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Increasing marketing and legislative requirements put heavy demands on the environmental performance of future transportation solutions. The resulting need to reduce total environmental impacts presents both challenges and opportunities to the transport sector as a whole, including the automotive industry. Life cycle assessment (LCA) is commonly used to evaluate environmental performance in the automotive industry. However, the static nature of LCAlimits its usefulness for capturing dynamic environmental consequences in the manufacturing and operational phase. This thesis proposes a simulation-based approach to LCA that addresses this problem. Selected real-world case studies demonstrate the potential of the approach in both vehicle production processes and end-user applications. The work was preceded by a comprehensive review of the potential benefits and challenges of using simulation-based LCA in production processes. This review laid the foundation for the development and implementation of this method inthe automotive industry. Two real-world case studies demonstrate its value. The first was a waste collection case study in which LCA was integrated in an existing simulation-based decision support tool to optimize the company’s activities froma life cycle environmental impact perspective. A simultaneously developed simulation-based LCA model of an iron foundry production line extended the applicability of the method with a proposed decision support interpretation approach. The study shows that data and information from both simulation model and LCA databases can be integrated and utilized in the developed simulation-based LCA method. This allows different systems with different configurations to be combined to assess the relevant parameters, and eventually to provide information about overall environmental impacts to decision makers to improvethe environmental sustainability of the automotive industry. / Ökade marknadsförings-och lagstiftningskrav ställer höga krav på miljöprestandan hos framtida transportlösningar. Det behov som detta innebär vad gäller att minska den totala miljöpåverkan medför både utmaningar och möjligheter för transportsektorn som helhet, inklusive fordonsindustrin. Livscykelanalys (LCA) används ofta för att utvärdera miljöprestanda inom fordonsindustrin. Den statiska karaktären hos LCA begränsar dock dess användbarhet när det handlar om att representera dynamiska miljökonsekvenser i tillverknings-och driftsfasen. Denna avhandling föreslår en simuleringsbaserad metod för LCA som tar itu med detta problem. Utvalda fallstudier från verkligheten påvisar potentialen för tillvägagångssättet i både fordonsproduktionsprocesser och slutanvändarapplikationer. Metodens utveckling har föregåtts av en omfattande genomgång av potentiella fördelar och utmaningar med att använda simuleringsbaserad LCA i produktionsprocesser. Denna granskning har sedan lagt grunden för utvecklingen och implementeringen av den föreslagna metoden. Två verkliga fallstudier påvisar dess värde. Den första är en fallstudie inom avfallsinsamling där LCA integrerats i ett befintligt simuleringsbaserat beslutsstödsverktyg för att optimera organisationens aktiviteter ur ett livscykelperspektiv utifrån miljöpåverkan. En simuleringsbaserad LCA-modell av en järngjuteriproduktionslinje utökade användbarheten hos metoden genom att en beslutsstödsmetod föreslogs. De genomförda studierna visar att data och information från både simuleringsmodeller och LCA-databaser kan integreras och utnyttjas i den utvecklade simuleringsbaserade LCA-metoden. Detta gör att olika system med olika konfigurationer kan kombineras för att utvärdera relevanta parametrar, och så småningom ge information om övergripande miljöpåverkan till beslutsfattare för att förbättra fordonsindustrins miljömässiga hållbarhet.

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A common problem in regression analysis is that some covariates are measured with errors. In this dissertation we present simulation-based approach to estimation in two popular regression models with a categorical response variable and classical measurement errors in covariates. The first model is the regression model with a binary response variable. The second one is the proportional odds regression with an ordinal response variable. In both regression models we consider method of moments estimators for therein unknown parameters that are defined via minimizing respective objective functions. The later functions involve multiple integrals and make obtaining of such estimators unfeasible. To overcome this computational difficulty, we propose Simulation-Based Estimators (SBE). This method does not require parametric assumptions for the distributions of the unobserved covariates and error components. We prove consistency and asymptotic normality of the proposed SBE's under some regularity conditions. We also examine the performance of the SBE's in finite-sample situations through simulation studies and two real data sets: the data set from the AIDS Clinical Trial Group (ACTG175) study for our logistic and probit regression models and one from the Adult Literacy and Life Skills (ALL) Survey for our regression model with the ordinal response variable and mismeasured covariates. / October 2016

