<p>Models based on micro-simulation of traffic flows have proven to be useful tools in the study of various traffic systems. Today, there is a wealth of traffic microsimulation models developed for freeway and urban street networks. The road mileage is however in many countries dominated by rural highways. Hence, there is a need for rural road traffic simulation models capable of assessing the performance of such road environments. This thesis introduces a versatile traffic micro-simulation model for the rural roads of today and of the future. The developed model system considers all common types of rural roads including effects of intersections and roundabouts on the main road traffic. The model is calibrated and validated through a simulation study comparing a two-lane highway to rural road designs with separated oncoming traffic lanes. A good general agreement between the simulation results and the field data is established.</p><p>The interest in road safety and the environmental impact of traffic is growing. Recent research has indicated that traffic simulation can be of use in these areas as well as in traditional capacity and level-of-service studies. In the road safety area more attention is turning towards active safety improving countermeasures designed to improve road safety by reducing the number of driver errors and the accident risks. One important example is Advanced Driver Assistance Systems (ADAS). The potential to use traffic simulation to evaluate the road safety effects of ADAS is investigated in the last part of this thesis. A car-following model for simulation of traffic including ADAS-equipped vehicles is proposed and the developed simulation framework is used to study important properties of a traffic simulation model to be used for safety evaluation of ADAS. Driver behavior for ADAS-equipped vehicles has usually not been considered in simulation studies including ADAS-equipped vehicles. The work in this thesis does however indicate that modeling of the behavior of drivers in ADAS-equipped vehicles is essential for reliable conclusions on the road safety effects of ADAS.</p> / Report code: LiU-Tek-Lic-2005:60.

<p>Operators of public transport always try to make their service as attractive as possible, to as many persons as possible and in a so cost effective way as possible. One way to make the service more attractive, especially to elderly and disabled, is to offer door-to-door transportation. The cost for the local authorities to provide this service is very high and increases every year.</p><p>To better serve the needs of the population and to reduce the cost for transportation of elderly and disabled, public transportation systems are evolving towards more flexible solutions. One such flexible solution is a demand responsive service integrated with a fixed route service, together giving a form of flexible public transport system. The demand responsive service can in such a system be used to carry passengers from their origin to a transfer location to the fixed route network, and/or from the fixed route network to their destination.</p><p>This thesis concerns the development of a framework for evaluation and design of such an integrated public transport service. The framework includes a geographic information system, optimization tools and simulation tools. This framework describes how these tools can be used in combination to aid the operators in the planning process of an integrated service. The thesis also presents simulations made in order to find guidelines of how an integrated service should be designed. The guidelines are intended to help operators of public transport to implement integrated services and are found by evaluating the effects on availability, travel time, cost and other service indicators for variations in the design and structure of the service.</p><p>In a planning system for an integrated public transport service, individual journeys must in some way be scheduled. For this reason the thesis also presents an exact optimization model of how journeys should be scheduled in this kind of service.</p> / Report code: LiU-TEK-LIC- 2006:38

På IKEA går produktionsflödet för en produktbild i dagsläget från konstruktionsritning till fotografering via tillverkning och montering. En produkt som är färdig för tillverkning definieras av sin mekaniska konstruktion och sina ytegenskaper. Ledtiden och kostnaden för bildproduktionen skulle kunna minskas betydligt om produkten kunde avbildas redan i detta stadium, utan att finnas tillverkad. För detta ändamål såg IKEA en möjlighet i att introducera ett nytt produktionsflöde där avancerad datorgrafik, grafisk teknik och bildbehandling omvandlar konstruktionsritningen till produktbild. Ambitionen är att från ritningen ta ut en 3D-modell, placera den i en omgivning, ljussätta och belägga den med material och av detta skapa en tryckbar produktbild som uppfyller företagets höga kvalitetskrav. Syftet med examensarbetet var att ta fram förslag på ett konkret sådant flöde genom att undersöka olika programvaror som skulle kunna användas samt att identifiera problemområden och komma med lösningsförslag på dessa. Flödet delades upp i de fem problemområdena konvertering, modellering, ljussättning, material och rendering som bearbetades parallellt. Fokus har under hela projektet legat på färghantering och upplevd bildkvalitet genom att korrekt färg- och detaljåtergivning i bilderna varit pekpinne och ledsagare. Konstruktionsritningarna som görs i SolidWorks har konverterats till 3D-modeller med programvaran PolyTrans. I 3ds max har produktmodellerna satts in i en miljö som liknar den verkliga fotostudion, belysts och belagts med material. Efter en studie av olika programvaror för rendering beslutades det att mental ray skulle användas varpå alla bilder skapats med denna. mental ray är en komplex renderare som beräknar ljussättning fysikaliskt riktigt vilket bidrar till fotorealistiska bilder. Examensarbetet handlade till mångt och mycket om att köra olika produkter genom flödet och testa med olika inställningar i de olika stegen. Flödet utvärderades kontinuerligt genom att bilderna som kom ut bedömdes visuellt. Dessutom genomfördes några tester för att undersöka inblandade programvarors eventuella brister vad gäller färghantering och upplevd bildkvalitet. Det slutliga resultatet av examensarbetet blev ett flöde som i stor utsträckning liknar arbetsflödet vid nuvarande bildproduktion. Med minimal insats från retuschavdelningen uppfyller bilderna de krav som ställs för att de skall kunna tryckas i IKEA katalogen.

