scholarly journals DETECTION OF A HARMONIC SIGNAL AGAINST THE BACKGROUND OF A NONSTATIONARY GAUSSIANINTERFERENCE WITH COMPLEX SPECTRUM

2021 ◽  
pp. 5-15
Author(s):  
Igor Prokopenko ◽  
Igor Omelchuk ◽  
Anastasiia Dmytruk ◽  
Yuliia Petrova
Keyword(s):  
Bayesian Approach ◽  
Adaptive Algorithm ◽  
Harmonic Signal ◽  
Adaptive Signal Processing ◽  
Radar Signal ◽  
Complex Spectrum ◽  
Complex Frequency ◽  
Two Dimensional ◽  
Empirical Bayesian ◽  
Empirical Bayesian Approach

Background. Modern radar stations for various purposes operate in the conditions of interference created by the imprints of the radar signal from the background surface, from metrological formations (precipitation, clouds, etc.) and artificial radiation sources. Ensuring the operation of the radar in such difficult conditions requires the construction of adaptive signal processing algorithms that have high efficiency and maintain them when changing signal-to-noise situations. Objective. The purpose of the paper is creation of an adaptive algorithm for detecting a harmonic signal against the background of spatially correlated interference and estimating its parameters. Methods. Construction of a two-dimensional autoregressive model of a mixture of correlated spatial noise and harmonic signal and application of the empirical Bayesian approach to the synthesis of an adaptive algorithm for detecting and evaluating signal and noise parameters. Results. A two-dimensional adaptive space-time algorithm for detecting a radar signal reflected from a moving target against the background of a space-correlated interference is synthesized. The analysis of the efficiency of the algorithm by the Monte Carlo method is carried out. Conclusions. It is shown that the empirical Bayesian approach is an effective working methodology in solving the problem of detecting a harmonic signal and estimating its parameters under conditions of interference with a complex frequency spectrum under different conditions of a priori uncertainty of their parameters.

scholarly journals An empirical Bayesian approach to incorporate directional movement information from a forage fish into the Arnason-Schwarz mark-recapture model

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Mary A. Bishop ◽  
Jordan W. Bernard
Keyword(s):  
Bayesian Approach ◽  
Gulf Of Alaska ◽  
Forage Fish ◽  
Pacific Herring ◽  
Prince William Sound ◽  
Modeling Framework ◽  
Empirical Bayesian ◽  
Directional Information ◽  
Directional Movement ◽  
Empirical Bayesian Approach

Abstract Background Over the past two decades, various species of forage fish have been successfully implanted with miniaturized acoustic transmitters and subsequently monitored using stationary acoustic receivers. When acoustic receivers are configured in an array, information related to fish direction can potentially be determined, depending upon the number and relative orientation of the acoustic receivers. However, it can be difficult to incorporate directional information into frequentist mark-recapture methods. Here we show how an empirical Bayesian approach can be used to develop a model that incorporates directional movement information into the Arnason-Schwarz modeling framework to describe survival and migration patterns of a Pacific herring (Clupea pallasii) population in coastal Alaska, USA. Methods We acoustic-tagged 326 adult Pacific herring during April 2017 and 2018 while on their spawning grounds in Prince William Sound Alaska, USA. To monitor their movements, stationary acoustic receivers were deployed at strategic locations throughout the Sound. Receivers located at the major entrances to the Gulf of Alaska were arranged in parallel arrays to determine the directional movements of the fish. Informative priors were used to incorporate the directional information recorded at the entrance arrays into the model. Results A seasonal migratory pattern was found at one of Prince William Sound’s major entrances to the Gulf of Alaska. At this entrance, fish tended to enter the Gulf of Alaska during spring and summer after spawning and return to Prince William Sound during the fall and winter. Fish mortality was higher during spring and summer than fall and winter in both Prince William Sound and the Gulf of Alaska. Conclusions An empirical Bayesian modeling approach can be used to extend the Arnason-Schwarz modeling framework to incorporate directional information from acoustic arrays to estimate survival and characterize the timing and direction of migratory movements of forage fish.

scholarly journals An Empirical Bayesian Approach to Item Banking

1986 ◽  
Vol 10 (4) ◽  
pp. 345-354 ◽  
Author(s):  
Wim J. van der Linden ◽  
Theo J. H. M. Eggen
Keyword(s):  
Bayesian Approach ◽  
Empirical Bayesian ◽  
Empirical Bayesian Approach

scholarly journals An empirical bayesian approach for testing gene expression fold change and its application in detecting global dosage effects

2020 ◽  
Vol 2 (3) ◽  
Author(s):  
Zhenxing Guo ◽  
Ying Cui ◽  
Xiaowen Shi ◽  
James A Birchler ◽  
Igor Albizua ◽  
...  
Keyword(s):  
Gene Expression ◽  
Change Detection ◽  
Bayesian Approach ◽  
Variance Estimation ◽  
T Test ◽  
Fold Change ◽  
Empirical Bayesian ◽  
Biological Studies ◽  
Fold Change Detection ◽  
Empirical Bayesian Approach

