Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Linear Approximation in Time Domain01:21

Linear Approximation in Time Domain

460
Nonlinear systems often require sophisticated approaches for accurate modeling and analysis, with state-space representation being particularly effective. This method is especially useful for systems where variables and parameters vary with time or operating conditions, such as in a simple pendulum or a translational mechanical system with nonlinear springs.
For a simple pendulum with a mass evenly distributed along its length and the center of mass located at half the pendulum's length,...
460
Model Approaches for Pharmacokinetic Data: Distributed Parameter Models01:06

Model Approaches for Pharmacokinetic Data: Distributed Parameter Models

333
Pharmacokinetic models are mathematical constructs that represent and predict the time course of drug concentrations in the body, providing meaningful pharmacokinetic parameters. These models are categorized into compartment, physiological, and distributed parameter models.
The distributed parameter models are specifically designed to account for variations and differences in some drug classes. This model is particularly useful for assessing regional concentrations of anticancer or...
333
Linear time-invariant Systems01:23

Linear time-invariant Systems

1.1K
A system is linear if it displays the characteristics of homogeneity and additivity, together termed the superposition property. This principle is fundamental in all linear systems. Linear time-invariant (LTI) systems include systems with linear elements and constant parameters.
The input-output behavior of an LTI system can be fully defined by its response to an impulsive excitation at its input. Once this impulse response is known, the system's reaction to any other input can be...
1.1K
BIBO stability of continuous and discrete -time systems01:24

BIBO stability of continuous and discrete -time systems

1.1K
System stability is a fundamental concept in signal processing, often assessed using convolution. For a system to be considered bounded-input bounded-output (BIBO) stable, any bounded input signal must produce a bounded output signal. A bounded input signal is one where the modulus does not exceed a certain constant at any point in time.
To determine the BIBO stability, the convolution integral is utilized when a bounded continuous-time input is applied to a Linear Time-Invariant (LTI) system....
1.1K
Mechanistic Models: Compartment Models in Individual and Population Analysis01:23

Mechanistic Models: Compartment Models in Individual and Population Analysis

359
Mechanistic models are utilized in individual analysis using single-source data, but imperfections arise due to data collection errors, preventing perfect prediction of observed data. The mathematical equation involves known values (Xi), observed concentrations (Ci), measurement errors (εi), model parameters (ϕj), and the related function (ƒi) for i number of values. Different least-squares metrics quantify differences between predicted and observed values. The ordinary least...
359
Multicompartment Models: Overview01:14

Multicompartment Models: Overview

712
Multicompartment models are mathematical constructs that depict how drugs are distributed and eliminated within the body. They segment the body into several compartments, symbolizing various physiological or anatomical areas connected through drug transfer processes such as absorption, metabolism, distribution, and elimination.
These models offer a more comprehensive representation of drug behavior in the body than one-compartment models. They accommodate the complexity of drug distribution,...
712

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Self-assembed Fe-doped tobacco straw rich in lignin biochar towards efficient activation of peroxymonosulfate for sulfonamide elimination: Characterization, experimental study, and theoretical calculation.

International journal of biological macromolecules·2025
Same author

High-performance air filters via NH<sub>2</sub>-MIL-101 deposition on cellulosic paper substrate.

International journal of biological macromolecules·2025
Same author

Epidemiology and genetic characterization of <i>tet</i>(X4)-positive <i>Klebsiella pneumoniae</i> and <i>Klebsiella quasipneumoniae</i> isolated from raw meat in Chengdu City, China.

Biosafety and health·2025
Same author

Enhancing T-Cell Infiltration and Immunity in Solid Tumors via DNA Nanolinker-Mediated Monocyte Hitchhiking.

Journal of the American Chemical Society·2025
Same author

Correction to: Metanephric mesenchyme-derived Foxd1<sup>+</sup> mesangial precursor cells alleviate mesangial proliferative glomerulonephritis.

Journal of molecular medicine (Berlin, Germany)·2025
Same author

Inorganic arsenic in aquatic products in Shenzhen, China from 2018 to 2024: Levels, temporal variation and health risk assessment.

Food and chemical toxicology : an international journal published for the British Industrial Biological Research Association·2025
Same journal

Correction.

Journal of biopharmaceutical statistics·2026
Same journal

Leveraging external controls in clinical trials: estimands, estimation, assumptions.

