cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Two-Player Continuous Game Theory for Product Portfolio Management in a Competitive Manufacturing Market
Creators: name: Esmaeili, Maryam
Publisher: name: figshare
Year: 2021
Subjects: subject: 91503 Engineering Practice
subject: FOS: Other engineering and technologies

description: Todays, the variety of new products will raise the competition between manufacturers. Product portfolio management (PPM) as a suitable tool can influence the customer’s taste and increase the profit of firms. In this paper, the factors of PPM, production planning and a two-player continuous game theory are considered simultaneously. Some constraints are also assumed such as the availability of raw materials and the demand of each product based on some criteria. Two firms have same offered products and compete with each other. The relationships between two producers will be modeled by a non-zero two- player game. A numerical example is presented too. The proposed model is single period that the inventory is equal to zero in the start and finish of period. The objective functions show the profit of products and the constraints are included the utility of products for each customer, the market's share as a function of the probability of customer selection for each section, the type of distribution function for sale quantity, the accessible quantity of the sum of used materials by two producers and etc.
The results shows that demand changing effects on the profit of two players, but effects more on the second player. Also the sale price changing effects on the profit of two players, but effects more on the first player. The obtained data shows that if extra sale price increase the profit of first player will increase while the profit of second player is constant approximately.
Polymer heat transport enhancement in thermal convection: the case of Rayleigh-Taylor turbulence
Creators: name: Boffetta, G.
name: Mazzino, A.
name: Musacchio, S.
name: Vozella, L.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Chaotic Dynamics (nlin.CD)
subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: We study the effects of polymer additives on turbulence generated by the ubiquitous Rayleigh-Taylor instability. Numerical simulations of complete viscoelastic models provide clear evidence that the heat transport is enhanced up to 50% with respect to the Newtonian case. This phenomenon is accompanied by a speed up of the mixing layer growth. We give a phenomenological interpretation of these results based on small-scale turbulent reduction induced by polymers.
description: 4 pages, 5 figures
Common Bugs in Scratch Programs
Creators: name: Frädrich, Christoph
name: Obermüller, Florian
name: Körber, Nina
name: Heuer, Ute
name: Fraser, Gordon
Publisher: name: arXiv
Year: 2021
Subjects: subject: Software Engineering (cs.SE)
subject: FOS: Computer and information sciences
subject: D.2.5; K.3.2
subject: 97P50

description: Bugs in Scratch programs can spoil the fun and inhibit learning success. Many common bugs are the result of recurring patterns of bad code. In this paper we present a collection of common code patterns that typically hint at bugs in Scratch programs, and the LitterBox tool which can automatically detect them. We empirically evaluate how frequently these patterns occur, and how severe their consequences usually are. While fixing bugs inevitably is part of learning, the possibility to identify the bugs automatically provides the potential to support learners
description: Proceedings of the 2020 ACM Conference on Innovation and Technology in Computer Science Education (pp. 89-95)
Predictors of response to iron and erythropoietin stimulating agents in haemodialysis patients
Creators: name: Hildebrand, Sarah Valerie
Publisher: name: Imperial College London
Year: 2019

description: Renal anaemia affects a large proportion of haemodialysis patients. Treatment for this is with erythropoietin stimulating agents (ESA) and intravenous iron, response to which is unpredictable. These medications are titrated according to haemoglobin and ferritin levels which are measured monthly in these individuals. This study aims to evaluate the role of alternate biomarkers in predicting a treatment response. Method This study randomised individuals with a haemoglobin (Hb) between 90 and 104g/l and ferritin between 100 and 800ng/l to either an incremental increase in ESA dose or a course of intravenous iron sucrose, with bloods for biomarkers taken prior to the receipt of this medication. A positive treatment response was defined as an increase in haemoglobin of 5g/l within two months. Non-responders received the alternate treatment with response re-assessed. Results Over 2423 patient months amongst 196 individuals, there were 160 completed randomisation episodes. Response to ESA was seen in 61/84 (72.6%) and to iron in 53/76 (69.7%). C-reactive protein (CRP) was the strongest predictor of a positive treatment response (13.46mg/l versus 28.59mg/l in non-responders, p=0.038) with a lesser impact of a lower baseline ESA dose (2529.5 versus 2913.0 units/session, p=0.243). Successful iron treatment was associated with lower reticulocyte haemoglobin (33.8 vs 35.5pg, p=0.047), lower hepcidin (91.4 vs 131.0ug/ml, p=0.021) and higher C-reactive protein (29.5 vs 12.6mg/l, p=0.085). Interaction modelling indicated that CRP (p=0.08) and ESA dose (p=0.058) were the strongest differentiators of response to the two different treatments. Discussion Increased ESA and iron are equally effective, though treatment failure occurs in almost 30%. Baseline variables can predict treatment response, and a four-variable score shows promise in allowing directed treatment with improved response rates.
On the concentration-compactness phenomenon for the first Schrodinger eigenvalue
Creators: name: Kokarev, Gerasim
Publisher: name: arXiv
Year: 2009
Subjects: subject: Spectral Theory (math.SP)
subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics
subject: 58C40, 58E30

