cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Planetary system around LTT 1445A unveiled by ESPRESSO: Multiple planets in a triple M-dwarf system
Creators: name: Lavie, B.
name: Bouchy, F.
name: Lovis, C.
name: Osorio, M. Zapatero
name: Deline, A.
name: Barros, S.
name: Figueira, P.
name: Sozzetti, A.
name: Hernandez, J. I. Gonzalez
name: Lillo-Box, J.
name: Rodrigues, J.
name: Mehner, A.
name: Damasso, M.
name: Adibekyan, V.
name: Alibert, Y.
name: Prieto, C. Allende
name: Cristiani, S.
name: DOdorico, V.
name: Di Marcantonio, P.
name: Ehrenreich, D.
name: Santos, R. Genova
name: Curto, G. Lo
name: Martins, C. J. A. P.
name: Micela, G.
name: Molaro, P.
name: Nunes, N.
name: Palle, E.
name: Pepe, F.
name: Poretti, E.
name: Rebolo, R.
name: Santos, N.
name: Sousa, S.
name: Mascareno, A. Suarez
name: Tabrenero, H.
name: Udry, S.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We present radial velocity follow-up obtained with ESPRESSO of the M-type star LTT 1445A (TOI-455), for which a transiting planet b with an orbital period of~5.4 days was detected by TESS. We report the discovery of a second transiting planet (LTT 1445A c) and a third non-transiting candidate planet (LTT 1445A d) with orbital periods of 3.12 and 24.30 days, respectively. The host star is the main component of a triple M-dwarf system at a distance of 6.9 pc. We used 84 ESPRESSO high-resolution spectra to determine accurate masses of 2.3$\pm$0.3 $\mathrm{M}_\oplus$ and 1.0$\pm$0.2 $\mathrm{M}_\oplus$ for planets b and c and a minimum mass of 2.7$\pm$0.7 $\mathrm{M}_\oplus$ for planet d. Based on its radius of 1.43$\pm0.09$ $\mathrm{R}_\oplus$ as derived from the TESS observations, LTT 1445A b has a lower density than the Earth and may therefore hold a sizeable atmosphere, which makes it a prime target for the James Webb Space Telescope. We used a Bayesian inference approach with the nested sampling algorithm and a set of models to test the robustness of the retrieved physical values of the system. There is a probability of 85$\%$ that the transit of planet c is grazing, which results in a retrieved radius with large uncertainties at 1.60$^{+0.67}_{-0.34}$ $\mathrm{R}_\oplus$. LTT 1445A d orbits the inner boundary of the habitable zone of its host star and could be a prime target for the James Webb Space Telescope.
description: 31 pages, 20 figures Accepted A&A
title: Development of a steam generator simulation model
Creators: name: Üner, Hakki
Publisher: name: TU Wien
Year: 2013

description: To keep up with today's new technologies & work environment, engineers & researchers have to use their time and work in an efficient way. To achieve results in a quick fashion, use of engineering simulation programs & software is getting more and more important everyday. In the energy industrial sector, engineers face similar challenges. Complex calculations for thermodynamics, heat transfer, fluid mechanics applications lead engineers & researchers to use up-to-date simulation and modeling tools. One of them is Simulation Software IPSEpro which is used in this master's thesis. The subject of this master's thesis is the development of a steam generator simulation model in terms of convection and radiation calculations. It comprises of six chapters. The first chapter gives an overview of steam generators, introduces a water-tube boiler concept, a summary of available simulation software in the market. In the second chapter, Simulation Software IPSEpro is defined. Its Model Development Kit and Process Simulation Environment are mentioned; some significant points such as model-connections, systems analysis, numerical simulation methods are described. The third chapter consists of two sections. In the first section, considerable theoretical approaches and formulas are given. To complement this, the second section introduces models developed in this work, the practical side and visual diagrams of sub-models. The fourth chapter enlightens the reader about the structure of the developed model, the path that should be followed for the convergence method, the features used within the simulation software IPSEpro and the parameters considered for the simulated process. The fifth chapter presents the test results of an entire steam generator process and a duct with different bundles. The influence of coatings for exterior walls and tube types on system, is evaluated. Regarding steam generator process, simulation results are shown and validated with a practical example. The sixth chapter is the conclusions section. The aim of this master's thesis is briefly mentioned, literature survey is given. Advices and recommendations are given to engineers or researchers who want to study this subject further.
LeMoN: Lens Modelling with Neural networks -- I. Automated modelling of strong gravitational lenses with Bayesian Neural Networks
Creators: name: Gentile, Fabrizio
name: Tortora, Crescenzo
name: Covone, Giovanni
name: Koopmans, Léon V. E.
name: Li, Rui
name: Leuzzi, Laura
name: Napolitano, Nicola R.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The unprecedented number of gravitational lenses expected from new-generation facilities such as the ESA Euclid telescope and the Vera Rubin Observatory makes it crucial to rethink our classical approach to lens-modelling. In this paper, we present LeMoN (Lens Modelling with Neural networks): a new machine-learning algorithm able to analyse hundreds of thousands of gravitational lenses in a reasonable amount of time. The algorithm is based on a Bayesian Neural Network: a new generation of neural networks able to associate a reliable confidence interval to each predicted parameter. We train the algorithm to predict the three main parameters of the Singular Isothermal Ellipsoid model (the Einstein radius and the two components of the ellipticity) by employing two simulated datasets built to resemble the imaging capabilities of the Hubble Space Telescope and the forthcoming Euclid satellite. In this work, we assess the accuracy of the algorithm and the reliability of the estimated uncertainties by applying the network to several simulated datasets of 10.000 images each. We obtain accuracies comparable to previous studies present in the current literature and an average modelling time of just 0.5s per lens. Finally, we apply the LeMoN algorithm to a pilot dataset of real lenses observed with HST during the SLACS program, obtaining unbiased estimates of their SIE parameters. The code is publicly available on GitHub (https://github.com/fab-gentile/LeMoN).
description: Submitted to MNRAS; The code will be available on GitHub upon acceptance of the paper
title: Tax Challenge Working Papers
Creators: name: Allen, Hal
Publisher: name: Utah State University
Year: 2003

