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357 results on '"Ioannides, Andreas A."'

3. Characterisation of monolithic tandem solar cells containing strain balanced quantum well sub-cells

Author

Ioannides, Andreas and Barnham, Keith

Subjects
530
Abstract

This thesis presents the milestone efficiency of 30.6% under 54x concentration achieved by a monolithic tandem solar cell containing strain balanced quantum well sub-cells. This is the first demonstration of tandem cells containing quantum well sub-cells. Characterisation and modelling of the quantum efficiency and dark currents of monolithic tandem cells containing quantum well sub-cells are also presented for the first time. Predictions performed by a simulation program indicate that 32.3% efficiency at 500x concentration can be achieved and in combination with an active Ge substrate efficiencies of 37.5% are possible. The model created in the simulation program is presented which makes possible the accurate fitting of quantum efficiency and prediction of dark current. The procedure developed to process tandem solar cells into concentrator devices is presented. A detailed account of the characterisation methods used for tandem solar cells are also described. Going further, a new optical concept for building integrated PV design was examined in this thesis. The design is based on a Buffon lens as an alternative to convex and Fresnel lens designs. The low cost design presented can be accommodated in the space of a double glazing window for glass facades.

Published
2016
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4. Using spectral continuity to extract breathing rate from heart rate and its applications in sleep physiology.

Author

Orphanides, Gregoris A., Karittevlis, Christodoulos, Alsadder, Lujain, and Ioannides, Andreas A.

Subjects
SLEEP physiology, SLEEP stages, HEART beat, SLEEP, DISTRIBUTION (Probability theory)
Abstract

Introduction: ECG Derived Respiration (EDR) are a set of methods used for extracting the breathing rate from the Electrocardiogram (ECG). Recent studies revealed a tight connection between breathing rate and more specifically the breathing patterns during sleep and several related pathologies. Yet, while breathing rate and more specifically the breathing pattern is recognised as a vital sign it is less employed than Electroencephalography (EEG) and heart rate in sleep and polysomnography studies. Methods: This study utilised open-access data from the ISRUC sleep database to test a novel spectral-based EDR technique (scEDR). In contrast to previous approaches, the novel method emphasizes spectral continuity and not only the power of the different spectral peaks. scEDR is then compared against a more widely used spectral EDR method that selects the frequency with the highest power as the respiratory frequency (Max Power EDR). Results: scEDR yielded improved performance against the more widely used Max Power EDR in terms of accuracy across all sleep stages and the whole sleep. This study further explores the breathing rate across sleep stages, providing evidence in support of a putative sleep stage "REM0" which was previously proposed based on analysis of the Heart Rate Variability (HRV) but not yet widely discussed. Most importantly, this study observes that the frequency distribution of the heart rate during REM0 is closer to REM than other NREM periods even though most of REM0 was previously classified as NREM sleep by sleep experts following either the original or revised sleep staging criteria. Discussion: Based on the results of the analysis, this study proposes scEDR as a potential low-cost and non-invasive method for extracting the breathing rate using the heart rate during sleep with further studies required to validate its accuracy in awake subjects. In this study, the autonomic balance across different sleep stages, including REM0, was examined using HRV as a metric. The results suggest that sympathetic activity decreases as sleep progresses to NREM3 until it reaches a level similar to the awake state in REM through a transition from REM0. [ABSTRACT FROM AUTHOR]

Published
2024
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6. Asymmetric random matrices: What do we need them for?

Author

Drozdz, Stanislaw, Kwapien, Jaroslaw, and Ioannides, Andreas A.

Subjects
Physics - Data Analysis, Statistics and Probability, Computer Science - Computational Engineering, Finance, and Science, Quantitative Finance - Statistical Finance
Abstract

Complex systems are typically represented by large ensembles of observations. Correlation matrices provide an efficient formal framework to extract information from such multivariate ensembles and identify in a quantifiable way patterns of activity that are reproducible with statistically significant frequency compared to a reference chance probability, usually provided by random matrices as fundamental reference. The character of the problem and especially the symmetries involved must guide the choice of random matrices to be used for the definition of a baseline reference. For standard correlation matrices this is the Wishart ensemble of symmetric random matrices. The real world complexity however often shows asymmetric information flows and therefore more general correlation matrices are required to adequately capture the asymmetry. Here we first summarize the relevant theoretical concepts. We then present some examples of human brain activity where asymmetric time-lagged correlations are evident and hence highlight the need for further theoretical developments.

