The research described in this thesis concentrates on the development of an integrated assembly process design for aircraft systems. Assembly process design is one of the most important and complicated activities in aircraft manufacturing. Many solutions are suggested in previous research to develop process design method. But gaps are found in assembly process design of aircraft system in following studies. In this research, an integration approach which combined with product development philosophy, design for assembly method and digital assembly technology is proposed to solve the issues in the whole product development lifecycle. Three case studies from different design phase are used to examine the integrated process design method. The research results demonstrate that the proposed digital process design method can be used to develop manufacturing strategies of system assembly in early design phase, and improve the accuracy and operability of assembly instructions according to 3-D assembly process plans in detailed design phase. The product design also benefits from this method in terms of correcting design errors in the concurrent engineering process. A proposed process planning system framework based on lightweight CAD is developed in this research. The customized assembly representation of 3DVIA system illustrates the advantages of lightweight CAD when applying in shop floor.

The natural capacity of DNA for molecular self-assembly has already been exploited to create DNA based tiles which can self-assemble into nano-scale arrays and carry out nano-scale computation. Thus far, however, all such self-assembly has been passive, in the sense that the binding capacities of a tile are never altered throughout the assembly. The idea of active tiles, tiles that can send signals to each other and activate latent binding sites, has been proposed but never incorporated into a formal model. Here, I present an extension of the existent abstract tile assembly model by defining an active tile assembly and give a detailed example of an aperiodic set of active tiles which hierarchically produces a self-similar L-shape tiling. This yields a technique utilizing active tiles for the assembly of aperiodic self-similar shapes.

Motivated by genome rearrangements that take place in some species of ciliates we introduce a combinatorial model for these processes based on spatial graphs. This model builds up on two earlier models for pointer-guided DNA recombination (intramolecular model introduced in [22, 23] and intermolecular model introduced in [35, 36]) and is influenced by a molecular model for RNA guided DNA recombination (introduced in [2]). Despite their differences, the intermolecular and intramolecular model formalize the recombination events through rewriting operations applied on formal words. Both models predict the same set of molecules as a result of correct rearrangement. Here, we give an algorithm that for an input of scrambled gene structure outputs a set of strings which represents the expected set of molecules after complete assembly. Moreover, we prove that both the set of all realistic words (words that model a possible gene structure) and the set of all nonrealistic words are closed under the rewriting operations in the intramolecular model. We investigate spatial graphs that consist of 4-valent rigid vertices, called assembly graphs. An assembly graph can be seen as a representation of DNA molecule during certain recombination processes, in which 4-valent vertices represent molecular alignment of the recombination sites. We introduce a notion of polygonal path in assembly graph as a model for a single gene. Polygonal paths are defined as paths that make “90◦ -turn” at each vertex of the assembly graph and define smoothing of the vertices visited by the paths. Such vertex smoothing models a homologous DNA recombination. We investigate the minimal number of polygonal paths that visit all vertices of a given graph exactly once, called assembly number. We prove that for every positive integer n there is assembly graph with assembly number n. We also study the relationship between the number of vertices in assembly graph and its assembly number. One of the results is that every assembly graph with assembly number n has at least 3n − 2 vertices. In addition, we show that there is an embedding in three dimensional space of each assembly graph with a given set of polygonal paths, such that smoothing of vertices with respect to the polygonal paths results in unlinked circles. We study the recombination strategies by subsets of vertices. Such a subset is called a successful set if smoothing of all vertices from the set with respect to a polygonal path results in a graph that contains the polygonal path in a single component. We characterize the successful sets in a given assembly graph by a notion of complementary polygonal path. Furthermore, we define a smoothing strategy in assembly graph relative to a polygonal path as a sequence of successful sets which model a successive DNA recombinations for correct gene assembly. Recent experimental results suggest that there might be different pathways for unscrambling a gene. These results lead to a mathematical model for gene recombination that builds upon the intermolecular model. We introduce assembly words as a formalization of a set of linear and circular DNA molecules. Assembly words are partially ordered, so that any linearly ordered subset models a pathway for gene rearrangement. We suggest two different pathways for unscrambling of the actin I gene in O.Trifallax and we prove that they are the only theoretically possible pathways.

