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54. Flash Flood Forecasting Using Integrated Meteorological-Hydrological-Hydraulic Modeling: Application in a Mediterranean River.

Author

Varlas, George, Papaioannou, George, Papadopoulos, Anastasios, Markogianni, Vassiliki, Vardakas, Leonidas, and Dimitriou, Elias

Subjects
FLOOD warning systems, HYDRAULIC models, HYDROMETEOROLOGY, RAINFALL, ATMOSPHERIC models
Abstract

This study aims at assessing meteorological, hydrological, and hydraulic modeling to develop a flash flood forecasting tool. The flash flood that occurred in the Evrotas River Basin (ERB) on 26 January 2023 is used as a case study. Precipitation over 150 mm and water depths exceeding 2.5 m were recorded. The meteorological model initialized one day before flooding and simulated precipitation; the hydrological model, using meteorological input data, simulated discharge; and the hydraulic model, using discharge, estimated water depth at a bridge. The results indicate that the system can provide skillful and timely flash flood forecasts, thereby facilitating flood warnings. [ABSTRACT FROM AUTHOR]

Published
2023
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55. A Unified Hydrologic Framework for Flood Design Estimation in Ungauged Basins †.

Author

Vasiliades, Lampros, Papaioannou, George, and Loukas, Athanasios

Subjects
HYDRAULIC structures, HYDROGRAPHY, FLOOD risk, DIGITAL elevation models, METEOROLOGICAL databases
Abstract

Design flood hydrograph estimation is a key problem in hydrology and is necessary for a variety of applications from the design of hydraulic structures to flood risk mapping processes. Furthermore, in large ungauged basins (>1000 km2), design flood estimation methods mainly rely on single-event theories using digital elevation models, land use/land cover and soil type data, and relevant meteorological information (temperature and rainfall data). The single event-based deterministic approach was adopted based on three modelling components: (i) a synthetic storm generator; (ii) a hydrological simulation model; and (iii) a hydrological routing model. In this study the 100-year design flood (which is assumed equal to 100-year extreme rainfall) was estimated for the Pinios River Basin, Thessaly, Greece, at Larissa outlet station (upstream of the area by about 6500 km2). The hydrological approach is based on semi-distributed modelling of the rainfall–run-off process (at the sub-basin scale) using HEC-HMS v.4.10 software and the SCS-CN method for estimating rainfall excess, as well as the unit hydrograph theory and the Muskingum hydrological flow routing method for propagating the surface run-off to the sub-basin outlets. [ABSTRACT FROM AUTHOR]

Published
2023
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60. An internally validated prediction model for critical COVID-19 infection and intensive care unit admission in symptomatic pregnant women

Author

Kalafat, Erkan, primary, Prasad, Smriti, additional, Birol, Pinar, additional, Tekin, Arzu Bilge, additional, Kunt, Atilla, additional, Di Fabrizio, Carolina, additional, Alatas, Cengiz, additional, Celik, Ebru, additional, Bagci, Helin, additional, Binder, Julia, additional, Le Doare, Kirsty, additional, Magee, Laura A., additional, Mutlu, Memis Ali, additional, Yassa, Murat, additional, Tug, Niyazi, additional, Sahin, Orhan, additional, Krokos, Panagiotis, additional, O’brien, Pat, additional, von Dadelszen, Peter, additional, Palmrich, Pilar, additional, Papaioannou, George, additional, Ayaz, Reyhan, additional, Ladhani, Shamez N., additional, Kalantaridou, Sophia, additional, Mihmanli, Veli, additional, and Khalil, Asma, additional

Published
2022
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71. Inter-Area Oscillation Study of the Greek Power System Using an Automatic Toolbox

Author

Patino Duque, Jhon Fredy, primary, Villen Martinez, Maria Teresa, additional, Hurtado, Anibal Prada, additional, Carrasco, Eduardo Martinez, additional, Sancho, Borja Loren, additional, Krommydas, Konstantinos F., additional, Plakas, Konstantinos A., additional, Karavas, Christos-Spyridon G., additional, Kurashvili, Andreas S., additional, Dikaiakos, Christos N., additional, and Papaioannou, George P., additional

Published
2021
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81. Complexity analysis of the brain activity in Autism Spectrum Disorder (ASD) and Attention Deficit Hyperactivity Disorder (ADHD) due to cognitive loads/demands induced by Aristotle's type of syllogism/reasoning. A Power Spectral Density and multiscale entropy (MSE) analysis

Author

Papaioannou, Anastasia G. Kalantzi, Eva Papageorgiou, Christos C. Korombili, Kalliopi Bokou, Anastasia Pehlivanidis, Artemios Papageorgiou, Charalabos C. Papaioannou, George

