cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Beyond Basins of Attraction: Quantifying Robustness of Natural Dynamics
Creators: name: Heim, Steve
name: Spröwitz, Alexander
Publisher: name: arXiv
Year: 2018
Subjects: subject: Robotics (cs.RO)
subject: FOS: Computer and information sciences

description: Properly designing a system to exhibit favorable natural dynamics can greatly simplify designing or learning the control policy. However, it is still unclear what constitutes favorable natural dynamics and how to quantify its effect. Most studies of simple walking and running models have focused on the basins of attraction of passive limit-cycles and the notion of self-stability. We instead emphasize the importance of stepping beyond basins of attraction. We show an approach based on viability theory to quantify robust sets in state-action space. These sets are valid for the family of all robust control policies, which allows us to quantify the robustness inherent to the natural dynamics before designing the control policy or specifying a control objective. We illustrate our formulation using spring-mass models, simple low dimensional models of running systems. We then show an example application by optimizing robustness of a simulated planar monoped, using a gradient-free optimization scheme. Both case studies result in a nonlinear effective stiffness providing more robustness.
description: 15 pages. This work has been accepted to IEEE Transactions on Robotics (2019)
Error Approximation and Bias Correction in Dynamic Problems using a Recurrent Neural Network/Finite Element Hybrid Model
Creators: name: von Tresckow, Moritz
name: De Gersem, Herbert
name: Loukrezis, Dimitrios
Publisher: name: arXiv
Year: 2023
Subjects: subject: Computational Engineering, Finance, and Science (cs.CE)
subject: FOS: Computer and information sciences

description: This work proposes a hybrid modeling framework based on recurrent neural networks (RNNs) and the finite element (FE) method to approximate model discrepancies in time dependent, multi-fidelity problems, and use the trained hybrid models to perform bias correction of the low-fidelity models. The hybrid model uses FE basis functions as a spatial basis and RNNs for the approximation of the time dependencies of the FE basis' degrees of freedom. The training data sets consist of sparse, non-uniformly sampled snapshots of the discrepancy function, pre-computed from trajectory data of low- and high-fidelity dynamic FE models. To account for data sparsity and prevent overfitting, data upsampling and local weighting factors are employed, to instigate a trade-off between physically conforming model behavior and neural network regression. The proposed hybrid modeling methodology is showcased in three highly non-trivial engineering test-cases, all featuring transient FE models, namely, heat diffusion out of a heat sink, eddy-currents in a quadrupole magnet, and sound wave propagation in a cavity. The results show that the proposed hybrid model is capable of approximating model discrepancies to a high degree of accuracy and accordingly correct low-fidelity models.
Motacilla modularis Linnaeus, 1758, spec. nov.
Creators: name: Linnaeus, Carolus
Publisher: name: Laurentius Salvius
Year: 1758
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Aves
Passeriformes
Motacillidae
Motacilla
Motacilla modularis

description: Motacilla modularis [spec. nov.]
M. supra griseo-fusca, tectricibus alarum apice albis, pectore caerulescente-cinereo. Fn. svec. 223.
Curruca cantu lusciniae. Frisch. av. t. 21. f. 3. Klein. av. 73. t. 1.
Habitat in Europa.
description: Published as part of Linnaeus, Carolus, 1758, Systema Naturae per regna tria naturae: secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis, Stockholm :Laurentius Salvius on page 184, DOI: 10.5962/bhl.title.542, http://zenodo.org/record/3922206
Additional file 1: of A genome wide survey reveals multiple nematocyst-specific genes in Myxozoa
Creators: name: Shpirer, Erez
name: Diamant, Arik
name: Paulyn Cartwright
name: DorothĂŠe Huchon
Publisher: name: figshare
Year: 2018
Subjects: subject: Biochemistry
subject: Microbiology
subject: FOS: Biological sciences
subject: Genetics
subject: Evolutionary Biology
subject: 59999 Environmental Sciences not elsewhere classified
subject: FOS: Earth and related environmental sciences
subject: Ecology
subject: 69999 Biological Sciences not elsewhere classified
subject: 110309 Infectious Diseases
subject: FOS: Health sciences
subject: 60506 Virology
subject: Computational Biology