Abstract We are motivated by biological studies intended to understand global gene expression fold change. Biologists have generally adopted a fixed cutoff to determine the significance of fold changes in gene expression studies (e.g. by using an observed fold change equal to two as a fixed threshold). Scientists can also use a t-test or a modified differential expression test to assess the significance of fold changes. However, these methods either fail to take advantage of the high dimensionality of gene expression data or fail to test fold change directly. Our research develops a new empirical Bayesian approach to substantially improve the power and accuracy of fold-change detection. Specifically, we more accurately estimate gene-wise error variation in the log of fold change. We then adopt a t-test with adjusted degrees of freedom for significance assessment. We apply our method to a dosage study in Arabidopsis and a Down syndrome study in humans to illustrate the utility of our approach. We also present a simulation study based on real datasets to demonstrate the accuracy of our method relative to error variance estimation and power in fold-change detection. Our developed R package with a detailed user manual is publicly available on GitHub at https://github.com/cuiyingbeicheng/Foldseq.

Hierarchical modeling of sequential behavioral data: An empirical Bayesian approach.

2002 ◽  
Vol 7 (2) ◽  
pp. 262-280 ◽  
Author(s):  
Getachew A. Dagne ◽  
George W. Howe ◽  
C. Hendricks Brown ◽  
Bengt O. Muthén
Keyword(s):  
Bayesian Approach ◽  
Hierarchical Modeling ◽  
Behavioral Data ◽  
Empirical Bayesian ◽  
Empirical Bayesian Approach

A regional meta-model for stock–recruitment analysis using an empirical Bayesian approach

2002 ◽  
Vol 59 (9) ◽  
pp. 1503-1514 ◽  
Author(s):  
D G Chen ◽  
L Blair Holtby
Keyword(s):  
Bayesian Approach ◽  
Prior Distribution ◽  
Coho Salmon ◽  
Population Diversity ◽  
Empirical Bayesian ◽  
Meta Model ◽  
Resource Managers ◽  
Stock Recruitment ◽  
Two Parameters ◽  
Empirical Bayesian Approach

A regional stock–recruitment meta-model is developed using a hierarchical Bayesian framework to combine information from multiple fish populations. The use of the meta-model is illustrated through analysis of the regional stock–recruitment parameters of the coho salmon (Oncorhynchus kisutch) within two large fisheries management units in southern and northern British Columbia. We construct our regional prior distribution from an analysis of all stock-recruitment data rather than by the more usual approach of assuming a prior distribution. That preliminary analysis indicated that the regional prior distribution for the two parameters of the Ricker model was bivariate normal–lognormal (NLN) with a high degree of correlation between the two Ricker parameters. Because this distribution had not been fully developed, we formulated the density function for the NLN distribution and proved some of its important properties. An empirical Bayesian approach was then used to estimate the regional distributions of the Ricker parameters and derived management parameters. Characterization of the distributional properties of productivity within management regions is a necessary step for resource managers seeking to prosecute mixed-stock fisheries while conserving population diversity.

scholarly journals Exchange Rate Uncertainty and Workers’ Remittances: Empirical Bayesian Approach

2019 ◽  
Vol 3 (2) ◽  
pp. 90-109
Author(s):  
Muhammad Jalib Sikandar ◽  
Hafiz Muhammad Yasin ◽  
Malik Muhammad
Keyword(s):  
Exchange Rate ◽  
Bayesian Approach ◽  
Negative Impact ◽  
Host Countries ◽  
Empirical Bayesian ◽  
Exchange Rate Uncertainty ◽  
Country Level ◽  
Country Characteristics ◽  
Empirical Bayesian Approach

Exchange rate is one of the important determinates of worker’s remittances to a country. Level of exchange rate as well as any fluctuation in it influences the volume of workers’ remittances. The present study uses data of workers’ remittances from ten major countries to Pakistan for the period 1973 to 2012. Uncertainty of exchange rate is estimated through GARCH model. We use Empirical Bayesian approach to compute posterior information (estimates, for which, the GMM estimates are used as prior in order to avoid biasness and inconsistency due to the presence of endogeniety in our model. The Empirical Bayesian estimates are found to be more efficient in terms of significance and correct signs of modeled variables. The findings suggest a significant role of home and host country characteristics in most of the cases. The findings also reveal a negative impact of exchange rate uncertainty on the inflow of remittances. The political instability reveals an insignificant impact on remittances. The study recommends different policy options for different host countries. Apart from the Middle East, the policy for other regions (like USA, Canada, and Germany etc.) must be considered separately to encourage inflow of remittances. Appropriate stabilization measures have to be taken on priority basis to curtail volatility of exchange rates and to ascertain regular inflow of remittances. 

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