Journal of biopharmaceutical statistics·2026
Same journal

Special issue of nonclinical statistics in regulatory applications guest editors' notes.

Journal of biopharmaceutical statistics·2026
Same journal

Comparison of flexible parametric modeling and nonparametric methods to estimate restricted mean survival time: A simulation study.

Journal of biopharmaceutical statistics·2026
Same journal

Simulated treatment comparisons with jackknife pseudo values for estimating population-adjusted marginal treatment effects.

Journal of biopharmaceutical statistics·2026
Same journal

Sample sizes for randomized controlled trials utilizing Bayesian response adaptive randomization for continuous outcomes.

Journal of biopharmaceutical statistics·2026
See all related articles

Related Experiment Video

Updated: May 1, 2026

A Method of Trigonometric Modelling of Seasonal Variation Demonstrated with Multiple Sclerosis Relapse Data
10:46

A Method of Trigonometric Modelling of Seasonal Variation Demonstrated with Multiple Sclerosis Relapse Data

Published on: December 9, 2015

10.3K

A smoothing dynamic model for irregularly time-spaced longitudinal data.

Bo Fu1, Wenyang Zhang

  • 1a Centre for Biostatistics, Institute of Population Health , University of Manchester , Manchester , United Kingdom.

Journal of Biopharmaceutical Statistics
|April 5, 2014
PubMed
Summary
This summary is machine-generated.

This study introduces a dynamic model for analyzing unbalanced longitudinal data, common in observational studies. The proposed method offers a more accurate assessment of risk factors compared to traditional intention-to-treat analyses.

Keywords:
Dynamic modelIrregularly spaced measurementsLongitudinal dataVarying coefficient

More Related Videos

Development of an Individual-Tree Basal Area Increment Model using a Linear Mixed-Effects Approach
04:35

Development of an Individual-Tree Basal Area Increment Model using a Linear Mixed-Effects Approach

Published on: July 3, 2020

2.9K
Quantifying Cytoskeleton Dynamics Using Differential Dynamic Microscopy
06:37

Quantifying Cytoskeleton Dynamics Using Differential Dynamic Microscopy

Published on: June 15, 2022

5.0K

Related Experiment Videos

Last Updated: May 1, 2026

A Method of Trigonometric Modelling of Seasonal Variation Demonstrated with Multiple Sclerosis Relapse Data
10:46

A Method of Trigonometric Modelling of Seasonal Variation Demonstrated with Multiple Sclerosis Relapse Data

Published on: December 9, 2015

10.3K
Development of an Individual-Tree Basal Area Increment Model using a Linear Mixed-Effects Approach
04:35

Development of an Individual-Tree Basal Area Increment Model using a Linear Mixed-Effects Approach

Published on: July 3, 2020

2.9K
Quantifying Cytoskeleton Dynamics Using Differential Dynamic Microscopy
06:37

Quantifying Cytoskeleton Dynamics Using Differential Dynamic Microscopy

Published on: June 15, 2022

5.0K

Area of Science:

  • Biostatistics
  • Longitudinal Data Analysis
  • Observational Studies

Background:

  • Irregularly spaced measurements are common in longitudinal observational studies.
  • Analyzing highly unbalanced longitudinal data presents significant challenges.
  • Existing methods like intention-to-treat with last-value-carried-forward may underestimate effects.

Purpose of the Study:

  • To propose a novel smoothing dynamic model for analyzing unbalanced longitudinal data.
  • To accurately estimate model parameters using B-splines techniques.
  • To compare the proposed method with traditional approaches using rheumatoid arthritis patient data.

Main Methods:

  • Development of a smoothing dynamic model incorporating varying coefficients.
  • Implementation of B-splines technique for parameter estimation.
  • Application to a primary care-based longitudinal cohort of rheumatoid arthritis patients.

Main Results:

  • The proposed varying coefficients dynamic model effectively analyzes unbalanced longitudinal data.
  • B-splines provide a robust method for parameter estimation in this context.
  • The new method revealed potential underestimation of risk factor effects by last-value-carried-forward imputation.

Conclusions:

  • The smoothing dynamic model offers an improved approach for analyzing unbalanced longitudinal data.
  • This method provides more accurate insights into risk factor effects in cohort studies.
  • It is particularly relevant for rheumatoid arthritis research and similar observational studies.