Digital Commons Network^™

Dynamic Transfer Of Control Between Manned And Unmanned Simulation Actors, Neal W. Schneider

Theses and Dissertations

This thesis continues the ongoing research at the Air Force Institute of Technology's Virtual Environments Laboratory in the area of distributed simulation. As the relevance and interest of interactive simulation as a training medium continues to grow, there is a pressing need to provide more realistic and numerous intelligent autonomous agents for simulations. As those autonomous agents mature and become more realistic, the need exists to be able to handle individual agents by taking control of them and operating them as manned agents at certain points within the simulation. The author started with a protocol proposed in a working draft …

Bit-Sequences: A New Cache Invalidation Method In Mobile Environments, Jin Jing, Ahmed K. Elmagarmid, Abdelsalam Helal, Rafael Alonso

Department of Computer Science Technical Reports

No abstract provided.

Partitioned Data Management In Mobile Environments, Ahmed K. Elmagarmid, Jin Jing, Abdelsalam Helal, Rafael Alonso

Department of Computer Science Technical Reports

No abstract provided.

Sliced Configuration Spaces For Curved Planar Bodies, Elisha Sacks, Chandrajit Bajaj

Department of Computer Science Technical Reports

No abstract provided.

Inverse Pattern Matching, Amihood Amir, Alberto Apostolico, Moshe Lewenstein

Department of Computer Science Technical Reports

No abstract provided.

Migrant Threads On Process Farms: Parallel Programming With Ariadne*, Edward Mascarenhas, Vernon Rego

Department of Computer Science Technical Reports

No abstract provided.

Packet Routing In Networks With Long Wires, Ronald I. Greenberg, Hyeong-Cheol Oh

Computer Science: Faculty Publications and Other Works

In this paper, we examine the packet routing problem for networks with wires of differing length. We consider this problem in a network independent context, in which routing time is expressed in terms of "congestion" and "dilation" measures for a set of packet paths. We give, for any constant ϵ > 0, a randomized on-line algorithm for routing any set of Npackets in O((C lg^ϵ(Nd) + D lg(Nd))/lg lg(Nd)) time, where C is the maximum congestion and D is the length of the longest path, both taking wire delays into …

The Effects Of Conceptual And Logical Interfaces On Visual Query Performance Of End Users, Keng Siau, H. Chan, K. Wei

Research Collection School Of Computing and Information Systems

To the end users, the interface is the system. A better interface not only facilitates end user interaction with the database, it also enables them to formulate queries more efficiently and effectively. Two of the most important user-database interfaces are the conceptual and logical interfaces. With the conceptual interface, the user communicates with tile database system in terms ofentities, objects and relationships. On the other hand, the current user-database interaction is mainly based on the logical interface where the user expresses the queries in terms of relations and join operations. Because the concepts at the logical iliterface are abstract and …

Adaptive Methods For Distributed Video Presentation, Crispin Cowan, Shanwei Cen, Jonathan Walpole, Carlton Pu

Computer Science Faculty Publications and Presentations

This paper describes problems and solutions for delivering real-time, multi-media presentations across the Internet. A key characteristic of presentations of continuous media datatypes, such as digital video and audio, is their need for predictable real-time data delivery. For example, an NTSC quality video presentation requires video frames to be displayed every 1/30th of a second. Variations in this display rate can be observable as stalls or glitches in the video stream and reduce the quality of the presentation [6]. Delivering such presentations across the Internet is difficult because highly variable band- width and latency make it difficult to predict the …

An Api For Choreographing Data Accesses, Elizabeth A.M. Shriver, Leonard F. Wisniewski

Computer Science Technical Reports

Current APIs for multiprocessor multi-disk file systems are not easy to use in developing out-of-core algorithms that choreograph parallel data accesses. Consequently, the efficiency of these algorithms is hard to achieve in practice. We address this deficiency by specifying an API that includes data-access primitives for data choreography. With our API, the programmer can easily access specific blocks from each disk in a single operation, thereby fully utilizing the parallelism of the underlying storage system. Our API supports the development of libraries of commonly-used higher-level routines such as matrix-matrix addition, matrix-matrix multiplication, and BMMC (bit-matrix-multiply/complement) permutations. We illustrate our API …

