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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Gestão integrada dos recursos hídricos : alocação otimizada com uso conjunto de água superficial e subterrânea para redução da escassez hídrica na bacia do rio Santa Maria/RS

Mattiuzi, Camila Dalla Porta January 2018 (has links)
A falta de gestão integrada das águas superficiais e subterrâneas, aliada ao seu uso intensivo, acarretou em efeitos indesejados como escassez hídrica e perdas econômicas. A partir do conhecimento sobre as disponibilidades e demandas hídricas é possível promover estratégias de alocação otimizada de água para redução da escassez e dos custos da escassez. O uso conjunto de água superficial e subterrânea consiste no desenvolvimento de estratégias de alocação que explorem as vantagens e particularidades de cada manancial, assim reduzindo o efeito das variabilidades e incertezas na disponibilidade de água. O presente trabalho apresenta um estudo de alocação otimizada utilizando água superficial e subterrânea visando à redução da escassez hídrica, a redução no custo da escassez e o aumento no atendimento das demandas agrícolas na Bacia do Rio Santa Maria, localizada no Rio Grande do Sul/Brasil. O trabalho foi estruturado em três artigos científicos. O primeiro artigo apresenta uma revisão bibliográfica sobre o conceito, benefícios e desafios na implementação de estratégias de uso conjunto; a partir da análise das informações levantadas na revisão bibliográfica foi possível delinear estratégias que podem ser aplicadas no contexto brasileiro, embasadas nos instrumentos de gestão previstos na Política Nacional de Recursos Hídricos. O segundo artigo apresenta a obtenção das funções de benefício marginal dos usuários de água para irrigação na área estudada; estas funções são conhecidas como "curvas de demanda" e avaliam a disponibilidade de um usuário a pagar pelo recurso, de maneira que, quanto mais escasso o recurso, maior será seu valor marginal; estas funções são necessárias para a aplicação do modelo hidroeconômico Neste artigo também foi realizado um estudo do caso dos eventos de estiagem de 2006 e 2011 na Bacia do Rio Santa Maria, sendo analisados os prejuízos econômicos advindos da escassez. O terceiro artigo apresenta a aplicação do modelo hidroeconômico de alocação da água no sistema da Bacia do Rio Santa Maria; a função objetivo do modelo é minimizar o custo da escassez. Os resultados apontaram a alocação de água otimizada economicamente e os benefícios advindos da utilização de água subterrânea no atendimento das demandas, evidenciando a importância da gestão eficiente da água para flexibilizar e tornar o sistema hídrico mais resiliente. / The lack of integrated management of surface and groundwater, coupled with its intensive use, has led to undesirable effects such as water shortages and economic losses. The knowledge about water availabilities and demands makes it possible to promote optimized water allocation strategies to reduce scarcity and scarcity costs. Conjunctive use of surface water and groundwater consists of the development of allocation strategies that explore the advantages and peculiarities of each source, thus reducing the effect of variability and uncertainties on water availability. This work presents an optimized allocation study using surface and groundwater to reduce water scarcity, reduce scarcity cost, and increase agricultural demand attendance in the Santa Maria River Basin, located in Rio Grande do Sul/Brazil. This work was structured in three scientific articles. The first article presents a bibliographic review about the concept, benefits and challenges in the implementation of conjunctive use strategies; from the analysis of the information collected in the bibliographic review it was possible to outline strategies that can be applied in the Brazilian context, based on the management instruments provided in the National Water Resources Policy The second article presents the obtaining of the marginal benefit curves of water used in irrigation in the studied area; these functions are known as "demand curves" and evaluate the user’s willingness to pay for the resource, so that the scarcer the resource, greater is its marginal value; these functions are input data for the hydroeconomic model. In this paper it was also studied the droughts of 2006 and 2011 in the Santa Maria River Basin, analyzing the economic losses due to the scarcity. The third article presents the application of the hydroeconomic model to solve the problem of water allocation in the Santa Maria River basin system; the objective function of the model is to minimize scarcity cost. The results showed the economically optimized water allocation and the benefits derived from the use of groundwater in meeting the demands, showing the importance of efficient water management to make water systems more flexible and resilient.
32

Gestão integrada dos recursos hídricos : alocação otimizada com uso conjunto de água superficial e subterrânea para redução da escassez hídrica na bacia do rio Santa Maria/RS

