<p>The development of advanced embedded systems requires a systematic approach as well as advanced tool support in dealing with their increasing complexity. This complexity is due to the increasing functionality that is implemented in embedded systems and stringent (and conflicting) requirements placed upon such systems from various stakeholders. The corresponding system development involves several specialists employing different modeling languages and tools. Integrating their work and the results thereof then becomes a challenge. In order to facilitate system architecting and design integration of different models, an approach that provides dedicated workspaces/views supported by structured information management and information exchange between domain models and tools is required.</p><p>This work is delimited to the context of embedded systems design and taking a model based approach. The goal of the work is to study possible technical solutions for integrating different models and tools, and to develop knowledge, support methods and a prototype tool platform.</p><p>To this end, this thesis examines a number of approaches that focus on the integration of multiple models and tools. Selected approaches are compared and characterized, and the basic mechanisms for integration are identified. Several scenarios are identified and further investigated in case studies. Two case studies have been performed with model transformations as focus. In the first one, integration of Matlab/Simulink® and UML2 are discussed with respect to the motivations, technical possibilities, and challenges. A preliminary mapping strategy, connecting a subset of concepts and constructs of Matlab/Simulink® and UML2, is presented together with a prototype implementation in the Eclipse environment. The second case study aims to enable safety analysis based on system design models in a UML description. A safety analysis tool, HiP-HOPS (Hierarchically Performed Hazard Origin and Propagation Studies), is partially integrated with a UML tool where an EAST-ADL2 based architecture model is developed. The experience and lessons learned from the experiments are reported in this thesis.</p><p>Multiple specific views are involved in the development of embedded systems. This thesis has studied the integration between system architecture design, function development and safety analysis through using UML tools, Matlab/Simulink, and HiP-HOPS. The results indicate that model transformations provide a feasible and promising solution for integrating multiple models and tools. The contributions are believed to be valid for a large class of advanced embedded systems. However, the developed transformations so far are not really scalable. A systematic approach for efficient development of model transformations is desired to standardize the design process and reuse developed transformations. To this end, future studies will be carried out to develop guidelines for model and tool integration and to provide support for structured information at both meta level and instance level.</p>

<p>The finite response time of the turbocharger is the most notable effect oftransient operation on a turbocharged diesel engine. To fulfil future emission requirements high amounts of transient EGR will be required. This impliesthat advanced turbocharger systems have to be introduced to enable high boost pressures with improved or at least maintained response time. The increased amount of tunable parameters from the more advanced turbocharging system will make it difficult to optimise the engine experimentally. Therefore the wish is to optimise the engine numerically, however this is a difficult task which demands more knowledge within the field of modelling the gas exchange system and its components, which is the aim of the present work. Engine simulations have been performed in the 1-dimensional fluid dynamic code GT-Power for transient operation and validated with engine measurements. The turbine was modelled according to the state of the art which is via look-up tables with measured turbine performance data from a steady-flow rig and used under the assumption that the turbine behaves in a quasi-steady manner. Turbine performance data was also obtained via the semi-empirical turbine design software, Rital for comparison. A heavy-duty diesel engine has been modelled with two different gas exchange system configurations. The standard configuration with a single twin-entry turbine and a rebuilt gas exchange system including a two-stage turbocharging system and high pressure loop for EGR. The results shows that it is difficult to predict the performance of the gas exchange system and its components, especially the turbine performance. When trying to predict turbine performance under transient operation the difficulties added, compared to stationary operation are long scale transients as wall temperature gradients in the cylinder and the exhaust manifold which directly influences the amount of isentropic energy to the turbine. This makes it even more difficult to predict the isentropic exhaust gas energy content compared to stationary operation, which is difficult to measure and therefore to state how well the turbine model actually performs. However, even though it is difficult to predict engine performance in detail the models have proved to be useful for concept studies as a help in engine design.</p>

<p>The drying sequence in the manufacturing process for paperboard involves evaporation of water, primarily from within the fibres. The vapour is then transported out of the web by pressure or concentration gradients. As the moisture transport from the paper web to the ambient is quicker than the moisture transport within the fibre network to the surfaces of the web, moisture gradients develop through the thickness of the web. This work concerns effects on the mechanics of paper drying from the variation in moisture through the relatively thin structures of paper and paperboard.</p><p>Distributions of inplane residual stresses through paper materials in the unloaded state after drying are believed to be caused by the varying moisture through the thickness during drying. The distributions in general exhibit compressive stress near the board surfaces and tensile stress in the interior of the board. This may be modified after drying and is also affected by structural variation in the material between different plies of multi-ply paperboards.</p><p>The stress development during drying is important because it influences the resulting material properties of the paper and because it can lead to curl, which is a quality problem. The residual stresses themselves are an error source in simulation or evaluation of the mechanical behaviour of paper.</p><p>In this work, residual stress distributions in paperboard were determined experimentally, to clarify the mechanisms of residual stress build-up. An experimental method for such tests was also developed. Based on the experimental findings, the mechanics of paper drying was modelled and the stress build-up simulated. Simulation offers a way of studying how the properties of paper develop during drying of wet paper webs.</p>

No description available.