description: We study a variational problem for the first Schrodinger eigenvalue on closed Riemannian surfaces. More precisely, we explore concentration-compactness properties of sequences formed by its extremal potentials.
description: 14 pages
Classical isotropic two body potentials generating martensitic transformations
Creators: name: Laguna, M. F.
name: Jagla, E. A.
Publisher: name: arXiv
Year: 2009
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: An isotropic interaction potential for classical particles is devised in such a way that the crystalline ground state of the system changes discontinuously when some parameter of the potential is varied. Using this potential we model martensitic transformations, and are able to study in detail the processes that are usually associated with it: shape memory effect, superelasticity, as well as many details concerning the dynamics of the transformation, particularly the characteristics of the martensitic texture obtained as a function of parameters affecting the transformation rate. Here we introduce the interaction potentials and present some basic results about the transformation it describes, for the particular case of two dimensional triangular-rombohedral and triangular-square transformation.
description: 13 pages, 14 figures
Study of the archetypal patterns in "The Princess", "The Woman Who Rode Away", and St. Mawr, by D.H. Lawrence
Creators: name: MacPhee, Marilynne Ann Cawker
Publisher: name: University of British Columbia
Year: 2011

description: Lawrence's Letters dated September and October, 1924 give clear evidence that Lawrence considered St. Mawr, "The Princess", and "The Woman Who Rode Away" to be an organic group related in terms of theme, mood and setting. My interpretation of the archetypal patterns underlying these three works gives further evidence of their overall unity in symbolic and structural design, a design which consists of five major features: 1) a marked dependence on mythic patterns which manifest the psychic growth of the heroines, and structure that growth in terms of the heroic quest. 2) an emphatic change in mood from alienation and numb despair to hope and belief in fulfillment marks the onset of the quest, and separates each work into two distinct modes: satire and romance in St. Mawr, irony and romance in "The Princess" and "The Woman Who Rode Away". 3) the quest involves not only a rejection of social values and conduct but also a full acceptance of the living cosmos. This acceptance is sparked by a new relationship between person and place which entails the discovery that human growth and fulfillment is possible only through finding one's true identity within the whole fabric of nature. 4) a central concern with defining power in its positive aspects as the vitality and creativity of being, and in its negative aspects as the force and bullying of the will and ego. Power can either renew or distort and destroy life. 5) the major focus of the works is on the process of metamorphosis, or death and rebirth, which promises the reintegration of man, society, and nature. The New Mexican works show Lawrence exploring the existential process of maturation—how the spirit develops and comes to fruition, and striving to realize the furthest limits of human awareness through symbol and myth. These limits are expressed by means of the archetypal pattern of the quest which Lawrence uses to celebrate the unfolding and completion of the human spirit in all its beauty and vitality. Each work builds towards two climaxes: the moment of choice at which the heroine must decide whether her deepest loyalties lie with her family and her society, or with her deepest self; and the moment of illumination at which the heroine either accepts the responsibility of a freedom that is paradoxically a submission to the cosmic life force, or else loses courage and is broken by the battle of conscious and unconscious forces within her psyche.
On a Classification of Irreducible Almost-Commutative Geometries V
Creators: name: Jureit, Jan-Hendrik
name: Stephan, Christoph A.
Publisher: name: arXiv
Year: 2009
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We extend a classification of irreducible, almost-commutative geometries whose spectral action is dynamically non-degenerate, to internal algebras that have six simple summands. We find essentially four particle models: An extension of the standard model by a new species of fermions with vectorlike coupling to the gauge group and gauge invariant masses, two versions of the electro-strong model and a variety of the electro-strong model with Higgs mechanism.
Exploring experimental conditions to reduce uncertainties in the optical potential
Creators: name: Catacora-Rios, M.
name: King, G. B.
name: Lovell, A. E.
name: Nunes, F. M.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: Background: Uncertainty quantification for nuclear theories has gained a more prominent role in the field, with more and more groups attempting to understand the uncertainties on their calculations. However, recent studies have shown that the uncertainties on the optical potentials are too large for the theory to be useful. Purpose: The purpose of this work is to explore possible experimental conditions that may reduced the uncertainties on elastic scattering and single-nucleon transfer cross sections that come from the fitting of the optical model parameters to experimental data. Method: Using Bayesian methods, we explore the effect of the uncertainties of optical model parameters on the angular grid of the differential cross section, including cross section data at nearby energies, and changes in the experimental error bars. We also study the effect on the resulting uncertainty when other observables are included in the fitting procedure, particularly the total (reaction) cross sections. Results: We study proton and neutron elastic scattering on 48Ca and 208Pb. We explore the parameter space with Markov- Chain Monte Carlo, produce posterior distributions for the optical model parameters, and construct the corresponding 95% confidence intervals on the elastic-scattering cross sections. We also propagate the uncertainties on the optical potentials to the 48Ca(d,p)49Ca(g.s.) and 208Pb(d,p)209Pb(g.s.) cross sections. Conclusions: We find little sensitivity to the angular grid and an improvement of up to a factor of 2 on the uncertainties by including data at a nearby energy. Although reducing the error bars on the data does reduce the uncertainty, the gain is often considerably smaller than one would naively expect.
Investigating the role of the bone marrow stroma in the response of haematopoietic stem cells to Plasmodium berghei infection
Creators: name: Haltalli, Myriam Luydmila Rachelle
Publisher: name: Imperial College London
Year: 2019

