In recent years, researchers have developed virtual environments, which allow more realistic human-computer interactions and have become increasingly popular for engineering applications such as computer-aided design and process evaluation. For instance, the demand for product service, remanufacture, and recycling has forced companies to consider ease of assembly and disassembly during the design phase of their products. Evaluating these processes in a virtual environment during the early stages of design not only increases the impact of design modifications on the final product, but also eliminates the time, cost, and material associated with the construction of physical prototypes. Although numerous virtual environments for assembly analysis exist or are under development, many provide only visual feedback. A real-time haptic simulation test bed for the analysis of assembly and disassembly operations has been developed, providing the designer with force and tactile feedback in addition to traditional visual feedback. The development such a simulation requires the modeling of collisions between virtual objects, which is a computationally expensive process. Also, the demands of a real-time simulation incorporating haptic feedback introduce additional complications for reliable collision detection. Therefore, the first objective of this work was to discover ways in which current collision detection libraries can be improved or supplemented to create more robust interaction between virtual objects. Using the simulation as a test bed, studies were then conducted to determine the potential usefulness of haptic feedback for analysis of assembly and disassembly operations. The following significant contributions were accomplished: (1) a simulation combining the strengths of an impulse-based simulation with a supplemental constraint maintenance scheme for modeling object interactions, (2) a toolkit of supplemental techniques to support object interactions in situations where collision detection algorithms commonly fail, (3) a haptic assembly and disassembly simulation useful for experimentation, and (4) results from a series of five experimental user studies with the focus of determining the effectiveness of haptic feedback in such a simulation. Additional contributions include knowledge of the usability and functionality of current collision detection libraries, the limitations of haptic feedback devices, and feedback from experimental subjects regarding their comfort and overall satisfaction with the simulation.

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2007. / Härtill 4 uppsatser.

Thesis (Ph.D. in Biochemistry) -- University of Colorado, 2006. / Typescript. Includes bibliographical references (leaves 153-171). Free to UCDHSC affiliates. Online version available via ProQuest Digital Dissertations;

Ce travail de thèse s’inscrit dans un contexte d’intégration des contraintes de désassemblage dans la conception modulaire des produits manufacturés. Ce contexte est caractérisé par une collaboration pluridisciplinaire où un nombre très important d’informations est utilisé, manipulé et échangé. Pour ce faire, la contribution de ce travail consiste en :• La définition d’un modèle multi-vues orienté désassemblage permettant une représentation et l’exploitation des informations associées aux domaines du produit et du processus de désassemblage et en conséquence, une aide à l’intégration.• La définition d’un cadre méthodologique permettant de prendre en compte les problématiques de désassemblage dès la phase préliminaire de conception modulaire de produits manufacturés. Ce cadre méthodologique vise à :o Faire intervenir les différents acteurs concernés par les problématiques de désassemblage au moment le plus opportun et en particulier lors de la phase de conception préliminaire.o Définir une architecture modulaire d’une famille de produits. Un algorithme dédié au développement des modules de composants qui sont utilisés dans la conception d’une famille de produits est proposé.o Générer les séquences de désassemblage en phase préliminaire de conception. Un algorithme de définition des séquences de désassemblage admissible d’une famille de produits prenant en compte l’architecture modulaire est proposé.o Faire une optimisation multi-objective des séquences de désassemblage admissibles pour identifier la séquence de désassemblage optimale en fonction des critères imposés (critères fonctionnels, géométriques,…).o Apporter un contexte de désassemblage à l’architecte produit et au concepteur. Les informations issues de la séquence de désassemblage sont considérées afin de définir un contexte de désassemblage qui servira de base aux concepteurs pour identifier la géométrie du produit.Le modèle et le cadre méthodologique sont validés par l’expérimentation sur différents produits. À titre d’exemple, ils sont illustrés sur la conception de différentes familles de produits.Mots clés : Modèle multi-vues, Conception modulaire, séquence de désassemblage, Optimisation multi-objective. / This thesis work fails with in context of the integration of disassembly constraints into the modular design of manufactured products. This context is characterized by a multidisciplinary collaboration where a large deal of information is used, handled and exchanged. To this end the contribution of this work is:• The definition of a multi-view model oriented disassembly allowing representation and exploitation of information associated with the areas of product and disassembly process and consequently integration assistance.• The definition of methodological framework allowing taking into account the disassembly issues from the preliminary phases of modular design of manufactured products. This methodological framework aims to:o Involve different stakeholders by disassembly issues at the most appropriate time and in particular during the preliminary design phase.o Define a modular products family. An algorithm dedicated to the development of the component modules that are used in the design of a family of products is proposed.o Generated disassembly sequences in the preliminary design phase. An algorithm for defining the eligible disassembly sequences of products by taking into account the modular architecture is proposed.o Perform a multi-objective optimization of the eligible disassembly sequences in order to identify the optimal one. The uncertainties inherent in the disassembly area as well as functional and geometric criteria are taken into consideration in order to find the optimal disassembly sequence thus providing a generic structure of a family of products.o Provide the disassembly context to the product architect and the product designer. The information from the disassembly sequence is considered to define a disassembly context as a basis for designers to identify the geometry of the product.The model and the methodological framework are validated by experiments on different products. They are illustrated in the design of different products family.Keywords: Multi-view model, Modular design, Disassembly sequence, Multi-objective Optimization.

