Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 11 of 11

Full-Text Articles in Entire DC Network

Structured P2p Technologies For Distributed Command And Control, Daniel R. Karrels, Gilbert L. Peterson, Barry E. Mullins Dec 2009

Structured P2p Technologies For Distributed Command And Control, Daniel R. Karrels, Gilbert L. Peterson, Barry E. Mullins

Faculty Publications

The utility of Peer-to-Peer (P2P) systems extends far beyond traditional file sharing. This paper provides an overview of how P2P systems are capable of providing robust command and control for Distributed Multi-Agent Systems (DMASs). Specifically, this article presents the evolution of P2P architectures to date by discussing supporting technologies and applicability of each generation of P2P systems. It provides a detailed survey of fundamental design approaches found in modern large-scale P2P systems highlighting design considerations for building and deploying scalable P2P applications. The survey includes unstructured P2P systems, content retrieval systems, communications structured P2P systems, flat structured P2P systems and …


Sharing Landmark Information Using Mixture Of Gaussian Terrain Spatiograms, Damian M. Lyons Oct 2009

Sharing Landmark Information Using Mixture Of Gaussian Terrain Spatiograms, Damian M. Lyons

Faculty Publications

In this paper we evaluate the use of a novel spatial histogram called the terrain spatiogram as a common representation for exchanging landmark information between robots working as a team to map an area. Individual robots use range sensors to provide the spatial dimension of the spatiogram and video for the image dimension. We have previously shown that terrain spatiograms can be shared between robots in a heterogeneous team to recognize landmarks and to fuse observations from multiple sensors or multiple platforms. A terrain spatiogram using a mixture of Gaussians (MOG) model is introduced and a corresponding normalized spatiogram similarity …


Combining Multiple Scoring Systems For Target Tracking Using Rank-Score Characteristics, Damian M. Lyons, D. Frank Hsu Oct 2009

Combining Multiple Scoring Systems For Target Tracking Using Rank-Score Characteristics, Damian M. Lyons, D. Frank Hsu

Faculty Publications

Video target tracking is the process of estimating the current state, and predicting the future state of a target from a sequence of video sensor measurements. Multitarget video tracking is complicated by the fact that targets can occlude one another, affecting video feature measurements in a highly non-linear and difficult to model fashion. In this paper, we apply a multisensory fusion approach to the problem of multitarget video tracking with occlusion. The approach is based on a data-driven method (CFA) to selecting the features and fusion operations that improve a performance criterion. Each sensory cue is treated as a scoring …


Phage-Induced Alignment Of Membrane Proteins Enables The Measurement And Structural Analysis Of Residual Dipolar Couplings With Dipolar Waves And Lambda-Maps, Sang Ho Park, Woo Sung Son, Rishi Mukhopadhyay, Homayoun Valafar, Stanley J. Opella Sep 2009

Phage-Induced Alignment Of Membrane Proteins Enables The Measurement And Structural Analysis Of Residual Dipolar Couplings With Dipolar Waves And Lambda-Maps, Sang Ho Park, Woo Sung Son, Rishi Mukhopadhyay, Homayoun Valafar, Stanley J. Opella

Faculty Publications

At pH > 6 added filamentous bacteriophage fd is compatible with many of the detergents used to solubilize membrane proteins for solution NMR studies of membrane proteins and, therefore, serves as an alignment media. In combination with strained polyacrylamide gel alignment, Dipolar Waves can be used to directly assess the secondary structure and a λ-map extracts the order tensors for de novo structure calculation of membrane proteins without distance restraints.


Gene Order Phylogeny And The Evolution Of Methanogens, Haiwei Luo, Zhiyi Sun, William Arndt, Jian Shi, Robert Friedman, Jijun Tang Jun 2009

Gene Order Phylogeny And The Evolution Of Methanogens, Haiwei Luo, Zhiyi Sun, William Arndt, Jian Shi, Robert Friedman, Jijun Tang

Faculty Publications

Methanogens are a phylogenetically diverse group belonging to Euryarchaeota. Previously, phylogenetic approaches using large datasets revealed that methanogens can be grouped into two classes, “Class I” and “Class II”. However, some deep relationships were not resolved. For instance, the monophyly of “Class I” methanogens, which consist of Methanopyrales, Methanobacteriales and Methanococcales, is disputable due to weak statistical support. In this study, we use MSOAR to identify common orthologous genes from eight methanogen species and a Thermococcale species (outgroup), and apply GRAPPA and FastME to compute distance-based gene order phylogeny. The gene order phylogeny supports two classes of methanogens, but it …


