Intelligent Geometric Modeling of Standard Bridges

Abstract: Artificial intelligence (AI) is a branch of computer science that deals with the development of approaches and techniques for enabling the machine to mimic human intelligence. The marriage of AI and computer-aided design (CAD) results in a new breed of systems called intelligent CAD systems. These systems are superior to conventional CAD systems in that they exhibit certain capabilities, such as deductive reasoning, that have been attributes to intelligent beings.
Deductive reasoning is a central activity in CAD in general and in geometric modeling in particular. This paper presents a framework for developing intelligent CAD systems that support deductive reasoning. More specifically, the paper (1) discusses the integration of predicate logic as a mechanism for deductive reasoning with conventional CAD systems and (2) illustrates the use of the framework for geometric modeling of standard bridges. This illustration involves (1) representing the geometry of standard bridges using the language of predicate logic and (2) generating, modifying, and verifying the geometry of standard bridges via logical inference.     

A logic-based mechanism for integrity maintenance of engineering databases

The semantics of engineering data can be represented in terms of constraints and can be maintained via constraint checking and enforcement. Conventional databases (e.g. Relational Databases) are inadequate for maintaining engineering data semantics because they have no effective means for representing and checking/enforcing constrains. As an extension of relational databases, deductive databases overcome this inadequacy by enabling constraint representation and checking. However, they too lack the constraint enforcement ability. a logic-based mechanism for enforcing constrainst in deductive databases is presented in this paper. The mechanism is composed of two operators: a truth enforcement operator and a falsity enforcement operator. The mechanics of these operators and their use for integrity enfocement are described herein.     

The analysis and partial synthesis of truss structures via theorem proving

A use of theorem proving for the analysis and partial synthesis of truss structures is presented. The behavior of a truss structure is modeled as the set union of the behavior of its constituent components where the behavior of each component is modeled by a set of constraints. This component/constraint model is formally represented by a set of axioms using predicate logic. The axioms are then used toanalyze and partiallysynthesize truss structures via theorem proving.Constraint logic programming is identified as a suitable implementation vehicle for the analysis and partial synthesis of truss structures via theorem proving. Several important implications of the formulation for structural design automation, data base integrity, and parallel processing are discussed.     

Logic-based 2D geometric modeling in a CAD environment

This paper examines the use of predicate logic for deductive construction of geometric models. The process of logical inference and its use for geometric modeling is examined. The logic-based definition of a retaining wall is presented, the implementation of a logic-based CAD system using a commercial software is briefly discussed and its use is illustrated.