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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.
61

Non-Linear FE-Analysis of a Composite Action Girder with Coiled Spring Pins as Shear Connectors

Stahlin, Simon January 2019 (has links)
For bridges to cope with increased requirements such as increased loads, strengthening work can be carried out. In cases where older steel-concrete bridges do not have a composite action, an alternative is to create composite-action to achieve a higher flexural strength. It is introduced by post-installing shear connectors. There are many different alternatives of shear connectors that can be used, hence a number that can be installed from below the bridge to minimize the impact on the traffic. Coiled Spring Pins are of the interference fit type connector and are put in place from below the bridge by first drilling a hole upward through the upper steel flange and then into the concrete slab. Then, the spiral bolt is pushed up into the drilled hole by means of a hydraulic hammer. Using data from push-out tests and non-linear material models for steel and concrete, a non-linear finite element analysis was created using the commercial finite element software Abaqus. The analysis is based on dimensions and load cases that will mimic a planned full-scale beam test that will be carried out later in 2019. To verify that the material and the model behave in a realistic manner, an analysis was initially performed on a beam without composite-action, and a full-composite action beam with infinitely rigid connectors. These were then compared with hand calculations according to Eurocode. When the material models were verified, it is seen that the materials steel and concrete work for themselves in the analysis without composite-action and together in the analysis with full composite-action. The data for the spiral bolts is than defined instead of infinitely rigid connectors and new analyzes were performed to see the effect of the coiled spring pins properties. The results show that a significant increase in the point load in the middle of the beam can take place before failure occurs after installation of this type of shear connector. Already at a low number of connectors and a low shear connection-ratio, a significant increase in the flexural strength is seen in the beam. By using partial-composite action, with a lower number of spiral bolts, a significant higher flexural strength can be achieved in an economical way. / När kraven på att broar ska klara av ökade laster, kan förstärkningsarbeten utföras. I de fall där äldre stål-betongbroar saknar samverkanseffekt, är det ett alternativ att inför samverkan för att uppnå en högre böj-hållfastighet. Det införs genom att man installerar skjuvförbindare i efterhand. Det finns många olika alternativ av skjuvförbindare som kan användas, därav ett antal som går att installera underifrån bron för att minimera påverkan på trafiken. Spiralbultar (Coiled Spring Pins) är av typen presspassnings-förbindare och sätts på plats underifrån bron genom att det först borras ett hål uppåt genom övre stålflänsen och sedan upp i betongplattan. Därefter pressas spiralbulten upp i det borrade hålet med hjälp av en hydraulisk hammare. Med hjälp av data ifrån push-out-tester samt icke-linjära material modeller för stål och betong, skapades en icke-linjär analys i det finita element metods programmet Abaqus. Analysen är uppbyggd med dimensioner och lastfall som ska efterlikna ett planerat full-skaligt balktest som kommer utföras under 2019. För att verifiera att materialet och modellen beter sig realistiskt, utförs en analys på en balk utan samverkan, samt en full-samverkans balk med oändligt styva förbindare. Dessa jämförs sedan med handberäkningar enligt Eurokod. När materialmodellerna var verifierade sågs det att materialen stål och betong arbetar för sig själva i analysen utan samverkan och tillsammans i analysen med full-samverkan. Data för spiralbultarna lades sedan in istället för oändligt styva förbindare och nya analyser utförs för att se påverkan av spiralbultarnas egenskaper. Resultaten visade att en betydande ökning av punklasten i mitten av balken kan ske innan brott uppstår vid installation i efterhand av denna typen skjuvförbindare. Redan vid ett lågt antal förbindare och ett lågt skjuv-förhållande ses en betydande ökning av böj-hållfastigheten i balken. Genom att använda delvis-samverkan med ett lägre antal spiralbultar kan man på ett ekonomiskt sätt uppnå en betydligt högre böj-hållfasthet.
62

L'apport des concepts du Web sémantique et normes associées aux échanges inter applicatifs dans un SI d'entreprise ou RECAP (Référentiels et connecteurs a priori) / The contribution of Semantic Web and Associate International Standard to the exchanges between applications of a company information system or RECAP (referential and connector a priori)

