Model Fusion for the Compatibility Verification of Software Components

Similarly as in earlier work on component compatibility, the behavior of components is specified by component interface languages, defined by labeled Petri nets. In the case of composition of concurrent components, the requests from different components can be interleaved, and - as shown earlier - such interleaving can result in deadlocks in the composed system even if each pair of interacting components is deadlock–free. Therefore the elements of a component–based system are considered compatible only if the composition is deadlock–free. This paper formally defines model fusion, which is a composition of net models of individual components that represents the interleaving of interface languages of interacting components. It also shows that the verification of component compatibility can avoid the exhaustive analysis of the composed state space

Common Data Fusion Framework : An open-source Common Data Fusion Framework for space robotics

Multisensor data fusion plays a vital role in providing autonomous systems with environmental information crucial for reliable functioning. In this article, we summarize the modular structure of the newly developed and released Common Data Fusion Framework and explain how it is used. Sensor data are registered and fused within the Common Data Fusion Framework to produce comprehensive 3D environment representations and pose estimations. The proposed software components to model this process in a reusable manner are presented through a complete overview of the framework, then the provided data fusion algorithms are listed, and through the case of 3D reconstruction from 2D images, the Common Data Fusion Framework approach is exemplified. The Common Data Fusion Framework has been deployed and tested in various scenarios that include robots performing operations of planetary rover exploration and tracking of orbiting satellites

A Virtual Model of the Human Cervical Spine for Physics-based Simulation and Applications

Utilizing recent advances in computer technology, Our Biomechanics Laboratory have made an effort to integrate computer animation and engineering analysis software into biomedical research, specifically towards simulation and animation of in vitro experimentation of the human cervical spine in the virtual world. The objectives of this study were to develop a virtual model of the human cervical spine for physics-based simulation and to apply the virtual model to studies of different surgical procedures and instrumentation. A process for creating an accurate virtual model of the human cervical spine was developed. The model consisted of seven vertebrae (C2-T1) connected with soft tissue components: intervertebral joint, facet joints, and ligaments. The soft tissue components were assigned nonlinear viscoelastic properties. The evaluation of the model included the percent contribution of rotation relative to global rotation, coupling behaviors, helical axes of motion pattern, global rotational stiffness curves, and animations of the disc and facet forces. This model was used to evaluate different mounting configurations for axial rotation testing and to identify a set of end constraint conditions that produced physiologic responses during axial rotational loading. This model was also used to simulate the biomechanical responses of single-level cervical fusion. The single-level fusion was found to produce increased motion compensation at the adjacent segments during flexion and extension. Greater increases in the disc forces were found in the spinal level superior to the fusion during flexion and inferior to the fusion during flexion extension. This model was also used to study of the biomechanical effects of different design features for cervical disc arthroplasty. A constrained spherical joint placed at the disc level significantly increased facet loads during extension. Lowering the rotational axis of the spherical joint into the subjacent body also caused a marginal increase in facet loading during flexion, extension, and lateral bending. Un-constraining the spherical joint to a plane at the disc level minimized facet load build up. The virtual model bridges the gap between the cadaveric-based in vitro tests and clinicalbased experimental studies to further the research and educational knowledge of cervical spine biomechanics

Dynamic thermal-hydraulic modelling of the EU DEMO HCPB breeding blanket cooling loops

A global, system-level thermal-hydraulic model of the EU DEMO tokamak fusion reactor is currently under development and implementation in a suitable software at Politecnico di Torino, including the relevant heat transfer and fluid dynamics phenomena, which affect the performance of the different cooling circuits and components and their integration in a consistent design. The model is based on an object-oriented approach using the Modelica language, which easily allows to preserve the high modularity required at this stage of the design. The first module of the global model will simulate the blanket cooling system and will be able to investigate different coolant options and different cooling schemes, to be adapted to the different blanket systems currently under development in the Breeding Blanket (BB) project. The paper presents the Helium-Cooled Pebble Bed (HCPB) module of the EU DEMO blanket cooling loops system model. The model is used to compare different schemes for the cooling of the different components of the HCPB BB, and to suggest improvements aimed at optimizing the pumping power required by the cooling system. The model is then used to analyse a pulsed scenario, characteristic of the EU DEMO operation

City Data Fusion: Sensor Data Fusion in the Internet of Things

Internet of Things (IoT) has gained substantial attention recently and play a significant role in smart city application deployments. A number of such smart city applications depend on sensor fusion capabilities in the cloud from diverse data sources. We introduce the concept of IoT and present in detail ten different parameters that govern our sensor data fusion evaluation framework. We then evaluate the current state-of-the art in sensor data fusion against our sensor data fusion framework. Our main goal is to examine and survey different sensor data fusion research efforts based on our evaluation framework. The major open research issues related to sensor data fusion are also presented.Comment: Accepted to be published in International Journal of Distributed Systems and Technologies (IJDST), 201

Using Taguchi method to optimize welding pool of dissimilar laser welded components

In the present work CO2 continuous laser welding process was successfully applied and optimized for joining a dissimilar AISI 316 stainless steel and AISI 1009 low carbon steel plates. Laser power, welding speed, and defocusing distance combinations were carefully selected with the objective of producing welded joint with complete penetration, minimum fusion zone size and acceptable welding profile. Fusion zone area and shape of dissimilar austenitic stainless steel with ferritic low carbon steel were evaluated as a function of the selected laser welding parameters. Taguchi approach was used as statistical design of experiment (DOE) technique for optimizing the selected welding parameters in terms of minimizing the fusion zone. Mathematical models were developed to describe the influence of the selected parameters on the fusion zone area and shape, to predict its value within the limits of the variables being studied. The result indicates that the developed models can predict the responses satisfactorily