Telecommunications 2000 Strategy, HR Practices & Performance

This report constitutes the first benchmarking survey of business and human resource practices among a nationally representative sample of workplaces in the broadly defined telecommunications industry that includes wireline, wireless, cable, and internet providers. It grows out of a multi-year study of organizational change in the industry, and is based on extensive field study, site visits, interviews, and surveys conducted by research teams at Cornell and Rutgers Universities. Managers at 577 establishments across the country gave generously of their time during a lengthy telephone survey. The study was made possible through a generous grant by the Alfred P. Sloan Foundation. While this report is based on data collected among workplaces in the U.S., it has implications for the restructuring of the global telecommunications industry. In other research, we have found that the United States has been at the forefront of market deregulation and technology change, but many other countries have followed a similar path and look to the United States as a model for organizational restructuring (Katz 1997). Thus, at least some of the patterns we find here are likely to occur in other countries undergoing similar patterns of deregulation

Telecommunications 2004: Business Strategy, HR Practices, and Performance

This national benchmarking report of the U.S. telecommunications services industry traces the tumultuous changes in management and workforce practices and performance in the sector over the last 5 years. This is a follow-up report to our 1998 study. At that time, when the industry was booming, we conducted a national survey of establishments in the industry. In 2003, we returned to do a second national survey of the industry, this time in a sector that was recovering from one of the worst recessions in its history

Industrial Relations and Productivity in the U.S. Automobile Industry

macroeconomics, Automobile, industrial relations, productivity

A study of air-to-ground sound propagation using an instrumented meteorological tower

The results of an exploratory NASA study, leading to a better understanding of the effects of meteorological conditions on the propagation of aircraft noise, are reported. The experimental program utilized a known sound source fixed atop an instrumented meteorological tower. The basic experimental scheme consisted of measuring the amplitude of sound radiated toward the ground along a line of microphones fixed to a tower guy wire. Experimental results show the feasibility of this approach in the acquisition of data indicating the variations encountered in the time-averaged and instantaneous amplitudes of propagated sound. The investigation included a consideration of ground reflections, a comparison of measured attenuations with predicted atmospheric absorption losses, and an evaluation of the amplitude fluctuations of recorded sound pressures

GP-BART: a novel Bayesian additive regression trees approach using Gaussian processes

The Bayesian additive regression trees (BART) model is an ensemble method extensively and successfully used in regression tasks due to its consistently strong predictive performance and its ability to quantify uncertainty. BART combines "weak" tree models through a set of shrinkage priors, whereby each tree explains a small portion of the variability in the data. However, the lack of smoothness and the absence of a covariance structure over the observations in standard BART can yield poor performance in cases where such assumptions would be necessary. We propose Gaussian processes Bayesian additive regression trees (GP-BART) as an extension of BART which assumes Gaussian process (GP) priors for the predictions of each terminal node among all trees. We illustrate our model on simulated and real data and compare its performance to traditional modelling approaches, outperforming them in many scenarios. An implementation of our method is available in the R package rGPBART available at: https://github.com/MateusMaiaDS/gpbar

Storm Surges in the Region of Western Alaska

Within the period of the historical record there have been several occurrences of extensive damage from storm-surge-related coastal flooding in the region of Nome, Alaska. The most recent of these events, although by no means the most destructive, occurred in association with the storm of 5–6 October 1992. Despite the small population of Nome (approximately 4000 people), total damage costs exceeded $6 million. The research into the nature and causes of such flooding events has focused on this October 1992 case. The authors have, however, also examined a weaker, shorter-duration event that occurred on 20 August 1993 and, for contrast, a case in September 1993 where a sustained offshore wind transported water out of Norton Sound. Tide gauge data from Nome were used to quantitatively assess the associated changes in water level, and meteorological analyses were utilized to examine the associated synoptic-scale circulations and their evolution. In addition, numerical modeling experiments were conducted using an extratropical storm surge model. (A version of this model is operational for the east coast of the United States.) Hindcasts of phase and amplitude for the October 1992 and September 1993 events agreed well with observations. Simulations of the shorter- duration August 1993 event were in poorer agreement with observations and indicate several possibilities for future improvement of the performance of the surge model: enhancement of the horizontal and temporal resolution of the model domain; more accurate input sea level pressure and wind data; and improvements to the surge model itself (e.g., inclusion of sea ice). Overall, however, results indicate that recent operational implementation of the model should be of significant benefit to coastal forecasters

Storm Surges in the Region of Western Alaska

Within the period of the historical record there have been several occurrences of extensive damage from storm-surge-related coastal flooding in the region of Nome, Alaska. The most recent of these events, although by no means the most destructive, occurred in association with the storm of 5–6 October 1992. Despite the small population of Nome (approximately 4000 people), total damage costs exceeded $6 million. The research into the nature and causes of such flooding events has focused on this October 1992 case. The authors have, however, also examined a weaker, shorter-duration event that occurred on 20 August 1993 and, for contrast, a case in September 1993 where a sustained offshore wind transported water out of Norton Sound. Tide gauge data from Nome were used to quantitatively assess the associated changes in water level, and meteorological analyses were utilized to examine the associated synoptic-scale circulations and their evolution. In addition, numerical modeling experiments were conducted using an extratropical storm surge model. (A version of this model is operational for the east coast of the United States.) Hindcasts of phase and amplitude for the October 1992 and September 1993 events agreed well with observations. Simulations of the shorter-duration August 1993 event were in poorer agreement with observations and indicate several possibilities for future improvement of the performance of the surge model: enhancement of the horizontal and temporal resolution of the model domain; more accurate input sea level pressure and wind data; and improvements to the surge model itself (e.g., inclusion of sea ice). Overall, however, results indicate that recent operational implementation of the model should be of significant benefit to coastal forecasters