55,584 research outputs found
A Method for Establishing Outdoor Recreation Project Priorities in Alaska
The authors thank Theodore Smith, Edward Kramer and Nat Goodhue
of the Division of Parks for information and comments supplied during this
study, and Frank Orth, Charles Marsh, Ed Kramer, C.E. Logsdon, and Frank
Wooding for reviewing the manuscript.
Thanks is also due the Department of Business Administration,
University of Alaska, Fairbanks, Dale Swanson, Head, for their cooperation
in this research project.The objectives of this study are to define outdoor recreation benefits to
the public and to develop a priority ranking method for proposed outdoor
recreation projects. A careful analysis of the benefits which people derive
from outdoor recreation provides a frame of reference for evaluating a
recreational facility. A project should supply those benefits which are most
highly demanded by the public. Fifteen benefits of recreation are defined
and discussed. They are divided into two major categories; those which
accrue to recreational participants and those which accrue to
non-participants.This research was supported by a grant from the Division of Parks,
State of Alaska
Flight research capabilities of the NASA/Army rotor systems research aircraft
A description is given of the capabilities and limitations of the Rotor Systems Research Aircraft (RSRA) that was demonstrated during the development contract, and assesses the expected research capabilities of the RSRA on delivery to the government
Electronics implementation of the solar neutron experiment
The electronic equipment design and function are discussed for the solar neutron counter experiment. Circuit diagrams are included
Linear Optical CNOT Gate in the Coincidence Basis
We describe the operation and tolerances of a non-deterministic, coincidence
basis, quantum CNOT gate for photonic qubits. It is constructed solely from
linear optical elements and requires only a two-photon source for its
demonstration.Comment: Submitted to Physical Review
Evaluating implicit feedback models using searcher simulations
In this article we describe an evaluation of relevance feedback (RF) algorithms using searcher simulations. Since these algorithms select additional terms for query modification based on inferences made from searcher interaction, not on relevance information searchers explicitly provide (as in traditional RF), we refer to them as implicit feedback models. We introduce six different models that base their decisions on the interactions of searchers and use different approaches to rank query modification terms. The aim of this article is to determine which of these models should be used to assist searchers in the systems we develop. To evaluate these models we used searcher simulations that afforded us more control over the experimental conditions than experiments with human subjects and allowed complex interaction to be modeled without the need for costly human experimentation. The simulation-based evaluation methodology measures how well the models learn the distribution of terms across relevant documents (i.e., learn what information is relevant) and how well they improve search effectiveness (i.e., create effective search queries). Our findings show that an implicit feedback model based on Jeffrey's rule of conditioning outperformed other models under investigation
The design, development, and flight test results of the Boeing 737 aircraft antennas for the ICAO demonstration of the TRSB microwave landing system
The Research Support Flight System, a modified Boeing 737, was used to evaluate the performance of several aircraft antennas and locations for the Time Reference Scanning Beam (TRSB) Microwave Landing System (MLS). These tests were conducted at the National Aviation Facilities Experimental Center (NAFEC), Atlantic City, New Jersey on December 18, 1975. The flight tests measured the signal strength and all pertinent MLS data during a straight-in approach, a racetrack approach, and ICAO approach profiles using the independent antenna-receiver combinations simultaneously on the aircraft. Signal drop-outs were experienced during the various approaches but only a small percentage could be attributed to antenna pattern effects
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