المؤلفون: Stedtler, Samantha, Fantasia, Valentina, Tjøstheim, Trond A., Johansson, Birger, Brinck, Ingar, Balkenius, Christian

المصدر: HRI ’24: ACM/IEEE International Conference on Human-Robot Interaction,Boulder, CO, United States,-- HRI '24 : Companion of the 2024 ACM/IEEE International Conference on Human-Robot Interaction - Companion of the 2024 ACM/IEEE International Conference on Human-Robot Interaction eSSENCE: The e-Science Collaboration. :1013-1017

مصطلحات موضوعية: Social Robots, Time delays, Robotic Movements, Turn-taking, Fluency, Animacy, Naturvetenskap, Data- och informationsvetenskap (Datateknik), Datorseende och robotik (autonoma system), Natural Sciences, Computer and Information Science, Computer Vision and Robotics (Autonomous Systems)

الوصف: Humans are expert percievers of behavioural properties, including the timing of movements. Even short hesitancies and delays can be salient depending on the context. This article presents results from a pilot study on time delays in a human-robot interaction setting using the Wizard of Oz paradigm. Participants (n=17) played Tic-Tac-Toe with the humanoid robot Epi. They were randomized into one of three groups, where Epi either executed its movements with no delay, a short delay (4s) or a long delay (10s). Results from questionnaires measuring fluency, trust, anthropomorphism, animacy and likability were compared before and after the interaction and between the different groups. Although there was evidence of decreased perceived fluency after delays, the difference between the groups did not meet the threshold for statistical significance. The latter is true for our other measures used. We conclude that better statistical power is needed to be sure whether there is indeed an effect of time delays on robot-related attribution of social features. Suggestions are made in regards to how the study design could become more robust for a future, more large-scale study. In addition, we propose using measures that better account for the participants' embodied experiences by taking emotional and bodily states into consideration for future studies.

الوصول الحر: https://lup.lub.lu.se/record/de830080-5273-4b9c-89e4-d2df50adc7c4Test
http://dx.doi.org/10.1145/3610978.3640667Test

المؤلفون: Devalle, Federico

المساهمون: University/Department: Universitat Pompeu Fabra. Departament de Tecnologies de la Informació i les Comunicacions

مرشدي الرسالة: Montbrió, Ernest

المصدر: TDX (Tesis Doctorals en Xarxa)

مصطلحات موضوعية: Mathematical neuroscience, Oscillations, Synaptic kinetics, Time delays, Synchronization, Neural population, Firing rate, Population model, Spiking neurons, Quadratic integrate-and-fire, Coupled oscillators, Mean-field, Wilson-Cowan model, Neurociència matemàtica, Oscil·lacions, Cinètica sinàptica, Retards temporals, Sincronització, Població neuronal, Model de població, Integrate-and-fire quadràtic, Oscil·ladors acoblats, Model Wilson-Cowan

الوصف: A prominent feature of the dynamics of large neuronal networks are the synchrony-driven collective oscillations generated by the interplay between synaptic coupling and synaptic delays. This thesis investigates the emergence of delay-induced oscillations in networks of heterogeneous spiking neurons. Building on recent theoretical advances in exact mean field reductions for neuronal networks, this work explores the dynamics and bifurcations of an exact firing rate model with various forms of synaptic delays. In parallel, the results obtained using the novel firing rate model are compared with extensive numerical simulations of large networks of spiking neurons, which confirm the existence of numerous synchrony-based oscillatory states. Some of these states are novel and display complex forms of partial synchronization and collective chaos. Given the well-known limitation of traditional firing rate models to describe synchrony-based oscillations, previous studies greatly overlooked many of the oscillatory states found here. Therefore, this thesis provides a unique exploration of the oscillatory scenarios found in neuronal networks due to the presence of delays, and may substantially extend the mathematical tools available for modeling the plethora of oscillations detected in electrical recordings of brain activity.