Berisha, Suela 15 September 2011 (has links)
Le sujet de thèse a été traité dans le cadre d’un Système d’Information d’Entreprise (SIE) contenant un grand volume d’informations, très diverses, circulant au sein d’un groupe avec une cinquantaine de filiales. Initialement, les sources informatiques de chaque entité stockaient des données structurées, suivant des logiques métiers locales. Les descriptions de ces sources, destinées prioritairement aux informaticiens, se trouvent dans des documents textuels. Elles ne visaient pas le partage et la compréhension des systèmes par les différents types d’acteurs métiers qui fournissent le contenu. C’est également le cas des référentiels métiers, qui contiennent des connaissances métiers fondamentales. Ainsi, la localisation d’informations pertinentes, permettent un aiguillage et un accès aisé aux sources qui répondent aux attentes et aux contraintes des acteurs métiers, devient une problématique principale du SI. Depuis une décennie, la SNCF vise à répondre à cette problématique par une démarche stratégique de gouvernance inscrite dans les processus de l’urbanisme du SI. Nous sommes concernés par mise sous contrôle des référentiels de données métiers, la standardisation et la simplification des échanges inter applicatifs. Malgré cette démarche, les initiatives de partage d’informations et des connaissances métiers restent ponctuelles, fortement dépendantes des motivations personnelles (et non pas métiers) d’acteurs éclairés du SI. Notre objectif est de fournir une vue stratégique sur le partage des connaissances des différents types d’acteurs du SI en favorisant leur collaboration dans le contexte du déroulement d’un processus, ou d’une activité métier. Pour y parvenir, nous proposons une démarche pour la construction d’une couche du SI en s’appuyant sur de nouveaux concepts fonctionnels : le "référentiel de référentiels" et les "connecteurs a priori". Le premier correspond à un référentiel transverse par rapport à un périmètre métier. Le second correspond à des connexions logiques assurant une interopérabilité entre les applications qui ne sont pas conçues pour cohabiter. D’un point de vue technologique, le "référentiel des référentiels" prend ses fondements dans la modélisation et le stockage des connaissances par les démarches sémantiques. Les "connecteurs a priori" puisent leurs apports dans les Services Web Sémantiques. Le sujet de thèse développe des compétences comme les architectures middlewares orientées services, la modélisation sémantique de documents, la modélisation du SI et les techniques de Recherche d’Information (RI). Ce sont autant de sujets qui s’intègrent dans le projet scientifique de l’équipe DRIM (Distribution et Recherche d'Information Multimédia) du département « Données, Connaissances et Services » du laboratoire LIRIS (Laboratoire d’InfoRmatique en Images et Systèmes d’Informations), CNRS UMR 5205. / This thesis came about a very large and complex Enterprise Information System (EIS) containing a huge amount of information that moves through a company consisted of a main group and about fifty subsidiaries. At the beginning, computer science resources of each business unit stored structured data, according to a local business logic. The descriptions of these sources, intended first of all for computer specialists, were saved in text documents. They were not meant to help system sharing and understanding by different types of actors, who provide the business content. It's also true for the enterprise repositories, which contain fundamental business knowledge. Thus, finding the relevant information allowing fast and easy access to sources that meet the expectations and constraints of business actors, became a main problematic of IS. Since ten years, our company aims to address this problem by a strategic approach of IS governance included in the process of the IS planning. We are involved in the activity of business data repositories brought under control and information exchanges standardization and simplification between applications. Our goal is to provide a strategic view of knowledge sharing by promoting the IS actor collaboration in a business process context, or in business activity. To achieve this, we propose an approach for the construction of a layer of the IS based on new functional concepts: the "Reference Enterprise Repository (RER)" and " a priori connectors ". The first is about a transverse enterprise repository corresponding to a business context. The second is logical connections ensuring interoperability between applications that weren’t designed to coexist. From a technological point of view, the RER is based on semantic modelling and the knowledge representation. The "a priori connectors" involve integration technologies of Semantic Web Services. The thesis develops skills such as service-oriented middleware architectures, modelling semantics of documents, modelling IS and Information Retrieval (IR) techniques. All these subjects are part of the DRIM (Distribution and Multimedia Information Retrieval) team’s scientific project of the Department "Information, Knowledge and Services' at the LIRIS (Laboratoire d'Informatique en Images and Systems information), CNRS UMR 5205.
63