description: Complete ML phylogenetic tree reconstructed using the NSP6 dataset. ML bootstrap (BPML)/Bayesian posterior probabilities supports are given for nodes with BPML above 50%. Red, orange, blue and green represent Myxozoa, Polypodium, Medusozoa, and Anthozoa respectively. The original H. vulgaris (syn. H. magnipapillata) protein appears in bold. The tree was rooted with distant animal and cnidarian sequence with an E-value below 1E-05. (PDF 28Â kb)
kHz Quasi Periodic Oscillations in Low Mass X-ray Binaries as Probes of General Relativity in the Strong Field Regime
Creators: name: Stella, Luigi
name: Vietri, Mario
Publisher: name: arXiv
Year: 1998
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We consider the interpretation of a pair of kHz Quasi Periodic Oscillations (QPOs) in the Fourier spectra of two Low Mass X-Ray Binaries, Sco X-1 and 4U1608-52, hosting an old accreting neutron star. The observed frequency difference of these QPOs decreaseas as their frequency increases, contrary to simple beat frequency models, which predict a constant frequency difference. We show that the behaviour of these QPOs is instead well matched in terms of the fundamental frequencies (in the radial and azimuthal directions) for test particle motion in the gravitational field of the neutron star, for reasonable star masses, and nearly independent of the star spin. The radial frequency must be much smaller than the azimuthal one, testifying that kHz QPOs are produced close to the innermost stable orbit. These results are not reproduced through the post--Newtonian (PN) approximation of General Relativity (GR). kHz QPOs from X-ray binaries likely provide an accurate laboratory for strong field GR.
description: to appear in Physical Review Letters, PRL Latex plus 2 figures in standard PostScript format
Additional file 1: of Perceived barriers and facilitators in providing palliative care for people with severe dementia: the healthcare professionalsâ experiences
Creators: name: Midtbust, May
name: Alnes, Rigmor
name: Gjengedal, Eva
name: Lykkeslet, Else
Publisher: name: figshare
Year: 2018
Subjects: subject: Molecular Biology
subject: Sociology
subject: FOS: Sociology
subject: 69999 Biological Sciences not elsewhere classified
subject: FOS: Biological sciences
subject: Developmental Biology

description: Interview guide focus groups. (DOCX 13 kb)
title: ADCO, Cartulaire de Cîteaux dit Cartularium Vetus (milieu XIIIe siècle) et Notices du XIIe siècle, Cart. 169 (11 H 63), f. 0028r
Creators: name: de la Côte d'Or, Archives départementales
name: Archives Départementales De La Côte-D'Or
name: Petot, Frédérique
name: Projet CBMA
name: CG21/F.PETOT/2011
Publisher: name: NAKALA - https://nakala.fr (Huma-Num - CNRS)
publisherIdentifier: https://ror.org/04ces3204
publisherIdentifierScheme: ROR
Year: 2020
Subjects: subject: LaMOP
subject: Laboratoire de Médiévistique Occidentale de Paris
subject: cartulaire
subject: Corpus Burgundiae Medii Aevi
subject: Chartes de la Bourgogne du Moyen Âge

description: Cartulaire de Cîteaux dit Cartularium Vetus (milieu XIIIe siècle) et Notices du XIIe siècle, Archives départementales de la Côte-d'Or, Cart. 169 (11 H 63), f. 0028r, Numérisation en mode image.
description: Relation: http://www.cbma-project.eu/
description: Bibliographic citation: Cartulaire de Cîteaux dit Cartularium Vetus (milieu XIIIe siècle) et Notices du XIIe siècle, Archives départementales de la Côte-d'Or, Cart. 169 (11 H 63), f. 0028r, in Projet CBMA - Corpus Burgundiae Medii Aevi [Ressource en ligne], https:// manuscrits.cbma-project.eu/
description: Provenance: https://www.geonames.org/3024876
description: Provenance: http://www.idref.fr/030974844/id
description: Provenance: https://catalogue.bnf.fr/ark:/12148/cb12228351v
description: Provenance: abbaye de Cîteaux
description: Provenance: http://www.wikidata.org/entity/Q843261
Cosmic microwave background constraints on the epoch of reionization
Creators: name: Griffiths, Louise M
name: Barbosa, Domingos
name: Liddle, Andrew R
Publisher: name: arXiv
Year: 1998
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We use a compilation of cosmic microwave anisotropy data to constrain the epoch of reionization in the Universe, as a function of cosmological parameters. We consider spatially-flat cosmologies, varying the matter density $Ω_0$ (the flatness being restored by a cosmological constant), the Hubble parameter $h$ and the spectral index $n$ of the primordial power spectrum. Our results are quoted both in terms of the maximum permitted optical depth to the last-scattering surface, and in terms of the highest allowed reionization redshift assuming instantaneous reionization. For critical-density models, significantly-tilted power spectra are excluded as they cannot fit the current data for any amount of reionization, and even scale-invariant models must have an optical depth to last scattering of below 0.3. For the currently-favoured low-density model with $Ω_0 = 0.3$ and a cosmological constant, the earliest reionization permitted to occur is at around redshift 35, which roughly coincides with the highest estimate in the literature. We provide general fitting functions for the maximum permitted optical depth, as a function of cosmological parameters. We do not consider the inclusion of tensor perturbations, but if present they would strengthen the upper limits we quote.
description: 9 pages LaTeX file with ten figures incorporated (uses mn.sty and epsf). Corrects some equation typos, superseding published version
Thermomechanical study of complex structures in the aperture of superconducting magnets: application to the design of the High-Luminosity LHC shielded beam screen
Creators: name: Morrone, Marco
Publisher: name: Imperial College London
Year: 2018

