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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.
481

Percep????o e mitiga????o de riscos por investidores-anjos em startups: um estudo multicaso

BURKE, Jo??o 18 August 2015 (has links)
Submitted by Elba Lopes (elba.lopes@fecap.br) on 2016-03-15T18:38:28Z No. of bitstreams: 2 Joao_Burke.pdf: 1956451 bytes, checksum: adadb62fea074a2e87b02a52a5f2328a (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2016-03-15T18:38:28Z (GMT). No. of bitstreams: 2 Joao_Burke.pdf: 1956451 bytes, checksum: adadb62fea074a2e87b02a52a5f2328a (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2015-08-18 / The purpose of this thesis is to study the perception and the mitigation of diversifiable risks by angelinvestors in their investments in startups. Such theme is relevant in the entrepreneurship context in Brazil, and in the theoretical body of knowledge on Entrepreneurship and Corporate Finances. Angel investment is growing in Brazil, although only a few studies about risks in such context are found. In order to reach such goals, this thesis presents a chart of risks and relevant mitigation procedures, and proposes relevant classification in accordance with the angel investment phases and prominent risk dominion, as well as an exploratory study with three experienced Brazilian angels, following a semi-structured script whose empirical findings are framed into the relevant theories. Adopted data analysis technique is content analysis.In terms of results, based on fragments extracted from the interviews, angels are mostly concerned with operational risks, followed by market, financial and technological ones. In what refers to the 38 mechanisms of risk mitigation gathered in this thesis, answers point the majority of risk mitigation strategies organized in this thesis isreflected in the experience of the interviewed angels, since 26 mitigation mechanisms are endorsed by three or two of the interviewed angels. Additionally, another 10 mitigation mechanisms out of the 38 are endorsed by one of the interviewed angels; only two out of the mentioned 38 mitigation mechanisms are not adopted by any of the interviewed angels. / O objetivo desse trabalho ?? estudar a percep????o e a mitiga????o de riscos diversific??veis por investidores-anjos em seus investimentos em startups. Tal tem??tica tem relev??ncia no contexto do empreendedorismo no Brasil e no corpo te??rico sobre o empreendedorismo e finan??as. O volume de investimentos de tal natureza cresce no Brasil e, n??o obstante, h?? poucos estudos que versam sobre riscos neste contexto. Visando a atingir tais objetivos, realiza-se quadro resumo de riscos e 38 mecanismos correspondentes de mitiga????o apontados pela literatura, com proposta de classifica????o conforme fases do investimento-anjo e dom??nio de risco preponderante, bem como se efetua estudo explorat??rio com tr??s investidores-anjos brasileiros experientes, seguindo roteiro semiestruturado,cujos dados emp??ricos s??o cruzados com as teorias pertinentes. A t??cnica de an??lise de dados utilizada ?? a an??lise de conte??do. No que se refere aos resultados obtidos, conclui-se que fragmentos dos discursos dos entrevistados revelaram preocupa????es mais frequentemente relacionada aos riscos do dom??nio operacional, seguidos de riscos de mercado, financeiros e tecnol??gicos. No que tange aos 38 mecanismos de mitiga????o agrupados no presente trabalho, as respostas dos anjos apontam que a maioria das estrat??gias de mitiga????o colacionadas neste trabalho ?? corroboradapela pr??ticados anjos entrevistados, pois 26estrat??gias s??o endossadas por tr??s ou dois dos entrevistados. Complementarmente, 10 das 38 formas de mitiga????o s??o endossadas por um dos anjos entrevistados; apenas duas das 38 formas de mitiga????o n??o encontram apelo junto aos entrevistados.
482

"Estudo observacional de aspectos relacionados à adesão ao tratamento da incontinência urinária em mulheres que realizaram exercícios da musculatura do assoalho pélvico" / Observational study of adhesion to treatment of female urinary incontinence with pelvic floor exercises