description: My thesis project for my honors degree consisted of preparing working papers for the tax challenge team in the Accounting department of the College of Business. The Tax Challenge team has competed two years ago in the Anderson Tax Challenge and then the Deloitte & Touche Tax Challenge this last year. The tax challenge team has begun to build a credible reputation for the tax program at Utah State University. The last two years the graduate tax team was one of the top six teams in the nation. Dr. Grange is the tax challenge advisor and is working hard to learn more ways to improve the preparation of the tax team. Last fall when I expressed my interest to Dr. Grange about participating on the tax team he talked about how he wanted the team to prepare for the next year. He told me that he wanted to have some completed working papers for the team to be able to see and use to understand the format that is wanted in the tax challenge.
The Agricultural Outlook for 1931
Creators: name: Bureau Of Agricultural Economics
name: Bureau Of Agricultural Economics
Publisher: name: Unknown
Year: 1931
Subjects: Crop Production/Industries
Farm Management
Livestock Production/Industries

description: Excerpts from the report: Farmers may reasonably expect somewhat lower production costs, a possible tendency toward improvement in market demand, and a greater degree of stability in general commodity prices during 1931. The situation at present, however, is clouded by an unusual combination of circumstances, chief among these being the general business depression, the large supplies of wheat, cotton, and certain livestock products, the disturbed conditions in various producing areas resulting from the drought, unusually severe import restrictions imposed by foreign countries against agricultural products, and the maladjustment of price relationships accompanying the recent world-wide decline in all commodity prices. The drought in 1930 was the most severe and widespread in 29 years. It reduced the production of principal crops about 5.5 per cent below the average of the preceding 10 years. For many of the States affected, the reduction was much more severe than indicated by the reduction in the percentage of the total output. Not only was the gross income from crops reduced greatly in many of the central States but the cost of maintenance of livestock was materially increased and the effects of this drought upon livestock production will continue for some time.
title: Helping COB Students Use their Business Degree to Get into Law School
Creators: name: Carlston, Jon Jeffery
Publisher: name: Utah State University
Year: 2003

description: Getting into law school these days has become ultra-competitive. GPA's and LSAT scores that worked just a few years ago will not get a law school applicant into the same schools they will today. The economy as well as the attractiveness of a law degree (J.D.) have lead to record increases in the number of students applying for law school. Law schools have been forced to "raise the bar" in order to deal with the demand. Because this is the case, undergraduate students must find ways to distinguish themselves among applicants, stay on top of the application process, and achieve better scores. As an undergraduate student majoring in accounting and applying for law school this fall, the purpose of my thesis is to both attract COB students to the study of law and to serve as a source of information for the often confusing and tedious application process. My motives are to help other USU COB students get into the schools they want to and because I feel the needs of USU's pre-law undergraduate students are underserved -especially in the COB. The information I have gathered and the research I have done should be thought of as opinionated and subjective - I am only trying to pass on what I have learned about the process and as such my recommendations should only be thought of as opinions, or at the very least, items to consider and take into account to insure the student ends up in the right law school for him or her.
MISQ WHEN JUSTICE IS BLIND TO ALGORITHMS: MULTILAYERED BLACKBOXING OF ALGORITHMIC DECISION MAKING IN THE PUBLIC SECTOR
Creators: name: Kronblad, Charlotta
Publisher: name: OSF Registries
Year: 2024
Subjects: subject: Business
subject: Management Information Systems
subject: Algorithmic injustice

description: Transparency material applicable to the MISQ article (WHEN JUSTICE IS BLIND TO ALGORITHMS: MULTILAYERED BLACKBOXING OF ALGORITHMIC DECISION MAKING IN THE PUBLIC SECTOR) containing: coding examples, media headlines and reports, and legal court case argumentation.
title: Under the Bridge: Poems by Faith Shepherd with Critical Introduction
Creators: name: Shepherd, Faith
Publisher: name: Utah State University
Year: 2004

description: The first poem with which I became fully engaged--that is, the first poem with which I interacted beyond one or two readings--was Wallace Stevens' "Autumn Refrain" my senior year in high school. At this point in my life, I was already enamored with literature, and I had written fair amounts of "poetry" for my high school creative writing classes. However, even though I occasionally enjoyed reading poetry and understood that its language tended to be more compact than other types of literature, if I didn't understand a poem after reading it through once or twice I set it aside and moved on, usually figuring a teacher would explain or map out difficult passages. As a result, reading more than three or four poems at a time simply left me with a headache.
title: ÐÑÑÐ»ÐµÐ´Ð¾Ð²Ð°Ð½Ð¸Ðµ Ð¾Ð¿ÑÐ¸Ð¼Ð°Ð»ÑÐ½Ð¾Ð¹ Ð°ÑÑ Ð¸ÑÐµÐºÑÑÑÑ Ð¼Ð½Ð¾Ð³Ð¾Ð¿Ð¾Ð»ÑÐ·Ð¾Ð²Ð°ÑÐµÐ»ÑÑÐºÐ¾Ð³Ð¾ Ð¿ÑÐ¸Ð»Ð¾Ð¶ÐµÐ½Ð¸Ñ Ð½Ð° Ð¿ÑÐ¸Ð¼ÐµÑÐµ ÑÑÐ°Ð½ÑÐ¿Ð¾ÑÑÐ½Ð¾Ð¹ ÑÐ¸ÑÑÐµÐ¼Ñ
title: Ð²ÑÐ¿ÑÑÐºÐ½Ð°Ñ ÐºÐ²Ð°Ð»Ð¸ÑÐ¸ÐºÐ°ÑÐ¸Ð¾Ð½Ð½Ð°Ñ ÑÐ°Ð±Ð¾ÑÐ° Ð¼Ð°Ð³Ð¸ÑÑÑÐ°
titleType: Subtitle
title: Research of the optimal multi-user application architecture using the example of a transportation system
Creators: name: Ð¡Ð¼Ð¸ÑÐ½Ð¾Ð², ÐÐ²Ð³ÐµÐ½Ð¸Ð¹
Publisher: name: Ð¡Ð°Ð½ÐºÑ-ÐÐµÑÐµÑÐ±ÑÑÐ³ÑÐºÐ¸Ð¹ Ð¿Ð¾Ð»Ð¸ÑÐµÑÐ½Ð¸ÑÐµÑÐºÐ¸Ð¹ ÑÐ½Ð¸Ð²ÐµÑÑÐ¸ÑÐµÑ ÐÐµÑÑÐ° ÐÐµÐ»Ð¸ÐºÐ¾Ð³Ð¾
Year: 2021
Subjects: ÐÑÑÐ¸ÑÐ»Ð¸ÑÐµÐ»ÑÐ½ÑÐµ Ð¼Ð°ÑÐ¸Ð½Ñ ÑÐ»ÐµÐºÑÑÐ¾Ð½Ð½ÑÐµ
Ð¼Ð¸ÐºÑÐ¾ÑÐµÑÐ²Ð¸ÑÑ
Ð¼Ð¸ÐºÑÐ¾ÑÐµÑÐ²Ð¸ÑÐ½Ð°Ñ Ð°ÑÑ Ð¸ÑÐµÐºÑÑÑÐ°
Ð¼Ð¾Ð½Ð¾Ð»Ð¸Ñ
Ð¾Ð¿ÑÐ¸Ð¼Ð°Ð»ÑÐ½Ð°Ñ Ð°ÑÑ Ð¸ÑÐµÐºÑÑÑÐ°
Ð¿ÐµÑÐµÐ²Ð¾Ð´ Ð½Ð° Ð¼Ð¸ÐºÑÐ¾ÑÐµÑÐ²Ð¸ÑÑ
microservices
microservice architecture
monolith
optimal architecture
transfer to microservices

