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Využití útoku "Pass the hash attack" na kompromitaci vysoce privilegovaných účtů / Using of the attack "Pass the hash attack" for the compromising of high privileged accounts.Jakab, Vojtěch January 2014 (has links)
The master thesis deals with the attack "‘pass the hash"’ on high privileged accounts. Within the theoretical part is discussed creating hashes and its use. Next is a descrip- tion of the authentication in Windows operating system. There are also pointed out weaknesses in the design of authentication mechanisms. The last part deals with the individual attack and security options for mitigating the impacts. In the practical part are tested available tools for retrieving hashes from the files of the operating systems and tools which allow the attack itself. The output of this section is selection of the appropriate tools to demonstrate the attack in a proposed real environ- ment. The last topic is about designing the experimental environment, demostration of the attack with the possibility of getting through the network. The last steps deal with mitigating the impact of the attack.
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Map Partition and Loop Closure in a Factor Graph Based SAM SystemRelfsson, Emil January 2020 (has links)
The graph-based formulation of the navigation problem is establishing itself as one of the standard ways to formulate the navigation problem within the sensor fusion community. It enables a convenient way to access information from previous positions which can be used to enhance the estimate of the current position.To restrict working memory usage, map partitioning can be used to store older parts of the map on a hard drive, in the form of submaps. This limits the number of previous positions within the active map. This thesis examines the effect that map partitioning information loss has on the state of the art positioning algorithm iSAM2, both in open routes and when loop closure is achieved. It finds that larger submaps appear to cause a smaller positional error than smaller submaps for open routes. The smaller submaps seem to give smaller positional error than larger submaps when loop closure is achieved. The thesis also examines how the density of landmarks at the partition point affects the positional error, but the obtained result is mixed and no clear conclusions can be made. Finally it reviews some loop closure detection algorithms that can be convenient to pair with the iSAM2 algorithm.
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Development of a methodology to simulate simple mismatching in photovoltaic systemsFrid, Gustav January 2015 (has links)
The currently available tools to simulate solar photovoltaic (PV) systems do not offer a reliable solution to simulate string or module level inverter systems with partial shading and modules with mismatching electrical characteristics. The available methodologies to simulate this satisfying require computational power that is not commonly available. To make it possible to simulate these kinds of systems a methodology based around the software “System Advisory Model” (SAM) is proposed. The methodology assumes that shading is binary, meaning a module can either be fully shaded or not shaded at all. Two different global IV curve models are presented and evaluated in comparison with a more detailed Matlab global IV model based on the one diode equivalent circuit. All these methodologies disregards the impact of the bypass diodes in the PV module and this is considered a significant error, which has to be quantified. It is proposed that this should be done by using the two-diode equivalent circuit instead of the one diode model. Finally the methodology is not concluded to be reliable until verified in comparison with real world data. / De för närvarande tillgängliga simuleringsverktygen för solcellssystem erbjuder inte en tillförlitlig metod för simulering av delvis skuggade system eller system med moduler med olika elektriska egenskaper. De metoder som är tillgängliga för att simulera detta tillförlitligt kräver datorkraft som inte är allmäntillgänglig. För att göra det möjligt att simulera dessa typer av system föreslås en metod baserad kring programvaran "System Advisory Model" (SAM). Metoden utgår från antagandet att skuggning är binärt, vilket innebär att en modul kan antingen vara helt skuggad eller inte skuggad alls. Två olika globala IV-modeller presenteras och utvärderas i jämförelse med en detaljerad Matlab global IV-modell baserad på enkel-diods ekvivalenta kretsen. Denna metod bortser dock från effekterna av bypass-dioderna i PV-modulen och detta antas medföra betydande fel som måste kvantifieras, detta bör då göras med hjälp av två-diods ekvivalenta kretsen. Slutligen så kan metoden inte anses pålitlig förrän den har blivit verifierad med verkliga data.
