An enhanced linear amplification with non-linear component (ELINC) system

Author(s):  
Jian Gu
2019 ◽  
Vol 23 ◽  
pp. 233121651988761 ◽  
Author(s):  
Gilles Courtois ◽  
Vincent Grimaldi ◽  
Hervé Lissek ◽  
Philippe Estoppey ◽  
Eleftheria Georganti

The auditory system allows the estimation of the distance to sound-emitting objects using multiple spatial cues. In virtual acoustics over headphones, a prerequisite to render auditory distance impression is sound externalization, which denotes the perception of synthesized stimuli outside of the head. Prior studies have found that listeners with mild-to-moderate hearing loss are able to perceive auditory distance and are sensitive to externalization. However, this ability may be degraded by certain factors, such as non-linear amplification in hearing aids or the use of a remote wireless microphone. In this study, 10 normal-hearing and 20 moderate-to-profound hearing-impaired listeners were instructed to estimate the distance of stimuli processed with different methods yielding various perceived auditory distances in the vicinity of the listeners. Two different configurations of non-linear amplification were implemented, and a novel feature aiming to restore a sense of distance in wireless microphone systems was tested. The results showed that the hearing-impaired listeners, even those with a profound hearing loss, were able to discriminate nearby and far sounds that were equalized in level. Their perception of auditory distance was however more contracted than in normal-hearing listeners. Non-linear amplification was found to distort the original spatial cues, but no adverse effect on the ratings of auditory distance was evident. Finally, it was shown that the novel feature was successful in allowing the hearing-impaired participants to perceive externalized sounds with wireless microphone systems.


2021 ◽  
Author(s):  
Karina Loviknes ◽  
Danijel Schorlemmer ◽  
Fabrice Cotton ◽  
Sreeram Reddy Kotha

<p>Non-linear site effects are mainly expected for strong ground motions and sites with soft soils and more recent ground-motion models (GMM) have started to include such effects. Observations in this range are, however, sparse, and most non-linear site amplification models are therefore partly or fully based on numerical simulations. We develop a framework for testing of non-linear site amplification models using data from the comprehensive Kiban-Kyoshin network in Japan. The test is reproducible, following the vision of the Collaboratory for the Study of Earthquake Predictability (CSEP), and takes advantage of new large datasets to evaluate <span>whether or not</span> non-linear site effects predicted by site-amplification models are supported by empirical data. The site amplification models are tested using residuals between the observations and predictions from a GMM based only on magnitude and distance. When the GMM is derived without any site term, the site-specific variability extracted from the residuals is expected to capture the site response of a site. The non-linear site amplification models are tested against a linear amplification model on individual well-record<span>ing</span> stations. Finally, the result is compared to building codes where non-linearity is included. The test shows that for most of the sites selected as having sufficient records, the non-linear site-amplification models do not score better than the linear amplification model. This suggests that including non-linear site amplification in GMMs and building codes may not yet be justified, at least not in the range of ground motions considered in the test (peak ground acceleration < 0.2 g).</p>


1970 ◽  
Vol 7 (3) ◽  
pp. 544-564 ◽  
Author(s):  
Niels G. Becker

To explain the growth of interacting populations, non-linear models need to be proposed and it is this non-linearity which proves to be most awkward in attempts at solving the resulting differential equations. A model with a particular non-linear component, initially proposed by Weiss (1965) for the spread of a carrier-borne epidemic, was solved completely by different methods by Dietz (1966) and Downton (1967). Immigration parameters were added to the model of Weiss and the resulting model was made the subject of a paper by Dietz and Downton (1968). It is the aim here to further generalize the model by introducing birth and death parameters so that the result is a linear birth and death process with immigration for each population plus the non-linear interaction component.


2000 ◽  
Vol 111 (7) ◽  
pp. 1282-1292 ◽  
Author(s):  
Hongkui Jing ◽  
Morikuni Takigawa
Keyword(s):  

Author(s):  
Hortense Santos ◽  
◽  
Rui Dias ◽  
Paula Heliodoro ◽  
Paulo Alexandre ◽  
...  

The new coronavirus disease (Covid-19) evolved quickly from a regional health outbreak to a global collapse, stopping the global economy in a unprecedented way, creating uncertainty and chaos in the financial markets. Based on these events, it is intended in this paper to test the persistence of profitability in the financial markets of Argentina, Brazil, Chile, Colombia, Peru and Mexico, in the period between January 2018 to July 2020. In order to perform this analysis where undertaken different approaches in order to analyze if: (i) the financial markets of Latin America are efficient in their weak-form during the global pandemic (Covid-19)? ii) If so, the persistent long memories cause risks between these regional markets? The results suggest that the returns don’t follow the i.i.d. hypothesis, from dimension 2, reinforcing the idea that returns of stock indexes have a non-linear nature or a significant non-linear component, exception made to the Argentina market, which was expected in virtue of the Ljung-Box (with the return squares) test results, and ARCH-LM. Corroborating the exponents Detrended Fluctuation Analysis (DFA), indicate the presence of persistent long memories, namely into the following markets: Colombia (0.72), Chile (0.66), Brazil (0.58) and Peru (0.57). The Argentina market does not reject the random walk hypothesis, while the Mexican market suggests some anti-persistence (0.41). This situation has implications for investors, once that some returns can be expected, creating arbitration opportunities and abnormal income, contrary to the supposed from the random walk hypothesis and information efficiency. The t-test results of the heteroscedasticity form the two samples suggest that there is no risk transmission between these regional markets, with the exception to the BOVESPA / BOLSAA MX markets, that is, the existence of persistent long memories in the returns does not imply the risk transmission between markets. These finds allow the creation of strategies of diversification inefficient portfolios. These conclusions also open space for the market regulators to implement measures that guarantee a better informational information of these regional markets.


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