8,831 research outputs found
Are Business Cycles All Alike?
This paper examines two questions. The first is whether economic fluctuations-business cycles-are due to an accumulation of nall shocks or instead mostly to infrequent large shocks. The paper concludes that neither of these two extreme views accurately characterize fluctuations. The second question is whether fluctuations are due mostly to one source of shocks, for example monetary, or instead to many sources. The paper concludes that evidence strongly supports the hypothesis of many, about equally important, sources of shocks.To analyze the empirical evidence and to reach these conclusions, the paper uses two different statistical approaches. The first is estimation ofa structural model, using a set of just identifying restrictions. The secondis non-structural and may be described as a formalization of the Burns Mitchell techniques. Both approaches are somewhat novel and should be of independent interest.
Development of land based radar polarimeter processor system
The processing subsystem of a land based radar polarimeter was designed and constructed. This subsystem is labeled the remote data acquisition and distribution system (RDADS). The radar polarimeter, an experimental remote sensor, incorporates the RDADS to control all operations of the sensor. The RDADS uses industrial standard components including an 8-bit microprocessor based single board computer, analog input/output boards, a dynamic random access memory board, and power supplis. A high-speed digital electronics board was specially designed and constructed to control range-gating for the radar. A complete system of software programs was developed to operate the RDADS. The software uses a powerful real time, multi-tasking, executive package as an operating system. The hardware and software used in the RDADS are detailed. Future system improvements are recommended
Dryland pasture and crop conditions as seen by HCMM
The author has identified the following significant results. The soil moisture difference between the flight lines was partly due to water-holding capacity differences of the two soil types. Fields along the east flight line were in clay; while along the west flight line, the soil was sandy loam which holds less moisture. Due to differences in the amount of green material, the pastures were wetter than the wheat fields. Most of the pastures average from 40-80% green material, while wheat averages from 90-100% green material. A large amount of green material transpired more water and depleted the soil water content faster than dead vegetation. Visicorder data found temperature differences between the rangeland and winter wheat fields. Pasture had a larger percentage of dead material with different thermal properties than live vegetation, and surface temperature was primarily dependent on insolation. Dead material transpired less, but warms up faster than wheat fields
Dryland pasture and crop conditions as seen by HCMM
There are no author-identified significant results in this report
Biochemical and physiological evaluation of human subjects in a life support systems evaluator
Biochemical and physiological evaluation of human nutritional requirements under simulated aerospace condition
Analysis of surface moisture variations within large field sites
A statistical analysis was made on ground soils to define the general relationship and ranges of values of the field moisture relative to both the variance and coefficient of variation for a given test site and depth increment. The results of the variability study show that: (1) moisture variations within any given large field area are inherent and can either be controlled nor reduced; (2) neither a single value of the standard deviation nor coefficient of variation uniquely define the variability over the complete range of mean field moisture contents examined; and (3) using an upper bound standard deviation parameter clearly defines the maximum range of anticipated moisture variability. 87 percent of all large field moisture content standard deviations were less than 3 percent while about 96 percent of all the computed values had an upper bound of sigma=4 percent for these intensively sampled fields. The limit of accuracy curves of mean soil moisture measurements for large field sites relative to the required number of samples were determined
Results of soil moisture flights during April 1974
The results presented here are derived from measurements made during the April 5 and 6, 1974 flights of the NASA P-3A aircraft over the Phoenix, Arizona agricultural test site. The purpose of the mission was to study the use of microwave techniques for the remote sensing of soil moisture. These results include infrared (10-to 12 micrometers) 2.8-cm and 21-cm brightness temperatures for approximately 90 bare fields. These brightness temperatures are compared with surface measurements of the soil moisture made at the time of the overflights. These data indicate that the combination of the sum and difference of the vertically and the horizontally polarized brightness temperatures yield information on both the soil moisture and surface roughness conditions
Self-adjoint Time Operator is the Rule for Discrete Semibounded Hamiltonians
We prove explicitly that to every discrete, semibounded Hamiltonian with
constant degeneracy and with finite sum of the squares of the reciprocal of its
eigenvalues and whose eigenvectors span the entire Hilbert space there exists a
characteristic self-adjoint time operator which is canonically conjugate to the
Hamiltonian in a dense subspace of the Hilbert space. Moreover, we show that
each characteristic time operator generates an uncountable class of self-
adjoint operators canonically conjugate with the same Hamiltonian in the same
dense subspace.Comment: accepted for publication in the Proceedings of the Royal Society of
London
A Way Out of the Quantum Trap
We review Event Enhanced Quantum Theory (EEQT). In Section 1 we address the
question "Is Quantum Theory the Last Word". In particular we respond to some of
recent challenging staments of H.P. Stapp. We also discuss a possible future of
the quantum paradigm - see also Section 5. In Section 2 we give a short sketch
of EEQT. Examples are given in Section 3. Section 3.3 discusses a completely
new phenomenon - chaos and fractal-like phenomena caused by a simultaneous
"measurement" of several non-commuting observables (we include picture of
Barnsley's IFS on unit sphere of a Hilbert space). In Section 4 we answer
"Frequently Asked Questions" concerning EEQT.Comment: Replacement. Corrected affiliation. Latex, one .jpg figure. To appear
in Proc. Conf. Relativistic Quantum Measurements, Napoli 1998, Ed. F.
Petruccion
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