990 resultados para produce design
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Over the past two decades there has been a profusion of empirical studies of organizational design and its relationship to efficiency, productivity and flexibility of an organization. In parallel, there has been a wide range of studies about innovation management in different kind of industries and firms. However, with some exceptions, the organizational and innovation management bodies of literature tend to examine the issues of organizational design and innovation management individually, mainly in the context of large firms operating at the technological frontier. There seems to be a scarcity of empirical studies that bring together organizational design and innovation and examine them empirically and over time in the context of small and medium sized enterprises. This dissertation seeks to provide a small contribution in that direction. This dissertation examines the dynamic relationship between organizational design and innovation. This relationship is examined on the basis of a single-case design in a medium sized mechanical engineering company in Germany. The covered time period ranges from 1958 until 2009, although the actual focus falls on the recent past. This dissertation draws on first-hand qualitative empirical evidence gathered through extensive field work. The main findings are: 1. There is always a bundle of organizational dimensions which impacts innovation. These main organizational design dimensions are: (1) Strategy & Leadership, (2) Resources & Capabilities, (3) Structure, (4) Culture, (5) Networks & Partnerships, (6) Processes and (7) Knowledge Management. However, the importance of the different organizational design dimensions changes over time. While for example for the production of simple, standardized parts, a simple organizational design was appropriate, the company needed to have a more advanced organizational design in order to be able to produce customized, complex parts with high quality. Hence the technological maturity of a company is related to its organizational maturity. 2. The introduction of innovations of the analyzed company were highly dependent on organizational conditions which enabled their introduction. The results of the long term case study show, that some innovations would not have been introduced successfully if the organizational elements like for example training and qualification, the build of network and partnerships or the acquisition of appropriate resources and capabilities, were not in place. Hence it can be concluded, that organizational design is an enabling factor for innovation. These findings contribute to advance our understanding of the complex relationship between organizational design and innovation. This highlights the growing importance of a comprehensive, innovation stimulating organizational design of companies. The results suggest to managers that innovation is not only dependent on a single organizational factor but on the appropriate, comprehensive design of the organization. Hence manager should consider to review regularly the design of their organizations in order to maintain a innovation stimulating environment.
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This paper deals with the design of a network-on-chip reconfigurable pseudorandom number generation unit that can map and execute meta-heuristic algorithms in hardware. The unit can be configured to implement one of the following five linear generator algorithms: a multiplicative congruential, a mixed congruential, a standard multiple recursive, a mixed multiple recursive, and a multiply-with-carry. The generation unit can be used both as a pseudorandom and a message passing-based server, which is able to produce pseudorandom numbers on demand, sending them to the network-on-chip blocks that originate the service request. The generator architecture has been mapped to a field programmable gate array, and showed that millions of numbers in 32-, 64-, 96-, or 128-bit formats can be produced in tens of milliseconds. (C) 2011 Elsevier B.V. All rights reserved.
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This paper introduces an improved tabu-based vector optimal algorithm for multiobjective optimal designs of electromagnetic devices. The improvements include a division of the entire search process, a new method for fitness assignment, a novel scheme for the generation and selection of neighborhood solutions, and so forth. Numerical results on a mathematical function and an engineering multiobjective design problem demonstrate that the proposed method can produce virtually the exact Pareto front, in both parameter and objective spaces, even though the iteration number used by it is only about 70% of that required by its ancestor.
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Planning hot forging processes is a time-consuming activity with high costs involved because of the trial-and-error iterative methods used to design dies and to choose equipment and process conditions. Some processes demand many months to produce forged parts with controlled shapes, dimensions and microstructure. This paper shows how expert systems can help engineers to reduce the time needed to design precision forged parts and dies from machined parts. The software ADHFD interfacing MS Visual Basic v.5.0 and SolidEdge v.3.0 was used to design flashless hot forged gears, chosen from families of gears. © 1998 Elsevier Science S.A. All rights reserved.
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Molecular hybridization is a new concept in drug design and development based on the combination of pharmacophoric moieties of different bioactive substances to produce a new hyrid compound with improved affinity and efficacy, when compared to the parent drugs. Additionally, this strategy can results in compounds presenting modified selectivity profile, different and/or dual modes of action and reduced undesired side effects. So, in this described several example of different strategies for drug design, discovery and pharmacomodulation focused on new innovative hybrid compounds presenting analgesic, anti-inflammatory, platelet anti-aggregating, anti-infections, anticancer, cardio- and neuroactive properties.