Silveira, Simone dos Reis Brandao da 25 April 2006 (has links)
A incontinência urinária na mulher é uma afecção crônica que altera a sua qualidade de vida. Um dos tratamentos propostos é o exercício da musculatura do assoalho pélvico. A eficácia desse tipo de terapêutica depende da adesão da paciente a ele. Aderir a um tratamento é seguir as orientações dadas; no caso dos exercícios da musculatura do assoalho pélvico, envolve a incorporação da terapêutica ao cotidiano. O objetivo deste estudo é descrever três aspectos relacionados à adesão ao tratamento: satisfação, expectativa e repetição ou não do tratamento. Para a sua realização foram entrevistadas 50 mulheres que aderiram ao tratamento, atendidas no setor de Uroginecologia da Disciplina de Ginecologia do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo. Os resultados mostraram que 68% das mulheres estavam satisfeitas com o tratamento, 62% tinham expectativa de cura e apenas 12% não o repetiriam. Quando questionadas sobre os motivos para a não repetição do tratamento, a maior parte das mulheres referiu a não melhora do quadro clínico. Concluiu-se que a satisfação é alta nas mulheres que aderiram ao tratamento, a expectativa mais comum entre as entrevistadas é de cura e que o fator mais importante para repetir a terapêutica foi a melhora do quadro clínico. / The female urinary incontinence is a chronic disease which affects life quality. One of the treatments suggested is the pelvic floor exercises. The therapy depends on the patient’s adhesion. Adhesion to treatment implies to follow all medical instructions; in case of pelvic floor exercises, it involves its incorporation to daily routine. The aim of this study is to describe tree aspects regarding to the treatment adhesion – satisfaction, expectation and repetition (or not). Fifty women who have followed the treatment were interviewed. They were recruited from the Urogynecology Service of Clínicas Hospital of São Paulo University Medical School. The results demonstrated that 68% of women were satisfied with the treatment, 62% expected to be cured, and only 12% hadn’t undergone the treatment appropriately. When inquired about the reasons for not repeating the treatment, most of the women have mentioned that they haven’t seen positive results. In conclusion, patient’s satisfaction level was high, cure was the main expectation, and the good response to clinical treatment was the most important reasons to repeat the treatment.
483

Självkompakterande betong : Ytjämnhet utan efterbehandling / Self-Compacting Concrete : Flat surface without after-treatment