description: In the framework of the High-Luminosity Large Hadron Collider (HL-LHC) project, a complex structure, known as the beam screen, will be installed by 2024 in the aperture of the inner triplet superconducting magnets nearby the ATLAS and CMS experiments. The beam screen is an octagonal shaped pipe that shields the 1.9 K magnet cryogenic system from the heat loads and damage to the magnet coils that would be otherwise induced by the highly penetrating collision debris. It also ensures that the vacuum conditions, required for the stability of the beam, are met. This thesis describes the design of the beam screen and proposes extensions to important components and features. The unknown physical properties of the beam screen materials have been characterised. The thermal behaviour of the beam screen during normal working conditions has been optimised by simulations and validated by measurements. The behaviour of the beam screen during a magnet quench, a resistive transition of the superconducting magnet, has been studied. Two magnet quench protection systems have been considered: the Quench Heaters (QH) by themselves and in conjunction with the Coupling Loss Induced Quench (CLIQ) device. To this purpose two innovative coupled multiphysic models have been developed, which have been veriﬁed by comparison with a closed form expression showing the advantages of considering self-inductance phenomena. In the case of the QH the force distribution per quadrant gives rise to forces up 330 N/mm in the beam screen closest to the interaction point, while in the case of the CLIQ a torque load-type is induced, whose maximum intensity is around 2 N m/mm. With the new multiphysic models an unprecedented level of accuracy has been achieved, which has permitted to demonstrate the mechanical integrity of the proposed beam screen design during a quench.
Motacilla calidris Linnaeus, 1758, spec. nov.
Creators: name: Linnaeus, Carolus
Publisher: name: Laurentius Salvius
Year: 1758
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Aves
Passeriformes
Motacillidae
Motacilla
Motacilla calidris

description: Motacilla calidris [spec. nov.]
M. supra fusco-virescens, subtus fulva, linea oculari subocularique nigra.
Luscinia americana. Edw. av. 121. t. 121. f. 2.
Icterus minor nidum suspendens. Sloan. jam. 2. p. 299. Raj. av. 184. n. 27.
Habitat in America.
Rectrices apice luteae.
description: Published as part of Linnaeus, Carolus, 1758, Systema Naturae per regna tria naturae: secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis, Stockholm :Laurentius Salvius on page 184, DOI: 10.5962/bhl.title.542, http://zenodo.org/record/3922206
Frugal innovation for healthcare: strategies and tools for the identification and evaluation of frugal and reverse innovations in healthcare
Creators: name: Prime, Matthew Stewart
Publisher: name: Imperial College London
Year: 2017

description: Global healthcare systems are united by their desire to widen patient access to safe and effective clinical services in the face of increasing demand and financial constraints. In low- and middle-income countries (LMICs), a variety of ingenious product and process solutions, termed frugal innovations, have been able to deliver services at a fraction of the cost. It is the broad proposition of this work that such ideas could be applicable to high-income countries (HICs), a concept labeled reverse innovation. Using a conceptual model of innovation scouting derived from the causal mechanism of critical realism, this work examined the development and testing of a tool to deductively identify frugal innovations in healthcare (FIH-ID tool) and then evaluated methodology to assess the reversibility of potential of frugal innovations. The FIH-ID tool demonstrated consistently acceptable inter-rater reliability scores using different methods of application and different raters, moreover, construct validity was shown by its ability to identify well-known frugal innovations. With respect to the assessment of the reversibility potential, the results of the present study highlighted the challenges of undertaking such a complex evaluation process using a simple scoring system. Raters achieved poor levels of inter-rater reliability and only 2 innovations were thought likely to reverse to a HIC. This study presents the first application of a critical realist approach to innovation scouting. It has identified a cohort of 76 potential frugal innovations in healthcare suggesting that the FIH-ID tool is likely to be a valuable asset for similar studies in the future. It has highlighted the challenges of assessing the reversibility potential of innovations from LMICs. It has documented the emergence of the global innovation curator, entities that seek to identify, curate and promote innovations from LMICs, and it proposes a conceptual model for the role of global innovation curators in the diffusion of innovation.
Reflection full waveform inversion
Creators: name: Irabor, Kenneth Otabor
Publisher: name: Imperial College London
Year: 2016

