Computer Sciences Commons^™

Handling Catastrophic Failures In Scalable Internet Applications, Michael Haungs, Raju Pandey, Earl Barr

Computer Science and Software Engineering

User perceived quality is the most important aspect of Internet applications. After a single negative experience, users tend to switch to one of the other myriad of alternatives available to them on the Internet. Two key components of Internet application quality are scalability and reliability. In this paper, we present the first general-purpose mechanism capable of maintaining reliability in the face of process, machine, and catastrophic failures. We define catastrophic failures as events that cause entire clusters of servers to become unavailable such as network partitioning, router failures, natural disasters, or even terrorist attacks. Our mechanism utilizes client-side tunneling, clientside …

Sils Mrat: A Multi-Agent Decision-Support System For Shipboard Integration Of Logistics Systems, Michael Zang, Jonathan Lee, Joyce Gaoiran, Adam Gray, Jered Gray, Charles Hayek, David Nau, Chad Pond, Michael Rutter, Zachary Speck, Jens G. Pohl

Collaborative Agent Design (CAD) Research Center

This report describes work performed by CDM Technologies Inc. on subcontract to ManTech Advanced Systems International, Inc. (Fairmont, West Virginia), and under sponsorship of the Office of Naval Research (ONR). The principal aim of the SILS (Shipboard Integration of Logistics Systems) project is to provide a decision-support capability for Navy ships that integrates shipboard logistical and tactical systems within a near real-time, automated, computer-based shipboard readiness and situation awareness facility. Specifically, SILS is intended to provide the captain of a ship and his staff with an accurate evaluation of the current condition of the ship, based on the ability of …

Human-Robot Interaction, Erika Rogers

Computer Science and Software Engineering

The relationship between robots and humans is so different in character from other human-machine relationships that it warrants its own field of study. Robots differ from simple machines and even from complex computers in that they are often designed to be mobile and autonomous. They are not as predictable as other machines; they can enter a human’s personal space, forcing a kind of social interaction that does not happen in other human-machine relationships.

When Plans Distinguish Bayes Nets, Alex Dekhtyar, Judy Goldsmith, Janice Pearce

Computer Science and Software Engineering

We consider the complexity of determining whether differing probability distributions for the same Bayes net result in different policies, significantly different policy outcomes or optimal value functions.

Ustranscom: Corporate Information-Centric Environment, Collaborative Agent Design Research Center

Collaborative Agent Design (CAD) Research Center

As a result of foresight and planning that has established a logical data model (i.e., the Master Model), a set of standard reference tables and 17 migration software systems as the foundation of a disciplined Corporate Data Environment (CDE), USTRANSCOM now finds itself in the enviable position of being able to implement DoD’s vision of a Global Information Grid (GIG) with speed and confidence. The urgency with which DoD views the need to shift the burden of tedious data filtering and interpretation tasks from human operators to automated machine-based processes, is reflected in the CDE and provides the opportunity for …

Split Knowledge Level Modeling, Michael A. Zang, Jens G. Pohl

Collaborative Agent Design (CAD) Research Center

Traditional approaches to building intelligent information systems employ an object model to define a representational structure for the information of interest within the target domain of the system. At runtime, the model provides a constrained template for the creation of the individual object instances and relationships that together define the state of the system at a given point in time. The ontology also provides a vocabulary for expressing domain knowledge typically in the form of rules (declarative knowledge) or methods (procedural knowledge). Agents operating within the system utilize the encoded knowledge to progress the state of the system towards the …

Implications Of Test-Driven Development: A Test Study, Reid Kaufmann, David S. Janzen

Computer Science and Software Engineering

A Spring 2003 experiment examines the claims that test-driven development or test-first programming improves software quality and programmer confidence. The results indicate support for these claims and inform larger future experiments.

