Patents by Inventor Ashok K. Agrawala

Ashok K. Agrawala 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).

  • Patent number: 8837530
    Abstract: A system and method are provided for adaptive synchronization of timing information provided in communications messages transmitted between independently clocked communication nodes of a wireless communications network. The system and method include measures for collecting timestamps of messages generated by a plurality of the nodes, each timestamp being generated by one of the nodes relative to a local time reference thereof. A pairwise clock error is computed for at least one pair of nodes based upon a plurality of network messages passed therebetween. A global time reference is adaptively established for the timestamps responsive to the pairwise clock error. A plurality of mapping factors are defined each for translating from one local time reference to the global time reference. The mapping factors are selectively applied to corresponding ones of the timestamps.
    Type: Grant
    Filed: March 14, 2011
    Date of Patent: September 16, 2014
    Assignee: University of Maryland
    Inventors: Ashok K. Agrawala, Matthew Mah
  • Patent number: 8219670
    Abstract: A multifunctional interaction system which is capable of spatio-temporal context localization of users and of communication of audio/video streams to an entity of interest defined by the user, includes a communication domain supporting a predefined localization service, a server associated with the communication domain, client devices, and a dynamically changing context database which is customized in accord with the dynamics of interaction sessions of client devices with the server. The client communicates with the system to either request services therefrom or to send a message to the entity of interest. The system is provided with a panic alert mechanism which, upon actuation, transmits an audio/video data stream along with the client location tag, time stamp, and client ID, to a police precinct for prompt action.
    Type: Grant
    Filed: November 10, 2008
    Date of Patent: July 10, 2012
    Assignee: University of Maryland
    Inventors: Ashok K. Agrawala, Amitabh Varshney, Christian B. Almazan
  • Publication number: 20110268097
    Abstract: A system and method are provided for adaptive synchronization of timing information provided in communications messages transmitted between independently clocked communication nodes of a wireless communications network. The system and method include measures for collecting timestamps of messages generated by a plurality of the nodes, each timestamp being generated by one of the nodes relative to a local time reference thereof. A pairwise clock error is computed for at least one pair of nodes based upon a plurality of network messages passed therebetween. A global time reference is adaptively established for the timestamps responsive to the pairwise clock error. A plurality of mapping factors are defined each for translating from one local time reference to the global time reference. The mapping factors are selectively applied to corresponding ones of the timestamps.
    Type: Application
    Filed: March 14, 2011
    Publication date: November 3, 2011
    Applicant: UNIVERSITY OF MARYLAND
    Inventors: ASHOK K. AGRAWALA, MATTHEW MAH
  • Publication number: 20090125584
    Abstract: A multifunctional interaction system which is capable of spatio-temporal context localization of users and of communication of audio/video streams to an entity of interest defined by the user, includes a communication domain supporting a predefined localization service, a server associated with the communication domain, client devices, and a dynamically changing context database which is customized in accord with the dynamics of interaction sessions of client devices with the server. The client communicates with the system to either request services therefrom or to send a message to the entity of interest. The system is provided with a panic alert mechanism which, upon actuation, transmits an audio/video data stream along with the client location tag, time stamp, and client ID, to a police precinct for prompt action.
    Type: Application
    Filed: November 10, 2008
    Publication date: May 14, 2009
    Applicant: UNIVERSITY OF MARYLAND
    Inventors: ASHOK K. AGRAWALA, AMITABH VARSHNEY, CHRISTIAN B. ALMAZAN
  • Patent number: 7406116
    Abstract: In a wireless communication network, the location of an addressable receiver relative to the locations of a plurality of addressable sources of electromagnetic radiation is found using probabilistic models of the signal strength measured at the addressable receiver. The inventive method provides location determination on a finer spatial scale than was heretofore available. A region of interest is calibrated via a discrete-space radio map storing probability distributions of received signal strength at the measurement locations. The stored probability distributions are compensated for temporal variability and biases, such as through temporal correlations of the sampled received signal strength.
    Type: Grant
    Filed: March 26, 2004
    Date of Patent: July 29, 2008
    Assignee: University of Maryland
    Inventors: Ashok K Agrawala, Moustafa Youssef
  • Patent number: 6320865
    Abstract: Nodes in a network transmit information among one another without the need for identifying headers. A calendar is maintained, indicating the times at which various data chunks are to be sent. When a request is made, the calendar is checked to see whether resources are free to accommodate the request. If so, the calendar is revised to reserve resources for the request.
    Type: Grant
    Filed: June 9, 1997
    Date of Patent: November 20, 2001
    Assignee: University of Maryland at College Park
    Inventors: Ashok K. Agrawala, Christopher A. Landauer, Sung Lee
  • Patent number: 4183013
    Abstract: A system for sequentially processing an image in order to identify objects in the image, and extract a variety of shape features of the identified objects. The system includes an image preprocessor, a controller, an object boundary resolver and identifier and a feature extractor. The image preprocessor scans the image and generates digital scan line signals wherein each bit is representative of a detected characteristic of an elemental region associated with a current scan position in the image. The object boundary resolver and identifier identifies object edge points from the digital scan line signals and maintains edge point data records representative of the position of the edge points in the two most recent scan lines. The resolver and identifier further processes the edge point data to identify continuation, creation, termination and merge conditions for the various objects within the image.
    Type: Grant
    Filed: November 29, 1976
    Date of Patent: January 8, 1980
    Assignee: Coulter Electronics, Inc.
    Inventors: Ashok K. Agrawala, Ashok V. Kulkarni, Edwin H. Paul, Jr.