 5 figures, to be presented at IEEE ICT 2014
Clustering Effects on Wireless Mobile Ad-Hoc Networks Performances
Creators: name: Naah, Gideon
name: Okoampa, Edwin Boadu
Publisher: name: arXiv
Year: 2014
Subjects: subject: Networking and Internet Architecture (cs.NI)
subject: FOS: Computer and information sciences

description: A new era is dawning for wireless mobile ad hoc networks where communication will be done using a group of mobile devices called cluster, hence clustered network. In a clustered network, protocols used by these mobile devices are different from those used in a wired network; which helps to save computation time and resources efficiently. This paper focuses on Cluster-Based Routing Protocol and Dynamic Source Routing. The results presented in this paper illustrates the implementation of Ad-hoc On-Demand Distance Vector routing protocol for enhancing mobile nodes performance and lifetime in a clustered network and to demonstrate how this routing protocol results in time efficient and resource saving in wireless mobile ad hoc networks.
description: journal, 19 pages, 14 figures and 1 table, http://airccse.org/journal/ijcsit2014_curr.html
Flat functions in Carleman ultraholomorphic classes via proximate orders
Creators: name: Sanz, Javier
Publisher: name: arXiv
Year: 2014
Subjects: subject: Complex Variables (math.CV)
subject: FOS: Mathematics
subject: Primary 30D60, secondary 30E05, 30D15, 47A57, 34E05

description: Whenever the defining sequence of a Carleman ultraholomorphic class (in the sense of H. Komatsu) is strongly regular and associated with a proximate order, flat functions are constructed in the class on sectors of optimal opening. As consequences, we obtain analogues of both Borel-Ritt-Gevrey theorem and Watson's lemma in this general situation.
description: 22 pages. arXiv admin note: text overlap with arXiv:1402.1669
Plectoneme tip bubbles: Coupled denaturation and writhing in supercoiled DNA
Creators: name: Matek, Christian
name: Ouldridge, Thomas E.
name: Doye, Jonathan P. K.
name: Louis, Ard A.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Biological Physics (physics.bio-ph)
subject: Chemical Physics (physics.chem-ph)
subject: Biomolecules (q-bio.BM)
subject: FOS: Physical sciences
subject: FOS: Biological sciences

description: Biological information is not only stored in the digital chemical sequence of double helical DNA, but is also encoded in the mechanical properties of the DNA strands, which can influence biochemical processes involving its readout. For example, loop formation in the Lac operon can regulate the expression of key genes, and DNA supercoiling is closely correlated to rhythmic circardian gene expression in cyanobacteria. Supercoiling is also important for large scale organisation of the genome in both eukaryotic and prokaryotic cells. DNA can respond to torsional stress by writhing to form looped structures called plectonemes, thus transferring energy stored as twist into energy stored in bending. Denaturation bubbles can also relax torsional stress, with the enthalpic cost of breaking bonds being compensated by their ability to absorb undertwist. Here we predict a novel regime where bubbles form at the tips of plectonemes, and study its properties using coarse-grained simulations. These tip bubbles can occur for both positive and negative supercoiling and greatly reduce plectoneme diffusion by a pinning mechanism. They can cause plectonemes to preferentially localise to AT rich regions, because bubbles more easily form there. The tip-bubble regime occurs for supercoiling densities and forces that are typically encountered for DNA in vivo, and may be exploited for biological control of genomic processes.
