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Articles 1 - 12 of 12

Full-Text Articles in Engineering

Loss Aware Rate Allocations In H.263 Coded Video Transmissions, Xiao Su, Benjamin Wah Dec 2005

Loss Aware Rate Allocations In H.263 Coded Video Transmissions, Xiao Su, Benjamin Wah

Faculty Publications

For packet video, information loss and bandwidth limitation are two factors that affect video playback quality. Traditional rate allocation approaches have focused on optimizing video quality under bandwidth constraint alone. However, in the best-effort Internet, packets carrying video data are susceptible to losses, which need to be reconstructed at the receiver side. In this paper, we propose loss aware rate allocations in both group-of-block (GOB) level and macroblock level, given that certain packets are lost during transmissions and reconstructed using simple interpolation methods at the receiver side. Experimental results show that our proposed algorithms can produce videos of higher quality …


Analysis Of Gaits For A Rotating Tripedal Robot, Damian M. Lyons, Kiran Pamnany Oct 2005

Analysis Of Gaits For A Rotating Tripedal Robot, Damian M. Lyons, Kiran Pamnany

Faculty Publications

A goal of robotics has been to develop mechanisms that have the efficiency and speed of wheeled robots with the terrain flexibility of legged robots. In previous work, we have proposed a unique three-legged mechanism, the rotopod, designed to integrate these two useful approaches to locomotion. In this paper, we present an analysis of the variety of gaits that can be exhibited by the rotopod. We present examples of many of these gaits and discuss their potential use. A trajectory generation algorithm is presented that can be used to generate point to point trajectories using one of three different styles …


Ontologies In Web Personalization, Magdalini Eirinaki, Michalis Vazirgiannis Oct 2005

Ontologies In Web Personalization, Magdalini Eirinaki, Michalis Vazirgiannis

Faculty Publications

No abstract provided.


Optimizing Transmission Time Of Scalable Coded Images In Peer-To-Peer Networks, Xiao Su, Rod Fatoohi, Tao Wang Aug 2005

Optimizing Transmission Time Of Scalable Coded Images In Peer-To-Peer Networks, Xiao Su, Rod Fatoohi, Tao Wang

Faculty Publications

In this paper, we study how to optimize image transmission time in peer-to-peer networks by considering the property of bitstreams generated by image coding algorithms. Images can be either scalable coded or nonscalable coded. Since transmission of nonscalable coded images is well understood, we focus on the transmission of scalable coded images in this paper.Because scalable coding embeds lower bit-rate bitstreams into higher bit-rate bitstreams, there exists a many-to-one relationship between supplying and requesting peers. When a requesting peer asks for an image coded in a particular bit rate, multiple peers with the same image but coded in different bit …


Rotational Legged Locomotion, Damian M. Lyons, Kiran Pamnany Jul 2005

Rotational Legged Locomotion, Damian M. Lyons, Kiran Pamnany

Faculty Publications

In this paper we presented a novel, agile robot mechanism, which we call a rotopod, which combines aspects of wheeled and legged locomotion. A general description of how a tripedal rotopod can be made to step, rotating the mechanism about one leg, and moving the center of the mechanism, is presented. The concept of a gait for this mechanism is defined, and is used to show how extremely agile the mechanism can be. Specific resistance is employed as a way to explore the relative efficiency of this mechanism versus a wheel. Finally, we describe our first prototype rotopod and report …


Rank-Based Multisensory Fusion In Multitarget Video Tracking, Damian M. Lyons, D. Frank Hsu Jul 2005

Rank-Based Multisensory Fusion In Multitarget Video Tracking, Damian M. Lyons, D. Frank Hsu

Faculty Publications

An attractive approach to improve tracking performance for visual surveillance is to use information from multiple visual sensory cues such as position, color, shape, etc. Previous work in fusion for tracking has tended to focus on fusion by numerically combining the scores assigned by each cue. We argue that for video scenes with many targets in a crowded situation, the splitting and merging of regions associated with targets, and the subsequent dramatic changes in cue values and reliabilities, renders this form of fusion less effective. In this paper we present experimental results showing that use of cue rank information in …


Salient Closed Boundary Extraction With Ratio Contour, Song Wang, Toshiro Kubota, Jeffrey Mark Siskind, Jun Wang Apr 2005

Salient Closed Boundary Extraction With Ratio Contour, Song Wang, Toshiro Kubota, Jeffrey Mark Siskind, Jun Wang

Faculty Publications

We present ratio contour, a novel graph-based method for extracting salient closed boundaries from noisy images. This method operates on a set of boundary fragments that are produced by edge detection. Boundary extraction identifies a subset of these fragments and connects them sequentially to form a closed boundary with the largest saliency. We encode the Gestalt laws of proximity and continuity in a novel boundary-saliency measure based on the relative gap length and average curvature when connecting fragments to form a closed boundary. This new measure attempts to remove a possible bias toward short boundaries. We present a polynomial-time algorithm …


