13,730 research outputs found
FOMC communications and the predictability of near-term policy decisions
In February 1994, the FOMC began a new era in transparency, gradually building a communications apparatus that conveys information about the Committee’s decisions and expectations. Has the new apparatus improved the public’s ability to predict FOMC interest rate decisions? New research based on the prices of fed funds futures shows that over the past decade, it has, especially over horizons of two to three months.Federal Open Market Committee ; Federal funds rate
Role of oxygen in the electron-doped superconducting cuprates
We report on resistivity and Hall measurements in thin films of the
electron-doped superconducting cuprate PrCeCuO.
Comparisons between x = 0.17 samples subjected to either ion-irradiation or
oxygenation demonstrate that changing the oxygen content has two separable
effects: 1) a doping effect similar to that of cerium, and 2) a disorder
effect. These results are consistent with prior speculations that apical oxygen
removal is necessary to achieve superconductivity in this compound.Comment: 5 pages, 5 figure
An examination of the effects of self-regulatory focus on the perception of the media richness: the case of email
Communication is a key element in organizations’ business success. The media richness theory and the channel expansion theory are two of the most influential theories regarding the selection and use of communication media in organizations; however, literature has focused little on the effects of self-regulation by managers and employees in these theories. To analyze these topics, this study develops an empirical investigation by gathering data from 600 managers and employees using a questionnaire. The results suggest that the perception of media richness is positively affected when the individual shows a promotion focus or strategy.Peer ReviewedPostprint (author’s final draft
The distribution of extremal points of Gaussian scalar fields
We consider the signed density of the extremal points of (two-dimensional)
scalar fields with a Gaussian distribution. We assign a positive unit charge to
the maxima and minima of the function and a negative one to its saddles. At
first, we compute the average density for a field in half-space with Dirichlet
boundary conditions. Then we calculate the charge-charge correlation function
(without boundary). We apply the general results to random waves and random
surfaces. Furthermore, we find a generating functional for the two-point
function. Its Legendre transform is the integral over the scalar curvature of a
4-dimensional Riemannian manifold.Comment: 22 pages, 8 figures, corrected published versio
Experimental phase diagram of moving vortices
In the mixed state of type II superconductors, vortices penetrate the sample
and form a correlated system due to the screening of supercurrents around them.
Interestingly, we can study this correlated system as a function of density and
driving force. The density, for instance, is controlled by the magnetic field,
B, whereas a current density j acts as a driving force F=jxB on all vortices.
The free motion of vortices is inhibited by the presence of an underlying
potential, which tends to pin the vortices. Hence, to minimize the pinning
strength we studied a superconducting glass in which the depinning current is
10 to 1000 times smaller than in previous studies, which enables us to map out
the complete phase diagram in this new regime. The diagram is obtained as a
function of B, driving current and temperature and led a remarkable set of new
results, which includes a huge peak effect, an additional reentrant depinning
phase and a driving force induced pinning phase.Comment: 4 page
From Prediction to Explanation: Reconceptualizing and Extending the Perceived Characteristics of Innovating
Individual adoption and use of technology remains a critical concern for both managers and professionals. Despite the widespread integration of technology into work and organizations, there remain many opportunities for individuals to either extend or limit their use of IT at work. This paper extends work on the Perceived Characteristics of Innovating (PCI), as defined by Moore and Benbasat in 1991. Building on studies over the past ten years as well as on additional empirical research, we provide two contributions ?a reconceptualization and refinement of the PCI constructs, and an extended theoretical model of their influence on users?behavior. The construct refinements aim to provide greater theoretical clarity and to address challenges in the measurement of the constructs. The extended theoretical model provides a more complete picture of the influence of the PCIs, by considering the complex web of relationships among them in addition to their potential direct effects on usage
Assessment of body composition by air-displacement plethysmography: influence of body temperature and moisture
BACKGROUND: To investigate the effect of body temperature and moisture on body fat (%fat), volume and density by air-displacement plethysmography (BOD POD). METHODS: %fat, body volume and density by the BOD POD before (BOD POD(BH)) and immediately following hydrostatic weighing (BOD POD(FH)) were performed in 32 healthy females (age (yr) 33 ± 11, weight (kg) 64 ± 14, height (cm) 167 ± 7). Body temperature and moisture were measured prior to BOD POD(BH )and prior to BOD POD(FH )with body moisture defined as the difference in body weight (kg) between the BOD POD(BH )and BOD POD(FH )measurements. RESULTS: BOD POD(FH )%fat (27.1%) and body volume (61.5 L) were significantly lower (P ≤ 0.001) and body density (1.0379 g/cm(3)) significantly higher (P ≤ 0.001) than BOD POD(BH )%fat (28.9%), body volume (61.7 L), and body density (1.0341 g/cm(3)). A significant increase in body temperature (~0.6°C; P ≤ 0.001) and body moisture (0.08 kg; P ≤ 0.01) were observed between BOD POD(BH )and BOD POD(FH). Body surface area was positively associated with the difference in %fat independent of changes in body temperature and moisture, r = 0.30, P < 0.05. CONCLUSION: These data demonstrate for the first time that increases in body heat and moisture result in an underestimation of body fat when using the BOD POD, however, the precise mechanism remains unidentified
An anisotropic distribution of spin vectors in asteroid families
Current amount of ~500 asteroid models derived from the disk-integrated
photometry by the lightcurve inversion method allows us to study not only the
spin-vector properties of the whole population of MBAs, but also of several
individual collisional families. We create a data set of 152 asteroids that
were identified by the HCM method as members of ten collisional families, among
them are 31 newly derived unique models and 24 new models with well-constrained
pole-ecliptic latitudes of the spin axes. The remaining models are adopted from
the DAMIT database or the literature. We revise the preliminary family
membership identification by the HCM method according to several additional
criteria - taxonomic type, color, albedo, maximum Yarkovsky semi-major axis
drift and the consistency with the size-frequency distribution of each family,
and consequently we remove interlopers. We then present the spin-vector
distributions for eight asteroidal families. We use a combined orbital- and
spin-evolution model to explain the observed spin-vector properties of objects
among collisional families. In general, we observe for studied families similar
trends in the (a_p, \beta) space: (i) larger asteroids are situated in the
proximity of the center of the family; (ii) asteroids with \beta>0{\deg} are
usually found to the right from the family center; (iii) on the other hand,
asteroids with \beta<0{\deg} to the left from the center; (iv) majority of
asteroids have large pole-ecliptic latitudes (|\beta|\gtrsim 30{\deg}); and
finally (v) some families have a statistically significant excess of asteroids
with \beta>0{\deg} or \beta<0{\deg}. Our numerical simulation of the long-term
evolution of a collisional family is capable of reproducing well the observed
spin-vector properties. Using this simulation, we also independently constrain
the age of families Flora (1.0\pm0.5 Gyr) and Koronis (2.5-4 Gyr).Comment: Accepted for publication in A&A (September 16, 2013
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