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2007

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Articles 841 - 870 of 1355

Full-Text Articles in Computer Sciences

Performance Evaluation Of Vision-Based Navigation And Landing On A Rotorcraft Unmanned Aerial Vehicle, David Hubbard, Timothy W. Mclain, Bryan S. Morse, Colin Theodore, Mark Tischler Feb 2007

Performance Evaluation Of Vision-Based Navigation And Landing On A Rotorcraft Unmanned Aerial Vehicle, David Hubbard, Timothy W. Mclain, Bryan S. Morse, Colin Theodore, Mark Tischler

Faculty Publications

A Rotorcraft UAV provides an ideal experimental platform for vision-based navigation. This paper describes the flight tests of the US Army PALACE project, which implements Moravec’s pseudo-normalized correlation tracking algorithm. The tracker uses the movement of the landing site in the camera, a laser range, and the aircraft attitude from an IMU to estimate the relative motion of the UAV. The position estimate functions as a GPS equivalent to enable the rotorcraft to maneuver without the aid of GPS. With GPS data as a baseline, tests were performed in simulation and in flight that measure the accuracy of the position …


Lecture Video Enhancement And Editing By Integrating Posture, Gesture, And Text, Feng Wang, Chong-Wah Ngo, Ting-Chuen Pong Feb 2007

Lecture Video Enhancement And Editing By Integrating Posture, Gesture, And Text, Feng Wang, Chong-Wah Ngo, Ting-Chuen Pong

Research Collection School Of Computing and Information Systems

This paper describes a novel framework for automatic lecture video editing by gesture, posture, and video text recognition. In content analysis, the trajectory of hand movement is tracked and the intentional gestures are automatically extracted for recognition. In addition, head pose is estimated through overcoming the difficulties due to the complex lighting conditions in classrooms. The aim of recognition is to characterize the flow of lecturing with a series of regional focuses depicted by human postures and gestures. The regions of interest (ROIs) in videos are semantically structured with text recognition and the aid of external documents. By tracing the …


Towards Efficient Planning For Real World Partially Observable Domains, Pradeep R. Varakantham Feb 2007

Towards Efficient Planning For Real World Partially Observable Domains, Pradeep R. Varakantham

Research Collection School Of Computing and Information Systems

My research goal is to build large-scale intelligent systems (both single- and multi-agent) that reason with uncertainty in complex, real-world environments. I foresee an integration of such systems in many critical facets of human life ranging from intelligent assistants in hospitals to offices, from rescue agents in large scale disaster response to sensor agents tracking weather phenomena in earth observing sensor webs, and others. In my thesis, I have taken steps towards achieving this goal in the context of systems that operate in partially observable domains that also have transitional (non-deterministic outcomes to actions) uncertainty. Given this uncertainty, Partially Observable …


Clustering And Combinatorial Optimization In Recursive Supervised Learning, Kiruthika Ramanathan, Sheng Uei Guan Feb 2007

Clustering And Combinatorial Optimization In Recursive Supervised Learning, Kiruthika Ramanathan, Sheng Uei Guan

Research Collection School Of Computing and Information Systems

The use of combinations of weak learners to learn a dataset has been shown to be better than the use of a single strong learner. In fact, the idea is so successful that boosting, an algorithm combining several weak learners for supervised learning, has been considered to be the best off the shelf classifier. However, some problems still exist, including determining the optimal number of weak learners and the over fitting of data. In an earlier work, we developed the RPHP algorithm which solves both these problems by using a combination of global search, weak learning and pattern distribution. In …


Quality Of Service Routing Strategy Using Supervised Genetic Algorithm, Zhaoxia Wang, Yugeng Sun, Zhiyong Wang, Huayu Shen Feb 2007

Quality Of Service Routing Strategy Using Supervised Genetic Algorithm, Zhaoxia Wang, Yugeng Sun, Zhiyong Wang, Huayu Shen

Research Collection School Of Computing and Information Systems

A supervised genetic algorithm (SGA) is proposed to solve the quality of service (QoS) routing problems in computer networks. The supervised rules of intelligent concept are introduced into genetic algorithms (GAs) to solve the constraint optimization problem. One of the main characteristics of SGA is its searching space can be limited in feasible regions rather than infeasible regions. The superiority of SGA to other GAs lies in that some supervised search rules in which the information comes from the problems are incorporated into SGA. The simulation results show that SGA improves the ability of searching an optimum solution and accelerates …


