On the bridge number of knot diagrams with minimal crossings

Given a diagram $D$ of a knot $K$, we consider the number $c(D)$ of crossings and the number $b(D)$ of overpasses of $D$. We show that, if $D$ is a diagram of a nontrivial knot $K$ whose number $c(D)$ of crossings is minimal, then $1+\sqrt{1+c(D)} \leq b(D)\leq c(D)$. These inequalities are shape in the sense that the upper bound of $b(D)$ is achieved by alternating knots and the lower bound of $b(D)$ is achieved by torus knots. The second inequality becomes an equality only when the knot is an alternating knot. We prove that the first inequality becomes an equality only when the knot is a torus knot.Comment: 18 pages, 7 figure

Productive efficiency and privatisation : an evaluation of Korean ports policy

Korea has experienced remarkable economic growth during the last four decades due to its trade-oriented development policy. Since the international trade of Korea is carried predominantly by sea transport, its ports play a pivotal role in national economic development. This impressive development in a short period of time has resulted in rapidly increasing seaborne cargoes. All the parties involved in port activities have made a significant effort to keep pace with the ever-growing export and import cargoes. Korean ports, however, still have a number of problems including insufficient port and terminal capacity, inefficient management and operation, and bureaucratic administration, all of which weaken the competitiveness of the country's products by adding heavy logistics costs. Th deal appropriately with these problems, the newly established public port authority, the Ministry of Maritime Affairs and Fisheries, has launched a new port and terminal development plan to attract private capital into both existing and new facilities. As a consequence, this scheme has introduced new competition into the Korean port industry combined with some degree of privatisation. The motives for privatisation are complex and varied, but one key claim made is that the transformation of ownership from public to private improves economic efficiency. Economic theories and existing empirical studies, however, fail to establish clear-cut evidence supporting this claim. This phenomenon may reflect, to some extent, a paucity of performance indicators systematically applicable across enterprises and industries. It is essential, therefore, to have a systematic and pragmatic analytical framework to assess the process of privatisation and its results. With this context in mind, this thesis aims to critically review the characteristics of international port privatisation together with the economic theory of privatisation, to apply a new econometric technique for efficiency measurement to a port: the frontier model, and to assess the policy implications for the Korean government and port authority, paying particular reference to the privatisation strategy and its implementation within the nation's seaports and terminals. This research makes an original contribution to knowledge in three respects: firstly, port privatisation, in particular the Korean case has, for the first time, been scientifically investigated on the basis of the economic theory of privatisation; secondly, the industry was analysed through the application of a recently developed econometric efficiency measurement method based on the estimation of two frontier models (i.e. cross-sectional and panel models); and finally, the results of the research undoubtedly provide government, port authority and other interested parties with information and guidelines for implementing the policy of port privatisation

Academic and Research Programs in Exercise Science, South Korea

We appreciate the opportunity to review academic curriculum and current research focus of Exercise Science programs in South Korea. The information of this paper was collected by several different methods, including e-mail and phone interviews, and a discussion with Korean professors who attended the 2009 ACSM annual conference. It was agreed that exercise science programming in South Korea has improved over the last 60 years since being implemented. One of distinguishable achievement is that exercise science programs after the 1980’s has been expanded to several different directions. It does not only produce physical education teachers but also attributes more to research, sports medicine, sports, leisure and recreation. Therefore, it has produced various jobs in exercise-related fields. Some of exercise science departments do not require teacher preparation course work in their curriculum which allows students to focus more on their specialty. Secondly, we believe we South Korea has caught up with advanced countries in terms of research quality. Many Korean researchers have recently published and presented their investigations in international journals and conferences. The quality and quantity of these studies introduced to international societies indicate that Exercise Science programs in South Korea is continuing to develop and plays an important part in the world

Near-Complete Teleportation of a Superposed Coherent State

The four Bell-type entangled coherent states, |\alpha>|-\alpha> \pm |-\alpha> |\alpha> and |\alpha>|\alpha> \pm |-\alpha> |-\alpha>, can be discriminated with a high probability using only linear optical means, as long as |\alpha| is not too small. Based on this observation, we propose a simple scheme to almost completely teleport a superposed coherent state. The nonunitary transformation, that is required to complete the teleportation, can be achieved by embedding the receiver's field state in a larger Hilbert space consisting of the field and a single atom and performing a unitary transformation on this Hilbert space.Comment: 4 pages,3 figures, Two columns, LaTex2

Editorial Special issue: Managing logistics processes and redesigning logistics networks

Transport and logistics are essential to modern societies including Europe. Not only do they enable an unprecedented mobility to individuals, they also offer us a wide variety of products and services affecting our world view and even our portrayal of mankind. The main functions being taken and provided by transport and logistics are geographic and time utility – the former is enhanced by linking scattered locations in a harmonised manner, while the latter is enhanced by offering that what is needed, at the right time. These functions become even more evident as we are now living in an era of globalisation