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1.
Comput Math Methods Med ; 2020: 7574531, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32849910

RESUMEN

In the past few decades, identification recognition based on electroencephalography (EEG) has received extensive attention to resolve the security problems of conventional biometric systems. In the present study, a novel EEG-based identification system with different entropy and a continuous convolution neural network (CNN) classifier is proposed. The performance of the proposed method is experimentally evaluated through the emotional EEG data. The conducted experiment shows that the proposed method approaches the stunning accuracy (ACC) of 99.7% on average and can rapidly train and update the DE-CNN model. Then, the effects of different emotions and the impact of different time intervals on the identification performance are investigated. Obtained results show that different emotions affect the identification accuracy, where the negative and neutral mood EEG has a better robustness than positive emotions. For a video signal as the EEG stimulant, it is found that the proposed method with 0-75 Hz is more robust than a single band, while the 15-32 Hz band presents overfitting and reduces the accuracy of the cross-emotion test. It is concluded that time interval reduces the accuracy and the 15-32 Hz band has the best compatibility in terms of the attenuation.


Asunto(s)
Algoritmos , Identificación Biométrica/métodos , Electroencefalografía/métodos , Emociones/fisiología , Redes Neurales de la Computación , Identificación Biométrica/estadística & datos numéricos , Biología Computacional , Electroencefalografía/estadística & datos numéricos , Humanos , Conceptos Matemáticos , Dinámicas no Lineales , Procesamiento de Señales Asistido por Computador
2.
Sci Rep ; 9(1): 8684, 2019 06 18.
Artículo en Inglés | MEDLINE | ID: mdl-31213619

RESUMEN

We present the work towards strengthening the security of DNA-sequencing functionality of future bioinformatics systems against bio-computing attacks. Recent research has shown how using common tools, a perpetrator can synthesize biological material, which upon DNA-analysis opens a cyber-backdoor for the perpetrator to hijack control of a computational resource from the DNA-sequencing pipeline. As DNA analysis finds its way into practical everyday applications, the threat of bio-hacking increases. Our wetlab experiments establish that malicious DNA can be synthesized and inserted into E. coli, a common contaminant. Based on that, we propose a new attack, where a hacker to reach the target hides the DNA with malicious code on common surfaces (e.g., lab coat, bench, rubber glove). We demonstrated that the threat of bio-hacking can be mitigated using dedicated input control techniques similar to those used to counter conventional injection attacks. This article proposes to use genetic similarity of biological samples to identify material that has been generated for bio-hacking. We considered freely available genetic data from 506 mammary, lymphocyte and erythrocyte samples that have a bio-hacking code inserted. During the evaluation we were able to detect up to 95% of malicious DNAs confirming suitability of our method.


Asunto(s)
Biología Computacional/métodos , Seguridad Computacional/estadística & datos numéricos , ADN/genética , Almacenamiento y Recuperación de la Información/métodos , Análisis de Secuencia de ADN/métodos , Secuencia de Bases , Identificación Biométrica/métodos , Identificación Biométrica/estadística & datos numéricos , Seguridad Computacional/normas , ADN/química , Eritrocitos/metabolismo , Escherichia coli/genética , Variación Genética , Humanos , Linfocitos/metabolismo , Medición de Riesgo/métodos , Medición de Riesgo/estadística & datos numéricos , Factores de Riesgo
3.
Comput Methods Programs Biomed ; 165: 89-105, 2018 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-30337084

