Patents Assigned to Bolt Beranek and Newman, Inc.
  • Patent number: 5796849
    Abstract: An active noise and vibration control system is constructed such that the residual signal from the residual sensor is fed back into the controller and used to generate the probe signal. Measurements of the residual signal are used to create a related signal, which has the same magnitude spectrum as the residual signal, but which is phase-uncorrelated with the residual signal. This latter signal is filtered by a shaping filter and attenuated to produce the desired probe signal. The characteristics of the shaping filter and the attenuator are chosen such that when the probe signal is filtered by the plant transfer function, its contribution to the magnitude spectrum of the residual signal is uniformly below the measured magnitude spectrum of the residual by a prescribed amount (for example, 6 dB) over the entire involved frequency range. The probe signal is then used to obtain a current estimate of the plant transfer function.
    Type: Grant
    Filed: November 8, 1994
    Date of Patent: August 18, 1998
    Assignee: Bolt, Beranek and Newman Inc.
    Inventors: Ronald Bruce Coleman, Bill Gene Watters, Roy Allen Westerberg
  • Patent number: 5628407
    Abstract: A method and apparatus for automated separation of fluid borne magnetically responsive spheres into different populations by carefully manipulating forces of gravity, buoyancy, fluid friction, and magnetism. Distinct homogeneous sphere populations are separated from a non-homogeneous population including a plurality of intermixed homogeneous sphere populations, without significant manual processing, by: effecting magnetic distancing of an initial non-homogeneous sphere population; facilitating enhanced separation of the non-homogeneous population in accordance with rate of descent of spheres within homogeneous populations; providing magnetic acceleration of the separation process; and effecting magnetic concentration of the separated homogeneous sphere populations. The process and apparatus provide for improved bio-sensing resulting from the automated condensing of homogeneous groups of spheres from a non-homogeneous sphere population.
    Type: Grant
    Filed: December 5, 1994
    Date of Patent: May 13, 1997
    Assignee: Bolt Beranek and Newman, Inc.
    Inventors: Douglas C. Gilbert, Peter G. Cable
  • Patent number: 5615868
    Abstract: In the active pneumatic mount disclosed herein, a bellows or other flexible sealing means is utilized for containing a volume of pressurized gas which supports the weight of the equipment which is to be isolated. Within the pressurized volume is a means defining a chamber having an opening for receiving an acoustic transducer. An acoustic transducer is mounted in that opening for generating, in the pressurized volume, oscillatory pressure variations which reduce dynamic pressure variations induced by the vibrations which are to be blocked. The space within the chamber is vented to the pressurized volume, thereby to equalize the static pressure in the space.
    Type: Grant
    Filed: October 4, 1995
    Date of Patent: April 1, 1997
    Assignee: Bolt Beranek and Newman Inc.
    Inventor: Bruce S. Murray
  • Patent number: 5587615
    Abstract: The electromagnetic force generator disclosed herein employs first and second elongate magnetic cores having transversely facing pole faces at each end, the cores being essentially parallel with pole faces aligned and facing. Between each pair of aligned pole faces is a relatively moveable core. A suspension provides a compliant mechanical connection between the moveable and elongate cores. The moveable cores are polarized by a permanent magnet mounted between the elongate cores and polarized along an axis paralleling the length of the elongate cores. Respective windings are provided around the elongate cores. A.c. energization of the windings creates a corresponding vibratory force between the movable cores and the elongate cores.
    Type: Grant
    Filed: December 22, 1994
    Date of Patent: December 24, 1996
    Assignee: Bolt Beranek and Newman Inc.
    Inventors: Bruce S. Murray, Howard C. Noble, Wilma W. Quinn
  • Patent number: 5471567
    Abstract: Depth buffered anti-aliasing in a real time image generation system utilizing two separate buffers, one for combining attributes of object pixel definitions which are of less than full coverage and another for storing the attributes of each new object pixel definition which is of full coverage and which is closer to the viewpoint than any attributes currently stored. If the depth value in the partial buffer is closer the viewpoint than that in the full buffer, a set of attributes is output which is a weighted mixture of those stored in the two buffers.