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Optimization and characterization of a centrally functionalized quartz crystal microbalance sensor surface for Norovirus detection : Optimering och karakterisering av en centralt funktionaliserad kvartskristall mikrovåg sensoryta för norovirus detektionSelvaratnam, Thevapriya January 2015 (has links)
In this study a biosensor based on real time quartz crystal microbalance (QCM) monitoring is optimized and characterized for the application in the Norosensor. This biosensor is aimed to recognise, capture and amplify Norovirus (NoV). In an initial step a simplified bioassay was developed that focuses on the latter parts of the assay which consists of DNA-guided probing and amplification of the captured virus and includes the development of an amplification model assay directly to the functionalised crystal surface. A padlock probe with matching sequence to the conjugated oligonucleotide on the quartz crystal surface is used as target in the model assay. Although a number of studies have been carried out based on padlock probe ligation and rolling circle amplification (RCA) based QCM sensing, these studies utilize the entire crystal surface to capture and amplify the biomolecule. In this research work the QCM monitoring is explored on a centrally functionalised electrode surface through conjugation only at the centre of the electrode for increased mass sensitivity. Thus, allowing capture and amplification of the padlock probe only at the centre of the quartz crystal. A 14mm diameter, thermoncompensated AT-cut, nonpolished quartz crystal with a 10mm diameter gold surface coating acting as electrode was utilized for QCM measurements. The detection system is based on mass binding and amplification on the QCM to produce a negative frequency shift in the fundamental frequency of the vibrating quartz crystal. The amplification products were additionally fluorescently labelled and fluorescent microscopy images were also obtained at the end of every experiment to verify the presence or absence of DNA capture and amplification. Experimental findings show that the current flow chamber with a 15ul capacity is able to detect a specific padlock probe concentration of 1nM on a conjugated region of ~2.5mm diameter. RCA amplified the mass with an average frequency shift of -80Hz in 60mins RCA incubation time. Further, the specificity and sensitivity of the QCM system was explored. However, the system has limitations where sensor binding of reaction proteins, such as DNA ligase and BSA, to some extent is observed. The storage stability of the functionalized self-assembled monolayer (SAM) on the QCM is also observed to deteriorate and thus, is of concern. Nevertheless the combination of RCA based amplification with QCM real-time monitoring has the potential for rapid and simple, low cost detection of the Norovirus. / I det här arbetet har vi optimerat och karateriserat en biosensor för detektion av Norovirus som orsakar häftiga utbrott av kräksjuka under vinterhalvåret vilket leder till både försämrad vård samt stora ekonomiska förluster för samhället. Målet inom EU projektet “Norosensor” är att utveckla ett snabbtest som kan tillämpas efter ett utbrott på till exempel en vårdavdelning och som ska mäta mängden virus i luften vilket kan fungera som riktlinje för om en avdelning är säker att användas eller ej. Tekniskt är målet med testet att fånga in viruspartiklar från luften som specifikt binds till sensorytan. Därefter ökar vi känsligheten från bundna partiklar genom en DNA-baserad amplifiering. Detta genererar specifik, viruskorrelerad massa som mäts med en kvartskristall mikrovågs sensor. När massan ökar minskar frekvenser vid vilken kristallen vibrerar och detta mäts i realtid. Det här arbetet har inte behandlat infångande eller inbindning av virus utan har fokuserat på den senare delen av protokollet som omfattar amplifieringen på sensorytan. En modell-assay har därför utvecklats där viruspartikeln istället representeras av en så kallad “padlock probe” (hänglås probe). Då sensorn är mycket känslig har först olika protokoll testats för effektiv rengöring av ytan med hjälp av ultraljud. I nästa steg har ytan funktionaliserats med thiol-modifierade syntetiska DNA molekyler som används för infångningen av målmolekylen på sensorytan (virus eller i detta fall padlock proben). Det har tidigare uppskattats att för att få maximal känslighet i massmätningen så är det fördelaktigt att binda viruset endast i mitten på en mycket liten yta av kristallen. Den här avhandlingen har därför fokuserat på att utveckla protokoll för detta där ytan först funtionaliserats i mitten innan resten av ytan blockats för att undvika ospecific inbindning. Resultaten visar att vi kan generera en centrerad funtionalisering och att vi får låg ospecifik binding. Protokollet består av flera biokemiska reakionssteg såsom (i) inbindning och lingering av padlock probe och (ii) amplifiering av den ligerade proben genom “rolling circle amplification”. För att kunna verifiera att vi fått amplifieringsprodukter på ytan har vi dels mätt frekvensändringen på grund av ökad massa men också märkt in dem med fluorescerande molekyler och detekterat dem i microskop. Under arbetets gång har ett flertal olika typer av kristaller testats. Det visade sig att om en polerad yta används (1μm grovhet) så migrerade molekylerna iväg från mitten när vi oscillerade kristallen medan vi fick bättre resultat om något grövre (3μm) ytor användes. Vi testade även ett flertal olika flödesceller av olika material och med olika reaktionsvolymer. Eftersom kristallen är mycket känslig så påverkar faktorer som flödeshastigheter och eventuella luftbubblor frekvensen. Vi optimerade därför detta och körde mätningarna vi6konstant flöde men med alternerande, låga hastigheter när vi tillsatte nya reagens eller inkuberade reaktionerna. Vi förvärmde även reaktionsmixarna för att minska ospeficika effekter och konstaterade att den funktionaliserade ytan påverkades av lagring över tid. I våra försök såg vi att protein såsom ligeringsenzymet och albumin, vilka har förhållandevis stor massa, hade effekter på frekvensen redan i sig genom att binda till ytan. Ytterligare optimeringar måste därför göras framöver för att minska denna inbinding bland annat genom bättre tvättsteg. Vi kunde dock påvisa linjär massökning med ökad amplifieringstid och har bevisad hög specificitet. Slutligen utvecklades ett litet mjukvaruprogram för att automatisera analysen och minska bruset. Sammanfattingsvis har vi lyckats utveckla ett enkelt och snabbt system för specifik massamplifering av Norovirus.
