Robustness of the DeLury Population Estimator

1969 ◽  
Vol 26 (2) ◽  
pp. 339-355 ◽  
Author(s):  
Duane O. Braaten
Keyword(s):  
Population Size ◽  
Environmental Conditions ◽  
Random Error ◽  
Marked Effect ◽  
Simulated Data ◽  
Constant Level ◽  
Subsequent Increase ◽  
Weighted Estimator

This is a study of the robustness, in estimating population size, of the usual DeLury Estimator and three modifications of it derived from the generalized exact deterministic catch equation of Beverton and Holt (1956, 1957). These estimators are called the Generalized DeLury Estimator, the Weighted Generalized DeLury Estimator, and the Effort-corrected DeLury Estimator.A computer was used to simulate varying environmental conditions, which included combinations of several vectors of catchability and effort and several types of random error. The results indicate that the generalized estimator is overall the best, at least for these simulated data. The effort-corrected estimator is just as effective, but requires effort correction. The usual DeLury estimator underestimates on the average. The weighted estimator has high variance.Catchability behavior has a marked effect on accuracy of any of these estimators. An increase in catchability from a previously constant level results in a subsequent increase in the estimate of population size. A decrease in catchability results in a decrease in the estimate. If catchability cycles, the estimate cycles with the same crest and period.Effort has little effect, at least for the vectors studied in this model.

Wavelet Transform Modulus Maxima Decay Lines

2015 ◽  
pp. 48-68
Author(s):  
Andreas Kyprianou ◽  
Andreas Tjirkallis
Keyword(s):  
Experimental Data ◽  
Wavelet Transform ◽  
Damage Detection ◽  
Environmental Conditions ◽  
Simulated Data ◽  
Random Excitation ◽  
Operating Conditions ◽  
Structural Behaviour ◽  
Operational Conditions ◽  
Three Degree Of Freedom

An important task in structural health monitoring (SHM) is that of damage detection under varying environmental and operational conditions. Structures, under varying environmental conditions, change their mass, elasticity and damping properties whereas changing operational conditions cause changes to excitations. A damage detection methodology implemented in these circumstances faces serious challenges since changes to structural behaviour imparted by environmental or operational conditions could be wrongly attributed to damage. The part of a damage detection decision algorithm that removes environmental and operational effects is called normalization. In this chapter a normalization methodology that is based on the similarity between continuous wavelet transform maxima decay lines is presented. This methodology is implemented on both simulated and experimental data. Simulated data were obtained from a three degree of freedom system. Varying environmental conditions were simulated by temperature dependent stiffness parameters and operating conditions by changing the colour of random excitation. Experimental data were obtained from damaged cantilever beams that were subjected to random excitations of different colour and varying temperatures.

Morphological evolution of the murine rodent Paraethomys in response to climatic variations (Mio-Pleistocene of North Africa)

Paleobiology ◽  
1999 ◽  
Vol 25 (3) ◽  
pp. 369-382 ◽  
Author(s):  
Sabrina Renaud ◽  
Mouloud Benammi ◽  
Jean-Jacques Jaeger
Keyword(s):  
North Africa ◽  
Environmental Conditions ◽  
Morphological Evolution ◽  
Middle Pleistocene ◽  
Metabolic Adaptation ◽  
Subsequent Increase ◽  
Evolutionary Patterns ◽  
The North ◽  
Murine Rodent ◽  
Evolutionary Response

The North African murine rodent Paraethomys evolved as an anagenetic lineage from the late Miocene until its extinction in the late—middle Pleistocene. A Fourier analysis of the outlines of the first upper and lower molars of this rodent was used to quantify the evolutionary patterns of this lineage and to compare evolutionary patterns to the climatic record. Morphological evolution and long-term environmental variations are strongly correlated. A change in molar shape, which may be related to the development of a more grass-eating diet, corresponds to the global cooling beginning around 3 Ma and the subsequent increase in aridity in North Africa. Concurrently, size increased, which may be related to increased masticatory efficiency or to metabolic adaptation to the cooler environmental conditions according to Bergmann's rule. This adaptive response to changing environmental conditions corresponds to an acceleration of evolutionary rates in the lineage. The modalities of the evolutionary response in size and shape are probably controlled by intrinsic factors such as different genetic determinisms for both characters.

