Doctorat en Sciences / info:eu-repo/semantics/nonPublished

The main aim of this paper is to propose a methodology for implementation of spatial interaction models in the GIS environment. This methodology is then verified by creating functional tool for calculating potential accessibility model. The first part summarizes the available literature about those issues. The second part presents the source data and analysis methodology. ESRI ArcGIS and Python are main technologies used. Subsequently, a description of creation tool itself. In conclusion the test analyses and results are described and discussed. Powered by TCPDF (www.tcpdf.org)

Le principal objectif de cette thèse est d'évaluer les protocoles qui prennent en considération la protection de la vie privée et qui nécessitent seulement des métadonnées locales pour détecter les comportements malveillants sur les réseaux sociaux décentralisés. En appliquant des techniques d'analyse de réseaux sociaux qui réduisent la quantité de métadonnées sensibles, nous obtenons des résultats acceptables comparé aux techniques qui ne préservent pas la vie privée. De plus, nous prévoyons d'élaborer une série de recommandations pour construire de futurs réseaux sociaux décentralisés qui découragent cette type des comportements abusifs. / The main goal of this thesis is to evaluate privacy-preserving protocols to detect abuse in future decentralised online social platforms or microblogging services, where often limited amount of metadata is available to perform data analytics. Taking into account such data minimization, we obtain acceptable results compared to techniques of machine learning that use all metadata available. We draw a series of conclusion and recommendations that will aid in the design and development of a privacy-preserving decentralised social network that discourages abusive behavior.

Project management methods can be used in many areas of human activity. In this diploma thesis they are applied to the creation of an e-shop communication campaign. The theoretical part describes the basic concepts of project management and presents the stages of the life cycle of the project. The main part of the theoretical part is the project planning phase with a focus on time analysis, analysis of resources, costs and risks. The described methods and analyzes are applied in the practical part to a real project - the communication campaign of the newly created e-shop Motovidlo.cz, which offers various printed products. The final part of the thesis deals with the success of the project, the fulfillment of the goals and recommendations for the project team.

How do local homeland security organizations respond to catastrophic events such as hurricanes and acts of terrorism? Among the most important aspects of this response are these organizations ability to adapt to the uncertain nature of these “focusing events” (Birkland 1997). They are often behind the curve, seeing response as a linear process, when in fact it is a complex, multifaceted process that requires understanding the interactions between the fiscal pressures facing local governments, the institutional pressures of working within a new regulatory framework and the political pressures of bringing together different levels of government with different perspectives and agendas. This dissertation has focused on tracing the factors affecting the individuals and institutions planning, preparing, responding and recovering from natural and man-made disasters. Using social network analysis, my study analyzes the interactions between the individuals and institutions that respond to these “focusing events.” In practice, it is the combination of budgetary, institutional, and political pressures or constraints interacting with each other which resembles a Complex Adaptive System (CAS). To investigate this system, my study evaluates the evolution of two separate sets of organizations composed of first responders (Fire Chiefs, Emergency Management Coordinators) and community volunteers organized in the state of Florida over the last fifteen years. Using a social network analysis approach, my dissertation analyzes the interactions between Citizen Corps Councils (CCCs) and Community Emergency Response Teams (CERTs) in the state of Florida from 1996- 2011. It is the pattern of interconnections that occur over time that are the focus of this study. The social network analysis revealed an increase in the amount and density of connections between these organizations over the last fifteen years. The analysis also exposed the underlying patterns in these connections; that as the networks became more complex they also became more decentralized though not in any uniform manner. The present study brings to light a story of how communities have adapted to the ever changing circumstances that are sine qua non of natural and man-made disasters

