Log in

Relevant bibliographies by topics / Parameter estimates / Journal articles

To see the other types of publications on this topic, follow the link: Parameter estimates.

Journal articles on the topic 'Parameter estimates'

Author: Grafiati

Published: 4 June 2021

Last updated: 25 July 2025

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the top 50 journal articles for your research on the topic 'Parameter estimates.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.

1

Mead, J. L. "Discontinuous parameter estimates with least squares estimators." Applied Mathematics and Computation 219, no. 10 (2013): 5210–23. http://dx.doi.org/10.1016/j.amc.2012.11.067.

Full text

APA, Harvard, Vancouver, ISO, and other styles

2

Robitzsch, Alexander. "Linking Error Estimation in Fixed Item Parameter Calibration: Theory and Application in Large-Scale Assessment Studies." Foundations 5, no. 1 (2025): 4. https://doi.org/10.3390/foundations5010004.

Full text

Abstract:

In fixed item parameter calibration (FIPC), an item response theory (IRT) model is estimated with item parameters fixed at reference values to estimate the distribution parameters within a specific group. The presence of random differential item functioning (DIF) within this group introduces additional variability in the distribution parameter estimates, which is captured by the linking error (LE). Conventional LE estimates, based on item jackknife methods, are subject to positive bias due to sampling errors. To address this, this article introduces a bias-corrected LE estimate. Moreover, the

APA, Harvard, Vancouver, ISO, and other styles

3

Pilling, Graham M., Geoffrey P. Kirkwood, and Stephen G. Walker. "An improved method for estimating individual growth variability in fish, and the correlation between von Bertalanffy growth parameters." Canadian Journal of Fisheries and Aquatic Sciences 59, no. 3 (2002): 424–32. http://dx.doi.org/10.1139/f02-022.

Full text

Abstract:

A new method for estimating individual variability in the von Bertalanffy growth parameters of fish species is presented. The method uses a nonlinear random effects model, which explicitly assumes that an individual's growth parameters represent samples from a multivariate population of growth parameters characteristic of a species or population. The method was applied to backcalculated length-at-age data from the tropical emperor, Lethrinus mahsena. Individual growth parameter variability estimates were compared with those derived using the current "standard" method, which characterizes the j

APA, Harvard, Vancouver, ISO, and other styles

4

Coventry, William L., and Matthew C. Keller. "Estimating the Extent of Parameter Bias in the Classical Twin Design: A Comparison of Parameter Estimates From Extended Twin-Family and Classical Twin Designs." Twin Research and Human Genetics 8, no. 3 (2005): 214–23. http://dx.doi.org/10.1375/twin.8.3.214.

Full text

Abstract:

AbstractThe classical twin design (CTD) circumvents parameter indeterminacy by assuming (1) negligible higher-order epistasis; and (2) either nonadditive genetic or common environmental effects are nonexistent, creating two potential sources of bias (Eaves et al., 1978; Grayson, 1989). Because the extended twin-family design (ETFD) uses many more unique covariance observations to estimate parameters, common environmental and nonadditive genetic parameters can be simultaneously estimated. The ETFD thereby corrects for what is likely to be the largest of the two sources of bias in CTD parameter

APA, Harvard, Vancouver, ISO, and other styles

5

Yi, Kyongsu, and Karl Hedrick. "Observer-Based Identification of Nonlinear System Parameters." Journal of Dynamic Systems, Measurement, and Control 117, no. 2 (1995): 175–82. http://dx.doi.org/10.1115/1.2835177.

Full text

Abstract:

This paper deals with an observer-based nonlinear system parameter identification method utilizing repetitive excitation. Although methods for physical parameter identification of both linear and nonlinear systems are already available, they are not attractive from a practical point of view since the methods assume that all the system, x, and the system input are available. The proposed method is based on a “sliding observer” and a least-square method. A sufficient condition for the convergence of the parameter estimates is provided in the case of “Lipschitz” nonlinear second-order systems. Th

APA, Harvard, Vancouver, ISO, and other styles

6

Rajanayaka, Channa, and Don Kulasiri. "Investigation of a parameter estimation method for contaminant transport in aquifers." Journal of Hydroinformatics 3, no. 4 (2001): 203–13. http://dx.doi.org/10.2166/hydro.2001.0019.

Full text

Abstract:

Real world groundwater aquifers are heterogeneous and system variables are not uniformly distributed across the aquifer. Therefore, in the modelling of the contaminant transport, we need to consider the uncertainty associated with the system. Unny presented a method to describe the system by stochastic differential equations and then to estimate the parameters by using the maximum likelihood approach. In this paper, this method was explored by using artificial and experimental data. First a set of data was used to explore the effect of system noise on estimated parameters. The experimental dat

APA, Harvard, Vancouver, ISO, and other styles

7

Luo, Yong, and Dimiter M. Dimitrov. "A Short Note on Obtaining Point Estimates of the IRT Ability Parameter With MCMC Estimation in Mplus: How Many Plausible Values Are Needed?" Educational and Psychological Measurement 79, no. 2 (2018): 272–87. http://dx.doi.org/10.1177/0013164418777569.

