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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.
31

Assisted Tele-Remote Control of Wheel Loaders in Underground Mining

Dadhich, Siddharth January 2016 (has links)
Tele-remote operation of mobile earth-moving machines in underground mines supported byoperator assistance functions is attractive for safety and productivity reasons. This way, operatorscan avoid hazardous underground environments with poor air quality and the productivitycan, in principle, be improved by saving the time required to commute drivers to and fromthe operational areas. The infrastructure needed to do tele-remote control in the form of highcapacitywireless IP networks is nowadays being deployed in underground mines. In mineswith sufficiently high ceilings, wheel loaders are used in short loading cycles to load blastedrock onto dump trucks. Bucket filling on remote control is less efficient than manual operationdue to the loss of sensory perception resulting from not being in the actual environment.Automatic bucket filling algorithms have been developed earlier but, due to the complexity ofbucket-environment interactions, such algorithms have not produced satisfactory results and arenot commercially available. If tele-remote operation is enabled, it can also be used to rescuefuture autonomous machines, when they malfunction. This thesis presents the key challengesin automation and tele-remote operation of earth-moving machines, surveys the literature andavailable technologies to address these challenges. The key contributions of this thesis are highlightingimportant knowledge gaps based on a survey in the field of automation of earth-movingmachines and proposing a machine learning based framework for automatic bucket filling forfront-end loaders. The proposed machine learning based approach to automatic bucket fillinguses linear regression and classification models of lift and tilt actions, which are fitted to thebehavior of an expert driver filling the bucket with gravel pile. The models of operator behaviorfrom the recorded data reveals relationships between sensor data and operator actionsand shows that a learning based approach is feasible. A case study has been done on the useof wheel-loaders in underground mining presenting the use case of assisted tele-remote controlbased on audio-video and sensor feedback. A good communication setup, that considers requirementsof real-time video transmission, is important for tele-remote control. Furthermore,a simulation study evaluates two transport layer protocols with respect to video quality for teleremotecontrol over wireless IEEE 802.11 networks. It has been identified that adding operatorassistance functions to tele-remote control is a good approach towards autonomous operation ofearth moving equipment.i
32

Supporting the Embodied Energy Assessment in a BIM-driven Design Process

Shadram, Farshid January 2016 (has links)
Recent studies indicate that the embodied energy originating from the buildingmaterial supply chain (i.e. off-site production of materials and components andassociated transportation to the construction site) contributes significantly tothe total life-cycle energy use. Therefore, considering its impact during thebuilding design and pre-construction stage provides an opportunity to affect thebuilding energy use and sustainability performance. However, there are twomajor shortcomings with the life cycle assessment (LCA) tools used forassessment and reduction of the embodied energy use during the buildingdesign and pre-construction stage. (1) Many of the LCA tools use databasesbased on industry-average values which hinders the possibility to account forthe differences in the embodied impact of specific materials sourced fromindividual suppliers. (2) Lack of interoperability between the LCA tools andthe Building Information Modeling (BIM) software which has become an assetfor supporting decisions during building design and pre-construction. Thisinteroperability issue increases the amount of time and effort required forassessment of the embodied energy and also increases the risks for mistakes,misunderstandings and errors due to the manual re-entry of BIM data into the LCA tools. Therefore, the overall purpose of the research is to investigate the possibility tomitigate the aforementioned shortcomings by integrating the analyses of theembodied energy into a BIM-driven design process. Two research questionshave been defined: (1) What is a suitable data source for assessment of theembodied energy? (2) How can the embodied energy assessment be integratedinto a BIM-driven design process? To address the first research question in identifying a suitable data source forassessing the embodied energy, literature studies were conducted to provideinsights into the existing Life-Cycle Inventory (LCI) data used for assessmentof the embodied energy. To address the second research question, several caseswere studied using a prototyping approach which enabled the identification ofrequired processes and functions for supporting assessment of the embodiedenergy in a BIM-driven design process. The result of the literature studies and answer to the first research questionindicate that Environmental Product Declaration (EPD) of materials andcomponents can be recognized as a suitable data source for assessment of theembodied energy. EPDs provide a detailed LCA data for a specific productwhich is implemented according to Product Category Rules (PCR) and verifiedby an independent third party. PCRs provide pre-established guidelines andrequirements for the LCA of a certain product category and by this meanensure the principle for comparability of the LCA data. The main outcome ofthe second research question is a framework which highlights the requiredprocesses for facilitating and supporting assessment of the embodied energy ina BIM-driven design process. The framework uses the suppliers’ EPDs tosupport the design decisions and enable assessment of the embodied impactcaused by the building material supply chain. The framework also ensuresBIM-LCA interoperability by integrating the Extract, Transform Load (ETL)technology with BIM, enabling an automated or semi-automated assessmentprocess, to reduce the amount of time, efforts and risks for mistakes that wasreported to be the major obstacles within the embodied energy assessment.
33

