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When Does Chaos Appear While Driving?

J. Alberto Conejero
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When Does Chaos Appear While Driving?

In mathematics, a dynamical system is a system in which a function describes the time dependence of a point in a geometrical space. There are many examples of this, including the very famous mathematical model describing the swinging of a clock pendulum, which started with Galileo’s research in 1602, and the famous three-dimensional Lorenz attractor, which provided the earliest example of chaos in a dynamical system in the early 1960s.

In this paper, we are interested in innovating by employing a different approach to teaching dynamical systems. Towards that end, we propose the use of the “not that typical” car-following models. Our concern here is to study the dynamics of the continuous dynamical system that represents the behavior of cars driving on a road when considering some classical car-following models, such as the Quick thinking Driver and Near Nearest models. More concretely, we determine their equilibria and stability in terms of the parameters involved in the models. Moreover, we illustrate the outcome with numerical solutions.

You can have access to the content here.

J. Alberto Conejero, Marina Murillo-Arcila, Jesús M. Seoane & Juan B. Seoane-Sepúlveda (2022): When Does Chaos Appear While Driving? Learning Dynamical Systems Via Car-Following Models, Mathematics Magazine, DOI: 10.1080/0025570X.2022.2092382

Fractional vs. ordinary control systems: What does the fractional derivative provide?

J. Alberto Conejero
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Fractional vs. ordinary control systems: What does the fractional derivative provide?

The concept of a fractional derivative is not at all intuitive, starting with not having a clear geometrical interpretation. Many different definitions have appeared, to the point that the need for order has arisen in the field. The diversity of potential applications is even more overwhelming.

When modeling a problem, one must think carefully about what the introduction of fractional derivatives in the model can provide that was not already adequately covered by classical model with integer derivatives. In this joint work with Jonathan Franceschi and Enric Picó-Marco, we present some examples from control theory where we insist on the importance of the non-local character of fractional operators and their suitability for modeling non-local phenomena either in space (action at a distance) or time (memory effects). In contrast, when we encounter completely different nonlinear phenomena, the introduction of fractional derivatives does not provide better results or further insight. Of course, both phenomena can coexist and interact, as in the case of hysteresis, and then we would be dealing with fractional nonlinear models.

This work has been dedicated to Prof. Carlos Lizama on the occasion of his 60th birthday.

You can have access to the manuscript here https://www.mdpi.com/2227-7390/10/15/2719/htm and in PDF here https://www.mdpi.com/2227-7390/10/15/2719/pdf

La iniciativa Valencia IA4COVID (Revista Índice)

J. Alberto Conejero
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La iniciativa Valencia IA4COVID (Revista Índice)

En este artículo divulgativo en la revista ÍNDICE, de la Universidad Autónoma de Madrid y del Instituto Nacional de Estadística, conjunto con Nuria Oliver, hablamos modelos predictivos que han servido de base para la toma de decisiones por parte de las administraciones públicas de la Comunitat Valenciana. Estos se han basado en torno a 4 ejes:

  1. Modelado de la movilidad humana a gran escala gracias al análisis de datos agregados  y anonimizados de movilidad compartidos por el INE1, gracias a un acuerdo de colaboración entre el INE y las tres operadoras móviles más grandes en España (Telefónica, Vodafone y Orange). 
  2. Desarrollo de modelos epidemiológicos computacionales para predecir la evolución de la curva pandémica. 
  3. Desarrollo de modelos predictivos de ocupación hospitalaria en planta y en UCI. 
  4. Elaboración y difusión de una iniciativa de ciencia ciudadana a través de la macroencuesta covid-19 impact survey. Con más de 700.000 respuestas, es una de las mayores del mundo. Nos ha permitido entender el impacto de la pandemia en la vida de las personas.

Podéis encontrar el artículo en abierto aquí: http://www.revistaindice.com/numero86/p33.pdf

Soft skills workshop at BAC 2022

J. Alberto Conejero
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Soft skills workshop at BAC 2022

Nowadays, it is clear that success in any field and in life does not only depend on technical (hard) skills. Soft skills are a core part of success. Identifying how we behave with others and how they interact and respond to us it is fundamental for understanding how things happen and gives the keys to fixing problems in our relations.

I have been invited to the XV Congreso Anual de Biotecnología (BAC 2022) to deliver a workshop on soft skills, jointly with Jose Luis Poza. There, we have illustrated their importance and expose some basic principles of self-management and human interaction. As always, it is a pleasure when we share all we developed within the Erasmus + project CoSki 21.