Moving-Object Detection, Association, And Selection In Home Videos, Zailiang Pan, Chong-Wah Ngo Feb 2007

Moving-Object Detection, Association, And Selection In Home Videos, Zailiang Pan, Chong-Wah Ngo

Research Collection School Of Computing and Information Systems

Due to the prevalence of digital video camcorders, home videos have become an important part of life-logs of personal experiences. To enable efficient video parsing, a critical step is to automatically extract objects, events and scene characteristics present in videos. This paper addresses the problem of extracting objects from home videos. Automatic detection of objects is a classical yet difficult vision problem, particularly for videos with complex scenes and unrestricted domains. Compared with edited and surveillant videos, home videos captured in uncontrolled environment are usually coupled with several notable features such as shaking artifacts, irregular motions, and arbitrary settings. These …


Human–Robot Interaction: A Survey, Michael A. Goodrich, Alan C. Schultz Feb 2007

Human–Robot Interaction: A Survey, Michael A. Goodrich, Alan C. Schultz

Faculty Publications

Human–Robot Interaction (HRI) has recently received considerable attention in the academic community, in labs, in technology companies, and through the media. Because of this attention, it is desirable to present a survey of HRI to serve as a tutorial to people outside the field and to promote discussion of a unified vision of HRI within the field. The goal of this review is to present a unified treatment of HRI-related problems, to identify key themes, and discuss challenge problems that are likely to shape the field in the near future. Although the review follows a survey structure, the goal of …


A Collaborative, Hierarchical, Incremental, And Problem Solving Information Systems Development Model, Timothy Joseph Burns Jan 2007

A Collaborative, Hierarchical, Incremental, And Problem Solving Information Systems Development Model, Timothy Joseph Burns

Dissertations

The "software crisis" has been a much discussed and debated topic in Information Systems research. A core cause of the crisis is often identified as the methodologies and approaches used to develop information systems. Thus, over the years a multitude of methodologies have emerged in support of quality software. While many of these methodologies have been effective, research has shown that system development is a highly circumstantial process, and that no one methodology can be optimal in every context of every project. It is also a fact that system development practitioners have employed ad hoc approaches to modify formal methodologies …


Novel Force Matrix Transformations With Optimal Load-Balance For 3-Body Potential Based Parallel Molecular Dynamics In A Heterogeneous Cluster Environment, Sumanth J.V, David Swanson, Hong Jiang Jan 2007

Novel Force Matrix Transformations With Optimal Load-Balance For 3-Body Potential Based Parallel Molecular Dynamics In A Heterogeneous Cluster Environment, Sumanth J.V, David Swanson, Hong Jiang

School of Computing: Technical Reports

Evaluating the Force Matrix constitutes the most computationally intensive part of a Molecular Dynamics (MD) simulation. In three-body MD simulations, the total energy of the system is determined by the energy of every unique triple in the system and the force matrix is three-dimensional. The execution time of a three-body MD algorithm is thus proportional to the cube of the number of atoms in the system. Fortunately, there exist symmetries in the Force Matrix that can be exploited to improve the running time of the algorithm. While this optimization is straight forward to implement in the case of sequential code, …


Soldier/Hardware-In-The-Loop Simulation-Based Combat Vehicle Duty Cycle Measurement: Duty Cycle Experiment 2, Mark Brudnak, Mike Pozolo, Victor Paul, Syed Mohammad, Marc Compere, Et Al. Jan 2007

Soldier/Hardware-In-The-Loop Simulation-Based Combat Vehicle Duty Cycle Measurement: Duty Cycle Experiment 2, Mark Brudnak, Mike Pozolo, Victor Paul, Syed Mohammad, Marc Compere, Et Al.

Publications

This paper describes a human-in-the-loop motion-based simulator interfaced to hybrid-electric power system hardware both of which were used to measure the duty cycle of a combat vehicle in a virtual simulation environment. The project discussed is a greatly expanded follow-on to the experiment published in [1]. This paper is written in the context of [1] and therefore highlights the enhancements. The most prominent of these enhancements is the integration (in real-time) of the Power & Electric System Integration Lab (P&E SIL) with a motion base simulator by means of a “long haul” connection over the Internet (a geographical distance of …


Compact Real-Time Modeling Of Seated Humans By Video Sprite Sequence Quantization, Chun Jia, Voicu Popescu Jan 2007

Compact Real-Time Modeling Of Seated Humans By Video Sprite Sequence Quantization, Chun Jia, Voicu Popescu

Department of Computer Science Technical Reports

No abstract provided.


