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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.
341

Développement d’un indice de vitalité dérivé à partir du Hexoskin afin d’obtenir une mesure d’angine digitale et raffiner l’étude de la maladie cardiaque athérosclérotique

Avram, Robert 12 1900 (has links)
Introduction: Jusqu’à la moitié des patients souffrant d’angine de poitrine vont continuer à être symptomatiques malgré une revascularisation coronarienne pour leur angine. Par ailleurs, l’évaluation de l’angine souffre du biais d’adaptation au seuil ischémique, phénomène par lequel les patients réduisent leur niveau d’activité physique pour limiter leurs symptômes. L’étude NOVA-SKIN (NCT02591758) utilise une veste intelligente (Hexoskin™) afin de (i) valider l’électrocardiogramme (ECG) de cette veste avec le Holter et l’épreuve d’effort (ii) dériver un “indice de vitalité” à partir des mesures biométriques de la veste, afin d’ajuster les mesures conventionnelles d’angine pour le biais d’adaptation au seuil ischémique et dériver des mesures d’angine digitale et (iii) évaluer si la réadaptation cardiaque à domicile peut être surveillée à distance avec le Hexoskin. Méthodes: Trente patients référés pour angiographie coronarienne pour leur angine réfractaire au traitement médical ont complété une épreuve d’effort et ont porté la veste Hexoskin (avec enregistrement simultané d’Holter) pendant 48 heures, 2 semaines avant leur examen. Les patients furent revus 2 semaines après la revascularisation coronarienne percutanée ou 6 semaines après la chirurgie cardiaque s’ils ont eu des pontages, où ils ont porté la veste Hexoskin avec Holter pendant 48 heures et fait une épreuve d’effort. Nous avons dérivé un indice de vitalité digital (Indice de vitalité = fréquence cardiaque * activité) chez chaque patient pour les deux enregistrements de la veste. Nous avons dérivé des mesures d’angine digitale en divisant ou multipliant (selon la direction de l’effet post coronarographie attendu) les mesures d’angine conventionnelle (classe SCC, pointage de qualité de vie, décompte de nitroglycérine et décompte d’angine) par l’indice de vitalité propre au patient. Nous avons comparé les différences (pré- et post-coronarographie) de mesures d’angine ajustées pour l’indice de vitalité dérivé à partir d’une veste intelligente (« angine digitale ») avec les mesures d’angine conventionnelles non ajustées. Les participants devaient ensuite compléter 6 sessions de réadaptation cardiaque à domicile sur une période de 1 mois. Une corrélation de Pearson fut obtenue entre la fréquence cardiaque de l’ECG de l’Hexoskin et celle du Holter et du tapis roulant. L’indice de vitalité pré et post-angiographie fut comparé en utilisant un test t et nous avons mesuré la taille de l’effet du traitement de l’angine dans le même patient, pour les mesures ajustées et non ajustées d’angine. Résultats: Trente patients, âgés de 68.0±7.0 ans, majoritairement des hommes (n=28; 93.3%) ont subi une angiographie coronarienne et ont été traités, pour leur angine, de façon percutanée (n=20; 66.7%), avec pontages (n=6; 20.0%) ou avec traitement médical (n= 4; 13.3%). Tous les patients étaient en rythme sinusal au départ. La fréquence cardiaque obtenue avec l’ECG de l’Hexoskin avait une corrélation très forte avec celle obtenue avec l’ECG du tapis roulant (r=0.95) et forte avec l’Holter (r=0.85). L’indice de vitalité a augmenté de manière significative (2.30±1.38 pré vs 2.70±1.12 post-traitement de l’angine; p=0.05). Les mesures d’angine digitale ayant montré une différence plus importante que les mesures conventionnelles sont le décompte hebdomadaire de nitroglycérine, l’échelle de santé globale du SF-36, la durée d’effort sur le tapis roulant et le nombre de METS maximal. Par ailleurs, chez les patients classifiés comme non-répondants au traitement de l’angine par mesures conventionnelles, les mesures d’angine digitale suivantes se sont améliorées de façon significative: classe SCC, décompte hebdomadaire d’angine, questionnaire d’angine de Seattle et la durée d’effort pendant l’épreuve d’effort. Aucun évènement cardiovasculaire ne s’est produit durant la réadaptation cardiaque à domicile et 93.3% des patients ont complété les 6 sessions. Conclusion : Dans notre étude pilote, l’ECG de Hexoskin a obtenu des mesures de fréquence cardiaque valides lorsque comparées au Holter et au tapis d’effort. L’incorporation d’un indice de vitalité obtenu à partir d’une veste intelligente a permis d’ajuster des mesures d’angine pour celui-ci et obtenir une angine