Comportamento de conectores de cisalhamento em vigas mistas aço-concreto com análise da resposta numérica / Behaviour of shear connectors in steel-concrete composite beams with numerical analysis

Tristão, Gustavo Alves 25 April 2002 (has links)
As vigas mistas aço-concreto têm sido bastante utilizadas na engenharia civil, tanto no Brasil como no contexto mundial. O comportamento adequado deste elemento estrutural faz-se pela interação entre ambos os materiais, a qual é garantida por conectores de cisalhamento. O presente trabalho apresenta uma visão geral do comportamento das vigas mistas aço-concreto, e, principalmente o estudo do comportamento estrutural de conectores de cisalhamento. Para tanto, faz-se uma simulação numérica dos conectores tipo pino com cabeça (stud) e perfil “U" formado a frio, por meio de uma modelagem do ensaio experimental tipo “Push-out", cujos resultados são confrontados com valores experimentais obtidos de ensaios realizados em laboratório. Para a simulação numérica utiliza-se um código de cálculo com base nos Método dos Elementos Finitos (MEF), cujas ferramentas disponibilizadas permitem análises dos modelos em regime de não-linearidade física e geométrica. Os modelos numéricos apresentam como variáveis de interesse o número de conectores na laje de concreto, a quantidade de armadura inserida no concreto, o diâmetro do conector tipo pino com cabeça (stud), a resistência do concreto, a espessura e posição de soldagem do conector tipo perfil “U" formado a frio. A variação desses parâmetros tem como finalidade a determinação da resistência última e da relação força-deslocamento dos conectores, bem como avaliar a concentração de tensão e deformação nas partes constituintes dos modelos / Composite steel-concrete beams have been used in civil engineering in Brazil as well other countries. A realistic determination of the behaviour of this structural element is estimated by considering the interaction between the two materials, which is safeguarded by providing shear connectors. The present research presents a general view of the behaviour of steel-concrete composite beams, and primarily the study of the behaviour of shear connectors. To meet this ends, a numerical analysis of stud bolt and cold formed U-channel under push-out test geometry was carried out and the results compared to experimental test results. The numerical analysis utilises a Finite Element Method (FEM) code that permits the analysis under non-linear material and geometric regimes. The main numerical variables in the study were the number of connectors used in the concrete plate, the quantity steel reinforcement, the diameter of stub bolt connector, concrete strength, the thickness and position of welding of the cold-formed U-channel. The main objective of varying these parameters was to determine the ultimate strength and the load-slip behaviour of the connectors as well as evaluate the stress and strain concentrations in certain parts that constitute the models
64

