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Quality Tolerance Limits: A General Guidance for Parameter Selection and Threshold Setting

THERAPEUTIC INNOVATION & REGULATORY SCIENCE 2024年第3期58卷 423-430页

作者： Keller, Annett van Borrendam, Nathalie Benner, Patrice Gilbert, Steven Saino, Stefano Jendrasek, Debra Young, Steve Muli, Marcus Wang, Jim Kozinska, Marta Liu, Jun Boehringer Ingelheim Pharm GmbH KG & Co Global Biostat & Data Sci Binger Str 173 D-55216 Ingelheim Germany Janssen Res & Dev Integrated Data Analyt & Reporting Graaf Engelbertlaan 75 NL-4837DS Breda Netherlands Merck & Co Inc Global Data Management & Stand 770 Sumneytown Pike West Point PA 19486 USA Pfizer Stat Res & Innovat 100 Cambridge Pk Dr Cambridge MA 02140 USA Palazzo Canova Risk Evaluat & Adapt Integrated Monitoring MSD V Flli Cervi I-20090 Milan Italy Daiichi Sankyo Risk Based Qual Management 211 Mt Airy Rd Basking Ridge NJ 07920 USA Cluepoints Research 1000 Continental Dr Suite 240 King Of Prussia PA 19406 USA Merck & Co Inc Biostat & Res Decis Sci 351 N Sumneytown Pike N Wales PA 19454 USA Janssen Res & Dev Stat & Decis Sci 920 Route 202 Raritan NJ 08869 USA AstraZeneca Centralized Monitoring BioPharmaceut Clin Operat R&D Postepu 14 PL-02676 Warsaw Poland Astellas Centralized Monitoring 1 Astellas Way Northbrook IL 60062 USA

The past years have sharpened the industry's understanding of a Quality by Design (QbD) approach toward clinical trials. Using QbD encourages designing quality into a trial during the planning phase. The identification of Critical to Quality (CtQs) factors and specifically Critical data and Processes (CD&Ps) is key to such a risk-based monitoring approach. A variable that allows monitoring the evolution of risk regarding the CD&Ps is called a Quality Tolerance Limit (QTL) parameter. These parameters are linked to the scientific question(s) of a trial and may identify the issues that can jeopardize the integrity of trial endpoints. This paper focuses on defining what QTL parameters are and providing general guidance on setting thresholds for these parameters allowing for the derivation of an acceptable range of the risk.

关键词： CtQ factor Quality Tolerance Limits (QTLs) QTL Parameter QTL Threshold setting methodologies data simulation Historical data

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Analyzing evidence-based falls prevention data with significant missing information using variable selection after multiple imputation

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JOURNAL OF APPLIED STATISTICS 2023年第3期50卷 724-743页

作者： Cheng, Yujia Li, Yang Lee Smith, Matthew Li, Changwei Shen, Ye Univ Georgia Athens GA 30602 USA Renmin Univ China Beijing Peoples R China Texas A&M Univ College Stn TX 77843 USA Tulane Univ New Orleans LA 70118 USA

Falls are the leading cause of fatal and non-fatal injuries among older adults. Evidence-based fall prevention programs are delivered nationwide, largely supported by funding from the Administration for Community Living (ACL), to mitigate fall-related risk. This study utilizes data from 39 ACL grantees in 22 states from 2014 to 2017. The large amount of missing values for falls efficacy in this national database may lead to potentially biased statistical results and make it challenging to implement reliable variable selection. Multiple imputation is used to deal with missing values. To obtain a consistent result of variable selection in multiply-imputed datasets, multiple imputation-stepwise regression (MI-stepwise) and multiple imputation-least absolute shrinkage and selection operator (MI-LASSO) methods are used. To compare the performances of MI-stepwise and MI-LASSO, simulation studies were conducted. In particular, we extended prior work by considering several circumstances not covered in previous studies, including an extensive investigation of data with different signal-to-noise ratios and various missing data patterns across predictors, as well as a data structure that allowed the missingness mechanism to be missing not at random (MNAR). In addition, we evaluated the performance of MI-LASSO method with varying tuning parameters to address the overselection issue in cross-validation (CV)-based LASSO.

