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Chui, Hiu-fai Sam. "Evaluation of measures taken by financial institutes under the interest rate swing caused by the currency attack /." Hong Kong : University of Hong Kong, 1998. http://sunzi.lib.hku.hk/hkuto/record.jsp?B19882117.
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Chui, Hiu-fai Sam, and 徐曉暉. "Evaluation of measures taken by financial institutes under the interest rate swing caused by the currency attack." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1998. http://hub.hku.hk/bib/B31268766.
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Saran, Nurdan A. "Time Memory Trade Off Attack On Symmetric Ciphers." Phd thesis, METU, 2009. http://etd.lib.metu.edu.tr/upload/12610437/index.pdf.
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Time Memory Trade O (TMTO) is a cryptanalytic method that aims to develop an attack
which has a lower memory complexity than lookup table and a lower online time complexity
than exhaustive search. TMTO methods are widely studied in the literature and used for
inverting various cryptosystems. We focus on the design and the analysis of TMTO on symmetric
ciphers in this thesis. Firstly, the summary of the random mapping statistics from the
view point of TMTO is presented. We also recalculate some expected values with a simpler
approach than the existing proofs. Then, we propose some variant constructions and
also present three new distinguishers based on random mappings. Next, we provide a detailed
analysis of the success rate of two main improvements of the attackDistinguished Point Method and Rainbow Method. Finally, we discuss the adjustment of the parameters to achieve a high success rate. To support our theoretical framework, we also present empirical results of our analysis to actual ciphers.
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Xia, Yu. "Selective Dropping of Rate Limiting Against Denial of Service Attacks." University of Dayton / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1461705316.
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Bencel, Jozef. "Analýza bezpečnosti bezdrátových sítí." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2009. http://www.nusl.cz/ntk/nusl-218125.
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This master's thesis deals with security of wireless network standard 802.11. There are described security mechanisms as hide SSID, MAC address filtering, WEP, WPA, WPA2 protocols. There are described also the most often kinds of attacks (Denial of Service, disclosure WEP key, Man-in-the-Middle). The work contains investigation of used security mechanisms in wireless networks in parts of Brno. There were used NetStumbler and inSSIDer applications for this measurement. The last part of work contains measurement of security mechanisms (WEP, WPA, WPA2) effect to transfer rate from the point of view of the end user. The measurement was realized with Iperf application.
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Ikusan, Ademola A. "Collaboratively Detecting HTTP-based Distributed Denial of Service Attack using Software Defined Network." Wright State University / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=wright1515067456228498.
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Taylor, Matthew H. "Defining a Model for Tool Consumption Rate on Asphalt Reclamation Machines." BYU ScholarsArchive, 2006. https://scholarsarchive.byu.edu/etd/1293.
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Asphalt and concrete reclamation machines are used to cut roadways when a repair is required. The performance of these machines can affect the quality of road repairs, and cost/profitability for both contractors and governments. We believe that several performance characteristics in reclamation machines are governed by the placement and pattern of cutting picks on the cutter head. Previous studies, focused on mining and excavation applications, have shown strong correlation between placement and wear. The following study employs a screening experiment (observational study) to find significant contributors to tool wear, in applications of asphalt milling or reclamation. We have found that picks fail by two primary modes: tip breakage, and body abrasive wear. Results indicate that the circumferential spacing of a bit, relative to neighboring bits, has the strongest effect on tip breakage. We have also shown that bit skew angle has a large positive effect on body abrasive wear.
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Larsson, Niklas, and Josefsson Fredrik Ågren. "A study of slow denial of service mitigation tools and solutions deployed in the cloud." Thesis, Linköpings universitet, Institutionen för datavetenskap, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-157721.
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Slow rate Denial of Service (DoS) attacks have been shown to be a very effective way of attacking vulnerable servers while using few resources. This thesis investigates the effectiveness of mitigation tools used for protection against slow DoS attacks, specifically slowheader and slow body. Finally, we propose a service that cloud providers could implement to ensure better protection against slow rate DoS attacks. The tools studied in this thesis are, a Web Application firewall, a reverse proxy using an event-based architecture and Amazon’s Elastic Load Balancing. To gather data a realistic HTTP load script was built that simulated load on the server while using probe requests to gather response time data from the server. The script recorded the impact the attacks had for each server configuration.The results show that it’s hard to protect against slow rate DoS attacks while only using firewalls or load balancers. We found that using a reverse proxy with an event-based architecture was the best way to protect against slow rate DoS attacks and that such a service would allow the customer to use their server of choice while also being protected.
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SEGAFREDO, GIULIA. "New Heart Failure Hospitalization in the Italian region of Lombardy - Epidemiological and economic impact." Doctoral thesis, Università degli Studi di Milano-Bicocca, 2015. http://hdl.handle.net/10281/76821.
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Le ospedalizzazioni per scompenso cardiaco (hospitalized heart failure, HHF) costituiscono un notevole problema per i sistemi sanitari, sia dal punto di vista clinico che di salute pubblica.
Data l’eterogeneità delle manifestazioni e degli esiti della malattia, la letteratura più recente ha suggerito di distinguere i pazienti ambulatoriali con scompenso cardiaco da quelli con un’ospedalizzazione per scompenso cardiaco. La ragione di questa scelta è che la prognosi di questi due gruppi di pazienti sembra essere molto diversa. La prognosi dei pazienti ambulatoriali, infatti, è cambiata radicalmente, in modo positivo, negli ultimi vent’anni, grazie allo sviluppo di nuovi trattamenti, come gli ACE-inibitori, i bloccanti del recettore dell'angiotensina (ARB), i beta-bloccanti, gli antagonisti del recettore dei mineralcorticoidi, l’utilizzo della terapia di risincronizzazione e di defibrillatori impiantabili, mentre quella dei pazienti HHF è rimasta pressoché invariata.
Inoltre, sebbene la ricerca clinica ed epidemiologica abbia posto grande attenzione a diversi aspetti della gestione dei pazienti ambulatoriali, portando ad una buona conoscenza delle caratteristiche epidemiologiche, fisiopatologiche e farmacologiche, tali conoscenze non sono completamente applicabili all’ambito del HHF, lasciando aperti alcuni importanti quesiti riguardo l’impatto di tale condizione.
L'obiettivo di questo progetto è stato, attraverso l'utilizzo dei database sanitari amministrativi della Regione Lombardia, di meglio caratterizzare l'impatto di HHF cercando di fornire una risposta a queste tre domande:
1. Quanti sono i nuovi pazienti con HHF nella Regione Lombardia?
In questo capitolo sono stati descritti i metodi sviluppati per quantificare l'impatto epidemiologico del HHF in questa regione. Più in dettaglio, è descritto il processo che ha portato all’identificazione della fonte di dati appropriata, allo sviluppo di un algoritmo per l'identificazione del paziente, alla selezione dei casi e alla quantificazione del tasso d'incidenza e del tasso di attacco.
2. Determinanti di nuove ospedalizzazioni per scompenso - Fattori di rischio
In questo capitolo è stato valutato il ruolo del trattamento antipertensivo nella prevenzione HHF.
Più specificamente è stato valutato (i) l'effetto dell’aderenza al trattamento antipertensivo (ii) l'effetto del farmaco all'ingresso (iii) l'effetto dell’aderenza ad una specifica classe antipertensivi, sulla comparsa del primo episodio di HHF in una popolazione di nuovi utilizzatori di antipertensivi.