System For Collision Detection Between Deformable Models Built On Axis Aligned Bounding Boxes And Gpu Based Culling, David Owen Tuft Jan 2007

System For Collision Detection Between Deformable Models Built On Axis Aligned Bounding Boxes And Gpu Based Culling, David Owen Tuft

Theses and Dissertations

Collision detection between deforming models is a difficult problem for collision detection systems to handle. This problem is even more difficult when deformations are unconstrained, objects are in close proximity to one another, and when the entity count is high. We propose a method to perform collision detection between multiple deforming objects with unconstrained deformations that will give good results in close proximities. Currently no systems exist that achieve good performance on both unconstrained triangle level deformations and deformations that preserve edge connectivity. We propose a new system built as a combination of Graphics Processing Unit (GPU) based culling and …


Eliminating Redundant And Less-Informative Rss News Articles Based On Word Similarity And A Fuzzy Equivalence Relation, Ian Garcia Jan 2007

Eliminating Redundant And Less-Informative Rss News Articles Based On Word Similarity And A Fuzzy Equivalence Relation, Ian Garcia

Theses and Dissertations

The Internet has marked this era as the information age. There is no precedent in the amazing amount of information, especially network news, that can be accessed by Internet users these days. As a result, the problem of seeking information in online news articles is not the lack of them but being overwhelmed by them. This brings huge challenges regarding processing of online news feeds, i.e., how to determine which news article is important, how to determine the quality of each news article, and how to filter irrelevant and redundant information. In this thesis, we propose a method for filtering …


Implicit Affinity Networks, Matthew Scott Smith Jan 2007

Implicit Affinity Networks, Matthew Scott Smith

Theses and Dissertations

Although they clearly exist, affinities among individuals are not all easily identified. Yet, they offer unique opportunities to discover new social networks, strengthen ties among individuals, and provide recommendations. We propose the idea of Implicit Affinity Networks (IANs) to build, visualize, and track affinities among groups of individuals. IANs are simple, interactive graphical representations that users may navigate to uncover interesting patterns. This thesis describes a system supporting the construction of IANs and evaluates it in the context of family history and online communities.


Virtual Classroom Extension For Effective Distance Education, Radu Dondera, Chun Jia, Voicu Popescu, Cristina Nita-Rotaru, Melissa Dark Jan 2007

Virtual Classroom Extension For Effective Distance Education, Radu Dondera, Chun Jia, Voicu Popescu, Cristina Nita-Rotaru, Melissa Dark

Department of Computer Science Technical Reports

No abstract provided.


Idea: An Infrastructure For Detection-Based Adaptive Consistency Control In Replicated Services, Yijun Lu, Ying Lu, Hong Jiang Jan 2007

Idea: An Infrastructure For Detection-Based Adaptive Consistency Control In Replicated Services, Yijun Lu, Ying Lu, Hong Jiang

School of Computing: Technical Reports

In Internet-scale distributed systems, replication-based scheme has been widely deployed to increase the availability and efficiency of services. Hence, consistency maintenance among replicas becomes an important research issue because poor consistency results in poor QoS or even monetary loss. Recent research in this area focuses on enforcing a certain consistency level, instead of perfect consistency, to strike a balance between consistency guarantee and system’s scalability.
In this paper, we argue that, besides balancing consistency and scalability, it is equally, if not more, important to achieve adaptability of consistency maintenance. I.e., the system adjusts its consistency level on the fly to …


Cvretrieval: Separating Consistency Retrieval From Consistency Maintenance, Yijun Lu, Hong Jiang, Ying Lu Jan 2007

Cvretrieval: Separating Consistency Retrieval From Consistency Maintenance, Yijun Lu, Hong Jiang, Ying Lu

School of Computing: Technical Reports

In distributed online collaboration applications, such as digital white board and online gaming, it is important to guarantee the consistency among participants’ views to make collaboration meaningful. However, maintaining even a relaxed consistency in a distributed environment with a large number of geographically dispersed participants still involves formidable communication and management cost among them.
In this paper, we propose CVRetrieval (Consistency View Retrieval) to solve this scalability problem. Based on the observation that not all participants are equally active or engaged in distributed online collaboration applications, CVRetrieval differentiates the notions of consistency maintenance and consistency retrieval. Here, consistency maintenance implies …


