The mobility attribute of a mobile agent implies deployment thereof in untrustworthy environments, which introduces malicious host threats. The research question deals with how a security framework could be constructed to address the mentioned threats without introducing high costs or restraining the mobile agent's autonomy or performance. Available literature have been studied, analysed and discussed. The salient characteristics as well as the drawbacks of current solutions were isolated. Through this knowledge a dynamic mobile agent security framework was defined. The framework is based on the definition of multiple security levels, depending on type of deployment environment and type of application. A prototype was constructed and tested and it was found to be lightweight and efficient, giving developers insight into possible security threats as well as tools for maximum protection against malicious hosts. The framework outperformed other frameworks / models as it provides dynamic solutions without burdening a system with unnecessary security gadgets and hence paying for it in system cost and performance / Computing / D.Phil.

O peixe-boi marinho, Trichechus manatus manatus, à um mamÃfero com dieta herbÃvora, e distribuiÃÃo costeira em rios, estuÃrios e Ãguas litorÃneas da Zona Tropical brasileira. No Estado do Cearà ocorre em duas Ãreas distintas, no extremo dos seus setores leste e oeste. No litoral leste nÃo existe nenhuma Unidade de ConservaÃÃo com abrangÃncia marinha que restrinja os impactos causados ao meio ambiente e à populaÃÃo do peixe-boi, tais como urbanizaÃÃo, turismo e ocupaÃÃo de praias, dunas, falÃsias e manguezais. Sendo considerado pela UniÃo Internacional para ConservaÃÃo da Natureza como âespÃcie vulnerÃvelâ e estando inserido na Lista Oficial de EspÃcies da Fauna Brasileira AmeaÃadas de ExtinÃÃo de acordo com o IBAMA, corre risco de extinÃÃo extremamente alto num futuro prÃximo. Os objetivos desta DissertaÃÃo foram determinar a distribuiÃÃo espacial e padrÃes de uso da Ãrea, escolha da metodologia mais adequada ao monitoramento da populaÃÃo, e realizar levantamento das Ãreas de alimentaÃÃo e fontes e Ãgua doce provavelmente utilizadas pelos animais. A base de dados foi obtida atravÃs de prospecÃÃes aÃrea, realizada de junho/2003 a outubro/2004, totalizando 11 sobrevÃs e 24 horas de esforÃo de monitoramento, e nÃutica, realizada de agosto/2003 a novembro/2004, num total de 10 embarques e 157 horas de esforÃo de monitoramento. Dentre os mÃtodos de prospecÃÃo aÃrea e nÃutica, o primeiro gera erros devido à turbidez da Ãgua, e dificuldades de identificaÃÃo e contagem dos indivÃduos, enquanto o segundo, por sua maior proximidade em relaÃÃo aos animais, mostrou-se mais eficiente. O status da populaÃÃo do peixe-boi marinho foi avaliado atravÃs dos seguintes parÃmetros: (a) conservaÃÃo do habitat, com Ãnfase para a manutenÃÃo do territÃrio; (b) acesso a fontes de Ãgua doce e a Ãreas preferenciais de alimentaÃÃo e reproduÃÃo; (c) geraÃÃo de condiÃÃes ambientais Ãtimas para os cuidados parentais. Os fatores de ameaÃa de extinÃÃo nessa Ãrea estariam relacionados com reduÃÃo das fontes de alimento e Ãgua doce, assoreamento do Rio Jaguaribe, alÃm de captura acidental por aparelhos de pesca. Estes se traduzem nas seguintes conseqÃÃncias: reduÃÃo do habitat; aumento da frequÃncia de encalhes de recÃm-nascidos; aumento da mortalidade de adultos. A regiÃo de Picos, com destaque para o Banco dos Cajuais, foi definida como Zona de Alta Densidade, com padrÃo de distribuiÃÃo âaltamente agregadaâ por causa da abundÃncia de macroalgas e do menor fluxo de barcos motorizados. Dentre as recomendaÃÃes para se minimizar os riscos de extinÃÃo do peixe-boi, destacam-se: (a) desenvolvimento de campanhas educacionais que ressaltem aspectos importantes da conservaÃÃo do ambiente marinho; (b) reintroduÃÃo de espÃcimes em locais onde o declÃnio populacional à evidente; (c) criaÃÃo de unidades de conservaÃÃo com abrangÃncia marinha e aplicaÃÃo e fiscalizaÃÃo da legislaÃÃo pertinente ao habitat do peixe-boi e (d) monitoramento sistemÃtico da populaÃÃo no litoral leste para determinaÃÃo dos padrÃes ambientais que influenciam na ocorrÃncia do peixe-boi no municÃpio de IcapuÃ, litoral leste do CearÃ. / The Antillean manatee, Trichechus manatus manatus, is a mammal with an herbivorous diet and costal distribution in rivers, estuaries and inshore waters of the Brazilian Tropical Zone. In Cearà State, the species may found in the outermost ends of its western and eastern sectors. In the eastern sector there are no Marine Conservation Units to ward off impacts to the environment and the manatee population, such as urban development, tourism and occupation of beaches and mangrove forests. Manatees have been classified by the International Union for Nature Conservation as a âvulnerable speciesâ and included on the Official List of Endangered Species of the Brazilian Fauna. According to the Brazilian Institute for the Environment, it runs an extremely high risk of extinction in the near future. The objectives of this Thesis have been to determine the spatial distribution and patterns of usage of the living area, choice of the most appropriate methodology for population monitoring and mapping of feeding grounds and freshwater sources likely to used by the animals. The database was obtained by means of aerial surveys from June, 2003 to October, 2004, making up a 24-hour monitoring effort during 11 overhead flights, as well as nautical surveys performed from August, 2003 to November, 2004, making up a 157-hour monitoring effort during 10 voyages. Of the two prospecting techniques, the aerial one was less practical because of water turbidity, which made it difficult to identify and count manatee specimens, whereas the nautical one, because of its nearness to the targets, proved to the most efficient. The status of the Antillean manatee population was evaluated through the following parameters: (a) habitat conservation, with emphasis on territory maintenance; (b) access to freshwater sources and areas suitable for feeding and reproduction; (c) yielding of optimum environmental conditions for parental care. The threatened extinction in the studied area is related to factors such as decreasing of food and freshwater sources, silting-up of the Jaguaribe River, by-catch by trawl and gillnet fishing. The worrying outcome of such a scenario is likely to result in a reduction of the habitat size; increase in the straying of newborns plus an increase in adult mortality rates. The Picos region, specially the Cajuais sandbank, was defined as a High Density Zone, which displays a highly aggregate distribution because of seaweed abundance and smaller deployment of fishing boats. Among the suggestions for lowering the extinction risks of the Antillean manatee in Eastern Cearà State, the following ones stand out; (a) development of education campaigns which deal with the main aspects of environment preservation; (b) reintroduction of specimens in zones where population decline is evident; (c) installation of Marine Conservation Units and enforcement of the pertinent management measures and (d) constant monitoring of the population in the known habitat to determine environmental patterns which influence manatees in Icapuà county, eastern Cearà State.

