cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Synchrotron Emission from Elliptical Galaxies Consequent to AGN outbursts
Creators: name: Jiang, Y. -F.
name: Ciotti, L.
name: Ostriker, J. P.
name: Spitkovsky, A.
Publisher: name: arXiv
Year: 2009
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: Both radiative and mechanical feedback from Active Galactic Nuclei have been found to be important for the evolution of elliptical galaxies. We compute how a shock may be driven from a central black hole into the gaseous envelope of an elliptical galaxy by mechanical as well as radiative feedback (in the form of nuclear winds) using high resolution 1-D hydrodynamical simulations. We calculate the synchrotron emission from the electron cosmic rays accelerated by the shocks (not the jets) in the central part of elliptical galaxies, and we also study the synchrotron spectrum's evolution using the standard diffusive shock acceleration mechanism, which is routinely applied to the scaled volume case of supernova remnants. We find good agreement quantitatively between the synchrotron radio emission produced via this mechanism with extant observations of elliptical galaxies which are undergoing outbursts. Additionally, we also find that synchrotron optical and X-ray emission can co-exist inside elliptical galaxies during a certain phase of evolution subsequent to central outbursts. In fact, our calculations predict a synchrotron luminosity of $\sim 1.3\times 10^6 L_{\odot}$ at the frequency 5 GHz (radio band), of $\sim 1.1\times 10^6 L_{\odot}$ at $4.3\times10^{14}$ Hz (R band, corresponding to the absolute magnitude -10.4), and of $\sim 1.5\times 10^{7} L_{\odot}$ at $2.4\times10^{17}$ Hz (soft X-ray, 0.5 -- 2.0 keV band).
description: 15 pages, 11 figures, resubmitted to ApJ, add one more figure, typos corrected
title: Interpretación de las lesiones esplénicas traumáticas
Creators: name: Sola Garcia, Marta
Publisher: name: Sociedad Española de Radiología Médica
Year: 2014
Subjects: subject: Trauma
subject: Haemorrhage
subject: CT
subject: Emergency
subject: Abdomen

description: Objetivos
Material y método
Resultados
Conclusiones
Bibliografía
description: Objetivos:
- Valorar la concordancia entre tres radiólogos especializados en patología abdominal al usar la clasificación de la AAST para gradar lesiones esplénicas traumáticas. - Valorar la concordancia entre tres radiológos especializados en patología...
Studying strangeness and baryon production mechanisms through angular correlations between charged $Ξ$ baryons and identified hadrons in pp collisions at $\sqrt{s}$ = 13 TeV
Creators: name: ALICE Collaboration
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: The angular correlations between charged $Ξ$ baryons and associated identified hadrons (pions, kaons, protons, $Λ$ baryons, and $Ξ$ baryons) are measured in pp collisions at $\sqrt{s} = 13$ TeV with the ALICE detector to give insight into the particle production mechanisms and balancing of quantum numbers on the microscopic level. In particular, the distribution of strangeness is investigated in the correlations between the doubly-strange $Ξ$ baryon and mesons and baryons that contain a single strange quark, K and $Λ$. As a reference, the results are compared to $Ξπ$ and $Ξ\mathrm{p}$ correlations, where the associated mesons and baryons do not contain a strange valence quark. These measurements are expected to be sensitive to whether strangeness is produced through string breaking or in a thermal production scenario. Furthermore, the multiplicity dependence of the correlation functions is measured to look for the turn-on of additional particle production mechanisms with event activity. The results are compared to predictions from the string-breaking model PYTHIA 8, including tunes with baryon junctions and rope hadronisation enabled, the cluster hadronisation model HERWIG 7, and the core-corona model EPOS-LHC. While some aspects of the experimental data are described quantitatively or qualitatively by the Monte Carlo models, no model can match all features of the data. These results provide stringent constraints on the strangeness and baryon number production mechanisms in pp collisions.
description: 37 pages, 14 captioned figures, 3 tables, authors from page 31, published version, figures at http://alice-publications.web.cern.ch/node/9678
title: Diagnósticos incidentales en la ecografía doppler de miembros inferiores por sospecha de trombosis venosa profunda
Creators: name: Silla, Gerardo
Publisher: name: Sociedad Española de Radiología Médica
Year: 2014
Subjects: subject: Extremities
subject: Musculoskeletal soft tissue
subject: Ultrasound
subject: Ultrasound-Colour Doppler
subject: Embolism / Thrombosis

description: Objetivo docente
Revisión del tema
Conclusiones
Bibliografía
description: Objetivo docente:
- Enumerar los diagnósticos incidentales más frecuentes en ecografía doppler de miembros inferiores realizada por sospecha de trombosis venosa profunda (TVP). - Describir las localizaciones más frecuentes y sus principales...
title: Tuberculosis Pulmonar: Manifestaciones infrecuentes.
Creators: name: Beltrán Salazar, Viviana
Publisher: name: Sociedad Española de Radiología Médica
Year: 2014
Subjects: subject: Infection
subject: Education
subject: CT
subject: Conventional radiography
subject: Thorax

