15267324
The Contract Net Protocol: High-Level Communication and Control in a Distributed Problem Solver
The contract net protocol has been developed to specify problem-solving communication and control for nodes in a distributed problem solver. Task distribution is affected by a negotiation process, a discussion carried on between nodes with tasks to be executed and nodes that may be able to execute those tasks.
3190919
Negotiation as a Metaphor for Distributed Problem Solving
Abstract We describe the concept of distributed problem solving and define it as the cooperative solution of problems by a decentralized and loosely coupled collection of problem solvers. This approach to problem solving offers the promise of increased performance and provides a useful medium for exploring and developing new problem-solving techniques. We present a framework called the contract net that specifies communication and control in a distributed problem solver. Task distribution is viewed as an interactive process, a discussion carried on between a node with a task to be executed and a group of nodes that may be able to execute the task. We describe the kinds of information that must be passed between nodes during the discussion in order to obtain effective problem-solving behavior. This discussion is the origin of the negotiation metaphor: Task distribution is viewed as a form of contract negotiation. We emphasize that protocols for distributed problem solving should help determine the content of the information transmitted, rather than simply provide a means of sending bits from one node to another. The use of the contract net framework is demonstrated in the solution of a simulated problem in area surveillance, of the sort encountered in ship or air traffic control. We discuss the mode of operation of a distributed sensing system, a network of nodes extending throughout a relatively large geographic area, whose primary aim is the formation of a dynamic map of traffic in the area. From the results of this preliminary study we abstract features of the framework applicable to problem solving in general, examining in particular transfer of control. Comparisons with planner, conniver, hearsay-ii , and pup 6 are used to demonstrate that negotiation—the two-way transfer of information—is a natural extension to the transfer of control mechanisms used in earlier problem-solving systems.
11197998
A Modular Tool Kit for Knowledge Management
We describe an integrated programming environment for develop ing knowledge-based systems. The environment contains a variety of general-purpose tools: a rule interpretation system, a semantic integrity manager, a task representation system and a file manager. Although the tools have different origins (eg. rule based systems, database management, process control), an obiect-oriented foundation lends modularity and consistency to the tool kit.
16344666
A Model for Learning Systems
A model for learning systems is presented, and representative AI, pattern recognition, and control systems are discussed in terms of its framework. The model details the functional components felt to be essential for any learning system, independent of the techniques used for its construction, and the specific environment in which it operates. These components are Performance element, instance selector, critic, earning element, blackboard, and world model. Consideration of learning system design leads naturally to the concept of a layered system, each layer operating at a different level of abstraction.
33698159
On the Development of Commercial Expert Systems
We use our experience with the Dipmeter Advisor system for well-log interpretation as a case study to examine the development of commercial expert system. We discuss the nature of these systems as we see them in the coming decade, characteristics of the evolution process, development methods, and skills required in the development team. We argue that the tools and ideas of rapid prototyping and successive refinement accelerate the development process. We note that different types of people are required at different stages of expert system development: Those who are primarily knowledgeable in the domain, but who can use the framework to expand the domain knowledge; and those who can actually design and build expert systems. Finally, we discuss the problem of technology transfer and compare our experience with some of the traditional wisdom of expert system development.
36936116
Design of Knowledge-Based Systems with a Knowledge-Based Assistant
The authors propose a model for an intelligent assistant to aid in building knowledge-based systems (KBSs) and discuss a preliminary implementation. The assistant participates in KBS construction, including acquisition of an initial model of a problem domain, acquisition of control and task-specific inference knowledge, testing and validation, and long-term maintenance of encoded knowledge. The authors present a hypothetical scenario in which the assistant and a KBS designer cooperate to create an initial domain model and then discuss five categories of knowledge the assistant requires to offer such help. They discuss two software technologies on which the assistant is based: an object-oriented programming language, and a user-interface framework. >
18420869
Simultaneous measurement of steering performance and perceived heading on a curving path
The ability to judge heading (direction of travel) has been the focus of much research, but a role for perceived heading in steering has not been firmly established. Subjects steered down a road consisting of straight and curved segments and made heading judgments along the way. Heading judgments while traversing curved road segments were biased in the direction of the curve by up to 5° and position errors on the same curved roads were highly correlated with heading biases. This correlation was revealed by the simultaneous measurement of steering performance and perceived heading.
6086610
Security for fixed sensor networks
Sensor networks consist of resource-constrained sensors operating in a variety of environments. Given the severe constraints on these sensors, it is a particularly challenging problem to choose and design valid security protocols for such networks. This problem has recently given rise to new research addressing the security issues. This paper presents an overview of the important works, specifically the new mechanisms and protocols, which have been introduced or are still under development in this area.
19889388
Directed Web Searching
16267823
Variable selection and ranking for analyzing automobile traffic accident data
Variable ranking and feature selection are important concepts in data mining and machine learning. This paper introduces a new variable ranking technique named Sum Max Gain Ratio (SMGR). The new technique is evaluated within the domain of traffic accident data and against a more generalized dataset. In certain cases, SMGR is empirically shown to provide similar results to established approaches with significantly better runtime performance.
17403700
Planning horizons for the deterministic capacity problem
Abstract We consider the problem of determining the optimal timing and sizing of new facility construction under a continuous technology model of possible sizes. The rate of convergence of short to long run optimal policies is established and planning horizon implications are explored. We also present an efficient algorithm for solving such problems for all horizon times by solving a single horizon time problem