<p>Abstract</p><p>As online social network services are becoming one of the dominant media channels the importance of disseminating messages through them is of high importance for governments, organizations, companies etc. The online social network services are several and changes rapidly as they grow and evolve. Being networks, the services give the user the tools to send, as well as receive text and information. This proposes us with yet another obstacle in communication via online social network services since sender and receiver merges together.</p><p>Online social network services and the Blogosphere, which essentially also is a network, exist in the context of Web 2.0. The crucial feature of Web 2.0 is to a large degree the harnessing of collective intelligence i.e. the collection of individual knowledge and information. Many of the tools and sites within Web 2.0 are therefore of a network structure, hence further stressing the importance to communicate via networks in general.</p><p>Network Analysis is the discipline through which we can see and understand the larger patterns of networks. In this thesis I have looked into three key concepts of Network Analysis; Weak Links, Growth and Preferential Attachment. I have found that we can use the knowledge of Network Analysis to disseminate messages via online social network services since it provides us with the raw structures of how networks tend to grow, and how messages tend to disseminate.</p><p>Title: Web 2.0 and Network Society – PR and Communication: The Challenge of Online Social Networks</p><p>Number of pages: 34</p><p>Author: Max Tandefelt</p><p>Tutor: Else Nygren</p><p>Course: Media and Communication Studies C</p><p>Period: HT 07</p><p>University: Division of Media and Communication, Department of Information Science, Uppsala University.</p><p>Purpose/Aim: Facilitate message dissemination through online social network services, as they are becoming one of the dominant media channels</p><p>Material/Method: Network Analysis</p><p>Main results: I have presented crucial concepts of Network Analysis that can be used for message dissemination via online social network services</p><p>Keywords: Online Social Network Services, Network Analysis, Web 2.0, Message Dissemination</p>

Despite the fact that swidden agriculture has been the subject of decades of research, questions remain about the extent to which it is constrained by demographic growth and if it can adapt to environmental limits. In this dissertation I analyze ethnographic and ethnohistorical evidence from the Toledo District, Belize, and suggest that Q'eqchi' Maya swidden agriculture may be more ecologically adaptive than previously thought. I use social network analysis to examine farmer labor exchange networks from a chronosequence of five villages where swidden is used. Results suggest that changes in land-use patterns, network structure, and reciprocity rates may increase the system's resilience to changes in the forest's agricultural productivity. I develop a novel interpretation of labor reciprocity that highlights how unreciprocated exchanges, when they occur within the context of a social network, may limit overexploitation of a common property resource. These results are then interpreted in the context of panarchy theory; I suggest that the structural variability observed in labor exchange networks may explain how Q'eqchi' swidden maintains its identity under changing environmental conditions - a definition of resilience. Thus, the resulting picture of Q'eqchi' swidden is one of socioecological resilience rather than homeostasis; dynamic labor exchange networks help maintain a village's social cohesion, ultimately limiting pioneer settlements and slowing overall rates of deforestation. A historical and demographic analysis of market incursions into southern Belize supports this conclusion.

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社會網路分析（social network analysis）將社會關係以網路形式表示，從原本純粹分析社會互動的工具，到近年來被廣泛被應用在社會學、組織研究、資訊科學、生物學、語言學等各種領域，藉由引入數學圖學理論與與日益精進的電腦處理能力，使得社會網路分析能從有別於以往的角度找出個體間行動的規律；而詞義相似度（word similarity）是資訊檢索等技術發展的基礎課題之一，近年來對詞義相似度的量測有許多方法的提出。 本研究針對英語字詞利用社會網路分析這樣的工具，藉由提出不同的網路建構方式，以語料庫為資料來源，設定網路節點與連結關係，以共現網路（co-occurrence networks）為基礎，經由改變產生與篩選的條件，觀察以社會網路分析已有的性質或指標做調整，是否可以對詞義相似度提供另一種量測方式；同時以目前詞義相似度研究上已有同義詞標準評比對前述產生的網路與所計算的性質做驗證，並進一步探討使用社會網路分析在詞義相似度研究上的適用性。

