Neurofeedback (NF) offers potential for cognitive enhancement and brain rehabilitation, yet a substantial proportion of individuals fail to acquire self-regulation of brain activity. Task engagement, strongly linked to attentional focus and arousal, is a critical determinant of NF success. Frontal theta and alpha band oscillations, as well as pupil diameter and skin conductance responses are known to reflect attentional control, cognitive workload and arousal, all of which influence task performance. The present study investigates the relationship between frontal theta and alpha power, pupil diameter and skin conductance with performance during motor imagery NF training. By examining these multimodal physiological markers, we aimed at identifying reliable indicators of cognitive engagement and predictors of NF performance. Our findings indicate that fluctuations in NF performance are systematically associated with distinct psychophysiological changes within individuals, but also globally at a group level. Frontal theta synchronization, alpha desynchronization and pupil diameter were strongly related to NF performance. Notably, alpha desynchronization and pupil diameter emerged as significant predictors of the individual performance level, with stronger frontal alpha desynchronization and increased pupil diameter predicting higher performance. Our results suggest the potential of theta synchronization, alpha desynchronization and pupil diameter as dynamic markers of engagement and performance during NF sessions.
Components with different nature and forms are more and more integrated in the reduced space of the SIP. To ensure the required operating performances, the management of the positioning of the last components in the package becomes a key step in the design flow. In this paper, some steps of the design, conception and manufacturing process of a SIP are proposed. The choice of the package, the electronic system configuration and the integrated components natures are treated by considering the final environmental constraint of the SIP. The cavity of the package is studied to appreciate perturbations phenomena’s that can reduce the SIP performances. Particular cavity comportment is studied in accordance with the positioning of a component. The impact of the presence and location of a QFN package in the environment is analyzed with the support of EM simulations to better understand the SIP implantation step.
This paper describes a novel image encryption scheme that combines Lorenz chaotic maps, the secure Hash Algorithm 256 (SHA-256), and Discrete-Time Quantum Walks (DTQWs). It exploits their sensitivity to their initial conditions, their innate capacity to produce complex randomness, and their adaptability for rapid computational procedures. The chaotic sequences resulting from the Lorenz maps undergoes are utilized in bitwise modular addition operations, for diffusion. DTQWs develop dynamic Substitution Boxes (S-Boxes), that increase confusion by modifying the adaptability of rows/columns. To achieve stronger security, SHA-256 is used to encrypt the plaintext in successive stages, producing hash-dependent quantum coin rotation angles and thereby injects plaintext sensitivity into S-Box construction. It guarantees high-level randomness, low correlation coefficients close to zero, and high immunity to statistical and differential attacks. Outcomes demonstrate better security and computation efficiency compared to available methods, qualifying it as an efficient and reliable solution for secure image transmission within present-day communication systems.
