Abstract: Modeling of a three-dimensional object includes storing data representing a computer model of the three-dimensional object. The data includes a number of feature objects each of which defines a feature of the computer model. A feature chain is formed and includes at least one feature object having a design effect limited in scope such that an operation for removing material operates to affect the feature of the computer model defined by another feature object in the same feature chain and does not affect the feature of the computer model defined by the feature object not in said same feature chain. Multiple feature chains can be combined to form an interrelationship among feature objects that represents a hierarchy defining construction of the model from the feature objects.

Abstract: A device for increasing the incident energy of an ion for coating a disc in an ion beam deposition process. The ion beam deposition process is performed in a chamber with the disc to be coated disposed therein. An ion source, having a voltage level, is introduced into the chamber for generating an ion beam for depositing ions on the disc. A bias contact is coupled to the disc and a power supply is coupled to the bias contact. The power supply applies a voltage level to the bias contact that is less than the voltage level of the ion source thereby creating a negative bias voltage between the disc and the ion source. This negative bias voltage causes the incident energy of the ion to increase. As a result, the optimal incident energy can be achieved using a lower original energy.

Abstract: A system for encoding images by assigning variable-length code words to fixed positions in a dynamic stack. Each position in the dynamic stack is occupied by a representation of an encodable image feature, such as a run-length or a vertical correlation. These codes are arranged in order of their respective frequencies of occurrence. The order in which these features are stacked is varied dynamically by the system, in accordance with their respective frequencies of occurrence and a predetermined scheme. Thus, the system can adapt to different types of documents being scanned, or to changes of scanning resolution. A relationship exists between the code words and the stack positions, which are not permanently assigned to specific image features. This arrangement ensures that the lengths of code words will be inversely related to their frequencies of occurrence under all conditions.

Abstract: This is a cipher system for enciphering a stream of binary data by means of a product cipher. A clear message represented in a binary data format is transformed into a cipher message by operating on each bit of clear information with a complex modulo-two addition function. This function is dependent on previous internal cipher digits transmitted and varies for each message bit processed. The function is developed by continually shifting a key matrix under the control of a varying control matrix. The control matrix is formed from the sub-product of the complex function developed in generating each cipher bit.

Abstract: A closed loop communication system in which the terminals are grouped into priority classes. Any terminal can seize a free channel if certain priority conditions exist. A channel (frame) is always preceded by a header comprising a priority request field and a priority grant field. The request field has n bits assigned to the n priority classes; a terminal requiring service sets that bit to "1" which corresponds to its class. Thus, the controller receives a compiled overall request and inserts, for the next cycle, into the grant field an indication as to which priority class or classes are now allowed access to the channel. This is accomplished by shifting the contents of the request field to the grant field. A terminal can only seize the channel if its priority class is allowed for that cycle by the grant field, and if the channel is still free.