• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 661
  • 497
  • 176
  • 176
  • 86
  • 80
  • 28
  • 27
  • 26
  • 18
  • 17
  • 16
  • 9
  • 9
  • 8
  • Tagged with
  • 2089
  • 371
  • 278
  • 210
  • 207
  • 173
  • 170
  • 161
  • 159
  • 157
  • 149
  • 147
  • 143
  • 128
  • 113
  • 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.
161

Modeling Alternatives for Implementing the Point-based Bundle Block Adjustment

Chen Ma (10693164) 06 May 2021 (has links)
<div>This thesis examines the multilinear equations of the calibrated pinhole camera. </div><div>The multilinear equations describe the linear relations between camera parameters and image observations in matrix or tensor formats. </div><div>This thesis includes derivations and analysis of the trilinear equations through the point feature relation. For the four-frame and more than four frame cases, this paper gives derivations and analysis using a combination of the bilinear and trilinear equations to represent general multi-frame point geometry. As a result, a three-frame model (TFM) for general multi-frame point geometry is given. This model provides a concise set of minimal and sufficient equations and minimal unknowns.</div><div> </div><div>Based on the TFM, there are two bundle adjustment (BA) approaches developed. </div><div>The TFM does not involve the object parameters/coordinates necessary and indispensable for the collinearity equation employed by BA. </div><div>The two methods use TFM as the condition equation fully and partially, replacing the collinearity equation. </div><div>One operation using both TFM and the collinearity equation is designed to engage the object structures' prior knowledge. </div><div>The synthetical and real data experiments demonstrate the rationality and validity of the TFM and the two TFM based methods. </div><div>When the unstable estimate of the object structures appears, the TFM-based BA methods have a higher acceptance ratio of the adjustment results. </div>
162

Medias inramning av Nordkorea : En studie av nyhetsmediers representation av Nordkorea / Media framing of North Korea : A study of the representation of North Korea in news media

Nguyen, Catalena January 2019 (has links)
Representations have a significant part in our everyday lives as they shape our understanding of the world and are related to the construction of knowledge and the formation of social relations between different cultural groups. Previous studies have questioned the objectivity of news media and representations and argued that representations are not as objective as they often claim to be. Conscious and unconscious choices such as what is to be emphasized, included, excluded, choices of words, examples, metaphors, the journalist's background and more are examples of what makes the neutrality and objectivity of news reporting questionable. This argument is further strengthened by emphasizing that news production and its consumption is neither isolated nor independent and is influenced by different levels of power. The production of news is therefore a complex interaction between different stakeholders that influence what is interesting and newsworthy to be published because in the end, news is a product to be sold. This study examines the geographical representation of North Korea in the news media with a frame perspective. Framing has in this study been interpreted as a way of representing and is understood as a framework that frames a news subject and sets the tone on how the news subject can be interpreted and understood by the receiver. The empirical data, collected from two Swedish and two South Korean digital newspapers from two time periods, April 2017 and April 2018, were analyzed using a combination of a frame analysis and a content analysis. The conclusion of this study is that there are to some extent differences on how the news media in Sweden and South Korea choose to frame North Korea. During the two time periods, the Swedish news medias makes generally a more negative representation of North Korea compared to the South Korean news medias. But overall are the frames used by the news media in both countries reflected by the situation in North Korea and the world.
163

En jämförelsestudie av två byggnadsstommar med avseende på deras klimatpåverkan & beständighet

