Uncertainty analyses of the behaviour of the Carolina locust, Dissosteira Carolina (Orthoptera: Acrididae)

1978 ◽  
Vol 56 (2) ◽  
pp. 201-214 ◽  
Author(s):  
Gordon E. Kerr
Keyword(s):  
Information Transmission ◽  
Markov Processes ◽  
The Other ◽  
Likelihood Approximation ◽  
Bidirectional Communication ◽  
Log Likelihood ◽  
Low Diversity ◽  
Uncertainty Analyses

Uncertainty analyses of sequences of actions by wild Dissosteira Carolina gave average uncertainties (Ĥ) of 2.4 male and 1.9 female bits/act in all contexts. Noninteracting males show low diversity and insignificant between-act predictability (log-likelihood approximation). Males interacting with males or females had higher uncertainties and significant between-act predictabilities. In male–male interactions, approaching and responding animals were nearly equivalent and Ĥ(I) was 2.02 bits/act for both. Three-way analysis showed that the effect of an animal's last act was slightly lower than that of the other animal's last act with some overlap. Bidirectional-communication and character analyses were also performed. Male–male interactions are neither stationary nor Markov processes. In male–female interactions, males had much higher uncertainties than females (2.25 versus 0.83 bits/act) and interanimal information transmission was very low.

On two classes of interacting stochastic processes arising in cancer modeling

1983 ◽  
Vol 15 (4) ◽  
pp. 695-712 ◽  
Author(s):  
Robert Bartoszyński ◽  
Prem S. Puri
Keyword(s):  
Markov Processes ◽  
Branching Processes ◽  
The Other ◽  
Time Interval ◽  
Positive Probability ◽  
Martingale Convergence Theorem ◽  
Limiting Behavior ◽  
State Dependent ◽  
Cancer Modeling ◽  
Martingale Convergence

The processes X and Y are said to interact if the laws governing the changes of either of them at time t depend on the values of the other process at times up to t. For bivariate interacting Markov processes, their limiting behavior is analysed by means of an approximation suggested by Fuhrmann, consisting of discretizing time, and assuming that in each time interval the processes develop independently, according to the laws obtained by fixing the value of the other process at its level attained at the beginning of the interval.In this way the conditions for almost sure extinction, escape to ∞ with positive probability, etc., are obtained (by using the martingale convergence theorem) for state-dependent branching processes studied by Roi, and for bivariate processes with one component piecewise determined.

scholarly journals Controlled Bidirectional Quantum Secure Direct Communication

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Yao-Hsin Chou ◽  
Yu-Ting Lin ◽  
Guo-Jyun Zeng ◽  
Fang-Jhu Lin ◽  
Chi-Yuan Chen
Keyword(s):  
Quantum Information ◽  
Secure Communication ◽  
Quantum Secure Direct Communication ◽  
The Other ◽  
Secret Message ◽  
Quantum Bits ◽  
Legitimate User ◽  
Quantum Secure Communication ◽  
Bidirectional Communication ◽  
The Cost

We propose a novel protocol for controlled bidirectional quantum secure communication based on anonlocal swapgate scheme. Our proposed protocol would be applied to a system in which a controller (supervisor/Charlie) controls the bidirectional communication with quantum information or secret messages between legitimate users (Alice and Bob). In this system, the legitimate users must obtain permission from the controller in order to exchange their respective quantum information or secret messages simultaneously; the controller is unable to obtain any quantum information or secret messages from the decoding process. Moreover, the presence of the controller also avoids the problem of one legitimate user receiving the quantum information or secret message before the other, and then refusing to help the other user decode the quantum information or secret message. Our proposed protocol is aimed at protecting against external and participant attacks on such a system, and the cost of transmitting quantum bits using our protocol is less than that achieved in other studies. Based on thenonlocal swapgate scheme, the legitimate users exchange their quantum information or secret messages without transmission in a public channel, thus protecting against eavesdroppers stealing the secret messages.

scholarly journals Stochastic Analysis of a Two-Unit Cold Standby System Wherein Both Units May Become Operative Depending upon the Demand

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Reetu Malhotra ◽  
Gulshan Taneja
Keyword(s):  
Markov Processes ◽  
Stochastic Analysis ◽  
The Other ◽  
Regenerative Processes ◽  
Cold Standby ◽  
Standby System ◽  
Semi Markov Processes ◽  
System Effectiveness

The present paper analyzes a two-unit cold standby system wherein both units may become operative depending upon the demand. Initially, one of the units is operative while the other is kept as cold standby. If the operative unit fails or the demand increases to the extent that one operative unit is not capable of meeting the demand, the standby unit becomes operative instantaneously. Thus, both units may become operative simultaneously to meet the increased demand. Availability in three types of upstates is as follows: (i) when the demand is less than or equal to production manufactured by one unit; (ii) when the demand is greater than whatever produced by one unit but less than or equal to production made by two units; and (iii) when the demand is greater than the produces by two units. Other measures of the system effectiveness have also been obtained in general case as well as for a particular case. Techniques of semi-Markov processes and regenerative processes have been used to obtain various measures of the system effectiveness.

