• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 3
  • 2
  • 2
  • 1
  • 1
  • 1
  • Tagged with
  • 13
  • 13
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 2
  • 2
  • 2
  • 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.
1

On Traffic Analysis Attacks To Encrypted VoIP Calls

Lu, Yuanchao 10 December 2009 (has links)
No description available.
2

Endocuff-assistierte Koloskopie versus Standardkoloskopie zur Detektion von Adenomen – Eine prospektive randomisierte Multicenterstudie – / Higher adenoma detection rates with endocuff-assisted colonoscopy - a randomized controlled multicenter trial

Röming, Alexander Klaus Hermann 06 April 2017 (has links)
No description available.
3

Úloha preventivní kolonoskopie v detekci kolorektální neoplázie. / The role of preventive colonoscopy in the detection of colorectal neoplasia.

Vojtěchová, Gabriela January 2020 (has links)
Colonoscopy is used in colorectal cancer (CRC) screening either as an independent screening method (screening colonoscopy) or following a positive result of a primary screening test (eg. fecal occult blood test, FOBT). Preventive colonoscopy is the collective name for screening and FOBT+ colonoscopy. Due to the considerable variability in the detection of colorectal neoplasia between individual endoscopists, colonoscopy quality indicators were introduced. Adenoma detection rate (ADR) and polyp detection rate (PDR) are defined as the proportion of colonoscopies in which at least one adenoma (for ADR) or polyp (for PDR) was detected to the total number of colonoscopies performed. ADR is considered a key indicator of the quality of colonoscopy. Adenoma per colonoscopy (APC), defined as the total number of adenomas detected relative to the total number of colonoscopies performed, is the most accurate indicator currently available. However, APC limit values have not yet been set. Both ADR and APC are validated indicators, but their evaluation is time-consuming and personnel-intensive, which limits their use in clinical practice. The main purpose of the presented work is to simplify the monitoring of colonoscopy quality by introducing a more user-friendly indicator, which does not require histological...
4

Improved performance high speed network intrusion detection systems (NIDS). A high speed NIDS architectures to address limitations of Packet Loss and Low Detection Rate by adoption of Dynamic Cluster Architecture and Traffic Anomaly Filtration (IADF).

Akhlaq, Monis January 2011 (has links)
Intrusion Detection Systems (IDS) are considered as a vital component in network security architecture. The system allows the administrator to detect unauthorized use of, or attack upon a computer, network or telecommunication infrastructure. There is no second thought on the necessity of these systems however; their performance remains a critical question. This research has focussed on designing a high performance Network Intrusion Detection Systems (NIDS) model. The work begins with the evaluation of Snort, an open source NIDS considered as a de-facto IDS standard. The motive behind the evaluation strategy is to analyze the performance of Snort and ascertain the causes of limited performance. Design and implementation of high performance techniques are considered as the final objective of this research. Snort has been evaluated on highly sophisticated test bench by employing evasive and avoidance strategies to simulate real-life normal and attack-like traffic. The test-methodology is based on the concept of stressing the system and degrading its performance in terms of its packet handling capacity. This has been achieved by normal traffic generation; fussing; traffic saturation; parallel dissimilar attacks; manipulation of background traffic, e.g. fragmentation, packet sequence disturbance and illegal packet insertion. The evaluation phase has lead us to two high performance designs, first distributed hardware architecture using cluster-based adoption and second cascaded phenomena of anomaly-based filtration and signature-based detection. The first high performance mechanism is based on Dynamic Cluster adoption using refined policy routing and Comparator Logic. The design is a two tier mechanism where front end of the cluster is the load-balancer which distributes traffic on pre-defined policy routing ensuring maximum utilization of cluster resources. The traffic load sharing mechanism reduces the packet drop by exchanging state information between load-balancer and cluster nodes and implementing switchovers between nodes in case the traffic exceeds pre-defined threshold limit. Finally, the recovery evaluation concept using Comparator Logic also enhance the overall efficiency by recovering lost data in switchovers, the retrieved data is than analyzed by the recovery NIDS to identify any leftover threats. Intelligent Anomaly Detection Filtration (IADF) using cascaded architecture of anomaly-based filtration and signature-based detection process is the second high performance design. The IADF design is used to preserve resources of NIDS by eliminating large portion of the traffic on well defined logics. In addition, the filtration concept augment the detection process by eliminating the part of malicious traffic which otherwise can go undetected by most of signature-based mechanisms. We have evaluated the mechanism to detect Denial of Service (DoS) and Probe attempts based by analyzing its performance on Defence Advanced Research Projects Agency (DARPA) dataset. The concept has also been supported by time-based normalized sampling mechanisms to incorporate normal traffic variations to reduce false alarms. Finally, we have observed that the IADF has augmented the overall detection process by reducing false alarms, increasing detection rate and incurring lesser data loss. / National University of Sciences & Technology (NUST), Pakistan
5