<p>Intensive competition on the global market puts great pressure on manufacturing companies to develop and produce products that meet requirements from customers and investors. One key factor in meeting these requirements is the efficiency of the product development and the production preparation process. Design automation is a powerful tool to increase efficiency in these two processes.</p><p>The benefits of automating the production preparation process are shortened led-time, improved product performance, and ultimately decreased cost. Further, automation is beneficial as it increases the ability to adapt products to new product specifications with production preparations done in few or in a single step. During the automation process, knowledge about the production preparation process is collected and stored in central systems, thus allowing full control over the design of production equipments.</p><p>Three main topics are addressed in this thesis: the flexibility of design automation systems, knowledge bases containing conflicting rules, and the automation of the finite element analysis process. These three topics are discussed in connection with the production preparation process of rotary draw bending.</p><p>One conclusion drawn from the research is that it is possible to apply the concept of design automation to the production preparation process at different levels of automation depending on characteristics of the implemented knowledge. In order to make design automation systems as flexible as possible, the concept of object orientation should be adapted when building the knowledge base and when building the products geometrical representations. It is possible to automate the process of setting up, running, and interpreting finite element analyses to a great extent and making the automated finite element analysis process a part of the global design automation system.</p>

<p>Kärnkraften ser vi som ett miljövänligt och bra alternativ för framtiden. Därför kändes det intressant att undersöka om vi som blivande sjöingenjörer har en framtid där efter våran karriär till sjöss. Syftet med detta arbete är att få ökad insikt om vilka teoretiska kunskaper, praktiska och personliga egenskaper som gör sjöingenjören attraktiv i ledande befattningar vid kärnkraftsverk. Datainsamlingen skedde med hjälp av en enkätundersökning och en intervju. Undersökningen skickades ut till Sveriges samtliga kärnkraftverk och intervjun gjordes med en anställd på ett utav dem. Detta citat ifrån en av undersökningens respondenter kan sammanfatta vår slutsats. ” Sjöingenjörsprogrammet är en mycket attraktiv utbildning för oss!”. Detta resultat, kan bero på den stora bristen och ointresse från unga att läsa till ingenjörsyrken, samt ingenjörernas höga medelålder och kommande pensionsavgångar.</p> / <p>It is our belief that nuclear power constitutes a future environmentally friendly alternative power source. Based on this conviction, our study was conducted with the principal aim of investigating whether or not a marine engineer would be eligible for employment at a nuclear power plant in Sweden after having ended his sea-going career.</p><p>The primary objective of our investigation was to examine what type of theoretical knowledge that the nuclear industry required. Furthermore, we also wanted to find answers to questions related to such requirements as practical and personal characteristics. Overall, we wanted to find out what personal and educational qualities that were needed to make marine engineers attractive as prospective employees for the nuclear power industry.</p><p>The collection of data was primarily made with the help of a questionnaire, which was sent to all nuclear power plants in Sweden. We also conducted an in-depth interview with one nuclear power plant employee.</p><p>The conclusion of our investigation into this field of possible future employment for a marine engineer can be deduced from the answer given by one of the questionnaire respondents: “The marine engineering programme is a very attractive education for us.”</p><p>The latter answer together with our general conclusions from the questionnaire, substantiate the fact that marine engineers will be plausible candidates for employment at nuclear power plants in the future.</p>