Nucleic Acid Based Pathogen Diagnostics

Akhras, Michael S. January 2008 (has links)
Pathogenic organisms are transmitted to the host organism through all possible connected pathways, and cause a myriad of diseases states. Commonly occurring curable infectious diseases still impose the greatest health impacts on a worldwide perspective. The Bill & Melinda Gates Foundation partnered with RAND Corporation to form the Global Health Diagnostics Forum, with the goal of establishing and interpreting mathematical models for what effects a newly introduced point-of-care pathogen diagnostic would have in developing countries. The results were astonishing, with potentially millions of lives to be saved on an annual basis. Golden standard for diagnostics of pathogenic bacteria has long been cultureable medias. Environmental biologists have estimated that less than 1% of all bacteria are cultureable. Genomic-based approaches offer the potential to identify all microbes from all the biological kingdoms. Nucleic acid based pathogen diagnostics has evolved significantly over the past decades. Novel technologies offer increased potential in sensitivity, specificity, decreased costs and parallel sample management. However, most methods are confined to core laboratory facilities. To construct an ultimate nucleic acid based diagnostic for use in areas of need, potential frontline techniques need to be identified and combined. The research focus of this doctoral thesis work has been to develop and apply nucleic acid based methods for pathogen diagnostics. Methods and assays were applied to the two distinct systems i) screening for antibiotic resistance mutations in the bacterial pathogen Neisseria gonorrhoeae, and ii) genotype determination of the cancer causative Human Papillomavirus (HPV). The first part of the study included development of rapid, direct and multiplex Pyrosequencing nucleic acid screenings. With improved methodology in the sample preparation process, we could detect an existence of multiple co-infecting HPV genotypes at greater sensitivities than previously described, when using the same type of methodology. The second part of the study focused on multiplex nucleic acid amplification strategies using Molecular Inversion Probes with end-step Pyrosequencing screening. The PathogenMip assay presents a complete detection schematic for virtually any known pathogenic organism. We also introduce the novel Connector Inversion Probe, a padlock probe capable of complete gap-fill reactions for multiplex nucleic acid amplifications. / Patogena organismer smittas till värd organismen genom alla möjliga kontaktnätverk och skapar en mångfald olika sjukdomstillstånd. Dock är det fortfarande vanligt förekommande behandlingsbara infektiösa sjukdomar som orsakar den största hälsoförlusten, sett från ett globalt perspektiv. Bill och Melinda Gates Stiftelsen samarbetade med RAND kooperation för att forma “The Global Health Diagnostics Forum”. Deras mål var att etablera och analysera matematiska modeller för vilka effekter en ny diagnostisk metod utrustat för fältarbete skulle ha i utvecklingsländer. Resultaten var häpnadsveckande, med potentiellt miljoner av liv som skulle kunna räddas på en årlig basis. Den etablerade standarden för diagnostik av patogena bakterier har länge varit kultiveringsmedia baserad. Miljö specialiserade biologer har estimerat att mindre än 1 % av alla bakterie arter går att kultivera. Dock erbjuder genetiska analyser potentialen att kunna identifiera alla mikrober från alla de biologiska rikena. Nukleinsyrebaserade diagnostiska metoder har märkbart förbättrats över de senaste årtionden. Nya tekniker erbjuder utökad sensitivitet, selektivitet, sänkta kostnader och parallella analyser av patient prover. Dock är de flesta metoderna begränsade till standardiserade laboratoriemiljöer. För att konstruera en väl fungerande diagnostisk fältutrustning för användning i problem områden, behöver världsledande tekniker identifieras och kombineras. Fokuseringsområdet för denna doktorsavhandling har varit att utveckla och utföra nukleinsyrebaserade metoder för patogen diagnostik. Metoder och experimentella utförande applicerades på två distinkta system i) sökning av antibiotika resistens relaterade mutationer i den patogena bakterien Neisseria gonorrhoeae och ii) genotypning av det cancer orsakande Humana Papillomaviruset (HPV). Den första delen av studien inriktade sig mot utveckling av snabba, direkta och multiplexa Pyrosekvenserings baserade nukleinsyreanalyser. Med förbättrad provprepareringsmetodologi kunde vi detektera multipla HPV infektioner med högre sensitivitet än vad tidigare beskrivits med liknande metodologi. Den andra delen av studien fokuserades på multiplexa nukleinsyre amplifikationer med “Molecular Inversion Probe” tekniken med sista steg Pyrosekvenserings analys. “PathogenMip assay” erbjuder ett komplett detektionsprotokoll för alla kända patogena organismer. Vi introducerar även den nya “Connector Inversion Probe”, en “Padlock Probe” kapabel att genomföra kompletta gap fyllningar för multiplex nukleinsyre amplifiering. / QC 20100624
65