description: Haematopoietic stem cells (HSCs) maintain the turnover of all blood cell lineages and reside within the bone marrow (BM), where they are critically dependant on interactions with complex and specialised niches. Severe infections can have profound effects on haematopoiesis and HSCs will adapt their progeny output to promptly cope with the increased demand for immune cells. This can often lead to exhaustion of the stem cell pool. BM niches have been shown to be altered during ageing and haematopoietic malignancies, but whether they play a role in mediating the effects of infection on HSCs remains an open question. Using a murine model of malaria infection, I established, through phenotypic analysis and mathematical modelling, that the entire haematopoietic stem and progenitor cell (HSPC) compartment is affected and activated by Plasmodium berghei infection, with significant changes in their proliferation rates (Chapter 3). Transplantation assays demonstrated a loss of long-term function of HSCs exposed to P. berghei and this was accompanied by an overall loss of the transcriptional HSC signature and rewiring of haematopoiesis assessed by single cell RNA sequencing (Chapter 4). I also show that, as well as a global interferon (IFN) response by HSPCs, IFN dramatically affects the BM microenvironment with diffuse disruption of BM vascular integrity and a systemic loss of osteoblasts over the course of P. berghei infection (Chapter 5). By targeting the osteolineage with parathyroid hormone, I was able to reduce osteoblast loss, lower local and systemic IFN levels and prevent HSC proliferation. Together, this thesis provides an insight into how severe infection affects both haematopoiesis and the BM microenvironment and opens up new avenues for further research and therapeutic interventions that may improve the health of survivors of severe infection.
Differential operator realizations of superalgebras and free field representations of corresponding current algebras
Creators: name: Yang, Wen-Li
name: Zhang, Yao-Zhong
name: Kault, Samuel
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Based on the particular orderings introduced for the positive roots of finite dimensional basic Lie superalgebras, we construct the explicit differential operator representations of the $osp(2r|2n)$ and $osp(2r+1|2n)$ superalgebras and the explicit free field realizations of the corresponding current superalgebras $osp(2r|2n)_k$ and $osp(2r+1|2n)_k$ at an arbitrary level $k$. The free field representations of the corresponding energy-momentum tensors and screening currents of the first kind are also presented.
description: Latex file; 41 pages; V2, typos corrected
Digital Citizenship "Consumer Awareness" Course
Creators: name: XYLOURI Ourania
name: TEAM4Excellence Association
Publisher: name: Zenodo
Year: 2022
Subjects: Model course

description: The development of technology has created a new social structure that controls who, how and when individuals interact with society. In less than 30 years, the use of the Internet, mobile phones and computers has increased to the point that we hardly know what we would do without them. Digital citizens are required to act in a certain way that fits with accepted norms, standards and regulations.

The Consumer awareness course is needed because it covers specific issues related to online shopping and consumer awareness, which young people often neglect or are unaware of. Online shopping has grown in popularity over the years. A December 2011 study, Equation Research found that 87% of tablet users made an online transaction with their tablet device during the early holiday shopping season.

This course was designed as an instrument to assist teachers, trainers and youth workers in their daily work with young people. However, the course may be also followed directly by young people on their own. It includes readings, exercises, case studies, quizzes and self-reflection questions, divided into five modules:

Introduction to consumer awareness in digital environments;

Ethical considerations and risks for online shopping;

Online marketing;

E-Entrepreneurship;

Getting deeper into consumers’ rights and responsibilities.

While this Consumer awareness course textbook is available to download for free here and in the TrainingClub.eu European non-formal education platform of TEAM4Excellence, it is also available as a Moodle massive open online course in English. Furthermore, each module was translated into three languages: Romanian, Greek and German.

“Consumer awareness” is the result of the Erasmus+ project “Strategic partnership to develop open educational resources for teaching digital citizenship”, implemented by a consortium of four partners from Romania, Cyprus, Germany and Greece, aiming at improving a broad range of competences, so citizens are able to actively, positively and responsibly engage in both on and offline communities.