Volvo trucks can be ordered with many options to meet customers' demands. This challenges the efficiency of the manufacturing process, especially at the final assembly line where bare chassis are customised with parts and accessories. In the future, assembly lines may be more flexible to allow for assembly of different parts at higher efficiency. This thesis presents problem areas in traditional assembly lines and proposes a proof-of-concept for future flexible assembly line sequencing, as well as a computer simulation tool with the capability to evaluate variances in production capacity when trucks of different size and parts are assembled in consecutive order. Virtual models of flexible assembly lines are constructed as part of a software solution and used to simulate production sequences of varying truck configurations. Data collected from all simulations show a correlation between production capacity and the order in which vehicles are produced. The assembly line configuration itself has also shown to greatly impact efficiency and might lead to an improvement of at least 39%, as well as limitations of tools and workers with specific capabilities. However, the presented performance numbers do not represent all possible simulation outcomes, which beyond the assembly line configuration also depend on things like product complexity and the assembly sequence of individual products.

No description available.

Dans les Constitutions française, italienne et espagnole, les mentions expresses relatives au droit des assemblées régionales sont rares, mais elles sont déterminantes. L’autonomie régionale a, en effet, pour composante organique l’existence d’une assemblée, dotée d’une nature représentative et d’un caractère délibérant, que l’État soit de forme décentralisée ou régionale. Or, la reconnaissance constitutionnelle d’un organe délibérant propre à chaque région conditionne nécessairement sa nature ainsi que les règles relatives à son organisation et à son fonctionnement. L’étude comparée du droit des assemblées régionales à travers le prisme du droit constitutionnel révèle que l’action des auteurs de ce droit est encadrée par la Constitution. Quelle que soit la valeur des normes qui les consacrent, différents principes issus du droit parlementaire s’imposent ainsi comme des garanties des exigences constitutionnelles en la matière et permettent d’assurer l’autonomie statutaire et fonctionnelle de l’organe. Il existe, dès lors, un degré minimum d’harmonisation du droit des assemblées régionales et parlementaires, qui découle des prescriptions constitutionnelles. Pour autant, ces deux types d’assemblées ne peuvent être confondus dans un État unitaire, ce qui implique que cette transposition ne vise pas les principes liés à leur nature propre. Il existe donc également un degré maximum d’harmonisation qui ne peut pas être dépassé. Par ailleurs, le droit des assemblées régionales peut s’éloigner du droit parlementaire et prendre une forme innovante, pour mieux garantir les fonctions de ces assemblées en prenant en compte leurs spécificités. Donner les moyens aux assemblées régionales d’exercer leurs fonctions, que ce soit en leur appliquant des règles issues du droit parlementaire ou en créant des règles propres à cet échelon, c’est garantir l’autonomie de la région, telle qu’elle est définie par la Constitution. / Within the French, Italian and Spanish Constitutions, the direct references to laws regulating regional assemblies are rare, yet determining. Regional autonomy in any of the three countries entails the existence of an assembly, having a representative nature and a deliberative character, regardless of whether the national state of the given country exists in a decentralized or regional form. The nature and internal rules of the regional assemblies are conditioned by the extent to which they are recognized in the constitutions of their respective countries. This comparative study examines the laws governing the regional assemblies, through the prism of constitutional law, and shows that their normative sources are structured by the Constitutions. Different principles of parliamentary law protect the assemblies' structural and functional autonomy, and serve as guarantees for the constitutional exigencies they are submitted to, no matter the value of the normative sources. The constitutions prescribe the minimum threshold for the level of harmonization between parliamentary and regional assembly laws. Yet, a regional assembly cannot be equated with the parliament of a unitary state, and as a consequence, the transposition of laws does not target the inherent principles of each assembly’s particular nature. Hence, there is also a maximum threshold of harmonization that cannot be exceeded. Further, regional assembly law may deviate from parliamentary law and take an innovative form in order to secure the assemblies' functions through the accommodation of their specificities.To give regional assemblies the means to exercise their functions, either through the application of rules governed by parliamentary law or by the creation of particular rules at the regional level, is to guarantee the regions' autonomy as defined by the Constitutions.