Alternative electronic packaging concepts for high frequency electronics

Siebert, Wolfgang Peter January 2005 (has links)
The aim of the research work presented here, is to contribute to the adaptation of electronic packaging towards the needs of high frequency applications. As the field of electronic packaging stretches over several very different professional areas, it takes an interdisciplinary approach to optimize the technology of electronic packaging. Besides this, an extensive knowledge of industrial engineering should be an essential part of this undertaking to improve electronic packaging. Customary advances in technology are driven by new findings and a continuous development of processes in clearly defined fields. However, in the field of the higher levels of the interconnection hierarchy, that is external to the chip level interconnections and chip packaging, it is supposed that a wide combination of disciplines and technical creativity, instead of advanced technology in a special area should produce most added value. The thesis is divided into five areas, interlinked by the overall aim of there advantages to the common goal. These areas are the Printed Wiring Board (PWB) technology, PWB connections using flexible printed circuit boards, multiconductor cable connections, shielded enclosures and the related EMC issues, and finally the cooling of electronics. A central issue was to improve the shielded enclosures to be effective also at very high frequencies; it will be shown that shielded enclosures without apertures can cope with frequencies up to and above 15 GHz. Due to this enclosure without apertures, it was necessary to develop a novel cooling structure. This cooling structure consists of a heat sink where the PCB’s are inserted in close contact to the cooling fins on one side, whereas the other side of the heat sink is cooled by forced ventilation. The heat transfer between these parts is completely inside the same body. Tests carried out on a prototype have shown that the performance of the cooling structure is satisfactory for electronic cooling. Another problem area that is addressed are the interconnect problems in high frequency applications. Interconnections between parts of a local electronic system, or as within the telecom and datacom field between subscribers, are commonly accomplished by cable connections. In this research work multiconductor cables are examined and a patented novel cable-connector for high frequency use is presented. Further, an experimental complex soldering method between flexible printed circuits boards and rigid printed circuits boards, as part of connections between PCBs, is shown. Finally, different sectors of the PCB technology for high frequency applications are scrutinized and measurements on microstrip structures are presented. / QC 20101006
66

Förslag till övervakningslösning med värmekameror för Magnetgärdets transformatorstation / Suggestion for a monitoring solution with infrared cameras in the substation Magnetgärdet

Carse, Eddie, Garsallawi, Naman, Wennström-Juslin, Christina January 2010 (has links)
Magnetgärdets transformatorstation är belägen i Ludvika och ägs av Västerbergslagens Energi AB. Transformatorstationen är nyligen ombyggd och nu mer placerad inomhus, vilket gör att påkänningar från väder och vind minskar. För att minimera behovet av personlig tillsyn och öka tillgängligheten behövs dock någon form av tillståndsövervakning. Syftet med examensarbetet har varit att undersöka om det med hjälp av värmekameror är möjligt att tillståndsövervaka de kritiska punkterna i transformatorstationen. För att fastställa detta har teori kring tillståndsövervakning, termografering och värmekameror sammanställts tillsammans med utförda mätningar och tester. Resultaten har sedan diskuterats för att se om ett möjligt lösningsförslag kan presenteras. Viktiga kriterier för att möjligöra tillståndsövervakning med hjälp av värmekameror har tagits fram. Slutsatsen är att det är möjligt, men kräver en komplicerad systemlösning. Lösningsförslaget bygger på flera samspelande delar och bör bli ett kraftfullt övervakningssystem. Huruvida värmekameror är det bästa och enda verktyget är dock tveksamt. Det anses därför väsentligt att även undersöka andra övervakningsmöligheter, som exempel termistorgivare. / The substation called Magnetgärdet is located in Ludvika, Sweden and it is owned by Västerbergslagens Energi AB. The substation has recently been renovated and is now placed indoors, which reduces the influence of weather on the station. To decrease the need for personal supervision and increase the availability of the station a monitoring solution is needed. The purpose of this degree thesis is to examine if it is possible to monitor the condition of critical items in the station with infrared cameras. To determine this, theory on condition monitoring, thermography and thermal imaging cameras has been compiled together with relevant measurements and tests. The results are then discussed to see if a possible solution can be presented. Important criteria for making condition monitoring with infrared cameras possible have also been formulated in this degree thesis. The conclusion is that it is possible, but a complicated system is required. The solution we have given is based on different parts interplaying with each other and it should become a powerful monitoring system. It is however uncertain whether infrared cameras are the only and best tools, therefore other tools should be considered. It might be possible to use thermistors with, or instead of infrared cameras.
67

