The aim of this essay was to describe the power elite of the Swedish town Karlshamn, and its influences on the local political process before the realization of the narrow-gauge railway Karlshamn-Wislanda-Jernväg. During the mid 19th century, a revolutionary period began in the Swedish pre-industrial epoch. The political and institutional regulatory frameworks were disassembled and restructured, away from protectionism and centrally controlled administration, for the benefit of free trade, local self-government and liberalism. The changes were carried through during times marked by a drastic increasing native population and upcoming demands for adjustments to meet the growth of the industrial-, trade- and labour markets. An essential industrial development factor was the building of the national railway network, which started after some important decisions in the Swedish Riksdag during the 1850´s. In close connection with governmental initiatives to build national trunk lines, processes on the local political arenas were initiated to rapidly obtain connections to these planned main lines. Focus in this study was put on the town Karlshamn 1855-1874 and the main document sources that were examined consisted of protocols and petitions from errands on the local political arenas, f.e. the town council. The material was methodically revised by means of a network- and field analysis. Through this analytical method it was possible to confirm the power elite actors, their potential networks and reproduced groups. The results point to the importance of the formal networks an their contributions to the accumulation of social capital. Above all, this was significant for the most important individuals in the process, the local wholesale dealers Edvard Ferdinand Meyer and Carl Gustaf Berg. The process also resulted in a reproduction of local political power, and the dominance on the political field was continued. All through the twenty-year lasting process, the railway issue became a possibility for the local elite, with representatives from the trading companies, to mobilize the political decisions in the direction of continuous economic development, and enlargement of the town´s commercial area. In the town of Karlshamn, with a stagnating economy, the new infrastructure, beside the connection to the main national lines, constituted a lifeline towards continuous financial expansion and competitiveness.

<p>What are the effects of political information on public opinion, political participation, and electoral outcomes? In this dissertation, I address these questions and investigate the ways that people acquire and incorporate information based on their levels of political knowledge and attentiveness. I examine the effects of political information among three groups whom we would expect to learn differently: those people with little knowledge or interest in politics; the potentially interested who possess some, but not much, knowledge; and the attentive experts. </p><p>In my first chapter, I look at the effects of information on people with little or no knowledge of politics by asking, "Do candidate visits affect voting decisions and candidate evaluations?" I link survey data with the location and topics of all speeches given by George W. Bush and John Kerry in 2004 to empirically test the conventional wisdom that candidate appearances change electoral outcomes. I find that candidate visits do provide information to voters and that those effects are conditioned on consumption of local media. In my second chapter, I look at people with some knowledge of politics: college students. I ask, "How does the information that students 'incidentally' encounter in electronic social networks like Facebook.com shape their knowledge of current political events and their participation?" To answer these questions, I conducted a survey with an embedded experiment. I find that students do learn from Facebook, though the effects are small and vary across groups. My third chapter investigates the ways that the politically attentive incorporate information by asking, "What campaign information matters? Which campaign events are actually informative?" I develop a new measure of information flow using data from a political prediction market and a Bayesian estimation technique that adapts models from the economics literature. This measure offers a reliable way to describe the importance of campaign events that does not suffer from either post hoc judgments or reports from the principals involved in the campaign. Together, these projects address the consequences of political information in contemporary politics.</p> / Dissertation

