Mirage cosmology with an unstable probe D3-brane

We consider the mirage cosmology by an unstable probe brane whose action is represented by BDI action with tachyon. We study how the presence of tachyon affects the evolution of the brane inflation. At the early stage of the brane inflation, the tachyon kinetic term can play an important role in curing the superluminal expansion in mirage cosmology.Comment: 11 pages, improved presentation with some clarifications, typos corrected, references adde

Terrorism and the new international environment

This thesis examines the characteristics of terrorism in the new international environment following the Cold War in which international terrorism is undergoing drastic changes in its sources and characteristics; The breakdown of the bipolar system and concomitant diffusion of political power have given way to rivalry between regional states; especially, one of the key factors is the effect of weapons proliferation on the dynamics of conflict between regional rivals including nuclear, biological, and chemical-weapons capability. The world is also confronting an assortment of prodemocracy and anti-colonial movements which tend to erupt in civil disorder. The above ingredients are currently fomenting the new environment for terrorism; This thesis first looks at the nature of terrorism and examines the background to the issue; it then assesses how the international environments characterizes the new trend of terrorism that necessitates international cooperation to cope with it

On extensions of representations for compact Lie groups

Let $H$ be a closed normal subgroup of a compact Lie group $G$ such that $G/H$ is connected. This paper provides a necessary and sufficient condition for every complex representation of $H$ to be extendible to $G$, and also for every complex $G$-vector bundle over the homogeneous space $G/H$ to be trivial. In particular, we show that the condition holds when the fundamental group of $G/H$ is torsion free.Comment: 10 pages, AMS-LaTeX v1.

Monomial Relization of Crystal Bases for Special Linear Lie Algebras

We give a new realization of crystal bases for finite dimensional irreducible modules over special linear Lie algebras using the monomials introduced by H. Nakajima. We also discuss the connection between this monomial realization and the tableau realization given by Kashiwara and Nakashima.Comment: 15 page

Multi Criteria Decision on Selecting Optimal Ship Accident Rate for Port Risk Mitigation

AbstractLarge ports have potential catastrophic accidents by handling enormous amount of hazardous and dangerous materials which tend to increase the risk of port and the facilities in its vicinity. In the paper, we propose a mathematical method to identify the ship accident types affecting risk in port areas which propagate into death of people as a consequence of the accidents. We consider a multi criteria port risk problem and a goal programming modeling is constructed for calculating accident rates of each accident type. The obtained results can be employed by decision makers or port authorities in implementing the port risk mitigation measures or in designing (planning) future port construction.For the study, we use the accident data for the 12 domestic ports over the last 5 years from 2002 to 2007