description: Objetivo docente
Revisión del tema
Conclusiones
Bibliografía
description: Objetivo docente:
Mostrar mediante imágenes radiológicas (Radiografía y TC) los hallazgos atípicos y complicaciones infrecuentes de la TBC pulmonar. Mostrar las características más útiles que nos lleven a un adecuado diagnóstico. Tener una herramienta de uso...
Machine learning methods to predict Sea Surface Temperature and Marine Heatwave occurrence: a case study of the Mediterranean Sea
Creators: name: Giulia Bonino
Publisher: name: Zenodo
Year: 2023

description: This repository contains the code to produce the results of  " Machine learning methods to predict Sea Surface Temperature and Marine Heatwave occurrence: a case study of the Mediterranean Sea" a discussion paper by Giulia Bonino, Giuliano Galimberti , Simona Masina, Ronan McAdam , and Emanuela Clementi submitted to Ocean Science journal.

Abstract of the manuscript:

Marine heatwaves (MHWs) have significant social and ecological impacts, necessitating the prediction of these extreme events to prevent and mitigate their negative consequences and provide valuable information to decision-makers about MHW-related risks. In this study, machine learning (ML) techniques are applied to predict Sea Surface Temperature (SST) time series and Marine Heatwaves in 16 regions of the Mediterranean Sea. ML algorithms, including Random Forest (RForest), Long short-term memory (LSTM), and Convolutional Neural Network (CNN), are used to create competitive predictive tools for SST. The ML models are designed to forecast SST and MHWs up to 7 days ahead. For each area, we performed 15 different experiments for ML techniques, modifying the training and testing periods. Alongside SST, other relevant atmospheric variables are utilized as potential predictors of MHWs. Datasets from the European Space Agency Climate Change Initiative (ESA CCI SST) v2.1 and the European Centre for Medium-Range Weather Forecasts (ECMWF) ERA5 reanalysis from 1981 to 2021 are used to train and test the ML techniques. For each area the results show that all the ML methods performed with minimum Root Mean Square Errors (RMSE) of about 0.1°C at a 1-day lead time and maximum values of about 0.8°C at a 7-day lead time. In all regions, both the RForest and LSTM models consistently outperformed the CNN model across all lead times. Importantly, the ML techniques show results similar to the dynamical Copernicus Mediterranean Forecasting System (MedFS) for both SST and MHW forecasts, especially in the early forecast days. For MHW forecasting, ML methods compare favorably with MedFS up to 3-day lead time in 14 regions, while MedFS shows superior skill at 5-day lead time in 9 out of 16 regions. All methods predict the occurrence of MHWs with a confidence level greater than 50% in each region. Additionally, the study highlights the importance of incoming solar radiation as a significant predictor of SST variability along with SST itself.

This repository contains:

