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Clusterová analýza datového provozu / Cluster analysis of data trafficNagyová, Simona January 2016 (has links)
This thesis is meant to present the methods of cluster analysis, their use for detecting network traffic anomalies. It deals with various types of cyber attacks particularly DoS (DDoS) attacks. It contains a list of well-known DoS attacks. Also includes a program in Python, using the k-means method for detection of anomalous traffic.
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Security Risk Analysis based on Data CriticalityZhou, Luyuan January 2020 (has links)
Nowadays, security risk assessment has become an integral part of network security as everyday life has become interconnected with and dependent on computer networks. There are various types of data in the network, often with different criticality in terms of availability or confidentiality or integrity of information. Critical data is riskier when it is exploited. Data criticality has an impact on network security risks. The challenge of diminishing security risks in a specific network is how to conduct network security risk analysis based on data criticality. An interesting aspect of the challenge is how to integrate the security metric and the threat modeling, and how to consider and combine the various elements that affect network security during security risk analysis. To the best of our knowledge, there exist no security risk analysis techniques based on threat modeling that consider the criticality of data. By extending the security risk analysis with data criticality, we consider its impact on the network in security risk assessment. To acquire the corresponding security risk value, a method for integrating data criticality into graphical attack models via using relevant metrics is needed. In this thesis, an approach for calculating the security risk value considering data criticality is proposed. Our solution integrates the impact of data criticality in the network by extending the attack graph with data criticality. There are vulnerabilities in the network that have potential threats to the network. First, the combination of these vulnerabilities and data criticality is identified and precisely described. Thereafter the interaction between the vulnerabilities through the attack graph is taken into account and the final security metric is calculated and analyzed. The new security metric can be used by network security analysts to rank security levels of objects in the network. By doing this, they can find objects that need to be given additional attention in their daily network protection work. The security metric could also be used to help them prioritize vulnerabilities that need to be fixed when the network is under attack. In general, network security analysts can find effective ways to resolve exploits in the network based on the value of the security metric.
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Qualification des matériaux cimentaires exposés à l’attaque sulfatique externe : étude des mécanismes et proposition d’indicateurs / Specification of cementitious materials exposed to external sulphate attack : Study of mechanisms and proposal of indicatorsBoudache, Sonia 29 October 2019 (has links)
L’attaque sulfatique externe est un processus de dégradation au cours duquel les propriétés mécaniques et la composition chimique d’un matériau cimentaire vont être fortement affectées par la pénétration de sulfates en solution. La réponse à ce problème repose en partie sur la maîtrise de la composition des ciments. A ce titre, la capacité d’un ciment CEM I à former de l’ettringite lors de l’ASE et donc, par extension, d’être considéré comme résistant ou pas face aux sulfates, peut être évaluée par la formule de Sadran qui prend en compte les taux du C3A et C3S. Nous avons mis en place une méthode de caractérisation pour analyser le comportement de ciments CEM I de différents indices de Sadran. L’analyse s’appuie sur une méthodologie permettant une caractérisation globale de la dégradation. La teneur en C3A plus que l’indice de Sadran détermine le type de dégradation d’un ciment. La méthode de suivi et d’analyse utilisée sur les CEM I a été appliquée pour l’étude de ciments composés CEM V afin de comparer leur comportement avec celui de ciments résistants aux sulfates. Un essai incluant un pré conditionnement thermique, pour l’accélération de la dégradation, a été choisi et les résultats obtenus ont été comparés à ceux de l’essai développé précédemment au GeM. Il a été démontré que le pré conditionnement thermique ne permet pas une accélération significative de la dégradation. De plus, le séchage mis en place modifie la microstructure des échantillons de mortiers CEM V ; il ralentit la progression des sulfates et donc allonge le temps de réponse. L’adsorption des sulfates par les C-S-H fait l’objet de la dernière partie de cette thèse, tout en ouvrant sur des perspectives. / During external sulphate attack the mechanical properties and the chemical composition of a cementitious material are strongly affected by the penetration of sulphate in solution. The answer to this problem lies partly in the control of the composition of the cements. The ability of CEM I cements to form ettringite during external sulfate attack and therefore to be considered resistant, or not, to sulphates, can be evaluated by the formula of Sadran which considers the rates of C3A and C3S. We set up a characterization method to analyze the behavior of CEM I cements with different Sadran indexes. Two degradation mechanisms were observed, marked by either expansive phase precipitation or leaching. The monitoring and analysis method used on the CEM I cements has been applied to the study of CEM V blended cements in order to compare their behavior with that of sulphate resistant cements. A test including a thermal pre-conditioning was chosen and the results obtained were compared with those of the test previously developed at GeM. It has been shown that thermal pre-conditioning does not allow a significant acceleration of degradation. The adsorption of sulphates by C-S-H, as well as the loss of calcium, is the subject of the last part of this thesis, while opening up perspectives. The first results showed that sulphate fixation by C-S-H increases with the concentration of the sulphate solution.
