Spontaneous Synchronization in Two Mutually Coupled Memristor-Based Chua’s Circuits: Numerical Investigations

Chaotic dynamics of numerous memristor-based circuits is widely reported in literature. Recently, some works have appeared which study the problem of synchronization control of these systems in a master-slave configuration. In the present paper, the spontaneous dynamic behavior of two chaotic memristor-based Chua’s circuits, mutually interacting through a coupling resistance, was studied via computer simulations in order to study possible self-organized synchronization phenomena. The used memristor is a flux controlled memristor with a cubic nonlinearity, and it can be regarded as a time-varying memductance. The memristor, in effect, retains memory of its past dynamic and any difference in the initial conditions of the two circuits results in different values of the corresponding memductances. In this sense, due to the memory effect of the memristor, even if coupled circuits have the same parameters they do not constitute two completely identical chaotic oscillators. As is known, for nonidentical chaotic systems, in addition to complete synchronizations (CS) other weaker forms of synchronization which provide correlations between the signals of the two systems can also occur. Depending on initial conditions and coupling strength, both chaotic and nonchaotic synchronization are observed for the system considered in this work

The development and application of an optimization tool in industrial design

AbstractDesigners are identified, in industry 4.0, as the professional figures that have to design well performing new object. In order to do this, it is necessary to take into account a series of properties called design objectives. Often the structural problem of new design is underestimated or even not considered. This can be a real problem because this objective is in competitive and in contrast with other design objectives. So, this can bring to substantial change in a design in the final phase and sometimes to the complete change. In this paper is presented an optimization workflow that adopt a Multi Objective Optimization engine so called "Octopus" and Karamba3D, that is a Finite Elements (FE) plug-in, typically used in structural simulations, these extensions run in a software: Grassopper3D, that is a parametric design tool. The workflow allows designers to explore a large range of solutions and at the same time permits to filter and sort the optimized models in order to analyze the tradeoff of the resultant solution space, both qualitatively and quantitatively. In such way designers can obtain easily a lot of information of the generate design and identify potential solution for immediate use or for further optimization. In this paper is analyzed a design problem of an ergonomic chair in order to provide the efficiency of the workflow. The design criteria and the structural problem for this type of design object are identified as the main optimization objectives in order to iteratively improve the design solutions

VALE-Emotions: Teaching mobile application for individuals with Autism Spectrum Disorders

In this paper, the development of an interactive mobile application to strengthen the learning of emotion recognition in children with Autism Spectrum Disorders (ASD) is presented. This App is part of an authoring Virtual Advanced Learning Environment (VALE) devoted to support teaching and learning activities. VALE-Emotions App is based on the six basic emotions studied by (Paul Ekman, 1992), but it is not only limited to the recognition of such emotions in their highest intensity levels. In fact, the app allows for determining the effective recognition of these emotions at different intensity levels. Such intensity levels are generated by an authoring Dynamic Facial Expressions (DFE) coding using virtual avatars. Each learning activity is carried out through training and tests applications, giving to the users the opportunity of freely developing, learning, and strengthen social skills in an entertaining way. The results of the experimentation of the VALE-Emotions on subjects with ASD are also reported. In general, the participants showed efficient response at the stimulus during the developed activities obtaining a high and fast recognition of certain emotions

A social robot connected with chatGPT to improve cognitive functioning in ASD subjects

Neurodevelopmental Disorders (NDDs) represent a significant healthcare and economic burden for families and society. Technology, including AI and digital technologies, offers potential solutions for the assessment, monitoring, and treatment of NDDs. However, further research is needed to determine the effectiveness, feasibility, and acceptability of these technologies in NDDs, and to address the challenges associated with their implementation. In this work, we present the application of social robotics using a Pepper robot connected to the OpenAI system (Chat-GPT) for real-time dialogue initiation with the robot. After describing the general architecture of the system, we present two possible simulated interaction scenarios of a subject with Autism Spectrum Disorder in two different situations. Limitations and future implementations are also provided to provide an overview of the potential developments of interconnected systems that could greatly contribute to technological advancements for Neurodevelopmental Disorders (NDD)

