Spelling suggestions: "subject:"week.""
261 |
Conhecimento para inovar : um estudo sobre o processamento de sinais fracos e o desempenho em inovaçãoRibeiro, Jairo Moran Carvalho 03 December 2013 (has links)
Tanto as inovações como o conhecimento desempenham um papel fundamental no atual cenário econômico e organizacional. Por outro lado, incertezas e turbulências, que podem estar associadas a processos e mudanças nestes cenários, emitem sinais, o que, no âmbito organizacional, denota a necessidade de monitoramento do ambiente competitivo. Os sinais, ainda que fracos e uma vez identificados representam estímulos externos que, associados ao conhecimento fomentam a inovação e, desta forma, podem ser considerados como um dos antecedentes da inovação. Segundo Arboniés (2009), os sinais fracos permitem a criação individual a partir da associação de diferentes sinais entre si e ao conhecimento tácito detido
por um grupo de indivíduos. Esse processo denominado de rotinas criativas amplia o campo de alternativas e pode antecipar ameaças e oportunidades, a partir da interpretação criativa de sinais fracos e da concepção de rotinas para o seu processamento. Assim, este trabalho se propôs a estudar o conhecimento como um antecedente da inovação e como resultante do monitoramento externo. O foco estava no papel dos sinais fracos, em seu processamento por meio de rotinas criativas e em sua influência no desempenho em inovação. O objetivo foi então o de analisar as práticas de rotinas criativas para o processamento de sinais fracos e o desempenho em inovação. O método de pesquisa utilizado foi o descritivo exploratório, com um estudo de caso realizado nas empresas do Grupo Alfa. Os resultados indicaram que as empresas que possuem rotinas criativas apresentam desempenho superior em inovação. / Submitted by Marcelo Teixeira (mvteixeira@ucs.br) on 2014-04-30T13:20:50Z
No. of bitstreams: 1
Dissertacao Jairo Moran C. Ribeiro.pdf: 2844874 bytes, checksum: 6449394bd3c6eb42842ed08f08c62748 (MD5) / Made available in DSpace on 2014-04-30T13:20:50Z (GMT). No. of bitstreams: 1
Dissertacao Jairo Moran C. Ribeiro.pdf: 2844874 bytes, checksum: 6449394bd3c6eb42842ed08f08c62748 (MD5) / As innovations as knowledge show a main role in the organizational economic scenery nowadays. Furthermore uncertainties and turbulence may be associated with changes in these processes and sceneries, emitting signals and within the organizational context indicate the need of monitoring the competitive environment. These signals still so weak and once a time identified represent the external stimuli which associated to the knowhow can feed, and this way are considered like a background of the innovation. According Arboniés (2009), weak signal allow an individual creation from the association in different signals among theirselves and a tacit knowledge held by a group of individuals. This process called creative routines broadens the alternatives and can anticipate threats and opportunities, from the creative interpretation of weak signals and designing routines for processing. Thus, this study aimed to analyze the knowledge as a background of innovation and as a result of external monitoring.
The focus was on the role of weak signals in their processing through creative routines and their influence on innovation performance. Then the goal was to analyse the practice of creative routines for a processing of weak signs and performance in innovation. The method used was the descriptive and exploratory with a case study from Alpha Group Companies. The outcomes indicate that the enterprises that have creative routines also show a superior performance in innovation.
|
262 |
[en] INSTRUMENT SELECTION AND IDENTIFICATION OF MACROECONOMIC EQUILIBRIUM CONDITIONS / [pt] SELEÇÃO DE INSTRUMENTOS E IDENTIFICAÇÃO DE EQUAÇÕES DE EQUILÍBRIO MACROECONÔMICOMARCELO MOURA JARDIM TEIXEIRA SENA 29 May 2018 (has links)
[pt] Mavroeidis (2005) alertou que equações de equlíbrio motivadas por
modelos macroeconômicos com expectatvas racionais poderiam ser fracamente
identificados devido ao uso de instrumentos fracos. Eu argumento que,
embora tais preocupações sejam legítimas, elas não são empiricamente graves,
contanto que instrumentos sejam devidamente selecionados. Eu utilizo
um modelo DSGE estimado de média escala como laboratório para avaliar
estimação uniequacional de condições de equilíbrio macroeconômicas.