description: Ð Ð´Ð°Ð½Ð½Ð¾Ð¹ ÑÐ°Ð±Ð¾ÑÐµ Ð¿ÑÐ¾Ð²Ð¾Ð´Ð¸ÑÑÑ Ð¸ÑÑÐ»ÐµÐ´Ð¾Ð²Ð°Ð½Ð¸Ðµ Ð°ÑÑÐ¸ÑÐµÐºÑÑÑÐ½ÑÑ Ð¿Ð¾Ð´ÑÐ¾Ð´Ð¾Ð², Ð¿ÑÐ¸Ð¼ÐµÐ½ÑÐµÐ¼ÑÑ Ð² ÑÐ°Ð·ÑÐ°Ð±Ð¾ÑÐºÐµ Ð²ÐµÐ±-Ð¿ÑÐ¸Ð»Ð¾Ð¶ÐµÐ½Ð¸Ð¹, Ñ ÑÐµÐ»ÑÑ Ð²ÑÐ±Ð¾ÑÐ° Ð¾Ð¿ÑÐ¸Ð¼Ð°Ð»ÑÐ½Ð¾Ð¹ Ð°ÑÑÐ¸ÑÐµÐºÑÑÑÑ Ð´Ð»Ñ Ð·Ð°Ð´Ð°Ð½Ð½Ð¾Ð³Ð¾ Ð½Ð°Ð±Ð¾ÑÐ° ÐºÑÐ¸ÑÐµÑÐ¸ÐµÐ². Ð ÑÐ¾Ð´Ðµ ÑÐ°Ð±Ð¾ÑÑ Ð±ÑÐ» Ð²ÑÐ¿Ð¾Ð»Ð½ÐµÐ½ Ð¾Ð±Ð·Ð¾Ñ Ð½Ð°Ð¸Ð±Ð¾Ð»ÐµÐµ Ð·Ð½Ð°ÑÐ¸Ð¼ÑÑ Ð°ÑÑÐ¸ÑÐµÐºÑÑÑ Ð´Ð»Ñ ÑÐ°Ð·ÑÐ°Ð±Ð¾ÑÐºÐ¸ Ð²ÐµÐ±-Ð¿ÑÐ¸Ð»Ð¾Ð¶ÐµÐ½Ð¸Ð¹, ÑÐ°Ð·ÑÐ°Ð±Ð¾ÑÐ°Ð½Ð¾ Ð¿ÑÐ¸Ð»Ð¾Ð¶ÐµÐ½Ð¸Ðµ Ð½Ð° Ð¼Ð½Ð¾Ð³Ð¾ÑÑÐ¾Ð²Ð½ÐµÐ²Ð¾Ð¹ Ð¼Ð¾Ð½Ð¾Ð»Ð¸ÑÐ½Ð¾Ð¹ Ð°ÑÑÐ¸ÑÐµÐºÑÑÑÐµ, Ð¿ÑÐ¸Ð»Ð¾Ð¶ÐµÐ½Ð¸Ðµ Ð¿ÐµÑÐµÐ²ÐµÐ´ÐµÐ½Ð¾ Ð½Ð° Ð¼Ð¸ÐºÑÐ¾ÑÐµÑÐ²Ð¸ÑÑ, Ð²ÑÐ¿Ð¾Ð»Ð½ÐµÐ½Ð¾ ÑÑÐ°Ð²Ð½ÐµÐ½Ð¸Ðµ Ð°ÑÑÐ¸ÑÐµÐºÑÑÑÐ½ÑÑ Ð¿Ð¾Ð´ÑÐ¾Ð´Ð¾Ð² Ð¿Ð¾ Ð²ÑÑÐ²Ð»ÐµÐ½Ð½ÑÐ¼ ÐºÑÐ¸ÑÐµÑÐ¸ÑÐ¼ Ð¸ Ð¿ÑÐ¾Ð²ÐµÐ´ÐµÐ½ Ð°Ð½Ð°Ð»Ð¸Ð· Ð¿Ð¾Ð»ÑÑÐµÐ½Ð½ÑÑ ÑÐµÐ·ÑÐ»ÑÑÐ°ÑÐ¾Ð².
description: In this paper, we study the architectural approaches used in the development of web applications in order to select the optimal architecture for a given set of criteria. In the course of the work, an overview of the most significant architectures for the development of web applications was carried out, an application was developed on a multi-level monolithic architecture, the application was transferred to microservices, a comparison of architectural approaches was carried out according to the identified criteria, and an analysis of the results obtained was carried out.
title: The Election Cycle, and the U.S. Withdrawal from Vietnam
Creators: name: Stoddard, Steven Thomas
Publisher: name: Utah State University
Year: 2005

