8,024 research outputs found
ASIAN AMERICANS IN PSYCHIATRIC SYSTEMS
Prior to the l960\u27s, very little interest had been shown in researching patterns of American utilization of mental health facilities. The notion of culturally different patterns of psychological “normalcy” for Asian Americans as a distinct population had not been adequately explored. Although a few case studies of Asian-American patients did appear in the literature from time to time, no extensive or systematic research into the demographic and psychological characteristics of Asian-American patient populations had been presented
On the complexity of solving linear congruences and computing nullspaces modulo a constant
We consider the problems of determining the feasibility of a linear
congruence, producing a solution to a linear congruence, and finding a spanning
set for the nullspace of an integer matrix, where each problem is considered
modulo an arbitrary constant k>1. These problems are known to be complete for
the logspace modular counting classes {Mod_k L} = {coMod_k L} in special case
that k is prime (Buntrock et al, 1992). By considering variants of standard
logspace function classes --- related to #L and functions computable by UL
machines, but which only characterize the number of accepting paths modulo k
--- we show that these problems of linear algebra are also complete for
{coMod_k L} for any constant k>1.
Our results are obtained by defining a class of functions FUL_k which are low
for {Mod_k L} and {coMod_k L} for k>1, using ideas similar to those used in the
case of k prime in (Buntrock et al, 1992) to show closure of Mod_k L under NC^1
reductions (including {Mod_k L} oracle reductions). In addition to the results
above, we briefly consider the relationship of the class FUL_k for arbitrary
moduli k to the class {F.coMod_k L} of functions whose output symbols are
verifiable by {coMod_k L} algorithms; and consider what consequences such a
comparison may have for oracle closure results of the form {Mod_k L}^{Mod_k L}
= {Mod_k L} for composite k.Comment: 17 pages, one Appendix; minor corrections and revisions to
presentation, new observations regarding the prospect of oracle closures.
Comments welcom
A linearized stabilizer formalism for systems of finite dimension
The stabilizer formalism is a scheme, generalizing well-known techniques
developed by Gottesman [quant-ph/9705052] in the case of qubits, to efficiently
simulate a class of transformations ("stabilizer circuits", which include the
quantum Fourier transform and highly entangling operations) on standard basis
states of d-dimensional qudits. To determine the state of a simulated system,
existing treatments involve the computation of cumulative phase factors which
involve quadratic dependencies. We present a simple formalism in which Pauli
operators are represented using displacement operators in discrete phase space,
expressing the evolution of the state via linear transformations modulo D <=
2d. We thus obtain a simple proof that simulating stabilizer circuits on n
qudits, involving any constant number of measurement rounds, is complete for
the complexity class coMod_{d}L and may be simulated by O(log(n)^2)-depth
boolean circuits for any constant d >= 2.Comment: 25 pages, 3 figures. Reorganized to collect complexity results; some
corrections and elaborations of technical results. Differs slightly from the
version to be published (fixed typos, changes of wording to accommodate page
breaks for a different article format). To appear as QIC vol 13 (2013),
pp.73--11
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