The authors consider that digital citizenship should be faced as a multidimensional and complex concept. Based on this aspect, they created 10 courses that together help improve the digital citizenship skills of people: Access and Inclusion, Learning and Creativity, Media and Information Literacy, Ethics and Empathy, Health and Wellbeing, ePresence and Communication, Active Participation, Rights and Responsibilities, Privacy and Security, Consumer Awareness.

Besides English, each course was translated into three more languages: Romanian, Greek and German. All the courses may be accessed online and anyone can enrol on Moodle and follow the courses for free.
description: Grant Agreement 2019-3-RO01-KA205-078053, Strategic partnership to develop open educational resources for teaching digital citizenship (DIGCIT)
Defining the members of the microbiota that regulate innate immunity and protect against respiratory infection
Creators: name: Brown, Rebecca Louise
Publisher: name: Imperial College London
Year: 2019

description: Humans are colonised by myriad bacteria, viruses and fungi, which constitute the microbiota. The majority reside in the gut and provide benefits to the host including regulating the development and maturation of the immune system. How the host’s innate immune system detects and responds to individual commensal species, and what the contributions of specific species are to immune regulation are poorly defined. This thesis investigates the immuno-stimulatory capacity of commensals from major phyla in the human gut by analysing cytokine induction and PRR activation by each species, thereby revealing their individual immunological fingerprint. Potent NOD2-activating commensal bacteria were identified and found, as a consortium, to boost resistance to a pulmonary S. pneumoniae infection. Protection was mediated by a GM-CSF-dependent mechanism which potentiated the bactericidal activity of alveolar macrophages. Signalling pathways activated downstream of PRRs by gut commensals were defined and found to vary between species, which may tailor the immune response to the specific stimulus. Important signalling nodes, common to all commensals such as ERK, RIP2 and the negative regulators MSK1 and MSK2, were also identified. Commensal gut bacteria were shown to induce memory, termed ‘trained immunity’, in innate cells and this altered the cytokine response to subsequent stimulations. An mTOR/AKT/HIF1-α-dependent mechanism of metabolic changes was identified to be important for most species to produce memory, however a reliance on glutaminolysis and cholesterol synthesis was also shown for certain commensals. The importance of epigenetic modifications facilitated by methyltransferase enzymes was demonstrated and supports the requirement for open chromatin, produced by histone methylation, at inflammatory cytokine promoters during innate immune training. This thesis establishes the variance in detection of, and immediate and long-term responses to, gut commensal bacteria by the innate immune system. Key species have been identified as major regulators of immunity and which protect the host against infection. These organisms could be investigated as novel therapeutics to manipulate innate immunity in diseases characterised by hypo- or hyper-inflammatory responses.
Unsettling grounds historiography and archaeology in Greek ‘colonization’
Creators: name: Georgopoulos, Panagiotis
Publisher: name: University of Leicester
Year: 2021
Subjects: Uncategorized

description: The present research responds to the long discussion about the nature of Greek colonization which is characterized by an uninspiring progress in international scholarship, and remarkable divergences in national scholarships.This study aims to unlock the debates concerning the approach to Greek ‘colonization’. By examining the course of historiography and archaeology related to Greek ‘colonization’ during the 20th century, it presents and explains our modern divergent stances towards the phenomenon as being influenced by wider intellectual trends, disciplinary methodologies and national politics: factors that influence our general view of antiquity. Until today, different paths are followed by both international scholarship and national traditions, in such a way that they perpetuate this ancient phenomenon and make it difficult to comprehend it. The scholarship about Greek ‘colonization’ is thus fragmented and characterized by numerous and different voices.This thesis advocates that multivocality be embraced as the medium for a fuller understanding of Greek ‘colonization’. Employing contemporary models from the disciplines of ancient history and art history – John Ma’s ‘Black Hunter variations’ and Richard Brilliant’s My Laocoön – this thesis asserts that a combinative approach provides a more thorough understanding of ancient interaction in the Greek ‘colonies’.The Aristonothos Krater and the Iron Age settlement of Smyrna will be the case studies. I have chosen these examples so that I can offer two different scales of analysis: from the micro (a single object) to the macro (an entire site). For each case study, I will offer a series of different readings/interpretations focused on what each example tells us about cultural interaction, based on the different national schools and approaches. By showcasing the diverse interpretations alongside each other, I will demonstrate the fundamental subjectivity of cultural interaction in the Greek ‘colonies’ as well as showing that insight can be gained by combining different perspectives.
Generating argumentation frameworks from text
Creators: name: Cocarascu, Oana
Publisher: name: Imperial College London
Year: 2019