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The constant increase in digital systems complexity definitely demands the automation of the corresponding synthesis process. This paper presents a computational environment designed to produce both software and hardware implementations of a system. The tool for code generation has been named ACG8051. As for the hardware synthesis there has been produced a larger environment consisting of four programs, namely: PIPE2TAB, AGPS, TABELA, and TAB2VHDL. ACG8051 and PIPE2TAB use place/transition net descriptions from PIPE as inputs. ACG8051 is aimed at generating assembly code for the 8051 micro-controller. PIPE2TAB produces a tabular version of a Mealy type finite state machine of the system, its output is fed into AGPS that is used for state allocation. The resulting digital system is then input to TABELA, which minimizes control functions and outputs of the digital system. Finally, the output generated by TABELA is fed to TAB2VHDL that produces a VHDL description of the system at the register transfer level. Thus, we present here a set of tools designed to take a high-level description of a digital system, represented by a place/transition net, and produces as output both an assembly code that can be immediately run on an 8051 micro-controller, and a VHDL description that can be used to directly implement the hardware parts either on an FPGA or as an ASIC.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Pós-graduação em Educação - FFC
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The PhD activity described in the document is part of the Microsatellite and Microsystem Laboratory of the II Faculty of Engineering, University of Bologna. The main objective is the design and development of a GNSS receiver for the orbit determination of microsatellites in low earth orbit. The development starts from the electronic design and goes up to the implementation of the navigation algorithms, covering all the aspects that are involved in this type of applications. The use of GPS receivers for orbit determination is a consolidated application used in many space missions, but the development of the new GNSS system within few years, such as the European Galileo, the Chinese COMPASS and the Russian modernized GLONASS, proposes new challenges and offers new opportunities to increase the orbit determination performances. The evaluation of improvements coming from the new systems together with the implementation of a receiver that is compatible with at least one of the new systems, are the main activities of the PhD. The activities can be divided in three section: receiver requirements definition and prototype implementation, design and analysis of the GNSS signal tracking algorithms, and design and analysis of the navigation algorithms. The receiver prototype is based on a Virtex FPGA by Xilinx, and includes a PowerPC processor. The architecture follows the software defined radio paradigm, so most of signal processing is performed in software while only what is strictly necessary is done in hardware. The tracking algorithms are implemented as a combination of Phase Locked Loop and Frequency Locked Loop for the carrier, and Delay Locked Loop with variable bandwidth for the code. The navigation algorithm is based on the extended Kalman filter and includes an accurate LEO orbit model.
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Fibre-Reinforced-Plastics are composite materials composed by thin fibres with high mechanical properties, made to work together with a cohesive plastic matrix. The huge advantages of fibre reinforced plastics over traditional materials are their high specific mechanical properties i.e. high stiffness and strength to weight ratios. This kind of composite materials is the most disruptive innovation in the structural materials field seen in recent years and the areas of potential application are still many. However, there are few aspects which limit their growth: on the one hand the information available about their properties and long term behaviour is still scarce, especially if compared with traditional materials for which there has been developed an extended database through years of use and research. On the other hand, the technologies of production are still not as developed as the ones available to form plastics, metals and other traditional materials. A third aspect is that the new properties presented by these materials e.g. their anisotropy, difficult the design of components. This thesis will provide several case-studies with advancements regarding the three limitations mentioned. In particular, the long term mechanical properties have been studied through an experimental analysis of the impact of seawater on GFRP. Regarding production methods, the pre-impregnated cured in autoclave process was considered: a rapid tooling method to produce moulds will be presented, and a study about the production of thick components. Also, two liquid composite moulding methods will be presented, with a case-study regarding a large component with sandwich structure that was produced with the Vacuum-Assisted-Resin-Infusion method, and a case-study regarding a thick con-rod beam that was produced with the Resin-Transfer-Moulding process. The final case-study will analyse the loads acting during the use of a particular sportive component, made with FRP layers and a sandwich structure, practical design rules will be provided.
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Fra i sistemi di propulsione elettrica per satelliti, il Pulsed Plasma Thruster, PPT, è quello dal design più semplice. È anche il primo sistema di propulsione elettrica utilizzato in un satellite artificiale, ossia ZOND-2 lanciato nel 1964 dall’Unione Sovietica. Tuttavia, dopo circa 50 anni di ricerca, la comprensione teorica e sperimentale di questo dispositivo rimane limitata. Questo elaborato di tesi magistrale indaga sul sottosistema di accensione del PPT, cercando di mettere in luce alcuni aspetti legati al lifetime della spark plug, SP. Tale SP, o candela, è l’attuatore del sottosistema di accensione. Questa produce una scintilla sulla sua superficie, la quale permette la realizzazione della scarica elettrica principale fra i due elettrodi del motore. Questa scarica crea una sottile parete di plasma che, per mezzo della forza elettromagnetica di Lorentz, produce la spinta del PPT. Poiché la SP si trova all’interno del catodo del motore e si affaccia nella camera di scarica, questa soffre di fenomeni di corrosione e di deposizione carbonacea proveniente dal propellente. Questi fenomeni possono limitare notevolmente il lifetime della SP. I parametri connessi alla vita operativa della SP sono numerosi. In questo elaborato si è analizzata la possibilità di utilizzare una elettronica di accensione della candela alternativa alla classica soluzione che utilizza un trasformatore. Il sottosistema di accensione classico e quello nuovo sono stati realizzati e testati, per metterne in luce le differenze ed i possibili vantaggi/svantaggi.