RESUMEN

BACKGROUND AND OBJECTIVES: In order to improve assistive technologies for people with reduced mobility, this paper develops a new intelligent real-time emotion detection system to control equipment, such as electric wheelchairs (EWC) or robotic assistance vehicles. Every year, degenerative diseases and traumas prohibit thousands of people to easily control the joystick of their wheelchairs with their hands. Most current technologies are considered invasive and uncomfortable such as those requiring the user to wear some body sensor to control the wheelchair. METHODS: In this work, the proposed Human Machine Interface (HMI) provides an efficient hands-free option that does not require sensors or objects attached to the user's body. It allows the user to drive the wheelchair using its facial expressions which can be flexibly updated. This intelligent solution is based on a combination of neural networks (NN) and specific image preprocessing steps. First, the Viola-Jones combination is used to detect the face of the disability from a video. Subsequently, a neural network is used to classify the emotions displayed on the face. This solution called "The Mathematics Behind Emotion" is capable of classifying many facial expressions in real time, such as smiles and raised eyebrows, which are translated into signals for wheelchair control. On the hardware side, this solution only requires a smartphone and a Raspberry Pi card that can be easily mounted on the wheelchair. RESULTS: Many experiments have been conducted to evaluate the efficiency of the control acquisition process and the user experience in driving a wheelchair through facial expressions. The classification accuracy can expect 98.6% and it can offer an average recall rate of 97.1%. Thus, all these experiments have proven that the proposed system is able of accurately recognizing user commands in real time. Indeed, the obtained results indicate that the suggested system is more comfortable and better adapted to severely disabled people in their daily lives, than conventional methods. Among the advantages of this system, we cite its real time ability to identify facial emotions from different angles. CONCLUSIONS: The proposed system takes into account the patient's pathology. It is intuitive, modern, doesn't require physical effort and can be integrated into a smartphone or tablet. The results obtained highlight the efficiency and reliability of this system, which ensures safe navigation for the disabled patient.


Asunto(s)
Identificación Biométrica/métodos , Personas con Discapacidad , Expresión Facial , Interfaz Usuario-Computador , Silla de Ruedas , Algoritmos , Inteligencia Artificial , Identificación Biométrica/estadística & datos numéricos , Sistemas de Computación , Diseño de Equipo , Femenino , Humanos , Masculino , Redes Neurales de la Computación
4.
Comput Methods Programs Biomed ; 164: 101-109, 2018 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-30195418

RESUMEN

BACKGROUND AND OBJECTIVES: Telecare Medicine Information System (TMIS) enables physicians to efficiently and conveniently make certain diagnoses and medical treatment for patients over the insecure public Internet. To ensure patients securely access to medicinal services, many authentication schemes have been proposed. Although numerous cryptographic authentication schemes for TMIS have been proposed with the aim to ensure data security, user privacy and authentication, various forms of attacks make these schemes impractical. METHODS: To design a truly secure and practical authentication scheme for TMIS, a new biometrics-based authentication key exchange protocol for multi-server TMIS without sharing the system private key with distributed servers is presented in this work. RESULTS: Our proposed protocol has perfect security features including mutual authentication, user anonymity, perfect forward secrecy and resisting various well-known attacks, and these security feathers are confirmed by the BAN logic and heuristic cryptanalysis, respectively. CONCLUSIONS: A secure biometrics-based authentication key exchange protocol for multi-server TMIS is presented in this work, which has perfect security properties including perfect forward secrecy, supporting user anonymity, etc., and can withstand various attacks such as impersonation attack, off-line password guessing attack, etc.. Considering security is the most important factor for an authentication scheme, so our scheme is more suitable for multi-server TMIS.


Asunto(s)
Identificación Biométrica/métodos , Seguridad Computacional/normas , Intercambio de Información en Salud/normas , Telemedicina/normas , Identificación Biométrica/normas , Identificación Biométrica/estadística & datos numéricos , Seguridad Computacional/estadística & datos numéricos , Confidencialidad , Lógica Difusa , Intercambio de Información en Salud/estadística & datos numéricos , Humanos , Sistemas de Información/normas , Sistemas de Información/estadística & datos numéricos , Telemedicina/estadística & datos numéricos
5.
Sud Med Ekspert ; 61(4): 35-38, 2018.
Artículo en Ruso | MEDLINE | ID: mdl-30168527