description: Artificial Intelligence targets the design and creation of intelligent machines that behave like humans. One fundamental aspect of human intelligence is the ability to argue. In the past years, the field of Computational Argumentation has seen a remarkable expansion within the Natural Language Processing (NLP) community with the potential to have an impact on real world applications ranging from legal and healthcare to finance and (social) media. Our contributions to this field are threefold: we develop models for Argument Mining (AM), methods for mining Argumentation Frameworks (AFs) from text, and applications of the two in real world settings. We focus on one area in AM, namely Relation-based AM (RbAM), that deals with determining the argumentative relation of attack or support between texts. We bring together existing datasets available for RbAM, covering various domains and topics, and propose neural models for the cross-domain RbAM classification task. We show that our models perform homogeneously over all existing datasets for relation prediction in AM overcoming the issue of AM models that are hardly portable from one application domain to another. We also present methods for extracting AFs from text, using the developed AM models in combination with NLP techniques, and Abstract Argumentation (AA)-driven Case-Based Reasoning (CBR), an existing reasoning formalism. We apply AM in detecting deceptive reviews and in extracting arguments from a movie review website, Rotten Tomatoes, one of the most trusted websites for movies, whilst providing explanations extracted from the AFs mined from reviews. We apply AA-CBR in the Sentiment Analysis task to determine the sentiment polarity of short texts and show empirically that reasoning with AFs leads to an improvement in results compared to standard machine learning models whilst also illustrating the portability of explanations to binary classification problems.
On injective modules and support varieties for the small quantum group
Creators: name: Drupieski, Christopher M.
Publisher: name: arXiv
Year: 2009
Subjects: subject: Representation Theory (math.RT)
subject: Quantum Algebra (math.QA)
subject: FOS: Mathematics
subject: 17B37 (Primary), 20G10 (Secondary)

description: Let $u_ζ(g)$ denote the small quantum group associated to the simple complex Lie algebra $g$, with parameter $q$ specialized to a primitive $\ell$-th root of unity $ζ$ in the field $k$. Generalizing a result of Cline, Parshall and Scott, we show that if $M$ is a finite-dimensional $u_ζ(g)$-module admitting a compatible torus action, then the injectivity of $M$ as a module for $u_ζ(g)$ can be detected by the restriction of $M$ to certain root subalgebras of $u_ζ(g)$. If the characteristic of $k$ is positive, then this injectivity criterion also holds for the higher Frobenius--Lusztig kernels $U_ζ(G_r)$ of the quantized enveloping algebra $U_ζ(g)$. Now suppose that $M$ lifts to a $U_ζ(g)$-module. Using a new rank variety type result for the support varieties of $u_ζ(g)$, we prove that the injectivity of $M$ for $u_ζ(g)$ can be detected by the restriction of $M$ to a single root subalgebra.
description: 21 pages. Title changed from previous version. Various other minor corrections and changes made
Mode changing in J1909$-$3744: the most precisely timed pulsar
Creators: name: Miles, Matthew T.
name: Shannon, Ryan M.
name: Bailes, Matthew
name: Reardon, Daniel J.
name: Buchner, Sarah
name: Middleton, Hannah
name: Spiewak, Renee
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: We present baseband radio observations of the millisecond pulsar J1909$-$3744, the most precisely timed pulsar, using the MeerKAT telescope as part of the MeerTime pulsar timing array campaign. During a particularly bright scintillation event the pulsar showed strong evidence of pulse mode changing, among the first millisecond pulsars and the shortest duty cycle millisecond pulsar to do so. Two modes appear to be present, with the weak (lower signal-to-noise ratio) mode arriving $9.26$ $\pm 3.94$ $μ$s earlier than the strong counterpart. Further, we present a new value of the jitter noise for this pulsar of $8.20 \pm 0.14$ ns in one hour, finding it to be consistent with previous measurements taken with the MeerKAT ($9 \pm 3$ ns) and Parkes ($8.6 \pm 0.8$ ns) telescopes, but inconsistent with the previously most precise measurement taken with the Green Bank telescope ($14 \pm 0.5$ ns). Timing analysis on the individual modes is carried out for this pulsar, and we find an approximate $10\%$ improvement in the timing precision is achievable through timing the strong mode only as opposed to the full sample of pulses. By forming a model of the average pulse from templates of the two modes, we time them simultaneously and demonstrate that this timing improvement can also be achieved in regular timing observations. We discuss the impact an improvement of this degree on this pulsar would have on searches for the stochastic gravitational wave background, as well as the impact of a similar improvement on all MeerTime PTA pulsars.
Phase transitions and bunching of correlated particles in a non-Hermitian quasicrystal
Creators: name: Longhi, Stefano
Publisher: name: arXiv
Year: 2023
Subjects: subject: Quantum Physics (quant-ph)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: Non-interacting particles in non-Hermitian quasi crystals display localization-delocalization and spectral phase transitions in complex energy plane, that can be characterized by point-gap topology. Here we investigate the spectral and dynamical features of two interacting particles in a non-Hermitian quasi crystal, described by an effective Hubbard model in an incommensurate sinusoidal potential with a complex phase, and unravel some intriguing effects without any Hermitian counterpart. Owing to the effective decrease of correlated hopping introduced by particle interaction, doublon states, i.e. bound particle states, display a much lower threshold for spectral and localization-delocalization transitions than single-particle states, leading to the emergence of mobility edges. Remarkably, since doublons display longer lifetimes, two particles initially placed in distant sites tend to bunch and stick together, forming a doublon state in the long time limit of evolution, a phenomenon that can be dubbed {\em non-Hermitian particle bunching}.
description: Editors' Suggestion
The study of singular plasmonic metasurfaces with Transformation Optics
Creators: name: Yang, Fan
Publisher: name: Imperial College London
Year: 2019

