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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.
191

Metapopulations dynamics and sex-specific resource allocation in Silene dioica

Peedu, Elisabet January 2018 (has links)
Rising archipelagos provide unique settings for the study of the temporal and spatial dynamics of their biota. This offers the possibility to study the ecology and genetics of early successional processes; both between islands that differ in age and within islands when already established organisms have to keep pace with the changing environment. I have worked in the Skeppsvik Archipelago housing about 100 islands that due to land uplift vary in age, thus representing various stages of primary succession. I have utilized a naturally created metapopulation of Silene dioica, which in this archipelago is a dominant plant of the deciduous border, offering the possibility to study subpopulations on islands of different ages and in different phases of primary succession. Many plant species exist as metapopulations, which consists of many local populations which may differ in size and degree of connectivity. Metapopulations are further characterized by recurrent colorizations and extinctions of local populations, meaning that a species continually must disperse and relocate to allow for persistence in this system. For a dioecious plant species, gene flow is in the shape of seeds and pollen and to allow for the persistence of populations, it is necessary that levels of seed dispersal and pollen gene flow are enough to ensure both colonisation, establishment and subsequent population growth. Levels of seed dispersal and pollen gene flow is in turn influenced by how the two sexes partition resources between reproduction, growth and survival. In paper I, I combined a field survey, a common garden experiment and a nine-year demographic study to assess the demographic consequences of sex-specific resource allocation and to investigate if differential costs of reproduction may be a driver in the evolution of sexual dimorphism in dioecious Silene dioica. Significant somatic intersexual dimorphism was found with females being the larger sex, both in terms of above – and belowground biomass. Furthermore, the reproductive effort of females exceeds that of males across a growing season which largely confirms what has been observed earlier in dioecious, herbaceous plant species. According to the cost of reproduction hypothesis, high reproductive investment should result in trade-offs with somatic and/or life-history traits. Somatic trade-offs were not observed, and instead I found strong, positive associations between reproductive investment and vegetative growth in both males and females. Compensation mechanisms were found in both sexes although females are generally more efficient at compensating their reproductive costs. At the end of a flowering season, after having paid the current costs of reproduction, females are better than males at provisioning perennial roots and rosettes potentially influencing the ability to set future flower buds and winter survival. Trade-offs were found between current and future reproduction and survival, but this is condition dependent and compensation through frequency of flowering plays an important role. The cost of reproduction hypothesis appears to play some role in driving the somatic and demographic sexual dimorphisms observed in this system but sexual selection acting on males will be a fruitful avenue for future research. In paper II, I investigated the population genetic consequences of metapopulation dynamics in Silene dioica. The occurrence of islands in different phases of primary succession together with successional gradients across islands, makes it possible to investigate the genetic dynamics occurring in an age-structured metapopulation across several hierarchical levels. Genetic diversity and differentiation were estimated in eight young, recently colonised populations and in ten populations of an intermediate successional stage. Young populations were less genetically diverse compared to older populations, indicating that bottlenecks, created by small founding groups derived from a limited number of source populations, reduce the genetic diversity within newly founded populations. The observation of strong genetic structure both between islands and between patches with islands, indicates that gene flow is restricted across several spatial levels in this system. However, the lack of statistically significant differences in genetic differentiation between young and intermediate populations, indicates that levels of gene flow may not be high enough to reduce the genetic differentiation that arise from the initial founder event. The patterns of sexual dimorphism and the roles of males and females in Silene dioica have evolved to allow persistence in an ecological and population context of this species. The nature of this habitat, where islands rise up from the sea creating new environments for colonisation while at the same time, autogenic primary succession processes eventually leads to extinction, means that S. dioica continuously must relocate within successional phases for its persistence. The obvious success of this dioecious plant is apparent as it is one of the few dominant species in the deciduous border. This suggests that levels of seed dispersal and gene flow are sufficient enough to allow for establishment and persistence of island populations and that the sexual dimorphisms that have evolved in this metapopulation system act to increase levels of gene flow. The "live hard – die young" strategy, with extensive flowering bouts, which we find in the males may have evolved as a way of maintaining sufficient levels of genetic diversity in the metapopulation but will only be a possible strategy if there are continuous opportunities for re-establishments. Thus, the continuous land uplift that is occurring in the northern part of the Gulf of Bothnia may very well be a prerequisite for the long-term