Full text

Abstract:

Plausible values can be used to either estimate population-level statistics or compute point estimates of latent variables. While it is well known that five plausible values are usually sufficient for accurate estimation of population-level statistics in large-scale surveys, the minimum number of plausible values needed to obtain accurate latent variable point estimates is unclear. This is especially relevant when an item response theory (IRT) model is estimated with MCMC (Markov chain Monte Carlo) methods in Mplus and point estimates of the IRT ability parameter are of interest, as Mplus only

APA, Harvard, Vancouver, ISO, and other styles

8

Fieberg, J., and D. F. Staples. "The role of variability and uncertainty in testing hypotheses involving parameters in stochastic demographic models." Canadian Journal of Zoology 84, no. 11 (2006): 1698–701. http://dx.doi.org/10.1139/z06-153.

Full text

Abstract:

Hierarchical / random effect models provide a statistical framework for estimating variance parameters that describe temporal and spatial variability of vital rates in population dynamic models. In practice, estimates of variance parameters (e.g., process error) from these models are often confused with estimates of uncertainty about model parameter estimates (e.g., standard errors). These two sources of “error” have different implications for predictions from stochastic models. Estimates of process error (or variability) are useful for describing the magnitude of variation in vital rates over

APA, Harvard, Vancouver, ISO, and other styles

9

Koots, Kenneth R., and John P. Gibson. "Realized Sampling Variances of Estimates of Genetic Parameters and the Difference Between Genetic and Phenotypic Correlations." Genetics 143, no. 3 (1996): 1409–16. http://dx.doi.org/10.1093/genetics/143.3.1409.

Full text

Abstract:

Abstract A data set of 1572 heritability estimates and 1015 pairs of genetic and phenotypic correlation estimates, constructed from a survey of published beef cattle genetic parameter estimates, provided a rare opportunity to study realized sampling variances of genetic parameter estimates. The distribution of both heritability estimates and genetic correlation estimates, when plotted against estimated accuracy, was consistent with random error variance being some three times the sampling variance predicted from standard formulae. This result was consistent with the observation that the varian

APA, Harvard, Vancouver, ISO, and other styles

10

Jiang, Renyan. "A Quasi-Normal Distribution and its Application in Parameter Estimation on Heavily Censored Data." International Journal of Reliability, Quality and Safety Engineering 28, no. 05 (2021): 2150027. http://dx.doi.org/10.1142/s0218539321500273.

Full text

Abstract:

Parameter estimation on heavily censored data is a challenging issue. This paper addresses this issue using a two-step single-parameter maximum likelihood method to estimate mean time to failure (MTTF) and Weibull shape parameter (WSP). The first step fits the data to three one-parameter auxiliary models, which are special cases of a two-parameter quasi-normal distribution with nonnegative support, to obtain three estimates of the MTTF. The second step estimates the WSP through fixing each of the MTTF estimates. The best estimates are selected from three pairs of estimates based on appropriate

APA, Harvard, Vancouver, ISO, and other styles

11

Uzhga Rebrov, Oleg, and Galina Kuleshova. "FUZZY ROBUST ESTIMATES OF LOCATION AND SCALE PARAMETERS OF A FUZZY RANDOM VARIABLE." ENVIRONMENT. TECHNOLOGIES. RESOURCES. Proceedings of the International Scientific and Practical Conference 2 (June 17, 2021): 181–86. http://dx.doi.org/10.17770/etr2021vol2.6566.

Full text

Abstract:

A random variable is a variable whose components are random values. To characterise a random variable, the arithmetic mean is widely used as an estimate of the location parameter, and variation as an estimate of the scale parameter. The disadvantage of the arithmetic mean is that it is sensitive to extreme values, outliers in the data. Due to that, to characterise random variables, robust estimates of the location and scale parameters are widely used: the median and median absolute deviation from the median. In real situations, the components of a random variable cannot always be estimated in

APA, Harvard, Vancouver, ISO, and other styles

12

Lappi, Juha, and Juha Malinen. "Random-Parameter Height/Age Models when Stand Parameters and Stand Age are Correlated." Forest Science 40, no. 4 (1994): 715–31. http://dx.doi.org/10.1093/forestscience/40.4.715.

Full text

Abstract:

Abstract Height/age curves of dominant trees in a stand can be predicted using models containing random stand and tree parameters. If the population mean curve is estimated from the data where stand-specific parameters are correlated with stand age (e.g., because old stands are growing on poor sites), this correlation may cause biased estimates. The same bias problem occurs in traditional site index methods. It is shown how ordinary least squares estimates of tree specific parameters can be used for computing unbiased estimates of the population mean parameters and for estimating the relations

APA, Harvard, Vancouver, ISO, and other styles

13

Riswan, Riswan. "Sample Size and Test Length for Item Parameter Estimate and Exam Parameter Estimate." Al-Khwarizmi : Jurnal Pendidikan Matematika dan Ilmu Pengetahuan Alam 9, no. 1 (2021): 69–78. http://dx.doi.org/10.24256/jpmipa.v9i1.2384.

