scholarly journals Sybil-proof Answer Querying Mechanism

Author(s):  
Yao Zhang ◽  
Xiuzhen Zhang ◽  
Dengji Zhao

We study a question answering problem on a social network, where a requester is seeking an answer from the agents on the network. The goal is to design reward mechanisms to incentivize the agents to propagate the requester's query to their neighbours if they don't have the answer. Existing mechanisms are vulnerable to Sybil-attacks, i.e., an agent may get more reward by creating fake identities. Hence, we combat this problem by first proving some impossibility results to resolve Sybil-attacks and then characterizing a class of mechanisms which satisfy Sybil-proofness (prevents Sybil-attacks) as well as other desirable properties. Except for Sybil-proofness, we also consider cost minimization for the requester and agents' collusions.

2010 ◽  
Vol 18 (3) ◽  
pp. 885-898 ◽  
Author(s):  
Haifeng Yu ◽  
Phillip B. Gibbons ◽  
Michael Kaminsky ◽  
Feng Xiao

2015 ◽  
Vol 3 ◽  
pp. 449-460 ◽  
Author(s):  
Michael Roth ◽  
Mirella Lapata

Frame semantic representations have been useful in several applications ranging from text-to-scene generation, to question answering and social network analysis. Predicting such representations from raw text is, however, a challenging task and corresponding models are typically only trained on a small set of sentence-level annotations. In this paper, we present a semantic role labeling system that takes into account sentence and discourse context. We introduce several new features which we motivate based on linguistic insights and experimentally demonstrate that they lead to significant improvements over the current state-of-the-art in FrameNet-based semantic role labeling.


2021 ◽  
Vol 12 (4) ◽  
pp. 33-63
Author(s):  
Ирина Евгеньевна Калабихина ◽  
Наталья Валентиновна Лукашевич ◽  
Евгений Петрович Банин ◽  
Камила Винеровна Алибаева ◽  
Софья Михайловна Ребрей

В данной работе мы представляем специализированный датасет, с разметкой мнений пользователей о репродуктивном поведении. Мы анализируем особенности распределение оценок «за» и «против» по конкретным аспектам репродуктивного поведения. Созданный датасет используется для решения двух задач классификации: классификации сообщений по релевантности изучаемых тем и позиции автора по той или иной теме. Для классификации сообщений используются классические методы машинного обучения, а также нейросетевая модель BERT. Лучшие результаты классификации в обеих задачах достигаются на основе вариантов модели BERT с использованием в классификации пар предложений — варианты NLI (natural language inference — вывод по тексту) и QA (question-answering — вопросно/̄ответный подход). Кроме того, созданный датасет позволяет сделать содержательные выводы по вопросам отношения пользователей сети ВКонтакте к вопросам репродуктивного поведения. Выявлено, что феномен сознательной бездетности активно представлен в сети, а многодетность остается слабо распространенной моделью поведения. В рамках пронаталистской политики важно формировать позитивное общественное мнение о родительстве, смягчать дефицит времени у родителей.


2016 ◽  
Vol 2016 (4) ◽  
pp. 4-20
Author(s):  
Frederick Douglas ◽  
Weiyang Pan ◽  
Matthew Caesar ◽  

Abstract Many governments block their citizens’ access to much of the Internet. Simple workarounds are unreliable; censors quickly discover and patch them. Previously proposed robust approaches either have non-trivial obstacles to deployment, or rely on low-performance covert channels that cannot support typical Internet usage such as streaming video. We present Salmon, an incrementally deployable system designed to resist a censor with the resources of the “Great Firewall” of China. Salmon relies on a network of volunteers in uncensored countries to run proxy servers. Although any member of the public can become a user, Salmon protects the bulk of its servers from being discovered and blocked by the censor via an algorithm for quickly identifying malicious users. The algorithm entails identifying some users as especially trustworthy or suspicious, based on their actions. We impede Sybil attacks by requiring either an unobtrusive check of a social network account, or a referral from a trustworthy user.


Author(s):  
Wen Shen ◽  
Yang Feng ◽  
Cristina V. Lopes

Strategic diffusion encourages participants to take active roles in promoting stakeholders’ agendas by rewarding successful referrals. As social media continues to transform the way people communicate, strategic diffusion has become a powerful tool for stakeholders to influence people’s decisions or behaviors for desired objectives. Existing reward mechanisms for strategic diffusion are usually either vulnerable to falsename attacks or not individually rational for participants that have made successful referrals. Here, we introduce a novel multi-winner contests (MWC) mechanism for strategic diffusion in social networks. The MWC mechanism satisfies several desirable properties, including false-name-proofness, individual rationality, budget constraint, monotonicity, and subgraph constraint. Numerical experiments on four real-world social network datasets demonstrate that stakeholders can significantly boost participants’ aggregated efforts with proper design of competitions. Our work sheds light on how to design manipulation-resistant mechanisms with appropriate contests.


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