6,659 research outputs found
Vehicle Choices, Miles Driven, and Pollution Policies
Mobile sources contribute large percentages of each pollutant, but technology is not yet available to measure and tax emissions from each vehicle. We build a behavioral model of household choices about vehicles and miles traveled. The ideal-but-unavailable emissions tax would encourage drivers to abate emissions through many behaviors, some of which involve market transactions that can be observed for feasible market incentives (such as a gas tax, subsidy to new cars, or tax by vehicle type). Our model can calculate behavioral effects of each such price and thus calculate car choices, miles, and emissions. A nested logit structure is used to model discrete choices among different vehicle bundles. We also consider continuous choices of miles driven and the age of each vehicle. We propose a consistent estimation method for both discrete and continuous demands in one step, to capture the interactive effects of simultaneous decisions. Results are compared with those of the traditional sequential estimation procedure.
A General Theory for Direct Quantitative Analysis of Antigen
A theory for direct quantitative analysis of an antigen is proposed. It is
based on a potential homogenous immunoreaction system. It establishes an
equation to describe the concentration change of the antigen and antibody
complex. A maximum point is found in the concentration profile of the complex
which can be used to calculate the concentration of the antigen. An
experimental scheme was designed for a commercial time-resolved
fluoroimmunoassay kit for HBsAg, which is based heterogeneous immunoreaction.
The results showed that the theory is practically applicable.Comment: 7pages, 2 figure
Investigation of robustness and numerical stability of multiple regression and PCA in modeling world development data
Popular methods for modeling data both labelled and unlabeled, multiple
regression and PCA has been used in research for a vast number of datasets. In
this investigation, we attempt to push the limits of these two methods by
running a fit on world development data, a set notorious for its complexity and
high dimensionality. We assess the robustness and numerical stability of both
methods using their matrix condition number and ability to capture variance in
the dataset. The result indicates poor performance from both methods from a
numerical standpoint, yet certain qualitative insights can still be captured.Comment: 8 pages, 4 figures, high-dimensional data analysis, world development
data, conference, publishing by IEEE, indexed by EI compende
From Discovery to Delivery: Successful Systems Integration
Patrons want library collections to be unrestricted in scope. Demands for information resources are increasing while libraries are facing decreasing budgets and minimal staffing support. ILL and consortial services can help libraries expand access to collections. Patron-initiated borrowing systems are a current trend in libraries, but seamlessly integrating them is challenging. Our poster will analyze problems in patron-initiated consortial borrowing and lending services. We will introduce our new generation service, which combines more than four complex library systems and allows them to work together in real-time availability: the OPAC, a consortial borrowing system, an ILL system, an ILS, and an authentication system. This service has seamlessly integrated our new discovery tool, WorldCat Local, with our borrowing and lending systems: local, consortial and worldwide ILL. Our patron requests have dramatically increased as requests are now automatically transferred from system to system based on the itemâs availability, maintaining rapid delivery. This technological advancement provides more services to our patrons, costs less and improves the time management of our staff
A search for 95 GHz class I methanol masers in molecular outflows
We have observed a sample of 288 molecular outflow sources including 123
high-mass and 165 low-mass sources to search for class I methanol masers at 95
GHz transition and to investigate relationship between outflow characteristics
and class I methanol maser emission with the PMO-13.7m radio telescope. Our
survey detected 62 sources with 95 GHz methanol masers above 3
detection limit, which include 47 high-mass sources and 15 low-mass sources.
Therefore the detection rate is 38% for high-mass outflow sources and 9% for
low-mass outflow sources, suggesting that class I methanol maser is relatively
easily excited in high-mass sources. There are 37 newly detected 95 GHz
methanol masers (including 27 high-mass and 10 low-mass sources), 19 of which
are newly identified (i.e. first identification) class I methanol masers
(including 13 high-mass and 6 low-mass sources). Statistical analysis for the
distributions of maser detections with the outflow parameters reveals that the
maser detection efficiency increases with outflow properties (e.g. mass,
momentum, kinetic energy and mechanical luminosity of outflows etc.).
Systematic investigations of relationships between the intrinsic luminosity of
methanol maser and the outflow properties (including mass, momentum, kinetic
energy, bolometric luminosity and mass loss rate of central stellar sources)
indicate a positive correlations. This further supports that class I methanol
masers are collisionally pumped and associated with shocks, where outflows
interact with the surrounding ambient medium.Comment: 32 pages, 5 figures, accepted by Ap
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