description: 5 pages + 26 pages Supplementary Material
MetSizeR: selecting the optimal sample size for metabolomic studies using an analysis based approach
Creators: name: Nyamundanda, Gift
name: Gormley, Isobel Claire
name: Fan, Yue
name: Gallagher, William M
name: Brennan, Lorraine
Publisher: name: arXiv
Year: 2013
Subjects: subject: Applications (stat.AP)
subject: FOS: Computer and information sciences

description: Background: Determining sample sizes for metabolomic experiments is important but due to the complexity of these experiments, there are currently no standard methods for sample size estimation in metabolomics. Since pilot studies are rarely done in metabolomics, currently existing sample size estimation approaches which rely on pilot data can not be applied. Results: In this article, an analysis based approach called MetSizeR is developed to estimate sample size for metabolomic experiments even when experimental pilot data are not available. The key motivation for MetSizeR is that it considers the type of analysis the researcher intends to use for data analysis when estimating sample size. MetSizeR uses information about the data analysis technique and prior expert knowledge of the metabolomic experiment to simulate pilot data from a statistical model. Permutation based techniques are then applied to the simulated pilot data to estimate the required sample size. Conclusions: The MetSizeR methodology, and a publicly available software package which implements the approach, are illustrated through real metabolomic applications. Sample size estimates, informed by the intended statistical analysis technique, and the associated uncertainty are provided.
description: 15 pages, 3 figures
From Tevatron's top and lepton-based asymmetries to the LHC
Creators: name: Carmona, Adrian
name: Chala, Mikael
name: Falkowski, Adam
name: Khatibi, Sara
name: Najafabadi, Mojtaba Mohammadi
name: Perez, Gilad
name: Santiago, Jose
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We define a lepton-based asymmetry in semi-leptonic ttbar production at the LHC. We show that the ratio of this lepton-based asymmetry and the ttbar charge asymmetry, measured as a function of the lepton transverse momentum or the ttbar invariant mass is a robust observable in the Standard Model. It is stable against higher order corrections and mis-modeling effects. We show that this ratio can also be a powerful discriminant among different new physics models and between them and the Standard Model. Finally, we show that a related ratio defined at the Tevatron is also robust as a function of the ttbar invariant mass.
description: 20 pages
Meta Heuristics based Machine Learning and Neural Mass Modelling Allied to Brain Machine Interface
Creators: name: Zareian, Elham
Publisher: name: University of Lincoln
Year: 2023
Subjects: I460 - Machine learning

description: New understanding of the brain function and increasing availability of low-cost-non-invasive electroencephalograms (EEGs) recording devices have made brain-computer-interface (BCI) as an alternative option to augmentation of human capabilities by providing a new non-muscular channel for sending commands, which could be used to activate electronic or mechanical devices based on modulation of thoughts. In this project, our emphasis will be on how to develop such a BCI using fuzzy rule-based systems (FRBSs), metaheuristics and Neural Mass Models (NMMs). In particular, we treat the BCI system as an integrated problem consisting of mathematical modelling, machine learning and classification. Four main steps are involved in designing a BCI system: 1) data acquisition, 2) feature extraction, 3) classification and 4) transferring the classification outcome into control commands for extended peripheral capability. Our focus has been placed on the first three steps. This research project aims to investigate and develop a novel BCI framework encompassing classification based on machine learning, optimisation and neural mass modelling. The primary aim in this project is to bridge the gap of these three different areas in a bid to design a more reliable and accurate communication path between the brain and external world. To achieve this goal, the following objectives have been investigated: 1) Steady-State Visual Evoked Potential (SSVEP) EEG data are collected from human subjects and pre-processed; 2) Feature extraction procedure is implemented to detect and quantify the characteristics of brain activities which indicates the intention of the subject.; 3) a classification mechanism called an Immune Inspired Multi-Objective Fuzzy Modelling Classification algorithm (IMOFM-C), is adapted as a binary classification approach for classifying binary EEG data. Then, the DDAG-Distance aggregation approach is proposed to aggregate the outcomes of IMOFM-C based binary classifiers for multi-class classification; 4) building on IMOFM-C, a preference-based ensemble classification framework known as IMOFM-CP is proposed to enhance the convergence performance and diversity of each individual component classifier, leading to an improved overall classification accuracy of multi-class EEG data; and 5) finally a robust parameterising approach which combines a single-objective GA and a clustering algorithm with a set of newly devised objective and penalty functions is proposed to obtain robust sets of synaptic connectivity parameters of a thalamic neural mass model (NMM). The parametrisation approach aims to cope with nonlinearity nature normally involved in describing multifarious features of brain signals.
