15,458 research outputs found
An FBSDE approach to the Skorokhod embedding problem for Gaussian processes with non-linear drift
We solve the Skorokhod embedding problem for a class of Gaussian processes
including Brownian motion with non-linear drift. Our approach relies on solving
an associated strongly coupled system of Forward Backward Stochastic
Differential Equation (FBSDE), and investigating the regularity of the obtained
solution. For this purpose we extend the existence, uniqueness and regularity
theory of so called decoupling fields for Markovian FBSDE to a setting in which
the coefficients are only locally Lipschitz continuous
Polythiophene and oligothiophene systems modified by TTF electroactive units for organic electronics
The aim of this review is to give an update on current progress in the synthesis, properties and applications of thiophene-based conjugated systems bearing tetrathiafulvalene (TTF) units. We focus mostly on the synthesis of poly- and oligothiophenes with TTF moieties fused to the thiophene units of the conjugated backbone either directly or via a dithiin ring. The electrochemical behaviour of these materials and structure–property relationships are discussed. The study is directed towards the development of a new type of organic semiconductors based on these hybrid materials for application in organic field effect transistors and solar cells
A Continuous Time GARCH Process of Higher Order
A continuous time GARCH model of order (p,q) is introduced, which is driven by a single Lévy process. It extends many of the features of discrete time GARCH(p,q) processes to a continuous time setting. When p=q=1, the process thus defined reduces to the COGARCH(1,1) process of Klüppelberg, Lindner and Maller (2004). We give sufficient conditions for the existence of stationary solutions and show that the volatility process has the same autocorrelation structure as a continuous time ARMA process. The autocorrelation of the squared increments of the process is also investigated, and conditions ensuring a positive volatility are discussed
Twitter’s big hitters
We describe the results of a new computational experiment on Twitter data. By listening to Tweets on a selected topic, we generate a dynamic social interaction network. We then apply a recently proposed dynamic network analysis algorithm that ranks Tweeters according to their ability to broadcast information. In particular, we study the evolution of importance rankings over time. Our presentation will also describe the outcome of an experiment where results from automated ranking algorithms are compared with the views of social media experts
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