11 research outputs found
Method and apparatus for detecting a fall by a user
According to an aspect, there is provided a fall detection apparatus for detecting a fall by a user, the fall detection apparatus comprising a processing unit configured to: receive measurements of movements of the user over time from a first movement sensor that is to be worn or carried by the user; determine if any of one or more objects are being carried or used by the user; and determine whether the user has fallen by processing the received measurements of the movements of the user and measurements of movements of any object that is being carried or used by the user
TĂ©moignage
Journaliste littéraire, plus informateur donc que critique, je ressens une contradiction entre d’une part l’immensité d’un pays comme le Brésil, sa diversité correspondant à la diversité et à la quantité de ce qui s’y écrit et publie, et d’autre part le mince filet auquel cela se réduit en France. Je ne possède pas le chiffre annuel des traductions de livres brésiliens, mais je suppose qu’il est faible... La contradiction dont je parle ne peut à mon sens aboutir qu’à une déformation, à une si..
Depoimento
Jornalista literário, portanto voltado mais para a informação do que para a crĂtica, percebo uma contradição entre, de um lado, a imensidĂŁo de um paĂs como o Brasil, sua heterogeneidade manifesta na diversidade e na quantidade do que lá se escreve e publica e, de outro, o inexpressivo quadro a que isto se reduz na França. NĂŁo possuo o montante anual de traduções de livros brasileiros, mas suponho que Ă© insignificante... No meu entender a contradição de que falo sĂł pode levar a uma deformação,..
On the partial Haar dual adaptive filter for sparse echo cancellation
Typical sparse echo cancellers employ adaptive filtering algorithms that, update only a small number of filter coefficients that, produce the actual echo. Usually, these algorithms provide increased convergence speed at the cost of an increase in computational complexity for locating these significant filter coefficients. Recently, a coupled echo canceller was proposed that uses two short adaptive filters in tandem. The first adaptive filter operates in the partial Haar domain and is solely used to estimate the location of the channel's dispersive region. A short time-domain filter is then centred around this estimate to cancel echo. Using two short filters instead of one long filter not only reduces computational complexity, while substantially increasing the convergence speed of the echo canceller.The focus of this thesis is twofold. First, it analyzes the partial Haar echo canceller and attempts to clarify some issues with its implementation. Second and foremost, it, identifies and proposes feasible solutions to three inherent weaknesses of the coupled echo canceller. These include alleviating the adverse effect caused by the shift-variant property of wavelets, improving the tracking performance of the coupled echo canceller in response to abrupt changes in the echo path impulse response, and extending the original echo canceller to support the cancellation of multiple echoes. Simulations support the resulting improvements when each of the proposed solutions is incorporated into the coupled echo canceller
Robustness analysis of speech enhancement using a bone conduction microphone - Preliminary results
Previously, the use of a bone-conducting sensor worn on the neck was shown to improve the performance of a codebook-based speech enhancement system for non-stationary noise suppression, while reducing computational complexity. This system relies on a mapping between bone-conducted and air-conducted signals that is learned during an offline training phase for a certain location of the sensors. Signal properties such as speech intensity, quality, and intelligibility are more location-dependent for a bone-conducting sensor. This paper studies aspects of robustness related to location-errors between the original training location and those used in practice. The two main regions considered for sensor placement are the neck and temple areas to understand the benefits and tradeoff between higher signal-to-noise ratio (neck) and higher speech intelligibility (temple) for such a system
Model-based speech enhancement using a bone-conducted signal
Codebook-based single-microphone noise suppressors, which exploit prior knowledge about speech and noise statistics, provide better performance in nonstationary noise. However, as the enhancement involves a joint optimization over speech and noise codebooks, this results in high computational complexity. A codebook-based method is proposed that uses a reference signal observed by a bone-conduction microphone, and a mapping between air- and bone-conduction codebook entries generated during an offline training phase. A smaller subset of air-conducted speech codebook entries that accurately models the clean speech signal is selected using this reference signal. Experiments support the expected improvement in performance at low computational complexit
Effects of noise on arousal in a speech communication setting
Speech communication in natural environments is often impaired by varying levels of ambient noise. Such noise can reduce speech intelligibility and make conversations more effortful, consequently causing an increase in arousal, frustration or stress in the partaking speakers. This contribution investigates the effects of background noise on arousal in a speech communication setting using collaborative tasks and examines the measurability of such detrimental effects through physiological signals – heart rate variability and skin conductance. We focus on the differences in responses between the various noise conditions aiming to establish the sensitivity of the employed physiological measures. Furthermore, self-reported mental effort scores are used to assess the dependency of subjective mental effort requirements on background noise for the examined communication setting. Our results indicate that while mental effort scores show a significant positive relationship with background noise level, skin conductance and heart rate variability features, which are commonly employed for arousal state detection, may be inappropriate and lack sensitivity to distinguish communication settings differing solely by the level of background noise
Robustness improvement of ultrasound-based sensor systems for speech communication
\u3cp\u3eIn recent years, auxiliary sensors have been employed to improve the robustness of emerging hands-free speech communication systems based on air-conduction microphones, especially in low signal-to-noise-ratio environments. One such sensor, based on ultrasound, captures articulatory movement information during speech production and has been used in a voice activity detector and also shown to improve the performance of speech recognizers. However, studies thus far have tested such sensors in ideal scenarios where only relevant ar-ticulatory information was assumed to be present. Therefore, in this paper the robustness of such sensors in realistic scenarios is investigated. Challenges arising from non-articulatory movements and other environmental influences captured by ultrasound sensors are discussed and strategies for their detection presented. Finally, the proposed strategies are evaluated in an ultrasound-based voice activity detector.\u3c/p\u3
Method and apparatus for detecting a fall by a user
According to an aspect, there is provided a fall detection apparatus for detecting a fall by a user, the fall detection apparatus comprising a processing unit configured to: receive measurements of movements of the user over time from a first movement sensor that is to be worn or carried by the user; determine if any of one or more objects are being carried or used by the user; and determine whether the user has fallen by processing the received measurements of the movements of the user and measurements of movements of any object that is being carried or used by the user