MLtechniques.ipynb is the code to build ML techniques (e.g. LSTM, CNN, RForest) to predict seven days of SST over the 16 selected regions.
description: This research has been funded by the European Space Agency (ESA) as part of the FEVERSEA Climate Change Initiative (CCI) fellowship (ESA ESRIN/Contract No. 4000133282/20/I/NB).
Smoothing of Singular Legendre Transforms in Renormalization Group Flows
Creators: name: Husemann, Christoph
name: Salmhofer, Manfred
Publisher: name: arXiv
Year: 2009
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We consider O(N)-symmetric potentials with a logarithmic singularity in the second field derivative. This class includes BCS and Gross Neveu potentials. Formally, the exact renormalization group equation for the Legendre transform of these potentials seems to have ill-defined initial conditions. We show that the renormalization group equation for the local potential has well-defined initial conditions and that the logarithmic singularity is smoothed rapidly in the flow. Our analysis also provides an efficient method for numerical studies.
description: 14 pages; introduction expanded, references added
Human and Scene Motion Deblurring using Pseudo-blur Synthesizer
Creators: name: Lumentut, Jonathan Samuel
name: Park, In Kyu
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: Present-day deep learning-based motion deblurring methods utilize the pair of synthetic blur and sharp data to regress any particular framework. This task is designed for directly translating a blurry image input into its restored version as output. The aforementioned approach relies heavily on the quality of the synthetic blurry data, which are only available before the training stage. Handling this issue by providing a large amount of data is expensive for common usage. We answer this challenge by providing an on-the-fly blurry data augmenter that can be run during training and test stages. To fully utilize it, we incorporate an unorthodox scheme of deblurring framework that employs the sequence of blur-deblur-reblur-deblur steps. The reblur step is assisted by a reblurring module (synthesizer) that provides the reblurred version (pseudo-blur) of its sharp or deblurred counterpart. The proposed module is also equipped with hand-crafted prior extracted using the state-of-the-art human body statistical model. This prior is employed to map human and non-human regions during adversarial learning to fully perceive the characteristics of human-articulated and scene motion blurs. By engaging this approach, our deblurring module becomes adaptive and achieves superior outcomes compared to recent state-of-the-art deblurring algorithms.
Chemical stratification in a long gamma-ray burst cocoon and early-time spectral signatures of supernovae associated with gamma-ray bursts
Creators: name: Suzuki, Akihiro
name: Maeda, Keiichi
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: We present the results of 3D hydrodynamic simulations of gamma-ray burst (GRB) jet emanating from a massive star with a particular focus on the formation of high-velocity quasi-spherical ejecta and the jet-induced chemical mixing. Recent early-time optical observations of supernovae associated with GRBs (e.g., GRB 171205A/SN 2017iuk) indicate a considerable amount of heavy metals in the high-velocity outer layers of the ejecta. Using our jet simulations, we show that the density and chemical structure of the outer ejecta implied by observations can be naturally reproduced by a powerful jet penetrating the progenitor star. We consider three representative jet models with a stripped massive star, a standard jet, a weak jet, and a jet choked by an extended circumstellar medium, to clarify the differences in the dynamical evolution and the chemical properties of the ejected materials. The standard jet successfully penetrates the progenitor star and creates a quasi-spherical ejecta component (cocoon). The jet-induced mixing significantly contaminates the cocoon with heavy elements that have been otherwise embedded in the inner layer of the ejecta. The weak and choked jet models fail to produce an ultra-relativistic jet but produce a quasi-spherical cocoon with different chemical properties. We discuss the impact of the different jet-star interactions on the expected early-time electromagnetic signatures of long GRBs and how to probe the jet dynamics from observations.
description: 21 pages, 10 figures, accepted for publication in ApJ
Fault tolerant quantum key distribution based on quantum dense coding with collective noise
Creators: name: Li, Xi-Han
name: Zhao, Bao-Kui
name: Sheng, Yu-Bo
name: Deng, Fu-Guo
name: Zhou, Hong-Yu
Publisher: name: arXiv
Year: 2009
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We present two robust quantum key distribution protocols against two kinds of collective noise, following some ideas in quantum dense coding. Three-qubit entangled states are used as quantum information carriers, two of which forming the logical qubit which is invariant with a special type of collective noise. The information is encoded on logical qubits with four unitary operations, which can be read out faithfully with Bell-state analysis on two physical qubits and a single-photon measurement on the other physical qubit, not three-photon joint measurements. Two bits of information are exchanged faithfully and securely by transmitting two physical qubits through a noisy channel. When the losses in the noisy channel is low, these protocols can be used to transmit a secret message directly in principle.
description: 5 page, no figures
Electric field control of a quantum spin liquid in weak Mott insulators
Creators: name: Schultz, Daniel J.
name: Khoury, Alexandre
name: Desrochers, Félix
name: Tavakol, Omid
name: Zhang, Emily Z.
name: Kim, Yong Baek
Publisher: name: arXiv
Year: 2023
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: The triangular lattice Hubbard model at strong coupling, whose effective spin model contains both Heisenberg and ring exchange interactions, exhibits a rich phase diagram as the ratio of the hopping $t$ to onsite Coulomb repulsion $U$ is tuned. This includes a chiral spin liquid (CSL) phase. Nevertheless, this exotic phase remains challenging to realize experimentally because a given material has a fixed value of $t/U$ that can difficultly be tuned with external stimuli. One approach to address this problem is applying a DC electric field, which renormalizes the exchange interactions as electrons undergo virtual hopping processes; in addition to creating virtual doubly occupied sites, electrons must overcome electric potential energy differences. Performing a small $t/U$ expansion to fourth order, we derive the ring exchange model in the presence of an electric field and find that it not only introduces spatial anisotropy but also tends to enhance the ring exchange term compared to the dominant nearest-neighbor Heisenberg interaction. Thus, increasing the electric field serves as a way to increase the importance of the ring exchange at constant $t/U$. Through density matrix renormalization group calculations, we compute the ground state phase diagram of the ring exchange model for two different electric field directions. In both cases, we find that the electric field shifts the phase boundary of the CSL towards a smaller ratio of $t/U$. Therefore, the electric field can drive a magnetically ordered state into the CSL. This explicit demonstration opens the door to tuning other quantum spin systems into spin liquid phases via the application of an electric field.
description: 9 + 17 pages, 10 + 13 figures
Valutazione della sostenibilità ambientale tramite metodologia LCA di sistemi per lo sfruttamento di fonti alternative di energia e materiali
Sustainability analysis through Life Cycle Assessment methodology of systems for alternative production of energy and material
Creators: name: Chiavetta, Cristian <1982>
Publisher: name: Alma Mater Studiorum - Università di Bologna
Year: 2013
Subjects: ING-IND/29 Ingegneria delle materie prime

