Disk drives are now available with capacity and price per capacity comparable to (and in some cases better than) nearline tape systems. Given disks' superior performance , density and maintainability characteristics, it seems likely that disks will soon overtake tapes as the backup medium of choice. In this paper, we outline the potential advantages of a backup system composed of high-capacity ...

In this study a hierarchical hub location problem with two layers is considered. The first layer includes small hubs and the second one includes a star-shaped network central hub. The considered case is a cargo delivery network where there is hierarchy between hubs. All the hubs and links are capacitated and there are three kinds of commodities for each of which there is a special kind of vehic...

Hub location problems, with the hub-and-spoke network structure, involve locating hub facilities, allocating the non-hubs (spokes) to the hubs, and determining the path for each origin-destination pair. In a pure hub-and-spoke network, all hubs, which act as intermediate switching or transshipment points for internodal flows, are fully interconnected and none of the non-hubs are directly connec...

We present a novel peer-to-peer backup technique that allows computers connected to the Internet to back up their data cooperatively: Each computer has a set of partner computers, which collectively hold its backup data. In return, it holds a part of each partner’s backup data. By adding redundancy and distributing the backup data across many partners, a highly-reliable backup can be obtained i...

Since first introduced by Satoshi Nakamoto in 2008, Bitcoin has become the biggest and most well-known decentralized digital currency. Its anonymity allows users all over the world to make transactions with each other and keep their identities hidden. However, protecting private key becomes a very important issue because it is the only access to a unique account and can hardly be recovered if m...

Wireless sensor and actor networks are becoming more and more popular in the recent years. Each WSAN consists of numerous sensors and a few actors working collaboratively to carry out specific tasks. Unfortunately, actors are prone to failure due to harsh deployment environments and constrained power, which may break network connectivity resulting in disjoint components. Thus, maintaining the c...

In real-time systems, tasks have deadlines to be met despite the presence of faults. Primary-Backup (PB) scheme is one of the most common schemes that has been employed for fault-tolerant scheduling of real-time tasks, wherein each task has two versions and the versions are scheduled on two different processors with time exclusion. There have been techniques proposed for improving schedulabilit...

This article develops a model and analysis to provide insight into two effective remedies to increase supply chain resilience: (i) contracting with a secondary flexible backup supplier; and (ii) monitoring primary suppliers to obtain disruption risk information. To investigate the true value of these strategies, an analysis is performed under imperfect information concerning the disruption risk...

Stem cells can be controlled by their local microenvironment, known as the stem cell niche. The Drosophila testes contain a morphologically distinct niche called the hub, composed of a cluster of between 8 and 20 cells known as hub cells, which contact and regulate germline stem cells (GSCs) and somatic cyst stem cells (CySCs). Both hub cells and CySCs originate from somatic gonadal precursor c...

P2P architecture is a viable option for enterprise backup. In contrast to dedicated backup servers, nowadays a standard solution, making backups directly on organization’s workstations should be cheaper as existing hardware is used; more efficient as there is no single bottleneck server; and more reliable as the machines can be geographically dispersed. We present an architecture of a p2p backu...