Parameter Estimate

2017 ◽  
pp. 97-127 ◽  
Author(s):  
Luca Lista
Keyword(s):  
Parameter Estimate

Adaptive Estimation Using Multiagent Network Identifiers With Undirected and Directed Graph Topologies

2013 ◽  
Vol 136 (2) ◽  
Author(s):  
Teymur Sadikhov ◽  
Michael A. Demetriou ◽  
Wassim M. Haddad ◽  
Tansel Yucelen
Keyword(s):  
Directed Graph ◽  
Adaptive Estimation ◽  
Parameter Estimate ◽  
The State ◽  
Adaptive Observer ◽  
Parameter Estimates ◽  
Communication Architecture ◽  
Adaptive Identifier ◽  
The Mean ◽  
Additive Term

In this paper, we present an adaptive estimation framework predicated on multiagent network identifiers with undirected and directed graph topologies. Specifically, the system state and plant parameters are identified online using N agents implementing adaptive observers with an interagent communication architecture. The adaptive observer architecture includes an additive term which involves a penalty on the mismatch between the state and parameter estimates. The proposed architecture is shown to guarantee state and parameter estimate consensus. Furthermore, the proposed adaptive identifier architecture provides a measure of agreement of the state and parameter estimates that is independent of the network topology and guarantees that the deviation from the mean estimate for both the state and parameter estimates converge to zero. Finally, an illustrative numerical example is provided to demonstrate the efficacy of the proposed approach.

Parameter Estimate Biases in Geoacoustic Inversion From Neglected Range Dependence

2008 ◽  
Vol 33 (3) ◽  
pp. 255-265 ◽  
Author(s):  
M.G. Morley ◽  
S.E. Dosso ◽  
N.R. Chapman
Keyword(s):  
Parameter Estimate ◽  
Geoacoustic Inversion

scholarly journals Better Coverage Intervals for Estimators from a Complex Sample Survey

2020 ◽  
Author(s):  
Phillip S. Kott
Keyword(s):  
Normal Distribution ◽  
Parameter Estimate ◽  
Regression Coefficients ◽  
Sample Survey ◽  
Complex Survey ◽  
Asymptotically Normal ◽  
Complex Survey Data ◽  
Complex Sample ◽  
Chi Squared ◽  
Coverage Interval

Coverage intervals for a parameter estimate computed using complex survey data are often constructed by assuming the parameter estimate has an asymptotically normal distribution and the measure of the estimator’s variance is roughly chi-squared. The size of the sample and the nature of the parameter being estimated render this conventional “Wald” methodology dubious in many applications. I developed a revised method of coverage-interval construction that “speeds up the asymptotics” by incorporating an estimated measure of skewness. I discuss how skewness-adjusted intervals can be computed for ratios, differences between domain means, and regression coefficients.

scholarly journals On the Non-Negative Radial Solutions of the Two Dimensional Bratu Equation

2021 ◽  
Vol 45 (02) ◽  
pp. 275-288
Author(s):  
MBE KOUA CHRISTOPHE NDJATCHI ◽  
PANAYOTIS VYRIDIS ◽  
JUAN MARTÍNEZ ◽  
J. JUAN ROSALES
Keyword(s):  
Finite Difference ◽  
Boundary Value Problem ◽  
Theoretical Result ◽  
Theoretical Method ◽  
Parameter Estimate ◽  
Two Dimensional ◽  
Negative Solution ◽  
Radial Solutions ◽  
Seidel Method ◽  
Bratu Equation

In this paper, we study the boundary value problem on the unit circle for the Bratu’s equation depending on the real parameter μ. From the parameter estimate, the existence of non-negative solution is set. A numerical method is suggested to justify the theoretical result. It is a combination of the adaptation of finite difference and Gauss-Seidel method allowing us to obtain a good approximation of μc, with respect to the exact theoretical method μc = λ = 5.7831859629467.

Abstract 5686: Predictors of Hypocalcemia after Wide Area Circumferential Ablation of Atrial Fibrillation

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Matthew S Forcina ◽  
Matthew Luff ◽  
Anish Amin ◽  
Frank A Cuoco ◽  
Matthew H Klein ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Multivariate Analysis ◽  
Normal Saline ◽  
Troponin I ◽  
Calcium Absorption ◽  
Parameter Estimate ◽  
Wide Area ◽  
P Value ◽  
Principal Mechanism ◽  
Post Procedure

