With the daily and minutely data of the German DAX and Chinese indices, we investigate how the return-volatility correlation originates in financial dynamics. Based on a retarded volatility model, we may eliminate or generate the return-volatility correlation of the time series, while other characteristics, such as the probability distribution of returns and longrange time-correlation of volati...

Abstract In this paper, income per capita convergence hypothesis is tested in selected OIC countries. For this purpose, we use the time series model and univariate KPSS stationary test with multiple structural breaks (Carrion-i-Silvestre et al. (2005)) over the period 1950-2008. The results show that most OIC countries could not catch up toward USA. Although because of some positive term of tra...

Multi-item mechanisms can be very complex offering many different randomized bundles to the buyer. Such complexity is thought necessary as revenue gaps between optimal and simple are unbounded. Our work shows these do not apply most natural situations: they require that mechanism overcharges buyer for a bundle while selling individual items at much lower prices. We study maximization under buy-...

Most clustering strategies have not changed considerably since their initial definition. The common improvements are either related to the distance measure used to assess dissimilarity, or the function used to calculate prototypes. Time-series clustering is no exception, with the Dynamic Time Warping distance being particularly popular in that context. This distance is computationally expensive...