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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Seismic imaging of sandbox models.

Sherlock, Donald H. January 1999 (has links)
Analogue sandbox models are important in the study of reservoir geology because they can offer insight into geological processes that we are rarely able to observe in nature. Seismic physical modelling is used to study the effects of seismic wave propagation in isotropic and anisotropic media and is particularly suited to isolating the effects of a single parameter independently from all others in an infinitely complex geological system. Seismic physical modelling has also been used for the testing of numerical processing algorithms, aid to evaluate interpretations of field seismic sections with scaled representations of geological formations. For this project, I set about developing methods to combine these two independent modelling techniques for the first time. However, previous attempts to use sand as a seismic modelling material failed due mainly to problems with understanding and controlling the distribution of the grain packing.This research has addressed a number of these problems through systematic laboratory experimentation that has provided new insight into the factors that affect unconsolidated sediment acoustics. An innovative technique of recording seismic physical modelling surveys has been developed so that it is now possible to successfully record ultrasonic reflections within analogue sandbox models in three-dimensions (3-D), providing benefits for both analogue sandbox and seismic modelling disciplines. For sandbox modelling, the recording of seismic images allows more detailed analyses of the structures than previously possible. For seismic modelling, more geologically realistic settings can be modelled at a fraction of the cost and construction time of conventional models. However, the greatest benefit of this new technology is that it is now possible to build seismic physical models from porous media, rather than solid, non-porous materials that ++ / are conventionally used. This scientific advance allows different fluids to be incorporated into physical models for the first time.Time-lapse 3-D seismic is becoming increasingly important in the management of hydrocarbon production, yet there is a lack of model data to support some of the conclusions being deduced. The controlled physical modelling laboratory environment combined with the ability to consistently repeat the 3-D seismic survey process now allows time-lapse seismic experiments to be performed without the need for the costly and time consuming data processing that is necessary to match legacy 3-D field data. This subsequently avoids any pitfalls that may be associated with the process, such as the masking of true fluid flow anomalies or the generation of false anomalies from data acquisition footprints.A series of time-lapse models are presented where the three-dimensional movement of fluids through the models is remotely monitored using time-lapse 3-D seismic data. These models demonstrate the true seismic response that comes from recording real data from models that undergo real changes representative of reservoir environments. Such models are inexpensive and allow rapid data turn around in a matter of days. The techniques developed here provide a new research tool that can be used to improve our understanding of the dynamics of fluid flow within porous sediments, or to study the seismic response of reservoirs as they change with time.
2

Regulační sandbox - mezinárodní zkušenosti / Regulatory Sandbox - International Experience

Černecka, Anastasija January 2021 (has links)
The regulatory sandbox is a special regime provided by regulators and super- visory authorities to market participants for testing their innovative business models, while temporarily reducing certain regulatory requirements. It is a very recent topic and so far its impact has not been sufficiently empirically tested. However, the empirical evidence may be crucial for the authorities hesitating to adopt their regulatory sandboxes. The main contribution of this thesis is the empirical testing of the effect of the sandbox on the investments into FinTech in three European countries, using the Synthetic control method. The yearly aggregate amounts and numbers of FinTech investments were selected as mea- surable indices of the FinTech sector development. The most significant results show that in the United Kingdom, the aggregate yearly amounts invested into FinTech grew considerably compared to the values of the synthetic control unit, after the sandbox introduction. For the other two tested countries (the Nether- lands, Denmark), no significant outcomes were observed due to insufficiency of data. In the theoretical part, this thesis gathers information about the existing regulatory sandboxes in European countries. Also, the author seeks to outline the main legal issues related to the regulatory sandbox...
3

Vylepšený sandboxing pro pokročilé kmeny malwaru / Enhanced Sandboxing for Advanced Malware Families

Sidor, Samuel January 2021 (has links)
This Master’s thesis describes reverse engineering with focus on malware analysis. Reader will be informed about theoretical description of static and dynamic analysis. These techniques are later used on analysis of 5 malware families with focus on detection of used anti-sandbox techniques. After that new theoretical improvements are proposed with detection of anti-sandbox techniques or fully avoiding such anti-sandbox evasion techniques. Finally these changes are implemented on main sandbox of Avast Software from which reader can see how effective these improvements are.
4

Dynamic Behavioral Analysis of Malicious Software with Norman Sandbox

Shoemake, Danielle 05 August 2010 (has links)
Current signature-based Anti-Virus (AV) detection approaches take, on average, two weeks from discovery to definition update release to AV users. In addition, these signatures get stale quickly: AV products miss between 25%-80% of new malicious software within a week of not updating. This thesis researches and develops a detection/classification mechanism for malicious software through statistical analysis of dynamic malware behavior. Several characteristics for each behavior type were stored and analyzed such as function DLL names, function parameters, exception thread ids, exception opcodes, pages accessed during faults, port numbers, connection types, and IP addresses. Behavioral data was collected via Norman Sandbox for storage and analysis. We proposed to find which statistical measures and metrics can be collected for use in the detection and classification of malware. We conclude that our logging and cataloging procedure is a potentially viable method in creating behavior-based malicious software detection and classification mechanisms.
5