Dans un contexte de développement durable, les enjeux de la dernière phase du cycle de vie d'un système, la phase de retrait de service, se sont accrus ces dernières années. Les systèmes en fin de vie doivent être déconstruits afin d'être revalorisés pour répondre aux différentes exigences environnementales. Cette responsabilité incombe au concepteur qui doit définir le sous-système support de la phase de retrait de service : le système de déconstruction. Sa principale fonction est la réalisation de l'activité de déconstruction dans l'objectif de favoriser en aval le recyclage de la matière des constituants du système en fin de vie et/ou leur recyclage fonctionnel. Les stratégies de déconstruction doivent répondre à l'ensemble des problèmes de décision posés lors de la phase de retrait de service d'un système. Il s'agit notamment de sélectionner les constituants valorisables suivant des critères techniques, économiques et environnementaux puis de définir et optimiser le système de déconstruction permettant l'obtention de ces produits. La solution obtenue définie ce que nous avons appelé une trajectoire de déconstruction. Nos travaux portent sur la modélisation et l'optimisation de ces trajectoires. Nos développements s'articulent en quatre phases. Etat de l'art et démarche de définition d'une trajectoire. Dans cette phase, une structure de démarche de définition de trajectoires de déconstruction est proposée puis instrumentée. Les modèles généralement utilisés dans ce cadre sont de type déterministe et ne permettent pas de prendre en compte et de gérer les incertitudes inhérentes au processus de déconstruction (état dégradé du système en fin de vie et de ses constituants, demandes en produits issus de la déconstruction, dates de fin de vie des systèmes, …). Pour déterminer une solution robuste de déconstruction d'un système en fin de vie, l'aide à la décision proposée doit intégrer des incertitudes de nature diverse tout en facilitant leur gestion et leurs mises à jour. Incertitudes en déconstruction. Sur la base de ce constat, l'ensemble d'incertitudes couramment mises en jeu dans l'optimisation des trajectoires est identifié et caractérisé. Les méthodes probabilistes apparaissent comme des approches privilégiées pour intégrer ces incertitudes dans une démarche d'aide la décision. Les réseaux bayésiens et leur extension aux diagrammes d'influence sont proposés pour répondre à différents problèmes de décision posés lors de la définition d'une trajectoire de déconstruction. Ils servent de support au développement d'un outil d'aide à la décision. Modélisation de trajectoires de déconstruction : principes et approche statique d'optimisation. Après avoir présenté ses principes de modélisation, l'outil est développé dans une approche de détermination d'une trajectoire de déconstruction d'un système en fin de vie donné. La trajectoire obtenue fixe la profondeur de déconstruction, les options de revalorisation, les séquences et les modes de déconstruction suivant des critères économiques et environnementaux tout en permettant de gérer différents types d'incertitude. L'utilisation de critères économiques est ici privilégiée. Un exemple d'application sur un système aéronautique est développé pour illustrer les principes de modélisation. Approche dynamique pour l'optimisation d'une trajectoire de déconstruction. Le champ d'application de l'outil d'aide à la décision est étendu en intégrant une dimension temporelle à la modélisation du problème à l'aide des réseaux bayésiens dynamiques. Les trajectoires de déconstruction peuvent ainsi être établies sur des horizons couvrant les arrivées de plusieurs systèmes en fin de vie en présence d'incertitudes. Le modèle permet de déterminer des politiques de déconstruction pour chaque opération identifiée dans la trajectoire en fonction de différents paramètres liés à la gestion des demandes et des arrivées ou encore au processus d'obtention de ces produits. Le décideur peut ainsi adapter l'outil à différents contextes de détermination de trajectoire de déconstruction de systèmes en fin de vie. / In a sustainable development context, stakes of the last stage of system life cycle, the end-of-life stage, increase these last years. End-of-life systems have to be demanufactured in order to be valued and answer environmental requirements. The aim of disassembly strategies is to bring solutions to the whole decision problem put during the end-of-life stage of systems. In particular, decision maker have to select valuable products in function of technical, economical and environmental criteria and, then, design and optimise disassembly support system allowing generating these products. The solution determines what we call a disassembly trajectory and ours works deal with modelling and optimization of these trajectories. Definition steps of disassembly trajectories are proposed, structured and instrumented. Models that are generally used in this frame are determinist and do not allow taking into account and managing uncertainties that are inherent to disassembly process (degradation of products, demand for valuable product, systems end-of-life dates, ...). In order to determine a robust disassembly solution, decision aid has to integrate uncertainties from various origins while facilitating their management and their update. On the basis this observation, all the uncertainties involved in disassembly trajectory optimization are identified and characterized. Basing on Bayesian networks, the proposed tool is developed through a “static” approach of disassembly trajectory. Indeed, the obtained trajectory gives the disassembly level of the end-of-life system, recycling options, sequences and disassembly modes in function of economical criteria while allowing managing uncertainties. An application example on an aeronautical system is developed to illustrate the modelling method. The application field of the model is extended to take into account time dimension (dynamic approach) by using dynamic Bayesian networks. Trajectories can be defined on horizons that integrate several arrivals of end-of-life systems. Decision makers can so adapt the model to various contexts

