cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Lattice Boltzmann model for collisionless electrostatic drift wave turbulence obeying Charney-Hasegawa-Mima dynamics
Creators: name: Held, M.
name: Kendl, A.
Publisher: name: arXiv
Year: 2015
Subjects: subject: Plasma Physics (physics.plasm-ph)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences

description: A lattice Boltzmann method (LBM) approach to the Charney-Hasegawa-Mima (CHM) model for adiabatic drift wave turbulence in magnetised plasmas, is implemented. The CHM-LBM model contains a barotropic equation of state for the potential, a force term including a cross-product analogous to the Coriolis force in quasigeostrophic models, and a density gradient source term. Expansion of the resulting lattice Boltzmann model equations leads to cold-ion fluid continuity and momentum equations, which resemble CHM dynamics under drift ordering. The resulting numerical solutions of standard test cases (monopole propagation, stable drift modes and decaying turbulence) are compared to results obtained by a conventional finite difference scheme that directly discretizes the CHM equation. The LB scheme resembles characteristic CHM dynamics apart from an additional shear in the density gradient direction. The occuring shear reduces with the drift ratio and is ascribed to the compressible limit of the underlying LBM.
description: Lattice Boltzmann model; Charney-Hasegawa-Mima equation; plasma physics; electrostatic drift wave turbulence; magnetised plasma turbulence;
Additional file 4 of An uncertainty estimate of the prevalence of stunting in national surveys: the need for better precision
Creators: name: Santu Ghosh
name: Nirupama Shivakumar
name: Sulagna Bandyopadhyay
name: Harshpal S. Sachdev
name: Anura V. Kurpad
name: Thomas, Tinku
Publisher: name: figshare
Year: 2020
Subjects: subject: Statistics
subject: FOS: Mathematics

description: Additional file 4: Additional Figure 2. Distribution of height-for-age in NFHS-3 and MGRS
Closing in on singlet scalar dark matter: LUX, invisible Higgs decays and gamma-ray lines
Creators: name: Feng, Lei
name: Profumo, Stefano
name: Ubaldi, Lorenzo
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We study the implications of the Higgs discovery and of recent results from dark matter searches on real singlet scalar dark matter. The phenomenology of the model is defined by only two parameters, the singlet scalar mass $m_S$ and the quartic coupling $a_2$ between the SU(2) Higgs and the singlet scalar. We concentrate on the window $5 < m_S/{\rm GeV} < 300$. The most dramatic impact on the viable parameter space of the model comes from direct dark matter searches with LUX, and, for very low masses in the few GeV range, from constraints from the invisible decay width of the Higgs. In the resonant region the best constraints come from gamma-ray line searches. We show that they leave only a small region of viable parameter space, for dark matter masses within a few percent of half the mass of the Higgs. We demonstrate that direct and indirect dark matter searches (especially the search for monochromatic gamma-ray lines) will play a key role in closing the residual parameter space in the near future.
description: 7 pages + appendices, 2 figures. Plots corrected and updated in the latest version
title: Exploration of non-thermal plasma for chemical reactions. Reactor development and testing.
Creators: name: Roszkowska, Patrycja
Publisher: name: University of Liverpool Repository
Year: 2024

description: Atmospheric pressure non-thermal plasma (NTP)-liquid systems are characterised by their unique properties of energetic environments operating at mild conditions. The non-equilibrium state of NTP means that despite highly energetic electrons, the system's overall temperature remains ambient. As a result, NTP-liquid systems provide a rich source of reactive species such as free electrons, ions, radicals, and excited molecules, which can be customised based on the choice of gas and liquid. The appeal of NTP as an alternative for reaction processing stems from its potential to deliver tailored reactivity within NTP-liquid systems, provided we thoroughly understand its processes.
This thesis explores developing and testing NTP systems for chemical reactions, focusing on reactor design and microfluidic technology. Transparent microfluidic chips were developed to facilitate real-time examination of plasma-liquid interactions, approaching the enhancement of understanding of plasma-liquid contact mechanisms. Additionally, this work demonstrates the use of both microfluidic and scaled-up batch reactors to compare NTP systems with conventional laboratory methods, highlighting the advantages of each approach.
Significant findings of this thesis include the ability of both setups to facilitate NTP-liquid contact and enable effective species transfer between NTP and the liquid phase for both water and organic solvents. Evidence of this was demonstrated by the high degradation efficiency of methylene blue with NTP and the successful synthesis of various imine macrocycles, showcasing the potential for NTP systems to perform established chemistry using standard laboratory equipment. The research underscores the importance of systematic and standardised reporting in advancing the field and calls for further studies to unravel the fundamental mechanisms of NTP-liquid interactions. While this study does not delve into mechanistic understanding, it highlights the need to comprehend the physicochemical pathways of reactive species generation and diffusion between phases. Consequently, further studies focusing on fundamental understanding are necessary, and the setups outlined in this thesis can help facilitate such experiments. This thesis demonstrates the promising potential of NTP technology in chemical processing, advocating for its broader application and integration into standard chemical practices.
Additional file 3 of An uncertainty estimate of the prevalence of stunting in national surveys: the need for better precision
Creators: name: Santu Ghosh
name: Nirupama Shivakumar
name: Sulagna Bandyopadhyay
name: Harshpal S. Sachdev
name: Anura V. Kurpad
name: Thomas, Tinku
Publisher: name: figshare
Year: 2020
Subjects: subject: Statistics
subject: FOS: Mathematics