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ENERGIANALYS AV FASTIGHETEN ANDERSLUND 12 : Energieffektiviseringsmöjlighet med solcellerAndersson, Alexander, Lindström, FAHRIYE Cennet January 2021 (has links)
Today's society is dependent on energy and the increasing use of energy affects the environment in a negative way. In Sweden, homes and premises account for 39% of total energy use. Achieving national environmental quality goals requires a reduction in energy use and the energy saving potential in the real estate sector is large. Energy use in buildings can be reduced by carrying out certain energy efficiency measures. Kårhuset by Mälardalen University was built in 1997 and it is a gathering place for students. The building is located on the campus area in Västerås and includes an office, restaurant kitchen, dining room, pub and meeting rooms for line associations. In this work, an energy survey has been carried out by the property Anderslund 12 (Kårhuset) to find out the current energy use and investigate the energy saving potential in the building. The work's literature study analyzes previous research and similar case studies. Thereafter, the building's energy use has been simulated by IDA ICE by creating a basic model in the software using data from various authorities and site visits. The results of the basic model were then compared with simulations of various energy efficiency measures to evaluate the energy saving potential. The measures examined are window replacement, additional insulation of exterior walls and replacement of heat exchangers in the air handling units. As a complementary alternative, energy efficiency with solar cells on the roof was investigated. The conclusion is that the property's energy use exceeds the average of Swedish premises' energy use. In connection with a possible renovation, the building has good opportunities for more efficient energy use. By carrying out all the measures that have been proposed, the heating demand can be reduced by 39% and the energy supplied can be reduced from 156.9 kWh / m2, Atemp, year to 103 kWh / m2, Atemp, year. Complementary installation of solar cells is a profitable alternative for reducing the building's extremely high electricity consumption.
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Determination of the acousto-mechanical properties of chitosan and age dependent characteristics of red blood cells by confocal scanning acoustic microscopy with vector contrastAhmed Mohamed, Esam Eldin 22 November 2012 (has links)
The acoustic microscope is an efficient non-invasive tool that can explore the acoustic properties and the related mechanical microstructure of a wide diversity of materials, including biomedical and biological samples, which are, nowadays, among the most intriguing targets for investigations. In the presented work, an acoustic microscope with vector contrast is used to image and characterize the acousto-mechanical properties of chitosan, an abundant natural derivative of chitin known to be a biodegradable, nontoxic and versatile biopolymer that suits many biomedical applications such as its usage in tissue engineering. The work also presents key measurements for the study of the acousto-mechanical properties that are subject to variations during the life span of red blood cells (RBCs). The characteristic signature of fixed cells from groups of three different ages, fractionated according to mass density, is obtained from the acoustic microscope images. The analysis of these data enabled the quantitative comparisons between the acousto-mechanical properties (velocity and attenuation of ultrasound propagating in the cells, mass density, and bulk modulus of compression). Comparison of the contrasts in the acoustic micrographs for the cells of the different age groups is exploited to generate a model that determines the age of the individual cells in a sample of red blood cells collected from a healthy person. The dependence of the parameters of the cells including density, velocity and attenuation of longitudinal polarized ultrasonic waves travelling in the cells on the age of the cell is also presented. The output signal in dependence on the thickness of the sample, the so called V(d), represented as polar graph was exploited as the method of analysis of the data extracted from the acoustic micrographs imaged with ultrasound of a center frequency of 1.2 GHz. This procedure allows for the extraction of the quantitative information from a single image in magnitude and phase contrast and allows for height profiling with so called super resolution, relating to resolution below the diffraction limit, based on the developed modeling, beside of other advantages concerning the acoustic characterization of biomedical and biological samples. This method and the applications are presented and discussed together with the developed or adapted modeling.
