Object-orientated planning domain engineering

The development of domain independent planners focuses on the creation of generic problem solvers. These solvers are designed to solve problems that are declaratively described to them. In order to solve arbitrary problems, the planner must possess efficient and effective algorithms; however, an often overlooked requirement is the need for a complete and correct description of the problem domain. Currently, the most common domain description language is a prepositional logic, state-based language called STRIPS. This thesis develops a new object-orientated domain description language that addresses some of the common errors made in writing STRIPS domains. This new language also features powerful semantics that are shown to gready ease the description of certain domain features. A common criticism of domain independent planning is that the requirement of being domain independent necessarily precludes the exploitation of domain specific knowledge that would increase efficiency. One technique used to address this is to recognise patterns of behaviour in domains and abstract them out into a higher-level representations that are exploitable. These higher-level representations are called generic types. This thesis investigates the ways in which generic types can be used to assist the domain engineering process. A language is developed for describing the behavioural patterns of generic types and the ways in which they can be exploited. This opens a domain independent channel for domain specific knowledge to pass from the domain engineer to the planner

Plan reuse versus plan generation : a theoretical and empirical analysis

The ability of a planner to reuse parts of old plans is hypothesized to be a valuable tool for improving efficiency of planning by avoiding the repetition of the same planning effort. We test this hypothesis from an analytical and empirical point of view. A comparative worst-case complexity analysis of generation and reuse under different assumptions reveals that it is not possible to achieve a provable efficiency gain of reuse over generation. Further, assuming "conservative" plan modification, plan reuse can actually be strictly more difficult than plan generation. While these results do not imply that there won\u27t be an efficiency gain in the "average case", retrieval of a good plan may present a serious bottleneck for plan reuse systems, as we will show. Finally, we present the results of an empirical study of three different plan reuse systems, which leads us to the conclusion that the utility of plan-reuse techniques is limited and that these limits have not been determined yet

Program/Project Management Resources: A collection of 50 bibliographies focusing on continual improvement, reinventing government, and successful project management

These Program/Project Management Resource Lists were originally written for the NASA project management community. Their purpose was to promote the use of the NASA Headquarters Library Program/Project Management Collection funded by NASA Headquarters Code FT, Training & Development Division, by offering introductions to the management topics studied by today's managers. Lists were also written at the request of NASA Headquarters Code T, Office of Continual improvements, and at the request of NASA members of the National Performance Review. This is the second edition of the compilation of these bibliographies; the first edition was printed in March 1994

First Year Projects and Activities of the Environmental Remote Sensing Applications Laboratory (ERSAL)

Activities, pilot projects, and research that will effectively close the gap between state-of-the-art remote sensing technology and the potential users and beneficiaries of this technological and scientific progress are discussed in light of the first year of activity. A broad spectrum of resource and man-environment problems are described in terms of the central thrust of the first-year program to support land use planning decisions with information derived from the interpretation of NASA highlight and satellite imagery

Using hierarchical constraint satisfaction for lathe-tool selection in a CIM environment

In this paper we shall discuss how to treat the automatic selection of appropriate lathe tools in a computer-aided production planning (CAPP) application as a constraint satisfaction problem (CSP) over hierarchically structured finite domains. Conceptually it is straightforward to formulate lathe-tool selection in terms of a CSP, however the choice of constraint and domain representations and of the order in which the constraints are applied is nontrivial if a computationally tractable system design is to be achieved. Since the domains appearing in technical applications often can be modeled as a hierarchy, we investigate how constraint satisfaction algorithms can make use of this hierarchical structure. Moreover, many real-life problems are formulated in a way that no optimal solution can be found which satisfies all the given constraints. Therefore, in order to bring AI technology into real-world applications, it becomes very important to be able to cope with conflicting constraints and to relax the given CSP until a (suboptimal) solution can be found. For these reasons, the constraint system CONTAX has been developed, which incorporates an extended hierarchical arc-consistency algorithm together with discrete constraint relaxation and has been used to implement the lathe-tool selection module of the ARC-TEC planning system

Expert system verification and validation study: Workshop and presentation material

Workshop and presentation material are included. Following an introduction, the basic concepts, techniques, and guidelines are discussed. Handouts and worksheets are included