Gabriela M. Marinescu

Ad hoc grids: communication and computing in a power constrained environment

We introduce ad hoc grids as a hierarchy of mobile devices with different computing and communication capabilities. An ad hoc grid allows a group of individuals to accomplish a mission, often in a hostile environment; examples of applications of ad hoc grids are disaster management, wild-fire prevention, and peacekeeping operations. We are concerned with the interplay between computing and communication in the power-constrained environment of an ad hoc grid.

Self-organizing sensor networks

In this paper we propose a scheme for self-organizing sensor networks; the scheme allows a sensor network to adapt to topological changes, include new batches of sensors, and disregard the sensors that have depleted their power reserves, or have been compromised. The algorithm for self-organization allows the sensor network to carry out its mission, has built-in provisions for information assurance, and extends the lifetime of the network by reducing the power consumption; it minimizes the number of collisions experienced by a sensor when it transmits and maximizes the time a sensor is either idle or dedicated to monitoring and/or internal data processing.

Coordination in Intelligent Grid Environments

A computational grid is a complex system. The state space of a complex system is very large and it is infeasible to create a rigid infrastructure implementing optimal policies and strategies which take into account the current state of the system. An alternative to a rigid infrastructure is to base the systems reactions on logical inference, planning, and learning, the quintessential elements of an intelligent system. An intelligent grid is one where societal services exhibit intelligent behavior. A coordination service acting as a proxy on behalf of end users reacts to unforeseen events, plans how to carry out complex tasks, and learns from the history of the system. Various policies implemented by the societal services of an intelligent grid, such as brokerage and matchmaking, are based upon rules and facts gathered with the aid of a monitoring service. The question we address is how to construct intelligent computational grids which are truly scalable and could respond to the needs of a diverse user community. We present a prototype of a system used for a virtual laboratory in computational biology.

Scale-free, self-organizing very large sensor networks

In this paper we introduce SFSN, an algorithm for self-organization of Very Large Sensor Networks (VLSN). The 10^6 or more tiny and inexpensive sensors of a VLSN are indistinguishable from one another; they do not have either a physical or a logical address, as required by the traditional communication protocols. The self-organization scheme limits the number of partners each sensor collaborates with, thus, it limits the amount of communication and the complexity of coordination. The system is scalable, the amount of state information each node has to maintain is strictly limited regardless of the total number of sensors in the network. The systems we consider mimic biological systems where individual cells of the same type are indistinguishable.

A reputation algorithm for a self-organizing system based upon resource virtualization

In the service-oriented architecture introduced in D.C. Marinescu and J.P. Morrison (2007), the reputation affects the prices producers could ask for their resources, the prices consumers of resources are willing to pay, and the commission charged for every contract. In this paper we introduce the GRB algorithm to quantify the reputations of the participants. The system is self-organizing and this affects the space requirements and the communication complexity of the algorithm.

The Boole Lecture Quantum Information

Quantum and biological information processing could revolutionize computing and communication in the third millennium. In the 2007 Boole Lecture, we discussed the necessity to explore alternative paradigms for computing and communication and presented some striking features of quantum information processing and provided some insights into quantum parallelism as well as quantum communication and teleportation.

Self-organization of Very Large Sensor Networks Based on Small-worlds Principles

We study networks consisting of a very large number of tiny and inexpensive sensors and introduce SWAS (Small-Worlds of Anonymous Sensors), an algorithm combining self-organization based upon smallworlds principles and Medium Access Control based upon a stack protocol for VLSNs and we report on a preliminary study of the algorithm. The nodes of Very Large Sensor Networks (VLSN) have limited resources; to reduce the power consumption the processor is less powerful and the amount of storage available is smaller than those of traditional sensor networks. Moreover, the nodes are indistinguishable from one another; they do not have a physical address, as required by the traditional communication protocols. VLSNs mimic biological systems where individual cells of the same type are indistinguishable. Small-worlds networks [11] combine two desirable features of networks namely high clustering and small path length. I. INTRODUCT

A Parallel Simulator for Quantum Fault Tolerance in the Presence of Correlated Errors

Summary form only given. The only realistic means to assess the reliability of a fault tolerant quantum circuit is through simulation. Quantum circuit simulators use Monte Carlo (MC) strategy to randomly sample possible error scenarios using a random number generator. Monte Carlo simulation can be conducted in parallel, but it requires a large amount of CPU cycles and a fair amount of time. All quantum circuit simulators assume a Markovian quantum error model. The simulator we are currently developing uses a combinatorial model and the simulation is carried out in parallel. The simulator is driven by a component which triggers noise events based upon the noise model for a particular physical implementation of quantum gates.

A Secure Self-Organizing Sensor Network

In this paper we discuss a scheme that allows sensor networks to operate securely and efficiently. In this scheme after deployment the sensors go through a self-organization phase when they establish a communication pattern among themselves; then they follow this pattern through multiple activity phases when they collect, process, and transmit information. The algorithm for self-organization assumes anonymous sensors and random times of the communication events, as well as random communication frequencies; the sensors use random number generators and a set of shared seeds so no external entity can either join in, or predict the time when the sensors in the set will transmit and attempt to interfere with the transmissions. The scheme extends the lifetime of the network by reducing the power consumption; it minimizes the number of collisions experienced by a sensor when it transmits and maximizes the time a sensor is either idle or dedicated to monitoring and/or internal data processing.

Managing Contracts in Pleiades Using Trust Management

The advent of multicore technologies is set to significantly increase the average compute power per machine. Effective and efficient exploitation of this power poses unprecedented challenges and opportunities. The Pleiades system, currently under development in UCF, CSU and UCC [1], proposes the construction of a distributed, heterogeneous, and secure marketplace for trading and administer these resources whose owners sign up to various quality of service (QoS) contracts, in return for financial and in-kind payment. This paper presents a very important part of the Pleiades system: addressing the role of Trust Management (TM) in the generation and enforcement of these contracts. The approach taken significantly reduces the overhead that is traditionally assumed with cryptographic solutions, by the dynamic and a priory creation of a secure environment in which these expensive checks associated with cryptographic solutions, are not required.