    Type: Grant
    Filed: August 8, 1991
    Date of Patent: November 28, 1995
    Assignee: Bolt Beranek and Newman Inc.
    Inventors: Brian T. Soderberg, Mark L. Kenworthy
  • Patent number: 5394394
    Abstract: The classifier device disclosed herein analyzes message headers of the type which comprise a sequence of bit groups presented successively. The device employs a read/write memory for storing at a multiplicity of addresses, an alterable parse graph of instructions. The parse graph instructions include node instructions which comprise opcodes in association with respective next address characterizing data and terminator instructions which comprise identifying data for previously characterized header types. A logical processor responds to a node instruction read from memory either by initiating another memory read at a next address which, given the current state of the processor, is determinable from the current node instruction and the current header bit group or by outputting data indicating recognition failure if no next address is determinable. The logical processor responds to a terminator instruction by outputting respective header identifying data.
    Type: Grant
    Filed: June 24, 1993
    Date of Patent: February 28, 1995
    Assignee: Bolt Beranek and Newman Inc.
    Inventors: William R. Crowther, Stanley A. Lackey, Jr., C. Philip Levin, Daniel C. Tappan
  • Patent number: 5359902
    Abstract: In the load cell disclosed herein, relative displacement between bridging members or end caps mounted at different points along the axis of an elastic hollow cylinder is sensed by means of a variable reluctance transducer employing a pair of magnetically permeable core elements. One of the core elements is mounted on one of the bridging members and the other core element is C-shaped and mounted on the other bridging member with the ends of the C-shape in close proximity to the first core member thereby providing magnetic gaps whose widths are aligned with the cylinder axis. Windings around the ends of the C-shaped core provide electrical connection for an inductance which is variable as a function of the widths of the gaps and thus also of the axial displacement between the bridging members.
    Type: Grant
    Filed: July 15, 1993
    Date of Patent: November 1, 1994
    Assignee: Bolt Beranek and Newman Inc.
    Inventors: James E. Barger, Richard Madden
  • Patent number: 5339386
    Abstract: In a real time image generation system opaque or planar object pixels are defined by at least a color attribute and a depth value and volumetric pixels are defined by at least a color attribute, a depth value and an opacity gradient value. A volumetric data buffer is provided for storing attributes and values associated with volumetric pixels and the volumetric items are processed first to load that buffer. Successive object pixel definitions are then read and the depth value of each current object pixel definition is compared with the depth value in the buffer and a relative weight for the volumetric effect is calculated as a function of the relative depth values and the corresponding volume gradient value. The color attributes of the object pixel and the volumetric data are then mixed as a function of the relative weighting to obtain a result color attribute which is output as the color for the respective pixel.
    Type: Grant
    Filed: August 8, 1991
    Date of Patent: August 16, 1994
    Assignee: Bolt Beranek and Newman Inc.
    Inventors: Brian T. Sodenberg, Mark L. Kenworthy
  • Patent number: 5319735
    Abstract: A code signal representing a sequence of code symbols carrying digital information is generated with the frequency components of the code signal being essentially confined to a preselected signalling band lying within the bandwidth of an audio signal within which the code signal is to be embedded. The audio signal is continuously frequency analyzed over a frequency band encompassing the signalling band and the code signal is dynamically filtered as a function of the analysis thereby to provide a modified code signal with frequency components which are, at each time instant, essentially a preselected small proportion of the levels of the corresponding audio signal frequency components. Accordingly, the modified code signal can be combined with the audio signal to obtain a composite audio signal which is not readily distinguishable from the original audio signal by listening.
    Type: Grant
    Filed: December 17, 1991
    Date of Patent: June 7, 1994
    Assignee: Bolt Beranek and Newman Inc.
    Inventors: Robert D. Preuss, Salim E. Roukos, A. W. F. Huggins, Herbert Gish, Marcos A. Bergamo, Patrick M. Peterson, Alan G. Derr
  • Patent number: 5319781
    Abstract: In the scheduling method disclosed herein, a genetic algorithm is employed to improve a population of possible schedules represented by respective chromosomes, where the chromosomes upon which the genetic algorithm operates are not a direct encoding of a possible schedules. Rather, the details of the scheduling problem and the real life constraints typically associated with such problems are hidden from the genetic algorithm by the use of a deterministic schedule builder which operates on lists of the desired tasks and which generates legal schedules, i.e. schedules which do not violate hard constraints. The legal schedules so generated are evaluated or scored and the scores are provided to the genetic algorithm as feedback for influencing subsequent operation of the genetic algorithm.
