This paper investigates a fundamental networking problem in underwater sensor networks: robust and energy-efficient routing. We present an adaptive location-based routing protocol, called hop-by-hop vector-based forwarding (HH-VBF). It uses the notion of a "routing vector" (a vector from the source to the sink) acting as the axis of the "routing pipe", similar to the vector based forward (VBF) routing in the work of P. Xie, J.-H. Cui and L. Lao (VBF: Vector-Based Forwarding Protocol for Underwater Sensor Networks. Technical report, UCONN CSE Technical Report: UbiNet-TR05-03 (BECAT/CSE-TR-05-6), Feb. 2005). Unlike the original VBF approach, however, HH-VBF suggests the use of a routing vector for each individual forwarder in the network, instead of a single network-wide source-to-sink routing vector. By the creation of the hop-by-hop vectors, HH-VBF can overcome two major problems in VBF: (1) too small data delivery ratio for sparse networks; (2) too sensitive to "routing pipe" radius threshold. We conduct simulations to evaluate HH-VBF, and the results show that HH-VBF yields much better performance than VBF in sparse networks. In addition, HH-VBF is less sensitive to the routing pipe radius threshold. Furthermore, we also analyze the behavior of HH-VBF and show that assuming proper redundancy and feedback techniques, HH-VBF can facilitate the avoidance of any "void" areas in the network.

In recent years, two distinct electronic voting technologies have been introduced and extensively utilized in election procedures: direct recording electronic systems and optical scan (OS) systems. The latter are typically deemed safer, as they inherently provide a voter-verifiable paper trail that enables hand-counted audits and recounts that rely on direct voter input. For this reason, OS machines have been widely deployed in the United States. Despite the growing popularity of these machines, they are known to suffer from various security vulnerabilities that, if left unchecked, can compromise the integrity of elections in which the machines are used. This article studies general auditing procedures designed to enhance the integrity of elections conducted with optical scan equipment and, additionally, describes the specific auditing procedures currently in place in the State of Connecticut. We present an abstract view of a typical OS voting technology and its relationship to the general election process. With this in place, we lay down a ldquotemporal-resourcerdquo adversarial model, providing a simple language for describing the disruptive power of a potential adversary. Finally, we identify how audit procedures, injected at various critical stages before, during, and after an election, can frustrate such adversarial interference and so contribute to election integrity. We present the implementation of such auditing procedures for elections in the State of Connecticut utilizing the Premiere (Diebold) AccuVote OS; these audits were conducted by the UConn VoTeR Center, at the University of Connecticut, on request of the Office of the Secretary of the State. We discuss the effectiveness of such procedures in every stage of the process and we present results and observations gathered from the analysis of past election data.

Atomically consistent memory services provide resiliency in dynamic settings.