Using Passion System On Lu Factorization, Haluk Rahmi Topcuoglu, Alok Choudhary

Electrical Engineering and Computer Science - Technical Reports

Parallel I/0 subsystems are added to massively parallel computers in order to lessen I/0 bottleneck to some extent. Up to now, a few number of parallel software systems have been designed and implemented to assist programmers in I/0 intensive applications; PASSION is one of them. By providing parallel I/0 support at the language, compiler and run-time level, PASSION system explores the large design space of parallel systems. The target of this paper is to show the performance benefits of using PASSION I/0 libraries at runtime in comparison with using conventional parallel I/0 primitives for high performance parallel I/0 in LU …

On The Equivalence Of Upward And Downward Inheritance Reasoners, Krishnaprasad Thirunarayan

Kno.e.sis Publications

In this paper, we analyze systematically the downward (property flow) and the upward (individual flow) views of inheritance for different categories of inheritance networks. We observe that both these views assign the same meaning to tree-structured hierarchies, and explain the divergence in the interpretation of more general networks in terms of their expressive power. This simple analysis sheds light on the inherent nature of nonmonotonic inheritance and can form the basis for the design of efficient algorithms for certain classes of queries. In addition, we describe the notion of preferential inheritance to specify additional conflict resolution information that can be …

Multi-View Access Protcols For Large-Scale Replication, Xiangning (Sean) Liu, Abdelsalam (Sumi) Helal, Bharat K. Bhargava

Department of Computer Science Technical Reports

No abstract provided.

A Simple Solver For Linear Equations Containing Nonlinear Operators, Norman Ramsey

Department of Computer Science Technical Reports

No abstract provided.

Optimal P-Cyclic Sor For Complex Spectra, S. Galanis, A. Hadjidimos, D. Noutsos

Department of Computer Science Technical Reports

No abstract provided.

Intelligent Control Of Vehicles: Preliminary Results On The Application Of Learning Automata Techniques To Automated Highway System, Cem Unsal, John S. Bay, Pushkin Kachroo

Electrical & Computer Engineering Faculty Research

We suggest an intelligent controller for an automated vehicle to plan its own trajectory based on sensor and communication data received. Our intelligent controller is based on an artificial intelligence technique called learning stochastic automata. The automaton can learn the best possible action to avoid collisions using the data received from on-board sensors. The system has the advantage of being able to work in unmodeled stochastic environments. Simulations for the lateral control of a vehicle using this AI method provides encouraging results.

Customizable Operating Systems, Jonathan Walpole, Crispin Cowan, Andrew P. Black, Jon Inouye, Calton Pu, Shanwei Cen

Computer Science Faculty Publications and Presentations

A customizable operating system is one that can adapt to improve its functionality or performance. The need for customizable and application-specific operating systems has been recognized for many years, but they have yet to appear in the commercial market. This paper explores the notion of operating system customizability and examines the limits of existing approaches. The paper begins by surveying system structuring approaches for the safe and efficient execution of customizable operating systems. Then it discusses the burden that existing approaches impose on application software, and explores techniques for reducing this burden. Finally, support for customizability in the Synthetix project …

Quality Of Service Specification For Multimedia Presentations, Richard Staehli, Jonathan Walpole, David Maier

Computer Science Faculty Publications and Presentations

The bandwidth limitations of multimedia systems force tradeoffs between presentation data fidelity and real-time performance. For example, digital video is commonly encoded with lossy compression to reduce bandwidth and frames may be skipped during playback to maintain synchronization. These tradeoffs depend on device performance and physical data representations that are hidden by a database system. If a multimedia database is to support digital video and other continuous media data types, we argue that the database should provide a Quality of Service (QOS) interface to allow application control of presentation timing and information loss tradeoffs.

This paper proposes a data model …

Device And Physical Data Independence For Multimedia Presentations, Richard Staehli, Jonathan Walpole, David Maier

Computer Science Faculty Publications and Presentations

Multimedia computing promises access to any type of visual or aural medium on the desktop. But in this networked future, will every type of media be accessible from every terminal device? Current multimedia standards do not allow content that is authored for high-bandwidth workstations to scale down for low-bandwidth applications. The problem is that application requests are commonly interpreted as requests for the highest possible quality and resource overloads are handled by ad hoc methods. We can begin to solve this problem by specifying Quality of Service (QOS) requirements based on functionality rather than on content encoding and device capabilities.

