1,826 research outputs found
The demand for M2, opportunity cost, and financial change
An analysis of the recent weakness in M2 growth that attempts to measure the opportunity cost of the aggregate more accurately and that explores the potential effects of the thrift industry restructuring on the adjustment of money demand to its long-run equilibrium level.Money supply ; Savings and loan associations
Understanding the recent behavior of M2
A discussion of the unanticipated weakness in the M2 monetary aggregate in recent years, suggesting that the shortfall may be largely attributable to the restructuring of the thrift industry, and an explanation of why economic models predicting M2 growth have had difficulty tracking this weakness.Money supply ; Savings and loan associations
Nonlinear acoustic theory for thin porous sheets
Nonlinear method for predicting acoustic properties of thin porous sheet
Self-consistent calculation of electric potentials in Hall devices
Using a first-principles classical many-body simulation of a Hall bar, we
study the necessary conditions for the formation of the Hall potential: (i)
Ohmic contacts with metallic reservoirs, (ii) electron-electron interactions,
and (iii) confinement to a finite system. By propagating thousands of
interacting electrons over million time-steps we capture the build-up of the
self-consistent potential, which resembles results obtained by
conformal-mapping methods. As shown by a microscopic model of the current
injection, the Hall effect is linked to specific boundary conditions at the
particle reservoirs.Comment: 6 pages, 7 figure
Experimental feasibility of investigating acoustic waves in Couette flow with entropy and pressure gradients
The feasibility is discussed for an experimental program for studying the behavior of acoustic wave propagation in the presence of strong gradients of pressure, temperature, and flow. Theory suggests that gradients effects can be experimentally observed as resonant frequency shifts and mode shape changes in a waveguide. A convenient experimental geometry for such experiments is the annular region between two co-rotating cylinders. Radial temperature gradients in a spinning annulus can be generated by differentially heating the two cylinders via electromagnetic induction. Radial pressure gradients can be controlled by varying the cylinder spin rates. Present technology appears adequate to construct an apparatus to allow independent control of temperature and pressure gradients. A complicating feature of a more advanced experiment, involving flow gradients, is the requirement for independently controlled cylinder spin rates. Also, the boundary condition at annulus terminations must be such that flow gradients are minimally disturbed. The design and construction of an advanced apparatus to include flow gradients will require additional technology development
Models of brain injury vocational rehabilitation: The evidence for resource facilitation from efficacy to effectiveness
BACKGROUND:
Resource Facilitation (RF) is an intervention developed to improve return to work (RTW) following brain injury. RF is an individualized treatment specializing in connecting patients and caregivers with community-based resources and services to mitigate barriers to return to work.
OBJECTIVES:
Examine the effectiveness of the RHI RF program for a clinical prospective cohort of participants referred to this program from the State Vocational Rehabilitation agency.
METHODS:
Participants were 243 participants with data drawn from the two sources: 33 from previous randomized controlled trial (RCT) control groups who did not receive RF and 210 from clinical patients discharged from the RHI RF program.
RESULTS:
At discharge from RF, a greater proportion of the treatment group obtained employment than the control group [X2 (1)  = 5.39, p = 0.018]. When controlling for baseline level of disability, treatment group significantly predicted employment outcome (Wald = 4.52, p = 0.033) and participants in the treatment group were 2.3 times more likely to return to work than controls.
CONCLUSIONS:
Previous RCTs have studied the RHI RF model and demonstrated significant efficacy. The findings from the present study are consistent with the employment rates found in the previous RCT's following RF, and also provide initial support for the clinical effectiveness of RF
Theory of the quantum Hall effect in graphene
We study the quantum Hall effect (QHE) in graphene based on the current
injection model. In our model, the presence of disorder, the edge-state
picture, extended states and localized states, which are believed to be
indispensable ingredients in describing the QHE, do not play an important role.
Instead the boundary conditions during the injection into the graphene sheet,
which are enforced by the presence of the Ohmic contacts, determine the
current-voltage characteristics.Comment: 4 pages, 3 figures, rewritten, role of contacts for boundary
conditions in small device
Data handling methods and target detection results for multibeam and sidescan data collected as part of the search for SwissAir Flight 111
The crash of SwissAir Flight 111, off Nova Scotia in September 1998, triggered one of the largest seabed search surveys in Canadian history. The primary search tools used were sidescan sonars (both conventional and focussed types) and multibeam sonars. The processed search data needed to be distributed on a daily basis to other elements of the fleet for precise location of divers and other optical seabed search instruments (including laser linescan and ROV video). As a result of the glacial history of the region, many natural targets, similar in gross nature to aircraft debris were present. These included widespread linear bedrock outcrop patterns together with near ubiquitous glacial erratic boulders. Because of the severely broken-up nature of the remaining aircraft debris, sidescan imaging alone was often insufficient to unambiguously identify targets. The complementary attributes of higher resolution, but poorly located, sidescan imagery together with slightly lower resolution, but excellently navigated multibeam sonar proved to be one of critical factors in the success of the search. It proved necessary to rely heavily on the regional context of the seabed (provided by the multibeam sonar bathymetry and backscatter imagery) to separate natural geomorphic targets from anomalous anthropogenic debris. In order to confidently prove or disprove a potential target, the interpreter required simultaneous access to the full resolution sidescan data in the geographic context of the multibeam framework. Specific software tools had to be adapted or developed shipboard to provide this capability. Whilst developed specifically for this application, these survey tools can provide improved processing speed and confidence as part of more general mine hunting, hydrographic, engineering or scientific surveys
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