O protocolo International Electrotechnical Commission (IEC)-61850 tornou possível integrar os equipamentos das subestações de energia elétrica, através de uma rede de comunicação de dados Ethernet de alta velocidade. A utilização deste protocolo tem como objetivo principal a interligação dos Intelligent Electronic Devices (IEDs) para a automatização dos processos no sistema elétrico. As contribuições deste protocolo para a integração do controle e supervisão do sistema elétrico são diversas, porém, o fato de utilizar uma rede de comunicação de dados Ethernet integrada expõe o sistema elétrico à ataques cibernéticos. A norma IEC-62351 estabelece uma série de recomendações para prover segurança à rede de comunicação do sistema elétrico, dentre elas, o gerenciamento da rede de comunicação, a análise dos campos da mensagem Generic Object Oriented Substation Event (GOOSE) e a utilização de sistemas de detecção de intrusão. O presente trabalho descreve o desenvolvimento de um Intrusion Detection System (IDS) que atende os requisitos de segurança propostos pelo protocolo IEC-62351, para a identificação de ataques à comunicação realizada por mensagens GOOSE do protocolo IEC-61850, e entre equipamentos do sistema elétrico. Para o desenvolvimento desta aplicação, foram identificados os campos que compõem as mensagens GOOSE, de forma a reconhecer os valores esperados em diferentes situações de operação do sistema elétrico. Determinaram-se padrões de comportamento a serem utilizados para discernir mensagens falsas na rede de comunicação. Instalou-se e configurou-se um sistema operacional de tempo real embarcado na plataforma de desenvolvimento Zynq Board (ZYBO), juntamente com o controlador Open-Mul, para gerenciar a rede de comunicação da subestação, através do protocolo OpenFlow, realizando otimizações para o tráfego multicast. Foi desenvolvido um sistema de detecção e bloqueio de mensagens GOOSE falsas que utiliza o protocolo OpenFlow para controle da rede de comunicação do Sistema Elétrico. Desenvolveu-se ainda um sistema inteligente, utilizando-se uma Rede Neural Artificial (RNA) Nonlinear Autoregressive Model with Exogenous Input (NARX), para predição do tráfego realizado por mensagens GOOSE e detecção de ataques Distributed Deny of Service (DDOS). Os resultados obtidos demonstraram que o protocolo OpenFlow pode ser uma ferramenta interessante para controle da rede, porém, os fabricantes necessitam amadurecer sua implementação nos switches, para que sejam utilizados em produção nas redes de comunicação das subestações. O sistema de predição do tráfego gerado por mensagens GOOSE apresentou benefícios interessantes para a segurança da rede de comunicação, demonstrando potencial para compor um sistema de detecção de ataques DDOS realizado por mensagens GOOSE, na rede de comunicação das subestações de energia elétrica. / The IEC-61850 made it possible to integrate equipments of electric power system substations to a high-speed Ethernet data communication network. Its main goal is the interconnection of IEDs for the automation of processes in an electrical system. The contributions of this protocol for the integration of the control and supervision of the electrical system are diverse, although an Ethernet network exposes the electrical system for cyber attacks. The IEC-62351 states a series of recommendations to provide security to the communication network of the electrical system, such as the communication network management, the analysis of GOOSE messages and the use of intrusion detection systems. This study describes the development of an IDS that meets the security requirements proposed by the IEC-62351 standard to identify attacks on communication between GOOSE messages exchanged by electrical equipment using IEC-61850. For the development of this application, fields of the GOOSE messages were identified, in order to recognize the expected values in different power system operating conditions. Behaviour patterns were determined to detect false messages on the communication network. A real-time embedded operating system on ZYBO was installed and configured, as well as the OpenMul controller to manage the communication network of the substation through the OpenFlow protocol, performing optimizations for multicast traffic. A detection system and block tamper GOOSE messages, using the OpenFlow protocol for control of the electrical system communication network, were developed. In addition, an intelligent system using an Artificial Neural Network (ANN) Nonlinear Autoregressive Model with Exogenous Input (NARX) for predicting of the GOOSE messages traffic and the detection of Distributed Deny of Service attack (DDOS) were also developed. The results obtained show that the OpenFlow protocol may be a valuable tool for network control, however, manufacturers should maturely carry on with its implementation in the switches, so that it be used in substation communication networks. The traffic prediction system of the GOOSE messages presented interesting benefits for the security of the communication network, demonstrating potential to built a DDOS attack detection system performed by GOOSE messages on the communication network of electric power substations.