The gradually increasing competition that occurs in mature markets, pushes the companies to consider new ways of competing. The more mature the market becomes the higher level of competitive fulfillment and edge is needed. E.g. for Scania the dimension high quality was until now considered a competitive advantage, but is currently evolving towards a dimension that is necessary to fulfill to even act within the market. Thus, companies such as Scania have to push their limits everywhere possible across their organization. One way to push the limits of R&D and product development (PD) is, based on this thesis and other work, implementing a simulation based product development (SBPD) process. The aim of this thesis has been, by applying a quality function deployment (QFD) model, to show the influence a SBPD process can have on increased competitiveness. By combining published literature within the field with empirical results mostly gained from interviews, nine components representing a SBPD process could be found. These components were characterized in the following categories: IT-infrastructure, design, model & test, and organizational. Depending on the level of fulfillment of these components the SBPD process is more or less implemented within the company. The two components that are considered the most important for Scania in terms of both increased competitiveness and a possible transition towards a SBPD process are Virtual representa-tion of the product and the process throughout the whole PD process and A model driven/model based approach. The work of this thesis has also shown, in correlations with previous published literature, that a SBPD process can significantly decrease the lead-time and cost of development, and at the same time increase the knowledge about the product and the process. The research has also shown that a SBPD process can considerably improve both the internal and the external collaboration. However attaining such a process where these competitive advantages can be gained affects the whole organization, the way development is performed and also the way resources are used. A fully implemented SBPD process has been shown to positively impact the following competitive dimensions; Frequency of product introductions, Lead-time of development, PD process flexibility, Degree of innovation, Customization of the offer, Collaboration with internal and external partners, Knowledge about products and processes, R&D cost, manufacturing cost, Focus on customers operational economics, Product quality, Product safety and Focus on environmental sustainability of the product & the processes. But, to get a positive impact on all these dimensions the components representing a SBPD process must be implemented and applied. Furthermore, this thesis also provides a framework for other companies to evaluate the impact a SBPD process can have on their competitiveness. The analysis model aims to guide companies that want to adopt a SBPD process. The framework can indicate how a SBPD process would impact the firm's competitive strategy. But also to provide guidance to which components that would be more important to implement in order to reach a competitive SBPD process. / Den gradvis ökande konkurrens som uppstår på mogna marknader driver företagen att finna nya sätt att konkurrera. Ju mer mogen marknaden blir desto högre blir kraven på konkurrens. För Scania har faktorn hög kvalitet tills nu betraktas som en konkurrensfördel, men utveckling sker istället mot att det kommer att vara en faktor som är nödvändig att uppfylla för att ens kunna agera på marknaden. Företag som Scania måste således utvecklas över hela organisationen. Ett sätt att tänja på gränserna för FoU och produktutveckling (PD) är, baserat på detta arbete och annan tidigare forskning, att genomföra en förändring mot en simulering baserad produktutvecklings-process (SBPD). Syftet med detta examensarbete har varit att, genom att tillämpa en quality function deployment (QFD) modell, visa effekten en SBPD-process kan ha på ökad konkurrenskraft. Genom att kombinera tidigare publicerad litteratur inom området med empiriska resultat, mestadels insamlat genom intervjuer, kunde nio komponenter som utgör en SBPD-process finnas. Dessa komponenter karakteriserades i följande kategorier: IT-infrastruktur, design, modellera och testa och organisatorisk. Beroende på graden av uppfyllnad på dessa komponenter blir den SBPD-processen mer eller mindre implementerad inom företaget. De två komponenterna som anses viktigast för Scania i form av både ökad konkurrenskraft och en eventuell övergång till en SBPD-process är Virtuell representation av produkten och processen genom hela PD-processen och Ett modellbaserat/ modelldrivet arbetssätt används. Arbetet har också visat i korrelation med tidigare publicerad litteratur, att en SBPD-process kommer att minska ledtiden och kostnaden för utveckling avsevärt och samtidigt öka kunskapen om produkten och processen. Denna studie har också visat att en SBPD-process kan förbättra både interna och externa samarbeten. Men att uppnå en sådan process där dessa konkurrens-fördelar kan vinnas kommer att påverka hela organisationen, det sätt som utveckling utförs på och också hur resurserna används. En fullt implementerad SBPD-process har visat positivt påverkan följande konkurrens faktorer; frekvens av produktlanseringar, ledtiden för utveckling, PD-processflexibilitet, innovationsgrad, anpassning av erbjudandet, samarbete med interna och externa partners, kunskap om produkter och processer, FoU kostnader, tillverkningskostnad, fokus på kundernas driftsekonomi, produktkvalitet, produktsäkerhet och miljöpåverkan av både produkten och processen. För att få en positiv inverkan på alla dessa faktorer måste alla komponenter som utgör en SBPD-process implementeras och tillämpas. Dessutom så presenteras även ett ramverk för andra företag att utvärdera effekterna en SBPD-process skulle ha på deras konkurrenskraft. Analysmodellen syftar till att vägleda företag som vill övergå till en SBPD-process. Ramverket kan ange hur en SBPD-process skulle kunna påverka företagets konkurrensstrategi men också ge vägledning om vilka komponenter som kan vara viktigare att börja implementera för att nå en konkurrenskraftig SBPD-process.