description: La dissertazione ha riguardato l’analisi di sostenibilità di un sistema agronomico per la produzione di olio vegetale a fini energetici in terreni resi marginali dall’infestazione di nematodi. Il processo indagato ha previsto il sovescio di una coltura con proprietà biofumiganti (brassicacea) coltivata in precessione alla specie oleosa (soia e tabacco) al fine di contrastare il proliferare dell’infestazione nel terreno. Tale sistema agronomico è stato confrontato attraverso una analisi di ciclo di vita (LCA) ad uno scenario di coltivazione della stessa specie oleosa senza precessione di brassica ma con l’utilizzo di 1-3-dicloropropene  come sistema di lotta ai nematodi. Allo scopo di completare l’analisi LCA con una valutazione dell’impatto sull’uso del suolo (Land use Impact) generato dai due scenari a confronto, sono stati costruiti due modelli nel software per il calcolo del Soil Conditioning Index (SCI), un indicatore quali-quantitativo della qualità del terreno definito dal Dipartimento per l’Agricoltura degli Stati Uniti d’America (USDA).
description: The dissertation aims to provide the sustainability analysis of an agronomic system for biodiesel production in soil made infertile by  namatode pests. The analysis has been performed through a comparative Life Cycle Assessment of an agronomic system of tobacco oil production with Ethiopian mustad green manure in order to contrast nematodes proliferation thanks to the Ethiopian mustar chemical composition, compared to a traditional tobacco cultivation using 1-3-dichloropropene to face the nematodes problem. In order to integrate the Life Cycle Assessment results with a Land use impact evaluation, the Soil Conditioning Index model (developed by the Agricultural Department of the United States, USDA)  has been used.
The arity gap of polynomial functions over bounded distributive lattices
Creators: name: Couceiro, Miguel
name: Lehtonen, Erkko
Publisher: name: arXiv
Year: 2009
Subjects: subject: Rings and Algebras (math.RA)
subject: FOS: Mathematics
subject: 08A40, 06D99

description: Let A and B be arbitrary sets with at least two elements. The arity gap of a function f: A^n \to B is the minimum decrease in its essential arity when essential arguments of f are identified. In this paper we study the arity gap of polynomial functions over bounded distributive lattices and present a complete classification of such functions in terms of their arity gap. To this extent, we present a characterization of the essential arguments of polynomial functions, which we then use to show that almost all lattice polynomial functions have arity gap 1, with the exception of truncated median functions, whose arity gap is 2.
description: 7 pages
Littlewood-Paley-Stein type square functions based on Laguerre semigroups
Creators: name: Szarek, Tomasz
Publisher: name: arXiv
Year: 2010
Subjects: subject: Classical Analysis and ODEs (math.CA)
subject: FOS: Mathematics
subject: 42C10

description: We investigate g-functions based on semigroups related to multi-dimensional Laguerre function expansions of convolution type. We prove that these operators can be viewed as Calderon-Zygmund operators in the sense of the underlying space of homogeneous type, hence their mapping properties follow from the general theory.
description: 30 pages
Manuel Bandeira - o enforcado
Creators: name: Pessôa, Mercia
Publisher: name: Labfront/UEMG
Year: 2023

description: Aos domingos acontece uma feira no Parque Manuel Bandeira, popularmente denominado Aterro do Cocotá, localizado na Ilha do Governador, Rio de Janeiro. Neste parque, encontra-se um monumento. Cabeça e pescoço, em peça única, esculpida em bronze e sustentada sobre uma coluna de cimento, fixada num dos canteiros de vegetação que contornam o parque. Feirantes locais montam suas barracas no sábado, quando a primeira corda é amarrada ao pescoço da  figura do poeta Manuel Bandeira, autor de obras como o “Guia de Ouro Preto” e de “Itinerário de Pasárgada”. As cordas são amarras que sustentam e dão suporte aos toldos das barracas, destinadas à venda  de alimentos, roupas e outras mercadorias. O objetivo deste trabalho é mostrar a asfixia, literal, de uma figura representativa do modernismo brasileiro, os nós que tensionam os elos transversais entre o consumo, a cultura e seus espelhamentos.
Quantization of the Myers-Pospelov model: the photon sector interacting with standard fermions as a perturbation of QED
Creators: name: Reyes, C. M.
name: Urrutia, L. F.
name: Vergara, J. D.
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We study the quantization of the electromagnetic sector of the Myers-Pospelov model coupled to standard fermions. Our main objective, based upon experimental and observational evidence, is to construct an effective theory which is a genuine perturbation of QED, such that setting zero the Lorentz invariance violation parameters will reproduce it. To this end we provide a physically motivated prescription, based on the effective character of the model, regarding the way in which the model should be constructed and how the QED limit should be approached. This amounts to the introduction of an additional coarse-graining physical energy scale $M$, under which we can trust the effective field theory formulation. The prescription is successfully tested in the calculation of the Lorentz invariance violating contributions arising from the electron self-energy. Such radiative corrections turn out to be properly scaled by very small factors for any reasonable values of the parameters and no fine-tuning problems are found. Microcausality violations are highly suppressed and occur only in a space-like region extremely close to the light-cone. The stability of the model is guaranteed by restricting to concordant frames satisfying $1-|\mathbf{v}_{max}|> 6.5\times10^{-11}$.
description: 24 pages, revtex, no figures
College Students’ Solutions to Linear Functions Problems: Identifying and Interpreting Common Mistakes
Creators: name: Elagha, Noor
Publisher: name: University of Illinois at Chicago
Year: 2021
Subjects: Uncategorized

