Patents Assigned to Massachusetts Institute Technology
  • Patent number: 5394508
    Abstract: An audio type signal is encoded. The signal is first divided into bands. For each band, a yardstick signal element is selected. Its magnitude is quantized using a first level of accuracy. This magnitude is used for various purposes, including assigning bits to the different bands, and for establishing reconstruction levels within a band. The magnitude of non yardstick signal elements is quantized with less accuracy than are the yardstick signal elements. The encoded signal is also decoded. Apparatus for both encoding and decoding are also disclosed. The location of the yardstick element within its band may also be recorded and encoded, and used for efficiently allocating bits to non-yardstick signal elements.
    Type: Grant
    Filed: January 17, 1992
    Date of Patent: February 28, 1995
    Assignee: Massachusetts Institute of Technology
    Inventor: Jae S. Lim
  • Patent number: 5391490
    Abstract: A ubiquitin-specific protease which cleaves ubiquitin from any protein or peptide to which ubiquitin is joined and the gene encoding the protease are disclosed. The protease specifically cleaves the peptide bond in a fusion of ubiquitin to a protein or peptide between the carboxyl-terminal amino acid residue of a ubiquitin moiety and the .alpha.-amino group of any non-ubiquitin protein or peptide to which ubiquitin is joined. Recombinant expression vectors containing a DNA sequence encoding the ubiquitin-specific protease can be used to transform cells for production of the protease or to provide the cell with the ability to proteolytically deubiquitinate, in vivo, ubiquitin fusions co-produced by the cell. The protease can also be isolated and used to deubiquitinate ubiquitin fusions in vitro.
    Type: Grant
    Filed: January 25, 1994
    Date of Patent: February 21, 1995
    Assignee: Massachusetts Institute of Technology
    Inventors: Alexander J. Varshavsky, John W. Tobias
  • Patent number: 5390141
    Abstract: An electrical path can be formed through a transformable insulator between first and second conductors by applying a voltage between such conductors across at least one selected region of the insulator. Much of the current required to complete the link is provided from parasitic capacitance of the writing circuit or from capacitance which is removable from the circuit during normal operations. As a result, small transistors of less than 100 microamps may be used in the writing circuit which applies the programming voltage.
    Type: Grant
    Filed: July 7, 1993
    Date of Patent: February 14, 1995
    Assignee: Massachusetts Institute of Technology
    Inventors: Simon S. Cohen, Jack I. Raffel
  • Patent number: 5388527
    Abstract: A positioning apparatus for a maglev vehicle includes multiple vehicle magnets. The magnets are paired For a suspension configuration, the magnets are one above the other, with a plurality of pairs arranged along the length of the vehicle. The poles are of adjacent magnets are opposite each other, transverse of the guideway. The guideway carries a conductor that is located symmetrically with respect to the two vehicle magnets. Among other things, the conductor may be a ladder, discrete coils or a helical winding. As the vehicle moves along the guideway, the voltages are induced in the circuits of the guideway conductor by the moving vehicle magnetic fields. If the vehicle is at a symmetry position with respect to the guideway, no current is induced in the guideway conductors because the magnetic fields from the pair of magnets cancel each other.
    Type: Grant
    Filed: May 18, 1993
    Date of Patent: February 14, 1995
    Assignee: Massachusetts Institute of Technology
    Inventor: Richard D. Thornton
  • Patent number: 5389539
    Abstract: A purified heparinase I, II and III free of lyase activity and each having a molecular weight of 42,800 84,100, 70,800, respectively, are produced by culturing Flavobacterium heparinum. The kinetic properties of the heparinases have been determined as well as the conditions to optimize their activity and stability.
