Modern-day terrorist attacks present a considerable danger for commercial aircrafts. This thesis analyzes potential methods of such attacks with a critical analysis of the most dangerous type: an attack from the outside of the aircraft via a fragmentation missile warhead. Such missiles cause damage to the airframe of the aircraft through fragments created by the explosion. In this thesis, analytical geometry is used to determine the area of the aircraft affected by the fragmentation. The aircraft’s geometry and the fragments’ dispersion are calculated by analytical functions, and the effect of the damage is analyzed. A shooting experiment was also carried out, in which fragments were shot at a reinforced skin panel that was manufactured according to the real design of commercial aircraft. The results of the experiment revealed that only directly hit sections of the structure are damaged. Data obtained by the experiment was then used for the creation and improvement of the model used in the simulation by means of the finite element method. This model is used for the numerical calculation of the damage sustained. Further included in the thesis is an analysis of the change in the load-bearing capacity after such an attack. The relationship between the size of the damage and its effect on the load-bearing capacity of the component as well as the entire structure is defined. First, the effect of component damage is analyzed via the FMEA/FMECA methods. This analysis is then extended using fuzzy logic. Fuzzy logic analysis is based on the determination of the size of the damaged component area and the component’s importance on the structure’s carry loads. Application of the defined approach is described for several parts of an aircraft’s life cycle, including development, operation after the terrorist attack, and assessment of causes after a crash caused by a fragmentation missile warhead.

This report is a technical verification and validation of ADS-B (Automatic Dependent Surveillance – Broadcast) over VDL Mode 4 (Very High Frequency Data Link Mode 4) for the use in the surveillance element of an A-SMGCS (Advanced Surface Movement Guidance and Control System). The main objective of this report is to examine if ADS-B/VDL Mode 4 fulfils the technical requirements for an implementation at Arlanda airport, Stockholm Sweden. The report also includes a FMECA (Failure Mode, Effects and Criticality Analysis), a theoretical background and methods for monitoring. The process of making this report can be divided into three phases: 1. Preliminary Study. In this phase the requirements were examined and structured. 2. Verification. In this phase the system performance has been verified both theoretically and by several tests at Arlanda Airport. Simulation results have also been used. 3. Validation and documentation. The tests and verifications that were performed in phase 2 were validated in the third phase of the project. The final project document was also written in this phase. The main conclusion from this analysis is that ADS-B/VDL Mode 4 is well suited for surveillance. ADS-B/VDL Mode 4 has the possibility to fulfil all considered requirements, apart from detecting all obstacles. But if all the requirements are going to be fulfilled depends both on the implementation and the operational environment. The results from this verification and validation should be used as the technical subset in a future safety case, both in Sweden and internationally.

<p>This report is a technical verification and validation of ADS-B (Automatic Dependent Surveillance – Broadcast) over VDL Mode 4 (Very High Frequency Data Link Mode 4) for the use in the surveillance element of an A-SMGCS (Advanced Surface Movement Guidance and Control System). </p><p>The main objective of this report is to examine if ADS-B/VDL Mode 4 fulfils the technical requirements for an implementation at Arlanda airport, Stockholm Sweden. The report also includes a FMECA (Failure Mode, Effects and Criticality Analysis), a theoretical background and methods for monitoring. </p><p>The process of making this report can be divided into three phases: </p><p>1. Preliminary Study. In this phase the requirements were examined and structured. </p><p>2. Verification. In this phase the system performance has been verified both theoretically and by several tests at Arlanda Airport. Simulation results have also been used. </p><p>3. Validation and documentation. The tests and verifications that were performed in phase 2 were validated in the third phase of the project. The final project document was also written in this phase. </p><p>The main conclusion from this analysis is that ADS-B/VDL Mode 4 is well suited for surveillance. ADS-B/VDL Mode 4 has the possibility to fulfil all considered requirements, apart from detecting all obstacles. But if all the requirements are going to be fulfilled depends both on the implementation and the operational environment. </p><p>The results from this verification and validation should be used as the technical subset in a future safety case, both in Sweden and internationally.</p>