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In a world focused on the need to produce energy for a growing population, while reducing atmospheric emissions of carbon dioxide, organic Rankine cycles represent a solution to fulfil this goal. This study focuses on the design and optimization of axial-flow turbines for organic Rankine cycles. From the turbine designer point of view, most of this fluids exhibit some peculiar characteristics, such as small enthalpy drop, low speed of sound, large expansion ratio. A computational model for the prediction of axial-flow turbine performance is developed and validated against experimental data. The model allows to calculate turbine performance within a range of accuracy of ±3%. The design procedure is coupled with an optimization process, performed using a genetic algorithm where the turbine total-to-static efficiency represents the objective function. The computational model is integrated in a wider analysis of thermodynamic cycle units, by providing the turbine optimal design. First, the calculation routine is applied in the context of the Draugen offshore platform, where three heat recovery systems are compared. The turbine performance is investigated for three competing bottoming cycles: organic Rankine cycle (operating cyclopentane), steam Rankine cycle and air bottoming cycle. Findings indicate the air turbine as the most efficient solution (total-to-static efficiency = 0.89), while the cyclopentane turbine results as the most flexible and compact technology (2.45 ton/MW and 0.63 m3/MW). Furthermore, the study shows that, for organic and steam Rankine cycles, the optimal design configurations for the expanders do not coincide with those of the thermodynamic cycles. This suggests the possibility to obtain a more accurate analysis by including the computational model in the simulations of the thermodynamic cycles. Afterwards, the performance analysis is carried out by comparing three organic fluids: cyclopentane, MDM and R245fa. Results suggest MDM as the most effective fluid from the turbine performance viewpoint (total-to-total efficiency = 0.89). On the other hand, cyclopentane guarantees a greater net power output of the organic Rankine cycle (P = 5.35 MW), while R245fa represents the most compact solution (1.63 ton/MW and 0.20 m3/MW). Finally, the influence of the composition of an isopentane/isobutane mixture on both the thermodynamic cycle performance and the expander isentropic efficiency is investigated. Findings show how the mixture composition affects the turbine efficiency and so the cycle performance. Moreover, the analysis demonstrates that the use of binary mixtures leads to an enhancement of the thermodynamic cycle performance.
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The thesis work is developed under the European Student Earth Orbiter (ESEO) project supported by the European Space Agency (ESA) in order to help prepare a well-qualified space-engineering workforce for Europe's future. In the following chapters we are going to analyse how to simulate some ESEO subsystem. First of all, the Thermal Subsystem that evaluates the temperature evolution of on-board instruments. For this purpose, simulating also the orbital and attitude dynamics of the spacecraft, it is necessary in order to evaluate external environmental fluxes. The Power Subsystem will be the following step and it models the ability of a spacecraft to produce and store electrical energy. Finally, we will integrate in our software a block capable of simulating the communication link between the satellite and the Ground Station (GS). This last step is designed and validated during the thesis preparation.
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The Gracias Laboratory at Johns Hopkins University has developed microgrippers which utilize chemically-actuated joints to be used in micro-surgery. These grippers, however, take up to thirty minutes to close fully when activated biochemicals in the human body. This is very problematic and could limit the use of the devices in surgery. It is the goal of this research to develop a gripper that uses theGracias Laboratory's existing joints in conjunction with mechanical components to decrease the closing time. The purpose of including the mechanical components is to induce a state of instability at which time a small perturbation would cause the joint to close fully.The main concept of the research was to use the lateral buckling of a triangular gripper geometry and use a toggle mechanism to decrease the closure time of the device. This would create a snap-action device mimicking the quick closure of a Venus flytrap. All developed geometries were tested using finite element analysis to determine ifloading conditions produced the desired buckled shape. This research examines lateral buckling on the micro-scale and the possibility ofusing this phenomenon in a micro-gripper. Although a final geometry with the required deformed shaped was not found, this document contains suggestions for future geometries that may produce the correct deformed shape. It was determined through this work that in order to obtain the desired deformed shape, polymeric sections need to be added to the geometry. This simplifies the analysis and allows the triangular structure to buckle in the appropriate way due to the added joints. Future work for this project will be completed by undergraduate students at Bucknell University. Fabrication and testing of devices will be done at Johns Hopkins University in the Gracias Laboratory.