The minerals ${A}_{2}{\mathrm{Cu}}_{3}\mathrm{O}{({\mathrm{SO}}_{4})}_{3}({A}_{2}={\mathrm{Na}}_{2},\mathrm{NaK},{\mathrm{K}}_{2})$ constitute quantum spin systems with copper hexamers as basic structural units. Strong intrahexamer couplings give rise to an effective triplet ground state. Weak interhexamer are responsible for two-dimensional long-range magnetic order in the ($b,\phantom{\rule{0...

The IP-multicast architecture is extended with addressing information along multicast routing trees that permits more eecient and sophisticated multicast routing options and encourages communication and cooperation between IP and higher-layer protocols. The Addressable Internet Multi-cast (AIM) architecture is introduced that enables sources to restrict the delivery of packets to a subset of th...

Tree-based reliable multicast protocols are known to provide better scalability than the protocols based on pure senderand receiver-initiated schemes. However, previous analytical work that has provided these results is based on a system model which assumes reliable control message delivery and synchronized local clocks. These assumptions are questionable simplifications, since they favor proto...

Abstract The recent success of multicast applications such as Internet teleconferencing tools and distributed simulation illustrates the tremendous potential of applications built upon wide-area reliable multicast communication services. However, in order to fully realize this potential, a detailed understanding of the interplay between the reliable multicast protocol and the service characteri...

It is shown that the BRS-formulated two-dimensional BF theory in the light-cone gauge (coupled with chiral Dirac fields) is solved very easily in the Heisenberg picture. The structure of the exact solution is very similar to that of the BRS-formulated twodimensional quantum gravity in the conformal gauge. In particular, the BRS Noether charge has anomaly. Based on this fact, a criticism is made...

In this paper, we propose a transport layer protocol for one-to-many multicast that is designed to have good scalability properties in large receiver groups and provides reliable transmission. Reliability is achieved using forward error correction (FEC) in combination with selective repeat NAK-based ARQ. Using FEC can signiicantly reduce the necessity for retransmission requests or make them to...