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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
141

Automatic Person Verification Using Speech and Face Information

Sanderson, Conrad, conradsand@ieee.org January 2003 (has links)
Identity verification systems are an important part of our every day life. A typical example is the Automatic Teller Machine (ATM) which employs a simple identity verification scheme: the user is asked to enter their secret password after inserting their ATM card; if the password matches the one prescribed to the card, the user is allowed access to their bank account. This scheme suffers from a major drawback: only the validity of the combination of a certain possession (the ATM card) and certain knowledge (the password) is verified. The ATM card can be lost or stolen, and the password can be compromised. Thus new verification methods have emerged, where the password has either been replaced by, or used in addition to, biometrics such as the person’s speech, face image or fingerprints. Apart from the ATM example described above, biometrics can be applied to other areas, such as telephone & internet based banking, airline reservations & check-in, as well as forensic work and law enforcement applications. Biometric systems based on face images and/or speech signals have been shown to be quite effective. However, their performance easily degrades in the presence of a mismatch between training and testing conditions. For speech based systems this is usually in the form of channel distortion and/or ambient noise; for face based systems it can be in the form of a change in the illumination direction. A system which uses more than one biometric at the same time is known as a multi-modal verification system; it is often comprised of several modality experts and a decision stage. Since a multi-modal system uses complimentary discriminative information, lower error rates can be achieved; moreover, such a system can also be more robust, since the contribution of the modality affected by environmental conditions can be decreased. This thesis makes several contributions aimed at increasing the robustness of single- and multi-modal verification systems. Some of the major contributions are listed below. The robustness of a speech based system to ambient noise is increased by using Maximum Auto-Correlation Value (MACV) features, which utilize information from the source part of the speech signal. A new facial feature extraction technique is proposed (termed DCT-mod2), which utilizes polynomial coefficients derived from 2D Discrete Cosine Transform (DCT) coefficients of spatially neighbouring blocks. The DCT-mod2 features are shown to be robust to an illumination direction change as well as being over 80 times quicker to compute than 2D Gabor wavelet derived features. The fragility of Principal Component Analysis (PCA) derived features to an illumination direction change is solved by introducing a pre-processing step utilizing the DCT-mod2 feature extraction. We show that the enhanced PCA technique retains all the positive aspects of traditional PCA (that is, robustness to compression artefacts and white Gaussian noise) while also being robust to the illumination direction change. Several new methods, for use in fusion of speech and face information under noisy conditions, are proposed; these include a weight adjustment procedure, which explicitly measures the quality of the speech signal, and a decision stage comprised of a structurally noise resistant piece-wise linear classifier, which attempts to minimize the effects of noisy conditions via structural constraints on the decision boundary.
142

Arizona law enforcement biometrics identification and information sharing technology framework

Kalaf, William M. January 2010 (has links) (PDF)
Thesis (M.A. in Security Studies (Homeland Security and Defense))--Naval Postgraduate School, March 2010. / Thesis Advisor(s): Bergin, Richard ; Josefek, Robert. "March 2010." Description based on title screen as viewed on April 28, 2010. Author(s) subject terms: Arizona Criminal Justice Commission, biometrics technology, biometrics identification, facial recognition, fingerprint identification, law enforcement, information sharing, criminal information sharing, Arizona, Mexico, New Mexico, Texas, California, RISC, AFIS, IAFIS, NGI, governors border conferences, Central America, south west border initiative. Includes bibliographical references (p. 87-92). Also available in print.
143

Learning person-specific face representations = Aprendendo representações específicas para a face de cada pessoa / Aprendendo representações específicas para a face de cada pessoa