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Resource Clogging Attacks in Mobile Crowd-Sensing: AI-based Modeling, Detection and MitigationZhang, Yueqian 17 January 2020 (has links)
Mobile Crowdsensing (MCS) has emerged as a ubiquitous solution for data collection from embedded sensors of the smart devices to improve the sensing capacity and reduce the sensing costs in large regions. Due to the ubiquitous nature of MCS, smart devices require cyber protection against adversaries that are becoming smarter with the objective of clogging the resources and spreading misinformation in such a non-dedicated sensing environment. In an MCS setting, one of the various adversary types has the primary goal of keeping participant devices occupied by submitting fake/illegitimate sensing tasks so as to clog the participant resources such as the battery, sensing, storage, and computing. With this in mind, this thesis proposes a systematical study of fake task injection in MCS, including modeling, detection, and mitigation of such resource clogging attacks.
We introduce modeling of fake task attacks in MCS intending to clog the server and drain battery energy from mobile devices. We creatively grant mobility to the tasks for more extensive coverage of potential participants and propose two take movement patterns, namely Zone-free Movement (ZFM) model and Zone-limited Movement (ZLM) model. Based on the attack model and task movement patterns, we design task features and create structured simulation settings that can be modified to adapt different research scenarios and research purposes.
Since the development of a secure sensing campaign highly depends on the existence of a realistic adversarial model. With this in mind, we apply the self-organizing feature map (SOFM) to maximize the number of impacted participants and recruits according to the user movement pattern of these cities. Our simulation results verify the magnified effect of SOFM-based fake task injection comparing with randomly selected attack regions in terms of more affected recruits and participants, and increased energy consumption in the recruited devices due to the illegitimate task submission.
For the sake of a secure MCS platform, we introduce Machine Learning (ML) methods into the MCS server to detect and eliminate the fake tasks, making sure the tasks arrived at the user side are legitimate tasks. In our work, two machine learning algorithms, Random Forest and Gradient Boosting are adopted to train the system to predict the legitimacy of a task, and Gradient Boosting is proven to be a more promising algorithm. We have validated the feasibility of ML in differentiating the legitimacy of tasks in terms of precision, recall, and F1 score. By comparing the energy-consuming, effected recruits, and impacted candidates with and without ML, we convince the efficiency of applying ML to mitigate the effect of fake task injection.
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Analýza tréninkového procesu v požárním sportu - požární útok / Analysis of the training process in fire sport - fire attackŠkodová, Barbora January 2017 (has links)
Title: Analysis of the training process in fire sport - fire attack. Objectives: Verify the effectiveness of the training process for the fire attack discipline, which was designed in the bachelor thesis. Methods: The method used for the elaboration of the diploma thesis was observation, analysis, testing, meansurement. Results: There was an improvement on the test file following the proposed training plan. Improvements to the test file were more than 10% over the control file in the key tests. Keywords: Fire sport, fire attack, training process, analysis.