Hanseníase no estado de Goiás: um recorte de 10 anos / Leprosy in the state of Goiás: a 10 year-cut-out

Issler , Sônia Cristina Moreira 18 June 2014 (has links)
Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2017-03-03T15:19:08Z No. of bitstreams: 2 Dissertação - Sônia Cristina Moreira Issler - 2014.pdf: 2964898 bytes, checksum: fd9559238e1e42140b9553ff3fe717a3 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2017-03-03T15:19:27Z (GMT) No. of bitstreams: 2 Dissertação - Sônia Cristina Moreira Issler - 2014.pdf: 2964898 bytes, checksum: fd9559238e1e42140b9553ff3fe717a3 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-03-03T15:19:27Z (GMT). No. of bitstreams: 2 Dissertação - Sônia Cristina Moreira Issler - 2014.pdf: 2964898 bytes, checksum: fd9559238e1e42140b9553ff3fe717a3 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2014-06-18 / Leprosy is a serious public health problem worldwide ranking second in reported cases in the year. In Brazil it remains a public health problem. The knowledge of its clinical and epidemiological characteristics is of fundamental importance to subsidize disease control actions. The objective of the study was to know the epidemiological profile of leprosy patients in the state of Goiás from 2002 to 2013. A descriptive study, to be carried out in 17 microregions of the State of Goiás, where leprosy cases were obtained from the databases Of the Notification of Injury Information System (SINAN). The study variables include: age, sex, race, schooling, clinical form, operational classification, degree of physical incapacity in diagnosis, mode of detection of the new case. Chi-square test was applied to compare the variables and significance level of 5% (p <0.05). Data were analyzed in EpiInfo software version 3.5.1 and the Statistical Puckage for Social Science (SPSS) package. In the 10-year period, a total of 28,041 new cases were reported, of which 74.12% were aged between 20 and 59 years, 57.3% were males, 42.8% were brown, 47.3% were (52.1%), 71.6% with multibacillary operational classification, 48.6%, detected by spontaneous demand, and 72.2% did not present deformities in the diagnosis. The coefficient of detection of the new cases in the state of Goiás showed high indices. There is evidence of the need to intensify the development of leprosy control actions in the state, facilitating access to diagnosis and treatment, reorganizing the work process in order to integrate control actions to basic health services with emphasis on the collective approach. New studies will be needed to better understand the influence of the health services organization and the dynamics of work processes in order to subsidize the development of other strategies for the control of leprosy. / A Hanseníase é um sério problema de saúde pública mundial ocupando o segundo lugar em casos notificados no ano. No Brasil permanece como um problema de saúde pública. O conhecimento de suas características clínicas e epidemiológicas é de fundamental importância para subsidiar ações de controle da doença. O objetivo do estudo foi conhecer o perfil epidemiológico de portadores de hanseníase no estado de Goiás no período de 2002 a 2013. Estudo descritivo, a ser realizado em 17 microrregiões do Estado de Goiás, onde foram analisados os casos hanseníase, obtidos nos bancos de dados do Sistema de Informação de Agravos de Notificação (SINAN). As variáveis do estudo englobam: idade, sexo, raça, escolaridade, forma clínica, classificação operacional, grau de incapacidade física no diagnóstico, modo de detecção do caso novo. Teste Qui-quadrado, foi aplicado para comparar as variáveis e nível de significância de 5% (p<0,05). Os dados foram analisados no software EpiInfo versão 3.5.1 e o pacote Statistical Puckage for the Social Science (SPSS). No período de 10 anos um total de 28.041 casos novos foram notificados, sendo que 74,12% com idade entre 20 a 59 anos, 57,3% do sexo masculino, 42,8% da raça parda, 47,3% dos casos possuem ensino fundamental incompleto, a forma clínica da hanseníase mais frequente foi dimorfa (52,1%), 71,6% com classificação operacional multibacilar, 48,6%, detectados por demanda espontânea, 72,2% não apresentam deformidades no diagnóstico. O coeficiente de detecção dos casos novos no estado de Goiás demonstrou índices elevados. Evidencia-se a necessidade de intensificar o desenvolvimento das ações de controle da hanseníase no estado, facilitando acesso ao diagnóstico e ao tratamento, reorganizando o processo de trabalho de forma a integrar as ações de controle aos serviços de atenção básica com ênfase na abordagem coletiva. Novos estudos serão necessários para compreender melhor a influência da organização dos serviços de saúde e da dinâmica dos processos de trabalho de forma a subsidiar o desenvolvimento de outras estratégias para o controle da hanseníase.
6