Chiachia, Giovani, 1981- 23 August 2018 (has links)
Orientadores: Alexandre Xavier Falcão, Anderson de Rezende Rocha / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Computação / Made available in DSpace on 2018-08-23T15:41:33Z (GMT). No. of bitstreams: 1 Chiachia_Giovani_D.pdf: 4376963 bytes, checksum: 8f7d18d591f2a5d943313d89416f96d4 (MD5) Previous issue date: 2013 / Resumo: Os seres humanos são especialistas natos em reconhecimento de faces, com habilidades que excedem em muito as dos métodos automatizados vigentes, especialmente em cenários não controlados, onde não há a necessidade de colaboração por parte do indivíduo sendo reconhecido. No entanto, uma característica marcante do reconhecimento de face humano é que nós somos substancialmente melhores no reconhecimento de faces familiares, provavelmente porque somos capazes de consolidar uma grande quantidade de experiência prévia com a aparência de certo indivíduo e de fazer uso efetivo dessa experiência para nos ajudar no reconhecimento futuro. De fato, pesquisadores em psicologia têm até mesmo sugeridos que a representação interna que fazemos das faces pode ser parcialmente adaptada ou otimizada para rostos familiares. Enquanto isso, a situação análoga no reconhecimento facial automatizado | onde um grande número de exemplos de treinamento de um indivíduo está disponível | tem sido muito pouco explorada, apesar da crescente relevância dessa abordagem na era das mídias sociais. Inspirados nessas observações, nesta tese propomos uma abordagem em que a representação da face de cada pessoa é explicitamente adaptada e realçada com o intuito de reconhecê-la melhor. Apresentamos uma coleção de métodos de aprendizado que endereça e progressivamente justifica tal abordagem. Ao aprender e operar com representações específicas para face de cada pessoa, nós somos capazes de consistentemente melhorar o poder de reconhecimento dos nossos algoritmos. Em particular, nós obtemos resultados no estado da arte na base de dados PubFig83, uma desafiadora coleção de imagens instituída e tornada pública com o objetivo de promover o estudo do reconhecimento de faces familiares. Nós sugerimos que o aprendizado de representações específicas para face de cada pessoa introduz uma forma intermediária de regularização ao problema de aprendizado, permitindo que os classificadores generalizem melhor através do uso de menos |, porém mais relevantes | características faciais / Abstract: Humans are natural face recognition experts, far outperforming current automated face recognition algorithms, especially in naturalistic, \in-the-wild" settings. However, a striking feature of human face recognition is that we are dramatically better at recognizing highly familiar faces, presumably because we can leverage large amounts of past experience with the appearance of an individual to aid future recognition. Researchers in psychology have even suggested that face representations might be partially tailored or optimized for familiar faces. Meanwhile, the analogous situation in automated face recognition, where a large number of training examples of an individual are available, has been largely underexplored, in spite of the increasing relevance of this setting in the age of social media. Inspired by these observations, we propose to explicitly learn enhanced face representations on a per-individual basis, and we present a collection of methods enabling this approach and progressively justifying our claim. By learning and operating within person-specific representations of faces, we are able to consistently improve performance on both the constrained and the unconstrained face recognition scenarios. In particular, we achieve state-of-the-art performance on the challenging PubFig83 familiar face recognition benchmark. We suggest that such person-specific representations introduce an intermediate form of regularization to the problem, allowing the classifiers to generalize better through the use of fewer | but more relevant | face features / Doutorado / Ciência da Computação / Doutor em Ciência da Computação
144

Acceptance of biometric authentication security technology on mobile devices

Malatji, W. R. January 2022 (has links)
M. Tech. (Department of Information and Communication Technology, Faculty of Applied and Computer Sciences), Vaal University of Technology. / Mobile devices are rapidly becoming a key computing platform, transforming how people access business and personal information. Accessing business and personal data using mobile devices requires authentication that is secure. The world is rapidly becoming connected and all users of mobile devices need to be clear regarding individual data security. As a result, biometrics for mobile devices has come into existence. Biometric technology can be applied on mobile devices to improve the trustworthiness of wireless services. Furthermore, it is of great importance and necessary to start paying attention to and investing in mobile biometric technologies, as they are quickly turning into tools of choice for productivity. In the literature review, it shows that few studies measured the acceptance of biometric authentication technology on mobile devices. This study seeks to find out the perceptions as to the acceptance of biometric authentication technology on mobile devices. TAM2 was used as the foundation for generating the hypothesis and developing the conceptual framework for this study. This quantitative study used a survey-based questionnaire to collect data from 305 participants. The simple random sampling technique was used to select participants for this study. The response rate was 98% of the expected population, which was a total of 302 valid responses. A descriptive analysis was deployed to provide a description of respondents’ demographic characteristics. SPSS was used to compute the multiple regressions in order to evaluate the research hypotheses. The findings of this study revealed that perceived humanness, perceived interactivity, perceived social presence, perceived ease of use and subjective social norm, and perceived usefulness and trust are important determinants of customers’ intention to accept and use mobile biometric devices. It was found that reliability is a good predictor of trust. On the other hand privacy, identity theft and combining data are also important determinants of trust. This work can be used to strengthen biometric authentication technology in-cooperation with mobile devices for simplicity of use. Since most mobile devices are used for personal and business information, further research on the acceptance of biometric authentication technology on mobile devices is needed.
145

