In the context of existing adversarial attack schemes based on unsupervised graph contrastive learning, a common issue arises due to the discreteness of graph structures, leading to reduced ...reliability of structural gradients and consequently resulting in the problem of attacks getting trapped in local optima. An adversarial attack method based on momentum gradient candidates is proposed in this research. Firstly, the gradients obtained by back-propagation are transformed into momentum gradients, and the gradient update is guided by overlaying the previous gradient information in a certain proportion to accelerate convergence speed and improve the accuracy of gradient update. Secondly, the exploratory process of candidate and evaluation is carried out by summing the momentum gradients of the two views and ranking them in descending order of saliency. In this process, selecting adversarial samples with stronger perturbation effects effectively improves the success rate of adversarial attacks. Finally, extensive experiments were conducted on three different datasets, and our generated adversarial samples were evaluated against contrastive learning models across two downstream tasks. The results demonstrate that the attack strategy proposed outperforms existing methods, significantly improving convergence speed. In the link prediction task, targeting the Cora dataset with perturbation rates of 0.05 and 0.1, the attack performance outperforms all baseline tasks, including the supervised baseline methods. The attack method is also transferred to other graph representation models, validating the method's strong transferability.
Networks pervade social and economic life, and they play a prominent role in explaining a huge variety of social and economic phenomena. Standard economic theory did not give much credit to the role ...of networks until the early 1990s, but since then the study of the theory of networks has blossomed. At the heart of this research is the idea that the pattern of connections between individual rational agents shapes their actions and determines their rewards. The importance of connections has in turn motivated the study of the very processes by which networks are formed.
The rapid evolution of the Internet is reshaping the media landscape, with frequent claims of an accelerated and increasingly outraged news cycle. We test these claims empirically, investigating the ...dynamics of news spread, decay, and sentiment on Twitter (now known as X) compared to talk radio. Analyzing 2019-2021 data including 517,000 hour of radio content and 26.6 million tweets by elite journalists, politicians, and general users, we identified 1694 news events. We find that news on Twitter circulates faster, fades faster, and is more negative and outraged compared to radio, with Twitter outrage also more short-lived. These patterns are consistent across various user types and robustness checks. Our results illustrate an important way social media may influence traditional media: framing and agenda-setting simply by speaking first. As journalism evolves with these media, news audiences may encounter faster shifts in focus, less attention to each news event, and much more negativity and outrage.
For decades, a new type of terrorism has been quietly gathering ranks in the world. America's ability to remain oblivious to these new movements ended on September 11, 2001. The Islamist fanatics in ...the global Salafi jihad (the violent, revivalist social movement of which al Qaeda is a part) target the West, but their operations mercilessly slaughter thousands of people of all races and religions throughout the world. Marc Sageman challenges conventional wisdom about terrorism, observing that the key to mounting an effective defense against future attacks is a thorough understanding of the networks that allow these new terrorists to proliferate. Based on intensive study of biographical data on 172 participants in the jihad,Understanding Terror Networksgives us the first social explanation of the global wave of activity. Sageman traces its roots in Egypt, gestation in Afghanistan during the Soviet-Afghan war, exile in the Sudan, and growth of branches worldwide, including detailed accounts of life within the Hamburg and Montreal cells that planned attacks on the United States. U.S. government strategies to combat the jihad are based on the traditional reasons an individual was thought to turn to terrorism: poverty, trauma, madness, and ignorance. Sageman refutes all these notions, showing that, for the vast majority of the mujahedin, social bonds predated ideological commitment, and it was these social networks that inspired alienated young Muslims to join the jihad. These men, isolated from the rest of society, were transformed into fanatics yearning for martyrdom and eager to kill. The tight bonds of family and friendship, paradoxically enhanced by the tenuous links between the cell groups (making it difficult for authorities to trace connections), contributed to the jihad movement's flexibility and longevity. And although Sageman's systematic analysis highlights the crucial role the networks played in the terrorists' success, he states unequivocally that the level of commitment and choice to embrace violence were entirely their own.Understanding Terror Networkscombines Sageman's scrutiny of sources, personal acquaintance with Islamic fundamentalists, deep appreciation of history, and effective application of network theory, modeling, and forensic psychology. Sageman's unique research allows him to go beyond available academic studies, which are light on facts, and journalistic narratives, which are devoid of theory. The result is a profound contribution to our understanding of the perpetrators of 9/11 that has practical implications for the war on terror.
