Autonomous multiagent teams can be used in complex exploration tasks to both expedite the exploration and improve the efficiency. However, use of multiagent systems presents additional challenges. Specifically, in domains where the agents' actions are tightly coupled, coordinating multiple agents to achieve cooperative behavior at the group level is difficult. In this work, we demonstrate that ...

The tightly coupled strapdown inertial navigation system (SINS)/global position system (GPS) has been widely used. The system observability determines whether the system state can be estimated by a filter efficiently or not. In this paper, the observability analysis of a two-channel and a three-channel tightly coupled SINS/GPS are performed, respectively, during arbitrary translational maneuver...

We report our experience of tightly coupling a global change simulation of the terrestrial carbon cycle with an object{oriented database. By tightly coupled, we mean an interleaving of computational and data access statements within the same module so that intermediate model values are easily represented in persistent storage. This implementation approach opens up the \black box" character of s...

Continuous technology miniaturization allows to build massively parallel embedded computer architectures within a single silicon chip. Programming that leverages the abundant parallelism in such architectures, however, is very difficult, tedious, and error-prone. Thus, compiler support is paramount. We therefore present LoopInvader, a loop compiler for a particular class of massively parallel p...

The need to provide for robust GPS navigation in challenging environments such as urban or dense vegetation is established. The use of ultra-tightly coupled techniques can significantly extend the tracking threshold of GPS receivers in these environments providing for robust navigation using code and carrier measurements at C/No levels previously unobtainable. The use of conventional tracking l...

ABSTRACT This paper describes the design and implementation of a tightly coupled integration of the Global Positioning System (GPS) and Inertial Navigation System (INS) based on the sigma-point Kalman filtering (SPKF) method. The SPKF uses a set of sigma points to completely capture the first and second order moments of the apriori random variable. In contrast to extended Kalman filtering (EKF)...

We describe the design and implementation of a distributed, searchable web proxy cache designed to reduce and eliminate web traffic for itermittently connected environments with low bandwidth and/or high latency. We characterize our system using a proxy cache trace. We have found that searching over the cache using queries from extracted the cache tends to yield higher results than searching us...

A prevailing trend in computer graphics is the demand for increasingly realistic global illumination models and algorithms. Despite the fact that the computational power of uniprocessors is increasing, it is clear that much greater computational power is required to achieve satisfactory throughput. The obvious next step is to employ parallel processing. The advent of affordable, tightly-coupled...

A strategy is presented for exploiting the frequency stability, transmit location, and timing information of ambient radio-frequency “signals of opportunity” for the purpose of navigating in deep urban and indoor environments. The strategy, referred to as tightly-coupled opportunistic navigation (TCON), involves a receiver continually searching for signals from which to extract navigation and t...

Processor speed and available computing power constantly increases, enabling computation of more and more complex problems such as numerical simulations of physical processes. In this domain, however, the problem of accuracy arises due to rounding of intermediate results. One solution is to avoid intermediate rounding by using exact arithmetic. The use of FPGAs as application-specific accelerat...