Anomalous Stark Shifts in Single Vertically Coupled Pairs of InGaAs Quantum Dots

Vertically coupled Stranski Krastanow QDs are predicted to exhibit strong tunnelling interactions that lead to the formation of hybridised states. We report the results of investigations into single pairs of coupled QDs in the presence of an electric field that is able to bring individual carrier levels into resonance and to investigate the Stark shift properties of the excitons present. Pronounced changes in the Stark shift behaviour of exciton features are identified and attributed to the significant redistribution of the carrier wavefunctions as resonance between two QDs is achieved. At low electric fields coherent tunnelling between the two QD ground states is identified from the change in sign of the permanent dipole moment and dramatic increase of the electron polarisability, and at higher electric fields a distortion of the Stark shift is attributed to a coherent tunnelling effect between the ground state of the upper QD and the excited state of the lower QD.Comment: Conference paper for QD2004 3 figure

Estimating The Quality Of Data Using Provenance: A Case Study In Escience

Data quality assessment is a key factor in data-intensive domains. The data deluge is aggravated by an increasing need for interoperability and cooperation across groups and organizations. New alternatives must be found to select the data that best satisfy users' needs in a given context. This paper presents a strategy to provide information to support the evaluation of the quality of data sets. This strategy is based on combining metadata on the provenance of a data set (derived from workflows that generate it) and quality dimensions defined by the set's users, based on the desired context of use. Our solution, validated via a case study, takes advantage of a semantic model to preserve data provenance related to applications in a specific domain. © (2013) by the AIS/ICIS Administrative Office All rights reserved.214421451IBM,SAP University Alliances,Microsoft,DePaul University,Georgia State University - J. Mack Robinson College of Business,et alBallou, D., Modeling Information Manufacturing Systems to Determine Information Product Quality (1998) Manage. Sci, 44, pp. 462-484Barga, R.S., Digiampietri, L.A., Automatic capture and efficient storage of e-Science experiment provenance (2008) Concurr. Comput.□: Pract. Exper, 20 (5), pp. 419-429Batini, C., Scannapieco, M., (2006) Data Quality: Concepts, Methodologies and Techniques (Data-Centric Systems and Applications), , Springer-VerlagBlake, R., Mangiameli, P., The Effects and Interactions of Data Quality and Problem Complexity on Classification (2011) Journal of Data and Information Quality, 2 (2), pp. 1-28Chapman, A.D., (2005) Principles of Data Quality, , Global Biodiversity Information Facility, CopenhagenChen, P., Plale, B., Aktas, M.S., Temporal Representation for Scientific Data Provenance (2012) In Proc. 8th IEEE Int. Conf. On EScience 2012Cugler, D.C., Medeiros, C.B., Toledo, F., An architecture for retrieval of animal