To be able to protect an organisation's resources, it is important to understand what there is to protect and what to protect it from. The first step is to try to analyse the security threats that exist against an organisation's resources to explore the risks. Threats have to be identified, for the organisation to protect its resources and find where the optimal placement against threats is. This thesis analysis whether it is possible to obtain a Threat Tree Analysis that is useful for developing an information security policy for the municipality in Ronneby, using the SS 62 77 99-1 standard. A co-operation between the technical solutions and the administrative security is necessary to achieve information security, together with ordinary common sense. True, each of these can help improve security, but none of them is a complete solution. Security is not a product - it is a process. Threat trees form the basis of understanding that process. In this thesis, we have been using a qualitative method. The analysis method is a case study at the Social Department, at the municipality in Ronneby. Through interviews it has come us to hand, that the organisation has not established an information security policy which should give the code of practice for how the work of information security will pursue within the organisation. The organisation does neither use a model for structuring threats nor a method for collecting threats against information today. Through the structure of possible threats, the personnel generates an understanding of the organisation and takes active part finding adequate threats within the Social Department. As users understand the importance of security, how to use it, and where to report suspected violations, they can do a great deal to reduce the risk to loose information. Important to remember is that the education is an ongoing process, new users need training and trained users need reminding, especially when new technologies or processes are introduced. Thus, Threat Tree Analysis is useful for continuing towards developing an information security policy according to SS 62 77 99-1 standard. / För att kunna skydda en organisations resurser är det viktigt att förstå vad organisationen behöver skydda och vad den ska skydda det ifrån. Det första steget är att analysera hot mot organisationens resurser för att uppskatta riskerna. Hot måste identifieras för att organisationen ska kunna skydda sina resurser och hitta den optimala placeringen av åtgärder mot hot. Denna uppsatsen undersöker om det är möjligt att skapa en hotträdsanalys som är användbar för skapandet av en informationssäkerhetspolicy för Ronneby kommun, genom att använda standarden SS 62 77 99-1. Vi betonar i uppsatsen att ett samarbete mellan existerande tekniska lösningar och administrativ säkerhet är nödvändigt för att uppnå informationssäkerhet. Visst kan var och en av dessa hjälpa till att förbättra säkerheten, men ingen av dem är ensam den kompletta lösningen. Säkerhet är inte en produkt - det är en process. Hotträd formar grunden för en förståelse av den processen. I denna uppsats har vi använt en kvalitativ metod. Analysmetoden är en fallstudie på Socialförvaltningen i Ronneby kommun. Genom intervjuer har vi fått fram att organisationen inte har etablerat en informationssäkerhetspolicy, vilken ska ge riktlinjer för hur säkerhetsarbetet ska fullföljas inom organisationen. Organisationen använder varken en modell för att identifiera hot mot information eller en metod för att strukturera hoten. Genom strukturen av möjliga hot, genererar personalen en förståelse för organisationen och tar aktivt del i att identifiera hot mot Socialförvaltningen. Detta medför att alla användare förstår hur viktigt det är med säkerhet, vart de ska rapportera misstänkta händelser och de kan göra mycket för att minska risken att förlora information. Det är viktigt att komma ihåg att utbildning är en pågående process, nya användare behöver utbildning och utbildade användare behöver vidareutbildning, speciellt när nya tekniker eller processer introduceras. Därför är hotträdsanalysen en användbar modell för arbetet mot att skapa en informationssäkerhetspolicy enligt standarden SS 62 77 99-1. / Sandra Olandersson Blåbärsvägen 27 372 38 RONNEBY 0457 / 12084 Jeanette Fredsson Villa Viola 372 36 RONNEBY 0457 / 26616

Component failures can result in catastrophic behaviors in safety critical embedded systems, sometimes resulting in loss of life. Component failures can be treated as off nominal behaviors (ONBs) with respect to the components and sub systems involved in an embedded system. A lot of research is being carried out to tackle the problem of ONBs. These approaches are mainly focused on the states (i.e., desired and undesired states of a system at a given point of time to detect ONBs). In this paper, an approach is discussed to detect component failures and critical components of an embedded system. The approach is based on fault tree analysis (FTA), applied to the requirements specification of embedded systems at design time to find out the relationship between individual component failures and overall system failure. FTA helps in determining both qualitative and quantitative relationship between component failures and system failure. Analyzing the system at design time helps in detecting component failures and critical components and helps in devising strategies to mitigate component failures at design time and improve overall safety and reliability of a system.

Yes / Dynamic systems exhibit time-dependent behaviours and complex functional dependencies amongst their components. Therefore, to capture the full system failure behaviour, it is not enough to simply determine the consequences of different combinations of failure events: it is also necessary to understand the order in which they fail. Pandora temporal fault trees (TFTs) increase the expressive power of fault trees and allow modelling of sequence-dependent failure behaviour of systems. However, like classical fault tree analysis, TFT analysis requires a lot of manual effort, which makes it time consuming and expensive. This in turn makes it less viable for use in modern, iterated system design processes, which requires a quicker turnaround and consistency across evolutions. In this paper, we propose for a model-based analysis of temporal fault trees via HiP-HOPS, which is a state-of-the-art model-based dependability analysis method supported by tools that largely automate analysis and optimisation of systems. The proposal extends HiP-HOPS with Pandora, Petri Nets and Bayesian Networks and results to dynamic dependability analysis that is more readily integrated into modern design processes. The effectiveness is demonstrated via application to an aircraft fuel distribution system. / Partly funded by the DEIS H2020 project (Grant Agreement 732242).