digitale. La mesure d’angine digitale a une plus grande taille de l’effet post traitement de l’angine par revascularisation et peut détecter davantage de changements, au-delà des mesures d’angine conventionnelles. Cela est plus marqué chez les patients initialement classifiés comme “non-répondants” au traitement de l’angine. La réadaptation cardiaque à domicile fut sécuritaire et complétée par la majorité des patients. / Introduction : Up to half of coronary artery disease patients will remain symptomatic of angina, despite coronary revascularization. Moreover, the assessment of angina suffers from the ischemic threshold adaptation bias where patients will restrict their physical activity level in order to minimize their angina symptoms. The NOVA-SKIN study (NCT02591758) was designed to use a novel “smart clothing” (Hexoskin™) to (i) validate the electrocardiogram (ECG) signal of against traditional Holter and Treadmill stress tests (ii) to derive a ‘vitality index’ using the biometric measures obtained from the Hexoskin in order to adjust conventional angina assessment metrics to account for the ischemic threshold adaptation bias and derive a digital measure of angina and to (iii) assess if home cardiac rehabilitation can be remotely monitored using the Hexoskin system. Methods: Thirty stable angina patients referred for coronary angiography for refractory angina underwent a treadmill stress test and then simultaneously wore the Hexoskin vest and a traditional Holter monitor for 48 hours, 2 weeks before their exam. The patients were followed up 2 weeks after the percutaneous coronary intervention and 6 weeks after their cardiac surgery if they had coronary artery bypass graft. During the follow-up visit, they wore the vest with a Holter monitor for 48 hours and underwent another treadmill stress test. We obtained an average vitality index pre- and post-angiogram (Vitality index=heart rate * activity) using recordings from the vest. We also obtained health related questionnaires during the same timeframe. We compared differences in conventional angina metrics adjusted for the vitality index (“digital angina”) with the conventional metrics unadjusted for the vitality index, pre- and post-coronary angiography. Patients then had to complete 6 home cardiac rehabilitation sessions during a 1-month period. Pearson correlation was obtained between the heart rate (HR) derived from the ECG of the vest and the HR of the Holter and treadmill stress test. The vitality index pre and post-angiography was compared using a t-test. We derived digital angina metrics by dividing or multiplying (according to the direction of the effect expected post-coronarography) the conventional angina metrics. Then we measured the effect size of the angina treatment and compared it between adjusted and unadjusted metrics within the same patient. Results: Thirty patients aged 68.0±7.0 years (93.3% men; n=28) were enrolled in the study. Patients were treated with percutaneous coronary intervention (n=20; 66.7%), coronary artery bypass grafting (n=6; 20.0%) or medical therapy (n=4; 13.3%). The heart rate from ECG signal of the Hexoskin demonstrated a very strong correlation with that of the treadmill stress test ECG (r=0.95) and a strong correlation with the Holter (r=0.85). The vitality index increased significantly from 2.30±1.38 to 2.70±1.12 (p=0.05). The digital angina metrics (adjusted for the vitality index) that were found to be more responsive to the treatment of the angina than conventional were: the weekly nitroglycerin count, the global health sub-scale of the SF-36, the treadmill stress test length and the peak METs. Furthermore, in patients classified as non-responders to the treatment of angina by conventional metrics, the digital angina measures improved significantly, when looking at the CCS class, the weekly angina count, the Seattle Angina Questionnaire metrics and the duration of exercise on the treadmill stress test. No adverse events occurred during home cardiac rehabilitation and 28 patients completed all 6 sessions wearing the Hexoskin. Conclusion : In our pilot study, the Hexoskin ECG was well correlated with standard HR measurement using a treadmill ECG or a Holter. Adjusting conventional metrics for the vitality index allows for greater sensitivity in gauging the effect of revascularization on angina than conventional metrics alone, particularly for patients who would be considered non-responders to their treatment based on conventional metrics. Home cardiac rehabilitation was safe and was completed by most patients.
342