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Kvinnors upplevelse av sexuell hälsa efter hjärtinfarkt : En litteraturöversikt / Women's experience of sexual health after a heart attack : A literature reviewDavidsson, Nellie, Kamperin, Cajsa, Wadenborg, Esther January 2021 (has links)
Bakgrund: Sexuell hälsa är ett tillstånd av emotionellt, fysiskt, psykiskt och socialt välbefinnande och kan förändras efter en hjärtinfarkt. Sjuksköterskor kan uppleva samtal om sexuell hälsa som tabu, samtidigt önskar kvinnor information om sexuell hälsa. Syfte: Syftet var att beskriva kvinnors upplevelse av sin sexuella hälsa efter hjärtinfarkt. Metod: En litteraturöversikt med nio artiklar med kvalitativ metod genomfördes. Resultat: Huvudtemat som framkom var Rädsla och oro, med sex subteman: Att sakna information, Att vara rädd för att återinsjukna, Att vara rädd för fysisk kontakt, Att sakna tilltro till sig själv, Att kommunicera med partnern och Att ha behov av närhet. Kvinnorna upplevde rädsla och oro efter hjärtinfarkten som kunde spegla sig på hur de såg på sin sexuella hälsa. Bristfällig information från sjukvården var den bidragande faktorn till kvinnornas rädsla som utgjorde hinder för kvinnan gällande hennes sexuella hälsa. Stödet från partnern upplevdes ha stor betydelse för hennes självkänsla, lust och trygghet. Slutsats: Bristande eller felaktig information kan leda till onödiga begränsningar i kvinnans liv. Kunskapen hos sjuksköterskor gällande sexuell hälsa behöver förbättras för att en adekvat behandling ska kunna ges. Likväl behöver sjuksköterskor ges mer gynnsamma förutsättningar för att kunna identifiera kvinnans resurser och förmåga till egenvård. / Background: Sexual health is a state of emotional, physical, mental and social well-being and can change after a heart attack. Nurses can experience conversations about sexual health as taboo, while women want information about sexual health. Aim: The aim was to describe women's experience of their sexual health after a heart attack. Method: A literature review with nine articles with a qualitative method was conducted. Result: The main theme that emerged was Fear and anxiety, with six sub-themes: Lacking information, Being afraid of re-illness, Being afraid of physical contact, Lacking confidence in oneself, Communicating with the partner and Having a need for closeness. The women experienced fear and anxiety after the heart attack that could be reflected in how they viewed their sexual health. Lack of information from the health service was the contributing factor to the women's fear that posed obstacles for the woman regarding her sexual health. The support from the partner was felt by the woman to be of great importance for her self-esteem, desire and security. Conclusions: Lack of or incorrect information may lead to unnecessary restrictions in the woman's life. The knowledge of nurses regarding sexual health needs to be improve for adequate treatment to be given to women. Nevertheless, nurses need to be given more favourable conditions to be able to identify the woman's resources and ability to self-care.
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Hypersonic Stationary Crossflow Waves: Receptivity to RoughnessVarun Viswanathan (8032571) 04 December 2019 (has links)
<div>Experiments were performed on a sharp-nosed 7° half-angle cone at a 6° angle of attack in the Boeing/AFOSR Mach-6 Quiet Tunnel (BAM6QT) to study the stationary crossflow instability and its receptivity to small surface roughness. Heat transfer measurements were obtained using temperature sensitive paint (TSP) and Schmidt Boelter (SB) heat transfer gauges. Great care was taken to obtain repeatable, quantitative measurements from TSP.</div><div></div><div>Consecutive runs were performed at a 0° angle of attack, and the heat transfer measured by the SB was found to drop as the initial model temperature increased, while other initial conditions such as stagnation pressure were held constant. This agreed with calculations done using a similarity solution. It was found that repeatable measurements at a 6° angle of attack could be made if the initial model temperature was controlled and the patch location that was used to calibrate the TSP was picked in a reasonable and consistent manner.</div><div></div><div>The Rod Insertion Method (RIM) roughness, which was used to excite the stationary crossflow instability, was found to be responsible for the appearance of the streaks that were analyzed. The signal-to-noise ratio in the TSP was too low to properly measure the streaks directly downstream of the roughness insert. The heat transfer along the streak experienced linear growth, peaked, and then slightly decayed. It is possible this peak was saturation. The general trend was that the growth of the streaks moved farther upstream as the roughness element height increased, which agreed with past computations and low speed experiments. The growth of the streak also moved farther upstream as the freestream Reynolds number increased. The amplitude of the streaks was calculated by non-dimensionalizing the heat transfer using the laminar theoretical mean-flow solution for a 7° half-angle cone at a 6° angle of attack. The relationship between the amplitude and the non-dimensional roughness height was approximately linear in the growth region of the streaks.</div>