Idea: An Infrastructure For Detection-Based Adaptive Consistency Control In Replicated Services, Yijun Lu, Ying Lu, Hong Jiang Jan 2007

Idea: An Infrastructure For Detection-Based Adaptive Consistency Control In Replicated Services, Yijun Lu, Ying Lu, Hong Jiang

School of Computing: Technical Reports

In Internet-scale distributed systems, replication-based scheme has been widely deployed to increase the availability and efficiency of services. Hence, consistency maintenance among replicas becomes an important research issue because poor consistency results in poor QoS or even monetary loss. Recent research in this area focuses on enforcing a certain consistency level, instead of perfect consistency, to strike a balance between consistency guarantee and system’s scalability.
In this paper, we argue that, besides balancing consistency and scalability, it is equally, if not more, important to achieve adaptability of consistency maintenance. I.e., the system adjusts its consistency level on the fly to …


Skuery: Manipulation Of S-Expressions Using Xquery Techniques, Kevin Burke Tew Jan 2007

Skuery: Manipulation Of S-Expressions Using Xquery Techniques, Kevin Burke Tew

Theses and Dissertations

Data query operations inside programming languages presently perform their functions through the use of domain-specific, declarative expressions and by way of course-grain, API library calls. These methods of operation are practiced by relational databases as well as semistructured XML data stores. Layers of translation, which are necessary to transform data and instructions from the domain of programming languages to data query systems, negtatively effect the performance of data query operations. Skuery resolves this impedance by adopting XML as a native data type with a native representation (SXML). Likewise, query operations are defined in a general purpose programming language (Scheme in …


History Of The Internet, San Antonio Public Library Jan 2007

History Of The Internet, San Antonio Public Library

Communication

Bibliography and photographs of a display of government documents from San Antonio Public Library, Texas.


Tr-2007011: Numerical Computation Of Determinants With Additive Preconditioning, V. Y. Pan, B. Murphy, G. Qian, R. E. Rosholt, I. Taj-Eddin Jan 2007

Tr-2007011: Numerical Computation Of Determinants With Additive Preconditioning, V. Y. Pan, B. Murphy, G. Qian, R. E. Rosholt, I. Taj-Eddin

Computer Science Technical Reports

No abstract provided.


Enumerating Building Block Semantics In Genetic Programming, Nicholas Freitag Mcphee, Brian Ohs, Tyler Hutchinson Jan 2007

Enumerating Building Block Semantics In Genetic Programming, Nicholas Freitag Mcphee, Brian Ohs, Tyler Hutchinson

Faculty Working Papers

This report provides a collection of definitions for the semantics of sub-trees and contexts as manipulated by standard sub-tree crossover in genetic programming (GP). These definitions allow us to completely and compactly describe the exact semantics of the components manipulated by sub-tree crossover, and the semantic results of those interactions. Sub- sequent work shows how these definitions can be used to collect valuable data about the available diversity in a GP population and the opportunities available to sub-tree crossover.


Semantic Building Blocks In Genetic Programming, Nicholas Freitag Mcphee, Brian Ohs, Tyler Hutchinson Jan 2007

Semantic Building Blocks In Genetic Programming, Nicholas Freitag Mcphee, Brian Ohs, Tyler Hutchinson

Faculty Working Papers

In this paper we present a new mechanism for studying the impact of subtree crossover in terms of semantic building blocks. This approach allows us to completely and compactly describe the semantic action of crossover, and provide insight into what does (or doesn’t) make crossover effective. Our results make it clear that a very high proportion of crossover events (typically over 75% in our experiments) are guaranteed to perform no immediately useful search in the semantic space. Our findings also indicate a strong correlation between lack of progress and high proportions of fixed contexts. These results then suggest several new, …


Applying The Levels Of Conceptual Interoperability Model In Support Of Integratability, Interoperability, And Composability For System-Of-Systems Engineering, Charles D. Turnitsa Jan 2007

Applying The Levels Of Conceptual Interoperability Model In Support Of Integratability, Interoperability, And Composability For System-Of-Systems Engineering, Charles D. Turnitsa

Faculty Bibliography

The Levels of Conceptual Interoperability Model (LCIM) was developed to cope with the different layers of interoperation of modeling & simulation applications. It introduced technical, syntactic, semantic, pragmatic, dynamic, and conceptual layers of interoperation and showed how they are related to the ideas of integratability, interoperability, and composability. The model was successfully applied in various domains of systems, cybernetics, and informatics.


