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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.
71

Kvalitet i stora infrastrukturprojekt : En kartläggning av brister och potentiella åtgärder i ett företags kvalitetsledningssystem

Svahn, Simon, Jernlund, Anna January 2019 (has links)
Adapting a strategy concerning quality management can be an effective means for organizations striving to enhance the quality which is delivered to its customers. Especially within large infrastructure projects, which concern products with considerable production costs and long technical life spans, tending to issues regarding quality becomes important. The ISO 9000 series offers a quality management standardization framework of which a plurality of organizations have certified themselves as being practitioners. The standard encompasses quality control, quality assurance, and quality improvement as core elements in quality management. The standard also integrates management of requirements as a fundamental part, and a prerequisite, for the quality work in general. Despite the framework supplied by the ISO 9000 series there are still degrees of freedom which introduces risk. By looking at how a certified company has implemented quality management in large infrastructure projects this study is aiming to identify eventual deficiencies within the quality systems employed, and potential measures which can remediate the deficiencies. Qualitative interviews and literature studies are used to form the empirical data.  Although the study confirms substantial quality management is undertaken in such ways the delivered quality appears to be enhanced, some issues emerge. The most comprehensive issue is confirmed as the need of the company to become less dependent on its client’s ability to provide comprehensive set of requirements. Undertaken projects in general could benefit by increasing the abilities within eliciting requirements from stakeholders, which could be achieved by integrating stakeholder analysis into the processes of the company.
72

Miljöförbättrande åtgärder inom asfaltproduktion : En sammanställning av asfaltbranschens aktuella tekniker / Environmental improvement measures in asphalt

Fors, Sofia January 2019 (has links)
This report deals with environmental improvement measures in asphalt production and examines the willingness to invest in environmentally friendly technologies. The main reasons of this paper are that the asphalt industry have a large impact on the environment and the transition to green technologies is slow, and to clarify the opportunities around environmentally friendly asphalt production. The main purpose of this report is to compile relevant knowledge in the improvement of the environmental measures of the asphalt production and thus contribute to a faster reduction of carbon dioxide emissions. The questions covered are: • How has the asphalt been used over time and until? • How does the asphalt industry effect the environment? • What are the technical solutions? • What are the costs of the different technical solutions? • What is the trend for more environmentally friendly asphalt production? The thesis was concluded through literature studies, consultations with people in the asphalt industry and trough several interviews. The results of the report show that there are many different measures to reduce the environmental impacts from asphalt production, and the main challenge for producers is to choose which method is most suitable for their company. The interviews report that the willingness to invest in environmentally improving techniques exists and that the trend to produce more environmentally friendly will increase. Increased requirements and a greater demand for environmentally friendly asphalt production from customers are desired.
73

Blockkedjan : Organisationers möjligheter och utmaningar

Wallin, Rickard January 2019 (has links)
Organizations wants to be at the top when it comes to using new technologies in order to retain a strong position on the market and also create innovative and unique service offerings. New technologies put pressure on organizations, that have to answer to its challenges. Blockchain is a new technology that is very well heard of, it is a complicated technology and is in constant development. The purpose of this study is to identify challenges that the blockchain technology brings to organizations as well what opportunities organizations are looking with the technology. There will also be discussions about potential opportunities that arise when organizations overcome the challenges and what the blockchain can contribute to digital services. / Organisationer vill vara ledande inom nya teknologier för att skapa unika tjänsteerbjudande och behålla drivkraft. Nya teknologier sätter press på organisationer som måste besvara dess utmaningar. Blockkedjetekniken är en omtalad teknologi som har fått stor uppmärksamhet de senaste åren, tekniken är komplicerad och i ständig utveckling. Syftet med denna studie är att identifiera utmaningar som blockkedjetekniken medför till organisationer samt vad organisationer ser för möjligheter med tekniken. Det kommer att diskuteras potentiella möjligheter som uppstår när organisationer överkommer utmaningarna och vad tekniken kan bidra med till digitala tjänster. I kombination med tidigare forskning och en kvalitativ studie som utförts hos en organisation som tillhandahåller digitala tjänster och som är intresserade att investera i blockkedjan har utmaningar och möjligheter identifierats.
74

VA-organisationers beslutsprocess om förnyelse av dagens VA-nät / Sewage system Managing Agencies' decision-making process on renewing today's sewage system networks