persistence of this dioecious, perennial plant species. / Landhöjningsprocesser i skärgårdsmiljöer skapar nya habitat som gör det möjligt att studera naturliga populationer i ett rumsligt och tidsmässigt sammanhang. Detta möjliggör studier av ekologi och genetik i tidiga successionsprocesser, både mellan öar som skiljer sig åt åldersmässigt och inom öar, där redan etablerade organismer måste anpassa sig till en föränderlig miljö. Jag har utfört studier i Skeppsviks skärgård som rymmer cirka 100 öar. På grund av landhöjningen så varierar dessa öar i ålder och de representerar således olika stadier i primärsuccession. Jag har använt mig av en naturlig Silene dioica metapopulation lokaliserad i Skeppsviks skärgård. Många växtarter existerar i metapopulationer, vilket består av ett antal lokala populationer som kan skilja sig åt i storlek och grad av anknytning. Metapopulationer kännetecknas även av återkommande koloniseringar och utrotningar av lokala populationer, vilket innebär att en art kontinuerligt måste sprida sig för att garantera sin fortlevnad i detta system. Genflöde inom dioika växtarter är i form av pollen och frön, och för att populationer skall kunna överleva så är det nödvändigt att nivåerna av fröspridning och pollen-genflöde är tillräckliga för att säkerhetsställa både kolonisering, etablering och efterföljande populationstillväxt. Nivåer av fröspridning och pollen-genflöde påverkas i sin tur av hur de två könen partitionerar resurser mellan reproduktion, tillväxt och överlevnad. I den första studien har jag kombinerat en fältundersökning, ett frilandsexperiment och en nioårig demografisk studie för att undersöka de demografiska konsekvenserna av könsspecifik resursallokering och för att utreda om könsspecifika skillnader i reproduktiv kostnad kan vara en drivkraft för evolutionen av sexuell dimorfism hos den dioika växten Silene dioica. Jag upptäckte signifikant somatisk intersexuell dimorfism där honor hade betydligt mer ovanjordisk och underjordisk biomassa jämfört med hanar. Över en växtsäsong så investerar honorna mer resurser i reproduktion, vilket i stor utsträckning bekräftar vad som tidigare har observerats i örtartade, dioika växter. Enligt hypotesen för reproduktiv kostnad så bör en hög investering i reproduktion leda till trade-offs med somatiska egenskaper, t.ex. tillväxt. Jag observerade inga somatiska trade-offs och istället fann jag positiva associationer mellan reproduktion och tillväxt hos både honor och hanar. Båda könen verkar ha utvecklat kompensationsmekanismer, även om honorna generellt är mer effektiva i hur de kompenserar för sina reproduktiva kostnader. Vid slutet av en växtsäsong, efter att ha betalat för de nuvarande reproduktiva investeringarna, så är honor bättre än hanar på att allokera resurser till fleråriga strukturer, såsom bladrosetter och rötter. Detta kan potentiellt påverka hur de anlägger sina knoppanlag för nästkommande år och hur väl de överlever vintern. Trade-offs hittades mellan nuvarande reproduktion och framtida reproduktionsmöjligheter och överlevnad men detta var habitat-specifikt och kompensation med hjälp av hur ofta en växt blommar under sin livstid spelar en viktig roll. Hypotesen för reproduktiv kostnad verkar vara en del av förklaringen till den somatiska och demografiska könsdimorfism som observerats i detta system men sexuell selektion, som verkar på hanar, kan vara ett möjligt område för framtida studier. I den andra studien undersökte jag populationsgenetiska konsekvenser av metapopulationsdynamik i Silene dioica. Förekomsten av öar i olika faser av primär succession tillsammans med olika grader av succession inom öar gör det möjligt att undersöka den genetiska dynamiken som uppträder i en åldersstrukturerad metapopulation över flera hierarkiska nivåer. Genetisk mångfald och differentiering uppskattades i åtta unga, nyligen koloniserade populationer och i tio populationer av ett intermediärt successionsstadium. Unga populationer hade lägre genetisk diversitet jämfört med äldre populationer, vilket indikerar att genetiska flaskhalsar, skapade av fåtal antal koloniserande individer, s.k. founders, som härrör från ett begränsat antal källpopulationer, minskar den genetiska diversiteten inom nybildade populationer. Observationen av stark genetisk strukturering, mellan och inom öar, indikerar att genflödet är begränsat över flera rumsliga nivåer i detta system. Bristen på statistiskt signifikanta skillnader i genetisk differentiering mellan unga och intermediära populationer indikerar emellertid att nivåer av genflöde kanske inte är tillräckligt höga för att minska den genetiska differentieringen som uppstår från den ursprungliga founder-händelsen. Mönstren av sexuell dimorfism och hanarnas och honornas roll har utvecklats för att möjliggöra fortlevnad i ett ekologisk och populationsmässigt sammanhang hos Silene dioica. I denna livsmiljö, där öar stiger upp ur havet och skapar nya miljöer för kolonisering samtidigt som autogena primära successionsprocesser leder till utrotning, måste S. dioica kontinuerligt sprida sig mellan olika successionsfaser för att överleva. Den uppenbara framgången för den här dioika växten är uppenbar eftersom den är en av de få dominerande arterna i lövkanten. Detta tyder på att nivåer av fröspridning och genflöde är tillräckliga för att möjliggöra etablering och beständighet av ö-populationer och att de sexuella dimorfismer som har utvecklats i detta metapopulationssystem verkar för att öka nivåerna av genflöde. "Lev hårt – dö ung" -strategin med omfattande blomningar som vi finner hos hanarna kan ha utvecklats som ett sätt att upprätthålla tillräckliga nivåer av genetisk diversitet i metapopulationen men den kommer endast att vara en möjlig strategi om det finns kontinuerliga möjligheter för re-etableringar. Således kan den kontinuerliga landupphöjningen som förekommer i norra delen av Bottniska viken mycket väl vara en förutsättning för den långsiktiga beständigheten av denna dioika, fleråriga växtart. / <p>Felaktigt angivet "Dissertation for PhD" i kolofon.</p>
192