Experimental Design and Statistical Methods for Improved Hit Detection in High-Throughput Screening

2010 ◽  
Vol 15 (8) ◽  
pp. 990-1000 ◽  
Author(s):  
Nathalie Malo ◽  
James A. Hanley ◽  
Graeme Carlile ◽  
Jing Liu ◽  
Jerry Pelletier ◽  
...  
Keyword(s):  
Experimental Design ◽  
High Throughput ◽  
Random Error ◽  
Statistical Models ◽  
False Positive ◽  
High Throughput Screening ◽  
Operating Characteristic ◽  
Simulated Data ◽  
True Positive ◽  
Replicate Measurements

Identification of active compounds in high-throughput screening (HTS) contexts can be substantially improved by applying classical experimental design and statistical inference principles to all phases of HTS studies. The authors present both experimental and simulated data to illustrate how true-positive rates can be maximized without increasing false-positive rates by the following analytical process. First, the use of robust data preprocessing methods reduces unwanted variation by removing row, column, and plate biases. Second, replicate measurements allow estimation of the magnitude of the remaining random error and the use of formal statistical models to benchmark putative hits relative to what is expected by chance. Receiver Operating Characteristic (ROC) analyses revealed superior power for data preprocessed by a trimmed-mean polish method combined with the RVM t-test, particularly for small- to moderate-sized biological hits.

scholarly journals Photovoltaic models parameter estimation via an enhanced Rao-1 algorithm

2021 ◽  
Vol 19 (2) ◽  
pp. 1128-1153
Author(s):  
Junhua Ku ◽  
◽  
Shuijia Li ◽  
Wenyin Gong ◽  
Keyword(s):  
Parameter Estimation ◽  
Population Size ◽  
Evolution Operator ◽  
Evolutionary Process ◽  
Simulated Data ◽  
Local Optimum ◽  
Unknown Parameters ◽  
Estimation Algorithms ◽  
Arduous Task ◽  
Important Position

<abstract><p>The accuracy of unknown parameters determines the accuracy of photovoltaic (PV) models that occupy an important position in the PV power generation system. Due to the complexity of the equation equivalent of PV models, estimating the parameters of the PV model is still an arduous task. In order to accurately and reliably estimate the unknown parameters in PV models, in this paper, an enhanced Rao-1 algorithm is proposed. The main point of enhancement lies in i) a repaired evolution operator is presented; ii) to prevent the Rao-1 algorithm from falling into a local optimum, a new evolution operator is developed; iii) in order to enable population size to change adaptively with the evolutionary process, the population size linear reduction strategy is employed. To verify the validity of ERao-1 algorithm, we embark a study on parameter estimation of three different PV models. Experimental results show that the proposed ERao-1 algorithm performs better than existing parameter estimation algorithms in terms of the accuracy and reliability, especially for the double diode model with RMSE 9.8248E-04, three diode model with RMSE 9.8257E-04 for the R.T.C France silicon cell, and 2.4251E-03 for the three diode model of Photowatt- PWP201 cell. In addition, the fitting curve of the simulated data and the measured data also shows the accuracy of the estimated parameters.</p></abstract>

scholarly journals A Simulation Study on Increasing Capture Periods in Bayesian Closed Population Capture-Recapture Models with Heterogeneity

2020 ◽  
Vol 18 (1) ◽  
pp. 2-23
Author(s):  
Ross M. Gosky ◽  
Joel Sanqui
Keyword(s):  
Population Size ◽  
Simulation Study ◽  
Simulated Data ◽  
Population Models ◽  
Data Set ◽  
Closed Population ◽  
Population Sizes ◽  
Capture Recapture

Capture-Recapture models are useful in estimating unknown population sizes. A common modeling challenge for closed population models involves modeling unequal animal catchability in each capture period, referred to as animal heterogeneity. Inference about population size N is dependent on the assumed distribution of animal capture probabilities in the population, and that different models can fit a data set equally well but provide contradictory inferences about N. Three common Bayesian Capture-Recapture heterogeneity models are studied with simulated data to study the prevalence of contradictory inferences is in different population sizes with relatively low capture probabilities, specifically at different numbers of capture periods in the study.

scholarly journals Joint Estimation of Pedigrees and Effective Population Size Using Markov Chain Monte Carlo

2018 ◽  
Author(s):  
Amy Ko ◽  
Rasmus Nielsen
Keyword(s):  
Monte Carlo ◽  
Markov Chain ◽  
Markov Chain Monte Carlo ◽  
Population Size ◽  
Effective Population Size ◽  
Simulated Data ◽  
Composite Likelihood ◽  
Joint Estimation ◽  
Pedigree Information ◽  
Effective Population

