Search results for "Synchronization"
showing 10 items of 248 documents
Understanding the Role of Sensorimotor Beta Oscillations
2021
Beta oscillations have been predominantly observed in sensorimotor cortices and basal\ud ganglia structures and they are thought to be involved in somatosensory processing\ud and motor control. Although beta activity is a distinct feature of healthy and pathological\ud sensorimotor processing, the role of this rhythm is still under debate. Here we review\ud recent findings about the role of beta oscillations during experimental manipulations (i.e.,\ud drugs and brain stimulation) and their alteration in aging and pathology. We show how\ud beta changes when learning new motor skills and its potential to integrate sensory input\ud with prior contextual knowledge. We conclude by discussing a n…
Smart switching in feedforward control of grip force during manipulation of elastic objects
2017
AbstractSwitching systems are common in artificial control systems. Here, we suggest that the brain adopts a switched feedforward control of grip forces during manipulation of objects. We measured how participants modulated grip force when interacting with soft and rigid virtual springs when stiffness varied nearly continuously between trials. We identified a sudden phase transition between two forms of feedforward control that differed in the timing of the synchronization between the anticipated load force and the applied grip force. The switch occurred several trials after a threshold stiffness level. These results suggest that in the control of grip force, the brain acts as a switching c…
Improved superresolution in coherent optical systems.
2001
Objects that temporally vary slowly can be superresolved by the use of two synchronized moving masks such as pinholes or gratings. This approach to superresolution allows one to exceed Abbe’s limit of resolution. Moreover, under coherent illumination, superresolution requires a certain approximation based on the time averaging of intensity rather than of field distribution. When extensive digital postprocessing can be incorporated into the optical system, a detector array and some postprocessing algorithms can replace the grating that is responsible for information decoding. In this way, no approximation is needed and the synchronization that is necessary when two gratings are used is simpl…
Towards a method to generate GUI prototypes from BPMN
2018
Business Process Model and Notation (BPMN) provides organizations with a standard that facilitates further compression of the business process. BPMN focuses on the functional processes, leaving the development of interfaces to one side. Thereby, interface design usually depends on the subjective experience of the analyst. This article aims to propose a new method to generate user interfaces from BPMN models and Class Diagrams. The proposed method is based on the identification of different rules and makes use of stereotypes to extend BPMN notation. The rules have been extracted from seven existing projects on the Bizagi repository. Specifically, the proposal is based on the extraction of ru…
Superresolving optical system with time multiplexing and computer decoding
2008
Objects that have slow temporal variations may be superresolved with two moving masks such as pinhole or grating. The first mask is responsible for encoding the input image, and the second one performs the decoding operation. This approach is efficient for exceeding the resolving capability beyond Abbe’s limit of resolution. However, the proposed setup requires two physical gratings that should move in a synchronized manner. We propose what is believed to be a novel configuration in which the second grating responsible for the information decoding is replaced with a detector array and some postprocessing digital procedures. In this way the synchronization problem that exists when two gratin…
DTMC modeling for performance evaluation of DW-MAC in wireless sensor networks
2016
Synchronized duty cycling (DC) aligns sensor nodes to wake up at the same time in order to reduce idle listening for medium access control (MAC) in wireless sensor networks (WSNs). Demand wakeup MAC (DW-MAC) is a popular synchronous DC MAC protocol which allows nodes to compete and transmit multiple packets in one operational cycle. This multiple packet transmission (MPT) feature makes DW-MAC more energy efficient when comparing with other existing single time competition based protocols such as sensor MAC (S-MAC). In the literature, no analytical model exists to evaluate the performance of DW-MAC. In this paper, we develop two associated discrete time Markov chain (DTMC) models and incorpo…
Learning from Errors: Detecting ZigBee Interference in WiFi Networks
2014
In this work we show how to detect ZigBee interference on commodity WiFi cards by monitoring the reception errors, such as synchronization errors, invalid header formats, too long frames, etc., caused by ZigBee transmissions. Indeed, in presence of non-WiFi modulated signals, the occurrence of these types of errors follows statistics that can be easily recognized. Moreover, the duration of the error bursts depends on the transmission interval of the interference source, while the error spacing depends on the receiver implementation. On the basis of these considerations, we propose the adoption of hidden Markov chains for characterizing the behavior of WiFi receivers in presence of controlle…
A possible easy way to predict response to cardiac resynchronization therapy: The role of QRS Index
2023
Background: Some studies have evaluated the role of QRS duration (QRSd) as predictor of response to Cardiac Resynchronization Therapy (CRT). However, their results are still not entirely clear. The goal of our study was to determine the correlation between the relative change in QRS narrowing index (QI) compared to clinical outcome and prognosis in patients who underwent CRT implantation. Methods: We collected clinical and echocardiographic data of 115 patients in whome a CRT device was implanted in accordance with current guidelines. QRS duration before and after CRT implantation and QI were measured. Results: After 6 months, a signifi cant improvement in all echocardiographic parameters w…
Reproducibility of Rolandic beta rhythm modulation in MEG and EEG
2022
The Rolandic beta rhythm, at ∼20 Hz, is generated in the somatosensory and motor cortices and is modulated by motor activity and sensory stimuli, causing a short lasting suppression that is followed by a rebound of the beta rhythm. The rebound reflects inhibitory changes in the primary sensorimotor (SMI) cortex, and thus it has been used as a biomarker to follow the recovery of patients with acute stroke. The longitudinal stability of beta rhythm modulation is a prerequisite for its use in long-term follow-ups. We quantified the reproducibility of beta rhythm modulation in healthy subjects in a 1-year-longitudinal study both for MEG and EEG at T0, 1 month (T1-month, n = 8) and 1 year (T1-ye…