Search results for "formation."

A New Family of Deformations of Darboux-Pöschl-Teller Potentials

2004

The aim of this Letter is to present a new family of integrable functional-difference deformations of the Schrodinger equation with Darboux–Poschl–Teller potentials. The related potentials are labeled by two integers m and n, and also depend on a deformation parameter h. When h→ 0 the classical Darboux–Poschl–Teller model is recovered.

High Resolution Coherent Anti-Stokes Raman Spectroscopy (CARS) Of O 2 And CO 2

1988

With the help of high spectral quality (linewidth , 6 MHz) injection-locked flashlamp-pumped dye lasers, high resolution Coherent Anti-Stokes Raman Spectroscopy (CARS) has been applied to the study of the Q-branches of 0 2 and CO 2 . The Q-branch linewidths of 02 were obtained from the first nine transitions (J 2 = 1 to 17) recorded at pressures from 0.094 to 1 atm at room temperature. A least squares program was employed to fit calculated spectra to experimental spectra by adjusting different parameters. The collisional broadening coefficients we have obtained are consistent with available Raman data. We have also studied the Q-branch of the fundamental v1 band of CO 2 in the Fermi resonan…

Phonon Deformation Potentials from Raman Measurements on Semiconductor Membranes

1997

Carleson's counterexample and a scale of Lorentz-BMO spaces on the bitorus

2005

We introduce a full scale of Lorentz-BMO spaces BMO L p,q on the bidisk, and show that these spaces do not coincide for different values ofp andq. Our main tool is a detailed analysis of Carleson's construction in [C].

A comparison between two feature selection algorithms

2017

This article provides a comparison of two feature selection algorithms, Information Gain Thresholding and Koller and Sahami's algorithm in the context of text document classification on the Reuters Corpus Volume 1 dataset. The algorithms were evaluated by testing the performance of classifiers trained on the features they select from a given dataset. Results show that Koller and Sahami's algorithm consistently outperforms Information Gain Thresholding by capturing interactions between features and avoiding redundancy among features, although it achieves its gains through increased complexity and longer running time.

Computing variations of entropy and redundancy under nonlinear mappings not preserving the signal dimension: quantifying the efficiency of V1 cortex

2021

In computational neuroscience, the Efficient Coding Hypothesis argues that the neural organization comes from the optimization of information-theoretic goals [Barlow Proc.Nat.Phys.Lab.59]. A way to confirm this requires the analysis of the statistical performance of biological systems that have not been statistically optimized [Renart et al. Science10, Malo&Laparra Neur.Comp.10, Foster JOSA18, Gomez-Villa&Malo J.Neurophysiol.19]. However, when analyzing the information-theoretic performance, cortical magnification in the retina-cortex pathway poses a theoretical problem. Cortical magnification stands for the increase the signal dimensionality [Cowey&Rolls Exp. Brain Res.74]. Conventional mo…

Paschen β line shape studies in low-temperature plasmas

2003

Line shape calculations and measurements of the Paschen β line of hydrogen (λ=12818 Å) are reported. Measurements were performed at electron densities of the plasma between 1015 cm-3 and 1016 cm-3. A wall-stabilized arc operated at atmospheric pressure in a helium-hydrogen gas mixture was applied as the excitation source. The radiation of the plasma, originating from nearly homogeneous plasma layers, in the end-on direction, was analyzed. A grating spectrometer equipped with a CCD detector was used for the radiation detection. The measured line profiles are compared with results of available experimental and theoretical Stark broadening data e.g. based on simulation techniques, applied also…

Crowdsourcing as a mode of open innovation: Exploring drivers of success of a multisided platform through system dynamics modelling

2020

This article aims to explore drivers of success of a crowdsourcing platform. The study conceptualizes crowdsourcing as a mode of open innovation and places such a concept within the context of the sharing economy. Upon this framework, the paper analyses the case of InnoCentive, a successful crowdsourcing platform where innovation-driven organizations search for solutions to their R&D tasks. The system dynamics model frames main InnoCentive business processes and offers a causal perspective on the relationships between platform performance—in terms of users base—and resources structure. The discussion on simulation outputs is carried out through a dynamic performance management view of p…

Timing the information system upgrade

2010

A system upgrade requires careful planning as its implications to organizational systems might be enormous. Although in IS literature the requirements and process of systems upgrade have been discussed, the timing when to upgrade and what factors guide it has been of lesser interest. Consequently, in this paper we focus on information systems upgrading and its timing from the perspective of the user organization. Upgrading is enabled by the availability of a new software version. When to upgrade, meanwhile, is determined by the business interests of the customer organization, business calendar, development projects, and the vendor. These factors were identified by interviewing 14 IT manager…

Systematic conformational search analysis of the SRR and RRR epimers of 7-hydroxymatairesinol

2010

An extensive and systematic conformational search was performed on the two epimers of the natural lignan 7-hydroxymatairesinol (HMR), by means of a home-made Systematic Conformational Search Analysis (SCSA) code, designed to select more and more stable conformers through sequential geometry optimization of trial structures at increasing levels of calculation theory. In the present case, the starting molecular structures were selected by the semi-empirical AM1 method and filtered – i.e. decreased in number by choosing the more stable species – on the basis of their energy calculated by the HF method and the 6-31G(d) basis set. The geometries obtained were further refined by performing densit…