Erdestål, Marcus, Olsson, Anders January 2018 (has links)
Purpose: Rejuvenating the water and sewer system is called a renewal step, which is a planned replacement of ground wiring in the field, which restores the operation of the wiring or improves its capacity. Most of Sweden's VA pipelines are built in the 19th century. They are now in need to be renewed. The county's in Sweden finance and manage the VA networks using a VA-tax which is paid by all users. Sweden has had a low VA-tax for many years. A low VA tax can lead that county's are not afford to replace the existing pipeline network. The purpose is to provide the reader with the knowledge that Sweden's municipalities have at the renewal stage of the VA network, and the approach to the choice of prioritization measures. Method: The work has focused on qualitative and quantitative processing in form of literature studies, document analysis and interviews. The work contains seven qualitative semi-structured and five structured interviews. The document analysis shows a clear picture of the renewal and renewal needs in VA organizations. Findings: All requested VA managers use some type of GIS system, in the category of database-based decision support systems specified by Power (2002), as a way to handle and analyse large amounts of structured data. The municipalities that are most worried about not being able to finance the renewal act are the municipalities that are small and have less resources to work with, for example, fees, work teams and civil servants. In the question of what measures must be taken to increase focus on the existing VA network and a stepping stone to the renewal act. The VA tax should be designed more according to the actual cost, despite politicians consider. This in order to avoid shock increases in the farm fee that goes against a long-term planning. Implications: The report has focused on gaining insight into why the renewal rate is too low. This may have several reasons, however VA-organizations describe that they are not used to work in decision support systems and the importance of making decisions in combination with other methods. Limitations: This thesis shows only county's decision-making process and what kind of decision support system they have in use in their operations. The thesis focuses on why the renewal pact is not prioritized higher but does not go into detail why another priority is costlier or timelier to implement. Keywords: Decision-making process, Decision Support System, Lead network, Revenue, Renewable needs, Self-sufficiency, Sewer planning, Sewage System Taxes, Water Services Act.
75

OPTIMERING AV SAMVERKANSBROAR : En jämförande studie av stålbalkars tvärsnitt med avseende på bärighet, ekonomi och miljö.

Hellström, Martin January 2017 (has links)
Den här undersökningen strävar efter att ge en bild av möjligheterna för att minska materialmängden i samverkansbroar med hänsyn till kostnadsbesparing och miljöpåverkan. Kan mindre stål användas i balktvärsnittet med bibehållen kapacitet?   Objektet för undersökningen är en samverkansbro i Gallsbo, Borlänge som projekterats av konsultföretaget Tyréns i Uppsala. Tyréns valde att dimensionera en 1100 mm hög balk som senare kort efter dimensionerades om till 1300 mm, på förfrågan från Trafikverket för att minska materialkostnaden och miljöpåverkan. Men är det den mest optimala balkdimensionen? Går det att optimera balken ännu mera. Det förklarar intresset av att göra balken än högre, vilket även är anledning till det här examensarbetet. Genom att använda företagets beräkningsmetoder har ett nytt tvärsnitt med höjden 1500 mm dimensionerats med tillräcklig bärförmåga.   Resultatet visar att det är möjligt att optimera balken ytterligare och minska mängden stål i balken med tillräcklig bärförmåga i alla dimensioneringsavseenden. I vissa dimensioneringsaspekter ökar bärförmågan samtidigt som den minskar i andra i enlighet med Eurokod. Alla kontroller visar dock att bärförmågan är fullt tillräcklig. Kostnadsbesparingen som uppkommer vid minskat tvärsnitt bör dock jämföras med kostnaden för optimeringsarbetet av balken.
76

Trafiksäkerhetsförbättrande åtgärder för gång- och cykeltrafikanter i korsningen Hallgrensvägen – Timmerleden i Piteå

