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International audienc

Unsupervised Polygonal Reconstruction of Noisy Contours by a Discrete Irregular Approach

International audienceIn this paper, we present an original algorithm to build a polygonal reconstruction of noisy digital contours. For this purpose, we first improve an algorithm devoted to the vectorization of discrete irregular isothetic objects. Afterwards we propose to use it to define a reconstruction process of noisy digital contours. More precisely, we use a local noise detector, introduced by Kerautret and Lachaud in IWCIA 2009, that builds a multi-scale representation of the digital contour, which is composed of pixels of various size depending of the local amount of noise. Finally, we compare our approach with previous works, by con- sidering the Hausdorff distance and the error on tangent orientations of the computed line segments to the original perfect contour. Thanks to both synthetic and real noisy objects, we show that our approach has interesting performance, and could be applied in document analysis systems

Virtual Reality Simulation of Glenoid Reaming Procedure

Glenoid reaming is a bone machining operation in Total Shoulder Arthroplasty (TSA) in which the glenoid bone is resurfaced to make intimate contact with implant undersurface. While this step is crucial for the longevity of TSA, many surgeons find it technically challenging. With the recent advances in Virtual Reality (VR) simulations, it has become possible to realistically replicate complicated operations without any need for patients or cadavers, and at the same time, provide quantitative feedback to improve surgeons\u27 psycho-motor skills. In light of these advantages, the current thesis intends to develop tools and methods required for construction of a VR simulator for glenoid reaming, in an attempt to construct a reliable tool for preoperative training and planning for surgeons involved with TSA. Towards the end, this thesis presents computational algorithms to appropriately represent surgery tool and bone in the VR environment, determine their intersection and compute realistic haptic feedback based on the intersections. The core of the computations is constituted by sampled geometrical representations of both objects. In particular, point cloud model of the tool and voxelized model of bone - that is derived from Computed Tomography (CT) images - are employed. The thesis shows how to efficiently construct these models and adequately represent them in memory. It also elucidates how to effectively use these models to rapidly determine tool-bone collisions and account for bone removal momentarily. Furthermore, the thesis applies cadaveric experimental data to study the mechanics of glenoid reaming and proposes a realistic model for haptic computations. The proposed model integrates well with the developed computational tools, enabling real-time haptic and graphic simulation of glenoid reaming. Throughout the thesis, a particular emphasis is placed upon computational efficiency, especially on the use of parallel computing using Graphics Processing Units (GPUs). Extensive implementation results are also presented to verify the effectiveness of the developments. Not only do the results of this thesis advance the knowledge in the simulation of glenoid reaming, but they also rigorously contribute to the broader area of surgery simulation, and can serve as a step forward to the wider implementation of VR technology in surgeon training programs

Insurance law and the Financial Ombudsman Service [in 3 volumes]

This thesis is the only study there is of the workings of the Financial Ombudsman Service ('FOS') and a comparison between court and FOS attitudes and approaches to insurance cases. A court and the FOS may decide matters differently because the FOS does not have to apply the law strictly, whilst a court does. The author of this thesis has examined the FOS and Financial Services Authority ('FSA') websites, handbooks and other material, and all of the near monthly journals of Ombudsman News ('O.N.') since the FOS began in 2001, analysing it against the law to determine the question of this thesis: whether the FOS should in fact apply the law strictly, and not allow principles of fairness and reasonableness to override the law in the particular circumstances of a case. Should certainty of outcome and of applying law established and modified over hundreds of years be sacrificed to allow the FOS to apply its overriding discretion in the interests of justice in a relatively few cases? Should both insurers and insureds be able to obtain legal advice on their relative positions, without that advice having to mention unpredictable outcomes if the ombudsman chooses not to follow the strict legal position? If the law does not offer the consumer insured enough protection, should the FOS be the forum that does, and if so, does it give enough protection? This study does not look at the decisions of the Insurance Ombudsman Bureau ('IOB') which preceded the FOS. Where a point is not dealt with below, it has not been highlighted in FOS publications to date and it is unclear how relevant IOB decisions on that point will be