Submitted by Sara Ribeiro (sara.ribeiro@ucb.br) on 2018-08-08T13:28:15Z No. of bitstreams: 1 RenataAfonsoFerreiraMadeiraMadrugaDissertacao2018.pdf: 1228352 bytes, checksum: 282fcd565dc1a0ef03d49106ffbbb562 (MD5) / Approved for entry into archive by Sara Ribeiro (sara.ribeiro@ucb.br) on 2018-08-08T13:28:44Z (GMT) No. of bitstreams: 1 RenataAfonsoFerreiraMadeiraMadrugaDissertacao2018.pdf: 1228352 bytes, checksum: 282fcd565dc1a0ef03d49106ffbbb562 (MD5) / Made available in DSpace on 2018-08-08T13:28:44Z (GMT). No. of bitstreams: 1 RenataAfonsoFerreiraMadeiraMadrugaDissertacao2018.pdf: 1228352 bytes, checksum: 282fcd565dc1a0ef03d49106ffbbb562 (MD5) Previous issue date: 2018-06-29 / This dissertation presents a communication approach to the understanding of the organizational strategy of a public institution of education in the Federal District, based on the systemic theory of Niklas Luhmann and the discursive theory of Eliseo Verón. This systemic-discursive perspective enabled the exploration of communication elements, which were articulated in a theoretical model aimed at understanding the strategy called the Communicational Decisional Network, and in this context, the organization was understood as a social system constituted by communication in the form of a decision. The objective was to understand, principally, what the meanings of strategy are and how it is (re) constructed in communication. To do so, we conducted a qualitative research, through a case study, with individual interviews and document analysis, which took into account aspects of the organization's strategy. From the communication elements such as decision, identification, institutionalization, mediation, organizational culture and organizational communication, it was possible to understand which decisions were revealed in the texts analyzed. The decisions go through these discourses revealing an authoritative and formal dynamic of organizational communication in parallel with the informal dimensions including the diverse perceptions of the different actors involved in the strategic process. However, it is worth mentioning that with the analysis of the data from the communicational decision network it was possible to reaffirm the possibility of thinking about the organizational strategy and how it is carried out within the scope of the researched scenario. / Esta dissertação apresenta uma abordagem comunicacional para a compreensão da estratégia organizacional de uma instituição pública de ensino do Distrito Federal, fundamentada na teoria sistêmica de Niklas Luhmann e na teoria discursiva de Eliseo Verón. Essa perspectiva sistêmico-discursiva possibilitou a exploração de elementos comunicacionais, que foram articulados em um modelo teórico voltado para a compreensão da estratégia chamado Rede Decisória Comunicacional, e nesse contexto, a organização foi compreendida como um sistema social constituído por comunicação em forma de decisão. O objetivo foi compreender, principalmente, quais os sentidos da estratégia e como a mesma é (re) construída em comunicação. Para tanto, realizamos uma pesquisa qualitativa, por meio de um estudo de caso, com entrevistas individuais e análise de documentos, que levaram em consideração aspectos da estratégia da organização. A partir dos elementos comunicacionais como a decisão, a identificação, a institucionalização, a mediação, a cultura organizacional e a comunicação organizacional, foi possível compreender quais decisões foram reveladas nos textos analisados. As decisões atravessam esses discursos revelando uma dinâmica autorizada e formal da comunicação organizacional em paralelo com as dimensões informais incluindo as diversas percepções dos diferentes atores envolvidos no processo estratégico. No entanto, vale ressaltar que com a análise dos dados a partir da rede decisória comunicacional foi possível reafirmar a possibilidade de pensar a estratégia organizacional e como ela se realiza no âmbito do cenário pesquisado.