RESUMEN

We undertook the analysis of the archive data of forensic medical expertises of the non-identified corpses accumulated at the tanatological divisions of the Moscow Bureau of Forensic Medical Expertise for the period from 2012 till 2016. Special attention was given to sex and age composition of the deceased as well as the structure of mortality and the traces of ethyl alcohol, if any, present in the blood. It was shown that the majority of the unidentified bodies were those of the young men, with the main cause of the non-violent deaths being the cardiovascular pathology. Ethyl alcohol was found in the blood of 43% of the corpses. The analysis encompassed also the most frequently used methods for personality identification based on the data available from the medical-criminalistic department of the Bureau of Forensic Medical Expertise. The statistical treatment of the results of the study provided materials making it possible to envision the tendencies of the further development and improvement of the methods for personality identification for the purpose of forensic medical expertise and judicial practice.


Asunto(s)
Identificación Biométrica , Causas de Muerte , Antropología Forense , Adulto , Anciano , Intoxicación Alcohólica/mortalidad , Identificación Biométrica/métodos , Identificación Biométrica/estadística & datos numéricos , Enfermedades Cardiovasculares/mortalidad , Testimonio de Experto/métodos , Femenino , Antropología Forense/métodos , Antropología Forense/estadística & datos numéricos , Patologia Forense/métodos , Patologia Forense/estadística & datos numéricos , Humanos , Masculino , Persona de Mediana Edad , Moscú
6.
Rev. esp. med. legal ; 44(3): 99-107, jul.-sept. 2018. tab, graf
Artículo en Español | IBECS | ID: ibc-178174

RESUMEN

Introducción: Se ha realizado una comparación de las características dentales de 2poblaciones militares de Portugal y España. El objetivo principal de esta investigación fue identificar aquellas características dentales que podrían ser de utilidad para diferenciar estas poblaciones en un análisis forense. Material y métodos: El estudio se realizó en una muestra compuesta por 5.136 militares profesionales de las fuerzas armadas, el 31,9% eran militares portugueses y el 68,1% del total de la muestra pertenecían a las fuerzas armadas españolas. Los datos dentales se registraron empleando los símbolos dentales descritos en Forensic Dental Symbols(R), gestionados con la base de datos Dental Encoder(R). Resultados: La población de estudio estaba constituida por un 86,6% de hombres (88,1% en la muestra española y 83,4% en la muestra portuguesa) y un 13,4% de mujeres (11,9% en la muestra española y 16,6% en la muestra portuguesa). La frecuencia de dientes no restaurados fue menor para los primeros molares en todos los cuadrantes, mientras que la mayor frecuencia de esta característica (>90%) se observó en los dientes anteriores, superiores e inferiores, y en los primeros premolares inferiores. Las frecuencias más altas de tratamientos restauradores fueron encontradas para los primeros y segundos molares en todos los cuadrantes, y las mayores frecuencias de ausencias dentarias se observaron en los terceros molares (superior al 28% en todos los cuadrantes). El análisis de concordancia mostró que las correlaciones entre los dientes contralaterales fueron significativamente mayores que entre los dientes antagonistas, para ambas muestras poblacionales de estudio. Conclusiones: Nuestros resultados proporcionan información potencialmente útil sobre la importancia de las bases de datos de registros dentales y el análisis de las características dentales con fines de identificación


Introduction: Dental characteristics were compared in population samples of Spanish and Portuguese military personnel. The main aim of this study was to identify those dental characteristics that could potentially serve to differentiate between these populations in a forensic analysis. Material and methods: A sample of 5136 individuals belonging to the professional military staff of the Portuguese and Spanish armed forces was studied. Dental data were recorded with the Forensic Dental Symbols(R) for the Dental Encoder(R) database. The population sample analysed in this study consisted of 68.1% Spanish and 31.9% Portuguese individuals. Results: The population was mostly male, with 86.6% men (88.1% in the Spanish sample versus 83.4% in the Portuguese sample), and 13.4% women (11.9% Spanish and 16.6% Portuguese). The frequency of unrestored teeth was lowest for first molars in all quadrants, and the highest frequency of unrestored teeth (>90%) was for the upper and lower anterior teeth and lower first premolars. The highest frequencies of restorative treatment were found for the first and second molars in all quadrants, and the highest frequencies of missing teeth were found for the third molars (always >28%). Concordance analysis showed that correlations between contralateral teeth were significantly higher than between antagonist teeth in both samples. Conclusions: Our findings provide potentially useful information on the importance of dental record databases and their value for identification purposes