Quality of Colonoscopy: A Comparison Between Gastroenterologists and Nongastroenterologists

Muthukuru, Sujit, Alomari, Mohammad, Bisen, Ruchi, Parikh, Malav P., Al Momani, Laith, Talal Sarmini, Muhammad, Lopez, Rocio, Muthukuru, Shamant, Thota, Prashanthi N., Sanaka, Madhusudhan R. 01 July 2020 (has links)
BACKGROUND: Colonoscopy performance by gastroenterologists has been shown to be associated with lower rates of developing interval colorectal cancer. However, it is unclear if this difference among specialists stems from a difference in meeting colonoscopy quality indicators. OBJECTIVE: The purpose of this study is to determine and compare the rates of colonoscopy quality indicators between different specialties. DESIGN: This is a cohort study of patients undergoing screening colonoscopy investigating quality metrics as compared by the proceduralist specialty. SETTING: All screening colonoscopies performed at the Cleveland Clinic between 2012 and 2014 were followed by manual chart review. PATIENTS: Average-risk patients, ≥50 years of age, who had a complete screening colonoscopy were included. MAIN OUTCOME MEASURES: Adenoma detection rate, cecal intubation rate, withdrawal time, and other nonestablished overall and segment-specific rates were calculated and compared using t tests. RESULTS: A total of 4151 patients were included in the analysis. Colonoscopies were performed by 54 (64.3%) gastroenterologists, 21 (25%) colorectal surgeons, and 9 (10.7%) general surgeons. Gastroenterologists had the highest overall adenoma detection rate (28.6 ± 1.2; p < 0.001), followed by colorectal surgeons (24.3 ± 1.5) and general surgeons (18.4 ± 2.3), as well as the highest adenoma detection rate in men (34.7 ± 1.3; p < 0.001), followed by colorectal surgeons (28.2 ± 1.6) and general surgeons (23.7 ± 2.6). Similarly, gastroenterologists had the highest adenoma detection rate in women (24.3 ± 1.1; p < 0.001), followed by colorectal surgeons (21.6 ± 1.4) and general surgeons (12.9 ± 2.0). Withdrawal time was the longest among general surgeons (11.1 ± 5.5; p = 0.041), followed by colorectal surgeons (10.94 ± 5.2) and gastroenterologists (10.16 ± 1.26). LIMITATIONS: We could not adjust for some procedure-related details such as retroflexion in the right colon and the use of end-of-scope devices. CONCLUSIONS: In this study, only gastroenterologists met the currently accepted overall and sex-specific adenoma detection rate benchmarks. They also outperformed nongastroenterologists in many other nonestablished quality metrics. See Video Abstract at http://links.lww.com/DCR/B232.
7

Improved performance high speed network intrusion detection systems (NIDS) : a high speed NIDS architectures to address limitations of packet loss and low detection rate by adoption of dynamic cluster architecture and traffic anomaly filtration (IADF)