description: The singular plasmonic metasurfaces differ from the conventional metasurface, as they are featured with singular points, like sharp corners or small gaps. Even though these singularities are tiny for the whole structure, they totally change the optical response of the metasurface. Instead of a discrete nature of conventional metasurface, the singular metasurface possesses a continuous spectrum. This continuous nature comes from the hidden dimensions at the singular point, making the mode of singular metasurface excited at whatever incident angle or frequency. This continuous nature of a singular metasurface leads to a broadband absorption, forming a grey or even black surface. For instance, a shining flat gold surface becomes a black surface after structuring the surface with sharp tips. These sharp singular points have a broadband absorption such that the light with different colors are all absorbed, leading to a black surface. This thesis is devoted to the analytic study of the singular metasurface. By transforming the complex singular metasurface into the simple slab geometry, the analytic solution is obtained. In the slab frame, we acquire the source excitation, the dispersion relation and the absorption. This absorption is then modeled as the surface conductivity in the metasurface frame, largely simplifying the calculation. However, the sharp vertex in the singular metasurface can go down to the screening length that the spatial dispersion should be considered. After introducing the nonlocal effect into the calculation, the continuous spectrum becomes discrete for the singular metasurface. The role of spatial dispersion is to smear the singular point such that the field enhancement there is reduced. Also, we point out that the degree of nonlocality can be measured from the discrete spectrum by observing the spacing between the peaks. In addition, we also apply our calculation in the field of electron energy loss spectroscopy (EELS), where the optical response of the singular metasurface in time domain is investigated. Finally, we have also implemented transformation optics to facilitate the calculation of the coaxial aperture array in the field of extraordinary optical transmission (EOT), for which the calculation efficiency has been increased at least tenfold.
Indication for the coexistence of closed orbit and quantum interferometer with the same cross section in the organic metal (ET)4(H3O)[Fe(C2O4)3].C6H4Cl2: Persistence of SdH oscillations above 30 K
Creators: name: Vignolles, David
name: Audouard, Alain
name: Laukhin, Vladimir N.
name: Canadell, Enric
name: Prokhorova, Tatyana G.
name: Yagubskii, Eduard B.
Publisher: name: arXiv
Year: 2009
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Shubnikov-de Haas (SdH) and de Haas-van Alphen (dHvA) oscillations spectra of the quasi-two dimensional charge transfer salt $β$"-(ET)$_4$(H$_3$O)[Fe(C$_2$O$_4$)$_3$]$\cdot$C$_6$H$_4$Cl$_2$ have been investigated in pulsed magnetic fields up to 54 T. The data reveal three basic frequencies F$_a$, F$_b$ and F$_{b - a}$, which can be interpreted on the basis of three compensated closed orbits at low temperature. However a very weak thermal damping of the Fourier component F$_b$, with the highest amplitude, is evidenced for SdH spectra above about 6 K. As a result, magnetoresistance oscillations are observed at temperatures higher than 30 K. This feature, which is not observed for dHvA oscillations, is in line with quantum interference, pointing to a Fermi surface reconstruction in this compound.
description: published in Eur. Phys. J. B 71 203 (2009)
Single Pixel Polarimetric Imaging through Scattering Media
Creators: name: Seow, Cheryl
Publisher: name: Imperial College London
Year: 2020