Asunto(s)
Humanos , Antropología Forense/métodos , Odontología Forense/métodos , Registros Odontológicos/estadística & datos numéricos , Información Personal/estadística & datos numéricos , Boca/anatomía & histología , Portugal/epidemiología , España/epidemiología , Identificación Biométrica/estadística & datos numéricos , Personal Militar/estadística & datos numéricos
7.
Public Underst Sci ; 26(2): 195-211, 2017 02.
Artículo en Inglés | MEDLINE | ID: mdl-28168941

RESUMEN

The decision in Europe to implement biometric passports, visas and residence permits was made at the highest levels without much consultation, checks and balances. Council regulation came into force relatively unnoticed in January 2005, as part of wider securitization policies urging systems interoperability and data sharing across borders. This article examines the biometric imaginary that characterizes this European Union decision, dictated by executive powers in the policy vacuum after 9/11 - a depiction of mobility governance, technological necessity and whom/what to trust or distrust, calling upon phantom publics to justify decisions rather than test their grounding. We consult an online blog we operated in 2010 to unravel this imaginary years on. Drawing on Dewey's problem of the public, we discuss this temporary opening of a public space in which the imaginary could be reframed and contested, and how such activities may shape, if at all, relations between politics, publics, policy intervention and societal development.


Asunto(s)
Identificación Biométrica/estadística & datos numéricos , Participación de la Comunidad , Unión Europea , Política Pública , Confianza , Identificación Biométrica/tendencias , Imaginación
8.
Forensic Sci Int ; 263: 92-100, 2016 06.
Artículo en Inglés | MEDLINE | ID: mdl-27100858

RESUMEN

A survey was conducted of the use of speaker identification by law enforcement agencies around the world. A questionnaire was circulated to law enforcement agencies in the 190 member countries of INTERPOL. 91 responses were received from 69 countries. 44 respondents reported that they had speaker identification capabilities in house or via external laboratories. Half of these came from Europe. 28 respondents reported that they had databases of audio recordings of speakers. The clearest pattern in the responses was that of diversity. A variety of different approaches to speaker identification were used: The human-supervised-automatic approach was the most popular in North America, the auditory-acoustic-phonetic approach was the most popular in Europe, and the spectrographic/auditory-spectrographic approach was the most popular in Africa, Asia, the Middle East, and South and Central America. Globally, and in Europe, the most popular framework for reporting conclusions was identification/exclusion/inconclusive. In Europe, the second most popular framework was the use of verbal likelihood ratio scales.


Asunto(s)
Identificación Biométrica/métodos , Identificación Biométrica/estadística & datos numéricos , Aplicación de la Ley , Voz , Bases de Datos Factuales , Agencias Gubernamentales , Humanos , Fonética , Espectrografía del Sonido , Encuestas y Cuestionarios
9.
PLoS One ; 11(1): e0145640, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26751208