Apresento estimadores baseados no LASSO que selecionam instrumentos e
tem boa performance em amostra finita, que argumento funcionam melhor
em relações que incluem termos de expectativa, como a Curva de Phillips
Novo Keynesiana. Por último, faço uma aplicação empírica para a Curva
de Phillips da economia dos Estados-Unidos e as estimativas validam um
componente de expectativa predominante. / [en] Mavroeidis (2005) alerted that equilibrium conditions from typical rational
expectations macroeconomic models could be weakly identified due
to the use of poor instruments. I argue that, although such concerns are legitimate,
they are not empirically severe, provided instruments are properly
selected. I use an estimated medium scale DSGE model as a laboratory to
assess single-equation estimation of macroeconomic equilibrium conditions.
I present LASSO-based estimators to select instruments that perform well
in finite samples, which I argue have a better chance of performing for
forward-looking relationships, such as the New Keynesian Phillips Curve.
Finally, I provide an empirical application of the estimators for the US
economy s Phillips Curve and show that it validates a dominant forward looking
behavior.
|
263 |
Extensões de Ore e álgebras de Hopf fracasSantos, Ricardo Leite dos January 2017 (has links)
Extensões de Ore são anéis de polinômios, denotados por R[x o &], nos quais a variável x e os elementos de R não comutam necessariamente. Algebras de Hopf fracas são algebras que tamb em são coálgebras e satisfazem um conjunto de axiomas de compatibilidade entre essas estruturas. Neste trabalho investigamos extensões de Ore cujo anel base e uma algebra de Hopf fraca. Mais especi camente, dada uma algebra de Hopf fraca R, estudamos sob quais condições R[x o &] e uma algebra de Hopf fraca com uma estrutura que estende a estrutura de R. Sob certas hipóteses, obtemos condições necessárias e su cientes para que a extensão de Ore seja uma álgebra de Hopf fraca, obtendo assim um resultado que generaliza um teorema de Panov para o contexto de algebras de Hopf fracas. / Ore extensions are polynomial rings, denoted by R[x o &], in which the variable x and the elements of R do not commute necessarily. Weak Hopf algebras are algebras which are also coalgebras and satisfy a set of axioms of compatibility betweem these structures. In this work, we investigate Ore extensions whose base ring is a weak Hopf algebra. More speci cally, if R is a weak Hopf algebra then we study under what conditions R[xo &] is a weak Hopf algebra extending the structure of R. Under certain hypotheses, we obtain necessary and su cient conditions for an Ore extension to be a weak Hopf algebra, obtaining a result that generalizes a Panov's theorem to the setting of weak Hopf algebras.
|
264 |
Stabilita v autoregresních modelech časových řad / Stability in Autoregressive Time Series ModelsDvořák, Marek January 2015 (has links)
The main subject of this thesis is a change point detection in stationary vector autoregressions. Various test statistics are proposed for the retrospective break point detection in the parameters of such models, in particular, the derivation of their asymptotic distribution under the null hypothesis of no change. Testing procedures are based on the maximum like- lihood principle and are derived under normality, nevertheless the asymptotic results are valid for broader class of distributions and involve also the models with certain form of dependence. Simulation studies document the quality of the results.
|
265 |
An analytic representation of weak mutually unbiased basesOlupitan, Tominiyi E. January 2016 (has links)
Quantum systems in the d-dimensional Hilbert space are considered. The mutually unbiased bases is a deep problem in this area. The problem of finding all mutually unbiased bases for higher (non-prime) dimension is still open. We derive an alternate approach to mutually unbiased bases by studying a weaker concept which we call weak mutually unbiased bases. We then compare three rather different structures. The first is weak mutually unbiased bases, for which the absolute value of the overlap of any two vectors in two different bases is 1/√k (where k∣d) or 0. The second is maximal lines through the origin in the Z(d) × Z(d) phase space. The third is an analytic representation in the complex plane based on Theta functions, and their zeros. The analytic representation of the weak mutually unbiased bases is defined with the zeros examined. It is shown that there is a correspondence (triality) that links strongly these three apparently different structures. We give an explicit breakdown of this triality.