description: The Full Waveform Inversion (FWI) gradient is composed of a low wavenumber tomographic component and a high wavenumber migration component. A successful application of FWI requires that the low wavenumber parts of the model be recovered before the high wavenumbers. This process becomes difficult in datasets dominated by pre-critical angle reflection energies. Reflection waveform inversion (RWI) has been proposed as an alternative to help bootstrap the FWI method for reflection data. In this thesis, I have made a novel contribution to RWI using Finite Di fference Explicit Wavefi eld Decomposition (FDEWD). This method improves the wavefi eld decomposition process by cleanly decomposing the wavefi elds into four components using fi nite diff erence method and Fourier transform. Four component wavefi elds travelling left, right, up and down are simultaneously derived in this method compared to just opposite directions possible with most other methods. FDEWD also lacks the evanescent energy present in traditional Fourier based separation. The extra layer of separation introduced by FDEWD ensures that the tomographic component of the gradient is formed by energies propagating within and close to the first Fresnel zone, hence yielding a cleaner tomographic update. The FDEWD method developed here was then used in an RWI context to successfully invert a synthetic dataset and a blind dataset. The scheme involved a migration update step with an exaggerated step length and a tomographic update step with true step length computation. The results obtained shows that the new method produces superior results compared to the method based on direct separation of the total wavefi elds. FDEWD also allows for transmission FWI to be performed without the need to mute the data in any way. We have implemented the scheme here in a 2-D constant density acoustic wave equation. It is, however, possible to extend this method to 3-D, anisotropic and elastic problems.
Gait Event Detection and Travel Distance Using Waist-Worn Accelerometers across a Range of Speeds: Automated Approach
Creators: name: Ramli, Albara Ah
name: Liu, Xin
name: Berndt, Kelly
name: Chuah, Chen-Nee
name: Goude, Erica
name: Kaethler, Lynea B.
name: Lopez, Amanda
name: Nicorici, Alina
name: Owens, Corey
name: Rodriguez, David
name: Wang, Jane
name: Aranki, Daniel
name: McDonald, Craig M.
name: Henricson, Erik K.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Signal Processing (eess.SP)
subject: Artificial Intelligence (cs.AI)
subject: Machine Learning (cs.LG)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Computer and information sciences

description: Estimation of temporospatial clinical features of gait (CFs), such as step count and length, step duration, step frequency, gait speed, and distance traveled, is an important component of community-based mobility evaluation using wearable accelerometers. However, accurate unsupervised computerized measurement of CFs of individuals with Duchenne muscular dystrophy (DMD) who have progressive loss of ambulatory mobility is difficult due to differences in patterns and magnitudes of acceleration across their range of attainable gait velocities. This paper proposes a novel calibration method. It aims to detect steps, estimate stride lengths, and determine travel distance. The approach involves a combination of clinical observation, machine-learning-based step detection, and regression-based stride length prediction. The method demonstrates high accuracy in children with DMD and typically developing controls (TDs) regardless of the participant's level of ability. Fifteen children with DMD and fifteen TDs underwent supervised clinical testing across a range of gait speeds using 10 m or 25 m run/walk (10 MRW, 25 MRW), 100 m run/walk (100 MRW), 6-min walk (6 MWT), and free-walk (FW) evaluations while wearing a mobile-phone-based accelerometer at the waist near the body's center of mass. Following calibration by a trained clinical evaluator, CFs were extracted from the accelerometer data using a multi-step machine-learning-based process and the results were compared to ground-truth observation data. Model predictions vs. observed values for step counts, distance traveled, and step length showed a strong correlation. Our study findings indicate that a single waist-worn accelerometer calibrated to an individual's stride characteristics using our methods accurately measures CFs and estimates travel distances across a common range of gait speeds in both DMD and TD peers.
Natural illumination solution for rotating space settlements
Creators: name: Janhunen, Pekka
Publisher: name: arXiv
Year: 2018
Subjects: subject: Popular Physics (physics.pop-ph)
subject: FOS: Physical sciences

description: Cylindrical kilometre-scale artificial gravity space settlements were proposed by Gerard O'Neill in the 1970s. The early concept had two oppositely rotating cylinders and moving mirrors to simulate the diurnal cycle. Later, the Kalpana One concept exhibited passively stable rotation and no large moving parts. Here we propose and analyse a specific light transfer solution for Kalpana One type settlements. Our proposed solution is technically reliable because it avoids large moving parts that could be single failure points. The scheme has an array of cylindrical paraboloid concentrators in the outer wall and semi-toroidal reflectors at the equator which distribute the concentrated sunlight onto the living surface. The living cylinder is divided into a number of $φ$-sections (valleys) that are in different phases of the diurnal and seasonal cycles. To reduce the mass of nitrogen needed, a shallow atmosphere is used which is contained by a pressure-tight transparent roof. The only moving parts needed are local blinders installed below the roof of each valley. We also find that settlements of this class have a natural location at the equator where one can build multi-storey urban blocks. The location is optimal from the mass distribution (rotational stability) point of view. If maximally built, the amount of urban floorspace per person becomes large, up to 25,000 m$^2$, which is an order of magnitude larger than the food-producing rural biosphere area per person. Large urban floorspace area per person may increase the material standard of living much beyond Earth while increasing the total mass per person relatively little.
description: Missing *10^3 in mass density fixed in Appendix A, 13 pages, 8 figures, 3 tables
Prediction of long-term static and cyclic creep rupture and crack growth of grade 92 steels under different stress states
Creators: name: Alang, Nasrul Azuan
Publisher: name: Imperial College London
Year: 2017