A Framework For Management Of Concurrent Xml Markup, Alex Dekhtyar, Ionut E. Iacob

Computer Science and Software Engineering

The problem of concurrent markup hierarchies in XML encodings of documents has attracted attention of a number of humanities researchers in recent years. The key problem with using concurrent hierarchies to encode documents is that markup in one hierarchy is not necessarily well-formed with respect to the markup in another hierarchy. Previously proposed solutions to this problem rely on the XML expertise of the editors and their ability to maintain correct DTDs for complex markup languages. In this paper, we approach the problem of maintenance of concurrent XML markup from the Computer Science perspective. We propose a framework that allows …

Motion Planning For Multiple Mobile Robots Using Dynamic Networks, Christopher M. Clark, Stephen M. Rock, Jean-Claude Latombe

Computer Science and Software Engineering

A new motion planning framework is presented that enables multiple mobile robots with limited ranges of sensing and communication to maneuver and achieve goals safely in dynamic environments. To combine the respective advantages of centralized and de-centralized planning, this framework is based on the concept of centralized planning within dynamic robot networks. As the robots move in their environment, localized robot groups form networks, within which world models and robot goals can be shared. Whenever a network is formed, new information then becomes available to all robots in this network. With this new information, each robot uses a fast, centralized …

Demonstration Of A Typical Ontology-Based Collaborative Agents System: Seaway, Anthony Wood, Jens G. Pohl

Collaborative Agent Design (CAD) Research Center

In San Luis Obispo we have seventy-seven SEAWAY systems which are being prepared for fielding, and we are deep into the design of the follow on version. So, we are discussing a decision support system which is operational. Before we explore SEAWAY, we probably ought to talk about defining decision making problems and applying decision support.

In the case where the senior decision maker has poor decision skills, even the best decision support will make only the most marginal of difference. However, good decision support can make a huge difference if you have just an adequate decision process and adequate …

Ontological Approaches For Semantic Interoperability, Michael A. Zang, Jens G. Pohl

Collaborative Agent Design (CAD) Research Center

This paper provides a basic description of the concept of an ontology. It then describes how ontologies are structured and employed in the context of interfaces between software based information systems. This usage is discussed in the context of three successive levels of semantic interoperability between two example systems. The paper goes on to suggest that the interfaces between information systems should perhaps be viewed and implemented as systems themselves. The paper concludes by providing a brief summary of what was discussed.

Proceedings Of The 2003 Onr Decision-Support Workshop Series: Developing The New Infostructure, Collaborative Agent Design Research Center

Collaborative Agent Design (CAD) Research Center

In August of 1998 the Collaborative Agent Design Research Center (CADRC) of the California Polytechnic State University in San Luis Obispo (Cal Poly), approached Dr. Phillip Abraham of the Office of Naval Research (ONR) with the proposal for an annual workshop focusing on emerging concepts in decision-support systems for military applications. The proposal was considered timely by the ONR Logistics Program Office for at least two reasons. First, rapid advances in information systems technology over the past decade had produced distributed, collaborative computer-assistance capabilities with profound potential for providing meaningful support to military decision makers. Indeed, some systems based on …

Index Selection For Embedded Control Applications Using Description Logics, Lubomir Stanchev, Grant Weddell

Computer Science and Software Engineering

We consider the problem of automated index selection for embedded control programs (ECPs). Such systems have the property that the transaction types, which can consist of queries and updates, are predefined and can be classified as either critical or non-critical. In this paper, we focus on the critical part of the transaction workload for ECPs. More precisely, our problem input consists of a set of critical transaction types and a database schema. The goal is to find a minimum number of extended indices that enable every critical operation to be performed efficiently. The proposed solution is novel in that it …

Improving Requirements Tracing Via Information Retrieval, Jane Huffman Hayes, Alex Dekhtyar, James Osborne

Computer Science and Software Engineering

This paper presents an approach for improving requirements tracing based on framing it as an information retrieval (IR) problem. Specifically, we focus on improving recall and precision in order to reduce the number of missed traceability links as well as to reduce the number of irrelevant potential links that an analyst has to examine when performing requirements tracing. Several IR algorithms were adapted and implemented to address this problem. We evaluated our algorithms by comparing their results and performance to those of a senior analyst who traced manually as well as with an existing requirements tracing tool. Initial results suggest …

802.11 Denial-Of-Service Attacks: Real Vulnerabilities And Practical Solutions, John M. Bellardo, Stefan Savage

Computer Science and Software Engineering

The convenience of 802.11-based wireless access networks has led to widespread deployment in the consumer, industrial and military sectors. However, this use is predicated on an implicit assumption of confidentiality and availability. While the security flaws in 802.11's basic confidentially mechanisms have been widely publicized, the threats to network availability are far less widely appreciated. In fact, it has been suggested that 802.11 is highly susceptible to malicious denial-of-service (DoS) attacks targeting its management and media access protocols. This paper provides an experimental analysis of such 802.11-specific attacks - their practicality, their efficacy and potential low-overhead implementation changes to mitigate …

