8 research outputs found

    Kliniczne zasady planowania i realizacji radioterapii modulacją intensywnoƛci wiązki (IMRT) u chorych na nowotwory gƂowy i szyi - częƛć 1

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    Intensity modulated radiation therapy is one of the newest method in use in contemporary radiotherapy. In the presented article the authors show the advantages of using IMRT in patients with head and neck cancers. The detailed methodÂŽs description, protecting normal tissue and treatment planning were presented.Jedną z najnowoczeƛniejszych technik radioterapii konformalnej jest napromienianie z zastosowaniem modulacji intensywnoƛci wiązki (IMRT). W niniejszej pracy przedstawiono korzyƛci z zastosowania IMRT u pacjentĂłw z nowotworami gƂowy i szyi. SzczegóƂowo opisano techniki, wedƂug ktĂłrych naleĆŒy tę metodę stosować, oraz sposoby ochrony narządĂłw krytycznych, a takĆŒe zasady powstawania planu leczenia metodą IMRT

    Fan's condition on induced subgraphs for circumference and pancyclicity

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    Modélisation formelle et analyse quantitative de la sécurité à l'aide d'arbres les attaques et de défense

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    Risk analysis is a very complex process. It requires rigorous representation and in-depth assessment of threats and countermeasures. This thesis focuses on the formal modelling of security using attack and defence trees. These are used to represent and quantify potential attacks in order to better understand the security issues that the analyzed system may face. They therefore make it possible to guide an expert in the choice of countermeasures to be implemented to secure their system. The main contributions of this thesis are as follows: - The enrichment of the attack and defence tree model allowing the analysis of real security scenarios. In particular, we have developed the theoretical foundations and quantitative evaluation algorithms for the model where an attacker's action can contribute to several attacks and a countermeasure can prevent several threats. - The development of a methodology based on Pareto dominance and allowing several quantitative aspects to be taken into account simultaneously (e.g., cost, time, probability, difficulty, etc.) during a risk analysis. - The design of a technique, using linear programming methods, for selecting an optimal set of countermeasures, taking into account the budget available for protecting the analyzed system. It is a generic technique that can be applied to several optimization problems, for example, maximizing the attack surface coverage, or maximizing the attacker's investment. To ensure their practical applicability, the model and mathematical algorithms developed were implemented in a freely available open source tool. All the results were also validated with a practical study on an industrial scenario of alteration of electricity consumption meters.L'analyse de risque est un processus trĂšs complexe. Elle nĂ©cessite une reprĂ©sentation rigoureuse et une Ă©valuation approfondie des menaces et de leur contre-mesures. Cette thĂšse porte sur la modĂ©lisation formelle de la sĂ©curitĂ© Ă  l'aide d'arbres d'attaque et de dĂ©fense. Ces derniers servent Ă  reprĂ©senter et Ă  quantifier les attaques potentielles afin de mieux comprendre les enjeux de sĂ©curitĂ© auxquels le systĂšme analysĂ© peut ĂȘtre confrontĂ©. Ils permettent donc de guider un expert dans le choix des contre-mesures Ă  implĂ©menter pour sĂ©curiser son systĂšme. - Le dĂ©veloppement d'une mĂ©thodologie basĂ©e sur la dominance de Pareto et permettant de prendre en compte plusieurs aspects quantitatifs simultanĂ©ment (e.g., coĂ»t, temps, probabilitĂ©, difficultĂ©, etc.) lors d'une analyse de risques. - La conception d'une technique, utilisant les mĂ©thodes de programmation linĂ©aire, pour sĂ©lectionner un ensemble de contre-mesures optimal, en tenant compte du budget destinĂ© Ă  la protection du systĂšme analysĂ©. C'est une technique gĂ©nĂ©rique qui peut ĂȘtre appliquĂ©e Ă  plusieurs problĂšmes d'optimisation, par exemple, la maximisation de la couverture de surface d'attaque, Les principales contributions de cette thĂšse sont les ou encore la maximisation du investissement de suivantes : l'attaquant. - L'enrichissement du modĂšle des arbres d'attaque et de dĂ©fense permettant d'analyser des scĂ©narios de Pour garantir leur applicabilitĂ© pratique, le modĂšle et sĂ©curitĂ© rĂ©els. Nous avons notamment dĂ©veloppĂ© les les algorithmes mathĂ©matiques dĂ©veloppĂ©s ont Ă©tĂ© fondements thĂ©oriques et les algorithmes d'Ă©valuation implĂ©mentĂ©s dans un outil informatique Ă  source quantitative pour le modĂšle oĂč une action de ouverte et accĂšs gratuit. Tous les rĂ©sultats ont l'attaquant peut contribuer Ă  plusieurs attaques et oĂč Ă©galement Ă©tĂ© validĂ©s lors d'une Ă©tude pratique une contre-mesure peut prĂ©venir plusieurs menaces. portant sur un scĂ©nario industriel d'altĂ©ration de compteurs de consommation d'Ă©lectricitĂ©

    A Fan-Type Heavy Pair Of Subgraphs For Pancyclicity Of 2-Connected Graphs

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    Let G be a graph on n vertices and let H be a given graph. We say that G is pancyclic, if it contains cycles of all lengths from 3 up to n, and that it is H-f1-heavy, if for every induced subgraph K of G isomorphic to H and every two vertices u, v ∈ V (K), dK(u, v) = 2 implies min⁥{dG(u),dG(v)}≄n+12min⁥{dG(u),dG(v)}≄n+12\min \{ d_G (u),d_G (v)\} \ge {{n + 1} \over 2} . In this paper we prove that every 2-connected {K1,3, P5}-f1-heavy graph is pancyclic. This result completes the answer to the problem of finding f1-heavy pairs of subgraphs implying pancyclicity of 2-connected graphs

    On implicit heavy subgraphs and hamiltonicity of 2–connected graphs

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    International audienceA graph G of order n is implicit claw–heavy if in every induced copy of K 1,3 in G there are two non–adjacent vertices with sum of their implicit degrees at least n. We study various implicit degree conditions (including, but not limiting to, Ore– and Fan–type conditions) imposing of which on specific induced subgraphs of a 2–connected implicit claw–heavy graph ensures its hamiltonicity. In particular, we improve a recent result of [X. Huang, Implicit degree condition for hamiltonic-ity of 2–heavy graphs, Discrete Appl. Math. 219 (2017) 126–131] and complete the characterizations of pairs of o–heavy and f–heavy sub-graphs for hamiltonicity of 2–connected graphs

    On Implicit Heavy Subgraphs and Hamiltonicity of 2-Connected Graphs

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    A graph G of order n is implicit claw-heavy if in every induced copy of K1,3 in G there are two non-adjacent vertices with sum of their implicit degrees at least n. We study various implicit degree conditions (including, but not limiting to, Ore- and Fan-type conditions) imposing of which on specific induced subgraphs of a 2-connected implicit claw-heavy graph ensures its Hamiltonicity. In particular, we improve a recent result of [X. Huang, Implicit degree condition for Hamiltonicity of 2-heavy graphs, Discrete Appl. Math. 219 (2017) 126–131] and complete the characterizations of pairs of o-heavy and f-heavy subgraphs for Hamiltonicity of 2-connected graphs
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