Akhlaq, Monis January 2011 (has links)
Intrusion Detection Systems (IDS) are considered as a vital component in network security architecture. The system allows the administrator to detect unauthorized use of, or attack upon a computer, network or telecommunication infrastructure. There is no second thought on the necessity of these systems however; their performance remains a critical question. This research has focussed on designing a high performance Network Intrusion Detection Systems (NIDS) model. The work begins with the evaluation of Snort, an open source NIDS considered as a de-facto IDS standard. The motive behind the evaluation strategy is to analyze the performance of Snort and ascertain the causes of limited performance. Design and implementation of high performance techniques are considered as the final objective of this research. Snort has been evaluated on highly sophisticated test bench by employing evasive and avoidance strategies to simulate real-life normal and attack-like traffic. The test-methodology is based on the concept of stressing the system and degrading its performance in terms of its packet handling capacity. This has been achieved by normal traffic generation; fussing; traffic saturation; parallel dissimilar attacks; manipulation of background traffic, e.g. fragmentation, packet sequence disturbance and illegal packet insertion. The evaluation phase has lead us to two high performance designs, first distributed hardware architecture using cluster-based adoption and second cascaded phenomena of anomaly-based filtration and signature-based detection. The first high performance mechanism is based on Dynamic Cluster adoption using refined policy routing and Comparator Logic. The design is a two tier mechanism where front end of the cluster is the load-balancer which distributes traffic on pre-defined policy routing ensuring maximum utilization of cluster resources. The traffic load sharing mechanism reduces the packet drop by exchanging state information between load-balancer and cluster nodes and implementing switchovers between nodes in case the traffic exceeds pre-defined threshold limit. Finally, the recovery evaluation concept using Comparator Logic also enhance the overall efficiency by recovering lost data in switchovers, the retrieved data is than analyzed by the recovery NIDS to identify any leftover threats. Intelligent Anomaly Detection Filtration (IADF) using cascaded architecture of anomaly-based filtration and signature-based detection process is the second high performance design. The IADF design is used to preserve resources of NIDS by eliminating large portion of the traffic on well defined logics. In addition, the filtration concept augment the detection process by eliminating the part of malicious traffic which otherwise can go undetected by most of signature-based mechanisms. We have evaluated the mechanism to detect Denial of Service (DoS) and Probe attempts based by analyzing its performance on Defence Advanced Research Projects Agency (DARPA) dataset. The concept has also been supported by time-based normalized sampling mechanisms to incorporate normal traffic variations to reduce false alarms. Finally, we have observed that the IADF has augmented the overall detection process by reducing false alarms, increasing detection rate and incurring lesser data loss.
8

Détection d'attaques dans un système WBAN de surveillance médicale à distance / Attacks detection in a WBAN system for remote medical monitoring

Makke, Ali 30 May 2014 (has links)
L'un des défis majeurs du monde de ces dernières décennies a été l'augmentation continue de la population des personnes âgées dans les pays développés. D’où la nécessité de fournir des soins de qualité à une population en croissance rapide, tout en réduisant les coûts des soins de santé. Dans ce contexte, de nombreux travaux de recherche portent sur l’utilisation des réseaux de capteurs sans fil dans les systèmes WBAN (Wireless Body Area Network), pour faciliter et améliorer la qualité du soin et de surveillance médicale à distance. Ces réseaux WBAN soulèvent de nouveaux défis technologiques en termes de sécurité et de protection contre les anomalies et les attaques. Le mode de communication sans fil utilisé entre ces capteurs et l’unité de traitement accentue ces vulnérabilités. En effet les vulnérabilités dans un système WBAN se décomposent en deux parties principales. La première partie se compose des attaques possibles sur le réseau des capteurs médicaux et sur le médium de communications sans fils entre ces capteurs et l’unité de traitement. La deuxième partie se compose des attaques possibles sur les communications à haut débit entre le système WBAN et le serveur médical. L’objectif de cette thèse est de répondre en partie aux problèmes de détection des attaques dans un système WBAN de surveillance médicale à distance. Pour atteindre cet objectif, nous avons proposé un algorithme pour détecter les attaques de brouillage radio (jamming attack) qui visent le médium de communications sans fils entre les capteurs et l’unité de traitement. Ainsi nous avons proposé une méthode de mesure de divergence pour détecter les attaques de type flooding qui visent les communications à haut débit entre le système WBAN et le serveur médical. / One of the major challenges of the world in recent decades is the continued increase in the elderly population in developed countries. Hence the need to provide quality care to a rapidly growing population while reducing the costs of health care is becoming a strategic challenge. In this context, many researches focus on the use of wireless sensor networks in WBAN (Wireless Body Area Network) systems to facilitate and improve the quality of medical care and remote monitoring. These WBAN systems pose new technological challenges in terms of security and protection against faults and attacks. The wireless communication mode used between the sensors and the collection node accentuates these vulnerabilities. Indeed vulnerabilities in a WBAN system are divided into two main parts. The first part consists of the possible attacks on the network of medical sensors and on the wireless communications medium between the sensors and the processing unit. The second part consists of possible attacks on high-speed communications between the WBAN system and the medical server. The objective of this thesis is to meet some of the problems of detecting attacks in a WBAN system for remote medical monitoring. To achieve this goal, we propose an algorithm to detect the jamming attacks targeting the wireless communications medium between the sensors and the processing unit. In addition we propose a method of measuring divergence to detect the flooding attacks targeting the high-speed communications between the WBAN system and the medical server.
9

