Determination and representation of electric charge distributions associated with adverse weather conditions

Algorithms are presented for determining the size and location of electric charges which model storm systems and lightning strikes. The analysis utilizes readings from a grid of ground level field mills and geometric constraints on parameters to arrive at a representative set of charges. This set is used to generate three dimensional graphical depictions of the set as well as contour maps of the ground level electrical environment over the grid. The composite, analytic and graphic package is demonstrated and evaluated using controlled input data and archived data from a storm system. The results demonstrate the packages utility as: an operational tool in appraising adverse weather conditions; a research tool in studies of topics such as storm structure, storm dynamics, and lightning; and a tool in designing and evaluating grid systems

On the acquisition and representation of procedural knowledge

Historically knowledge acquisition has proven to be one of the greatest barriers to the development of intelligent systems. Current practice generally requires lengthy interactions between the expert whose knowledge is to be captured and the knowledge engineer whose responsibility is to acquire and represent knowledge in a useful form. Although much research has been devoted to the development of methodologies and computer software to aid in the capture and representation of some of some types of knowledge, little attention has been devoted to procedural knowledge. NASA personnel frequently perform tasks that are primarily procedural in nature. Previous work is reviewed in the field of knowledge acquisition and then focus on knowledge acquisition for procedural tasks with special attention devoted to the Navy's VISTA tool. The design and development is described of a system for the acquisition and representation of procedural knowledge-TARGET (Task Analysis and Rule Generation Tool). TARGET is intended as a tool that permits experts to visually describe procedural tasks and as a common medium for knowledge refinement by the expert and knowledge engineer. The system is designed to represent the acquired knowledge in the form of production rules. Systems such as TARGET have the potential to profoundly reduce the time, difficulties, and costs of developing knowledge-based systems for the performance of procedural tasks

Declarative Specification

Deriving formal specifications from informal requirements is extremely difficult since one has to overcome the conceptual gap between an application domain and the domain of formal specification methods. To reduce this gap we introduce application-specific specification languages, i.e., graphical and textual notations that can be unambiguously mapped to formal specifications in a logic language. We describe a number of realised approaches based on this idea, and evaluate them with respect to their domain specificity vs. generalit

Computer-mediated knowledge communication

New communication technologies enable an array of new working and learning scenarios in which knowledge is being communicated. This article deals with the question to what extent these technologies can impede or facilitate knowledge communication. First, the various computer-based communication technologies will be classified. Second, effects of the medium on knowledge communication will be discussed based on results of studies of the current special priority program "Net-based Knowledge Communication in Groups". Third and last, computer-based possibilities to facilitate computer-mediated knowledge communication will be reviewNeue Kommunikationstechnologien ermöglichen eine Reihe neuer Arbeits- und Lernszenarien in denen Wissen kommuniziert wird. Dieser Beitrag beschäftigt sich damit, inwiefern diese Technologien Wissenskommunikation einschränken oder fördern können. Dazu werden in einem ersten Schritt die verschiedenen computerbasierten Kommunikationstechnologien untergliedert. In einem zweiten Schritt werden Wirkungen des Mediums auf die Wissenskommunikation diskutiert. Dazu werden u. a. die Ergebnisse von Studien des aktuellen Forschungsschwerpunkts "Netzbasierte Wissenskommunikation in Gruppen" berichtet. In einem dritten und letzten Schritt werden computerbasierte Möglichkeiten zusammengefasst, computervermittelte Wissenskommunikation zu förd

Profile of On-Line Anatomy Information Resources: Design and Instructional Implications

This study is based on a review of 40 on-line anatomy web resources compiled from sites selected from our own searches as well as sites reviewed and published by an external group (Voiglio et al., 1999, Surg. Radiol. Anat. 21:65-68; Frasca et al., 2000, Surg. Radiol. Anat. 22:107-110). The purpose of our survey was to propose criteria by which anatomy educators could judge the characteristics of the currently available web-based resources for incorporation into the courses they teach. Each site was reviewed and scored based on a survey matrix that included four main categories: 1). site background information, 2). content components, 3). interactivity features, and 4). user interface design components. The average score of the reviewed sites was 3.3 of the total possible score of 10, indicating the limited use of computer-based design features by the majority of sites. We found, however, a number of programs in each of the survey categories that could serve as prototypes for designing future on-line anatomy resources. From the survey we conclude that various design features are less important than the comprehensiveness, depth, and logical organization of content. We suggest that the content should be sufficient for supporting explicitly defined educational objectives, which should target specific end-user populations. The majority of anatomy programs currently accessible on-line fall short of these requirements. There is a need for a coordinated and synergistic effort to generate a comprehensive anatomical information resource that is of sufficient quality and depth to support higher levels of learning beyond the memorization of structure names. Such a resource is a prerequisite for meaningful on-line anatomy education