scholarly journals Advances in Time Estimation Methods for Molecular Data

2016 ◽  
Vol 33 (4) ◽  
pp. 863-869 ◽  
Author(s):  
Sudhir Kumar ◽  
S. Blair Hedges
Keyword(s):  
Time Estimation ◽  
Molecular Data ◽  
Estimation Methods

scholarly journals A Fusion Algorithm for Estimating Time-Independent/-Dependent Parameters and States

Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 4068
Author(s):  
Zheshuo Zhang ◽  
Jie Zhang ◽  
Jiawen Dai ◽  
Bangji Zhang ◽  
Hengmin Qi
Keyword(s):  
Unscented Kalman Filter ◽  
Time Estimation ◽  
Estimation Algorithm ◽  
Estimation Methods ◽  
Fusion Algorithm ◽  
State Variable ◽  
Current Estimation ◽  
Real Time Estimation ◽  
And Control ◽  
Independent Parameters

Vehicle parameters are essential for dynamic analysis and control systems. One problem of the current estimation algorithm for vehicles’ parameters is that: real-time estimation methods only identify parts of vehicle parameters, whereas other parameters such as suspension damping coefficients and suspension and tire stiffnesses are assumed to be known in advance by means of an inertial parameter measurement device (IPMD). In this study, a fusion algorithm is proposed for identifying comprehensive vehicle parameters without the help of an IPMD, and vehicle parameters are divided into time-independent parameters (TIPs) and time-dependent parameters (TDPs) based on whether they change over time. TIPs are identified by a hybrid-mass state-variable (HMSV). A dual unscented Kalman filter (DUKF) is applied to update both TDPs and online states. The experiment is conducted on a real two-axle vehicle and the test data are used to estimate both TIPs and TDPs to validate the accuracy of the proposed algorithm. Numerical simulations are performed to further investigate the algorithm’s performance in terms of sprung mass variation, model error because of linearization and various road conditions. The results from both the experiment and simulation show that the proposed algorithm can estimate TIPs as well as update TDPs and online states with high accuracy and quick convergence, and no requirement of road information.

Time Estimation Methods—Do They Influence Prospective Duration Estimates?

Perception ◽  
1993 ◽  
Vol 22 (1) ◽  
pp. 91-101 ◽  
Author(s):  
Dan Zakay
Keyword(s):  
Information Processing ◽  
Positive Relationship ◽  
Negative Relationship ◽  
Estimation Method ◽  
Time Estimation ◽  
Estimation Methods ◽  
Clock Time ◽  
Processing Load ◽  
Attentional Model ◽  
Time Length

The validity of an attentional model of prospective time estimation was tested in three experiments. In the first experiment two variables were manipulated: (1) nontemporal information processing load during the estimated interval, and (2) time estimation method, ie production of time simultaneously with the performance of a second task, or reproduction of time immediately upon termination of a task whose duration has to be measured. As predicted, a positive relationship between produced time length and information processing load demanded by a simultaneous task, and a negative relationship between reproduced time length and information processing load during the estimated interval, were found. The results were replicated in a second experiment in which verbal estimates of time were also measured and the objective duration of the estimated interval was varied. The pattern of results obtained for verbal estimates was similar to that obtained for reproduced ones. The results of a third experiment indicated that produced and reproduced times were positively correlated with clock time. The results are interpreted as supporting an attentional model of prospective time estimation.

Global classification and evolution of brushlegged mayflies (Insecta: Ephemeroptera: Oligoneuriidae): phylogenetic analyses of morphological and molecular data and dated historical biogeography

2019 ◽  
Vol 187 (2) ◽  
pp. 378-412 ◽  
Author(s):  
Fabiana Criste Massariol ◽  
Daniela Maeda Takiya ◽  
Frederico Falcão Salles
Keyword(s):  
Phylogenetic Analyses ◽  
Divergence Time ◽  
Time Estimation ◽  
Single Species ◽  
Molecular Data ◽  
Neotropical Region ◽  
Fossil Species ◽  
Divergence Time Estimation ◽  
The Family ◽  
Family Based

AbstractOligoneuriidae is a Pantropical family of Ephemeroptera, with 68 species described in 12 genera. Three subfamilies are recognized: Chromarcyinae, with a single species from East Asia; Colocrurinae, with two fossil species from Brazil; and Oligoneuriinae, with the remaining species distributed in the Neotropical, Nearctic, Afrotropical and Palaearctic regions. Phylogenetic and biogeographical analyses were performed for the family based on 2762 characters [73 morphological and 2689 molecular (COI, 16S, 18S and 28S)]. Four major groups were recovered in all analyses (parsimony, maximum likelihood and Bayesian inference), and they were assigned to tribal level, namely Oligoneuriini, Homoeoneuriini trib. nov., Oligoneuriellini trib. nov. and Elassoneuriini trib. nov. In addition, Yawari and Madeconeuria were elevated to genus level. According to Statistical Dispersal-Vicariance (S-DIVA), Dispersal Extinction Cladogenesis (DEC) and divergence time estimation analyses, Oligoneuriidae originated ~150 Mya in the Gondwanan supercontinent, but was probably restricted to the currently delimited Neotropical region. The initial divergence of Oligoneuriidae involved a range expansion to Oriental and Afrotropical areas, sometime between 150 and 118 Mya. At ~118 Mya, the family started its diversification, reaching the Nearctic through dispersal from the Neotropical region and the Palaearctic and Madagascar from the Afrotropical region.

