Querying large numbers of data sources is gaining importance due to increasing numbers of independent data providers. One of the key challenges is executing queries on all relevant information sources in a scalable fashion and retrieving fresh results. The key to scalability is to send queries only to the relevant servers and avoid wasting resources on data sources which will not provide any re...

We consider the distributed source coding system of L correlated Gaussian sources Yl, l = 1, 2, · · · , L which are noisy observations of correlated Gaussian remote sources Xk, k = 1, 2, · · · ,K. We assume that Y L = (Y1, Y2, · · · , YL) is an observation of the source vector X = (X1, X2, · · · , XK), having the form Y L = AX+N, where A is a L×K matrix and N = (N1, N2, · · · , NL) is a vector ...

In this paper we present robust algorithms of transmission and reconstruction of attacking path(s) in IDS for providing traceback information in IP packets without requiring interactive operational support from Internet Service Providers, which is based on IP address compression techniques, polynomial theory and techniques from algebraic coding theory. Our best scheme has improved robustness ov...

This paper presents a measurement-based comparison between distributed and concentrated massive multiple-input multiple-output (MIMO) systems, which are called D-mMIMO C-mMIMO in an indoor environment considering 400 MHz bandwidth centered at 3.5 GHz. In both cases, we have considered array of 64 antennas the base station eight simultaneously active users. The work focuses on characterization s...

In antenna array applications, the propagation environment is often more complicated than the ordinary assumption of plain wavefronts. Here, a low complexity algorithm is suggested for estimating both the DOA and the spread angle of a mobile source subject to local scattering, using a uniform linear array. The parameters are calculated from the estimates obtained using a standard algorithm such...

We address the problem of integrating heterogeneous data sources for collaborative environments such as Groupware systems. Pre-existing related distributed data is modeled by a composite object, where each data source is treated as a fragment of the composite object. We define a collection of methods which allow manipulation of the related distributed data in a controlled and consistent manner....

Recent development of high throughput data acquisition technologies in a number of domains (e.g., biological sciences, atmospheric sciences, space sciences, commerce) together with advances in digital storage, computing, and communications technologies have resulted in the proliferation of a multitude of physically distributed data repositories created and maintained by autonomous entities (e.g...

Recent advancements in mobile devices and the omnipresence of wireless connectivity have turned handheld devices into powerful mobile web clients. This evolution has made the wealth of online Semantic Web data accessible to mobile devices. To support this new opportunity, we present a semantic technology-based client-side solution to efficiently query large amounts of distributed online RDF sou...

Integrated access to multiple distributed and autonomous RDF data sources is a key challenge for many semantic web applications. As a reaction to this challenge, SPARQL, the W3C Recommendation for an RDF query language, supports querying of multiple RDF graphs. However, the current standard does not provide transparent query federation, which makes query formulation hard and lengthy. Furthermor...