Khadra, Charbel, Möller, Robin January 2020 (has links)
Utförandet av klimatdeklarationer för nya byggnader är ett nationellt initiativ i Sverige som syftar till att minska den bebyggda miljöns klimatpåverkan. Denna undersökning syftar till att utföra två klimatdeklarationer för ett LSS-boende för att jämföra dess ursprungliga betongstomme med ett alternativ i stål ur ett klimatperspektiv. Stomalternativens påverkan på byggnadsdelars värmegenomgångskoefficienter (U-värde) och beständighet undersöks också för att få en helhetsbild av stålstommens konsekvenser på byggnaden. Den alternativa stommen baseras på en konstruktion från ett komparativt projekt och anpassas för att uppfylla brandskydds- och ljudisoleringskraven för den undersökta byggnaden. I den nya stommen används stålregelväggar, fackverkstakstolar och en reducerad grundkonstruktion.De frågeställningar som besvaras under studien är; vilken av de undersökta stommarna medför minst klimatpåverkan enligt de utförda klimatdeklarationerna, vilken byggnadsdel medför störst klimatpåverkan i varje stomme och hur påverkas byggnadsdelars initiala värmegenomgångskoefficienter samt beständighet vid byte till stålstommen. En klimatdeklaration definieras som ett dokument som redovisar en byggnads klimatpåverkan fördelad på dess bruttoarea (kg CO2eq/m2 BTA) under hela dess livscykel. Dokumentet grundar sig i livscykelanalys-metoden och omfattar Byggnadsskedet (A1-4 inklusive spill i A5) till en början enligt Boverkets rekommendation. De deklarationer som studien baseras på utförs med Byggsektorns miljöberäkningsverktyg med hjälp av generisk klimatdata från verktygets databas. Mängdningen av byggnadens material baseras på en Revit modell och ritningar utgivna av Här! Malmö samt information från produkttillverkare. U-värdena för konstruktionerna beräknas huvudsakligen i Excel enligt metoden beskriven i en byggnadsfysikbok. För att besvara frågorna om beständighet utförs en litteraturstudie baserad på information från materialböcker, varudeklarationer samt “Peer-reviewed” vetenskapliga artiklar hämtade från “Libsearch”. Enligt resultatet från deklarationerna medför betongstommen en total klimatpåverkan på 371,55 kg CO2eq/m2 BTA medan stålstommen medför en påverkan på 193,14 kg CO2eq/m2 BTA vilket motsvarar ett reduktionstal på 48 procent. Från deklarationerna går det också att avläsa att grunden medför störst klimatpåverkan för stålkonstruktionen medan stommen har störst påverkan i betongkonstruktionen. Vid beräkning av värmegenomgångskoefficienten medför bytet till stålstomme en reduktion av värdet för vindsbjälklaget från 0,137 till 0,104 W/m2K medan plattan på mark är i princip oförändrad (0,073 till 0,074 W/m2K). U-värdet för stålregelväggen (0,148 W/m2K) hamnar mellan de beräknade värdena för betongväggen med förbättrad och standard isolering (0,134 respektive 0,198 W/m2K). Enligt resultatet från litteraturstudien kan betong anses vara ett underhållsfritt material med högre beständighet mot brand och fukt än trä och stål som oftast måste behandlas och skyddas.Vid jämförelse med referensvärden från Svenska Miljöinstitutet hamnar endast stålstommen klimatpåverkan under det angivna gränsvärdet för flerbostadshus (216 kg CO2eq/m2 BTA). Betongstommens relativt höga klimatpåverkan anses bero på att stommen används i ett envåningshus. Stålstommen anses vara bättre ur klimatperspektiv men faktorer som kortare underhållsintervall och livslängd innebär att reduktionstalet som beskrivs är förmodligen mindre över hela livscykeln. / The introduction of climate declarations aims at minimizing the building sector's climate impact but earlier studies compare building frames by using declarations from two different buildings. This study focuses on creating two climate declarations in order to compare the concrete frame of a residential building with an alternative steel frame on the same building from a climate perspective. The steel frames’ effect on different building components thermal transmittance (U-value) and on the building’s durability are also analysed. The climate declarations in this study span over the Manufacture and Construction Process stages of the building’s life-cycle and are created with the use of the Construction Sector’s Environmental Calculation Tool and its built-in database. U-values for building components were calculated with Excel and a literature study was used to determine different building materials durability. The results from the climate declarations show that the concrete frame leads to a climate impact of 371,55 kg CO2eq/m2 gross floor area while the steel frame leads to an impact of 193,14 kg CO2eq/m2 gross floor area which corresponds to a reduction of the building's climate impact by 48 percent with the steel frame. The concrete frame accounts for the biggest amount of the building’s total climate impact while the foundation has the highest impact with the steel frame. The results from the U-value calculations show a decrease in the roof’s U-value from 0,137 to 0,104 W/m2K with the steel frame while the foundations U-value remains virtually unchanged (0,073 to 0,074 W/m2K). The comparison of the U-value for steel and concrete outer walls was inconclusive. According to the results from the literary study concrete was proved to be more durable and have better resistance to fire and humidity when compared to wood and steel and was considered to need little to no maintenance during a building’s lifespan.
164