scholarly journals The Exponentiated Gumbel Type-2 Distribution: Properties and Application

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
I. E. Okorie ◽  
A. C. Akpanta ◽  
J. Ohakwe
Keyword(s):  
Lifetime Distribution ◽  
The Other ◽  
Maximum Likelihood Estimates ◽  
Model Parameters ◽  
Lifetime Data ◽  
Data Set ◽  
Method Of Maximum Likelihood ◽  
Log Likelihood ◽  
New Distribution

We introduce a generalized version of the standard Gumble type-2 distribution. The new lifetime distribution is called the Exponentiated Gumbel (EG) type-2 distribution. The EG type-2 distribution has three nested submodels, namely, the Gumbel type-2 distribution, the Exponentiated Fréchet (EF) distribution, and the Fréchet distribution. Some statistical and reliability properties of the new distribution were given and the method of maximum likelihood estimates was proposed for estimating the model parameters. The usefulness and flexibility of the Exponentiated Gumbel (EG) type-2 distribution were illustrated with a real lifetime data set. Results based on the log-likelihood and information statistics values showed that the EG type-2 distribution provides a better fit to the data than the other competing distributions. Also, the consistency of the parameters of the new distribution was demonstrated through a simulation study. The EG type-2 distribution is therefore recommended for effective modelling of lifetime data.

A pre-trilobite shelly fauna from the White–Inyo region of eastern California and western Nevada

1987 ◽  
Vol 61 (3) ◽  
pp. 425-438 ◽  
Author(s):  
Philip W. Signor ◽  
Jeffrey F. Mount ◽  
Beth R. Onken
Keyword(s):  
Original Composition ◽  
Siberian Platform ◽  
The Other ◽  
Acid Digestion ◽  
Low Diversity ◽  
Stratigraphic Interval

A low-diversity shelly fauna occurs in the Deep Spring Formation of the White–Inyo Mountains of eastern California and in Esmeralda County, Nevada. Although poorly preserved, specimens can be recovered through acid digestion of the limestone matrix. The fauna is composed of three tubes of uncertain affinities and a hyolith.Nevadatubulus dunfeein. gen. and sp., a distinctive, randomly curved and annulated tube, is abundant and far outnumbers the remaining three elements:Coleoloides inyoensisn. sp.,Sinotubulites cienegensisMcMenamin, and the hyolith Salanytheca sp. The original composition of the faunal elements appears to have been calcite or aragonite, but recrystallization has destroyed any ultrastructure. No phosphatic elements occur with the fauna nor have phosphatic fossils been recovered from the underlying Wyman and Reed Formations or the other members of the Deep Spring Formation.The fauna occurs 1,500 meters below the first trilobite body fossils and may be coeval with faunas from the basal Cambrian Tommotian Stage of the Siberian Platform.Wyattia, the only previously described pre-trilobite shelly fossil from the region, occurs in approximately the same stratigraphic interval but was not recovered in our samples.

scholarly journals Weak Identification in Maximum Likelihood: A Question of Information

2014 ◽  
Vol 104 (5) ◽  
pp. 195-199 ◽  
Author(s):  
Isaiah Andrews ◽  
Anna Mikusheva
Keyword(s):  
Maximum Likelihood ◽  
Fisher Information ◽  
Quadratic Variation ◽  
The Other ◽  
Asymptotic Approximations ◽  
Dsge Model ◽  
Weak Identification ◽  
Log Likelihood

In this paper we connect the discrepancy between two estimates of Fisher information, one based on the quadratic variation of the score and the other based on the negative Hessian of the log-likelihood, to weak identification. Classical asymptotic approximations assume that these two estimates are asymptotically equivalent, but we show that this equivalence fails in many weakly identified models, which can distort the behavior of the MLE. Using a stylized DSGE model we show that the discrepancy between information estimates is large when identification is weak.

scholarly journals Benthic Macrofauna Associated with Submerged Bottoms of a Tectonic Estuary in Tropical Eastern Pacific

2011 ◽  
Vol 2011 ◽  
pp. 1-13 ◽  
Author(s):  
Carlos E. Guevara-Fletcher ◽  
Jaime R. Cantera Kintz ◽  
Luz M. Mejía-Ladino ◽  
Fabián A. Cortés
Keyword(s):  
Dissolved Oxygen ◽  
Pacific Coast ◽  
Abiotic Factors ◽  
Fine Sand ◽  
Benthic Macrofauna ◽  
The Other ◽  
Tropical Eastern Pacific ◽  
Low Diversity ◽  
Soft Bottoms ◽  
Hard Substrates