description: During long-term exposure in creep or creep-fatigue environment, the creep strength of 9-12%Cr steel drops significantly due to the damage developed from metallurgical and microstructural changes occurring in complex subgrain structures. As creep time increases, failure strain of the material is reduced and the reduction is further enhanced under multiaxial condition, where a localised damage zone formed thus leading to crack initiation and growth under increased constraint. The present work focuses on high-temperature creep and fatigue behaviour, and life prediction of Grade 92 steel. Long-term data from literature is utilised to establish creep constitutive properties and to develop the predictive model. The expected scatter in the data is accounted for and it is shown that the important upper and lower bound trend under short and long-term tests can be identified irrespective of the variability of the data. Modelling approach is first applied to the stress-based Continuum Damage Mechanics (CDM) model coupled with a concept of representative stress to predict notched bar failures. Exponential-type predictive model which consists of two material constants, compared to standard CDM model with six is proposed as an alternative to the prediction. Furthermore, a semi-empirical constraint-based approach to predict creep rupture and crack growth under simple and complex stress state condition is presented. The model relates the Monkman-Grant failure strain to the constraint which arises from the geometry and time-dependent creep damage process in microscopic level. The model is consistent with the NSW (Nikbin-Smith-Webster) crack growth model which predicts the crack initiation and growth under the range of plane stress and strain. Finally, finite element (FE) analysis is performed on plain and notched bar to examine the influence of stress state on creep rupture and damage behaviour, and to validate the proposed predictive approach. The model is sufficiently simple yet reliable in predicting long-term failures.
Infrared imaging of WENSS radio sources
Creators: name: Villani, D.
name: Alighieri, S. di Serego
Publisher: name: arXiv
Year: 1998
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We have performed deep imaging in the IR J- and K-bands for three sub-samples of radio sources extracted from the Westerbork Northern Sky Survey, a large low-frequency radio survey containing Ultra Steep Spectrum (USS), Gigahertz Peaked Spectrum (GPS) and Flat Spectrum (FS) sources. We present the results of these IR observations, carried out with the ARcetri Near Infrared CAmera (ARNICA) at the Nordic Optical Telescope (NOT), providing photometric and morphologic information on high redshift radio galaxies and quasars. We find that the radio galaxies contained in our sample do not show the pronounced radio/IR alignment claimed for 3CR sources. IR photometric measurements of the gravitational lens system 1600+434 are also presented.
description: 8 pages, 54 Postscript figures, to be published in Astronomy and Astrophysics, Supplement Series
Electricity system modelling for optimal planning and technology valuation
Creators: name: Heuberger, Clara Franziska
Publisher: name: Imperial College London
Year: 2018

description: This dissertation explores the field of electricity systems modelling and optimisation. We develop new tools, techniques, and concepts to advance systems and technology analysis. Based on a process systems engineering approach, we apply mixed-integer linear programming (MILP) to develop least-cost optimisation models of a national-scale power system in different temporal and complexity variations. The Electricity Systems Optimisation models integrate detailed power plant operation and long-term systems planning to overcome limitations of existing models for technology and system design. We present implementation strategies to include endogenous technology learning and myopic versus perfect foresight planning considering disruptive events. This is enabled through data processing and MILP reformulation techniques developed and applied in this work. We further introduce a new technology valuation metric, the System Value (SV), which quantifies the reduction in total system cost caused upon the deployment of a power generation or storage technology. Unlike purely cost-based metrics, the SV enables a fair comparison of different power technologies taking the whole-system impacts of deployment into account. We find that the SV of a given technology is a function of its penetration level and initial configuration of the system. In a future United Kingdom setting, grid-level energy storage provides the greatest value under a premise of decarbonisation and maintaining security of supply. Additionally, dispatchable and flexible low-carbon power generation, such as Carbon Capture and Storage equipped power plants prove particularly valuable in being able to accommodate higher levels of intermittent renewable power generation and providing ancillary services. On a systems level, we find that including endogenous technology learning in power systems planning emphasises the economic advantage of early investments in low-carbon technology. Myopic power systems planning can lead to sub-optimal capacity expansion. Even under the possibility of breakthrough technologies becoming available before mid-century, deploying existing low-carbon technologies early on proves advantageous from an economic and climate perspective.
Emergent clustering due to quorum sensing interactions in active matter
Creators: name: Thapa, Samudrajit
name: Pinchasik, Bat-El
name: Shokef, Yair
Publisher: name: arXiv
Year: 2023
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: Many organisms in nature use local interactions to generate global cooperative phenomena. To unravel how the behavior of individuals generates effective interactions within a group, we introduce a simple model, wherein each agent senses the presence of others nearby and changes its physical motion accordingly. This generates non-physical, or virtual interactions between agents. We study the radial distribution function and the cluster size distribution to quantify the emergent interactions for both social and anti-social behavior; We identify social behavior as when an agent exhibits a tendency to remain in the vicinity of other agents, whereas anti-social behavior as when it displays a tendency to escape from the vicinity of others. Using Langevin dynamics simulations in two and three spatial dimensions, we discover that under certain conditions, positive correlations, which indicate attraction can emerge even in the case of anti-social behavior. Our results are potentially useful for designing robotic swimmers that can swim collectively only based on sensing the distance to their neighbors, without measuring any orientational information.
Development of a systems approach for studying decarbonisation pathways of heat demand in the UK
Creators: name: Jalil Vega, Francisca Alejandra
Publisher: name: Imperial College London
Year: 2018