University Students’ Hangover May Affect Cognitive Research

open access articleUniversity students are the most employed category of participants in cognitive research. However, researchers cannot fully control what their participants do the night before the experiments (e.g., consumption of alcohol) and, unless the experiment specifically concerns the effects of alcohol consumption, they often do not ask about it. Despite previous studies demonstrating that alcohol consumption leads to decrements in next-day cognitive abilities, the potential confounding effect of hangover on the validity of cognitive research has never been addressed. To address this issue, in the present study, a test-retest design was used, with two groups of university students: at T0, one group was constituted by hungover participants, while the other group was constituted by non-hungover participants; at T1, both groups were re-tested in a non-hangover state. In particular, the tests used were two versions of a parity judgment task and an arithmetic verification task. The results highlight that: (a) the response times of university students experiencing a hangover are significantly slower than those of non-hangover students and (b) the response times of hungover students are slower than those of the same students when re-tested in a non-hangover state. Additionally, it was also observed that the prevalence of hungover students in the university campus varies depending on the day of the week, with a greater chance of enrolling hungover participants on specific days. In light of the latter result, the recruitment of university students as participants in cognitive experiments might lead researchers to erroneously attribute their results to the variables they are manipulating, ignoring the effects of the potential hangover state

Digital manipulation versus real one: learning and motivation in a case study on Storytelling

Abstract In this work, a Storytelling FabLab has been designed for the realization of virtual performances on a Shakesperian play in an elementary school. In this FabLab, many elements have been digitally manipulated: text, audio files, virtual actors on a 3D stage, and 3D Greek masks. Learning of contents and motivation have been assessed and compared to those of a traditional class working on the construction of real masks as artefacts. Regarding learning effectiveness, data show that there is no great difference between the score gained by the experimental group and the control one; however, results emphasize a high intrinsic motivation for both experimental and control groups. Moreover, qualitative results of both groups highlight the positive feeling of doing things reflecting user's own interest: pupils want to invent their own stories and realize them (physically or digitally)

It’s SNARC o’ clock: manipulating the salience of the context in a conceptual replication of Bächtold et al.’s (1998) clockface study

The Spatial-Numerical Association of Response Codes (SNARC) effect consists in faster left-/right-key responses to small/large numbers. (Bächtold et al., Neuropsychologia 36:731–735, 1998) reported the reversal of this effect after eliciting the context of a clockface—where small numbers are represented on the right and large numbers on the left. The present study investigates how the salience of a particular spatial-numerical context, which reflects the level of activation of the context in working memory, can alter Spatial Numerical Associations (SNAs). Four experiments presented the clockface as context and gradually increased its salience using different tasks. In the first two experiments (low salience), the context was presented at the beginning of the experiment and its retrieval was not required to perform the tasks (i.e., random number generation in Experiment 1, magnitude classification and parity judgement in Experiment 2). Results revealed regular left-to-right SNAs, unaffected by the context. In Experiment 3 (medium salience), participants performed magnitude classification and parity judgement (primary task), and a Go/No-go (secondary task) which required the retrieval of the context. Neither the SNARC effect nor a reversed-SNARC emerged, suggesting that performance was affected by the context. Finally, in Experiment 4 (high salience), the primary task required participants to classify numbers based on their position on the clockface. Results revealed a reversed SNARC, as in (Bächtold et al., Neuropsychologia 36:731–735, 1998). In conclusion, SNARC is disrupted when the context is retrieved in a secondary task, but its reversal is observed only when the context is relevant for the primary task

Granulocytic myeloid-derived suppressor cells increased in early phases of primary HIV infection depending on TRAIL plasma level

Background It has been demonstrated that Myeloid Derived Suppressor Cells (MDSC) are expanded in HIV-1 infected individuals and correlated with disease progression. The phase of HIV infection during which MDSC expansion occurs, and the mechanisms that regulate this expansion remain to be established. In this study we evaluated the frequency of MDSC in patients during primary HIV infection, and factors involved in MDSC control. Methods Patients with primary (PHI) and chronic (CHI) HIV infection were enrolled. PHI staging was performed according to Fiebig classification, and circulating MDSC frequency and function were evaluated by flow cytometry. Cytokine levels were evaluated by Luminex technology. Results We found that granulocytic MDSC (Gr-MDSC) frequency was higher in PHI compared to healthy donors, but lower than CHI. Interestingly, Gr-MDSC expansion was observed in the early phases of HIV infection (Fiebig II/III), but it was not associated to HIV viral load and CD4 T cell count. Interestingly, in PHI Gr-MDSC frequency was inversely correlated with plasmatic level of TRAIL, while a direct correlation was observed in CHI. Further, lower level of GMCSF was observed in PHI compared with CHI. In vitro experiments demonstrated that, differently from CHI, recombinant TRAIL induced apoptosis of Gr-MDSC from PHI, can effect that can be abrogated by GM-CSF. Conclusion We found that Gr-MDSC are expanded early during primary HIV infection and may be regulated by TRAIL and GM-CSF levels. These findings shed light on the fine mechanisms regulating the immune system during HIV infection, and open new perspectives for immune-based strategies