CONECTOR DE CISALHAMENTO EM PERFIL FORMADO A FRIO: ANÁLISE VIA MODELAGEM COMPUTACIONAL

SILVA, Paulo Henrique Menezes 14 September 2006 (has links)
Made available in DSpace on 2014-07-29T15:03:37Z (GMT). No. of bitstreams: 1 dissertacao paulo menezes.pdf: 3080026 bytes, checksum: 27fc4469f9413ad9117d4813295e9db7 (MD5) Previous issue date: 2006-09-14 / In a composite system, a steel beam (laminated, welded or cold formed) is associated with a concrete slab, forming a composite beam. The interaction between concrete and steel can be mechanical, by friction or, in some cases, only by adherence. One of the major advantages of the composite beams is the increase in strength and stiffness due to association of steel and concrete that makes possible the reduction of the height of the structural elements, implicating in material economy. The present research has the purpose to present a general vision of the structural behavior of the composite steel-concrete beams and to proceed to a more detailed study of the behavior of the shear connectors made from cold formed steel. A modeling study of the push-out test is accomplished with the intention to find the factors that influences the resistance and rigidity of the connection. The numerical study consists in the elaboration of a three-dimensional numerical model to simulate the push-out test from which is obtained the force-displacement curve, ultimate load, deformations and tensions along the connector. The numeric results are compared with obtained experimental values of rehearsals accomplished at laboratory for validation of the same ones. For the accomplishment of the numeric modeling the computational program ANSYS® 6.1 was used, which uses non-linear material and geometric Finite Element Method models. The numeric models present as variables of interest the thickness, the height of the shear connectors made of cold formed steel and the resistance of the concrete used in the premolded slab with reinforced concrete lattice joist. Results showed that the thickness of the connector is the most important variable in the connection strength, however the height of the connector also has influence in the resistance and, mainly, in the rigidity of the connection. / Denomina-se sistema misto aço-concreto aquele no qual um perfil de aço (laminado, dobrado ou soldado) trabalha em conjunto com uma laje de concreto, formando uma viga mista. A interação entre o concreto e o perfil de aço pode se dar por meios mecânicos, por atrito, ou, em alguns casos, por simples aderência. Uma das vantagens da utilização de vigas mistas em sistemas de pisos é o acréscimo de resistência e de rigidez propiciados pela associação dos elementos de aço e de concreto, o que possibilita a redução da altura dos elementos estruturais, implicando em economia de material. O presente trabalho tem por finalidade apresentar uma visão geral do comportamento estrutural das vigas mistas aço-concreto e proceder a um estudo mais detalhado do comportamento da ligação com conectores de cisalhamento tipo U em perfil formado a frio. É realizada a modelagem computacional do ensaio de cisalhamento direto (push-out test) com o intuito de determinar os fatores que mais influenciam na resistência e rigidez da ligação A modelagem computacional consiste na elaboração de um modelo numérico tridimensional para simular o ensaio de cisalhamento direto, do qual se obtém a curva força-deslocamento, a força última e as deformações e tensões ao longo do conector. Os resultados numéricos são confrontados com valores experimentais obtidos de ensaios realizados em laboratório para validação dos mesmos. Para a realização da modelagem computacional, foi utilizado o programa comercial ANSYS® 6.1, elaborado com base no Método dos Elementos Finitos, cujas ferramentas disponibilizadas permitem análises em regime de não-linearidade física e geométrica. Os modelos computacionais apresentam como variáveis de interesse a espessura e a altura do conector tipo perfil U formado a frio e a resistência do concreto utilizado na confecção das lajes treliçadas. Os resultados obtidos mostram que a espessura do conector é a variável que mais influência a resistência da ligação, porém a altura do conector também tem influência na resistência e, principalmente, na rigidez da ligação.
68

