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We consider the problem of building a P2P-based search engine for massive document collections. We describe a prototype system called ODISSEA (Open DIStributed Search Engine Architecture) that is currently under development in our group. ODISSEA provides a highly distributed global indexing and query execution service that can be used for content residing(More)
Modern frameworks, such as Hadoop, combined with abundance of computing resources from the cloud, offer a significant opportunity to address long standing challenges in distributed processing. Infrastructure-as-a-Service clouds reduce the investment cost of renting a large data center while distributed processing frameworks are capable of efficiently(More)
An important problem in mobile ad-hoc wireless sensor networks is the localization of individual nodes, i.e., each node's awareness of its position relative to the network. In this paper, we introduce a variant of this problem (directional localization) where each node must be aware of both its position and orientation relative to the network. This variant(More)
Infrastructure-as-a-Service clouds offer entire virtual infrastructures for distributed processing while concealing all physical underlying machinery. Current cloud interface abstractions restrict users from providing information regarding usage patterns of their requested virtual machines (VMs). In this paper, we propose Nefeli, a virtual infrastructure(More)
We present a new approach for indexing animated objects and efficiently answering queries about their position in time and space. In particular, we consider an animated movie as a evolution. A movie is viewed as an ordered sequence of frames, where each frame is a 2-dimensional space occupied by the objects that appear in that frame. The queries of interest(More)
A fundamental application in vehicular ad-hoc networks (VANETs) is the discovery of available parking spaces as vehicles navigate through urban road networks. Vehicles are now capable of finding such parking spots using their on-board sensing and computational infrastructure and then they can disseminate this information for use by other members of the(More)
The goal of the ADMS project is to create a framework for caching materialized views, access paths, and experience obtained during query execution. The rationale behind this project is to amortize database access cost over an extended time period and adapt execution strategies based on experience. ADMS demonstrates the versatility of the views and their(More)
In contemporary IaaS configurations, resources are distributed to users primarily through the assignment of virtual machines (VMs) to physical nodes (PMs). This resource allocation is typically done in a way that does not consider user preferences and is unaware of the underlying network layout. The latter is of key significance as cost of the cloud's(More)
Malware encyclopedias nowplay a vital role indisseminating information about security threats. Coupled with categorization and generalization capabilities, such encyclopedias might help better defend against both isolated and clustered specimens.In this paper, we presentMalware Evaluator, a classification framework that treats malware categorization as a(More)
The introduction of powerful workstations connected through LAN networks inspired new DBMS architectures which ooer high performance characteristics. In this paper, we examine three such software architecture conngurations, namely: Client-Server (CS), RAD-UNIFY 1 type of DBMS (RU) and Enhanced Client-Server (ECS). Their speciic functional components and(More)