Méthodes d’étude et modélisation de la dynamique de population du triton marbré dans le cadre du projet de construction d’une infrastructure de grande ampleur en zone bocagère dans l’ouest de la France / Methods of study and modeling of the marbled newts' population dynamics within the framework of a large-scale infrastructure project in a wooded area in western France

Guerin, Sandra 15 December 2017 (has links)
La perte d’habitat et la fragmentation sont les principales causes de déclin des amphibiens en Europe de l’ouest. Malgré les réglementations mises en place concernant la construction de nouvelles infrastructures, le manque de connaissances fondamentales concernant les espèces et leurs habitats rendent difficiles l’évaluation des impacts ainsi que la mise en place de solutions efficaces pour conserver la biodiversité. En se basant sur l’exemple du triton marbré (Triturus marmoratus), espèce protégée présente dans l’ouest de la France, ce travail vise à évaluer la pertinence des méthodes de terrain et de modélisation disponibles pour la récolte des données nécessaires à la caractérisation de la dynamique des populations chez cette espèce. Pour ce faire, deux populations de tritons marbrés (Loire Atlantique et Vendée) ont été étudiées grâce à des techniques de comptages à la lampe, piégeage, utilisation d’épuisettes avec un suivi intensif par capture-marquage-recapture (CMR), complété par la méthode de l’ADN environnemental (ADNe). Dans une première partie ce travail a permis de montrer que dans le cadre de la caractérisation quantitative de la dynamique d’une population, les informations apportées par la CMR sont les plus fiables. Ceci est notamment dû au taux de détection faible et hétérogène dans l’espace et dans le temps du triton marbré, qui ne permet pas aux autres méthodes s’en affranchissant de produire des résultats reproductibles et transposables. L’ADNe est la méthode permettant d’estimer l’occurrence le plus efficacement mais la possibilité d’une utilisation pour estimer des abondances absolues voire des abondances relatives reste du domaine des perspectives prometteuses mais non abouties à ce jour. Dans un second chapitre, nous avons montré comment les récentes avancées méthodologiques dans les approches de modélisation permettent de déterminer le temps passé par une espèce sur un site grâce aux données de CMR. Ces méthodes ont été appliquées au triton marbré pour mettre en évidence une phénologie particulière avec des individus arrivant et repartant du site de reproduction de manière non simultanée et n’occupant chacun la mare qu’une partie de la période de reproduction. L’ensemble de ces résultats permettent de définir un cadre méthodologique adapté pour développer un suivi dans le temps des mesures de compensation envisagées dans le cadre du projet de construction, mais aussi pour le suivi des populations d’urodèles en général. / Habitat loss and fragmentation are the main causes of amphibian decline in Western Europe. In spite of regulations concerning the construction of new infrastructures, the lack of knowledge concerning species and their habitat make difficult to evaluate the impact as well as the implementation of effective solutions to preserve biodiversity. Using the example of marbled newt (Triturus marmoratus), a protected species presents in Western France, this works aims at estimating the relevance of the fieldwork and modeling methods available to obtain data necessary for characterizing the dynamic of population for this species. To do so, two populations of marbled newts (situated in Loire Atlantique and Vendée) were studied using torch counts, traps, dip nets, with an intensive capture recapture (CR) protocol, and environmental DNA (eDNA) method. In the first part, this work allowed us to show that within the framework of quantitative characterization of the dynamics of a population, the information gathered by CR is the most reliable. This is especially due to the low and heterogeneous detection rate in space and time for marbled newt, which does not allow traditional methods to get reproducible and transposable results. eDNA is the most accurate method when it comes to estimating occurence but the possibility to use it to estimate absolute or even relative abundances stays a promising perspective that did not succeed yet. In a second chapter, we showed how recent methodological advances in modeling approaches allow estimating time spent by a species in a site thanks to CR data. These methods were applied to marbled newts to highlight a particular phenology, with arriving and leaving individuals being not simultaneous but progressive and each individual occupying the pond only for a part of the breeding season. These results allows to define a methodological frame adapted to develop long term studies of compensation measures within the framework of the construction project, but also more generally for future studies of urodele species.
10

Performance Evaluation of a Newly Developed MR-Compatible Mobile PET Scanner with Two Detector Layouts / 新規に開発したMR対応可搬型PET装置の2通りの検出器配置における性能評価

Watanabe, Masao 23 March 2020 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第22305号 / 医博第4546号 / 新制||医||1040(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 増永 慎一郎, 教授 鈴木 実, 教授 溝脇 尚志 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

Page generated in 0.0883 seconds