description: Few events in American history have proved to be as divisive and controversial as U.S. involvement in the Vietnam War. Although U.S. policy in Indochina has its roots in the Truman Administration, the two presidents most closely associated with the conflict are Lyndon B. Johnson, and Richard M. Nixon. These two are particularly important because they both occupied the White House during the highest levels of direct U.S. involvement in the war. In terms of troop deployments to Southeast Asia, the level and intensity of U.S. involvement peaked under the Johnson Administration and it was at this time that the war began to be the focus of one of the largest and most controversial social-political movements that this country has ever seen.
Adjoint Majorana QCD$_2$ at Finite $N$
Creators: name: Dempsey, Ross
name: Klebanov, Igor R.
name: Lin, Loki L.
name: Pufu, Silviu S.
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The mass spectrum of $1+1$-dimensional $\mathrm{SU}(N)$ gauge theory coupled to a Majorana fermion in the adjoint representation has been studied in the large $N$ limit using Light-Cone Quantization. Here we extend this approach to theories with small values of $N$, exhibiting explicit results for $N=2, 3$, and $4$. In the context of Discretized Light-Cone Quantization, we develop a procedure based on the Cayley-Hamilton theorem for determining which states of the large $N$ theory become null at finite $N$. For the low-lying bound states, we find that the squared masses divided by $g^2 N$, where $g$ is the gauge coupling, have very weak dependence on $N$. The coefficients of the $1/N^2$ corrections to their large $N$ values are surprisingly small. When the adjoint fermion is massless, we observe exact degeneracies that we explain in terms of a Kac-Moody algebra construction and charge conjugation symmetry. When the squared mass of the adjoint fermion is tuned to $g^2 N / π$, we find evidence that the spectrum exhibits boson-fermion degeneracies, in agreement with the supersymmetry of the model at any value of $N$.
description: 45 pages, 7 figures
title: Non ketotic hyperglycaemic hemichorea: CT and MRI findings
Creators: name: Spalding, Julie
Publisher: name: EURORAD
Year: 2021
Subjects: subject: Neuroradiology
subject: CNS
subject: Neuroradiology brain
subject: CT
subject: MR
subject: Clinical Cases

description: Clinical History: A 68-year-old gentleman presented with episodic speech disturbance and choreiform movements of the left side of his face. The episodes were recurrent, lasting less than a minute, and he retained awareness throughout. Past medical history included cardiovascular disease and a recent diagnosis of type II diabetes mellitus. 

description: 68 years, male
Non-reciprocal interactions spatially propagate fluctuations in a 2D Ising model
Creators: name: Seara, Daniel S.
name: Piya, Akash
name: Tabatabai, A. Pasha
Publisher: name: arXiv
Year: 2022
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: Motivated by the anisotropic interactions between fish, we implement spatially anisotropic and therefore non-reciprocal interactions in the 2D Ising model. First, we show that the model with non-reciprocal interactions alters the system critical temperature away from that of the traditional 2D Ising model. Further, local perturbations to the magnetization in this out-of-equilibrium system manifest themselves as traveling waves of spin states along the lattice, also seen in a mean-field model of our system. The speed and directionality of these traveling waves are controllable by the orientation and magnitude of the non-reciprocal interaction kernel as well as the proximity of the system to the critical temperature.
description: 4 figures
The Farm Outlook for 1931
Creators: name: Bureau Of Agricultural Economics
name: Bureau Of Agricultural Economics
Publisher: name: Unknown
Year: 1931
Subjects: Crop Production/Industries
Farm Management
Livestock Production/Industries

description: Excerpts from the report: Farmers are faced with unusual difficulties this spring in planning their farm operations. The whole situation has been seriously clouded by conditions arising out of the world-wide business depression, the drought, and the drastic fall in commodity prices. There is a widespread tendency to seek new lines of production or to undertake new efforts which might seem to promise relief. The following statements, based upon the more complete outlook reports issued by this bureau, are intended to give a reasonably accurate idea of the probable conditions ahead. This brief survey indicates the limitations in certain lines of production and the apparent possibilities in other lines. It must be borne in mind that the general national outlook report and this summary must be interpreted according to local circumstances.
title: Investigation of the Toxic Affect of Manganese on Ruminal Microbial Digestion and Growth
Creators: name: Dearing, Erin
Publisher: name: Utah State University
Year: 2005

description: This research investigated the toxic effect of manganese, in a reduced chemical state, on rumen microbial metabolism and growth. The reduced form of manganese is the soluble state found in subsurface waters and has a high red-ox potential. In the study, we investigated the effects of reduced manganese at varying concentrations, on rumen microbial ability to replicate and metabolize carbohydrates. The hypotheses that we tested were as follows: (1) reduced manganese decreases the rate of pH drop associated with rumen culture fermentation of a com based diet and (2) reduced manganese decreases the bacterial growth in rumen culture, as measured by bacterial DNA quantification. In this study, rumen culture material was obtained from a rumen canulated cow and dosed with test materials in randomly assigned flasks at 37° C. Cultures were replicated three times on different days. Test materials were dosed to result in the reduced form of manganese at concentrations of 0 ppm, 1.5 ppm, 3 ppm, 6 ppm, 12 ppm, 24 ppm, 48 ppm, and 96 ppm. Samples from each flask were obtained at 0 hr., 3 hr., 6 hr., 9 hr., and 12 hr. for measuring pH and at 0 hr., 3 hr., and 6 hr. for DNA. In these experiments, manganese inhibited the growth of the microbial population at > 3 ppm, but the rate of pH drop was not altered among the treatments used in this study.
Effects of climate change on the habitat suitability of 4 relatively new invasive plant species in the Pacific Northwest
Creators: name: Nikkel, Emma
Publisher: name: University of British Columbia
Year: 2022