scholarly journals Phylogenetic systematics of Glassfrogs (Amphibia: Centrolenidae) and their sister taxon Allophryne ruthveni

Zootaxa ◽  
2009 ◽  
Vol 2100 (1) ◽  
pp. 1-97 ◽  
Author(s):  
JUAN M. GUAYASAMIN ◽  
SANTIAGO CASTROVIEJO-FISHER ◽  
LINDA TRUEB ◽  
JOSÉ AYARZAGÜENA ◽  
MARCO RADA ◽  
...  
Keyword(s):  
Morphological Characters ◽  
Molecular Data ◽  
Estimation Methods ◽  
Sister Taxon ◽  
Zoological Nomenclature ◽  
Phenotypic Traits ◽  
Phylogenetic Taxonomy ◽  
Biogeographic Regions ◽  
Allophryne Ruthveni ◽  
Name Changes

Based on a molecular phylogeny, a new phylogenetic taxonomy that is compatible with both the International Code of Zoological Nomenclature (ICZN) and the PhyloCode is proposed for Glassfrogs and their sister taxon, Allophryne ruthveni. The arrangement presented herein emphasizes the recognition of clades having (i) significant statistical support and congruence among phylogenetic estimation methods (i.e., parsimony, maximum likelihood, and Bayesian inference criteria), (ii) congruence among genetic markers, and (iii) morphological and/or behavioral distinctiveness. Also, when previously recognized groups are recovered as monophyletic or nearly monophyletic, we propose taxa that minimize the number of name changes required to make these groups monophyletic, preserving the names and contents of previous classifications (i.e., nomenclatural stability). The evolutionary proximity of Centrolenidae and Allophrynidae is recognized by combining these families into an unraked taxon, Allocentroleniae—a proposal that maintains the traditional names and species contents of Centrolenidae and Allophrynidae. We arrange centrolenid diversity in two subfamilies: Centroleninae and Hyalinobatrachinae. Within Centroleninae, the diagnosis and species content of the genera Centrolene, Cochranella, and Nymphargus are modified; Teratohyla is resurrected and modified, and Chimerella, Espadarana, Rulyrana, Sachatamia, and Vitreorana are proposed as new genera. The other subfamily, Hyalinobatrachinae, contains the new genus Celsiella and a modified Hyalinobatrachium that fully corresponds to the former fleischmanni Group. Additionally, the genus Ikakogi is described. Ikakogi could not be assigned with confidence to either subfamily and it is placed as incertae sedis in Centrolenidae. The data at hand suggest that Ikakogi tayrona is a lineage as old as the subfamilies Hyalinobatrachinae and Centroleninae. The revised taxonomy differs markedly from previous arrangements, which were based on phenetics and few morphological characters. Most of the genera defined herein are confined to distinct biogeographic regions, highlighting the importance of geography in the speciation of Glassfrogs. The principal limitation of this proposal is that it is based on an incomplete sampling of taxa (54% of the recognized Glassfrogs). Although diagnoses are based on phenotypic traits, there are several cases (16% of all species) in which the allocation of species is ambiguous because of morphological homoplasy and the lack of molecular data. Finally, in an attempt to facilitate species identification, comparison, and generic placement, we provide photographs for most (~ 96%) of the recognized centrolenid species.

scholarly journals Accurate Direction-of-Arrival Estimation Method based on Space-Time Modulated Metasurface

2022 ◽  
Author(s):  
Mengmeng Li
Keyword(s):  
Plane Wave ◽  
Incident Angle ◽  
Estimation Method ◽  
Time Estimation ◽  
Direction Of Arrival ◽  
Doa Estimation ◽  
Space Time ◽  
Estimation Methods ◽  
Estimation Accuracy ◽  
Hardware Complexity

In this paper, we present a metasurface-based Direction of Arrival (DoA) estimation method that exploits the properties of space-time modulated reflecting metasurfaces to estimate in real-time the impinging angle of an illuminating monochromatic plane wave. The approach makes use of the amplitude unbalance of the received fields at broadside at the frequencies of the two first-order harmonics generated by the interaction between the incident plane wave and the modulated metasurface. Here, we first describe analytically how to generate the desired higher-order harmonics in the reflected spectrum and how to realize the breaking of the spatial symmetry of each order harmonic scattering pattern. Then, the one dimensional (1D) omnidirectional incident angle can be analytically computed using +1st and -1st order harmonics. The approach is also extended to 2D DoA estimation by using two orthogonally arranged 1D DoA modulation arrays. The accuracy of 1D DoA estimation is verified through full-wave numerical simulations. Compared to conventional DoA estimation methods, the proposed approach simplifies the computation and hardware complexity, ensuring at the same time estimation accuracy. The proposed method may have potential applications in wireless communications, target recognition, and identification.

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