RESUMEN

We simulated multistate capture histories (CHs) by varying state survival (ϕ), detection (p) and transition (ψ), number of total capture occasions and releases per capture occasion and then modified these scenarios to mimic false rejection error (FRE), a common misidentification error, resulting from the failure to match samples of the same individual. We then fit a multistate model and estimated accuracy, bias and precision of state-specific ϕ, p and ψ to better understand the effects of FRE on different simulation scenarios. As expected, ϕ, and p, decreased in accuracy with FRE, with lower accuracy when CHs were simulated under a shorter-term study and a lower number of releases per capture occasion (lower sample size). Accuracy of ψ estimates were robust to FRE except in those CH scenarios simulated using low sample size. The effect of FRE on bias was not consistent among parameters and differed by CH scenario. As expected, ϕ was negatively biased with increased FRE (except for the low ϕ low p CH scenario simulated with a low sample size), but we found that the magnitude of bias differed by scenario (high p CH scenarios were more negatively biased). State transition was relatively unbiased, except for the low p CH scenarios simulated with a low sample size, which were positively biased with FRE, and high p CH scenarios simulated with a low sample size. The effect of FRE on precision was not consistent among parameters and differed by scenario and sample size. Precision of ϕ decreased with FRE and was lowest with the low ϕ low p CH scenarios. Precision of p estimates also decreased with FRE under all scenarios, except the low ϕ high p CH scenarios. However, precision of ψ increased with FRE, except for those CH scenarios simulated with a low sample size. Our results demonstrate how FRE leads to loss of accuracy in parameter estimates in a multistate model with the exception of ψ when estimated using an adequate sample size.


Asunto(s)
Identificación Biométrica/estadística & datos numéricos , Genotipo , Modelos Estadísticos , Fotograbar/estadística & datos numéricos , Animales , Identificación Biométrica/métodos , Simulación por Computador , Conservación de los Recursos Naturales , Repeticiones de Microsatélite , Polimorfismo de Nucleótido Simple , Dinámica Poblacional , Tamaño de la Muestra , Tasa de Supervivencia
10.
Arq. ciênc. vet. zool. UNIPAR ; 18(1): 27-32, jan.-mar. 2015. tab, graf
Artículo en Portugués | LILACS, VETINDEX | ID: biblio-151

RESUMEN

As análises da relação entre características biométricas em juvenis de robalo-flecha (Centropomus undecimalis) cultivados proporcionam dados importantes para avaliação da biologia e do crescimento, entretanto, mais estudos são necessários nessa área. Dessa forma, esse trabalho teve como objetivo investigar em juvenis de robalo-flecha cultivados, a relação entre o peso vivo com a distância pré-dorsal, largura, comprimento da nadadeira caudal, altura do pedúnculo caudal, altura, comprimento da cabeça, comprimento padrão e comprimento total, identificando o tipo de crescimento envolvido nessa relação. As características comprimento total, comprimento padrão, altura e comprimento da cabeça, apresentaram alta correlação com o peso vivo variando entre 0,92 e 0,94. O tipo de crescimento entre as características relacionadas foi alométrico positivo (b > 3). Os resultados obtidos desse estudo proporcionam informações para ampliar o entendimento na avaliação do crescimento do robalo-flecha em cativeiro, bem como contribuições em estudos realizados com outras espécies e com a aquicultura.(AU)


The analyses of the relationship among the biometric characteristics of reared juvenile common snook (Centropomus undecimalis) provide important data for evaluating the biology and growth, but further studies are still necessary in this area. Therefore, the present study aimed to investigate, in reared juvenile common snook, the relationship between body weight and pre-dorsal distance, width, length of caudal fin, caudal peduncle height, height, head length, standard length and overall length, identifying the type of growth involved in this relationship. The characteristics of overall length, standard length, height and head length were highly correlated with body weight, ranging between 0.92 and 0.94. The type of growth among the related characteristics was allometrically positive (b>3). These results provide important information to increase the understanding of growth evaluation of reared common snook, as well as providing contributions in studies with other species in aquaculture.(AU)


Los análisis de la relación entre características biométricas en róbalos juveniles (Centropomus undecimalis), cultivados, proporcionan datos importantes para la evaluación de la biología y del crecimiento, pero es necesario más estudios en esta área. Por lo tanto, este estudio tuvo como objetivo investigar en róbalos juveniles cultivados, la relación entre el peso vivo con la distancia pre-dorsal, anchura, longitud de la aleta caudal, altura del pedúnculo caudal, altura, longitud de la cabeza, longitudes estándar y longitud total, identificando el tipo de crecimiento involucrado en esa relación. Las características longitud total, longitudes estándar, altura y longitud de la cabeza, presentaron alta correlación con el peso vivo variando entre 0,92 y 0,94. El tipo de crecimiento entre las características relacionadas fue alométrico positivo (b> 3). Los resultados de ese estudio proporcionan informaciones para ampliar el entendimiento en la evaluación del crecimiento de róbalo en cautiverio, así como contribuciones en estudios realizados con otras especies y con la acuicultura.(AU)


