Active shape model unleashed with multi-scale local appearance

We focus on optimising the Active Shape Model (ASM) with several extensions. The modification is threefold. First, we tackle the over-constraint problem and obtain an optimal shape with minimum energy considering both the shape prior and the salience of local features, based on statistical theory: a compact closed form solution to the optimal shape is deduced. Second, we enhance the ASM searching method by modelling and removing the variations of local appearance presented in the training data. Third, we speed up the convergence of shape fitting by integrating information from multi-scale local features simultaneously. Experiments show significant improvement brought by these modifications, i.e., optimal shape against standard relaxation methods dealing with inadequate training samples; enhanced searching method against standard gradient descent methods in searching accuracy; multi-scale local features against popular coarse-to-fine strategies in convergence speed

Active appearance pyramids for object parametrisation and fitting

Object class representation is one of the key problems in various medical image analysis tasks. We propose a part-based parametric appearance model we refer to as an Active Appearance Pyramid (AAP). The parts are delineated by multi-scale Local Feature Pyramids (LFPs) for superior spatial specificity and distinctiveness. An AAP models the variability within a population with local translations of multi-scale parts and linear appearance variations of the assembly of the parts. It can fit and represent new instances by adjusting the shape and appearance parameters. The fitting process uses a two-step iterative strategy: local landmark searching followed by shape regularisation. We present a simultaneous local feature searching and appearance fitting algorithm based on the weighted Lucas and Kanade method. A shape regulariser is derived to calculate the maximum likelihood shape with respect to the prior and multiple landmark candidates from multi-scale LFPs, with a compact closed-form solution. We apply the 2D AAP on the modelling of variability in patients with lumbar spinal stenosis (LSS) and validate its performance on 200 studies consisting of routine axial and sagittal MRI scans. Intervertebral sagittal and parasagittal cross-sections are typically used for the diagnosis of LSS, we therefore build three AAPs on L3/4, L4/5 and L5/S1 axial cross-sections and three on parasagittal slices. Experiments show significant improvement in convergence range, robustness to local minima and segmentation precision compared with Constrained Local Models (CLMs), Active Shape Models (ASMs) and Active Appearance Models (AAMs), as well as superior performance in appearance reconstruction compared with AAMs. We also validate the performance on 3D CT volumes of hip joints from 38 studies. Compared to AAMs, AAPs achieve a higher segmentation and reconstruction precision. Moreover, AAPs have a significant improvement in efficiency, consuming about half the memory and less than 10% of the training time and 15% of the testing time

Turning inside out?: Globalization, neo-liberalism and welfare states

Apocalyptic accounts of globalization bringing about the end of the welfare state (and the nation state) have been countered by political-institutionalist views of adaptation. Such views treat globalization as an external force, or pressure, rather than a set of processes that are also internalized within nations. I argue that a more differentiated view of globalization can reveal how it has unsettled welfare state/nation-state formations. In the process, taken-for-granted meanings and boundaries of nation-state-welfare have been destabilized. I conclude by suggesting that these processes have made citizenship a distinctive focus of political tensions and conflicts

Another thread in the tapestry of stellar feedback: X-ray binaries

We consider X-ray binaries (XBs) as potential sources of stellar feedback. XBs observationally appear able to deposit a high fraction of their power output into their local interstellar medium, which may make them a non-negligible source of energy input. The formation rate of the most luminous XBs rises with decreasing metallicity, which should increase their significance during galaxy formation in the early universe. We also argue that stochastic effects are important to XB feedback (XBF) and may dominate the systematic changes due to metallicity in many cases. Large stochastic variation in the magnitude of XBF at low absolute star formation rates provides a natural reason for diversity in the evolution of dwarf galaxies which were initially almost identical, with several percent of such halos experiencing energy input from XBs roughly two orders of magnitude above the most likely value. These probability distributions suggest that the effect of XBF is most commonly significant for total stellar masses between ~10^7 and 10^8 Msun, which might resolve a current problem with modelling populations of such galaxies. We explain how XBs might inject energy before luminous supernovae (SNe) contribute significantly to feedback and how XBs can assist in keeping gas hot long after the last core-collapse SN has exploded. [...] XBF could be especially important to some dwarf galaxies, potentially heating gas without expelling it; the properties of XBF also match those previously derived as allowing episodic star formation. We also argue that the efficiency of SN feedback (SNF) might be reduced when XBF has had the opportunity to act first. In addition, we note that the effect of SNF is unlikely to be scale-free; galaxies smaller than ~100 pc might well experience less effective SNF. (Slightly abbreviated to fit arXiv size limit.)Comment: Very belatedly updated to include a note added in proof and additional reference. The definitive version is at: mnras.oxfordjournals.org/content/423/2/164

