Discrimination of Black Pen Inks on Writing Documents Using Visible Reflectance Spectroscopy and PLS-DA

Silva, Verônica A.G. da; Talhavini, Márcio; Zacca, Jorge Jardim; Trindade, Bruno Rodrigues; Braga, Jez Willian Batista

doi:10.5935/0103-5053.20140140

Cited by 10 publications

(8 citation statements)

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“…13,15,18,20 PLS-DA is performed using binary coding, in which a dummy discrete response vector y is attributed to the data set, such as 0 for counterfeit samples and 1 for original samples. 14,17,21,22 In the training stage, the method is trained to assign "membership values", one for each class; a test sample is then assigned to a specific class if its y value surpasses a specific prediction threshold that may be estimated by establishing confidence limits for each sample classified. 17,21,23 Therefore, estimated values in y are approximations of 0 or 1, and a good discrimination is obtained when the distributions of the estimated values belonging to classes 1 and 0 are not overlapped.…”

Section: Partial Least Squares -Discriminant Analysis (Pls-da)mentioning

confidence: 99%

“…17,21,23 Therefore, estimated values in y are approximations of 0 or 1, and a good discrimination is obtained when the distributions of the estimated values belonging to classes 1 and 0 are not overlapped. 22 In this study, PLS-DA was applied using the same spectral regions and pre-processing methods as with PCA. The number of latent variables for the model was defined using the smallest root mean squared error of crossvalidation (RMSECV) determined by full cross-validation (leave-one-out approach) in the training set.…”

Section: Partial Least Squares -Discriminant Analysis (Pls-da)mentioning

confidence: 99%

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Detection of Counterfeit Durateston® Using Fourier Transform Infrared Spectroscopy and Partial Least Squares - Discriminant Analysis

Neves¹,

Talhavini²,

Braga³

et al. 2016

J. Braz. Chem. Soc.

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Medicines containing anabolic steroids are one of the main targets for counterfeiting worldwide, including Brazil. The aim of this work was to propose a method for discriminating original and counterfeit Durateston ® ampoules by Fourier transform infrared spectroscopy (FTIR) followed by chemometric analysis. Ninety-six ampoules of Durateston ® , 49 originals and 47 counterfeits, were analyzed by gas chromatography with mass spectrometry (GC-MS) and by FTIR. Principal component analysis was applied to the infrared spectra to detected different clusters, corresponding to original samples and different types of counterfeits. A partial least squares -discriminant analysis method was proposed to discriminate original samples from those counterfeits that were indistinguishable from the originals in the infrared analysis. A training subset comprised of onethird of the available spectra was used to establish a suitable model that correctly discriminated all samples in the test subset, resulting in 0% of false positive or negative results and 100% of efficiency rate, sensitivity and specificity. In addition to the low cost of the infrared technique, the proposed method is fast, reliable and suitable to replace GC-MS methods used in Durateston ® ampoule analyses to detect counterfeiting.

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Section: Partial Least Squares -Discriminant Analysis (Pls-da)mentioning

confidence: 99%

Section: Partial Least Squares -Discriminant Analysis (Pls-da)mentioning

confidence: 99%

Detection of Counterfeit Durateston® Using Fourier Transform Infrared Spectroscopy and Partial Least Squares - Discriminant Analysis

Neves¹,

Talhavini²,

Braga³

et al. 2016

J. Braz. Chem. Soc.

Self Cite

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show abstract

“…A Video Spectral Comparator (VSC) imaging device allows a document examiner to analyze inks, visualize hidden security features, and reveal alterations in a document [9]. It allows for the non-destructive visualization of security elements and the acquisition of reflectance measurements in both visible and shortwave near infrared region at focused areas in the document [10].…”

Section: Introductionmentioning

confidence: 99%

Enhancement of Handwritings on Selected Charred Documents using Video Spectral Comparator (VSC)

Moorthy¹,

Narayanan²

2016

AJFSFM

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Sciences www.nauss.edu.sa http://ajfsfm.nauss.edu.sa Arab Journal of Forensic Sciences & Forensic MedicineOpen Access the white beam by adjusting the wavelengths.Results showed that the writings on the charred document exhibited appreciable enhancement suitable for forensic investigation. The writings were comparatively more visible under the white spot beam than the flood light beam. These findings were recorded through photography.The present study provides a promising method and an effective alternative way to enhance writings on charred documents.