Exploration interactive, incrémentale et multi-niveau de larges collections d'images / Interactive, incremental and multi-level exploration of large collections of images

Rayar, Frédéric 22 November 2016 (has links)
Les travaux de recherche présentés et discutés dans cette thèse s’intéressent aux grandes collections d’images numériques. Plus particulièrement, nous cherchons à donner à un utilisateur la possibilité d’explorer ces collections d’images, soit dans le but d’en extraire de l’information et de la connaissance, soit de permettre une certaine sérendipité dans l’exploration. Ainsi, cette problématique est abordée du point de vue de l’analyse et l’exploration interactive des données. Nous tirons profit du paradigme de navigation par similarité et visons à respecter simultanément les trois contraintes suivantes : (i) traiter de grandes collections d’images, (ii) traiter des collections dont le nombre d’images ne cesse de croître au cours du temps et (iii) donner des moyens d’explorer interactivement des collections d’images. Pour ce faire, nous proposons d’effectuer une étude conjointe de l’indexation et de la visualisation de grandes collections d’images qui s’agrandissent au cours du temps. / The research work that is presented and discussed in this thesis focuses on large and evergrowing image collections. More specifically, we aim at providing one the possibility to explore such image collections, either to extract some kind of information and knowledge, or to wander in the collections. This thesis addresses this issue from the perspective of Interactive Data Exploration and Analytics. We take advantage of the similarity-based image collection browsing paradigm and aim at meeting simultaneously the three following constraints: (i) handling large image collections, up to millions of images, (ii) handling dynamic image collections, to deal with ever-growing image collections, and (iii) providing interactive means to explore image collections. To do so, we jointly study the indexing and the interactive visualisation of large and ever-growing image collections.
193

Problem structuring methods: um estudo metodológico em cartografia estrutural e sua aplicação

Heck, Joaquim 23 February 2018 (has links)
Submitted by Joaquim Heck (joaquimheck@uol.com.br) on 2018-03-06T23:24:07Z No. of bitstreams: 1 PDF_CDAE_Tese_Joaquim_Heck.pdf: 10473820 bytes, checksum: ad23dda74b39a1cdacaf8ac5345e3c9d (MD5) / Approved for entry into archive by Debora Nunes Ferreira (debora.nunes@fgv.br) on 2018-03-07T12:33:18Z (GMT) No. of bitstreams: 1 PDF_CDAE_Tese_Joaquim_Heck.pdf: 10473820 bytes, checksum: ad23dda74b39a1cdacaf8ac5345e3c9d (MD5) / Made available in DSpace on 2018-03-07T12:39:47Z (GMT). No. of bitstreams: 1 PDF_CDAE_Tese_Joaquim_Heck.pdf: 10473820 bytes, checksum: ad23dda74b39a1cdacaf8ac5345e3c9d (MD5) Previous issue date: 2018-02-23 / Esta tese apresenta os resultados de um estudo em metodologia que estabeleceu um novo método específico de análise documental e histórica, denominado cartografia estrutural para revisão de literatura, e que foi aplicado de forma experimental no estudo histórico de um tema da área de Pesquisa Operacional, os Problem Structuring Methods (PSMs). A cartografia estrutural para revisão de literatura é um método rigoroso e interdisciplinar que revela a estrutura subjacente à uma literatura por meio dos conceitos metodológicos encontrados em pesquisa documental, pesquisa histórica, Teoria dos Grafos, Análise de redes de citações e Cartografia. Verificou-se, a partir dessa interdisciplinaridade, que as relações entre diferentes autores, de diferentes épocas e que publicaram em diferentes periódicos são essenciais para aprofundar a compreensão e familiarizar o pesquisador com uma determinada área do conhecimento. Depois de introduzir a natureza básica da indexação de citações e da análise de rede, esse estudo apresenta a elaboração de um atlas bibliográfico, formado por mapas visuais e diagramas. A aplicação desse método resultou na composição do atlas bibliográfico sobre os PSMs no período de 1950 a 1989. O mapeamento de ideias e conceitos em um arranjo organizado, obtido pela análise exploratória de uma rede de citações longitudinal, assegura familiaridade com os conceitos constitutivos dos PSMs. O atlas bibliográfico é constituído por três análises principais: a exploração da abrangência panorâmica, a das referências e a dos periódicos. Esse estudo fornece subsídios para uma reflexão importante sobre a noção de unidade dos PSMs e a coesão de seus conceitos constituintes encontrada em seus precedentes teóricos. Finalmente, o método de cartografia estrutural possibilita realizar uma revisão de literatura sofisticada, bem como identificar temas fundamentais para futuras pesquisas mais produtivas. / This thesis presents the results of a methodological study that has established a specific method of historical and documental investigation, denominated structural cartography for literature review, which was experimentally applied in the study of Problem Structuring Methods (PSMs) history. Structural cartography for literature review is a rigorous and interdisciplinary method that reveals the underlying structure of a field literature through the methodological notions found in historical research, documental investigation, Graph Theory, and its subfield of citation network analysis, and Cartography. Due to its interdisciplinarity, it becomes clear that the relations between different authors, from different periods of time and from different media are essential to familiarize scholars with their fields of knowledge. After introducing the basic concepts of citation indexing and network analysis, this study shows how to build a bibliographic atlas composed of visual maps and diagrams. The application of this method resulted in the bibliographic atlas on the PSMs from 1950 to 1989. The mapping of ideas and concepts in an organized arrangement, which is obtained by the analysis of a longitudinal exploratory citation network, ensures familiarity with primitive concepts. The bibliographic atlas is composed by three main analysis: the exploration of coverage, of sources and of media. Moreover, this study provided insights for an important reflection on the notion of PSMs unity and the cohesion of their constituent concepts found in their theoretical precedents. Finally, the method of structural cartography for literature review made possible to conduct sophisticate literature review and has provided substantial themes for future research.
194