sound recordings based on context variables (2012) Concurrency and Computation - Practice and ExperienceDavies, J., Studer, R., Warren, P., (2006) Semantic Web Technologies: Trends and Research In Ontology-based Systems, , Wiley(2010) The Dublin Core Metadata Initiative, , http://dublincore.org/, DCMI, Available atDeVries, P.J., (2009) GeoSpecies Ontology, , http://bioportal.bioontology.org/ontologies/1247, Available at(2009) Darwin Core Task Group, , http://www.tdwg.org/standards/450/, DwC, Available atGoodchild, M.F., Li, L., Assuring the quality of volunteered geographic information (2012) Spatial Statistics, 1, pp. 110-120Hartig, O., Zhao, J., Using web data provenance for quality assessment (2009) In Proc. of the Workshop On Semantic Web and Provenance Management At ISWC(2011) The Kepler Project, , https://kepler-project.org/, Kepler, Available atKondo, A.A., Traceability in Food for Supply Chains (2007) In Proc. 3rd Int. Conf. On Web Information Systems and Technologies (WEBIST), pp. 121-127. , INSTICCLassila, O., Swick, R.R., (1999) Resource Description Framework (RDF) Model and Syntax SpecificationMalaverri, J.E.G., Medeiros, C.B., A Provenance-based Approach to Evaluate Data Quality in eScience (2013) Int. J. Metadata, Semantics and Ontology - Special Issue On Metadata For E-science and E-researchMoreau, L., The Open Provenance Model core specification (v1.1) (2011) Future Generation Comp. Syst, 27 (6), pp. 743-756Parssian, A., Managerial decision support with knowledge of accuracy and completeness of the relational aggregate functions (2006) Decis. Support Syst, 42, pp. 1494-1502Pernici, B., Scannapieco, M., Data Quality in Web Information Systems (2002) In Proc. of the 21st Int. Conf. On Conceptual Modeling, pp. 397-413. , Springer-VerlagPipino, L.L., Lee, Y.W., Wang, R.Y., Data Quality Assessment (2002) Commun. ACM, 45, pp. 211-218Prat, N., Madnick, S., Measuring Data Believability: A Provenance Approach (2008) Proc. of the 41st Hawaii Int. Conf. On System Sciences, p. 393Richard, Y., Diane, M., Beyond accuracy□: What data quality means to data consumers (1996) Journal of ManagementSahoo, S.S., Sheth, A.P., Henson, C.A., Semantic Provenance for eScience: Managing the Deluge of Scientific Data (2008) IEEE Internet Computing, 12 (4), pp. 46-54Simmhan, Y., Plale, B., Using Provenance for Personalized Quality Ranking of Scientific Datasets (2011) I. J. Comput. Appl, 18 (3), pp. 180-195(2009) The Taverna Project, , http://www.taverna.org.uk/, Taverna, Available at(2011) The VisTrails Project, , http://www.vistrails.org, VisTrails, Available at(2012) The PROV Ontology, , http://www.w3.org/TR/prov-o/, W3C, Available atWang, X., Gorlitsky, R., Almeida, J.S., From XML to RDF: How semantic web technologies will change the design of omic standards (2005) Nat Biotech, 23 (9), pp. 1099-1103Yeganeh, S.H., Hassanzadeh, O., Miller, R.J., Linking Semistructured Data on the Web (2011) In Proc. 14th Int. Workshop On the Web and DatabasesZhao, J., Mining Taverna's semantic web of provenance (2008) Concurr. Comput.□: Pract. Exper, 20, pp. 463-47