|
266 |
PARITY VIOLATION IN THE HADRONIC WEAK INTERACTIONJanuary 2012 (has links)
abstract: This thesis deals with the first measurements done with a cold neutron beam at the Spallation Neutron Source at Oak Ridge National Laboratory. The experimental technique consisted of capturing polarized cold neutrons by nuclei to measure parity-violation in the angular distribution of the gamma rays following neutron capture. The measurements presented here for the nuclei Chlorine ( 35Cl) and Aluminum ( 27Al ) are part of a program with the ultimate goal of measuring the asymmetry in the angular distribution of gamma rays emitted in the capture of neutrons on protons, with a precision better than 10-8, in order to extract the weak hadronic coupling constant due to pion exchange interaction with isospin change equal with one ( hπ 1). Based on theoretical calculations asymmetry in the angular distribution of the gamma rays from neutron capture on protons has an estimated size of 5·10-8. This implies that the Al parity violation asymmetry and its uncertainty have to be known with a precision smaller than 4·10-8. The proton target is liquid Hydrogen (H2) contained in an Aluminum vessel. Results are presented for parity violation and parity-conserving asymmetries in Chlorine and Aluminum. The systematic and statistical uncertainties in the calculation of the parity-violating and parity-conserving asymmetries are discussed. / Dissertation/Thesis / Ph.D. Physics 2012
|
267 |
Numerical Analysis of Coal Pillar Stability on Variable Weak Floor with Paste BackfillJessu, Kashi Vishwanath 01 December 2016 (has links)
This thesis investigates the stability of coal pillars under realistic conditions of varying weak floor thickness with and without the use of paste backfill. Weak floor strata underlying coal seams are common in the Illinois Basin. They consist mainly of underclay, which is a gray, argillaceous rock that usually occurs immediately beneath beds of coal. Underclay thickness may vary from less than a foot to twenty feet at different locations in the basin (Grim and Allen, 1938). Locally, underclay thickness may vary gradationally over a distance of two pillars. Even though weak floor thickness is not consistent (Gadde, 2009), most research to date has focused on parametric studies with a fixed underclay thickness and formulated coal pillar designs on the basis of the maximum underclay thickness measured in the field. Therefore, it is necessary to investigate more realistic field conditions and quantify the influence of a gradated weak floor thickness using additional parametric studies. This research is primarily numerical modeling incorporating various constitutive models and using some calibration. Therefore, the two dimensional plane strain finite difference model in FLAC 3D is employed to carry out parametric studies on gradated weak floor conditions. Underclay exhibits Mohr Coulomb elastic plastic behavior; hence, the Mohr Coulomb constitutive model is used for the behavior of overburden, coal, and floor. Well-calibrated numerical models can assist in understanding load and failure processes provided that coal, overburden, and weak floor are modeled with sufficient realism. The theoretical approach considers a friction angle of 0° to calculate the load bearing capacity of the weak floor for design of pillars with long-term stability, even if the weak floor has a non-zero friction angle. The stiffness of the weak floor increases with an increase in friction angle (Gadde, 2009; Kostecki and Spearing, 2015). As stiffness increases, a point can be reached where floor bearing capacity exceeds coal pillar strength and coal pillar strength becomes the governing factor. For this scenario, the Mohr Coulomb strain softening model is more realistic in estimating loads carried by coal pillars in the post-failure stage. The three-dimensional Mohr Coulomb strain softening model in FLAC 3D is employed to study qualitatively the floor response in strain softening coal behavior conditions. Maintaining stable coal pillar responses has been a challenge for the coal mining industry due to attempts to increase the primary extraction ratio. Presently, the best available solution seems to be backfilling when considering short-term pillar stability (i.e., less than the long-term factor of safety) with increased extraction ratio. There are various types of mine backfill that have benefits to the mining industry depending on the application, but paste backfill produced from total mill tailings containing no free water is the best option for post-mining ground control in room-and-pillar mines as it prevents weakening of the floor and will not contaminate the ground water. The influence of paste backfill on floor bearing capacity and coal pillar response is studied with numerical modeling using the same constitutive models already identified. Finally, an economic analysis is carried out to look at cost implications of a proposed system with backfill.