O protocolo International Electrotechnical Commission (IEC)-61850 tornou possível integrar os equipamentos das subestações de energia elétrica, através de uma rede de comunicação de dados Ethernet de alta velocidade. A utilização deste protocolo tem como objetivo principal a interligação dos Intelligent Electronic Devices (IEDs) para a automatização dos processos no sistema elétrico. As contribuições deste protocolo para a integração do controle e supervisão do sistema elétrico são diversas, porém, o fato de utilizar uma rede de comunicação de dados Ethernet integrada expõe o sistema elétrico à ataques cibernéticos. A norma IEC-62351 estabelece uma série de recomendações para prover segurança à rede de comunicação do sistema elétrico, dentre elas, o gerenciamento da rede de comunicação, a análise dos campos da mensagem Generic Object Oriented Substation Event (GOOSE) e a utilização de sistemas de detecção de intrusão. O presente trabalho descreve o desenvolvimento de um Intrusion Detection System (IDS) que atende os requisitos de segurança propostos pelo protocolo IEC-62351, para a identificação de ataques à comunicação realizada por mensagens GOOSE do protocolo IEC-61850, e entre equipamentos do sistema elétrico. Para o desenvolvimento desta aplicação, foram identificados os campos que compõem as mensagens GOOSE, de forma a reconhecer os valores esperados em diferentes situações de operação do sistema elétrico. Determinaram-se padrões de comportamento a serem utilizados para discernir mensagens falsas na rede de comunicação. Instalou-se e configurou-se um sistema operacional de tempo real embarcado na plataforma de desenvolvimento Zynq Board (ZYBO), juntamente com o controlador Open-Mul, para gerenciar a rede de comunicação da subestação, através do protocolo OpenFlow, realizando otimizações para o tráfego multicast. Foi desenvolvido um sistema de detecção e bloqueio de mensagens GOOSE falsas que utiliza o protocolo OpenFlow para controle da rede de comunicação do Sistema Elétrico. Desenvolveu-se ainda um sistema inteligente, utilizando-se uma Rede Neural Artificial (RNA) Nonlinear Autoregressive Model with Exogenous Input (NARX), para predição do tráfego realizado por mensagens GOOSE e detecção de ataques Distributed Deny of Service (DDOS). Os resultados obtidos demonstraram que o protocolo OpenFlow pode ser uma ferramenta interessante para controle da rede, porém, os fabricantes necessitam amadurecer sua implementação nos switches, para que sejam utilizados em produção nas redes de comunicação das subestações. O sistema de predição do tráfego gerado por mensagens GOOSE apresentou benefícios interessantes para a segurança da rede de comunicação, demonstrando potencial para compor um sistema de detecção de ataques DDOS realizado por mensagens GOOSE, na rede de comunicação das subestações de energia elétrica. / The IEC-61850 made it possible to integrate equipments of electric power system substations to a high-speed Ethernet data communication network. Its main goal is the interconnection of IEDs for the automation of processes in an electrical system. The contributions of this protocol for the integration of the control and supervision of the electrical system are diverse, although an Ethernet network exposes the electrical system for cyber attacks. The IEC-62351 states a series of recommendations to provide security to the communication network of the electrical system, such as the communication network management, the analysis of GOOSE messages and the use of intrusion detection systems. This study describes the development of an IDS that meets the security requirements proposed by the IEC-62351 standard to identify attacks on communication between GOOSE messages exchanged by electrical equipment using IEC-61850. For the development of this application, fields of the GOOSE messages were identified, in order to recognize the expected values in different power system operating conditions. Behaviour patterns were determined to detect false messages on the communication network. A real-time embedded operating system on ZYBO was installed and configured, as well as the OpenMul controller to manage the communication network of the substation through the OpenFlow protocol, performing optimizations for multicast traffic. A detection system and block tamper GOOSE messages, using the OpenFlow protocol for control of the electrical system communication network, were developed. In addition, an intelligent system using an Artificial Neural Network (ANN) Nonlinear Autoregressive Model with Exogenous Input (NARX) for predicting of the GOOSE messages traffic and the detection of Distributed Deny of Service attack (DDOS) were also developed. The results obtained show that the OpenFlow protocol may be a valuable tool for network control, however, manufacturers should maturely carry on with its implementation in the switches, so that it be used in substation communication networks. The traffic prediction system of the GOOSE messages presented interesting benefits for the security of the communication network, demonstrating potential to built a DDOS attack detection system performed by GOOSE messages on the communication network of electric power substations.