Acquiring Three-Dimensional Data From Small Mammalian Teeth : Laser Scanning Eocene Marsupials, Nicholas E. Smith Jan 2007

Acquiring Three-Dimensional Data From Small Mammalian Teeth : Laser Scanning Eocene Marsupials, Nicholas E. Smith

Theses, Dissertations and Capstones

Three-dimensional laser scanning is an effective method of digitization in paleontology, but has traditionally been restricted to larger specimens. The goal of this study was to develop a laser scanning technique applicable to small mammalian (< 5 mm) dentition. Modeling protocols were developed, and a morphometric error study showed the system highly accurate (percent error = 1D- 0.4%, 2D- 0.05%, 3D- 1.74%). Automation and standardization were accomplished by implementation of a multiscan platform and autosurfacing macro reducing modeling time by 60%. To highlight one morphometric application, 3D models (n=61) of three sympatric Eocene marsupials were digitized, and traditionally qualitative diagnostic characters were quantified and assessed. All but two of the 19 characters examined proved diagnostic (p < 0.05), and exploratory canonical discriminant analysis confirmed three distinct species. Incorporating type specimens revealed a familial overlap, therefore, this novel modeling technique can be employed in a full revision of early Eocene marsupials.


Fusion For Component Based Face Recognition, Yanjun Yan, Lisa Ann Osadciw Jan 2007

Fusion For Component Based Face Recognition, Yanjun Yan, Lisa Ann Osadciw

Electrical Engineering and Computer Science - All Scholarship

This paper proposes a practical way to realize the diversity in face recognition system for performance improvement by fusing the classification results from the components (characteristic regions such as eyes, nose and mouth) and from the whole face image, instead of concatenating the face feature and the modular features for a single classifier. The extracted sub-images are not totally independent from the face image, but the experiments show that the fused result is improved from the recognition result based on the face or components alone. The fusion is implemented and compared at both score level and decision level. Communication resources …


Computational Soundness Of A Call By Name Calculus Of Recursively-Scoped Records, Elena Machkasova Jan 2007

Computational Soundness Of A Call By Name Calculus Of Recursively-Scoped Records, Elena Machkasova

Faculty Working Papers

The paper presents a calculus of recursively-scoped records: a two-level calculus with a traditional call-by-name lambda-calculus at a lower level and unordered collections of labeled lambda-calculus terms at a higher level. Terms in records may reference each other, possibly in a mutually recursive manner, by means of labels. We define two relations: a rewriting relation that models program transformations and an evaluation relation that defines a small-step operational semantics of records. Both relations follow a call-by-name strategy. We use a special symbol called a black hole to model cyclic dependencies that lead to infinite substitution.

Computational soundness is a property …


Head-Elementary-Set-Free Logic Programs, Martin Gebser, Joohyung Lee, Yuliya Lierler Jan 2007

Head-Elementary-Set-Free Logic Programs, Martin Gebser, Joohyung Lee, Yuliya Lierler

Computer Science Faculty Proceedings & Presentations

The recently proposed notion of an elementary set yielded a refinement of the theorem on loop formulas, telling us that the stable models of a disjunctive logic program can be characterized by the loop formulas of its elementary sets. Based on the notion of an elementary set, we propose the notion of head-elementary-set-free (HEF) programs, a more general class of disjunctive programs than head-cycle-free (HCF) programs proposed by Ben-Eiiyahu and Dechter. that can still be turned into nondisjunct:ive programs in polynomial time and space by "shifting" the head atoms into the body. We show several properties of HEF programs that …


Mars: An Education-Oriented Mips Assembly Language Simulator, Pete Sanderson, Kenneth Vollmar Jan 2007

Mars: An Education-Oriented Mips Assembly Language Simulator, Pete Sanderson, Kenneth Vollmar

Mathematics Faculty Scholarship

We describe the implementation of “MARS,” a GUI, Java-based simulator for the MIPS assembly language. MIPS, the computer architecture underlying the simulated assembly language, is widely used in industry and is the basis of the popular textbook Computer Organization and Design [6], used at over 400 universities. The MARS simulator has been implemented with characteristics that are especially useful to undergraduate computer science students and their instructors.


Extrapolation Of Operators Defined On Domains And Boundary Respecting Ap Weights, Ryan Berndt Jan 2007

Extrapolation Of Operators Defined On Domains And Boundary Respecting Ap Weights, Ryan Berndt

Mathematics Faculty Scholarship

No abstract provided.