Subjects
mental disorders, behavioral disciplines and activities
Abstract

Objective: We aim to investigate whether EEG dynamics differ in adults with ASD (Autism Spectrum Disorders), ADHD (attention-deficit/hyperactivity disorder), compared with healthy subjects during the performance of an innovative cognitive task: Aristotle’s valid and invalid syllogisms. We follow the Neuroanatomical differences type of criterion in assessing the results of our study in supporting or not the dual-process theory of Kahneman, 2011) (Systems I & II of thinking). Method: We recorded EEGs from 14 scalp electrodes in 30 adults with ADHD, 30 with ASD and 24 healthy, normal subjects. The subjects were exposed in a set of innovative cognitive tasks (inducing varying cognitive loads), the Aristotle’s four types of syllogism mentioned above. The multiscale entropy (MSE), a nonlinear informationtheoretic measure or tool was computed to extract features that quantify the complexity of the EEG. Results: The dynamics of the curves of the grand average of MSE values of the ADHD and ASD participants was significantly in higher levels for the majority of time scales, than the healthy subjects over a number of brain regions (electrodes locations), during the performance of both valid and invalid types of syllogism. This result is seemingly not in accordance of the broadly accepted ‘theory’ of complexity loss in ‘pathological’ subjects, but actually this is not the case as explained in the text. ADHD subjects are engaged in System II of thinking, for both Valid and Invalid syllogism, ASD and Control in System I for valid and invalid syllogism, respectively. A surprising and ‘provocative’ result of this paper, as shown in the next sections, is that the Complexity-variability of ASD and ADHD subjects, when they face Aristotle’s types of syllogisms, is higher than that of the control subjects. An explanation is suggested as described in the text. Also, in the case of invalid type of Aristotelian syllogisms, the linguistic and visuo-spatial systems are both engaged ONLY in the temporal and occipital regions of the brain, respectively, of ADHD subjects. In the case of valid type, both above systems are engaged in the temporal and occipital regions of the brain, respectively, of both ASD and ADHD subjects, while in the control subjects only the visuo-spatial type is engaged (Goel et al., 2000; Knauff, 2007). Conclusion: Based on the results of the analysis described in this work, the differences in the EEG complexity between the three groups of participants lead to the conclusion that cortical information processing is changed in ASD and ADHD adults, therefore their level of cortical activation may be insufficient to meet the peculiar cognitive demand of Aristotle’s reasoning. Significance: The present paper suggest that MSE, is a powerful and efficient nonlinear measure in detecting neural dysfunctions in adults with ASD and ADHD characteristics, when they are called on to perform in a very demanding as well as innovative set of cognitive tasks, that can be considered as a new diagnostic ‘benchmark’ in helping detecting more effectively such type of disorders. A linear measure alone, as the typical PSD, is not capable in making such a distinction. The work contributes in shedding light on the neural mechanisms of syllogism/reasoning of Aristotelian type, as well as toward understanding how humans reason logically and why ‘pathological’ subjects deviate from the norms of formal logic.

Published
2021

82. Assessment of optimal passive suspensions regarding motion sickness mitigation in different road profiles and sitting conditions

Author

Papaioannou, George (author), Jerrelind, Jenny (author), Drugge, Lars (author), Shyrokau, B. (author), Papaioannou, George (author), Jerrelind, Jenny (author), Drugge, Lars (author), and Shyrokau, B. (author)

Abstract

Automated vehicles (AVs) are expected to lead the evolution of mobility. Motion sickness, known as car sickness, is one of the main issues AVs will face, and could jeopardise their wide impact. However, a limited work has been done on how the optimisation of suspension dynamics could contribute. In this direction, this paper explores the mitigation of car sickness and the improvement of ride comfort through the optimisation of passive suspension systems. More specifically, a half car model, which represents a passenger vehicle from IPG/CarMaker, is used to optimise front suspension system for minimising comfort, but also maintaining vehicle handling while the vehicle is driving over two different road classes. The evaluation of comfort is conducted using the common standardised metric suggested by ISO-2631. After having obtained the optimum design solutions, the optimal solutions are simulated using IPG/CarMaker by assigning the road profiles on a 23 km long countryside road path. Then, vehicle accelerations are transferred to the occupant's head using appropriate models from the literature for both back-on and back-off sitting conditions. Afterwards, car sickness and ride comfort are further assessed to explore in detail how the tuning of the suspension systems through optimisation has minimised the first and enhanced the latter. For the assessment of car sickness, a three dimensional detailed biomechanical human model is used. The results imply that the pitch velocity seems more suitable, as a cost function for optimising the suspension systems with regards to motion sickness mitigation. Therefore, it should be considered either on its own or in combination with metric suggested by ISO-2631., Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., Intelligent Vehicles

Published
2021
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90. Ancillary Services Market Design in Distribution Networks: Review and Identification of Barriers

Author

Oureilidis, Konstantinos (author), Malamaki, Kyriaki-Nefeli (author), Gkavanoudis, Spyros (author), Cvetkovic, M. (author), Mauricio, Juan Manuel (author), Maza Ortega, Jose Maria (author), Martinez Ramos, Jose Luis (author), Papaioannou, George (author), Demoulias, Charis (author), Oureilidis, Konstantinos (author), Malamaki, Kyriaki-Nefeli (author), Gkavanoudis, Spyros (author), Cvetkovic, M. (author), Mauricio, Juan Manuel (author), Maza Ortega, Jose Maria (author), Martinez Ramos, Jose Luis (author), Papaioannou, George (author), and Demoulias, Charis (author)

Abstract

The high proliferation of converter-dominated Distributed Renewable Energy Sources (DRESs) at the distribution grid level has gradually replaced the conventional synchronous generators (SGs) of the transmission system, resulting in emerging stability and security challenges. The inherent characteristics of the SGs are currently used for providing ancillary services (ASs), following the instructions of the Transmission System Operator, while the DRESs are obliged to offer specific system support functions, without being remunerated for these functions, but only for the energy they inject. This changing environment has prompted the integration of energy storage systems as a solution for transfusing new characteristics and elaborating their business in the electricity markets, while the smart grid infrastructure and the upcoming microgrid architectures contribute to the transformation of the distribution grid. This review investigates the existing ASs in transmission system with the respective markets (emphasizing the DRESs’ participation in these markets) and proposes new ASs at distribution grid level, with emphasis to inertial response, active power ramp rate control, frequency response, voltage regulation, fault contribution and harmonic mitigation. The market tools and mechanisms for the procurement of these ASs are presented evolving the existing role of the Operators. Finally, potential barriers in the technical, regulatory, and financial framework have been identified and analyzed., Intelligent Electrical Power Grids

Published
2020
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