الوصف (مترجم): Una característica fonamental de la dinàmica d'una xarxa neuronal és l'emergència d'oscil·lacions degudes a sincronització. L'origen d'aquestes oscil·lacions és molt sovint degut les interaccions sinàptiques i als seus retards temporals inherents. Aquesta tesi analitza la emergència d'oscil·lacions produïdes per retards sinàptics en xarxes neuronals heterogènies. A partir de troballes recents en teories de camp mig per xarxes neuronals, aquest treball explora la dinàmica i les bifurcacions d'un model de {\it rate} amb diferents tipus de retards sinàptics. En paral·lel els resultats obtinguts mitjançant el nou model de rate són comparats amb simulacions numèriques de grans xarxes neuronals. Aquestes simulacions confirmen l'existència de nombrosos estats oscil·latoris produïts per sincronització. Alguns d'aquests estats són nous I mostren formes complexes de sincronització parcial i de caos col·lectiu. Gran part d'aquestes oscil·lacions han estat àmpliament ignorades a la literatura, degut a la limitació dels models tradicionals de rate per descriure estats amb un alt nivell de sincronització. Així doncs aquesta tesi ofereix una exploració única dels possibles escenaris oscil·latoris en xarxes neuronals amb retards sinàptics, i amplia significativament les eines matemàtiques disponibles per a la modelització de la gran diversitat d'oscil·lacions neuronals presents en les mesures elèctriques de l'activitat cerebral.
Programa de doctorat en Tecnologies de la Informació i les Comunicacions

وصف الملف: application/pdf

الوصول الحر: http://hdl.handle.net/10803/666912Test

المؤلفون: Ting Yang, Li Cao, Wanli Zhang

المصدر: AIMS Mathematics, Vol 9, Iss 8, Pp 20350-20366 (2024)

مصطلحات موضوعية: practical generalized finite-time synchronization, duplex networks, quantized couplings, time delays, intermittent control, Mathematics, QA1-939

الوصف: This paper investigates the practical generalized finite-time synchronization (PGFETS) of duplex networks with quantized and delayed couplings. Given that continuous transmission of signals will increase the load and cost of communication, we introduce quantized couplings in the model. Then, via the theorem of finite-time stability, the PGFETS is proposed based on the fact that PGFETS is much more extensive and practical than classical finite-time synchronization. Some sufficient criteria are formulated to achieve the goal of synchronization by utilizing quantized intermittent control schemes. Lastly, the validity of the theoretical results is illustrated by numerical simulations.

وصف الملف: electronic resource

العلاقة: https://doaj.org/toc/2473-6988Test

الوصول الحر: https://doaj.org/article/55c61b4f83b64b68ac4fd2296a3eef4cTest

المؤلفون: Călin-Adrian Popa

المصدر: AIMS Mathematics, Vol 9, Iss 7, Pp 18796-18823 (2024)

مصطلحات موضوعية: clifford-valued neural networks (clvnns), synchronization analysis, time scales, time delays, infinite distributed delays, Mathematics, QA1-939

الوصف: Neural networks (NNs) with values in multidimensional domains have lately attracted the attention of researchers. Thus, complex-valued neural networks (CVNNs), quaternion-valued neural networks (QVNNs), and their generalization, Clifford-valued neural networks (ClVNNs) have been proposed in the last few years, and different dynamic properties were studied for them. On the other hand, time scale calculus has been proposed in order to jointly study the properties of continuous time and discrete time systems, or any hybrid combination between the two, and was also successfully applied to the domain of NNs. Finally, in real implementations of NNs, time delays occur inevitably. Taking all these facts into account, this paper discusses ClVNNs defined on time scales with leakage, time-varying delays, and infinite distributed delays, a type of delays which have been relatively rarely present in the existing literature. A state feedback control scheme and a generalization of the Halanay inequality for time scales are used in order to obtain sufficient conditions expressed as algebraic inequalities and as linear matrix inequalities (LMIs), using two general Lyapunov-like functions, for the exponential synchronization of the proposed model. Two numerical examples are given in order to illustrate the theoretical results.