Eccentrically Braced Frames in Combination with Moment Frames to Re-Center Buildings After a Seismic Event

Liebau, Corey 04 November 2020 (has links)
No description available.
165

Analytical Investigation of the Effect of Partially-Restrained Connections on Hybrid Moment-Resisting Steel Frames

Kozma Thomas, Mathias A. 13 October 2014 (has links)
No description available.
166

From Protest to Prayer: Bound4Life, A New Trend in Pro-Life Rhetoric

Lehman, Alaina 20 September 2012 (has links)
No description available.
167

Experimental investigation of the thermo-mechanical response of Intumescent Mat Material

Kim, Hyungjun January 2000 (has links)
No description available.
168

Berätta inte hur dum du är! : En studie av svensklärares upplevda ramar kring skönlitteraturundervisning / Do not tell people how stupid you are! : A study of how teachers in Swedish consider frame factors on their teaching in fiction

Björnler, Magdalena, Bergmark, Lovisa January 2024 (has links)
This study aims to explore the framework behind teachers’ choice of fiction in their teaching in the subject Swedish. The two research questions examine how teachers discuss their possibilities to choose fiction and how it affects their teaching methods and what they think they need to consider when they select fiction for use in their teaching. Earlier research shows that reading comprehension among students have decreased throughout the years. Furthermore, earlier research discusses the different factors that show why reading fiction is important. The aim is examined through a qualitative thematic analysis where interviews with four teachers in upper secondary school is the material for analysis. Results are analyzed by the help of frame factor theory in order to investigate how the frame affects the teachers’ planning and teaching methods. Results also show that the curriculum and syllabus direct the teachers more than they perceive. The other frame factor that is significant in the teachers’ teaching methods is the students’ ability to read because it directly affects the way teachers approach literature to motivate them.
169

Development of a Progressive Failure Finite Element Analysis For a Braided Composite Fuselage Frame

Hart, Daniel Constantine 29 July 2002 (has links)
Short, J-section columns fabricated from a textile composite are tested in axial compression to study the modes of failure with and without local buckling occuring.The textile preform architecture is a 2x2, 2-D triaxial braid with a yarn layup of [0 deg 18k/+-64 deg 6k] 39.7% axial. The preform was resin transfer molded with 3M PR500 epoxy resin. Finite element analyses (FEA) of the test specimens are conducted to assess intra- and inter- laminar progressive failure models. These progressive failure models are then implemented in a FEA of a circular fuselage frame of the same cross section and material for which test data was available. This circular frame test article had a nominal radius of 120 inches, a forty-eight degree included angle, and was subjected to a quasi-static, radially inward load, which represented a crash type loading of the frame. The short column test specimens were cut from some of the fuselage frames. The branched shell finite element model of the frame included geometric nonlinearity and contact of the load platen of the testing machine with the frame. Intralaminar progressive failure is based on a maximum in-plane stress failure criterion followed by a moduli degradation scheme. Interlaminar progressive failure was implemented using an interface finite element to model delamination initiation and the progression of delamination cracks. Inclusion of both the intra- and inter- laminar progressive failure models in the FEA of the frame correlated reasonably well with the load-displacement response from the test through several major failure events. / Master of Science
170