description: Additional file 3: Additional Figure 1. Flow diagram of country selection from DHS data to calculate the prevalence of relative stunting; DHS: Demographic Health Survey
Robust Calibration of a Universal Single-Qubit Gate-Set via Robust Phase Estimation
Creators: name: Kimmel, Shelby
name: Low, Guang Hao
name: Yoder, Theodore J.
Publisher: name: arXiv
Year: 2015
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: An important step in building a quantum computer is calibrating experimentally implemented quantum gates to produce operations that are close to ideal unitaries. The calibration step involves estimating the systematic errors in gates and then using controls to correct the implementation. Quantum process tomography is a standard technique for estimating these errors, but is both time consuming, (when one only wants to learn a few key parameters), and is usually inaccurate without resources like perfect state preparation and measurement, which might not be available. With the goal of efficiently and accurately estimating specific errors using minimal resources, we develop a parameter estimation technique, which can gauge key systematic parameters (specifically, amplitude and off-resonance errors) in a universal single-qubit gate-set with provable robustness and efficiency. In particular, our estimates achieve the optimal efficiency, Heisenberg scaling, and do so without entanglement and entirely within a single-qubit Hilbert space. Our main theorem making this possible is a robust version of the phase estimation procedure of Higgins et al. [B. L. Higgins, New J. Phys. 11, 073023 (2009)].
description: Errata added; our error analysis is based on an incorrect assumption. However, our overall approach for robust calibration via phase estimation is still valid with a looser error bound - see the Errata before the Introduction for more information
Additional file 1 of β-lactamase-mediated resistance in MDR-Pseudomonas aeruginosa from Qatar
Creators: name: Ahmed, Mazen A. Sid
name: Khan, Faisal Ahmad
name: Sultan, Ali A.
name: Söderquist, Bo
name: Ibrahim, Emad Bashir
name: Jass, Jana
name: Omrani, Ali S.
Publisher: name: figshare
Year: 2020
Subjects: subject: Medicine
subject: Microbiology
subject: FOS: Biological sciences
subject: Genetics
subject: Molecular 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: Cancer
subject: 110309 Infectious Diseases
subject: FOS: Health sciences
subject: 60506 Virology

description: Additional file 1. Supplementary data file.
title: Molecular diversity and functional composition of cellulose degrading communities in anoxic environments
Creators: name: Houghton, James
Publisher: name: University of Liverpool Repository
Year: 2014

description: The major fraction of microbial communities cannot be cultivated by artificial means in the laboratory. In order to access the full diversity of microbial life in the open environment it is necessary to employ culture independent methods. Molecular biology and now metagenomics have enabled the phylogenetic and functional investigation of microbial communities without isolation and cultivation of organisms and has led to a new appreciation of the breadth of diversity of microbes on Earth and to the discovery and characterisation of new enzymes. Here, molecular biological techniques have been applied to the study of microbial communities specifically in anaerobic environments and with an emphasis on those involved in the primary degradation of plant cellulosic biomass. Quantitative PCR was used to assess the presence of cellulolytic bacteria both in landfill leachate and specifically in association with cotton cellulose “baits” maintained in leachate microcosms. Lineages of clostridia previously associated with cellulose degrading strains were detected in all five of the landfill leachate samples, and Fibrobacter spp. were detected at low abundance (2.3% of total bacteria) in one sample. Clostridia Group III and Fibrobacter spp. were enriched on the surface of a bait (17% and 29% of total bacteria, respectively) that was rapidly degraded by the colonising community and were present in low abundance (
GPU Performance Portability Using Standard C++ and SYCL
Creators: name: Delaney, Hugh
Publisher: name: Zenodo
Year: 2023
Subjects: C++
SYCL

description: The proliferation of accelerators, in particular GPUs, over the past decade is im-
 pacting the way software is being developed. Most developers who have been using
 CPU based machines are now considering how it’s possible to improve the per-
 formance of applications by offloading execution to many core processors. Many
 emerging disciplines including AI, deep neural networks and machine learning have
 shown that GPUs can increase performance by many times compared to CPU-only
 architectures. New hardware features such as ”tensor cores” are also starting to
 emerge to address specific problems including mixed precision computing. The new
 challenge for developers is figuring out how to develop for heterogeneous architec-
 tures that include GPUs made by different companies. Currently the most common
 way to develop software for GPUs is using the CUDA programming model but this
 has pitfalls. CUDA uses non-standard C++ syntax and semantics, is a proprietary
 interface, and can only be used to target Nvidia GPUs. Alternatives include HIP
 which offers another proprietary programming interface only capable of targeting
 AMD GPUs.
 This presentation will demonstrate how standard C++ code with SYCL can be
 used to achieve performance portability on processors from multiple vendors includ-
 ing Nvidia GPUs, AMD GPUs and Intel GPUs. The SYCL programming interface
 is a royalty free and industry defined open standard designed to enable the latest
 features of accelerators. Using an open source project, we’ll show how standard
 C++ syntax and semantics are used to define the SYCL kernel and memory man-
 agement code required to offload parallel execution to a range of GPUs. Further to
 this, we’ll explain how easy it is to compile this C++ code using a SYCL compiler
 so that it can be run on Nvidia, AMD and Intel GPUs and compare this execu-
 tion performance with the same code written using proprietary CUDA and HIP
 environments.
title: A GEANT4 simulation of the SAGE spectrometer and its first application to 255Lr
Creators: name: Cox, Daniel
Publisher: name: University of Liverpool Repository
Year: 2014

