Search results for "Approx"

A Surrogate-assisted Reference Vector Guided Evolutionary Algorithm for Computationally Expensive Many-objective Optimization

2018

We propose a surrogate-assisted reference vector guided evolutionary algorithm for computationally expensive optimization problems with more than three objectives. The proposed algorithm is based on a recently developed evolutionary algorithm for many-objective optimization that relies on a set of adaptive reference vectors for selection. The proposed surrogateassisted evolutionary algorithm uses Kriging to approximate each objective function to reduce the computational cost. In managing the Kriging models, the algorithm focuses on the balance of diversity and convergence by making use of the uncertainty information in the approximated objective values given by the Kriging models, the distr…

Approximation through interpolation in nonconvex multiobjective optimization

2011

Approximation method for computationally expensive nonconvex multiobjective optimization problems

2012

On Approximate Jumbled Pattern Matching in Strings

2011

Given a string s, the Parikh vector of s, denoted p(s), counts the multiplicity of each character in s. Searching for a match of a Parikh vector q in the text s requires finding a substring t of s with p(t) = q. This can be viewed as the task of finding a jumbled (permuted) version of a query pattern, hence the term Jumbled Pattern Matching. We present several algorithms for the approximate version of the problem: Given a string s and two Parikh vectors u, v (the query bounds), find all maximal occurrences in s of some Parikh vector q such that u <= q <= v. This definition encompasses several natural versions of approximate Parikh vector search. We present an algorithm solving this problem …

M/M/1 queue in two alternating environments and its heavy traffic approximation

2018

We investigate an M/M/1 queue operating in two switching environments, where the switch is governed by a two-state time-homogeneous Markov chain. This model allows to describe a system that is subject to regular operating phases alternating with anomalous working phases or random repairing periods. We first obtain the steady-state distribution of the process in terms of a generalized mixture of two geometric distributions. In the special case when only one kind of switch is allowed, we analyze the transient distribution, and investigate the busy period problem. The analysis is also performed by means of a suitable heavy-traffic approximation which leads to a continuous random process. Its d…

Identification of Distributed Systems with Logical Interaction Structure

2012

This paper focuses on the structure identification problem for a class of networked systems, where the interaction among components or agents is described through logical maps. In particular, agents are heterogeneous cooperating systems, i.e. they may have different individual dynamics and different interaction rules depending on input events. While we assume that the individual agents' dynamics are known, each agent has partial knowledge of the logical map encoding the interaction of another agent with its neighbors. Based on the so-called algebraic normal form for binary functions, we present a technique by which the network structure described by a logical function can be dynamically est…

Sensitivities to neutrino electromagnetic properties at the TEXONO experiment

2015

18 pages.- 4 figures.- 1 table

Measurement of e+e−→π+π−ψ(3686) from 4.008 to 4.600 GeV and observation of a charged structure in the π±ψ(3686) mass spectrum

2018

We study the process e(+)e(-) -> p(+)p(-)psi(3686) using 5.1 fb(-1) of data collected at 16 center-of-mass energy (root s) points from 4.008 to 4.600 GeV by the BESIII detector operating at the BEPCII collider. The measured Born cross sections for e(+)e(-) -> p(+)p(-)psi(3686) are consistent with previous results, but with much improved precision. A fit to the cross section shows contributions from two structures: the first has M = 4209.5 +/- 7.4 +/- 1.4 MeV/c(2) and Gamma = 80.1 +/- 24.6 +/- 2.9 MeV, and the second has M = 4383.8 +/- 4.2 +/- 0.8 MeV/c(2) and Gamma = 84.2 +/- 12.5 +/- 2.1 MeV, where the first errors are statistical and the second systematic. The lower-mass resonance is obse…

Fitting particle size distribution models to data from Burundian soils for the BEST procedure and other purposes

2009

Testing the Beerkan Estimation of Soil Transfer (BEST) soil particle size distribution (PSD) model is necessary to evaluate the applicability of the BEST procedure for characterising soil hydraulics. In this investigation, the fitting performance of the BEST PSD model was tested using a database of 114 Burundian soils with 14 measured particle size fractions for each soil sample, and also by considering a reduced number of measured particle size fractions for a sample. The fitting performance of the model developed by Fredlund et al. (2000) (FR model) was also considered for comparative purposes. On average, the BEST model yielded satisfactory results (i.e., mean relative error, E r ¯ = 3.9…

Half-width plots, a simple tool to predict peak shape, reveal column kinetics and characterise chromatographic columns in liquid chromatography: Stat…

2013

Peak profiles in chromatography are characterised by their height, position, width and asymmetry; the two latter depend on the values of the left and right peak half-widths. Simple correlations have been found between the peak half-widths and the retention times. The representation of such correlations has been called half-width plots. For isocratic elution, the plots are parabolic, although often, the parabolas can be approximated to straight-lines. The plots can be obtained with the half-widths/retention time data for a set of solutes experiencing the same kinetics, eluted with a mobile phase at fixed or varying composition. When the analysed solutes experience different resistance to mas…