CHALLENGES AND OPPORTUNITIES OF ADOPTING MANAGEMENT INFORMATION SYSTEMS (MIS) FOR PASSPORT PROCESSING: COMPARATIVE STUDY BETWEEN LESOTHO AND SOUTH AFRICA

Maime, Ratakane. Baptista. January 2014 (has links)
Thesis ( M. Tech. (Business Administration )) - Central University of Technology, Free State, 2014 / Fast and secure public service delivery is not only a necessity, but a compulsory endeavour. However, it is close to impossible to achieve such objectives without the use of Information Technology (IT). It is correspondingly important to find proper sustainability frameworks of technology. Organisations do not only need technology for efficient public service; the constant upgrading of systems and cautious migration to the newest IT developments is also equally indispensable in today’s dynamic technological world. Conversely, countries in Africa are always lagging behind in technological progresses. Such deficiencies have been identified in the passport processing of Lesotho and South Africa, where to unequal extents, problems related to systems of passport production have contributed to delays and have become fertile grounds for corrupt practices. The study seeks to identify the main impediments in the adoption of Management Information Systems (MIS) for passport processing. Furthermore, the study explores the impact MIS might have in attempting to combat long queues and to avoid long waiting periods – from application to issuance of passports to citizens. The reasonable time frame between passport application and issuance, and specific passport management systems, have been extensively discussed along with various strategies that have been adopted by some of the world’s first movers in modern passport management technologies. In all cases and stages of this research, Lesotho and South Africa are compared. The research approach of the study was descriptive and explorative in nature. As a quantitative design, a structured questionnaire was used to solicit responses in Lesotho and South Africa. It was established that both Lesotho and South Africa have somewhat similar problems – although, to a greater extent, Lesotho needs much more urgent attention. Although the processes of South Africa need to be improved, the Republic releases a passport much faster and more efficiently than Lesotho. Economic issues are also revealed by the study as unavoidable factors that always affect technological developments in Africa. The study reveals that the latest MIS for passport processing has facilitated modern, automated border-control systems and resultant e-passports that incorporate more biometric information of citizens to passports – thanks to modern RFID technologies. One can anticipate that this study will provide simple, affordable and secure IT solutions for passport processing. Key words: Information Technology (IT); Management Information Systems (MIS); E-Government; E-Passport; Biometrics; and RFID.
146