3. Conseguenze dei nuovi ricoveri per scompenso cardiaco - Esiti, fattori prognostici e impatto economico. In questo capitolo, sono stati descritti (i)frequenza di mortalità e riospdedalizzazioni a breve (trenta giorni) e lungo (un anno) termine dopo la prima ospedalizzazione per HF, (ii) fattori prognostici a breve e lungo termine, (iii) impatto economico di HHF in Regione Lombardia.
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Carvalho, Thiago Lima de Carvalho. "Comparação de respotas funcionais de duas espécie de peixes píscivoras." Universidade Federal Rural do Semi-Árido, 2016. http://bdtd.ufersa.edu.br:80/tede/handle/tede/573.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
Species of the Cichla genus have been introduced in a variety of tropical aquatic ecosystems, thus resulting in a marked reduction in diversity and population size of native fish assemblies due to their predatory behavior. Despite Cichla induced impact the mechanisms by which the species are still poorly known. In this study we compared the functional response of an alien predator fish C. kelberi and a native predator H. aff. malabaricus. More specifically, the tested hypotheses were: 1) both predator species have functional responses of type II on different prey species, and 2) the functional responses of the alien predator were higher for all preys when compared to the native predator. The predators were acclimated in tanks of 500 liters and fed twice daily with preys O. niloticus and L.vannamei for 3 days, 4 preys in the morning and 4 in the afternoon. Hunger levels were standardized after a fast of 48 hours. After the pre-experimental phase an exemplar of C. kelberi was randomly introduced in each tank of O. niloticus with initial prey densities of 2, 4, 8, 16, 25 and 40, and for L. vannamei 2, 4, 8, 16, 32 and 64 (n = 4 per density). After 24 hours the number of prey consumed was counted. This method was repeated for the native predator H. aff. malabaricus. Totaling 48 experimental units. The functional response C. kelberi was greater than or equivalent to the native predator H. aff. malabaricus. There was no difference in consumption between the two species at low densities. The attack rate did not differ between the two predators and handling time was driven by C. kelberi for the species O. niloticus. However, the two species showed functional response type II, thus corroborating with the comparative functional response method to predict the impact on native communities. Functional Comparative Response is a quick and reliable method to predict the ecological impacts of invasive species
Espécies do gênero Cichla têm sido introduzidas em vários ecossistemas aquáticos tropicais, resultando em uma redução na diversidade e tamanho populacional de assembleias de peixes nativos, devido a sua atuação predatória. Os mecanismos de predação pelos quais o tucunaré (Cichla kelberi) permanece pouco conhecido. Nesse estudo foram comparadas as resposta funcionais de um peixe predador alienígena C. kelberi e de um predador nativo Hoplias aff. malabaricus. Especificamente, foram testadas as hipóteses: 1) que ambas as espécies de predador apresentam respostas funcionais do Tipo II, na qual a espécie preda em baixa densidade, sobre diferentes espécies de presas, e que 2) as respostas funcionais do predador alienígena foram maiores para todas as presas, quando comparados com o predador nativo. Os predadores foram aclimatados nos tanques de 500 litros e alimentados duas vezes ao dia com alevinos de Oreochromis niloticus e Litopenaeus vannamei durante 3 dias, 4 presas pela manhã e 4 presas a tarde. Os níveis de fome foram padronizados depois de um jejum de 48 horas. Foi introduzido aleatoriamente um exemplar de C. kelberi em cada tanque de O. niloticus com densidades iniciais de presas de 2, 4, 8, 16, 25 e 40 e para L. vannamei 2, 4, 8, 16, 32 e 64 (n = 4 por densidade), e depois de 24 horas contabilizado o número de presas consumidas. Este método foi repetido para o predador nativo H. aff. malabaricus. Totalizando 48 unidades experimentais. A resposta funcional de C, kelberi foi maior ou equivalente a do predador nativo H. aff. malabaricus. Não houve diferença no consumo entre as duas espécies nas baixas densidades. A taxa de ataque não diferenciou entre os dois predadores e o tempo de manipulação foi impulsionado por C, kelberi para a espécie O. niloticus. As duas espécies apresentaram resposta funcional do tipo II corroborando com o método de resposta funcional comparativa de prever os impactos nas comunidades nativas. Respostas funcionais é um método rápido e confiável para previsão de impactos ecológicos de espécies invasoras
2017-03-20
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Hilborn, Anne Winona. "The effect of individual variability and larger carnivores on the functional response of cheetahs." Diss., Virginia Tech, 2018. http://hdl.handle.net/10919/82040.
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Functional response is the framework thorough which we can quantify how predator hunting behaviors such as rate of successful attack and time spent handling prey interact with prey density to determine the rate at which prey are killed. Cheetahs are mesopredators and their behavior can be shaped by the need to avoid larger predators while hunting relatively large bodied and mobile prey. I used data from 34 years of observed cheetah hunts in Serengeti National Park in Tanzania to investigate how reproductive condition, prey density, seasonality, and the proximity of larger predators affect cheetah kill rates, probability of successful attack, and time spent handling prey. Mothers with cubs had an asymptotic Type II functional response where kill rate increased but eventually leveled-off at high prey densities, while cheetahs without cubs had a dome shaped Type IV functional response where kill rates actually declined at high prey density. Probability of successful attack on prey was higher for mothers with cubs, and increased slightly with prey density. Mothers with cubs had different prey handling behavior than other cheetahs. Cheetah mothers spend longer at kills then other cheetahs despite the risk that the carcass can attract lions and hyenas that could steal the carcass and potentially kill her cubs. Mothers must make sure their cubs have sufficient time at the carcass to eat their fill, thus they minimize risk from larger predators by being vigilant. In contrast, cheetahs without cubs are unconcerned with cub predation and can eat quickly to minimize the risk of kleptoparasitism. My results show how the pressures of cub rearing and coexisting with larger carnivores differentially shape the hunting behavior of cheetahs, and suggest that intensity of mesopredator suppression may depend on individual variability. This is the first time the functional response for a large mesopredator, has been quantified and the first time a dome shaped response has been recorded in a mammal. My work shows the value in accounting for individual variability in functional response and how linking of carnivore hunting behavior to multiple species interactions advances our understanding of how classical ecological theory applies to wild ecosystems.Ph. D.
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Lyons, James Edward. "Population Ecology and Foraging Behavior of Breeding Birds in Bottomland Hardwood Forests of the Lower Roanoke River." Diss., Virginia Tech, 2001. http://hdl.handle.net/10919/26429.
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Nest survival often is lower at habitat edges than in habitat cores because of greater nest predation and parasitism near edges. I studied nest survival of breeding birds in bottomland hardwood forests of the lower Roanoke River, North Carolina. Nesting success was monitored in two forest width classes: narrow bands of levee forest that were dominated by two edge types, and wide, continuous levee forest stands that have edges but most forest is relatively far from edge. Nest success of Acadian Flycatchers and Prothonotary Warblers was similar in narrow and wide levees; nest success of Northern Cardinals was greater in narrow levees. Results of my study indicate that edge effects are not universal, and that amount of contrast at edges may interact with landscape context to alter ecological processes, such as nest predation.