description: In the UK, 45% of the total energy demand in 2016 was used for heating purposes, 68% of which was supplied by natural gas. Credible alternatives for decarbonising heat include district heating combined with low carbon heat sources, heat electrification using heat pumps (with a decarbonised electricity system), or hydrogen-fuelled heat technologies. Adoption of these technologies must proceed alongside network infrastructure investment and developments in the broader energy system, such as increased renewable power generation. At the time of writing, no systematic framework exists that trades off individual building and district heat supply technologies and their associated infrastructures at high spatial resolutions. This work formulates and applies such framework. It presents a mixed integer linear optimisation model that decides on investments and operation of gas, electricity, heat, and hydrogen technologies and associated network infrastructures, for supplying commercial and domestic heat and electricity demands in spatially-resolved urban areas, minimising the net present cost through 2050. This model is implemented to study four key issues related to heat decarbonisation: Comparing different temperature heat networks for decarbonising heat; the effect of spatial resolution in outcomes of energy systems models for heat; the role of hydrogen in heat decarbonisation pathways in the UK; and the sensitivity of heat decarbonisation outcomes to uncertainty in techno-economic parameters. Results show that adoption of heat technologies depends, among several factors, on linear heat density, zone-to-zone connectivity, and scenario-specific techno-economic assumptions such as technology, fuels, or electricity prices. Linear heat density adoption thresholds were found for individual technologies. Medium and high temperature heat networks were adopted in high and medium/high linear heat density zones, respectively. Hydrogen boilers were adopted when enabling gas networks to be retrofitted to transport hydrogen. Finally, spatial resolution was shown to be a determining factor for finding cost-effective heat decarbonisation pathways through energy systems models.
Motacilla alba Linnaeus, 1758, spec. nov.
Creators: name: Linnaeus, Carolus
Publisher: name: Laurentius Salvius
Year: 1758
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Aves
Passeriformes
Motacillidae
Motacilla
Motacilla alba

description: Motacilla alba [spec. nov.]
M. pectore nigro, rectricibus duabus lateralibus dimidiato oblique albis.
Motacilla pectore nigro. Fn. svec. 214.
Motacilla. Gesn. av. 618. Aldr. orn. l. 17. c. 23. Bell. av. 88. 6. Will. orn. 171. t. 42. Raj. av. 75. n. 1. Alb. av. 1. p. 49. t. 49. Frisch. av.. t. 23. f. 4. Olin. av. 43.
Habitat in Europa.
description: Published as part of Linnaeus, Carolus, 1758, Systema Naturae per regna tria naturae: secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis, Stockholm :Laurentius Salvius on page 185, DOI: 10.5962/bhl.title.542, http://zenodo.org/record/3922206
Subwavelength manipulation of light via low-loss metamaterials
Creators: name: Ma, Zhijie
Publisher: name: Imperial College London
Year: 2018