Le progrès constant des technologies électroniques, la courte durée de vie commerciale des produits, et la diversité croissante de la demande client font de l’industrie du semi-conducteur un environnement de production contraint par le changement continu des mix produits et des technologies. Dans un tel environnement, le succès dépend de la capacité à concevoir et à industrialiser de nouveaux produits rapidement tout en gardant un bon niveau de critères de coût, rendement et temps de cycle. Une haute disponibilité des capacités de production est assurée par des politiques de maintenance appropriées en termes de diagnostic, de supervision, de planification et des protocoles opératoires. Au démarrage de cette étude, l’approche AMDEC (analyse des modes de défaillance, leurs effets et de leur criticité) était seule mobilisée pour héberger les connaissances et le savoir-faire des experts. Néanmoins, la nature évolutive du contexte industriel requiert la mise à jour à des fréquences appropriées de ces connaissances pour adapter les procédures opérationnelles aux changements de comportements des équipements et des procédés. Cette thèse entend montrer que la mise à jour des connaissances peut être organisée en mettant en place une méthodologie opérationnelle basée sur les réseaux bayésiens et la méthode AMDEC. Dans cette approche, les connaissances et les savoir-faire existants sont tout d’abord capitalisés en termes des liens de cause à effet à l’aide de la méthode d’AMDEC pour prioriser les actions de maintenance et prévenir leurs conséquences sur l’équipement, le produit et la sécurité des personnels. Ces connaissances et savoir-faire sont ensuite utilisés pour concevoir des procédures opérationnelles standardisées permettant le partage des savoirs et savoir-faire des experts. Les liens causaux stockés dans l’AMDEC sont modélisés dans un réseau bayésien opérationnel (O-BN), afin de permettre l’évaluation d’efficacité des actions de maintenance et, par là même, la pertinence des connaissances existantes capitalisées. Dans un contexte incertain et très variable, l’exécution appropriée des procédures est mesurée à l’aide des indicateurs standards de performance de maintenance (MPM) et la précision des connaissances existantes en évaluant la précision de l’O-BN. Toute dérive de ces critères conduit à l'apprentissage d'un nouveau réseau bayésien non-supervisé (U-BN) pour découvrir de nouvelles relations causales à partir de données historiques. La différence structurelle entre O-BN et U-BN met en évidence de nouvelles connaissances potentielles qui sont validées par les experts afin de modifier l’AMDEC existante ainsi que les procédures de maintenance associées. La méthodologie proposée a été testée dans un des ateliers de production contraint par un haut mix de produits pour démontrer sa capacité à renouveler dynamiquement les connaissances d’experts et d'améliorer l'efficacité des actions de maintenance. Cette expérimentation a conduit à une diminution de 30% des reprises d’opérations de maintenance attestant une meilleure qualité des connaissances modélisées dans les outils fournis par cette thèse. / The constant progress in electronic technology, the short commercial life of products, and the increasing diversity of customer demand are making the semiconductor industry a production environment constrained by the continuous change of product mix and technologies. In such environment, success depends on the ability to develop and industrialize new products in required competitive time while keeping a good level of cost, yield and cycle time criteria. These criteria can be ensured by high and sustainable availability of production capacity which needs appropriate maintenance policies in terms of diagnosis, supervision, planning and operating protocols. At the start of this study, the FMEA approach (analysis of failure modes, effects and criticality) was only mobilized to capitalize the expert’s knowledge for maintenance policies management. However, the evolving nature of the industrial context requires knowledge updating at appropriate frequencies in order to adapt the operational procedures to equipment and processes behavior changes.This thesis aims to show that the knowledge update can be organized by setting up an operational methodology combine both Bayesian networks and FMEA method. In this approach, existing knowledge and know-how skills are initially capitalized in terms of cause to effect links using the FMEA method in order to prioritize maintenance actions and prevent their consequences on the equipment, the product quality and personal safety. This knowledge and expertise are then used to develop unified operating procedures for expert’s knowledge and know-how sharing. The causal links stored in the FMEA are modeled in an operational Bayesian network (BN-O), in order to enable the assessment of maintenance actions effectiveness and, hence, the relevance of existing capitalized knowledge. In an uncertain and highly variable environment, the proper execution of procedures is measured using standards maintenance performance measurement indicators (MPM). Otherwise, the accuracy of existing knowledge can be assessed as a function of the O-BN model accuracy. Any drift of these criteria leads to learning a new unsupervised Bayesian network (U-BN) to discover new causal relations from historical data. The structural difference between O-BN (built using experts judgments) and U-BN (learned from data) highlights potential new knowledge that need to be analyzed and validated by experts to modify the existing FMEA and update associated maintenance procedures.The proposed methodology has been tested in a production workshop constrained by high product mix to demonstrate its ability to dynamically renew expert knowledge and improve the efficiency of maintenance actions. This experiment led to 30% decrease in failure occurrence due to inappropriate maintenance actions. This is certifying a better quality of knowledge modeled in the tools provided by this thesis.

