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This paper presents an efficient method for recovery of SIMS signals from strongly noised blurred discrete data. This technique is based on Tikhonov-Miller regularization where a priori model of solution is included. The latter is a denoisy signal obtained using the Kalman filter. This is an interesting estimation method, but it can only be used when the system is described precisely. By comparing the results of the proposed technique with those of the literature, our algorithm gives the best results without artifacts and oscillations related to noise and significant improvement of the depth resolution. While, the gain in FWHM is less improved than those obtained by the wavelet technique. Therefore, this new algorithm can push the limits of SIMS measurements towards its ultimate resolution. [ABSTRACT FROM AUTHOR]

This work is mainly on the detection of the bulk acoustic waves (BAWs), where we have compared two Lithium Niobate cuts (Y-Z and Y-X), during the propagation of the acoustic microwaves in the piezoelectric LiNbO3-substrate. In this paper, we have used the classification by Probabilistic Neural Network (PNN) as a tool for numerical analysis in which we classify all the values of the real and imaginary parts of the attenuation coefficient for the propagation velocity. This analysis can allow us to demonstrate the best possibility in utilization for the BAW generation. This study will be very interesting in modeling and realization of acoustic wave devices (ultrasound) based on the propagation of acoustic microwaves. Keywords: Acoustics microwaves, Bulk waves, Piezoelectric material, Probabilistic Neural Network (PNN), The attenuation coefficient

In this paper the case of finite users in Slotted Aloha System is studied, the scheme of two channels, uplink and downlink in satellite communication in presented, the error probability, signal to signal plus interference ratio and the probability of a successful transmission using the CDMA Model are also presented. [ABSTRACT FROM AUTHOR]

The aim of this paper is the improvement of slotted Aloha performance, using Reed- Solomon erasure coding scheme, this technique can be used in Satellite communication to recover lost packets. Although erasure coding increases offered load, the probability of successful packet transmission can also be increased. An approach to define the behavior of throughput of erasure scheme based on fitting method is presented. The results obtained give a best approximation with polynomial form of throughput in function of the offered load. [ABSTRACT FROM AUTHOR]

In this paper we propose a study based on the model of Markov chain, to define optimal binomial distribution probabilities of retransmission and arrival packets, in the case of random multiple access protocol (slotted Aloha), to describe their evolution in function of the number of transmissions in a slot time, with parameters, probabilities of backlogged and generation packets, this permits us to define the average packet delay and the throughput which is the main parameter of random multiple access model, and see the effect of the increase of the number of sources. [ABSTRACT FROM AUTHOR]

In this paper, the analysis of pseudo-singularities (corresponding to rapid variations) which appear in some parameters during the propagation of acoustic microwaves in a piezoelectric substrate is considered. These pseudo-singularities have a major importance because they can inform of the presence of bulk waves. However, there is a problem for the detection of the waves when the pseudo-singularities exist but is unobservable with the classical methods. To solve this problem, it is proposed that a new technique of detection based on the famous wavelet transform. This transform insures the detection of pseudo-singularities because it has the property of being locally maximal around the points where the signal is singular (or pseudo-singular). [ABSTRACT FROM AUTHOR]

To effectively respond to an emerging infectious disease outbreak, policymakers need timely and accurate measures of disease prevalence in the general population. This paper presents a new methodology to estimate real-time population infection rates from non-random testing data. The approach compares how the observed positivity rate varies with the size of the tested population and applies this gradient to infer total population infections. Applying this methodology to daily testing data across U.S. states during the first wave of the COVID-19 pandemic, we estimated widespread undiagnosed COVID-19 infections. Nationwide, we found that for every identified case, there were 12 population infections. Our prevalence estimates align with results from seroprevalence surveys, alternate approaches to measuring COVID-19 infections, and total excess mortality during the first wave of the pandemic., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Benatia et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

This article estimates population infection rates from coronavirus disease 2019 (COVID-19) across four Canadian provinces from late March to early May 2020. The analysis combines daily data on the number of conducted tests and diagnosed cases with a methodology that corrects for non-random testing. We estimate the relationship between daily changes in the number of conducted tests and the fraction of positive cases in the non-random sample (typically less than 1 percent of the population) and apply this gradient to extrapolate the predicted fraction of positive cases if testing were expanded to the entire population. Over the sample period, the estimated population infection rates were 1.7-2.6 percent in Quebec, 0.7-1.4 percent in Ontario, 0.5-1.2 percent in Alberta, and 0.2-0.4 percent in British Columbia. In each province, these estimates are substantially below the average positive case rate, consistent with non-random testing of higher-risk populations. The results also imply widespread undiagnosed COVID-19 infection. For each identified case by mid-April, we estimate there were roughly 12 population infections., (© Canadian Public Policy / Analyse de politiques.)