Cette recherche se compose de trois études. La première, qualitative, met en exergue la transition culturelle qu’a connue le groupe La Poste durant cette dernière décennie. Ainsi, les effets de l’intégration progressive d’une culture de marché sont investigués à travers le discours de cadres, d’encadrants et de facteurs. La transformation de la culture organisationnelle est mise en avant ainsi que les répercussions de cette évolution sur le travail, la dimension axiologique et la santé des employés. La deuxième étude transpose dans le domaine de l’organisation des modèles d’intégrations identitaires habituellement associés à la santé et utilisés le plus souvent pour mettre en perspective le processus acculturatif de migrants avec des dimensions liées à la santé psychologique. Ainsi, le modèle de l’acculturation (Berry, 1990), le modèle de l’intégration biculturelle (Benet-Martinez & Haritatos, 2005) et le modèle cognitivo-développemental de l’intégration des identités sociales (Amiot et al., 2007) permettent d’expliquer, en partie, le bien-être et la détresse psychologique au travail ainsi que l’absentéisme des employés du groupe La Poste. Un pan de l’étude est consacré à expliquer les différentes identifications par le biais des motivations identitaires, de la menace perçue et des valeurs. Ces trois dimensions jouent un rôle prépondérant dans l’intégration culturelle des employés. Enfin, une dernière étude, utilisant des méthodes d’évaluations implicites, est réalisée dans le but de mettre à jour de potentielles dissonances cognitives, pouvant impacter la santé des individus, en mesurant des différences significatives entre l’identification implicite et l’identification autodéclarée. Cette étude montre des résultats contrastés ne pouvant être retenus, l’efficacité de la manipulation n’ayant pu être validée. Toutefois, certains indicateurs poussent à poursuivre les recherches en ce sens. / This research consists of three studies. The first study is qualitative. It highlights the cultural transition within the La Poste Group during the last decade. The effects of the gradual integration of a market culture are investigated through the speeches of executives, supervisors and postmen. The transformation of the corporate culture is highlighted as well as its impact on the work, the axiological dimension and the employees’ health. The second study transposes into the field of the organization of identity integration’s models. These models, usually associated with health, are often used to put into perspective the acculturative process of migrants with psychological health’s dimensions. Thus, the acculturation model (Berry, 1990), the bi-cultural integration model (Benet-Martinez & Haritatos, 2005) and the cognitive developmental model of social identities’ integration (Amiot et al. 2007 ) may explain, partly, the well-being and the psychological distress at work as well as the absenteeism of employees of La Poste Group. A section of the study focuses to explain the different identifications through identity motivations, perceived threat and values. These three dimensions play a major role in the cultural integration of employees. At last, a final study using methods of implicit assessment is performed in order to update potential cognitive dissonance which could affect the health of individuals. It measures significant differences between the implicit identification and self-declared identification. This study shows contrasting results that won’t hold because the effectiveness of the manipulation has not been proven. However, some indicators urge to continue research in this direction.