Bird populations are remarkably constant over time relative to other taxa, implying strong regulation. Avian population ecologists, however, have not studied regulatory mechanisms as often as seasonal limiting factors. Conversely, avian behavioral ecologists seldom emphasize the population dynamic consequences of habitat selection and reproductive success. This study describes the intersection of individual behavior and population regulation in the context of a new model of population regulation, site dependence, which is based on characteristics of breeding sites and behavior of individuals. I studied habitat distribution, age structure, reproductive output, and breeding site fidelity of Prothonotary Warblers (Protonotaria citrea) in two different bottomland hardwood forest habitats of the lower Roanoke River in North Carolina. Older males (³ 2 yr old) were equally common in cypress-gum swamps and mixed oak hardwood levee forest. Pairing success and success of first nests indicated that older males occupied the most suitable territories available in each habitat. Bird density was three times greater in swamps, and birds nesting in swamps averaged greater clutch sizes and fledged more young per nest than birds in levees. Greater reproductive output was the result of greater fecundity because nest survival and predation pressure appeared equal in the two habitats. Annual return rates for plot immigrants vs. previous residents did not differ in swamps. In levees, newly arriving birds were less likely to return the following year than previous residents. Immigrants most likely occupied low quality sites and dispersed in an attempt to improve breeding site quality. Habitat-specific demography and density patterns of this study indicate ideal preemptive distribution. Variance in site quality, between and within habitats, and preemptive use of sites are consistent with theory of population regulation via site dependence.
Foraging behavior often reflects food availability. For example, in habitats where food availability is high, predators should move more slowly and attack prey more often than in habitats where food availability is low. I studied the foraging behavior of breeding Prothonotary Warblers in two habitat types to assess relative food availability and implications for habitat quality. The two habitats, levee and swamp forest, differ in hydrology, forest structure, and tree species composition. I quantified foraging behavior with focal animal sampling and continuous recording during foraging bouts. I measured two aspects of foraging behavior: 1) prey attacks per minute, using four attack types (glean, sally, hover, strike), and 2) number of movements per minute (foraging speed), using three types of movement (hop, short flight [£ 1 m], long flight [>1 m]). Male warblers made significantly more prey attacks per minute in swamp forest than in levee forest; the same trend was evident in females. Foraging speed, however, was not different between habitats for males or females. Results indicate that foraging effort is similar in swamps and levees, but that warblers encounter more prey in swamps. Greater food availability may be related to greater reproductive success of warblers nesting in cypress-gum swamps than in coastal plain levee forest.Ph. D.
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Huang, Wei. "A Population-Based Perspective on Clinically Recognized Venous Thromboembolism: Contemporary Trends in Clinical Epidemiology and Risk Assessment of Recurrent Events: A Dissertation." eScholarship@UMMS, 2014. https://escholarship.umassmed.edu/gsbs_diss/730.
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Background: Venous thromboembolism (VTE), comprising the conditions of deep vein thrombosis (DVT) and pulmonary embolism (PE), is a common acute cardiovascular event associated with increased long-term morbidity, functional disability, all-cause mortality, and high rates of recurrence. Major advances in identification, prophylaxis, and treatment over the past 3-decades have likely changed its clinical epidemiology. However, there are little published data describing contemporary, population-based, trends in VTE prevention and management.
Objectives: To examine recent trends in the epidemiology of clinically recognized VTE and assess the risk of recurrence after a first acute episode of VTE.
Methods: We used population-based surveillance to monitor trends in acute VTE among residents of the Worcester, Massachusetts, metropolitan statistical area (WMSA) from 1985 through 2009, including in-hospital and ambulatory settings.
Results: Among 5,025 WMSA residents diagnosed with acute PE and/or lower-extremity DVT between 1985 and 2009 (mean age = 65 years), 46% were men and 95% were white. Age- and sex-adjusted annual event rates (per 100, 000) of clinically recognized acute first-time and recurrent VTE was 142 overall, increasing from 112 in 1985/86 to 168 in 2009, due primarily to increases in PE occurrence. During this period, non-invasive diagnostic VTE testing increased, vi while treatment shifted from the in-hospital (chiefly with warfarin and unfractionated heparin) to out-patient setting (chiefly with low-molecular-weight heparins and newer anticoagulants). Among those with community-presenting first-time VTE, subsequent 3-year cumulative event rates of key outcomes decreased from 1999 to 2009, including all-cause mortality (41% to 26%), major bleeding episodes (12% to 6%), and recurrent VTE (17% to 9%). Active-cancer (with or without chemotherapy), a hypercoagulable state, varicose vein stripping, and Inferior vena cava filter placement were independent predictors of recurrence during short- (3-month) and long-term (3-year) follow-up after a first acute episode of VTE. We developed risk score calculators for VTE recurrence based on a 3-month prognostic model for all patients and separately for patients without active cancer.
Conclusions: Despite advances in identification, prophylaxis, and treatment between 1985 and 2009, the disease burden from VTE in residents of central Massachusetts remains high, with increasing annual events. Declines in the frequency of major adverse outcomes between 1999 and 2009 were reassuring. Still, mortality, major bleeding, and recurrence rates remained high, suggesting opportunities for improved prevention and treatment. Clinicians may be able to use the identified predictors of recurrence and risk score calculators to estimate the risk of VTE recurrence and tailor outpatient treatments to individual patients.
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Huang, Wei. "A Population-Based Perspective on Clinically Recognized Venous Thromboembolism: Contemporary Trends in Clinical Epidemiology and Risk Assessment of Recurrent Events: A Dissertation." eScholarship@UMMS, 2011. http://escholarship.umassmed.edu/gsbs_diss/730.
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Background: Venous thromboembolism (VTE), comprising the conditions of deep vein thrombosis (DVT) and pulmonary embolism (PE), is a common acute cardiovascular event associated with increased long-term morbidity, functional disability, all-cause mortality, and high rates of recurrence. Major advances in identification, prophylaxis, and treatment over the past 3-decades have likely changed its clinical epidemiology. However, there are little published data describing contemporary, population-based, trends in VTE prevention and management.
Objectives: To examine recent trends in the epidemiology of clinically recognized VTE and assess the risk of recurrence after a first acute episode of VTE.
Methods: We used population-based surveillance to monitor trends in acute VTE among residents of the Worcester, Massachusetts, metropolitan statistical area (WMSA) from 1985 through 2009, including in-hospital and ambulatory settings.
Results: Among 5,025 WMSA residents diagnosed with acute PE and/or lower-extremity DVT between 1985 and 2009 (mean age = 65 years), 46% were men and 95% were white. Age- and sex-adjusted annual event rates (per 100, 000) of clinically recognized acute first-time and recurrent VTE was 142 overall, increasing from 112 in 1985/86 to 168 in 2009, due primarily to increases in PE occurrence. During this period, non-invasive diagnostic VTE testing increased, vi while treatment shifted from the in-hospital (chiefly with warfarin and unfractionated heparin) to out-patient setting (chiefly with low-molecular-weight heparins and newer anticoagulants). Among those with community-presenting first-time VTE, subsequent 3-year cumulative event rates of key outcomes decreased from 1999 to 2009, including all-cause mortality (41% to 26%), major bleeding episodes (12% to 6%), and recurrent VTE (17% to 9%). Active-cancer (with or without chemotherapy), a hypercoagulable state, varicose vein stripping, and Inferior vena cava filter placement were independent predictors of recurrence during short- (3-month) and long-term (3-year) follow-up after a first acute episode of VTE. We developed risk score calculators for VTE recurrence based on a 3-month prognostic model for all patients and separately for patients without active cancer.