The Feasibility of Wood and its Derivatives as a Bicycle Frame Building Material

BRENT TAYLOR, NICHOLAS 05 May 2016 (has links)
[EN] The bicycle is often considered as one of the most important inventions of all time. In addition, it is the most efficient form of human transport in the world. It is non pollutant, uses no fuel other than human power and its carbon footprint is neutralised in a short time. Today, faced with the threat of global warming brought about by fossil fuels, countries such as Denmark, the Netherlands and Columbia actually encourage the use of the bicycle as a viable means of urban transport, and in the city of Paris there are financial incentives for cycling commuters. In China alone there are 450 Million bicycles. The form of the bicycle is universally recognisable, it is easy to use and simple to maintain. However, in spite of its apparent simplicity, the bicycle is made up of numerous components and sub-assemblies. Over the years these components and sub-assemblies have undergone a succession of changes and modifications. As with the evolution, development, and life cycle of any product, some of the modifications were relatively short lived. Others for various reasons have been adopted almost universally, such as steel ball bearings, the roller chain, pneumatic tires, tension spoked wheels, etc. In order to more fully understand the bicycle, its advantages, its shortcomings, and its place in the modern world, the first part of this study aims to address the various criteria which apply to bicycle typology, differentiation, use and construction. However, although numerous types of Human Powered Vehicles (HPVs) exist, the initial part of this research is constrained to the evolution and development of the "Safety" type bicycle - attributed to J. K. Starley of Coventry in 1895 - up to the present day, taking into account such factors as; design, material selection, manufacturing technology, and diversity. The first part of the study is a comprehensive overview of the bicycle which identifies crucial technological aspects and categorises bicycle by type and intended use. Due to the huge quantities and types of bicycles produced worldwide this research identifies generic types of each category irrespective of origin or manufacturer. The second part of this dissertation is devoted to the study of wooden bicycles and the specific requirements of this type of bicycle such as the use of wood and its derivatives e.g. engineered wood, as a bicycle frame construction material and some of the solutions arrived at and the special parts or components required. Contemporary and historical bicycles made from wood, other organic material and its derivatives have been investigated and conclusions drawn regarding their functionality and purpose. Part three is dedicated to the Design, Development, and Evaluation of a Wooden Bicycle prototype undertaken by the Author with the assistance of three Industrial Design Students. Part four describes the design, construction and testing of subsequent prototypes in detail including the fabrication of pre-production bicycles and proposals for manufacture on a commercial level. Parts five and six outline the empirical findings from the previous section and attempt to define strategies for marketing bicycles manufactured from wood and its derivatives as an alternative to conventional materials with a view to reanimating small local industries which have a strong base of expertise and knowhow working with wood, such as producers of furniture and similar products (broom handles, tool handles, boxes etc.). Part seven is devoted to the potential diversification of wooden framed bicycles which are electrically assisted. The fabrication of a prototype is discussed but no conclusions were made due to constraints beyond my control. Keywords: Design, Product, Frame, Bicycle / [ES] La bicicleta es frecuentemente considerada como una de las invenciones más importantes de todos los tiempos. Es también una de las formas de transporte humano más eficiente en el mundo. Hoy en día, por la amenaza del calentamiento global provocado por las fuentes de energía no renovables, países como Dinamarca, Holanda y Colombia animan a usar la bicicleta como un medio de transporte urbano. La figura de la bicicleta es universalmente reconocida, es fácil de usar y su mantenimiento es simple. A pesar de su aparente simplicidad, la bicicleta está compuesta de numerosos componentes y subconjuntos. A lo largo de los años, los subconjuntos sufrieron una serie de cambios y transformaciones. Como en cualquier evolución y desarrollo, los cambios influyen en el ciclo de vida de cualquier producto, a pesar que algunas de estas aportaciones tuvieron una vida efímera. Otras, por razones varias, fueron adoptadas casi universalmente. Entre estas podemos citar los rodamientos de esferas de azor, la cadena, los neumáticos, etc. Para comprender mejor el producto bicicleta, se ha considerado como objetivo en la primera parte de este estudio, abordar varios criterios que se aplican de acuerdo con la tipología, diferenciación, uso y construcción de la bicicleta. A pesar de existir numerosos tipos de Human Powered Vehicles (HPVs), la primera parte de esta investigación se