<p>Dealing properly with electronics and software will be a strong competitive advantage in the automotive sector in the near future. Electronics are driving current innovations and are at the same time becoming a larger part of the cost of the vehicle. In order to be successful as an automotive manufacturer, innovations must be introduced in the vehicle without compromising the final price tag. Also, the electronics has to compete with, and win over, the dependability of well known and proven mechanical solutions.</p><p>Structure related costs can be reduced by designing a modular system, volume related costs can be reduced by utilizing fewer electronic control units that shares software performing a variety of functions. To achieve a modular system careful consideration must be applied in the architecture design process. Architecting is commonly referred to as an art, performed in a qualitative manner. This thesis provides a quantitative method for architecture design and evaluation targeting modular architectures.</p><p>The architecture design method is based on a simple underlying information model. This model is extended through practical experiences in case studies to include support for configuration and documentation.</p><p>An information model is a key enabler for managing the increasing complexity of automotive embedded systems. The model provides the basis for establishing the analyzable documentation that is required to ensure the dependability of the systems, specifically in terms of need for reliability, maintainability and safety. An information model supports traceability both within the product, across components, and also between different organizational units using different views of the product throughout the lifecycle.</p><p>Further, some general issues of systems engineering and model based development related to the engineering of automotive embedded systems are discussed. Considerations for introducing a model based development process are covered. Also, the maturity of development processes and requirements on tools in an automotive context are evaluated. The ideas and methods presented in this thesis have been developed and tried in an industrial setting through a range of case studies.</p>

<p>This licentiate thesis highlights some topics on modular modelling for dynamical simulation with application to fluid systems. The results are based on experience from the development of the fuel cell component simulation environment NFCCPP. The general application is cross-enterprise simulation of technical systems. There are four main topics: component definition including selection of interfaces, lumped modelling of fluid components, the use of dynamical equations to reduce simulation time in large systems and methods of to protect the intellectual property (IP) of a component.</p><p>An overview of different dynamical fluid simulation tools such as HOPSAN, MATLAB/Simulink and Easy5 is presented. Special focus is on interfaces, where different approaches for representing interfaces are presented using an illustrative example. Selecting interfaces is however not a separated task from how to set up and solve the underlying equations, which also is shown. Equations to model a lumped component are derived, to get a mathematical background to what problems there are to solve. These equations are derived especially to be applicable in block model software simulation tools such as MATLAB/Simulink. The equations are also compared with the bond-graph approach of representing dynamical systems. A twinscrew compressor is modelled in MATLAB/Simulink as an implementation of these equations. A method to decrease the simulation time in dynamical fluid system is also presented. The technique is to add virtual mass in the force equation to get a slower acceleration of the fluid. Using this slower response, it is possible to use larger time-steps when integrating the equations and thus the total simulation time can be reduced. The error introduced using this method is a modelling error in the time domain, and it is comparable with using unit transmission lines (UTL:s), as does HOPSAN.</p><p>The protection of the intellectual property (IP) of a component model is presented. The concept of clamping is thoroughly explained, as it often is overlooked in conventional IPprotection. Three concepts for code protection are presented: “Centralised simulation with remote user control”, “Localised simulation with simulation-time model usage control” and “Parallel distributed simulation”. The NFCCPP implementation of the concept “Localised simulation with simulation-time model usage control” is presented in more detail.</p>

Background: Ureteral herniations are a rare occurrence, generally found incidentally on cross sectional imaging or during surgical intervention for unrelated processes. Several locations of ureteral herniations can occur including the inguinal, femoral, sciatic, obturator, and thoracic regions. While few reports of ureteral hernias are reported in the literature overall, the vast majority of those reported are inguinoscrotal herniations found during evaluation and treatment of inguinal hernias. Pelvic outlet ureteral herniations intrinsically are more common secondary to their dependent locations. Intrathoracic ureteral herniations through diaphragmatic defects are an exceptionally rare subset of ureteral herniations and have only been described sparingly. Fewer than ten case reports of diaphramatic ureteral herniations have been reported and none have described both cystoscopic management and open reconstruction. Case presentation: We report the case of a 81 year old female with flank pain who was found to have idiopathic diaphragmatic hernia with incarcerated proximal ureter. She had no prior injury or surgery that explained her clinical presentation. She was initially observed and then managed conservatively with ureteral stent exchanges. Ultimately she underwent open surgical repair of her diaphragmatic hernia, reduction, resection and anastomosis of redundant proximal incarcerated ureteral segment, and nephropexy for a hypermobile right renal unit. This case report illustrates the pre-and post-operative imaging studies of a very rare intrathoracic ureteral herniation as well as surgical approach to repair. Conclusion: A herniated ureter is a potential source of serious renal and ureteral complications. The thoracic herniation of ureter is the rarest of the ureteral herniations. When discovered, they should be managed to preserve renal function and prevent strangulation of the affected segment of ureter. This case report documents the treatment of a thoracic ureteral herniation with observation, conservative endoscopic management, and finally open surgical reconstruction.

Thesis (M. Div.)--St. Vladimir's Orthodox Theological Seminary, Crestwood, N.Y., 2003. / Abstract. Includes bibliographical references (leaves 99-102).

Thesis (M. Div.)--St. Vladimir's Orthodox Theological Seminary, Crestwood, N.Y., 2003. / Abstract. Includes bibliographical references (leaves 99-102).

Thesis (M. Div.)--St. Vladimir's Orthodox Theological Seminary, Crestwood, N.Y., 2003. / Abstract. Includes bibliographical references (leaves 99-102).