Comportamento de conectores de cisalhamento em vigas mistas aço-concreto com análise da resposta numérica / Behaviour of shear connectors in steel-concrete composite beams with numerical analysis

Gustavo Alves Tristão 25 April 2002 (has links)
As vigas mistas aço-concreto têm sido bastante utilizadas na engenharia civil, tanto no Brasil como no contexto mundial. O comportamento adequado deste elemento estrutural faz-se pela interação entre ambos os materiais, a qual é garantida por conectores de cisalhamento. O presente trabalho apresenta uma visão geral do comportamento das vigas mistas aço-concreto, e, principalmente o estudo do comportamento estrutural de conectores de cisalhamento. Para tanto, faz-se uma simulação numérica dos conectores tipo pino com cabeça (stud) e perfil “U” formado a frio, por meio de uma modelagem do ensaio experimental tipo “Push-out”, cujos resultados são confrontados com valores experimentais obtidos de ensaios realizados em laboratório. Para a simulação numérica utiliza-se um código de cálculo com base nos Método dos Elementos Finitos (MEF), cujas ferramentas disponibilizadas permitem análises dos modelos em regime de não-linearidade física e geométrica. Os modelos numéricos apresentam como variáveis de interesse o número de conectores na laje de concreto, a quantidade de armadura inserida no concreto, o diâmetro do conector tipo pino com cabeça (stud), a resistência do concreto, a espessura e posição de soldagem do conector tipo perfil “U” formado a frio. A variação desses parâmetros tem como finalidade a determinação da resistência última e da relação força-deslocamento dos conectores, bem como avaliar a concentração de tensão e deformação nas partes constituintes dos modelos / Composite steel-concrete beams have been used in civil engineering in Brazil as well other countries. A realistic determination of the behaviour of this structural element is estimated by considering the interaction between the two materials, which is safeguarded by providing shear connectors. The present research presents a general view of the behaviour of steel-concrete composite beams, and primarily the study of the behaviour of shear connectors. To meet this ends, a numerical analysis of stud bolt and cold formed U-channel under push-out test geometry was carried out and the results compared to experimental test results. The numerical analysis utilises a Finite Element Method (FEM) code that permits the analysis under non-linear material and geometric regimes. The main numerical variables in the study were the number of connectors used in the concrete plate, the quantity steel reinforcement, the diameter of stub bolt connector, concrete strength, the thickness and position of welding of the cold-formed U-channel. The main objective of varying these parameters was to determine the ultimate strength and the load-slip behaviour of the connectors as well as evaluate the stress and strain concentrations in certain parts that constitute the models
69

Integrace datových schránek do informačního systému / Data boxes integration into information systems

Jakeš, Jiří January 2009 (has links)
This diploma thesis discusses problems of data boxes information system and its possible integration with various information systems through the use of particular software tool developed by company Ixtent s.r.o. In the first part of this thesis is data boxes information system (ISDS) established into wider contexts and defined by terms. In the second part of this thesis are described options to connect ISDS and other various business applications. In so doing the software tool "connector ISDS" id used. In the third part are discussed particular realized project, case studies and real benefits of these projects.
70

台灣高中英文教科書與學生英文作文佳作之文體與因果關係探討 / The use of causal relations in narrations and expositions: a case study of Taiwan senior high school textbooks and high performance students' compositions