|
268 |
Surfaces quantile : propriétés, convergences et applications / Quantile surfaces : properties, convergence and applicationsAhidar-Coutrix, Adil 03 July 2015 (has links)
Dans la thèse on introduit et on étudie une généralisation spatiale sur $\R^d$ du quantile réel usuel sous la forme d'une surface quantile via des formes $\phi$ et d'un point d'observation $O$. Notre point de départ est de simplement admettre la subjectivité due à l'absence de relation d'ordre totale dans $\R^d$ et donc de développer une vision locale et directionnelle des données. Ainsi, les observations seront ordonnées du point de vue d'un observateur se trouvant à un point $O \in \R^d$. Dans le chapitre 2, on introduit la notion du quantile vue d'un observateur $O$ dans la direction $u \in \Sd$ et de niveau $\alpha$ via des des demi-espaces orthogonaux à chaque direction d'observation. Ce choix de classe implique que les résultats de convergence ne dépendent pas du choix de $O$. Sous des hypothèses minimales de régularité, l'ensemble des points quantile vue de $O$ définit une surface fermée. Sous hypothèses minimales, on établit pour les surfaces quantile empiriques associées les théorèmes limites uniformément en le niveau de quantile et la direction d'observation, avec vitesses asymptotiques et bornes d'approximation non-asymptotiques. Principalement la LGNU, la LLI, le TCLU, le principe d'invariance fort uniforme puis enfin l'approximation du type Bahadur-Kiefer uniforme, et avec vitesse d'approximation. Dans le chapitre 3, on étend les résultats du chapitre précédent au cas où les formes $\phi$ sont prises dans une classe plus générale (fonctions, surfaces, projections géodésiques, etc) que des demi-espaces qui correspondent à des projections orthogonales par direction. Dans ce cadre plus général, les résultats dépendent fortement du choix de $O$, et c'est ce qui permet de tirer des interprétations statistiques. Dans le chapitre 4, des conséquences méthodologiques en statistique inférentielle sont tirées. Tout d'abord on introduit une nouvelle notion de champ de profondeurs directionnelles baptisée champ d'altitude. Ensuite, on définit une notion de distance entre lois de probabilité, basée sur la comparaison des deux collections de surfaces quantile du type Gini-Lorrentz. La convergence avec vitesse des mesures empiriques pour cette distance quantile, permet de construire différents tests en contrôlant leurs niveaux et leurs puissances. Enfin, on donne une version des résultats dans le cas où une information auxiliaire est disponible sur une ou plusieurs coordonnées sous la forme de la connaissance exacte de la loi sur une partition finie. / The main issue of the thesis is the development of spatial generalizations on $\R^d$ of the usual real quantile. Facing the usual fact that $\R^d$ is not naturally ordered, our idea is to simply admit subjectivity and thus to define a local viewpoint rather than a global one, anchored at some point of reference $O$ and arbitrary shape $\phi$ with the motivation of crossing information gathered by changing viewpoint $O$, shape $\phi$ and $\alpha$-th order of quantile. In Chapter 2, we study the spatial quantile points seen from an observer $O$ in a direction $u \in \Sd$ of level $\alpha$ through the class of the half-spaces orthogonal to the direction $u$. This choice implies that the convergence theorems do not depend on the choice of $O$. Under minimal regularity assumptions, the set of all quantile points seen from $O$ is a closed surface. Under minimal assumptions, we establish for the associated empirical quantile surfaces the convergence theorems uniformly on the quantile level and the observation direction with the asymptotic speed and non-asymptotic bounds of approximation. Mainly, we establish the ULLN, the ULIL, the UCLT, the uniform strong invariance principle and finally the Bahadur-Kiefer type embedding, with the approximation speed rate. In Chapter 3, all the results of the previous chapter are extended to the case where the shapes $ \phi $ are taken in a class more general (functions, surfaces, geodesic projections, etc) than orthogonal projections (half-spaces). In this general setting, the results depend strongly on the choice of $ O $. It is this dependence which permit to draw statistical interpretations: modes detection, mass localization, etc. In Chapter 4, some methodological consequences in inferential statistics are drawn. First we introduce a new concept of directional depth fields called altitude fields. In a second application is defined a new distances between probability distributions, based on the comparison of two collections of quantile surfaces, which are indexes of the type Gini-Lorrentz. The convergence with speed of the empirical quantile measures for these distances, can build different tests with control of their level and their power. A third use of the quantile surfaces is for the case where $ \alpha = 1/2$. Finally, we give a version of our theorems in the case where auxiliary information is available on one or more coordinates of the random variable. By assuming known the probability of the elements of a finite partition, the asymptotic variance of the limiting process decreases and the simulations with few points clearly shows the reframe of the estimated surfaces to the real ones.
