Abstract: A database management system is disclosed having an object oriented representation of information describing characteristics of instances organized in a hierarchical structure that may be logically represented as a tree structure. The hierarchical structure includes a parent-child/class-subclass structure. The internal representation of an instance is dependent upon information that is locally available from a class to which that instance belongs plus inherited attributes from a parent class. A class is represented as a class object having a handle. The class object has a parent handle associated with it that identifies the parent class of the class object. The class object has a subclass list associated with it that identifies the handles of the classes that are subclasses of the class object. The class object has an attribute list associated with it that includes a list of handles which may be used to identify the attributes of the class object.

Abstract: The present invention is an improvement upon an object oriented database management system and provides a method and apparatus for a user to visually compare attribute values of instances retrieved in a search in a way that highlights attribute values that do not match or are not equal. The present invention provides a method and apparatus for determining which of the attributes are not equal or do not match, and which attribute values are the same for all of the instances that are retrieved by a search. A method and apparatus is provided for visually indicating such determinations in a way that is immediately understandable by a user.

Abstract: A dynamically selectable language display system for object oriented database management systems is disclosed. Class objects are provided having international string parameters that include a pointer to an international string list, the international string list including a language handle structure linked to a plurality of character strings in different languages. A handle manager is provided which is operative to select a character string corresponding to one of said plurality of character strings for display which corresponds to a dynamically selectable user specified language handle, whereby a representation of said class object may be simultaneously displayed to a plurality of users in different languages based upon a language handle individually selectable by each of said plurality of users.

Abstract: The present invention provides a method and apparatus for concurrency control in an object oriented database management system having a plurality of users accessing the system at the same time, and allowing editing of the database while other users are concurrently searching the database. The present invention may be advantageously used in a client/server architecture comprising a knowledge base client and a knowledge base server. In a preferred embodiment, the knowledge base server may include an object oriented lock manager, a dynamic class manager, a connection manager, a query manager, a handle manager, a units manager, a database manager, and a file manager. The concurrency control mechanism includes a lock holder table. The present invention provides a method and apparatus for providing concurrency control in an object oriented database managemant system using only three types of lock modes: a class share lock, a tree update lock, and a tree exclusive lock.

Abstract: The present invention relates to processes for the automatic generation of numerical control (NC) tool paths in a CAD/CAM environment. The present invention operates on mechanical parts described as solid models. The process employs well-defined solid models of the part to be machined and the raw stock from which it will be machined. The volumetric difference between the stock and the part defines the material (delta volumes) that must be cut away during the actual machining process. Delta volumes are solid models, and users (or an expert system) can subdivide delta volumes into smaller volumes that are consistent with a manufacturing process plan. A delta volume and a user-defined strategy for machining the delta volume are then input to NC algorithms. The algorithms generate NC tool paths that remove as much delta volume material as possible. Tool volumes are automatically generated from NC tool paths to represent the volume traversed by the cutting tool.