Energy production predication via Internet of Thing based machine learning system

© 2019 Elsevier B.V. Wind energy is an interesting source of alternative energy to complement the Brazilian energy matrix. However, one of the great challenges lies in managing this resource, due to its uncertainty behavior. This study addresses the estimation of the electric power generation of a wind turbine, so that this energy can be used efficiently and sustainable. Real wind and power data generated in set of wind turbines installed in a wind farm in Ceará State, Brazil, were used to obtain the power curve from a wind turbine using logistic regression, integrated with Nonlinear Autoregressive neural networks to forecast wind speeds. In our system the average error in power generation estimate is of 29 W for 5 days ahead forecast. We decreased the error in the manufacturer\u27s power curve in 63%, with a logics regression approach, providing a 2.7 times more accurate estimate. The results have a large potential impact for the wind farm managers since it could drive not only the operation and maintenance but management level of energy sells

X-ray Diffraction Mapping Of Strain Fields And Chemical Composition Of Sige:si(001) Quantum Dot Molecules

A variety of surface morphologies can be formed by controlling kinetic parameters during heteroepitaxial film growth. The system reported is a Si0.7 Ge0.3 film grown by molecular beam epitaxy at 550°C and a 1 s deposition rate, producing quantum dot molecule (QDM) structures. These nanostructures are very uniform in size and shape, allowing strain mapping and chemical composition evaluation by means of anomalous x-ray diffraction in a grazing incidence geometry. Tensile and compressed regions coexist inside QDMs, in accordance with the finite-element calculations of lattice relaxation. The Ge content was found to vary significantly within the structures, and to be quite different from the nominal composition. © 2006 The American Physical Society.7312Chen, K.M., (1995) Appl. Phys. Lett., 66, p. 34. , APPLAB 0003-6951 10.1063/1.114172Goldfarb, I., (1997) Phys. Rev. Lett., 78, p. 3959. , PRLTAO 0031-9007 10.1103/PhysRevLett.78.3959Mo, Y.-W., (1990) Phys. Rev. Lett., 65, p. 1020. , PRLTAO 0031-9007 10.1103/PhysRevLett.65.1020Tomitori, M., (1994) Appl. Surf. Sci., 76-77, p. 322. , ASUSEE 0169-4332Floro, J.A., (1998) Phys. Rev. Lett., 80, p. 4717. , PRLTAO 0031-9007 10.1103/PhysRevLett.80.4717Ross, F.M., (1998) Phys. Rev. Lett., 80, p. 984. , PRLTAO 0031-9007 10.1103/PhysRevLett.80.984Medeiros-Ribeiro, G., (1998) Science, 279, p. 353. , SCIEAS 0036-8075 10.1126/science.279.5349.353Chaparro, S.A., (1999) Phys. Rev. Lett., 83, p. 1199. , PRLTAO 0031-9007 10.1103/PhysRevLett.83.1199Denker, U., (2005) Appl. Phys. Lett., 772, p. 599. , APPLAB 0003-6951Gray, J.L., (2002) Appl. Phys. Lett., 81, p. 2445. , APPLAB 0003-6951 10.1063/1.1509094Vandervelde, J.T.E., (2003) Appl. Phys. Lett., 83, p. 2505. , APPLAB 0003-6951Jesson, D.E., (1996) Phys. Rev. Lett., 77, p. 1330. , PRLTAO 0031-9007 10.1103/PhysRevLett.77.1330Gray, J.L., (2004) Phys. Rev. Lett., 92, p. 135504. , PRLTAO 0031-9007 10.1103/PhysRevLett.92.135504Schülli, T.U., (2003) Phys. Rev. Lett., 90, p. 066105. , PRLTAO. 0031-9007. 10.1103/PhysRevLett.90.066105Malachias, A., (2003) Phys. Rev. Lett., 91, p. 176101. , PRLTAO 0031-9007 10.1103/PhysRevLett.91.176101Magalhães-Paniago, R., (2002) Phys. Rev. B, 66, p. 245312. , PRBMDO. 0163-1829. 10.1103/PhysRevB.66.245312Krause, B., (2005) Phys. Rev. B, 72, p. 085339. , PRBMDO 0163-1829 10.1103/PhysRevB.72.085339Zhang, Y., (2001) J. Appl. Phys., 90, p. 4748. , JAPIAU 0021-8979 10.1063/1.1407311Gray, J.L., (2005) Phys. Rev. B, 72, p. 155323. , PRBMDO 0163-1829 10.1103/PhysRevB.72.155323Tersoff, J., (1998) Phys. Rev. Lett., 81, p. 3183. , PRLTAO 0031-9007 10.1103/PhysRevLett.81.318

On the influence of a Coulomb-like potential induced by the Lorentz symmetry breaking effects on the Harmonic Oscillator

In this work, we obtain bound states for a nonrelativistic spin-half neutral particle under the influence of a Coulomb-like potential induced by the Lorentz symmetry breaking effects. We present a new possible scenario of studying the Lorentz symmetry breaking effects on a nonrelativistic quantum system defined by a fixed space-like vector field parallel to the radial direction interacting with a uniform magnetic field along the z-axis. Furthermore, we also discuss the influence of a Coulomb-like potential induced by Lorentz symmetry violation effects on the two-dimensional harmonic oscillator.Comment: 14 pages, no figure, this work has been accepted for publication in The European Physical Journal Plu

Relativistic quantum dynamics of a charged particle in cosmic string spacetime in the presence of magnetic field and scalar potential

In this paper we analyze the relativistic quantum motion of charged spin-0 and spin-1/2 particles in the presence of a uniform magnetic field and scalar potentials in the cosmic string spacetime. In order to develop this analysis, we assume that the magnetic field is parallel to the string and the scalar potentials present a cylindrical symmetry with their center on the string. Two distinct configurations for the scalar potential, $S(r)$, are considered: $(i)$ the potential proportional to the inverse of the polar distance, i.e., $S\propto1/r$, and $(ii)$ the potential proportional to this distance, i.e., $S\propto r$. The energy spectra are explicitly computed for different physical situations and presented their dependences on the magnetic field strength and scalar coupling constants.Comment: New version with 20 pages and no figure. Some minor revisions and six references added. Accepted for publication in EJP