Mattiuzi, Camila Dalla Porta January 2018 (has links)
A falta de gestão integrada das águas superficiais e subterrâneas, aliada ao seu uso intensivo, acarretou em efeitos indesejados como escassez hídrica e perdas econômicas. A partir do conhecimento sobre as disponibilidades e demandas hídricas é possível promover estratégias de alocação otimizada de água para redução da escassez e dos custos da escassez. O uso conjunto de água superficial e subterrânea consiste no desenvolvimento de estratégias de alocação que explorem as vantagens e particularidades de cada manancial, assim reduzindo o efeito das variabilidades e incertezas na disponibilidade de água. O presente trabalho apresenta um estudo de alocação otimizada utilizando água superficial e subterrânea visando à redução da escassez hídrica, a redução no custo da escassez e o aumento no atendimento das demandas agrícolas na Bacia do Rio Santa Maria, localizada no Rio Grande do Sul/Brasil. O trabalho foi estruturado em três artigos científicos. O primeiro artigo apresenta uma revisão bibliográfica sobre o conceito, benefícios e desafios na implementação de estratégias de uso conjunto; a partir da análise das informações levantadas na revisão bibliográfica foi possível delinear estratégias que podem ser aplicadas no contexto brasileiro, embasadas nos instrumentos de gestão previstos na Política Nacional de Recursos Hídricos. O segundo artigo apresenta a obtenção das funções de benefício marginal dos usuários de água para irrigação na área estudada; estas funções são conhecidas como "curvas de demanda" e avaliam a disponibilidade de um usuário a pagar pelo recurso, de maneira que, quanto mais escasso o recurso, maior será seu valor marginal; estas funções são necessárias para a aplicação do modelo hidroeconômico Neste artigo também foi realizado um estudo do caso dos eventos de estiagem de 2006 e 2011 na Bacia do Rio Santa Maria, sendo analisados os prejuízos econômicos advindos da escassez. O terceiro artigo apresenta a aplicação do modelo hidroeconômico de alocação da água no sistema da Bacia do Rio Santa Maria; a função objetivo do modelo é minimizar o custo da escassez. Os resultados apontaram a alocação de água otimizada economicamente e os benefícios advindos da utilização de água subterrânea no atendimento das demandas, evidenciando a importância da gestão eficiente da água para flexibilizar e tornar o sistema hídrico mais resiliente. / The lack of integrated management of surface and groundwater, coupled with its intensive use, has led to undesirable effects such as water shortages and economic losses. The knowledge about water availabilities and demands makes it possible to promote optimized water allocation strategies to reduce scarcity and scarcity costs. Conjunctive use of surface water and groundwater consists of the development of allocation strategies that explore the advantages and peculiarities of each source, thus reducing the effect of variability and uncertainties on water availability. This work presents an optimized allocation study using surface and groundwater to reduce water scarcity, reduce scarcity cost, and increase agricultural demand attendance in the Santa Maria River Basin, located in Rio Grande do Sul/Brazil. This work was structured in three scientific articles. The first article presents a bibliographic review about the concept, benefits and challenges in the implementation of conjunctive use strategies; from the analysis of the information collected in the bibliographic review it was possible to outline strategies that can be applied in the Brazilian context, based on the management instruments provided in the National Water Resources Policy The second article presents the obtaining of the marginal benefit curves of water used in irrigation in the studied area; these functions are known as "demand curves" and evaluate the user’s willingness to pay for the resource, so that the scarcer the resource, greater is its marginal value; these functions are input data for the hydroeconomic model. In this paper it was also studied the droughts of 2006 and 2011 in the Santa Maria River Basin, analyzing the economic losses due to the scarcity. The third article presents the application of the hydroeconomic model to solve the problem of water allocation in the Santa Maria River basin system; the objective function of the model is to minimize scarcity cost. The results showed the economically optimized water allocation and the benefits derived from the use of groundwater in meeting the demands, showing the importance of efficient water management to make water systems more flexible and resilient.
33

Kompilace KNF do backdoor decomposable monotone circuit / Compilation of a CNF into a backdoor decomposable monotone circuit

Illner, Petr January 2021 (has links)
An NNF circuit is a directed acyclic graph (DAG), where each leaf is labelled with either true/false or a literal, and each inner node represents either a conjunction (∧) or a disjunction (∨). A decomposable NNF (DNNF) is an NNF satisfying the decomposabi- lity property for each conjunction node. The C-BDMC language generalizes the DNNF language. In a C-BDMC, the leaves can contain CNF formulae from a given base class C. In this paper, we focus only on renamable Horn formulae. We experimentally compare the sizes of d-BDMC and d-DNNF representations. We describe a new compilation langu- age, called cara DNNF (c-DNNF), that generalizes the DNNF language. A c-DNNF circuit can be considered as a compressed representation of a DNNF circuit. We present a new experimental knowledge compiler, called CaraCompiler, for converting a CNF formula into a d-BDMC or a (c)d-DNNF circuit. CaraCompiler is based on the state-of-the-art compiler D4. Also, we mention some extensions for the compiler D4, such as caching hypergraph cuts that can reduce the compilation times. 1
34

