33 research outputs found
Insurance of Cyber Risks in International Transport
The international transport of goods, passengers and luggage is recently facing the threat of cyberattacks. The article is focused on the analysis of the possible cyber risks in the field of the international transport and their management created by the international governmental and non-governmental organisations. The international regulation of the cybersecurity has only recommendatory character and will be subject to future development. That’s the reason why should carriers pay greater attention to all possible cyber security measures. As the instrument of the reduction and mitigation of cyber risks could be used cyber-insurance. The insurance companies are offering insurance cover mainlyon individual base corresponding to the extent of protection required by the policyholder
Contribution à l’ordonnancement dynamique, tolérant aux fautes, de tâches pour les systèmes embarqués temps-réel multiprocesseurs
The thesis is concerned with online mapping and scheduling of tasks on multiprocessor embedded systems in order to improve the reliability subject to various constraints regarding e.g. time, or energy. To evaluate system performances, the number of rejected tasks, algorithm complexity and resilience assessed by injecting faults are analysed. The research was applied to: (i) the primary/backup approach technique, which is a fault tolerant one based on two task copies, and (ii) the scheduling algorithms for small satellites called CubeSats. The chief objective for the primary/backup approach is to analyse processor allocation strategies, devise novel enhancing scheduling methods and to choose one, which significantly reduces the algorithm run-time without worsening the system performances. Regarding CubeSats, the proposed idea is to gather all processors built into satellites on one board and design scheduling algorithms to make CubeSats more robust as to the faults. Two real CubeSat scenarios are analysed and it is found that it is useless to consider systems with more than six processors and that the presented algorithms perform well in a harsh environment and with energy constraints.La thèse se focalise sur le placement et l’ordonnancement dynamique des tâches sur les systèmes embarqués multiprocesseurs pour améliorer leur fiabilité tout en tenant compte des contraintes telles que le temps réel ou l’énergie. Afin d’évaluer les performances du système, le nombre de tâches rejetées, la complexité de l’algorithme et la résilience estimée en injectant des fautes sont principalement analysés. La recherche est appliquée (i) à l’approche de « primary/backup » qui est une technique de tolérance aux fautes basée sur deux copies d’une tâche et (ii) aux algorithmes de placement pour les petits satellites appelés CubeSats. Quant à l’approche de « primary/backup », l’objectif principal est d’étudier les stratégies d’allocation des processeurs, de proposer de nouvelles méthodes d’amélioration pour l’ordonnancement et d’en choisir une qui diminue considérablement la durée de l’exécution de l’algorithme sans dégrader les performances du système. En ce qui concerne les CubeSats, l’idée est de regrouper tous les processeurs à bord et de concevoir des algorithmes d’ordonnancement afin de rendre les CubeSats plus robustes. Les scénarios provenant de deux CubeSats réels sont étudiés et les résultats montrent qu’il est inutile de considérer les systèmes ayant plus de six processeurs et que les algorithmes proposés fonctionnent bien même avec des capacités énergétiques limitées et dans un environnement hostile
Comparison of Enhancing Methods for Primary/Backup Approach Meant for Fault Tolerant Scheduling
This report explores algorithms aiming at reducing the algorithm run-time and rejection rate when online scheduling tasks on real-time embedded systems consisting of several processors prone to fault occurrence. The authors introduce a new processor scheduling policy and propose new enhancing methods for the primary/backup approach and analyse their performances. The studied techniques are as follows: (i) the method of restricted scheduling windows within which the primary and backup copies can be scheduled, (ii) the method of limitation on the number of comparisons, accounting for the algorithm run-time, when scheduling a task on a system, and (iii) the method of several scheduling attempts. Last but not least, we inject faults to evaluate the impact on scheduling algorithms. Thorough experiments show that the best proposed method is based on the combination of the limitation on the number of comparisons and two scheduling attempts. When it is compared to the primary/backup approach without this method, the algorithm run-time is reduced by 23% (mean value) and 67% (maximum value) and the rejection rate is decreased by 4%. This improvement in the algorithm run-time is significant, especially for embedded systems dealing with hard real-time tasks. Finally, we found out that the studied algorithm performs well in a harsh environment