وصف الملف: electronic resource

العلاقة: https://doaj.org/toc/2473-6988Test

الوصول الحر: https://doaj.org/article/9b39f0c4cb984f1d91bf5fa7753ec0b7Test

المؤلفون: Mengqi Xie, Sami Ullah Khan, Wojciech Sumelka, Atif M. Alamri, Salman A. AlQahtani

المصدر: Scientific Reports, Vol 14, Iss 1, Pp 1-16 (2024)

مصطلحات موضوعية: Fractional delay stochastic differential equations, Stochasticity, Time delays, Fractional calculus, Stability analysis, Spectral method, Medicine, Science

الوصف: Abstract In recent years, there has been a growing interest in incorporating fractional calculus into stochastic delay systems due to its ability to model complex phenomena with uncertainties and memory effects. The fractional stochastic delay differential equations are conventional in modeling such complex dynamical systems around various applied fields. The present study addresses a novel spectral approach to demonstrate the stability behavior and numerical solution of the systems characterized by stochasticity along with fractional derivatives and time delay. By bridging the gap between fractional calculus, stochastic processes, and spectral analysis, this work contributes to the field of fractional dynamics and enriches the toolbox of analytical tools available for investigating the stability of systems with delays and uncertainties. To illustrate the practical implications and validate the theoretical findings of our approach, some numerical simulations are presented.

وصف الملف: electronic resource

العلاقة: https://doaj.org/toc/2045-2322Test

الوصول الحر: https://doaj.org/article/ef5a675be4584516b5c1dff569bea666Test

المؤلفون: Beibei Su, Liang Zhao, Liang Du, Qun Gu

المصدر: AIMS Mathematics, Vol 9, Iss 6, Pp 16586-16604 (2024)

مصطلحات موضوعية: time delays, reachable set, neutral-type systems, bounded disturbances, lyapunov function, ellipsoid boundary, Mathematics, QA1-939

الوصف: This research focuses on the challenge of defining the ellipsoidal boundaries of the reachable set (RS) for neutral-type dynamical systems with time delays. A novel analytical approach is proposed, leveraging the development of new Lyapunov functions and matrix inequality techniques. These methods provide powerful tools for determining the ellipsoidal boundaries of the system's RS. A comparative analysis, supported by numerical examples, demonstrates that the approach outlined in this study can accurately identify smaller yet effective RS boundaries compared to existing literature. This precise boundary determination offers significant theoretical support for state estimation and control design in dynamical systems, thereby enhancing their effectiveness and reliability in real-world applications.

وصف الملف: electronic resource

العلاقة: https://doaj.org/toc/2473-6988Test

الوصول الحر: https://doaj.org/article/c5bb0ae3531248e9ace53bb2a72c9babTest

المؤلفون: Khan, A., Hassan, W. U., Manzor, Adnan, Ahmed, S., Niazi, A. U. K.

المصدر: Systems Science & Control Engineering. 12(1)

مصطلحات موضوعية: Consensus, disturbance in centralized event-triggered protocol, framework for a multi-agent system (Leader–Follower), Lyapunov Krasovskii function, Delay control systems, Number theory, System stability, Time delay, Timing circuits, Vehicles, Centralised, Event-triggered, Event-triggered control systems, Leader-follower, Time-delays, Vehicle system, Multi agent systems

الوصف: This paper addresses the difficulties with connected vehicle systems (CVSs), particularly with vehicle platooning, are examined in this paper. For leader and follower-connected vehicles, the control protocol (which includes artificial delays, disturbances and proportional gains) is implemented. With tracking error systems, system dynamics are modelled while taking outside influences into consideration. Using creative thinking, a centralized event-triggered control system is implemented to maximize fleet wide communication updates. System stability is guaranteed by this centralized method in combination with quadratic form Lyapunov stability analysis. The risk of zeno behaviour is reduced by an event-triggered communication condition that is activated when a threshold is exceeded. The effectiveness of the centralized event-triggered system in improving stability and resilience in connected vehicle platooning scenarios is evaluated numerically through simulations.

وصف الملف: print

الوصول الحر: https://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-66559Test
https://doi.org/10.1080/21642583.2024.2342818Test

المؤلفون: Arvidson, Magnus, Westlund, Örjan

المصدر: Fire technology.