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.
343

The use of the Automated Fingerprint Identification System to improve the quality of service rendered by the South African Police Service on the East Rand

Matlala, Mpho Mark 2012 November 1900 (has links)
The globalisation process that drives the progression and trans-national nature of crime requires that the police should use sophisticated and/or state-of-the art technologies to help them to combat criminality. The use of technology by the police is thus viewed as one of the appropriate responses to deal with the threats posed by crime. In an attempt to ascertain the significance of technology in police work, this research examined the impact that the use of biometric technology such as the Automated Fingerprint Identification System, has had on the quality of seiVices rendered by the South African Police Service. Following the police's task of identifying criminal fingerprints, the problem encountered in this research was that, ever since the introduction of the Automated Fingerprint Identification System, no research had been conducted to assess the impact thereof on the level and quality of seiVices rendered by the South African Police SeiVice. This problem was further intensified by the fact that there was no framework to assess the impact that the utilisation of the Automated Fingerprint Identification System has had on police work in South Africa. Consequently, the problems that were identified in this research compromised not only the quality of seiVices rendered by the police, but also the safety and security within communities. The findings in this research showed that the utilisation of biometric technologies such as the Automated Fingerprint Identification System have helped the police to accurately identify and arrest criminal suspects. However, some of the conclusions reached suggested that the quantitative aspect of the utilisation of biometric systems and the elated portable apparatuses within the South African Police Service was emphasised more than the qualitative aspect thereof. The emphasis was evident in the statistics regarding the use of the Automated Fingerprint Identification System, which focused primarily on police productivity and to a lesser degree on accountability related issues. This study espoused a qualitative paradigm and the investigations in the research were focused on the East Rand policing precinct. The participants who informed this research were selected from the research population using random and purposive sampling techniques. In the same way, the data that informed this research was collected using semi-structured interviews and an in-depth review of the literature on policing and its utilisation of the different technologies. The research espoused social constructivism and phenomenology as the philosophical worldviews of choice to form constructivist phenomenology and to attain theoretical triangulation. Moreover, evaluation research and a case study were espoused as the research designs of choice, to attain methodological triangulation. The various triangulation techniques espoused in this research project were critical in attaining quality assurance in terms of the research methodology applied. In the same way, a myriad of qualitative techniques such as dependability, transferability, confimability and credibility were also employed in order to ensure that the integrity of the data that was collected in this study remained intact. Finally, the data that was collected to inform this research was analysed using the qualitative content analysis technique. Similarly, the measures taken to ensure that the safety of the research participants was delineated in this same research report. / Police Practice / M. Tech. (Police Science)
344

Demonstrate and document : the development of a best practice model for biometric access control management