Lundgren, Elin January 2017 (has links)
No description available.
77

Mathematical modelling of jointed rock masses

Olofsson, Thomas January 1985 (has links)
In this thesis, a theoretical model of the mechanical behaviour of jointed rock masses is developed. An equivalent material approach is used to formulate the constitutive equations, where the structural components, intact rock and joints are assigned continuous material properties. The elastic and inelastic properties of the joints are modelled by an elasto-viscoplastic formulation. The model can be used to study general stress and strain paths for both two- and three-dimensional structures based on constitutive equations, i.e. stress-strain relations or in finite element codes. The rock mass model using the equivalent material approach can be applied to hard rock masses with several sets of intersecting continuous joints. The theoretical model developed for a single joint can also be used for discrete formulation of joint elements in finite element codes, cf. chapter 3. The intact rock is treated as a linearly elastic material. The elastic behaviour of the joint is modelled with a constant stiffness matrix. The onset of plastic flow is initiated when the normal stress exceeds the normal compressive strength of the joint asperities or the tensile normal strength of the joint. the shear stress exceeds the cohesive strength and frictional resistance of the joint surface. The normal tensile strength and the cohesion of the joints are assumed to be constant material properties. The frictional parameters the dilation rate, and the shear asperity angle, and the compressive normal strength are functions of the the compressive normal strength are functions of the applied stress field and joint displacement. Simple relations based on Barton's constants joint roughness coefficient, JRC, joint compressive strength, JCS, and the residual friction angle, 0r, simple relations are fitted to these parameters. This implies that input data to the model can be extracted from the Rock Mechanics literature for a wide variety of joints. Results from laboratory shear box test and numerical calculations has been made for a number of different joints. Good agreement was obtained. It shows, that peak shear strength behaviour of joint in principal is a function of dilation rate. Further, the calculations indicated that the elastic off-diagonal behaviour of joints, reported in the rock mechanics literature, is related to the dilation angle at the asperities in contact. By means of finite element technique the model is applied to a circular opening in a jointed rock mass. It is concluded that the model offers several advantages over a discrete formulation. / Godkänd; 1985; 20070502 (ysko)
78

Progressive landslides in long natural slopes : potential extension and configuration of finished slides in strain-softening soils

Bernander, Stig January 2000 (has links)
A finite difference method is presented for progressive slides in long natural slopes. The method is based on a strain softening material model. A detailed worked out example is given as well as examples using a spread sheet PC program and a PC program for Windows. Several Scandinavian slides are analysed and discussed as case studies e g Tuve (1977), Surte (1951), Bekkelaget (1953), Rollsbo (1967), Rävekärr (1971), Tre-styckevattnet (1990) and Svärtaån (1938). The nature of down-slope progressive failures in natural slopes is described and the applicability of ideal-plastic failure analysis is questioned. Principles and procedures for investigation potential landslides are presented. A short historical background to the landslide problem is given in an introductory chapter. / <p>Godkänd; 2000; 20070318 (ysko)</p>
79

Korrelationen mellan fuktkvot och brandspjälkning i sprutbetong i tunnlar : Ett förberedande arbete inför brandprovning / Correlation between moisture ratio and fire spalling in shotcrete in tunnels

Nessmar, Benjamin, Eriksson, Jakob January 2020 (has links)
To test the fire resistance of shotcrete, fire tests are performed. There are no euro codes or similar regulations for how the test bodies are to be handled and it is left to the client of the project to prescribe how the tests should be conducted. This sometimes entails unrealistic goals, unreasonable conditions and some room for own interpretations of how the samples are to be handled. Since the moisture in fire testing of shotcrete has a large impact, the moisture ratio in the concrete should be investigated. By extension, this means that the handling process and the drying time of the test bodies must be reviewed. This thesis establishes a management protocol for how the moisture ratio in test specimens in shotcrete should be investigated. The result of such a test must be able to support which drying times are reasonable to mimic the actual conditions of a tunnel in operation. The report also generally addresses the importance of conducting fire tests on shotcrete in tunnels according to the most realistic conditions possible. Therefore, it is important to investigate what requirements are set today in connection with fire tests of shotcrete and how reality-adapted they are.
80

Styrande dokument för rutiner som ska säkerställa mätnoggrannhet Fallstudie Väg 55

Hellsing, Linnea January 2013 (has links)
Allt professionellt mätningsarbete i Sverige styrs av olika dokument för att säkerställa att kvalitetskraven uppnås, anläggningsarbeten är inget undantag. Därför var syftet att sammanställa de objektspecifika kraven på väg 55 Yxtatorpet – Malmköping och undersöka vilka rutiner och kontroller som genomförs för att säkerställa kvaliteten. Litteraturstudier har gjorts för att sammanställa kraven, främst av dokument som finns på arbetsplatsen. Sökningar på Internet har gjorts främst för att hitta kravdokument som styr handlingarna på arbetsplatsen. Intervjuer genomfördes med 2 personer på arbetsplatsen, med olika arbetsuppgifter för att ta reda på om det finns rutiner och kontroller som genomförs och vilka dessa i sådana fall är. Resultatet blev en sammanfattning av styrande dokument speciellt de som gäller för väg 55. De styrande dokumentens krav på metoder och kontroll styrks av de två intervjuerna.

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