312 research outputs found
Semiempirical Shell Model Masses with Magic Number Z = 126 for Superheavy Elements
A semiempirical shell model mass equation applicable to superheavy elements
up to Z = 126 is presented and shown to have a high predictive power. The
equation is applied to the recently discovered superheavy nuclei Z = 118, A =
293 and Z = 114, A = 289 and their decay products.Comment: 7 pages, including 2 figures and 2 table
Seasonality, Cost Shocks, and the Production Smoothing Model of Inventories
In recent years there has been a resurgence of interest in the empirical behavior of inventories. A great deal of this research examines some variant of the production smoothing model of finished goods inventories. The overall assessment of this model that exists in the literature is quite negative: there is little evidence that manufacturers hold inventories of finished goods in order to smooth production patterns. This paper examines whether this negative assessment of the model is due to one or both of two features: costs shocks and seasonal fluctuations. The reason for considering costs shocks is that if firms are buffetted more by cost shocks than demand shocks, production should optimally be more variable than sales. The reasons for considering seasonal fluctuations are that seasonal fluctuations account for a major portion of the variance in production and sales, that seasonal fluctuations are precisely the kinds of fluctuations that producers should most easily smooth and that seasonally adjusted data is likely to produce spurious rejections of the production smoothing model even when it is correct.Center for Research on Economic and Social Theory, Department of Economics, University of Michiganhttp://deepblue.lib.umich.edu/bitstream/2027.42/100882/1/ECON334.pd
Production, Sales, and the Change in Inventories: An Identity that Doesn't Add Up
In this paper we examine two different measures of monthly production that have been used by economists. The first measure, which we refer to as IP, is the index of industrial production constructed by the Board of Governors of the Federal Reserve. This measure is used extensively in empirical work on the business cycle, as well as by policymakers and others to assess the current state of the economy. The second measure, which we refer to as Y4, is constructed from the accounting identity that output equals sales plus the change in inventories. Sales and inventory data are reported by the Department of Commerce. This measure of output is frequently used to estimate models of inventory accumulation. theoretically, these two series measuare the same underlying economic variable--the production of goods by firms during the month. We show here that the time series properties of these two series are radically different.Center for Research on Economic and Social Theory, Department of Economics, University of Michiganhttp://deepblue.lib.umich.edu/bitstream/2027.42/100881/1/ECON333.pd
Microscopic structure of fundamental excitations in N=Z nuclei
Excitation energies of the =1 states in even-even as well as =0 and
=1 states in odd-odd = nuclei are calculated within the mean-field
approach. It is shown that the underlying structure of these states can be
determined in a consistent manner only when both isoscalar and isovector
pairing collectivity as well as isospin projection, treated within the
iso-cranking approximation, are taken into account. In particular, in odd-odd
= nuclei, the interplay between quasiparticle excitations (relevant for
the case of =0 states) and iso-rotations (relevant for the case of =1
states) explains the near-degeneracy of these fundamental excitations.Comment: 4 pages, 4 figure
Production, sales, and the change in inventories : An identity that doesn't add up
We examine two measures of monthly manufacturing production. The first is the index of industrial production; the second is constructed from the accounting identity that output equals sales plus the change in inventories. We show that the means, variances, and serial correlation coefficients of the log growth rates differ substantially between the two series, and the cross-correlations are in most cases less than 0.4. A model of classical measurement error indicates that in 15 of 20 two-digit industries measurement error accounts for over 35% of the variation in the monthly growth rates of seasonally adjusted industrial production.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/27856/1/0000268.pd
Semiempirical Shell Model Masses with Magic Number Z=126 for Translead Elements with N smaller or equal to 126
A semiempirical shell model mass equation based on magic number Z=126 and
applicable to translead elements with N smaller or equal to 126 is presented.
For alpha decay energies the equation is shown to have a high predictive power
and an rms deviation from the data of about 100 keV. The rms deviations for
masses and other mass differences are between about 200 and 300 keV.Comment: 8 pages including 3 figures and 3 table
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