    Type: Grant
    Filed: May 3, 1991
    Date of Patent: June 7, 1994
    Assignee: Bolt Beranek and Newman Inc.
    Inventor: Gilbert P. Syswerda
  • Patent number: 5301337
    Abstract: A resource managing method operates in a computer system in which a variety of processes run essentially simultaneously on a group of processors, each processor being provided with a respective section of memory which is also accessible by the other processors in the group though typically not as quickly as by the respective processor. Resource data objects corresponding to particular resources are located by means of a hash table which is divided into portions which are distributed over respective sections of the overall system memory. A resource manager program, which is essentially replicated for each processor, implements a hashing algorithm which directs requests for access to designated resources to the corresponding portion of the hash table irrespective of which processor originated the request. Each section of the hash table includes a series of entries which provide pointers to respective lists of resource data objects which hash to that entry.
    Type: Grant
    Filed: April 6, 1990
    Date of Patent: April 5, 1994
    Assignee: Bolt Beranek and Newman Inc.
    Inventors: Robert E. Wells, Kenneth A. Sedgwick
  • Patent number: 5266854
    Abstract: In the electromagnetic transducer disclosed herein, first and second magnetic core structures are oriented in opposition with a space therebetween. In the space between the core structures, an armature is provided for completing magnetic circuits for both of the core structures with respective gaps. Spring means normally centers the armature structure between the core structures so that the respective gaps are nominally equal. On each of the core structures there is provided a first winding and a second winding. The first windings are connected in series to a supply of direct current thereby to bias the magnetic circuits and the second windings are connected to a source of alternating current with the second windings being installed or phased so that one of them aids the corresponding first winding while the other opposes the corresponding first winding.
    Type: Grant
    Filed: August 30, 1990
    Date of Patent: November 30, 1993
    Assignee: Bolt Beranek and Newman Inc.
    Inventor: Bruce S. Murray
  • Patent number: 5241619
    Abstract: As a step in finding the one most likely word sequence in a spoken language system, an N-best search is conducted to find the N most likely sentence hypotheses. During the search, word theories are distinguished based only on the one previous word. At each state within a word, the total probability is calculated for each of a few previous words. At the end of each word, the probability score is recorded for each previous word theory, together with the name of the previous word. At the end of the sentence, a recursive traceback is performed to derive the list of the N best sentences.
    Type: Grant
    Filed: June 25, 1991
    Date of Patent: August 31, 1993
    Assignee: Bolt Beranek And Newman Inc.
    Inventors: Richard M. Schwartz, Stephen C. Austin
  • Patent number: 5206839
    Abstract: In the underwater sound source disclosed herein, rigid diaphragms are provided at opposed ends of a hollow shell, the periphery of each of the diaphragms being sealed to the shell. Respective spring means operating between the shell and each of the diaphragms allows axial displacement of the diaphragm in response to external pressure. A lightweight magnetic armature structure is connected to each of the diaphragms and opposed electromagnetic core structures provide magnetic circuits which link each of the armature structures across respective gaps. Further spring means are provided for centering each of the armature structures between the respective magnetic core structures. By appropriately energizing windings on the magnetic core structures, the armatures together with their respective diaphragms are caused to oscillate.
    Type: Grant
    Filed: November 20, 1991
    Date of Patent: April 27, 1993
    Assignee: Bolt Beranek and Newman Inc.
    Inventor: Bruce S. Murray
  • Patent number: 5155727
    Abstract: A method for controlling the access of a data transmitter unit to a signal line, enabling approximately full utilization of the bandwidth of the signal line for data transfer, avoidance of collisions, conveyance of the transmitted data amount independently of the signal line length, and ensuring access to the signal line when the unit is to transmit. An apparatus for performing the method, comprising an input (1) and an output (2), a delay unit (3), a data transmitter unit (4) and an activation circuit (5).