Cleavage fracture in ferritic steels can be defined as a sequence of few critical steps. At first nucleation of a microcrack takes place, often in a hard inclusion. This microcrack then propagates into the surrounding matrix material. The last obstacle before failure is the encounter of grain boundaries. If a microcrack is not arrested during any of those steps, cleavage takes place. Temperature plays an important role since it changes the failure mode from ductile to brittle in a narrow temperature interval. In papers A and B micromechanical models of the last critical phase are developed (cleavage over a grain boundary) in order to examine the mechanics of this phase. An extensive parameter study is performed in Paper A, where cleavage planes of two grains are allowed to tilt relative each other. It is there shown that triaxiality has a significant effect on the largest grain size that can arrest a rapidly propagating microcrack. This effect is explained by the development of the plastic zone prior to crack growth. The effect of temperature, addressed through a change in the visco-plastic response of the ferrite, shows that the critical grain size increases with the temperature. This implies that with an increasing temperature more cracks can be arrested, that is to say that less can become critical and thus that the resistance to fracture increases. Paper B shows simulations of microcrack propagation when the cleavage planes of two neighboring grains are tilted and twisted relatively each other. It is shown that when a microcrack enters a new grain, it first does it along primary cleavage planes. During further growth the crack front is protruded along the primary planes and lags behind along the secondary ones. The effect of tilt and twist on the critical grain size is decoupled with twist misorientation offering a greater resistance to propagation. Simulations of cracking of a particle and microcrack growth across an inclusion-matrix interface are made in Paper C. It is shown that the particle stress can be expressed by an Eshelby type expression modified for plasticity. The analysis of dynamic growth, results in a modified Griffith expression. Both findings are implemented into a micromechanics-based probabilistic model for cleavage that is of a weakest link type and incorporates all critical phases of cleavage: crack nucleation, propagation over particle-matrix interface and into consecutive grains. The proposed model depends on six parameters, which are obtained for three temperatures in Paper D using experimental data from SE(B) tests. At the lowest temperature, -30° , the model gives an excellent prediction of the cumulative failure probability by cleavage fracture and captures the threshold toughness and the experimental scatter. At 25º  and 55º  the model slightly overestimates the fracture probability. In Paper E a serie of fracture experiments is performed on half-elliptical surface cracks at 25º in order to further verify the model. Experiments show a significant scatter in the fracture toughness. The model significantly overestimates the fracture probability for this crack geometry. / QC 20100910

Derome Skog AB is a purchase company whose main task is to provide Derome Timber's sawmills in Halland with timber raw material. Because of the very hard competition in the roundwood market it is important to know what kind of purchase offers are required in order to buy a valuable product from forest owners. This study aims to elucidate the crucial factors when private forest owners choose to harvest and sell their forest. As base for this study, a questionnaire has been performed with private forest owners. The result of the study shows that it is not particularly often that the timber price is the crucial factor why the forest owners choose to harvest and sell the forest products; i.e. timber, pulpwood as well as energy assortments. Most often, it is entirely other reasons which drive the forest owner to harvest. The price of timber is however very important and can very well be the factor that determine to whom the forest owner chooses to sell his timber.

Kärnkraften ser vi som ett miljövänligt och bra alternativ för framtiden. Därför kändes det intressant att undersöka om vi som blivande sjöingenjörer har en framtid där efter våran karriär till sjöss. Syftet med detta arbete är att få ökad insikt om vilka teoretiska kunskaper, praktiska och personliga egenskaper som gör sjöingenjören attraktiv i ledande befattningar vid kärnkraftsverk. Datainsamlingen skedde med hjälp av en enkätundersökning och en intervju. Undersökningen skickades ut till Sveriges samtliga kärnkraftverk och intervjun gjordes med en anställd på ett utav dem. Detta citat ifrån en av undersökningens respondenter kan sammanfatta vår slutsats. ” Sjöingenjörsprogrammet är en mycket attraktiv utbildning för oss!”. Detta resultat, kan bero på den stora bristen och ointresse från unga att läsa till ingenjörsyrken, samt ingenjörernas höga medelålder och kommande pensionsavgångar. / It is our belief that nuclear power constitutes a future environmentally friendly alternative power source. Based on this conviction, our study was conducted with the principal aim of investigating whether or not a marine engineer would be eligible for employment at a nuclear power plant in Sweden after having ended his sea-going career. The primary objective of our investigation was to examine what type of theoretical knowledge that the nuclear industry required. Furthermore, we also wanted to find answers to questions related to such requirements as practical and personal characteristics. Overall, we wanted to find out what personal and educational qualities that were needed to make marine engineers attractive as prospective employees for the nuclear power industry. The collection of data was primarily made with the help of a questionnaire, which was sent to all nuclear power plants in Sweden. We also conducted an in-depth interview with one nuclear power plant employee. The conclusion of our investigation into this field of possible future employment for a marine engineer can be deduced from the answer given by one of the questionnaire respondents: “The marine engineering programme is a very attractive education for us.” The latter answer together with our general conclusions from the questionnaire, substantiate the fact that marine engineers will be plausible candidates for employment at nuclear power plants in the future.