description: Among the domains of math knowledge that college students need to master for success in college and future careers (Conley et al., 2011), students’ performance is lowest in the topic of linear functions (LF) (Britton & Henderson, 2009; Mielicki et al., 2019). Important benefits can result from analyses of performance on assessments that focus on students’ ability to solve description, graph, and table LF problems and, specifically, uncovering the types of errors students make to help understand and ameliorate their struggles with this domain of mathematics. This Master’s thesis project focused on exploring and modeling the cognitive underpinnings of common errors in LF problems to enable subsequent instructional research aimed at ameliorating major conceptual and/or procedural difficulties underlying performance. Empirical evidence showed that students performed considerably better on description items compared to table and graph items. Errors in the latter two problem types were mapped to the interpretation and construction aspects of the problem-solving process. Interpretation errors are predominantly observed in graph problems and errors in both interpretation and construction processes were observed for table problems. These error patterns reflected systematic inductive failures that were attributed to the overgeneralization of relevant conceptual and procedural knowledge based on familiar structural features that are conditional on the form in which the information is presented. The quantitative and qualitative analyses of the item level and student level responses can be used to inform the design of instructional interventions such as using worked examples.
Generic behaviour of nonlinear sound waves near the surface of a star: smooth solutions
Creators: name: Gundlach, Carsten
name: Please, Colin
Publisher: name: arXiv
Year: 2009
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We are interested in the generic behaviour of nonlinear sound waves as they approach the surface of a star, here assumed to have the polytropic equation of state $P=Kρ^Γ$. Restricting to spherical symmetry, and considering only the region near the surface, we generalise the methods of Carrier and Greenspan (1958) for the shallow water equations on a sloping beach to this problem. We give a semi-quantitative criterion for a shock to form near the surface during the evolution of generic initial data with support away from the surface. We show that in smooth solutions the velocity and the square of the sound speed remain regular functions of Eulerian radius at the surface.
description: Eqs. 28 and 29 corrected to reflect erratum submitted to PRD
Improving Hole Densities and Minority Carrier Lifetimes of Cadmium Telluride Solar Cells
Creators: name: Amarasinghe, Mahisha
Publisher: name: University of Illinois at Chicago
Year: 2021
Subjects: Uncategorized

description: The objective of this thesis is to address two of the main components that affect the VOC of polycrystalline cadmium telluride (CdTe) thin-film solar cells, namely improving the carrier lifetime and carrier concentration (doping). In order to reduce carrier recombination and increase carrier lifetimes in the device, strategies with and without Cl and Se are developed, to reduce and passivate the inherent recombination centers (grain boundaries, interfaces, intra-grain defects) in polycrystalline CdTe devices. Grain sizes in the order of 1 mm are achieved and mechanisms driving lifetimes exceeding 1 µs are discussed. Moreover, hole concentrations that are orders of magnitude higher than the standard 1014 cm-3 values (seen for traditional Cu doping), are achieved with Group-V dopants like P, As, and Sb. In the future, non-Cl methods would need to be developed not only for dopant activation but defect passivation and grain growth to overcome current material and device limitations
The Stellar Population of the Galactic Bulge
Creators: name: Zoccali, M.
Publisher: name: arXiv
Year: 2009
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: The Galactic bulge is the central spheroid of our Galaxy, containing about one quarter of the total stellar mass of the Milky Way (M_bulge=1.8x10^10 M_sun; Sofue, Honma & Omodaka 2009). Being older than the disk, it is the first massive component of the Galaxy to have collapsed into stars. Understanding its structure, and the properties of its stellar population, is therefore of great relevance for galaxy formation models. I will review our current knowledge of the bulge properties, with special emphasis on chemical abundances, recently measured for several hundred stars.
description: [one reference fixed] Invited review talk, IAU Symp. 265, Chemical Abundances in the Universe: Connecting First Stars to Planets (Rio de Janeiro, Aug. 2009)
Discrete hedging in insurance risk management
Creators: name: Sator, Imre Emil
Publisher: name: University of British Columbia
Year: 2010