The New Technologies: An Integrated view, July, 1986

This paper is an English translation, by the author herself, of a paper that until now has only been published in Spanish. The editors of this working paper series are of the opinion that the paper - although written 24 years ago - represents such an important element in the writings of Carlota Perez that it should be made available also to the English-speaking research community. The paper presents an early notion of a techno-economic paradigm and - although internet was years away from being available - it is indeed an outline of the paradigm we presently live in. Many of the issues raised here, like alternative sources of energy and biotechnology, are still with us today, and many of the predictions have proved to be based on accurate perceptions.

Lifeworld Inc. : and what to do about it

Can we detect changes in the way that the world turns up as they turn up? This paper makes such an attempt. The first part of the paper argues that a wide-ranging change is occurring in the ontological preconditions of Euro-American cultures, based in reworking what and how an event is produced. Driven by the security – entertainment complex, the aim is to mass produce phenomenological encounter: Lifeworld Inc as I call it. Swimming in a sea of data, such an aim requires the construction of just enough authenticity over and over again. In the second part of the paper, I go on to argue that this new world requires a different kind of social science, one that is experimental in its orientation—just as Lifeworld Inc is—but with a mission to provoke awareness in untoward ways in order to produce new means of association. Only thus, or so I argue, can social science add to the world we are now beginning to live in

Supervised cnn strategies for optical image segmentation and classification in interventional medicine

The analysis of interventional images is a topic of high interest for the medical-image analysis community. Such an analysis may provide interventional-medicine professionals with both decision support and context awareness, with the final goal of improving patient safety. The aim of this chapter is to give an overview of some of the most recent approaches (up to 2018) in the field, with a focus on Convolutional Neural Networks (CNNs) for both segmentation and classification tasks. For each approach, summary tables are presented reporting the used dataset, involved anatomical region and achieved performance. Benefits and disadvantages of each approach are highlighted and discussed. Available datasets for algorithm training and testing and commonly used performance metrics are summarized to offer a source of information for researchers that are approaching the field of interventional-image analysis. The advancements in deep learning for medical-image analysis are involving more and more the interventional-medicine field. However, these advancements are undeniably slower than in other fields (e.g. preoperative-image analysis) and considerable work still needs to be done in order to provide clinicians with all possible support during interventional-medicine procedures

Dorotea, the city, can be different: urban projects in Rome based on the seminal role of infrastructures

This paper offers a semiotic perspective of the city as an enunciation of different signs in which contemporary projects (the alleged urbanities) play a fundamental role in resemantizing the urban environment. Such design outcomes allow us to understand the city as a hypotactic complex system, not created then only by the simple juxtaposition of elements, but intended as the results of multiple primary and secondary intertwined narrations. The work adopts a structuralist-based approach to the topic where the examples presented act on two combinatory levels: a first one, where each of them maintains its autonomy and functions as an independent predicate, and a second one where the importance relies on the structural system in a dyachronic perspective. What we argue for is the possibility for architects to promote a bottom-up incremental design strategy in the urban enviroment to trigger sustainable urban transformation processes. Moreover, through the specific experience of the authors in the Tevere Cavo project, the papers aims to demonstrate the importance of multitasking interactive spaces and new generation infrastructures for the revitalization and re-activation of the abandoned urban spaces using the city of Rome as object of such investigation