In recent years, a surprising new phenomenon has emerged in which globally-distributed online communities collaborate to create useful and sophisticated computer software. These open source software groups are comprised of generally unaffiliated individuals and organizations who work in a seemingly chaotic fashion and who participate on a voluntary basis without direct financial incentive. The purpose of this research is to investigate the relationship between the social network structure of these intriguing groups and their level of output and activity, where social network structure is defined as 1) closure or connectedness within the group, 2) bridging ties which extend outside of the group, and 3) leader centrality within the group. Based on well-tested theories of social capital and centrality in teams, propositions were formulated which suggest that social network structures associated with successful open source software project communities will exhibit high levels of bridging and moderate levels of closure and leader centrality. The research setting was the SourceForge hosting organization and a study population of 143 project communities was identified. Independent variables included measures of closure and leader centrality defined over conversational ties, along with measures of bridging defined over membership ties. Dependent variables included source code commits and software releases for community output, and software downloads and project site page views for community activity. A cross-sectional study design was used and archival data were extracted and aggregated for the two-year period following the first release of project software. The resulting compiled variables were analyzed using multiple linear and quadratic regressions, controlling for group size and conversational volume. Contrary to theory-based expectations, the surprising results showed that successful project groups exhibited low levels of closure and that the levels of bridging and leader centrality were not important factors of success. These findings suggest that the creation and use of open source software may represent a fundamentally new socio-technical development process which disrupts the team paradigm and which triggers the need for building new theories of collaborative development. These new theories could point towards the broader application of open source methods for the creation of knowledge-based products other than software.

The focus of this research is on identifying the determinants of local-level climate change adaptive capacity in Caribbean small island communities. A single case study approach was employed to assess retrospectively both internal and external factors that contributed to the adaptive capacity of Paget Farm, Saint Vincent and the Grenadines. The Caribbean region’s first solar-powered desalination plant was implemented in the community specifically as a climate change adaptation strategy and thus provides an ideal case for retrospective analysis. A series of semi-structured interviews with local residents and key stakeholders revealed a number of interacting social and institutional factors that contribute to community-based adaptive capacity. Further analysis of institutional factors was undertaken using Social Network Analysis, which enabled visualization and quantification of vertical and horizontal institutional integration of the networks formed during different phases of project implementation. The research extends scholarly understanding of the determinants that influence local-level climate change adaptive capacity and provides practical evidence that can assist small island communities to respond to a changing climate.

The thesis focuses on the social web and on the analysis of social networks with particular emphasis on their temporal aspects. Social networks are represented here by Time Varying Graphs (TVG), a general model for dynamic graphs borrowed from distributed computing. In the first part of the thesis we focus on the temporal aspects of social networks. We develop various temporal centrality measures for TVGs including betweenness, closeness, and eigenvector centralities, which are well known in the context of static graphs. Unfortunately the computational complexities of these temporal centrality metrics are not comparable with their static counterparts. For example, the computation of betweenness becomes intractable in the dynamic setting. For this reason, approximation techniques will also be considered. We apply these temporal measures to two very different datasets, one in the context of knowledge mobilization in a small community of university researchers, the other in the context of Facebook commenting activities among a large number of web users. In both settings, we perform a temporal analysis so to understand the importance of the temporal factors in the dynamics of those networks and to detect nodes that act as “accelerators”. In the second part of the thesis, we focus on a more standard static graph representation. We conduct a propagation study on YouTube datasets to understand and compare the propagation dynamics of two different types of users: subscribers and friends. Finally, we conclude the thesis with the proposal of a general framework to present, in a comprehensive model, the influence of the social web on e-commerce decision making.

Sharing and inappropriate discarding of syringes and drug use equipment can lead to transmission of bloodborne pathogens and decreased sense of community safety. To reduce these risks, interventions such as syringe drop boxes, are implemented. However, little consideration has been made of the social and spatial networks of the injection drug use (IDU) populations in the placement of these drop boxes. A sample of IDU was obtained through respondent driven sampling in Winnipeg, Canada in 2009. Characteristics of the sample and distribution of these characteristics through the social network were assessed. A spatial network was constructed which focused on the connections between IDU and specific geographic locations. Measures of centrality were calculated using Pajek and the geographic network was mapped using ArcGIS. Analysis of the social network revealed variation among network components in demographic and drug use characteristics. Spatial analysis revealed geographic clustering, quantified through network centrality measures. There was congruence between locations of high degree and current drop box placement in Winnipeg. This research illustrates the benefit of combining IDU social network and spatial data to inform evidence-based municipal policies and programs.

The subject of this graduate thesis is primarily identification of influencers on the social network Facebook, group FM VŠE. Furthermore, the thesis deal with verification of influence power of influencers and comparison with the power of less influential people at the Faculty of Management. Thanks to literature review from international environment is in the thesis described the term influencer and for the purpose of identification of influencers is there also description of the theory of social network analysis. Identification is performed by analysing of the social network Facebook and for verification of powerful of influence is used questionnaire.