Comparison of Different Methods Making Use of Backup Copies for Fault-Tolerant Scheduling on Embedded Multiprocessor Systems
International audienceAs transistors scale down, systems are more vulnerable to faults. Their reliability consequently becomes the main concern, especially in safety-critical applications such as automotive sector, aeronautics or nuclear plants. Many methods have already been introduced to conceive fault-tolerant systems and therefore improve the reliability. Nevertheless, several of them are not suitable for real-time embedded systems since they incur significant overheads, other methods may be less intrusive but at the cost of being too specific to a dedicated system. The aim of this paper is to analyse a method making use of two task copies when on-line scheduling tasks on multiprocessor systems. This method can guarantee the system reliability without causing too much overhead and requiring any special hardware components. In addition, it remains general and thus applicable to large amount of systems. Last but not least, this paper studies two techniques of processor allocation policies: the exhaustive search and the first found solution search. It is shown that the exhaustive search is not necessary for efficient fault-tolerant scheduling and that the latter search significantly reduces the computation complexity, which is interesting for embedded systems
Fault-Tolerant Online Scheduling Algorithms for CubeSats
International audienceCubeSats are small satellites operating in harsh space environment. In order to ensure correct functionality on board despite faults, fault tolerant techniques taking into account spatial, time and energy constraints should be considered. This paper presents a software-level solution taking advantage of several processors available on board. Two online scheduling algorithms are introduced and evaluated. The results show their performances and the trade-off between the rejection rate and energy consumption. Last but not least, it is stated that ordering policies achieving low rejection rate when using the algorithm scheduling all tasks as aperiodic are the "Earliest Deadline" and "Earliest Arrival Time". As for the algorithm treating arriving tasks as aperiodic or periodic tasks, the "Minimum Slack" ordering policy provides reasonable results
Automobil Industry on the pages of newspaper in year 2007
Bakalářská práce zpracovává kvantitativnĂ obsahovou analĂ˝zu tĂ©matickĂ˝ch rubrik výše jmenovanĂ˝ch denĂkĹŻ na vzorku zahrnujĂcĂm všechna vydánĂ v roce 2007. Je soustĹ™edÄ›na vĂ˝hradnÄ› na rubriky zaštiĹĄujĂcĂ problematiku automobilismu a jejĂm cĂlem je popsat shodnosti a rozdĂly v obsahovĂ© nabĂdce, jakĂ˝m zpĹŻsobem je vedena, jakĂ˝ prostor zaujĂmá, a jakĂ˝ druh informacĂ svĂ˝m ÄŤtenářům pĹ™edává. Práce se vÄ›nuje segmentaci prostoru na kvantifikovatelnĂ© promÄ›nnĂ© a vĂ˝sledky šetĹ™enĂ podrobuje statistickĂ˝m analĂ˝zám. Veškerá zjištÄ›nĂ jsou prezentována prostĹ™ednictvĂm tabulek a grafĹŻ. VĂ˝sledkem je kvantitativnĂ popis zvolenĂ˝ch tĂ©matickĂ˝ch celkĹŻ, kterĂ˝ popisuje tĂ©matickĂ© a prostorovĂ© rozÄŤlenÄ›nĂ automobilismu jako tĂ©matu na stránkách podobnĂ˝ch oddÄ›lenĂ historicky, vĂ˝vojovÄ› i co se ÄŤtenářskĂ˝ch základen tĂ˝ká naprosto odlišnĂ˝ch denĂkĹŻ denĂkĹŻ. V závÄ›ru jsou zodpovÄ›zeny otázky na sezonalitu a prostor, kterĂ˝ jednotlivĂ© denĂky motorismu vÄ›nujĂ.Bachelor thesis deals with quantitative content analysis of topical rubrics of newspapers named above involving all releases in 2007. The analysis is focused just on rubrics conversant questions of automotive industry. Its goal is describe similarities and differences in content selections, how it is led along, what space is devoted to it and what kind of information gives to its readers. This thesis is devoted to segmentation of space on quantifiable parameters and outcomes of analysis are put through the statistic analysises . All the findings are presented through schemes and diagrams. An outcome is quantitative description of chosen topical units which describes topical and spatial zoning of automotive industry as a topic presented on pages of totally different newspapers regarding the historical background and different reader's bases. There are answered questions on seasonality and space devoted to motorism.Department of Media StudiesKatedra mediálnĂch studiĂFaculty of Social SciencesFakulta sociálnĂch vÄ›