Pedigrees provide a fine resolution of the genealogical relationships among individuals and serve an important function in many areas of genetic studies. One such use of pedigree information is in the estimation of short-term effective population size (Ne), which is of great relevance in fields such as conservation genetics. Despite the usefulness of pedigrees, however, they are often an unknown parameter and must be inferred from genetic data. In this study, we present a Bayesian method to jointly estimate pedigrees and Ne from genetic markers using Markov Chain Monte Carlo. Our method supports analysis of a large number of markers and individuals with the use of composite likelihood, which significantly increases computational efficiency. We show on simulated data that our method is able to jointly estimate relationships up to first cousins and Ne with high accuracy. We also apply the method on a real dataset of house sparrows to reconstruct their previously unreported pedigree.

scholarly journals Discrimination of Picea chihuahuana Martinez populations on the basis of numerous dendrometric, climatic and edaphic traits and genetic diversity

2017 ◽  
Author(s):  
Iliana Karina Dominguez-Guerrero ◽  
Samantha Mariscal-Lucero ◽  
José Ciro Hernández-Díaz ◽  
Berthold Heinze ◽  
José Ángel Prieto-Ruiz ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Discriminant Analysis ◽  
Population Size ◽  
Environmental Conditions ◽  
Diversity Indices ◽  
Ex Situ ◽  
Assisted Migration ◽  
Tree Community ◽  
Southern Central ◽  
The Mean

Background. Picea chihuahuana, which is endemic to Mexico, is currently listed as “Endangered” on the Red List. Chihuahua spruce is only found in the Sierra Madre Occidental (SMO), Mexico. About 42,600 individuals are distributed in forty populations. The populations are fragmented and can be classified into three distinct clusters in the SMO of the two States (south, center and north), each group separated by a distance of about 300 km. The total area covered P. chihuahuana trees is less than 300 ha. A recent study suggested assisted migration as an alternative to the ex situ conservation of P. chihuahuana, taking into consideration the genetic structure and diversity of the populations and also predictions regarding the future climate of the habitat. However, detailed background information is required to enable development of plans for protecting and conserving species and for successful assisted migration. Thus, it is important to identify differences between populations in relation to environmental conditions. The vitality and genetic diversity of populations, which affect vigour, evolution and adaptability of the species, must also be considered. In this study, we examined the P. chihuahuana tree community growing in fourteen different locations, with the overall aim of discriminating the populations and clusters of this species using 22 climatic, 27 edaphic and 15 dasometric variables and three genetic diversity indices. Methods. Each location was represented by one 50 x 50 m plot established in the center of the location in which was measured the climate, soil, dasometric and genetic variables. The putative neutral and adaptive AFLP were used to calculate genetic diversity. Multivariate discriminant analysis including cross-validation was considered to test for significant differences in variables in the southern, central and northern populations and locations of the P. chihuahuana tree community. Spearman's correlation test was used to analyze the relationships between genetic diversity, population size, and the climatic, soil and dasometric variables. Results. The discriminant analysis revealed 22 highly significant variables, which separated the southern, central and northern populations. The mean genetic diversity of P. chihuahuana was significantly correlated with the mean temperature in the warmest month. Genetic diversity of P. chihuahuana calculated with putative adaptive AFLP was not statistically significantly correlated with any environmental factor. Finally, no significant correlations were observed between any of the three genetic diversity indices and population size. Discussion. At least three different ecotypes of P. chihuahuana probably exist, as local adaptation may take place because of the different environmental conditions. Therefore, future reforestation programs should take into account these different ecotypes and environmental conditions.

scholarly journals Variasi Karakter Pembungaan Antar Varian dan Ras Lahan Cendana Sepanjang Gradien Geografis di Gunung Sewu

2017 ◽  
Vol 11 (2) ◽  
pp. 173
Author(s):  
Yeni Widyana Nurcahyani Cahyaningrum ◽  
Sapto Indrioko ◽  
Eny Faridah ◽  
Atus Syahbudin
Keyword(s):  
Genetic Differentiation ◽  
Population Size ◽  
Environmental Conditions ◽  
Extreme Temperature ◽  
Conservation Strategy ◽  
Floral Display ◽  
Flowering Period ◽  
Floral Structure ◽  
Lower Altitude ◽  
Land Races