Tracking Solar Active Region Outflow Plasma from its Source to the near-Earth Environment
Creators: name: Culhane, J. L.
name: Brooks, D. H.
name: van Driel-Gesztelyi, L.
name: Demoulin, P.
name: Baker, D.
name: DeRosa, M. L.
name: Mandrini, C. H.
name: Zhao, L.
name: Zurbuchen, T. H.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Seeking to establish whether active region upflow material contributes to the slow solar wind, we examine in detail the plasma upflows from Active Region (AR)10978, which crossed the Sun's disc in the interval 8 to 16 December, 2007 during Carrington rotation (CR)2064. In previous work, using data from the Hinode/EUV Imaging Spectrometer, upflow velocity evolution was extensively studied as the region crossed the disc while a linear force-free magnetic extrapolation was used to confirm aspects of the velocity evolution and to establish the presence of quasi-separatrix layers at the upflow source areas. The plasma properties, temperature, density and first ionisation potential bias (FIP-bias) were measured with the spectrometer during the disc passage of the active region. Global potential field source surface (PFSS) models showed that AR 10978 was completely covered by the closed field of a helmet streamer that is part of the streamer belt. Thus it is not clear how any of the upflowing AR-associated plasma could reach the source surface at 2.5 R(Sun)and contribute to the slow solar wind. However a detailed examination of solar-wind in-situ data obtained by the Advanced Composition Explorer (ACE) spacecraft at the L1 point shows that the increase in O^7+/O^6+, C^6+/C^5+ and Fe/O - a FIP-bias proxy - are present before the heliospheric current sheet crossing. These increases, along with an accompanying reduction in proton velocity and an increase in density are characteristic of both AR and slow-wind plasma. Finally we describe a two-step reconnection process by which some of the upflowing plasma from the AR could reach the heliosphere.
First spectroscopic observations of the sub-stellar companion of the young debris disk star PZ Telescopii
Creators: name: Schmidt, T. O. B.
name: Mugrauer, M.
name: Neuhäuser, R.
name: Vogt, N.
name: Witte, S.
name: Hauschildt, P. H.
name: Helling, Ch.
name: Seifahrt, A.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: In 2010 a sub-stellar companion to the solar analog pre-main sequence star PZ Tel and member of the about 12 Myr old Beta Pic moving group was found by high-contrast direct imaging independently by two teams. In order to determine the basic parameters of this companion more precisely and independent of evolutionary models, hence age independent, we obtained follow-up spectroscopic observations of primary and companion. We use the Spectrograph for INtegral Field Observations in the Near Infrared (SINFONI) at the Very Large Telescope Unit 4/YEPUN of ESO's Paranal Observatory in H+K band and process the data using the spectral deconvolution technique. The resulting spectrum of the companion is then compared to a grid of Drift-Phoenix synthetic model spectra, a combination of a general-purpose model atmosphere code with a non-equilibrium, stationary cloud and dust model, using a chi^2 minimization analysis. We find a best fitting spectral type of G6.5 for PZ Tel A. The extracted spectrum of the sub-stellar companion, at a spatial position compatible with earlier orbit estimates, yields a temperature Teff= 2500 +138-115 K, a visual extinction A_V= 0.53 +0.84-0.53 mag, a surface gravity of log g= 3.50 +0.51-0.30 dex, and a metallicity at the edge of the grid of [M/H]= 0.30 -0.30 dex. We derive a luminosity of log(Lbol/Lsun)= -2.66 +0.06-0.08, a radius of R= 2.42 +0.28-0.34 R_Jup and a mass of M= 7.5 +16.9-4.3 M_Jup for the PZ Tel companion, being consistent with most earlier estimates using photometry alone. Combining our results with evolutionary models, we find a best fitting mass of about 21 Jupiter masses at an age corresponding to the recently determined lithium depletion age of 7 +4-2 Myr. Hence, the PZ Tel companion is most likely a wide brown dwarf companion in the 12 +8-4 Myr old Beta Pic moving group.
