October 2022 - semfis - Mailman @ IFISC

IFISC Seminar on Wednesday, Nov 02, 2022 at 14:30

by semfis＠ifisc.uib-csic.es

IFISC Seminar on Wednesday Nov 02, 2022 at 14:30 Place: IFISC Seminar Room Title: Learn one size to infer all: Exploiting symmetries in dynamical systems using scalable neural networks Speaker: Mirko Goldmann, IFISC Abstract: Tackling unavailable analytical models, machine learning methods emerged that learn from large amounts of data to forecast the dynamics of complex systems. Yet such predictions are mainly restricted to the dynamical regime observed during training. Here, we attempt to answer the question - Is it possible to infer untrained (size-dependent) dynamical regimes of a complex system while learning from one example related to a certain system size only? Therefore, we design scalable neural networks capable of inferring untrained high-dimensional dynamics for different system sizes. We train these networks to predict the dynamics of delay-dynamical and spatio-temporal systems for a single size. Then, we drive the network by its own predictions. Subsequently, by scaling the size of the trained network, we can predict complex dynamics for larger or smaller system sizes. Thus, the network learns from a single example and by exploiting symmetry properties, infers entire bifurcation diagrams. Presential seminar, with parallel Zoom stream:&nbsp;&nbsp; https://zoom.us/j/98286706234?pwd=bm1JUFVYcTJkaVl1VU55L0FiWDRIUT09 Url event:https://ifisc.uib-csic.es/en/events/seminars/learn-one-size-to-infer-all-exploiting-symmetries/

7 months

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Reminder: IFISC Seminar, TODAY - Wednesday, Oct 26, 2022 at 14:30

by semfis＠ifisc.uib-csic.es

IFISC Seminar on Wednesday Oct 26, 2022 at 14:30 Place: IFISC Seminar Room Title: How not to construct functional brain networks Speaker: Onerva Korhonen, Aalto University Abstract: Human brain function relies on interactions between brain areas. Therefore, a complex network appears as a natural model for the brain, and network science indeed holds potential for understanding the brain. However, constructing a functional brain network is not trivial. I will address common problems in brain network construction, concentrating on a step that strongly affects obtained network properties: definition of network nodes. Using multiple fMRI datasets, I will show that the currently used node definition strategies produce nodes that suffer from low functional homogeneity, which may lead to spuriosity in observed network structure and data losses. Further, I will show that functional homogeneity changes in time, reflecting nodes&rsquo; roles in network topology. Finally, as a potential solution for node definition problem, I will introduce a flexible node definition strategy that accounts for the time-dependent nature of brain function. Presential seminar, with parallel Zoom stream:&nbsp;&nbsp; https://zoom.us/j/98286706234?pwd=bm1JUFVYcTJkaVl1VU55L0FiWDRIUT09 Url event:https://ifisc.uib-csic.es/en/events/seminars/how-not-to-construct-functional-brain-networks/

7 months

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Reminder: Talk, TODAY - Monday, Oct 24, 2022 at 10:00

by semfis＠ifisc.uib-csic.es

Talk on Monday Oct 24, 2022 at 10:00 Place: IFISC Seminar Room Title: Time delay reservoir computing with short-external-cavity laser dynamics and phase encoding Speaker: Lucas Talandier, IFISC (CSIC-UIB) Abstract: Semiconductor lasers with optical feedback or optical injection have been studied in recent years, especially for their capabilities for complex signal generation and information processing. The nonlinear behavior of this system can be used for solving nonlinear computing tasks, when operating in a transient input transformation regime and exploiting memory induced by the feedback. For tasks that require memory, increasing the feedback rate is often beneficial. However, this might be accompanied by the onset of complex dynamics resulting in inconsistent input signal transformations, which are detrimental for computing. In this talk, I will discuss a semiconductor laser system that operates in a short-cavity regime, for which chaotic dynamics appear only under strong feedback conditions. The extended feedback operating regime avoiding chaos, compared to the long-cavity regime, allows to realize better memory properties. I will discuss the&nbsp;trade-off between memory , speed of computation, dimensionality, and consistency. I will show examples of various parameter conditions, identifying short external cavity regimes with strong optical feedback and injection, which offer high memory capacity avoiding the laser&rsquo;s coherence collapse. I will also discuss how this system behaves when the input information is phase-encoded, and I will compare its performance to the commonly used amplitude encoding. Zoom:&nbsp;https://uibuniversitat.zoom.us/j/87008849910 Url event:https://ifisc.uib-csic.es/en/events/seminars/time-delay-reservoir-computing-with-short-external/

