A SAS macro to extend the Cox proportional hazards regression model to allow for positive stable frailties is presented. This macro computes, using a modi ed EM algorithm, estimates of the model parameters and their respective standard errors. The likelihood ratio test of the independence assumption is also provided. An example data set is used to illustrate the macro.

A macro-model is a simplified model that emulates functional characteristics of a device or circuit, and widely used in system-level simulation. In this paper, macro-model based SPICE simulation of DC/DC switching regulators is presented. Macro-models of a power switch and Pulse Width Modulation (PWM) control circuit are described. Two simulation examples are given to demonstrate the capability...

AbstmctTwo new DAC modeling techniques based on principles of wavelet theory are described in this paper. Macro model and mathematical model are developed for analog and digital circuit simulation, respectively for fast and accurate results using exponential function, damped sine wave, and linear waveform. An 8 bit DAC has been implemented to simulate and evaluate the models. The INLs of the ma...

population growth and unemployment issues caused to care about entrepreneurship in third and fourth economic development programs. now, after execution of these programs, it is essential to assess entrepreneurship development progress. this article designed to formulate a model of entrepreneurship policies in order to assess these policies. so, a conceptual model formulated with 12 dimensions b...

Double-diffusion model is used to simulate slightly compressible fluid flow in periodic porous media as a macro-model in place of the original highly heterogeneous micro-model. In this paper, we formulate an adaptive two-grid numerical finite element discretization of the double-diffusion system and perform a comparison between the microand macro-model. Our numerical results show that the micro...

Introduction: Complex sociotechnical systems, such as automotive industry, require a proper macro-ergonomic approach to design and implement the work system at micro-ergonomic level. The purpose of this study was to develop and validate effective macroeconomic factors to improve productivity, health and safety of employees in the automotive industry based on Holden & Karsh model. Material and ...

A finite model updating method that combines dynamic-static long-gauge strain responses is proposed for highway bridge static loading tests. For this method, the objective function consisting of static long-gauge stains and the first order modal macro-strain parameter (frequency) is established, wherein the local bending stiffness, density and boundary conditions of the structures are selected ...