Patents by Inventor David S. K. Chan

David S. K. Chan has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20130085661
    Abstract: According to aspects of the embodiments, there is provided an apparatus and method to synchronize trajectories from independent systems such as from a flight management system and the ground Air traffic control during the entire history of a flight. Since a number of trajectory discrepancy factors will intervene during the lifetime of a flight, such as a change in flight intent, controller intervention, or large deviations of the actual flight from the predicted trajectory due to prediction errors, there is need to dynamically monitor these deviations and control a dynamic synchronization cycle. A dynamic trajectory synchronization algorithm attempts to bring each of the systems back into balance whenever a disturbance causes an imbalance.
    Type: Application
    Filed: September 14, 2012
    Publication date: April 4, 2013
    Inventors: David S. K. Chan, Sergio TORRES, Joel KLOOSTER
  • Patent number: 5142488
    Abstract: Serial memories are operated so as to reorder samples as they are serially supplied in a pipelined electronics system, such as one for performing matrix multiplications on a chain serial basis. A serial memory comprising (m-1) delay elements and a write multiplexer is operated so as to respond to data samples that occur every m.sup.th one of a series of consecutive sample intervals to generate successive groups of m successive samples, for example. As a further example, a serial memory comprising (mn-1) delay elements and a write multiplexer is operated so as to respond to every m.sup.th one of data samples supplied thereto, which said every m.sup.th data sample is in a first scanning order, to supply those every m.sup.th data samples in a second scanning order. The first scanning order may correspond to scanning in row major order a matrix of samples arranged in m rows and n columns, in which case the second scanning order corresponds to column major scanning order of that matrix of samples.
    Type: Grant
    Filed: October 22, 1990
    Date of Patent: August 25, 1992
    Assignee: General Electric Company
    Inventors: David S. K. Chan, Daniel A. Staver
  • Patent number: 5021987
    Abstract: Digital electronic apparatus for performing chain-serial matrix multiplications using a single pipeline multiplier supplies elements of the multiplicand and multiplier matrices to the digital memory from first and second memories. Each product matrix is temporarily stored in a third memory until such time as it is used to write the first memory for the next matrix multiplication in the series. This procedure avoids overwriting the first memory when its data are still required for application to the pipeline multiplier.
    Type: Grant
    Filed: August 31, 1989
    Date of Patent: June 4, 1991
    Assignee: General Electric Company
    Inventors: David S. K. Chan, Daniel A. Staver
  • Patent number: 4567759
    Abstract: A technique is described for producing an image log of an investigation of the wall of a borehole with a high resolution tool. The tool employs sensors for measuring a characteristic such as the conductivity of the wall at locations which circumferentially overlap. An accurate tool depth measuring device is employed to modify the measured characteristic so that the measurement can be displayed as a linear function of depth without visually detectable artifacts. Various signal processing and image enhancing techniques are described to produce an image log on which the characteristic can be seen as a variable intensity image in which small scale variations of the measured characteristic remain discernable and significant features visually stand out from the log.
    Type: Grant
    Filed: December 18, 1984
    Date of Patent: February 4, 1986
    Assignee: Schlumberger Technology Corporation
    Inventors: Michael P. Ekstrom, David S. K. Chan
  • Patent number: 4545242
    Abstract: A high resolution method and apparatus for measuring the depth of a tool suspended from a cable inside a borehole are described. The tool includes accelerometers for measuring its acceleration and this measurement is combined with a cable depth measurement with which the amount of cable in the borehole is determined. A Kalman filter is employed to continually provide estimates of the velocity and depth of the tool from the accelerometer and cable depth measurements. A filter modifier alters operation of the filter during discontinuous motions of the tool such as when it is stuck and slips. A tool sticking detector senses when the tool is stuck and for how long to correspondingly modify the filter by forcing it to more strongly rely upon accelerometer measurements when the tool is stuck and gradually return to normal filter operation when the tool resumes movement after having been stuck.
    Type: Grant
    Filed: October 27, 1982
    Date of Patent: October 8, 1985
    Assignee: Schlumberger Technology Corporation
    Inventor: David S. K. Chan
  • Patent number: 4468623
    Abstract: Methods and apparatuses for electrically investigating a borehole are described. Tool mounted pads are provided, each with a plurality of small measure electrodes from which individually measurable survey currents are injected toward the wall of the borehole. The measure electrodes are arranged in an array in which the measure electrodes are so placed at intervals along at least a circumferential direction (about the borehole axis) as to inject survey currents into the borehole wall segments which overlap with each other to a predetermined extent as the tool is moved along the borehole. The measure electrodes are made small to enable a detailed electrical investigation over a circumferentially contiguous segment of the borehole so as to obtain indications of the stratigraphy of the formation near the borehole wall as well as fractures and their orientations.
    Type: Grant
    Filed: July 30, 1981
    Date of Patent: August 28, 1984
    Assignee: Schlumberger Technology Corporation
    Inventors: Stanley C. Gianzero, David E. Palaith, David S. K. Chan
  • Patent number: 4355357
    Abstract: Methods and apparatus, for processing signals derived along portions of the length of a borehole to determine the relative position of geological formation characteristics, effect the correlation of pairs of signals using substantially overlapping correlation intervals to obtain cross-correlation functions for each pair of signals. These cross-correlation functions are then displayed as a function of borehole depth for each pair of curves such that discontinuities in the cross-correlation functions are rendered obvious. From such discontinuities, zoning of the data is enabled through determination of the position of significant continuous intervals. Sequences of cross-correlation functions which belong to one of these intervals may then be used to directly determine the corresponding relative position of a formation characteristic. When applied to dipmeter signals, the method produces more accurate and geologically consistent dip and azimuth values for subsurface formations.
    Type: Grant
    Filed: March 31, 1980
    Date of Patent: October 19, 1982
    Assignee: Schlumberger Technology Corporation
    Inventor: David S. K. Chan