Query Algebra Operations For Interval Probabilities, Wenzhong Zhao, Alex Dekhtyar, Judy Goldsmith

Computer Science and Software Engineering

The groundswell for the `00s is imprecise probabilities. Whether the numbers represent the probable location of a GPS device at its next sounding, the inherent uncertainty of an individual expert's probability prediction, or the range of values derived from the fusion of sensor data, probability intervals became an important way of representing uncertainty. However, until recently, there has been no robust support for storage and management of imprecise probabilities. In this paper, we define the semantics of traditional query algebra operations of selection, projection, Cartesian product and join, as well as an operation of conditionalization, specific to probabilistic databases. We …

Pre-Conference Proceedings Of The Focus Symposium On Collaborative Decision-Support Systems, Collaborative Agent Design Research Center

Collaborative Agent Design (CAD) Research Center

The papers included in these pre-conference proceedings reflect the increasing focus on the utilization of computers as collaborating, decision-assistance partners in complex and often time-critical problem situations. There are high expectations that intelligent software agents will solve many of our current information system woes, such as lack of interoperability, multiple failure points, vulnerability to intrusion, making the right information available to the right person at the right time, and proposing solutions under time-critical conditions. Software agents do not have magical human-like capabilities. It is not possible to simply develop a piece of software code that is capable of reasoning about …

The Knowledge Level Approach To Intelligent Information System Design, Michael A. Zang, Jens G. Pohl

Collaborative Agent Design (CAD) Research Center

Traditional approaches to building intelligent information systems employ an ontology to define a representational structure for the data and information of interest within the target domain of the system. At runtime, the ontology provides a constrained template for the creation of the individual objects and relationships that together define the state of the system at a given point in time. The ontology also provides a vocabulary for expressing domain knowledge typically in the form of rules (declarative knowledge) or methods (procedural knowledge). The system utilizes the encoded knowledge, often in conjunction user input, to progress the state of the system …

The Emerging Knowledge Management Paradigm: Some Organizational And Technical Issues, Jens G. Pohl

Collaborative Agent Design (CAD) Research Center

This paper addresses the expectations, organizational implications, and information processing requirements, of the emerging knowledge management paradigm. A brief discussion of the enablement of the individual through the wide-spread availability of computer and communication facilities, is followed by a description of the structural evolution of organizations, and the architecture of a computer-based knowledge management system. The author discusses two trends that are driven by the treatment of information and knowledge as a commodity: increased concern for the management and exploitation of knowledge within organizations; and, the creation of an organizational environment that facilitates the acquisition, sharing and application of knowledge. …

Tegrid: Demonstration Of A Semantic Web Environment, Steven Gollery, Jens G. Pohl

Collaborative Agent Design (CAD) Research Center

Over the past several years there has been an increasing recognition of the shortcomings of message-passing data-processing systems that compute data without understanding, and the vastly superior potential capabilities of information-centric systems that incorporate an internal information model with sufficient context to support a useful level of automatic reasoning.

The key difference between a data-processing and an information-centric environment is the ability to embed in the information-centric software some understanding of the information being processed. The term information-centric refers to the representation of information in the computer, not to the way it is actually stored in a digital machine. This …

Multi-Chart Geometry Images, P. V. Sander, Z. J. Wood, S. J. Gortler, H. Hoppe

Computer Science and Software Engineering

We introduce multi-chart geometry images, a new representation for arbitrary surfaces. It is created by resampling a surface onto a regular 2D grid. Whereas the original scheme of Gu et al. maps the entire surface onto a single square, we use an atlas construction to map the surface piecewise onto charts of arbitrary shape. We demonstrate that this added flexibility reduces parametrization distortion and thus provides greater geometric fidelity, particularly for shapes with long extremities, high genus, or disconnected components. Traditional atlas constructions suffer from discontinuous reconstruction across chart boundaries, which in our context create unacceptable surface cracks. Our solution …