<p>Trust has played a central role in the design of open distributed systems that span distinct administrative domains. When components of a distributed system can assess the trustworthiness of their peers, they are in a better position to interact with them. There are numerous examples of distributed systems that employ trust inference techniques to regulate the interactions of their components including peer-to-peer file sharing systems, web site and email server reputation services and web search engines.</p> <p>The recent rise in popularity of Online Social Networking (OSN) services has made an additional dimension of trust readily available to system designers: social trust. By social trust, we refer to the trust information embedded in social links as annotated by users of an OSN. This thesis' overarching contribution is methods for employing social trust embedded in OSNs to solve two distinct and significant problems in distributed information systems. </p> <p>The first system proposed in this thesis assesses the ability of OSN users to correctly classify online identity assertions. The second system assesses the ability of OSN users to correctly configure devices that classify spamming hosts. In both systems, an OSN user explicitly ascribes to his friends a value that reflects how trustworthy he considers their classifications. In addition, both solutions compare the classification input of friends to obtain a more accurate measure of their pairwise trust. Our solutions also exploit trust transitivity over the social network to assign trust values to the OSN users. These values are used to weigh the classification input by each user in order to derive an aggregate trust score for the identity assertions or the hosts.</p> <p>In particular, the first problem involves the assessment of the veracity of assertions on identity attributes made by online users. Anonymity is one of the main virtues of the Internet. It protects privacy and freedom of speech, but makes it hard to assess the veracity of assertions made by online users concerning their identity attributes (e.g, age or profession.) We propose FaceTrust, the first system that uses OSN services to provide lightweight identity credentials while preserving a user's anonymity. FaceTrust employs a ``game with a purpose'' design to elicit the</p> <p>opinions of the friends of a user about the user's self-claimed identity attributes, and uses attack-resistant trust inference to compute veracity scores for the attributes. FaceTrust then provides credentials, which a user can use to corroborate his online identity assertions. </p> <p>We evaluated FaceTrust using a crawled social network graph as well as a real-world deployment. The results show that our veracity scores strongly correlate with the ground truth, even when a large fraction of the social network users are dishonest. For example, in our simulation over the sample social graph, when 50% of users were dishonest and each user employed 1000 Sybils, the false assertions obtained approximately only 10% of the veracity score of the true assertions. We have derived the following lessons from the design and deployment of FaceTrust: a) it is plausible to obtain a relatively reliable measure of the veracity of identity assertions by relying on the friends of the user that made the assertion to classify them, and by employing social trust to determine the trustworthiness of the classifications; b) it is plausible to employ trust inference over the social graph to effectively mitigate Sybil attacks; c) users tend to mostly correctly classify their friends' identity assertions.</p> <p>The second problem in which we apply social trust involves assessing the trustworthiness of reporters (detectors) of spamming hosts in a collaborative spam mitigation system. Spam mitigation can be broadly classified into two main approaches: a) centralized security infrastructures that rely on a limited number of trusted monitors (reporters) to detect and report malicious traffic; and b) highly distributed systems that leverage the experiences of multiple nodes within distinct trust domains. The first approach offers limited threat coverage and slow response times, and it is often proprietary. The second approach is not widely adopted, partly due to the </p> <p>lack of assurances regarding the trustworthiness of the reporters. </p> <p>Our proposal, SocialFilter, aims to achieve the trustworthiness of centralized security services and the wide coverage, responsiveness, and inexpensiveness of large-scale collaborative spam mitigation. It enables nodes with no email classification functionality to query the network on whether a host is a spammer. SocialFilter employs trust inference to weigh the reports concerning spamming hosts that collaborating reporters submit to the system. To the best of our knowledge, </p> <p>it is the first collaborative threat mitigation system that assesses the trustworthiness of the reporters by both auditing their reports and by leveraging the social network of the reporters' human administrators. Subsequently, SocialFilter weighs the spam reports according to the trustworthiness of their reporters to derive a measure of the system's belief that a host is a spammer. </p> <p>We performed a simulation-based evaluation of SocialFilter, which indicates its potential: </p> <p>during a simulated spam campaign, SocialFilter classified correctly 99% of spam, while yielding no false positives. The design and evaluation of SocialFilter offered us the following lessons: a) it is plausible to introduce Sybil-resilient OSN-based trust inference mechanisms to improve the reliability and the attack-resilience of collaborative spam mitigation; b) using social links to obtain the trustworthiness of reports concerning spammers (spammer reports) can result in comparable spam-blocking effectiveness with approaches that use social links to rate-limit spam (e.g., Ostra); c) unlike Ostra, SocialFilter yields no false positives. We believe that the design lessons from SocialFilter are applicable to other collaborative entity classification systems.</p> / Dissertation