关键词： Multiple imputation variable selection stepwise regression group LASSO penalty Rubin's rules data simulation fall prevention falls efficacy

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Comprehensive Airborne Laser Scanning (ALS) simulation

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JOURNAL OF THE INDIAN SOCIETY OF REMOTE SENSING 2021年第7期49卷 1603-1622页

作者： Dayal, Shikhar Goel, Salil Lohani, Bharat Mittal, Namit Mishra, R. K. Indian Inst Technol Dept Civil Engn Kanpur Uttar Pradesh India Univ New Dept Geodesy & Geomat Engn Brunswick ME USA

The 3D topographic data generated by airborne laser scanning (ALS) has numerous applications such as urban planning, transportation planning, flood modeling and mapping. Various types of LiDAR (light detection and ranging) datasets are needed for testing and development of algorithms for these applications. Such datasets are not readily available as the LiDAR data capturing process is complex, time-consuming and expensive. Simulated ALS data can be a low-cost alternative to the expensive LiDAR datasets. This paper presents the development of a simulator (called Limulator 4.0) for ALS data. Limulator includes four components, namely 3D model component, camera component, laser component and LiDAR data generation. The first component provides a user, the facility to input user-defined 3D models of various objects. The laser component mathematically models the scanner movement and flight trajectory to generate simulated ALS parameters. The camera component takes user-defined parameters to generate images captured by a virtual camera. The effects of external and internal forces on flight movement and various errors are also modeled mathematically. Software for this simulation is developed in C + + , and its user-friendly GUI is developed using QT Creator 5.6. Limulator can serve as the ideal testbed for developing, testing and validation of various algorithms.

关键词： ALS LiDAR simulator Camera simulator data simulation Limulator

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Evaluating sampling techniques for quantifying Asiatic garden beetle (Maladera formosae) (Coleoptera: Scarabaeidae) infestations in commercial mint

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JOURNAL OF ECONOMIC ENTOMOLOGY 2024年第6期117卷 2557-2566页

作者： Sturr, Connor E. Richmond, Douglas S. Long, Elizabeth Y. Purdue Univ Dept Entomol W Lafayette IN 47907 USA

The Asiatic garden beetle, Maladera formosae Brenske (AGB), has become a significant pest of commercial mint fields in northern Indiana. Larval feeding on mint roots can cause stunted growth and plant death when densities are high. Sampling approaches that provide reliable estimates of larval densities in mint have not been established, leaving farmers without the knowledge necessary to implement integrated pest management (IPM) strategies. To address this knowledge gap, we evaluated strategies for estimating AGB larval densities and plant performance in commercial mint systems. We used 2 sampling methods to collect larval density and plant performance data from 3 mint fields and conducted simulations to optimize sampling intensity (accuracy and precision) and sampling scheme (random vs. systematic) using these data. Additionally, we examined the sensitivity and efficiency of each sampling method. Compared to the cup-cutter method, the quadrat method provided the most accurate and precise estimates of larval density and plant performance, with <= 7 samples required per 0.2 ha. Quadrat excavation was also more sensitive, increasing the probability of detecting AGB larvae within a 32 m2 plot by 76.7%, and requiring significantly less time to survey an equivalent volume of soil for AGB larvae. When the quadrat method was employed, random sampling schemes provided below-ground biomass estimates that were significantly closer to the true mean of the sampling area. The results of this research will facilitate the development of IPM decision-making tools for farmers and support future research for AGB and other soil insect pests affecting mint production.

关键词： data simulation sampling intensity sensitivity sampling scheme soil insect

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Application of a normalised plot to the study of ter ter enzyme systems

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BIOCHIMIE 2004年第7期86卷 463-469页

作者： Bravo, IG Reglero, A Univ Leon Dpto Bioquim & Biol Mol Leon 24071 Spain Deustch Krebsforschungszentrum Heidelberg Germany

The kinetic characterisation of multisubstrate systems is not a trivial task. Common approaches simplify the experimental procedures by sequentially fixing saturating concentrations of different substrates/products, thereby attempting to isolate the influence of the varying molecule. Even after such tedious work, only apparent K-m values can be determined, preventing serious comparison among differential substrate behaviours. Moreover, the choice among rival kinetic models is not statistically guaranteed;instead, classical tools such as re-plots continue to be used. Here, we report the application of a normalisation of kinetic data, formerly applied to simpler systems, to the description of ter ter systems. This data treatment is able to provide true K-m values and a reliable description of the system, at the same time reducing the experimental work and statistically supporting the choice of kinetic schemes. (C) 2004 Elsevier SAS. All rights reserved.