Determination of water in food samples - III
StanovenĂ vody v jogurtech nÄ›kolika rĹŻznĂ˝mi metodami - Karl Fischerovou titracĂ. infraÄŤervenou spektroskopiĂ s Fourierovou transformacĂ v blĂzkĂ© a stĹ™ednĂ infraÄŤervenĂ© oblasti, sušenĂm v sušárnÄ› a infraÄŤervenĂ˝m sušenĂm. Práce porovnává vĂ˝sledky zĂskanĂ© metodami a diskutuje vhodnost pouĹľitĂ tÄ›chto metod.Katedra analytickĂ© chemieDokonÄŤená práce s Ăşspěšnou obhajobo
Contribution à l’ordonnancement dynamique, tolérant aux fautes, de tâches pour les systèmes embarqués temps-réel multiprocesseurs
The thesis is concerned with online mapping and scheduling of tasks on multiprocessor embedded systems in order to improve the reliability subject to various constraints regarding e.g. time, or energy. To evaluate system performances, the number of rejected tasks, algorithm complexity and resilience assessed by injecting faults are analysed. The research was applied to: (i) the primary/backup approach technique, which is a fault tolerant one based on two task copies, and (ii) the scheduling algorithms for small satellites called CubeSats. The chief objective for the primary/backup approach is to analyse processor allocation strategies, devise novel enhancing scheduling methods and to choose one, which significantly reduces the algorithm run-time without worsening the system performances. Regarding CubeSats, the proposed idea is to gather all processors built into satellites on one board and design scheduling algorithms to make CubeSats more robust as to the faults. Two real CubeSat scenarios are analysed and it is found that it is useless to consider systems with more than six processors and that the presented algorithms perform well in a harsh environment and with energy constraints.La thèse se focalise sur le placement et l’ordonnancement dynamique des tâches sur les systèmes embarqués multiprocesseurs pour améliorer leur fiabilité tout en tenant compte des contraintes telles que le temps réel ou l’énergie. Afin d’évaluer les performances du système, le nombre de tâches rejetées, la complexité de l’algorithme et la résilience estimée en injectant des fautes sont principalement analysés. La recherche est appliquée (i) à l’approche de « primary/backup » qui est une technique de tolérance aux fautes basée sur deux copies d’une tâche et (ii) aux algorithmes de placement pour les petits satellites appelés CubeSats. Quant à l’approche de « primary/backup », l’objectif principal est d’étudier les stratégies d’allocation des processeurs, de proposer de nouvelles méthodes d’amélioration pour l’ordonnancement et d’en choisir une qui diminue considérablement la durée de l’exécution de l’algorithme sans dégrader les performances du système. En ce qui concerne les CubeSats, l’idée est de regrouper tous les processeurs à bord et de concevoir des algorithmes d’ordonnancement afin de rendre les CubeSats plus robustes. Les scénarios provenant de deux CubeSats réels sont étudiés et les résultats montrent qu’il est inutile de considérer les systèmes ayant plus de six processeurs et que les algorithmes proposés fonctionnent bien même avec des capacités énergétiques limitées et dans un environnement hostile
Analytical procedures for isolation and determination of important antioxidants
Tato práce je zaměřena na izolace a stanovenĂ vybranĂ˝ch antioxidantĹŻ v rostlinnĂ©m materiálu. K tomuto účelu bylo vyuĹŁito širokĂ© škály extrakÄŤnĂch metod, a to extrakÄŤnĂ metody vyuĹŁĂvajĂcĂ ultrazvukovĂ© láznÄ› (USE) nebo ultrazvukovĂ© sondy (HOM), vysokotlakou extrakci rozpouštÄ›dlem (PFE), extrakci nadkritickou tekutinou (SFE) a klasickou extrakci v SoxhletovÄ› extraktoru. OrientaÄŤnÄ› byla testována takĂ© moĹŁnost provedenĂ vĂ˝luhu antioxidantĹŻ do vody. ZĂskanĂ© extrakty byly analyzovány metodou vysokoúčinnĂ© kapalinovĂ© chromatografie ve spojenĂ se spektrofotometrickĂ˝m detektorem v UV oblasti (HPLC-UV).
Ăšvodnà část je zaměřena na teoretickĂ© aspekty celĂ© práce. Jsou zde popsány antioxidanty z hlediska jejich vĂ˝skytu, vlastnostĂ, chemickĂ© struktury a jejich účinkĹŻ v organismu. Dále jsou podrobnÄ› popsány extrakÄŤnĂ metody jak pro izolaci antioxidantĹŻ, tak pro jejich analĂ˝zu, vÄŤetnÄ› kapitoly vÄ›novanĂ© rĹŻznĂ˝m technikám stanovenĂ antioxidaÄŤnĂ kapacity.