Exploiting Matrix Symmetry To Improve Fpgaaccelerated Conjugate Gradient, Jason D. Bakos, Krishna K. Nagar Apr 2009

Exploiting Matrix Symmetry To Improve Fpgaaccelerated Conjugate Gradient, Jason D. Bakos, Krishna K. Nagar

Faculty Publications

In this paper we describe a new approach for accelerating the Conjugate Gradient (CG) method using an FPGA co-processor. As in previous approaches, our co-processor performs a double-precision sparse matrix-vector multiplication. However, our implementation doubles the amount of computation per unit of input data by exploiting the symmetry of the input matrix and computing the upper and lower triangle of the input matrix in parallel. Using a Virtex-2 Pro 100 FPGA, we have achieved an observed computational throughput of 1155 MFLOPS.


Sharing And Fusing Landmark Information In A Team Of Autonomous Robots, Damian M. Lyons Mar 2009

Sharing And Fusing Landmark Information In A Team Of Autonomous Robots, Damian M. Lyons

Faculty Publications

A team of robots working to explore and map a space may need to share information about landmarks so as register local maps and to plan effective exploration strategies. In this paper we investigate the use of spatial histograms (spatiograms) as a common representation for exchanging landmark information between robots. Each robot can use sonar, stereo, laser and image information to identify potential landmarks. The sonar, laser and stereo information provide the spatial dimension of the spatiogram in a landmark-centered coordinate frame while video provides the image information. We call the result a terrain spatiogram. This representation can be shared …


Mobility Handling In Mac For Wireless Ad Hoc Networks, Anjali Raja, Xiao Su Mar 2009

Mobility Handling In Mac For Wireless Ad Hoc Networks, Anjali Raja, Xiao Su

Faculty Publications

Wireless Sensor Networks (WSNs) are becoming popular in a wide variety of applications. In a WSN, sensor nodes can be static or mobile, depending on applications. Handling mobility in a sensor network can pose interesting challenges in sensor protocol design, and special algorithms are needed to adapt to mobility in the network. In this paper, we survey the current state of art in handling mobility in sensor networks. We first study how mobility affects the design of different layers in the sensor network architecture, and then take a closer look at mobility handling in the MAC layer. We also describe …


Locating And Tracking Objects By Efficient Comparison Of Real And Predicted Synthetic Video Imagery, Damian M. Lyons, D. Paul Benjamin Jan 2009

Locating And Tracking Objects By Efficient Comparison Of Real And Predicted Synthetic Video Imagery, Damian M. Lyons, D. Paul Benjamin

Faculty Publications

A mobile robot moving in an environment in which there are other moving objects and active agents, some of which may represent threats and some of which may represent collaborators, needs to be able to reason about the potential future behaviors of those objects and agents. In this paper we present an approach to tracking targets with complex behavior, leveraging a 3D simulation engine to generate predicted imagery and comparing that against real imagery. We introduce an approach to compare real and simulated imagery and present results using this approach to locate and track objects with complex behaviors. In this …


Query Recommendations For Interactive Database Exploration, Gloria Chatzopoulou, Magdalini Eirinaki, Neoklis Polyzotis Jan 2009

Query Recommendations For Interactive Database Exploration, Gloria Chatzopoulou, Magdalini Eirinaki, Neoklis Polyzotis

Faculty Publications

Relational database systems are becoming increasingly popular in the scientific community to support the interactive exploration of large volumes of data. In this scenario, users employ a query interface (typically, a web-based client) to issue a series of SQL queries that aim to analyze the data and mine it for interesting information. First-time users, however, may not have the necessary knowledge to know where to start their exploration. Other times, users may simply overlook queries that retrieve important information. To assist users in this context, we draw inspiration from Web recommender systems and propose the use of personalized query recommendations. …


Agents And Service-Oriented Computing For Autonomic Computing: A Research Agenda, Frances M.T. Brazier, Jeffrey O. Kephart, H. Van Dyke Parunak, Michael N. Huhns Jan 2009

Agents And Service-Oriented Computing For Autonomic Computing: A Research Agenda, Frances M.T. Brazier, Jeffrey O. Kephart, H. Van Dyke Parunak, Michael N. Huhns

Faculty Publications

Autonomic computing is the solution proposed to cope with the complexity of today's computing environments. Self-management, an important element of autonomic computing, is also characteristic of single and multiagent systems, as well as systems based on service-oriented architectures. Combining these technologies can be profitable for all - in particular, for the development of autonomic computing systems.