description: Invasive species are a substantial threat to biodiversity and ecosystem structure. This threat is exacerbated by the increasingly concerning and urgent outlook of predicted climate change, land cover change, and other human influences. Specifically, an increasing number of invasive plant species are spreading in the Pacific Northwest (PNW), an area of unique natural areas, economic value, and increasing human population. Predicting the potential habitat suitability for invasive plant species that are not yet established in the region is crucial for developing preventative management strategies. To this end, I developed habitat suitability models for four invasive plant species, two terrestrial species: Geranium lucidum and Pilosella officinarum; and two aquatic species: Butomus umbellatus and Pontederia crassipes. I initially considered 33 bioclimatic variables, 10 land cover types, and a human influence index as current model predictor variables with location records for each species drawn from the introduced range (North America). I projected each species’ current habitat suitability in the PNW region using ensemble modelling of six algorithms to 2050 and 2080, under 3 potential future climate scenarios. The majority of the coastal PNW is predicted to remain potential habitat for Geranium lucidum under all future climate scenarios, with some loss of habitat suitability in Oregon. In contrast, Pilosella officinarum, while currently suited to most inland regions of the PNW, is predicted to lose suitable habitat by 2050 under all climate scenarios, retaining high elevations as potential habitat. The suitable habitat for Butomus umbellatus in the PNW, which is currently moderately suitable, is not predicted to increase substantially in the future. Likewise, potential future habitat suitability remains relatively unchanged for Pontederia crasipes, which is currently highly suitable for inland waterways that do not experience freezing temperatures. Overall, the bioclimatic variables and human influence index were more important than land cover variables, suggesting that climate change and human activity are the determining factors for changes in future suitable habitat. My research provides a template to model other concerning species, assisting local land managers and practitioners to inform current and future management strategies and increasing the efficiency of allocating limited resources toward species with expanding ranges.
Natural Boundaries for Scattering Amplitudes
Creators: name: Mizera, Sebastian
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Singularities, such as poles and branch points, play a crucial role in investigating the analytic properties of scattering amplitudes that inform new computational techniques. In this note, we point out that scattering amplitudes can also have another class of singularities called natural boundaries of analyticity. They create a barrier beyond which analytic continuation cannot be performed. More concretely, we use unitarity to show that $2 \to 2$ scattering amplitudes in theories with a mass gap can have a natural boundary on the second sheet of the lightest threshold cut. There, an infinite number of ladder-type Landau singularities densely accumulates on the real axis in the center-of-mass energy plane. We argue that natural boundaries are generic features of higher-multiplicity scattering amplitudes in gapped theories.
description: 38 pages
Massive Prestellar Cores in Radiation-magneto-turbulent Simulations of Molecular Clouds
Creators: name: He, Chong-Chong
name: Ricotti, Massimo
Publisher: name: arXiv
Year: 2022
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We simulate the formation and collapse of prestellar cores at few-AU resolution in a set of radiation-magneto-hydrodynamic simulations of giant molecular clouds (GMCs) using the grid-based code RAMSES-RT. We adopt, for the first time to our best knowledge, realistic initial/boundary conditions by zooming-in onto individual massive prestellar cores within the GMC. We identify two distinct modes of fragmentation: "quasi-spherical" and "filamentary". In both modes the fragments eventually become embedded in a quasi-steady accretion disk or toroid with radii ~ 500-5000 AU and opening angles $H/R \sim 0.5-1$. The disks/toroids are Toomre stable but the accreted pre-existing fragments are found orbiting the outer disk, appearing as disk fragmentation. Each core converts nearly 100 percent of the gas mass into a few massive stars forming near the disk center. Large and massive disks around high-mass stars are supported by magnetic pressure in the outer disk, at radii >200-1000 AU, and turbulent pressure in the inner disk. The most massive core accretes several times more mass than its initial mass, forming a (proto)star cluster of 8 massive stars enshrouded by a toroid, suggesting a competitive accretion scenario for ultra-high-mass star formation. We also find that the HII regions produced by a single massive star remain trapped in the dense circumstellar disks for a few hundred kiloyears, while the dynamic motions of massive stars in wide binaries or multiple systems displace the stars from the densest parts of the disk, allowing UV radiation to escape producing steady or pulsating bipolar HII regions.
description: 20 pages, 13 figures, submitted to MNRAS. Comments welcome. Simulation movie available at https://chongchonghe.github.io/data/#cores
Replication and Reproducibility in Social Sciences and Statistics: Context, Concerns, and Concrete Measures
Creators: name: Vilhuber, Lars
Publisher: name: Zenodo
Year: 2019

description: Replicability is at the core of the scientific enterprise. In the past 30 years, recurring concerns about the extent of replicability (or lack thereof) of the research in various disciplines have surfaced, including in economics.

In this talk, I describe the context in which the current discussion in the social science is occurring: what are the definitions of replicability and reproducibility, what is failing, and to what extent. In particular, I discuss the concerns in economics: to what extent is this a problem in economics, what are the approaches that are being considered, and what are the possible broader implications of those approaches. Finally, I discuss the concrete measures that are being implemented under my guidance at the American Economic Association, and that are being discussed in the broader economics community.

The solutions to these problems will change the way research will be taught and conducted, in economics in particular, and in the social sciences more broadly. The implications affect undergraduate and graduate teaching, research infrastructure, and habits.

Presented at "Using Administrative Data to Inform Public Policy" at UQAM, 2019-04-05
description: A cleaner version is available.
title: Ð­Ð»ÐµÐºÑÑÐ¸ÑÐµÑÐºÐ°Ñ ÑÐ°ÑÑÑ ÐÐ­Ð¡ Ð¼Ð¾ÑÐ½Ð¾ÑÑÑÑ 8*300 ÐÐÑ
title: Ð²ÑÐ¿ÑÑÐºÐ½Ð°Ñ ÐºÐ²Ð°Ð»Ð¸ÑÐ¸ÐºÐ°ÑÐ¸Ð¾Ð½Ð½Ð°Ñ ÑÐ°Ð±Ð¾ÑÐ° Ð±Ð°ÐºÐ°Ð»Ð°Ð²ÑÐ°
titleType: Subtitle
title: Electric part of Condensation Electric Power Plant with a power of 8*300 MW
Creators: name: ÐÐµÐ±ÐµÐ´ÐµÐ²Ð°, ÐÑÐ¸Ð½Ð°
Publisher: name: Ð¡Ð°Ð½ÐºÑ-ÐÐµÑÐµÑÐ±ÑÑÐ³ÑÐºÐ¸Ð¹ Ð¿Ð¾Ð»Ð¸ÑÐµÑÐ½Ð¸ÑÐµÑÐºÐ¸Ð¹ ÑÐ½Ð¸Ð²ÐµÑÑÐ¸ÑÐµÑ ÐÐµÑÑÐ° ÐÐµÐ»Ð¸ÐºÐ¾Ð³Ð¾
Year: 2019
Subjects: ÐºÐ¾Ð½Ð´ÐµÐ½ÑÐ°ÑÐ¸Ð¾Ð½Ð½Ð°Ñ ÑÐ»ÐµÐºÑÑÐ¾ÑÑÐ°Ð½ÑÐ¸Ñ
ÑÑ ÐµÐ¼Ð° ÑÐ»ÐµÐºÑÑÐ¸ÑÐµÑÐºÐ¸Ñ ÑÐ¾ÐµÐ´Ð¸Ð½ÐµÐ½Ð¸Ð¹
Ð²ÑÐ±Ð¾Ñ ÑÐ¸Ð»Ð¾Ð²Ð¾Ð³Ð¾ Ð¾Ð±Ð¾ÑÑÐ´Ð¾Ð²Ð°Ð½Ð¸Ñ
Ð²ÑÐ±Ð¾Ñ Ð°Ð¿Ð¿Ð°ÑÐ°ÑÐ¾Ð² Ð¸ ÑÐ¾ÐºÐ¾Ð²ÐµÐ´ÑÑÐ¸Ñ ÑÐ°ÑÑÐµÐ¹
ÑÐ°ÑÑÑÑ ÑÐ¾ÐºÐ¾Ð² ÐºÐ¾ÑÐ¾ÑÐºÐ¾Ð³Ð¾ Ð·Ð°Ð¼ÑÐºÐ°Ð½Ð¸Ñ
condensation power plant
scheme of the electrical circuit
choice of power equipment
choice of devices and conductive parts
calculation of short circuit currents