Full text

Abstract:

The Item Response Theory (IRT) model contains one or more parameters in the model. These parameters are unknown, so it is necessary to predict them. This paper aims (1) to determine the sample size (N) on the stability of the item parameter (2) to determine the length (n) test on the stability of the estimate parameter examinee (3) to determine the effect of the model on the stability of the item and the parameter to examine (4) to find out Effect of sample size and test length on item stability and examinee parameter estimates (5) Effect of sample size, test length, and model on item stabilit

APA, Harvard, Vancouver, ISO, and other styles

14

Skopintseva, Lyubov, and Alexey Stovas. "Overburden dependent AVA inversion." GEOPHYSICS 75, no. 2 (2010): C15—C23. http://dx.doi.org/10.1190/1.3332529.

Full text

Abstract:

Amplitude-variation-with-offset (AVO) analysis is strongly dependent on interpretation of the estimated traveltime parameters. In practice, we can estimate two or three traveltime parameters that require interpretation within the families of two- or three-parameter velocity models, respectively. Increasing the number of model parameters improves the quality of overburden description and reduces errors in AVO analysis. We have analyzed the effect of two- and three-parameter velocity model interpretation for the overburden on AVO data and have developed error estimates in the reservoir parameter

APA, Harvard, Vancouver, ISO, and other styles

15

Bellsky, Thomas, Jesse Berwald, and Lewis Mitchell. "Nonglobal Parameter Estimation Using Local Ensemble Kalman Filtering." Monthly Weather Review 142, no. 6 (2014): 2150–64. http://dx.doi.org/10.1175/mwr-d-13-00200.1.

Full text

Abstract:

Abstract The authors study parameter estimation for nonglobal parameters in a low-dimensional chaotic model using the local ensemble transform Kalman filter (LETKF). By modifying existing techniques for using observational data to estimate global parameters, they present a methodology whereby spatially varying parameters can be estimated using observations only within a localized region of space. Taking a low-dimensional nonlinear chaotic conceptual model for atmospheric dynamics as a numerical test bed, the authors show that this parameter estimation methodology accurately estimates parameter

APA, Harvard, Vancouver, ISO, and other styles

16

Ahmad, W. M. A. W., R. A. A. Rohim, and N. H. Ismail. "Forecasting Parameter Estimates: A Modeling Approach Using Exponential and Linear Regression." Engineering, Technology & Applied Science Research 8, no. 4 (2018): 3162–67. https://doi.org/10.5281/zenodo.1450645.

Full text

Abstract:

This paper supplies a calculation method for the parameter estimates of an exponential equation through SAS algorithm. The aim of this paper is to investigate the efficiency of the gained parameter estimates through the forecasting performance. The proposed calculation method can provide a very useful technique to develop an exponential equation with better accuracy performance. This research paper illustrates a sample of the data obtained from the established study, which characterize the proliferative capacity of mesenchymal stem cells. This paper also provides the specific algorithm for the

APA, Harvard, Vancouver, ISO, and other styles

17

Bako, Sunday Samuel, Mohd Bakri Adam, and Anwar Fitrianto. "Impact of Dependence on Parameter Estimates of Autoregressive Process with Gumbel Distributed Innovation." MATEMATIKA 34, no. 2 (2018): 365–80. http://dx.doi.org/10.11113/matematika.v34.n2.941.

Full text

Abstract:

Recent studies have shown that independent identical distributed Gaussian random variables is not suitable for modelling extreme values observed during extremal events. However, many real life data on extreme values are dependent and stationary rather than the conventional independent identically distributed data. We propose a stationary autoregressive (AR) process with Gumbel distributed innovation and characterise the short-term dependence among maxima of an (AR) process over a range of sample sizes with varying degrees of dependence. We estimate the maximum likelihood of the parameters of t

APA, Harvard, Vancouver, ISO, and other styles

18

Lasslop, G., M. Reichstein, J. Kattge, and D. Papale. "Influences of observation errors in eddy flux data on inverse model parameter estimation." Biogeosciences Discussions 5, no. 1 (2008): 751–85. http://dx.doi.org/10.5194/bgd-5-751-2008.

Full text

Abstract:

Abstract. Eddy covariance data are increasingly used to estimate parameters of ecosystem models and for proper maximum likelihood parameter estimates the error structure in the observed data has to be fully characterized. In this study we propose a method to characterize the random error of the eddy covariance flux data, and analyse error distribution, standard deviation, cross- and autocorrelation of CO2 and H2O flux errors at four different European eddy covariance flux sites. Moreover, we examine how the treatment of those errors and additional systematic errors influence statistical estima

APA, Harvard, Vancouver, ISO, and other styles

19

Lasslop, G., M. Reichstein, J. Kattge, and D. Papale. "Influences of observation errors in eddy flux data on inverse model parameter estimation." Biogeosciences 5, no. 5 (2008): 1311–24. http://dx.doi.org/10.5194/bg-5-1311-2008.