Elofsson, Andreas, Hallin, Mikael January 2006 (has links)
<p>Betonggjutning är ett tungt moment inom byggproduktion och entreprenörer har länge använt betong med flyttillsats för att få en mer lättarbetad betong. Ändå har det krävts långa arbetspass och många tungarbetade moment. Efter lasernivellering, vibrering, slodning och glättning har man kunnat uppnå en yta som nästan är helt jämn. Dock ej så jämn att avjämningsmassa kunnat elimineras för att inte få sviktande parkett eller buktande plastmattor.</p><p>Självkompakterande betong (SKB), eller vibreringsfri betong som man först kallade den, forskades fram på 80-talet i Japan och dök upp i Sverige i slutet på 90-talet. Det är en betong som innehåller en flyttillsats och en så kallad filler vars gemensamma egenskaper ger en betong som har bibehållen homogenitet samtidigt som den fyller ut formen och omsluter armering endast genom gravitationskraften. SKB är ca 10-15 % dyrare än traditionell betong men har motiverats med framförallt minskad produktionstid, färre betongarbetare och bättre arbetsmiljö.</p><p>Eftersom SKB mer eller mindre är flytande så blir jämnheten mycket god. Erfarenhetsmässigt har ytorna blivit i det närmaste perfekta efter lasernivellering, slodning och torrslipning. Trots stora konstaterade arbetsmiljövinster och vetskapen om den goda ytjämnheten har AB Färdig Betong i Karlstad endast levererat SKB till 8 projekt sedan 1997.</p><p>Examensarbetets syfte är att fastställa om SKB kan motiveras baserat på den goda ytjämnhet som kan uppnås redan efter gjutning jämfört med normalpresterande betong (NPB).</p><p>Examensarbetet har utförts i samarbete med Skanska Sverige AB i Karlstad, som under våren 2006 genomförde två projekt med SKB. Mätningar av ytor med SKB gjordes på Färjstad i Karlstad och mätningar av referensytor med NPB gjordes i Karlstad med omnejd. Mätningarna kompletteras med intervjuer i form av erfarenhetsåterföring från dem som tillverkat, levererat, mottagit, gjutit och efterbehandlat betongtypen.</p><p>De krav på ytjämnhet av platsgjuten betong som generellt tillämpas återfinns i Hus AMA 98 och definieras som buktighet, lutning och nivåskillnad. Resultaten från mätningarna bedömdes i enlighet med Hus AMA 98, därefter har betongtypernas mätvärden analyserats och jämförts.</p><p>Utifrån resultaten har bland annat följande slutsatser kunnat konstateras:</p><p>Självkompakterande betong kan vid rätt handhavande ge en yta som uppfyller kraven enligt Hus AMA’s krav för undergolv i klass B utan varken vibrering, slipning eller efterbehandling.</p><p>Användandet av SKB i större bostadsprojekt skapar stora förutsättningar för lägre totalekonomi jämfört med användandet av NPB. Detta baseras huvudsakligen på minskat behov av arbetskraft vid gjutning och efterbehandling av den gjutna ytan.</p><p>De bekräftade möjligheterna för förbättrad ytkvalitet redan efter gjutning kommer i framtiden innebära att fler entreprenörer väljer SKB.</p> / <p>Concrete moulding is a heavy moment in the building process and for a long time contractors have used an admixture to create a concrete that is easier to handle. However many hours of work and heavy moments has been required. After laser levelling, vibrating, screeding and troweling a surface that is almost flat has been obtained. Yet not flat enough to eliminate floor levelling and thereby avoiding bending parquet flooring or curved plastic flooring.</p><p>Self-compacting concrete (SCC), or vibrating free concrete as it was named in the beginning, was developed in the eighties in Japan and showed up in Sweden in the late nineties. It is a concrete that contains an admixture and filler that together makes the concrete flow under its own weight, completely filling the formwork and achieving full compaction, even in the presence of congested reinforcement. SCC is approximately 10-15 % more expensive than traditional concrete but is motivated with faster construction times, fewer workers and an improved work environment.</p><p>Since SCC just about flows the resulting surface becomes almost perfect. Experience shows that surfaces are nearly perfect after laser levelling, screeding and dry smoothing. Despite the advantages of the flat surfaces and the established improvement on the work environment, AB Färdig Betong in Karlstad, Sweden has only delivered SCC to eight projects since 1997.</p><p>The aim of this degree thesis is to determine if SCC can be motivated based on the flat surfaces that can be obtained after moulding compared to traditional concrete.</p><p>The degree thesis has been performed in cooperation with Skanska Sverige AB in Karlstad, Sweden at their two projects with SCC in spring 2006. The measurement of SCC surfaces was made in Färjestad, Karlstad and reference measurements of traditional concrete was made in Karlstad and surroundings. The measurement have been complemented with interviews that present experience of producing, delivering, receiving, moulding and after treating SCC.</p><p>The requirements for on site moulding concrete surfaces that are to be followed are found in Hus AMA 98 and is defined as curve, rake and level variance. The result from the measurements are judged on the basis of the requirements.</p><p>Conclusions</p><p>Correctly performed SCC can create a surface that fulfils the requirements in Hus AMA 98 for a class B floor.</p><p>The use of SCC in larger housing constructions makes conditions for a lower total cost. This is based principally on fewer workers, faster construction times and less after treatment of the moulded surfaces.</p><p>The confirmed possibilities of improved surfaces after moulding should mean that more contractors will use SCC in the future.</p>
484

Tapping into Floor Staff: Using the knowledge of floor staff to conduct formative evaluations of exhibits in a Canadian science centre

Lebel, Josée January 2008 (has links)
Most science centres in Canada employ science-educated floor staff to motivate visitorsto have fun while enhancing the educational reach of the exhibits. Although bright andsensitive to visitors’ needs, floor staff are rarely consulted in the planning,implementation, and modification phases of an exhibit. Instead, many developmentteams rely on costly third-party evaluations or skip the front-end and formativeevaluations all together, leading to costly errors that could have been avoided. This studywill seek to reveal a correlation between floor staff’s perception of visitors’ interactionswith an exhibit and visitors’ actual experiences. If a correlation exists, a recommendationcould be made to encourage planning teams to include floor staff in the formative andsummative evaluations of an exhibit. This is especially relevant to science centres withlimited budgets and for whom a divide exists between floor staff and management.In this study, a formative evaluation of one exhibit was conducted, measuring both floorstaff’s perceptions of the visitor experience and visitors’ own perceptions of the exhibit.Floor staff were then trained on visitor evaluation methods. A week later, floor staff andvisitors were surveyed a second time on a different exhibit to determine whether anincrease in accuracy existed.The training session increased the specificity of the motivation and comprehensionresponses and the enthusiasm of the staff, but not their ability to predict observedbehaviours with respect to ergonomics, learning indicators, holding power, and successrates. The results revealed that although floor staff underestimated visitors’ success ratesat the exhibits, staff accurately predicted visitors’ behaviours with respect to holdingpower, ergonomics, learning indicators, motivation and comprehension, both before andafter the staff training.
485

