4,614 research outputs found
Multidimensional optimization algorithms numerical results
This paper presents some multidimensional optimization algorithms. By using the "penalty function" method, these algorithms are used to solving an entire class of economic optimization problems. Comparative numerical results of certain new multidimensional optimization algorithms for solving some test problems known on literature are shown.optimization algorithm, multidimensional optimization, penalty function
Proposal for a quantum delayed-choice experiment
Gedanken experiments are important conceptual tools in the quest to reconcile
our classical intuition with quantum mechanics and nowadays are routinely
performed in the laboratory. An important open question is the quantum
behaviour of the controlling devices in such experiments. We propose a
framework to analyse quantum-controlled experiments and illustrate the
implications by discussing a quantum version of Wheeler's delayed-choice
experiment. The introduction of a quantum-controlled device (i.e., quantum
beamsplitter) has several consequences. First, it implies that we can measure
complementary phenomena with a single experimental setup, thus pointing to a
redefinition of complementarity principle. Second, a quantum control allows us
to prove there are no consistent hidden-variable theories in which "particle"
and "wave" are realistic properties. Finally, it shows that a photon can have a
morphing behaviour between "particle" and "wave"; this further supports the
conclusion that "particle" and "wave" are not realistic properties but merely
reflect how we 'look' at the photon. The framework developed here can be
extended to other experiments, particularly to Bell-inequality tests
HEURISTIC AND OPTIMUM SOLUTIONS IN ALLOCATION PROBLEMS
In this paper we present some models and algoritms for solving some typical production planning and scheduling problems. We present the Resource-Constrained Project Scheduling Problem (RCPSP) and algorithms for the determination of maximal couplings with minimal arch length in the graph attached to an allocation problem, and for the determination of the solution of Dirichlet problem and of the potential-voltage problem which appear in a production planning. We develop a model for allocating work among potential VO partners, taking into account fixed and variable work costs and transportation costs.Dirichlet’s problem, conex graph, maximal coupling, RCPS problem, virtual organization, allocation problem
Determinism, independence and objectivity are incompatible
Hidden-variable models aim to reproduce the results of quantum theory and to
satisfy our classical intuition. Their refutation is usually based on deriving
predictions that are different from those of quantum mechanics. Here instead we
study the mutual compatibility of apparently reasonable classical assumptions.
We analyze a version of the delayed-choice experiment which ostensibly combines
determinism, independence of hidden variables on the conducted experiments, and
wave-particle objectivity (the assertion that quantum systems are, at any
moment, either particles or waves, but not both). These three ideas are
incompatible with any theory, not only with quantum mechanics.Comment: 4 pages, published versio
Thermodynamical description of stationary, asymptotically flat solutions with conical singularities
We examine the thermodynamical properties of a number of asymptotically flat,
stationary (but not static) solutions having conical singularities, with both
connected and non-connected event horizons, using the thermodynamical
description recently proposed in arXiv:0912.3386 [gr-qc]. The examples
considered are the double-Kerr solution, the black ring rotating in either S^2
or S^1 and the black Saturn, where the balance condition is not imposed for the
latter two solutions. We show that not only the Bekenstein-Hawking area law is
recovered from the thermodynamical description but also the thermodynamical
angular momentum is the ADM angular momentum. We also analyse the
thermodynamical stability and show that, for all these solutions, either the
isothermal moment of inertia or the specific heat at constant angular momentum
is negative, at any point in parameter space. Therefore, all these solutions
are thermodynamically unstable in the grand canonical ensemble.Comment: 19 pages, 12 figure
SQCD Vacua and Geometrical Engineering
We consider the geometrical engineering constructions for the N = 1 SQCD
vacua recently proposed by Giveon and Kutasov. After one T-duality, the
geometries with wrapped D5 branes become N = 1 brane configurations with NS
branes and D4 branes. The field theories encoded by the geometries contain
extra massive adjoint fields for the flavor group. After performing a flop, the
geometries contain branes, antibranes and branes wrapped on non-holomorphic
cycles. The various tachyon condensations between pairs of wrapped D5 branes
and anti D5 branes together with deformations of the cycles give rise to a
variety of supersymmetric and metastable non-supersymmetric vacua.Comment: 21 Pages, Latex, 8 Figure
Is wave-particle objectivity compatible with determinism and locality?
Wave-particle duality, superposition and entanglement are among the most
counterintuitive features of quantum theory. Their clash with our classical
expectations motivated hidden-variable (HV) theories. With the emergence of
quantum technologies we can test experimentally the predictions of quantum
theory {\em versus} HV theories and put strong restrictions on their key
assumptions. Here we study an entanglement-assisted version of the quantum
delayed-choice experiment and show that the extension of HV to the controlling
devices only exacerbates the contradiction. We compare HV theories that satisfy
the conditions of objectivity (a property of photons being either particles or
waves, but not both), determinism, and local independence of hidden variables
with quantum mechanics. Any two of the above conditions are compatible with it.
The conflict becomes manifest when all three conditions are imposed and
persists for any non-zero value of entanglement. We propose an experiment to
test our conclusions.Comment: A published version. The logic is similar to the original version,
but many changes were introduce
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