267 research outputs found
Optimal information diffusion in stochastic block models
We use the linear threshold model to study the diffusion of information on a
network generated by the stochastic block model. We focus our analysis on a two
community structure where the initial set of informed nodes lies only in one of
the two communities and we look for optimal network structures, i.e. those
maximizing the asymptotic extent of the diffusion. We find that, constraining
the mean degree and the fraction of initially informed nodes, the optimal
structure can be assortative (modular), core-periphery, or even disassortative.
We then look for minimal cost structures, i.e. those such that a minimal
fraction of initially informed nodes is needed to trigger a global cascade. We
find that the optimal networks are assortative but with a structure very close
to a core-periphery graph, i.e. a very dense community linked to a much more
sparsely connected periphery.Comment: 11 pages, 6 figure
Alien Registration- Curato, Joseph (Rumford, Oxford County)
https://digitalmaine.com/alien_docs/13637/thumbnail.jp
Respondents as Interlocutors: Translating Deliberative Democratic Principles to Qualitative Interviewing Ethics
The epistemic interview is a conversational practice, which aims to generate knowledge by subjecting respondentsâ beliefs to dialectical tests of reasons. Developed by Svend Brinkmann, this model draws inspiration from Socratic dialogues where the interviewer asks confronting questions to press respondents to articulate the normative bases of their views. In this article, the author argues that Brinkmannâs model is a valuable methodological innovation but warrants further development. The author suggests that the epistemic interview can be put on a stronger methodological footing when the Socratic model is complemented by developments in democratic theory, particularly its deliberative variety. Translating deliberative democratic virtues to methodological terms addresses some of the epistemic modelâs gaps, including an account of the dynamic of knowledge production and the ethical norms that govern this method. To illustrate the practice of epistemic interviewing, the author draws on her experience in interviewing junior military officer
âWe havenât even buried the dead yetâ:Ethics of discursive contestation in a crisis situation
Disasters are often described as exceptional moments that demand global solidarity. A âstate of humanitarian exceptionâ emerges as citizens foreground norms of compassion and cooperation while contestatory discourse â the argumentative, blame-seeking and fault-finding forms of speech â are stigmatized as inappropriate interventions in a society seeking to recover from a distressful crisis situation. This article critically unpacks these representations of post-disaster situations empirically and normatively. By analysing the discussions in the public sphere over the first 100 days after Typhoon Haiyan battered Central Philippines, the article examines the moral force behind the âdiscourse of compassionâ and its âethical boundary workâ that places the âdiscourse of contestationâ outside the scope of acceptable conduct. It proposes that the discourse of compassionâs ethical boundary work is only democratically acceptable when one takes a short view of a crisis situation. Drawing on deliberative democracy theory, the article argues for the importance of contestatory discourse in fostering inclusive discourse formation and ensuring that the state of humanitarian exception does not become the rule.</jats:p
Nonlinearity in high-frequency finance and optimal execution
In this thesis we consider two problems regarding the eld of market microstructure:
the analysis and modeling of high frequency nancial data and the optimal
execution of large orders. The rst problem is analyzed empirically within the
context of the dynamics of limit order books. Such context imposes a discrete
modeling approach about the variables of interest, like prices and bid-ask spreads.
The optimal execution problem, instead, is analyzed within the context of a price
model which allows for a nonlinear-transient market impact [43, 104]. Our interest
is motivated by the fact that the study and implementation of optimal strategies is
one of the main tasks of large banks and capital investment rms. The two problems
are de ned by two di erent nonlinear models. A nonlinear modeling approach is
necessary in order to reproduce the empirical data. Our work focuses on the analysis
of the implications of such nonlinearities on the stochastic dynamics of prices and on
optimal strategies. [...
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