Dans cette thèse, j'étudie des jeux de données concernant des liens sociaux entre personnes (appels et SMS), leur mobilité ainsi que des informations économiques sur ces personnes, comme leur revenu et leurs dépenses. Les sept travaux couvrent un spectre assez large et apportent des contributions en informatique des réseaux mais aussi en sociologie, économie et géographie. Les questions posées sont très diverses. Comment quantifier la perte d'information causée par une agrégation de flot de liens en série de graphe ? Comment inférer les mouvements des utilisateurs quand on ne connaît que les localisations des utilisateurs aux moments des appels, et que l'on ne détecte donc que les mouvements qui ont eu lieu entre deux appels consécutifs, sans connaître leur nombre ni les instants auxquels ils ont lieu ? Est-il possible de transmettre des SMS dans une région dense en utilisant la densité des téléphones, la mobilité des utilisateurs ainsi que la localité des messages échangés ? Est-il possible de comprendre les inégalités sociales avec une approche Big Data ? Cette dernière question fait l'objet d'une première étude socio-économique approfondie au prisme du Big Data. Il a été possible d'étudier à grande échelle la stratification de la société, l'existence de clubs de riches, la ségrégation spatiale et la structure des dépenses par classe sociale.Au delà de la variété de ces études et de ces nombreuses applications, cette thèse montre que l'analyse de données individuelles riches à l'échelle d'une population permettent de répondre à de nouvelles questions et à d'anciennes hypothèses avec une approche Big Data. Cette thèse tient à mettre l'accent sur la potentialité d'une approche Big Data mais aussi de sa complémentarité avec les approches classiques (modélisation, sociologie avec enquêtes, …). Un effort particulier a été mis dans l'explication des étapes qui amènent aux résultats et dans la prise en compte des biais ce qui est trop souvent négligé. / In this thesis, I have carried out data-driven studies based on rich, large-scale combined data sets including social links between users (calls and SMS), their demographic parameters (age and gender), their mobility and their economic information such as income and spendings. These seven studies bring insights in network science but also in sociology, economy and geography. The questions asked are very diversified. How can one quantify the loss of temporal information caused by the aggregation of link streams into series of graphs? How can one infer mobility of a user from his or her localisations of calls? Is it possible to transmit SMS in a dense region by using the density of phones, the mobility of users and the locality of the messages? How can one quantify and prove empirically the social stratification of the society at a large population scale? I present, for this last question, a first socio-economic study with a data-driven approach. It has been possible to study, at a very large scale, the stratification of the society, the existence of "rich-clubs", the spatial segregation and purchase patterns for each social class. Beyond the variety of studies and their numerous applications, this thesis shows that the analysis of individual rich combined datasets at a large population scale gives the opportunity to answer long-standing hypotheses and to address novel questions. This work not only points out the potentiality of Big Data approach but also its complementarity to classical approaches (modelization, surveys, …). Particular attention was given in order to explain each steps that lead to results and to take into account biases which is too often neglected.