7 months, 1 week

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Reminder: Master Thesis, TODAY - Monday, Oct 24, 2022 at 10:20

by semfis＠ifisc.uib-csic.es

Master Thesis on Monday Oct 24, 2022 at 10:20 Place: IFISC Meeting Room Title: Analysis and the Action Curve of Agent Zero: Theory and Simulation Speaker: Benjamin Maxwell Fried, IFISC / UIB Abstract: &nbsp; In this thesis I explore a theoretical neurocognitively ground agent put forth by Joshua Epstein to advance social science research. In particular I begin to develop a probabilistic framework in which theoretical predictions can be made about the dynamics of Agent Zero. Furthermore, I study the collective behavior of an ensemble of Einstein&#39;s agents and compare the results with a modified version. Supervisor: Maxi San Miguel Jury: Tobias Galla, Maxi San Miguel, Raul Toral Presential in the IFISC meeting room (room 215), with parallel Zoom stream:&nbsp;https://zoom.us/j/98286706234?pwd=bm1JUFVYcTJkaVl1VU55L0FiWDRIUT09 Url event:https://ifisc.uib-csic.es/en/events/seminars/analysis-and-the-action-curve-of-agent-zero-theory/

7 months, 1 week

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Talk on Monday, Oct 24, 2022 at 10:00

by semfis＠ifisc.uib-csic.es

Talk on Monday Oct 24, 2022 at 10:00 Place: IFISC Seminar Room Title: Time delay reservoir computing with short-external-cavity laser dynamics and phase encoding Speaker: Lucas Talandier, IFISC (CSIC-UIB) Abstract: Semiconductor lasers with optical feedback or optical injection have been studied in recent years, especially for their capabilities for complex signal generation and information processing. The nonlinear behavior of this system can be used for solving nonlinear computing tasks, when operating in a transient input transformation regime and exploiting memory induced by the feedback. For tasks that require memory, increasing the feedback rate is often beneficial. However, this might be accompanied by the onset of complex dynamics resulting in inconsistent input signal transformations, which are detrimental for computing. In this talk, I will discuss a semiconductor laser system that operates in a short-cavity regime, for which chaotic dynamics appear only under strong feedback conditions. The extended feedback operating regime avoiding chaos, compared to the long-cavity regime, allows to realize better memory properties. I will discuss the&nbsp;trade-off between memory , speed of computation, dimensionality, and consistency. I will show examples of various parameter conditions, identifying short external cavity regimes with strong optical feedback and injection, which offer high memory capacity avoiding the laser&rsquo;s coherence collapse. I will also discuss how this system behaves when the input information is phase-encoded, and I will compare its performance to the commonly used amplitude encoding. Zoom:&nbsp;https://uibuniversitat.zoom.us/j/87008849910 Url event:https://ifisc.uib-csic.es/en/events/seminars/time-delay-reservoir-computing-with-short-external/

7 months, 1 week

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Master Thesis on Monday, Oct 24, 2022 at 10:20

by semfis＠ifisc.uib-csic.es

Master Thesis on Monday Oct 24, 2022 at 10:20 Place: IFISC Meeting Room Title: Analysis and the Action Curve of Agent Zero: Theory and Simulation Speaker: Benjamin Maxwell Fried, IFISC / UIB Abstract: &nbsp; In this thesis I explore a theoretical neurocognitively ground agent put forth by Joshua Epstein to advance social science research. In particular I begin to develop a probabilistic framework in which theoretical predictions can be made about the dynamics of Agent Zero. Furthermore, I study the collective behavior of an ensemble of Einstein&#39;s agents and compare the results with a modified version. Supervisor: Maxi San Miguel Jury: Tobias Galla, Maxi San Miguel, Raul Toral Presential in the IFISC meeting room (room 215), with parallel Zoom stream:&nbsp;https://zoom.us/j/98286706234?pwd=bm1JUFVYcTJkaVl1VU55L0FiWDRIUT09 Url event:https://ifisc.uib-csic.es/en/events/seminars/analysis-and-the-action-curve-of-agent-zero-theory/