关键词： kinetics multisubstrate ter ter normalised plot data simulation

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The P-h² relationship on load-displacement curve considering pile-up deformation mode in instrumented indentation

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JOURNAL OF MATERIALS RESEARCH 2021年第15期36卷 3074-3085页

作者： Habibi, S. Chicot, D. Mejias, A. Boutabout, B. Zareb, E. Semsoum, D. E. Benaissa, S. Mezough, A. Merzouk, H. Ahmed Zabana Univ Relizane Dept Mech Engn Relizane 48000 Algeria Univ Lille ULR 4515 F-59000 Lille France Univ Lille Dept GMP IUTA F-59650 Villeneuve Dascq France DjillaliLiabes Univ Sidi Bel Abbes Dept Mech Engn Sidi Bel Abbes 22000 Algeria

A microhardness tester equipped with a Vickers indenter allows the determination of mechanical properties of a large variety of materials by analyzing load-displacement curves. In present work, a new model to compute the coefficient of proportionality K (named K-factor) between P and h relating to the pile-up have been developed. It was proved that indenter tip defect must be absolutely considered for an accurate determination of the contact area reducing an overestimation of mechanical properties and better fitting the loading curve. The proposed model is validated on a large variety of materials, i.e. carbides, nitrides and oxides showing sink-in phenomenon and steel, stainless steel, brass, bronze and copper having pile-up deformation mode. The model is compared with previous developed ones for sink-in and pile-up that can be easily applied but ignoring deformation mode and discarding the indenter defects will lead to not quite right no phenomenologically representative mechanical properties.

关键词： Instrumented indentation Hardness Modeling data simulation

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Performance of inhomogeneous Poisson point process models under different scenarios of uncertainty in species presence-only data

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ENVIRONMENTAL SYSTEMS RESEARCH 2023年第1期12卷 1-18页

作者： Mugumaarhahama, Yannick Fandohan, Adande Belarmain Kakai, Romain L. Glele Univ Abomey Calavi Fac Sci Agron Lab Biomath & Estimat Forestieres LABEF 04 BP 1525 Cotonou Benin Univ Evangel Afrique Fac Agr & Environm Sci Unit Appl Biostat POB 3323 Bukavu DEM REP CONGO Univ Natl Agr Ecole Foresterie Tropicale Unite Rech Foresterie & Conservat Bioressources POB 45 Ketou Benin

Haphazard and opportunistic species occurrence (PO) data are widely used in species distribution models (SDMs) instead of high-quality species data gathered using appropriate and structured sampling methods, which is expensive and often spatially limited. Despite their widespread use in ecology, PO data are prone to errors and uncertainties, such as imperfect detectability, positional imprecision, and spatial niche truncation, which make their use analytically challenging for effective and adaptive biodiversity management and conservation. Using simulated data, this study investigates the effects of these uncertainties on the performance of spatial point process based presence-only and integrated SDMs. We investigated three SDMs in this study, one that ignores imperfect detectability: the presence-only model (PO model), and two that account for it: the thinned presence-only model (THINPO model) and the integrated model (PBPC model). The ability of these SDMs to produce accurate maximum likelihood estimates of intensity model coefficients and reliable predictions of species distributions under different data quality scenarios was investigated. The results show that SDMs that account for imperfect detectability (THINPO or PBPC models) are not applicable in situations of high detectability. In this situation, the PO model produces the most accurate maximum likelihood estimates of the models' coefficients (beta<^>k\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\hat{\beta }}_k$$\end{document}), and consequently the most accurate predictions of species distributions (lambda<^>(s)\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \beg

关键词： Imperfect detection Sampling bias Positional uncertainty Species distribution models Poisson point process data integration data simulation

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CATALYTIC COOPERATIVITY IN THE CA2+-DEPENDENT ATPASE ACTIVITY OF SPINACH CHLOROPLAST COUPLING FACTOR (CF1)

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BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 1994年第1期1184卷 54-64页