Conclusions: Despite advances in identification, prophylaxis, and treatment between 1985 and 2009, the disease burden from VTE in residents of central Massachusetts remains high, with increasing annual events. Declines in the frequency of major adverse outcomes between 1999 and 2009 were reassuring. Still, mortality, major bleeding, and recurrence rates remained high, suggesting opportunities for improved prevention and treatment. Clinicians may be able to use the identified predictors of recurrence and risk score calculators to estimate the risk of VTE recurrence and tailor outpatient treatments to individual patients.
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Wong, Yuen-ting, and 黃婉婷. "Inferring influenza epidemic attack rates from serological surveillance data." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2010. http://hub.hku.hk/bib/B45174696.
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Makke, Ali. "Détection d'attaques dans un système WBAN de surveillance médicale à distance." Thesis, Paris 5, 2014. http://www.theses.fr/2014PA05S006/document.
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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 médicalOne 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
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Broome, Simon Jeremy. "Essays on exchange rate target zone theory and speculative attacks." Thesis, University of York, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.362061.
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Lu, Yuanchao. "On Traffic Analysis Attacks To Encrypted VoIP Calls." Cleveland State University / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=csu1260222271.
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Vuchuru, Mayura Uppuluri Prem. "Detecting race condition attacks on file systems." Diss., UMK access, 2005.
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Thesis (M.S.)--School of Computing and Engineering. University of Missouri--Kansas City, 2005."A thesis in computer science." Typescript. Advisor: Prem Uppuluri. Vita. Title from "catalog record" of the print edition Description based on contents viewed June 27, 2006. Includes bibliographical references (leaves 80-82). Online version of the print edition.
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SHARMA, RISHIE. "Detection of Low-Rate DoS Attacks againstHTTP Servers using Spectral Analysis." Thesis, KTH, Skolan för datavetenskap och kommunikation (CSC), 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-155895.
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Denial-of-Service (DoS) attacks pose a serious threat to any service provider on the Internet. While traditional DoS flooding attacks require the attacker to control at least as much resources as the service provider in order to be effective, so called lowrate DoS attacks can exploit weaknesses in careless design to effectively deny a service using minimal amounts of network traffic.This thesis investigates one such weakness in version 2.2 of the popular Apache HTTP Server software. The weakness regards how the server handles the persistent connection feature in HTTP 1.1. An attack simulator exploiting this weakness has been developed and shown to be effective. The attack was then studied with spectral analysis with the purpose of examining how well the attack could be detected.In line with other papers on spectral analysis of lowrate DoS attacks,the results show that there are disproportionate amounts of energyin the lower frequencies when the attack is present. However, by randomising the attack pattern, an attacker can reduce the disproportionto a degree where it might be impossible to correctly identify an attack in a real world scenario.
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Al-Saydali, Josef, and Mahdi Al-Saydali. "Performance comparison between Apache and NGINX under slow rate DoS attacks." Thesis, Linnéuniversitetet, Institutionen för datavetenskap och medieteknik (DM), 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-103181.
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One of the novel threats to the internet is the slow HTTP Denial of Service (DoS) attack on the application level targeting web server software. The slow HTTP attack can leave a high impact on web server availability to normal users, and it is affordable to be established compared to other types of attacks, which makes it one of the most feasible attacks against web servers. This project investigates the slow HTTP attack impact on the Apache and Nginx servers comparably, and review the available configurations for mitigating such attack. The performance of the Apache and NGINX servers against slow HTTP attack has been compared, as these two servers are the most globally used web server software. Identifying the most resilient web server software against this attack and knowing the suitable configurations to defeat it play a key role in securing web servers from one of the major threats on the internet. From comparing the results of the experiments that have been conducted on the two web servers, it has been found that NGINX performs better than the Apache server under slow rate DoS attack without using any configured defense mechanism. However, when defense mechanisms have been applied to both servers, the Apache server acted similarly to NGINX and was successful to defeat the slow rate DoS attack.
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Syrichas, G. "Balance of payments crises : The theory of speculative attacks and optimal regime switching." Thesis, University of Essex, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.381260.
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Andell, Oscar, and Albin Andersson. "Slow rate denial of service attacks on dedicated- versus cloud based server solutions." Thesis, Linköpings universitet, Institutionen för datavetenskap, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-148480.
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Denial of Service (DoS) attacks remain a serious threat to internet stability. A specific kind of low bandwidth DoS attack, called a slow rate attack can with very limited resources potentially cause major interruptions to the availability of the attacked web servers. This thesis examines the impact of slow rate application layer DoS attacks against three different server solutions. The server solutions are a static cloud solution and a load-balancing cloud solution running on AmazonWeb Services (AWS) as well as a dedicated server. To identify the impact in terms of responsiveness and service availability a number of experiments were conducted on the web servers using publicly available DoS tools. The response times of the requests were measured. The results show that the dedicated and static cloud based server solutions are severely impacted by the attacks while the AWS load-balancing cloud solution is not impacted nearly as much. We concluded that all solutions were impacted by the attacks and that the readily available DoS tools are sufficient for creating a denial of service state on certain web servers.
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Silva, Maria Luiza Falcao. "Modern exchange-rate regimes, stabilisation programmes, and co-ordination of macroeconomic policies : recent experiences of selected developing Latin American economies." Thesis, Heriot-Watt University, 1997. http://hdl.handle.net/10399/1237.
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Sola, Martin. "Essays on speculative attacks on fixed exchange rate regimes, speculative bubbles and endogenous switching regime estimation." Thesis, University of Southampton, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.316309.
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Sikora, Marek. "Detekce slow-rate DDoS útoků." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2017. http://www.nusl.cz/ntk/nusl-317019.
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This diploma thesis is focused on the detection and protection against Slow DoS and DDoS attacks using computer network traffic analysis. The reader is introduced to the basic issues of this specific category of sophisticated attacks, and the characteristics of several specific attacks are clarified. There is also a set of methods for detecting and protecting against these attacks. The proposed methods are used to implement custom intrusion prevention system that is deployed on the border filtering server of computer network in order to protect Web servers against attacks from the Internet. Then created system is tested in the laboratory network. Presented results of the testing show that the system is able to detect attacks Slow GET, Slow POST, Slow Read and Apache Range Header and then protect Web servers from affecting provided services.
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Milutin, Otilia Clara. "Panic attacks violent female displacement in The Tale of Genji /." Connect to this title, 2008. http://scholarworks.umass.edu/theses/128/.
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Beck, Tino Niclas. "Zelluläre und humorale Faktoren für das Überleben diskordanter Herzxenotransplantate in Abwesenheit des Membran-Attack-Complex eine experimentelle Studie im Meerschweinchen-Ratte-Xenotransplantationsmodell /." [S.l.] : [s.n.], 2002. http://deposit.ddb.de/cgi-bin/dokserv?idn=967127319.
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Lefébure, Robert. "Effects of temperature and terrestrial carbon on fish growth and pelagic food web efficiency." Doctoral thesis, Umeå universitet, Institutionen för ekologi, miljö och geovetenskap, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-54028.