Continuing airworthiness policy and application to flying crane aircraft

Gao, Fei 01 1900 (has links)
This project is part of a collaborative MSc training programme between the Aviation Industries of China (AVIC) and Cranfield University, aiming at enhancing the competitiveness of AVIC in both international and domestic aviation market through applying continuing airworthiness policies in the whole aircraft development process. The arrangement of the research project is that all students start with a Group Design Project which is based on the Flying Crane Project provided by AVIC. Individual research projects will address some aspects of the Flying Crane Project during the Group Design Project, and then further developed during the period for individual projects. The aim of this research is to apply the airworthiness requirements and the methodology of the Maintenance Steering Group logic (MSG-3) in the Flying Crane Project. This is because that maintenance is one of the key factors of Continuing Airworthiness, and MSG-3 logic is the most accepted and approved method to develop scheduled maintenance for civil aircrafts. The main objectives of this project include: (1) To investigate current Continuing Airworthiness regulations, including European airworthiness requirements (as the main regulation to comply with) and Chinese airworthiness regulations (as an important reference and supplement to the research); (2) To investigate the main analysis methodology of reliability and maintainability, including Damage Tolerance and Failure Mode and Effect Analysis (FMEA); (3) To analyse the data resulted from the Group Design Project using MSG-3 logic to produce a set of Continuing Airworthiness instructions, for the operator and maintenance organisation of the aircraft, from the design organization’s perspective; (4) To develop Continuing Airworthiness instructions for airline operators to compose maintenance programmes for Flying Crane aircrafts, including maintenance tasks and intervals for the selected airframe systems and structural components; and (5) To identify applicable maintenance organisations in China for Flying Crane aircrafts in accordance with both European and Chinese airworthiness requirements. On completion of this research, two aspects of Continuing Airworthiness have been investigated, including maintenance programme and maintenance organization. With MSG-3 logic, the author developed the maintenance plan for three structural components (fuselage skin panel, wing root joint, and fin-fuselage attachment) and one airframe system (fuel system) based on results from the Group Design Project. The author also investigated the Chinese domestic aircraft maintenance companies, and selected suitable maintenance organizations based on technical and economical criteria.
486

Utvärdering av styvhetsegenskaper hos ett nyutvecklat träbjälklag av limmade sidobräder / Evaluation of stiffness properties of a novel wooden floor system of glued side boards

Wadefur, Tommy, Karlsson, Viktor January 2007 (has links)
Idag blir det allt vanligare med träbyggnader högre än två våningar. Detta tillsammans med en modern arkitektur som ger stora öppna planlösningar ställer höga krav på bjälklagen i träbyggnader. Problematiken med långa spännvidder för bjälklag i trä är att klara kraven för svikt och nedböjning. Dessa krav måste uppfyllas för att säkerställa funktioner hos andra byggdelar och för att människor inte ska uppleva att golvet sviktar eller vibrerar på ett obehagligt sätt. Ett träbjälklag bestående av limmade balkar av sidobräder har utvecklats. Bjälklaget är utformat av balkar med I-tvärsnitt i primärriktningen och rektangulära balktvärsnitt i sekundärriktningen. Examensarbetet omfattar laborativa provningar och beräkningar dels för att bestämma en böjelasticitetsmodul för varje enskild limmad balk och dels för att bestämma styvhetsegenskaperna för bjälklaget. De limmade träbalkarna ingår i ett forskningsprojekt vid Växjö universitet finansierat av KK-stiftelsen, som syftar till att undersöka möjligheterna att tillverka en konkurrenskraftig produkt genom att i grönt tillstånd (otorkat) limma ihop bräder från stockens yttre delar till balkar. Balkarna levererades limmade och hyvlade till universitet där en böjelasticitetsmodul först bestämdes för varje enskild balk. Därefter monterades balkarna ihop till ett fullskaligt bjälklag som provades med olika försöksuppställningar/lastfall varvid deformationen mättes upp. Dessa deformationer blir underlag för att bestämma bjälklagets styvhet. Böjstyvheten i primärriktningen uppgår till 17,55 x 1012 Nmm2/m enligt beräkningar baserade på laborativa resultat. Böjstyvheten i sekundärriktningen uppgår till 4,5 % av primärriktningens böjstyvhet, dvs. 0,79 x 1012 Nmm2/m. Sammanfattningsvis kan man säga att böjstyvheten är hög i båda riktningar i jämförelse med vanliga träbjälklag. / In Sweden it becomes more and more common with wood buildings higher than two floors. This along with a modern architecture that gives big open plan solutions sets high requirements on the floor systems in wood buildings. The complexes of problems with long spans for floor systems in wood are to match the requirements for elasticity and deformation. These requirements must be met in order to ensure functions of other construction components, and not be unpleasant for people to walk on with respect to vibrations. A wooden floor system consisting of green glued side wood sections has been developed. The floor system is made with I-profiled beams in the primary direction and rectangular cross-sections in the secondary direction. This diploma work is based on that through elaborative testing and numeric calculations to decide the stiffness properties for each individual green glued side wood section and for the floor system. The glued side wood sections are included in a project at Växjö University, which is financed by the KK-foundation. The sections were delivered glued and planed to the university where the stiffness properties were first determinded for each individual section. Then, the sections were assembled to one fully sized floor system that was exposed to different experiments as the deformation was measured. These deformations were later used in order to decide the stiffness of the floor system. The stiffness in the primary direction was prescribed to 17,55 x 1012 Nmm2/m after calculations using results from the tests. The stiffness in the secondary direction amounts to 4,5% of the primary directions stiffness, i e. 0,79 x 1012 Nmm2/m. To sum up, one can say that the stiffness is high in both directions compared to regular wooden floor systems.
487