Αναγνώριση δικτύου αγγείων στο υπέρυθρο φάσμα

Βλάχος, Μάριος 13 July 2010 (has links)
Η κατασκευή συστημάτων τομογραφίας του ανθρώπινου ιστού τα οποία θα χρησιμοποιούν το υπέρυθρο φάσμα ακτινοβολίας αποτελεί σημαντική προοπτική για τη δημιουργία νέων ιατρικών διαγνωστικών μεθόδων. Ένα από τα σημαντικότερα προβλήματα που πρέπει να επιλυθούν είναι η μικρή διεισδυτική ικανότητα και ο υψηλός βαθμός απορρόφησης και σκέδασης που παραμορφώνει ισχυρά την ακτινοβολία που διαδίδεται μέσα από τον ανθρώπινο ιστό. Στα πλαίσια της διδακτορικής διατριβής, μελετήθηκε το πρόβλημα του εντοπισμού της θέσης των αγγείων σε ψηφιακές φωτογραφίες του ανθρώπινου δακτύλου που έχουν ληφθεί στο υπέρυθρο φάσμα. Για τον σκοπό αυτό αναπτύχθηκε μεγάλος αριθμός πρωτότυπων μεθόδων κανονικοποίησης της φωτεινότητας της εικόνας, μη-γραμμικής ενίσχυσης της αντίθεσης, αφαίρεσης των γραμμών δακτυλικών αποτυπωμάτων, εντοπισμού του προτύπου ή δικτύου αγγείων και βελτίωσης του προτύπου των αγγείων χρησιμοποιώντας μεθόδους μαθηματικής μορφολογίας. Συνοπτικά στην παρούσα διδακτορική διατριβή προτάθηκαν και εξετάσθηκαν διαφορετικές πρωτότυπες μέθοδοι και αλγόριθμοι με επίβλεψη ή χωρίς επίβλεψη για την εξαγωγή του προτύπου αγγείων από υπέρυθρες εικόνες του ανθρώπινου δακτύλου καθώς και διαφορετικές πρωτότυπες μέθοδοι και αλγόριθμοι χωρίς επίβλεψη για την εξαγωγή του δικτύου αγγείων από αμφιβληστροειδικές εικόνες του ανθρώπινου οφθαλμού. Επίσης, η ερευνητική προσπάθεια επικεντρώθηκε στην βελτίωση των εικόνων που λαμβάνονται από το προτεινόμενο σύστημα απόκτησης εικόνων, γεγονός το οποίο οδήγησε στην ανάπτυξη πρωτότυπων μεθόδων προ-επεξεργασίας και τη μετέπειτα βελτίωση των αρχικών αποτελεσμάτων κατάτμησης που προκύπτουν από την εφαρμογή των μεθόδων ή αλγορίθμων κατάτμησης προτύπου αγγείων, γεγονός το οποίο οδήγησε στην ανάπτυξη πρωτότυπων μεθόδων μετά-επεξεργασίας. / The construction of tomographic systems of human tissue which use the infrared spectrum of radiation constitutes an important capability of making new medical diagnostic methods. One of the most crucial problems which must be resolved is the low penetrating ability and the high degree of absorption and scattering which strongly distort the radiation that pass through the human tissue. In this thesis, the problem of the extraction of finger vein pattern from infrared images of finger and the similar problem of retinal vessel tree segmentation were studied. Moreover, the problem of shading and non-uniform illumination correction was also studied in images which suffer from the above problems either due to imperfect set-up of the image acquisition system or due to the interaction between objects and illumination on the scene. In this thesis, existing algorithms were improved and novel algorithms were developed. Both vein pattern extraction algorithms and shading and non-uniform illumination correction algorithms were proposed. The proposed methods include novel preprocessing modules for intensity normalization, elimination of fingerprint lines, non linear contrast enhancement using spatial information, and shading and non uniform illumination correction. The vein pattern extraction was performed using ten novel methods that use structural classification methods, spatial derivatives information and fuzzy set theory. The effectiveness of the proposed methods and algorithms was evaluated both on real and artificial images distorted by different types of noise and different signal to noise ratios. The majority of the methods present satisfactory accuracy on the detection of vein network, something happens due to the successful collaboration between the preprocessing methods and the vein pattern extraction methods. In addition, the problem of improving the vein network extraction accuracy was successfully handled using advanced postprocessing methods based on binary mathematical morphology. Finally, in this thesis two novel methods for retinal vessel segmentation were proposed and evaluated. They also compared with the most important methods have already been presented in the literature and one of them achieved the best experimental results from all the unsupervised methods evaluated in the publicly available DRIVE database.
147

O uso de tecnologia biométrica para o combate à fraude e a melhoria da gestão de pessoas no serviço público

Lima, Henrique Garcia de 30 April 2014 (has links)
Submitted by Henrique Garcia de Lima (hgdlima@gmail.com) on 2014-07-01T02:56:41Z No. of bitstreams: 1 2014-06-30_FGV_Dissertação - Henrique Lima_versão Biblioteca Digital.pdf: 6573543 bytes, checksum: 10d52e68445c89c829a62146889b904f (MD5) / Approved for entry into archive by ÁUREA CORRÊA DA FONSECA CORRÊA DA FONSECA (aurea.fonseca@fgv.br) on 2014-07-07T13:34:56Z (GMT) No. of bitstreams: 1 2014-06-30_FGV_Dissertação - Henrique Lima_versão Biblioteca Digital.pdf: 6573543 bytes, checksum: 10d52e68445c89c829a62146889b904f (MD5) / Approved for entry into archive by Marcia Bacha (marcia.bacha@fgv.br) on 2014-07-14T13:58:09Z (GMT) No. of bitstreams: 1 2014-06-30_FGV_Dissertação - Henrique Lima_versão Biblioteca Digital.pdf: 6573543 bytes, checksum: 10d52e68445c89c829a62146889b904f (MD5) / Made available in DSpace on 2014-07-14T13:58:29Z (GMT). No. of bitstreams: 1 2014-06-30_FGV_Dissertação - Henrique Lima_versão Biblioteca Digital.pdf: 6573543 bytes, checksum: 10d52e68445c89c829a62146889b904f (MD5) Previous issue date: 2014-04-30 / Este trabalho teve como objetivo analisar o uso da biometria no serviço público como forma de redução das oportunidades de fraudes e melhoria da gestão de pessoas na administração pública. Para isso, foi feita uma comparação semiestruturada da experiência internacional e um estudo de caso aprofundado do projeto Identidade Funcional, desenvolvido pelo governo do Estado do Rio de Janeiro. As lições mais importantes, derivadas destas experiências, estão refletidas em um modelo de projeto para formação de uma base biométrica capaz de garantir a integridade do cadastro de pagamento dos salários e benefícios de previdência da administração pública. O modelo tomou por referência a prefeitura de Duque de Caxias, porém foi estruturado de modo a ser viável em municípios do mesmo porte. / This study aims to analyze the use of biometrics in the public service as a way of reducing opportunities for fraud and improving the management of public affairs. The current study uses a semi-structured comparison of international experiences and an in-depth case study of Functional Identity design undertaken by the state government of Rio de Janeiro. The most important lessons derived from these cases were then used to develop a project template for registering biometric data to ensure the integrity of salary and pension benefit within the public administration. The template took as a reference the municipality of Duque de Caxias, but was structured to be viable in cities of a similar size.
148