Full text

Abstract:

Abstract. Eddy covariance data are increasingly used to estimate parameters of ecosystem models. For proper maximum likelihood parameter estimates the error structure in the observed data has to be fully characterized. In this study we propose a method to characterize the random error of the eddy covariance flux data, and analyse error distribution, standard deviation, cross- and autocorrelation of CO2 and H2O flux errors at four different European eddy covariance flux sites. Moreover, we examine how the treatment of those errors and additional systematic errors influence statistical estimates

APA, Harvard, Vancouver, ISO, and other styles

20

Hac, A., and P. D. Spanos. "Time Domain Method for Parameter System Identification." Journal of Vibration and Acoustics 112, no. 3 (1990): 281–87. http://dx.doi.org/10.1115/1.2930506.

Full text

Abstract:

In this paper a method of parameter identification for a multi-degree-of-freedom structural system in a noisy environment is presented. The method involves an iterative procedure in which initial parameter estimates are obtained by relying on a least squares kind of approximation. This estimate is used in an adaptive Kalman filter to obtain an improved estimate of the system state. The improved estimate is then utilized in the least squares approximation to produce refined estimates of the system parameters. The iteration is repeated until it converges within an acceptable margin. The paramete

APA, Harvard, Vancouver, ISO, and other styles

21

Zala, Cedric A., and John M. Ozard. "Estimation of Geoacoustic Parameters from Narrowband Data Using a Search-Optimization Technique." Journal of Computational Acoustics 06, no. 01n02 (1998): 223–43. http://dx.doi.org/10.1142/s0218396x98000168.

Full text

Abstract:

Geoacoustic parameters were estimated for vertical array data from the matched-field inversion benchmark data sets. Separate inversions were performed for narrowband data at 25 Hz, 50 Hz and 75 Hz, using a matching function consisting of the incoherent sum of the Bartlett outputs for the five vertical arrays at ranges of 1, 2, 3, 4 and 5 km. Parameter estimation was performed using a parabolic equation sound propagation algorithm to generate the replica fields, and a search-optimization technique to obtain estimates of the optimized parameter values. This technique involved an initial search s

APA, Harvard, Vancouver, ISO, and other styles

22

Hollenbach, Florian M., Jacob M. Montgomery, and Adriana Crespo-Tenorio. "Bayesian Versus Maximum Likelihood Estimation of Treatment Effects in Bivariate Probit Instrumental Variable Models." Political Science Research and Methods 7, no. 3 (2018): 651–59. http://dx.doi.org/10.1017/psrm.2018.15.

Full text

Abstract:

Bivariate probit models are a common choice for scholars wishing to estimate causal effects in instrumental variable models where both the treatment and outcome are binary. However, standard maximum likelihood approaches for estimating bivariate probit models are problematic. Numerical routines in popular software suites frequently generate inaccurate parameter estimates and even estimated correctly, maximum likelihood routines provide no straightforward way to produce estimates of uncertainty for causal quantities of interest. In this note, we show that adopting a Bayesian approach provides m

APA, Harvard, Vancouver, ISO, and other styles

23

Mohamed, M., and N. Joy. "Lateral directional aircraft aerodynamic parameter estimation using adaptive stochastic nonlinear filter." Aeronautical Journal 125, no. 1294 (2021): 2217–28. http://dx.doi.org/10.1017/aer.2021.61.

Full text

Abstract:

AbstractThis paper aims to accurately estimate the lateral directional aerodynamic parameters in real time irrespective of the variations in the process and measurement covariance matrices. The proposed algorithm for parameter estimation is based on the integration of adaptive techniques into a stochastic nonlinear filter. The proposed adaptive estimation algorithm is applied to flight test data, and the lateral directional derivatives are estimated in real time. The estimates are compared with those obtained from the Filter Error Method (FEM), an offline parameter estimation method accounting

APA, Harvard, Vancouver, ISO, and other styles

24

Jacquez, J. A., and T. Perry. "Parameter estimation: local identifiability of parameters." American Journal of Physiology-Endocrinology and Metabolism 258, no. 4 (1990): E727—E736. http://dx.doi.org/10.1152/ajpendo.1990.258.4.e727.

Full text

Abstract:

For biological systems one often cannot set up experiments to measure all of the state variables. If only a subset of the state variables can be measured, it is possible that some of the system parameters cannot influence the measured state variables or that they do so in combinations that do not define the parameters' effects separately. Such parameters are unidentifiable and are in theory unestimable. Given a model of the system, linear or nonlinear, and initial estimates of the values of all parameters, we exhibit a simple theory and describe a program for checking the local identifiability

APA, Harvard, Vancouver, ISO, and other styles

25

Epstein, Michael P., Xihong Lin, and Michael Boehnke. "Ascertainment-Adjusted Parameter Estimates Revisited." American Journal of Human Genetics 70, no. 4 (2002): 886–95. http://dx.doi.org/10.1086/339517.

Full text

APA, Harvard, Vancouver, ISO, and other styles

26

Parrilo, Pablo A., and Lennart Ljung. "Initialization of Physical Parameter Estimates." IFAC Proceedings Volumes 36, no. 16 (2003): 1483–88. http://dx.doi.org/10.1016/s1474-6670(17)34969-8.