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Sam Rayburn: Trials of a Party ManDaniel, Edward O. 05 1900 (has links)
Several books have been written about Sam Rayburn, but thus far there has been no attempt to analyze Rayburn's rise to power. No one has delved sufficiently into his political philosophy, his motivations, and his personal convictions regarding the pivotal events of the turbulent 1930s. This dissertation endeavors to fill that void by tracing the course of events which led Sam Rayburn to the speakership of the United States House of Representatives. It records his triumphs, his shortcomings, the concessions he made, and the people he served in order to achieve his life's ambition. The scope of this study ranges from Rayburn's first expression of interest in the speakership to his elevation to that position in 1940. Brief coverage is given to his three terms in the Texas Legislature, beginning in 1906, and his election to Congress in 1912. A more extensive analysis is made of his early congressional association with John Nance Garner and its pivotal influence on his career. A brief analysis is offered of Rayburn's political and legislative activities prior to the election of 1932. The primary emphasis of this study, however, revolves around Rayburn's activities during the years 1932-1940-- the first two terms of President Franklin D. Roosevelt, and the period in which Sam Rayburn completed his methodical odyssey to the speakership.
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Arbetsmiljö : En fallstudie med servicekontoret Borås / Working environmentAndersson, Tobias, Kolivand, Maryam January 2020 (has links)
Byggbranschen står inför en utmanande situation där efterfrågan är stor, men tillgång till resurser är begränsad, många utländska yrkesarbetare och företag är verksamma i Sverige och det har skett en stor nyrekrytering av inte minst byggtjänstemän, tidplaner är snäva, och det finns riskarbetsmiljön i projekt kan bli lidande. Det är därför extra viktigt att det görs genomarbetade riskbedömningar och att dessa följs upp och revideras fortlöpande under hela projekttiden. Analyser i projekten görs regelbundet för att förbättra och uppdatera AMP/ arbetsmiljön. Detta för att förebygga och undvika risker. AMP ska uppdateras och följas upp regelbundet under hela projektet. Risker som redan finns kan minimeras eller helt försvinna, nya risker uppstår fortlöpande som måste hanteras-förebyggas. Även om byggbranschen har uppnått en säkrare arbetsmiljö under åren så förekommer det alltid risker. Genom att ha tydliga roller och riktlinjer inom företagen blir det lättare att jobba för en bättre arbetsmiljö. Denna rapport är grundad på en kvalitativ studie där tre arbetstagare har gett oss en inblick kring arbetsmiljön i ett specifikt projekt. Rapportens syfte har varit att undersöka arbetsmiljöproblem och följa upp riskhanteringen under projektets gång för att sedan finna vad som kan vara orsaken till arbetsmiljöproblemen men också hur de kan elimineras. Rapporten kommer också bestå av information hur kommunikation, attityd, planering, kontroller och mänskliga faktorers samspel, men även väderförhållanden kan påverka arbetsmiljöproblem på arbetsplatsen. Genom semistrukturerade intervjuer har det bekräftats att riskbedömningar är viktiga att utföra i det dagliga arbetet i anläggningsbranschen. Varje moment i projektet innebär en risk som behövs åtgärdas. Under intervjuerna har det bekräftats att riskanalyser utförs under projektets gång och detta görs på grund av att nya risker ständigt uppkommer. Slutsatsen av denna studie är att Servicekontoret har en god arbetsmiljö, men det finns plats till förbättringar. Risker är något som arbetstagarna utsätts för var dag och för att förebygga dom bör de jobbas med i ett tidigt skede för en bättre arbetsmiljö. Genom att aktivt arbeta med att förebygga dessa risker kommer det leda till en bättre arbetsmiljö men också en effektivare produktion. / The building industry is facing a great deal of pressure as demand is high and the resources at their disposal are far too small. This contributes to time-schedules being pushed down which in turn leads to the safety of the project suffering. Companies usually aim to finish their projects in as short a time span as possible, thereby losing focus of safety and risks. Analyzes of the projects are being done regularly to improve the working environment. This is being done to not negatively affect the job, but also to avoid risks. The work will then be updated and followed up regularly throughout the project. Risks that already exist can be reduced or completely disappear while new ones can be reduced quickly. Even though the construction industry has achieved a safer working environment over the years, there are always risks. By having clear rules and guidelines within the companies, it will be easier to reach a better work environment. This report is based on a qualitative study in which there have been three employees who have given us an insight into the working environment of a specific project. The purpose of the report has been to investigate the work environment issues and follow up the risk management during the project, to find out not only what could be the cause of these issues, but also how they can be eliminated. The report will also consist of information on how communication, attitude, planning, controls, human factors and also how weather conditions can affect work environment issues inthe workplace. Through semi-structured interviews, it has been confirmed that risk assessment is an important part of the daily work in the construction industry. Every step in the project is a risk that needs to be evaluated. During the interviews it has been confirmed that risk observations are carried out during the course of the project and this is done due to a lack of time. Based on the information we have gathered through these interviews, there seems to be a relatively good working environment at Servicekontoret, but there is still room for improvement. Communication and collaboration are two important factors that need to be worked on more diligently and discussed more often. A suggestion for Servicekontoret is to frequently work towards reducing these risks by carefully reviewing them before the start of the project, at the place where the project will be held.