description: Based upon the Black-Scholes option pricing model, Schwartz developed an equilibrium pricing definition of the equity-linked life insurance contract with an asset value guarantee. Under the conditions of this contract, the beneficiary may elect to receive the value of a reference portfolio of securities or a minimum guaranteed amount, whichever is greater. In this sense, the contract is synonymous to investment in a mutual fund and a term insurance policy, The guarantee provision, however, gives rise to non-diversifiable risk. In the event of a general market collapse, the company becomes simultaneously liable for the guarantee on all mature contracts. Such an eventuality could prove to be disasterous. The equilibrium model proposes a hedging strategy which eliminates the probability of this type of a loss. At any point in time, the benefits of the contract may be viewed as the present value of the guarantee plus the value of a call option on the reference portfolio. Conversely, it can also be stated as the present value of the reference portfolio plus the value of the put option. Since the call option is sold short, a fully hedged position may be established by the appropriate investment in the reference portfolio. Maintenance of this position implies that no gains or losses will occur. In practise, however, continuous hedging is impossible because of transaction costs. Adoption of a policy of periodic revision to re-establish the hedged position will result in gains and losses. Exposure to risk, therefore, is not eliminated. This dissertation deals with the problem of risk exposure resulting from a discrete revision strategy. Through the employment of simulation techniques, the impact of various revision strategies and transaction cost levels on the losses is examined. As a basis of comparison, a naive strategy was also developed. That is, under the naive strategy, the company buys the market portfolio with the premium and holds it until maturity. The case under consideration is that of the single premium contract with a known maturity date, The results of the analysis establish the dominance of the periodic revision strategy over the naive. Furthermore, for lower transaction cost levels, the dispersion of losses is reduced as the number of revisions is increased. Although the simulation model does not provide an optimal solution, it does provide the framework for the establishment of a management strategy which is consistent with the firm's perception of acceptable risk. It is hoped that the proposed strategy will find acceptance not only by the insurance industry but also in the areas of mutual and pension fund management.
Improving the convergence of an iterative algorithm for solving arbitrary linear equation systems using classical or quantum binary optimization
Creators: name: Castro, Erick R.
name: Martins, Eldues O.
name: Sarthour, Roberto S.
name: Souza, Alexandre M.
name: Oliveira, Ivan S.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Quantum Physics (quant-ph)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences

description: Recent advancements in quantum computing and quantum-inspired algorithms have sparked renewed interest in binary optimization. These hardware and software innovations promise to revolutionize solution times for complex problems. In this work, we propose a novel method for solving linear systems. Our approach leverages binary optimization, making it particularly well-suited for problems with large condition numbers. We transform the linear system into a binary optimization problem, drawing inspiration from the geometry of the original problem and resembling the conjugate gradient method. This approach employs conjugate directions that significantly accelerate the algorithm's convergence rate. Furthermore, we demonstrate that by leveraging partial knowledge of the problem's intrinsic geometry, we can decompose the original problem into smaller, independent sub-problems. These sub-problems can be efficiently tackled using either quantum or classical solvers. While determining the problem's geometry introduces some additional computational cost, this investment is outweighed by the substantial performance gains compared to existing methods.
description: 17 pages, 4 figures
Surviving Cancer: The Role of Rural Women's Households and Social Networks in Coping with Cancer
Creators: name: Hallgren, Emily
Publisher: name: University of Illinois at Chicago
Year: 2021
Subjects: Uncategorized

description: Drawing on survey data and 36 interviews with rural women cancer survivors, I examine the role of women’s communities, social networks, and households as they cope with cancer in rural America financially, physically, and mentally. The findings improve our knowledge of the complex interplay between cancer-related financial hardship and social networks for rural women. Over a quarter of rural women experience cancer-related financial hardship, and those who report such hardship also report lower quality of life. I expand the concept of cancer-related financial coping to include informal financial assistance from rural women’s family/friend networks and ‘the community’ at large. Finally, I find that women’s cancer acts as a gender disruption in rural, heterosexual homes, catalyzing temporary transformations in the gendered division of housework and care work in their homes. Overall, the research for this dissertation highlights the importance of social networks, social embeddedness and informal practices for rural women surviving cancer and offers a nuanced portrait of cancer survival in rural America, a spatial context often assumed to be disadvantageous and lacking resources.
Sharp weighted estimates for approximating dyadic operators
Creators: name: Cruz-Uribe, David
name: Martell, Jose Maria
name: Perez, Carlos
Publisher: name: arXiv
Year: 2010
Subjects: subject: Classical Analysis and ODEs (math.CA)
subject: Functional Analysis (math.FA)
subject: FOS: Mathematics
subject: 42B20, 42B25

description: We give a new proof of the sharp weighted $L^2$ inequality ||T||_{L^2(w)} \leq c [w]_{A_2} where $T$ is the Hilbert transform, a Riesz transform, the Beurling-Ahlfors operator or any operator that can be approximated by Haar shift operators. Our proof avoids the Bellman function technique and two weight norm inequalities. We use instead a recent result due to A. Lerner to estimate the oscillation of dyadic operators.
description: To appear in the Electronic Research Announcements in Mathematical Sciences
The Role of Public Policy in Nutrition, Childhood Stunting, and Corruption
Creators: name: Hashad, Reem Nabil
Publisher: name: University of Illinois at Chicago
Year: 2021
Subjects: Uncategorized