Norris-Jones, Lynne January 2011 (has links)
This thesis investigates the social, legal and ethical perceptions of participants towards the implementation of biometric access control systems within a sample of United Kingdom work-based environments. It focuses on the application of fingerprint scanning and facial recognition systems, whilst alluding to the development of more advanced (bleeding edge) technologies in the future. The conceptual framework is based on a tripartite model in which Maslow's Hierarchy of Needs is applied to the workforce whilst the principles of Utilitarianism and the Psychological Contract are applied to both management strategies and workforce perceptions. A qualitative paradigm is used in which semi-structured interviews are conducted with management and workforce participants within a sample of United Kingdom-based organisations (represented by Case Studies A-D). Discourse from these interviews are analysed, leading to the development of a series of first-cut findings for suggested "Best Practice " in the social, legal and ethical management of biometric access control systems. This process is subsequently developed with a refined sample of respondents (Case Studies A and C) culminating in the presentation of a suggested "Best Practice Model" for application to all four case studies. The model is based upon elements of a pre-determined Code of Practice (ISO/IEC 27002lnformation Technology - Security techniques - Code of Practice for Information Security Management) towards fostering acceptance of biometric technology within the workplace, in answering the question: How should organisations using biometric access control systems address social, legal and ethical concerns in the management of specific working environments in the United Kingdom?
345

Investigação biométrica em imagens digitais para detecção de faces humanas através da proporção divina / Biometric investigation in digital images for the detection of human faces by divine proportion

Prado, Junior Leal do 23 December 2004 (has links)
O crescimento da utilização de sistemas de reconhecimento no mundo contemporâneo exige processos de detecção cada vez mais robustos e ágeis. Aplicáveis desde sistemas de teleconferência empresarial até mecanismos de segurança e vigilância, a detecção e o reconhecimento de pessoas tornaram-se uma constante. Na tentativa de buscar caminhos alternativos, tanto para os problemas de detecção, quanto para os de reconhecimento, este trabalho propõe a utilização de medidas biométricas, mensuradas em imagens digitalizadas de faces humanas. A partir do estudo de tais medidas, torna-se possível a verificação de proporções existentes na face, especialmente a proporção divina, podendo constituir, no futuro, a base para algoritmos de detecção e/ou reconhecimento que usufruam das informações trazidas por tais proporções. Diante de uma reduzida quantidade de publicações no meio científico que utilizam a proporção divina como meio de detecção e/ou reconhecimento em processamento de imagens, esta investigação vem contribuir com alguns passos nessa direção / The increase of recognition systems in the contemporary world has demanded robust and agile detection processes. From teleconference systems to security and monitoring mechanisms, the detection and recognition of people have became constantly used and applied. In attempt to search for alternative ways to solve both detection and recognition problems, this work proposes the utilization of biometric measures, taken in digital image of human faces. From the study of such measures, it’s possible to verify face proportions, especially the divine proportion, which could allows, in the future, to implement the detection and/or recognition algorithms that utilize such proportions. Due to small amount of scientific publications that use the divine proportion as a way of detection and/or recognition in image processing, this investigation contributes with some steps in this direction
346

Qualidade da romã "molar" submetida a temperatura de armazenamento e biofilmes. / Quality of pomegranate 'Molar' posted at temperatures of storage and edible biofilms.