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Formation électro-assistée de monocouches auto-assemblées sur or. Suivi in situ et effets du potentiel appliqué à l'électrode sur le mécanisme de formation / Electro-assisted formation of self-assembled monolayers on gold. In situ study and effects of the applied potential on the mechanism of formation.Capitao, Dany 10 October 2016 (has links)
Créer des surfaces spécifiques apparaît comme un enjeu majeur de la chimie actuelle. La formation de monocouches auto-assemblées (SAMs) à partir de dérivés soufrés est l’une des stratégies pour modifier des surfaces d’or. A ce jour, le mécanisme de formation des SAMs sur or n’est toujours pas élucidé.Une nouvelle approche de formation de SAMs par voie électrochimique a récemment été développée, avec la possibilité de suivre in-situ en temps réel la chimisorption de dérivés soufrés, notamment avec un cycle dithiolane. Contrairement aux méthodes standards d’adsorption par simple immersion, cette approche par polarisation de l’électrode tend à faciliter la chimisorption (cinétique, reproductibilité …). L’excellente résolution temporelle du suivi cinétique conjuguée à une bonne reproductibilité met en évidence un mécanisme d’adsorption via un phénomène de nucléation-croissance. Déjà identifié pour la formation de SAMs en phase gazeuse, il n’a jamais été clairement établi en phase liquide. L’utilisation de cette méthode a également permis l'élaboration de monocouches mixtes binaires de manière contrôlée et prédictible. En se basant sur les constantes d’affinité, nous avons pu réaliser des SAMs dont les proportions en surface reflétaient celles en solution. Ce résultat majeur laisse entrevoir des applications en particulier pour l’étude de systèmes enzymatiques sur surface.Enfin, afin de mieux cerner les facteurs clés régissant le mécanisme de formation, une étude systématique en fonction de la nature du groupe d’ancrage a permis de souligner le rôle crucial de celui-ci concernant aussi bien la cinétique d’adsorption que la stabilité de la monocouche. / Create specific surfaces appears as a major issue in chemistry. The formation of self-assembled monolayers (SAMs) using sulfur derivatives is one of the most commonly used strategy to modify gold surfaces. Nowadays, the formation mechanism of self-assembled monolayers (SAMs) on gold is still investigated.A new electrochemical approach for SAMs formation has recently been developed allowing an in situ and real time monitoring of the chemisorption of various sulfur compounds including dithiolane derivatives. Unlike standard adsorption methods which consist in a simple immersion, this approach tends to facilitate the chemisorption by polarizing the electrode. The high temporal resolution coupled to this good reproducibility highlight an adsorption mechanism which proceeds by a nucleation-growth process. This type of mechanism, already identified for the SAMs formation in the gas phase, has never been reported in the liquid phase.In addition, this method allows the preparation of binary mixed monolayers in a controlled and predictable manner. Knowing the affinity constants, it is possible to produce SAMs whose surface proportions reflect those in solution.Finally, to better understand the key factors governing the SAMs formation mechanism, a systematic study depending on the nature of the anchoring group has highlighted a significant difference between the different anchoring groups for the kinetics as well as for the stability of the monolayer.
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Interfacial Electron Transfer in p-Type Dye-Sensitized Nickel Oxide and Machine Learning for Energy MaterialsYu, Yongze, Yu January 2019 (has links)
No description available.
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