description: A two-part experiment studying 255Lr was performed in the University of Jyväskylä, Finland. The nucleus was created in the fusion-evaporation reaction 209Bi(48Ca,2n)255Lr. The first part was performed using RITU and GREAT, and was run at a high intensity to study the decay properties of 255Lr. The second part combined RITU, GREAT, and SAGE, and was run at a lower intensity to study excited states in 255Lr. In parallel a comprehensive GEANT4 simulation has for the SAGE spectrometer has been developed. With the goals of better characterising the experimental setup, and allowing the simulation of complex level schemes such as those seen in 255Lr for the purposes of testing proposed level schemes by direct comparison to experimental data. This thesis reports the results of both the decay and in-beam spectroscopy of 255Lr, including observation of the previously seen isomeric state with a half-life of 1.73(4) ms and the observation of two previously unseen transitions in the ground-state rotational band at energies of 91 and 140 keV.
Cluster Synchronization of Coupled Systems with Nonidentical Linear Dynamics
Creators: name: Liu, Zhongchang
name: Wong, Wing Shing
name: Cheng, Hui
Publisher: name: arXiv
Year: 2015
Subjects: subject: Systems and Control (eess.SY)
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: This paper considers the cluster synchronization problem of generic linear dynamical systems whose system models are distinct in different clusters. These nonidentical linear models render control design and coupling conditions highly correlated if static couplings are used for all individual systems. In this paper, a dynamic coupling structure, which incorporates a global weighting factor and a vanishing auxiliary control variable, is proposed for each agent and is shown to be a feasible solution. Lower bounds on the global and local weighting factors are derived under the condition that every interaction subgraph associated with each cluster admits a directed spanning tree. The spanning tree requirement is further shown to be a necessary condition when the clusters connect acyclically with each other. Simulations for two applications, cluster heading alignment of nonidentical ships and cluster phase synchronization of nonidentical harmonic oscillators, illustrate essential parts of the derived theoretical results.
description: accepted version by International Journal of Robust and Nonlinear Control
Symmetry Breaking and the Geometry of Reduced Density Matrices
Creators: name: Zauner, V.
name: Draxler, D.
name: Vanderstraeten, L.
name: Haegeman, J.
name: Verstraete, F.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Quantum Physics (quant-ph)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: The concept of symmetry breaking and the emergence of corresponding local order parameters constitute the pillars of modern day many body physics. The theory of quantum entanglement is currently leading to a paradigm shift in understanding quantum correlations in many body systems and in this work we show how symmetry breaking can be understood from this wavefunction centered point of view. We demonstrate that the existence of symmetry breaking is a consequence of the geometric structure of the convex set of reduced density matrices of all possible many body wavefunctions. The surfaces of those convex bodies exhibit non-analytic behavior in the form of ruled surfaces, which turn out to be the defining signatures for the emergence of symmetry breaking and of an associated order parameter. We illustrate this by plotting the convex sets arising in the context of three paradigmatic examples of many body systems exhibiting symmetry breaking: the quantum Ising model in transverse magnetic field, exhibiting a second order quantum phase transition; the classical Ising model at finite temperature in two dimensions, which orders below a critical temperature $T_c$; and a system of free bosons at finite temperature in three dimensions, exhibiting the phenomenon of Bose-Einstein condensation together with an associated order parameter $\langleψ\rangle$. Remarkably, these convex sets look all very much alike. We believe that this wavefunction based way of looking at phase transitions demystifies the emergence of order parameters and provides a unique novel tool for studying exotic quantum phenomena.
description: 5 pages, 3 figures, Appendix with 2 pages, 3 figures
title: Manual assembly modelling and simulation for ergonomics analysis
Creators: name: Ding, Ziyun
Publisher: name: University of Liverpool Repository
Year: 2014

