30,507 research outputs found
Meaning, moral realism, and the importance of morality
Many philosophers have suspected that the normative importance of morality depends on moral realism. In this paper, I defend a version of this suspicion: I argue that if teleological forms of moral realism, those that posit an objective purpose to human life, are true, then we gain a distinctive kind of reason to do what is morally required. I argue for this by showing that if these forms of realism are true, then doing what is morally required can provide a life with meaning, which is a widespread human need. I also argue that rival meta-ethical views, like anti-realism or non-naturalist realism, cannot make morality meaning-conferring in this way
Optimal Sizing of Voltage Control Devices for Distribution Circuit with Intermittent Load
We consider joint control of a switchable capacitor and a D-STATCOM for
voltage regulation in a distribution circuit with intermittent load. The
control problem is formulated as a two-timescale optimal power flow problem
with chance constraints, which minimizes power loss while limiting the
probability of voltage violations due to fast changes in load. The control
problem forms the basis of an optimization problem which determines the sizes
of the control devices by minimizing sum of the expected power loss cost and
the capital cost. We develop computationally efficient heuristics to solve the
optimal sizing problem and implement real-time control. Numerical experiments
on a circuit with high-performance computing (HPC) load show that the proposed
sizing and control schemes significantly improve the reliability of voltage
regulation on the expense of only a moderate increase in cost.Comment: 10 pages, 7 figures, submitted to HICSS'1
On martingale approximations
Consider additive functionals of a Markov chain , with stationary
(marginal) distribution and transition function denoted by and , say
, where is square integrable and has mean 0 with
respect to . If has the form , where is a square
integrable martingale with stationary increments and , then
is said to admit a martingale approximation. Necessary and sufficient
conditions for such an approximation are developed. Two obvious necessary
conditions are and . Assuming the first of these, let ; then defines a
pseudo norm on the subspace of where it is finite. In one main
result, a simple necessary and sufficient condition for a martingale
approximation is developed in terms of . Let denote
the adjoint operator to , regarded as a linear operator from into
itself, and consider co-isometries (), an important special case that
includes shift processes. In another main result a convenient orthonormal basis
for is identified along with a simple necessary and sufficient
condition for the existence of a martingale approximation in terms of the
coefficients of the expansion of with respect to this basis.Comment: Published in at http://dx.doi.org/10.1214/07-AAP505 the Annals of
Applied Probability (http://www.imstat.org/aap/) by the Institute of
Mathematical Statistics (http://www.imstat.org
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