    Type: Grant
    Filed: November 30, 1992
    Date of Patent: February 14, 1995
    Assignees: Massachusetts Institute of Technology, University of Iowa Research Foundation
    Inventors: Ramnath Sasisekharan, Daniel L. Lohse, Charles L. Cooney, Robert J. Linhardt, Robert S. Langer
  • Patent number: 5389943
    Abstract: A filter utilizes a frequency selective, non-conductive, dielectric structure for filtering electromagnetic energy in the millimeter to far infrared frequency bands. The filter includes a non-conductive, high-dielectric, background material positioned to receive incident electromagnetic energy. A lattice structure comprised of a plurality of elongated elements formed of a non-conductive, high-dielectric material are disposed in a two-dimensional, periodic arrangement in the background material. The elements extend in parallel to one another through the background material for providing a range of frequencies over a band gap in which incident electromagnetic energy within the frequency range of the band gap is substantially prevented from propagating through the lattice structure. The dielectric structure can be adapted to operate as a band stop filter or a low pass filter.
    Type: Grant
    Filed: July 27, 1992
    Date of Patent: February 14, 1995
    Assignees: Lockheed Sanders, Inc., Massachusetts Institute of Technology
    Inventors: Karl Brommer, Henry Mullaney, Robert Meade, Andrew Rappe, John Joannopoulos
  • Patent number: 5389196
    Abstract: A method for producing a three-dimensional object includes the steps of providing an interface plane within a chamber and generating a beam of radiant energy having varied levels of beam energy density. The beam is directed to selectively expose a pattern of address points on the interface plane to the beam of radiant energy for a limited duration. Conditions are established in the chamber to enable the beam to induce a micro-chemical reaction at the interface plane at a rate which serves to form a portion of the three-dimensional object. A significant feature of the invention is that the micro-chemical reaction is substantially binary with respect to the beam energy density. That is, the reaction is either substantially "on" or substantially "off.
    Type: Grant
    Filed: January 30, 1992
    Date of Patent: February 14, 1995
    Assignee: Massachusetts Institute of Technology
    Inventors: Theodore M. Bloomstein, Daniel Ehrlich, Anita M. Flynn
  • Patent number: 5389069
    Abstract: A method and apparatus is disclosed for causing electroporation of remote cells and tissue, in vivo. The method includes directing an electrically conductive penetrator into an organism to a point which is approximate to the cells and/or tissue. An electrode is disposed at a surface of the organism, whereby a voltage applied between the electrically conductive penetrator and the electrode will cause electroporation of the cells and/or tissue. A voltage is applied between the electrically conductive penetrator and the electrode in an amount sufficient to cause electroporation of the cell or tissue. The method can also include treating remote tissue, in vivo, with a chemical agent, wherein the chemical agent is disposed in the organism in an amount sufficient to treat the cell or tissue during electroporation.
    Type: Grant
    Filed: September 17, 1993
    Date of Patent: February 14, 1995
    Assignee: Massachusetts Institute of Technology
    Inventor: James C. Weaver
  • Patent number: 5387380
    Abstract: A process for making a component by depositing a first layer of a powder material in a confined region and then depositing a binder material to selected regions of the layer of powder material to produce a layer of bonded powder material at the selected regions. Such steps are repeated a selected number of times to produce successive layers of selected regions of bonded powder material so as to form the desired component. The unbonded powder material is then removed. In some cases the component may be further processed as, for example, by heating it to further strengthen the bonding thereof.
    Type: Grant
    Filed: June 5, 1992
    Date of Patent: February 7, 1995
    Assignee: Massachusetts Institute of Technology
    Inventors: Michael Cima, Emanuel Sachs, Tailin Fan, James F. Bredt, Steven P. Michaels, Satbir Khanuja, Alan Lauder, Sang-Joon J. Lee, David Brancazio, Alain Curodeau, Harald Tuerck
  • Patent number: 5386586
    Abstract: In a data processing system, multiple requests for a service are stored on a deferred list formed out of already allocated memory space. Specifically, a received service request is added to the deferred list by altering the request as dictated by a stated convention. Preferably, the convention mandates that an instruction pointer of the received service request is decremented or otherwise manipulated. The altered received service request then is exchanged for a sevice request currently held at the service. The altering and exhanging are performed atomically. The service request that was previously held for the service is sent to the head of the current deferred list. It is preferred that the deferred list be formed out of activation frames.