Identifiering och analys av botnät med hjälp av aktiva säkerhetssystem / Identification and analysis of botnets with the help of active security systems

Mynarski, Pawel, Carlsson, Oscar January 2012 (has links)
Botnät är idag ett växande hot mot IT-säkerhet. Myndigheter, företag och stora organisationer utsätts dagligen för olika typer av attacker orsakade av botnät och rapporter i media redogör för endast en bråkdel av incidenter som inträffar på Internet. Säkerhetsföretag uppskattar att miljoner av datorer ingår idag i ett eller flera botnät. Bekämpningen av botnät är en komplicerad uppgift på grund av botnätens omfattning och komplexitet. Första steget i processen är identifiering och analys av sådana nätverk. I detta syfte har olika system skapats och s.k. \emph{honeypot}-system är några av dem. \emph{Honeypots} simulerar sårbarheter i nätverkstjänster och samlar in information om intrångsförsök utförda mot dessa tjänster. Honeypot-system har visat sig vara effektiva verktyg särskilt när det gäller detektering av attacker och insamling av data. Sådana lösningar har stor potential och kan utvecklas till att bli ännu mer produktiva genom att tillsammans med externa säkerhetstjänster utföra aktiva analyser av insamlad data om botnätsanslutna enheter. Det här arbetet fokuserar just på tjänster och system som kan användas för att identifiera och analysera botnät för att ta reda på vilken data är möjlig att samla in. På en relativt kort tid lyckades vi registrera över 1 miljon anslutningar från 6757 unika IP-adresser till vår honeypot och på så sätt har vi visat att även med små resurser och enbart fritt tillgänglig programvara och webbtjänster kan man identifiera och kartlägga botnät. Conficker har visat sig vara det mest dominanta botnätet och informationen som vi har lyckats samla in var i hög grad relaterad till attackerna från det botnätverket. Detta resulterade i att nästan all insamlad data var ganska ensidig då en viss typ av malware, vissa nätverkstjänster och några specifika länder var gravt överrepresenterade.
6

The sandbox line

Lacy, Stephen W. January 1997 (has links)
This Creative Project documents and explains the significance of the exhibition space known as the Sandbox and its members. The goal was to bring together a cohesive body of work that commemorated the people and events related to the Sandbox gallery. This was accomplished by using a variety of materials and tools including video tape, slides, bronze, paint, silk-screens, and super 8 film, to name a few. / Department of Art
7

Förskolebarns aktiviteter i sandlådan : En kvalitativ studie om barns meningsskapande i sandlådan ur ett naturvetenskapligt perspektiv / Preschool children´s activities in sandbox : A qualitative study of children´s meaning-making in the sandbox from a natual science perspective

Sand, Jörel, Jebens, Helena January 2014 (has links)
Sammanfattning   Arbetets art: Examensarbete i Lärarutbildningen, avancerad nivå, 15hp. Högskolan i Skövde.   Titel: Förskolebarns aktiviteter i sandlådan. En kvalitativ studie om barns meningsskapande i sandlådan ur ett naturvetenskapligt perspektiv.   Sidantal: 27   Författare: Helena Jebens och Jörel Sandh.   Handledare: Susanne Gustavsson.   Datum: januari 2014   Nyckelord: Meningsskapande, förskola, sandlåda, naturvetenskap.   Studien belyser barns möjligheter till naturvetenskapligt meningsskapande i sandlådan. Som pedagoger i förskolans verksamhet har vi dagligen sett barn aktivera sig i sandlådan, men inte reflekterat över vilket naturvetenskapligt meningsskapande som möjliggörs där. Vi har även i vår verksamhet uppmärksammat genom samtal med andra pedagoger att naturvetenskap upplevs som svårt och krångligt. Studiens syfte är att undersöka vilket naturvetenskapligt meningsskapande som möjliggörs i sandlådan. I bakgrunden presenteras forskning om naturvetenskap i förskolan och teorin utgår från det sociokulturella perspektivet. Insamlandet av data har skett genom videofilmning som består av sammanlagt 28 filmsekvenser.  Materialet har analyserats och bearbetats med hjälp av Susanne Klaars reflektionsverktyg. Studiens resultat visar att barns handlingar i sandlådan kan möjliggöra ett naturvetenskapligt meningsskapande. Pedagoger har enligt studiens resultat rika tillfällen att påverka och utveckla barns meningsskapande och utveckla intresset för naturvetenskap genom att tolka, bekräfta och sätta ord på de handlingar med naturvetenskaplig karaktär som sandlådan erbjuder. Barns naturliga intresse för naturvetenskap får med stöd av pedagogers guidning mot ett naturvetenskapligt meningsskapande, ökad möjlighet för lärande och förståelse genom de handlingar som sker. / Abstract   Study: Degree project in teacher education, advanced level 15hp. University of Skövde.   Title: Preschool children’s activities in the sandbox. A qualitative study of children’s meaning-making in the sandbox from a natural science perspective.   Pages: 27   Authors: Helena Jebens och Jörel Sandh.   Tutor: Susanne Gustavsson.   Date: January 2014   Keywords: Meaning- making, preschool, the sandbox, the natural sciences.   The study highlights the children's opportunities for scientific meaning-making in the sandbox. As teacher’s in the preschool's activities, we have seen children activate themselves on a daily basis in the sandbox, but not reflected of the natural sciences meaning-making that is possible there. We also have in our activities highlighted by talks with other teachers that natural science are perceived as difficult and complicated. The study's purpose is to investigate which natural sciences meaning-making is possible in the sandbox. In the background is presented research on natural science education in preschool and the theory is based on the socio-cultural perspective. The collection of data has been made by videotaping which consists of a total of 28 sequences. The material has been analyzed and processed with the help of Susanne Klaars reflection tool. Results of the study show that children's actions in the sandbox can allow a natural science meaning-making. Teachers, according to the results of the study, have rich opportunities to influence and develop children's meaning-making and developing interest in natural science by interpreting, confirming and put into words the acts of natural scientific character which the sandbox offers. Children's natural interest in natural science, with the support of teacher’s guidance toward a meaning making of natural science, increased opportunity for learning and understanding through the activities that is done.
8