description: Metamaterials are artificial materials with properties not found in nature, e.g. negative refractive index. However, the applications of metamaterials have been hindered by the inherent Ohmic loss in the metallic components. In this thesis, the possibilities of using low-loss dielectric metasurfaces and spoof plasmon surfaces to avoid the absorption loss have been investigated through both numerical and experimental studies. The controls of multiple light properties by these low-loss metamaterials are demonstrated. In the first part, an all-dielectric metasurface made of silicon resonator on insulator is designed and fabricated. By tailoring the electric and magnetic dipole modes in the dielectric resonators, a controllable phase range of 2π with high reflectance is achieved. Special beam generators of vortex beam and Bessel beam are numerically demonstrated in the reflection mode with high efficiency by the metasurface. Following that, an anisotropic dielectric metasurface is demonstrated, which functions effectively as an efficient reflective half-wave plate. Furthermore, local geometric phases can be imparted in the metasurface by simply changing the orientation of the resonator. In the second part, a dielectric planar chiral metasurface is studied. A Z-shaped dielectric resonator with broken in-plane mirror symmetry is designed to achieve giant optical chirality that breaks the limit in planar metallic structures. In addition, the circular polarization-selectivemetasurface converts the transmitted light into orthogonal polarization, with a geometric phase depending on the unit orientation. The chiral metasurface effectively integrates the functions of multiple optical components into a single piece. A computer generated hologram is demonstrated numerically as a proof of concept. In the last, a spoof surface plasmon waveguide is explored to achieve significant electric field confinement and enhancement at terahertz frequencies without inducing great loss in the structure. This greatly enhanced interaction between THz waves and matter is explored for sensing applications.
QDoor: Exploiting Approximate Synthesis for Backdoor Attacks in Quantum Neural Networks
Creators: name: Chu, Cheng
name: Chen, Fan
name: Richerme, Philip
name: Jiang, Lei
Publisher: name: arXiv
Year: 2023
Subjects: subject: Quantum Physics (quant-ph)
subject: Emerging Technologies (cs.ET)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: Quantum neural networks (QNNs) succeed in object recognition, natural language processing, and financial analysis. To maximize the accuracy of a QNN on a Noisy Intermediate Scale Quantum (NISQ) computer, approximate synthesis modifies the QNN circuit by reducing error-prone 2-qubit quantum gates. The success of QNNs motivates adversaries to attack QNNs via backdoors. However, naïvely transplanting backdoors designed for classical neural networks to QNNs yields only low attack success rate, due to the noises and approximate synthesis on NISQ computers. Prior quantum circuit-based backdoors cannot selectively attack some inputs or work with all types of encoding layers of a QNN circuit. Moreover, it is easy to detect both transplanted and circuit-based backdoors in a QNN.
 In this paper, we propose a novel and stealthy backdoor attack, QDoor, to achieve high attack success rate in approximately-synthesized QNN circuits by weaponizing unitary differences between uncompiled QNNs and their synthesized counterparts. QDoor trains a QNN behaving normally for all inputs with and without a trigger. However, after approximate synthesis, the QNN circuit always predicts any inputs with a trigger to a predefined class while still acts normally for benign inputs. Compared to prior backdoor attacks, QDoor improves the attack success rate by $13\times$ and the clean data accuracy by $65\%$ on average. Furthermore, prior backdoor detection techniques cannot find QDoor attacks in uncompiled QNN circuits.
The Growth of Correlations in the Matter Power Spectrum
Creators: name: Meiksin, A.
name: White, Martin
Publisher: name: arXiv
Year: 1998
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We find statistically significant correlations in the cosmological matter power spectrum over the full range of observable scales. While the correlations between individual modes are weak, the band-averaged power spectrum shows strong non-trivial correlations. The correlations are significant when the modes in either one or both bands are in the non-linear regime, and approach 100% for pairs of bands in which all the modes are non-linear. The correlations are weaker, but not absent, when computed in redshift space. Since estimates of the power spectrum from galaxy surveys require band-averaging, the correlations must be taken into account when comparing a measured power spectrum with theoretical models.
description: 7 pages, 6 Figures, accepted for publication to MNRAS. Revised
MOESM2 of Sex-specific associations between telomere length and candidate miRNA expression in placenta
Creators: name: Tsamou, Maria
name: Martens, Dries
name: Cox, Bianca
name: Madhloum, Narjes
name: Vrijens, Karen
name: Nawrot, Tim
Publisher: name: figshare
Year: 2018
Subjects: subject: Cell Biology
subject: Genetics
subject: FOS: Biological sciences
subject: Molecular Biology
subject: 69999 Biological Sciences not elsewhere classified
subject: Developmental Biology
subject: 110309 Infectious Diseases
subject: FOS: Health sciences
subject: Computational Biology

description: Additional file 2. Adjusted p-values after FDR correction for unadjusted, adjusted and sensitivity analyses.
Influence of coherent structures on the near- and far-field evolution of an axisymmetric turbulent jet.
Creators: name: Breda, Massimiliano
Publisher: name: Imperial College London
Year: 2018

description: The role of the initial conditions in affecting the near field and the evolution of an axisymmetric turbulent jet towards the far field is examined. The jet's near-field coherent structures are manipulated with the aid of noncircular geometries of identical open area $D^2_e$ , including a square and fractal exit, for comparison with a classical round orifice. The flow is studied between 0 and 26$D_e$ with the aid of planar particle image velocimetry (PIV), hot-wire anemometry and tomographic PIV. This study shows that the fractal orifice significantly changes the near-field properties of the jet, breaking-up the coherent structures and affects the entrainment of background (quiescent) fluid into the turbulent stream. Despite the different state of coherence, it is found that many of the jet's turbulent characteristics scale with the number of eddy turnover times rather than simply the streamwise coordinates. Investigating the jet's evolution towards the self-similar state, the presence of non-equilibrium dissipation was found for all jets studied, concurrent to self-similar scalings for mean velocity and Reynolds stresses. The thesis is concluded by analysing the turbulent/non-turbulent interface (TNTI) and the fine scales of round and fractal jets at various streamwise locations. In the near field, the exit geometry appears to primarily impact on the inner interface, separating the laminar core from the turbulent stream, rather than the outer interface between the jet and the background fluid. Moreover, analysing the fine scales of the flow, the presence of two interfaces in the near field constrains the development of the turbulent properties and the jets appear as if only "local" strain was present. Finally, the evolution of the jet properties and of the small scales of the flow from the TNTI towards the turbulent bulk is examined, which suggests that the TNTI has a thickness of one longitudinal Taylor lenghtscale $\lambda_f $.
Seis2Rock: A Data-Driven Approach to Direct Petrophysical Inversion of Pre-Stack Seismic Data
Creators: name: Corrales, Miguel
name: Hoteit, Hussein
name: Ravasi, Matteo
Publisher: name: arXiv
Year: 2023
Subjects: subject: Geophysics (physics.geo-ph)
subject: FOS: Physical sciences