    Type: Grant
    Filed: December 18, 1989
    Date of Patent: October 13, 1992
    Assignee: Bolt, Beranek and Newman, Inc.
    Inventors: Gottlob Borup, Flemming H. Pedersen
  • Patent number: 5041971
    Abstract: In parallel processing computational apparatus, a switching network employing both routing switch elements and concentrator elements efficiently couples bit serial messages from a multiplicity of processors to a multiplicity of memory modules. The apparatus operates in a highly synchronous mode in which all processors issue memory requests only at essentially the same predetermined time within a frame interval encompassing a predetermined substantial number of clock periods. The routing switch elements and concentrator elements incorporate circuitry for comparing the addresses of requests which may be blocked at any element with requests which get through and, if the addresses are the same, returning the memory response to all processors seeking the same memory location.
    Type: Grant
    Filed: November 30, 1988
    Date of Patent: August 20, 1991
    Assignee: Bolt Beranek and Newman Inc.
    Inventors: Philip P. Carvey, William R. Crowther, Randall D. Rettberg
  • Patent number: 4961152
    Abstract: The adaptive computing system disclosed herein employs a data structure involving a multiplicity of classifiers, each of which includes a match string of characters which the system attempts to match up with messages generated either by the environment or by other classifiers. Associated with each match string is a response message definer or action part which defines the response to be given when a match is obtained. To facilitate matching in a noisy or changing environment, there is associated with each character in the match string a weighting value and the degree of match is judged by means of a score value which is a function of the weighting values of the characters which match between the match string and the message.
    Type: Grant
    Filed: June 10, 1988
    Date of Patent: October 2, 1990
    Assignee: Bolt Beranek and Newman Inc.
    Inventor: Lawrence Davis
  • Patent number: 4943941
    Abstract: The floating point processor performs floating point addition or subtraction on a pair of binary arguments, each of which includes an exponent and a mantissa, without requiring a barrel shifter. The processor utilizes a serial arithmetic scheme in which corresponding portions of the arguments are examined sequentially as they are presented thereby to determine which argument is the larger. The exponent of the larger is loaded into a counter. The counter is decremented stepwise and each of the mantissas is shifted, most significant bits first, into an arithmetic circuit which generates carry save form results, starting when the value held by the counter corresponds to the respective exponent. The carry save form results are subsequently normalized and converted to canonical form by propagating the carries.
    Type: Grant
    Filed: January 13, 1989
    Date of Patent: July 24, 1990
    Assignee: Bolt Beranek and Newman Inc.
    Inventor: Edward S. Harriman, Jr.
  • Patent number: 4700347
    Abstract: In the apparatus disclosed herein, a data signal to be phase adjusted is applied to a plurality of delay lines providing progressively greater delays. The outputs of the several delay lines are compared over a period of time and a selection of one of the output signals for utilization is made based on choosing that delay line output which is in opposition to that pair of outputs which straddles or encompasses the most transitions.
    Type: Grant
    Filed: February 13, 1985
    Date of Patent: October 13, 1987
    Assignee: Bolt Beranek and Newman Inc.
    Inventors: Randall D. Rettberg, Lance A. Glasser
  • Patent number: 4674124
    Abstract: In the masking sound source disclosed herein, easily adjustable but matching acoustic energy spectrums are obtained from different channels by providing, for each channel, a plurality of bandpass filters, each of which is provided with a respective gain-controlled amplifier for selectively adjusting the respective signal level. The bandpass characteristics of each filter are matched to the corresponding filter in each other channel and a common control signal is applied to the respective gain-controlled amplifiers. The filtered and level-adjusted signals for each channel are then summed and applied to respective power amplifiers suitable for energizing loudspeakers. Accordingly, the frequency spectrum applied to all loud speakers will be the same even though the signals applied may be incoherently related within the spectrum.
    Type: Grant
    Filed: June 6, 1985
    Date of Patent: June 16, 1987
    Assignee: Bolt Beranek and Newman Inc.
    Inventors: Thomas R. Horrall, Richard A. Greiner