Modern-day terrorist attacks present a considerable danger for commercial aircrafts. This thesis analyzes potential methods of such attacks with a critical analysis of the most dangerous type: an attack from the outside of the aircraft via a fragmentation missile warhead. Such missiles cause damage to the airframe of the aircraft through fragments created by the explosion. In this thesis, analytical geometry is used to determine the area of the aircraft affected by the fragmentation. The aircraft’s geometry and the fragments’ dispersion are calculated by analytical functions, and the effect of the damage is analyzed. A shooting experiment was also carried out, in which fragments were shot at a reinforced skin panel that was manufactured according to the real design of commercial aircraft. The results of the experiment revealed that only directly hit sections of the structure are damaged. Data obtained by the experiment was then used for the creation and improvement of the model used in the simulation by means of the finite element method. This model is used for the numerical calculation of the damage sustained. Further included in the thesis is an analysis of the change in the load-bearing capacity after such an attack. The relationship between the size of the damage and its effect on the load-bearing capacity of the component as well as the entire structure is defined. First, the effect of component damage is analyzed via the FMEA/FMECA methods. This analysis is then extended using fuzzy logic. Fuzzy logic analysis is based on the determination of the size of the damaged component area and the component’s importance on the structure’s carry loads. Application of the defined approach is described for several parts of an aircraft’s life cycle, including development, operation after the terrorist attack, and assessment of causes after a crash caused by a fragmentation missile warhead.

This master thesis examines the functional safety of the pressure sensor XMP i which is produced by BD SENSORS Company. The aim of this thesis is the demonstration of compliance of the pressure sensor XMP I with functional safety integrity level SIL3 requirements. The thesis is divided into three parts. The first part deals with the concept of functional safety, defines the basic concepts of functional safety, compares the approaches of functional safety according to selected standards and provides a general procedure for the functional safety determination. The second part deal with technical systems reliability defines reliability indicators and describes selected types of reliability analysis used in practice, especially the FMEA/FMECA analysis. Third part deals with the reliability analysis of the sensor XMP i and with evaluation of results.

This diploma thesis concerns issues of predictive and condition based maintenance system of machine tools with using a vibrodiagnostics. It studies and researches its impacts through the basic processes of the maintenance system and characterizes the vibration diagnosis as its tool and mean. There is also described a process of putting condition based maintenance into practice in the practical part of the thesis. The development is realized at Siemens Ltd. Brno with all its requirements and aspects such as a maintenance audit which means the decision on the suitability of condition based maintenance within the current maintenance system, technical analysis as a part of introduction of vibration diagnosis and the practical example of acquiring, recording and assessment of measured vibration. Prior to the end the economic evaluation of the planned predictive maintenance system and the design of the general model of development and implementation of the maintenance system into practice are included.