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“…O PLS-DA é um método supervisionado utilizado para classificar uma amostra desconhecida como pertencente ou não a uma classe. 15,16,116 __________________________________________________________________3-Fundamentação Teórica…”

Section: Mínimos Quadrados Parciais Para Análise Discriminante (Pls-da)unclassified

“…Já nos métodos não destrutivos, a análise é realizada diretamente sobre o documento, preservando a integridade deste durante todo o processo. 11 Nos últimos anos, após o aprimoramento de técnicas analíticas modernas, novos estudos [12][13][14][15][16] vêm sendo divulgados evidenciando o potencial de técnicas tais como: espectroscopia no infravermelho, [17][18][19][20][21][22][23] espectroscopia raman, [24][25][26][27] espectrometria de massas, [28][29][30][31][32] como poderosas ferramentas não destrutivas para a discriminação de tintas. Mais recentemente, a utilização de técnicas não destrutivas associadas a Análise Multivariada [33][34][35][36][37][38] Ressalta-se que a utilização de dados espectroscópicos usando o VSC ® 6000 e Quimiometria, no melhor do nosso conhecimento, consiste de uma abordagem inédita na literatura.…”

Section: Introductionunclassified

Análise e caracterização de tintas em documentos por espectroscopia e quimiometria aplicada a química forense

Silva¹

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Agradeço a Deus por mais esta oportunidade, a Nossa Senhora por passar na frente e abrir todos os meus caminhos, a todos os Anjos e Santos por me acompanharem e cuidarem de mim ao longo desta jornada. Agradeço também... Aos meus pais que sempre primaram pela Educação e Cultura. Obrigada por sempre me oferecem uma boa educação e estarem ao meu lado me apoiando com muito amor, carinho e incentivo.Ao meu noivo, Eduardo, pela enorme paciência, dedicação e generoso amor, e que tão carinhosamente soube entender minha ausência nos infinitos dias de análise de dados.Ao CNPq pela concessão da bolsa para realização deste trabalho.À UnB e à DPF por fornecerem toda a estrutura física e tecnológica para realização deste trabalho Ao meu orientador Professor Doutor Jez Willian Batista Braga pelos ensinamentos, atenção, paciência e também pela excelente orientação ao longo deste trabalho.Ao meu co-orientador PCF Doutor Márcio Talhavini pela amizade, disponibilidade e colaboração neste trabalho.As amizades construídas e fortalecidas, principalmente nos momentos difíceis, ao longo deste doutorado. Em especial, agradeço as queridas Lilian e Lorrana. Com vocês eu aprendi que: "Amigo é aquele que chega quanto todo mundo já se foi..." Um agradecimento especial também ao amigo e advogado Dr. Arthur Emílio França, que sempre me conduziu a enxergar o lado positivo de tudo: "no final, tudo vai dar certo!".

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Discrimination of Black Pen Inks on Writing Documents Using Visible Reflectance Spectroscopy and PLS-DA

Cited by 10 publications

References 0 publications

Detection of Counterfeit Durateston® Using Fourier Transform Infrared Spectroscopy and Partial Least Squares - Discriminant Analysis

Detection of Counterfeit Durateston® Using Fourier Transform Infrared Spectroscopy and Partial Least Squares - Discriminant Analysis

Enhancement of Handwritings on Selected Charred Documents using Video Spectral Comparator (VSC)

Análise e caracterização de tintas em documentos por espectroscopia e quimiometria aplicada a química forense

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