Critical behavior of a three-dimensional hardcore-cylinder composite system

In this work the critical indices β, γ , and ν for a three-dimensional (3D) hardcore cylinder composite system with short-range interaction have been obtained. In contrast to the 2D stick system and the 3D hardcore cylinder system, the determined critical exponents do not belong to the same universality class as the lattice percolation,although they obey the common hyperscaling relation for a 3D system. It is observed that the value of the correlation length exponent is compatible with the predictions of the mean field theory. It is also shown that, by using the Alexander-Orbach conjuncture, the relation between the conductivity and the correlation length critical exponents has a typical value for a 3D lattice system.

INTEGRATED MANAGEMENT SYSTEMS: CRITICAL SUCCESS FACTORS

The purpose of this paper is to, in a holistic way, identify and explore the critical success factors (CSFs) that are considered in the context of the growing discussions, movements, proposed models, and case studies about the integration of management systems (MSs). This work is an investigation focused on the integration of MSs into an integrated management system (IMS) and the proposed approach takes into account the literature review as well as the experience gained by the authors on researches about Portuguese enterprises. This qualitative and empirical research, investigated the integration of MSs from existing scientific publications for the period 1999 to 2014, on-going case studies and one inquiry conducted by the authors. This research contributes to a better understanding of the CSFs regarding the integration of MSs and thus provides an insight on the preventive management. This research shows an evident lack of information regarding case studies on CSFs for integrated management systems (IMSs) and has identified a set of relevant CSFs, for MSs integration and associated guidelines that organizations should take as a priority, in order to be able to manage, on a preventive way, the implementation of IMSs, and consequently to become more competitive with added value for the stakeholders.

Fast left ventricle tracking in CMR images using localized anatomical affine optical flow

In daily cardiology practice, assessment of left ventricular (LV) global function using non-invasive imaging remains central for the diagnosis and follow-up of patients with cardiovascular diseases. Despite the different methodologies currently accessible for LV segmentation in cardiac magnetic resonance (CMR) images, a fast and complete LV delineation is still limitedly available for routine use. In this study, a localized anatomically constrained affine optical flow method is proposed for fast and automatic LV tracking throughout the full cardiac cycle in short-axis CMR images. Starting from an automatically delineated LV in the end-diastolic frame, the endocardial and epicardial boundaries are propagated by estimating the motion between adjacent cardiac phases using optical flow. In order to reduce the computational burden, the motion is only estimated in an anatomical region of interest around the tracked boundaries and subsequently integrated into a local affine motion model. Such localized estimation enables to capture complex motion patterns, while still being spatially consistent. The method was validated on 45 CMR datasets taken from the 2009 MICCAI LV segmentation challenge. The proposed approach proved to be robust and efficient, with an average distance error of 2.1 mm and a correlation with reference ejection fraction of 0.98 (1.9 ± 4.5%). Moreover, it showed to be fast, taking 5 seconds for the tracking of a full 4D dataset (30 ms per image). Overall, a novel fast, robust and accurate LV tracking methodology was proposed, enabling accurate assessment of relevant global function cardiac indices, such as volumes and ejection fraction.