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Both temperature and terrestrial dissolved organic carbon (TDOC) have strong impacts on aquatic food web dynamics and production. Temperature affects vital rates of all organisms and terrestrial carbon has been shown to alter the dynamics of phytoplankton and bacterial production and affect the trophic structure of planktonic food webs. As climate change predictions for the Baltic Sea suggests future increases in both terrestrial carbon run-off and increases in temperature, the aim of thesis was to adopt a system-ecological approach and study effects of these abiotic variables, not only on interactions within planktonic food webs, but also on the growth and consumption rates of one of the most common zooplanktivorous fish in the Baltic Sea, the three-spined stickleback Gasterosteus aculeatus. Results showed that three-spined sticklebacks display a high degree of resilience against increasing temperatures, as both growth rates as well as consumption rates on zooplankton were high at temperatures well over 20 °C. Furthermore, it was shown that the minimal resource densities required to sustain individual and population growth, actually decreased with increasing temperatures, implying that sticklebacks around their optimum temperature for growth at 21 °C will actually have an increased scope for growth. As stickleback population densities have increased over the last decade in the Baltic Sea and are now suggested to out-compete other coastal fish species for shared zooplankton resources, the results presented in this thesis suggest that increased water temperatures would only serve to increase sticklebacks competitive advantage. As the structuring role of this small zooplanktivore on pelagic communities might be considerable, further studies investigating competitive interactions as well as patterns of population abundances are definitely warranted. TDOC was overall shown to stimulate bacterial production and the microbial food web. Because of the longer trophic pathways required to transport carbon from bacterial production to higher trophic levels, the addition of TDOC always reduced food web transfer efficiency. However, it became apparent that the full effect of TDOC additions on pelagic food webs was complex and depended heavily not only on the existing trophic structure to which the carbon was introduced, but also on ambient temperature levels. When three-spined sticklebacks were part of food webs with significant TDOC inputs, the presence of fish, indirectly, through predator release of lower trophic levels, amplified the magnitude of the effects of carbon addition on bacterial production, turning the base of the system significantly more heterotrophic, which ultimately, impacted negatively on their own production. However, when a pelagic food web containing sticklebacks was simultaneously subjected to realistic increases in temperature and TDOC concentrations, food web efficiency and fish production increased compared to present day conditions. These results were explained by a temperature dependent increased production potential of zooplankton, sustained by an increased production of heterotropic microzooplankton via TDOC additions, which lead to higher fish production. Although the increased number of trophic linkages in heterotrophic food webs should have reduced energy transfer efficiency, these negative effects seem here to have been overridden by the positive increases in zooplankton production as a result of increased temperature. These results show that heterotrophic carbon transfer can be a viable pathway to top-consumers, but also indicates that in order to understand the full effects of climate change on trophic dynamics and fish production, abiotic variables cannot be studied in isolation.
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Schwarz, Christopher Charles. "Attack-ademically Ineligible: Student Athlete Sex Crimes and the Dangerous Misunderstandings of FERPA." The Ohio State University, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=osu1457096185.
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Bianco, Ilaria <1995>. "The correlation between crude oil price and key geopolitical events. An investigation of crude death rate of terroristic attacks and Pandemics from 1968 to 2019." Master's Degree Thesis, Università Ca' Foscari Venezia, 2020. http://hdl.handle.net/10579/18108.
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In the aftermath of the analysis of oil prices, I analyse real crude oil price during 1968-2019 using a model which incorporates standard demand and supply factors, proxies for speculative activity, Middle East terroristic attacks crude-death-rate and Pandemics crude-death-rates. Hong Kong Flu (1968-1969) and Swine Flue (2009-2010) are the Pandemic events discussed. Generally I test which of the variables has the strongest correlation to crude oil prices over the time-frame. More specifically I address the correlation between oil prices and death tolls. Research results reinfore evidences for Middle East supremacy in global oil markets.
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Bianco, Ilaria <1995>. "The correlation between crude oil price and key geopolitical events. An investigation of crude death rate of terroristic attacks and Pandemics from 1968 to 2019." Master's Degree Thesis, Università Ca' Foscari Venezia, 2020. http://hdl.handle.net/10579/18480.
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In the aftermath of the analysis of oil prices, I analyse real crude oil price during 1968-2019 using a model which incorporates standard demand and supply factors, proxies for speculative activity, Middle East terroristic attacks crude-death-rate and Pandemics crude-death-rates. Hong Kong Flu (1968-1969) and Swine Flue (2009-2010) are the Pandemic events discussed. Generally I test which of the variables has the strongest correlation to crude oil prices over the time-frame. More specifically I address the correlation between oil prices and death tolls. Research results reinfore evidences for Middle East supremacy in global oil markets.
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Nyberg, Ralph Heinz-Erik [Verfasser], Georg [Akademischer Betreuer] Sigl, Dirk [Gutachter] Rabe, Ulf [Gutachter] Schlichtmann, and Georg [Gutachter] Sigl. "New Techniques for Emulating Fault Attacks / Ralph Heinz-Erik Nyberg ; Gutachter: Dirk Rabe, Ulf Schlichtmann, Georg Sigl ; Betreuer: Georg Sigl." München : Universitätsbibliothek der TU München, 2018. http://d-nb.info/1176701770/34.
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Sicard, Kenneth M. "Multimodal MRI, Behavioral Testing, and Histology in a Rat Model of Transient Focal Cerebral Ischemia : A Dissertation." eScholarship@UMMS, 2006. http://escholarship.umassmed.edu/gsbs_diss/318.
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Cerebral ischemia is defined as a decrease in blood flow to the brain. It is most often caused by obstruction of a cerebral blood vessel, and is recognized by the World Health Organization as the leading cause of serious adult disability and one of the top three causes of adult death worldwide. Most survivors demonstrate partial restitution of function over time, but the underlying recovery mechanism(s) remain unclear especially in a subset of patients with persistent neurological morbidities despite normal-appearing brain on neuroimaging. The optimal way to understand any human disease state is via clinical studies. Unfortunately, well-controlled experiments in humans are difficult due to small patient populations, the presence of numerous confounding variables, and ethical issues associated with invasive or discomforting experimental procedures. Anesthetized animal models of cerebral ischemia afford a means of avoiding the above difficulties. However, anesthesia and physiological perturbations that occasionally follow brain ischemia may affect the reliability of certain tools used to study this disease, such as functional magnetic resonance imaging (fMRI). Therefore, the central goals of this thesis were: 1) to evaluate the feasibility of performing fMRI in anesthetized and awake animals, 2) to assess fMRI responses under various perturbations of cerebral perfusion and tissue oxygenation in order to identify key factors that may modulate functional signal changes following ischemia, and 3) to utilize fMRI, behavioral tests and histology in an anesthetized animal model of transient focal cerebral ischemia to explore postischemic changes in brain pathology/function and how they relate to changes in behavior.
In the first study of this dissertation, I report the evaluation of fMRI responses in anesthetized and awake animals. Anesthesia is frequently used in animal models of cerebral ischemia, but is known to alter brain perfusion and metabolism which may, in turn, affect fMRI responsivity. Perfusion-based fMRI was used to evaluate cerebral blood flow (CBF) and blood oxygenation level-dependent (BOLD) responses to hypercapnia in awake and isoflurane-anesthetized rats. Hypercapnia produced significant CBF and BOLD fMRI signal changes throughout the cerebrum in awake and isoflurane-anesthetized groups. These results show that perfusion-based fMRI can successfully detect stimulus-evoked hemodynamic changes in the brains of both conscious and isoflurane-anesthetized animals.