Utvärdering av styvhetsegenskaper hos ett nyutvecklat träbjälklag / Evaluation of stiffness properties of a novel wooden floor system

Dover, Pär, Berggren, Peter, Fahlgren, John January 2006 (has links)
I samband med att intresset för att bygga högre trähus har ökat så krävs nya lösningar för att t.ex. kunna möta efterfrågan på stora öppna ytor och långa spännvidder. Träbjälklag med lång spännvidd har dock oftast svårigheter med att klara kraven på svikt och vibrationer. Ett nyutvecklat förslag på träbjälklag som förmodas klara dessa krav bättre än traditionella träbjälklag har varit utgångspunkten för detta examensarbete där syftet har varit att undersöka bjälklagets styvhet. Detta gjordes laborativt genom att bygga och testa en prototyp av det föreslagna bjälklaget och genom att en numerisk modell baserad på finita element metoden togs fram och användes för att studera hur olika parametrar påverkar bjälklagets styvhetsegenskaper. Bjälklagets design bygger på fackverksprincipen i primärriktningen och på balkverkan i sekundärriktningen. De ingående komponenterna har kommit prefabricerade till Växjö universitet där de har monterats ihop till ett fullskaligt bjälklagselement. Elementet har sedan utsatts för ett antal belastningsfall där nedböjningarna uppmätts vilka sedan givit underlag för att få värden på bjälklagets effektiva styvhetsegenskaper. Både de laborativa och de simulerade resultaten visar på en hög böjstyvhet i primärriktningen d.v.s. 18,9•106 Nm2/m [EI/b] respektive 18,6•106 Nm2/m [EI/b]. Även böjstyvheten i sekundärriktningen är hög d.v.s. motsvarar 21,2 % respektive 17,1 % av styvheten i primärriktningen. I beräkningsmodellen har det dessutom undersökts hur ett övre lager av spånskivor inverkar på bjälklagets styvhet. / The interest for building higher and larger wooden houses has increased in Sweden during the last decade resulting in higher requirements on the technical performance of such structures in order to met demands on large open surfaces and large spans of floors. Wooden floor systems with large spans often have difficulties, however, to meet the vibration requirements. A novel floor system, likely to handle the vibration requirements better than traditional wooden floor systems, is the basis for this master thesis. The purpose is to examine the stiffness of the floor by building and testing a prototype and by producing a numerical model based on the finite element method. In the longitudinal, main load-bearing direction the floor system works as a truss with flanges of longitudinal oriented timber members and web diagonals of transversely oriented members. In the transverse direction the web diagonals work as beams. The components were prefabricated elsewhere and assembled at Växjö University into a prototype. The prototype was then exposed to a number of different load cases. Deflections were measured and stiffness properties of the floor were derived. In addition to the experimental analysis the numerical model was used to calculate deflections when subjected to different load cases and for evaluating the principal stiffness properties of the floor. Both the experimental and the calculated results using the numerical model show high bending stiffness in the longitudinal direction, EI/b = 18,9•106 Nm2/m and 18,6•106 Nm2/m respectively. Also the bending stiffness in the transversal direction is high and equivalent to 21,2 % or 17,1 % (testing and simulation respectively) of the bending stiffness in the longitudinal direction. Using numerical analysis, also the effect on the stiffness of adding an upper layer of a 22 mm particleboard was examined.
488