Asunto(s)
Animales , Identificación Biométrica/estadística & datos numéricos , Perciformes/clasificación , Perciformes/crecimiento & desarrollo , Explotaciones Pesqueras
11.
Arq. bras. med. vet. zootec ; 66(6): 1787-1794, 12/2014. tab, graf
Artículo en Portugués | LILACS | ID: lil-735771

RESUMEN

Objetivou-se com este trabalho descrever as medidas biométricas de cordeiros lactantes da raça Santa Inês criados em condições amazônicas; estabelecer relação entre a idade e as medidas corporais; bem como correlacionar essas medidas biométricas com o peso corporal. Utilizaram-se 75 animais criados em sistema semi-intensivo, submetidos a mensurações do peso corporal (PC), comprimento corporal (CC), altura do anterior (AA) e do posterior (AP), perímetro torácico (PT), largura da garupa (LG) e do peito (LP), comprimento da perna (CP), perímetro da perna (PP) e compacidade corporal (COMPC), ao nascer e aos 15, 30, 45 e 60 dias de idade. Somente as medidas LG e PP demonstraram regressões com R2 abaixo de 0,70 em relação à idade dos cordeiros. Todas as medidas corporais utilizadas nesta pesquisa, individualmente, demonstraram r positivo com o peso corporal. As variáveis biométricas que melhor compuseram a equação de predição do peso dos cordeiros utilizados neste estudo foram CC, AP, PT, LG e PP. Concluiu-se que a idade de cordeiros pode ser utilizada como preditora do peso e de algumas medidas biométricas corporais e que o peso pode ser estimado por meio de algumas medidas biométricas...


This study aimed to 1) describe the biometric measurements of Santa Inês lambs until weaning, when raised in the Amazonia conditions; 2) establish the relationship between age and body measurements; and 3) correlate these biometric measurements to body weight. 75 animals submitted to semi-intensive breeding were used, and underwent measurements of body weight (BW), body length (BL), height of the forelimb (HF) and hindlimb (HH), thoracic perimeter (TP), width of rump (WR) and chest (WC), length of leg (LL), perimeter of leg (PL) and more body compacity (COMP), at birth and at 15, 30, 45 and 60 days of age. As a result, the WR and PL measurements demonstrated regressions with R2 below 0.70 in relation to age of lambs. All biometrical measurements used in this study individually demonstrated positive r with body weight. Biometric variables that compose the equation for predicting weight of lambs used in this study were BL, HH, TP, WR and PL. It was concluded that the age of lambs can be used as a predictor of weight and some body biometric measurements. The weight can also be estimated by some biometric measurements...


Asunto(s)
Animales , Identificación Biométrica/estadística & datos numéricos , Identificación Biométrica/métodos , Ovinos/anatomía & histología , Ovinos/crecimiento & desarrollo , Biometría/métodos , Pesos y Medidas Corporales/estadística & datos numéricos , Pesos y Medidas Corporales/veterinaria
12.
PLoS One ; 9(6): e100120, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24940876