A Dynamic Pruning And Feature Selection Strategy For Real-Time Tracking, D. Frank Hsu, Damian M. Lyons Mar 2005

A Dynamic Pruning And Feature Selection Strategy For Real-Time Tracking, D. Frank Hsu, Damian M. Lyons

Faculty Publications

Automated video tracking is useful in a number of applications such as surveillance, multisensor networks, robotics and virtual reality. In this paper we investigate an approach to tracking based on fusing the output of a collection of video trackers, each attending to a different feature or cue on the target. We show both theoretically and experimentally that the method used to prune the growth of target hypotheses can have a great impact on the trackers performance, and indirectly, change the benefit of using linear score combination as opposed to a non-linear rank combination for fusion. We also show that the …


Delay-Constrained Transmission Of Fine Scalable Coded Content Over P2p Networks, Xiao Su, Yi Shang, Tao Wang, Yuqing Mai Jan 2005

Delay-Constrained Transmission Of Fine Scalable Coded Content Over P2p Networks, Xiao Su, Yi Shang, Tao Wang, Yuqing Mai

Faculty Publications

Images or videos are generally coded before transmission, and they can be either non-scalable coded or scalable coded, which can be further classified into fine-scalable coded and coarse-scalable coded. In this paper, we focus on delivery of fine-scalable coded content. The objective of our work is to design algorithms to optimize the quality of fine-scalable coded images or videos on peer-to-peer networks when a requesting peer is delay-sensitive and has to display content within a certain delay bound. Fine-scalable coding has two properties: (1) it embeds lower bit-rate bitstreams into higher bit-rate bitstreams; and (2) its coding quality increases with …


Research Directions For Service-Oriented Multiagent Systems, Michael N. Huhns, Munindar P. Singh, Mark Burstein, Keith Decker, Edmund Durfee, Tim Finin, Les Gasser, Hrishikesh Goradia, Nick Jennings, Kiran Lakkaraju, Hideyuki Nakashima, H. Van Dyke Parunak, Jeffrey S. Rosenschein, Alicia Ruvinsky, Gita Sukthankar, Samarth Swarup, Katia Sycara, Milind Tambe, Tom Wagner, Laura Zavala, Mas Research Roadmap Project Jan 2005

Research Directions For Service-Oriented Multiagent Systems, Michael N. Huhns, Munindar P. Singh, Mark Burstein, Keith Decker, Edmund Durfee, Tim Finin, Les Gasser, Hrishikesh Goradia, Nick Jennings, Kiran Lakkaraju, Hideyuki Nakashima, H. Van Dyke Parunak, Jeffrey S. Rosenschein, Alicia Ruvinsky, Gita Sukthankar, Samarth Swarup, Katia Sycara, Milind Tambe, Tom Wagner, Laura Zavala, Mas Research Roadmap Project

Faculty Publications

Today's service-oriented systems realize many ideas from the research conducted a decade or so ago in multiagent systems. Because these two fields are so deeply connected, further advances in multiagent systems could feed into tomorrow's successful service-oriented computing approaches. This article describes a 15-year roadmap for service-oriented multiagent system research.


A Semantic Web Services Architecture, Mark Burstein, Christoph Bussler, Michal Zaremba, Tim Finn, Michael N. Huhns, Massimo Paolucci, Amit P. Sheth, Stuart Williams Jan 2005

A Semantic Web Services Architecture, Mark Burstein, Christoph Bussler, Michal Zaremba, Tim Finn, Michael N. Huhns, Massimo Paolucci, Amit P. Sheth, Stuart Williams

Faculty Publications

The semantic Web services initiative architecture (SWSA) committee has created a set of architectural and protocol abstractions that serve as a foundation for semantic Web service technologies. This article summarizes the committee's findings, emphasizing its review of requirements gathered from several different environments. We also identify the scope and potential requirements for a semantic Web services architecture.


Service-Oriented Computing: Key Concepts And Principles, Michael N. Huhns, Munindar P. Singh Jan 2005

Service-Oriented Computing: Key Concepts And Principles, Michael N. Huhns, Munindar P. Singh

Faculty Publications

Traditional approaches to software development - the ones embodied in CASE tools and modeling frameworks - are appropriate for building individual software components, but they are not designed to face the challenges of open environments. Service-oriented computing provides a way to create a new architecture that reflects components' trends toward autonomy and heterogeneity. We thus emphasize SOC concepts instead of how to deploy Web services in accord with current standards. To begin the series, we describe the key concepts and abstractions of SOC and the elements of a corresponding engineering methodology.