Full text

APA, Harvard, Vancouver, ISO, and other styles

27

Roukema, B. F., Z. Buliński, and N. E. Gaudin. "Poincaré dodecahedral space parameter estimates." Astronomy & Astrophysics 492, no. 3 (2008): 657–73. http://dx.doi.org/10.1051/0004-6361:200810685.

Full text

APA, Harvard, Vancouver, ISO, and other styles

28

Kjeldsen, Thomas R., and David A. Jones. "Sampling variance of flood quantiles from the generalised logistic distribution estimated using the method of L-moments." Hydrology and Earth System Sciences 8, no. 2 (2004): 183–90. http://dx.doi.org/10.5194/hess-8-183-2004.

Full text

Abstract:

Abstract. The method of L-moments is the recommended method for fitting the three parameters (location, scale and shape) of a Generalised Logistic (GLO) distribution when conducting flood frequency analyses in the UK. This paper examines the sampling uncertainty of quantile estimates obtained using the GLO distribution for single site analysis using the median to estimate the location parameter. Analytical expressions for the mean and variance of the quantile estimates were derived, based on asymptotic theory. This has involved deriving expressions for the covariance between the sampling media

APA, Harvard, Vancouver, ISO, and other styles

29

Beltracchi, T. J., and G. A. Gabriele. "A Recursive Quadratic Programming Based Method for Estimating Parameter Sensitivity Derivatives." Journal of Mechanical Design 113, no. 4 (1991): 487–94. http://dx.doi.org/10.1115/1.2912809.

Full text

Abstract:

Parameter sensitivity analysis is defined as the estimation of changes in the modeling functions and design point due to small changes in the fixed parameters of the formulation. There are currently several methods for estimating parameter sensitivities which either require second order information, or do not return reliable estimates for the derivatives. This paper presents a method based on the use of the recursive quadratic programming method in conjunction with differencing formulas to estimate parameter sensitivity derivatives without the need to calculate second order information. In add

APA, Harvard, Vancouver, ISO, and other styles

30

Okumu, Otieno Kevin, Omondi Joseph Ouno, Anthony Nyutu Karanjah, and Samuel Nganga Muthiga. "Three-parameters Gumbel Distribution: Formulation and Parameter Estimation." International Journal of Statistical Distributions and Applications 10, no. 2 (2024): 25–37. http://dx.doi.org/10.11648/j.ijsd.20241002.12.

Full text

Abstract:

Modeling extreme value theories is really gaining interest in the world with scientist working to improve the flexibility of the distributions by adding parameter(s). Extreme value distributions are always described to include families of Gumbel, Weibull and Frechet distributions. Of the three distributions, Gumbel distribution is the most commonly used in the extreme value theory analysis. Existing literature has shown that the addition of parameter to a distribution makes it robust and/or more flexible hence the study intends to improve the existing two parameters Gumbel distribution using t

APA, Harvard, Vancouver, ISO, and other styles

31

Chandran, K., Z. Hu, and B. F. Smets. "Applicability of an extant batch respirometric assay in describing dynamics of ammonia and nitrite oxidation in a nitrifying bioreactor." Water Science and Technology 52, no. 10-11 (2005): 503–8. http://dx.doi.org/10.2166/wst.2005.0729.

Full text

Abstract:

Several techniques have been proposed for biokinetic estimation of nitrification. Recently, an extant respirometric assay has been presented that yields kinetic parameters for both nitrification steps with minimal physiological change to the microorganisms during the assay. Herein, the ability of biokinetic parameter estimates from the extant respirometric assay to adequately describe concurrently obtained NH4+-N and NO2−-N substrate depletion profiles is evaluated. Based on our results, in general, the substrate depletion profiles resulted in a higher estimate of the maximum specific growth r

APA, Harvard, Vancouver, ISO, and other styles

32

Badarisam, Fatin Najihah, Mohd Syazwan Mohamad Anuar, Abdul Ghapor Hussin, Adzhar Rambli, and Nurul Raudhah Zulkifli. "Confidence Interval for Parameters Estimates in Circular Simultaneous Functional Relationship Model (CSFRM) for Equal Variances using Normal Asymptotic and Bootstrap Confidence Intervals." Sains Malaysiana 51, no. 11 (2021): 3819–27. http://dx.doi.org/10.17576/jsm-2022-5111-25.

Full text

Abstract:

Few studies have considered the functional relationship model for circular variables. Anuar has proposed a new model of Circular Simultaneous Functional Relationship Model for equal variances. However, the confidence interval for all parameter estimates in this model has not received any consideration in any literature. This paper proposes the confidence interval for all parameter estimates of von Mises distribution in this model. The parameters are estimated using minimum sum (ms) and polyroot function provided in (built-in package) Splus statistical software. The parameters confidence may be

APA, Harvard, Vancouver, ISO, and other styles

33

Otunuga, Olusegun Michael. "Time Varying Parameter Estimation Scheme for a Linear Stochastic Differential Equation." International Journal of Statistics and Probability 6, no. 5 (2017): 84. http://dx.doi.org/10.5539/ijsp.v6n5p84.

