1,720,968 research outputs found
A time delay model using a convolution integral to describe salmon migration, 2004
Get PDFThis study examines the use of mathematical models in understanding the migration of juvenile fall Chinook salmon of the Snake River in the Pacific Northwest. This salmon population is currently listed as threatened under the U.S. Endangered Species Act, and special management actions are required to ensure its recovery. Based on the premise that these fish showed a substantial delay in their seaward migration after being released into the river, this study develops two mathematical models and analyzes them with regard to how well each characterizes the effects of this delay on the migration rate of the fish. The specific objectives of this study are to estimate parameters and construct confidence intervals for the data, determine whether the models' results are consistent with the data through goodness-of-fit tests, and to demonstrate the important link between mathematical theory and logic and the life sciences. Data from Passive Integrated Transponders (PIT)-tagged fish released at Billy Creek, Washington state in 1995, 1997, 1998, and 2000 were fed into a simple migration model, a migration model with a delay term, and a more complex migration model combining a delay term and a fish-length term via a convolution integral. The selected model for each release always had a delay term incorporated into the migration model. Results of the study lend credence to the theory that juvenile Snake River fall Chinook salmon delay before migration and indicate that the models with a delay parameter consistently improve the fit of the model to the data. Results also demonstrate the practical benefits of applying mathematical models to analyze life science data
Bounds on distortion due to error for rates below and above the channel capacity
No full textGallager in 1965IEEE Trans. Inform. Theory IT-11, 3) gave an elegant proof of coding theorem and obtained an upper bound over the probability of error in terms of reliability function. Its dual has recently been proved by Arimoto [(1973),IEEE Trans. Inform. Theory 19, 357]. We have modified the decoding scheme by bringing in the distortion. This provides an upper bound over distortion due to error when rate distortion function is less than capacity. When rate distortion function is above capacity a lower bound on distortion due to error gives the dual for code words of any block length
Multiple decoding scheme and bounds on the probability of error and erasure over a multiple channel
Get PDFNonadditive measures of average charge for heterogeneous questionnaires
No full textMechanical and logical systems admit an ‘additivity’ law of measures. However in other systems, such as biological and social systems, this may not hold. A simple non-additive model based on λ-non-additivity is considered. We characterize average charge for heterogeneous questionnaires under λ-nonadditivity and show that there are only two forms of the measure of charge, one containing one parameter and the other two. Limiting and particular cases cover those studied earlier. The average charges are shown to be bounded below by two non-additive mean value entropies of order 1, type β and order α, type β respectively
Exponential entropy on intuitionistic fuzzy sets
Get PDFsummary:In the present paper, based on the concept of fuzzy entropy, an exponential intuitionistic fuzzy entropy measure is proposed in the setting of Atanassov's intuitionistic fuzzy set theory. This measure is a generalized version of exponential fuzzy entropy proposed by Pal and Pal. A connection between exponential fuzzy entropy and exponential intuitionistic fuzzy entropy is also established. Some interesting properties of this measure are analyzed. Finally, a numerical example is given to show that the proposed entropy measure for Atanassov's intuitionistic fuzzy set is consistent by comparing it with other existing entropies
The difference matrices of the classes of a Sharma-Kaushik partition
Get PDFsummary:Sharma-Kaushik partitions have been used to define distances between vectors with -coordinates. In this paper, “difference matrices” for the partitioning classes have been introduced and investigated. It has been shown that the difference matrices are circulant and that the entries of a product of matrices is an extended intersection number of a distance scheme. The sum of the entries of each row or columns of the product matrix has been obtained. The algebra of matrices generated by the difference matrices of the classes of an SK-partition have another natural basis. The relationship between these two bases has been given
A note on bounds for burst correcting codes with Lee weight consideration
No full textLee weight is more appropriate for some practical situations than Hamming weight. Bounds over the number of parity checks in terms of Hamming weight have been obtained, but such a detailed study is not available in terms of Lee weight. In this paper, considering Lee weight, we obtain a necessary bound over the number of parity checks to correct a message which has both clustered errors and errors in separate positions. Also there is a bound for codes correcting bursts with limited intensity
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