Fast curve estimation using preconditioned generalized Radon transform.

A new algorithm for fast curve parameter estimation based on the generalized Radon transform is proposed. The algorithm works on binary images, obtained, e.g., by edge filtering or deconvolution. The fundamental idea of the suggested algorithm is the use of a precondition map to reduce the computational cost of the generalized Radon transform. The precondition map is composed of irregular regions in the parameter domain, which contain peaks that represent curves in the image. To generate the precondition map, a fast mapping procedure named image point mapping is developed. As the image point mapping scheme maps image points into the corresponding parameter values in the parameter domain, it is possible to improve computational efficiency by recognizing image points with value zero. Initially, the suggested algorithm estimates the precondition map and subsequently applies the generalized Radon transform within the regions specified by the precondition map. The required parameter domain sampling and the resulting blurring are also investigated. The suggested algorithm is successfully applied to the identification of hyperbolas in seismic images, and two numerical examples are given.

Organizational stress in the hospital: development of a model for diagnosis and prediction.

A model of organizational stress in the hospital was developed and tested. The model utilized measures of organizational climate, supervisory practices, and work group relations as predictors of the amount of role conflict and ambiguity that nurses perceived in providing patient care. Role conflict and ambiguity were treated as variables that intervene between organizational variables and the level of stress that the nursing staff experienced. Nursing stress was viewed as a direct cause of job dissatisfaction and as an indirect cause of absenteeism among the nursing staff. Data from 158 registered nurses, licensed practical nurses, and nursing assistants on seven nursing units in a 1,160-bed private teaching hospital were used to estimate the parameters of a structural equation model. The model was used to predict the results of a survey feedback project designed to change the supervisory style used on the units. Pre- and posttest data from four surgical units were used to validate the model. The findings suggest that, as predicted, supervisory practices that led to more open expression of views and joint problem solving resulted in reduced role conflict, ambiguity, and stress; increased job satisfaction; and lower levels of absenteeism among the nursing staff.