Full text

Abstract:

In this work, an attempt is made to estimate time varying parameters in a linear stochastic differential equation. By defining $m_{k}$ as the local admissible sample/data observation size at time $t_{k}$, parameters and state at time $t_{k}$ are estimated using past data on interval $[t_{k-m_{k}+1}, t_{k}]$. We show that the parameter estimates at each time $t_{k}$ converge in probability to the true value of the parameters being estimated. A numerical simulation is presented by applying the local lagged adapted generalized method of moments (LLGMM) method to the stochastic differential models

APA, Harvard, Vancouver, ISO, and other styles

34

Konečná, Tereza, and Zuzana Hübnerová. "Asymptotic Comparison of Parameters Estimates of Two-parameter Weibull Distribution." Acta Universitatis Agriculturae et Silviculturae Mendelianae Brunensis 67, no. 1 (2019): 253–63. http://dx.doi.org/10.11118/actaun201967010253.

Full text

Abstract:

The Weibull distribution is frequently applied in various fields, ranging from economy, business, biology, to engineering. This paper aims at estimating the parameters of two-parameter Weibull distribution are determined. For this purpose, the method of quantiles (three different choices of quantiles) and Weibull probability plot method is utilized. The asymptotic covariance matrix of the parameter estimates is derived for both methods. For optimal random choices of quantiles, the variance, covariance and generalized variance is computed. The main contribution of this study is the introduction

APA, Harvard, Vancouver, ISO, and other styles

35

Nizeyimana, Pacifique, Kyeong Eun Lee, and Gwangseob Kim. "Bayesian Estimation of Neyman–Scott Rectangular Pulse Model Parameters in Comparison with Other Parameter Estimation Methods." Water 16, no. 17 (2024): 2515. http://dx.doi.org/10.3390/w16172515.

Full text

Abstract:

Neyman–Scott rectangular pulse is a stochastic rainfall model with five parameters. The impacts of initial values and optimization methods on the parameter estimation of the Neyman–Scott rectangular pulse model were investigated using both the method of moments and the method of maximum likelihood. The estimates using the method of moments were influenced by the optimization method and were sensitive to the initial values and the aggregation scale of the data. Thus, by using frequentist estimation methods, we cannot guarantee the unique values as estimates. The aim of this study is to find mor

APA, Harvard, Vancouver, ISO, and other styles

36

Todini, E. "Influence of parameter estimation uncertainty in Kriging: Part 1 - Theoretical Development." Hydrology and Earth System Sciences 5, no. 2 (2001): 215–23. http://dx.doi.org/10.5194/hess-5-215-2001.

Full text

Abstract:

Abstract. This paper deals with a theoretical approach to assessing the effects of parameter estimation uncertainty both on Kriging estimates and on their estimated error variance. Although a comprehensive treatment of parameter estimation uncertainty is covered by full Bayesian Kriging at the cost of extensive numerical integration, the proposed approach has a wide field of application, given its relative simplicity. The approach is based upon a truncated Taylor expansion approximation and, within the limits of the proposed approximation, the conventional Kriging estimates are shown to be bia

APA, Harvard, Vancouver, ISO, and other styles

37

Faladiba, Muthia Nadhira, and Atina Ahdika. "BAYES ESTIMATION OF EXPONENTIALLY DISTRIBUTED SURVIVAL DATA UNDER SYMMETRIC AND ASYMMETRIC LOSS FUNCTIONS." BAREKENG: Jurnal Ilmu Matematika dan Terapan 18, no. 2 (2024): 0973–86. http://dx.doi.org/10.30598/barekengvol18iss2pp0973-0986.

Full text

Abstract:

In a research study, population data are often not available, so the population parameter is unknown. Meanwhile, knowledge about the population parameter is needed to know the characteristics of the studied population. Therefore, it is needed to estimate the parameter of the population which can be estimated by sample data. There are several methods of parameter estimation which are generally classified into classical and Bayesian method. This research studied the Bayesian parameter estimation method to determine the parameters of the exponentially distributed survival data associated with the

APA, Harvard, Vancouver, ISO, and other styles

38

Baneh, Hasan, Mojtaba Najafi, and Ghodrat Rahimi. "Genetic parameter estimates for early growth traits in Naeini goat." Animal Production Science 52, no. 11 (2012): 1046. http://dx.doi.org/10.1071/an12045.

Full text

Abstract:

The present study was carried out to estimate variance components for growth traits in Naeini goats. Bodyweight records were collected for two flocks under supervision of the Agriculture Organisation of the Esfahan province between 2000 and 2007. Investigated traits were birthweight (BW; n = 2483), weaning weight (WW; n = 1211) and average daily gain from birth to weaning (ADG; n = 1211). Environmental effects were investigated using fixed-effect models, while (co)variance components and genetic parameters were estimated with single- and three-trait analyses using REML methods and WOMBAT softw

APA, Harvard, Vancouver, ISO, and other styles

39

Eberhardt, L. L., B. M. Blanchard, and R. R. Knight. "Population trend of the Yellowstone grizzly bear as estimated from reproductive and survival rates." Canadian Journal of Zoology 72, no. 2 (1994): 360–63. http://dx.doi.org/10.1139/z94-049.