Identifiering av avgörande faktorer för optimal intern bygglogistik : En fallstudie av tre byggarbetsplatser

Karlsson, Elsa, Wallentinsson, Ewelina January 2014 (has links)
Unlike the manufacturing industry, the construction industry is always in motion. Each new construction project brings new opportunities, and it requires a new plan, new organisation, and new suppliers. All construction projects are very different from each other and in terms of a logistical perspective, this is very weak as it makes it difficult to get a flow in the production and to make flawless routines. The way the external and internal logistics are managed, can effect the final product in the time taken to produce it, the quality of the product and the profit made from it. When internal logistics are handled poorly, it could result in materials not being at the right place at the right time, or information not going through to the right person. Small details such as these, can make the production time increase continuously with the price. Logistics is all about efficiency; to make things quickly and in a well organised manner. Although making things right is vastly important, it is also important to make things correctly as doing things quickly and efficiently becomes meaningless if there are activities that are unnecessary. The purpose of this report is to identify factors that are central to an efficient logistic on the construction site and which factors can be influenced by the construction site. However, the study does not include any concrete suggestions for improvement, but there will be some discussion around it. There are already some concepts and tools that can improve the logistics, for example, the use of Lean Construction and BIM. Logistics work should be included in all stages of the construction process: design, planning, production and managing of the actual building. This report mainly relates to the design- and production phase. There are different approaches and objectives when planning projects. A primary objective is to reduce costs. The main goal in logistics planning is to achieve short lead times, short set-up times, short transport distances, and eliminate waste. The result of the report is based on literature studies, observations, but mostly interviews. Three interviews were held with the management, i.e. the supervisors and site managers. The implementation has compiled information from interviews, observations and literature studies. It was discovered that there were many similarities, but also differences that separated the various projects. For example, it was found that a crane is an important asset for a smooth operation as it moves material around the site, but there is a lot of time wasting when unloading, partly due to the lack of communication. It also revealed that it is hard to know what operations to begin with at the construction of the framework. Conclusions drawn after work designing is planning and communication are two of the most important building blocks to get a smooth production both for functioning internal and external logistics. What has also emerged is the importance of accessibility and that doing the right things should come easy. An external factor that effect logistics a lot on the construction site is the demand, for example, of materials from their suppliers. The final conclusion raised is ultimately an improvement suggestion: apply a logistics manager to all types of construction projects, from the beginning and throughout the project.
34

Hållbart byggande genom standardiserad miljöledning / Sustainable construction through standardized environmental management