description: 7 pages, 6 figures, accepted for publication in A&A
Detection of coherent structures in photospheric turbulent flows
Creators: name: Chian, Abraham C. -L.
name: Rempel, Erico L.
name: Aulanier, Guillaume
name: Schmieder, Brigitte
name: Shadden, Shawn C.
name: Welsch, Brian T.
name: Yeates, Anthony R.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We study coherent structures in solar photospheric flows in a plage in the vicinity of the active region AR 10930 using the horizontal velocity data derived from Hinode/SOT magnetograms. Eulerian and Lagrangian coherent structures are detected by computing the Q-criterion and the finite-time Lyapunov exponents of the velocity field, respectively. Our analysis indicates that, on average, the deformation Eulerian coherent structures dominate over the vortical Eulerian coherent structures in the plage region. We demonstrate the correspondence of the network of high magnetic flux concentration to the attracting Lagrangian coherent structures (a-LCS) in the photospheric velocity based on both observations and numerical simulations. In addition, the computation of a-LCS provides a measure of the local rate of contraction/expansion of the flow.
description: Submitted to ApJ
Don't Break my Flow: Effects of Switching Latency in Shooting Video Games
Creators: name: Halbhuber, David
name: Schwind, Valentin
name: Henze, Niels
Publisher: name: Universität Regensburg
Year: 2022
Subjects: subject: video games, latency, switching latency
subject: 004 Informatik

description: Latency is inherently part of every interactive computing system and particularly important for video games. Previous work shows that constant latency above 25 ms reduces game experience and player performance. However, latency in the wild varies and is never constant due to multiple factors, such as updates in routing tables, users changing their location, or the system's workload. It is unclear if switching latency impairs the gaming experience stronger than a constant high latency. To elucidate, we conducted an experiment with 264 participants playing a shooting video game induced with 0 ms, 33 ms, and 66 ms controlled latency. While playing, the game switched between different latency levels based on three frequencies. Our analysis shows that switching latency significantly impaired the participants' flow. Additionally, we found effects on the perceived tension, the experienced challenge, and the players' performance. We conclude that games should prioritize constant latency, even if that entails artificially adding latency.
A Neuron as a Signal Processing Device
Creators: name: Hu, Tao
name: Towfic, Zaid J.
name: Pehlevan, Cengiz
name: Genkin, Alex
name: Chklovskii, Dmitri B.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Neurons and Cognition (q-bio.NC)
subject: Machine Learning (stat.ML)
subject: FOS: Biological sciences
subject: FOS: Computer and information sciences

description: A neuron is a basic physiological and computational unit of the brain. While much is known about the physiological properties of a neuron, its computational role is poorly understood. Here we propose to view a neuron as a signal processing device that represents the incoming streaming data matrix as a sparse vector of synaptic weights scaled by an outgoing sparse activity vector. Formally, a neuron minimizes a cost function comprising a cumulative squared representation error and regularization terms. We derive an online algorithm that minimizes such cost function by alternating between the minimization with respect to activity and with respect to synaptic weights. The steps of this algorithm reproduce well-known physiological properties of a neuron, such as weighted summation and leaky integration of synaptic inputs, as well as an Oja-like, but parameter-free, synaptic learning rule. Our theoretical framework makes several predictions, some of which can be verified by the existing data, others require further experiments. Such framework should allow modeling the function of neuronal circuits without necessarily measuring all the microscopic biophysical parameters, as well as facilitate the design of neuromorphic electronics.