description: In manufacturing industry, although automation techniques have been employed widely, many tasks still require the flexibility and intelligence of human operators, especially in the product assembly process. Insufficient industrial ergonomics in the assembly process will cause the health problems and quality and productivity losses, ultimately increase costs of the final product. The purpose of this thesis is to integrate ergonomic considerations into the manual assembly process modelling and simulation in order to provide product/process design changes before their physical prototyping. In this research, a state-of-the-art commercial software tool - DELMIA - is adopted for the ergonomics simulation and analysis. Associated with its capabilities for the ergonomics solution, a series of human related issues in the manual assembly process is simulated and studied in order to demonstrate the benefits of a virtual assembly approach to the product deign, workplace deign, time and energy saving. Due to the poor repeatability and reproducibility of digital human postures in DELMIA manipulation, a posture prediction method is developed aiming at a practical and precise ergonomics analysis. A 10-degrees-of-freedom, 4-control-points digital human model concerned with assembly features and human diversity is established. The multi-objective optimisation method is applied to assembly posture prediction in which optimisation objectives (i.e. joint discomfort and metabolic energy expenditure) and constraints corresponding to manual assembly tasks are proposed and formulated. Following the verification of the posture prediction method, a series of posture strategies under different assembly conditions are investigated towards more comfortable and energy-efficient assembly postures. Thus far, the consideration on assembly operators in assembly sequencing is insufficient though it plays a key role in the integrative product and process design. In this research, the use of new ergonomic constraints into assembly sequencing optimisation is proposed. Feasible assembly sequences are generated and evaluated based on the product geometry, assembly workstation layout, operator characteristics and working posture. A new Liverpool Assembly Sequence Planning System (LASP) is developed to achieve the integration by applying two evaluation criteria, i.e. visibility criterion, accessibility criterion or both. With LASP, possible design faults with respect to restricted visibility and obstructed accessibility is obtainable during the early design stage. Meanwhile, the optimum sequences are provided to operators automatically for ease of manual assembly, facilitating higher assembly quality and efficiency.
Boundary and Interface CFTs from the Conformal Bootstrap
Creators: name: Gliozzi, F.
name: Liendo, P.
name: Meineri, M.
name: Rago, A.
Publisher: name: arXiv
Year: 2015
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: High Energy Physics - Lattice (hep-lat)
subject: FOS: Physical sciences

description: We explore some consequences of the crossing symmetry for defect conformal field theories, focusing on codimension one defects like flat boundaries or interfaces. We study surface transitions of the 3d Ising and other O(N) models through numerical solutions to the crossing equations with the method of determinants. In the extraordinary transition, where the low-lying spectrum of the surface operators is known, we use the bootstrap equations to obtain information on the bulk spectrum of the theory. In the ordinary transition the knowledge of the low-lying bulk spectrum allows to calculate the scale dimension of the relevant surface operator, which compares well with known results of two-loop calculations in 3d. Estimates of various OPE coefficients are also obtained. We also analyze in 4-epsilon dimensions the renormalization group interface between the O(N) model and the free theory and check numerically the results in 3d.
description: 40 pages, many figures v2: new results on 3d O(N) bulk spectrum added, one appendix eliminated, typos corrected, references updated. v3: two references to high precision Monte Carlo data added; they nicely agree with our bootstrap calculations. Matches published version. v4: results for the extraordinary transition for N=2,3 removed: see added note
Command Horizons: Coalescing Data Dependencies while Maintaining Asynchronicity
Creators: name: Thoman, Peter
name: Salzmann, Philip
Publisher: name: Zenodo
Year: 2023
Subjects: dependency tracking
task graph
asynchronicity
command generation
gpu cluster

description: Slides for our presentation on command horizons at WAMTA 2023. Abstract
 In runtime systems for distributed memory parallel computing which automatically manage dependencies and data transfers, a fundamental trade-off exists between the fidelity of dependency tracking and the overhead incurred by its implementation.
 Precise tracking of data state allows for effective scheduling, which can leverage opportunities for compute and transfer parallelism. However, it also induces more overhead, and with some data access patterns this overhead can grow with e.g. the number of iterations of an algorithm.
 We present the concept of command horizons, which allow coalescing of previous fine-grained tracking information while maintaining an easily configurable scheduling window with full information precision. Furthermore, they enable consistent cluster-wide decision points without requiring any inter-node communication, and effectively cap the size of state tracking data structures even in the presence of problematic access patterns.
 Experimental evaluation on microbenchmarks demonstrates that horizons are effective in keeping the scheduling complexity constant, while their own overhead is negligible -- below $10 \mu s$ per horizon when building a command graph for 512 GPUs. We additionally demonstrate the performance impact of horizons -- as well as their low overhead -- on a real-world application.
An atomic Hong-Ou-Mandel experiment
Creators: name: Lopes, Raphael
name: Imanaliev, Almazbek
name: Aspect, Alain
name: Cheneau, Marc
name: Boiron, Denis
name: Westbrook, Christoph I.
Publisher: name: arXiv
Year: 2015
Subjects: subject: Quantum Physics (quant-ph)
subject: Quantum Gases (cond-mat.quant-gas)
subject: FOS: Physical sciences