Chromatin remodeling is crucial to transcriptional regulation in vivo and a number of protein complexes capable of altering genomic architecture in the budding yeast Saccaromyces cerevisiaehave been identified. Among these, the SWI/SNF complex, a 2 MDa, eleven subunit protein assembly, has been the most extensively characterized. The SWI/SNF complex is required for the proper expression of a number of genes in yeast, although it is completely dispensable for the expression of others. Likewise, some, but not all, transcriptional activator proteins require SWI/SNF activity in order to function in vivo. The goal of this thesis work was to identify those components of the transcription process which dictate this dependence on SWI/SNF activity. Using the well characterized UASGALsystem, we have determined that one of these components is the nucleosome state of activator binding sites within a promoter. We find that while SWI/SNF activity is not required for the GAL4 activator to bind to and activate transcription from nucleosome-free binding sites, the complex is required for GAL4 to bind and function at low affinity, nucleosomal binding sites in vivo. The SWI/SNF -dependence of these nucleosomal binding sites can be overcome by 1) replacing the low affinity sites with higher affinity, consensus GAL4 binding sequences, or 2) placing the low affinity sites into a nucleosme-free region. These results provide the first in vivo evidence that the SWI/SNF complex can regulate gene expression by modulating the DNA binding of a transcriptional activator protein. To determine whether specific components of the GAL4 protein are necessary in order for the SWI/SNF complex to modulate binding to nucleosomal sites in our model system, we tested the SWI/SNF-dependent DNA binding of various derivative GAL4 proteins. We find that a functional activation domain is not required for SWI/SNF to modulate GAL4 binding in vivo. Interestingly, like the full length protein, GAL4 derivatives in which the activation domain has been mutated are able to partially occupy nucleosomal sites in the absence of SWI/SNF (binding in the absence of SWI/SNF is at least forty percent lower than in the presence of SWI/SNF), indicating the activation domain is also not required for SWI/SNF-independent DNA binding. These results support a model in which the SWI/SNF-dependence of a gene reflects the nucleosomal context of its important regulatory sequences, e.g. binding sites for transcriptional regulatory proteins. Although nucleosomal promoter regions have been correlated with SWI/SNF-dependence in the past, there has of yet been no gene at which nucleosome location has correlated with a specific genetic function. In the final part of this thesis work, we initiated a search for an endogenous SWI/SNF-dependent gene for which the nucleosome state of activator binding sites could be determined.