Introduction: Hypocalcemia occurs frequently after wide area circumferential ablation (WACA) of atrial fibrillation and is more common with the use of open-irrigated tip ablation catheters (ITAC) than 8-mm tip ablation catheters. The mechanism of this phenomenon is unknown, but may be related to binding of calcium to myocardial proteins, volume infusion, or other factors. The present study aims to identify variables associated with acute hypocalcemia after WACA with ITAC. Methods: We analyzed 106 patients undergoing WACA with ITAC. Pre- and post-procedural values of calcium, creatinine, glomerular filtration rate (GFR), hemoglobin, cardiac enzymes (CK, CK-MB and troponin-I), albumin, left atrial size, presence of post-procedure pericardial effusion, infused volume of normal saline, urine output, heparin, furosemide dosage, and procedure time were recorded. Univariate and multivariate analysis were performed to determine variables associated with post-ablation hypocalcemia. Results: The population had mean age of 59±9 years, mean weight of 95±22 kilograms, and 76% were male. Mean pre-procedure GFR was 101±39 mL/min, and mean volume of normal saline infused was 5.5±1.3 liters. The means for pre-procedure calcium, post-procedure calcium, and decrease in calcium were 9.2±0.4, 7.3±0.6, and 1.9±0.7 mg/dL respectively. Of the variables measured, multivariate analysis identified pre-procedure GFR (parameter estimate −0.005) and infused volume of normal saline (parameter estimate 0.11) as factors independently associated with post-ablation hypocalcemia (p value = 0.03). Factors associated with myocardial injury were not apparently related. Conclusions: Lower GFR and higher infused volume of normal saline correlated with acute hypocalcemia after WACA with ITAC. Rather than binding to injured myocardium, these results suggest impaired renal calcium absorption and/or dilutional effects as the principal mechanism(s).

Abstract 2623: Racial Disparities in Hospital Length of Stay among Native Hawaiians and other Pacific Islanders with Ischemic Stroke

Stroke ◽  
2012 ◽  
Vol 43 (suppl_1) ◽  
Author(s):  
Kazuma Nakagawa ◽  
Matthew Koenig ◽  
Todd Seto ◽  
Susan Asai ◽  
Cherylee Chang
Keyword(s):  
Ischemic Stroke ◽  
Length Of Stay ◽  
Medical Center ◽  
Parameter Estimate ◽  
Hospital Length ◽  
Pacific Islanders ◽  
Native Hawaiians ◽  
Hospital Length Of Stay ◽  
Primary Stroke Center ◽  
Stroke Center

Introduction: Native Hawaiians and other Pacific Islanders (NHPI) with ischemic stroke are younger and have more comorbidities compared to other major racial-ethnic groups. However, their impact on hospital length of stay (LOS) after ischemic stroke has not been studied. Hypothesis: We assessed the hypothesis that NHPI race is associated with a longer hospital LOS after ischemic stroke. Methods: Data from 2004 to 2010 were retrospectively obtained from the Get With the Guidelines-Stroke (GWTG-Stroke) database from The Queen’s Medical Center, the only primary stroke center for the state of Hawaii. Multivariable analyses were performed using a stepwise linear regression model to identify factors predictive of hospital LOS after ischemic stroke. Results: A total of 1921 patients hospitalized for ischemic stroke (NHPI 20%, Asians 53%, whites 24%, blacks 0.8%, others 2%) were studied. Univariate analyses showed that NHPI were younger (mean ages, NHPI 60±14 vs. Asians 72±14, p <0.0001; vs. whites 71±14, p <0.0001) and had higher prevalence of diabetes (NHPI 53% vs. Asians 67%, p <0.0001; vs. whites 22%, p <0.0001), hypertension (NHPI 82% vs. whites 22%, p <0.0001), prior stroke or TIA (NHPI 30% vs. Asians 23%, p =0.01), smoking (NHPI 19% vs. Asians 14%, p =0.01), dyslipidemia (NHPI 43% vs. whites 34%, p <0.01), and longer hospital LOS (NHPI 11±17 days vs. Asians 7±9 days, p <0.0001; whites 8±17 days, p <0.05). After adjusting for age, race, gender, and risk factors with predefined significance ( p <0.1), independent predictors for hospital LOS were NHPI race (parameter estimate, 2.67; 95% CI, 1.09 - 4.22, p =0.001), atrial fibrillation/atrial flutter (parameter estimate, 2.22; 95% CI, 0.53 - 3.90, p =0.01), and age (parameter estimate, -0.04; 95% CI, -0.09 - -0.002, p =0.04). Conclusions: Native Hawaiians and other Pacific Islanders with ischemic stroke have a longer hospital length of stay compared to Asians and whites. Further studies are needed to assess if other socioeconomic factors contribute to the observed differences.

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