Thunmarker, Josefine January 2017 (has links)
Miljö och hållbarhetsfrågor utgör en stor del av det samhället måste ta hänsyn till. För byggföretagen får dessa frågor en stor påverkan på verksamheten. Dels på grund av omfattande lagstiftning men också som en följd av att samhället blivit mer miljömedvetet. I Sverige står byggsektorn för en stor del av utsläppen av växthusgaser och för en stor del av den totala energianvändningen. För att kunna hantera de frågor som finns kopplade till miljöområdet använder sig företag och organisationer av miljöledningssystem som är förankrade i verksamheten. Dock är frågan om det finns någon vinning med att använda sig av sådana system och om det finns motiv att försöka certifiera dem enligt exempelvis ISO 14001 eller EMAS. Det finns också möjligheter att miljöcertifiera byggnader enligt olika system. Gemensamt för de systemen är att energiaspekter har en stor del i betygsunderlaget för byggnaden. Utifrån det går det att fråga sig om det finns någon skillnad mellan de projekterade värdena och uppmätta värden för en byggnad och vad avvikelser kan härledas till för orsaker. Detta arbete grundar sig på en litteraturstudie och en fallstudie av ett byggprojekt. Utifrån litteraturen går det att se att det finns fördelar i användandet av miljöledningssystem och i att certifiera systemen enligt en given standard. Ett område som särskilt tycks gynnas av de rutiner som kommer ur ett miljöledningssystem är avfallshanteringen. Detta på grund av att det är billigare för byggföretaget att lämna ett välsorterat avfall än ett blandat. Fallstudien visar att det fanns en skillnad mellan beräknade och uppmätta värden för energianvändning. Det är svårt att avgöra hur stor avvikelse som kan accepteras, men det är mycket viktigt att härleda varifrån avvikelserna härstammar. Framförallt för att kunna se om det går att göra något åt dem, men också för att ta lärdom och undvika liknande problem i framtiden. / Environment and sustainability issues constitute a large part of what society must consider. For construction companies, these issues have a major impact on the business. Partly due to extensive legislation but also as a result of the community becoming more environmentally conscious. In Sweden, the building sector accounts for a large part of greenhouse gas emissions and for a large part of total energy use. In order to handle the issues related to the environment, companies and organizations use environmental management systems. However, the question is whether there is any gain in using such systems and if there are motives to try to certify them, for example, according to ISO 14001 or EMAS. It is also possible to use environmental certification of buildings according to different systems. Common to these systems is that energy aspects have a large part in the rating base for the building. Based on this, it is possible to ask if there is a difference between the projected values and the measured values for a building and what deviations can be derived. The work is based on a literature study and a small case study . Based on the literature, it can be seen that there are advantages in the use of environmental management systems and in certifying the systems according to a given standard. An area that appears to be particularly beneficial from the routines that come from an environmental management system is waste management. Because it is cheaper for the construction company to ship a well-sorted waste than a mixed one. The case study shows that there was a difference between calculated and measured values for energy use. It is difficult to determine how much deviation can be accepted, but it is very important to derive from where the deviations originate. Especially to see if they can do something about them, but also to learn and avoid similar problems in the future.
35

EGENKONTROLLER OCH FUKT, EN DEL I KVALITETSARBETET / QUALITY CONTROL AND MOUISTURE, A PART IN THE QUALITYWORK

Amir, Halmat, Björk, Chritian January 2013 (has links)
För att kunna garantera hög kvalité på en slutprodukt är det viktigt att kvalitetsarbetet beaktas under produktionen. Kvalitetsarbete påverkar företaget på ett positivt sätt genom att säkerstäl-la nöjda kunder och bidra till både ett gott rykte och en god ekonomi. NCC misstänker att det förekommer bristfälligt kvalitetsarbete under produktion i byggbranschen och gav oss därför i uppdrag att undersöka hur deras arbete med detta fungerar. I examensarbetet har intervjuer gjorts ute på fem av NCC:s pågående projekt i Örebro län för att ge en bild av hur arbetet med egenkontroller och fukt ute på byggarbetsplatserna fungerar. Vi har kartlagt hur arbetstagarna jobbar med egenkontroller och fukt i produktion, om det finns några brister i arbete och i så-dana fall vad det beror på. Kartläggningen visar att upprättningen av mallarna till egenkon-troller behöver förbättras, dels beror det på tidsbrist och NCC:s verksamhetssystem som är begränsat. Det största problemet som de flesta upplever med kvalitetsarbete överlag är att det inte finns tillräckligt med tid för det. / To ensure a high quality of the final product it’s important that quality work is considered during the production. Quality work affects the company in a positive way by making our customers happy, improving and retaining our good reputation and leads to a good economy. NCC suspects that there’s insufficient quality work during production in the construction in-dustry across the country and based on that they want us to examine how they’re handling this. In this thesis we’ve done the interviews on five of NCC's ongoing projects in Örebro County in order to provide a picture about how the process of quality controls and moisture at the construction sites works. We’ll identify how employees work with their quality controls and moisture during the production, if there are any deficiencies in the work and in such case what’s causing it.
36