XVII CONGRESO INTERNACIONAL DE INVESTIGACIÓN CIENTÍFICA (XVII CIC)

J. Alberto Conejero
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XVII CONGRESO INTERNACIONAL DE INVESTIGACIÓN CIENTÍFICA (XVII CIC)

I have participated in the XVII CONGRESO INTERNACIONAL DE INVESTIGACIÓN CIENTÍFICA (XVII CIC) at Santo Domingo (Dominican Republic), showing how our AI models on the prediction of the evolution of the COVID-19. We have been collaborating with APEC University for trying to tune these models in the context of Caribbean countries with special attention to the Dominican Republic. I have also participated there delivering a workshop on data management for research. You have more information about this event at https://www.even3.com.br/xviicic2022/

 

Teaching Data Literacy: Experiences from the DaLiCo project

J. Alberto Conejero
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Teaching Data Literacy: Experiences from the DaLiCo project

On May 30th, I have participated in the Multiplier Event Teaching Data Literacy, showing experiences from the DaLiCo project. Here, we have presented some results of the different intellectual outputs of our project. We also have introduced the model that we have conceived for organizing summer schools on data literacy, with the showcases of Hamburg (2020) and Utrecht (2021). I also took part in moderating discussions on the implementation of data literacy into university curricula.

Network Medicine course at BIOCOM Master in ETSINF

J. Alberto Conejero
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Network Medicine course at BIOCOM Master in ETSINF

This week I have delivered a course on Network Medicine, jointly with my PhD student Lucas Goiriz, within the Máster en Bioinformática, Biología Computacional y Medicina Personalizada of the Escuela Técnica Superior de Ingeniería Informática (Universitat Politècnica de València). Network Medicine consists on the application of network science towards identifying, preventing, and treating diseases. We focus on the use of network topology and network dynamics towards identifying diseases and developing medical drugs. Networks considered in this field include Biological networks, such as protein-protein interactions and metabolic pathways,  and Disease networks. It is always a pleasure to share our interest in the discipline with new students.

Subphenotyping of Mexican Patients With COVID-19 at Preadmission To Anticipate Severity Stratification

J. Alberto Conejero
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Subphenotyping of Mexican Patients With COVID-19 at Preadmission To Anticipate Severity Stratification

In our recent paper published in JMIR Public Health and Surveillance, we aimed to discover age-sex unbiased COVID-19 patient subphenotypes based on easily available phenotypical data before admission, such as pre-existing comorbidities, lifestyle habits, and demographic features, to study the potential early severity stratification capabilities of the discovered subgroups through characterizing their severity patterns, including prognostic, intensive care unit (ICU), and morbimortality outcomes.

With our proposed 2-stage cluster analysis methodology produced a discriminative characterization of the sample and explainability over age and sex. These results can potentially help in understanding the clinical patient and their stratification for automated early triage before further tests and laboratory results are available and even in locations where additional tests are not available or to help decide resource allocation among vulnerable subgroups such as to prioritize vaccination or treatments.

Conference on Artificial Intelligence applications against COVID-19

J. Alberto Conejero
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Conference on Artificial Intelligence applications against COVID-19

I have participated as Keynote speaker in the Jornada Internacional de Investigación Científica held at UNAPEC University in Dominican Republic. The conference was entitled: Ciencia de Datos e Inteligencia Artificial en la lucha contra el COVID-19. In this talk I have spoken about the Data Science Task Force of the Valencia region in Spain and about our successful participation in the $500k Pandemic Response Challenge.

 

 

Conference at Universidad Sergio Arboleda

J. Alberto Conejero
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Conference at Universidad Sergio Arboleda

I have delivered the seminar «Modelos de Inteligencia Artificial para predecir la evolución del COVID-19» for Universidad Sergio Arboleda (Colombia) within the program Importancia de las «Matemáticas para el ejercicio de la ingeniería». It has been a pleasure to share our experiences in data analysis of COVID-19 cases in the Valencia region during the pandemics.

Collaboration in The Conversation

J. Alberto Conejero
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Collaboration in The Conversation

In this joint collaboration with Nuria Oliver for The Conversation, we explain our work in the Data Science group in the fight against the COVID-19 pandemics, covering the following areas.

