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.
18629340
Report on the 1984 Distributed Artificial Intelligence Workshop
The fifth Distributed Artificial Intclligencc Workshop tias held at the Schlumberger-Doll Research Laboratory from October 14 to 17, 1984 It was attended by 20 participants from academic and industrial institutions. As in the past,’ this workshop was designed as an informal meeting It included brief research rcport,s from individual groups along with genera1 discussion of questions of common interest. This report summarizes the general discussion and contains summaries of group presentations that have been contributed by individual speakers to scale the resources applied to a problem). Others arc motivated by problem characteristics, such as natural spatial or functional distribution. Finally, some researchers are motivated by the observation that some issues in problcm solving and reasoning (e.g., communication and coherent cooperation) are brought into sharp focus in the distributed setting. The main body of this report contains summaries written by individual attcndces of the workshop. This is, in turn, followed by a brief smnmary of the gcncral discus
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.
42162123
A Conceptual Clustering Program for Rule Generation
We present an Interesting Situation Generator (ISG) that assists in the synthesis of interpretation rules from basic domain knowledge. The ISG is a hierarchical clustering program that discovers equivalence classes of situations (e.g. types of geological formations) that give rise to qualitatively distinct manifestations (e.g. different patterns of geophysical measurements corresponding to types of geological formations). The equivalence classes can be used by a rule generator to construct an initial set of interpretation rules of the form manifestation ⇒ situation.
27655269
Unobserved heterogeneity in panel time series models
Recently, the large T panel literature has emphasized unobserved, time-varying heterogeneity that may stem from omitted common variables or global shocks that affect each individual unit differently. These latent common factors induce cross-section dependence and may lead to inconsistent regression coefficient estimates if they are correlated with the explanatory variables. Moreover, if the process underlying these factors is nonstationary, the individual regressions will be spurious but pooling or averaging across individual estimates still permits consistent estimation of a long-run coefficient. The need to tackle both error cross-section dependence and persistent autocorrelation is motivated by the evidence of their pervasiveness found in three well-known, international finance and macroeconomic examples. A range of estimators is surveyed and their finite-sample properties are examined by means of Monte Carlo experiments. These reveal that a mean group version of the common-correlated-effects estimator stands out as the most robust since it is the preferred choice in rather general (non) stationary settings where regressors and errors share common factors and their factor loadings are possibly dependent. Other approaches which perform reasonably well include the two-way fixed effects, demeaned mean group and between estimators but they are less efficient than the common-correlated-effects estimator.
19889388
Directed Web Searching
33919116
The Fighter Aircraft LCS: A Case of Different LCS Goals and Techniques
A system employed by the authors to acquire novel fighter aircraft manoeuvres from combat simulation is more akin to the traditional LCS model than to more recent systems. Given the difficulties often experienced in LCS research on simple problems, one must ask how a relatively primitive LCS has had consistent success in the complex domain of fighter aircraft manoeuvring. This paper presents the fighter aircraft LCS, in greater detail than in previous publications. Positive results from the system are discussed. The paper then focuses on the primary reasons the fighter aircraft LCS has avoided the difficulties of the traditional LCS. The authors believe the system's success has three primary origins: differences in credit assignment, differences in action encoding, and (possibly most importantly) a difference in system goals. In the fighter aircraft system, the goal has been simply the discovery of innovative, novel tactics, rather than online control. The paper concludes by discussing the most salient features of the fighter aircraft learning system, and how those features may be profitably combined with other LCS developments.
16499745
The Self-4.0 user interface: manifesting a system-wide vision of concreteness, uniformity, and flexibility
Manipulating programs is hard, while manipulating objects in the physical world is often easy. Several attributes of the physical world help make it comprehensible and manipulable: concreteness, uniformity, and flexibility. The Self programming system attempts to apply these attributes to the world within the computer. The semantics of the language, the efficiency and fidelity of its implementation, and the architecture of its user interface conspire to make the experience of constructing programs in Self immediate and tangible. We describe the mechanisms used to achieve this goal, and illustrate those mechanisms within the context of an extended programming task.
52856801
Subjectivity in object-oriented systems