A countermeasure method for video-based face spoofing attacks : Detecção de tentativas de ataque com vídeos digitais em sistemas de biometria de face / Detecção de tentativas de ataque com vídeos digitais em sistemas de biometria de face

Pinto, Allan da Silva, 1984- 23 August 2018 (has links)
Orientador: Anderson de Rezende Rocha / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Computação / Made available in DSpace on 2018-08-23T22:22:57Z (GMT). No. of bitstreams: 1 Pinto_AllandaSilva_M.pdf: 47523880 bytes, checksum: 072eb0490c26631b80cdcc47d55a4817 (MD5) Previous issue date: 2013 / Resumo: O resumo poderá ser visualizado no texto completo da tese digital / Abstract: The complete abstract is available with the full electronic document / Mestrado / Ciência da Computação / Mestre em Ciência da Computação
149

The use of Automated Fingerprint Identification System in identifying fraudulent voters’ registration in Lesotho

Chigando, Lesole John January 2018 (has links)
The research was prompted by constant criticism of the Independent Electoral Commission (IEC) because of its poor voter registration and voters’ roll. Free and fair elections are the strong arm of democracy. The identified research problem was investigated by means of qualitative research. A thorough literature study from various sources of information, a case file analysis and structured interviews were used to gather the required data. The interviews were conducted with fingerprint experts, a data processor and constituency electoral assistants from the Lesotho Mounted Police Service, the National Identity and Civil Registry at the Ministry of Home Affairs and the IEC respectively. It was found that using fingerprints and the Automated Fingerprint Identification System (AFIS) can assist in investigations and in combating voter’s fraud, as fingerprints are unique. AFIS can be utilised for various purposes by institutions in the private and public sectors. Like any apparatus, AFIS has its own strengths and weaknesses. / Criminology and Security Science / M. Tech. (Forensic investigation)
150

Design and evaluation of a secure, privacy-preserving and cancelable biometric authentication : Bio-Capsule

Sui, Yan 04 September 2014 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / A large portion of system breaches are caused by authentication failure either during the system login process or even in the post-authentication session, which is further related to the limitations associated with existing authentication approaches. Current authentication methods, whether proxy based or biometrics based, are hardly user-centric; and they either put burdens on users or endanger users' (biometric) security and privacy. In this research, we propose a biometrics based user-centric authentication approach. The main idea is to introduce a reference subject (RS) (for each system), securely fuse the user's biometrics with the RS, generate a BioCapsule (BC) (from the fused biometrics), and employ BCs for authentication. Such an approach is user-friendly, identity-bearing yet privacy-preserving, resilient, and revocable once a BC is compromised. It also supports "one-click sign on" across multiple systems by fusing the user's biometrics with a distinct RS on each system. Moreover, active and non-intrusive authentication can be automatically performed during the user's post-authentication on-line session. In this research, we also formally prove that the proposed secure fusion based BC approach is secure against various attacks and compare the new approach with existing biometrics based approaches. Extensive experiments show that the performance (i.e., authentication accuracy) of the new BC approach is comparable to existing typical biometric authentication approaches, and the new BC approach also possesses other desirable features such as diversity and revocability.

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