{"title":"A likelihood ratio model for three-way data coupled with a Tucker3 model","authors":"Agnieszka Martyna , Eugenio Alladio , Monica Romagnoli , Fabrizio Malaspina , Marco Pazzi","doi":"10.1016/j.chemolab.2025.105464","DOIUrl":null,"url":null,"abstract":"<div><div>In forensic science, the analysis of diesel fuel is particularly important in fire investigations. The task is usually to compare the original accelerant found among the suspect’s belongings with the fire debris to find out if the fire could have been caused by the use of that particular diesel fuel (called source). The major problem when comparing the original accelerant with the fire debris is the weathering process of the accelerant taking place during the fire. The weathering process makes the composition of the accelerant change with the weathering state and may differ from the composition of the original accelerant. In this context the question arises if samples of the fire debris containing the accelerant weathered to different degrees are still so similar to the original accelerant that they can be regarded as coming from the same source (this particular accelerant) and whether samples of fire debris with accelerants from different sources are easily identified as such regardless of their weathering state. The hybrid likelihood ratio (LR) model which takes into account the information about the similarity and the frequency of observing the compared features in the samples was used for answering the above issues. Hybrid LR models use the new set of a limited number of variables that is generated using a variety of chemometric tools to summarise the data as well as possible and highlight the features that make each source of samples uniquely defined. The model was built for three-way GC–MS data of diesel fuel samples. Tucker3 model decomposed the three-dimensional array of the database into three matrices referring to GC, MS and samples (concentration) modes. The scores on the linear discriminant functions for the concentration mode served as an input for LR models. True origins for the majority of samples were indicated despite different weathering.</div></div>","PeriodicalId":9774,"journal":{"name":"Chemometrics and Intelligent Laboratory Systems","volume":"264 ","pages":"Article 105464"},"PeriodicalIF":3.7000,"publicationDate":"2025-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Chemometrics and Intelligent Laboratory Systems","FirstCategoryId":"94","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0169743925001492","RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"AUTOMATION & CONTROL SYSTEMS","Score":null,"Total":0}
引用次数: 0
Abstract
In forensic science, the analysis of diesel fuel is particularly important in fire investigations. The task is usually to compare the original accelerant found among the suspect’s belongings with the fire debris to find out if the fire could have been caused by the use of that particular diesel fuel (called source). The major problem when comparing the original accelerant with the fire debris is the weathering process of the accelerant taking place during the fire. The weathering process makes the composition of the accelerant change with the weathering state and may differ from the composition of the original accelerant. In this context the question arises if samples of the fire debris containing the accelerant weathered to different degrees are still so similar to the original accelerant that they can be regarded as coming from the same source (this particular accelerant) and whether samples of fire debris with accelerants from different sources are easily identified as such regardless of their weathering state. The hybrid likelihood ratio (LR) model which takes into account the information about the similarity and the frequency of observing the compared features in the samples was used for answering the above issues. Hybrid LR models use the new set of a limited number of variables that is generated using a variety of chemometric tools to summarise the data as well as possible and highlight the features that make each source of samples uniquely defined. The model was built for three-way GC–MS data of diesel fuel samples. Tucker3 model decomposed the three-dimensional array of the database into three matrices referring to GC, MS and samples (concentration) modes. The scores on the linear discriminant functions for the concentration mode served as an input for LR models. True origins for the majority of samples were indicated despite different weathering.
期刊介绍:
Chemometrics and Intelligent Laboratory Systems publishes original research papers, short communications, reviews, tutorials and Original Software Publications reporting on development of novel statistical, mathematical, or computer techniques in Chemistry and related disciplines.
Chemometrics is the chemical discipline that uses mathematical and statistical methods to design or select optimal procedures and experiments, and to provide maximum chemical information by analysing chemical data.
The journal deals with the following topics:
1) Development of new statistical, mathematical and chemometrical methods for Chemistry and related fields (Environmental Chemistry, Biochemistry, Toxicology, System Biology, -Omics, etc.)
2) Novel applications of chemometrics to all branches of Chemistry and related fields (typical domains of interest are: process data analysis, experimental design, data mining, signal processing, supervised modelling, decision making, robust statistics, mixture analysis, multivariate calibration etc.) Routine applications of established chemometrical techniques will not be considered.
3) Development of new software that provides novel tools or truly advances the use of chemometrical methods.
4) Well characterized data sets to test performance for the new methods and software.
The journal complies with International Committee of Medical Journal Editors'' Uniform requirements for manuscripts.