description: Ð Ð´Ð°Ð½Ð½Ð¾Ð¹ ÑÐ°Ð±Ð¾ÑÐµ Ð¾ÑÑÑÐµÑÑÐ²Ð»ÐµÐ½Ð¾ Ð¿ÑÐ¾ÐµÐºÑÐ¸ÑÐ¾Ð²Ð°Ð½Ð¸Ðµ ÑÐ»ÐµÐºÑÑÐ¸ÑÐµÑÐºÐ¾Ð¹ ÑÐ°ÑÑÐ¸ Ð³Ð°Ð·Ð¾Ð¼Ð°Ð·ÑÑÐ½Ð¾Ð¹ ÐÐ­Ð¡. ÐÑÐ±ÑÐ°Ð½Ð¾ ÑÐ¸Ð»Ð¾Ð²Ð¾Ðµ Ð¾Ð±Ð¾ÑÑÐ´Ð¾Ð²Ð°Ð½Ð¸Ðµ. ÐÐ¿Ð¸ÑÐ°ÑÑÑ Ð½Ð° ÑÐºÐ¾Ð½Ð¾Ð¼Ð¸ÑÐµÑÐºÐ¸Ðµ ÑÐ°ÑÑÐµÑÑ, Ð²ÑÐ±ÑÐ°Ð½Ð° ÑÑÑÑÐºÑÑÑÐ½Ð°Ñ ÑÑÐµÐ¼Ð°. ÐÐ¾Ð´Ð¾Ð±ÑÐ°Ð½Ñ ÑÑÐµÐ¼Ñ ÑÐ°ÑÐ¿ÑÐµÐ´ÐµÐ»Ð¸ÑÐµÐ»ÑÐ½ÑÑ ÑÑÑÑÐ¾Ð¹ÑÑÐ² Ð¸ ÑÐ¾Ð±ÑÑÐ²ÐµÐ½Ð½ÑÑ Ð½ÑÐ¶Ð´. ÐÑÑÐ¾Ð´Ñ Ð¸Ð· Ð¿Ð°ÑÐ°Ð¼ÐµÑÑÐ¾Ð² ÑÐ»ÐµÐºÑÑÐ¾ÑÑÐ°Ð½ÑÐ¸Ð¸ Ð¸ ÑÐµÐ·ÑÐ»ÑÑÐ°ÑÐ¾Ð² ÑÐ°ÑÑÐµÑÐ° ÑÐ¾ÐºÐ¾Ð² ÐºÐ¾ÑÐ¾ÑÐºÐ¾Ð³Ð¾ Ð·Ð°Ð¼ÑÐºÐ°Ð½Ð¸Ñ, Ð²ÑÐ±ÑÐ°Ð½Ñ Ð°Ð¿Ð¿Ð°ÑÐ°ÑÑ Ð¸ ÑÐ¾ÐºÐ¾Ð²ÐµÐ´ÑÑÐ¸Ðµ ÑÐ°ÑÑÐ¸.
description: In the given work the design of electrical part of oil-gas condensation power plant is implemented. Power equipment is chosen. The structural scheme is chosen using the economic calculations. The schemes of switchboard devices and common auxiliaries are selected. Devices and conductive parts are chosen using of the calculation of short circuit currents.
The Rest-Frame Submillimeter Spectrum of High Redshift, Dusty, Star-Forming Galaxies from the SPT-SZ Survey
Creators: name: Reuter, C.
name: Spilker, J. S.
name: Vieira, J. D.
name: Marrone, D. P.
name: Weiss, A.
name: Aravena, M.
name: Archipley, M. A.
name: Chapman, S. C.
name: Gonzalez, A.
name: Greve, T. R.
name: Hayward, C. C.
name: Hill, R.
name: Jarugula, S.
name: Kim, S.
name: Malkan, M.
name: Phadke, K. A.
name: Stark, A. A.
name: Sulzenauer, N.
name: Vizgan, D.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We present the average rest-frame spectrum of the final catalog of dusty star-forming galaxies (DSFGs) selected from the South Pole Telescope SZ survey (SPT-SZ) and measured with Band 3 of the Atacama Large Millimeter/submillimeter Array (ALMA). This work builds on the previous average rest-frame spectrum, given in Spilker et al. (2014) for the first 22 sources, and is comprised of a total of 78 sources, normalized by their respective apparent dust masses. The spectrum spans $1.9$$<$z$<$$6.9$ and covers rest-frame frequencies of 240$-$800 GHz. Combining this data with low-J CO observations from the Australia Telescope Compact Array (ATCA), we detect multiple bright line features from $^{12}$CO, $[$CI$]$, and H$_2$O, as well as fainter molecular transitions from $^{13}$CO, HCN, HCO$^+$, HNC, CN, H$_2$O$^+$, and CH. We use these detections, along with limits from other molecules, to characterize the typical properties of the interstellar medium (ISM) for these high redshift DSFGs. We are able to divide the large sample into subsets in order to explore how the average spectrum changes with various galaxy properties, such as effective dust temperature. We find that systems with hotter dust temperatures exhibit differences in the bright $^{12}$CO emission lines, and contain either warmer and more excited dense gas tracers, or larger dense gas reservoirs. These observations will serve as a reference point to studies of the ISM in distant luminous DSFGs (L$_{\mathrm{IR}}$$>$$10^{12}$L$_\odot$), and will inform studies of chemical evolution before the peak epoch of star formation at $z=2-3$.
description: 26 pages, 10 figures, accepted for publication in ApJ
Bayesian Detection and Tracking of Odontocetes in 3-D from Their Echolocation Clicks
Creators: name: Jang, Junsu
name: Meyer, Florian
name: Snyder, Eric R.
name: Wiggins, Sean M.
name: Baumann-Pickering, Simone
name: Hildebrand, John A.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Signal Processing (eess.SP)
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: Localizing and tracking of marine mammals can reveal key insights into behaviors underwater that otherwise would remain unexplored. A promising nonintrusive approach to obtaining location information of marine mammals is based on recordings of bio-acoustic signals by volumetric hydrophone arrays. Time-difference-of-arrival (TDOA) measurements of echolocation clicks emitted by odontocetes can be extracted and used for detection, localization, and tracking in 3-D. We propose a data processing chain that automatically detects and tracks multiple odontocetes in 3-D from their echolocation clicks. First, TDOA measurements are extracted with a generalized cross-correlation that whitens received acoustic signals based on instrument noise statistics. Subsequently, odontocetes are tracked in the TDOA domain using a graph-based multi-target tracking (MTT) method to reject false TDOA measurements and close gaps of missed detections. The resulting TDOA estimates are then used by another graph-based MTT stage that estimates odontocete tracks in 3-D. The tracking capability of the proposed data processing chain is demonstrated on real acoustic data provided by two volumetric hydrophone arrays that recorded echolocation clicks from Cuvier's beaked whales (Ziphius cavirostris). Simulation results show that the presented 3-D MTT method can outperform an existing approach that relies on hand annotation.
description: 58 pages, 12 figures
Enhanced power of gravitational waves and rapid coalescence of black hole binaries through dark energy accretion
Creators: name: Sarkar, Arnab
name: Ali, Amna
name: Nayak, K. Rajesh
name: Majumdar, A. S.
Publisher: name: arXiv
Year: 2022
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We consider the accretion of dark energy by constituent black holes in binary formations during the present epoch of the Universe. In the context of an observationally consistent dark energy model, we evaluate the growth of black holes' masses due to accretion. We show that accretion leads to faster circularization of the binary orbits. We compute the average power of the gravitational waves emitted from binaries, which exhibits a considerable enhancement due to the effect of growth of masses as a result of accretion. This in turn, leads to a significant reduction of the coalescence time of the binaries. We present examples pertaining to various choices of the initial masses of the black holes in the stellar mass range and above, in order to clearly establish a possible observational signature of dark energy in the emerging era of gravitational wave astronomy.
description: 9 pages, 6 figures, 1 Table
Reproducibility in Social Sciences and Statistics: Context, Concerns, and Concrete Measures
Creators: name: Vilhuber, Lars
Publisher: name: Zenodo
Year: 2019

