1,721,260 research outputs found
The mirror neuron system.
No full textA category of stimuli of great importance for primates, humans in particular, is that formed by actions done by other individuals. If we want to survive, we must understand the actions of others. Furthermore, without action understanding, social organization is impossible. In the case of humans, there is another faculty that depends on the observation of others' actions: imitation learning. Unlike most species, we are able to learn by imitation, and this faculty is at the basis of human culture. In this review we present data on a neurophysiological mechanism—the mirror-neuron mechanism—that appears to play a fundamental role in both action understanding and imitation. We describe first the functional properties of mirror neurons in monkeys. We review next the characteristics of the mirror-neuron system in humans. We stress, in particular, those properties specific to the human mirror-neuron system that might explain the human capacity to learn by imitation. We conclude by discussing the relationship between the mirror-neuron system and language.A category of stimuli of great importance for primates, humans in particular, is that formed by actions done by other individuals. If we want to survive, we must understand the actions of others. Furthermore, without action understanding, social organization is impossible. In the case of humans, there is another faculty that depends on the observation of others' actions: imitation learning. Unlike most species, we are able to learn by imitation, and this faculty is at the basis of human culture. In this review we present data on a neurophysiological mechanism-the mirror-neuron mechanism-that appears to play a fundamental role in both action understanding and imitation. We describe first the functional properties of mirror neurons in monkeys. We review next the characteristics of the mirror-neuron system in humans. We stress, in particular, those properties specific to the human mirror-neuron system that might explain the human capacity to learn by imitation. We conclude by discussing the relationship between the mirror-neuron system and language
A Strong Physical Unclonable Function With Virgin State Embedded Phase Change Memory
Full text linkPhysical unclonable functions (PUFs) have gained attention in recent years due to the increasing demand for secure, compact, and power-efficient electronic devices in the Internet of Things (IoT). PUFs can provide a unique physical fingerprint to each device, which is a valuable means of enhancing security through the generation of unique and volatile cryptographic keys with no need to store them in nonvolatile memory (NVM). A major concern regarding PUF solutions for low-cost authentication is achieving robustness, a large challenge-response pair (CRP) space, and high reliability against environmental variations at the same time. In this work, we present a PUF system based on embedded phase change memory (PCM) in the virgin state with an industry-standard one-transistor/one-resistor (1T1R) cell, exploiting the wide resistance distribution as an entropy source. The PUF system is validated based on extensive physics-based simulations of embedded PCM cells integrated with 90-nm technology, showing raw reliability in temperature comparable with state-of-the-art solutions which can be further improved using dedicated schemes for the selection of reliable CRPs
A Digital Twin Proof of Concept to Support Machine Prognostics with Low Availability of Run-To-Failure Data
Full text linkThe present research illustrates a Digital Twin Proof of Concept to support machine prognostics with Low Availability of Run-to-Failure Data. Developed in the scope of the Industry 4.0 Lab of the Manufacturing Group of the School of Management of Politecnico di Milano, the Digital Twin is capable to run in parallel to the drilling machine operations and, as such, it enables to predict the evolution of the most critical failure mode, that is the imbalance in the drilling axis. The real-time monitoring of the drilling machine is realized with a low-cost and retrofit solution, which provides the installation of a Raspberry-Pi accelerometer, able to enhance the extant automation. Relying on a joint use of real-time monitoring and simulation, the Digital Twin implements a random coefficient statistical method through the so-called Exponential Degradation Model, eventually demonstrating to increase the prediction precision as monitoring data arrives. The Digital Twin Proof of Concept is described according to the entire process from data acquisition to Remaining Useful Life prediction, following the MIMOSA OSA-CBM standards
Stimulation of the dorsal premotor cortex, but not of the supplementary motor area proper, impairs the stop function in a STOP signal task
No full textBeing able to inhibit an impending movement in response to a contextual change is a distinctive feature of action control. Such inhibitory control relies on a complex cortical-subcortical network, including posterior prefrontal regions such as caudal inferior frontal gyrus and pre-supplementary motor area. According to hierarchical models of action control, both areas represent the intermediate level between prefronto-dependent and motor-related cortices. Going at a lower level, accumulating evidence speaks for an involvement of the primary motor cortex (M1) to dorsal premotor cortex (PMCd) or supplementary motor area proper (SMA-proper) pathways in producing inhibitory control. However, the clear-cut evidence for this conjecture is still missing. The aim of the present paper was to start filling this gap, investigating this lowest level of inhibitory control. We stimulated PMCd in a group of healthy volunteers with transcranial magnetic stimulation (TMS) or sham TMS during the response phase of a STOP-signal task performed with the lips. In a separate experimental group, we applied effective TMS/sham TMS to SMA-proper during the same task. We found that effective TMS over PMCd increased false-start errors in STOP trials (p=0.0005), but had no effect on GO trial performance (p=0.85). Effective TMS on SMA-proper produced no effect on STOP trials performance (p=0.31) nor in the GO trial performance (p=0.56). Our data show that there is at least a portion of PMCd playing a distinctive role in the control of mouth-related M1 during instructed visuomotor inhibitory behavior. This region could therefore represent a low-level hierarchical node for externally-cued action inhibition
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
A framework to integrate novelty detection and remaining useful life prediction in Industry 4.0-based manufacturing systems
Full text linkThe capability to predict the behaviour of machines is nowadays experiencing a tremendous growth of interest within Industry 4.0-based manufacturing systems. The route to this end is not straightforward when Run-To-Failure (RTF) data are poorly available or not available at all, thus a strategy must be properly defined. In this proposal, assuming no RTF data, a novelty detection is combined with random coefficient statistical modelling for Remaining Useful Life (RUL) prediction. This approach is formalized by means of a reference framework extending the ISO 13374–OSA-CBM standards. The framework guides the integration of novelty detection and RUL prediction finally implemented in the scope of a Flexible Manufacturing Line part of the Industry 4.0 Lab of the School of Management of Politecnico di Milano
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