Black/white joint small business ventures in South Africa

Miller, Patricia Kathryn 06 1900 (has links)
The political history of South Africa, especially that of the apartheid years, has affected the structuring and functioning of business in the country profoundly. In general, White business is highly developed and formal, with access to financial and infrastructural support. Black business is often subsistence-based, informal and struggles for access to support mechanisms. These structural inequities have had a depressing impact on the economy that will continue if they are not resolved. Following the 1994 elections, policies and legislation have been introduced aimed at redressing structural imbalances. There is thus both a political and an economic imperative to bridge the gaps that have arisen between Black and White business. The study proposes Black/White joint ventures as a mechanism to this end. The history of Black/White relationships means that these enterprises are likely to face many problems. A model has been developed through the study for the formulation, structuring and operation of Black/White joint ventures that takes into account the factors that are likely to impact on these ventures and affect their success potential. The process of applying the model in practice is directed towards results that are not prejudiced by the background of the parties to the venture. The study expands the concept of joint ventures within the South African context to incorporate initiatives along a continuum ranging from extensions to employment to full joint ventures. Depending on its nature and objectives, a venture may be placed and remain at any stage along the continuum, or may progress along it. Case studies of Black/White joint ventures were investigated in depth and analysed in terms of the application of the model, in order to determine the relevance of the model. In all cases, the success or failure of the venture under scrutiny could be ascribed to the way in which the presence of various elements identified as being components of the model had been accommodated in practice within the venture. The use of the model when applied to formulating, structuring and operating a Black/White joint venture can contribute to its success potential. / Business Management / DBL
195

Amélioration des ouvertures par chemins pour l'analyse d'images à N dimensions et implémentations optimisées / Image processing and analysis for non destructive real time quality control in 3D RX tomography

