Security issues are the most challenging problems in cloud computing environments as an emerging technology. Regarding to this importance, an efficient and reliable user authentication and data protection model has been presented in this paper to increase the rate of reliability cloud-based environments. Accordingly, two encryption procedures have been established in an independent middleware (...

The long-expected convergence of High Performance Computing and Big Data Analytics is upon us. Unfortunately, the computing environments created for each workload are not necessarily conducive for the other. In this paper, we evaluate the ability of traditional high performance computing architectures to run big data analytics. We discover and describe limitations which prevent the seamless uti...

This article considers environments in which individual preferences are single-peaked with respect to an unspecified, but unidimensional, ordering of the alternative space. We show that in these environments, any institution that is coalitionally strategy-proof must be dictatorial. Thus, any nondictatorial institutional environment that does not explicitly utilize an a priori ordering over alte...

In hybrid communication environments where both wired and wireless links exist, performance of the quality-of-service (QoS) provision can be enhanced if an application knows whether there exist wireless links in the communication channel and adapts its behavior accordingly. This paper presents a scheme using fuzzy reasoning to make applications wireless-aware. Based on the studies of statistica...

Crowdsourcing has revolutionized the process of knowledge building on the web. Wikipedia and StackOverflow are witness to this uprising development. However, the dynamics behind the process of crowdsourcing in the domain of knowledge building is an area relatively unexplored. It has been observed that an ecosystem exists in the collaborative knowledge building environments (KBE)(Chhabra, Iyenga...

In this paper the choice of DLL parameters is studied with special focus on multipath and Doppler sensitivity. The envisaged application is code tracking on navigation receivers and the multipath fading environments defined for next generation navigation systems are considered. Given the particular properties of these propagation environments, multipath estimating delay lock loop is shown to ha...

This paper investigates stochastic propagation models appropriate for Fixed Wireless Access (FWA) Systems. A widely used model for the prediction of path loss in mobile systems for urban environments is the Walfisch-Bertoni model [1]. It was later modified to accommodate FWA systems in [2] and is known as the Random Building Height (RBH) model. In this paper, a comparison is made between the pr...

We compare the Iserver-Occam, Parix, PVM, and Express parallel programming environments on a Parsytec GCel with 512 T805 transputers. The comparison will be made by a detailed analysis of the performance of one particular application. In our approach we start with this application and isolate the basic (environment dependent) building blocks. These basic building blocks, which depend on floatin...

the bahía blanca estuary, located at the atlantic coast of argentina, includes a governmental nature reserve to protect biodiversity, lands and water; however, as the process of industrialization and urbanization is stepping rapidly at the neighbouring area, the potential increase in contaminant loads is a serious concern. after several contaminants surveys at the estuary, no single study has b...