Made available in DSpace on 2015-10-19T11:50:06Z (GMT). No. of bitstreams: 1 anasilva2012.pdf: 1305931 bytes, checksum: 3b699e371da3ba9aaba1eb009ea9b71e (MD5) Previous issue date: 2012-03-19 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Research on the intellectual production of Antenor de Veras Nascentes, Brazilian professor and researcher, focusing on the aspects of Scientific Communication and on parameters of productivity in Science. The analysis was based on the author s life and production, in his biographical and bibliographical characteristics. The Colegio Pedro II and the Brazilian cultural life at his lifetime was the scenario. The analysis allowed to classify the documental typology of Antenor Nascentes as books, books chapters, national and interational scientific papers, and also translations and dictionaries. The latter were the central focus of his studies and research, which was manifested by the first Etimological Dictionary. The international letters received by him were the source for the identification of the his network, as a way to understand his impact outside Brazil. The research results point to multiple aspects that show Antenor Nascentes s work with a pionnering character, driven by his innovative thinking and its importance, specially in the fields of Linguistics, Phylology and Dialectology, that heavily influenced today s Linguistics. Antenor proposed paths that seem to transcend the common Brazilian thinking of his time / Pesquisa sobre a produção intelectual de Antenor de Veras Nascentes, professor e pesquisador brasileiro, sob a abordagem da Comunicação Científica e parâmetros de produtividade na Ciência. A base da análise foi a vida e obra do autor, nos seus traçados biográficos e bibliográficos, tendo como ambiente nucleador o Colégio Pedro Segundo, no cenário cultural brasileiro da época. A análise permitiu identicar a tipologia documental de Antenor Nascentes, como livros, capítulos de livros, artigos de periódicos nacionais e estrangeiros, além de traduções e dicionários, estes o foco central dos seus estudos e pesquisas, marcado pela elaboração do primeiro Dicionário Etimológico. Para a identificação da rede de comunicação do autor a fonte foi a correspondência internacional passiva, como forma de dimensionar a sua repercussão fora do Brasil. Os resultados da pesquisa revelam múltiplas facetas, desbravadoras pelo pensamento inovador e a grandeza da obra de Antenor Nascentes, especialmente nas áreas de Liguística, Filologia e Dialetologia, presente na Linguística até hoje. Os caminhos de Antenor Nascentes seguem itinerários muito além do Brasil com idéias que transcendem seu tempo

In this dissertation, we investigate a number of geometric problems in different settings. We present lower bounds and approximation algorithms for geometric problems in sequential and distributed settings. For the sequential setting, we prove the first hardness of approximation results for the following problems: \begin{itemize} \item Red-Blue Geometric Set Cover is APX-hard when the objects are axis-aligned rectangles. \item Red-Blue Geometric Set Cover cannot be approximated to within $2^{\log^{1-1/{(\log\log m)^c}}m}$ in polynomial time for any constant $c < 1/2$, unless $P=NP$, when the given objects are $m$ triangles or convex objects. This shows that Red-Blue Geometric Set Cover is a harder problem than Geometric Set Cover for some class of objects. \item Boxes Class Cover is APX-hard. \end{itemize} We also define MaxRM-3SAT, a restricted version of Max3SAT, and we prove that this problem is APX-hard. This problem might be interesting in its own right.\\ In the distributed setting, we define a new model, the fixed-link model, where each processor has a position on the plane and processors can communicate to each other if and only if there is an edge between them. We motivate the model and study a number of geometric problems in this model. We prove lower bounds on the communication complexity of the problems in the fixed-link model and present approximation algorithms for them. We prove lower bounds on the number of expected bits required for any randomized algorithm in the fixed-link model with $n$ nodes to solve the following problems, when the communication is in the asynchronous KT1 model: \begin{itemize} \item $\Omega(n^2/\log n)$ expected bits of communication are required for solving Diameter, Convex Hull, or Closest Pair, even if the graph has only a linear number of edges. \item $\Omega( min\{n^2,1/\epsilon\})$ expected bits of communications are required for approximating Diameter within a $1-\epsilon$ factor of optimal, even if the graph is planar. \item $\Omega(n^2)$ bits of communications is required for approximating Closest Pair in a graph on an $[n^c] \times [n^c]$ grid, for any constant $c>1+1/(2\lg n)$, within $\frac{n^{c-1/2}}{4}-\epsilon$ factor of optimal, even if the graph is planar. \end{itemize} We also present approximation algorithms in geometric communication networks with $n$ nodes, when the communication is in the asynchronous CONGEST KT1 model: \begin{itemize} \item An $\epsilon$-kernel, and consequently $(1-\epsilon)$-\diamapprox~ and \ep -Approximate Hull with $O(\frac{n}{\sqrt{\epsilon}})$ messages plus the costs of constructing a spanning tree. \item An $\frac{n^c}{\sqrt{\frac{k}{2}}}$-Approximate Closest Pair on an $[n^c] \times [n^c]$ grid , for a constant $c>1/2$, plus the cost of computing a spanning tree, for any $k\leq {n-1}$. \end{itemize} We also define a new version of the two-party communication problem, Path Computation, where two parties communicate through a path. We prove a lower bound on the communication complexity of this problem. / Graduate