The aim of this research is to bridge the gap between CAD modeling and kinematic analysis packages by extracting kinematic information directly from part genometries. It will relieve the designers from the tedious task of specifying assembly constraints and specifying redundant information for creating kinematic models. Automatic generation of kinematic assembly models is achieved by characterizing the lower kinematic pairs: cylindrical, spherical, prismatic, planar and revolute; from the geometries point of view. Based on characterization, the algorithms are developed to recognize these kinematic pairs from a pair of part genometries. The combinations of primitive genometric entities: vertices, edges and faces; forming point, line, arc and surface contacts are studied. The signature geometry is found to be associated with each type of joint. The contacts are analysed for restraining the relative motion between a pair of parts. Based on this, the form closure conditions are derived for surface, line, arc and point contacts for each type of joint. The algorithms are developed to automatically recognize these joints and to assemble them into a kinematic assembly model represented as a graph. The strength and novelty of the present procedure is that kinematic pairs can be recognized for conforming as well as non conforming genometries. A Visual Basic for Application (VBA) for Solid Works has been developed using Application Programming Interface (API) for user interaction. The part genometries can be in any 3D solid modeling neutral file format (.sat, .igs, etc) or some of the native formats of CAD softwares supported by Solid Works. The regions of interest can be directly identified through mouse pick on parts using Solid Works Graphical User Interface (GUI). The transformation matrices are derived automatically to position the parts relative to each other. The local interference between part geometries is also considered for checking the validity of the kinematic pair in the assembly. Assembly model is created and represented as a directed graph. The present implementation, built on the ACIS geometry kernel, imports the parts into SolidWorks, specifies the mating regions using a visual Basic interfaces and finally generates the kinematic assembly model as an ADAMS input file complete with part genometries, their mass properties, kinematic joints and their locations.

Global competition is growing for companies everywhere and the demand for new and improved products are rising for each day that passes. The globalization brings new opportunities as well as new challenges since companies need to stay up to date and implement new technologies to stay competitive. Not only do customers want up to date products, they also want high quality, low price and individualized products, customized for their needs. This puts high demand on manufacturing companies to adapt their businesses, increase product diversity and to being able to introduce new variations and new products quickly.  Since the drastic evolution of technology has increased the competitiveness of industrial companies, and the mass customization demands have increased, the necessity to investigate potential system alternatives towards improving production processes, with the help from the new technology, is required. One way of doing this is to revaluate one's assembly layouts since the layout design decision is highly connected to the product portfolio and the production volumes. The specific objective of this thesis is to broaden the case company’s, ABB, knowledge on ways their assembly of large robots can be improved with the focus on potential future assembly solutions. The overall aim of this thesis work is to identify state-of-the-art possible layout design alternatives, evaluate their performances and finding a method of choosing the final layout approach. This is answered by research questions connected to plant layout selection methodology, plant layout options and finally recommendations for the case company. The methodology chosen for deciding the recommended layout is the fuzzy Analytical Hierarchy Process which is a multi-criteria decision-making tool suitable for decision problems with a hierarchical structure, having main attributes and sub attributes connected to each main attribute. Twenty-four attributes were created and ten layouts based on company observations and a literature study. The layout with the highest score was a layout based on a modernized version of the common fixed position layout. The overall recommendation for the case company was to focus on having a layout in the future with focus on a high technology level as well as high flexibility, for also receiving high performance.

The aim of this diploma thesis is processing of the design of the assembly line for assembling of water ventilation systems of thermoregulation of an engine. The proposal is comprised of determination of the line cycle time, required number of workers and a creation of three possible options of assembly line solution. The final variant will be chosen by using a multi-criterion evaluation.

No description available.