Worcester Polytechnic Institute

About: Worcester Polytechnic Institute is a education organization based out in Worcester, Massachusetts, United States. It is known for research contribution in the topics: Computer science & Population. The organization has 6270 authors who have published 12704 publications receiving 332081 citations. The organization is also known as: WPI.

Organizational antecedents of second‐order competences

Abstract: According to dynamic capability theory, some firms are better able than others at altering their resource base by adding, reconfiguring, and deleting resources or competences. This study focuses on the first form of dynamic capability: the competence to build new competences. Two such second-order competences are studied: the ability to explore new markets and the ability to explore new technologies—referred to as marketing and R&D second-order competences, respectively. Using two wave panel data on a sample of U.S. public manufacturing firms, five organizational antecedents of these second-order competences are examined: willingness to cannibalize, constructive conflict, tolerance for failure, environmental scanning, and resource slack. Willingness to cannibalize, constructive conflict, scanning, and slack have contemporaneous effects, while scanning also has a lagged effect and slack has a U-shaped lagged effect on marketing and R&D second-order competences. Copyright © 2008 John Wiley & Sons, Ltd.

Power prior distributions for regression models

Abstract: We propose a general class of prior distributions for arbitrary regression models. We discuss parametric and semiparametric models. The prior specification for the regression coefficients focuses on observ- able quantities in that the elicitation is based on the availability of his- torical data Do and a scalar quantity ao quantifying the uncertainty in Do. Then Do and ao are used to specify a prior for the regression coeffi- cients in a semiautomatic fashion. The most natural specification of Do arises when the raw data from a similar previous study are available. The availability of historical data is quite common in clinical trials, car- cinogenicity studies, and environmental studies, where large data bases are available from similar previous studies. Although the methodology we present here is quite general, we will focus only on using historical data from similar previous studies to construct the prior distributions. The prior distributions are based on the idea of raising the likelihood function of the historical data to the power ao, where 0 < ao < 1. We call such prior distributions power prior distributions. We examine the power prior for four commonly used classes of regression models. These include generalized linear models, generalized linear mixed models, semipara- metric proportional hazards models, and cure rate models for survival data. For these classes of models, we discuss the construction of the power prior, prior elicitation issues, propriety conditions, model selec- tion, and several other properties. For each class of models, we present real data sets to demonstrate the proposed methodology.

The Hawthorne Experiments: First Statistical Interpretation

Abstract: A guide is provided to the proceedings of the Hawthorne experiments, and experimental data are now made readily available. Data from the main experiment (that in the first relay assembly test room at Western Electric) are interpreted statistically for the first time. Quantitative analysis of this quasi experiment is accomplished by time-series multiple regression using nearly five years of data. This analysis demonstrates that experimental variables account for some 90% of the variance in quantity and quality of output, both for the group andfor individual workers. Imposition of managerial discipline, economic adversity, and quality of raw materials provide most explanation, obviating the need to draw upon less clearly definable human relations mechanisms. For decades the Hawthorne studies have provided a rationale for humane approaches in the organization of work by suggesting that considerate or participative treatment of workers led to better economic performance. The present analysis suggests, to the contrary, that humanitarian procedures must provide their own justification.

Direct Numerical Simulations of Gas-Liquid Multiphase Flows

Abstract: Direct numerical simulations of bubbly flows are reviewed and recent progress is discussed. Simulations, of homogeneous bubble distribution in fully periodic domains at relatively low Reynolds numbers have already yielded considerable insight into the dynamics of such flows. Many aspects of the evolution converge rapidly with the size of the systems and results for the rise velocity, the velocity fluctuations, as well as the average relative orientation of bubble pairs have been obtained. The challenge now is to examine bubbles at higher Reynolds numbers, bubbles in channels and confined geometry, and bubble interactions with turbulent flows. We briefly review numerical methods used for direct numerical simulations of multiphase flows, with a particular emphasis on methods that use the so-called "one-field" formulation of the governing equations, and then discuss studies of bubbles in periodic domains, along with recent work on wobbly bubbles, bubbles in laminar and turbulent channel flows, and bubble formation in boiling.