limita al estudio de la evaluación y desenvolvimiento de la bicicleta "Safety" atribuida A J.K. Starley de Coventry UK.1895, desde su aparición hasta nuestros días, tomando en consideración la selección de materiales, las tecnologías de fabricación, el diseño, y el estatus de la bicicleta en la sociedad. La segunda parte de esta tesis está dedicada por completo al estudio de la madera y sus derivados como material de construcción de la bicicleta. Bicicletas contemporáneas e históricas de madera y sus derivados, que han sido investigados y se han presentado los resultados en relación a su funcionalidad y propósito. La tercera parte describe con detalle el diseño, desarrollo y evaluación de una bicicleta prototipo de madera, los prototipos posteriores y las bicicletas prototipo o de pre-producción de madera y sus derivados fabricados por el autor con la ayuda de los Estudiantes finalistas del grado de Diseño Industrial (ESTGAD CR, Portugal) En la cuarta parte se describe el diseño, construcción y prueba de prototipos posteriores en detalle, incluyendo la fabricación de bicicletas de pre-producción y propuestas para la fabricación a nivel comercial. La quinta y sexto partes resume los resultados empíricos de la sección anterior y trata de definir estrategias de marketing, para bicicletas fabricadas a partir de la madera y sus derivados como una alternativa a los materiales convencionales, con el fin de animar a producción industrial a las pequeñas industrias locales, que poseen una base sólida de experiencia en el trabajo con la madera, como productores de muebles y productos similares. En la última parte, se ha dedicado a la diversificación potencial de cuadros de bicicletas en madera que están asistidas eléctricamente. La fabricación de un prototipo forma parte de la discusión y pretende ser una proyección de futuro. Palabras Clave: Diseño, Producto, Madera, Bicicleta. / [CA] La bicicleta es freqüentment considerada com una de les invencions mes importants de tots els temps. Es tambe una de les formes de transport huma mes eficient en el mon. Hui en dia, per l'amenaça del calfament global provocat per les fonts d'energia no renovellables, països com Dinamarca, Holanda i Colombia animen a usar la bicicleta com un mig de transport urba. La figura de la bicicleta es universalment reconeguda, es facil d'usar i el seu manteniment es simple. A pesar de la seua aparent simplicitat, la bicicleta està composta de numerosos components i subconjuntos. A lo llarc dels anys, els subconjuntos patiren una serie de canvis i transformacions. Com en qualsevol evolucio i desenroll, els canvis influixen en el cicle de vida de qualsevol producte, a pesar que algunes d'estos aportaments tingueren una vida efimera. Atres, per raons varies, foren adoptades casi universalment. Entre estes podem citar els rodaments d'esferes d'azor, la cadena, els neumatics, etc. Per a comprendre millor el producte bicicleta, s'ha considerat com objectiu en la primera part d'este estudi, abordar varis criteris que s'apliquen d'acort en la tipología, diferenciacio, us i construccio de la bicicleta. A pesar d'existir numerosos tipos d'Human Powered Vehicles (HPVS), la primera part d'esta investigacio se llimita a l'estudi de l'evaluacio i desenvolupament de la bicicleta "Safety" atribuida A J.K. Starley de Coventry UK. 1895, des de la seua aparicio fins nostres dies, prenent en consideracio la seleccio de materials, les tecnologies de fabricacio, el disseny, i l'estat de la bicicleta en la societat. La segona part d'esta tesis està dedicada per complet a l'estudi de la fusta i els seus derivats com material de construccio de la bicicleta. Bicicletes contemporanees i historiques de fusta i els seus derivats, que han segut investigats i s'han presentat els resultats en relacio a la seua funcionalitat i proposit. La tercera part descriu en detall el disseny, desenroll i evaluacio d'una bicicleta prototip de fusta, els prototips posteriors i les bicicletes prototip o de PRE-produccio de fusta i els seus derivats fabricats per l'autor en l'ajuda dels Estudiants finalistes del grau de Disseny Industrial (ESTGAD CR, Portugal) En la quarta part se descriu el disseny, construccio i prova de prototips posteriors en detall, incloent la fabricacio de bicicletes de pre-produccio i propostes per a la fabricacio a nivell comercial. La quinta i sisè parts resumix els resultats empirics de la seccio anterior i tracta de definir estrategies de marketing, per a bicicletes fabricades a partir de la fusta i els seus derivats com una alternativa als materials convencionals, en el fi d'animar a produccio industrial a les menudes industries locals, que posseixen una base solida d'experiencia en el treball en la fusta, com productors de mobles i productes similars. En l'ultima part, s'ha dedicat a la diversificacio potencial de quadros de bicicletes en fusta que estan assistides electricament. La fabricacio d'un prototip forma part de la discussio i preten ser una proyeccio de futur. Paraules Clau: Disseny, Producte, Fusta, Bicicleta. / Brent Taylor, N. (2016). The Feasibility of Wood and its Derivatives as a Bicycle Frame Building Material [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/63663

Page generated in 0.05 seconds