description: The celebrated Hong, Ou and Mandel (HOM) effect is one of the simplest illustrations of two-particle interference, and is unique to the quantum realm. In the original experiment, two photons arriving simultaneously in the input channels of a beam-splitter were observed to always emerge together in one of the output channels. Here, we report on the realisation of a closely analogous experiment with atoms instead of photons. This opens the prospect of testing Bell's inequalities involving mechanical observables of massive particles, such as momentum, using methods inspired by quantum optics, with an eye on theories of the quantum-to-classical transition. Our work also demonstrates a new way to produce and benchmark twin-atom pairs that may be of interest for quantum information processing and quantum simulation.
title: Oxide structure prediction and synthesis
Creators: name: Collins, Christopher
Publisher: name: University of Liverpool Repository
Year: 2014

description: Introduction: The focus of this chapter is to introduce the perovskite structure, beginning from the ideal cubit perovskite with the ABX3 formula unit. The concept of introducing long range ordering into the material are then presented along with the driving forces behind the extension of the structure. Possible magnetic ordering and solid solutions of perovskites are then presented. This is followed by the introduction of how theoretical chemistry can provide useful information to investigations and begin to predict how new materials can be made and is followed by a summary of the techniques commonly used. Methods: This chapter introduces the experimental methods used within this thesis, along with a description of the diffraction techniques used in the characterisation of oxide materials; including x-ray and neutron diffraction, iodometric titrations and the basic concepts behind Mössbauer spectroscopy. The second part to the chapter provides details on density functional theory (DFT) and force field (FF) calculations that are used throughout the thesis for the prediction of new materials. Chapter 3: Details the use of a series of calculations with DFT on the chemical substitution in the YBa2Fe3-xMxO8 (where M = Co, Ni and Mn), where the calculations are first tested on doping with Co, where it has been previously been experimentally reported. Calculations for un-reported substitutions a new compound is predicted. Synthetic investigations are then undertaken across the series, and a new material found where DFT calculations predict a new compound. Characterisation of the new material reveals that it has a crystal structure in good agreement with the structure predicted by DFT. Chapter 4: Computationally investigates doping in the YBa2Ca2Fe5-xMxO13 (M = Co, Cu, Mn, Ni, Ti and Zn) solid oxide fuel cell cathode material using DFT. The results from the calculations predict stable doping for Cu and Co, with small doping levels favoured for M = Ni and Zn, with M = Mn yielding results predicting marginal doping and doping not favoured at all for M = Ti. Chapter 5: When D. Hodgeman was experimentally investigating Cu doping of the YBa2Ca2Fe5O13 material an unknown perovskite superstructure was observed by x-ray diffraction. This chapter then focuses on the development of the Extended Module Materials Assembly (EMMA) method. The method is validated be correctly computing the correct crystal structure for the YBa2Ca2Fe5O13 perovskite and is used to predict the structure for the new Y2.24Ba2.28Ca3.48Fe7.44Cu0.56O21perovskite. The crystal structure predicted by EMMA is then used as the basis for the experimental refinement of the structure and the structures found to be in good agreement.
title: Multi-agent and knowledge-based system for power transformer fault diagnosis
Creators: name: Davoodi Samirmi, Farhad
Publisher: name: University of Liverpool Repository
Year: 2014

description: Transformer reliability and stability are the key concerns. In order to increase their efficiency, an automatic monitoring and fault diagnosing of the power transformers are required. Dissolved Gas Analysis (DGA) is one of the most important tools to diagnose the condition of oil-immersed transformer. Agents technology as a new, robust and helpful technique, successfully applied for various applications. Integration of the Multi-Agent System (MAS) with knowledge base provides a robust system for various applications, such as fault diagnosis and automated actions performing, etc. For this purpose, the present study was conducted in the field of MAS based on Gaia methodology and knowledge base. The developed MAS followed by Gaia methodology represents a generic framework that is capable to manage agents executions and message delivery. Real-time data is sampled from a power transformer and saved into a database, and it is also available to the user on request. Three types of knowledge-based systems, namely the rule-based reasoning, ontology and fuzzy ontology, were applied for the MAS. Therefore, the developed MAS is shown to be successfully applied for condition monitoring of power transformer using the real-time data. The Roger’s method was used with all of the knowledge-based systems named above, and the accuracy of the results was compared and discussed. Of the knowledge-based systems studied, fuzzy ontology is found to be the best performing one in terms of results accuracy, compared to the rule-based reasoning and ontology. The application of the developed fuzzy ontology allowed to improve the accuracy by over 22%. Unlike the previous works in this field, that were not capable of dealing with the uncertainty situations, the present work based on fuzzy ontology has a clear advantage of successfully solving the problem with some degree of uncertainty. This is especially important, as the most of the real-world situations involve some uncertainty. Overall, the work contributes the use of the knowledge base and the multi-agent system for the fault diagnosis of the power transformer, including the novel application of fuzzy ontology for dealing with the uncertain situations. The advantages of the proposed method are the ease of the upgrade, flexibility, efficient fault diagnosis and reliability. The application of the proposed technique would benefit the power system reliability, as it would result in reduction of the number of engineering experts required, lower maintenance expenses and extended lifetime of power transformer.
title: Comparison of statistical methods of handling missing binary outcome data in randomized controlled trials of efficacy studies
Creators: name: Mukaka, Mavuto
Publisher: name: University of Liverpool Repository
Year: 2014

