Physical Sciences and Mathematics Commons^™

A Fast Connection-Time Redirection Mechanism For Internet Application Scalability, Michael Haungs, Raju Pandey, Earl Barr, J. Fritz Barnes

Computer Science and Software Engineering

Applications that are distributed, fault tolerant, or perform dynamic load balancing rely on redirection techniques, such as network address translation (NAT), DNS request routing, or middleware to handle Internet scale loads. In this paper, we describe a new connection redirection mechanism that allows applications to change end-points of communication channels. The mechanism supports redirections across LANs and WANs and is application-independent. Further, it does not introduce any central bottlenecks. We have implemented the redirection mechanism using a novel end-point control session layer. The performance results show that the overhead of the mechanism is minimal. Further, Internet applications built using this …

Measuring Packet Reordering, John M. Bellardo, Stefan Savage

Computer Science and Software Engineering

The Internet architecture provides an unsequenced datagram delivery service. Nevertheless, many higher-layer protocols, such as TCP, assume that packets are usually delivered in sequence, and consequently suffer significant degradation when packets are reordered in flight. While there have been several recent proposals to create protocols that adapt to reordering, evaluating their effectiveness requires understanding the dynamics of the reordering processes prevalent in the Internet. Unfortunately, Internet packet sequencing is a poorly characterized and understudied behavior. This failing can be largely attributed to the lack of accurate and universally applicable methods for measuring packet reordering. In this paper, we describe a …

Kinematic Path-Planning For Formations Of Mobile Robots With A Nonholonomic Constraint, Timothy D. Barfoot, Christopher M. Clark, Stephen M. Rock, Gabriele M.T. D'Eleuterio

Computer Science and Software Engineering

A method of planning paths for formations of mobile robots with nonholonomic constraints is presented. The kinematics equations presented in this paper allow a general geometrical formation of mobile robots to be maintained while the group as a whole travels an arbitrary path. It is possible to represent a formation of mobile robots by a single entity with the same type of nonholonomic constraint as the individual members. Thus, any path-planner or control method may be used with the formation as would be applied to an individual robot. Equations are developed for changing the geometrical formation and hardware results are …

Poet: The Online Preference Elicitation Tool, James Royalty, Robert Holland, Judy Goldsmith, Alex Dekhtyar

Computer Science and Software Engineering

If the goal of eliciting accurate user preferences over a complex value space is to be realized, the elicitation process must be through while at the same time not overly burdensome to the user. An ideal preference elicitation tool would maximize the information about preferences acquired from the user while minimizing the number of queries required. To this end, we present POET: the Online Preference Elicitation Tool.
POET is a graphical Java applet designed to elicit complex preference structures to form a utility function. Once the elicitation process is complete POET outputs the resulting utility function as an XML …

Special Issue On Integration Of Symbolic And Connectionist Systems, Paolo Frasconi, Marco Gori, Franz J. Kurfess, Alessandro Sperduti

Computer Science and Software Engineering

No abstract provided.

Conditionalization For Interval Probabilities, Alex Dekhtyar, Judy Goldsmith

Computer Science and Software Engineering

Conditionalization, i.e., computation of a conditional probability distribution given a joint probability distribution of two or more random variables is an important operation in some probabilistic database models. While the computation of the conditional probability distribution is straightforward when the exact point probabilities are involved, it is often the case that such exact point probability distributions of random variables are not known, but are known to lie in a particular interval.

This paper investigates the conditionalization operation for interval probability distribution functions under a possible world semantics. In particular, given a joint probability distribution of two or more random variables, …

Applying Kinodynamic Randomized Motion Planning With A Dynamic Priority System To Multi-Robot Space Systems, Christopher M. Clark, Tim Bretl, Stephen Rock

Computer Science and Software Engineering

Presents a new motion planning system that can construct collision-free trajectories for groups of robots in dynamic environments, without global knowledge or high-bandwidth communication. The robots plan within a confined environment that consists of stationary and moving obstacles. Each robot plans independently using Kinodynamic Randomized Motion Planner techniques to construct its own trajectory that is free of collisions with moving obstacles and other robots. To resolve conflicts between robot trajectories, a new Dynamic Priority System (DPS) is introduced which gives the right of way to the robot whose local workspace is the most crowded. The kinodynamic randomized motion planner allows …

Building Web Applications With Servlets And Javaserver Pages, David S. Janzen

Computer Science and Software Engineering

Servlets and JavaServer Pages provide the ability to dynamically generate web pages using the Java programming language. Among other benefits, the use of Java on the server-side allows the web developer to directly implement object-oriented designs, utilize multiple threads of execution, and employ JDBC to communicate with a database. This tutorial will introduce Servlets and JavaServer Pages through UML diagrams, code samples, and an example web application.

Ontology-Based Semantic Classification Of Unstructured Documents, Ching Kang Cheng, Xiao Shan Pan, Franz J. Kurfess

Computer Science and Software Engineering

As more and more knowledge and information becomes available through computers, a critical capability of systems supporting knowledge management is the classification of documents into categories that are meaningful to the user. In a step beyond the use of keywords, we developed a system that analyzes the sentences contained in unstructured or semi-structured documents, and utilizes an ontology reflecting the domain knowledge for a semantic classification of the documents. An experimental system has been implemented for the analysis of small documents in combination with a limited ontology; an extension to larger sets of documents and extended ontologies, together with an …

Integrating Symbol-Oriented And Sub-Symbolic Reasoning Methods Into Hybrid Systems, Franz J. Kurfess

Computer Science and Software Engineering

Knowledge representation and reasoning methods in artificial intelligence almost exclusively rely on symbol-oriented methods: Statements describing aspects and objects of the system to be modeled are represented through symbols (mostly text strings), and these symbols are stored in a computer, and manipulated according to the inference rules prescribed by the reasoning method. This works reasonably well in situations where knowledge is available in explicit form, typically through experts or written documents. In situations where knowledge is only available implicitly, e.g. in large data sets, other methods, often based on statistical approaches, have been used more successfully. Many of these methods …

Human-Robot Interaction: Final Report For Darpa/Nsf Study On Human-Robot Interaction, Erika Rogers, Robin R. Murphy

Computer Science and Software Engineering

No abstract provided.