Surface r Modes and Burst Oscillations of Neutron Stars

We study the $r$-modes propagating in steadily mass accreting, nuclear burning, and geometrically thin envelopes on the surface of rotating neutron stars. For the modal analysis, we construct the envelope models which are fully radiaitive or have a convective region. As the angular rotation frequency $\Omega$ is increased, the oscillation frequency $\omega$ of the $r$-modes in the thin envelopes deviates appreciably from the asymptotic frequency $\omega=2m\Omega/l^\prime(l^\prime+1)$ defined in the limit of $\Omega\to 0$, where $\omega$ is the frequency observed in the corotating frame of the star, and $m$ and $l^\prime$ are the indices of the spherical harmonic function $Y_{l^\prime}^m$ representing the angular dependence of the modes. We find that the fundamental $r$-modes in the convective models are destabilized by strong nuclear burning in the convective region. Because of excessive heating by nuclear buring, the corotating-frame oscillation frequency $\omega$ of the $r$-modes in the convective models becomes larger, and hence the inertial-frame oscillation frequency $|\sigma|$ becomes smaller, than those of the corresopnding $r$-modes in the radiative models, where $\sigma=\omega-m\Omega$ is negative for the $r$-modes of positive $m$. We find that the relative frequency change $f=-(\sigma_{conv}-\sigma_{rad})/\sigma_{rad}$ is always positive and becomes less than $\sim$0.01 for the fundamental $r$-modes of $l^\prime>|m|+1$ at $|\sigma_{rad}|/2\pi\sim$300Hz for $m=1$ or at $|\sigma_{rad}|/2\pi\sim$600Hz for $m=2$, where $\sigma_{conv}$ and $\sigma_{rad}$ denote the oscillation frequencies for the convective and the radiative envelope models, respectively.Comment: 20 pages, 12 figure

The Yard and Korean Shakespeare

Since the New Globe Theatre opened in 1996, they have used the yard as an acting area or entrances. Even though the authenticity of using the yard is disputable, nobody denies that the yard must be a very effective tool for performing Shakespeare at the Globe Theatre. The yard is an essential part of traditional Korean theatre, called “talchum (mask dance)” or “talnori (mask play).” The yard is its stage as well as the auditorium. Therefore, the players are surrounded by the audience, and the players can, and often do interact with the audience, speaking to the audience, or treating them as players, or acting as if they were some of the audience. The theatrical style of using the yard has much influenced the modern theatre of Korea. And many Korean directors including Oh Tae-suk, Yang Jung-ung, Sohn Jin-chaek, Park Sung-hwan, and myself, have applied the yard techniques to their Shakespearean productions. Korean Shakespearean productions, which use the yard actively, can be more evidence that the yard must be an effective tool for Shakespeare, not only at the Globe Theatre but also at any kind of theatres of today. No one knows whether Shakespeare actually used the yard or not. But the fact that many Shakespearean productions have used the yard successfully, implies that Shakespeare's texts themselves have enough room for the yard

Exchange Is No Change

With the continuing and seemingly unabated increase in the prices of oil and oil products, the clamor for government to do something to alleviate the situation has escalated. Amidst this clamor, the proposal to create a National Oil Exchange has sprung forward. The question is: will this oil exchange reduce oil prices? Dr. Peter Lee U unequivocally says "no" and states his reasons in this Policy Notes.oil price, oil deregulation, oil exchange

Policy compass: FCM-based policy impact evaluation using public open data

This paper presents how Fuzzy Cognitive Map (FCM) technique can be applied by a policy maker to support the policy impact evaluation using the example of Policy Compass, an EU research project. The practical usage example on interest rate policy shows the potential of FCMs as a policy impact modelling tool. Through the provision of a more intuitive and easier means of using open data based on FCM techniques, the Policy Compass project can play a critical role for both policy maker and lay public to evaluate the policy impact and prepare for future policy making