description: Replicability is at the core of the scientific enterprise. In the past 30 years, recurring concerns about the extent of replicability (or lack thereof) of the research in various disciplines have surfaced, including in economics.

In this talk, I describe the context in which the current discussion in the social science is occurring: what are the definitions of replicability and reproducibility, what is failing, and to what extent. In particular, I discuss the concerns in economics: to what extent is this a problem in economics, what are the approaches that are being considered, and what are the possible broader implications of those approaches. Finally, I discuss the concrete measures that are being implemented under my guidance at the American Economic Association, and that are being discussed in the broader economics community.

The solutions to these problems will change the way research will be taught and conducted, in economics in particular, and in the social sciences more broadly. The implications affect undergraduate and graduate teaching, research infrastructure, and habits.

Presented at "Using Administrative Data to Inform Public Policy" at UQAM, 2019-04-05
description: The opinions expressed in this talk are solely the authors, and do not represent the views of the U.S. Census Bureau, the American Economic Association, or any of the funding agencies.
title: The Composition and Comparison of Essential Oils and their Nutritional Benefits to Enhance and Decrease Risk for Chronic Disease
Creators: name: Wollschleger, Heather
Publisher: name: Utah State University
Year: 2005

description: This paper reviews the current status of our knowledge of essential oils and their nutritional contribution to our diet. The effects of dietary fats on our health differ markedly from the type and form of the fat. Special emphasis is placed on omega-3 and omega-6 fatty acids, and their dietary involvement. Specific oils increase our levels of vital vitamin E and the essential omega-3 and omega-6 fats humans need for mental and physical health. Chronic diseases remain a major cause of death and disability, and risk factors include diets high in saturated fatty acids and trans fatty acids. This risk is reduced most effectively when trans fatty acids and saturated fatty acids are replaced with cis unsaturated fatty acids.
title: Design Sales and Marketing - An Investigational Study
Creators: name: Kuddes, Katrina Jeanne
Publisher: name: Utah State University
Year: 2004

