Has the G7 business cycle become more synchronized ?

This paper adopts Friedman’s Plucking Markov Switching Model to decompose G7 real GDPs into common permanent components, common transitory components, infrequent Markov Switching negative shock and domestic idiosyncratic components. The findings show that the common components explain a 53.1% average volatility of G7 GDPs from 1960 to 2002. Despite the moderated volatility of G7 economies, the G7 business cycle (except Japan) has become more synchronized in its fluctuations. In addition, from the dynamic factor model with Markov switching, there appears to have been a common permanent synchronized fluctuation in the Euro-zone countries after 1984. The probability that the common transitory component is contracting, accords quite well with U.S recessionary dates.G7, GDP, business cycle, Friedman’s Plucking Markov Switching Model, permanent, transitory

Oil and the G7 business cycle : Friedman's Plucking Markov Switching Approach

To analyze whether oil price can account for the business cycle asymmetries in the G7, this paper adopts the Friedman’s Plucking Markov Switching Model to decompose G7 real GDPs into common permanent components, common transitory components, infrequent Markov Switching negative shock and domestic idiosyncratic components. The findings show that Hamilton’s 3 year net oil price increases account for 1973-75, 1980, partially 1990-1991 recessions and LNR oil price increases account for 1973-75, 1980, partially 1960, partially 1970, partially 1990-1991 recessions. These results indicate that oil price shocks have not been a principal determinant of common recessions in the G7 except two major OPEC oil price increases in 1973-1974, 1979-1980oil, OPEC, G7, GDP, business cycle, Friedman’s Plucking Markov Switching, permanent, transitory

Storage and Retrieval of Thermal Light in Warm Atomic Vapor

We report slowed propagation and storage and retrieval of thermal light in warm rubidium vapor using the effect of electromagnetically-induced transparency (EIT). We first demonstrate slowed-propagation of the probe thermal light beam through an EIT medium by measuring the second-order correlation function of the light field using the Hanbury-Brown$-$Twiss interferometer. We also report an experimental study on the effect of the EIT slow-light medium on the temporal coherence of thermal light. Finally, we demonstrate the storage and retrieval of thermal light beam in the EIT medium. The direct measurement of the photon number statistics of the retrieved light field shows that the photon number statistics is preserved during the storage and retrieval process.Comment: 4 pages, 4 figure

Hybrid Spam Filtering for Mobile Communication

Spam messages are an increasing threat to mobile communication. Several mitigation techniques have been proposed, including white and black listing, challenge-response and content-based filtering. However, none are perfect and it makes sense to use a combination rather than just one. We propose an anti-spam framework based on the hybrid of content-based filtering and challenge-response. There is the trade-offs between accuracy of anti-spam classifiers and the communication overhead. Experimental results show how, depending on the proportion of spam messages, different filtering %%@ parameters should be set.Comment: 6 pages, 5 figures, 1 tabl