مصطلحات موضوعية: Carbon dioxide, Hose, Sprinkler systems (irrigation), Vehicles, Carbon dioxide system, Delay Time, Floodings, Maritime vehicle carrier, Protected object, Ro-ro space, Sprinkler, System concepts, Time-delays, Vehicle fires, Fires

الوصف: Closed ro-ro spaces on maritime vehicle carriers are usually protected by a total-flooding carbon dioxide system. Such systems have many benefits, for example that there are no residues that can adversely affect the protected objects (in this case thousands of vehicles) and the agent is electrically non-conductive. However, there could be a considerable time delay from the start of a fire until the carbon dioxide system is discharged. Experience has shown that this delay time can cause significant fire damage and jeopardize the performance of the system. Within the EU funded LASH FIRE project, design and installation guidelines for supplementary automatic water-based fire sprinkler systems were developed. An important design feature is that the system automatically activates at an early stage of a fire. This would allow more time to fight the fire manually or to safely evacuate the space and discharge the CO2 system when the fire is controlled to one or a few vehicles instead of at a time when it has escalated in size. The work was partly based on a comprehensive literature review that identified relevant standards and information applicable to the design of automatic fire sprinkler and deluge water spray systems. Large-scale fire tests verified that the suggested system designs were able to provide control of realistic vehicle fires, including fires in passenger cars and a freight truck.

وصف الملف: electronic

الوصول الحر: https://urn.kb.se/resolve?urn=urn:nbn:se:ri:diva-72869Test
https://doi.org/10.1007/s10694-024-01563-3Test
https://ri.diva-portal.org/smash/get/diva2:1854759/FULLTEXT01.pdfTest

المؤلفون: Jiashu Gao, Jing Han, Guodong Zhang

المصدر: AIMS Mathematics, Vol 9, Iss 4, Pp 9211-9231 (2024)

مصطلحات موضوعية: fixed/preassigned-time stabilization, event-triggered control, state-dependent switching, mixed time delays, Mathematics, QA1-939

الوصف: This study employed an event-triggered control (ETC) strategy to investigate the problems of fixed-time stabilization (FTS) and preassigned-time stabilization (PTS) for state-dependent switching neural networks (SDSNNs) that involved mixed time delays. To enhance the network's generalization capability and accelerate convergence stabilization, a more intricate weight-switching mechanism was introduced, then to mitigate transmission energy consumption, this paper proposed a tailored event-triggering rule that triggered the ETC solely at predetermined time points. This rule ensured the stability of the system while effectively reducing energy consumption. Using the Lyapunov stability theory and various inequality techniques, this paper presented new results for FTS and PTS of SDSNNs. The validity of these findings was supported by conducting data simulations in two illustrative examples.

وصف الملف: electronic resource

العلاقة: https://doaj.org/toc/2473-6988Test

الوصول الحر: https://doaj.org/article/3a05496581b043e28714f0cc5e065c95Test

المؤلفون: Tanveer, Binish, 1979, Zabardast, Ehsan, 1990, Gonzalez-Huerta, Javier

المصدر: Proceedings - IEEE 20th International Conference on Software Architecture Companion, ICSA-C 2023. :341-347

مصطلحات موضوعية: Agile methods, Compile time, Large organizations, Large-scales, Runtimes, Scaling results, Small scale, Sociotechnical, Time-delays, Waiting time, Software design

الوصف: Seeking the advantages delivered by agile methods in small-scale software development, large organisations are also adopting agile methods. However, scaling results in a huge growth of socio-technical dependencies that can lead to waiting time, delays, and defects and hinder the teams' ability to recognize their own responsibilities. This research proposes an approach to enable teams' autonomy and clarifies teams' responsibility assignments by aligning socio-technical dependencies. By utilising compile-time, run-time, and task dependencies, our approach identifies the wasteful dependencies between the social structures (teams) and the corresponding technical structures (architecture) and also suggests improvements. The initial results suggest that the approach correctly identifies the wasteful dependencies that are hindering teams' responsibility assignments. The suggested solution proposals are also considered useful. Awareness of such wasteful dependencies is the first step toward being able to handle them successfully. © 2023 IEEE.

وصف الملف: electronic

الوصول الحر: https://urn.kb.se/resolve?urn=urn:nbn:se:bth-25263Test
https://bth.diva-portal.org/smash/get/diva2:1787083/FULLTEXT01.pdfTest