7,665 research outputs found
The Thrift Industry and the Community Reinvestment Act: Assessing the Cost of Social Responsibility
A stochastic frontier cost function indicates that the annual cost of complying with the anti-redlining Community Reinvestment Act (CRA) is 38,000 per loan. The regulations whose compliance cost is estimated apply to about 80 percent of all U.S. banks.
The Cost of Corporate Social Responsibility: The Case of the Community Reinvestment Act
A Data Envelopment Analysis (DEA) cost minimization model is employed to estimate the cost to thrift institutions of achieving a rating of 'Outstanding' under the anti-redlining Community Reinvestment Act, which is viewed as an act of voluntary Corporate Social Responsibility (CSR). There is no difference in overall cost efficiency between 'Outstanding' and minimally compliant 'Satisfactory' thrifts. However, the sources of cost inefficiency do differ, and an 'Outstanding' rating involves annual extra cost of $7.4 million or, 1.3% of total costs. This added cost is the shadow price of CSR since it is not an explicit output or input in the DEA cost model. Before and After-tax rates of return are the same for the 'Outstanding' and 'Satisfactory' thrifts, which implies a recoupment of the extra cost. The findings are consistent with CSR as a management choice based on balancing marginal cost and marginal revenue. An incidental finding is that larger thrifts are less efficient
Simulated space flight testing of commercial terrestrial silicon cells
Low cost silicon solar cells manufactured for the terrestrial market are examined for possible space flight use. The results of preliminary space environmental testing are reported and discussed. In addition, a number of possible obstacles to the use of these cells is examined. It is concluded that the terrestrial industry could provide an extremely low cost and reliable cell for space use
Approximate performance analysis of generalized join the shortest queue routing
In this paper we propose a highly accurate approximate performance analysis
of a heterogeneous server system with a processor sharing service discipline
and a general job-size distribution under a generalized join the shortest queue
(GJSQ) routing protocol. The GJSQ routing protocol is a natural extension of
the well-known join the shortest queue routing policy that takes into account
the non-identical service rates in addition to the number of jobs at each
server. The performance metrics that are of interest here are the equilibrium
distribution and the mean and standard deviation of the number of jobs at each
server. We show that the latter metrics are near-insensitive to the job-size
distribution using simulation experiments. By applying a single queue
approximation we model each server as a single server queue with a
state-dependent arrival process, independent of other servers in the system,
and derive the distribution of the number of jobs at the server. These
state-dependent arrival rates are intended to capture the inherent correlation
between servers in the original system and behave in a rather atypical way.Comment: 16 pages, 5 figures -- version 2 incorporates minor textual change
What is the length of a knot in a polymer?
We give statistical definitions of the length, l, of a loose prime knot tied
into a long, fluctuating ring macromolecule. Monte Carlo results for the
equilibrium, good solvent regime show that ~ N^t, where N is the ring
length and t ~ 0.75 is independent of the knot topology. In the collapsed
regime below the theta temperature, length determinations based on the entropic
competition of different knots within the same ring show delocalization (t~1).Comment: 9 pages, 5 Postscript figure
GaP betavoltaic cells as a power source
Maximum power output for the GaP cells of this study was found to be on the order of 1 microW. This resulted from exposure to 200 and 40 KeV electrons at a flux of 2 x 10(exp 9) electrons/sq cm/s, equivalent to a 54 mCurie source. The efficiencies of the cells ranged from 5 to 9 percent for 200 and 40 KeV electrons respectively. The lower efficiency at higher energy is due to a substantial fraction of energy deposition in the substrate, further than a diffusion length from the depletion region of the cell. Radiation damage was clearly observed in GaP after exposure to 200 KeV electrons at a fluence of 2 x 10(exp 12) electrons/sq cm. No discernable damage was observed after exposure to 40 KeV electrons at the same fluence. Analysis indicates that a GaP betavoltaic system would not be practical if limited to low energy beta sources. The power available would be too low even in the ideal case. By utilizing high activity beta sources, such as Sr-90/Y-90, it may be possible to achieve performance that could be suitable for some space power applications. However, to utilize such a source the problem of radiation damage in the beta cell material must be overcome
Iron line emission in X-ray afterglows
Recent observations of X-ray afterglows reveal the presence of a redshifted
Kalpha iron line in emission in four bursts. In GRB 991216, the line was
detected by the low energy grating of Chandra, which showed the line to be
broad, with a full width of ~15,000 km/s. These observations indicate the
presence of a >1 solar mass of iron rich material in the close vicinity of the
burst, most likely a supernova remnant. The fact that such strong lines are
observed less than a day after the trigger strongly limits the size of the
remnant, which must be very compact. If the remnant had the observed velocity
since the supernova explosion, its age would be less than a month. In this case
nickel and cobalt have not yet decayed into iron. We show how to solve this
paradox.Comment: 3 pages, to appear in the proceedings of the the 2nd Workshop on
Gamma-Ray Bursts in the Afterglow Era, Rome, Oct. 200
Strong electronic correlation in the Hydrogen chain: a variational Monte Carlo study
In this article, we report a fully ab initio variational Monte Carlo study of
the linear, and periodic chain of Hydrogen atoms, a prototype system providing
the simplest example of strong electronic correlation in low dimensions. In
particular, we prove that numerical accuracy comparable to that of benchmark
density matrix renormalization group calculations can be achieved by using a
highly correlated Jastrow-antisymmetrized geminal power variational wave
function. Furthermore, by using the so-called "modern theory of polarization"
and by studying the spin-spin and dimer-dimer correlations functions, we have
characterized in details the crossover between the weakly and strongly
correlated regimes of this atomic chain. Our results show that variational
Monte Carlo provides an accurate and flexible alternative to highly correlated
methods of quantum chemistry which, at variance with these methods, can be also
applied to a strongly correlated solid in low dimensions close to a crossover
or a phase transition.Comment: 7 pages, 4 figures, submitted to Physical Review
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