<p>Abstract</p> <p>Risky foraging is a male reproductive tactic in most polygynous mammals. It is speculated to result from intense intra-sexual reproductive competition. Consequently this behavior has been speculated to increase a male's reproductive competitiveness. However, individual males may differ in their propensity to take foraging risks. </p> <p>We therefore conducted a study on crop raiding behavior (a risky foraging strategy) in African elephants from the greater Amboseli ecosystem, in southern Kenya. We specifically examined the population sizes, gender and patterns of raiding elephants and investigated the effect of crop-raiding and genetic heterozygosity on male body size. We also examined the influence of age and genetic relatedness on observed patterns of association. Finally, we examined the role of life history milestones, association patterns and social structure on the acquisition of crop raiding behavior among wild free ranging male African elephants. With regard to the influence of association patterns on crop raiding behavior, we were specifically interested in understanding the mechanisms by which social learning might occur among male elephants.</p> <p>Our results showed that 241elephants from different populations in the ecosystem converged to raid farms. Approximately 35% of raiders were from Amboseli National Park, and the rest were other populations in the ecosystem. We observed only post-pubertal males but not females to raid. About one third of post-pubertal males from the Amboseli population were raiders. We found evidence of habitual raiding by some individuals. Crop raiding predicted post-pubertal male size, with raiders being larger than non-raiders. This result suggests that taking risks pays off for males. Our results also showed that other variables known to influence growth like genetic heterozygosity had no effect on size-for-age in male elephants, because low-heterozygosity males were rare. The probability that an individual male is a crop raider was greater for older individuals than young males. The probability that a male is a raider was greater when his two closest associates were raiders versus when they were not raiders and when a male's second closest associate was older, versus when his second closest associate was of similar age or younger. These results suggest that increasing energetic demands associated with life history milestones and social learning play a significant role in the initiation of crop raiding behavior. Raiders did not cluster into separate social units from non-raiders, probably due to the nature of social learning exhibited by this species and due to the diffuse nature of male elephant social units.</p> <p>These results have implications for understanding the evolution of risky foraging behavior in males, and for understanding the role of kin selection, dominance hierarchies and social learning in male elephant social systems. Results also have implications for understanding the spread of adaptive complex behavior in natural populations.</p> / Dissertation

<p>Online Social Network (OSN) services such as Facebook and Google+ are fun and useful. Hundreds of millions of users rely on these services and third-party applications to process and share personal data such as friends lists, photos, and geographic location histories. The primary drawback of today's popular OSNs is that users must fully trust a centralized service provider to properly handle their data.</p><p>This dissertation explores the feasibility of building feature-rich, privacy-preserving OSNs by shifting the bases for trust away from centralized service providers and third-party application developers and toward infrastructure providers and OSN users themselves.</p><p>We propose limiting the trust users place in service providers through two decentralized OSNs: Vis-a-Vis and Confidant. In Vis-a-Vis, privacy-sensitive data is only accessed by user-controlled code executing on ``infrastructure as a service" platforms such as EC2. In Confidant this data may only be accessed by code running on desktop PCs controlled by a user's close friends. To reduce</p><p>the risks posed by third-party OSN applications, we also developed a Multi-User Taint Tracker (MUTT). MUTT is a secure ``platform as a service" that ensures that third-party applications adhere to access policies defined by service providers and users. </p><p>Vis-a-Vis is a decentralized framework for location-based OSN services based on the</p><p>privacy-preserving notion of a Virtual Individual Server (VIS). A VIS is a personal virtual machine running within a paid compute utility. In Vis-a-Vis, a person stores her data on her own VIS, which arbitrates access to that data by others. VISs self-organize into overlay networks corresponding to social groups with whom their owners wish to share location information. Vis-a-Vis uses distributed location trees to provide efficient and scalable operations for creating, joining, leaving, searching, and publishing location data to these groups.</p><p>Confidant is a decentralized OSN platform designed to support a scalable application framework for OSN data without compromising users' privacy. Confidant replicates a user's data on servers controlled by her friends. Because data is stored on trusted servers, Confidant allows application code to run directly on these storage servers. To manage access-control policies under weakly-consistent replication, Confidant eliminates write conflicts through a lightweight cloud-based state manager and through a simple mechanism for updating the bindings between access policies and replicated data.</p><p>For securing risks from third-party OSN applications, this thesis proposes a Multi-User Taint Tracker (MUTT) -- a secure ``platform as a service'' designed to ensure that third-party applications adhere to access policies defined by service providers and users. Mutt's design is informed by a careful analysis of 170 Facebook apps, which allows us to characterize the requirements and risks posed by several classes of apps. Our MUTT prototype has been integrated into the AppScale cloud system, and experiments show that the additional data-confidentiality guarantees of running an app on MUTT come at a reasonable performance cost.</p> / Dissertation