Full text

Abstract:

The trend of the Yellowstone grizzly bear (Ursus arctos horribilis) population was estimated using reproductive rates calculated from 22 individual females and survival rates from 400 female bear-years. The point estimate of the rate of increase was 4.6%, with 95% confidence limits of 0 and 9%. Caution in interpreting this result is advised because of possible biases in the population parameter estimates. The main prospects for improving present knowledge of the population trend appear to be further study of possible biases in the parameter estimates, and the continued use of radiotelemetry to

APA, Harvard, Vancouver, ISO, and other styles

40

Mohamed, Majeed, and Vikalp Dongare. "Aircraft neural modeling and parameter estimation using neural partial differentiation." Aircraft Engineering and Aerospace Technology 90, no. 5 (2018): 764–78. http://dx.doi.org/10.1108/aeat-02-2016-0021.

Full text

Abstract:

Purpose The purpose of this paper is to build a neural model of an aircraft from flight data and online estimation of the aerodynamic derivatives from established neural model. Design/methodology/approach A neural model capable of predicting generalized force and moment coefficients of an aircraft using measured motion and control variable is used to extract aerodynamic derivatives. The use of neural partial differentiation (NPD) method to the multi-input-multi-output (MIMO) aircraft system for the online estimation of aerodynamic parameters from flight data is extended. Findings The estimatio

APA, Harvard, Vancouver, ISO, and other styles

41

Godinez, Humberto C., Jon M. Reisner, Alexandre O. Fierro, Stephen R. Guimond, and Jim Kao. "Determining Key Model Parameters of Rapidly Intensifying Hurricane Guillermo (1997) Using the Ensemble Kalman Filter." Journal of the Atmospheric Sciences 69, no. 11 (2012): 3147–71. http://dx.doi.org/10.1175/jas-d-12-022.1.

Full text

Abstract:

Abstract In this work the authors determine key model parameters for rapidly intensifying Hurricane Guillermo (1997) using the ensemble Kalman filter (EnKF). The approach is to utilize the EnKF as a tool only to estimate the parameter values of the model for a particular dataset. The assimilation is performed using dual-Doppler radar observations obtained during the period of rapid intensification of Hurricane Guillermo. A unique aspect of Guillermo was that during the period of radar observations strong convective bursts, attributable to wind shear, formed primarily within the eastern semicir

APA, Harvard, Vancouver, ISO, and other styles

42

Villa-Diharce, Enrique R., Miguel Á. Cisneros-Mata, and Evlin A. Ramírez-Félix. "Effects of misrepresentative length samples on individual growth and stock condition estimates." Scientia Marina 87, no. 2 (2023): e062. http://dx.doi.org/10.3989/scimar.05313.062.

Full text

Abstract:

Despite its importance in fisheries studies, there is insufficient understanding on the effect of sampling error or bias on individual growth and other stock indicators. We show the influence of sample length distributions on parameter estimates, illustrating with an example. For the brown swimming crab, we simulated length samples in five configurations and estimated parameters of von Bertalanffy (k, L∞L∞ , t0), asymptotic weight ( W∞W∞ ), weight-length relationship (a, b), growth performance (ϕ’) and condition factor (Kn). Parameter estimates were compared with baseline values using relative

APA, Harvard, Vancouver, ISO, and other styles

43

Mikhailov, V. S. "A simple criterion for the effectiveness of biased estimators." Dependability 24, no. 1 (2024): 25–33. http://dx.doi.org/10.21683/1729-2646-2024-24-1-25-33.

Full text

Abstract:

Point estimation is one of the most common forms of statistical inference. This paper touches upon the concepts of unbiasedness and effectiveness of biased estimates. An attractive approximation for the true (quantitative) value of the estimated parameter t whose values belong to a certain numerical set t T is an estimate , for which the sum of the mathematical expectation of the square of the differences between the possible realization of and the estimated parameter t is minimal (least squares estimation). Another approach is to find the value of the parameter t based on the sum of the mathe

APA, Harvard, Vancouver, ISO, and other styles

44

Durban, J. W., D. A. Elston, X. Lambin, and P. M. Thompson. "A role for Bayesian inference in cetacean population assessment." J. Cetacean Res. Manage. 2, no. 2 (1999): 117–23. http://dx.doi.org/10.47536/jcrm.v2i2.495.

Full text

Abstract:

Decisions concerning the management and conservation of cetacean populations depend upon knowledge of population parameters, which generally must be estimated from sample data using statistical models. However, data from the cetacean populations are often sparse, and resultant parameter estimates can be uncertain and difficult to obtain. This review uses examples from published work to highlight the utility of the Bayesian statistical paradigm as a suitable estimation framework in these situations. By evaluating the probability of obtaining the available data, given a specified estimator model

APA, Harvard, Vancouver, ISO, and other styles

45

Rowling, K. R., and DD Reid. "Effect of temporal changes in size composition on estimates of von Bertalanffy growth parameters for Gemfish, Rexa solandri (Cuvier), Gempylidae." Marine and Freshwater Research 43, no. 5 (1992): 1229. http://dx.doi.org/10.1071/mf9921229.