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Attack-Resilient Adaptive Load-Balancing in Distributed Spatial Data Streaming SystemsAnas Hazim Daghistani (9143297) 05 August 2020 (has links)
<div>The proliferation of GPS-enabled devices has led to the development of numerous location-based services. These services need to process massive amounts of spatial data in real-time with high-throughput and low response time. The current scale of spatial data cannot be handled using centralized systems. This has led to the development of distributed spatial streaming systems. The performance of distributed streaming systems relies on how even the workload is distributed among their machines. However, the real-time streamed spatial data and query follow non-uniform spatial distributions that are continuously changing over time. Therefore, Distributed spatial streaming systems need to track the changes in the distribution of spatial data and queries and redistribute their workload accordingly. This thesis addresses the challenges of adapting to workload changes in distributed spatial streaming systems to improve the performance while preserving the system's security. </div><div>The thesis proposes TrioStat, an online workload estimation technique that relies on a probabilistic model for estimating the cost of partitions and machines of distributed spatial streaming systems. TrioStat has a decentralised technique to collect and maintain the required statistics in real-time with minimal overhead. In addition, this thesis introduces SWARM, a light-weight adaptive load-balancing protocol that continuously monitors the data and query workloads across the distributed processes of spatial data streaming systems, and redistribute the workloads soon as performance bottlenecks get detected. SWARM uses TrioStat to estimate the workload of the system's machines. Although using adaptive load-balancing techniques significantly improves the performance of distributed streaming systems, they make the system vulnerable to attacks. In this thesis, we introduce a novel attack model that targets adaptive load-balancing mechanisms of distributed streaming systems. The attack reduces the throughput and the availability of the system by making it stay in a continuous state of rebalancing. The thesis proposes Guard, a component that detects and blocks attacks that target the adaptive load balancing of distributed streaming systems. Guard is deployed in SWARM to develop an attack-resilient adaptive load balancing mechanism for Distributed spatial streaming systems.<br></div>
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Znalosti žáků určitých středních škol severních a středních Čech o vybraných civilizačních onemocněních / The knowledge of certain pupils in secondary schools from the area of North and Central Bohemia about selected diseases of civilisationJírová, Kateřina January 2020 (has links)
This diploma thesis deals with the problems of diseases of civilization. The work is divided into theoretical and practical parts. The theoretical part explains what are diseases of civilization, how they arise and how they can be prevented. For each disease (coronary heart disease, obesity, diabetes, cancer) the thesis describes in more detail how and why they arise, what are the risk factors, what preventive measures exist and how to treat the disease. In the practical part, the thesis is devoted to the research of pupils' knowledge in the field of diseases of civilization of selected schools. Using a questionnaire, we dermined the knowledge of the pupils of two secondary schools and found the variance in their knowledge. Furthermore, this knowledge of pupils was compared with their knowledge two years ago when a similar questionnaire was completed in the same schools. The purpose of this thesis was to find out how the knowledge of identical pupils of these two schools changed after two years. The final discussion shows how the knowledge of pupils has changed after two years. It was found that pupils' knowledge improved overall. Cancer, diabetes and obesity knowledge have all improved. There was a slight deterioration in the question concern the number of patients. There was no change in the...
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Cooling of U.S.C.G. Reliance-B Class Cutter engine rooms utilizing recovered heat from propulsion machinery / Cooling of USCG Reliance-B Class Cutter engine rooms utilizing recovered heat from propulsion machinery / Cooling of United States Coast Guard Reliance-B Class Cutter engine rooms utilizing recovered heat from propulsion machineryHalsch, Joseph A. January 1980 (has links)
Thesis: M.S., Massachusetts Institute of Technology, Department of Mechanical Engineering, 1980 / Includes bibliographical references. / by Joseph A. Halsch. / M.S. / M.S. Massachusetts Institute of Technology, Department of Mechanical Engineering
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