Along with the rise of smart phones, Google announced a mobile platform named Android, having the advantages of open source, free, etc, had become one of the popular mobile development platforms. But there are following restrictions on the file sharing of the smart phones: 1. The File Sharing between mobiles is used frequently, but the APP of the File Sharing in Google play contains user sharing their files on the same LAN, can¡¦t share on the WAN. 2. The cloud storage space has the file sharing strategy on WAN, but doesn¡¦t on LAN. 3. File sharing of mobile devices always hope to be able to share file through one-to-many Push, delivery to the nearby users but the app of the smart phone file sharing don¡¦t have this function. Therefore, this thesis architects a File Sharing platform, which is based on social networks, passing through pub/sub pattern to sharing files.In the File Sharing System, if users are on the same LAN can share files directly. We implement one-to-many file sharing system, so that users can obtain files automatically. If on the WAN, files are delivered by the intermediary server. This System also supports Multimedia streaming, users can play media from Server; need not download files in the local device. This paper use protocol buffer to the communication between devices, compared with the current common XML, JSON and other common file formats, there is a better package rates and privacy, and provides a convenient user interface to share files.

This research addresses the question of what factors lead Mexican-origin individuals living in the U.S. to seek a new residence outside their Southwestern state of residence. The analysis examines three hypotheses: (1) the human capital hypothesis that college graduates have higher odds of migrating out of the core region than those with less than a high school education; (2) the household social capital hypothesis that posits that the presence of a household member born outside the core increases the odds of migration; and (3) the community social capital hypothesis which states that householders residing in an area with community social capital will have higher odds of leaving the core than those living in areas with no community social capital. These hypotheses are investigated using three models: (1) a full model that includes both native- and foreign-born Mexican-origin householders; (2) a native-born model which includes only native-born Southwest householders; and (3) a foreign-born models that includes only foreign-born Mexican-origin householders. By using the Saenzian region-concepts of core, periphery, and frontier, I find: (1) limited support for the human capital hypothesis; (2) consistent support for the household social capital; and (3) no support for the community social capital. The analysis is important to sociological theory and demography because it specifically endeavors to explain how the connections between three kinds of capital?human, household, and community?shape the decision to leave the Southwest for other regions of the country. By computing statistical and theoretical particulars, the thesis ascertains that migration-selectivity theories regarding the general population are useful in theorizing Mexican-origin interregional migration. Findings expand existing sociological literature by theorizing how human, household, and community capital operate under the Saenzian regions to shape the interregional migration of the growing Mexican-origin population of the U.S.

Providing support for the agricultural development of small farmers is the main goal of the project Agriculture in Guatemala: Technology, Education and Commercialization (AGTEC). To accomplish this, it is necessary, to identify the characteristics and needs of participants, as well as their environmental, social, and farming conditions. Through this study, two case studies were conducted to identify and analyze the context of small farmers of the region. This research study used qualitative and participative methods, such as interviews, focus groups, and observation, to gather data about the participants' thoughts and opinions concerning their situations. The case study systemically gathered information about the conditions and needs of small farmers to provide a better understanding of the people and their interactions within the farm systems. This needs assessment showed how the farmers' decisions about adoption are related to their interactions on their farms. Therefore, this study analyzed the system, as a whole, to identify priorities among different critical components that will provide optimum results for beneficiaries. These priorities will allow the identification of appropriate technologies that will satisfy the needs of small farmers according to their local, cultural, and economic conditions. The appropriate technologies need to be diffused among the farmers for adoption. Rogers observed that technologies that are diffused by opinion leaders are adopted by their peers. Thus, the second case study analyzed the social networks and their leaders to observe their potential to support the diffusion process of technologies. The study revealed the presence of diverse social networks, one provided by the political structure, others based on organized groups of farmers and other informal networks formed by independent farmers. Data also showed that opinion leaders have desired roles and characteristics among their networks. Therefore diffusion of innovations through formal and non-formal leaders represents a promising strategy as they are recognized and respected by peers. The diffusion of innovations through opinion leaders promotes the active participation of local members, validates the innovations, and sustains adoption over time. Therefore, the analysis of the social networks and selection of opinion leaders supports the diffusion process of the AGTEC project in Chimaltenango, Guatemala.