description: The presence of some missing outcomes in randomized studies often complicates the estimation of measures of effect, even in well designed randomized controlled trials. The process may be complicated further when the efficacy rates are close to 0% or 100% as the standard binomial model is susceptible to model non-convergence. The main objective of this study was to compare the performance of multiple imputation (MI) and Complete Case analysis for dealing with missing binary outcomes when modeling a risk difference. Firstly, however, the binomial regression COPY method and the Cheung’s modified Ordinary Least Squares (OLS) method were examined using simulation processes for their appropriateness in risk difference modeling. It was found that the number of copies (for the COPY method) required to minimize non-convergence coincided with the number of copies that gave the most biased estimates of the true efficacy difference while increasing the number of copies made the problems of non-convergence and bias worse; using Cheung’s method, however, there was 100% convergence with unbiased estimates of effect size. Simulation methods were used to compare the performance of complete case (CC) analysis and several multiple imputation (MI) models for handling missing outcome data over a wide range of efficacy environments and missing value assumptions. When outcomes were missing at random (MAR) or completely at random (MCAR), MI analyses that included treatment group membership in the imputation calculations yielded unbiased estimates of efficacy differences. The CC method was found to be as good, and often better, than MI methods when outcomes were MAR or MCAR, with coverage close to 95% in many situations – but neither CC nor MI produced unbiased estimates of effect difference when outcomes were missing not at random (MNAR). It was concluded that CC and MI methods are equally good in terms of producing unbiased estimates of effect difference in most missing outcome situations, but applying the intention to treat principle (ITT) which requires all randomized patients to be included in the primary analysis of a RCT, MI should be adopted as the analysis method of first choice, accompanied by a secondary CC analysis for sensitivity purposes (i.e. to investigate the extent of any likely bias).
A radial velocity survey for post-common-envelope Wolf-Rayet central stars of planetary nebulae: First results and discovery of the close binary nucleus of NGC 5189
Creators: name: Manick, Rajeev
name: Miszalski, Brent
name: McBride, Vanessa
Publisher: name: arXiv
Year: 2015
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: The formation of Wolf-Rayet central stars of planetary nebulae ([WR] CSPNe) whose spectroscopic appearance mimics massive WR stars remains poorly understood. Least understood is the nature and frequency of binary companions to [WR] CSPNe that may explain their H-deficiency. We have conducted a systematic radial velocity (RV) study of 6 [WR] CSPNe to search for post-common-envelope (post-CE) [WR] binaries. We used a cross-correlation method to construct the RV time-series as successfully done for massive close binary WR stars. No significant RV variability was detected for the late-[WC] type nuclei of Hen 2-113, Hen 3-1333, PMR 2 and Hen 2-99. Significant, large-amplitude variability was found in the [WC4] nucleus of NGC 5315. In the [WO1] nucleus of NGC 5189 we discovered significant periodic variability that reveals a close binary with $P_\mathrm{orb}=4.04\pm0.1$ d. We measured a semi-amplitude of $62.3\pm1.3$ km s$^{-1}$ that gives a companion mass of $m_2\ge0.5$ $M_\odot$ or $m_2=0.84$ $M_\odot$ (assuming $i=45^\circ$). The most plausible companion type is a massive WD as found in Fleming 1. The spectacular nebular morphology of NGC 5189 fits the pattern of recently discovered post-CE PNe extremely well with its dominant low-ionisation structures (e.g. as in NGC 6326) and collimated outflows (e.g. as in Fleming 1). The anomalously long 4.04 d orbital period is either a once-off (e.g. NGC 2346) or it may indicate there is a sizeable population of [WR] binaries with massive WD companions in relatively wide orbits, perhaps influenced by interactions with the strong [WR] wind.
description: Accepted for publication by MNRAS, 22 pages, 7 figures, 10 tables
Recognizing nullhomotopic maps into the classifying space of a Kac-Moody group
Creators: name: Foley, John D.
Publisher: name: arXiv
Year: 2015
Subjects: subject: Algebraic Topology (math.AT)
subject: FOS: Mathematics
subject: 57T99, 20E42

description: This paper extends certain characterizations of nullhomotopic maps between p-compact groups to maps with target the p-completed classifying space of a connected Kac-Moody group and source the classifying space of either a p-compact group or a connected Kac-Moody group. A well known inductive principle for p-compact groups is applied to obtain general, mapping space level results. An arithmetic fiber square computation shows that a null map from the classifying space of a connected compact Lie group to the classifying space of a connected topological Kac-Moody group can be detected by restricting to the maximal torus. Null maps between the classifying spaces of connected topological Kac-Moody groups cannot, in general, be detected by restricting to the maximal torus due to the nonvanishing of an explicit abelian group of obstructions described here. Nevertheless, partial results are obtained via the application of algebraic discrete Morse theory to higher derived limit calculations. These partial results show that null maps are detected by restricting to the maximal torus in many cases of interest.
description: Sections 2 & 3 combined, exposition updates, new article style; 36 pages, 4 figures, one table
title: Synthesis and characterization of, and dynamic processes occurring in, highly active Pd catalyst for alkyne and alkene hydroesterification
Creators: name: Al-Mosule, Firas
Publisher: name: University of Liverpool Repository
Year: 2014