Säkerhetsanalys av Android som plattform förföretagsapplikationer / A security analysis of Android as a platform for enterprise applications

Jinnegren, Per, Thorselius, Erik January 2011 (has links)
I rapporten undersöks säkerhetsaspekter för företagsapplikationer utvecklade till androidplattformen. Rapporten tar även upp Androids grunder och dess säkerhetsmodell. Syftet med rapporten var att undersöka Androids lämplighet för projekt som HOW Solutions har planerade. Under arbetet har en applikation för trådlös öppning av lås utvecklats. Resultatet var att många av de hot som upptäcktes var, för företag, i vissa fall är svåra att mitigera och att viss relevant funktionalitet saknas på plattformen. Trots det är slutsatsen att Android är en mogen plattform med ett gediget säkerhetsarbete och därför lämpar sig bra för företagsapplikationer.
9

CONTROLLED ENVIRONMENT TO RUN UNTRUSTED APPLICATIONS

Albalawi, Tahani F. 25 July 2013 (has links)
No description available.
10

[en] CONCURRENCY AND SANDBOXES MODELS APPLIED TO LUA HTTP SERVERS / [pt] MODELOS DE CONCORRÊNCIA E SANDBOXES APLICADOS A SERVIDORES HTTP EM LUA

LEONARDO GODINHO DA CUNHA 09 April 2007 (has links)
[pt] Os desenvolvedores de sistemas cliente-servidor constantemente se deparam com questões de desempenho e escalabilidade, muitas vezes o número de clientes simultâneos de um servidor pode crescer de forma significativa. Além disso, se esses sistemas podem executar códigos de terceiros, passa a existir a preocupação com a questão de segurança da execução destes trechos de códigos. O objetivo desse trabalho é testar o desempenho de diversas combinações de modelos de concorrência e sandboxes. Como exemplo de sistema sujeito a solicitações concorrentes que precisa permitir a execução de programas de terceiros, temos os servidores web. O Xavante é um servidor web desenvolvido na linguagem de programação Lua que originalmente utiliza um modelo de programação concorrente baseado em co-rotinas. Esse servidor já possuía a flexibilidade de mapear tipos de requisição a tratadores diferentes. Alguns desses tratadores de requisi ção permitem a utilização de código de terceiros em tempo de execução e, por isso, já fazem uso de sandboxes a fim de oferecer um ambiente de execução protegido. Nesse trabalho testamos o uso dessas sandboxes nativas ao Xavante além de outros tipos de sandboxes. Também aumentamos as possibilidades de extensão do servidor, flexibilizando a arquitetura de modo a permitir diferentes estratégias de concorrência. Utilizando a nova arquitetura testamos o desempenho das diversas combinações de sandboxes e modelos de programação concorrente, permitindo a comparação dos modelos não só do ponto de vista qualitativo mas também medindo o impacto de desempenho do seu uso. / [en] Client-server developers constantly have to deal with questions concerning performance and scalability, since the number of simultaneous clients can grow significantly. Moreover, if these systems can execute third-party code, there is also the concern of secure execution of these pieces of code. This work goal is to benchmark several combinations of concurrency and sandboxes models. As an example of a system exposed to several concurrent requests that must be able to execute third-party code, we have the web servers. Xavante is a web server developed in the Lua programming language that originally uses an concurrency programming model based on coroutines. This server offers the flexibility to map request types to different handlers. Some of these request handlers dynamically allow the use of third-party code, therefore they make use of sandboxes in order to offer a protected running environment. In this work we test the use of Xavante´s native sandboxes and other types of sandboxes.We also improve the extensibility of the server, using a different architecture in order to allow different concurrency strategies. Using the new architecture we tested the performance of several combinations of sandboxes and concurrency programming models, allowing the model comparison not only in a qualitative point of view but also measuring the related performance impacts.

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