This Master Thesis aims to present the current existential threats to Israeli security. Israel is a Jewish country in the middle of the Muslim region and her demise is wished by many involved parties. The Author describes sophisticated security systems of Israel, their efficiency and its unofficial nuclear program. From the state actors, it is Iran that has become the number one perceived threat in Israel thanks to its officials' rhetoric, its support towards terrorist organizations and its nuclear program. Israel is often involved in asymmetrical conflicts against non-state actors like Hamas and Hezbollah. The new extremist group Islamic State can also potentially pose a threat. Has Israel got reasons to worry about her existence? Has the Arab Spring brought about positives, negatives, or new possibilities? The Author aims to answer these questions.

The aim of the diploma thesis is to solve a particular problem via methods and instruments of multi-criteria decision-making under risk -- the choice of a suitable location of a swimming pool in the city of Písek. Every single phase of the decision-making process is described in the theoretical part of the thesis and followed in the practical part. The process was divided into stages: the problem specification, setting objectives, determination of the importance of the criteria, generation of alternatives and identification of their consequences, determination the significance of the risk factors, the probability of their occurrence, setting the impacts of the risk alternatives, evaluation of the alternatives and the choice of the most desirable one, potential threats and opportunities analysis. The theoretical part consists of a review of methods suitable for the given phase. More in-detail focus is put on the methods used in the practical part. To sum up, the diploma thesis provide the reader with the recommendation of the most appropriate location for the construction of the swimming pool. Additionally, it identifies the most important threats and opportunities related to this preference.

This dissertation thesis is dedicated to on-line services security management from service provider's and service consumer's viewpoints. The main goal is to propose a framework for on-line services security risk management, to develop a supporting software tool prototype and to validate them through a case study performed in a real-world environment. The key components of the proposed framework are a threat model and a risk model. These models are designed to fit specific features of on-line services and the surrounding environment. A risk management process is an integral part of the framework. The process is suitable for frequent and recurrent risk assessments. The process comprises of eight steps, related roles and responsibilities are defined for each step. The process execution results in identification and execution of proper tasks which contribute to treatment of identified security risks and deficiencies. Documentation and reporting of an overall level of on-line services security over time is possible if the process is executed on a regular basis. The proposed framework was validated through a case study performed in a large enterprise environment.