description: Chapter one reviews the literature surrounding three main areas of interest relevant to the research carried out. These areas include industrial process for the synthesis of methyl methacrylate, the carbonylation of alkynes and alkenes. In addition, review effect of the ligands and counterion on the catalyst system, and dynamic process and NMR of the catalyst. Chapter two outlines simple, generic procedures to Pd-‘chelate-monodentate’ complexes and investigates the coordination chemistry and hemilability of such complexes. In addition, an explanation of the organometallic chemistry of the Pd-‘chelate-monodentate’ complexes and synthesis of these complexes illustrates the possibility of nitrogen playing a role in proton relay. Also, introduces the variable temperature spectra of a [Pd(ҡ2-Ph2Ppy)(ҡ1-Ph2Ppy)2] [CH3SO3]2 (6), and [Pd(ҡ2-Ph2Ppy)(ҡ1-Ph2Ppy)Cl][X] (3[X]), (X = Cl, OTf, BF4), uses a computer program to simulate gNMR discusses the associative mechanism of exchange in Pd-‘chelate-monodentate’ complexes. Finally, details the experimental procedures undertaken in the above work. Chapter three illustrates how can preparation of the new alkanesulfonic acids (R = C8, C9, C11, C14, C16, C18) which use instead of methanesulfonic acid in hydroesterification of alkene process. In terms of follow the two strategies, first strategy depends on synthesis of silver alkanesulfonate salts from interaction of sodium alkanesulfonate salts with AgNO3 then reaction with palladium complex. While in the second strategy, free alkanesulfonic acid was prepared in situ, via reaction of HBF4 with a series of sodium alkanesulfonate salts (R = C8, C9, C11, C14, C16, C18), then added to palladium complex in a sapphire tube of HPNMR spectroscopy for studies and confirm steps of the catalytic cycle. Chapter four draws on the conclusions derived from the above work and relates it to work previously carried out in the field.
Root functional traits determine the magnitude of the rhizosphere priming effect among eight tree species
Creators: name: Chao, Lin
name: Liu, Yanyan
name: Zhang, Weidong
name: Wang, Qingkui
name: Guan, Xin
name: Yang, Qingpeng
name: Chen, Longchi
name: Zhang, Jianbing
name: Hu, Baoqing
name: Liu, Zhanfeng
name: Wang, Silong
name: Freschet, Grégoire T.
Publisher: name: Zenodo
Year: 2023
Subjects: rhizosphere priming effect
Plant functional traits
fine roots
13C natural abundance

description: Rhizosphere priming effect can accelerate or decelerate the decomposition of soil organic matter. Using a natural abundance 13C tracer method allowing partitioning of native soil organic carbon (SOC) decomposition and plant rhizosphere respiration, we studied the effects of eight tree species on the strength of the rhizosphere priming. All tree species enhanced the rate of SOC decomposition, by 82% on average. Mean diameter of first-order roots and root exudate-derived respiration were positively correlated with the RPE, together explaining a large part of the observed variation in the RPE (R2 = 0.72), whereas root branching density was negatively associated with the RPE. Path analyses further suggested that mean diameter of first-order roots was the main driver of the RPE owing to its positive direct effect on the RPE and its indirect effects via root exudate-derived respiration and root branching density. These results demonstrate that the magnitude of the RPE is regulated by complementary aspects of root morphology, architecture and physiology, implying that comprehensive approaches are needed to reveal the multiple mechanisms driving plant effects on the RPE.
description: Funding provided by: National Natural Science Foundation of China
Crossref Funder Registry ID: http://dx.doi.org/10.13039/501100001809
Award Number: U22A20612Funding provided by: National Natural Science Foundation of China
Crossref Funder Registry ID: http://dx.doi.org/10.13039/501100001809
Award Number: 32201540Funding provided by: National Natural Science Foundation of China
Crossref Funder Registry ID: http://dx.doi.org/10.13039/501100001809
Award Number: 42177289Funding provided by: National Key Research and Development Program of China
Crossref Funder Registry ID: http://dx.doi.org/10.13039/501100012166
Award Number: 2022YFF1303003Funding provided by: National Key Research and Development Program of China
Crossref Funder Registry ID: http://dx.doi.org/10.13039/501100012166
Award Number: 2021YFD2201303Funding provided by: Laboratoires d'Excellences (LABEX)" TULIP*
Crossref Funder Registry ID:
Award Number: ANR-10-LABX-41
Numerical methods in the context of compartmental models in epidemiology
Creators: name: Kratz, Peter
name: Pardoux, Etienne
name: Kepgnou, Brice Samegni
Publisher: name: arXiv
Year: 2015
Subjects: subject: Probability (math.PR)
subject: FOS: Mathematics
subject: 92C60, 60F10, 65C30, 65L12

