33,211 research outputs found
The Effect of Employee Involvment on Firm Performance: Evidence from an Econometric Case Study
We provide some of the most reliable evidence to date on the direct impact of employee involvement through participatory arrangements such as teams on business performance. The data we use are extraordinary --daily data for rejection, production and downtime rates for all operators in a single plant during a 35 month period, almost 53,000 observations. Our key findings are that: (i) membership in offline teams initially enhances individual productivity by about 3% and reduces rejection rates by more than 25%; (ii) these improvements are dissipated, typically at a rate of 10 to 16% per 100 working days; (iii) the introduction of teams is initially accompanied by increased rates of downtime and these costs diminish over time. In addition: (iv) the performance-enhancing effects of team membership are greater and more long-lasting for team members who are solicited by management to join teams; similar relationships exist for more educated team members. These findings, which are best interpreted as lower bound estimates of the effects of teams, are consistent with the diverse hypotheses including propositions that: (i) employee involvement will produce improved enterprise performance through diverse channels including enhanced discretionary effort by employees; (ii) various kinds of complementarities accompany many changes in organizational design (such as between teams and formal education); (iii) the introduction of high performance workplace practices are best viewed as investments, though there are significant learning effects; (iv) differences in performance for team members solicited by mangers compared to those who volunteer are consistent with various hypotheses including management signaling and opportunistic behavior by employees, but inconsistent with hypotheses based on Hawthorne effectshttp://deepblue.lib.umich.edu/bitstream/2027.42/39998/2/wp612.pd
Antiferromagnetic Order in Pauli Limited Unconventional Superconductors
We develop a theory of the coexistence of superconductivity (SC) and
antiferromagnetism (AFM) in CeCoIn5. We show that in Pauli-limited nodal
superconductors the nesting of the quasi-particle pockets induced by Zeeman
pair-breaking leads to incommensurate AFM with the moment normal to the field.
We compute the phase diagram and find a first order transition to the normal
state at low temperatures, absence of normal state AFM, and coexistence of SC
and AFM at high fields, in agreement with experiments. We also predict the
existence of a new double-Q magnetic phase
The Effect of Employee Involvment on Firm Performance: Evidence from an Econometric Case Study
We provide some of the most reliable evidence to date on the direct impact of employee involvement through participatory arrangements such as teams on business performance. The data we use are extraordinary --daily data for rejection, production and downtime rates for all operators in a single plant during a 35 month period, almost 53,000 observations. Our key findings are that: (i) membership in offline teams initially enhances individual productivity by about 3% and reduces rejection rates by more than 25%; (ii) these improvements are dissipated, typically at a rate of 10 to 16% per 100 working days; (iii) the introduction of teams is initially accompanied by increased rates of downtime and these costs diminish over time. In addition: (iv) the performance-enhancing effects of team membership are greater and more long-lasting for team members who are solicited by management to join teams; similar relationships exist for more educated team members. These findings, which are best interpreted as lower bound estimates of the effects of teams, are consistent with the diverse hypotheses including propositions that: (i) employee involvement will produce improved enterprise performance through diverse channels including enhanced discretionary effort by employees; (ii) various kinds of complementarities accompany many changes in organizational design (such as between teams and formal education); (iii) the introduction of high performance workplace practices are best viewed as investments, though there are significant learning effects; (iv) differences in performance for team members solicited by mangers compared to those who volunteer are consistent with various hypotheses including management signaling and opportunistic behavior by employees, but inconsistent with hypotheses based on Hawthorne effectsProductivity, High Performance Work Practices, Employee Participation, Human Resource Management Practices
The X-ray Outburst of H1743-322: High-Frequency QPOs with a 3:2 Frequency Ratio
We observed the 2003 X-ray outburst of H1743-322 in a series of 130 pointed
observation with RXTE. We searched individual observations for high-frequency
QPOs (HFQPOs) and found only weak or marginal detections near 240 and 160 Hz.
We next grouped the observations in several different ways and computed the
average power-density spectra (PDS) in a search for further evidence of HFQPOs.