description: This dissertation examines government policies in the context of nutrition and corruption.The first chapter studies the effect of expanding eligibility to food assistance through a policy called Broad Based Categorical Eligibility (BBCE). Evidence is based on event study and regression designs that exploit quasi-experimental variation in income eligibility cutoffs across states over time. I find that expanding eligibility through BBCE does not create work disincentives, has no effect on food security, and reduces financial hardships for inframarginal families. The second chapter explores the factors that led the height-for-age z score (HAZ) distribution and stunting rates in Egypt to change markedly. Despite increased access to health care and better maternal nutrition, the stunting rate has increased. However, what factors led to these changes remain unknown. Using a dinardo, fortin, and Lemieux decomposition, and a recentered influence function, the results indicate that the variation in HAZ and stunting are driven mainly by changes in the association between mother's height and weight and children's height. Rising socio-economic inequality is a potential explanation for this result. The third chapter examines whether firm growth affects corruption. Corruption is costly yet its determinants are not well understood given its illicit nature. Using a bartik instrument approach, I exploit plausibly exogenous variation in firm growth, in terms of sales, resulting from oil price fluctuations. Oil price fluctuations lead to oil cost shocks that differ by industry based on the industry's intensity of oil usage in production. The results indicate that oil cost shocks negatively affect firm sales, and contrary to macro-evidence, government officials do not extract more bribes as oil prices change.
The counterbalanced adversary model of government-business interaction : an evaluation
Creators: name: Whetter, David Clinton
Publisher: name: University of British Columbia
Year: 2010

description: The free enterprise ideals which have been the major philosophical base for the private sector of western economies since the days of Adam Smith, delineate very clearly the roles of government and business in society. The earliest models prescribed a supplementary role to government since the market place was supposed to resolve and provide for public needs. As the 'ideal' market became less and less representative of actual conditions the role of government became more central. In the public mind governments became charged with the responsibility of ensuring that the public interest was protected and fulfilled while business remained responsible only for achieving its private objectives. However, governments are still supposed to discharge their duty with as little interference in the activities of the private sector as possible. The underlying assumption of this philosophy is that governments will be effective in ensuring that the public interest is protected, that is, that there is a balance of power between government and business. Most of the major problems facing various societies today, including famine, poverty, pollution and inequitable distribution of wealth and resources, would seem to indicate that the public interest is not being adequately protected. This raises the possibility that the counterbalanced adversary model of government-business interaction is based on assumptions which no longer hold in our society. If this is so then decision makers in both government and business should consider the implications of the inappropriateness of their philosophical base and make adjustments accordingly. The major goal of this thesis is to examine the assumptions which underlie the counterbalanced, adversary model of government business interactions on the basis of actual interactions and performance so that an assessment of the validity of the model can be made. It is not my intention to conclusively disprove the validity of the model, since the amount of research required to accomplish such a task is beyond the scope of a thesis at this level. In any case, the value of attempting such an elusive goal is questionable, given that the main purpose of examining the validity of the model is to provide an impetus to decision makers to re-examine their philosophical base. No proof in such a topic is likely to be universally accepted as conclusive, therefore, the establishment of a reasonable doubt serves much the same purpose. This rationale provided the basis for my decision to examine the major assumptions of the model in a comprehensive manner, rather than analysing one particular assumption in considerable depth. I felt it was more valuable to set out the total picture in a holistic context than to develop a more conclusive examination of one part of the process.
Classification of symmetry-enriched topological quantum spin liquids
Creators: name: Ye, Weicheng
name: Zou, Liujun
Publisher: name: arXiv
Year: 2023
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Quantum Gases (cond-mat.quant-gas)
subject: High Energy Physics - Theory (hep-th)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: We present a systematic framework to classify symmetry-enriched topological quantum spin liquids in two spatial dimensions. This framework can deal with all topological quantum spin liquids, which may be either Abelian or non-Abelian, chiral or non-chiral. It can systematically treat a general symmetry, which may include both lattice symmetry and internal symmetry, may contain anti-unitary symmetry, and may permute anyons. The framework applies to all types of lattices, and can systematically distinguish different lattice systems with the same symmetry group using their Lieb-Schultz-Mattis anomalies. We apply this framework to classify $U(1)_{2N}$ chiral states and non-Abelian Ising$^{(ν)}$ states enriched by a $p6\times SO(3)$ or $p4\times SO(3)$ symmetry, and $\mathbb{Z}_N$ topological orders and $U(1)_{2N}\times U(1)_{-2N}$ topological orders enriched by a $p6m\times SO(3)\times\mathbb{Z}_2^T$, $p4m\times SO(3)\times\mathbb{Z}_2^T$, $p6m\times\mathbb{Z}_2^T$ or $p4m\times\mathbb{Z}_2^T$ symmetry, where $p6$, $p4$, $p6m$ and $p4m$ are lattice symmetries, while $SO(3)$ and $\mathbb{Z}_2^T$ are spin rotation and time reversal symmetries, respectively. In particular, we identify symmetry-enriched topological quantum spin liquids that are not easily captured by the usual parton-mean-field approach, including examples with the familiar $\mathbb{Z}_2$ topological order.
description: Minor modification, nearly identical to the published version in PRX, Reference Fixed
Sphalerons on Orbifolds
Creators: name: Ahriche, Amine
Publisher: name: arXiv
Year: 2009
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: In this work, we study the electroweak sphalerons in a 5D background, where the fifth dimension lies on an interval. We consider two specific cases: flat space-time and the anti-de Sitter space-time compactified on S^{1}/Z_{2}. In our work, we take the SU(2) gauge-Higgs model, where the gauge fields reside in the 5D bulk; but the Higgs doublet is confined in one brane. We find that the results in this model are close to those of the 4D Standard Model (SM). The existence of the warp effect, as well as the heaviness of the gauge Kaluza-Klein modes make the results extremely close to the SM ones.
description: 10 pages, 4 figures. To appear in EPJC
Single-photon entanglement concentration for long-distance quantum communication
Creators: name: Sheng, Yu-Bo
name: Deng, Fu-Guo
name: Zhou, Hong-Yu
Publisher: name: arXiv
Year: 2009
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We present a single-photon entanglement concentration protocol for long-distance quantum communication with quantum nondemolition detector. It is the first concentration protocol for single-photon entangled states and it dose not require the two parties of quantum communication to know the accurate information about the coefficient $α$ and $β$ of the less entangled states. Also, it does not resort to sophisticated single-photon detectors, which makes this protocol more feasible in current experiments. Moreover, it can be iterated to get a higher efficiency and yield. All these advantages maybe make this protocol have more practical applications in long-distance quantum communication and quantum internet.
description: 6 pages, 2 figures
An Exploratory Analysis Investigating the Significant Turn Demands of the Premier League, FA Cup, League Cup and UEFA Europa League for an English Soccer Team
Creators: name: Griffiths, Erin
Publisher: name: Lancaster University
Year: 2023

