Automatic initialisation of 3D deformable models for cartilage segmentation

Deformable models are a highly accurate and flexible approach to segmenting structures in medical images. The primary drawback of deformable models is that they are sensitive to initialisation, with accurate and robust results often requiring initialisation close to the true object in the image. Automatically obtaining a good initialisation is problematic for many structures in the body. The cartilages of the knee are a thin elastic material that cover the ends of the bone, absorbing shock and allowing smooth movement. The degeneration of these cartilages characterize the progression of osteoarthritis. The state of the art in the segmentation of the cartilage are 2D semi-automated algorithms. These algorithms require significant time and supervison by a clinical expert, so the development of an automatic segmentation algorithm for the cartilages is an important clinical goal. In this paper we present an approach towards this goal that allows us to automatically providing a good initialisation for deformable models of the patella cartilage, by utilising the strong spatial relationship of the cartilage to the underlying bone.

Fracture toughness of SIC, Si3N4, and sialon ceramics using controlled surface flaws

Knoop and Vickers indentation cracks have frequently been used as model 'precracks' in ceramic bend specimens for fracture toughness (K1c) determination. Indentation residual stress reduces the measured K1c but can be removed or accounted for by grinding, annealing, or modelling. Values of K1c are obtained for four materials using Vickers indentations and an improved stress intensity factor. Methods for residual stress removal or incorporation are compared, and the most reliable stress removal alternative is identified for each material. © 1996 The Institute of Materials.

Juror need for cognition and sensitivity to methodological flaws in expert evidence

Two studies investigated the influence of juror need for cognition on the systematic and heuristic processing of expert evidence. U.S. citizens reporting for jury duty in South Florida read a 15-page summary of a hostile work environment case containing expert testimony. The expert described a study she had conducted on the effects of viewing sexualized materials on men's behavior toward women. Certain methodological features of the expert's research varied across experimental conditions. In Study 1 (N = 252), the expert's study was valid, contained a confound, or included the potential for experimenter bias (internal validity) and relied on a small or large sample (sample size) of college undergraduates or trucking employees (ecological validity). When the expert's study included trucking employees, high need for cognition jurors in Study 1 rated the expert more credible and trustworthy than did low need for cognition jurors. Jurors were insensitive to variations in the study's internal validity or sample size. Juror ratings of plaintiff credibility, plaintiff trustworthiness, and study quality were positively correlated with verdict. In Study 2 (N = 162), the expert's published or unpublished study (general acceptance) was either valid or lacked an appropriate control group (internal validity) and included a sample of college undergraduates or trucking employees (ecological validity). High need for cognition jurors in Study 2 found the defendant liable more often and evaluated the expert evidence more favorably when the expert's study was internally valid than when an appropriate control group was missing. Low need for cognition jurors did not differentiate between the internally valid and invalid study. Variations in the study's general acceptance and ecological validity did not affect juror judgments. Juror ratings of expert and plaintiff credibility, plaintiff trustworthiness, and study quality were positively correlated with verdict. The present research demonstrated that the need for cognition moderates juror sensitivity to expert evidence quality and that certain message-related heuristics influence juror judgments when ability or motivation to process systematically is low. ^

Chance to put right the flaws in insanity laws

Opinion & Analysis: Chance to put right the flaws in insanity laws

“I woke up and realised the ground had shifted”: the shifting terrain of English curriculum

The theme of this conference comes from the epitaph on the Lewis Carroll’s gravesite. “Is All our Life then But A Dream?” This seems fitting for a time when so much change in the terrain of English makes us feel as if we are somnambulating through a surrealist landscape. Like Lewis Carroll’s Alice, (Carroll, 2003) we might find ourselves at strange tea parties with bureaucratic mad hatters, and just when we think we have a grasp of applying new theory in our teaching, we fall down another rabbit hole, to swim in confusion as some queen calls out, ‘off with their heads!’. The shifting ground in English inevitably moves in response to waves of theory influencing classroom practice. Each new paradigm has claimed to liberate language learners from the flaws of the previous model. Each linguist or literary theorist who shaped the new paradigm no doubt dreamt of a new population emerging from school as more powerfully literate citizens than the previous generation.

