30,215 research outputs found
The Search for Extraterrestrial Intelligence (SETI)
A bibliography of reports concerning the Search for Extraterrestrial Intelligence is presented. Cosmic evolution, space communication, and technological advances are discussed along with search strategies and search systems
Service Offshoring and White-Collar Employment
I study the effects of service offshoring on white-collar employment, using highly disaggregated occupational data for the U.S.. I present a structural model of the firm’s behavior that allows tractable derivation of labor demand elasticities for highly detailed occupations. I estimate the model using Quasi-Maximum Likelihood, to simultaneously account for the high degree of censoring of the employment variable and the small cross-sectional dimension of the panel. I find that service offshoring is skill-biased, because it raises employment among high-skilled occupations and lowers employment among medium- and low-skilled ones. Within each skill group, service offshoring penalizes tradeable occupations and tends to benefit complex non tradeable jobs.service offshoring, white-collar occupations, labor demand elasticities, homothetic weak separability, censored demand system estimation
Modelling environmentally-mediated infectious diseases of humans: transmission dynamics of schistosomiasis in China.
Macroparasites of humans are sensitive to a variety of environmental variables, including temperature, rainfall and hydrology, yet current comprehension of these relationships is limited. Given the incomplete mechanistic understanding of environment-disease interactions, mathematical models that describe them have seldom included the effects of time-varying environmental processes on transmission dynamics and where they have been included, simple generic, periodic functions are usually used. Few examples exist where seasonal forcing functions describe the actual processes underlying the environmental drivers of disease dynamics. Transmission of human schistosomes, which involves multiple environmental stages, offers a model for applying our understanding of the environmental determinants of the viability, longevity, infectivity and mobility of these stages to controlling disease in diverse environments. Here, a mathematical model of schistosomiasis transmission is presented which incorporates the effects of environmental variables on transmission. Model dynamics are explored and several key extensions to the model are proposed
Fourth Symposium on Chemical Evolution and the Origin and Evolution of Life
This symposium was held at the NASA Ames Research Center, Moffett Field, California, July 24-27, 1990. The NASA exobiology investigators reported their recent research findings. Scientific papers were presented in the following areas: cosmic evolution of biogenic compounds, prebiotic evolution (planetary and molecular), early evolution of life (biological and geochemical), evolution of advanced life, solar system exploration, and the Search for Extraterrestrial Intelligence (SETI)
Publications of the Jet Propulsion Laboratory, July 1961 through June 1962
Jpl bibliography on space science, 1961-196
An adsorbed gas estimation model for shale gas reservoirs via statistical learning
Shale gas plays an important role in reducing pollution and adjusting the
structure of world energy. Gas content estimation is particularly significant
in shale gas resource evaluation. There exist various estimation methods, such
as first principle methods and empirical models. However, resource evaluation
presents many challenges, especially the insufficient accuracy of existing
models and the high cost resulting from time-consuming adsorption experiments.
In this research, a low-cost and high-accuracy model based on geological
parameters is constructed through statistical learning methods to estimate
adsorbed shale gas conten
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