33,211 research outputs found

    The Effect of Employee Involvment on Firm Performance: Evidence from an Econometric Case Study

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    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

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    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

    Get PDF
    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

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    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 166±5166 \pm 5 Hz. (4.1σ4.1 \sigma; 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 242±3242 \pm 3 Hz (6.0σ6.0 \sigma; 7--35 keV). The ratio of these two frequencies is 1.46±0.051.46 \pm 0.05. 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

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    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

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    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

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    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

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    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

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    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 (m=±1m=\pm 1) 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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