Cendana merupakan spesies asli Indonesia bagian timur, yang menjadi ras lahan di Gunung Sewu. Sembilan ras lahan di Gunung Sewu, seluruhnya tersusun atas tiga varian yang berbeda struktur dan warna bunganya (MK, merah kecil; MB, merah besar; dan KB, kuning besar). Penelitian ini bertujuan untuk menganalisis karakter pembungaan ketiga varian cendana di Gunung Sewu pada periode pembungaan tahun 2015; di tiga ras lahan yang mewakili tiap zona yaitu Nglanggeran (Zona Utara), Bleberan (Zona Tengah), dan Petir (Zona Selatan). Observasi meliputi fenologi, kemasakan organ reproduksi, display, dan struktur pembungaan. Struktur pembungaan dan longevity organ reproduksi berbeda antar varian. MB dan KB didominasi warna merah dan marun, perigonium lebih besar, organ reproduksi lebih panjang, posisi putik sejajar/lebih rendah dari benang sari, dan longevity lebih singkat. MK didominasi kuning hingga oranye, lebih kecil, posisi putik sejajar/lebih tinggi, dan longevity lebih lama. Display pembungaan berbeda antar ras lahan, namun tidak berbeda antar varian. Petir, dengan ukuran populasi terbesar, memproduksi paling banyak pohon berbunga dan total bunga untuk seluruh varian. Ras lahan dan varian berbunga dua kali setahun, namun dengan inisiasi dan durasi yang berbeda. KB berbunga lebih awal di seluruh ras lahan, sedangkan MB paling akhir. MK memiliki durasi pembungaan terpanjang. Perbedaan antar ras lahan lebih dipengaruhi oleh faktor lingkungan seperti ketinggian, jenis tanah, dan iklim. Ras lahan yang lebih rendah, kering, dan panas berbunga lebih awal dan singkat. Peningkatan temperatur dan turunnya status air tanah menyebabkan keguguran massal yang diikuti sequential replacement, mengakibatkan perubahan frekuensi pembungaan. Strategi konservasi cendana di Gunung Sewu perlu dirancang berbasis keragaman genetik, sinkroni pembungaan, dan kompatibilitas antar varian, dengan tetap mempertimbangkan keberagaman tempat tumbuhnya.Kata kunci: cendana; Gunung Sewu; pembungaan; ras lahan; varian bunga The Flowering Characters Variation Among Floral Variants and Landraces Along Geographical Gradients in Gunung SewuAbstractSandalwood was origin to the south-eastern islands of Indonesia, but is recently occured as new land-races in Gunung Sewu, Java island. All of land-races consisted of three floral variants (MK, refers to “merah kecil”; MB, “merah besar”; and KB, “kuning besar”, respectively). This research aimed to determine flowering of these variants among three of land-races which were representing geographical zone in Gunung Sewu: Nglanggeran, Blebera, and Petir. Observation on phenology, sexual organs maturity, floral structure, and display was conducted in 2015. Floral structures varied among variants. MB and KB dominated by red and maroon colors, possessed bigger perigonium, longer sexual organs but with shorter longevity, and similar/lower position of stylus to stamens. MK dominated by yellow to orange colors, smaller, similar/higher position of stylus, and longer longevity. Floral display varied among land-races but were similar among variants. Petir, with biggest population size, produced the most abundant flowers and flowering trees at all variants. Sandalwood flowered twice a year in all of land-races and variants, however, the onset and duration varied. KB flowered earliest while MB was the latest. MK possessed longest flowering period. Flowering varied among land-races due to the altitude, soils, and climatic differences. Lower altitude, drier, and warmer sites flowered earlier and shorter. Mass abortion and sequential replacement, resulting in the alteration on flowering frequency, occured due to the extreme temperature increment. Conservation strategy should be arranged based on genetic differentiation, flowering differences, and crossing abilities among variants. Differences of landscapes, which may contribute to the differences of environmental conditions and flowering processes, should also be considered.

scholarly journals Epidemiology of Septoria leaf blotch on spring triticale in West Lithuania

2017 ◽  
Vol 38 (SI 2 - 6th Conf EFPP 2002) ◽  
pp. 338-390
Author(s):  
D. Janušauskaitė
Keyword(s):  
Environmental Conditions ◽  
Marked Effect ◽  
First Year ◽  
Disease Development ◽  
Septoria Nodorum ◽  
Ripening Stage ◽  
Septoria Leaf Blotch ◽  
Leaf Blotch ◽  
Spring Triticale ◽  
Second Year

The effects of environmental conditions on the dynamics of Septoria leaf blotch, Septoria nodorum (Berk.) E. Castell et. Germano, incidence and severity on the spring triticale cv. Gabo were studied in 2000 and 2001 in littoral lowland of Lithuania. Disease assessments were carried out once a week from GS 31–32 to GS 81–83 on the three primary leaves. At milk ripening stage (GS 75) the incidence of Septoria on F leaves reached 44.9% in 2000 and 97.7% in 2001. The disease severity was 3.5% in the first year, and 11.5% in the second year. Comparison of 2 years’ data revealed that whether conditions had a marked effect on the manner of disease development.

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