V experimentálnà části práce byly optimalizovány pracovnĂ postupy pro všechny výše uvedenĂ© extrakÄŤnĂ metody. ZvolenĂ© podmĂnky byly aplikovány na izolaci antioxidantĹŻ z 16 reálnĂ˝ch vzorkĹŻ rostlin. Dále byla vyvinuta vhodná HPLC-UV metoda, která byla pouĹŁita pĹ™i analĂ˝ze zĂskanĂ˝ch extraktĹŻ. U všech extraktĹŻ byla takĂ© stanovena jejich antioxidaÄŤnĂ kapacita. K tomuto účelu byla vyuĹŁita metoda zaloĹŁená na redukci 2,2-difenyl-1-pikrylhydrazyl radikálu (DPPH*), pĹ™iÄŤemĹľ hodnota byla vyjádĹ™ena jako ekvivalent kyseliny galovĂ© (GAE).This dissertation is focused on isolation and analysis of target antioxidant mixture in plant material. For this purpose several extraction techniques were used. These were ultrasonic bath extraction method (USE), ultrasonic probe extraction method (HOM), pressurised fluid extraction (PFE), supercritical fluid extraction (SFE) and method using the Soxhlet extractor. Water infusion was also tested. All obtained extracts were analysed by high performance liquid chromatography coupled with ultraviolet detector (HPLC-UV).
The first part deals with theoretical aspects of the work. Antioxidants, their occurrence, characteristics, chemical structures and their effect on organisms are described. Also the fundamentals of the analytical methods for antioxidant extraction and their analysis are mentioned there. One chapter is also focused on different methods for antioxidant capacity evaluation.
All extraction techniques were optimised in the experimental part of this work. Also the HPLC-UV method suitable for antioxidant analysis was optimised. Obtained conditions were applied for the 16 real plant samples analyses. The antioxidant capacity of all plant extracts was measured. For this purpose the method using the 2,2-diphenyl-1-picrylhydrazyl radical (DPPH?) reduction was used, while the antioxidant capacity value was expressed as gallic acid equivalent (GAE).Katedra analytickĂ© chemieKomise souhlasĂ s tĂm, aby posudek oponentky doc. RNDr. Ireny ValterovĂ©, CSc. prezentoval pĹ™edseda komise. PĹ™edseda komise doc. Ing. Jan Fischer, CSc. pĹ™edstavil dizertanta a seznámil ÄŤleny komise se základnĂmi ĹľivotopisnĂ˝mi Ăşdaji.VedoucĂ práce prof. Ing. Karel Ventura, CSc. prezentoval hodnocenĂ dizertanta vÄŤetnÄ› jeho studijnĂch a vÄ›deckĂ˝ch vĂ˝sledkĹŻ. Prof. Ventura rovněž prezentoval stanovisko pracovištÄ› k pĹ™edkládanĂ© doktorskĂ© práci. Dizertant prezentoval vĂ˝sledky doktorskĂ© práce a zodpovÄ›dÄ›l dotazy oponentĹŻ a ÄŤlenĹŻ komise. ProbÄ›hla diskuse tĂ˝kajĂcĂ se posudkĹŻ oponentĹŻ a pĹ™edevšĂm prezentovanĂ˝ch vĂ˝sledkĹŻ dizertaÄŤnĂ práce. PĹ™edseda konstatoval, Ĺľe nebyly doruÄŤeny žádnĂ© pĂsemnĂ© pĹ™ipomĂnky k dizertaÄŤnĂ práci. Komise i oponentka byli s prezentovanĂ˝mi vĂ˝sledky i se závÄ›ry dizertanta vÄŤetnÄ› odpovÄ›di na dotazy spokojeni. Diskuse probÄ›hla i nad otázkou moĹľnostĂ kvantifikace antioxidantĹŻ v reálnĂ˝ch vzorcĂch i nad metodami urÄŤenĂ detekÄŤnĂch limitĹŻ
Contamination for Stochastic Integer Programs
The requirement on some of the variables to be integer appears quite naturally in many optimization problems. The complexity of such models and the incomplete information force us usually to solve only an approximated stochastic program instead of the original model. A postoptimality analysis is then quite necessary. Application of the contamination method on stochastic integer programs will be described.Stochastic integer programming. Contamination technique. Stability. Sensitivity