Statistical cerebrovascular segmentation in three-dimensional rotational angiography based on maximum intensity projections

Vascular segmentation of three-dimensional rotational angiography (3D-RA) is important in the clinical environment since it can provide 3D information of vasculature before, during and after the treatments. This paper extends our prior work on vascular segmentation method for 3D-RA, which is based on maximum intensity projections (MIP). The method is fully automatic and computationally efficient. Experimental results on 12 3D-RA clinical data sets indicate that our method can produce segmentations of major vessels in the data sets, which are the current radiologists' primary interest in this work. Moreover, the segmentations obtained by our method exhibit a high degree of agreement to the ground truth segmentations and are comparable to those produced by the optimal global thresholding method. (C) 2004 CARS and Elsevier B.V. All rights reserved

Heat transport modification by finitely extensible polymers in laminar boundarya layera flow

We study how heat transport is affected by finitely extensible polymers in a laminar boundary layer flow within the framework of the Prandtl–Blasius–Pohlhausen theory. The polymers are described by the finitely extensible nonlinear elastic-Peterlin model with a parameter b2, which is the ratio of the maximum to the equilibrium value of the trace of the polymer conformation tensor. For very large b2, heat transport is reduced. When b2 is small, heat transport is enhanced. We investigate the transition from heat reduction to heat enhancement as a function of the polymer relaxation time and concentration, and show that the transition can be explained in terms of the functional shape of the space-dependent effective viscosity due to the polymers

Effects of service climate and leadership behavior on service quality: a multi-level analysis

Conference Theme: Creating Actionable Knowledg

The effects of service climate and the effective leadership behaviour of supervisors on frontline employee service quality: A multi-level analysis

A supervisor's behaviour may not be the only factor that determines the performance of team members (Kerr & jermier, 1978). Taking this postulation as a basis, we formulated a model to describe how service climate moderates the effects of the leadership behaviour of supervisors. When the organization and working environment are not conducive to providing a good service to colleagues and customers, the supervisor's leadership behaviour makes an important difference. However, when the service climate is good, a supervisor's leadership behaviour makes no substantial difference. This hypothesis was supported in an examination of the service quality of 511 frontline service providers as sampled from 55 work groups in 6 service organizations. The employee service quality was low when both the service climate and the supervisor's leadership behaviour were lacking. However, when the service climate was unfavourable, effective leadership behaviour played a compensatory role in maintaining performance standards towards external customers. When the leadership was ineffective, a favourable service climate nullified the negative effect on service quality to internal customers