The presence of naturally occurring and man-made public health threats necessitate the design and implementation of mitigation strategies, such that adequate response is provided in a timely manner. Since multiple variables, such as geographic properties, resource constraints, and government mandated time-frames must be accounted for, computational methods provide the necessary tools to develop contingency response plans while respecting underlying data and assumptions. A typical response scenario involves the placement of points of dispensing (PODs) in the affected geographic region to supply vaccines or medications to the general public. Computational tools aid in the analysis of such response plans, as well as in the strategic placement of PODs, such that feasible response scenarios can be developed. Due to the sensitivity of bio-emergency response plans, geographic information, such as POD locations, must be kept confidential. The generation of synthetic geographic regions allows for the development of emergency response plans on non-sensitive data, as well as for the study of the effects of single geographic parameters. Further, synthetic representations of geographic regions allow for results to be published and evaluated by the scientific community. This dissertation presents methodology for the analysis of bio-emergency response plans, methods for plan optimization, as well as methodology for the generation of synthetic geographic regions.

Masters of Science / The aim of this study was to develop a Stock Control Assessment Tool for use in the public health care sector and then to apply it to identify problems in the stock control system. This would help authorities to optimize the system. The advantages experienced with such a dynamic Assessment Tool were many: The Tool was quick and easy to apply; it was user friendly; it provided an immediate SWOT analysis of a particular facility; it is in line with the SA NDP directives and it provides an indication of which structures are in place and whether they are functioning properly. Furthermore; it could determine the increase or decrease in performance of a facility (therefore identify trends within the functional status of a system) when data is collected over a period of time; and finally, it could also be used to prioritize drug policy directives. The following steps were established in the development of the Tool: A literature review of pharmaceutical stock control and Drug Supply Management was addressed to provide the background information for the motivation of this study and to identify the various elements that could influence stock control at a facility level. Observational studies were applied at selected private and public facilities to observe the impact of these identified stock control elements. An 'ideal' stock control system was then generated from the literature review and observational assessment. A structured questionnaire was developed and surveyed at these facilities to generate key areas of concern of a stock control system. A study and adaptation of the indicator methods used by the World Health Organization (WHO) to monitor drug use in health facilities resulted in the formulation of a practical Stock Control Assessment Tool based on 11 key indicators and a number of sub-indicators, all of which were objectively defined. The Tool was then applied at selected public facilities and the results were analyzed quantitatively, qualitatively and subjectively. Each of the indicators was then applied and results examined closely with a view to possible refinements of the indicator. The refinements were made and the Tool was re-applied at two selected facilities. These two facilities were randomly selected from the original six facilities included for the testing of the Tool. Final conclusions and specific recommendations were generated to improve the stock control systems at the selected public health care facilities.

Táto práca sa zaoberá problematikou škodlivého kódu na webe so zameraním na analýzu a detekciu škodlivého JavaScriptu umiestneného na strane klienta s využitím strojového učenia. Navrhnutý prístup využíva známe i nové pozorovania s ohľadom na rozdiely medzi škodlivými a legitímnymi vzorkami. Tento prístup má potenciál detekovať nové exploity i zero-day útoky. Systém pre takúto detekciu bol implementovaný a využíva modely strojového učenia. Výkon modelov bol evaluovaný pomocou F1-skóre na základe niekoľkých experimentov. Použitie rozhodovacích stromov sa podľa experimentov ukázalo ako najefektívnejšia možnosť. Najefektívnejším modelom sa ukázal byť Adaboost klasifikátor s dosiahnutým F1-skóre až 99.16 %. Tento model pracoval s 200 inštanciami randomizovaného rozhodovacieho stromu založeného na algoritme Extra-Trees. Viacvrstvový perceptrón bol druhým najlepším modelom s dosiahnutým F1-skóre 97.94 %.

This Master’s thesis analyses the current status of the small selling company, which sells sport articles. The thesis investigates impact extenrnal environment on the firm and also analyse internal environment. It defines strategic targets, contains propsal of competitive strategy of the company and its time implementation.