Cokelaer, François 22 February 2013 (has links)
La détection de structures fines et orientées dans une image peut mener à un très large champ d'applications en particulier dans le domaine de l'imagerie médicale, des sciences des matériaux ou de la télédétection. Les ouvertures et fermetures par chemins sont des opérateurs morphologiques utilisant des chemins orientés et flexibles en guise d'éléments structurants. Ils sont utilisés de la même manière que les opérateurs morphologiques utilisant des segments orientés comme éléments structurants mais sont plus efficaces lorsqu'il s'agit de détecter des structures pouvant être localement non rigides. Récemment, une nouvelle implémentation des opérateurs par chemins a été proposée leur permettant d'être appliqués à des images 2D et 3D de manière très efficace. Cependant, cette implémentation est limitée par le fait qu'elle n'est pas robuste au bruit affectant les structures fines. En effet, pour être efficaces, les opérateurs par chemins doivent être suffisamment longs pour pouvoir correspondre à la longueur des structures à détecter et deviennent de ce fait beaucoup plus sensibles au bruit de l'image. La première partie de ces travaux est dédiée à répondre à ce problème en proposant un algorithme robuste permettant de traiter des images 2D et 3D. Nous avons proposé les opérateurs par chemins robustes, utilisant une famille plus grande d'éléments structurants et qui, donnant une longueur L et un paramètre de robustesse G, vont permettre la propagation du chemin à travers des déconnexions plus petites ou égales à G, rendant le paramètre G indépendant de L. Cette simple proposition mènera à une implémentation plus efficace en terme de complexité de calculs et d'utilisation mémoire que l'état de l'art. Les opérateurs développés ont été comparés avec succès avec d'autres méthodes classiques de la détection des structures curvilinéaires de manière qualitative et quantitative. Ces nouveaux opérateurs ont été par la suite intégrés dans une chaîne complète de traitement d'images et de modélisation pour la caractérisation des matériaux composite renforcés avec des fibres de verres. Notre étude nous a ensuite amenés à nous intéresser à des filtres morphologiques récents basés sur la mesure de caractéristiques géodésiques. Ces filtres sont une bonne alternative aux ouvertures par chemins car ils sont très efficaces lorsqu'il s'agit de détecter des structures présentant de fortes tortuosités ce qui est précisément la limitation majeure des ouvertures par chemins. La combinaison de la robustesse locale des ouvertures par chemins robustes et la capacité des filtres par attributs géodésiques à recouvrer les structures tortueuses nous ont permis de proposer un nouvel algorithme, les ouvertures par chemins robustes et sélectives. / The detection of thin and oriented features in an image leads to a large field of applications specifically in medical imaging, material science or remote sensing. Path openings and closings are efficient morphological operators that use flexible oriented paths as structuring elements. They are employed in a similar way to operators with rotated line segments as structuring elements, but are more effective as they can detect linear structures that are not necessarily locally perfectly straight. While their theory has always allowed paths in arbitrary dimensions, de facto implementations were only proposed in 2D. Recently, a new implementation was proposed enabling the computation of efficient d-dimensional path operators. However this implementation is limited in the sense that it is not robust to noise. Indeed, in practical applications, for path operators to be effective, structuring elements must be sufficiently long so that they correspond to the length of the desired features to be detected. Yet, path operators are increasingly sensitive to noise as their length parameter L increases. The first part of this work is dedicated to cope with this limitation. Thus, we will propose an efficient d-dimensional algorithm, the robust path operators, which use a larger family of flexible structuring elements. Given an arbitrary length parameter G, path propagation is allowed if disconnections between two pixels belonging to a path is less or equal to G and so, render it independent of L. This simple assumption leads to a constant memory bookkeeping and results in a low complexity. The developed operators have been compared qualitatively and quantitatively to other efficient methods for the detection of line-like features. As an application, robust path openings have been integrated into a complete chain of image processing for the modelling and the characterization of glass fibers reinforced polymer. Our study has also led us to focus our interest on recent morphological connected filters based on geodesic measurements. These filters are a good alternative to path operators as they are efficient at detecting the so-called "tortuous" shapes in an image which is precisely the main limitation of path operators. Combining the local robustness of the robust path operators with the ability of geodesic attribute-based filters to recover "tortuous" shapes have enabled us to propose another original algorithm, the selective and robust path operators.
196

Significado em práticas matemáticas não escolares: estudo com alunos do ensino fundamental / Meaning in non-school mathematics practice: study with elementary students

Costa, Daniela Netto Scatolin 12 February 2014 (has links)
Made available in DSpace on 2016-06-02T19:39:46Z (GMT). No. of bitstreams: 1 6037.pdf: 968767 bytes, checksum: 8fb7f515768cae960495efe96022b1da (MD5) Previous issue date: 2014-02-12 / This research has the purpose to analyze the influence of situations in order to deal with mathematics in different social practices. As a specific goal, it investigates the meanings in various school and non-school mathematical practices. Among these purposes there is an analysis about the switch of meanings between one and another practice. The development of this work is based on a review of studies about the exploitation of Mathematics on the day to day problems and in other areas of knowledge that could contribute to the learning of mathematics as a school subject. Considering the idea of mathematics as a social practice, the theoretical framework of the present research has centered on the design of means of structuring and situated learning by Jean Lave. The research follows a naturalistic perspective with ethnographicins piration and uses as a methodological resource the participant observation with a group of elementary school students. The data collected were recorded by the researcher in field activities, through interviews, diaries and field recordings. The activities observed occur inside and outside the school. For the analysis it is considered the resource association between the object and the theoretical framework consisting drawn from Lave s studies. Concerning the results obtained, it is possible to realize the strength of the situation and sometimes, how crucial it is in order to practice math. It stands out especially the prevalence of different meanings in different practices. The present study also promotes questions about the proposal to take the students everyday situations to inside the classroom and therefore, it intermediates my work as a mathematics teacher at elementary schools. / Esta pesquisa tem por objetivo geral analisar a influência das situações no modo de lidar com a matemática em diferentes práticas sociais. Como propósito específico, busca investigar os significados em diferentes práticas matemáticas escolares e não escolares. Destes propósitos decorre uma análise da transferência de significados entre uma prática e outra. O desenvolvimento deste trabalho se apoia em uma revisão bibliográfica de estudos sobre como a exploração da matemática nos problemas do dia a dia e nas demais áreas do conhecimento poderiam contribuir para o aprendizado da matemática escolar. Partindo da ideia da matemática como prática social, a referência teórica da pesquisa tem como eixo central a concepção de meios de estruturação e aprendizagem situada de Jean Lave. A pesquisa segue uma perspectiva naturalística com inspiração etnográfica e usa como recurso metodológico a observação participante com um grupo de estudantes do ensino fundamental. Os dados foram constituídos pela pesquisadora em atividades de campo, por meio de entrevistas, diários de campo e gravações. As atividades observadas ocorrem dentro e fora da escola. Para a análise é considerado o recurso de associação entre o objeto constituído e o referencial teórico elaborado a partir dos estudos de Lave. Dos resultados obtidos, é possível perceber a força da situação e, por vezes, como ela é determinante no modo de se praticar matemática. Destaca-se, sobretudo a prevalência de diferentes significados em práticas distintas. O presente estudo também promove questionamentos acerca da proposta de se levar as situações do cotidiano do aluno para a sala de aula e com isso, intervém na minha atuação como professora de matemática do ensino fundamental.
197