Full text

Abstract:

Estimates of von Bertalanffy growth parameters were made for mature (>3-year-old) gemfish (Rexea solandri), using otoliths sampled biennially from commercial catches between 1980 and 1986. During this period, there was a significant decline in the mean length of mature gemfish in the catch. Large variations in growth-parameter estimates were found over the period sampled (e.g. L∞ ranged between 87.3 and 130.3 cm for males and between 113.1 and 134.7 cm for females). Likelihood-ratio tests showed many of the growth-parameter estimates to be significantly different between the years sampled.

APA, Harvard, Vancouver, ISO, and other styles

46

Shawkat, Lina, and Qutaiba Nayef. "A Comparison between (ECM) and (KNN) Methods for the Multivariate skew-normal model with incomplete data." Journal of Al-Rafidain University College For Sciences ( Print ISSN: 1681-6870 ,Online ISSN: 2790-2293 ), no. 1 (October 1, 2021): 377–93. http://dx.doi.org/10.55562/jrucs.v46i1.89.

Full text

Abstract:

Statistical parameter estimation for multivariate data leads to waste of information, if the missing data are omitted, and in return will lead to inaccurate estimates, that is why incomplete data should be estimated using one of the statistical estimation methods to get accurate results and in return good estimates for the parameters. This paper aims to estimate the missing values for a multivariate skew normal model using the Expectation Conditional Maximization (ECM) algorithm and the K-Nearest Neighbour (KNN) method. After estimating the missing values, the model parameters will be estimate

APA, Harvard, Vancouver, ISO, and other styles

47

Okasha, Hassan M., Heba S. Mohammed, and Yuhlong Lio. "E-Bayesian Estimation of Reliability Characteristics of a Weibull Distribution with Applications." Mathematics 9, no. 11 (2021): 1261. http://dx.doi.org/10.3390/math9111261.

Full text

Abstract:

Given a progressively type-II censored sample, the E-Bayesian estimates, which are the expected Bayesian estimates over the joint prior distributions of the hyper-parameters in the gamma prior distribution of the unknown Weibull rate parameter, are developed for any given function of unknown rate parameter under the square error loss function. In order to study the impact from the selection of hyper-parameters for the prior, three different joint priors of the hyper-parameters are utilized to establish the theoretical properties of the E-Bayesian estimators for four functions of the rate param

APA, Harvard, Vancouver, ISO, and other styles

48

Kim, Seonghoon. "Standard Errors of Estimators for IRT Ability Distribution Parameters." Korean Society for Educational Evaluation 38, no. 2 (2025): 273–304. https://doi.org/10.31158/jeev.2025.38.2.273.

Full text

Abstract:

In item response theory (IRT), the normal and nonparametric methods have been used to estimate the ability distribution of an examinee population. The purpose of this study is to examine the characteristics of the formulas for the standard errors of the estimators of IRT ability distribution parameters (mean and standard deviation) through simulations. The simulation factors considered were test length (25 and 50), population distribution type (normal, positively-skewed and negatively-skewed distributions), sample size (500 and 2000), and number and range of ability points to be used for estim

APA, Harvard, Vancouver, ISO, and other styles

49

Gimenez, O., A. Villefont, E. A. Catchpole, R, Choquet, and B. J. T. Morgan. "Methods for investigating parameter redundancy." Animal Biodiversity and Conservation 27, no. 1 (2004): 561–72. http://dx.doi.org/10.32800/abc.2004.27.0561.

Full text

Abstract:

The quantitative study of marked individuals relies mainly on the use of meaningful biological models. Classical inference is then conducted based on the model likelihood, parameterized by parameters such as survival, recovery, transition and recapture probabilities. In classical statistics, we seek parameter estimates by maximising the likelihood. However, models are often overparameterized and, as a consequence, some parameters cannot be estimated separately. Identifying how many and which (functions of) parameters are estimable is thus crucial not only for proper model selection based upon

APA, Harvard, Vancouver, ISO, and other styles

50

Kim, Seonghoon. "Estimation of Asymptotic Standard Errors of Bayesian Modal Item Parameter Estimators: Application to the 2PL and 3PL Models." Korean Society for Educational Evaluation 38, no. 1 (2025): 143–78. https://doi.org/10.31158/jeev.2025.38.1.143.

Full text

Abstract:

Item parameters of item response theory (IRT) models are often estimated by the Bayesian modal (BM) method, which is an extension of the marginal maximum likelihood (MML) method. The purpose of this study is to present a general method to estimate the asymptotic standard errors (SEs) of MML or BM item parameter estimators and to examine its specific performance under the two-parameter logistic (2PL) and three-parameter logistic (3PL) models. The asymptotic SEs of BM item parameter estimators can be computed theoretically based on the posterior information matrix. Before examining the performan

APA, Harvard, Vancouver, ISO, and other styles

We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!