Score Fusion by Maximizing the Area under the ROC Curve

The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-642-02172-5_61Information fusion is currently a very active research topic aimed at improving the performance of biometric systems. This paper proposes a novel method for optimizing the parameters of a score fusion model based on maximizing an index related to the Area Under the ROC Curve. This approach has the convenience that the fusion parameters are learned without having to specify the client and impostor priors or the costs for the different errors. Empirical results on several datasets show the effectiveness of the proposed approach.Work supported by the Spanish projects DPI2006-15542-C04 and TIN2008-04571 and the Generalitat Valenciana - Consellería d’Educació under an FPI scholarship.Villegas Santamaría, M.; Paredes Palacios, R. (2009). Score Fusion by Maximizing the Area under the ROC Curve. En Pattern Recognition and Image Analysis: 4th Iberian Conference, IbPRIA 2009 Póvoa de Varzim, Portugal, June 10-12, 2009 Proceedings. Springer Verlag (Germany). 473-480. https://doi.org/10.1007/978-3-642-02172-5_61S473480Toh, K.A., Kim, J., Lee, S.: Biometric scores fusion based on total error rate minimization. Pattern Recognition 41(3), 1066–1082 (2008)Jain, A., Nandakumar, K., Ross, A.: Score normalization in multimodal biometric systems. Pattern Recognition 38(12), 2270–2285 (2005)Gutschoven, B., Verlinde, P.: Multi-modal identity verification using support vector machines (svm). In: Proceedings of the Third International Conference on Information Fusion. FUSION 2000, vol. 2, pp. THB3/3–THB3/8 (July 2000)Ma, Y., Cukic, B., Singh, H.: A classification approach to multi-biometric score fusion. In: Kanade, T., Jain, A., Ratha, N.K. (eds.) AVBPA 2005. LNCS, vol. 3546, pp. 484–493. Springer, Heidelberg (2005)Maurer, D.E., Baker, J.P.: Fusing multimodal biometrics with quality estimates via a bayesian belief network. Pattern Recogn. 41(3), 821–832 (2008)Ling, C.X., Huang, J., Zhang, H.: Auc: a statistically consistent and more discriminating measure than accuracy. In: Proc. of IJCAI 2003, pp. 519–524 (2003)Yan, L., Dodier, R.H., Mozer, M., Wolniewicz, R.H.: Optimizing classifier performance via an approximation to the wilcoxon-mann-whitney statistic. In: Machine Learning, Proceedings of the Twentieth International Conference (ICML 2003), Washington, DC, USA, pp. 848–855. AAAI Press, Menlo Park (2003)Marrocco, C., Molinara, M., Tortorella, F.: Exploiting auc for optimal linear combinations of dichotomizers. Pattern Recogn. Lett. 27(8), 900–907 (2006)Marrocco, C., Duin, R.P.W., Tortorella, F.: Maximizing the area under the roc curve by pairwise feature combination. Pattern Recogn. 41(6), 1961–1974 (2008)Paredes, R., Vidal, E.: Learning prototypes and distances: a prototype reduction technique based on nearest neighbor error minimization. Pattern Recognition 39(2), 180–188 (2006)Villegas, M., Paredes, R.: Simultaneous learning of a discriminative projection and prototypes for nearest-neighbor classification. In: IEEE Conference on Computer Vision and Pattern Recognition. CVPR 2008, pp. 1–8 (2008)Nandakumar, K., Chen, Y., Dass, S.C., Jain, A.: Likelihood ratio-based biometric score fusion. IEEE Transactions on Pattern Analysis and Machine Intelligence 30(2), 342–347 (2008)Poh, N., Bengio, S.: A score-level fusion benchmark database for biometric authentication. In: Kanade, T., Jain, A., Ratha, N.K. (eds.) AVBPA 2005. LNCS, vol. 3546, pp. 1059–1070. Springer, Heidelberg (2005)National Institute of Standards and Technology: NIST Biometric Scores Set - Release 1 (BSSR1) (2004), http://www.itl.nist.gov/iad/894.03/biometricscores/Bengio, S., Mariéthoz, J., Keller, M.: The expected performance curve. In: Proceedings of the Second Workshop on ROC Analysis in ML, pp. 9–16 (2005

Tattoo Antenna Temporary Transfers Operating On-Skin (TATTOOS)

This paper discusses the development of RFID logo antennas based on the logos of Loughborough University and the University of Kent which can be tattooed directly onto the skin’s surface. Hence, this paper uses aesthetic principles to create functional wearable technology. Simulations of possible designs for the tattoo tags have been carried out to optimize their performance. Prototypes of the tag designs were fabricated and read range measurements with the transfer tattoos on a volunteers arm were carried out to test the performance. Measured Read ranges of approximately 0.5 m have been achieved with the antenna 10 µm from the body

Estimated prevalence of undiagnosed HCV infected individuals in Italy: A mathematical model by route of transmission and fibrosis progression