Självkompakterande betong : Ytjämnhet utan efterbehandling / Self-Compacting Concrete : Flat surface without after-treatment

Elofsson, Andreas, Hallin, Mikael January 2006 (has links)
Betonggjutning är ett tungt moment inom byggproduktion och entreprenörer har länge använt betong med flyttillsats för att få en mer lättarbetad betong. Ändå har det krävts långa arbetspass och många tungarbetade moment. Efter lasernivellering, vibrering, slodning och glättning har man kunnat uppnå en yta som nästan är helt jämn. Dock ej så jämn att avjämningsmassa kunnat elimineras för att inte få sviktande parkett eller buktande plastmattor. Självkompakterande betong (SKB), eller vibreringsfri betong som man först kallade den, forskades fram på 80-talet i Japan och dök upp i Sverige i slutet på 90-talet. Det är en betong som innehåller en flyttillsats och en så kallad filler vars gemensamma egenskaper ger en betong som har bibehållen homogenitet samtidigt som den fyller ut formen och omsluter armering endast genom gravitationskraften. SKB är ca 10-15 % dyrare än traditionell betong men har motiverats med framförallt minskad produktionstid, färre betongarbetare och bättre arbetsmiljö. Eftersom SKB mer eller mindre är flytande så blir jämnheten mycket god. Erfarenhetsmässigt har ytorna blivit i det närmaste perfekta efter lasernivellering, slodning och torrslipning. Trots stora konstaterade arbetsmiljövinster och vetskapen om den goda ytjämnheten har AB Färdig Betong i Karlstad endast levererat SKB till 8 projekt sedan 1997. Examensarbetets syfte är att fastställa om SKB kan motiveras baserat på den goda ytjämnhet som kan uppnås redan efter gjutning jämfört med normalpresterande betong (NPB). Examensarbetet har utförts i samarbete med Skanska Sverige AB i Karlstad, som under våren 2006 genomförde två projekt med SKB. Mätningar av ytor med SKB gjordes på Färjstad i Karlstad och mätningar av referensytor med NPB gjordes i Karlstad med omnejd. Mätningarna kompletteras med intervjuer i form av erfarenhetsåterföring från dem som tillverkat, levererat, mottagit, gjutit och efterbehandlat betongtypen. De krav på ytjämnhet av platsgjuten betong som generellt tillämpas återfinns i Hus AMA 98 och definieras som buktighet, lutning och nivåskillnad. Resultaten från mätningarna bedömdes i enlighet med Hus AMA 98, därefter har betongtypernas mätvärden analyserats och jämförts. Utifrån resultaten har bland annat följande slutsatser kunnat konstateras: Självkompakterande betong kan vid rätt handhavande ge en yta som uppfyller kraven enligt Hus AMA’s krav för undergolv i klass B utan varken vibrering, slipning eller efterbehandling. Användandet av SKB i större bostadsprojekt skapar stora förutsättningar för lägre totalekonomi jämfört med användandet av NPB. Detta baseras huvudsakligen på minskat behov av arbetskraft vid gjutning och efterbehandling av den gjutna ytan. De bekräftade möjligheterna för förbättrad ytkvalitet redan efter gjutning kommer i framtiden innebära att fler entreprenörer väljer SKB. / Concrete moulding is a heavy moment in the building process and for a long time contractors have used an admixture to create a concrete that is easier to handle. However many hours of work and heavy moments has been required. After laser levelling, vibrating, screeding and troweling a surface that is almost flat has been obtained. Yet not flat enough to eliminate floor levelling and thereby avoiding bending parquet flooring or curved plastic flooring. Self-compacting concrete (SCC), or vibrating free concrete as it was named in the beginning, was developed in the eighties in Japan and showed up in Sweden in the late nineties. It is a concrete that contains an admixture and filler that together makes the concrete flow under its own weight, completely filling the formwork and achieving full compaction, even in the presence of congested reinforcement. SCC is approximately 10-15 % more expensive than traditional concrete but is motivated with faster construction times, fewer workers and an improved work environment. Since SCC just about flows the resulting surface becomes almost perfect. Experience shows that surfaces are nearly perfect after laser levelling, screeding and dry smoothing. Despite the advantages of the flat surfaces and the established improvement on the work environment, AB Färdig Betong in Karlstad, Sweden has only delivered SCC to eight projects since 1997. The aim of this degree thesis is to determine if SCC can be motivated based on the flat surfaces that can be obtained after moulding compared to traditional concrete. The degree thesis has been performed in cooperation with Skanska Sverige AB in Karlstad, Sweden at their two projects with SCC in spring 2006. The measurement of SCC surfaces was made in Färjestad, Karlstad and reference measurements of traditional concrete was made in Karlstad and surroundings. The measurement have been complemented with interviews that present experience of producing, delivering, receiving, moulding and after treating SCC. The requirements for on site moulding concrete surfaces that are to be followed are found in Hus AMA 98 and is defined as curve, rake and level variance. The result from the measurements are judged on the basis of the requirements. Conclusions Correctly performed SCC can create a surface that fulfils the requirements in Hus AMA 98 for a class B floor. The use of SCC in larger housing constructions makes conditions for a lower total cost. This is based principally on fewer workers, faster construction times and less after treatment of the moulded surfaces. The confirmed possibilities of improved surfaces after moulding should mean that more contractors will use SCC in the future.
489