Master´s thesis deals about problematic of fuzzy logic, fuzzy sets and operation with them. Also thesis describing procedure of quantification risks through fuzzy sets, process of fuzzyfication, defuzzyfication a theirs application in the expert systems FMEA and FMECA. Using selected chapters of czech states standards are established critical areas in building process, it is a chapters about quality, safety and environment. With these areas by using fuzzy sets theory are created the procentual input values in the decision program, created by Matlab. Output from program is decision how big the risk rate is and if is necessarily make corrective measures. A concrete example is the production of concrete goods, describing production process and composition of fresh concrete. A practical example, created by using information from real company, is a decision about the risk rate in the qualitative area.

L’amélioration des systèmes électroniques pour le déploiement de l'avion tout électrique dépend de la capacité des composants passifs, tels que les condensateurs, à réduire leur volume, leur masse et leur coût, et augmenter leurs performances et leur fiabilité, particulièrement dans l’environnement aéronautique. Dans ce contexte, cette thèse a eu pour objectif l’étude et le développement de nouvelles technologies de condensateurs pour des applications avioniques. Dans la première partie des travaux, nous abordons l’évaluation de condensateurs céramique de puissance. La technologie céramique constitue, en effet, l’une des rares solutions matures capables de répondre aux exigences des équipementiers. La caractérisation, l’analyse des mécanismes de défaillance, de leurs effets et de leur criticité (AMDEC) ainsi que l’étude de fiabilité et de robustesse de composants commerciaux présentant des architectures originales (condensateurs multi-chips) ont été réalisées. Ces résultats ont été complétés par une étude plus amont sur la caractérisation de céramiques frittées par frittage flash (SPS). Les permittivités colossales de ces matériaux permettraient d’accroitre la fiabilité et la miniaturisation des condensateurs tout en conservant de fortes valeurs de capacité et de tension nominale. La seconde partie, plus fondamentale, a été consacrée au développement de nanoparticules céramique/polymère coeur-écorce pour des applications de condensateurs enterrés, opérant aux radiofréquences. La synthèse et les caractérisations physico-chimiques des nanocomposites ainsi que les procédés de fabrication de condensateurs en couches épaisses sont, en premier lieu, décrits. Une méthode de caractérisation électrique large bande a été mise au point pour permettre l’analyse des propriétés diélectriques et des mécanismes de conduction des nanoparticules. Les performances des dispositifs ont été recherchées en fonction de la température et des procédés de mise en forme. En outre, la durabilité en température de ces derniers a été évaluée. / The improvement of electronic systems for the deployment of all-electric aircrafts depends on the ability of passive components, such as capacitors, to reduce their volume, weight and cost, and to increase their performance and reliability, particularly in the aeronautical environment. In this context, the objective of this thesis was to study and develop novel capacitor technologies for avionics. In the first part of this work, the evaluation of power ceramic capacitors has been discussed. Indeed, the ceramic technology appeared to be one of the few mature solutions meeting the requirements of OEMs. The characterization, the failure mode, effects and criticality analysis (FMECA) and reliability and robustness assessment of commercial components using original architectures (multi-chip capacitors) have been performed. These results have been completed by a more advanced study on the characterization of new ceramics sintered by spark plasma sintering (SPS). The colossal permittivity of these materials could allow to increase reliability and miniaturization of capacitors while maintaining high values of capacitance and voltage rating. The second part, more fundamental, is devoted to the development of core-shell ceramic/polymer nanoparticles for embedded capacitors operating at radiofrequencies. The synthesis and the physicochemical characterization of the nanocomposites as well as the manufacturing processes of the thick film capacitors are first described. A new broadband electrical characterization methodology has been developed to analyze the dielectric properties and the conduction mechanisms of the nanoparticles. The effects of the temperature and the manufacturing process on the device performance have been investigated. In addition, the durability was evaluated.