PHYSICAL TOPOLOGY DESIGN AND ROUTING ALGORITHMS FOR DEGREE-CONSTRAINED FSO MESH NETWORKS

Free-space optical (FSO) mesh networks are emerging as broadband communication networks because of their high bandwidth (up to Gbps), low cost, and easy installation. However, there are two existing problems in the deployment of FSO networks: the physical topology design problem, and the routing problem. This dissertation presents an algorithm for the physical topology design of FSO mesh networks in order to enhance network reliability under defined degree constraint of each FSO node. The methodology presented enlarges the minimum angle between adjacent links at each node. Simulation results show that, compared to other methods, the proposed algorithm not only provides higher connectivity and lower delay for FSO networks, but also makes the FSO networks so constructed more tolerant in a dynamically changing environment. Further, this algorithm is enhanced to include the 3-dimensional (3-D) space, where the heights of the FSO nodes are not identical. This enhancement will apply to FSO nodes in difficult terrains where it is not feasible or desirable to have the FSO transceivers on a plane.This dissertation also addresses the routing problem in degree-constrained free-space optical (FSO) mesh networks. To solve the routing problem, four different routing algorithms are proposed. Their performances are evaluated through extensive simulations for a number of FSO mesh networks with different topologies and nodal degrees. The performance parameter against which these algorithms are evaluated is the mean end-to-end delay. The proposed least cost path (LCP) routing algorithm, which is based on minimizing the end-to-end delay, is considered as the bench mark. The performance of each of the other three algorithms is evaluated against the bench mark. The proposed minimum hop count with load-balancing (MHLB) routing algorithm is based on the number of hops between the source and the destination node to route the traffic. Simulation shows that the MHLB routing algorithm performs best in most cases compared with the other two. It results in minimum average delay and least blocked traffic

Advanced Characterization and On-Line Process Monitoring of Additively Manufactured Materials and Components

This reprint is concerned with the microstructural characterization and the defect analysis of metallic additively manufactured (AM) materials and parts. Special attention is paid to the determination of residual stress in such parts and to online monitoring techniques devised to predict the appearance of defects. Finally, several non-destructive testing techniques are employed to assess the quality of AM materials and parts

Enabling the Development and Implementation of Digital Twins : Proceedings of the 20th International Conference on Construction Applications of Virtual Reality

Welcome to the 20th International Conference on Construction Applications of Virtual Reality (CONVR 2020). This year we are meeting on-line due to the current Coronavirus pandemic. The overarching theme for CONVR2020 is "Enabling the development and implementation of Digital Twins". CONVR is one of the world-leading conferences in the areas of virtual reality, augmented reality and building information modelling. Each year, more than 100 participants from all around the globe meet to discuss and exchange the latest developments and applications of virtual technologies in the architectural, engineering, construction and operation industry (AECO). The conference is also known for having a unique blend of participants from both academia and industry. This year, with all the difficulties of replicating a real face to face meetings, we are carefully planning the conference to ensure that all participants have a perfect experience. We have a group of leading keynote speakers from industry and academia who are covering up to date hot topics and are enthusiastic and keen to share their knowledge with you. CONVR participants are very loyal to the conference and have attended most of the editions over the last eighteen editions. This year we are welcoming numerous first timers and we aim to help them make the most of the conference by introducing them to other participants

Defect Detection on Inclined Textured Planes Using the Shape from Texture Method and the Delaunay Triangulation

We present one method for detecting defects on an inclined textured plane. This method uses a combination of a shape from texture (SFT) method with the Delaunay triangulation technique. The SFT method provides the theoretical equation of the plane orientation in two steps. First, a wavelet decomposition allows us to build an image of the inverse of the local frequency, that is the scale, that we call the local scales map. Then we perform an interpolation of this map using the equation of the theoretical variation of the scales. With the interpolation parameters it is possible to extract the texels by the use of an adaptive thresholding for each pixel of this map. Then we compute the centers of each texel in order to match a mesh on it after processing a Delaunay triangulation. When there is a defect, the regularity of the triangulation is disturbed, so one hole appears in the mesh.</p

MC 2019 Berlin Microscopy Conference - Abstracts

Das Dokument enthält die Kurzfassungen der Beiträge aller Teilnehmer an der Mikroskopiekonferenz "MC 2019", die vom 01. bis 05.09.2019, in Berlin stattfand

Gaze-Based Human-Robot Interaction by the Brunswick Model

We present a new paradigm for human-robot interaction based on social signal processing, and in particular on the Brunswick model. Originally, the Brunswick model copes with face-to-face dyadic interaction, assuming that the interactants are communicating through a continuous exchange of non verbal social signals, in addition to the spoken messages. Social signals have to be interpreted, thanks to a proper recognition phase that considers visual and audio information. The Brunswick model allows to quantitatively evaluate the quality of the interaction using statistical tools which measure how effective is the recognition phase. In this paper we cast this theory when one of the interactants is a robot; in this case, the recognition phase performed by the robot and the human have to be revised w.r.t. the original model. The model is applied to Berrick, a recent open-source low-cost robotic head platform, where the gazing is the social signal to be considered