The composition and distribution of the main associations of submerged macrobenthos ofBahía Málaga(Colombian pacific coast), were studied in relation to the distribution of hard and soft substrates and some abiotic factors. Eight localities were sampled during six months: three in the external border of the estuary and five in the inner part. In total, 728 organisms were registered, belonging to 207 species, 132 genera, 86 families, and 14 orders of six invertebrate groups (Porifera, Cnidaria, Polychaeta, Mollusca, Crustacea, and Echinodermata). The submerged bottoms presented soft and hard substrates, with rocks and thick sand in five sites, soft bottoms with fine sand in one, and soft bottoms with slime and clay in two. The temperature and salinity values were higher in the external localities, while dissolved oxygen and pH were higher in the internal localities. The localities with hard substrates presented the highest richness of species while the soft substrates, were characterized by a paucity of species and individuals. The similarity classification analyses showed two groups: one characterized by having 61 species in common and high richness with 113 exclusive species. The other group with low diversity and richness values, 37 species in common and 23 exclusive species.

An application of the minimum discrimination information estimate to compute log-likelihood ratios

1973 ◽  
Vol 10 (2) ◽  
pp. 469-474
Author(s):  
E. L. Melnick ◽  
S. Kullback
Keyword(s):  
Continuous Time ◽  
Value Function ◽  
Mean Value ◽  
The Other ◽  
Likelihood Ratios ◽  
Log Likelihood ◽  
Discrimination Information ◽  
The Mean ◽  
Nikodym Derivative ◽  
Minimum Discrimination Information

In this paper the minimum discrimination information estimate is used to compute the log-likelihood ratio or logarithm of the Radon-Nikodym derivative In (dP1/dP2) when the stochastic process {x(t), t∈T) has either the probability measure P1 or P2. One example tests the mean value function of Gaussian processes. The other tests the mean value function of a continuous time Poisson process.

scholarly journals Genetic Diversity Estimates for the Genus Hydrangea and Development of a Molecular Key Based on SSR

2006 ◽  
Vol 131 (6) ◽  
pp. 787-797 ◽  
Author(s):  
Timothy A. Rinehart ◽  
Brian E. Scheffler ◽  
Sandra M. Reed
Keyword(s):  
Genetic Diversity ◽  
Genetic Similarity ◽  
Gene Diversity ◽  
The Other ◽  
Separate Species ◽  
Low Diversity ◽  
Wide Hybrids ◽  
Diversity Estimates ◽  
Total Diversity ◽  
Size Data

Using 14 codominant microsatellite markers that amplify loci across 14 different Hydrangea L. species, we analyzed gene diversity and genetic similarity within Hydrangea. Samples also included Dichroa Lour., Platycrater Sieb. and Zucc., and Schizophragma Sieb. and Zucc. genera to establish their relatedness to Hydrangea species since previous work suggests they may be closely related. Our results support the close affiliation between Macrophyllae E.M. McClint. and Petalanthe (Maxim.) Rehder subsections and their separation from the other Hydrangea species. Most of the Hydrangea species analyzed cluster within their designated sections and subsections; however, genetic distance between species within each subsection varied considerably. Our data suggest that morphological analyses which labeled H. serrata (Thunb.) Ser. as a subspecies of H. macrophylla (Thunb. Ex J.A. Murr.) Ser. are probably more accurate than recent genome size data suggesting H. macrophylla ssp. macrophylla (Thunb.) Ser. and H. macrophylla ssp. serrata (Thunb.) Makino are separate species. Gene diversity estimates indicate that 64.7% of the total diversity is due to differences between species and 49.7% of the overall variation is due to differences between subsections. Low diversity suggests a lack of gene flow between species and subsections and underscores the difficulty in making wide hybrids. Since only 35.3% of the genetic variation is common to all species, unique alleles were used to develop a molecular key for unambiguous species identification and interspecific hybrid verification. Genetic similarity estimates for all 85 samples suggests a roadmap for introgressing horticulturally important traits from different Hydrangea species.

scholarly journals On the Hurst exponents, Markov processes, and fractional Brownian motion

2021 ◽  
Author(s):  
Ginno Millán
Keyword(s):  
Brownian Motion ◽  
Fractional Brownian Motion ◽  
Markov Processes ◽  
The Other ◽  
Time Interval ◽  
Infinite Time Interval ◽  
Point Density ◽  
The Difference ◽  
The One ◽  
Hurst Exponents

There is much confusion in the literature over Hurst exponent (H). The purpose of this paper is to illustrate the difference between fractional Brownian motion (fBm) on the one hand and Gaussian Markov processes where H is different to 1/2 on the other. The difference lies in the increments, which are stationary and correlated in one case and nonstationary and uncorrelated in the other. The two- and one-point densities of fBm are constructed explicitly. The two-point density does not scale. The one-point density for a semi-infinite time interval is identical to that for a scaling Gaussian Markov process with H different to 1/2 over a finite time interval. We conclude that both Hurst exponents and one-point densities are inadequate for deducing the underlying dynamics from empirical data. We apply these conclusions in the end to make a focused statement about nonlinear diffusion.

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