Chromatin structure is intricately involved in the mechanisms of eukaryotic gene regulation. In general, the compact nature of chromatin blocks DNA accessibility such that components of the transcriptional machinery are unable to access regulatory sequences and gene activation is repressed. These repressive effects can be overcome or augmented by the actions of chromatin remodeling enzymes. Numerous studies highlight two classes of these enzymes: those that covalently modify nucleosomal histones and those that utilize energy derived from ATP hydrolysis to destabilize the histone-DNA contacts within the nucleosome (13, 14, 92). Members of each of these groups of chromatin remodeling enzymes play pivotal roles in modulating chromatin structure and in facilitating or blocking the binding of transcription factors. Mutations in genes encoding these enzymes can result in transcriptional deregulation and improper protein expression. Therefore, the regulation of chromatin structure is critical for precise regulation of almost all aspects of gene expression. Consequently, enzymes regulating chromatin structure are important modulators of cellular processes such as cell viability, growth, and differentiation. There remain many uncharacterized members of the ATP-dependent class of remodeling enzymes; characterization of these proteins will further elucidate the cellular functions these enzymes control. Here, we focus primarily on the ATP-dependent remodeling complexes, specifically the chromodomain helicase DNA-binding (CHD) family. The CHD proteins are distinguished from other ATP-dependent complexes by the presence of two N-terminal chromodomains that function as interaction surfaces for a variety of chromatin components. These proteins also contain a SNF2-like ATPase motif and are further classified based on the presence or absence of additional domains. Genetic, biochemical, and structural studies demonstrate that CHD proteins are important regulators of transcription and play critical roles during developmental processes. Numerous CHD proteins have also been implicated in human disease. The first CHD family member, mChd1, was identified in 1993 in a search for DNA-binding proteins with an affinity for immunoglobin promoters. Since then, additional CHD genes have been identified based on sequence and structural homology to mChd1. Despite an increase in the number of studies relating to CHD proteins, the function of most remains unknown or poorly characterized. Using embryonic stem (ES) cells containing an insertional mutation in the murine Chd2 locus, we generated a Chd2-mutant mouse model to address the biological effects of Chd2 in development and disease. The targeted Chd2 allele resulted in a stable Chd2-βgeo fusion protein that contained the tandem chromodomains, the SNF2-like ATPase motif, but lacked the C-terminal portion of the DNA-binding domain. We demonstrated that the mutation in Chd2 resulted in a general growth delay in homozygous mutants late in embryogenesis as well as perinatal lethality. Similarly, heterozygous mice showed a decreased neonatal viability. Moreover, the surviving heterozygous mice showed a general growth delay during the neonatal period and increased susceptibility to non-neoplastic lesions affecting multiple organs, most notably the kidneys. We further examined the connection between Chd2 and kidney disease in this murine model. Our findings revealed that the kidney phenotype observed in Chd2 mutant mice led to the development of membranous glomerulopathy, proteinuria, and ultimately to impaired kidney function. Additionally, serum analysis revealed decreased hematocrit levels in the Chd2-mutant mice, suggesting that the membranous glomerulopathy observed in these mice is associated with anemia. Lastly, we investigated whether the type of anemia observed in the Chd2-mutant mice. Red blood cell (RBC) indices and morphological examination of the RBCs indicated that the anemia seen in the Chd2-mutant mice can be classified as normocytic and normochromic. Further analyses have been initiated to determine if the anemia is due to an intrinsic effect in erythropoiesis or a secondary consequence of the glomerular disease. In summary, our findings have contributed to our understanding of the putative chromatin remodeling enzyme Chd2. Although much remains to be studied, these findings demonstrate a role for Chd2 in mammalian development and have revealed a link between Chd2 and disease.

Denna kandidatuppsatts behandlar hur demonteringsbara byggnationer påverkar byggbranschen. Syftet är att ta reda på totalentreprenörernas syn på Design for Deconstruction (DfD), eller som det kallas på svenska projektering för demontering, i den svenska byggsektorn. Vidare undersöks utmaningar och problem som DfD ger upphov till och vad som krävs för att införa DfD i byggsektorn. Studien baseras på en kvalitativ metod då vi genomförde åtta semistrukturerade intervjuer med totalentreprenörer. Resultatet grundas på respondenternas svar som innehåller deras erfarenhet, uppfattningar, reflektioner om DfD. Studiens resultat visar att det råder fortfarande okunskap bland totalentreprenörer gällande ämnet men samtidigt ett växande intresse för ämnet. Det krävs större ambitioner från politiker och internationella myndigheter för att utveckla styrmedel som möjliggör projektering för demontering i byggsektorn. Respondenterna ansåg att fördelarna med DfD är möjlighet att förflytta en byggnad, flexibla planlösningar som förenklar renoveringsarbete/ombyggnation, kortare byggtider, återanvändning. Detta kan skapa en ny marknadsföringsstrategi och höja kostnadsvärde för fastighetsägare. Den ekonomiska aspekten visade sig vara det främsta hindret för införande av DfD eftersom respondenterna ansåg projektering för demontering som en icke prövad metod. Dagens byggmodell är inte lämplig för DfD och innovationer krävs. Andra utmaningar som framkom är skepticism till återanvändning av byggmaterial och svårigheter att se de ekonomiska möjligheterna som kommer efter 50–70 år. Anledningarna är bland annat estetik och lastupptagningsförmåga av element samt förvaring. Det behövs också ekonomisk vinning för att fastighetsägare ska välja DfD. De förutsättningar som behövs för att DfD ska införas är ett gemensamt standardiseringssystem, utveckling av BIM-verktyg som stödjer DfD, nya innovationer, öppna byggsystem. Informationsflöde och interaktion mellan entreprenörer och materialleverantörer behöver förbättras för att uppnå den tekniska utformningen med avseende på återanvändningen. Det krävs att staten genomför förmåner i form av subventioner och ekonomiskt stöd för att stimulera införandet av Design for Deconstruction i byggsektorn. Intervjustudien visade att totalentreprenörer utför DfD om efterfrågan och begäran finns hos beställaren. Däremot behöver entreprenörer visa engagemang visas valet av en byggmodell. / This bachelor thesis is about how deconstruction of buildings affect the Swedish construction industry. The purpose with study is to explore how turnkeys’ contractors view of Design for Deconstruction (DfD). This study examines the challenges and problems linked to DfD and what is needed to introduce DfD into the construction sector. The research approach chosen is a qualitative method with semi structured interviews where eight turnkey contractors were interviewed. The result is based on the respondents' experiences, perceptions, and reflections on DfD. The results show that there is a potential for further competence development among the turnkey contractors. More ambitions are required from the politicians and international authorities to develop instruments that enable development DfD in the construction sector. Respondents saw the possible benefits of DfD are opportunities for relocation of the buildings, flexibility that simplifies renovation work, shorter construction times, re-use. This can create a new marketing strategy and increase the value for property owners. Current building model is not suitable for DfD and new innovations are required. Other challenges that emerged is scepticism of turnkeys’ constructors for the recycling of building materials and difficulty to see financial possibilities that will be after 50-70 years. Subsidies and financial support coming from the state may be beneficial for establishment of DfD in the construction sector.