Le contrôle hétérarchique des systèmes de production flexibles (FMS) préconise un contrôle peu complexe et hautement réactif supporté par des entités décisionnelles locales (DEs). En dépit d'avancées prometteuses, ces architectures présentent un comportement myope car les DEs ont une visibilité informationnelle limitée sue les autres DEs, ce qui rend difficile la garantie d'une performance globale minimum. Cette thèse se concentre sur les approches permettant de réduire cette myopie. D'abord, une définition et une typologie de cette myopie dans les FMS sont proposées. Ensuite, nous proposons de traiter explicitement le comportement myope avec une architecture semi-hétérarchique. Dans celle-ci, une entité décisionnelle globale (GDE) traite différents types de décisions myopes à l'aide des différentes techniques d'optimisation basée sur la simulation (SbO). De plus, les SbO peuvent adopter plusieurs rôles, permettant de réduire le comportement myope de plusieurs façons. Il est également possible d'avoir plusieurs niveaux d'autonomie en appliquant différents modes d'interaction. Ainsi, notre approche accepte des configurations dans lesquelles certains comportements myopes sont réduits et d'autres sont acceptés. Notre approche a été instanciée pour contrôler la cellule flexible AIP- PRIMECA de l'Université de Valenciennes. Les résultats des simulations ont montré que l'architecture proposée peut réduire les comportements myopes en établissant un équilibre entre la réactivité et la performance globale. Des expérimentations réelles ont été réalisées sur la cellule AIP-PRIMECA pour des scenarios dynamiques et des résultats prometteurs ont été obtenus. / Heterarchical-based control for flexible manufacturing systems (FMS) localizes control capabilities in decisional entities (DE), resulting in highly reactive and low complex control architectures. However, these architectures present myopic behavior since DEs have limited visibility of other DEs and their behavior, making difficult to ensure certain global performance. This dissertation focuses on reducing myopic behavior. At first, a definition and a typology of myopic behavior in FMS is proposed. In this thesis, myopic behavior is dealt explicitly so global performance can be improved. Thus, we propose a semi-heterarchical architecture in which a global decisional entity (GDE) deals with different kinds of myopic decisions using simulation-based optimization (SbOs). Different optimization techniques can be used so myopic decisions can be dealt individually, favoring GDE modularity. Then, the SbOs can adopt different roles, being possible to reduce myopic behavior in different ways. More, it is also possible to grant local decisional entities with different autonomy levels by applying different interaction modes. In order to balance reactivity and global performance, our approach accepts configurations in which some myopic behaviors are reduced and others are accepted. Our approach was instantiated to control the assembly cell at Valenciennes AIPPRIMECA center. Simulation results showed that the proposed architecture reduces myopic behavior whereby it strikes a balance between reactivity and global performance. The real implementation on the assembly cell verified the effectiveness of our approach under realistic dynamic scenarios, and promising results were obtained.

No description available.

No description available.

A vast array of computer-based simulation tools are used to support engineering design and analysis activities. Several such activities call for the simulation of various coupled sub-systems in parallel, typically to study the emergent behavior of large, complex systems. Most sub-systems have their own simulation models associated with them, which need to interoperate with each other in a federated fashion to simulate system-level behavior. The run-time exchange of information between federate simulations requires a common information model that defines the representation of simulation concepts shared between federates. However, most federate simulations employ disparate representations of shared concepts. Therefore, it is often necessary to implement transformation stubs that convert concepts between their common representation to those used in federate simulations. The tasks of defining a common representation for shared simulation concepts and building translation stubs around them adds to the cost of performing a system-level simulation. In this thesis, a framework to support automation and reuse in the process of achieving interoperability between federate simulations is developed. This framework uses ontologies as a means to capture the semantics of different simulation concepts shared in a federation in a formal, reusable fashion. Using these semantics, a common representation for shared simulation entities, and a corresponding set of transformation stubs to convert entities from their federate to common representations (and vice-versa) are derived automatically. As a foundation to this framework, a schema to enable the capture of simulation concepts in an ontology is specified. Also, a graph-based algorithm is developed to extract the appropriate common information model and transformation procedures between federate and common simulation entities. As a proof of concept, this framework is applied to support the development of a federated air traffic simulation. To progress with the design of an airport, the combined operation of its individual systems (air traffic control, ground traffic control, and ground-based aircraft services) in handling varying volumes of aircraft traffic is to be studied. To do so, the individual simulation models corresponding to the different sub-systems of the airport need to be federated, for which the ontology-based framework is applied.

This study sought to identify factors that optimize individual and collaborative cognitive processing in complex learning environments. Across two laboratory sessions, the effects of manipulating instructional sequence delivery (high cognitive load vs. low cognitive load) of a simulation-based game and learning condition (individual vs. collaborative) were examined on retention and transfer of instructional content. The instruction was a set of tutorials for preparing novice students to use Aspire, a simulation-based game, developed by Cisco, that teaches entrepreneurial and computer networking skills within the industry of information technology. An instructional sequence by learning condition interaction was found on transfer, but not retention, measures. For delayed transfer performance, individuals who received high load instruction experienced cognitive overload that exceeded their cognitive capacity. Collaborative students were able to collaborate with each other in a way that reduced the high cognitive load imposed by the instructional sequence; thus, they were able to process the instructional content across their collective working memory. Individual students were not able to reduce the cognitive load imposed by the instructional sequence; thus, they had less working memory capacity for processing the instructional content. Collaborative students who received the low load instruction also demonstrated lower motivation than those who received high load instruction. Taken together, these findings support the notions of individual and collective working memory processing differences. This study holds implications for leveraging technology to design learning environments that aid students in attaining collaborative skills and knowledge needed for the 21st century. / text