description: 2013 Asilomar Conference on Signals, Systems and Computers, see http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=6810296
Abstract Visual Programming of Social Robots for Novice Users
Creators: name: Brown, Onis
Publisher: name: University of Lincoln
Year: 2023
Subjects: I140 - Human-computer interaction

description: Human Robot Interaction is a rapidly growing field that blends multiple disciplineswith highly varied research methods. To better leverage experts in non-engineering(software/hardware) fields and increase engagement with the wider public, development of HRI components such as robot behaviours need to be made more accessible.This Project aims to develop and evaluate a system with a suitably high level of abstraction so that novices can create high level behaviours or tasks without having todeal with complexities such as low-level hardware control or the myriad of individualbehaviours that combine to form seemingly straightforward actions. The system wasdeveloped for use on simulated and physical forms of the Scitos G5, currently operating at the collection museum. Over the course of the project, two evaluationshave been performed. A study on the behaviours exhibited by the robot and a linearversion of the visual programming interface, and then workload and usability associated with the system interface after making more high-level blocks and programmingconstructs available. The study at the collection museum was used to inform theother study taking place using simulated sessions with the robot. The second studywas an evaluation of a more complex version of the system. Across both studies,the system was found to be favourable according to SUS responses, with TLX responses showing that the mental demand for the system was low in relation to otherdimensions. The latter study showed that that some people found that elements ofthe visual programming were slightly confusing, however the functionality of blocksand their relation to performing certain actions were easily learned. Results suggestfurther study may be useful with future development of this or similar systems inwider contexts.
Polar Confinement of Saturn's Magnetosphere Revealed by in-situ Cassini Observations
Creators: name: Pilkington, Nathan M.
name: Achilleos, Nicholas
name: Arridge, Christopher S.
name: Masters, Adam
name: Sergis, Nick
name: Coates, Andrew J.
name: Dougherty, Michele K.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: Plasma rotation plays a large role in determining the size and shape of Saturn's disc-like magnetosphere. A magnetosphere more confined to the equator in the polar regions is expected as a result of the interaction between this type of obstacle and the solar wind. In addition, at times away from equinox, a north-south asymmetry is expected where the magnetopause will be further confined in one hemisphere but less confined in the opposite hemisphere. Examining the extent of this confinement has been limited by a lack of high-latitude spacecraft observations. Here, for the first time, direct evidence for polar confinement of Saturn's magnetopause has been observed using in-situ data obtained by the Cassini spacecraft during a series of high-inclination orbits between 2007 and 2009. Following techniques established by previous authors, we assume an equilibrium between the solar wind dynamic pressure (which Cassini is generally unable to measure directly), and the magnetic plus plasma pressure inside the magnetosphere. This assumption thus allows us to estimate the upstream solar wind dynamic pressure ($D_P$) for a series of magnetopause crossings, and hence to determine the expected location and global shape of the magnetopause as a function of $D_P$. A clear divergence from the familiar axisymmetric models of the magnetosphere is observed which may be characterised by an 'apparent flattening parameter' of 0.81+0.03/-0.06 (representing a simple dilation of the nominal axisymmetric boundary along the $Z_{KSM}$ axis such that the extent is reduced by 19% in this direction). This figure is insensitive to variations in $D_P$.
description: 47 pages (draft), 10 figures
Brightness of the Sun's small scale magnetic field: proximity effects
Creators: name: Thaler, I.
name: Spruit, H. C.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: The net effect of the small scale magnetic field on the Sun's (bolometric) brightness is studied with realistic 3D MHD simulations. The direct effect of brightening within the magnetic field itself is consistent with measurements in high-resolution observations. The high 'photometric accuracy' of the simulations, however, reveal compensating brightness effects that are hard to detect observationally. The influence of magnetic concentrations on the surrounding nonmagnetic convective flows (a 'proximity effect') reduces the brightness by an amount exceeding the brightening by the magnetic concentrations themselves. The net photospheric effect of the small scale field (~ -0.34% at a mean flux density of 50 G) is thus negative. We conclude that the main contribution to the observed positive correlation between the magnetic field and total solar irradiance must be magnetic dissipation in layers around the temperature minimum and above (not included in the simulations). This agrees with existing inferences from observations.