The second study of this dissertation: 1) investigates the effects of alterations in cerebral perfusion and oxygenation on fMRI signal changes, and 2) examines the self-consistency of an imaging-based formalism for the calculation of the cerebral metabolic rate of oxygen (CMRO2). Functional MRI responses to a stimulus can be described in terms of relative or absolute signal change. A relative fMRI response is defined as a percent-change relative to its own respective baseline value. An absolute fMRI response is defined as a quantitative change relative to a single fixed baseline value that serves as a control. Thus, an absolute fMRI signal change is largely independent of the baseline state and may more accurately index brain activity when baseline fMRI signals change significantly over time due to, for example, hemodynamic-metabolic disturbances that occur during and/or after brain ischemia. To address these issues, the effects of inspired hypoxic, normoxic, hyperoxic, and hypercapnic gases on baseline and forepaw stimulation-evoked changes in BOLD and CBF fMRI signals were examined in isoflurane-anesthetized rats. Relative fMRI responses to forepaw stimulation varied-whereas. absolute responses were similar--across gas conditions. These results demonstrate that absolute measurements of fMRI signal change may lend a more accurate measure of brain activity during states of altered basal physiology as well as support the self-consistency of the imaging-based CMRO2 formalism under these conditions.
The third and last study of this dissertation utilized multimodal MRI, behavioral tests, and histology at acute to chronic periods following transient middle cerebral artery occlusion (tMCAO) in the rat to examine the evolution of pathological, functional, and behavioral parameters following transient focal cerebral ischemia. MRI was used to track the evolution of brain pathology and function following cerebral ischemia, and it was found that the cerebral sensorimotor network, critical for sensory and motor behavioral functions, showed profoundly abnormal signal changes that required up to one day to normalize. Adhesive removal, forepaw placement and beam-walk behavioral tests demonstrated sensorimotor dysfunctions that gradually improved but remained long after the recovery of MRI parameters. Postmortem histology confirmed the presence of selective neural cell death within the sensorimotor network at time points when behavior was abnormal. These results suggest that subtle postischemic pathological changes in the brain undetectable by MRI may be responsible for persistent behavioral deficits-a finding which may be relevant to a clinical subset of patients with persistent neurological morbidities despite negative MRI results following cerebral ischemia.
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Habr, Soraya Ferreira. "Efeitos da administração de interleucina-2 na liberação in vivo de dopamina no nucleus accumbens e no comportamento maternal em ratas." Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/42/42136/tde-24032009-133946/.
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A interleucina-2 (IL-2) atua na modulação da atividade dopaminérgica, que influencia o comportamento maternal. Neste estudo observou-se que o estado lactacional reduziu a atividade geral em campo aberto, porém não alterou os níveis de dopamina e seus metabólitos. A administração de IL-2, tanto sistêmica com diretamente no N.Ac não alterou a atividade geral em campo aberto, indicando a ausência de efeito motor da mesma. Além disso, a administração de IL-2 sistêmica e no N.Ac reduziu as porcentagens de ratas que agrupam os filhotes e de filhotes agrupados por rata. A injeção de IL-2 no N.Ac aumentou as latências de busca do primeiro e segundo filhotes e o comportamento agressivo. A administração sistêmica de IL-2 em ratas virgens reduziu somente do valor absoluto de DOPAC (metabólito de dopamina) após 100 e 120. Este achado corrobora a idéia de que o IL-2 altera a atividade dopaminérgica. Os resultados sugerem que a administração sistêmica da dose de IL-2 estudada não influencia de forma significativa os níveis de dopamina e de seus metabólitos no N.Ac.Interleukin-2 (IL-2) modulates the dopaminergic neurotransmission, that into the nucleus accumbens (N.Ac) plays a role in maternal behavior. The IL-2 dose used in this study does not have motor effects. Both peripheral and central N.Ac injections decreased the percent of mothers grouping pups together and the number of grouped pups. IL-2 injections into the N.Ac resulted in longer latencies to retrieve first and second pups and increased aggressive behavior. In order to test if these behavioral effects would be related to the IL-2 reduced the DOPAC (dopamine metabolite) concentrations in the N.Ac of virgin rats treated with IL-2. This suggests suggest that the IL-2 dose used in this study does not alter so much the dopaminergic transmission by influencing extracellular levels of this neurotransmitter.
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Bonsall, Todd Andrew. "The geochemistry of carbonate-hosted Pb-Zn-Ag mineralization in the Lavrion District, Attica, Greece fluid inclusion, stable isotope, and rare earth element studies /." [Ames, Iowa : Iowa State University], 2008.
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Al-Aulaqi, Nader. "Arab-Muslim views, images and stereotypes in United States." CSUSB ScholarWorks, 2003. https://scholarworks.lib.csusb.edu/etd-project/2275.
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陳志偉. "Preventing Low-Rate TCP Targeted Denial-of-Service Attack." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/70045731415546316093.
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碩士國立交通大學
資訊工程系所
92
Spurious timeout is very harmful to TCP. Two kinds of approaches were proposed to mitigate this problem, conservative approach and aggressive approach. In conservative approach, a conservative RTO (Retransmission Timeout), minRTO, is used. When RTO estimate form RTT (Round Trip Time) is less than minRTO, it is set to minRTO. This makes RTO become predictable and may be exploited by attackers. Low-Rate TCP Targeted Denial of Service is such kind of attack. In this thesis, we propose four schemes to deal with this problem. We make RTO unpredictable and keep conservative property. Analysis and experiment will be made to show that our schemes survive the attack. In our scheme, much better throughput is gained under attack. Besides, in usual condition, our schemes affect TCP performance only slightly. We will also analysis how Low-Rate TCP Targeted Denial of Service damages TCP operation inherently and how to gain the best throughput even if it is not achieved successfully.
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Chang, Chi-yu, and 張志宇. "A Coordinated defense scheme against high-rate DDoS Attack." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/19604905058759151790.
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碩士國立屏東商業技術學院
資訊管理系(所)
98
Distributed denial-of-service (DDoS) attacks can be regarded as the most serious threats for current Internet. This paper presents a two-tier coordination approach for detecting and mitigating DDoS attacks. The first tier filter (1st TF) filters suspicious traffic for possible flooding. This is achieved by using proactive tests to identify and isolate the malicious traffic. The second tier filter (2nd TF), which is deployed on network routers, performs online monitoring on queue length status with RED/Droptail mechanism for any incoming traffic. The simulation shows that the scheme can detect attacks accurately and effectively.
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"Defending against low-rate TCP attack: dynamic detection and protection." 2005. http://library.cuhk.edu.hk/record=b5892579.
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Sun Haibin.Thesis (M.Phil.)--Chinese University of Hong Kong, 2005.
Includes bibliographical references (leaves 89-96).
Abstracts in English and Chinese.
