Study of the Topology Mismatch Problem in Peer-to-Peer Networks

The advantages of peer-to-peer (P2P) technology are innumerable when compared to other systems like Distributed Messaging System, Client-Server model, Cloud based systems. The vital advantages are not limited to high scalability and low cost. On the other hand the p2p system suffers from a bottle-neck problem caused by topology mismatch. Topology mismatch occurs in an unstructured peer-to-peer (P2P) network when the peers participating in the communication choose their neighbors in random fashion, such that the resultant P2P network mismatches its underlying physical network, resulting in a lengthy communication between the peers and redundant network traffics generated in the underlying network[1] However, most P2P system performance suffers from the mismatch between the overlays topology and the underlying physical network topology, causing a large volume of redundant traffic in the Internet slowing the performance. This paper surveys the P2P topology mismatch problems and the solutions adapted for different applications

Workshop on disruptive information and communication technologies for innovation and digital transformation

The workshop on Disruptive Information and Communication Technologies for Innovation and Digital transformation, organized under the scope of the DISRUPTIVE project (disruptive.usal.es) and held on December 20, 2019 in Bragança, aims to discuss problems, challenges and benefits of using disruptive digital technologies, namely Internet of Things, Big data, cloud computing, multi-agent systems, machine learning, virtual and augmented reality, and collaborative robotics, to support the on-going digital transformation in society. The main topics included: • Intelligent Manufacturing Systems • Industry 4.0 and digital transformation • Internet of Things • Cyber-security • Collaborative and intelligent robotics • Multi-Agent Systems • Industrial Cyber-Physical Systems • Virtualization and digital twins • Predictive maintenance • Virtual and augmented reality • Big Data and advanced data analytics • Edge and cloud computing • Digital Transformation The workshop program included 16 accepted technical papers, 2 invited talks and 1 technical demonstration of use cases. This volume contains six of the papers presented at the Workshop on Disruptive Information and Communication Technologies for Innovation and Digital Transformation.info:eu-repo/semantics/publishedVersio

Invertible and Non-invertible Alloy Ising Models

Physical properties of alloys are compared as computed from ``direct'' and ``inverse'' procedures. The direct procedure involves Monte Carlo simulations of a set of local density approximation (LDA)-derived pair and multibody interactions {\nu_f}, generating short-range order (SRO), ground states, order- disorder transition temperatures, and structural energy differences. The inverse procedure involves ``inverting'' the SRO generated from {\nu_f} via inverse-Monte-Carlo to obtain a set of pair only interactions {\tilde{\nu}_f}. The physical properties generated from {\tilde{\nu}_f} are then compared with those from {\nu_f}. We find that (i) inversion of the SRO is possible (even when {\nu_f} contains multibody interactions but {\tilde{\nu}_f} does not) but, (ii) the resulting interactions {\tilde{\nu}_f} agree with the input interactions {\nu_f} only when the problem is dominated by pair interactions. Otherwise, {\tilde{\nu}_f} are very different from {\nu_f}. (iii) The same SRO pattern can be produced by drastically different sets {\nu_f}. Thus, the effective interactions deduced from inverting SRO are not unique. (iv) Inverting SRO always misses configuration-independent (but composition- dependent) energies such as the volume deformation energy G(x); consequently, the ensuing {\tilde{\nu}_f} cannot be used to describe formation enthalpies or two-phase regions of the phase diagram, which depend on G(x).Comment: 4 pages, ReVTeX galley format, 1 eps figures embedded using epsf, to be published in Solid State Communication

Quantum cryptography: key distribution and beyond

Uniquely among the sciences, quantum cryptography has driven both foundational research as well as practical real-life applications. We review the progress of quantum cryptography in the last decade, covering quantum key distribution and other applications.Comment: It's a review on quantum cryptography and it is not restricted to QK