Produktivitetsmätningar som förbättringsverktyg : en kartläggning av arbetsproduktivitetsmätningar på svenska byggarbetsplatser

Forsberg, Azam January 2008 (has links)
The Swedish construction industry has over the last few years been criticized for its high increase of production costs, poor quality and low productivity. Productivity improvements within the Swedish construction industries are lower than that of other comparable industries. Some researcher argue that two thirds of production activities in the construction industry do not produce value and causes low productivity improvement.The purpose of this research was to investigate types of labour performance in order to improve the production process in the Swedish construction industry. The study focused on measuring labour productivity as labour wages constitute a large part of the production cost.Five benchmarking studies were performed within companies and organisations outside of the traditional Swedish construction industry to examine their work process as far as improving labour productivity is concerned. Later a survey was performed among 74 respondents in five Swedish construction companies to investigate their ways of using labour productivity measurements. Finally five senior executive officials were interviewed to find out their point of view in the field of developing productivity in their companies.The result shows that measurement of labour productivity has an important role within the Swedish construction companies. The key factors to succeed in productivity improvement are the measurement of labour productivity and the follow-up of the results obtained. It is important that company management conveys the importance of improving productivity to all levels in the company. / Byggproduktionskostnaderna i Sverige har under de senaste åren ökat snabbare än kostnaderna inom flera andra områden. Snabbt ökande produktionskostnader tillsammans med bristande kvalitet har också uppmärksammats av bland annat statliga utredningar. Flera forskare hävdat att en stor del av arbetstiden åtgår till icke värdeskapande arbete och detta leder till låg produktivitet. I jämförelse med andra jämförbara branscher har byggindustrin i Sverige haft en sämre produktivitetstillväxt under senare år. Syftet med detta forskningsprojekt är att undersöka former för hur ett produktivitetsarbete kan effektivisera byggprocessen hos de svenska byggföretagen. Ett led i en förbättring av produktiviteten är att mäta och utvärdera resultaten av mätningarna. Eftersom en stor del av de totala byggkostnaderna utgörs av arbetskraftskostnader, fokuserades undersökningen på mätning av arbetsproduktiviteten. Studien bygger på benchmarking, enkät och intervjuer som primära empiriska källor. Benchmarkingstudien genomfördes i fem företag och organisationer utanför de traditionella byggföretagen för att se hur andra använder mätningar av arbetsproduktiviteten som ett hjälpmedel i förbättringsarbetet. Enkätundersökningen utfördes hos 74 respondenter i fem olika svenska byggentreprenadföretag. Fem fördjupande intervjuer utfördes hos företagsledare inom samma byggföretag. Resultatet av studien visar att mätning av arbetsproduktiviteten fyller en viktig roll. För att kunna åstadkomma förbättringar krävs att man arbetar målmedvetet med mätning och uppföljning av arbetsproduktiviteten. På mer parten av de svenska byggarbetsplatser som enkätstudien omfattande genomfördes också någon form av mätning av arbetsproduktiviteten. Syftet med dessa mätningar och användningen av resultaten varierade emellertid avsevärt. På samma sätt fanns betydande skillnader emellan hur respondenterna i enkätstudien svarade och hur företagsledarna i intervjustudien svarade. För att kunna åstadkomma förändringar fordras att företagsledningarna prioriterar ett strukturerat produktivitetsarbete i sina företag och kommunicerar detta i sina organisationer. Nyckelfaktorer för att lyckas med produktivitetsutveckling är mätning och uppföljning. / Godkänd; 2008; 20080325 (ysko)
37