Shifting the child protection juggernaut to earlier intervention

"For every complex problem there is a solution that is simple, neat and wrong (M.L. Mencken, US writer and social commentator). Nowhere is this quote more apt than when applied to finding over-simplified solutions to the complex problem of looking after the safety and well-being of vulnerable children. The easiest formula is, of course, to ‘rescue children from dysfunctional families’, a line taken recently in the monograph by the right wing think tank, Centre for Independent Studies (Sammut & O’Brien 2009). It is reasoning with fatal flaws. This commentary provides a timely reminder of the strong arguments which lie behind the national and international shift to supporting children and families through universal and specialist community-based services, rather than weighting all resources into statutory child protection interventions. A brief outline of the value of developing the resources to support children in their families, and the problems with 'rescuing' children through the child protection system are discussed.

Simulation of delaminations in composite laminates

Lamb waves propagation in composite materials has been studied extensively since it was first observed in 1982. In this paper, we show a procedure to simulate the propagation of Lamb waves in composite laminates using a two-dimensional model in ANSYS. This is done by simulating the Lamb waves propagating along the plane of the structure in the form of a time dependent force excitation. In this paper, an 8-layered carbon reinforced fibre plastic (CRFP) is modelled as transversely isotropic and dissipative medium and the effect of flaws is analyzed with respect to the defects induced between various layers of the composite laminate. This effort is the basis for the future development of a 3D model for similar applications.

Comprehensive standardized data definitions for acute coronary syndrome research in emergency departments in Australasia

Patients with chest discomfort or other symptoms suggestive of acute coronary syndrome (ACS) are one of the most common categories seen in many Emergency Departments (EDs). While the recognition of patients at high-risk of ACS has improved steadily, identifying the majority of chest pain presentations who fall into the low-risk group remains a challenge. Research in this area needs to be transparent, robust, applicable to all hospitals from large tertiary centres to rural and remote sites, and to allow direct comparison between different studies with minimum patient spectrum bias. A standardised approach to the research framework using a common language for data definitions must be adopted to achieve this. The aim was to create a common framework for a standardised data definitions set that would allow maximum value when extrapolating research findings both within Australasian ED practice, and across similar populations worldwide. Therefore a comprehensive data definitions set for the investigation of non-traumatic chest pain patients with possible ACS was developed, specifically for use in the ED setting. This standardised data definitions set will facilitate ‘knowledge translation’ by allowing extrapolation of useful findings into the real-life practice of emergency medicine.

Rethinking regional green space networks in China

Ecological networks are often represented as utopian webs of green meandering through cities, across states, through regions and even across a country (Erickson, 2006, p.28; Fabos, 2004, p.326; Walmsley, 2006). While this may be an inspiring goal for some in developed countries, the reality may be somewhat different in developing countries. China, in its shift to urbanisation and suburbanisation, is also being persuaded to adjust its planning schemes according to these aspirational representations of green spaces (Yu et al, 2006, p.237; Zhang and Wang, 2006, p.455). The failure of other countries to achieve regional goals of natural and cultural heritage protection on the ground in this way (Peterson et al, 2007; Ryan et al, 2006; von Haaren and Reich, 2006) suggests that there may be flaws in the underpinning concepts that are widely circulated in North American and Western European literature (Jongman et al, 2004; Walmsley, 2006). In China, regional open space networks, regional green infrastructure or regional ecological corridors as we know them in the West, are also likely to be problematic, at least in the foreseeable future. Reasons supporting this view can be drawn from lessons learned from project experience in landscape planning and related fields of study in China and overseas. Implementation of valuable regional green space networks is problematic because: • the concept of region as a spatial unit for planning green space networks is ambiguous and undefinable for practical purposes; • regional green space networks traditionally require top down inter-governmental cooperation and coordination which are generally hampered by inequalities of influence between and within government agencies; • no coordinating body with funding powers exists for regional green space development and infrastructure authorities are still in transition from engineering authorities; • like other infrastructure projects, green space is likely to become a competitive rather than a complementary resource for city governments; • stable long-term management, maintenance and uses of green space networks must fit into a ‘family’ social structure rather than a ‘public good’ social structure, particularly as rural and urban property rights are being re-negotiated with city governments; and • green space provision is a performance indicator of urban improvement in cities within the city hierarchy and remains quantitatively-based (land area, tree number and per capita share) rather than qualitatively-based with local people as the focus.

