20 research outputs found
Lohengrin
No full textEmpresa Juan A. PamiasOrquestra del Gran Teatre del Liceu. Director Kurt Wöss, director d'escena Enayat Rezai, mestre de cor Riccardo Bottino. Amb la participació de l'Orfeó Atlàntida dirigit per Antonio CollÒpera romàntica en quatre actes i quatre quadres amb llibret i música de Richard Wagne
Rigoletto
No full textEmpres Juan A. PamiasMelodrama en quatre actes amb llibret de Francesco M. Piave (segons Victor Hugo) i música de Giuseppe VerdiOrquestra del Teatre del Liceu, direcció d'Eugenio M. Marco, direcció d'escena d'Enayat Rezai, mestre de cor Riccardo Bottino i coreògraf Juan Magriñ
Ultraproducts and their applications
No full textDegree awarded: M.A. Mathematics and Statistics. American UniversityAn ultraproduct is a mathematical construction used primarily in abstract algebra and model theory to create a new structure by reducing a product of a family of existing structures using a class of objects referred to as filters. This thesis provides a rigorous construction of ultraproducts and investigates some of their applications in the fields of mathematical logic, nonstandard analysis, and complex analysis. An introduction to basic set theory is included and used as a foundation for the ultraproduct construction. It is shown how to use this method on a family of models of first order logic to construct a new model of first order logic, with which one can produce a proof of the Compactness Theorem that is both elegant and robust. Next, an ultraproduct is used to offer a bridge between intuition and the formalization of nonstandard analysis by providing concrete infinite and infinitesimal elements. Finally, a proof of the Ax-Grothendieck Theorem is provided in which the ultraproduct and other previous results play a critical role. Rather than examining one in depth application, this text features ultraproducts as tools to solve problems across various disciplines.Made available in DSpace on 2014-01-30T15:04:33Z (GMT). No. of bitstreams: 1
Purcell_american_0008N_10521display.pdf: 302060 bytes, checksum: d174eeb16fa26172f0451dd7e3bd2ef6 (MD5
Incompleteness of boundedly axiomatizable theories
No full textOur main result (Theorem A) shows the incompleteness of any consistent
sequential theory T formulated in a finite language such that T is axiomatized
by a collection of sentences of bounded quantifier-alternation-depth. Our proof
employs an appropriate reduction mechanism to rule out the possibility of
completeness by simply invoking Tarski's Undefinability of Truth theorem. We
also use the proof strategy of Theorem A to obtain other incompleteness results
(as in Theorems A+; B and B+).Comment: 6 pages; in this version reference to MathOverflow work of Emil
Je\v{r}\'{a}bek has been added, and the author list of [AGLRZ] is now
up-to-dat
End extending models of set theory via power admissible covers
No full text© 2022 The Author(s). Published by Elsevier B.V.Motivated by problems involving end extensions of models of set theory, we develop the rudiments of the power admissible cover construction (over ill-founded models of set theory), an extension of the machinery of admissible covers invented by Barwise as a versatile tool for generalising model-theoretic results about countable well-founded models of set theory to countable ill-founded ones. Our development of the power admissible machinery allows us to obtain new results concerning powerset-preserving end extensions and rank extensions of countable models of subsystems of ZFC . The canonical extension KP P of Kripke-Platek set theory KP plays a key role in our work; one of our results refines a theorem of Rathjen by showing that Σ 1 P -Foundation is provable in KP P (without invoking the axiom of choice).Unfunde
Knowledge-graph-based explainable AI : A systematic review
No full textIn recent years, knowledge graphs (KGs) have been widely applied in various domains for different purposes. The semantic model of KGs can represent knowledge through a hierarchical structure based on classes of entities, their properties, and their relationships. The construction of large KGs can enable the integration of heterogeneous information sources and help Artificial Intelligence (AI) systems be more explainable and interpretable. This systematic review examines a selection of recent publications to understand how KGs are currently being used in eXplainable AI systems. To achieve this goal, we design a framework and divide the use of KGs into four categories: extracting features, extracting relationships, constructing KGs, and KG reasoning. We also identify where KGs are mostly used in eXplainable AI systems (pre-model, in-model, and post-model) according to the aforementioned categories. Based on our analysis, KGs have been mainly used in pre-model XAI for feature and relation extraction. They were also utilised for inference and reasoning in post-model XAI. We found several studies that leveraged KGs to explain the XAI models in the healthcare domain. © The Author(s) 2022.</p