    Type: Grant
    Filed: December 28, 1993
    Date of Patent: January 31, 1995
    Assignee: Massachusetts Institute of Technology
    Inventor: Gregory M. Papadopoulos
  • Patent number: 5386398
    Abstract: Apparatus for displaying data such as time or weight samples, comprising a data generator means, a pseudorandom number generator, a function generator for generating modified data samples functionally related to the original data samples and the pseudorandom numbers, and display means for displaying the modified data. The function generator may be an adder, for example. The data may represent time, weight, or another quantity.
    Type: Grant
    Filed: December 28, 1990
    Date of Patent: January 31, 1995
    Assignee: Massachusetts Institute of Technology
    Inventors: Levan Hiemke, Emanuel Kwak
  • Patent number: 5386427
    Abstract: An apparatus and method for controlling the propagation path of a light beam are disclosed. A lens material having a temperature-dependent index of refraction is positioned in the path of the light beam. A heat source is disposed on one face of the lens material and a heat sink is disposed on the opposite face. A controller regulates the distribution of heat to the heat source and the extraction of heat from the heat sink so that a temperature gradient is formed within the lens material. The temperature gradient creates a refractive-index gradient in the lens material, causing a thermal lensing effect. The device may be used in a laser cavity for controlling laser-beam divergence caused by pump-induced thermal lensing in the gain medium.
    Type: Grant
    Filed: February 10, 1994
    Date of Patent: January 31, 1995
    Assignee: Massachusetts Institute of Technology
    Inventor: John J. Zayhowski
  • Patent number: 5386215
    Abstract: Efficient transmission and reception of electromagnetic radiation are achieved by an antenna on a substrate. An antenna is fabricated on the top surface of a substrate which includes a periodic dielectric structure. The antenna operates at a frequency within the band gap of the periodic dielectric structure. Radiation emitted by the antenna cannot propagate through the structure and is therefore emitted only into space away from the substrate. When the antenna is receiving, radiation striking the device does not propagate through the substrate but is concentrated at the antenna. A phased array with isolated elements is achieved by fabricating the array elements on top of a substrate having a periodic dielectric structure and by surrounding the circuits associated with each antenna element with the periodic dielectric structure. Radiation from an element or associated circuitry at a frequency within the band gap of the structure cannot propagate into the substrate to interfere with other elements.
    Type: Grant
    Filed: November 20, 1992
    Date of Patent: January 31, 1995
    Assignee: Massachusetts Institute of Technology
    Inventor: Elliott R. Brown
  • Patent number: 5384530
    Abstract: A bootstrap voltage reference circuit having an amplifier with a positive feedback network including a non-linear device which operates as a current source. The non-linear device may be an n-type negative resistance device such as a tunnel diode. The circuit is operable for generating a predetermined reference voltage as the difference between the signal applied to the positive input and a signal generated by the negative feedback network and applied to the negative input approaches zero.
    Type: Grant
    Filed: August 6, 1992
    Date of Patent: January 24, 1995
    Assignee: Massachusetts Institute of Technology
    Inventor: Randall J. Pflueger
  • Patent number: 5384301
    Abstract: A catalytic reduction process for the direct recovery of elemental sulfur from various SO.sub.2 -containing industrial gas streams. The catalytic process provides high activity and selectivity, as well as stability in the reaction atmosphere, for the reduction of SO.sub.2 to elemental sulfur product with carbon monoxide or other reducing gases. The reaction of sulfur dioxide and reducing gas takes place over a metal oxide composite catalyst having one of the following empirical formulas:[(OF.sub.2).sub.1-n (RO.sub.1)n].sub.1-k M.sub.k,[(FO.sub.2).sub.1-n (RO.sub.1.5).sub.n ].sub.1-k M.sub.k, or[Ln.sub.x Zr.sub.1-x O.sub.2-0.5x ].sub.1-k M.sub.kwherein FO.sub.2 is a fluorite-type oxide; RO represents an alkaline earth oxide; RO.sub.1.5 is a Group IIIB or rare earth oxide; Ln is a rare earth element having an atomic number from 57 to 65 or mixtures thereof; M is a transition metal or a mixture of transition metals; n is a number having a value from 0.0 to 0.35; k is a number having a value from 0.0 to about 0.
