Search results for " OPT"

Closedness properties in team learning of recursive functions

1997

This paper investigates closedness properties in relation with team learning of total recursive functions. One of the first problems solved for any new identification types is the following: “Does the identifiability of classes U1 and U2 imply the identifiability of U1∪U2?” In this paper we are interested in a more general question: “Does the identifiability of every union of n−1 classes out of U1,...,Un imply the identifiability of U1∪...∪Un?” If the answer is positive, we call such identification type n-closed. We show that n-closedness can be equivalently formulated in terms of team learning. After that we find for which n team identification in the limit and team finite identification t…

Introduction to General Duality Theory for Multi-Objective Optimization

1992

This is intended as a comprehensive introduction to the duality theory for vector optimization recently developed by C. Malivert and the present author [3]. It refers to arbitrarily given classes of mappings (dual elements) and extends the general duality theory proposed for scalar optimization by E. Balder, S. Kurcyusz and the present author [1] and P. Lindberg.

Ensuring High Performance of Consensus-Based Estimation by Lifetime Maximization in WSNs

2015

The estimation of a parameter corrupted by noise is a common tasks in wireless sensor networks, where the deployed nodes cooperate in order to improve their own inaccurate observations. This cooperation usually involves successive data exchanges and local information updates until a global consensus value is reached. The quality of the final estimator depends on the amount of collected observations, hence the number of active nodes. Moreover, the inherent iterative nature of the consensus process involves a certain energy consumption. Since the devices composing the network are usually battery powered, nodes becoming inactive due to battery depletion emerges as a serious problem. In this wo…

Luminescence of silica glass containing aluminum oxide

2004

Abstract Optical properties of silica glass with different doping of Al 2 O 3 up to 1.5 mol% were studied. Alumina stimulates creation of a luminescence centers with specific band at 3.3 eV. A new band at 8.2 eV appears in luminescence excitation spectra. There is transport of energy to other luminescence centers associated with an impurity (Ag, Ce) at this energy. Alumina stimulates creation of E′ centers under γ-irradiation beside trapped hole on AlO 4 tetrahedron as well as creation of a silicon related oxygen deficient center (SiODC) under cathodoexcitation. Visually, the samples look inhomogeneous even after γ-irradiation. The explanation could be heterogeneity of the samples. Alumina …

Interactions of Ultra-cold Alkaline-earth-like and Alkali Atoms with Light

2019

This paper presents the experimental results of photoionization and photoassociation experiments performed with both ultra-cold alkaline-earth-like and alkali atoms. Photoionization cross-section was studied for 88Sr at the blue magic 390 nm wavelength as well as for 87Rb at 254 nm. We also present preliminary results of photoassociation spectroscopy of the molecular line detected near the dissociation threshold of the excited Rb*Hg molecule at D1 Rb line (795 nm).

High-Pressure Phase Diagram and Superionicity of Alkaline Earth Metal Difluorides

2018

We study the high-pressure–high-temperature phase diagram and superionicity of alkaline earth metal (AEM) difluorides (AF2, A = Ca, Sr, Ba) with first-principles simulation methods. We find that the superionic behavior of SrF2 and BaF2 at high pressures differ appreciably from that previously reported for CaF2 [Phys. Rev. Lett. 2014, 113, 235902]. Specifically, the critical superionic temperature of SrF2 and BaF2 in the low-pressure cubic fluorite phase is not reduced by effect of compression, and the corresponding high-pressure orthorhombic contunnite phases become superionic at elevated temperatures. We get valuable microscopic insights into the superionic features of AEM difluorides in b…

2001

A new manganese(III) oxamato dimer possesing an unprecedented Mn2(μ-O2CR)(μ-OH2⋯O2 CR) core has been synthesised, structurally and magnetically characterised, and used as a catalyst for the oxidation of alkanes to alcohols and ketones by ButO2H and O2 in CH2Cl2 at rt.

Supramolecular Aggregates in Vacuum: Positively Mono-Charged Sodium Alkanesulfonate Clusters

2010

The formation and structural features of positively mono-charged aggregates of sodium bis(2-ethylhexyl) sulfosuccinate (AOT) and sodium methane—(MetS), butane—(ButS) and octane—(OctS) sulfonate molecules in the gas phase have been investigated by electrospray ionization mass spectrometry, energy-resolved mass spectrometry and density functional theory (DFT) calculations. The experimental results show that the center-of-mass collision energy required to dissociate 50% of these mono-charged aggregates scantly depends on the length of the alkyl chain as well as on the aggregation number. This, together with the large predominance of mono-charged species in the mass spectra, was rationalized i…

Waveguiding properties of a photonic crystal fiber with a solid core surrounded by four large air holes

2009

The polarization-dependent guiding properties of a hexagonal-lattice photonic crystal fiber with a solid-core surrounded by four large air holes are investigated. The appearance of a polarization dependent cutoff frequency, together with several parameters as the birefringence, the modal effective area, the group velocity dispersion and the polarization dependent loss are analyzed. A collection of fibers with different structural parameters were fabricated and characterized. An effective anti-guide structure from at least 450 nm to 1750 nm, a polarizing fiber with a polarization dependent loss of 16 dB/m at 1550 nm, and an endlessly singlemode polarization-maintaining fiber with group biref…

<title>Fibers supporting super-Gaussian beams: cladding effects</title>

1996

We define a matching function that describes the amplitude variations produced over supergaussian beams, by cladding optical fibers that, if uncladded, can sustain this type of beams as Eigenmodes.