description: 1. Abstract

 1.1 Objectives

 It is understood that change of direction (COD) movements elicit different
 biomechanical loads and injury risk factors depending on nature of the
 associated turn characteristics. However, there is limited research
 exploring differences in COD movements completed by each position in elite
 English soccer teams who compete in the Premier League, UEFA Europa
 League, FA Cup and League Cup. This study therefore aimed to complete an
 exploratory analysis to increase the understanding of the significant turn
 demands for these soccer players.

 1.2 Methods

 Turning data was obtained from 49 match fixtures during 2022-23 season,
 from the Premier League (35 matches), UEFA Europa League (5 matches),
 League Cup (5 matches) and FA Cup (4 matches). All turn data was collected
 using Sportlight® LiDAR tracking system (Sportlight®, Oxford, UK; LiDAR).
 Significant turns were analysed from 29 soccer players, all from the same
 team. Significant turns were defined as: a change of direction with a
 deceleration ≥−2 ms-2, an angle change in direction of travel ≥20°, and a
 subsequent acceleration ≥2 ms-2, all within a 1 second duration. Turns
 were further categorized into: high (120-180), medium (60-119) and low
 (20-60) angled turns, and very high (>7.0ms-1), high (5.5-7.0
 ms-1), medium (3.0-5.5ms-1), and low (<3.0ms-1) entry speed turns.

 Statistical analysis was completed to determine how turn demands varied
 between position groups and competition types. In addition to turn
 frequency, the turn characteristics analysed included: peak deceleration
 (ms-2), turn duration (s), entry speed (ms-1), turn angle ().

 1.3 Results

 Significant differences of increased turn frequency, turn angle and entry
 speed were identified between playing positions. Turn characteristics,
 such as entry speed, were also found to significantly increase depending
 on their interaction with other turn metrics, i.e. turn angle. Analysis of
 competition differences found no significances for comparisons between
 turn frequencies and turn characteristics.

 1.4 Conclusions

 This study further develops the knowledge of turn demands faced by English
 soccer players competing in the Premier League, League Cup, UEFA Europa
 League, and FA Cup. These findings aim to further educate practitioners of
 the more complex details of turn demands during match-play and influence
 return to play protocols, physical preparation strategies, drill design
 and rehabilitation programmes. Further research needs to be completed on
 the biomechanical loads injury risk factors associated with these
 findings.
Probing the anisotropic distribution of baryon matter in the Universe using fast radio bursts
Creators: name: Lin, Hai-Nan
name: Sang, Yu
Publisher: name: arXiv
Year: 2021
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We propose that fast radio bursts (FRBs) can be used as the probes to constrain the possible anisotropic distribution of baryon matter in the Universe. Monte Carlo simulations show that, 400 (800) FRBs are enough to detect the anisotropy at 95\% (99\%) confidence level, if the dipole amplitude is at the order of magnitude 0.01. However, much more FRBs are required to tightly constrain the dipole direction. Even 1000 FRBs are far from enough to constrain the dipole direction within angular uncertainty $Δθ<40^{\circ}$ at 95\% confidence level. The uncertainty on the dispersion measure of host galaxy does not significantly affect the results. If the dipole amplitude is in the level of 0.001, however, 1000 FRBs are not enough to correctly detect the anisotropic signal.
description: 9 pages, 4 figures