    Type: Grant
    Filed: July 23, 1993
    Date of Patent: January 24, 1995
    Assignee: Massachusetts Institute of Technology
    Inventors: Maria Flytzani-Stephanopoulos, Wei Liu
  • Patent number: 5381431
    Abstract: A Q-switched laser having a gain medium disposed within a first resonant cavity and a second resonant cavity, sharing a common mirror with the first cavity, whose optical length is adjustable such that the quality Q of the first resonant cavity is affected. One aspect of the invention is the selection of the cavity lengths and the reflectivities of the mirrors of the first and second cavity such that Q-switched pulses of less than 100-ps duration can be obtained. Another aspect of the invention is the ability to generate said pulses with peak powers in excess of 100 kW for applications in high-precision optical radar, nonlinear optics, micromachining, microsurgery, and other applications where short pulses with high peak powers are required.
    Type: Grant
    Filed: August 13, 1993
    Date of Patent: January 10, 1995
    Assignee: Massachusetts Institute of Technology
    Inventor: John J. Zayhowski
  • Patent number: 5381442
    Abstract: A radiometer is described which coherently detects the thickness of oil films on water by converting continuous-frequency microwave or millimeter-wave brightness temperature versus frequency measurements from the frequency/wavenumber domain to the oil-film-thickness domain (received power versus film thickness) using Fourier-transform signal processing.
    Type: Grant
    Filed: April 1, 1993
    Date of Patent: January 10, 1995
    Assignee: Massachusetts Institute of Technology
    Inventors: Elliott R. Brown, Gregory G. Hogan, Gerald M. Daniels
  • Patent number: 5378940
    Abstract: In a pipelined logic circuit, switches are only enabled when voltage differentials across the switches are zero. The switches are configured during a restored state of voltage rails, and a swing in voltage on the rails results in a swing in output voltage to a set level. To restore the logic circuit with minimal energy dissipation and permit useful pipelining, the inputs are regenerated through an inverse logic circuit. The voltage rail then swings back to its restored level. Full forward and reverse pipelines are formed with the individual forward and inverse logic circuits with the pipelines being driven by multiphase clock rails. Each logic stage includes a logic gate and a pass gate.
    Type: Grant
    Filed: August 3, 1993
    Date of Patent: January 3, 1995
    Assignee: Massachusetts Institute of Technology
    Inventors: Thomas F. Knight, Jr., Saed Younis
  • Patent number: 5377129
    Abstract: Fluid flow is simulated by a massively parallel data processor having combinational logic for processing collision rules at lattice sites. Following collision processing, particle representations are moved to different sites dependent on direction and velocity of the particles. The collision rules are based on collisions of particles positioned at sites of a three-dimensional lattice. Particle representations identify particles of plural energy levels, and the collision rules allow for transfer of energy between particles. Particle representations relate to particles which move along four-dimensional face-centered hypercube lattices which project to the three-dimensional lattice. The lattice may include interfacing grids of different unit dimensions depending on the resolution required in individual volumes of space.
    Type: Grant
    Filed: March 12, 1993
    Date of Patent: December 27, 1994
    Assignee: Massachusetts Institute of Technology
    Inventors: Kim Molvig, Gregory M. Papadopoulos
  • Patent number: RE34812
    Abstract: A Q-switched laser having a gain medium disposed within a first cavity and a second cavity whose optical path length is adjustable such that the quality of the first resonant cavity is affected. One aspect of the invention is the changing of the physical path length of the second cavity so as to effect the reflectivity of a mirror common to both cavities as seen from the first cavity. Another aspect of the invention is the incorporation, within the second cavity, of a material whose refractive index or absorption coefficient can be varied by the application of an electric field, a magnetic field, a temperature change or an applied pressure.
    Type: Grant
    Filed: October 26, 1992
    Date of Patent: December 27, 1994
    Assignee: Massachusetts Institute of Technology
    Inventors: John J. Zayhowski, Aram Mooradian