description: Dating back to the ancient Mesopotamian era, design has been a fundamental instigator of creations and inventions, leading us to the world we have today. Everything we have is the result of design: communities, architecture, mechanics, plumbing, furniture, clothing, etc. Design starts, often quietly, in the mind of an individual as an idea; but the idea begins to breathe when committed to paper or tangibly created.
Quantum circuit for measuring an operator's generalized expectation values and its applications to non-Hermitian winding numbers
Creators: name: Huang, Ze-Hao
name: He, Peng
name: Lang, Li-Jun
name: Zhu, Shi-Liang
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We propose a general quantum circuit based on the swap test for measuring the quantity $\langle ψ_1 | A | ψ_2 \rangle$ of an arbitrary operator $A$ with respect to two quantum states $|ψ_{1,2}\rangle$. This quantity is frequently encountered in many fields of physics, and we dub it the generalized expectation as a two-state generalization of the conventional expectation. We apply the circuit, in the field of non-Hermitian physics, to the measurement of generalized expectations with respect to left and right eigenstates of a given non-Hermitian Hamiltonian. To efficiently prepare the left and right eigenstates as the input to the general circuit, we also develop a quantum circuit via effectively rotating the Hamiltonian pair $(H,-H^\dagger)$ in the complex plane. As applications, we demonstrate the validity of these circuits in the prototypical Su-Schrieffer-Heeger model with nonreciprocal hopping by measuring the Bloch and non-Bloch spin textures and the corresponding winding numbers under periodic and open boundary conditions (PBCs and OBCs), respectively. The numerical simulation shows that non-Hermitian spin textures building up these winding numbers can be well captured with high fidelity, and the distinct topological phase transitions between PBCs and OBCs are clearly characterized. We may expect that other non-Hermitian topological invariants composed of non-Hermitian spin textures, such as non-Hermitian Chern numbers, and even significant generalized expectations in other branches of physics would also be measured by our general circuit, providing a different perspective to study novel properties in non-Hermitian as well as other physics realized in qubit systems.
description: 6+3 pages, 4+1 figures, published version
title: Women in International Development Theory, Policy and Progress
Creators: name: Tew, Melina
Publisher: name: Utah State University
Year: 2004

description: The Platform for Action of the Fourth World Conference on Women (1995) states: "Equality between women and men is a matter of human rights and a condition for social justice and is also a necessary and fundamental prerequisite for equality, development and peace." As this statement suggests, women are indispensable to any program in the developing world desiring sustainable, effective development. Despite efforts to thwart gender inequality, more women than men still live below the poverty line, and there is a global gender gap in levels of education and access to resources. In response to these conditions, the UN Population Fund reported the following:
"Programmes that reduce gender inequality can significantly improve individual and household welfare and national economic growth. If sub-Saharan Africa, South and West Asia had had the same female-male ratio in years of schooling that East Asia did in 1960, and had closed the education gender gap at the rate achieved by East Asia from 1960 to 1992, their per capita income could have grown by an additional 0.5 to 0.9 percentage points per year in sub-Saharan Africa, 1.7 per cent in South Asia and 2.2 per cent in West Asia."
KNOWLEDGE ASSESSMENT OF HOME SELF-CARE PRACTICES IN HEMODIALYSIS PATIENTS: A DESCRIPTIVE STUDY FROM SUDAN
Creators: name: ALDOWHA MOHAMMED ALDOWHA
name: AREEG SAIF ELDEIN ABDEL RAHMAN MAHJOUB
name: MOHAMMED EZZELDIEN HAMZA
name: MOHAMED SAIED HARFOUSH
Publisher: name: Zenodo
Year: 2025
Subjects: Hemodialysis Patients, Knowledge, Home Self-Care, Sudan.

description: Abstract

Background: Hemodialysis is a therapy that filters waste, removes excess fluid, and balances electrolytes (sodium, potassium, bicarbonate, chloride, calcium, magnesium, and phosphate) when the kidneys are in a state of renal failure. Home self-care is essential for hemodialysis patients, as it constitutes a significant part of their overall care. Aim: This study was conducted to assess knowledge about home self-care among hemodialysis patients. Methodology: This descriptive hospital-based study was conducted at Omdurman Teaching Hospital in Sudan. The target population included hemodialysis patients visiting the center to receive their treatments (n=100). A structured, self-administered, closed-ended questionnaire was used to collect data from the study subjects. Data were analyzed using the Statistical Package for Social Sciences (SPSS) and presented in the form of frequencies and percentages. Results: The study revealed that half of the participants had low knowledge about therapeutic nutrition, and more than half of the patients consumed fluids freely. Conclusion: The study concluded that approximately half of the patients were over 45 years old, with a majority being male. Most patients underwent regular hemodialysis twice a week for a duration of four hours. The study recommends the implementation of health education programs to enhance self-care among dialysis patients, enabling them to take a more active role in their care and supporting them in performing various tasks related to their dialysis according to their individual abilities.
Modular-invariant large-$N$ completion of an integrated correlator in $\mathcal{N}=4$ supersymmetric Yang-Mills theory
Creators: name: Dorigoni, Daniele
name: Green, Michael B.
name: Wen, Congkao
name: Xie, Haitian
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: The use of supersymmetric localisation has recently led to modular covariant expressions for certain integrated correlators of half-BPS operators in $\mathcal{N} = 4$ supersymmetric Yang-Mills theory with a general classical gauge group $G_N$. Here we determine generating functions that encode such integrated correlators for any classical gauge group and provide a proof of previous conjectured formulae. This gives a systematic understanding of the relation between properties of these correlators at finite $N$ and their expansions at large $N$. In particular, it determines a duality-invariant non-perturbative completion of the large-$N$ expansion in terms of a sum of novel non-holomorphic modular functions. These functions are exponentially suppressed at large $N$ and have the form of a sum of contributions from coincident $(p, q)$-string world-sheet instantons.
description: 25 + 15 pages; v2: minor changes, version published in JHEP
title: Multivariate extremes and dependence structures : a theoretical background for modelling
Creators: name: Heiny, Johannes
Publisher: name: TU Wien
Year: 2013

description: Many fields of modern science have to deal with events which are rare but of outstanding importance. Extreme value theory is a practical and useful mathematical tool for modelling events which occur with very small probability. In a wide variety of applications these extreme events have an inherently multivariate character. This thesis provides an overview of the relevant theoretical results for modelling multivariate extremes and their dependence structures. We study multivariate extreme value distributions (MEVDs) and characterise their maximum domain of attraction (MDA). We state the relationships between four equivalent representations of MEVDs which can be used as a basis for estimation. Moreover we look at tail dependence coefficients and provide information about the underlying dependence. The central result is the multivariate extension of the Fisher-Tippett Theorem which basically says that the maximum domain of attraction of a MEVD is characterised by the univariate MDAs of its margins and a so-called copula domain of attraction (CDA) of its copula. We construct explicit examples of copulas which are in no CDA and describe models for the tail of a multivariate distribution function. In order to facilitate model building, some methods to construct new extreme value copulas from known ones are presented.