Background: The universal treatment of diagnosed patients with chronic HCV infection has been widely conducted in Italy since 2017. However, the pool of individuals diagnosed but yet to be treated in Italy has been estimated to end around 2025, leaving a significant proportion of infected individuals undiagnosed/without care. Estimates of this population are currently unknown. Methods: A probabilistic modelling approach was applied to estimate annual historical HCV incident cases by their age-group (0–100 years) distribution from available literature and Italian National database (1952 to October 2019). Viraemic infection rates were modelled on the main infection routes in Italy: people who inject drugs (PWID), tattoos, sexual transmission, glass syringe use, blood transfusion and vertical transmission. Annual liver fibrosis stage transition probabilities were modelled using a Markov model. The number of HCV viraemic asymptomatic (fibrosis stage F0-F3:potentially undiagnosed/unlinked to care) and symptomatic (fibrosis stage F4: potentially linked to care) individuals was estimated. Results: By October 2019, total viraemic HCV individuals in Italy (excluding treated patients since 1992) were estimated to be 410,775 (0.68 % of current population of Italy; 95 % CI: 0.64−0.71%, based on the current Italian population), of which 281,809 (0.47 %; 95 % CI:0.35−0.60%) were fibrosis stage F0-F3. Among different high risk groups in stage F0-F3, the following distribution was estimated: PWID; 52.0 % (95 % CI:37.9–66.6 %), tattoo; 28.8 % (95 % CI:23–32.3 %), sexual transmission; 12.0 % (95 % CI:9.6–13.7 %), glass syringe and transfusion; 6.4 % (95 % CI:2.4–17.8 %), and vertical transmission; 0.7 % (95 % CI:0.4–1.2 %). Conclusion: Under the assumption that most untreated HCV-infected individuals with stage F0-F3 are undiagnosed, more than 280,000 individuals are undiagnosed and/or unlinked to care in Italy. Marked heterogeneity across the major routes of HCV transmission was estimated. This modelling approach may be a useful tool to characterise the HCV epidemic profile also in other countries, based on country specific epidemiology and HCV main transmission routes

Modélisation de systèmes électrotechniques par couplage des équations électriques et magnétiques

Pour modéliser des systèmes électromagnétiques en tenant compte du couplage entre les circuits magnétiques et électriques, on est amené à résoudre un système d'équations différentielles spatio-temporelles. En ayant recours à une discrétisation spatiale de type éléments finis et une discrétisation temporelle de type pas-à-pas, on aboutit à un système d'équations algébriques, dont les inconnues sont les valeurs nodales du potentiel vecteur et les courants. A ce niveau, deux approches peuvent être envisagées ; dans la première on conserve comme inconnues le potentiel vecteur et les courants, dans la seconde on se ramène à un système d'équations où les inconnues sont uniquement les valeurs nodales du potentiel vecteur. Dans cet article les deux stratégies sont développées ainsi que leurs influences sur le système matriciel à résoudre. Les résultats obtenus pour diverses applications sont donnés avec des comparaisons entre le calcul et l'expérience

A mathematical model by route of transmission and fibrosis progression to estimate undiagnosed individuals with HCV in different Italian regions

Background: Although an increase in hepatitis C virus (HCV) prevalence from Northern to Southern Italy has been reported, the burden of asymptomatic individuals in different Italian regions is currently unknown. Methods: A probabilistic approach, including a Markov chain for liver disease progression, was applied to estimate current HCV viraemic burden. The model defined prevalence by geographic area using an estimated annual historical HCV incidence by age, treatment rate, and migration rate from the Italian National database. Viraemic infection by age group was estimated for each region by main HCV transmission routes of individuals for stage F0–F3 (i.e. patients without liver cirrhosis and thus potentially asymptomatic) and F4 (patients with liver cirrhosis, thus potentially symptomatic). Results: By January 2020, it was estimated that there were 409,184 Italian individuals with HCV (prevalence of 0.68%; 95% CI: 0.54–0.82%), of which 300,171 (0.50%; 95% CI: 0.4–0.6%) were stage F0–F3. Considering all individuals with HCV in stage F0–F3, the geographical distributions (expressed as the proportion of HCV infected individuals by macroarea within the overall estimated number of F0–F3 individuals and prevalence values, expressed as the percentage of individuals with HCV versus the overall number of individuals for each macroarea) were as follows: North 42.1% (0.45%; 95% CI: 0.36–0.55%), Central 24.1% (0.61%; 95% CI: 0.48–0.74%), South 23.2% (0.50%; 95% CI: 0.4–0.61%), and the Isles 10.6% (0.49%; 95% CI: 0.39–0.59%). The population of people who inject drugs accounted for 50.4% of all individuals infected (F0–F3). Undiagnosed individuals (F0–F3) were ~ 15 years younger (⁓ 50 years) compared with patients with stage F4 (⁓ 65 years), with similar age distributions across macroareas. In contrast to what has been reported on HCV epidemiology in Italy, an increasing trend in the proportion of potentially undiagnosed individuals with HCV (absolute number within the F0–F3) from South (23.2%) to North (42.1%) emerged, independent of similar regional prevalence values. Conclusion: This targeted approach, which addresses the specific profile of undiagnosed individuals, is helpful in planning effective elimination strategies by region in Italy and could be a useful methodology for other countries in implementing their elimination plans

Allele-specific editing ameliorates dominant retinitis pigmentosa in a transgenic mouse model

Retinitis pigmentosa (RP) is a group of progressive retinal degenerations of mostly monogenic inheritance, which cause blindness in about 1:3,500 individuals worldwide. Heterozygous variants in the rhodopsin (RHO) gene are the most common cause of autosomal dominant RP (adRP). Among these, missense variants at C-terminal proline 347, such as p.Pro347Ser, cause severe adRP recurrently in European affected individuals. Here, for the first time, we use CRISPR/Cas9 to selectively target the p.Pro347Ser variant while preserving the wild-type RHO allele in vitro and in a mouse model of adRP. Detailed in vitro, genomic, and biochemical characterization of the rhodopsin C-terminal editing demonstrates a safe downregulation of p.Pro347Ser expression leading to partial recovery of photoreceptor function in a transgenic mouse model treated with adeno-associated viral vectors. This study supports the safety and efficacy of CRISPR/Cas9-mediated allele-specific editing and paves the way for a permanent and precise correction of heterozygous variants in dominantly inherited retinal diseases