Device And Physical Data Independence For Multimedia Presentations, Richard Staehli, Jonathan Walpole, David Maier

Computer Science Faculty Publications and Presentations

Multimedia computing promises access to any type of visual or aural medium on the desktop. But in this networked future, will every type of media be accessible from every terminal device? Current multimedia standards do not allow content that is authored for high-bandwidth workstations to scale down for low-bandwidth applications. The problem is that application requests are commonly interpreted as requests for the highest possible quality and resource overloads are handled by ad hoc methods. We can begin to solve this problem by specifying Quality of Service (QOS) requirements based on functionality rather than on content encoding and device capabilities.

Automatic Visual Recognition Using Parallel Machines, Yui-Liang Chen

Dissertations

Invariant features and quick matching algorithms are two major concerns in the area of automatic visual recognition. The former reduces the size of an established model database, and the latter shortens the computation time. This dissertation, will discussed both line invariants under perspective projection and parallel implementation of a dynamic programming technique for shape recognition. The feasibility of using parallel machines can be demonstrated through the dramatically reduced time complexity.

In this dissertation, our algorithms are implemented on the AP1000 MIMD parallel machines. For processing an object with a features, the time complexity of the proposed parallel algorithm is O(n) …

Estimating Time Available For Sensor Fusion Exception Handling, Robin R. Murphy, Erika Rogers

Computer Science and Software Engineering

In previous work, we have developed a generate, test, and debug methodology for detecting, classifying, and responding to sensing failures in autonomous and semi-autonomous mobile robots. An important issue has arisen from these efforts: how much time is there available to classify the cause of the failure and determine an alternative sensing strategy before the robot mission must be terminated?

In this paper, we consider the impact of time for teleoperation applications where a remote robot attempts to autonomously maintain sensing in the presence of failures yet has the option to contact the local for further assistance. Time limits are …

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 11, Number 8, October 1995, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

A ten page newsletter created by the Wright State University College of Engineering and Computer Science that addresses the current affairs of the college.

Relocating Machine Instructions By Currying, Norman Ramsey

Department of Computer Science Technical Reports

No abstract provided.

Effective Strategies For Multi-Media Message Transmission: Udp Cooling And Tcp, Xiangning Sean Liu, Lebin Cheng, Bharat Bhargava

Department of Computer Science Technical Reports

No abstract provided.

An Evaluation Of Transmitting Compressed Images In A Wide Area Network, Melliyal Annamalai, Bharat Bhargava

Department of Computer Science Technical Reports

No abstract provided.

Www//Pdepack A Web Based Problem Solving Environment For Partial Differential Equations, W. R. Dyksen, Elias N. Houstis, John R. Rice

Department of Computer Science Technical Reports

No abstract provided.

Formal Methods: How, When, And Why They Are Used, Beth Arrowsmith, Bruce Mcmillin, Ralph Wilkerson

Computer Science Technical Reports

Formal methods, theoretically a wonderful concept for ensuring a program's correctness, are not widely used in practice. This dichotomy between what theory advocates and practice might be due to programmers' lack of experience with formal methods. To determine if this was the case, a module on Formal Methods was introduced into a graduate course on distributed systems. This module first introduced the students to the theory of formal methods and then required students to program a distributed problem in CCSP, a subset of CSP, using formal methods. The results were abysmal. Students avoided using formal methods. When they did use …

Atomic Broadcast In Heterogeneous Distributed Systems, Osman Zeineldine

Computer Science Theses & Dissertations

Communication services have long been recognized as possessing a dominant effect on both performance and robustness of distributed systems. Distributed applications rely on a multitude of protocols for the support of these services. Of crucial importance are multicast protocols. Reliable multicast protocols enhance the efficiency and robustness of distributed systems. Numerous reliable multicast protocols have been proposed, each differing in the set of assumptions adopted, especially for the communication network. These assumptions make each protocol suitable for a specific environment. The presence of different distributed applications that run on different LANs and single distributed applications that span different LANs mandate …

Text Independent Speaker Verification Using Binary-Pair Partitioned Neural Networks, Claude A. Norton Iii

Electrical & Computer Engineering Theses & Dissertations

A method is presented for the application of binary-pair partitioned neural networks to the task of speaker verification. This technique is based on a previously developed neural network classifier for speaker identification.

The main focus of this research was the development and testing of the algorithms necessary to extend the binary-pair partitioning approach from speaker identification to speaker verification. The method is based on the development of a user profile which is obtained from discriminative data provided by the binary-pair partitioned neural networks.

Experimental results are provided which demonstrate the viability of this approach, using the TIMIT speech corpus for …