When was the last time you participated in an election for an online group chat or sat on a jury for a dispute about a controversial post? Platforms nudge users to tolerate nearly all-powerful ...admins, moderators, and “benevolent dictators for life.” In Governable Spaces, Nathan Schneider argues that the internet has been plagued by a phenomenon he calls “implicit feudalism”: a bias, both cultural and technical, for building communities as fiefdoms. The consequences have spread far beyond online spaces themselves. Feudal defaults train us to give up on our communities’ democratic potential, inclining us to be more tolerant of autocratic tech CEOs and authoritarian politicians. But online spaces could be sites of a creative, radical, and democratic renaissance. Schneider shows how the internet can learn from governance legacies of the past to become a more democratic medium, responsive and inventive unlike anything that has come before. “A prescient analysis of how we create democratic spaces for engagement in the age of polarization. Governable Spaces is new, impeccably researched, and imaginative.” — Zizi Papacharissi, Professor of Communication and Political Science, University of Illinois at Chicago “This visionary book points a way to scrapping capitalist realism for community control over our digital spaces. Nathan Schneider generously brings together disparate wisdom from abolitionists, Black feminists, and cooperative software engineers to spark our own imaginations and experiments.” — Lilly Irani, author of Chasing Innovation: Making Entrepreneurial Citizens in Modern India “From feminist theory to blockchain governance, this dizzying array of topics pulls readers out of their comfort zone and forces a novel look at very old questions.” — Ethan Zuckerman, Associate Professor of Public Policy, Communication, and Information and Computer Sciences, University of Massachusetts Amherst
This important new book is a comparative study of social mobility based on qualitative interviews with middle-class parents in America and Britain. It addresses the key issue in stratification ...research, namely, the stability of class relations and middle-class reproduction. Drawing on interviewee accounts of how parents mobilised economic, cultural and social resources to help them into professional careers, it then considers how the interviewees, as parents, seek to increase their children's chances of educational success and occupational advancement. Middle-class parents may try to secure their children's social position but it is not an easy or straightforward affair. With the decline of the quality of state education and increased job insecurity in the labour market since the 1970s and 1980s, the reproduction of advantage is more difficult than in the affluent decades of the 1950s and 1960s. The implications for public policy, especially public investment in higher education, are considered.
This book explores social mechanisms that drive network change and link them to computationally sound models of changing structure to detect patterns. This text identifies the social processes ...generating these networks and how networks have evolved. Reviews: "this book is easy to read and entertaining, and much can be learned from it. Even if you know just about everything about large-scale and temporal networks, the book is a worthwhile read; you will learn a lot about SNA literature, patents, the US Supreme Court, and European soccer." (Social Networks) "a clear and accessible textbook, balancing symbolic maths, code, and visual explanations. The authors' enthusiasm for the subject matter makes it enjoyable to read" (JASSS)
No one has failed to notice that the current generation of youth is deeply-some would say totally-involved with digital media. Professors Howard Gardner and Katie Davis name today's young people The ...App Generation, and in this spellbinding book they explore what it means to be "app-dependent" versus "app-enabled" and how life for this generation differs from life before the digital era.
Gardner and Davis are concerned with three vital areas of adolescent life: identity, intimacy, and imagination. Through innovative research, including interviews of young people, focus groups of those who work with them, and a unique comparison of youthful artistic productions before and after the digital revolution, the authors uncover the drawbacks of apps: they may foreclose a sense of identity, encourage superficial relations with others, and stunt creative imagination. On the other hand, the benefits of apps are equally striking: they can promote a strong sense of identity, allow deep relationships, and stimulate creativity. The challenge is to venture beyond the ways that apps are designed to be used, Gardner and Davis conclude, and they suggest how the power of apps can be a springboard to greater creativity and higher aspirations.
The American Family Physician (AFP) photo competition encourages students and residents to share their stories through photographs about how they use the AFP journal.
This book investigates regulatory and social pressures that social media companies face in the aftermath of high profile cyberbullying incidents. The author's research evaluates the policies ...companies develop to protect themselves and users. This includes interviews with NGO and social media company reps in the US and the EU. She triangulates these findings against news, policy reports, evaluations and interviews with e-safety experts. This book raises questions about the legitimacy of expecting companies to balance the tension between free speech and child protection without publicly revealing their decision-making processes. In an environment where e-safety is part of the corporate business model, this book unveils the process through which established social media companies receive less government scrutiny than start-ups. The importance of this research for law and policy argues for an OA edition to ensure the work is widely and globally accessible to scholars and decision makers.