  • Our work during these almost 2 years has been structured along four main lines:
  • Modeling human mobility on a large scale.
  • Computational epidemiological models.
  • Predictive models of hospital and ICU occupancy.
  • Citizen science through a citizen macro-survey called covid-19 impact survey. With more than 700,000 responses, it is one of the largest in the world. It has allowed us to understand the impact of the pandemic on people’s lives.

We also speak about about our participation in the $500k Pandemic Response Challenge sponsored by Cognizant in which we won the first prize.

Here, you can find a link to the publication Venciendo a la pandemia con inteligencia artificial.

Efficient RNN for anomalously diffusing single particle short and noisy trajectories (J. Phys. A Math. Theor.)

J. Alberto Conejero
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Efficient RNN for anomalously diffusing single particle short and noisy trajectories (J. Phys. A Math. Theor.)

Our paper entitled Efficient recurrent neural network methods for anomalously diffusing single particle short and noisy trajectories,  jointly with O. Garibo-i-Orts, A. Baeza-Bosca, and M.A. García March, has been recently published in J. Phys. A: Math. Theor.

In this work we present a data-driven method able to infer the anomalous exponent and to identify the type of anomalous diffusion process behind single, noisy and short trajectories, with good accuracy. This model was used in our participation in the anomalous diffusion (AnDi) challenge. A combination of convolutional and recurrent neural networks was used to achieve state-of-the-art results when compared to methods participating in the AnDi challenge, ranking top 4 in both classification and diffusion exponent regression.

Our method let us work with short, noisy trajectories either in one-, two- or three dimensions generated by the following models: Fractional Brownian Motion, Continuous Time Random Walk, Annealed Transient Time Motion, Scaled Brownian Motion, and Lévy Walks.

You can access to the work here. You can also write me for a complimentary copy.

i-Days 2021

J. Alberto Conejero
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i-Days 2021

I have participated in the round table Beyond the Msc and Bsc thesis, what are the opportunities that you will find in the health and wellness sector? There is no doubt that we will hear about multidisciplinary, agile, elastic, sustainable, human, climate change, …
But also AI, IoT, Blockchain, omics, robots, data / process mining, medtech, welltech, … as well as chronic, cardiovascular, COVID, cancer, diabetes, mental diseases,…

This was held on November 2nd at 6:30 p.m. online: https://lnkd.in/d8B4bWuk This was held in the framework of the EIT Health and the innovation days. Where I had the honor of participating with: Vicente Traver Salcedo (UPV_ITACA), Vicente J. García Gómez (DEXTRO)
Angel Alberich-Bayarri (Quibim), and Juan García Sánchez (Exponentia).

In this talk, I have participated summarizing the highlights of our participation in the XPRIZE Pandemic Response Challenge and our collaboration with the regional government of València. I have also shown how AI can contribute to improving health through the collaboration of regional governments.

Objective comparison of methods to decode anomalous diffusion (Nature Communications)

J. Alberto Conejero
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Objective comparison of methods to decode anomalous diffusion (Nature Communications)

Deviations from Brownian motion leading to anomalous diffusion are found in transport dynamics from quantum physics to life sciences. The characterization of anomalous diffusion from the measurement of an individual trajectory is a challenging task, which traditionally relies on calculating the trajectory mean squared displacement. However, this approach breaks down for cases of practical interest, e.g., short or noisy trajectories, heterogeneous behavior, or non-ergodic processes. Recently, several new approaches have been proposed, mostly building on the ongoing machine-learning revolution. To perform an objective comparison of methods, we gathered the community and organized an open competition, the Anomalous Diffusion challenge (AnDi). Although no single method performed best across all scenarios, machine-learning-based approaches achieved superior performance for all tasks. The discussion of the challenge results provides practical advice for users and a benchmark for developers.

In this work, I have participated in this Challenge jointly with Òscar Garibo and Nicolàs Firbas. We developed the best model for the regression task in 1 dimension. Our models also show a great performance for the regression task in 2 and 3 dimensions, and for the classification tasks in all of them.

Our work has been published in Nature Communications. You can access to the content here https://www.nature.com/articles/s41467-021-26320-w

Using ROC curves to evaluate a street lighting control system (IEEE Access)

J. Alberto Conejero
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Using ROC curves to evaluate a street lighting control system (IEEE Access)

Intelligent control of public lighting is nowadays one of the most challenging issues in smart city deployment. Lighting optimization entails a compromise between comfort, safety, and power consumption, affecting both vehicles and pedestrians. Smart solutions must estimate their characteristics to trade-off users’ needs and energy requirements.