Iterated ultrapowers for the masses
No full text© The Author(s) 2017. This article is an open access publication.We present a novel, perspicuous framework for building iterated ultrapowers. Furthermore, our framework naturally lends itself to the construction of a certain type of order indiscernibles, here dubbed tight indiscernibles, which are shown to provide smooth proofs of several results in general model theory.Unfunde
Evaluation of energy input and greenhouse gases emissions from alfalfa production in the Sistan region, Iran
No full textAbstractThe recognition of forage production methods that maximize energy efficiency and minimize Greenhouse Gases (GHGs) emissions is essential. The aims of this survey were to assess the energy consumption, emissions of GHGs and global warming potential (GWP) of alfalfa production systems in Sistan region, Sistan and Baluchestan province in the South–east of Iran. Data were collected randomly from 110 alfalfa farm using face-to-face questionnaire survey. Energy inputs included chemical fertilizers, diesel fuel, pesticides, seed, machinery and human labor. The results indicated that average total input and output energies in alfalfa production during the entire lifetime of the farm were 313.52GJha−1 and 962.85GJha−1, respectively. The most important energy inputs belonged to electricity (72.5%), followed by diesel fuel (12.3%) and N fertilizer (6.0%). Energy use efficiency and energy productivity were 3.07 and 0.209kgMJ−1, respectively. Share of direct and indirect energy were 85% and 15%, respectively. Total emissions of CO2, N2O and CH4 in alfalfa farms were 8262.67kgha−1, 557.31kgha−1 and 7.65kgha−1, respectively. Hence, total GWP was 181190 kg CO2eha−1 and 2.77 kg of CO2ekg−1 of dry hay produced. In terms of CO2e, 95.3% of the GWP originate from N2O, 4.6% from CO2 and 0.1% from CH4. Accordingly, efficient use of energy is essential to reduce the greenhouse gas emissions and environmental impact in alfalfa agroecosystems
Knowledge Graphs Applications in Smart Cities
No full textWith the invention of advanced technologies, there are millions of options to improve the quality of life in an urban city. Several innovative implementations transform urban cities into smart cities using new technologies to enhance urban inhabitants’ efficiency, sustainability, and overall quality of life. Our study shows that knowledge graphs play an important role in smart cities for transportation, parking, traffic, and city development. They serve as significant repositories, bringing together data from various sources. Several crucial domains of smart cities use knowledge graphs to resolve challenges that hinder urban development. In this paper, we discuss the applications of knowledge graphs in various smart city areas, identify existing challenges, and propose strategies to enhance the current implementation of knowledge graphs in smart cities. We highlight a few innovations that used knowledge graphs in smart cities, showcasing their versatility. Integrating knowledge graphs into smart cities significantly enhances the efficiency of urban services by consolidating and connecting data from different sources and constructing a graph, aiding in better decision-making. © 2024 Copyright held by the owner/author(s).</p
Largest initial segments pointwise fixed by automorphisms of models of set theory
No full text© The Author(s) 2017. This article is an open access publication.Given a model M of set theory, and a nontrivial automorphism j of M, let Ifix(j) be the submodel of M whose universe consists of elements m of M such that j(x)=x for every x in the transitive closure of m (where the transitive closure of m is computed within M). Here we study the class C of structures of the form Ifix(j), where the ambient model M satisfies a frugal yet robust fragment of ZFC known as MOST, and j(m)=m whenever m is a finite ordinal in the sense of M. Our main achievement is the calculation of the theory of C as precisely MOST+Δ0P Collection. The following theorems encapsulate our principal results: Theorem A. Every structure inC satisfies MOST+Δ0P Collection. Theorem B. Each of the following three conditions is sufficient for a countable structure (a) N is a transitive model of MOST+Δ0P Collection. (b) N is a recursively saturated model of MOST+Δ0P Collection. (c) N is a model of ZFC. Theorem C. Suppose M is a countable recursively saturated model of ZFC and I is a proper initial segment of OrdM that is closed under exponentiation and contains ωM. There is a group embedding j⟼j from Aut(Q) into Aut(M) such that I is the longest initial segment of OrdM that is pointwise fixed by jˇ for every nontrivial j∈Aut(Q). In Theorem C, Aut(X) is the group of automorphisms of the structure X, and Q is the ordered set of rationals.Unfunde