Development Of A Bidding Algorithm Used In An Agent-based Shop-floor Control System

Uluer, Muhtar Ural 01 January 2007 (has links) (PDF)
In this study a time based bidding framework is developed which is used for dispatching jobs to manufacturing resources in a virtual shop-floor environment. Agent-based shop-floor control approach is implemented with machine and part agents. The Contract-net communication protocol is utilized as the negotiation scheme between these agents. Single step product reservation (SSPR) technique is adopted throughout the study. Primary objective is determined as meeting the due dates and if the lateness is inevitable, avoiding the parts of high priority from being late. A balanced machine utilization rate is set as the secondary objective. During bid construction step, the SSPR technique is augmented with W(SPT+CR) sequencing rule in order to obtain weighted tardiness results. Bids containing Earliest Finishing Time (EFT) and machine loading values of the corresponding machine are evaluated with considering the priority of the part. An elimination algorithm which discards the highly deviated bids having obvious differences is implemented at the initial stage of the bid evaluation step. A basic algorithm to control the maximum tardiness value is applied, as well. A simulation test bed is developed in order to implement the time concept into the presented bidding framework. The test bed is mainly based on the Computer Integrated Manufacturing Laboratory (CIMLAB) located in Middle East Technical University, Department of Mechanical Engineering. The developed bidding algorithm is tested under several cases. Results revealed that the proposed bidding framework was quite successful in meeting the objectives. The study is concluded with some specific future work, outlined in the light of the results obtained.
490

Wärmeabgabe teilbeheizter Fußböden

Kremonke, André 16 September 2000 (has links) (PDF)
Mit Hilfe von experimentellen Untersuchungen wird nachgewiesen, daß sich die nutzerseitig abgegebene Wärmestromdichte des außenwandnahen Fußbodenbereiches nicht allein über die Differenz zwischen der Heizflächen- und Raumtemperatur beschreiben läßt. Die Ableitung verallgemeinerbarer Berechnungsansätze ist Schwerpunkt der Arbeit. Die experimentellen Untersuchungen erfolgen in einem Modellraum in Originalgröße. Meßtechnisch erfaßt werden die Oberflächentemperaturen, die Lufttemperaturverteilung, die Luftgeschwindigkeitsverteilung und die örtliche Gesamtwärmestromdichte der beheizten Fußbodenbereiche. Der konvektive Wärmeübergang wird maßgeblich von der über dem Fußboden umgelenkten Falluftströmung an der Außenwand beeinflußt. Zur Berechnung der örtlichen Maximalgeschwindigkeiten wird ein einfacher Berechnungsansatz entwickelt. Mit Hilfe numerischer Untersuchungen erfolgt ein Vergleich verschiedener Heizsysteme hinsichtlich der Empfindungstemperaturverteilung.

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