In this joint paper with J.L. Poza-Lujan, J.J. Sánez-Peñafiel, J.L. Posadas-Yagüe, and J.C. Cano we have proposed an intelligent street lighting control system and the Receiver Operating Characteristic (ROC) curve method to evaluate the best number of street lamps to achieve a balance between public road user comfort and system power consumption. The control system is based on the detection of users, mainly pedestrians, using presence sensors. From the detection of a pedestrian by two or more consecutive street lamps it is possible to determine their speed. Knowing the pedestrian speed, allows the system to anticipate and adjust the light intensity of the remaining street lamps, and provide a comfortable view of the street. Using the ROC curve, we evaluate the control algorithm in terms of the number of previous street lamps used. We have tested the system and the method in a model of pedestrians walking down a street. The obtained results show that ROC analysis used to control street lighting allows measuring the whole control system’s efficiency by providing a concrete number of previous street lamps.

You can access the paper here: https://ieeexplore.ieee.org/document/9583300?source=authoralert

Soft skills at ENHANCE GOES TO UPV

J. Alberto Conejero
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Soft skills at ENHANCE GOES TO UPV

The ENHANCE Alliance is part of the ERASMUS + funding program for European universities, promoted by the European Commission. The initiative aims to create an innovative framework of European networks, promoting greater mobility of students and staff, as well as innovative ways of learning and engagement with society. ENHANCE is a strong alliance of seven European technological universities, including UPV, that will inspire and drive the development and use of science and technology, for the benefit of society, turning global challenges into meaningful opportunities.

During October 19-21, 2021, the UPV held a training week for the university partners. I have participated in delivering a workshop with José Luis Poza-Lujan on Digital and soft skills in university administration.  During this workshop, we have introduced some background about the new demands of the labor market and the need to combine hard & soft skills. We also show some practical techniques and examples about how to improve your personal relations in the work environment and about how to organize and delegate tasks.

Lalaby, the app that will monitor the quality of life of cancer patients

J. Alberto Conejero
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Lalaby, the app that will monitor the quality of life of cancer patients

I have participated in the development of an app called Lalaby in collaboration with Sabina Asensio, Juanmi García, and Ángel sánchez, from BDSLab. This app allows you to monitor the patient’s day-to-day life and does so from the information collected by the sensors of your mobile phone and from other sources stored in it that allow you to calculate your physical activity (movement and displacement), social interaction (voice frequencies) and network activity (amount of data used). In addition, Lalaby allows the integration of questionnaires, such as the EORTC QLQ-C30 (European Organization for Research and Treatment of Cancer- QLQ-C30), widely used to assess the quality of life, as well as for the patient to directly record the activities carried out, your symptoms and pain level. From all this information, Lalaby makes it possible to obtain user behavior patterns and relate them to quality of life indicators, according to sources from the academic institution. These patterns can be of great help, for example, to monitor possible changes in mood, activity, symptoms, etc., in people starting cancer treatment, which offers doctors valuable information to make the best possible decisions for the day-to-day of the patient.

We are developing a pilot case in Hospital Dr. Peset (València), jointly with Inmaculada Maestu’s team. This study case has appeared in several media.

VALENCIA PLAZA: Lalaby, la «app» que monitorizará la calidad de vida de pacientes con cáncer

More details can be found here: https://aplicat.upv.es/exploraupv/ficha-tecnologia/patente_software/26083

Two-dimensional compact-finite-difference schemes for solving the bi-Laplacian operator (Mathematics)

J. Alberto Conejero
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Two-dimensional compact-finite-difference schemes for solving the bi-Laplacian operator (Mathematics)

In fluid mechanics, the bi-Laplacian operator with Neumann homogeneous boundary conditions emerges when transforming the Navier–Stokes equations to the vorticity–velocity formulation. In the case of problems with a periodic direction, the problem can be transformed into multiple, independent, two-dimensional fourth-order elliptic problems. An efficient method to solve these two-dimensional bi-Laplacian operators with Neumann homogeneous boundary conditions was designed and validated using 2D compact finite difference schemes. The solution is formulated as a linear combination of auxiliary solutions, as many as the number of points on the boundary, a method that was prohibitive some years ago due to the large memory requirements to store all these auxiliary functions. The validation has been made for different field configurations, grid sizes, and stencils of the numerical scheme, showing its potential to tackle high gradient fields as those that can be found in turbulent flows.