|
269 |
Alocação ótima de compensação de potência reativaStypulkowski, Yuri Solis January 2017 (has links)
Este trabalho propõe uma metodologia para enumerar soluções, que indiquem a barra e a compensação de potência reativa necessária para o sistema elétrico sob análise, que atendam aos requisitos avaliados pela função objetivo e as restrições. Nessa alocação de compensação ótima de potência reativa, obtemos as melhores barras e configurações de potências e tecnologias de dispositivos de compensação, minimizando as perdas totais de potência ativa da rede. Em redes fracas com conversores de frequência (por exemplo, para conexão de fontes renováveis, ou interligações utilizando conversores HVDC), esta metodologia proposta busca a melhor relação de curto-circuito trifásico (SCR) no ponto de conexão do conversor de frequência, melhorando a conexão da barra de interesse. O método busca soluções para alocar um único dispositivo de compensação, e soluções alocando simultaneamente dois dispositivos. A metodologia proposta baseia-se na enumeração exaustiva das soluções, e o estudo de caso nos sistemas de 14 e 30 barras do IEEE mostrou a aplicabilidade e funcionalidade da metodologia proposta. / This work proposes a methodology to enumerate solutions, which indicate the bar and the reactive power compensation required for the electrical system under analysis, that meet the requirements evaluated by the objective function and the constraints. In this allocation of optimal compensation of reactive power, we obtain the optimal bars and technologies of compensation devices, minimizing the total losses of active power of the network. In weak networks with frequency converters (e.g. for connection of renewable sources, or interconnections using HVDC converters), the proposed methodology seeks the best threephase short-circuit (SCR) relation at the connection point, improving the connection of the new generation. The method looks for solutions to allocate a single compensation device, and solutions to allocate two devices simultaneously. The proposed methodology is based on the exhaustive enumeration of the solutions. A case study carried out in the IEEE 14 and 30 bus systems shows the applicability and performance of the proposed methodology.
|
270 |
Reciprocal undervisning - en studie om lässtrategier och deras betydelserDirani, John, Doganson, Eveline January 2018 (has links)
One of the many core aspects of learning a language involves reading comprehension. Being able to not only read but understand and decipher the context of content is one of the many factors that are essential in order to fully comprehend a subject. Reading comprehension is this assignments main focus and we have delved into this category through a literature study.For this literature study, we have analyzed the research of multiple different theses as well as scientific articles. Various different studies have been made regarding reading comprehension. We however, have decided to primarily engage in the reading strategies that were originally formed by Palincsar and Brown. The research in which these two authors elaborated on a reading strategy called reciprocal teaching. The content of this assignment discusses the meaning of reciprocal teaching, its' benefits as well as the disadvantages of using the strategy.The reason why this reading comprehension strategy originated lies within the fact that many students were lacking in understanding what they were reading. This became an evident issue that had to be addressed as school results were gradually decreasing. As reciprocal teaching became some sort of phenomena, many countries wanted to implement the strategy into their schools - this includes Sweden.Throughout the many years in which the strategy has been used in schools all over the world, statistics have shown that reciprocal teaching is a valid method for increased knowledge in reading comprehension. In Swedish institutional schools, reciprocal teaching is being used on a daily basis. It has however translated and expanded itself into what is being called "läsfixarna" which this assignment will also discuss. The results show that reciprocal teaching is a fundamentally working strategy that has proven to improve reading comprehension.
|
Page generated in 0.0408 seconds