Transformation: The Human Obstacles, Jens G. Pohl

Collaborative Agent Design (CAD) Research Center

This paper addresses the human aspects of change at a time when the rapid wide-spread implementation of a new infostructure has become the cornerstone of national security policies. The author explores the behavioral characteristics of human beings from a point of view that is not based on inter-human comparisons, but on an examination of the innate physical, biological, intellectual, emotional, and social characteristics of our species. It is argued that the experience-based nature of the human cognitive system greatly reduces our ability to adapt to changes in our environment, exploit opportunities, and create new knowledge. A fundamental biological survival instinct …

Can Probabilistic Databases Help Elect Qualified Officials?, Judy Goldsmith, Alex Dekhtyar, Wenzhong Zhao

Computer Science and Software Engineering

We present a flexible framework for implementing reasoning with uncertainty: Semistructured Probabilistic Databases. This framework bridges the gap between the process of obtaining probabilistic information from data and its use in AI applications by providing the facilities to store and query diverse and complex probabilistic data.

Icodes: A Ship Load-Planning System, Stephen Goodman, Jens G. Pohl

Collaborative Agent Design (CAD) Research Center

The Integrated Computerized Deployment System (ICODES) is a logistic software application of ship load-planning tools that utilizes intelligent software agents in a human-computer collaborative mode. As an example of a new generation of ‘information-centric’ military decision-support systems, ICODES includes expert agents with automatic reasoning and analysis capabilities. This is made possible by an internal virtual representation of the load-planning environment, in terms of ship and cargo characteristics and the complex relationships that constitute the context within which load-planning operations are performed. ICODES agents monitor the principal determinants of cargo stowage, including: the placement and segregation requirements for hazardous cargo items; …

Sils Mrat: A Shipboard Integration Of Logistics Systems And Mission Readiness Analysis Tool, Michael A. Zang, Chris K. Neff, Jens G. Pohl

Collaborative Agent Design (CAD) Research Center

SILS (Shipboard Integration of Logistics Systems) is an umbrella program initiated and sponsored by Dr. Phillip Abraham in the Logistics Directorate of the U.S. Office of Naval Research (ONR). The SILS vision is a system of systems that brings together shipboard and shore based data and information sources in a single integrated environment. SILS MRAT (Mission Readiness Analysis Tool) is a high-level shipboard component of SILS, which applies intelligent agent technology to the near real time decision support needs of commanding officers, department heads, and key operations & maintenance personnel. This tool demonstrates the capability of a system architecture to …

Decision-Support Systems: Notions, Prototypes, And In-Use Applications With Emphasis On Military Applications, Jens G. Pohl, Arthur Chapman, Kym Jason Pohl, Jonathan Primrose, Adam Wozniak

Collaborative Agent Design (CAD) Research Center

This report describes work performed by the Collaborative Agent Design Research Center (CADRC) over the past several years in the design and implementation of collaborative, computer-based, decision-support systems, mostly for military applications. In these systems multiple components, either program modules or separate processes (i.e., software agents), cooperate with each other and human decision makers to solve complex problems. The components are essentially of two types: knowledge-based narrow domain experts that provide services to other agents (i.e., service-agents); and, more autonomous agents (i.e., object-agents) that represent the interests of selected objects in high level information representation schemas.

Based on the notion …

Dynamic Networks For Motion Planning In Multi-Robot Space Systems, Christopher M. Clark, Stephen M. Rock, Jean-Claude Latombe

Computer Science and Software Engineering

A new motion planning framework is presented that enables multiple mobile robots with limited ranges of sensing and communication to maneuver and achieve goals safely in dynamic environments. The framework is applicable to both planetary rover and free-floating space robot applications. To combine the respective advantages of centralized and de-centralized planning, this framework is based on the concept of centralized planning within dynamic robot networks. As the robots move in their environment, localized robot groups form networks, within which world models and robot goals can be shared. Whenever a network is formed, new information becomes available to all robots in …

A Tail-Recursive Semantics For Stack Inspections, John Clements, Mathias Felleisen

Computer Science and Software Engineering

Security folklore holds that a security mechanism based on stack inspection is incompatible with a global tail call optimization policy. An implementation of such a language may have to allocate memory for a source-code tail call, and a program that uses only tail calls (and no other memory-allocating construct) may nevertheless exhaust the available memory. In this paper, we prove this widely held belief wrong. We exhibit an abstract machine for a language with security stack inspection whose space consumption function is equivalent to that of the canonical tail call optimizing abstract machine. Our machine is surprisingly simple and suggests …

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 …