This work is a joint collaboration with Jesús Amo-Navarro and Sergio Hoyas-Calvo from UPV and Ricardo Vinuesa from KTH and it has been published in the journal Mathematics. doi:10.3390/math9192508

Invited speaker at XIV GAFEVOL (in honour of Prof. Lizama)

J. Alberto Conejero
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Invited speaker at XIV GAFEVOL (in honour of Prof. Lizama)

I have been invited as a speaker at the XIV GAFEVOL Conference (Evolution Equations and Functional Analysis Group). This conference has been held virtually at Universidad de Santiago de Chile for celebrating the 60th birthday of Prof. Carlos Lizama. This was a great pleasure since I am really indebted to him for his advice and collaboration during the last years.

The link to the conference website is here https://sites.google.com/view/gafevol2021

I also share a link to the video of the session in which I participated:

I have collaborated with Carlos for the last 8 years, obtaining remarkable results in the dynamics of solution C0-semigroups associated with second-order PDE on certain spaces of analytic functions of slow growth. We have also worked on the modeling of the Lambert-Beer equation on cyanobacteria cultures, on the dynamics of discrete fractional equations, the well-posedness for degenerate third order equations with delay, and the solutions of water hammer equations. Here, you can find the list of our collaborations:

  1. J.A. Conejero, C. Lizama, and F. Ródenas. Chaotic behaviour of the solutions of the Moore-Gibson-Thompson equation. Appl. Math. Inf. Sci. 9, No. 5, 2233-2238 (2015). doi:10.12785/amis/090503
  2. J.A. Conejero, C. Lizama, and F. Ródenas. Dynamics of the solutions of the water hammer equations. Topology Appl., 203, 67-83 (2016). doi:10.1016/j.topol.2015.12.076
  3. J.A. Conejero, C. Lizama, and M. Murillo-Arcila. On the existence of chaos for the viscous van Wijngaarden-Eringen equation. Chaos, Solitons & Fractals, 89, 100-104 (2016). doi:10.1016/j.chaos.2015.10.009
  4. J.A. Conejero, C. Lizama, M. Murillo-Arcila, and A. Peris. Linear dynamics of semigroups generated by differential operators. Open Math. 17, 745-767 (2017).  doi:10.1515/math-2017-0065
  5. J.A. Conejero, C. Lizama, M. Murillo-Arcila. Chaotic semigroups from second order partial differential equations. J. Math. Anal. Appl. 456:1, 402-411 (2017). doi:10.1016/j.jmaa.2017.07.013–C. Rodero-Gómez, J.A. Conejero, and I. García-Fernández. Shock wave formation in compliant arteries
  6. D. Fuente, C. Lizama, J.F. Urchueguía, and J.A. Conejero. Estimation of the light field inside photosynthetic microorganism cultures through Mittag-Leffler functions at depleted light conditions. J. Quant. Spectrosc. Radiat. Transfer, 204, 23-26 (2018).  doi:10.1016/j.jqsrt.2017.08.012
  7. J.A. Conejero, C. Lizama, M. Murillo-Arcila, and J.B. Seoane-Sepúlveda. Well posedness for abstract degenerate third order equations with infinite delay. Israel Math. J. 229:1, 219-254 (2019). doi:10.1007/s11856-018-1796-8
  8. J.A. Conejero, C. Lizama, A. Mira-Iglesias, C. Rodero-Gómez. Visibility graphs of fractional Wu Baleanu time series. J. Differ. Eq. Appl. 25(9-10), 1321-1331 (2019). doi: 10.1080/10236198.2019.1619714

 

 

Lessons learned from the COVID-19 pandemic in hospitals and social health centres in Spain (ONLINE)

J. Alberto Conejero
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Lessons learned from the COVID-19 pandemic in hospitals and social health centres in Spain (ONLINE)

As a member of the Valencia Data Science Task Force, I have participated with Miguel Rebollo in the summer school Lessons learned from the COVID-19 pandemic in hospitals and social health centers in Spain (ONLINE) held at the Escola de Salut Pública of Menorca held at the Lazaretto hospital of Menorca (Spain). We have talked about the evolution of the COVID-19 pandemics spreading modeling. We have also explained what lessons we have learned, from the Data Science perspective, that can be taken into account for the next pandemics. I want to thank Jose Felix Hoyo for giving me the chance to participate there.

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Personal website of J. Alberto Conejero (Full Professor of Applied Mathematics at Universitat Politècnica de València, Spain.

Contact us: aconejero@upv.es

J. Alberto Conejero - Universitat Politècnica de València