Social networks and social capital issues have been combined with organizational behavior scope for decades. Nevertheless, the difficulty of methodology and data collection causes the rareness of related empirical study. In this dissertation, multi-level research structure and hypothesis, including dyadic-level, individual-level, and network-level, are proposed to be examined respectively. 505 questionnaires were collected from 17 companies providing a great deal of support to be analyzed by social network analysis technique of UCINET VI for windows. The following are results and conclusions of each research level: For dyadic level, ¡§cognition-based trust¡¨ and ¡§affect-based trust¡¨ are core variables representing dyadic relationship quality. Similarity/attraction paradigm, self-categorizing, and social identity were used as theory basis to prove the positive effects of antecedents embracing gender, education level, age, and tenure similarity, also the ¡§value fit¡¨ and ¡§cognitive friendship¡¨, on dyadic relationship quality and interaction behaviors. The results demonstrate the higher similarity of education level and tenure between two individuals, the greater level of value fit, friendships, cognitive-based trust, affect-based trust, knowledge sharing, and citizenship behaviors. Cognition and affect trusts between two individuals cause the knowledge sharing and citizenship behaviors for each other. The positive effects of gender differences on relationship quality are discovered unexpectedly. For individual level, the normalized in-degree of centralities of ¡§advice networks¡¨ and ¡§friendship networks¡¨ were measured by social network analysis techniques to be examined as core variables. I draw on the formal organization structure (work flow network centrality and rank), personalities (conscientiousness, high-low self-monitoring, extraversion/introversion, collectivism/individualism), and job characteristics (job inter-dependency and work loading) for the antecedent variables of ¡§advice networks¡¨, ¡§friendship networks¡¨, and personal contextual performance (knowledge sharing and citizenship behaviors). Also treat the ¡§personal social capital¡¨ as the mediate variables among personal social networks and personal contextual performance. The results demonstrate the positive effects of rank, work flow network centrality, conscientiousness, self-monitoring, collectivism, and job inter-dependency on the centrality of advice network. The negative-effects of work loading are also verified. For the centrality of friendship network, the results proved the positive effects of the work flow network centrality, and conscientiousness, also the negative effects of work loading on it. Knowledge sharing behaviors representing the part of personal contextual performance are positively affected by conscientiousness, self-monitoring, rank, work flow network centrality, advice network centrality, friendship network centrality, and personal social capital. Work loading influences the knowledge sharing behaviors negatively. Citizenship behaviors that also represent the part of personal contextual performance are influenced by advice network centrality, friendship network centrality, and personal social capital. The mediating effects of social capital among personal social networks and personal contextual performance are also manifested. For network level, the comparisons among formal organization structure and nine intra-organizational social networks demonstrate the influences of rank and division on social network structural configuration. I also draw on the similarity-attraction paradigm as the theory basis to examine the positive effects of the similarity of department, gender, age, education-level, marriage status, and nine intra-organizational social network matrices on the relational matrices of friendship and affect-trust. MRQAP (Multiple Regression Quadratic Assignment Procedure) technique is applied on this analysis. The results verified the positive effects of the similarity of department, gender, and marriage status on friendship and affect-trust between two individuals. In addition, the theoretical and managerial implications, limitations and future research questions based on the findings and suggestions for future research are provided.

Recommender systems aim to suggest relevant items that are likely to be of interest to the users using a variety of information resources such as user pro