This effort yielded two significant results for those observations defined by
the presence of low-frequency QPOs (0.1-20 Hz) and an absence of
``band-limited'' power continua: (1) The 9 time intervals with the highest 7-35
keV count rates yielded an average PDS with a QPO at Hz. (; 3--35 keV); and (2) a second group with lower 7-35 keV count rates (26
intervals) produced an average PDS with a QPO at Hz (;
7--35 keV). The ratio of these two frequencies is . This finding
is consistent with results obtained for three other black hole systems that
exhibit commensurate HFQPOs in a 3:2 ratio. Furthermore, the occurrence of
H1743-322's slower HFQPO at times of higher X-ray luminosity closely resembles
the behavior of XTE J1550-564 and GRO J1655-40. We discuss our results in terms
of a resonance model that invokes frequencies set by general relativity for
orbital motions near a black-hole event horizon.Comment: 12 pages, 3 figures, submitted to Ap
Long term variation of the solar diurnal anisotropy of galactic cosmic rays observed with the Nagoya multi-directional muon detector
We analyze the three dimensional anisotropy of the galactic cosmic ray (GCR)
intensities observed independently with a muon detector at Nagoya in Japan and
neutron monitors over four solar activity cycles. We clearly see the phase of
the free-space diurnal anisotropy shifting toward earlier hours around solar
activity minima in A>0 epochs, due to the reduced anisotropy component parallel
to the mean magnetic field. The average parallel component is consistent with a
rigidity independent spectrum, while the perpendicular component increases with
GCR rigidity. We suggest that this harder spectrum of the perpendicular
component is due to contribution from the drift streaming. We find that the
bidirectional latitudinal density gradient is positive in A>0 epoch, while it
is negative in A<0 epoch, in accord with the drift model prediction. The radial
density gradient, on the other hand, varies with ~11-year cycle with maxima
(minima) in solar maximum (minimum) periods, but there is no significant
difference seen between average radial gradients in A>0 and A<0 epochs. The
average parallel mean free path is larger in A0. We also find,
however, that parallel mean free path (radial gradient) appears to persistently
increase (decreasing) in the last three cycles of weakening solar activity. We
suggest that simple differences between these parameters in A>0 and A<0 epochs
are seriously biased by these long-term trends.Comment: accepted for the publication in the Astrophysical Journa
Analycity and smoothing effect for the coupled system of equations of Korteweg - de Vries type with a single point singularity
We study that a solution of the initial value problem associated for the
coupled system of equations of Korteweg - de Vries type which appears as a
model to describe the strong interaction of weakly nonlinear long waves, has
analyticity in time and smoothing effect up to real analyticity if the initial
data only has a single point singularity at $x=0.
Electron spin interferometry using a semiconductor ring structure
A ring structure fabricated from GaAs is used to achieve interference of the
net spin polarization of conduction band electrons. Optically polarized spins
are split into two packets by passing through two arms of the ring in the
diffusive transport regime. Optical pumping with circularly polarized light on
one arm establishes dynamic nuclear polarization which acts as a local
effective magnetic field on electron spins due to the hyperfine interaction.
This local field causes one spin packet to precess faster than the other,
thereby controlling the spin interference when the two packets are combined.Comment: 4 pages, 2 figure
Theoretical Sensitivity Analysis for Quantitative Operational Risk Management
We study the asymptotic behavior of the difference between the values at risk
VaR(L) and VaR(L+S) for heavy tailed random variables L and S for application
in sensitivity analysis of quantitative operational risk management within the
framework of the advanced measurement approach of Basel II (and III). Here L
describes the loss amount of the present risk profile and S describes the loss
amount caused by an additional loss factor. We obtain different types of
results according to the relative magnitudes of the thicknesses of the tails of
L and S. In particular, if the tail of S is sufficiently thinner than the tail
of L, then the difference between prior and posterior risk amounts VaR(L+S) -
VaR(L) is asymptotically equivalent to the expectation (expected loss) of S.Comment: 21 pages, 1 figure, 4 tables, forthcoming in International Journal of
Theoretical and Applied Finance (IJTAF
Epicyclic oscillations of non-slender fluid tori around Kerr black holes
Considering epicyclic oscillations of pressure-supported perfect fluid tori
orbiting Kerr black holes we examine non-geodesic (pressure) effects on the
epicyclic modes properties. Using a perturbation method we derive fully general
relativistic formulas for eigenfunctions and eigenfrequencies of the radial and
vertical epicyclic modes of a slightly non-slender, constant specific angular
momentum torus up to second-order accuracy with respect to the torus thickness.
The behaviour of the axisymmetric and lowest-order () non-axisymmetric
epicyclic modes is investigated. For an arbitrary black hole spin we find that,
in comparison with the (axisymmetric) epicyclic frequencies of free test
particles, non-slender tori receive negative pressure corrections and exhibit
thus lower frequencies. Our findings are in qualitative agreement with the
results of a recent pseudo-Newtonian study of analogous problem defined within
the Paczy{\'n}ski-Wiita potential. Implications of our results on the
high-frequency QPO models dealing with epicyclic oscillations are addressed.Comment: 24 pages, 8 figure
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