Wireless mesh networks (WMNs) are two-tier wireless multihop networks. The top tier is made of wireless routers, which provide access to the wireless clients in the bottom tier. One technology for enabling multi-hop communication in the top tier is IEEE 802.16, which includes a mesh mode, in addition to the Point-to-Multipoint mode for cellular networks. As is often the case with wireless netwo...

Today ecotoxicological evaluations of surface water quality are either based on field surveys or online biomonitoring, whereas the ecotoxicological quality of wastewater is mostly determined with standardised acute toxicity tests. In this paper we present a concept for the ecotoxicological evaluation of surface waters, where mainly in vitro tests are used for the screening of water samples, pre...

This research adopts Barua’s [1] three-tier Business Value Complementarity (BVC) model to study the performance of telephone companies (Telcos). Our study integrates constructs such as spending on telecommunication infrastructure, assets, plant investment, and operating expenses into the bottom tier of BVC. The second layer incorporates measures of operational efficiency and customer satisfacti...

The need to federate repositories emerges in two distinctive scenarios. In one scenario, scalability-related problems in the operation of a repository reach a point beyond which continued service requires parallelization and hence federation of the repository infrastructure. In the other scenario, multiple distributed repositories manage collections of interest to certain communities or applica...

In six control subjects pars compacta nerve cells in the ventrolateral substantia nigra had a lower melanin content than nerve cells in the dorsomedial region. This coincides with a natural anatomical division into ventral and dorsal tiers, which represent functionally distinct populations. In six cases of Parkinson's disease (PD) the ventral tier showed very few surviving nerve cells compared ...

Identifying the location of performance bottlenecks is a non‐trivial challenge when scaling n‐tier applications in computing clouds. Specifically, we observed that an n‐tier application may experience significant performance loss when bottlenecks alternate rapidly between component servers. Such rapidly alternating bottlenecks arise naturally and often from resource dependencies in an n‐tier sy...

The deployment of server replicas of a service across an asynchronous distributed system (e.g., Internet) is a real practical challenge. This target cannot be indeed achieved by classical software replication techniques (e.g., passive and active replication) as these techniques usually rely on group communication toolkits that require server replicas to run over a partially synchronous distribu...

Hierarchical organizations in general boost overall system scalability. Some existing research work organizes peers into different hierarchical structures. In these systems, the top-tier overlay is either a completely-connected graph or a CHORD ring. These overlays can achieve good routing latency ( ) 1 ( O or ) (log O ), where n is the number of groups. However, each node has to keep a large n...

We present here the recent work at NPAC aimed at developing WebFlow|a general purpose Web based visual interactive programming environment for coarse grain distributed computing. We follow the 3-tier architecture with the central control and integration We-bVM layer in tier-2, interacting with the visual graph editor applets in tier-1 (front-end) and the legacy systems in tier-3. WebVM is given...