Abstract --- p.i
Chinese Abstract --- p.iii
Acknowledgement --- p.iv
Chapter 1 --- Introduction --- p.1
Chapter 2 --- Background Study and Related Work --- p.5
Chapter 2.1 --- Victim Exhaustion DoS/DDoS Attacks --- p.6
Chapter 2.1.1 --- Direct DoS/DDoS Attacks --- p.7
Chapter 2.1.2 --- Reflector DoS/DDoS Attacks --- p.8
Chapter 2.1.3 --- Spoofed Packet Filtering --- p.9
Chapter 2.1.4 --- IP Traceback --- p.13
Chapter 2.1.5 --- Location Hiding --- p.20
Chapter 2.2 --- QoS Based DoS Attacks --- p.22
Chapter 2.2.1 --- Introduction to the QoS Based DoS Attacks --- p.22
Chapter 2.2.2 --- Countermeasures to the QoS Based DoS Attacks --- p.22
Chapter 2.3 --- Worm based DoS Attacks --- p.24
Chapter 2.3.1 --- Introduction to the Worm based DoS Attacks --- p.24
Chapter 2.3.2 --- Countermeasures to the Worm Based DoS Attacks --- p.24
Chapter 2.4 --- Low-rate TCP Attack and RoQ Attacks --- p.26
Chapter 2.4.1 --- General Introduction of Low-rate Attack --- p.26
Chapter 2.4.2 --- Introduction of RoQ Attack --- p.27
Chapter 3 --- Formal Description of Low-rate TCP Attacks --- p.28
Chapter 3.1 --- Mathematical Model of Low-rate TCP Attacks --- p.28
Chapter 3 2 --- Other forms of Low-rate TCP Attacks --- p.31
Chapter 4 --- Distributed Detection Mechanism --- p.34
Chapter 4.1 --- General Consideration of Distributed Detection . --- p.34
Chapter 4.2 --- Design of Low-rate Attack Detection Algorithm . --- p.36
Chapter 4.3 --- Statistical Sampling of Incoming Traffic --- p.37
Chapter 4.4 --- Noise Filtering --- p.38
Chapter 4.5 --- Feature Extraction --- p.39
Chapter 4.6 --- Pattern Matching via the Dynamic Time Warping (DTW) Method --- p.41
Chapter 4.7 --- Robustness and Accuracy of DTW --- p.45
Chapter 4.7.1 --- DTW values for low-rate attack: --- p.46
Chapter 4.7.2 --- DTW values for legitimate traffic (Gaussian): --- p.47
Chapter 4.7.3 --- DTW values for legitimate traffic (Self-similar): --- p.48
Chapter 5 --- Low-Rate Attack Defense Mechanism --- p.52
Chapter 5.1 --- Design of Defense Mechanism --- p.52
Chapter 5.2 --- Analysis of Deficit Round Robin Algorithm --- p.54
Chapter 6 --- Fluid Model of TCP Flows --- p.56
Chapter 6.1 --- Fluid Math. Model of TCP under DRR --- p.56
Chapter 6.1.1 --- Model of TCP on a Droptail Router --- p.56
Chapter 6.1.2 --- Model of TCP on a DRR Router --- p.60
Chapter 6.2 --- Simulation of TCP Fluid Model --- p.62
Chapter 6.2.1 --- Simulation of Attack with Single TCP Flow --- p.62
Chapter 6.2.2 --- Simulation of Attack with Multiple TCP flows --- p.64
Chapter 7 --- Experiments --- p.69
Chapter 7.1 --- Experiment 1 (Single TCP flow vs. single source attack) --- p.69
Chapter 7.2 --- Experiment 2 (Multiple TCP flows vs. single source attack) --- p.72
Chapter 7.3 --- Experiment 3 (Multiple TCP flows vs. synchro- nized distributed low-rate attack) --- p.74
Chapter 7.4 --- Experiment 4 (Network model of low-rate attack vs. Multiple TCP flows) --- p.77
Chapter 8 --- Conclusion --- p.83
Chapter A --- Lemmas and Theorem Derivation --- p.85
Bibliography --- p.89
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Tseng, Sung-Chih, and 曾嵩智. "Attack Rate and Associated Factors of Intestinal Parasites Infection Among Foreign Workers." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/25618206463432584720.
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碩士國立陽明大學
公共衛生研究所
97
Background In order to meet the pressing human resource needs of employers, Taiwan hire thousands of foreign workers to help address skill and labour shortages every years. Most of the foreign workers are come from Philippine, Thailand, Indonesia and Vietnam. By the health policy, all foreign workers must complete a health examination before hiring in Taiwan. According to the statistic data from Centers for Disease Control, Taiwan；the highest abnormal health examination result was intestinal parasites infection. Object This study is focus on the analysis of intestinal parasites infection and associated factors of the Southeast Asia foreign workers who had work in Taiwan, base on our health examination data. Matterial and Methods We collected the health examination data of foreign worker who received examination in Lishin hospital , Taiwan from 2006 Jan to 2007 Dec. We included the Southeast Asia foreign workers who had received immigrate and regular health exam in Lishin hospital. Results We collected 9,363 foreign workers in this study. There were 4,415(47.2%) men, and 4,948(52.8%) women. There were 2,018(21.4%) persons from Indonesia, 2,741 (29.3%) from Philippine, 3,067(32.8%) from Thailand and 1,537(16.4%) from. Vietnam The abnormal stool examination rate of regular health exam is 6.5%(611 persons). According to sex, the prevalence rate in male is 4.7%, female 8.2%. The age specified prevalence rate in group younger than 25 years old is the highest.(6.5%). The overweight group has lower abnormal rate(5.6%). According to the country, the prevalence rate in Indonesia is 10.2%(206), 9.1%(109) in Vietnam, 5.8%(159) in Philippine and 4.5%(137) in Thailand. The worker who had abnormal stool data in immigrate health exam has higher abnormal rate(17.5%) in regular health exam. After multiple logistic regression analysis, we found The abnormal stool examination rate of regular health exam is associated with gender, age, nation, BMI, and stool exam data in immigrate health exam. Conclusion This study shows the intestinal parasites infection rate in the foreign workers from Indonesia, female, younger than 25 years old, and had abnormal stool exam in immigrate health exam was higher than others. Our government should pay more attention to prevent parasite infection from Southeast Asia country.
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Jen, Kuo han, and 郭瀚仁. "The Research of Interaction of Interest Rate and Exchange Rate - an Empirical Work of 911 terrorist attack in United States." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/74154802014106385097.
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碩士國立暨南國際大學
國際企業學系
94
In 1980s, the increase of the federal budget deficit and the trade deficit both happened. Feldstein (1982) stated the federal budget deficit will cause unprecedented trade deficit. In 2001, the 911 terrorist attack severely destroyed the New York and American society. The disaster had huge impact on the financial institutions and the international trade with foreign countries. We want to evaluate the impact of 911 disaster on capital mobility with the break in Sep 11 2001. In comparison with the past studies of interaction of the interest rate and exchange rate to evaluate the capital mobility, we use the new time series methodology to investigate the issue of the capital mobility and discuss the main theses about this research. According to the research by Hatemi-J and Irandoust (2000), we use the Granger-causality test of the interest rate and exchange rate to evaluate the capital mobility based on the model from the balance of payments. About the empirical results, at first, we use the unit root test to check if the series data are stationary. Secondly, we use Granger-causality test to find out the empirical results. Finally, we can prove that the Granger-causality relationships between the interest rate & the exchange rate, the interest rate & the financial account have been changed because they have unidirectional causality causes after the 911 terrorist attack. Hence, the 911 terrorist attack could have the significant influence on the capital mobility through the empirical results of Granger-causality test.
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Padhye, Jaideep D. "Stepping-stone network attack kit (SNEAK) for evading timing-based detection methods under the cloak of constant rate multimedia streams." 2008. http://hdl.handle.net/10106/1046.
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Shu-Hui, Shen. "Time Trend in Mortality and Attack rate of Nosocomial Infection by specific pathogens :surveillence data between 1994-2003 in SKH Hospital ,Taiwan." 2005. http://www.cetd.com.tw/ec/thesisdetail.aspx?etdun=U0001-2107200517364600.
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Shen, Shu-Hui, and 沈淑惠. "Time Trend in Mortality and Attack rate of Nosocomial Infection by specific pathogens :surveillence data between 1994-2003 in SKH Hospital ,Taiwan." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/64608726151372533324.