Rumo a um desenho técnico de um sistema de apoio à decisão para uma reconfiguração do soft systems methodology: o caso do planejamento sistêmico

Maranhão Filho, Éfrem de Aguiar 07 February 2013 (has links)
Submitted by Efrem Maranhão Filho (efremfilho@gmail.com) on 2013-03-08T18:52:46Z No. of bitstreams: 1 teseDoutoradoEfrem.pdf: 4695587 bytes, checksum: 70cbab7e35da687c5b0830b63dcd7115 (MD5) / Approved for entry into archive by Vera Lúcia Mourão (vera.mourao@fgv.br) on 2013-03-08T19:45:46Z (GMT) No. of bitstreams: 1 teseDoutoradoEfrem.pdf: 4695587 bytes, checksum: 70cbab7e35da687c5b0830b63dcd7115 (MD5) / Made available in DSpace on 2013-03-08T19:46:31Z (GMT). No. of bitstreams: 1 teseDoutoradoEfrem.pdf: 4695587 bytes, checksum: 70cbab7e35da687c5b0830b63dcd7115 (MD5) Previous issue date: 2013-02-07 / Multidisciplinary in decision-making undergoes the same specificities of any multidisciplinary field. Very often, the lack of communication generates problems and some different approaches can be found in other areas of expertise. The Problem Structuring Methods offers answers for current queries in business administration schools, being particularly useful when used in a multimethodological approach with others current methods. Having the Soft Systems Methodology – SSM – as the core, and the merged with Strategic Options Development and Analysis in the process, Georgiou (2012) presents the Systemic Planning in the latest configuration. Aiming to seek a computational tool that meets the assumptions of the SSM, and which incorporates the specifications of the configuration of Systemic Planning, here are defined a Notation for the method and a formalization of the existing communications between the elements, subsystems, system and environment and thus find a possible way of control the use of the method in a iteratively mode. In order to demonstrate such use of the Systemic Planning, A real case analysis is presented and shows the difficulties encountered in using the Notation defined and the Formalization of the communication. Subsequently, a design of a modular computational tool, and which can be used integrated with other tools of other methods, is presented. The contribution achieved are advances in the patterns in the use of SSM tools, presented the systemic aspects of the Systemic Planning, a demonstration of the iterative use and a blueprint for a computer tool. / A multidisciplinaridade da tomada de decisão sofre com as peculiaridades de qualquer campo multidisciplinar. A falta de comunicação, muitas vezes, gera problemas e as respostas que podem ser encontradas dentro de outras áreas. Os Métodos de Estruturação de Problemas são respostas para os questionamentos atuais nas escolas de administração e negócios, principalmente o uso multimetodológico destes com outros métodos. Tendo o Soft Systems Metholodogy – SSM – como base, e a incorporação do Strategic Options Development and Analysis – SODA – ao processo do SSM, Georgiou (2012) apresenta o Planejamento Sistêmico em sua configuração mais recente. Visando buscar uma ferramenta computacional que atenda os pressupostos do SSM, e que incorpore as especificações da configuração do Planejamento Sistêmico, definem-se uma notação para o método e uma formalização das para as comunicações existentes entre os elementos, subsistemas, sistema e ambiente e, com isso, torna-se possível controlar o uso do método de forma iterativa. Para demonstrar tal uso, apresenta-se uma análise de um caso real e demonstra as dificuldades encontradas na utilização da Notação e Comunicação definida. Posteriormente, apresenta-se um desenho técnico de uma ferramenta computacional modular e que pode ser usada de forma integrada com outras ferramentas de outros métodos. Como resultado, têm-se o avanço na definição de padrões no uso das ferramentas do SSM, na apresentação dos aspectos sistêmicos do Planejamento Sistêmico, na apresentação de um uso iterativo do método e na apresentação de um desenho técnico para uma ferramenta computacional.
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High aspect ratio sub-micron structuring of transparent materials using non-diffractive ultrafast laser beams : dynamics and interaction regimes / Structuration sub-micronique de matériaux transparents à haut rapport d'aspect par faisceaux laser ultra-rapides non-diffractifs : dynamique et régimes d'interaction

