A measure for the missed error detection probability for optimizing the forbidden symbol configuration in joint source-channel arithmetic codes

2016 ◽  
Author(s):  
Hossein Kourkchi ◽  
William E. Lynch ◽  
M. Omair Ahmad
Keyword(s):  
Error Detection ◽  
Detection Probability ◽  
Arithmetic Codes

scholarly journals Efficacy of visual surveys for monitoring populations of talus-roosting bats

2020 ◽  
Author(s):  
Paul R Moosman ◽  
David Marsh ◽  
Emily K Pody ◽  
Mitch P Dannon ◽  
Richard J Reynolds
Keyword(s):  
Error Detection ◽  
Detection Probability ◽  
Human Error ◽  
Western North America ◽  
False Negatives ◽  
Rock Outcrops ◽  
Site Characteristics ◽  
Myotis Leibii ◽  
Sources Of Variation ◽  
Talus Slopes

Winter cave and mine surveys have been the primary method to monitor status of bat populations but they are not equally effective across regions or species. Many species of bats that roost in rock outcrops during the non-hibernation period are difficult to monitor with existing methods. Visual surveys for bats roosting on talus slopes has been proposed as a means to monitor populations, but efficacy of the method is unknown. We used standardized plot-based visual surveys to quantify presence and abundance of eastern small-footed bats Myotis leibii on talus slopes in Virginia, and studied sources of variation and error. Detection probability for talus surveys was relatively high but varied based on search effort and site characteristics. Both abundance and detection probability varied more among plots within sites than among sites or years. In trials with radio-tagged bats to study the causes of false negatives, 18% of bats roosted where surveyors could not see them, and 18% of bats were visible but overlooked due to human error. Inexperienced surveyors counted slightly fewer bats than the principal investigator, perhaps as an artifact of the dual-observer approach. There also was a slight learning curve among students. Visual surveys have strong potential to aid in the study of bats that roost in talus slopes. Talus surveys, unlike longer established methods to monitor bat populations, provide ways to assess error. We recommend using talus surveys to monitor other rock roosting bat species with poorly understood populations, such as many species in western North America.

scholarly journals A Novel Error Detection due to Joint CRC Aided Denoise-and-Forward Network Coding for Two-Way Relay Channels

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Yulun Cheng ◽  
Longxiang Yang
Keyword(s):  
Network Coding ◽  
Error Detection ◽  
Spectral Efficiency ◽  
Detection Probability ◽  
Error Probability ◽  
Relay Channels ◽  
Promising Technique ◽  
Probability Bounds ◽  
Log Likelihood ◽  
Check Method

In wireless two-way (TW) relay channels, denoise-and-forward (DNF) network coding (NC) is a promising technique to achieve spectral efficiency. However, unsuccessful detection at relay severely deteriorates the diversity gain, as well as end-to-end pairwise error probability (PEP). To handle this issue, a novel joint cyclic redundancy code (CRC) check method (JCRC) is proposed in this paper by exploiting the property of two NC combined CRC codewords. Firstly, the detection probability bounds of the proposed method are derived to prove its efficiency in evaluating the reliability of NC signals. On the basis of that, three JCRC aided TW DNF NC schemes are proposed, and the corresponding PEP performances are also derived. Numerical results reveal that JCRC aided TW DNF NC has similar PEP comparing with the separate CRC one, while the complexity is reduced to half. Besides, it demonstrates that the proposed schemes outperform the conventional one with log-likelihood ratio threshold.

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