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碩士國立臺灣大學
預防醫學研究所
93
Objective We aimed to (1) assess time trend in attack rate, case-fatality rate, and mortality rate; (2) assess whether time trend vary multiple episodes, infection site , and pathogen; and to evaluate the interval between admission and onset of infection by pathogen Methods Data on surveillance of nosocomial infection in SKMH was available electronically. We collected information on discharged patients, episodes of nosocomial Infections, and deaths between 1994 and 2003. After excluding 19,271 deliveries in the contemporaneous period, a total of 282,898 discharged patients were included in the following analysis. Of these patients, we identified 5330 patients with 8885 episodes of NI during 10-year period. After linkage with Taiwan National Mortality Registry, 1,711 deaths were ascertained, including 965 in-hospital deaths and 746 critical against advice discharge (AAD) deaths. Among death cases, 1,495 deaths (87.4%) died within 30 days after onset of NIs. We used a decomposition method to divide mortality related to NI into attack rate and case-fatality rate and assess time trend for these three rates. Time-series Poisson regression model was used to assess the change of three rate after controlling for other significant factors. The comparison of interval between admission and onset of infection between the USA and Taiwan was also made. Results The overall time trend in attack rate has declined by 6%, decreasing from 3.30% in 1994 to 3.14 in 2003. However, the overall case-fatality rate was elevated by 55%, increasing from 13.96% in 1994 to 21.6% in 2003. Both yielded 46% increase in mortality rate attributed to NI, from 0.46% in 1994 to 0.67% in 2003.pathogens has declined from 1996 but rebounded since 2000. Episodes without culture had a slight increase since 1996. For case-fatality, the majority of pathogens showed an increasing trend. Only coagulase-negative Staphylococcus s and K pneumoniae showed a decreasing trend. The finding form attack rate together with case-fatality gives the results of mortality rate with an increasing trend for most pathogens. Only coagulase-negative Staphylococcus showed a decreasing trend. The mortality trend for P. aeruginosa, K.pneumoniae, and E. cloacae was fairly constant. For multiple pathogens, time trend in mortality trend was pursuant to that in attack rate with declining from the year of 1996 and resurged from the year of 2000. By using time-series Poisson regression analysis, after controlling for gender, age, frequency of admission, length of stays, and infection site, an increase (per week) in attack rate was 0.04% for fungus, 0.001% for S.aureus, 0.1% for E.coli, 0.047% for Acinetobacter spp, 0.037% for Enterococcus, and 0.33% for Enterobacter spp. The remaining pathogens showed a decline trend including Pseudomonas aeruginosa , coagulase-negative Staphylococcus, and E.coloacae. Episodes with multiple pathogens has declined from 1996 but rebounded since 2000. The average interval between admission and onset of infection in our study was longer that that in the USA. This is particularly seen for S.aureus, Coagulase-nagative Staphylococcus, fungus, and E.coli. Conclusions Nosocomial infection with time trend decomposed in to attack rate, case-fatality rate and mortality using data from a large medical center varied with age, pathogen and site of infection. Such heterogeneity of time trend in attack rate and case-fatality rate may imply different measures for control nosocomial infection and need to be clarified in future research.
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Chen, Che-Feng, and 陳哲鋒. "The detection and prevention of low-rate DoS attacks." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/03361065215645788942.
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碩士國防大學理工學院
資訊工程碩士班
101
The number of internet user increase in these years. According to the survey report of 2012 Internet Worlds Stats, the global online population is nearly up to 2.1 billion, compared to 1.15 billion people in 2007.It is about twice the growth. As the number of Internet population is doubling, information security incidents also are increasing. The Kaspersky Lab report said the Internet attacks in the past month (2013/4/6 ~ 2013/5/4) is about four million. That is a long-term job for IT staff to keep the network secure but not offence the network convenience. In Kaspersky Lab's data, denial of service attacks is about 70 % of all. The attacking target is to run out the servers’ resources. Therefore legal users cannot access servers normally. That result from attackers send a large number of packets. Defenders check the packet contents and observe flow change rate to figure out the attacks. The attackers then evolve into another type of attacks, named Low-Rate DoS. They use few packets to achieve the effect of denial of service attacks, which is different from traditional attacks sending a large number of packets in a short time. The attacks send “enough” packets to fill the buffer of service servers or “complex” packets to consume the computation power of service servers. There are many defense methods on low rate attacking proposed for making legal users access the server resources. Actually attacker can send requests to consume a lot of resources of the system, so legal users need waiting for a long time to get the response from servers. That is a kind of denial of service attacks. This thesis proposes the defense methods by observing the frequency of the user accessing times. Furthermore, we introduce the concept of priority to further obstruct the distributed low rate attacks. The maximum waiting time is assumed as the user response time tolerated. If the responding time exceeds the tolerate response time, the denial of service attacks achieve. According to the current network information magazine, the human maximum tolerate request time is 8 seconds. Without using the proposed defense methods, only 1.8% legal users can access servers. With the proposed defense mechanism, legal users access rate increases to 96.6%. It is about 50 times in increase.
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Yi-Hsuang, Chang, and 章玉鉉. "Target Zones and Speculative Attacks: An Analysis of Dual Exchange Rate Markets." Thesis, 1994. http://ndltd.ncl.edu.tw/handle/06166686583695023887.
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Anantharam, Karunakar. "An autonomous router-based solution to detect and defend low rate DDoS attacks." Thesis, 2005. http://library1.njit.edu/etd/fromwebvoyage.cfm?id=njit-etd2005-002.
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CHEN, CHI-WEN, and 陳麒文. "A novel research on defense against for low-rate distributed denial of service attacks." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/p6t9s9.
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碩士國立勤益科技大學
資訊工程系
106
This paper mainly discusses and studies the evolution of the current web protocol (HTTP), and how to face and effectively guard against the current attacks on this communication protocol. The HTTP protocol is currently the most widely used and most widely used protocol on the Internet, because currently all industries and industries use their own brands, products, images, advertisements, etc. to make use of the rich and diverse web pages. Content is used for promotion, marketing, etc... Beyond the B2C model; companies and companies will also use HTTP as a convenient communication protocol and use different HTTP methods (GET / POST / PUT / DELETE) to quickly establish APIs (Application) The communication interface of the Programming Interface allows both companies to more quickly integrate products and conduct business transactions. For example, online shopping websites that are very popular at present are using this feature to connect with third-party payment services and the system of logistics providers, so that consumers can choose not only to purchase a variety of products for purchase on the website, but also to allow Consumers can choose various payment modes and logistics methods to complete product distribution during checkout, thereby stimulating consumers' willingness to shop. As the most mainstream communication protocol, of course, it has become the biggest target of attacks. The HTTP-based attack model and methods are also dazzling. This dissertation focuses on one of the most common attack modes, Low-Rate Distributed Denial of Service, as the topic of this dissertation. In the paper's research results, it proposes how to build Nginx. A low-cost and effective defense against low-speed blocking attacks.
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LIOU, YAN-JIE, and 劉彥頡. "A Study on the Defense of Low-Rate Denial-of-Service Attacks against HTTP/2 Services." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/31216180136535154237.
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碩士國立高雄應用科技大學
資訊管理研究所碩士班
104
Network security has always been one of the most critical agenda to enterprises and researchers. Nowadays, with the widespread adoption of HTTP/2, more and more research has indicated that HTTP/2 is more vulnerable to Denial-of-Service (DoS) attacks. However, few solutions and mechanisms are available to defend the Denial-of-Service (DoS) attacks against the HTTP/2 services. In this paper, an algorithm for defending Low-Rate Denial-of-Service Attacks against HTTP/2 Services is proposed to reduce the security risk of HTTP/2 services.