Effects of opening in the cross girders of the flat bottom rail wagons to the load transferring mechanisms when used as road bridge deck

A Flat Bed Rail Wagon (FBRW) has been proposed as an alternative solution for replacing bridges on low traffic volume roads. The subject matter for this paper is to investigate the impediment to load transfer from cross girders to main girder, through visually identifiable structural flaws. Namely, the effect of having large openings at close proximity to the connection of the main girder to the cross girder of a FBRW was examined. It was clear that openings locally reduce the section modulus of the secondary members; however it was unclear how these reductions would affect the load transfer to the main girder. The results are presented through modeling grillage action for which the loads applied onto the FBRW were distributed through cross girders to the main girder.

Evaluations of Process Modeling Grammars : Ontological, Qualitative and Quantitative Analyses Using the Example of BPMN

Business processes have emerged as a well-respected variable in the design of successful corporations. However, unlike other key managerial variables, such as products and services, customers and employees, physical or digital assets, the conceptualization and management of business processes are in many respects in their infancy. In this book, Jan Recker investigates the notion of quality of business process modeling grammars. His evaluation is based on an ontological-, qualitative-, and quantitative analysis, applied to BPMN, a widely-used business process modeling grammar. His results reveal the ontological shortcomings of BPMN and how these manifest themselves in actual process modeling practice, as well as how they influence the usage behavior of modeling practitioners. More generally, his book constitutes a landmark for empirical technology assessment, analyzing the way in which design flaws in technology influence usage behavior.

Vision only pose estimation and scene reconstruction on airborne platforms

We aim to demonstrate unaided visual 3D pose estimation and map reconstruction using both monocular and stereo vision techniques. To date, our work has focused on collecting data from Unmanned Aerial Vehicles, which generates a number of significant issues specific to the application. Such issues include scene reconstruction degeneracy from planar data, poor structure initialisation for monocular schemes and difficult 3D reconstruction due to high feature covariance. Most modern Visual Odometry (VO) and related SLAM systems make use of a number of sensors to inform pose and map generation, including laser range-finders, radar, inertial units and vision [1]. By fusing sensor inputs, the advantages and deficiencies of each sensor type can be handled in an efficient manner. However, many of these sensors are costly and each adds to the complexity of such robotic systems. With continual advances in the abilities, small size, passivity and low cost of visual sensors along with the dense, information rich data that they provide our research focuses on the use of unaided vision to generate pose estimates and maps from robotic platforms. We propose that highly accurate (�5cm) dense 3D reconstructions of large scale environments can be obtained in addition to the localisation of the platform described in other work [2]. Using images taken from cameras, our algorithm simultaneously generates an initial visual odometry estimate and scene reconstruction from visible features, then passes this estimate to a bundle-adjustment routine to optimise the solution. From this optimised scene structure and the original images, we aim to create a detailed, textured reconstruction of the scene. By applying such techniques to a unique airborne scenario, we hope to expose new robotic applications of SLAM techniques. The ability to obtain highly accurate 3D measurements of an environment at a low cost is critical in a number of agricultural and urban monitoring situations. We focus on cameras as such sensors are small, cheap and light-weight and can therefore be deployed in smaller aerial vehicles. This, coupled with the ability of small aerial vehicles to fly near to the ground in a controlled fashion, will assist in increasing the effective resolution of the reconstructed maps.