A design process perspective on the energy performance of buildings

Schade, Jutta January 2013 (has links)
From a sustainable development perspective, buildings should be designed to be as energy-efficient as possible, as the contribution of buildings to total energy consumption has steadily increased, reaching between 20% and 40% in the developed countries. One of the main challenges for achieving this goal is to develop more cost-effective systems and processes for energy renovation and modernising of the building stock of Europe. This challenge is addressed in this thesis. The research presented herein has had the overall purpose to identify and explore obstacles in the design process of constructing more energy-efficient buildings. Three research questions have guided the research work: (1) How can life cycle cost be used to predict the cost benefits of energy efficient buildings?; (2) How can the handling of energy performance requirements in the design process for buildings be improved?; (3) How do client requirements, political governance and regulations affect the design of energy performance in buildings? The research is based on literature reviews, interviews and surveys, as well as case and computational studies. A computational study was performed with three different building types situated in Finland using three different energysaving design concepts for each building. Energy consumption and construction costs were analysed for each case and the financial viability was analysed using the discounted payback method. Individual interviews were carried out to determine to what extent life cycle cost calculations are used in the construction sector and how energy performance is taken into account in model-based design processes for buildings. A decision-making framework and an axiomatic design model for a performance-based design process was then developed and the conceptual model was compared with a real case of low energy design in Sweden. Finally, a survey explored energy conservation strategies in the design of buildings in Germany and Sweden and a longitudinal investigation of key policy instrument regarding energy conservation in Germany and Sweden was conducted to support the main findings of the survey. The main results of the research work show that: * There is no evidence that the design of energy performance is considered differently in the design process for buildings in Sweden and Germany, even if regulations and building codes differ between the two countries. However, the somewhat steeper reduction in space heating in Germany compared with Sweden could be due to the stricter regulation in the building codes in Germany over the last decade. * The transparency of the design and the associated decision-making about energy performance can be improved by using the requirement management model developed, which is based on axiomatic principles and the proposed decision-making framework for evaluating, structuring and detailing the requirements from the conceptual to the detailed design stages. * Energy performance design can give cost benefits over a specific time for a building, as measured by the resulting life cycle costs. In general, life cycle cost analysis can be a tool for evaluating cost benefits over time and provide support for the decision-makers, but the challenges and uncertainties of its use have to be taken into account in the decision-making process. To conclude, the "energy gap" between regulations and what is technologically possible can be reduced to a certain extent by facilitating the energy design process with a performance-based design process and decision-making tools that support the evaluation of life cycle performance. However, it seems that regulation is a more important driver for the development of technology for low energy housing than market forces so the regulatory limit should therefore be set with respect to what is possible and not with respect to current practice. / <p>Godkänd; 2013; 20121121 (jutsch); Disputation Ämne: Byggproduktion/Construction Engineering Opponent: Professor Johnny Kronvall, Strusoft AB/Malmö högskola, Malmö Ordförande: Professor Ove Lagerqvist, Institutionen för samhällsbyggnad och naturresurser, Luleå tekniska universitet Tid: Torsdag den 7 februari 2013, kl 10.30 Plats: F1031, Luleå tekniska universitet</p>
38

Erfarenhetsåterföring inom markanvisningsprocessen / Experience feedback in the Swedish land allocation system

Gustavsson, Simon, Gustafsson, Petter January 2017 (has links)
No description available.
39

Critical Path &amp; Line of Balance : Olika byggprojekt kräver olika planeringsmetoder

Axelsson, Malin, Svanberg, Nina January 2017 (has links)
The construction industry is currently known for projects often being delayed. Since planning is very important for the whole building project, it is very important that this is done correctly. More time should be put to plan the different projects so that the project should go on as smooth and efficient as possible. By using improved planning methods, you can contribute to a more efficient production on the construction site with less disturbances and corrections of errors. The purpose with this study is to compare the two planning methods, Critical Path and Line of Balance, and compare its strengths and weaknesses with each other. Hopefully, this study also contributes to development opportunities in planning in the construction sector. The result of the study has shown that Critical Path is a well-developed method that is best suited to non- repetitive projects such as construction of villas, schools and other unique projects. Line of Balance is better suited to projects with repetitive activities, for example construction of highways or the production of high-rise buildings.
40

Ett fall för fall A - En studie över hantering av schaktmassor vid anläggningsarbeten

Eneroth-Ädel, Joel, Bäsén, Sebastian January 2017 (has links)
No description available.

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