MOREIRA, Inácia dos Santos. 29 May 2018 (has links)
Submitted by Deyse Queiroz (deysequeirozz@hotmail.com) on 2018-05-29T17:56:21Z No. of bitstreams: 1 INÁCIA DOS SANTOS MOREIRA - DISSERTAÇÃO PPGSA PROFISSIONAL 2014..pdf: 1960619 bytes, checksum: 0eec38ed3470ea1ff2f29f63cf555e2b (MD5) / Made available in DSpace on 2018-05-29T17:56:21Z (GMT). No. of bitstreams: 1 INÁCIA DOS SANTOS MOREIRA - DISSERTAÇÃO PPGSA PROFISSIONAL 2014..pdf: 1960619 bytes, checksum: 0eec38ed3470ea1ff2f29f63cf555e2b (MD5) Previous issue date: 2014-02-26 / O presente trabalho teve como objetivo caracterizar a qualidade da romã „Molar‟ durante o armazenamento dos frutos in natura, sob diferentes temperaturas de refrigeração, e avaliar o uso de biofilmes à base de fécula de mandioca e Spirulina platensis nos frutos armazenados sob as condições ambiente à 25ºC e sob condições de armazenamento refrigerado a 10ºC. O estudo foi subdividido em duas etapas no Laboratório de Análise de Alimentos da UFCG, no Campus de Pombal - PB. Na primeira etapa, os frutos foram armazenados nas temperaturas 6°C, 10°C e 12°C e analisados ao 0, 12, 18, 24, 30, 36 dias de refrigeração, sendo cada intervalo acrescidos de dois dias de permanência em sala sob condição ambiente (24 ± 2ºC e 43 ± 5% UR), para simular as condições de comercialização (Shelf life). Na segunda etapa, foram selecionados doze frutos para sua caracterização inicial, os outros frutos receberam os seguintes tratamentos: T1 - Testemunha, sem recobrimento; T2 - 1% de fécula de mandioca; T3 - 3% de fécula de mandioca; T4 - 1% de Spirulina platensis; T5 - 3% de Spirulina platensis; T6 - 1% de fécula de mandioca e 1% de Spirulina platensis e T7 - 3% de fécula de mandioca e 3% de Spirulina platensis. Ao receber os tratamentos, os frutos foram separados em dois experimentos para o estabelecimento das condições de armazenamento, onde: Experimento I – Frutos tratados e armazenados em sala climatizada, com controle de temperatura e umidade, simulando condições de comercialização em temperatura ambiente (25,1ºC e 43,3% UR) durante 6 dias e Experimento II - Frutos tratados e refrigerados em B.O.D. (10ºC e 56,7% UR) por um período de 12 dias acrescidos de dois dias de permanência sob condições ambiente (Shelf life). Avaliou-se características biométricas, visuais e físico-químicas. Romãs „Molar‟ armazenadas a 10ºC por 36 dias seguidos de „shelf life‟ de dois dias a 24°C, se mantêm satisfatórias para comercialização in natura, sem prejuízos nos atributos de qualidade biométricos, visuais e físico-químicos. O armazenamento dos frutos a 6ºC proporciona prejuízos na qualidade visual dos frutos devido ao aparecimento de manchas, prejudicando a aparência externa. A temperatura de armazenamento a 12ºC proporciona sintomas de murcha apenas ao final do armazenamento. As temperaturas de armazenamento a 6ºC, 10ºC ou 12ºC podem ser temperaturas apropriadas para o armazenamento de romãs destinadas à indústria, por não prejudicarem os atributos internos de qualidade da romã „Molar‟, especialmente relacionados à integridade das sementes, arilos, rendimento de suco, sólidos solúveis, acidez tituláveis, flavonoides e antocianinas. O revestimento com 1% de fécula de mandioca no armazenamento a 25ºC reuniu boas caracterisiticas biométricas, visuais e físico-químicas para a conservação pós-colhetia da romã; A elevada perda dos diâmetros em frutos armazenados em condição ambiente foi fator limitante na qualidade e vida útil pós-colheita de romã „Molar‟. O revestimento com 3% de fécula de mandioca e com 3% de fécula de mandioca mais 3% de Spirulina plantensis associados à refrigeração apresentaram melhor qualidade biométrica, visual e fisico-química durante os quatorze dias de armazenamento. / The present study aimed to characterize the quality of Pomegranate ' Molar ' during storage of raw fruits under different cooling temperatures and evaluate the use of biofilms based on cassava starch and Spirulina platensis in fruits stored under ambient conditions at 25°C and under conditions of cold storage at 10ºC. The study was divided into two stages at the Laboratory of Food Analysis UFCG, Campus de Pombal - PB. In the first stage , the fruits were stored at temperatures 6°C , 10°C and 12°C and analyzed at 0, 12, 18, 24, 30, 36 days of refrigeration and each range , plus two days of stay in room under ambient conditions (24 ± 2ºC and 43 ± 5% RH) to simulate marketing conditions (Shelf Life). In the second stage, twelve fruits were selected for initial characterization , the other fruits received the following treatments : T1 - control , Uncoated; T2 - 1% of cassava starch ; T3 - 3% of cassava starch ; T4 - 1% of Spirulina platensis; T5 - 3% of Spirulina platensis; T6 - 1 % of cassava starch and 1% Spirulina platensis and T7 - 3 % of cassava starch and 3% Spirulina platensis . Upon receiving the treatments, fruits were separated into two experiments to establish the conditions of storage, where: Experiment I - Fruits processed and stored in a climatic chamber with controlled temperature and humidity conditions simulating marketing at room temperature (25,1ºC and 43,3 % RH) for 6 days and Experiment II - Fruits treated and chilled in BOD (10ºC and 56,7 % RH) for a period of 12 days plus two days under ambient conditions (Shelf Life). It was evaluated biometric, visual and physical- chemical characteristics. Pomegranates 'Molar' stored at 10ºC for 36 days followed by 'shelf life' two days at 24°C, remains satisfactory for fresh fruit market without losses in quality attributes biometric, visual and physical chemistry. The storage of fruits at 6ºC provides visual loss in fruit quality due to the appearance of blemishes, impairing external appearance. The storage temperature to 12ºC provides wilt symptoms only at the end of storage. Storage temperatures to 6°C, 10°C or 12°C may be appropriate temperatures for storage of pomegranates for industry not to harm the internal quality attributes of pomegranate ' Molar ', especially related to integrity seeds, arils, juice yield , solids soluble, titratable acidity, flavonoids and anthocyanins. The coating with 1% of cassava starch in storage at 25ºC has gathered good biometric, visual and physic chemical's characteristic for postharvest conservation pomegranate; The high loss of diameter in fruits stored at ambient condition was a limiting factor in the quality and postharvest pomegranate 'Molar' life. The coating with 3% of cassava starch and 3% of cassava starch 3% Spirulina plantensis associated with refrigeration showed better biometric, visual and physico-chemical quality during storage fourteen days.
347