Tato diplomová práce je studií, kvalitativním výzkumem, který má za cíl zjistit, zda ve vybraných dvou oblastech, chráněném a nechráněném území, funguje jezdecká turistika a do jaké míry odpovídá konceptu šetrné turistiky. Vzhledem k tomu, že jezdecká turistika je velmi mladý rozvíjející se druh sportovní aktivity, věnuje se práce i zodpovězení otázek, jaké má v dané oblasti jezdecká turistika podmínky a zda při jejím provozu nedochází k uživatelskému konfliktu na stezkách nebo jiným sporům. Důležité bylo i zjištění míry spolupráce jednotlivých aktérů, které tvoří komunikační síť. Pro realizaci výzkumu byla zvolena kvalitativní strategie sběru dat pomocí polostrukturovaných rozhovorů a analýza získaných dat prostřednictvím metody zakotvené teorie. Koncept tzv. měkké turistiky vychází z rešerše odborné literatury. Její znaky de facto apelují na dodržování zásad trvale udržitelného rozvoje, ze kterého tak nutně vychází teoretický rámec rozhovorů. Klíčová slova: jezdecká turistika, metoda zakotvené teorie, chráněná území, trvale udržitelný rozvoj, šetrná turistika, hipostezka, síť aktérů, komunikace, regionální politika, udržitelný cestovní ruch. Abstract My thesis is a qualitative research using inductive methods. Its aim is to create a theory about management of equine tourism in two selected areas,...

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Over the last decade, power systems have evolved dramatically around the world, owing to higher demand, stringent requirements on quality and environmental concerns that are becoming increasingly critical. With the introduction of new technologies like large-scale renewable energy, wide-area measurement based on phasor measurement units (PMUs) and consumer interaction in the distribution system, the power grid today has become more potent than ever before. Most of the defining features of the smart grid today rest on the integration of advanced communication capabilities into the grid. While communication infrastructure has become a key enabler for the smart grid, it also introduces new and complex control challenges that must be addressed. As we increasingly rely on information transmitted to distant areas over communication networks, it becomes imperative to model the effects of the communication system on the stability of the power grid. Several approaches exist in control theory to study such systems, widely referred to as Networked Control Systems (NCS). Networked control theory provides mathematical tools for system stability analysis and control in the presence of communication delays, packet dropouts and disordering due to transmission of sensor and actuator signals via a limited communication network. In this thesis, a networked control framework for smart grids with integrated commu-nication infrastructure (ICT) is developed. In particular, a networked control systems perspective is developed for two scenarios - wide-area monitoring control, and coordinated control of distributed generation sources. The effects of communication delays and packet dropouts on power system stability are modeled in detail. In the wide-area monitoring control problem, system state measurements are trans-mitted from remote locations through a communication network. The system is modeled as an NCS and a control design approach is presented to damp inter-area oscillations arising from various power system disturbances in the presence of communication constraints. In the coordinated control scenario, a power system with geographically dispersed sources is modeled as an NCS. A networked controller is designed to stabilize the system in the presence of small signal disturbances when system measurements are subject to communication delays and packet dropouts. A realistic output feedback networked control scheme that only uses voltage measurements from PMUs is also developed for practical implementation. The networked controllers designed in this thesis are validated against controllers designed by standard methods, by simulation on standard test systems. The networked controllers are found to enhance power system stability and load transfer capability even in the presence of severe packet dropouts and delays. Several extensions and theoretical problems motivated by this thesis are also proposed.