Conjunctive Relations in Argumentative Essays : Second language learners of English and the frequency of connective words

Blixt, Jojo January 2022 (has links)
This essay aims to examine texts written by students in upper secondary school year 10 to see which conjunctions and linking words students at that level use, the normalized frequency as well as how they are used. For the investigation, a corpus, the Swedish Learner English Corpus (SLEC), was searched using AntConc, a corpus analysis toolkit for concordancing and text analysis. The investigated and compared groups are vocational and academic students, girls and boys, all studying the English 5 course, and no one speaking English as their native language. The hypotheses were that academic students, due to higher motivation, would use a higher normalized frequency of internal conjunctive relations which create text cohesion compared to the vocational students, and also that girls would use a higher normalized frequency of the same type of conjunctive relations than boys due to better results in general. The results were as predicted that the students enrolled in the academic programs do use a higher frequency of conjunctive relations of the internal kind than students in the vocational programs, apart from the temporal category, and that the girls use a higher frequency of conjunctive relations of the internal kind, than the boys within all functions except the temporal.
35

Ontology-guided Health Information Extraction, Organization, and Exploration

Cui, Licong 02 September 2014 (has links)
No description available.
36

Category neutrality: A type-logical investigation

Whitman, Philip Neal 02 July 2002 (has links)
No description available.
37

Enantioselective Multi-Component Reactions: Conjunctive Coupling and Related Processes

Lovinger, Gabriel Jordan January 2019 (has links)
Thesis advisor: James P. Morken / This dissertation details the discovery, development, and mechanistic exploration of several enantioselective processes involving organoboronic esters. The first chapter will discuss electrophile-induced metallate rearrangement reactions, the fundamental reactivity that underlies much of the subsequently discussed work. The second chapter details the discovery and mechanistic study of the metal-induced metallate rearrangement reaction and the multi-component conjunctive coupling reaction manifold and related reactions it enables. The factors that govern the competition between metal-induced metallate rearrangement versus transmetallation will be explored. The third chapter will discuss efforts to understand and overcome the initial limitations of the conjunctive coupling reaction including halide inhibition of palladium catalysis and the inability to engage other organometallic reagents such as organomagnesium nucleophiles, and how this allowed the development of a more general reaction. The fourth chapter discusses the development of an enantioselective triamine–nickel-catalyzed conjunctive coupling reaction of alkyl electrophiles as well as a related nickel-promoted radical-polar crossover reaction and the mechanistic features leading to one reaction manifold or the other. A related enantioselective diamine–nickel-catalyzed tandem radical addition cross coupling reaction of alkyl iodides, alkenylboron reagents, and alkyl- or arylzinc reagents will also be discussed. The fifth chapter will cover the discovery of a diamine–nickel-catalyzed enantioselective carbozincation reaction of alkenylboron compounds which produces enantioenriched α-boryl alkylzinc reagents. The mechanistic investigations undertaken and application of these species in a variety of stereospecific transformation will be discussed along with the preliminary discovery and optimization of a diphosphine-Pd-catalyzed stereoconvergent Negishi cross-coupling reaction of racemic α-boryl alkylzinc reagents. / Thesis (PhD) — Boston College, 2019. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Chemistry.
38

On Implementing Temporal Query Answering in DL-Lite

Thost, Veronika, Holste, Jan, Özçep, Özgür 20 June 2022 (has links)
Ontology-based data access augments classical query answering over fact bases by adopting the open-world assumption and by including domain knowledge provided by an ontology. We implemented temporal query answering w.r.t. ontologies formulated in the Description Logic DL-Lite. Focusing on temporal conjunctive queries (TCQs), which combine conjunctive queries via the operators of propositional linear temporal logic, we regard three approaches for answering them: an iterative algorithm that considers all data available; a window-based algorithm; and a rewriting approach, which translates the TCQs to be answered into SQL queries. Since the relevant ontological knowledge is already encoded into the latter queries, they can be answered by a standard database system. Our evaluation especially shows that implementations of both the iterative and the window-based algorithm answer TCQs within a few milliseconds, and that the former achieves a constant performance, even if data is growing over time.
39