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No description available.

Quick clay slides are quite rare but often leads to major consequences for the society. These type of slides are complex and the true causes leading to a slide is difficult to map since the evidence is destroyed during the slide. Because of this, different theories develop of the causes of the slide based on the same information. It is also problematic to back-calculate the sliding event because the commonly applied concept of perfectly plastic limite quilibrium cannot be applied on many of the landslides in quick clay. The objectives of this thesis were to construct a fault tree that facilitate risk identification and risk analysis of quick clay slides and to evaluate the applicability of the constructed fault tree, especially in the feasibility study and design phase. Uncertainties within the subject require a careful approach when dealing with quick clay. An implementation of a fault tree for quick clay slides in a risk management could reduce the risk of a slide and better understand the phenomenon. Two case studies were approached with the created fault tree and two advanced calculation methods that account for the special behaviour of quickclay. The use of a qualitative fault tree analysis in combination with calculation methods enables an evaluation of isolated singular events that in the end can lead to a quick clay slide. With the possibility to study isolated events, the implementation of more advanced calculation methods may be facilitated in an early stage to predict and prevent quick clay slides. / Kvicklerskred är sällsynta men leder ofta till stor skada för samhället. Dessa skred är komplexa och orsaken till utlösandet av skredet är svårt att identifiera då bevisen förstörs under händelseförloppet. Detta leder till att olika teorier om orsaken av kvicklerskred kan variera från samma information. Det är också svårt att beräkna skredets omlopp i efterhand den vanliga beräkningsmetoden baseras på idealplastiska samband, något som inte går att applicera på kvicklera. Målet med denna studie var att konstruera ett felträd som underlättar riskidentifiering och riskanalyser av kvicklerskred. Målet var även att utvärdera användandet av felträdet i en byggnadsprocess, framförallt under förstudien och under projekteringsskedet. Osäkerheter inom området kräver en försiktig arbetsmetod när kvicklera finns i områden. Att använda sig av ett felträd för kvicklerskred i en riskhantering skulle kunna minska risken för ett skred och samtidigt öka systemförståelsen över fenomenet. Två fallstudier gjordes med det konstruerade felträdet, under dessa fältstudier gjordes även beräkningar med två avancerade beräkningsmetoder som tar hänsyn till det töjningsmjukande beteendet hos kvicklera. Användningav ett kvalitativt felträd i kombination med beräkningsmetoder möjligör en utvärdering av isolerade händelser som i slutändan kan leda till ett kvicklerskred. Möjligheten av att studera isolerade händelser kan underlätta en implementering av mer avancerade beräkningsmetoder i ett tidigt skede och på så vis förutse och förhindra kvicklerskred.

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No description available.

The dissertation thesis with the topic „Simulation Modelling of Electrical Drives for Selected Critical Applications“ focuses on the area of given applications in civil aviation. The selected application that the thesis deals with is an electrically driven and electronically controlled fuel pump supplying fuel to an aviation motor of the APU type. The thesis gives a comprehensive description of the design cycle of the unit and demonstrates implementing all the required critical functions. In the course of the design of the unit modern techniques in mathematical modelling, simulation, verification, monitoring and prediction of the operation status of airborne equipment were uses to the utmost extent. The purpose of these was to show the suitability of their application with regard to decreasing design time and cost, increasing lifetime and servicing intervals, as well as increasing user comfort and decreasing price. At the same time the required reliability was to be kept. The thesis also aims to prove and verify the suitability of using electronically commutated dc motors in critical applications in civil aviation. To reach this goal, it is necessary to design a robust drive control which would meet the given reliability requirements.

The dissertation thesis with the topic „Simulation Modelling of Electrical Drives for Selected Critical Applications“ focuses on the area of given applications in civil aviation. The selected application that the thesis deals with is an electrically driven and electronically controlled fuel pump supplying fuel to an aviation motor of the APU type. The thesis gives a comprehensive description of the design cycle of the unit and demonstrates implementing all the required critical functions. In the course of the design of the unit modern techniques in mathematical modelling, simulation, verification, monitoring and prediction of the operation status of airborne equipment were uses to the utmost extent. The purpose of these was to show the suitability of their application with regard to decreasing design time and cost, increasing lifetime and servicing intervals, as well as increasing user comfort and decreasing price. At the same time the required reliability was to be kept. The thesis also aims to prove and verify the suitability of using electronically commutated dc motors in critical applications in civil aviation. To reach this goal, it is necessary to design a robust drive control which would meet the given reliability requirements.