De senaste årens utveckling inom informationsteknik har påverkat organisationers struktur och arbetsmönster. Inom sjukvården har därför av flera anledningar behovet att studera olika former av kommunikation lyfts fram. Ur patientsäkerhetssynpunkt har problem med misstag kopplade till bristande informationsöverföring påtalats. Hierarkiska skillnader, otydliga roller och brister i själva informationsflödena har angetts som orsaker. Motåtgärderna är inte självklara. Sjukvården är en av samhällets mest komplexa kunskapsorganisationer och präglas av karaktärsdrag och informationsflöden kopplade till starka professioner. Kommunikationsgranskningar genomförs vanligen med målet att identifiera orsaker till ineffektiv kommunikation, brister i kommunikationsprocesser, föreslå förbättringar och ge ledning och medarbetare en mer objektiv bild av faktiska förhållanden. Forskningsområdet har dominerats av stora enkätstudier men en ökad efterfrågan har riktats mot studier på plats i den dagliga kommunikationsmiljön hos organisationer. I detta arbete har en sådan fallstudie utförts vid avdelningen för hematologisk slutenvård inom Karolinska Universitetssjukhuset i Huddinge, Stockholm. Avdelningen hade år 2012 i samband med ett lokalbyte inom sjukhuset genomfört omstruktureringar som berörde såväl roller som kanalerna för kommunikation. Verksamheten upplevdes nu inte bedrivas tillräckligt effektiv, den uppfattades ta tid och vara oöverskådlig där förbättrad kommunikation sågs som en lösning. Syftet med denna fallstudie har varit att utifrån roller och kanaler för kommunikation belysa aspekter på hur en tydligare formell struktur för dagens personalinterna kommunikation kan skapas och förmedlas. Syftet besvarades genom att kartlägga dagens formella struktur, vilket är det förväntade utbytet av information beskrivet i arbetsbeskrivningar och policys, men även genom att studera den informella struktur som utvecklats i det dagliga arbetet. En blandning av datainsamlingsmetoder har använts och organisationens kommunikationsnätverk i form av det nätverk som byggs upp av flödet av information mellan aktörer har visualiserats och analyserats. Resultatet visar på skillnader mellan den formella strukturen för personalintern kommunikation och den informella strukturen. Dessa har använts för att analysera, diskutera och föreslå hur de identifierade skillnaderna kan användas för att förtydliga roller och kanaler i den formella strukturen. Studien har identifierat sex områden där den formella strukturen kan förtydligas; en högre grad av dokumenterat kommunikativt ansvar och tydliga rutiner, en stärkt kommunikation inom arbetsteam istället för inom professioner, en definition av över-­‐ och underläkarnas kommunikativa roller, en ökad kontinuitet i centrala roller för kommunikation, en översyn av den fysiska strukturens påverkan på kommunikationen och slutligen ökade förutsättningar för snabb direkt kommunikation med informationsteknologi. / The recent technological development within information technology has affected the structure of organisations and the organisation of work. In health care, and for several reasons, the need for communication audits has thus been highlighted. Patient safety may be risked by mistakes linked to deficiencies in information transfer. Often are hierarchical structures, unclear roles and gaps in information flows suggested causes. On the other hand, the health care sector often is considered as one of society's most complex knowledge organizations, characterized by intense information flows with traits linked to strong professions. Communication audits are accomplished with the objective to identify causes of ineffective communication, lack of explicit communication processes, to suggest improvements and provide management and staff with more objective descriptions of roles and links. The research field has for a while been dominated by large-­‐scale surveys and resent studies has pointed at the need for studies of daily communication environments at site of organizations. This is such a study, carried through at a department for inpatient care at the University Hospital Karolinska, located in Huddinge, Stockholm. In 2012, the studied department relocated into new facilities and completed a small restructuring of its organization, affecting roles and channels of communication. The perception of the new organization was inefficiency, both in time and difficulties to overview the structure. The purpose of this thesis has therefore been to discuss and highlight how to clarify formal structure of the internal communication among staff based on parameters such as roles and channels of communication. The study maps today's formal structure, which is the expected exchange of information as described in job descriptions and work policies and compares this with developed informal structures based on how employees prefer to exchange information. A mix of data collection methods is used. An analysis is conducted were the organization's communication network as perceived as exchange of information between the employees is visualised. The results showed differences between the formal structure and the informal structure that could be used to highlight aspects of how the identified differences could be used to clarify the formal structure. The study points at six areas were the formal structure may be elucidated; more documented communicative responsibilities and procedures, a strengthening of communication within working groups rather than within professions, a definition of the chief physician and the assistant physicians' communicative roles, an increased continuity in key roles for communication, a review of the physical structure's impact on communication and finally, create conditions for fast communication with information technology.