Understanding of a global biological network structure by studying its simple local properties through the well-developed field of graph theory is of interest. In particular, in this research an observed biological network was explored through a simulation study. However, one difficulty in such exploration lies on the fitting of graphical models on biological network data. An Exponential Random Graph Model (ERGM) was considered to determine estimations of the several network attributes of complex biological network data. We also compared the estimates of observed network to our random simulated network for both Markov Chain Monte Carlo Maximum Likelihood Estimation (MCMCMLE) and Maximum Pseudo Likelihood Estimation (MPLE) methods under ERGM. The motivation behind this was to determine how different the observed network could be from a randomly simulated network if the physical numbers of attributes were approximately same. Cut-off points of some common attributes of interest for different order of nodes were determined through simulations. We implemented our method to a known regulatory network database of E. coli. / Department of Mathematical Sciences

<p>Ostensibly, BITs are the ideal international treaty. First, until just recently, they almost uniformly came with explicit dispute resolution mechanisms through which countries could face real costs for violation (Montt 2009). Second, the signing, ratification, and violation of them are easily accessible public knowledge. Thus countries presumably would face reputational costs for violating these agreements. Yet, these compliance devices have not dissuaded states from violating these agreements. Even more interestingly, in recent years, both developed and developing countries have moved towards modifying the investor-friendly provisions of these agreements. These deviations from the expectations of the credible commitment argument raise important questions about the field's assumptions regarding the ability of international treaties with commitment devices to effectively constrain state behavior.</p> / Dissertation

The study of social network dynamics has become an increasingly important component of many disciplines in the social sciences. In the past decade, statistical models and methods have been proposed which permit researchers to draw statistical inference on these dynamics. This thesis builds on one such family of models, the stochastic actor oriented model (SAOM) proposed by Snijders [2001]. Goodness of fit for SAOMs is an area that is only just beginning to be filled in with appropriate methods. This thesis proposes a Mahalanobis distance based, Monte Carlo goodness of fit test that can depend on arbitrary features of the observed network data and covariates. As remediating poor fit can be a difficult process, a modified model distance (MMD) estimator is devised that can help researchers to choose among a set of model elaborations. In practice, panel data is typically used to draw SAOM-based inference. This thesis also proposes a score-type test for time heterogeneity between the waves in the panel that is computationally cheap and fits into a convenient, forward model selecting workflow. Next, this thesis proposes a rigorous method for aggregating so-called relational event data (e.g. emails and phone calls) by extending the SAOM family to a family of hidden Markov models that suppose a latent social network is driving the observed relational events. Finally, this thesis proposes a measurement model for SAOMs inspired by error-in-variables (EiV) models employed in an array of disciplines. Like the relational event aggregation model, the measurement model is a hidden Markov model extension to the SAOM family. These models allow the researcher to specify the form of the mesurement error and buffer against potential attenuating biases and other problems that can arise if the errors are ignored.

The structure of social networks, and people's position within these networks, are important predictors of many individual and group-level outcomes. One type of social networks that is regularly studied are the mutually interdependent relations of friends. This thesis focusses on friendship networks between adolescents in the context of schools. Arguably the most important and consistently found regularities in adolescent friendship networks are i) the tendency of friendships to be mutual, called reciprocity; ii) their tendency to cluster in groups, known as transitivity; and iii) the tendency of friendships to be present between those that are similar to one another, called homophily. Various social theories originating in different disciplines have theoretically proposed and empirically found micro-mechanisms that explain the regular occurrence of these substructures in friendship networks. This thesis introduces a framework of how the relation between these different networks tendencies can be understood. I propose that each of the three network evolution mechanisms can be connected to a type of social situation in which friends interact to form and maintain their friendships. Social situations that are dyadic and only involve two persons are connected to reciprocal friendships. Group-based social situations, on the other hand, are related to transitivity and homophily, where the groups are either defined socially or through common characteristics. Starting from this proposition, I suggest that when two adolescents share one forum for interaction with one another, i.e. they regularly meet within one of the social situations, meeting in additional other situations does not increase the likelihood of a friendship tie existing as much as could be expected from the sum of the effect of meeting in either situation. Consequently, I expect a negative interaction between the different network mechanisms. After a series of empirical analyses that support the outlined reasoning, I use the developed perspective to investigate how the micro-mechanisms contribute differentially to the creation of newly formed friendships and to the maintenance of already existing friendships. Finally, I show how a situational understanding of friendship can be used to differentiate which friendships are most important for social influence and for peer pressure.