description: Compared to pure intensity-based imaging techniques, polarimetric imaging can provide additional information, particularly about an imaged object's compositional, morphological and microstructural properties. The value of polarimetric imaging has already been demonstrated in various applications, such as early glaucoma detection and cancer discrimination. Its applicability, however, to practical in vivo imaging situations is limited as the object of interest is often located behind a scattering layer, such as biological tissue, which scrambles both the spatial and polarimetric information about the object that is contained in the propagating light. As such, this work set out to find a means of conducting polarimetric imaging through scattering media. Under the assumption that it is possible to illuminate the object plane with the required spatial patterns, single pixel cameras can enable imaging in scattering environments and were hence thoroughly investigated in this thesis as a route to polarimetric imaging through scattering media. A theoretical model for single pixel polarimetric imaging was first developed, and conditions under which the proposed method was feasible were identified and verified using 2D coupled line dipole simulations. The proposed method was further tested through experiments conducted using an in-house custom-built setup, composed of off-the-shelf components. To mitigate noise and to ensure that the obtained polarimetric image was physical, a constrained least squares algorithm was proposed and implemented. Experiments with various test objects hidden behind scattering phantoms showed that single pixel polarimetric imaging was able to successfully reconstruct the polarimetric images of the hidden object, whereas a spatially resolved detector in the same configuration resulted in an image that bore no resemblance to the test object. Further experiments that were conducted with the same test objects hidden behind chicken breast slices were, unfortunately, unable to recover an accurate polarimetric image of the hidden object. Additional investigations identified two factors that had likely affected the image reconstruction - spatial inhomogeneity and temporally varying transmittance of the chicken breast, both of which were unaccounted for in the data processing. On the basis of the experiments and simulations conducted in this work, single pixel polarimetric imaging was found to be a feasible approach for polarimetric imaging through scattering media. Finally, further improvements to establish single pixel polarimetric imaging as a practical technique are discussed.
Aggregated demand flexibility prediction of residential thermostatically controlled loads and participation in electricity balance markets
Creators: name: Martín-Crespo, Alejandro
name: Baeyens, Enrique
name: Saludes-Rodil, Sergio
name: Frechoso-Escudero, Fernando
Publisher: name: arXiv
Year: 2023
Subjects: subject: Systems and Control (eess.SY)
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: The aggregate demand flexibility of a set of thermostatically controlled residential loads (TCLs) can be represented by a virtual battery (VB) in order to manage their participation in the electricity markets. For this purpose, it is necessary to know in advance and with a high level of reliability the maximum power that can be supplied by the aggregation of TCLs. A probability function of the power that can be supplied by a VB is introduced. This probability function is used to predict the demand flexibility using a new experimental probabilistic method based on a combination of Monte Carlo simulation and extremum search by bisection algorithm (MC&ESB). As a result, the maximum flexibility power that a VB can provide with a certain guaranteed probability is obtained. The performance and validity of the proposed method are demonstrated in three different case studies where a VB bids its aggregate power in the Spanish electricity balancing markets (SEBM).
Consciousness of guilt in tragic experience
Creators: name: Quickenden, Robert Henry
Publisher: name: University of British Columbia
Year: 2011

description: The thesis is an attempt to understand tragic guilt. My starting point is a comparison of Sophocles' Oedipus at Colonus with Shakespeare's Macbeth. The question of "guilt" is treated very differently in these two plays. Oedipus' guilt is a result of an action which is discovered, not chosen. He is the victim of a curse which lies upon his family and thus his own guilt is an ambiguous thing. He suffers against a background of a Law which demands punishment and a promise from a god that he shall be "saved". Oedipus at Colonus begins, as does Oedipus Rex, after the decisive act of murder and incest has been committed. But Macbeth begins before anything has been done; Macbeth is presented with a possibility and he chooses to believe that he can make it a reality. We are allowed to see the moment at which guilt appears in the individual. Macbeth becomes guilty before the very image of himself murdering Duncan. In Greek tragedy the guilt is often blood-guilt, a curse which descends from one member of a family to another and may devastate an entire house. But in Macbeth the guilt begins in the desires of one man. Macbeth is left with a personal despair which is different from the suffering that Oedipus undergoes. In the novels of Thomas Hardy, the perspective on guilt has shifted from the privacy that surrounds Macbeth at his death to the social world of nineteenth century England. Michael Henchard is perhaps closest to Macbeth in that he is destroyed more by the forces in his own personality than by the pressures of external society. But with Tess we have a heroine who is "pure", a woman who is defeated more as a result of the failings in a society than by any personal faults. There is little feeling of her having any particular "guilt". Jude Fawley's particular "tragedy" also must be seen in terms of the society that moves around him, its laws and conventions. The guilt is never entirely his own, nor is he simply an innocent victim. The presence of a definite society is hardly felt at all in the two novels of Conrad. Jim is a "romantic", a young man barely past adolescence who is obsessed with a concept of honour which he feels he has betrayed in a moment of cowardice. But he seems to become guilty in a deeper sense because of this obsession; he betrays others by choosing to live in an imaginary world of romantic achievement. Nostromo is also obsessed with a dream: to be a Man of the People. If Conrad's characters become guilty, it is because of their intense egoism, their inability to escape their passion for an idea. In Arthur Miller's The Crucible the guilt of an individual seems less important than the guilt present in a society. That guilt is an illusion based on a fear of not conforming to a rigorous law. We are left with the tragedy of a society which must find a victim to appease its own feeling of guilt. John Proctor is one of the chosen victims; a man who must die to save his integrity. But his death is the result of a web of guilt spread through an entire society.
Deep Gaussian Processes: Advances in Models and Inference
Creators: name: Salimbeni, Hugh
Publisher: name: Imperial College London
Year: 2019