As the world becomes increasingly aware of the need to better care for the environment, innovative business models are helping to counter the damage of the fast fashion system - a phenomenon in the fashion industry whereby production processes are expedited in order to get new trends to the market as quickly and cheaply as possible. Designing products with a focus on their renewability can shift the product-consumer relationship. The closed loop concept of a “circular economy” is emerging as a viable and promising solution to the current linear business model. This study explores the possibilities of a more mindful approach to systems of production and consumption through material explorations using plastic from water bottles, paper from old newspaper and magazines, and fabric leftovers from pattern making within a circular economy. It considers the generative and renewable approaches in redefining how fashion engages with the components and raw materials of the industry. The research demonstrates a circular approach to the production of hospitality accessories in an effort to develop new intersections between products, materials, and consumers. The accessories are designed using discarded, reformulated denim–an abundant and underutilized byproduct of the fashion industry­–to reduce waste that currently occurs every time hotel chains and airlines produce disposable giveaway products from new materials.

The Linear Economy cannot any longer be sustained by the eco-system: virgin resources are limited and destined to terminate soon if the contemporary production and consumption model will be maintained. For this reason, in the last few years Circular Economy has become an increasingly discussed topic worldwide. Through the adoption of strategies that close-the-loop of the traditional linear production system, Circular Economy aims to find solutions that can create a balance between economy, society and environment. This study aims to provide a holistic overview on the main theories and strategies that can ease a business transition to a Circular Economy model, to analyse challenges and opportunities connected to this conversion and to present a concrete tool developed for this purpose. The Life Cycle Design theory is here discussed and contextualised within the furniture industry reality since this study has been executed in collaboration with IKEA, the company case study of this thesis. An academic and professional literature review have been performed in order to gather information about theory and practice related to the implementation of strategies needed by a Circular Economy: product disassembly, recovery, reuse, refurbish, recycle and remanufacturing. The professional literature reviewed point out that the implementation of a circular model can lead to economic advantages and growth’s opportunities for manufacturers in various economic sectors. The implementation of Circular Economy in the furniture industry seems to be in its early stages and it mainly focus, with few exception, on recycling rather than on the more effective reuse, refurbish or remanufacturing operations. This study points out the two main issues that the furniture manufacturers need to solve in order to enable the implementation of more effective circular strategies: product disassembly and recovery. Furthermore, the need of an innovative and holistic approach is discussed with particular emphasis on the importance of a systemic thinking that enable organisation to create their own identity and objectives in relation to the Circular Economy model. The importance of a system that connects and coordinate the sustainable efforts and aims for new products and services is therefore highlighted, suggested and deeply considered in the development of the tool proposed. To conclude, a comparison between two IKEA products (the sofas Söderhamn and Knopparp) was performed to identify the role of the products’ design and development in relation with the implementation of a Circular Economy model. The products were briefly technically analysed and then a comparison between a linear and a circular end-of-life cycle scenario has been represented.