7 months, 1 week

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IFISC Seminar on Wednesday, Oct 26, 2022 at 14:30

by semfis＠ifisc.uib-csic.es

IFISC Seminar on Wednesday Oct 26, 2022 at 14:30 Place: IFISC Seminar Room Title: How not to construct functional brain networks Speaker: Onerva Korhonen, Aalto University Abstract: Human brain function relies on interactions between brain areas. Therefore, a complex network appears as a natural model for the brain, and network science indeed holds potential for understanding the brain. However, constructing a functional brain network is not trivial. I will address common problems in brain network construction, concentrating on a step that strongly affects obtained network properties: definition of network nodes. Using multiple fMRI datasets, I will show that the currently used node definition strategies produce nodes that suffer from low functional homogeneity, which may lead to spuriosity in observed network structure and data losses. Further, I will show that functional homogeneity changes in time, reflecting nodes&rsquo; roles in network topology. Finally, as a potential solution for node definition problem, I will introduce a flexible node definition strategy that accounts for the time-dependent nature of brain function. Presential seminar, with parallel Zoom stream:&nbsp;&nbsp;https://zoom.us/j/98286706234?pwd=bm1JUFVYcTJkaVl1VU55L0FiWDRIUT09 Url event:https://ifisc.uib-csic.es/en/events/seminars/how-not-to-construct-functional-brain-networks/

7 months, 1 week

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Reminder: Outreach Event, TODAY - Thursday, Oct 20, 2022 at 19:00

by semfis＠ifisc.uib-csic.es

Outreach Event on Thursday Oct 20, 2022 at 19:00 Place: Sala Mozart, Auditorium de Palma Title: CCS: Complejidad para Comprender la Sociedad Speaker: Anxo Sánchez, Marta González, Ernesto Estrada, Universidad Carlos III, UC Berkeley, IFISC Abstract: El jueves 21, en la Sala Mozart del Auditorio, a las 19 horas, tendr&aacute; lugar una sesi&oacute;n de divulgaci&oacute;n abierta al p&uacute;blico en general. La sesi&oacute;n, destinada a acercar la ciencia a la sociedad, se titula &quot;<a href="https://ifisc.uib-csic.es/documents/1471/ccs-outreach-poster.jpg">Complejidad para Comprender la Sociedad</a>&quot;, e incluye las charlas &quot;World Wide Waste Web: Red de comercio internacional de basuras&quot; de Ernesto Estrada (IFISC); &quot;Leyes de Movilidad Humana: desde el individuo a emisiones vehiculares en ciudades&quot; de Marta Gonz&aacute;lez (UC Berkeley y Lawrence Berkeley National Laboratory) y &quot;Aquellos maravillosos a&ntilde;os: los c&iacute;rculos de Dunbar y las amistades en el instituto&quot; de Anxo S&aacute;nchez (Universidad Carlos III).&nbsp; Url event:https://ifisc.uib-csic.es/en/events/seminars/ccs-complejidad-para-comprender-la-sociedad/

7 months, 1 week

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Reminder: Master Thesis, TODAY - Thursday, Oct 20, 2022 at 09:00

by semfis＠ifisc.uib-csic.es

Master Thesis on Thursday Oct 20, 2022 at 09:00 Place: IFISC Seminar Room Title: Network-based measure of the finite size Lyapunov exponent Speaker: Joan Antich Navarro, IFISC Abstract: Supervisors: Enrico Ser-Giacomi, Crist&oacute;bal L&oacute;pez Jury: Emilio Hern&aacute;ndez-Garc&iacute;a, Tom&aacute;s Sintes, Crist&oacute;bal L&oacute;pez Presential Url event:https://ifisc.uib-csic.es/en/events/seminars/network-based-measure-of-the-finite-size-lyapunov/

7 months, 1 week

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Reminder: Master Thesis, TODAY - Friday, Oct 14, 2022 at 11:00

by semfis＠ifisc.uib-csic.es

Master Thesis on Friday Oct 14, 2022 at 11:00 Place: IFISC Seminar Room Title: Partisan Voter Model: Noise-Induced Transitions Speaker: Jaume Llabrés Rubio, IFISC / UIB Abstract: Supervisors:&nbsp;&nbsp;Ra&uacute;l Toral,&nbsp;Maxi San Miguel Jury:&nbsp;David S&aacute;nchez,&nbsp;Tobias Galla,&nbsp;Ra&uacute;l Toral Presential, with parallel Zoom stream:&nbsp;&nbsp; https://zoom.us/j/98286706234?pwd=bm1JUFVYcTJkaVl1VU55L0FiWDRIUT09 Url event:https://ifisc.uib-csic.es/en/events/seminars/partisan-voter-model-noise-induced-transitions/

7 months, 2 weeks

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2023

2022

2021

semfis October 2022