RESUMEN

Recent years have witnessed a growing interest in developing methods for 3D face recognition. However, 3D scans often suffer from the problems of missing parts, large facial expressions, and occlusions. To be useful in real-world applications, a 3D face recognition approach should be able to handle these challenges. In this paper, we propose a novel general approach to deal with the 3D face recognition problem by making use of multiple keypoint descriptors (MKD) and the sparse representation-based classification (SRC). We call the proposed method 3DMKDSRC for short. Specifically, with 3DMKDSRC, each 3D face scan is represented as a set of descriptor vectors extracted from keypoints by meshSIFT. Descriptor vectors of gallery samples form the gallery dictionary. Given a probe 3D face scan, its descriptors are extracted at first and then its identity can be determined by using a multitask SRC. The proposed 3DMKDSRC approach does not require the pre-alignment between two face scans and is quite robust to the problems of missing data, occlusions and expressions. Its superiority over the other leading 3D face recognition schemes has been corroborated by extensive experiments conducted on three benchmark databases, Bosphorus, GavabDB, and FRGC2.0. The Matlab source code for 3DMKDSRC and the related evaluation results are publicly available at http://sse.tongji.edu.cn/linzhang/3dmkdsrcface/3dmkdsrc.htm.


Asunto(s)
Algoritmos , Identificación Biométrica/estadística & datos numéricos , Reconocimiento de Normas Patrones Automatizadas/estadística & datos numéricos , Programas Informáticos , Identificación Biométrica/instrumentación , Bases de Datos Factuales , Cara/anatomía & histología , Expresión Facial , Humanos , Procesamiento de Imagen Asistido por Computador , Internet , Reconocimiento de Normas Patrones Automatizadas/métodos
14.
PLoS One ; 8(12): e83291, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-24376680

RESUMEN

Projective non-negative matrix factorization (PNMF) projects high-dimensional non-negative examples X onto a lower-dimensional subspace spanned by a non-negative basis W and considers W(T) X as their coefficients, i.e., X≈WW(T) X. Since PNMF learns the natural parts-based representation Wof X, it has been widely used in many fields such as pattern recognition and computer vision. However, PNMF does not perform well in classification tasks because it completely ignores the label information of the dataset. This paper proposes a Discriminant PNMF method (DPNMF) to overcome this deficiency. In particular, DPNMF exploits Fisher's criterion to PNMF for utilizing the label information. Similar to PNMF, DPNMF learns a single non-negative basis matrix and needs less computational burden than NMF. In contrast to PNMF, DPNMF maximizes the distance between centers of any two classes of examples meanwhile minimizes the distance between any two examples of the same class in the lower-dimensional subspace and thus has more discriminant power. We develop a multiplicative update rule to solve DPNMF and prove its convergence. Experimental results on four popular face image datasets confirm its effectiveness comparing with the representative NMF and PNMF algorithms.


Asunto(s)
Algoritmos , Identificación Biométrica/métodos , Cara/anatomía & histología , Identificación Biométrica/estadística & datos numéricos , Bases de Datos Factuales , Humanos , Aumento de la Imagen , Interpretación de Imagen Asistida por Computador
15.
IEEE Trans Pattern Anal Mach Intell ; 31(12): 2211-26, 2009 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19834142

RESUMEN

Images of a human iris contain rich texture information useful for identity authentication. A key and still open issue in iris recognition is how best to represent such textural information using a compact set of features (iris features). In this paper, we propose using ordinal measures for iris feature representation with the objective of characterizing qualitative relationships between iris regions rather than precise measurements of iris image structures. Such a representation may lose some image-specific information, but it achieves a good trade-off between distinctiveness and robustness. We show that ordinal measures are intrinsic features of iris patterns and largely invariant to illumination changes. Moreover, compactness and low computational complexity of ordinal measures enable highly efficient iris recognition. Ordinal measures are a general concept useful for image analysis and many variants can be derived for ordinal feature extraction. In this paper, we develop multilobe differential filters to compute ordinal measures with flexible intralobe and interlobe parameters such as location, scale, orientation, and distance. Experimental results on three public iris image databases demonstrate the effectiveness of the proposed ordinal feature models.


Asunto(s)
Identificación Biométrica/métodos , Iris/anatomía & histología , Algoritmos , Identificación Biométrica/estadística & datos numéricos , Bases de Datos Factuales , Humanos , Procesamiento de Imagen Asistido por Computador
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