description: We consider compartmental models in epidemiology. For the study of the divergence of the stochastic model from its corresponding deterministic limit (i.e., the solution of an ODE) for long time horizon, a large deviations principle suggests a thorough numerical analysis of the two models. The aim of this paper is to present three such motivated numerical works. We first compute the solution of the ODE model by means of a non-standard finite difference scheme. Next we solve a constraint optimization problem via discrete-time dynamic programming: this enables us to compute the leading term in the large deviations principle of the time of extinction of a given disease. Finally, we apply the τ-leaping algorithm to the stochastic model in order to simulate its solution efficiently. We illustrate these numerical methods by applying them to two examples.
description: Conference Proceedings
J/ψ Production in d + Au and p + p Collisions at √s= 200 GeV
Creators: name: Kim, DongJo
Publisher: name: Zenodo
Year: 2004
Subjects: J/ψ
Color-octant Model
shadowing
cross section
antishadowing

description: We present the transverse momentum distribution above 2 GeV/c for p + p collisions which are reasonable well described by the color-octant model (COM). The COM calculations are able to reproduce √s dependence of the cross section using color octet matrix with a reasonable choice of QCD parameters. The differential cross section have been extracted for both muon and electron channels, we find that the rapidity distribution shape is consistent with known Parton Distribution Functions (PDF). We also report the ratio of the J/ψ production in d + Au collisions to p + p collisions as a function of rapidity which shows consistency with shadowing at low x and suppression at larger x.
title: Stochastic control methods to individualise drug therapy by incorporating pharmacokinetic, pharmacodynamic and adverse event data
Creators: name: Francis, Ben
Publisher: name: University of Liverpool Repository
Year: 2013

description: There are a number of methods available to clinicians for determining an individualised dosage regimen for a patient. However, often these methods are non-adaptive to the patient’s requirements and do not allow for changing clinical targets throughout the course of therapy. The drug dose algorithm constructed in this thesis, using stochastic control methods, harnesses information on the variability of the patient’s response to the drug thus ensuring the algorithm is adapting to the needs of the patient. Novel research is undertaken to include process noise in the Pharmacokinetic/Pharmacodynamic (PK/PD) response prediction to better simulate the patient response to the dose by allowing values sampled from the individual PK/PD parameter distributions to vary over time. The Kalman filter is then adapted to use these predictions alongside measurements, feeding information back into the algorithm in order to better ascertain the current PK/PD response of the patient. From this a dosage regimen is estimated to induce desired future PK/PD response via an appropriately formulated cost function. Further novel work explores different formulations of this cost function by considering probabilities from a Markov model. In applied examples, previous methodology is adapted to allow control of patients that have missing covariate information to be appropriately dosed in warfarin therapy. Then using the introduced methodology in the thesis, the drug dose algorithm is shown to be adaptive to patient needs for imatinib and simvastatin therapy. The differences, between standard dosing and estimated dosage regimens using the methodologies developed, are wide ranging as some patients require no dose alterations whereas other required a substantial change in dosing to meet the PK/PD targets. The outdated paradigm of ‘one size fits all’ dosing is subject to debate and the research in this thesis adds to the evidence and also provides an algorithm for a better approach to the challenge of individualising drug therapy to treat the patient more effectively. The drug dose algorithm developed is applicable to many different drug therapy scenarios due to the enhancements made to the formulation of the cost functions. With this in mind, application of the drug dose algorithm in a wide range of clinical dosing decisions is possible.
Removal and Stability for Erdős-Ko-Rado
Creators: name: Das, Shagnik
name: Tran, Tuan
Publisher: name: arXiv
Year: 2014
Subjects: subject: Combinatorics (math.CO)
subject: FOS: Mathematics

description: A $k$-uniform family of subsets of $[n]$ is intersecting if it does not contain a disjoint pair of sets. The study of intersecting families is central to extremal set theory, dating back to the seminal Erdős-Ko-Rado theorem of 1961 that bounds the size of the largest such families. A recent trend has been to investigate the structure of set families with few disjoint pairs. Friedgut and Regev proved a general removal lemma, showing that when $γn \le k \le (\tfrac12 - γ)n$, a set family with few disjoint pairs can be made intersecting by removing few sets. We provide a simple proof of a removal lemma for large families, showing that families of size close to $\ell \binom{n-1}{k-1}$ with relatively few disjoint pairs must be close to a union of $\ell$ stars. Our lemma holds for a wide range of uniformities; in particular, when $\ell = 1$, the result holds for all $2 \le k < \frac{n}{2}$ and provides sharp quantitative estimates. We use this removal lemma to settle a question of Bollobás, Narayanan and Raigorodskii regarding the independence number of random subgraphs of the Kneser graph $K(n,k)$. The Erdős-Ko-Rado theorem shows $α(K(n,k)) = \binom{n-1}{k-1}$. For some constant $c > 0$ and $k \le cn$, we determine the sharp threshold for when this equality holds for random subgraphs of $K(n,k)$, and provide strong bounds on the critical probability for $k \le \tfrac12 (n-3)$.
description: 13 pages; minor changes made following referee feedback