description: Hierarchical models are certainly in fashion these days. It seems difficult to navigate the field of machine learning without encountering `deep' models of one sort or another. The popularity of the deep learning revolution has been driven by some striking empirical successes, prompting both intense rapture and intense criticism. The criticisms often centre around the lack of model uncertainty, leading to sometimes drastically overconfident predictions. Others point to the lack of a mechanism for incorporating prior knowledge, and the reliance on large datasets. A widely held hope is that a Bayesian approach might overcome these problems. The deep Gaussian process presents a paradigm for building deep models from a Bayesian perspective. A Gaussian process is a prior for functions. A deep Gaussian process uses several Gaussian process functions and combines them hierarchically through composition (that is, the output of one is the input to the next). The deep Gaussian process promises to capture the compositional nature of deep learning while mitigating some of the disadvantages through a Bayesian approach. The thesis develops deep Gaussian process modelling in a number of ways. The model is first interpreted differently from previous work, not as a `hierarchical prior' but as a factorized prior with an hierarchical likelihood. Mean functions are suggested to avoid issues of degeneracy and to aid initialization. The main contribution is a new method of inference that avoids the burden of representing the function values directly through an application of sparse variational inference. This method scales to arbitrarily large data and is shown to work well in practice through experiments. The use of variational inference recasts (approximate) inference as optimization of Gaussian distributions. This optimization has an exploitable geometry via the natural gradient. The natural gradient is shown to be advantageous for single layer non-conjugate models, and for the (final layer of a) deep Gaussian process model. Deep Gaussian processes can be a model both for complex associations between variables and complex marginal distributions of single variables. Incorporating noise in the hierarchy leads to complex marginal distribution through the non-linearities of the mappings at each layer. The inference required for noisy variables cannot be handled with sparse methods, as sparse methods rely on correlations between variables, which are absent for noisy variables. Instead, a more direct approach is developed, using an importance weighted variational scheme.
Multiseed Lossless Filtration
Creators: name: Kucherov, Gregory
name: Noé, Laurent
name: Roytberg, Mikhail A.
Publisher: name: arXiv
Year: 2009
Subjects: subject: Quantitative Methods (q-bio.QM)
subject: FOS: Biological sciences

description: We study a method of seed-based lossless filtration for approximate string matching and related bioinformatics applications. The method is based on a simultaneous use of several spaced seeds rather than a single seed as studied by Burkhardt and Kärkkäinen [1]. We present algorithms to compute several important parameters of seed families, study their combinatorial properties, and describe several techniques to construct efficient families. We also report a large-scale application of the proposed technique to the problem of oligonucleotide selection for an EST sequence database.
Study of $ B_{u,d,s} \to K_0^*(1430) P $ and $K_0^*(1430) V$ decays within QCD factorization
Creators: name: Chen, Lili
name: Zhao, Mengfei
name: Zhang, Yunyun
name: Chang, Qin
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: We study the nonleptonic charmless $B_{u,d,s} \to K_0^*(1430)P$ $(P=K\,, π)$ and $ K_0^*(1430)V$ $ (V=K^*\,, ρ\,, ω\,, ϕ)$ decays. The amplitudes are calculated within the QCD factorization, and the non-perturbative quantities are evaluated by using a covariant light-front approach. The branching fractions and CP asymmetries of theses decay modes are calculated, some decay modes are first predicted, and some useful relations based on $SU(3)$ flavor symmetry are discussed. Comparing the theoretical results with the current available experimental data, it is found that $K_0^*(1430)$ can be described as the lowest-lying p-wave $(s,u/d)$ state rather than the first excited one.
description: 38 pages, 3 figures
Strain Engineering of Magnetic Anisotropy in Epitaxial Films of Cobalt Ferrite
Creators: name: Onoda, Hiroshige
name: Sukegawa, Hiroaki
name: Inoue, Jun-ichiro
name: Yanagihara, Hideto
Publisher: name: arXiv
Year: 2021
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Perpendicular magnetic anisotropy (PMA) energy up to $K_{\mathrm{u}}=6.1\pm0.8$ MJ m$^{-3}$ is demonstrated in this study by inducing large lattice-distortion exceeding 3% at room temperature in epitaxially distorted cobalt ferrite Co$ _{x} $Fe$ _{3-x} $O$ _{4} $ (x = 0.72) (001) thin films. Although the thin film materials include no rare-earth elements or noble metals, the observed $ K_{u} $ is larger than that of the neodymium-iron-boron compounds for high-performance permanent magnets. The large PMA is attributed to the significantly enhanced magneto-elastic effects, which are pronounced in distorted films with epitaxial lattice structures upon introducing a distortion control layer of composition Mg$ _{2-x} $Sn$_{1+x}$O$ _{4} $. Surprisingly, the induced $ K_{u} $ can be quantitatively explained in terms of the agreement between the local crystal field of Co$ ^{2+} $ and the phenomenological magneto-elastic model, indicating that the linear response of induced $K_u$ is sufficiently valid even under lattice distortions as large as 3.2%. Controlling tetragonal lattice deformation using a non-magnetic spinel layer for ferrites could be a promising protocol for developing materials with large magnetic anisotropies.
description: 22 pages, 11 figures