Published
2011
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7. Understanding How Learning Takes Place with Neuroscience and Applying the Results to Education

Author

Ioannides, Andreas A., Hutchison, David, Series editor, Kanade, Takeo, Series editor, Kittler, Josef, Series editor, Kleinberg, Jon M., Series editor, Mattern, Friedemann, Series editor, Mitchell, John C., Series editor, Naor, Moni, Series editor, Pandu Rangan, C., Series editor, Steffen, Bernhard, Series editor, Terzopoulos, Demetri, Series editor, Tygar, Doug, Series editor, Weikum, Gerhard, Series editor, Frasson, Claude, editor, and Kostopoulos, George, editor

Published
2017
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10. Introduction to ARMOR Project

Author

Voros, Nikolaos S., Antonopoulos, Christos P., Koutroumanidis, Michalis, Kostopoulos, George K., Ioannides, Andreas A., Voros, Nikolaos S., editor, and Antonopoulos, Christos P., editor

Published
2015
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14. Chapter Sleep Spindles – As a Biomarker of Brain Function and Plasticity

Author

Urakami, Yuko, Ioannides, Andreas A., and Kostopoulos, George K.

Subjects
Technology, engineering, agriculture, bic Book Industry Communication::T Technology, engineering, agriculture::TH Energy technology & engineering::THX Alternative & renewable energy sources & technology
Abstract

Alternative & renewable energy sources & technology

Published
2012
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17. A unified framework for analyzing complex systems: Juxtaposing the (Kernel) PCA method and graph theory

Author

Ioannides, Andreas A., primary, Kourouyiannis, Constantinos, additional, Karittevlis, Christodoulos, additional, Liu, Lichan, additional, Michos, Ioannis, additional, Papadopoulos, Michalis, additional, Papaefthymiou, Evangelos, additional, Pavlou, Orestis, additional, Papadopoulou Lesta, Vicky, additional, and Efstathiou, Andreas, additional

Published
2022
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20. M

Author

Wiltschko, Wolfgang, Kramer, Bernd, Winklhofer, Michael, Lohmann, Kenneth J., Lohmann, Catherine M. F., Fransson, Peter, Ioannides, Andreas A., Boeke, Heinz, Salcedo, Ernesto, Restrepo, Diego, Lamont, Elaine Waddington, Amir, Shimon, Lund, James P., Kolta, Arlette, Schröder, Jürgen, Dphil, Markus Schrenk, Herzog, Walter, Tscharner, Vinzenz von, Clark, Andrea L., Epstein, Marcelo, Ogawa, Hisashi, Rees, Adrian, Richerson, George, Ide, Chizuka, Tolleson, William H., Provencio, Ignacio, Arendt, Josephine, Lalley, P. M., Windhorst, U., Windhorst, Uwe, Lalley, Peter M., Manabe, Toshiya, Grossman, Murray, Shibata, Shigenobu, Bernstein, Daniel M., Loftus, Elizabeth F., Tachibana, Tamiko, Winn, Philip, Maruno, Shunichi, Kato, Kazuo, Kishi, Noriyuki, Sohur, U. Shivraj, Molyneaux, Bradley J., Arlotta, Paola, Macklis, Jeffrey D., Suzumura, Akio, Suk, Kyoungho, Groat, William C. de, Wulczyn, F. Gregory, Jeka, John, Kiemel, Tim, Nusbaum, Michael P., Nitabach, Michael N., Stoeckli, Esther T., Rodriguez Moncalvo, Veronica G., Campos, Ana R., Piazza, Stephen J., Yates, Bill J., Gielen, Stan C. A. M., Schieber, Marc H., Cheney, Paul, Bracha, Vlastislav, Bloedel, James R., Burke, Robert E., Taylor, Janet L., Soechting, John F., Lom, Barbara, Holmes, Nicholas P., Calvert, Gemma A., Spence, Charles, Bittman, Eric L., Leise, Tanya L., Lucas, Sylvia, Vereyken, Elly J. F., Dijkstra, Christine D., Teunissen, Charlotte E., Heckman, C. J., Perreault, Eric, Sandercock, Thomas, Maas, Huub, Lexell, Jan, Biewener, Andrew A., Dhaher, Yasin Y., Perreault, Eric J., Arendt-Nielsen, Lars, Graven-Nielsen, Thomas, d’Avella, Andrea, Nichols, T. Richard, Huyghues-Despointes, Clotilde M. J. I., Takamori, Masaharu, Gottschling, Verena, Yamada, Kiyofumi, Nabeshima, Toshitaka, Binder, Marc D., editor, Hirokawa, Nobutaka, editor, and Windhorst, Uwe, editor

Published
2009
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28. The Nurse Teacher's Clinical Role Now and in the Future.

Author

Ioannides, Andreas P.

Abstract

The clinical role of nurse teachers is the subject of long-standing debate. A triangular relationship among student, clinical mentor, and lecturer can guide the application of theory to practice. The lecturer-practitioner can play a role in identifying standards of practice and preparing educational programs. (SK)

Published
1999

39. Magnetoencephalography as a Research Tool in Neuroscience: State of the Art

Author

Ioannides, Andreas A.