林侑萱, Lin, Yu Hsuan Unknown Date (has links)
本研究旨在探討台灣英文教科書與學生英文作文佳作中,敘述文與說明文中的因果關係使用。因為因果關係在閱讀與寫作中很常見,所以對學生來說,學會如何正確使用因果關係是件極為重要的事。根據李(2003)的研究,她發現因果關係對學生來說是最難學好的因果關係。因此,本研究希望能了解教科書中的敘述文與說明文是如何介紹因果關係給學生。同時,本研究亦希望能得知學生如何在不同文體的英文作文中,使用因果關係。 本研究選用三個版本的高中英文教科書來進行研究,之所以選擇此三版本教科書的原因在於,此三個版本在台灣高中英文課本的市占率最高。而又因為敘述文和說明文在學測和指考的英文作文考試中是最常要測驗學生的文體,因此本研究進一步挑選課本中的敘述文和說明文來進行分析與探討。此外,本研究亦研究民國100年到105年的學測、指考英文作文佳作,舉凡是敘述文和說明文中所使用的因果關係都進行分析與探討。 研究結果顯示在三個版本中,敘述文和說明文的分布無明顯差異。此外,本文發現年級越高的高中生會接觸到愈多的敘述文,但愈少的說明文。研究結果亦顯示文體會影響因果關係的使用情形。相較於敘述文中的因果關係使用,我們發現教科書作者在說明文中使用較多因果關係。 而我們也發現在不同文體中的不同文章結構,因果關係使用的情形不同。在敘述文中,因果關係主要被使用於Complications和Resolutions中。在說明文中,因果關係則主要被使用於Arguments supported by evidence 和Summing up the position中。除此之外,本文亦發現在四類因果連接詞中,Reason和Result這兩類的因果連接詞最常被使用於敘述文和說明文中。 為了清楚看出因果關係,本文針對包含因果關係的句子皆進行了句法、時間及邏輯順序的分析。結果發現幾乎所有因果關係中的時間順序皆與邏輯順序一致。同時,本文亦歸納出教科書中的因果關係的七種使用形式,並提供教科書中的例句來進行討論。 最後,透過學生英文作文佳作的分析,我們發現在因果關係的使用量方面,這群學生與教科書作者相似。而本研究亦歸納出學生在佳作中的四個因果關係誤用的問題。 希望本研究的發現及所提供的建議可供台灣高中英文科教師、教科書作者以及高中生參考。 / The purpose of the study is to investigate the variations of causal relations in narrations and expositions in Taiwan senior high school's English textbooks, and high performance students’compositions. Since causal relations are common in reading and writing, it is important for students to learn to use it. According to Lee (2003), causal relations are the most difficult logical relations for students to master. The present study wants to know how causal relations are introduced to learners in the narrations and expositions from textbooks. Besides, the present study also wants to know how students use causal relations in different genres of compositions. In the study, three series of textbooks are selected for the examination. These three textbooks were chosen as they are commonly used textbooks in Taiwan senior high schools. The selected texts for examination are the texts of two genres: narration and exposition, for these two genres are frequently tested in College Entrance Exams. Moreover, the causal relations in narrations and expositions among the high-scoring essays in years of 2011 to 2016College Entrance Exams were examined as well. The results showed that three series of textbooks in have no significant differences in the distributions of narrations and expositions. Besides, senior high school students expose more narrations but fewer expositions in the higher grades. Furthermore, the result revealed that genres do influence the uses of causal relations, for expositions in the textbooks applied more causal relations than the narrations in the textbooks. Moreover, different usages among different text organizations in both narrations and expositions were found. In the text organizations of narrations, causal relations were mainly used in complications and resolutions.In the text organizations of expositions, causal relations were mainly used in Arguments supported by evidence and Summing up the position. The types of causal relations which are frequently used in textbooks were also found as well. The results showed that Reason and Result type of causal logical connectors were mainly used in both narrations and expositions. Analyses of casual relations’sequences were conducted to clearly see the syntactic sequences, temporal sequences, and logical sequences of the sentences with causal relations. It was found that almost all the causal relations in the textbooks had the temporal sequences equaled to the logical sequences. Moreover, six usages of causal logical connectors were categorized and presented with example sentences. Last but not least, through the analyses of causal relations in students’high-scoring essays, the result showed that high performance students used the similar amounts of causal relations in their compositions with the textbooks’ writers. The present study also categorizes the errors of misusing the causal relations into four problems. It is hoped that this study can provide insights for the senior high school English teachers, textbook publishers, and students to follow.

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