Abstract: A method for the direct reconstruction of an object from measurements of the transmitted intensity of diffusively scattered radiation effected by irradiating the object with a source of continuous wave radiation. The transmitted intensity is related to the absorption and the diffusion coefficients by an integral operator. The images are directly reconstructed by executing a prescribed mathematical algorithm, as determined with reference to the integral operator, on the transmitted intensity of the diffusively scattered radiation.

Abstract: A methodology for developing scalable systems based on a technique for the composition of objects to form a larger, composite object using Interface Cycles, which are canonical programs, hardware, or abstractions which interlock protection, distribution, and coordination of data and control from the objects. The methodology thus allows the interconnected objects to form the new composite object which is subject to the same principles as the underlying objects and which may then used in any stage of the life cycle of a system. An Interface Cycle transitions through discrete phases only by agreement of all object interfaces connected by the Interface Cycle. Protection and data distribution of composite data collected from all the objects are effected under control of the Interface Cycle.

Abstract: A distribution element composed of a crossbar-type switch with four independent ports and direct multicast transfer capability which effects a direct interface to applications with an instruction sets for the distribution element, the sets providing for global memory sharing, synchronization, and lossless flow control.

Abstract: A procedure for establishing a scalable spanning tree over a network composed of nodes and links in which the resources for each node is independent of the size of the network. The procedure involves the selection of a set of states, a set of messages, state transition rules as well as a completion rule to thereby detect the the setting up of the spanning tree. One established, data may be distributed over the spanning tree so that coordination of data is maintained over all the nodes in the network.

Abstract: A foldable and expandable pitch pocket for encompassing an element such as a vent pipe protruding from a roof structure. The pitch pocket is initially an elongated piecepart which is arranged with slits on a horizontal wall and notches on the vertical wall aligned with the slits, thereby making it feasible to use light hand pressure to bend creases in the vertical wall to obtain the folded pitch pocket. A slot and tab cooperatively arranged interlock the vertical wall to fixedly hold the folded shape of the pitch pocket.

Abstract: Method and apparatus for releasing a workpiece, such as a semiconductor wafer, from an electrostatic chuck. A "dechucking" voltage is applied to the chuck electrode having the same polarity as was used to retain the workpiece, but having a different magnitude selected to minimize the electrostatic attractive force between the workpiece and the chuck. There is an optimum value for the dechucking voltage which minimizes this force. The optimum value can be determined empirically, or it can be determined by a method based on the value of the current pulse produced when the workpiece is first mounted on the chuck.

Abstract: Methodology and concomitant circuitry for compacting an incoming data stream into an outgoing compacted data stream utilize a multiple, doubly-linked list and an associated class promotion data structure. The incoming data stream is partitioned into a sequence of symbols. A memory associated with the data structure stores each symbol, information regarding the recency rank of each symbol as it arrives in sequence as well as class information and pointer information for each symbol. For each symbol, the memory is checked to determine if the symbol is new or repeated. If the symbol is repeated, only the recency rank is used to form that part of the outgoing data stream associated with the new symbol. If the symbol is new, identification information is added to the symbol and both the identification information are emitted as part of the compacted stream. Memory update operations are then effected to change class, recency rank and pointer information.

Abstract: An automated system and concomitant methodology for minimizing the procurement costs of products and for generating a list of selected products based on the results of the minimization is disclosed for the Business Volume Discount regime. The system processing covers purchasing situations wherein multiple vendors offer a plurality of products and the vendors give discounts based on the total dollar amount of business received from the purchasers. The processing effected by the system utilizes a linear programming technique to solve a model of the business volume discount regime given a variety of constraints.

Abstract: An arrangement of coupled hybrid rings is disclosed which can withstand a failed node or a cut ring in either or both of the hybrid rings, as well as an outage of one of the two serving nodes utilized to interconnect the hybrid rings. The pair of serving nodes are interposed in each of the hybrid rings and serve to transmit signals between the two rings to satisfy the hybrid ring requirement of having equivalent signals propagating in two opposing directions on the unidirectional rings composing an individual hybrid ring.

Abstract: A technique for all-optical Code Division Multiple Access (CDMA) system based on optical holography is disclosed. In this technique the energy of an incoming information light signal is spread over a spatial domain by a two-dimensional spatial encoder which includes a mask having regions of first and second transmission characteristics corresponding to the unique code assigned to a particular source. Subsequent decoding, which is accomplished by an optical matched filter through the use of a hologram, spatially despreads the energy of the information light signal and produces a focused light beam which serves as input to a code division detector.

Abstract: A method is disclosed for configuring a network, composed of a plurality of nodes, to satisfy grade-of-service constraints such as traffic load and cost and, upon configuration, routing of service requests through admissible routes in the network in correspondence to the configuration topology. Both the configuration and routing are mutually dependent upon the selection of a set of integers which provide distinct sums over the integers in the set. The integers determine link interconnections between the nodes and the distinct sums are indicative of the admissible routes.