User Efficient Authentication Protocols with Provable Security Based on Standard Reduction and Model Checking

Lin, Yi-Hui 12 September 2012 (has links)
Authentication protocols are used for two parties to authenticate each other and build a secure channel over wired or wireless public channels. However, the present standards of authentication protocols are either insufficiently secure or inefficient for light weight devices. Therefore, we propose two authentication protocols for improving the security and user efficiency in wired and wireless environments, respectively. Traditionally, TLS/SSL is the standard of authentication and key exchange protocols in wired Internet. It is known that the security of TLS/SSL is not enough due to all sorts of client side attacks. To amend the client side security, multi-factor authentication is an effective solution. However, this solution brings about the issue of biometric privacy which raises public concern of revealing biometric data to an authentication server. Therefore, we propose a truly three factor authentication protocol, where the authentication server can verify their biometric data without the knowledge of users¡¦ templates and samples. In the major wireless technologies, extensible Authentication Protocol (EAP) is an authentication framework widely used in IEEE 802.11 WLANs. Authentication mechanisms built on EAP are called EAP methods. The requirements for EAP methods in WLANs authentication have been defined in RFC 4017. To achieve user efficiency and robust security, lightweight computation and forward secrecy, excluded in RFC 4017, are desired in WLAN authentication. However, all EAP methods and authentication protocols designed for WLANs so far do not satisfy all of the above properties. We will present a complete EAP method that utilizes stored secrets and passwords to verify users so that it can (1) meet the requirements of RFC 4017, (2) provide lightweight computation, and (3) allow for forward secrecy. In order to prove our proposed protocols completely, we apply two different models to examine their security properties: Bellare¡¦s model, a standard reduction based on computational model, that reduces the security properties to the computationally hard problems and the OFMC/AVISPA tool, a model checking approach based on formal model, that uses the concept of the search tree to systematically find the weaknesses of a protocol. Through adopting Bellare¡¦s model and OFMC/AVISPA tool, the security of our work is firmly established.
348