Intresset för biobränsleproducerad energi har ökat i takt med att kunderna blivit mer miljömedvetna. På grund av detta har efterfrågan på briketter ökat samtidigt som träindustrin har haft det svårt i en sviktande konjunktur. Därför har ett examensarbete utförts i samarbete med E.ON Värme Sverige AB där undersökningar på bränslebyte i pannor avsedda för torra bränslen till fuktigare, stamvedflis har utfört. För denna undersökning har begränsningar införts på övre och undre effekt i form av uppehållstid och slutförbränningstemperatur. Intervallen är enbart beräknade på stamvedflis med 30 och 40 % fukthalt. Undersökning visar att det går bra att elda stamvedsflis i briketteldade pannor utan att emissionerna ökar så pass mycket att villkoren för anläggningarna överskrids om lasten hålls inom vissa intervall. Det möjliga effektintervallet ökar med minskad fukthalt på bränslet. Undersökningen har visat att det är bränslets kvalitet som är den mest begränsande faktorn. / The interest in bioenergy has increased with increased environmental awareness. The increasing demand on biofuels and the decreasing availability of the rawmaterials for making refined biofuels such as wood briquettes and wood pellets have caused the prices of these biofuels to increase. This report is performed in collaboration with E.ON Värme Sverige AB and its purpose is to investigate the possibilities for a change of fuels in existing boilers designed for refined biofuels, from wood briquettes to wood chips. To be able to calculate a power interval where it would be possible to use wood chips with moisture contents of 30 and 40% by weight respectively, we had to make some assumptions regarding maximum flue gas flow, minimum retention time and the lowest temperature regarding complete combustion of CO. Our calculations show that it is possible to use woodchips with a moisture content of 30 % w/w without any significant problems in all our boilers. When the moisture content is increased to 40 % w/w the interval for possible power output becomes more narrow. The amount of dust that is being emitted from the boilers does not exceed the limits regulated by environmental law, unless the thermal load of the boiler is too high. The single most important factor for a successful change of fuel from wood briquettes to woodchips is that the fuel quality is good.

Trots att isen lagt sig på Bottenhavet avstannar inte handeln med de norrländska hamnarna. Många av de fartyg som anlöper dessa hamnar har som primär överlevnadsfarkost en frifallslivbåt, en typ av livbåt som av experter har blivit utdömda som värdelösa i samband med is. Även fartygens sekundära överlevnadssystem, som består av uppblåsbara flottar, har blivit kritiserat. Syftet med detta arbete var att undersöka vad svenska rederier med fartyg som bär denna typ av livbåt har för beredskap inför en eventuell nödsituation i isen.   Undersökningen har grundats på en kvalitativ intervjustudie med representanter från tre svenska rederier som bedriver vintersjöfart. Studien har visat på stora skillnader mellan de olika rederierna gällande rutiner för att operera i is. Inget av rederierna som intervjuats har haft en speciell plan för övergivandet av fartyg i isförhållanden, trots att de har en säkerhetsorganisation som blivit godkänd av den svenska Transportstyrelsen. / Even though the ice has formed on the Gulf of Bothnia the trade with the northern ports of Sweden and Finland does not cease. Many of the ships calling these ports have their primary survival craft in form the of a freefall lifeboat, a survival craft that experts have condemned as useless in ice. Even the ship's secondary survival system consisting of inflatable rafts has been criticized. The purpose of this study was to examine what kind of plan Swedish shipping companies, who operate vessels that carry this type of lifeboat, have to deal with a possible emergency situation in the ice. The study was based on qualitative interviews with representatives from three Swedish shipping companies operating in winter conditions. The study revealed great differences between the various companies in routine procedures when operating in ice. None of the interviewed companies had a special plan for the abandonment of ships in ice conditions, although they have a safety organization approved by the Swedish Transport Agency.