Abstract: A communication system for coordinated transmission of signals from two data sources over a pair of transmission lines includes a central office transceiver and a remote transceiver terminating the corresponding ends of the pair of transmission lines. Each transceiver includes a transmitter with a complementary receiver. The signal amplitudes propagated on the lines are related to each other according to a prescribed relation that effects enhanced signal-to-noise ratio. The transmitter includes a set of amplification factors determined by the prescribed relation; similarly, the receiver also includes two sets of amplication factors to perform the dual to the transmitter operation. The transmitter incorporates a two-dimensional generalization to a conventional echo canceler, namely, an implementation to cancel both echo and near-end crosstalk interfering components.

Abstract: A spread-time code division multiple access (ST-CDMA) technique is disclosed for bandlimited access to a channel. With ST-CDMA, pseudo-random (PN) sequences are assigned to each transmitter in the multi-transmitter system, and the Fourier transform of the transmitter pulse for a given transmitter is determined by modulating the phase of the desired transmitter spectrum by the PN sequence assigned to the transmitter. The data symbols produced by the transmitter are conveyed by delayed versions of the transmitter pulse. The transmitted data for a particular transmitter is recovered at a receiver synchronized to the transmitter by sampling the output of a filter matched to the corresponding transmitter pulse.

Abstract: A spread-time code division multiple access (ST-CDMA) technique is disclosed for bandlimited access to a channel. With ST-CDMA, pseudo-random (PN) sequences are assigned to each transmitter in the multi-transmitter system, and the Fourier transform of the transmitter pulse for a given transmitter is determined by modulating the phase of the desired transmitter spectrum by the PN Sequence assigned to the transmitter. The data symbols produced by the transmitter are conveyed by delayed versions of the transmitter pulse. The transmitted data for a particular transmitter is recovered at a receiver synchronized to the transmitter by sampling the output of a filter matched to the corresponding transmitter pulse.

Abstract: A spread-time code division multiple access (ST-CDMA) technique is disclosed for bandlimited access to a channel. With ST-CDMA, pseudo-random (PN) sequences are assigned to each transmitter in the multi-transmitter system, and the Fourier transform of the transmitter pulse for a given transmitter is determined by modulating the phase of the desired transmitter spectrum by the PN sequence assigned to the transmitter. The data symbols produced by the transmitter are conveyed by delayed versions of the transmitter pulse. The transmitted data for a particular transmitter is recovered at a receiver synchronized to the transmitter by sampling the output of a filter matched to the corresponding transmitter pulse.

Abstract: A spread-time code division multiple access (ST-CDMA) technique is disclosed for bandlimited access to a channel. With ST-CDMA, pseudo-random (PN) sequences are assigned to each transmitter in the multi-transmitter system, and the Fourier transform of the transmitter pulse for a given transmitter is determined by modulating the phase of the desired transmitter spectrum by the PN sequence assigned to the transmitter. The data symbols produced by the transmitter are conveyed by delayed versions of the transmitter pulse. The transmitted data for a particular transmitter is recovered at a receiver synchronized to the transmitter by sampling the output of a filter matched to the corresponding transmitter pulse.

Abstract: A process controls the routing of an arriving job in a job stream through a switch to one of a plurality of processing stations. At predetermined time intervals, occupancy factors associated with the stations are computed as determined by station configuration information and job stream information. Upon the arrival of an incoming job, the occupancy factors corresponding to the current processing status of the stations are used to compute station utilization values. The station having the minimum utilization value is selected to receive and process the incoming job provided this minimum value is less than a preselected threshold; otherwise, the incoming job is denied processing permission.

Abstract: A process is disclosed for routing service requests through a network comprising nodes interconnected with links. The network is also arranged so that each node may communicate with each of the other nodes. At preselected time intervals, sets of routes through the network are generated in response to the network configuration and traffic information. Also, at predetermined time intervals, occupancy factors are computed as determined by the network configuration and in response to traffic information. These occupancy factors are proportional to unassociated occupancy factrors and allocation factors associated with calls of the various node-pairs; each of these latter factors is derived from a nominal routing scheme in which a call of the corresponding node-pair is treated as lost only if it is blocked on all of its permitted routes. At predetermined intervals, traffic usage data is measured.

Abstract: A methodology is disclosed for traffic control administered locally at each individual node in a packet network. Packet level controls at a node pertain to whether to admit a new packet into the network and whether to momentarily detain passing-through packets. The nodes apply the "back-pressure" of congestion on one another and thereby cooperate to smooth traffic and alleviate the accumulation of packets at any single node. The decision process in packet level control involves two basic operations. First, the address of the packet is translated into a binary word via a static routing table and then, secondly, the binary word and control data representative of dynamic traffic information are operated on logically; traffic control decisions, such as detain a passing-through packet or permit entry of a packet into the network, are based primarily on the result of the logical operation.

Abstract: An arrangement of digital circuitry is disclosed for testing a cable communication system to determine its performance when subjected to near-end cable crosstalk. The circuitry digitally generates a crosstalk signal indicative of the combined effect of one or more interfering sources and the near-end crosstalk coupling path linking the interfering sources with the system-under-test. The circuitry includes a pseudo-noise sequence generator for producing a stream of bits that are normally distributed and a digital filter, responsive to the sequence generator, for implementing a frequency characteristic corresponding to the spectral content of the interfering source as weighted by the near-end crosstalk path.