Papers by Keyword: ALM

Abstract: Application Layer Multicast (ALM) is considered as an attractive approach for implementing wide area multicast services. In ALM, multicast functionality is implemented at the edge instead of the core network (routers). As opposed to network-layer multicast, application layer multicast requires no infrastructure support and can be easily deployed in the Internet. In this paper, we propose a new efficient and scalable model for optimizing application layer multicast using HPM architecture (HPM: A novel hierarchical Peer-to-Peer model for lookup acceleration with provision of physical proximity). This approach benefits from P2P properties and characteristics. In this contribution, we consider our optimized tree construction algorithm simultaneously for each ring of HPM. The global tree construction algorithm is composed of two steps. In the first step, we construct a sub-tree for each ring; the second step is to build a global tree using sub sets of adjacent rings in HPM architecture. The proposed model inherits from main P2P attributes such as: scalability, fault tolerance characterized HPM. Preliminarily performance evaluations show that results are globally satisfactory, the depth of the resulting multicast tree is optimized.

Abstract: In titanium alloys it is known that in bulk sections the solidification conditions in ALM commonly lead to undesirable, coarse, columnar β grain structures. Here, we have investigated the effect of build geometry on the grain structure and associated texture in Ti-6Al-4V ALM components produced by Selective Electron Beam Melting (SEBM). Through reconstruction of the primary β-phase, it has been confirmed that in thick sections large columnar β grains grow with a strong <001>_β fibre texture, although there is a significant skin effect. In contrast, in thin walls nucleation off the surrounding powder and growth inwards dominates. Local heterogeneities are also observed within section transitions. It is shown that the weaker α transformation texture arises from a random distribution across the possible habit variants.

Abstract: In this work, a simulative study on the cost of multisource ALM routing protocols is presented. The authors discuss a multiplicative pricing model for multisource ALM based on the single-source cost model. By simulating various ALM protocols, the study discovered that a multiplicative characteristic is held between the cost of single-source and multisource ALM routing. The multiplicative pricing model makes the minimum cost of multisource ALM more clear for protocol designer and gives a intuitive way to examine the cost of a designed multisource ALM without incurring too many computation complexity.