6,934 research outputs found
Software acquisition: a business strategy analysis
The paper argues that there are new insights to be gained from a strategic analysis of requirements engineering. The paper is motivated by a simple question: what does it take to be a world class software acquirer? The question has relevance for requirements engineers because for many organisations market pressures mean that software is commonly acquired rather than developed from scratch. The paper builds on the work of C. H. Fine (1998) who suggests that product, process and supply chain should be designed together, i.e., 3D concurrent engineering. Using a number of reference theories, it proposes a systematic way of carrying out 3D concurrent engineering. The paper concludes that the critical activity in supply chain design is the design of the distribution of skills and the nature of contract
Ferromagnetism of Weakly-Interacting Electrons in Disordered Systems
It was realized two decades ago that the two-dimensional diffusive Fermi
liquid phase is unstable against arbitrarily weak electron-electron
interactions. Recently, using the nonlinear sigma model developed by
Finkelstein, several authors have shown that the instability leads to a
ferromagnetic state. In this paper, we consider diffusing electrons interacting
through a ferromagnetic exchange interaction. Using the Hartree-Fock
approximation to directly calculate the electron self energy, we find that the
total energy is minimized by a finite ferromagnetic moment for arbitrarily weak
interactions in two dimensions and for interaction strengths exceeding a
critical proportional to the conductivity in three dimensions. We discuss the
relation between our results and previous ones
Fine-grain process modelling
In this paper, we propose the use of fine-grain process
modelling as an aid to software development. We suggest
the use of two levels of granularity, one at the level of the
individual developer and another at the level of the
representation scheme used by that developer. The
advantages of modelling the software development process
at these two levels, we argue, include respectively: (1) the
production of models that better reflect actual
development processes because they are oriented towards
the actors who enact them, and (2) models that are
vehicles for providing guidance because they may be
expressed in terms of the actual representation schemes
employed by those actors. We suggest that our previously
published approach of using multiple “ViewPoints” to
model software development participants, the perspectives
that they hold, the representation schemes that they
deploy and the process models that they maintain, is one
way of supporting the fine-grain modelling we advocate.
We point to some simple, tool-based experiments we have
performed that support our proposition
Universal Description of Granular Metals at Low Temperatures: Granular Fermi Liquid
We present a unified description of the low temperature phase of granular
metals that reveals a striking generality of the low temperature behaviors. Our
model explains the universality of the low-temperature conductivity that
coincides exactly with that of the homogeneously disordered systems and enables
a straightforward derivation of low temperature characteristics of disordered
conductors.Comment: 4 pages, 1 figur
Effects of fluctuations and Coulomb interaction on the transition temperature of granular superconductors
We investigate the suppression of superconducting transition temperature in
granular metallic systems due to (i) fluctuations of the order parameter
(bosonic mechanism) and (ii) Coulomb repulsion (fermionic mechanism) assuming
large tunneling conductance between the grains . We find the
correction to the superconducting transition temperature for 3 granular
samples and films. We demonstrate that if the critical temperature , where is the mean level spacing in a single grain the bosonic
mechanism is the dominant mechanism of the superconductivity suppression, while
for critical temperatures the suppression of
superconductivity is due to the fermionic mechanism.Comment: 12 pages, 9 figures, several sections clarifying the details of our
calculations are adde
Suppression of superconductivity in granular metals
We investigate the suppression of the superconducting transition temperature
due to Coulomb repulsion in granular metallic systems at large tunneling
conductance between the grains, . We find the correction to the
superconducting transition temperature for 3 granular samples and films. We
demonstrate that depending on the parameters of superconducting grains, the
corresponding granular samples can be divided into two groups: (i) the granular
samples that belong to the first group may have only insulating or
superconducting states at zero temperature depending on the bare intergranular
tunneling conductance , while (ii) the granular samples that belong to the
second group in addition have an intermediate metallic phase where
superconductivity is suppressed while the effects of the Coulomb blockade are
not yet strong.Comment: 4 pages, 3 figure
Are Bosonic Replicas Faulty?
Motivated by the ongoing discussion about a seeming asymmetry in the
performance of fermionic and bosonic replicas, we present an exact,
nonperturbative approach to zero-dimensional replica field theories belonging
to the broadly interpreted "beta=2" Dyson symmetry class. We then utilise the
formalism developed to demonstrate that the bosonic replicas do correctly
reproduce the microscopic spectral density in the QCD inspired chiral Gaussian
unitary ensemble. This disproves the myth that the bosonic replica field
theories are intrinsically faulty.Comment: 4.3 pages; final version to appear in PR
Medicaid Crowd-Out of Private Long-Term Care Insurance Demand: Evidence from the Health and Retirement Survey
This paper provides empirical evidence of Medicaid crowd out of demand for private long-term care insurance. Using data on the near- and young-elderly in the Health and Retirement Survey, our central estimate suggests that a 25,000 – demand for private long-term care insurance would rise by 2.7 percentage points. While this represents a 30 percent increase in insurance coverage relative to the baseline ownership rate of 9.1 percent, it also indicates that the vast majority of households would still find it unattractive to purchase private insurance. We discuss reasons why, even with extremely stringent eligibility requirements, Medicaid may still exert a large crowd-out effect on demand for private insurance.
The effects of massage therapy on delayed-onset muscle soreness after unaccustomed exercise for healthy, sedentary adults
This study examined the effects of massage therapy on delayed-onset muscle soreness (DOMS) following unaccustomed exercise in healthy, sedentary adults. Fifteen volunteers between the ages of 23 and 63 performed 100 calf raises followed by 15 minutes of rest. After the rest period, one leg was randomly assigned to receive a 5-minute massage while the other leg received a 5-minute placebo ultrasound treatment. A questionnaire was administered to evaluate DOMS at 24, 48, and 72 hour posttreatment intervals when DOMS reportedly is at its peak. A double blind control was employed so that the examiner was unaware as to which treatments were performed on each leg. A t-test for nonindependent samples was used with significance set at the 0.05 level. There was less DOMS reported in the massaged leg at each interval, however, only a significant reduction in DOMS was reported at the 24 hour posttreatment interval
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