A Study Of Utility Of Smile Profile For Face Recognition

Bhat, Srikrishna K K 08 1900 (has links)
Face recognition is one of the most natural activities performed by the human beings. It has wide range of applications in the areas of Human Computer Interaction, Surveillance, Security etc. Face information of people can be obtained in a non-intrusive manner, without violating privacy. But, robust face recognition which is invariant under varying pose, illumination etc is still a challenging problem. The main aim of this thesis is to explore the usefulness of smile profile of human beings as an extra aid in recognizing people by faces. Smile profile of a person is the sequence of images captured by a camera when the person voluntarily smiles. Using sequence of images instead of a single image will increase the required computational resources significantly. The challenge here is to design a feature extraction technique from a smile sample, which is useful for authentication and is also efficient in terms of storage and computational aspects. There are some experimental evidences which support the claim that facial expressions have some person specific information. But, to the best of our knowledge, systematic study of a particular facial expression for biometrical purposes has not been done so far. The smile profile of human beings, which is captured under some reasonably controlled setup, is used for first time for face recognition purpose. As a first step, we applied two of the recent subspace based face classifiers on the smile samples. We were not able to obtain any conclusive results out of this experiment. Next we extracted features using only the difference vectors obtained from smile samples. The difference vectors depend only on the variations which occur in the corresponding smile profile. Hence any characterization we obtain from such features can be fully attributed to the smiling action. The feature extraction technique we employed is very much similar to PCA. The smile signature that we have obtained is named as Principal Direction of Change(PDC). PDC is a unit vector (in some high dimensional space) which represents the direction in which the major changes occurred during the smile. We obtained a reasonable recognition rate by applying Nearest Neighbor Classifier(NNC) on these features. In addition to that, these features turn out to be less sensitive to the speed of smiling action and minor variations in face detection and head orientation, while capturing the pattern of variations in various regions of face due to smiling action. Using set of experiments on PDC based features we establish that smile has some person specific characteristics. But the recognition rates of PDC based features are less than the recent conventional techniques. Next we have used PDC based features to aid a conventional face classifier. We have used smile signatures to reject some candidate faces. Our experiments show that, using smile signatures, we can reject some of the potential false candidate faces which would have been accepted by the conventional face classifier. Using this smile signature based rejection, the performance of the conventional classifier is improved significantly. This improvement suggests that, the biometric information available in smile profiles does not exist in still images. Hence the usefulness of smile profiles for biometric applications is established through this experimental investigation.
349

從生物辨識應用探討隱私權之保護 / The privacy protection issues of biometric application

游璿樺, Yu, Hsuan Hua Unknown Date (has links)
自從美國911恐怖攻擊事件後,生物辨識技術受到世界各國重視,使得生物辨識應用大鳴大放,涵蓋範圍非常廣泛,從國家的入出境管理、國民身分證,到公司或住家的門禁管理、安全監控,乃至於個人身分確認,如電腦開機登錄、隨身碟資料加密。然而生物辨識應用,會涉及個人生物特徵之蒐集與相關個人資料之運用,一方面為生活上帶來便利,另一面也無聲無息為個人隱私帶來衝擊與威脅。本文從生物辨識技術之研究,藉由分析指紋辨識、臉型辨識及DNA辨識之應用所引發的隱私權問題,以及相關法令規範之探討,最後從法制面、政策面與執行面上提供建議,希望藉由完備的法令規範,評估各種應用可能引發之隱私爭議,建立完善的管理制度與監督機制,將生物辨識應用之隱私侵害與疑慮降到最低,得以享受生物辨識應用所帶來的安全性與方便性。
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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.

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