作者： ANDRALOJC, PJ HARRIS, DA UNIV OXFORD DEPT BIOCHEM OXFORD OX1 3QU ENGLAND

The Ca2+-ATPase activity of CF1, the soluble chloroplast coupling factor from spinach chloroplasts, was measured over ATP concentrations between 0.05 mu M and 1000 mu M. At very low ATP concentrations (<1 mu M), CF1 exhibited a high affinity, low capacity mode of catalysis (K-m = 0.05 mu M, V-max = 1 nmol min(-1) mg(-1)). This activity was unaffected by the epsilon-subunit of CF1, and was stimulated 2-3-fold by tentoxin or by anti-CF1 antibody. All three of these agents inhibit Ca2+-ATPase at higher ATP concentrations. The pattern of ATP and ITP stimulation of [P-32]P-i release from [gamma-P-32]ATP, over the entire range of ATP concentrations studied, was investigated by mathematical modelling. simulation of the observed data was possible only if three catalytic sites were operative, ruling out models for CF1 turnover with only two catalytic sites for ATP hydrolysis (whether or not a solely regulatory site was also present). Cooperativity between catalytic sites was also required for simulation of the data. The resultant mathematical model for ATP hydrolysis can most simply be accommodated using a structural model for CF1 in which three equivalent sites operate alternately during turnover (Boyer, P.D. (1989) FASEB J. 3, 2164-2178). We cannot, however, rule out a model in which an asymmetrical enzyme is maintained throughout turnover, providing that the catalytic sites in such an enzyme interact cooperatively during turnover.

关键词： CHLOROPLAST COUPLING FACTOR ATPASE, CA2+- UNISITE CATALYSIS COOPERATIVITY ALTERNATING SITE data simulation

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Diversity partitioning without statistical independence of alpha and beta

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ECOLOGY 2010年第7期91卷 1964-U98页

作者： Veech, Joseph A. Crist, Thomas O. Texas State Univ Dept Biol San Marcos TX 78666 USA Miami Univ Dept Zool Oxford OH 45056 USA

Diversity partitioning has become a popular method for analyzing patterns of alpha and beta diversity. A recent evaluation of the method emphasized a distinction between additive and multiplicative partitioning and further advocated the use of multiplicative partitioning based on a presumed independence between alpha and beta. Concurrently, additive partitioning was criticized for producing dependent alpha and beta estimates. Until now, the issue of statistical independence of alpha and beta (in either type of partitioning) has not been thoroughly examined, partly due to confusion about the meaning of statistical independence. Here, we adopted a probability-based definition of statistical independence that is essentially identical to the definition found in any statistics textbook. We used a data simulation approach to show that alpha and beta diversity are not statistically independent in either additive or multiplicative partitioning. However, the extent of the dependence is not so great that it cannot be overcome by using appropriate statistical techniques to control it. Both additive and multiplicative partitioning are statistically valid and logically sound approaches to analyzing diversity patterns.

关键词： additive partitioning alpha, beta, and gamma data simulation diversity partitioning multiplicative partitioning statistical independence

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A Framework for Analyzing the Impact of Missing data in Predictive Models 20

A Framework for Analyzing the Impact of Missing Data in Pred...

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29th ACM International Conference on Information and Knowledge Management (CIKM)

作者： Santore, Fabiola de Almeida, Eduardo C. Bonat, Wagner H. Pena, Eduardo H. M. de Oliveira, Luiz Eduardo S. Univ Fed Parana Curitiba Parana Brazil Univ Tecnol Fed Parana Toledo Brazil

ISBN: (纸本)9781450368599

We propose a stochastic framework to evaluate the impact of missing data on the performance of predictive models. The framework allows full control of important aspects of the data set structure. These include the number and type of the input variables, the correlation between the input variables and their general predictive power, and sample size. The missing process is generated from a multivariate Bernoulli distribution, which allows us to simulate missing patterns corresponding to the MCAR, MAR and MNAR mechanisms. Although the framework may be applied to virtually all types of predictive models, in this article, we focus on the logistic regression model and choose the accuracy as the predictive measure. The simulation results show that the effects of missing data disappear for large sample sizes, as expected. On the other hand, as the number of input variables increases, the accuracy decreases mainly for binary inputs.

关键词： data simulation Missing data Predictive Model

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