Subjects
Neurosciences -- Research -- Health aspects, Magnetic fields -- Health aspects -- Research, Magnetoencephalography -- Research -- Health aspects, Psychology and mental health, Research, Health aspects
Abstract

Magnetoencephalography (MEG) is a noninvasive neuroimaging method for detecting, analyzing, and interpreting the magnetic field generated by the electrical activity in the brain. Modern hardware can capture the MEG signal [...]

Published
2006

48. M

Author

Wiltschko, Wolfgang, primary, Kramer, Bernd, additional, Winklhofer, Michael, additional, Lohmann, Kenneth J., additional, Lohmann, Catherine M. F., additional, Fransson, Peter, additional, Ioannides, Andreas A., additional, Boeke, Heinz, additional, Salcedo, Ernesto, additional, Restrepo, Diego, additional, Lamont, Elaine Waddington, additional, Amir, Shimon, additional, Lund, James P., additional, Kolta, Arlette, additional, Schröder, Jürgen, additional, Dphil, Markus Schrenk, additional, Herzog, Walter, additional, Tscharner, Vinzenz von, additional, Clark, Andrea L., additional, Epstein, Marcelo, additional, Ogawa, Hisashi, additional, Rees, Adrian, additional, Richerson, George, additional, Ide, Chizuka, additional, Tolleson, William H., additional, Provencio, Ignacio, additional, Arendt, Josephine, additional, Lalley, P. M., additional, Windhorst, U., additional, Windhorst, Uwe, additional, Lalley, Peter M., additional, Manabe, Toshiya, additional, Grossman, Murray, additional, Shibata, Shigenobu, additional, Bernstein, Daniel M., additional, Loftus, Elizabeth F., additional, Tachibana, Tamiko, additional, Winn, Philip, additional, Maruno, Shunichi, additional, Kato, Kazuo, additional, Kishi, Noriyuki, additional, Sohur, U. Shivraj, additional, Molyneaux, Bradley J., additional, Arlotta, Paola, additional, Macklis, Jeffrey D., additional, Suzumura, Akio, additional, Suk, Kyoungho, additional, Groat, William C. de, additional, Wulczyn, F. Gregory, additional, Jeka, John, additional, Kiemel, Tim, additional, Nusbaum, Michael P., additional, Nitabach, Michael N., additional, Stoeckli, Esther T., additional, Rodriguez Moncalvo, Veronica G., additional, Campos, Ana R., additional, Piazza, Stephen J., additional, Yates, Bill J., additional, Gielen, Stan C. A. M., additional, Schieber, Marc H., additional, Cheney, Paul, additional, Bracha, Vlastislav, additional, Bloedel, James R., additional, Burke, Robert E., additional, Taylor, Janet L., additional, Soechting, John F., additional, Lom, Barbara, additional, Holmes, Nicholas P., additional, Calvert, Gemma A., additional, Spence, Charles, additional, Bittman, Eric L., additional, Leise, Tanya L., additional, Lucas, Sylvia, additional, Vereyken, Elly J. F., additional, Dijkstra, Christine D., additional, Teunissen, Charlotte E., additional, Heckman, C. J., additional, Perreault, Eric, additional, Sandercock, Thomas, additional, Maas, Huub, additional, Lexell, Jan, additional, Biewener, Andrew A., additional, Dhaher, Yasin Y., additional, Perreault, Eric J., additional, Arendt-Nielsen, Lars, additional, Graven-Nielsen, Thomas, additional, d’Avella, Andrea, additional, Nichols, T. Richard, additional, Huyghues-Despointes, Clotilde M. J. I., additional, Takamori, Masaharu, additional, Gottschling, Verena, additional, Yamada, Kiyofumi, additional, and Nabeshima, Toshitaka, additional

Published
2008
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49. The Pauli exclusion principle and the spin dependence of the deuteron-nucleus interaction

Author

Ioannides, Andreas Antonaki

Subjects
539.7
Abstract

A study is made of the propagation of a deuteron through a nuclear medium. We consider the effect of the Pauli exclusion principle on the internal motion of the deuteron, for the idealized case of a deuteron propagating through infinite nuclear matter, assumed to be adequately described by the Fermi-gas model. This greatly simplifies the calculations and enables us to include explicitly the D-state component of the deuteron wavefunction in our model. It is shown that the action of the Pauli exclusion principle, on the D-state part of the deuteron, endowes various properties of the deuteron with strong dependence on the relative orientation of the deuteron spin and its linear momentum. The dependence of the binding energy of the deuteron on this relative orientation is particularly important, because, it can be associated with a new tensor term, of the T[p] type, in the deuteron optical potential. The strength of this tensor potential is found to be non-negligible at high incident deuteron energies, for the realistic case of a deuteron propagating through a finite nucleus. Rough estimates of this strength at lower energies, indicate that this new tensor interaction is large for these energies too. The important implications of this, for the interpretation of experiment with polarized deuterons, are discussed.

Published
1976

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