Temporal Query Answering in DL-Lite with Negation

Borgwardt, Stefan, Thost, Veronika 20 June 2022 (has links)
Ontology-based query answering augments classical query answering in databases by adopting the open-world assumption and by including domain knowledge provided by an ontology. We investigate temporal query answering w.r.t. ontologies formulated in DL-Lite, a family of description logics that captures the conceptual features of relational databases and was tailored for efficient query answering. We consider a recently proposed temporal query language that combines conjunctive queries with the operators of propositional linear temporal logic (LTL). In particular, we consider negation in the ontology and query language, and study both data and combined complexity of query entailment.
40

Answering Conjunctive Queries and FO+MOD Queries under Updates

Keppeler, Jens 26 June 2020 (has links)
In dieser Arbeit wird das dynamische Auswertungsproblem über dynamische Datenbanken betrachtet, bei denen Tupel hinzugefügt oder gelöscht werden können. Die Aufgabe besteht darin einen dynamischen Algorithmus zu konstruieren, welcher unmittelbar nachdem die Datenbank aktualisiert wurde, die Datenstruktur, die das Resultat repräsentiert, aktualisiert. Die Datenstruktur soll in konstanter Zeit aktualisiert werden und das Folgende unterstützen: * Teste in konstanter Zeit ob ein Tupel zur Ausgabemenge gehört, * gebe die Anzahl der Tupel in der Ausgabemenge in konstanter Zeit aus, * zähle die Tupel aus der Ausgabemenge mit konstanter Taktung auf und * zähle den Unterschied zwischen der neuen und der alten Ausgabemenge mit konstanter Taktung auf. Im ersten Teil werden konjunktive Anfragen und Vereinigungen konjunktiver Anfragen auf relationalen Datenbanken betrachtet. Die Idee der q-hierarchischen Anfragen (und t-hierarchische Anfragen für das Testen) wird eingeführt und es wird gezeigt, dass das Resultat für jede q-hierarchische Anfrage auf dynamischen Datenbanken effizient in dem oben beschriebenen Szenario ausgewertet werden können. Konjunktive Anfragen mit Aggregaten werden weiterhin betrachtet. Es wird gezeigt, dass das Lernen von polynomiellen Regressionsfunktionen in konstanter Zeit vorbereitet werden kann, falls die Trainingsdaten aus dem Anfrageergebnis kommen. Mit logarithmischer Update-Zeit kann folgende Routine unterstützt werden: Bei Eingabe einer Zahl j, gebe das j-te Tupel aus der Aufzählung aus. Im zweiten Teil werden Anfragen, die Formeln der Logik erster Stufe (FO) und deren Erweiterung mit Modulo-Zähl Quantoren (FO+MOD) sind, betrachtet, und es wird gezeigt, dass diese effizient unter Aktualisierungen ausgewertet können, wobei die dynamische Datenbank die Gradschranke nicht überschreitet, und bei der Auswertung die Zähl-, Test-, Aufzähl- und die Unterschied-Routine unterstützt werden. / This thesis investigates the query evaluation problem for fixed queries over fully dynamic databases, where tuples can be inserted or deleted. The task is to design a dynamic algorithm that immediately reports the new result of a fixed query after every database update. In particular, the goal is to construct a data structure that allows to support the following scenario. After every database update, the data structure can be updated in constant time such that afterwards we are able * to test within constant time for a given tuple whether or not it belongs to the query result, * to output the number of tuples in the query result, * to enumerate all tuples in the new query result with constant delay and * to enumerate the difference between the old and the new query result with constant delay. In the first part, conjunctive queries and unions of conjunctive queries on arbitrary relational databases are considered. The notion of q-hierarchical conjunctive queries (and t-hierarchical conjunctive queries for testing) is introduced and it is shown that the result of each such query on a dynamic database can be maintained efficiently in the sense described above. Moreover, this notion is extended to aggregate queries. It is shown that the preparation of learning a polynomial regression function can be done in constant time if the training data are taken (and maintained under updates) from the query result of a q-hierarchical query. With logarithmic update time the following routine is supported: upon input of a natural number j, output the j-th tuple that will be enumerated. In the second part, queries in first-order logic (FO) and its extension with modulo-counting quantifiers (FO+MOD) are considered, and it is shown that they can be efficiently evaluated under updates, provided that the dynamic database does not exceed a certain degree bound, and the counting, testing, enumeration and difference routines is supported.

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