Velpula, Praveen Kumar 24 March 2015 (has links)
Cette thèse se concentre sur la contrôlabilité de l'indice de réfraction au niveau sub-micronique par changements d'indice induits par laser sur de longues dimensions i.e., avec des hauts rapports d'aspect élevés et des sections à l'échelle nanométrique. À cette fin, nous explorons les faisceaux ultracourts de Bessel non-diffractifs d'ordre zéro et les facteurs qui contribuent au confinement de l'énergie au-delà de la limite de diffraction. Le traitement par laser de matériaux transparents à l'aide de faisceaux non diffractifs offre un avantage important pour les structures sub-microniques en volume de haut rapport d'aspect à des fins applicatives en nanophotonique et en nanofluidique. Nous présentons l'effet de différentes conditions de focalisation et de paramètres laser sur la modification de la silice fondue, explorant ainsi les différents régimes d'interaction. Cette thèse aborde essentiellement des conditions modérées de focalisation car elles offrent un régime d'interaction stable sur une large gamme de paramètres laser, permettant l'ingénierie de la dispersion. La durée de l'impulsion laser s'est révélée être essentielle dans la définition du type de modification de l'indice de réfraction ou de modification structurale. Par exemple, l'usinage utilisant des impulsions laser femtosecondes entraîne une augmentation des structures d'indice de réfraction alors que les impulsions laser picosecondes engendrent une cavité uniforme i.e., des structures de faible indice. Pour acquérir un meilleur contrôle et une meilleure précision du dépôt d'énergie laser, un ensemble de mécanismes physiques responsables des dommages induits par laser dans des conditions d'excitation non-diffractives a été observé expérimentalement et examiné par des simulations indiquant le rôle essentiel de la diffusion de la lumière sur les électrons. Des mesures de microscopie pompe-sonde résolues en temps avec une résolution temporelle sub-picoseconde et spatiale sub-micronique donnent accès à l'excitation et à la relaxation dynamique instantanées. La transmission optique dynamique et le contraste de phase offrent des informations complémentaires sur la réponse électronique ou sur celle de la matrice vitreuse. La dynamique ultrarapide des porteurs libres a été particulièrement étudiée puisque le transfert d'énergie des électrons vers le réseau est la clé de transformation ultérieure du matériau. Le rôle de l'excitation instantanée pour différentes durées et énergie d'impulsion laser est exposé. Ainsi, la dynamique complète des porteurs de charge est présentée pour différents paramètres du laser. En particulier, la dynamique d'obtention de structures d'indice de réfraction positif et des cavités uniformes indique deux chemins différents de relaxation électronique et de dépôt de l'énergie: une relaxation rapide par l'intermédiaire de défauts pour les structures d'indice positif et une relaxation thermomécanique lente pour les cavités nanométriques. Enfin, en corrélant les résultats des études résolues en temps, les simulations et les résultats de photoluminescence après irradiation, nous formulons des scénarios potentiels de formation de l'indice de réfraction positif ainsi que des structures d'indice faible ou de vides uniformes / This thesis is focused on the controllability of laser-induced refractive index changes at sub-micron level over long dimensions i.e., with high aspect ratios and sections on the nanoscale. To this end, we explore non-diffractive zerothorder ultrafast Bessel beams and factors contributing to energy confinement beyond the diffraction limit. Laser processing of transparent materials using non-diffracting beams offers a strong advantage for high aspect ratio submicron structures inside the bulk in view of nanophotonics and nanouidics applications. We present the role of various focusing conditions and laser parameters on material modification in bulk fused silica and explore the different interaction regimes. This thesis tackles mostly the moderate focusing conditions as they offer a stable interaction regime backed up dispersion engineering over a large range of laser parameters. The laser pulse duration was found to be key in defining the type of laser induced refractive index or structural modification. For instance, machining using femtosecond laser pulses results in increased refractive index structures whereas picosecond laser pulses result in uniform void i.e., low index structures. To acquire better control over the laser energy deposition and precision, a range of physical mechanisms responsible for the laser induced damage in non-diffractive excitation conditions have been observed experimentally and further interrogated by simulations indicating a critical role of light scattering on carriers. Time-resolved pump-probe microscopy measurements with a sub-picosecond temporal and sub-micron spatial resolution allow access to the instantaneous excitation and relaxation dynamics. Dynamic optical transmission and phase contrast o_er complementary information of either electronic and glass matrix response. Primarily, ultrafast dynamics of free carriers was studied as the electron mediated energy transfer to the lattice is key to the subsequent material transformation. Role of instantaneous excitation at different laser pulse durations and energies is outlined. Then complete carrier dynamics is presented at different laser parameters. Particularly dynamics in conditions of positive refractive index structures and uniform voids is indicating two different paths of electronic relaxation and energy deposition: a fast defect mediated relaxation for positive index structures and slow thermomechanical relaxation for nanosize void structures. Finally, by correlating the results of time resolved studies, simulations and post-irradiated photoluminescence results, we formulate potential formation scenarios for the positive refractive index and low index or uniform void structures
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Vad gör medarbetare och chefer sjuka och varför går de till jobbet? : En kvalitativ fallstudie som undersöker orsaker till sjukfrånvaro och föreslår åtgärder inom en kommunal vård- och omsorgsorganisation / What makes employees and managers sick and why do they attend at work? : A qualitative case study that examines causes of sickness absence and proposes measures to reduce it within a municipal healthcare organization

