The PSN tribe

AbstractThe paper reviews the history, premises, research results and applications of the Procedural Semantic Network (hereafter PSN) formalism and two of its descendants, Taxis and Telos. The primary goal for the PSN project was to develop a knowledge representation formalism which combined gracefully semantic networks and procedural representations. After an initial proposal which set out a framework for the integration of these two types of representations [1], a number of features were investigated, including the treatment of contexts, the declarative representation of slots and procedures and several others. In parallel, attempts were made to apply some of the representation ideas embodied in PSN to the task of developing suitable languages for the early stages of information system design. During these stages, the designer is concerned with understanding the problem at hand and then proceeding with the specification of an initial conceptual design of an information system that meets stated requirements. Taxis and Telos were the result of this effort. Their features are outlined, along with a rationale for the differences between the three formalisms

An expert system for project controls in construction management

In this paper, I describe an expert project control system for construction management. The purpose of the project is to develop methods and strategies for expert system based planning, scheduling, chronicling and analysis for construction management. Planning defines the actions required to accomplish a goal? scheduling links the plan into a frame of time? chronicling is monitoring job performance and analysis defines reevaluation of the plan as conditions change. Conditions are modeled as constraints and will be coded as rules. As conditions change, constraints must be dynamically modified by the system to accommodate the changes. The research is a combination of three related areas: a. Domain dependent hierarchical planning techniques. b. Model-based planning/scheduling techniques developed for the job-shop environment. c. Expert construction planning/scheduling techniques

Quantitative discovery and qualitative reasoning about failure mechanisms in pavement

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Civil Engineering, 1986.MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERINGIncludes index.Bibliography: leaves 101-109.by Nayel S. el-Shafei.M.S

Head-driven machine translation

Despite initial optimism about the feasibility of Machine Translation, it is now accepted as being an extremely different task to implement. This is due in part to our lack of understanding of the human processes involved in language comprehension and production in general, and translation in particular. In addition, the myriad of problems posed by ambiguities caused by structural differences, category options etc , which in most cases are resolved subconsciously by humans, have slowed down the development of a Fully Automatic, High-Quality Machine Translation System, and have convinced many people that this goal is completely unattainable. This thesis is an investigation of the suitability of Head-Driven Phrase Structure Grammar (HPSG, Pollard and Sag, 1987, 1994) for use in a transfer-based translation environment. It provides an account of some of the problems tackled by such a system, as well as the reasons behind the decisions to chose HPSG and a transfer approach Moreover, some of the possible inadequacies of HPSG’s current semantic framework are addressed and some potential alternatives are suggested, namely the incorporation of case grammars and semantic features to guide lexical selection in the target language. The evaluation of these ideas is based on an implementation of these proposals in a system for translation between German and English, using the Attribute Logic Engine (ALE, Carpenter, 1992) for the purposes of monolingual analysis

The connection machine

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1988.Bibliography: leaves 134-157.by William Daniel Hillis.Ph.D

3D-in-2D Displays for ATC.

This paper reports on the efforts and accomplishments of the 3D-in-2D Displays for ATC project at the end of Year 1. We describe the invention of 10 novel 3D/2D visualisations that were mostly implemented in the Augmented Reality ARToolkit. These prototype implementations of visualisation and interaction elements can be viewed on the accompanying video. We have identified six candidate design concepts which we will further research and develop. These designs correspond with the early feasibility studies stage of maturity as defined by the NASA Technology Readiness Level framework. We developed the Combination Display Framework from a review of the literature, and used it for analysing display designs in terms of display technique used and how they are combined. The insights we gained from this framework then guided our inventions and the human-centered innovation process we use to iteratively invent. Our designs are based on an understanding of user work practices. We also developed a simple ATC simulator that we used for rapid experimentation and evaluation of design ideas. We expect that if this project continues, the effort in Year 2 and 3 will be focus on maturing the concepts and employment in a operational laboratory settings

The semantic database model as a basis for an automated database design tool

Bibliography: p.257-80.The automatic database design system is a design aid for network database creation. It obtains a requirements specification from a user and generates a prototype database. This database is compatible with the Data Definition Language of DMS 1100, the database system on the Univac 1108 at the University of Cape Town. The user interface has been constructed in such a way that a computer-naive user can submit a description of his organisation to the system. Thus it constitutes a powerful database design tool, which should greatly alleviate the designer's tasks of communicating with users, and of creating an initial database definition. The requirements are formulated using the semantic database model, and semantic information in this model is incorporated into the database as integrity constraints. A relation scheme is also generated from the specification. As a result of this research, insight has been gained into the advantages and shortcomings of the semantic database model, and some principles for 'good' data models and database design methodologies have emerged