description: The inversion of petrophysical parameters from seismic data represents a fundamental step in the process of characterizing the subsurface. We propose a novel, data-driven approach named Seis2Rock that utilizes optimal basis functions learned from well log information to directly link band-limited petrophysical reflectivities to pre-stack seismic data. Seis2Rock is composed of two stages: training and inference. During training, a set of optimal basis functions are identified by performing singular value decomposition on one or more synthetic AVO gathers created from measured or rock-physics synthesized elastic well-logs. In inference, seismic pre-stack data are first projected into a set of band-limited petrophysical properties using the previously computed basis functions; this is followed by regularized post-stack seismic inversion of the individual properties. In this work, we apply the Seis2Rock methodology to a synthetic dataset based on the Smeaheia reservoir model and the open Volve field dataset. Numerical results reveal the ability of the proposed method in recovering accurate porosity, shale content, and water saturation models. Finally, the proposed methodology is applied in the context of reservoir monitoring to invert time-lapse, pre-stack seismic data for water saturation changes.
On the Unusually High Temperature of the Cluster of Galaxies 1E 0657-56
Creators: name: Yaqoob, Tahir
Publisher: name: arXiv
Year: 1998
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: A recent X-ray observation of the cluster 1E0657-56 (z=0.296) with ASCA implied an unusually high temperature of ~17 keV. Such a high temperature would make it the hottest known cluster and severely constrain cosmological since, in a Universe with critical density Omega=1 the probability of observing such a cluster is only 4e-5. Here we test the robustness of this observational result since it has such important implications. We analysed the data using a variety of different data analysis methods and spectral analysis assumptions and find a temperature of ~11-12 keV in all cases, except for one class of spectral fits. These are fits in which the absorbing column density is fixed at the Galactic value. We show that a high temperature of ~17 keV is artificially obtained if the true spectrum has a stronger low- energy cut-off than that for Galactic absorption only. The extra absorption may be astrophysical in origin, or it may be a problem with the low-energy CCD efficiency. Although significantly lower than previous measurements, this temperature of kT ~11-12 keV is still relatively high since only a few clusters have been found to have temperatures higher than 10 keV and the data therefore still present some difficulty for an Omega=1 Universe. Our results will also be useful to anyone who wants to estimate the systematic errors involved in different methods of background subtraction of ASCA data for sources with similar S/N to that of the 1E0657-56 data reported here.
description: 14 pages plus 2 figures. Latex with separate postscript figure files. AASTEX 4.0 macro. Accepted for the Astrophysical Journal Letters
On the Origin of the Hard X-Ray Background
Creators: name: Di Matteo, T.
name: Esin, A.
name: Fabian, A. C.
name: Narayan, R.
Publisher: name: arXiv
Year: 1998
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Several models for the hard X-ray Background (XRB) suggest that it is due to the emission from heavily obscured AGN. Recent studies have revealed the presence of a new population of hard X-ray sources which must contribute significantly to the XRB. However, whether the majority of these sources are obscured AGN or some other type of object at present remains unclear. Here, we further examine the possibility that a significant fraction of the XRB comes from a population of galaxies undergoing advection-dominated accretion in the high-\mdot regime and thus produce intrinsically hard spectra. When the accretion rate is close to its critical value, above which an advection-dominated accretion flow (ADAF) no longer exists, the major contribution to X-ray emission is due to inverse Compton scattering of the soft seed photons produced by cyclo-synchrotron radiation. In this regime, the resulting ADAF spectra are relatively hard with a fairly constant X-ray spectral index α\sim 0.2-0.4 and a spectral cut-off at \sim 200 keV. We show that the integrated emission from such sources can provide a good fit to the hard (> 2 keV) X-ray background, provided that the spectrum is dominated by the contribution from objects located at redshifts z \sim 2-3. The model requires most of the contribution to the XRB to be due to objects accreting at the critical rate.
description: revised version, submitted to MNRAS, 6 pages, 3 figures in MNRAS LaTex style
Additional file 4: of Validation of the Jefferson Scale of Physician Empathy in Spanish medical students who participated in an Early Clerkship Immersion programme
Creators: name: Blanco, José
name: Caballero, Fernando
name: García, Fernando
name: Lorenzo, Fernando
name: Monge, Diana
Publisher: name: figshare
Year: 2018
Subjects: subject: Medicine
subject: Science Policy
subject: 111714 Mental Health
subject: FOS: Health sciences

description: Stability of test re-test response of dimension 3 of JSE-HP Spanish version. N = 48. Stability of test re-test response of dimension 3 of JSE-HP Spanish version, measured using the Bland-Altman method in 48 medical Spanish students. (DOCX 155 kb)
Motacilla hippolais Linnaeus, 1758, spec. nov.
Creators: name: Linnaeus, Carolus
Publisher: name: Laurentius Salvius
Year: 1758
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Aves
Passeriformes
Motacillidae
Motacilla
Motacilla hippolais

description: Motacilla hippolais [spec. nov.]
M. virescente-cinerea, subtus flavescens, abdomine albido, artubus fuscis. Fn. svec. 234.
Ficedula septima. Aldr. orn. l. 17. c. 37. Raj. av. 79. n. 7.
Habitat in Europa.
description: Published as part of Linnaeus, Carolus, 1758, Systema Naturae per regna tria naturae: secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis, Stockholm :Laurentius Salvius on page 185, DOI: 10.5962/bhl.title.542, http://zenodo.org/record/3922206