Karlsson, Isabel January 2020 (has links)
Sjukfrånvaron inom de svenska kommunala vård- och omsorgsorganisationerna ökar. Samtidigt har en organiserings- och styrningsförändring skett inom dessa organisationer de senaste decennierna i form av införandet av New Public Management (NPM) och dess reformer. Studien syftade till att genom en kvalitativ fallstudie få en ökad förståelse för hur psykosociala och organisatoriska faktorer tillsammans kunde ha inverkan på en kommunal vård- och omsorgsorganisations sjukfrånvaro för organisationens medarbetare inom kontaktyrken och dess chefer. Detta utifrån att identifiera vad organisationens sjukfrånvaro orsakades av samt för att föreslå åtgärder för att förebygga framtida sjukfrånvaro. För att uppfylla syftet och studiens frågeställningar genomfördes semistrukturerade intervjuer med totalt 19 intervjupersoner som representerade de arbetsgrupper med organisationens högsta och lägsta sjuktal under 2019 samt de chefsgrupper med organisationens högsta och lägsta sjuktal under 2019. Empirin analyserades utifrån den teoretiska referensramen. Denna innefattade tidigare forskning samt teorier gällande NPM, struktureringsteori, psykosociala sjukfrånvarofaktorer, organisatoriska sjukfrånvarofaktorer, psykosociala friskfaktorer, organisatoriska friskfaktorer samt organisationshälsa. Studiens resultat visade på tre framträdande psykosociala sjukfrånvarofaktorer för medarbetare respektive chefer, fyra organisatoriska sjukfrånvarofaktorer för medarbetare respektive chefer, fyra psykosociala friskfaktorer för medarbetare respektive chefer samt fyra organisatoriska friskfaktorer för medarbetare och fem organisatoriska friskfaktorer för chefer. Resultaten visade att de psykosociala och organisatoriska sjukfrånvaro- och friskfaktorerna påverkade varandra, att det fanns ett samband mellan chefers och medarbetares upplevda arbetsmiljö samt att sjukfrånvaron framförallt kunde härledas till strukturer medan frisknärvaron istället kunde härledas till individers handlingar. Tio åtgärder för att minska sjukfrånvaron inom kommunala vård- och omsorgsorganisationer presenterades utifrån studiens resultat och potentiell vidare forskning har föreslagits. / Sickness absence within the Swedish municipal healthcare organizations is increasing. At the same time, there has been a change in organization and governance within these organizations in recent decades in the form of the introduction of New Public Management (NPM) and its reforms. The study aimed to gain a better understanding of how psychosocial and organizational factors together could have an impact on a municipal healthcare organization's sickness absence, regarding employees in the human service profession and its managers, through a qualitative case study. This to identify what was causing the organization's sickness absence and on proposing measures to prevent future sickness absence. To fulfill the purpose and study questions, semi-structured interviews were conducted with a total of 19 informants representing the working groups with the organization's highest and lowest sickness numbers in 2019 and the management groups with the highest and lowest sickness numbers in 2019. The empirical data was analyzed based on the theoretical frame of reference. This included previous research as well as theories of NPM, structuring theory, psychosocial sickness absence factors, organizational sickness absence factors, psychosocial health factors, organizational health factors and organizational health. The study's results showed three prominent psychosocial sickness absence factors for employees and managers, four organizational sickness absence factors for employees and managers, four psychosocial health factors for employees and managers, four organizational health factors for employees and five organizational health factors for managers. The results showed that the psychosocial and organizational sickness absence and health factors affected each other, that there was a connection between managers and employees perceived work environment and that the sickness absence could primarily be attributed to structures, while work attendance instead could be attributed to individuals' actions. Ten measures to reduce sickness absence within municipal healthcare organizations has been presented based on the results of the study, as well as suggestions for further research.
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Gemeinschaftliche Strukturierung von Inhalten im elektronisch unterstützten Lernen

Lohmann, Steffen, Fienhold, Jan, Riechert, Thomas January 2007 (has links)
No description available.

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